Digestive

Question 1

Describe the splenic vasculature?

Answer 1

Celiac a.

• hepatic
• left gastric
• splenic
  
  • pancreatic
  • left gastroepiploic
  • short gastic

Splenic v. ⇒ gastrosplenic v. ⇒ portal v.

Question 2

What is the storage capacity of the spleen for rbc and platelets?

Answer 2

10-20% rbc mass

30% of platelet mass

Question 3

What are the 3 major functions of the spleen?

Answer 3

1. hematopoiesis: EMH fetal development, maturation of rbc, destruction of rbc, store iron (hemosiderin, ferritin). EMH dogs (uncommon cats)
2. Reservior function: 3 pools - rapid (30 sec), intermidate (8min), slow (1hr)
3. Immune: B-cells, T-cells, IgM, removal of IgG coated rbc/platelets.

Question 4

What are the 4 mechanisms of generlized splenomegally?

Answer 4

inflammation, congestion, neoplasia/cell infiltration, cellular hyperplasia.

Question 5

Difference between cat and dog spleen?

Answer 5

Dog: sinusoidal - combinaiton of direct arteriovenous AND areas where rbcs have transverse the red pulp before entering a sinus/venous side.

Cat: nonsinusoidal - open ended venous channels and perofrated endotheial channels = direct communication between arterial and venous vasculature.

Question 6

Name causes of localized splenomegally - nine.

Answer 6

1. Nodular hyperplasia: splenoma, fibrohistiocytic nodules (Cocker spaneils)
2. Pseudotumor - benign lesion (plasma cells, histiocytes and lymphocytes)
3. Hemangioma
4. Haratoma - mature splenic tissue,, not normal structure
5. Ascess - torsion, bacteremia, FB
6. Cysts - humans
7. Segemental infarction - poor profusion, hemobartenella
8. Plaques - hemosiderosis, siderocalcific = hemosiderin, calcium, bilirubin
9. Neoplasia: hemic vs. non-hemic

Question 7

What are predisposing factors for splenic infarcts (9-10)?

Answer 7

Hypercoaguable = sx not recommended for seg. infarct due to risk

splenomegaly

cardiac, liver or renal disease

neoplasia

excessive corticosteroids

sepsis

splenic hematoma

vasculitis

Question 8

On splenic US what is generally associated with the following:

Hypoechoic nodules

Diffuse hypoechogenicity

Hyperechoic nodules

Target lesions

multiple descreate lesions

Answer 8

Hypoechoic: lymphoid infiltration, infarction, necrosis

Diffuse hypoechoic: passive congestion, splenic torsion

Hyperechoic - nodular hyperplasia, neoplasia, fibrosis

Target lesions (hypoechoic rim): positive predicitve for malignacy

Multiple similar descreate lesion associated with maligancy

Question 9

How does contrast enhanced (microbubble) US help define malignancy?

Answer 9

Malignant lesions have a different pattern than surrounding tissue. Accuracy similar to contrast MRI and CT

Question 10

What changes are consistenty with malignancy on CT and MRI?

Answer 10

CT: lower Hounsfild units (pre and post contrast)

MRI: malignant hyperintense on T2 and postgadolinium

Question 11

How does cytology compare to histopathology for splenic masses?

Answer 11

Variable but overall good for dx hematopoietic neoplasia and hyperplasia.

59% agreement, 29% partial agreement and 12% disagreement in one study

Question 12

What stain can help ID cells of hmic origin?

Answer 12

Romanowsky

Question 13

When dividing the spleen for a partial splenectomy, what are options?

Answer 13

TA stapler

2 clamps, cut inbetween and suture

CO2 laser

Ultrasonic cutting device

Biopolar electrosurigcal device

Question 14

Ultrasongraphic appearence of splenic torsion?

Answer 14

Splenomegally, diffusely hypoechoic (also seen with necrosis and infarction)

6/7 dogs had hilar perivenous hyperechoic triangle

chronic may demonstrate gas shadowing

Absence of blood flow on color flow doppler US

Question 15

What is the signalment for dogs with splenic torsion?

Answer 15

Large/giant deep chested dogs, MALES

Danes, St. Bernard, GSD, Irish setters

Poss. associated with spontaneous resolved GDV??

Question 16

Percent of non-traumatic hemoabdomens with maligant cancer and what percent of these were HSA?

Answer 16

up to 80% malignant

of these 63-88% HSA

Question 17

Percent of non-traumatic hemoabdomens with splenectomy that had arrythmias postop?

Answer 17

44%

Question 18

What is the percent of arrhythmias associated with splenectomy for neoplasia and when are they more common?

Answer 18

35%

More common with anemia, hypotension, leukocytosis, and splenic mass rupture

Question 19

What is it called when poor organ profusion occurs due to too tight of a closure of an abdominal hernia?

Answer 19

Abdominal compartment syndrome - associated with loss of domain.

Question 20

What are the 4 priniciples of hernia repair?

Answer 20

1. ensure viability of entrapped hernia contents
2. release and return viable hernia contents into normal location
3. remove reduntant hernia sac
4. Provide tension free closure

Question 21

Name 8 common sites for abdominal hernias

Answer 21

Paracostal, dorsal lateral, inguinal, femoral, perineal, cranial pubic ligament rutpure, umbilical, scrotal, ventral (subxyphoid)

Question 22

How is the abdominal wall formed in embyro?

And what is the cause of an umbilical hernia?

Answer 22

Migration of the lateral, cephalic and caudal folds

Failure of the lateral folds to close

Question 23

What passes through the umblicus?

Answer 23

umbilical blood vessels - (vein = faliciform lig)

Vitelline duct

stalk of the allantosis

Question 24

What disease have been associated with umbilical hernias?

Answer 24

Fucosidosis = inherited neurovesical lysosomal storage disease

Ectodermal dysplasia

Cyrptorchidism

Other hernias and incomplete sternal fusion can co-exsist: ventral abdominal, diaphragmatic

Other midline defects and cardiac defects

Question 25

What is gastroschisis and how is it different than an omphalcele?

Answer 25

It is a congential **paramedian** defect (omphalocele midline) exposing abominal contents.

Question 26

What breed are at increased risk for umbilical hernia?

Answer 26

Airedale, basenji, Pekingese, pointers, weimerainers

Question 27

Describe the boundries of the internal and external inguinal ring.

Answer 27

Internal: Medial rectus m., cr. internal abdominal oblique, lat/caudal: inguinal lig. External: slit in apopneurosis of external abdominal oblique Together form inguinal canal

Question 28

What passes through the inguinal rings?

Answer 28

Gential branch of the gentifemoral a,v,n. External pudendal vessels Round lig (female), or spermatic cord

Question 29

What is an inguinal heria that contains a gravid uterus?

Answer 29

Hysterocele

Question 30

Three methods to repair a large inguinal hernia?

Answer 30

Own tissues polyethylene mesh cr. sartorius flap

Question 31

Describe the femoral canal.

Answer 31

2 areas within the limits of the inguinal lig and pelvis. 1. Muscular lacuna: Femoral n, and illiopsoas m. 2. Vascular launa: femoral a, v, n and saphenous Lacuna divided by the iliopectinal arch (iliac and transverse fascia = surrounds vasculature forming the femoral sheath)

Question 32

What are risk factors for abdominal incision dehisence?

Answer 32

Increased intraabdominal pressure (pain), entrapped fat btwn edges of repair, inappropriate surture, infection, chronic steroid and poor postop care

Question 33

What are methods to increase the strength of a prepubic tendon repair with mesh?

Answer 33

Mesh cuff with vertical mattress sutures double layer mesh technique

Question 34

What are factors associated with chronic incisional hernias

Answer 34

obesity, hypoproteinemia, cardiopulmonary complicaitons, absominal distension skin wound dehisence, and **deep fasical infection** Local wound complcaitons most improtant

Question 35

What are characteristerics of a desirable vascular muscle flap?

Answer 35

Avoid bulkiness Avoid tension Consistent vascular supply that is resistent to superfical trauma Not result in significant loss of function Be readily excessible

Question 36

What are 3 major vascularized muscle flaps?

Answer 36

Cranial sartorius musle flap External abdominal oblique myofascial flap Latissimus dorsi

Question 37

What is the origin and blood supply of the crainal sartorius flap? What is it useful for?

Answer 37

iliac crest and lumbodorsal fascia Branch of femoral a/v supplies proximal 1/3 Area covered: 30% caudal abdomen = transverse, 80% length btwn pubis and ribs Used for prepubic, femoral and inguinal hernias Delayed flap (distal blood supply) caudal abdominal repair in cats.

Question 38

Describe the external abdominal oblique flap

Answer 38

Myofasical **island** flap (middle zone of the lateral abdominal wall) Cr. branch of the cranial abdominal a. (hypogastric n and satellite v) ventral, cranial to mid abdominal wall 10cm x 10cm area

Question 39

Describe Marlex mesh.

Answer 39

Polypropylene mesh inert monofilament woven 4-5mm fibrous tissue ingrowth by 6 months Other meshes: Gore-tex (teflon) - permanent microporus, polygalctin 910 absorable

Question 40

List biologic tissue grafts and their potential use?

Answer 40

SIS, dermis, pericardium maybe useful for infected locations, avoids acute/chronic infection/inflammation completely replaced with collagen in 4 months Experimentally for abdominal wall defects, clinically for perneal hernias

Question 41

What are three methods of mesh reconstruction? Which is better?

Answer 41

**Onlay** - more complications (_\<_69% in people) increased infection, seroma, hematoma, extrusion = potentially due to more undermining/being superficial **Inlay** - poor tissue interface **Underlay** - best - lowest rate reherniation and wound complications = adhesions and enterocutaneous fisulas have been found in humans = need to use omentum

Question 42

What are the surgical goals of abdominal herniorraphy?

Answer 42

Asepsis tension free closure use of strong tissue only anatomaic closure proper technical execution

Question 43

What are the 4 major muscular and tendinous portions of the diaphram?

Answer 43

1. central tendon: 21% 2. Pars sternalis - xyphoid and 8th 3. Pars lumbaris = left and right crus (R\>L, lateral, intermediate and medial portions) - L3,L4 medial to psoas minor 4. Parscostalis - 8-10th costal cart, 11 chostrochondral, 12th (ventral), 13 (dorsal)

Question 44

What are the 3 opening of the diaphragm and what passes through?

Answer 44

**Esophageal hiatus** between 2 medial division of right crus: **esophagus, blood supply, dorsal/vental vagal trunck** **Aortic hiatus** dorsally vertebral, L/R crucal tendons: a**orta, azygos, hemiazygos, lumbar cysterna of thoracic duct** **Caval foramen:** within central tendon with fused adventia (only imobile of the 3): **vena cava**

Question 45

What is the difference between cats and dogs phrenic nn?

Answer 45

Dogs: C5-7 Cats: C4-6, 5&6 most important

Question 46

Described the embyrologic development of the diaphram

Answer 46

Transverse septum: central tendon Dorsal esophageal mesentary (similar to transverse septum: crua, aortic and esophageal hiatus Pleuroperitoneal folds: lateral portion that completes diaphram, myoblasts invade to form costal mm

Question 47

What are 2 apporaches for a diaphragmatic hernia?

Answer 47

Ceiliotomy 9th lateral thoracotomy - need to know side, containdicated for bilateral or PPHD

Question 48

WIth taumatic diaphragmatic hernias, what is the distrubution of the tears in dogs vs. cats?

Answer 48

Dogs: 40% circumferential, 40% radial, 20% combination Cats: \>59% cricumferential, 18%radial

Question 49

What is the normal pleuroperitoneal pressure gradient?

Answer 49

normal **7-20 cmH20**, during maximal inspiration **PPG \>100mmHg**

Question 50

What is the normal pressure gradient between the liver and vena cava?

Answer 50

Portal v: 8-12 mmHG intrahepatic sinusoids: 3-4mmHg Hepatic v and cd vena cava 0.5-1mmHg

Question 51

What are contrast studies that can be used to diagnose a diaphragmatic hernia?

Answer 51

oral barium studies pneumoperitoneography positive contrast pleurography portographycholecystography angiography

Question 52

What are alternative options of closure of a diaphragmatic defect if primary not possible?

Answer 52

Omentum muscle liver fascia mesh silicon rubber sheeting

Question 53

What is the Valsalva effect?

Answer 53

decreased venous reuturn from prolonged pulmonary expansion

Question 54

What are the physiologic effects of compartment syndrome?

Answer 54

Decreased renal functoin hypotension from decreased CO Hypoxia reduced ventilation and lung compliance Visceral hypoprofusion acidosis ICP

Question 55

What are 2 types of congential diaphramatic hernias?

Answer 55

Pleuroperitoneal Peritoneopericardial

Question 56

What are compilcations of PPDH that are not commonly reported with traumatic hernia?

Answer 56

RHF, cardiac tamponade, **hepatic cysts,** gallbladder torsion/rupture, **myelolipomatosis,** chylothorax.

Question 57

What are the bounderies of the epiploic foramen?

Answer 57

dorsally by the caudal vena cava, ventrally by the portal vein and hepatic artery, cranially by the caudate lobe of liver, and caudally by the celiac artery.

Question 58

What are the 3 portions of the greater omentum?

Answer 58

Bursal (pars superficialis, pars profundus) Splenic (gastrosplenic lig) Veil

Question 59

What are the size of the stomata in the peritoneum?

Answer 59

4-16 um mesotheilial process regulate size

Question 60

What is the classification of peritoneal fluid?

Answer 60

Normal: cells \<300, protein \<3, colloid osmotic pressure 28mmHg Transudate: cells \<1500, protein \<2.5g/dL Modefied transudate: cells 1000-7000, protein 2.5-7.5 Exudate: cells\>5000, protein \>3

Question 61

What are factors effecting particulate clearence via lymphatics from the abdomen?

Answer 61

Size gravity respirtatory and diaphragmatic movement intestinal activity Intraperitoneal pressure

Question 62

What rate can the peritoneal cavity absorb fluid?

Answer 62

3-8% of body wt in Kg/ hour

Question 63

What is normal intra-abdominal pressure?

Answer 63

2-7.5 cm H20

Question 64

What are signs of increase IAP (20m h20) ?

Answer 64

increased HR, BP, bacterial translocation decreased CO, GI blood flow

Question 65

What are acute phase pro-inflammatory mediators? What is an anti-inflammatory mediator?

Answer 65

Proinflammatory: TNF alpha, IL-8, IL-6, IL-1beta Anti-inflam: IL-10 Macro produce TNF alpha, IL-1beta ~ recruit neutro, increase prosteglandins Lymph = IL-6 mesothelial produce IL-8 Mast cell = histamine (+prosteglandin = vasdilation, increased permiability)

Question 66

List adjuvants in peritonitis.

Answer 66

Gastic mucin: inhibits phagocytosis Bile salts: alter cell adhesion, lyse rbc (increased Hb) Hb: interferes with chemotaxis, phagocytosis, lymphcytic clearence Barium Peritoneal fluid: increased bacterial proliferation, slowed clearence

Question 67

In dogs vs cats with primary peritonitis, what is the rate of monoclonal bacteria and what kind is present?

Answer 67

Dogs: 56% monoclonal, 80% gram + Cats: 100% monoclonal, 60% gram + Other organisms FIP, salmonella, chlamydia, clostridium, blasto, mycobacterium, citrobacter

Question 68

What are indications of a retained surgical sponge on US and cytology?

Answer 68

US: hypoechomass with hyperechoic center cyto: mononuclear cells with mulinucleat giant cells +/- fibers Particles \<15um can be removed by lymphatic circulation

Question 69

What are causes of aseptic peritonitis?

Answer 69

chemical peritonitis bile peritonitis uropertoneum peritoneal FB starch granulamatous peritonitis mechanical peritonitis sclerosing encapsulating peritonitis

Question 70

What has talcom powder in the abdomen been associated with?

Answer 70

Starch granulomatous peritonitis granulomas, fecal fistula, sinus formation, intestinal obstruction, delayed wound healing

Question 71

What has sclerosing encapsulating peritonitis been associated with?

Answer 71

Steatitis fat necrosis finerglass bacterial peritonitis chylous effusion leishmaniasis

Question 72

GI leakage is the cause of what % of secondary peritonitis in dogs and cats?

Answer 72

Dogs: 60% Cat: 47%

Question 73

What are possible risk factors after dehisence/peritonitis after GI surgery for incrased mortaliity?

Answer 73

longer duration of CS linear FB multiple intestinal procedures

Question 74

How does alpha hemolysin facilitate E.coli and bacteriudes fragilis in septic peritonitis?

Answer 74

toxic to cells decrease pH lyse rbc reduces viable leukocytes presense increases patient mortality and increases likihood of recovery of these 2 species

Question 75

What is the criteria for SIRIS in 1) dogs and 2) cats?

Answer 75

3 or more of these criteria Dogs: Temp \<100.4 \>104, HR \>120, R \>20, WBC \<5000 \>18,000 Cats: Temp: \>103.5, \<100. HR \>225 \< 140. R \>40. WBC \<5000 \>19500. Bands \>5%

Question 76

What is normal sonographic intestinal wall thickness?

Answer 76

Dogs: \<20kg: duodenum 4.7mm, jejunum 4.2mm \>20kg: 5.5mm, 4.7mm Cats: duodenum 2.7mm, jejunum 2.1mm

Question 77

How does the accuracy of a single needle tap compare to a pertioneal catheter vs. a DPL for septic abdomen?

Answer 77

Needle: 43% catheter: 83% Diagnostic peritoneal lavage: 95%

Question 78

How much fluid is instilled in diagnostic peritoneal lavage?

Answer 78

20-22ml/kg

Question 79

How does serosal patching protect an R&A site and what % does it decrease mortality in patients with colonic perforation?

Answer 79

proteolytic activity degrades collagen and ECM mortality decreased from 82% vs %56

Question 80

What are advantages of open peritoneal drainage?

Answer 80

Increased efficiency removal bacteria Improved metabolic state Decreased abominal adhesions Ease of inspection of abodmen Unsuitable enviorment for bacteria

Question 81

How do you diagnose uroabdomen?

Answer 81

Cre Fluid \> 2.4x serum Potssium fluid \>1.4x serum

Question 82

What is this?

Answer 82

Penrose sump drain

Question 83

How is enteral feeding beneficial?

Answer 83

Good for enterocytes Decreases bacterial translocation Decreases mucosal permiabiliyt Preserves secratory IgA conc in billary secreations Maintains intestinal structure and function

Question 84

What are benefical effects of low dose heprin therapy?

Answer 84

Improved clotting function improved bacterial clearence Decrased fibrin formation Increased survivial **Decreased abodominal abcess formation** Dose 100-200 U/kg SC TID or QID

Question 85

What is the mortality rate for septic peritonitis and what are indicators of a poor prognosis?

Answer 85

20-70% Refracotry hypotenision CV collapse Resp. distress DIC pre-op elevated ALT and GGT MODS

Question 86

What is the formula for determining blood volume inthe abdomen from DPL?

Answer 86

(Venous PCV)(V in abodomen) = PCV fluid ((V in abdomen) + (V infuse))

Question 87

What is the nerve supply and vascular supply to the muzzle?

Answer 87

nerve CN VII motor, CN V sensory Facial a = lower lip and cheek Infaorbital a = uper lip and cheek

Question 88

What mm. make up the root of the tongue?

Answer 88

Styloglossis Hypoglossus genioglossus Innervate by hypoglossal

Question 89

What is the tube like structure under the tongue (made of mm, fat, cartilage)?

Answer 89

Lyssa

Question 90

Name the gustatory and non-gustatory taste buds.

Answer 90

Gustatory: fungiform, vallate, foliate Non-gustatory: filiform, conical

Question 91

What are the 3 tonsils?

Answer 91

palatine linguial - tongue pharyngeal - nasopharx

Question 92

Describe the 3 phases of deglutinion

Answer 92

_1. Oropharyngeal_ - **oral** = bolus CN5, 7, 12 - **pharyngeal** = base tongue to pharynx CN9, 10. phayrngeal constrictor mm→food aborally, palatal/pharyngeal mm. close nasopharynx, caudal epigastric reflexion & vocal folds block trachea. - **pharyngosesophageal or cricopharyngeal** = pharynx - circopharyngeal sphinter - eso, CN 9,10. Relax thyropharyngeaus and cricopharyngeaus. 2. Esophageal - primary parastolic wave +/- secondary wave 3. Gastroesophageal - muscularis relaxes in front of bolus

Question 93

Reveiw mm. of tongue and pharynx

Answer 93

Question 94

Borders of the parotid gland?

Answer 94

rostral: masseter m. TMJ caudal: s**ternomastodideus** ventral: Mandibular SG superfiical: **parotidoauricularis**, platysma m

Question 95

What is the blood supply of the parotid gland, zygomatic gland, M SG, andsublingual SG?

Answer 95

Partoid: parotid (external carotid), superficial temporal v., great auricular v. zygomatic: infraorbital a, deep facial v. Mandibular: gladular br. of facial a., br. lingual v. Sublingual: - glandular br. facial a (monostomatic) - sublingual br. of lingual a. (polystomatic - rostral to lingual n)

Question 96

What mm. does the SL/Mandibular salivary duct run between?

Answer 96

Styloglossis mylohyoideus

Question 97

What are the minor salivary glands?

Answer 97

Buccal labial lingual tonsillar palatine molar (cats - buccal, angle mandibile)

Question 98

Functions salivary glands?

Answer 98

lubricate ingesta pack food thermoregulation oral cavity clensing buffering week acids decrease bacteria protect epithelium

Question 99

Describe the pathway of saliva

Answer 99

intercalated ducts intralobular ducts interlobular ducts lobular ducts lobar ducts major excretory ducts

Question 100

Which salivary glands produce a more mucus secreation?

Answer 100

SL/zyomatic - mucus parotid/mandibular -serous

Question 101

Question 102

Answer 102

A sliding bipedicle flap repair may be used to repair a congenital oronasal fistula. A, The dotted lines represent the mucoperiosteal incisions necessary to create two sliding flaps. B, The mucoperiosteum is elevated from the hard palate with the major palatine artery. C, The nasal mucosa and mucoperiosteum are apposed in two layers over the defect in the hard palate. D, Cross-sectional view of the repair.

Question 103

A congenital oronasal fistula may be repaired with an overlapping flap technique. A, The dotted lines represent the incisions necessary to allow soft tissue closure. B and C, Elevate the mucoperiosteal flap and rotate it medially to cover the hard palate defect. Insert the edge of this flap between the hard palate and the mucoperiosteum on the opposite side of the defect. Secure the flaps in position with horizontal mattress sutures (inset). D, Complete the repair by apposing the incised edges of the cleft soft palate in three layers. Make lateral relief incisions (broken lines) to reduce tension on the repair.

Question 104

A, Schematic drawing of a repair of a primary cleft palate involving the lip, premaxilla, and nostril. B, Create a flap from the nasal wall and suture it to a labial mucosal flap to separate the nasal cavity from the oral cavity. C, Repair the cleft lip with one or a series of Z-plasties: (1) Make incisions from A to B and a to c; (2) place a suture between A and a, and B and b, to transpose the flaps; (3) place additional sutures as needed.

Question 105

Single-flap technique for fistula repair. A, Incise mucosa around the fistula to create the buccal flap (dashed line), then débride the fistula. B and C, Advance a buccal flap over the defect and suture into place. D and E, After débriding the fistula, create a hard palate rotational flap (dashed line) and rotate the mucoperiosteal hard palate flap over the defect. Suture the flap to surround the mucoperiosteum. F and G, To repair lesions at the junction of the hard and soft palates, débride the defect, then create and close the defect with a soft palate advancement flap (caudal dashed line).

Question 106

A double-layer flap technique may be performed using tissue surrounding the fistula and a flap from the mucoperiosteum of the hard palate. Create the first flap (gingival dashed line) by rotating the gingival margins of the fistula medially and apposing with sutures (top insert). Cover this flap (bottom insert)with a rotational mucoperiosteal hard palate flap (palatal dashed).

Question 107

A double-layer flap technique for fistula repair may be performed using a mucoperiosteal hard palate flap (palatal dashed line) and a buccal flap (buccal dashed lines). A and B, Create a flap from the mucoperiosteum of the hard palate (palatal and gingival dashed lines); rotate and suture to gingival margin. C and D, Cover it with a second flap created from the buccal mucosa (inset), then advance and suture over the first flap

Question 108

Abdominal wall mm. anatomy

Answer 108

Question 109

What is a direct vs. indirect inguinal hernia?

Answer 109

Question 110

Describe scrotial hernia repair when castration not intended?

Answer 110

Repair of a scrotal hernia when castration is not intended. A, Proposed skin incision. B, Approach to the inguinal canal by blunt dissection. Evaluation of the hernia contents is made through an incision in the parietal vaginal tunic (hernial sac). The broken line indicates the direction of the abdominal incision if canal enlargement will facilitate reduction or resection of the hernia contents. C, After reduction, a transfixing ligature closes the enlarged vaginal process. D, Simple interrupted suture closure of the abdominal wall, the cranial part of the external inguinal ring, parietal vaginal tunic, and subcutaneous tissues.

Question 111

Describe en bloc removal of an inguinal hernia?

Answer 111

En bloc technique for removal of the hernial sac and macerated hernia contents, thereby reducing contamination at the surgical site. A, Scrotal hernia with necrotic bowel segment. The broken line indicates the proposed skin incision for exposure. B, Ventral midline approach with ligation of the involved vessels, including isolation, transection, and Parker-Kerr oversewing of stumps leading to diseased intestine. Viable intestinal stumps are anastomosed. C, Reduction of oversewn intestine by minimal opening of the hernial ring; simultaneous cross-clamping of the hernial sac neck allows complete removal of the intact hernial sac and autolytic contents.

Question 112

Describe how to repair a prepubic hernia with mesh?

Answer 112

Cuff mesh reinforcement of prepubic hernia. A, Ventral view showing damage and shredding of prepubic ligament. B, Interrupted vertical mattress suture fixation of mesh to the abdominal wall with interrupted sutures placed between reinforced prepubic tendon and pubic bone. C, Completed prepubic repair. D, Double-layer mesh technique to help prevent suture pull-out caused by weak hernia tissue edges

Question 113

Describe the external oblique release and lateral sheath release.

Answer 113

Rectus advancement techniques demonstrating possible dissection planes through abdominal muscle fascia to release tension on a midline defect.

Question 114

Describe the underlay mesh technique for hernia repair

Answer 114

Underlay mesh technique. A, Preplaced horizontal mattress suture catching omentum deep to the folded edge of the mesh. B, Rough edge of overlapped mesh faces away from abdominal viscera. C, Series of preplaced mattress sutures around the defect.

Question 115

How can the abdomen be divided into quardants or 9 sections?

Answer 115

he right and left hypochondriac regions, the epigastric or xyphoid region, the umbilical region, the right and left lateral regions (including the flanks and paralumbar fossae), the right and left inguinal regions, and the pubic region

Question 116

Structures of the oral cavity

Answer 116

General view of the oral cavity of the dog. 1, Vestibule; 2, canine tooth; 2a, philtrum; 3, hard palate; 4, soft palate; 5, tongue; 6, sublingual caruncle; 7, palatoglossal arch; 8, palatine tonsil; 9, frenulum

Question 117

Frontal section of the head and neck, ventral aspect.

Answer 117

Question 118

Antidrool cheiloplasty. A, Elevate the everted lip dorsally until it is taut when the dog's mouth is opened maximally. B, Make a 2.5- to 3-cm horizontal, full-thickness incision through the maxillary skin at the site of tautness near the upper fourth premolar, with the caudal edge of the incision ending at a line parallel to the medial canthus and the caudal labial commissure. C, Remove a 2-mm wide strip of mucosa 2.5-cm long from the mucocutaneous junction of the lower lip, beginning 2 cm rostral to the commissure. D, Create 0.5- to 0.75-cm flaps. E, Evert the flaps through the skin incision, using a hemostat or stay sutures to grip the flap. F and G, Secure with vertical mattress sutures. Dashed line (F) represents the mucosal flap from the lower lip

Answer 118

Question 119

What are phases of excretion of saliva?

Answer 119

Phase 1: - acinus make saliva, (cells absorb Na, draws in water, Na rich) Phase 2: - intralobular duct epithelium: resorb Na, **secreate bicarb and K**

Question 120

What does parasympathetic stimulation do to saliva production?

Answer 120

Increase = blood vessel dialation and stimulation of cGMP ⇒ upregulate acinar cell activity Via facial n. and mandibular nn. sympathetic = minor inhibition after initial myoepithelial cell contraction

Question 121

What are non-surgical disease of salivary tissue?

Answer 121

**Sialoadenosis** - treatment phenobarbital, limbic epilpsy - esophageal abnormalities may also be present (sx, abx, and steriods do not help CS) **Sialoadenitis** - terrier breeds predisposed - possible link to hyperstimulation of the vagas n. = neural reflex syndrome - may have similar cause as sialadenosis, some respond to phenobarb

Question 122

Leakage from which salivary gland is most common?

Answer 122

Sublingual SG and duct

Question 123

What dog breeds are predisposed to sialoceles?

Answer 123

poodles, GSD, Australian silky terriers, dachshunds

Question 124

What are the 4 kinds of sialoceles?

Answer 124

Pharyngeal - caudodorsal or lateral pharynx, rostral to epiglotis = dsypnea Zygomatic - orbital swelling, exopthalmous, elevated 3rd eyelid Sublingual Cervical

Question 125

What is a stain that is specific for mucin?

Answer 125

Periodic acid-schiff

Question 126

What is a differential dx for cervical mucocele?

Answer 126

Brachial cleft cyst - has true secretory lining

Question 127

What is the recurrence rate of siaocele post sx removal?

Answer 127

5%

Question 128

What are possible treatment strategies for sialoliths?

Answer 128

gland/duct removal duct ligation duct R & A duct marsupialization into the mouth incision over the stone +/- repair

Question 129

Where are sialoliths most commonly found?

Answer 129

Parotid duct

Question 130

What % of dogs and cats had regional lymph node involvement for sialoliths?

Answer 130

Cats: 39% regional, 16% distant Dogs: 17% regional, 8% distant

Question 131

What is the prognosis for salivary neoplasia?

Answer 131

MST 74-550d correlated with stage, not grade

Question 132

Describe approach to removal of the zyogmatic salivary gland

Answer 132

horizantal incision over dorsal aspect arch Aponeurosis of masseter m. reflected ventrally Orbital fascia reflected dorsally remove portion of the arch dissect gland - ligate br. infraorbital a. (malar a.) do not repalce bone

Question 133

Describe the approach to the parotid sialoadenctomy.

Answer 133

Incise over vertical ear canal (level fo the acoustic meatus) to angle mandible incise platysma and **parotidoauricularis m** **ligate caudal auricualr v.** ligate duct remove **accessory parotid SG** dorsal to the duct

Question 134

What are the orgin and attachments of the major mm of mastication?

Answer 134

Masseter: zygomatic arch → lateral surface caudal body/ramus Tempoalis: temporal skull → dorsal ramus Pterygoideus: pterygoid, palatine, sphenoid bones → angular process **Digastricus (open):** occiptal skull → ventral body

Question 135

What is the blood supply of the mandible?

Answer 135

Maxillary a. → mandbiluar foramen → **mandibular alveolar a.** → mental foramen

Question 136

Nervous supply of the mandible

Answer 136

Trigeminal n. → mandibular foramen → mandibular alveolar n. (sensory) →mental foramen →mental n. (incisors)

Question 137

What are the 3 bones of the maxilla?

Answer 137

**Maxilla:** canine through molars **Incisive/premaxila**: incisiors **Nasal**: dorsal midline

Question 138

What is the blood supply to teh maxilla?

Answer 138

Maxillary a → **major palatine a.** → caudal palatine foramen Maxillary a. →maxiallary foramen → **infraorbital a.** → infraorbital foramen

Question 139

What is the innervation of the maxilla?

Answer 139

CN 5 → maxillary n. →infraorbital canal

Question 140

Muscles of the mandibule and blood supply

Answer 140

Question 141

What are the 5 most common oral tumors? and what breeds are associated?

Answer 141

Melanoma: cockers, poodles, chows, goldens (small breeds) SCC: older large breeds FSA: middle to older large breeds: labs, goldens OSA: medium to large breeds Acanthomatous ameloblastoma: medium to large breeds

Question 142

What are the 3 epulidides and their origins?

Answer 142

Acanthomatous: odontogenic epithelium Fibroumatous eplis: peridontal lig. Ossifying epulis: unknown The last 2 can be cured with local excision, no bone removed

Question 143

What percent of gingival bone tumors causes radiographic osteolysis?

Answer 143

60-80%

Question 144

How does lymph node size relate to metastasis?

Answer 144

Inaccurate for metastatic disease sens 70%, spec 51%

Question 145

What are different types of mandibulectomeis?

Answer 145

Question 146

What is the general prognosis for oral tumors?

Answer 146

70-90% 1 year survival with aggressive surgery local recurrence \<50% usually much less

Question 147

What aspects of oral tumors are associated with a worse prognosis?

Answer 147

tumor type - melanoma and OSA worse bc malignant Location - caudal location incomplete excision: local reccurence complete ~20%, incomplete ~65% Overall recurrence rates and survival best for SCC and ameloblastoma

Question 148

What are the most common feline oral tumors?

Answer 148

SCC - 20-30% have nodal metastasis

Question 149

What is the prognosis for feline SCC: mandibulaectomy +/- RT?

Answer 149

Mandibulectomy: progession free survival 56% 1yr, 49% 2yr - 48% incomplete, 43% recurrence RT alone MST 3 months Mandibuletomy + RT = MST 14m 86% local recurrence

Question 150

What are the 4 layers of the esophagus?

Answer 150

**Adventitia** Muscularis - striated in dogs, caudal 1/3 smooth cats: arises from **cricopharyngeus m and cricoesophageal tendon** Submucosa Muscosa: **stratified squamous epithelium**

Question 151

What composes the upper and low esophageal sphincters?

Answer 151

Upper: thyroipharyngeus, cricopharyngeus Lower: thickended circum. striated mm, diaphragmatic crua, anlge meets stomach and the fold of the gastroesophageal mucosa

Question 152

What is the blood supply of the esophagus?

Answer 152

Cerival: cranial and caudal thyroid aa. Crainal 2/3 thoracic: bronchesophageal a. Caudal: esophageal br arota or intercostal a Terminal portion: left gastric a. Venous: cervical external jugular vv. , thoracic azygous v.

Question 153

What is the nervous supply of the esophagus?

Answer 153

branches of the vagus nn. - paried pharyngeal esophageal nn - recurrent laryngeal nn. - paralaryngeal n. - dorsa and ventral vagal trunks

Question 154

How do you do a hemi-mandibulectomy?

Answer 154

Total hemimandibulectomy. A, Position the patient in ventral recumbency. B, Incise the mucosa 1 to 2 cm from the lesion. Incise the commissure to allow better exposure of the caudal mandible. Separate the mandibular symphysis and identify and transect (broken line) the muscles. C, Dissect and transect the lateral mandibular muscles and expose the temporomandibular joint. D, Dissect and transect the medial muscles of the mandible and identify the mandibular artery entering the mandibular foramen. Ligate the mandibular vessels, disarticulate, and remove the mandible. E, Appose the buccal and sublingual mucosa with approximating sutures

Question 155

What are the transit times through the cervical esophagus?

Answer 155

Liquid in sternal: 2.54 cm/sec Liquid in lateral: 7.23cm/sec Kibble in sternal: 4.44cm/sec Kibble in lateral: 8.92cm/sec

Question 156

Reflex control of swollowing

Answer 156

Question 157

What are potential reasons that the esophagus has a higher dehisence rate?

Answer 157

_lack of serosa_ (**elaboration of fibrin seal,** source pluripotent mesothelial cells) segmental blood supply lack omentum comstant motion tension at site

Question 158

What happens if disrupt segmental blood supply?

Answer 158

Can disrupt throacic if cervial and abdominal intact disruption of cerival and thoracic = necrosis at inlet **most ischemic necrosis due to intramural vascular supply damage**

Question 159

What sx appraoches should be performed to reach the cervical, cr. thoracic and caudal esophagus?

Answer 159

- Cervical ventral midline - **Left 3-4 intercostal** (brachiocephalic trunk and subclavian ventallly), **right 3-5 intercosal** (ventral trachea, ligate/retract azygous v.) - **left 7-9** (avoid vena cava and dorsal/ventral vagus nn)

Question 160

How is the esophagus sutured and with what type of suture?

Answer 160

polydiaxonone or polyglyconate 2mm from edge and 2mm apart single layer simple interrupted, **continous (worse wound strength and apposition)** and double layer interupted described. interrupted prefered and double layer seems standard.

Question 161

How much esophagus can be removed in an R&A?

Answer 161

Clinically \>3-5cm increased risk dehisence Experimentally 20% of cervical esophagus or 50% thoracic esophagus

Question 162

Describe how to do an a circimferential partial myotomy for esophageal R&A.

Answer 162

Outter longitudial layer incised 2-3cm cranial or caudal to R & A. If inner muscular incised = **damage to submucosal vascualr plexus and necorsis**

Question 163

What was the mortality rate and complications with stapler and biofragmentable anastomsis ring devices?

Answer 163

No difference in complication rate or healing between the 2 devices 13. 3% mortality rate - all biofrag 14. 3% leak - all biofrag 11% stricture - all stapler

Question 164

What are 2 types of esophageal patching?

Answer 164

inlay = partial circumferntial replacement onlay = reinforce primary closure dt tension/decreased vascularity

Question 165

What are materials that can be used for patching?

Answer 165

Omentum = mimize stricture formation → need to ligate right gastroepipolitc a. Pericardium = increase strength without increased risk stricture Local muscle flaps: sternohyoideus, longus coli (decrease stricture formation), free buccal mucosal graft, vascularized pedicle graft of internal/external intercostal mm (elevate periosteum), diaphram pedicale graft Stomach, Jejunum (post mucosal stripping) Lung Porcine SIS, lyophilized dura mater, collagen coated vicryl mesh, expanded polytetrafluroehtylene patches

Question 166

What are some options for esophageal substitution?

Answer 166

Cervical: - Inverse tube skin graft: crainally based pedicle, inverted tube, sutured to distal esophagus, 2-3 weeks later cut pedicle. ALT: suture cranial and caudal esophagus to skin and 3-4 weeks later make tube. - omocerival cutaneous island axial pattern flap - one stage tube skin graft - possible complications; obstuction with hair, lack peristalsis and indistensibility Thoracic: - tubed inercostal musculopleural pedicle graft - diaphragmatic pedicle graft - tub lat dosi flap based on thoracoforal vessels - gastric advancement and esophagogastric anastomosis - isoperistalitc and antiperistaltic gastric tubes from greater curvature stomach (splenectomy required, consider pyloromyoplasty to enhance emptying since likely disrupt vagal innervation) - jejunum (free microvascular graft) - colon: more tolerent to ischemia than jejunum

Question 167

What is the normal embryonic fate of the arches?

Answer 167

Ventral arotas = (1-2) external carotid aa, (3-4) common cartid aa. Dorsal arotas = (1-2) internal carotid aa., (3-4) involution, (\>4) desecending aorta Left and right 1&2 = involution Left 4th root/arch = adult arotic arch Right 4th root = brachocephalic trunk Right 4th arch = right subcalvaian a. Left and right 5th = involuation 6th = pulmonary aa., left pulmonary retain connection to arota (left ductus arteriosus = ligamentum areriosum) Left 7th intersegmental a = left subclavian a.

Question 168

What are the most common vascular ring anomalies?

Answer 168

**PRAA + left ligmentum ateriosum (C)** **PRAA + aberrent left subcalvian**= incomplete ring = (described with both left LA (2 structures) or right LA(single structure (G,F) **Double AA** = both aortic arches persist, trachal stenosis (D) **Persistent right LA with normal left AA** (mirror image PRAA) - _cannot do left thorcotomy_ to correct (E) **Aberrant right subclavian a with normal left AA** (incomplete ring) (H) **Persistent left cr. vena cava with non-elastic band** around esophagus

Question 169

What are vascular ring anomalies in cats?

Answer 169

PRAA with left LA PRLA with left AA PRAA with right LA and aberrent left SC double AA

Question 170

What is the general % of congenital abnormalities in dogs and cats/

Answer 170

Overall 20% - most not clinically sig. Aberrant right SC most common, 6% - not clinically sig 95% clinical cases PRAA with left LA, Ductus arteriosis patent in 10% with PRAA Persistent left cr. vena cava in 45% - complicate approach

Question 171

What breeds are predisposed to VRA?

Answer 171

Irish setters, GSD, breeds \>15kg siamese, persians

Question 172

What is the prognosis for VRA?

Answer 172

No difference if operated early or late, survival at 2 weeks 92%, maybe good with some persistence of megaesphagus Factors that effect prognosis include: - degree of esophageal dialation - severity of debilitation - presence of aspiration pneumonia - medical management before and after surgery

Question 173

What breeds are effected by generalized megaesophagus and what is the suspected underlying cause?

Answer 173

Irish setters, GSD, danes, labs, shar-peis, newfies, mini schanauzers, fox terriers defect in **vagal afferent** innervation 74% dead by 1 year age

Question 174

What is a possible sx treatment for congenital megaesphagus?

Answer 174

**Esophagodiaphargmatic cardioplasty** - pulls caudally on esophagus during respiration Good outcome in 50%

Question 175

What is a esophageal duplication cyst?

Answer 175

Often fluctuant mass cranioventral cervial region 2 muscle layers and epithelium Can excise with good outcome

Question 176

Where do esophageal foreign bodies generally lodge for bones, fish hooks and dental chews?

Answer 176

Bones: heart- diaphram 65-79%, heart base 11-39% Fish hooks: pharyngeal esophag 34%, thoracic inlet 11%, heart bse 30%, heat-diaphram 5% Dental chews 74% in distal esophagus

Question 177

What are reasons for surgical removal of an esophageal forgein body?

Answer 177

Inability to remove endoscopy: 63% remove with endo, 29% pushed into stomach, 8% need sx If contrast migrates away (if compartamentalized around perf can med mang) pleural effusion pneumothroax pneumomediastinum sepsis endoscopic risk laceration

Question 178

What is the prognosis for penetrating forgein bodies?

Answer 178

Mortality rate 26% with stick penetration acute penetrating FB worse that oropharyngeal pentration

Question 179

What percent of post-anesthesia esophageal strictures are single or multiple?

Answer 179

Single 62-75% Multiple 38%

Question 180

What is the difference in force between bougienage or ballon dialation?

Answer 180

Bougies - longitudinal shear Balloon - radial force

Question 181

What is the incidence of perforation for ballon dialtion and bougienage of the esophageal strictures?

Answer 181

Balloon = 3.6-11% Bougienage 3.6%

Question 182

What are options for treatment of esophageal strictures?

Answer 182

bougienage balloon dialation steroids (oral/intralesional) - no evidence Esophageal stents Surgery: **esophagoplasty** - transverse closure, **esophageal R&A, patch esophagoplasty** - (incise longitudinally and inlay sternohyoid, incostal, diaphram, or pericardium), **esophageal substitution**

Question 183

What is the prognosis for general treatment of esophageal stricutre?

Answer 183

Good: 71-88% Surgery associated with high rate of stricture recurrence and dehisence

Question 184

What are 3 types of esophageal diverticulums?

Answer 184

Pulsion: outpouching of mucosa through tunica muscularis traction: full thickness deviation (assumed from inflammation of adjacent organ) Epiphrenic: between heart base and diverticulum

Question 185

What percent of canines with an esophageal diverticulum had a bronchoesophageal fistula?

Answer 185

50% If impacted → obstruction →chronic esophagitis → stricture → peridiverticulits → adhesion/fistula → rutpure

Question 186

What breeds tend to get an esophageal diverticula?

Answer 186

Small breeds Cairn terriers (propensity for FB??), mini poodles, Parson Russel terriers

Question 187

How are esophageal diverticula treated?

Answer 187

Small diverticula: conserative, guel diet Large: lateral thoracotomy Excision via stapler, partial resection and in-lay, complete R&A, esophageal substitution PX: good for simple, guarded for extensive repair

Question 188

How is a congenital esophageal fistulae caused?

Answer 188

Incomplete separation of the tracheobronchial tree from the digestive tract aquired due to FB Bronchoesophageal \> tracheoesophageal

Question 189

What is the most common lung lobe effected by esopheal fistula?

Answer 189

Right caudal (66%) Others: right cranial, middle, accessory and left caudal

Question 190

What is cricopharyngeal dysplasia?

Answer 190

Swallowing disorder characterized cricopharyngeal achalasia or asynchrony Usually congenital and dx by 12 m, older may be aquired

Question 191

What cricopharygeal achalasia? asynchrony?

Answer 191

Achalasia: upper esophageal sphincter fails to open during cricopharyngeal phase Asynchrony: incoordination between contraction of pharyngeal contractor mm. and relaxion of upper sphincter

Question 192

What is the treatment for cricopharyngeal dysphagia?

Answer 192

**CP myotomy or myectomy** Ventral or lateral approach Place orogastric tube, _remove 2cm of m._ → place metal clips for post-op fluroscopy Also described with **thyropharyngeal myotomy**

Question 193

Descrine the origin, insertion and innervation of the criopharyngeal m.?

Answer 193

Singel muscle Origin: lateral surface of cricoid cartilage → spreads over esophagus → attaches on other side. Innervation: CN9 (glossopharyngeal n.) and pharyngeal br. of vagus n. Blood supply: cranial thyroid a.

Question 194

How do you differeniate pharyngeal dysplasia from criocopharyngeal dysphagia?

Answer 194

Question 195

barium study for CP dyplasia

Answer 195

Lateral fluoroscopic view of barium swallow. Barium appears black on fluoroscopy. Row 1, Normal dog; 1A, liquid barium bolus in the pharynx; 1B, closure of the epiglottis at the onset of swallowing; 1C, opening of the cranial esophageal sphincter; and 1D, closure of the cranial esophageal sphincter and reopening of the epiglottis. Row 2, Dog with cricopharyngeal achalasia; 2A, liquid barium bolus in the pharynx; 2B, contraction of pharynx without opening of the cranial esophageal sphincter; 2C, opening of cranial esophageal sphincter and reopening of the epiglottis; and 2D, closure of the cranial esophageal sphincter.

Question 196

Lateral approach to the pharynx

Answer 196

Question 197

What is the prognosis for CP dysplasia?

Answer 197

Complete resolution CS in 49% dogs, another immediate resolution in 13/14 dogs Poorer px: failure to transect all bands, incorrect diagnosis, concurrent pharyngeal/esophageal dysfunction, structural problems (fibrosis), esophageal stricture, function disease, masticatory myosti, myasthenia gravis, aspiration pneumonia, malnutrition

Question 198

What the most common esophageal tumors in dogs and cats?

Answer 198

Dogs: SCC leiomyosarcoma, ODA, FSA \< sarcoma, leiomyoma, plasmacytoma - most common site caudal esophagus Cats: SCC - most common site cranial thoracic esophagus

Question 199

What parasite is associated with esophageal nodules in dogs?

Answer 199

Spirocerca lupi Dogs definative host: ingest coprophagous beatle → larvea gastric mucosa to aa. → thoracic aorta wall to caudal esophagus

Question 200

What tumors are associated with Spirocerce lupi?

Answer 200

OSA, FSA, undiffereniated sarcoma

Question 201

What are clinical signs assocaited with maligant spirocera tumors?

Answer 201

HO 38%, none with benign had Lower Hct, higher WBC and platelets Malignant masses larger (6x7cm) and more likely to cause bronchia displacement (52% vs 17%)

Question 202

Diagnostic findings consistent with spirocera?

Answer 202

**Microcytic anemia** Rads: masses, mets, HO **Caudal thoracic spondylitis and aortic mineralization**

Question 203

What % of esophageal tumors have mets at diagnosis?

Answer 203

50%

Question 204

Name important structures of the stomach.

Answer 204

4 parts: cardia, fundus, body, distal 1/3 (pylorus (double mm layer) , pyloric antrum, pyloric canal) **Cardiac notch:** btwn cardia and blind outpouching of stomach **Angular incisure:** where papliary process of liver lies

Question 205

Describe the blood supply of the stomach

Answer 205

Celiac a. 1. splenic → pancreatic and **L. gastroepipolic** (greater curve, anastoms with R. GE) , short gastric aa. 2. Hepatic → br. to liver and gallbladder 1. **Right gastic** → pylorus 1. **Gastroduodenal** 1. **Right gastroepipolic** 2. Cr. Pancreaaticoduodenal 3. **Left gastric** → lesser curvature Portal v. 1. Gastroduodenal → Right, gastric, R. gastroepiploic 2. Gastrosplenic → Left gastric, Left gastroepipolic

Question 206

What is the innervation to the stomach?

Answer 206

_Parasymphathetic_ → **vagus n.** → ventral vagal truck (pylorus, liver, lesser curve), dorsal vagal (lesser curve, ventral wall → then follows celiac and cr. mesenteric a.) _Sympathetic_ → **celiac plexus** (arise from celiacomesenteric plexus and follow gastric br celiac a)

Question 207

Describe the gastric layers.

Answer 207

Serosa Muscularis - **Circular** = cardia to pylorus _except fundus_, **Longitudinal** = esophagus to pylorus on greater curvature (_not lesser, ventral and dorsal body_), Fundus and body = **inner oblique fibers** Submucosa Mucosa - **Columnar surface epithelium, Glandular lamina propria and Lamina muscularis mucosa**

Question 208

Describe the locations and gland types of the stomach.

Answer 208

3 types: cardiac, pyloric and gastric. ## Footnote Cardiac (cardia and antrum): serous Pyloric (pylorus and gastric body): mucus Gastric (fundus and body): - Parietal - Cheif - Mucous neck - endocrine

Question 209

Describe the functions of the gastric cell types:

Answer 209

Parietal (oxyntic): - **maintain gastric acid pH** (pump H+ into lumen), allows activation of gastric enzymes food breakdown - produce **intrinsic factor:** mucoprotein that binds to B12 to allow absorption SI Cheif: **pepsinogen** → converts to pepsin (protein breakdown) Mucous: mucous to protect glandular cells from acid and enzymes Endocrine: **gastrin, histamine, serotonin**

Question 210

Describe the different mechanisms of healing in the stomach

Answer 210

Superfical: **epithelial migration** Mucosa erosions: **epithelial regeneration** Injury to submucosal = ulcer - s**hort-term fibrous protein synthesis** \> wound contration and scar resorbed - long-term: exuberant fibrotic repair with permanant scar Incisional healing: - similar to other areas: inflammation, debridment, repair, maturation - In contrast other tissue, **GI smooth muscle contribute to collagen production**

Question 211

What is the downside to withholding food 8-12 hours prior to sx?

Answer 211

Decreased gastric pH = increased GE reflux (**57% ortho procedures, 14% clinically noted. In post-anesthesia esophageal dysfunction, only 46% clincially noted)** Doesn't reliably decrease contents May help to feed small amounts q3hr

Question 212

What anesthestic agents may be beneficial for gastic sx?

Answer 212

Anticholingerics - decreased gastic secreations H2 blockers AVOID nitrous = rapid diffusion into gas filled organs

Question 213

Transection of which lig. may help with exposure of the stomach?

Answer 213

Hepatogastric hepatodoudenal

Question 214

What is a disadvantage of flush that is warmer than normal body temp?

Answer 214

Increase body temp ## Footnote **vasodilation/hypotension** **increased adhesion formation**

Question 215

Describe paracostal approch to stomach

Answer 215

In rare instances when exposure of only a portion of the stomach is required, a paracostal approach may be used. A paracostal approach is achieved by making a curved incision approximately 2 cm caudal to the last rib. The underlying muscle layers, including the external and internal abdominal oblique and transversus abdominis muscles, are split longitudinally along the direction of the muscle fibers. When ventral extension of the incision is necessary for visualization, the rectus abdominis muscle may require transection. Closure is achieved with a simple continuous pattern in each muscle layer

Question 216

What is the half life of PDS, maxon and monocryl in gastric fluid?

Answer 216

PDS: 12d - only suture tensile strength effected, @ 2pH 10x shorter than at 7.4 Monocyrl 15d Maxon 75d Polyglycolide and poly l-lactidie coglycolide had inital delays in linear absorption = coating

Question 217

What staples have been reported for stomach closure? And pexy?

Answer 217

TA, GIA, **skin stapler** (oversew of line recommended) Pexy: GIA or skin staples (_with skin staples tensile strength similar to **belt loop**_)

Question 218

What are methods of determining viabillity of the stomach?

Answer 218

Subjective (**85%** accurate): Wall thickness, perastalsis, _serosal capillary profusion_, serosal color - incise seromuscular layer = evaluate a. blood supply Objective: **Fluorescein dye** injection: 58% accurate **Lazer flow doppler** = to subjective **Scintigraphy:** 79%

Question 219

List types of gastropexy.

Answer 219

Incisional - _4-5cm, parralel or perpendicular to long axis_ Belt-loop Circumcostal - _double or single hinged_ Incorporating - no inicison in stomach **Tube gastropexy - highest recurrence rate 5-29%** **gastrocolopexy - nonabsorbable suture, scarified/not incised** Lap/Lap-assited **Endoscopically assicsted** **Grid approach** - mini-lap

Question 220

What is a Fredet-Ramstedt myotomy? Disadvantages?

Answer 220

Longitudinal seromuscular inision through the pylorus Does not allow: visualization gastric mucosa, relieve restrictions of the mucosa/submucosa, provide full thickness biopsy

Question 221

What is a Heineke-Mikuliez pyloroplasty?

Answer 221

Question 222

What is a Y-U pylorplasty?

Answer 222

Question 223

What are indictions for a bilroth 1?

Answer 223

Neoplasia confined to pyloric region Ulceration of outflow track Pyloric hypertrophy

Question 224

Describe technique for Bilroth 1.

Answer 224

Pylorectomy with end to end gastroduoenostomy No difference in leakage between a single and double layer closure

Question 225

What is the prognosis of a bilroth 1?

Answer 225

75% survive 2 weeks, but only 33.3% alive at 3 months Complications: - 63% hypoalbuminemia - 58% anemia - Decreased survial with preop weight loss

Question 226

What is a bilroth 2?

Answer 226

Partial gastrectomy with gastrojejunal anastomosis (duodenum and gastrotomy close, jejunum anastomsed to the side) poor results

Question 227

What is the classification system for hiatal hernia?

Answer 227

I: sliding hernia: intermittent movement GE junction into thoax, congenital common (Shar peis and English bulldogs). Aquired = BAS or upper resp. disease II:Paraesophageal: GE junct normal postion, fundus herniated III: Elements both I and II IV: herniation of other organs besides stomach A, Normal anatomy of the junction of the esophagus and stomach. B, Type I sliding hiatal hernia in which the gastroesophageal junction has moved cranial to the diaphragm. C, Type II paraesophageal hernia occurs when a portion of the stomach moves into the caudal thorax through the hiatus adjacent to the esophagus. D, Type III hiatal hernia combines the movement of the gastroesophageal junction into the thorax as well as movement of a portion of the stomach into the thorax adjacent to the esophagus. E, Gastroesophageal intussusception.

Question 228

What are the goals of medical management of hiatal hernia?

Answer 228

1. Reduce gastric acid: H2 blockers and proton pump inhibtors 2. Esophageal mucosas protection: sucralfate (_polyaluminum sucrose - binds denuded mucosa)_ 3. Increase gastric emptying: prokinetics, low fat diet in elevated postion (if megaesophogus) 4. Enhance LES tone: prokinetics

Question 229

How many hiatal hernias improve with medical management? And how long should it be attempted prior to surgery?

Answer 229

53% (8/15) recommend for 30 days

Question 230

How is hiatal hernia treated surgically?

Answer 230

1. Phenoplasty = Phernicoesophageal lig. transection OR horizantal mattress sutures with nylon 2-0. Alone = reherniation 2. Esophapexy: left esophagus to diaphram 3. Gastropexy: left body wall (increases LES tone) Before performing need to transect the hepatogastic lig. and place orogastric tube

Question 231

Describe the cause, breed, presentation and treatment of gastroesophageal intussusception.

Answer 231

Suspect esophageal abnormalitis (megaesophapgus), abnormal esophagus motility, laxity of hiatus \>50% GSD, \>75% less than 3 months Severe respiratory compromise and GI signs EMERGENCY - Left and right gastropexy Mortality rate 95% (1984), improved, life long management esophageal abonormalities and aspiration pneumonia

Question 232

What is hyperthrophic pylogastropathy?

Answer 232

Pyloric senosis. Bas → air=increased gastric pressure →increased gastrin, gastic acid = increased cholecystokinin and secretin → antral and pyloric mucosal hypertrophy Congential: BAS, \<1yr Aquired: small breed Treat with pylortomy, pyloroplasty, Y-U pyloroplasty = only plasty techniques have been shown to increase gastric emptying and allow full thickness biopsy to rule out neoplasia Px: good \>80% improve (ie no chronic vomiting)

Question 233

How to dx hypertrophic pylorogastropathy?

Answer 233

Retention gastric contents \> 8 hours Apple core appearence with contrast rads endo biopsy to rule out neoplasia

Question 234

What percent GI foreign bodies are gastric and what is the most common electorlyte abnormalitiy

Answer 234

16-50% in stomach 50% of GI FB are **HYPOchloremia**

Question 235

What are the most common GI tumor types in 1) dogs and 2) cats?

Answer 235

Dogs: adenocarcinoma Cats: LSA Others: LSA, FSA, gastric medullary plsmacytoma

Question 236

What percent of tumors are adenocarcinomas, breeds predisposed and percent mets?

Answer 236

42-90% of gastric tumors (usually pyolurs or lesser curvature) Mets 70-80% - lungs, nodes, liver Males, Belgian shepards, rough coated collies, staffies

Question 237

How can differentiate leiomyosarcoma from GIST?

Answer 237

GIST c-kit positive GIST from interstital cells of Cajal

Question 238

What is the MST of GI lymphoma in dogs?

Answer 238

17 days :(

Question 239

What is the MST of pythium?

Answer 239

MST 26 days Gastric outflow most commonly effected

Question 240

What are causes of gastric ulceration?

Answer 240

hepatic/renal disease neoplasia NSAID Steroids decreased blood flow, increase gastric acid, decrease proteglandin, decreased mucus/bicarb

Question 241

How does hepatic/renal disease cause gastric ulceration?

Answer 241

Renal = hypergastrinemia from decreased clearence or increased secreation gastrin Hepatic - decreased degradtion of gastrin and histamine → increased gastric acid secration - Portal hypertenision → derangement of mucosal blood flow

Question 242

How do NSAIDs cause GI ulceration?

Answer 242

1. Direct topical effect - weakly acidic, lipid soluable 2. Cox → decreased protective PG → decreased blood flow, epithelial mucus production, bicarb, epthelial turnover - (Cox 2 doesn't alter PGE1 and E2 but linked to slower gasric mucosal healing) - overall combination of COX 1&2, interaction of NSAID with phospolipids and subsequent uncoupling of mitochondrail oxidative phosphorylation

Question 243

H2 antagonists

Answer 243

least potent: **cimetidine q8 \< ranitidine q12 \< famotidine q24** cimetidine inhibits p450 → may interfere with metabol other drugs ranitidine: prokinetic

Question 244

How do proton pump inhibitors work?

Answer 244

**Covalent binds H+/K+ ATPase = block secreation H+** Absorbed in alkaline enviroment: proximal duodenum metbolized by p450 adminster 1 hr before food, complete inhibition of gastric acid secretion in 3-5 ays

Question 245

How does sucralfate work?

Answer 245

Sulfated diasaccide -aluminum hydroxide complex Acid→ sucralfate dissociates to sucrose octosulfate → polymerize to thick substance that binds electrostacially charged proteins (ulcer base) Prevents back diffuse of H+ ions, inactivates pepsin, absorb bile acids Stimulate PG release locally

Question 246

How does misoprostal work?

Answer 246

Synthetic analog of PGE **increases bicarb secreation, mucus production, mucosal blood flow** decreases cAMP → **decreases H/K ATPase pump activity → decreased acid secreation** half life 30 min, give 4 x daily **inhibits ulcer formation but doesn't heall**

Question 247

What tumors are associated with gastric perforation?

Answer 247

Gastrinoma and systemic mastocytosis Gastinoma: non-beta pancreatic islet cell tumor → hypersecreate gastrin from antral G cells → gastric hyperacidity/ulcers

Question 248

What direction does the stomach rotate with GDV?

Answer 248

pylorus moves ventrally and cranially Stretches hepatico**duodenal** ligament

Question 249

What are risk factors for GDV?

Answer 249

1st degree relative with GDV increased thoracic depth:width ratio feeding fewer meals, small particle size, exercise post meals, rapid eating aggressive temperment increased hepatogastric lig

Question 250

What breeds are predisposed to GDV?

Answer 250

Gordan and Irish setters, Poodles St. Bernards Weimies Bassetts Danes

Question 251

Describe pathophys of GDV

Answer 251

Blood supply: - Increase IAP → CVC and portal v. → decrase return blood to heart and portal hypertension → increased bacterial translocation (although no difference btwn control) and decrease liver clearence bacteria (decrease endoreticular funct. - increase pressure diaphragm → decrease O2 - increase intragastric pressure → stomach mucosal and wall necrosis Cardiac disease: - myocardial ischemia → arrythmias, mycardial depressent factor Reprofusion injury

Question 252

What percent of GDV have ECG abnormalities?

Answer 252

40-70% Cardiac troponin peak at 48-72hr and correlates with arrythmia severity

Question 253

How do lactate measurements corrleate with necrosis and survival for GDV?

Answer 253

Necrosis: \>6mmol/L → 61% sens, 88% spec Survival: \> 6 58%, \<6 99% \>9 54%, \<90% if \>9 response to therapy was predicitve: \>4 change → 86% survival \>42.5% percent change → 100% survival final value \<6.4 → 91% survival

Question 254

What are the recurrence rates for various gastropexys?

Answer 254

Circumcostal gastropexy 4-7% belt loop: none Gastrocolopexy: 3/20 (15%) Incorporaing: 4/61 (7%) → GD died/euth

Question 255

Mechanical testing of gastropexy

Answer 255

Circumcostal: strength N 109, 21d post test Belt loop: strength N 109, 50d post test Incisional: 60, 62, 85. 21d, 58d, 30d Laproscopic: 45, 77, 106. 30d, 50d, 30d.

Question 256

What is the survival rate GDV and factors that decrease survial?

Answer 256

73-90% Increased duation signs \>6h, gastrectomy/splenectomy, hypotension, arrythmias, peritonitis, sepsis, DIC, lactate, myoglobin Myoglobin: \<168ng/mL 60% sens, 84% spec = 50% above died, 90% below survived **Bacteremia NOT associated** with survival

Question 257

How does prophylactic gastropexy effect life time risk gastropexy?

Answer 257

Lifetime risk in risky breeds: 4-37% 29 fold decrease mortality rate with prophylactic

Question 258

Describe adhesion strength gastropexy

Answer 258

Similar for circumcostal, belt loop, incisional and lap-assited. Stapler for total lap: weaker first 7 days, then no diff at 30d

Question 259

What is the nervous supply to the small intestine?

Answer 259

splanchnic n. via celiac and cranial mesenteric plexus vagas Abdominal autonomic nervous system, left lateral view. The cranial mesenteric ganglion (34) is located on the sides and caudal surface of the cranial mesenteric artery. 1, Stomach; 2, ventral trunk of vagus nerve; 3, esophagus; 4, dorsal trunk of vagus nerve; 4a, celiac branch of dorsal vagal trunk; 5, aorta; 6, intercostal artery and nerve; 7, ramus communicans; 8, sympathetic trunk; 9, celiac artery; 10, quadratus lumborum; 11, major splanchnic nerve; 12, cranial mesenteric artery; 13, lumbar sympathetic ganglion at L2; 14, minor splanchnic nerve; 15, tendon of left crus of diaphragm; 16, psoas major; 17, lumbar splanchnic nerve; 18, transected psoas minor; 19, deep circumflex iliac artery; 20, caudal mesenteric artery; 21, left hypogastric nerve; 22, caudal mesenteric plexus; 23, caudal mesenteric ganglion; 24, testicular artery and vein; 25, descending colon; 26, cranial ureteral artery; 27, jejunum; 28, caudal vena cava; 29, greater omentum; 30, renal artery and plexus; adrenal gland; 32, common trunk for caudal phrenic and cranial abdominal vein; 33, adrenal plexus; 34, celiac and cranial mesenteric ganglia and plexus.

Question 260

What are the 2 types of contractions in the SI?

Answer 260

Semental: strech reflexes and vagas - mix food peristaltic: migrating myoelectricl complexes - cycel every 1.5-2h in periods between meals and pylorus opens during this time to let indigestible things pass

Question 261

Describe the general transport mechanisms and water absorption.

Answer 261

Active = sodium pump and N-K-ATPase, against conc. grad Passive= with conc grad. - Facilitated: Aid of protein/conc. grad to transport across cell membrane Jejunum absorbs 50% Ileum absorbs 75%

Question 262

What are the electrolyte changes associated with a proximal duodenal obstruction?

Answer 262

hypochloremia, hypokalemic, metabolic alkalosis not proximal = metabolic acidosis from loss of bicarb

Question 263

What are 2 forms of objective assessment of viability for the SI?

Answer 263

Fluroescein = organic dye fluroesencnt under UV light - inject 10-15ml/kg IV, assess with Woods lamp **Surface oximetry** = compare peripheral

Question 264

What enzymes allow glucose and fructose to enter the intestinal cells?

Answer 264

SGLUT1, SGLUT2 (fructose)

Question 265

Arterial supply to the small intestines

Answer 265

Question 266

Venous supply to SI

Answer 266

Question 267

The mesentery gathers and attaches to the abdominal wall opposite the second lumbar vertebra by a short peritoneal attachment known as the root of the mesentery (1) through which the proximal portion of the cranial mesenteric artery passes.

Answer 267

Question 268

The small intestines are structurally composed of four layers: the mucosa, submucosa, muscularis, and serosa. The cells at the base of the villi are dividing, undifferentiated epithelial cells that are primarily involved in fluid secretion. The cells mature and differentiate into immature enterocytes as they pass up the crypt.

Answer 268

Question 269

What is the maxium dose of potassium infusion 0.5mEq/kg/hr

Question 270

Enzymes involved in digestion?

Answer 270

Cholecystokinin = enzymes enter duodenum. Secretin= bicarb from pancreas Proteins: Trypsin, chymotrypsin, carboypeptidase, aminopepridase Carbs: amylase, suscrase, lactase Lipids: lipase, bile acids

Question 271

Key points related to suturing SI

Answer 271

Inflammation → collagenase in bowel wall, prolonged lag phase (cat gut causes inflammation and dissolves quickly) Poor submucoas apposition → healing second intention, worse apposition with 2 layer closure

Question 272

Simple appositional cause inversion/eversion in what percent of simple interrupted and simple continuous closures?

Answer 272

Interrupted: 66% eversion Continuous: 38% inversion, eversion or poor apposition

Question 273

What is the ideal knot tying force for the SI?

Answer 273

1.5N

Question 274

What are methods of suture line reinforcement?

Answer 274

**Omentum** - angiogenic, immunogenic, adhesive = sutured better than migrate on own. Can form adhernet sheath that prevents perforation **Jejunal serosal patch** **Gallbladder serosal patch** - ligate cystic duct, **but preseve a.**

Question 275

What are 4 ways to deal with lumen disparity?

Answer 275

- uneven suture placement (wider apart on larger side) Cut at angle Spatulate Reduce larger side

Question 276

What is a modefied Gambee stitch?

Answer 276

Emerges at the mucosa/submucoas junct = can help mucosal eversion

Question 277

Why is it not recommend to use polypropylene in a continous pattern for closure of an SI R&A?

Answer 277

Migrates into intestine and serves as an anchor point for foreign material - 6w to 7m later

Question 278

What are the three stapling techniques for SI R&A?

Answer 278

**Triangulating** end to end anastomosis with TA 30 staplers (3 cartridges - attached pic) **Inverting** end to end with EEA stapler **Side to side** (function end to end) using GIA

Question 279

End-to-end anastomosis using a triangulation technique and a skin stapler. Place three stay sutures to appose the ends of the intestine and divide the circumference into three equal parts. Apply tension between two sutures. Center the skin stapler between the two segments, then apply staples with gentle pressure approximately 2 to 3 mm apart. Apposed edges of the intestinal wall be slightly evected

Answer 279

Question 280

For an inverting end-to-end anastomosis, use an EEA stapler and a transverse stapler. Insert the stapler cartridge into the intestinal lumen through an enterotomy 3 to 4 cm from the transection site. Insert the anvil into the other intestinal end. Tie purse-string sutures securely around the shaft of the stapler. After completing the anastomosis, close the enterotomy with sutures or a transverse stapler

Answer 280

Question 281

What are advantages and disadvantages of GIA stapler?

Answer 281

Advantages: easy, fast, few cartridges, no lumen compromise, luminal disparty not an issue, length of stapler = stoma size, decrease manipulation of bowel Disadvantage: cost, need 60mm for GIA (may not be enough room in illium, too big for toy breeds (can use endoscopic linear cutting device), blunting of knife

Question 282

What are complications associated with enteroplication?

Answer 282

obstruction, strugulatoin, perforamtion, septic peritonitiis, perforaiton with abcess formation, mid jejunal volvulus complicaitons usually occur 1m or more post-op, rate of complication higher with enteroplication and rate of recurrence Experimentally: abdominal discomfort, vomiting diarrhea, decreased appetite, constipation

Question 283

What is the reported incidence of SI dehisence after R&A and after biopsy?

Answer 283

7-16% 12%

Question 284

How much fluid can the omentum and peritoneal membrane absorb?

Answer 284

3-5% body weight/hour

Question 285

What is the mortalitiy rate post intestinal dehisence?

Answer 285

50-85%

Question 286

What are factors that encourage adhesion formation?

Answer 286

ischemia, hemorrhage, FB, infection

Question 287

What are factors that can decrease adhesion formation?

Answer 287

200ml of peritoneal dialysis solution 3x daily for 4 days after clsoure - likely mechanical removal but may also be fibrinolytic intraabdominal recombinant tissue plasminogen activator (t-PA) - thrombolytic

Question 288

When does short bowel syndrome occur?

Answer 288

Resection of 50% or more of the proximal or distal small bowel (steatorrhea dt removal of distal ileum) (body wt, cholesterol and albumin lowest after distal resection) Can occur with 50% but some dogs have 85% resection without a problem

Question 289

What are the causes of short bowel syndorme?

Answer 289

Reduced mucosal surface area gastric and intestinal hypersecretion bacterial overgrowth decreased intestinal transit time

Question 290

How fast does contrast agent reach the colon in short bowel syndrome?

Answer 290

5-12 min

Question 291

What kind of food should be fed to patients with short bowel syndrome?

Answer 291

soluable fiber and glutamine 10-15% fiber: promotes intestinal adaptive changes, modulates motility, increses water resorption, binds excess bile salts (secratory diarrhea) Fat: delays gastric emptying, calories, stim enterocyte growth

Question 292

What are medications that can be used to treat short bowel syndrome?

Answer 292

Loperamide - antidarrhea, increases intestinal tone Antibiotics - treats intestinal overgrowth - amoxi, tertacycline, metronidazole, tylosin

Question 293

What surgical procedures to treat short bowel syndrome?

Answer 293

Construct intestinal vavles interposition of reversed bowel segment colonic interposition reversed electrical pacing

Question 294

What anatomic measurement on radiographs can be used to ID distended small intestine?

Answer 294

Measure height body L5 SI:L5 ratio \> 1.6 abnormal. \>2 very likely FB

Question 295

How can intestinal infarction be diagnosed?

Answer 295

mesenteric angiography, contrast MRI (T2), repeated US focal segments of bowl dilation progress to segmental thickening and loss of normal layer appearence over 24 hr

Question 296

What percent of cats have a linear FB caught around the tonge and what pecent improve with conservative management (i.e. cut the string)?

Answer 296

50% remanant passed in 1-3 days in 47%

Question 297

What percent of linear FB in dogs have peritonitis at the time of sx?

Answer 297

40%

Question 298

What is the prognosis for linear FB?

Answer 298

Probability of death/peritonitis 2x greater for dogs than cats Perforations = worse px survival 30% dogs have gross contamination and more than 40% require R&A

Question 299

Define intussusceptum and intssuscepiens

Answer 299

Intussusceptum: the part of the intestine that telloscopes in Intussuscepiens: the lumen the intussusceptum goes into

Question 300

What is the reccurence rate for intususecption and where do they generally recur?

Answer 300

6-27% recurrence recur proximal to previous site

Question 301

Laproscopic treatment iliocolic intusseption - only experimental

Answer 301

Laproscopically monitored and manipulated bowel while insuflating rectum with CO2 1 perf, 1 reccur cannot be done with fibrosis or vascualr collaspse

Question 302

What cuases have beed assocaited with mesenteric vovlulus?

Answer 302

lymphoplasmacytic enteritis ileocolic carcinoma GI FB recent GI surgery blunt abodminal trauma GDV EPI

Question 303

What is the signalment for mesenteric volvulus?

Answer 303

young male large breed dogs GSD, English pointers

Question 304

What chemical abnormalities are associated with mesenteric volvulus?

Answer 304

hypoproteinemia, hypokalemia, hypoalbuminemia

Question 305

What percent recover after derotation of a mesenteric volvulus?

Answer 305

36%

Question 306

What is the sensativity for peroneal penetration?

Answer 306

60%

Question 307

What are congenial malforations of the SI?

Answer 307

Intestinal diverticula intestinal duplication

Question 308

Colonic orifaces?

Answer 308

Question 309

Colonic blood supply

Answer 309

**Cr. mesenteric a.** 1. **common trunk** 1. **Middle colic** - desending colon 2. **Right colonic** - transverse colon 3. **Illeocololic** 2. Cd pancreaticoduodenal 3. Jejunal aa. 4. Ileal aa. **Caudal mesenteric a.** 1. cr. rectal 2. **left coloic** (anastomosis with middle colic) **Left colic → caudal mesenteric (middle colic), (ileocolic (right colic and cecal)) → portal v.**

Question 310

nervous supply colon

Answer 310

PLEXUS MAIN ARTERIAL BRANCHES GROSSLY DISSECTIBLE STRUCTURES SUPPLIED CONTINUING THE PLEXUS SOURCE Cranial mesenteric Common colic Cranial mesenteric ganglion Large intestine Caudal mesenteric Left colic Lumbar splanchnic nn (caudal group) Hypogastric nn (paired) Cranial hemorrhoidal Aortic plexus Distal colon (left)

Question 311

What is the function of the colon?

Answer 311

Resovior microbial ecosystem Resorb: H20, Na, Cl, short chain FA Secreate: K, HCO3 and mucus

Question 312

Describe electorlyte and water transport in colon

Answer 312

Electrical gradient: basolateral Na/K pump, apical brush border K selective channels Na/k pump (elecrogenic), Na/H 1-3 or Cl/HCO3 (electroneutral Aquaporins: Colon absorbs 1.5L fluid/d

Question 313

What are the names of the intrinsic plexuses that control motility of the colon?

Answer 313

intrinsic plexus: Myenteric or Auerbach (between longitudinal and circular mm) submucous or Meissner's (in submucosa)

Question 314

What do D and M cells do?

Answer 314

M cells (microfold): - produce proinflammatory cytokines, chemokines - move proteins, virus, etc. transepitheliallyto subepithelial lymphoid cells - invagination basolateral membrane where memory T and B cells interact and M and D cells interact D cells: - activated migrate to lymph node and prime T helper cells and B cells \*humoral immunity - also penetrate epithelium and directly sample luminal antigens

Question 315

What are the phases of healing of the colon?

Answer 315

Lag phase: 0-3 or 4d - fibrin clot, most likely time for dehisence, platelets initate, then neutrophils d2-3, then monocytes and macrophages Proliferation phase: 3 or 4 - 14d - fibroblasts proliferate (major by 4d) and clot replaced by collagen, type III collagen 30-40% of granulation tissue (normally 20%), with the remainder being type I. Diven by PDGF, TGF-beta, FGF. Bursting strength almost normal by 10-17d. Angiogenesis. Maturation phase: 17d onward: collagen reorganize/remodel. Macrophages and fibroblasts decrease, acute thin collagen fibers become thick bundles, amount of type III decreases.

Question 316

What is the collagen content of the submucosal layer?

Answer 316

Type I 68% Type III 20% Type IV: 12%

Question 317

When does the colon return to 75% of its normal strength?

Answer 317

4 months, takes longer than for SI

Question 318

What are factors that negatively effect healing in the colon?

Answer 318

hypoprofusion poor apposition wound tension infection distal obstruction systemic hypovolemia blood transfusion (impaired funct or migration of macrophages) icterus chemotherapy immunodeficiency DM Zn and Fe deficency

Question 319

When does PaO2 effect collagen synthesis and wound healing?

Answer 319

Collagen PaO2 \< 40mmHg Angiogenesis PaO2 \< 10mmHg

Question 320

What are methods that may imprve colonic wound healing?

Answer 320

Vascularized tissue wraps - omentalplasty (no increase brusting strength, no benefit in people but may help confine leakage, may increase but benefits outway risk), expirmentaly rectus abdominus flaps Colonic reinforcement - SIS (no association with acute stenosis, adhesions or abcessation) - amniotic membrane (experimental, rats) Cytokines = giving VEGF may increase angiogenesis

Question 321

What are suture less closures of the colon and what are some benefits?

Answer 321

Lazers: - Na: YAG: low power neodymium-dopedyttrium aluminum garnet : quicker healing with fewer adhesion, initially lower brusting strength - gallium arsenide lazer: stronger anastomosis tan sutured Cyanoacrylates - NOT recommended Fibrin glue - minimal inflammation and scar, rapid healing (ashesive of thrombin and fibrongen)

Question 322

What have post-op epidurals with bupivicaine been associated with?

Answer 322

Intusseption - decrease intersinal paralysis but alters myelectric impulses and propulsion

Question 323

What is a Parker-Kerr pattern?

Answer 323

Cushing pattern over a clump, then oversewn with Lembert

Question 324

Where did Bertog suggust as the lanfmark for the colorectal junction and the site to end a subtotal/total colectomy?

Answer 324

2cm cr. brim of pelvis, 1cm aborad to the enterence of the cd. mesenteric a. Subtotal preserves ileocolic valve, 1-2cm distal to ileocolic juntion

Question 325

What is a Furniss clamp?

Answer 325

Auto-suturing for purse string placement

Question 326

What are the 2 colostomy techniques reported in dogs?

Answer 326

End on colostomy Loop colostomy

Question 327

What is a paraneoplastic syndrome associated with cecal tumors?

Answer 327

Erythrocytosis - leiomyosarcomas (ectopic erythropoiten) Most common tumors cecum - GIST (/leiomyosarcoma), then adenocarcinoma and sarcoma MST 681d, 1yr 83%, 2y 62%

Question 328

When is megacolon reversible?

Answer 328

If mechanical obstructoin corrected within 6m

Question 329

What are the causes of feline megacolon?

Answer 329

Idiopathic 62% Pelvic stenosis: 23% Neurologic disorder: 6% Manx 5%

Question 330

What is the theroy behind megacolon?

Answer 330

Generalized dysfunction of longitudinal and circular smooth mm. seconday to disturbance in activation of smooth mm. myofilaments - no histologically sp. abnormality

Question 331

What is the signalment of megacolon in cats?

Answer 331

Middle aged male cats

Question 332

What is the radiographic basis of megacolon?

Answer 332

Normal colon: diameter = length of L2 Colon \> 1.5x the length of L7 = megacolon

Question 333

What is the medical management of megacolon in cats?

Answer 333

Stool softeners high-fiber diet periodic enemas cisapride - benzmide class: prokinetic causes release of acetylcholine from enteric nervous system which stimulates contraction fo snooth m. in descending colon

Question 334

What do phosphate enemas cause in cats?

Answer 334

rapid dehydration, hypocalcemia, hypophospatemia and death

Question 335

How to discern primary from seconday megacolon in cats

Answer 335

Question 336

How to manage idopathic megacolon

Answer 336

Question 337

how to manage seconday megacolon

Answer 337

Question 338

How does lactulose work?

Answer 338

disaccharide not hydrolyzable by mammals Bacteria digest into organic acids → increase osmotic pressure in lumen of colon → retain water

Question 339

What are surgical treatments for megacolon?

Answer 339

**Coloplasty with partial colectomy** = recurrence **Subtotal or total colectomy** - ileocolic orifice acts as sphincter = prevent reflux, removal may cause SIBO or increased severity/incidence of diarrhea - end to end, end to side, and side to side colocolostomy or entercolostomy

Question 340

How long does it take for normal enteric motility to re-establish?

Answer 340

8 weeks Some cats do not adapt (increase vilus height, entercyte number/density) and have chronic diarrhea Recurrence of constipation is ucommon but one study had 45% recurrnece rate. Stricutre rare.

Question 341

What are concurrent or previous diseases associated with coloinc and cecocolic volvulus?

Answer 341

Medium to large, young dogs previous intussusception and EPI or GDV with gastropexy

Question 342

What are common colonic tumors in cats and dogs?

Answer 342

Dogs: Adenocarcinoma, LSA, stromal tumors, extramedullary plasmacytoma Cats: LSA, adenocarcinoma, MCT, neuroendcrine tumors

Question 343

What are the MST for common colonic tumors in dogs and cats?

Answer 343

MST Dogs: ACA - 6-22m, GIST- 37m, Leiomyosarcoma 7.8m MST Cats: ACA - subtotal colecotmy 138d, R&A 68d. LSA 97d, MCT 199d mets at the time of sx in cats: ACA 80%, LSA 75%, MCT 75%

Question 344

What is the difference between type 1 and type 2 colonic duplication?

Answer 344

Type1 : limited to colon and rectum Type 2: associated with other congenital abnormalities (urogenital duplicaitons, veterbral colum abnormalities Subclassified: spherical noncommunicating, tubular noncommunicatong, tubular comminucating

Question 345

What is the vascular supply to rectum/anus?

Answer 345

Vaculature: intrapelvic * **Cranial rectal a.** (majority) * Internal iliac → Internal pudenal a * **Middle rectal** * **Caudal rectal** * Cats = intraplevic adequately supplied by middle and cd. Rectal (NOT dogs, need cr. Rectal)

Question 346

General anatomy of rectum

Answer 346

* Retroperitoneal portion: _lacks serosa_ – implications for healing * Anal canal – 1cm length * Columbar zone * Intermediate zone = **anocutaneous line** * Cutaneous zones * Internal zone * **Anal glands** * **Anal sacs** - ivaginations * External zone * **Circumanal glands (perianal, hepatoid)** * Anal glands (tubular swear glands): columnar and intermediate zones * Glycoproteins (**alpha-l-furctose)** = viscoelastic properties mucus

Question 347

Describe the ventral approach to the rectum

Answer 347

* Pubic symphysiotomy * Pubic or pubic and ischial osteotomy increses exposure * Ideally at least 2cm normal tissue should be removed on either side

Question 348

Describe dorsal approach to the rectum

Answer 348

* U shaped incision between anus and tail (extend to tubur ischium) * Rectococcygeus mm, dorsal rectum and sphinctes are visible * Rectoccygeus mm transected at attachement on coccygeal vertebra * Blunt dissect between the levator ani and sphintermm. And levator ani transected if needed

Question 349

Describe rectal pull though

Answer 349

* Rectal pull through, transanal pull through * If incison made at anal-cutaneous junct = incontence and removal of anal sacs, start 1.5cm internally to avoid this

Question 350

Describe Lateral approach

Answer 350

* Resection of a rectal diverticulum, rectocutaneous fistula, repair laceration of rectum * Curvilinear perianal incision – tail base to ischium * Dissect between external anal sphincter and levator ani

Question 351

What causes incontinence in colorectal surgery?

Answer 351

* Pelvic plexus at peritoneal reflection disrupted * Anal sphincter removed * Removal distal 1.5cm may (even if anal sphincter persevered) = incontinence * Resection of 6cm (with peritoneal reflextion) through dorsal approach = incontinence * Transection alone or resection 4cm defecated normally * Resection of more than 6cm with reflextion and maintaining distal 1.5cm = no incontinence

Question 352

Describe the types of atresia ani?

Answer 352

* Aresia Ani * Type 1: congenital stenosis * Type 2: persistence anal membrane, inperforate anus with blind pouch * Type 3: Like 2 but blind end further cranially * Type 4: caudal rectum/anus normal but cranially has blind pouch

Question 353

How does a rectovaginal or urethrorectal fistula form?

Answer 353

failure of the urorectal septum to separate the cloaca into anterior urethrovesical segment and posterior rectal segement Possibley more common in poodles Commonly present with atresia ani

Question 354

What is a anogenital cleft?

Answer 354

* Have cloaca, ventral aspect anus incomplete and forms dorasal part of cleft * Males often have hypospadias

Question 355

What are methods of treatment of rectal prolapse?

Answer 355

* **Reduce prolapse**/edema: saline, lubricants, 50% dextrose, liver yeast cell derivative, systemic furosemide * Apply purse string 3-5d (time to tx underlying cause) * Dicyclomine anticholinergic-antispasmatic * Retention enema with hydrocortisone or mesalamine * **Rectal resection and anastomosis** – place tube and cut full thickness (see Fig 94-12). * Multiple recurrence = **colopexy** * _No difference between incisional colopexy and scarifcation_ with 2 rows of 5 or 6 simple interrupted sutures

Question 356

What hormone is associated with perianal adenomas?

Answer 356

Androgens (testosterone) Look for cushings disease in females Adenocarcinoma is not hormone dependent

Question 357

What factors are assocaited with prognosis for perianal adenocarcinoma?

Answer 357

* Stage only factor for survival and DFI * \>5cm and mets increased death 11x and 45x respectively * recurrence increased with \>5cm and invasion of tissue * Nuclei size correlated with ln mets and survival

Question 358

What is the metastatic rate of perianal adenocarcinoma at diagnosis?

Answer 358

* 14.6% mets at dx – ln, lungs, liver, bone, kidney

Question 359

What is a paraneoplastic syndrome seen with adenomatous polyps?

Answer 359

leukocytosis hypocholesterolemia and hypoalbuminemia also common

Question 360

What are treatment options for benign rectal tumors?

Answer 360

* Mucosal eversion * Electrosurgery/ligation – small lesions * Cyrotherpay – applied to base prevent regrowth * Transanal endoscopic biopsy = more diffuse leasions: 38% cured, 20% palliated, 50% poor (15% death due to perf)

Question 361

Surigcal treatment options for perianal fistula

Answer 361

* Excision sinus +/- anoplasty (if around entire anus), cryosurgery, sx debride and chemical cauterization (not recommended due to cytotoxicity), high tail amputation, deroofing and fulguration, laser excision

Question 362

Perineal hernia types

Answer 362

* Caudal perineal hernia: btwn levator ani, internal/external anal sphincters * Dorsally: coccygeus and levator ani * Ventrally: ischiourethralis, bulbocavernosis and ischiocavernosis mm. * Latearlly coccygeus, sacrotuberous lig. (sciatic perineal hernia)

Question 363

Muscles and improtant structures for perineal hernia

Answer 363

Muscles: * Levator ani: attach 7^th cd vertebra, external anal sphincter * Iliocaudalis * Pubocaudalis – inserts perineal body * Coccygeus: originates spine of ishium, attach transvers process 2-5^th lumber vertebra * External anal sphincter: 3^rd cd vertebra and levator ani * Internal obturator * Sacrotuberous lig: ischiatic tuberosity to sacrum and 1^st cd vertebra * Ischiorectal fossa: laterally levator ani/coccygeus, dorsal/lat superficial gluteal, dorsal external anal sphincter and ventral internal obturator, constrictor vulae female, retractor penis make

Question 364

Bounderies perineum?

Answer 364

3^rd cd. Vertebra, sacrotuberous lig. And ischial arch

Question 365

Breeds with perineal hernia

Answer 365

intact older males 83-93% * Breeds: Pekingese, Boston, corgis, boxers, poodles, bouviers, old English, collies, doxies, kelpies, GSD

Question 366

Causes perineal hernia

Answer 366

* Association with non-traumatic inguinal hernias * Rectal abnormalies: result not cause * 100% rectal deviation, 40% rectal dilatation * Androgens * Risk recurrence 2.7x greater if not castrated * Castration reduces recurrenc rate 23-43% * Possibly low quanity of androgen rectors in diaphragm mm., but upregulation not seen post castration in dogs with perineal hernia unlike normal dogs * Gender related anatomic differences * Larger/broader levator ani mm with longer rectal attachment, larger sacrotuberous lig., peritoneal cavity ends more cranially, breed exceptions (greyhounds/bboxers) * Relaxin = higher expression relaxin receptors, no diff conc. * Leakage of cystic prostatic fluid with relaxin may predispose to pelvic and inguinal hernias * Prostatic disease * 25-59% concurrent prostatic disease * Neutering may not effect recurrence when prostate normal * Neurogenic atrophy * Poss dt traction of sacral plexus during straining * High incidence spontaneous potentials on electromyographic recordings of pelvic diaphragm mm.

Question 367

Perineal anatomy

Answer 367

* Levator ani: attach 7^th cd vertebra, external anal sphincter * Iliocaudalis * Pubocaudalis – inserts perineal body * Coccygeus: originates spine of ishium, attach transvers process 2-5^th lumber vertebra * External anal sphincter: 3^rd cd vertebra and levator ani * Internal obturator * Sacrotuberous lig: ischiatic tuberosity to sacrum and 1^st cd vertebra * Ischiorectal fossa: laterally levator ani/coccygeus, dorsal/lat superficial gluteal, dorsal external anal sphincter and ventral internal obturator, constrictor vulae female, retractor penis make Blood supply: * Internal pudendal: courses over internal obturator m.

Question 368

What percent of perineal hernias are unilateral

Answer 368

* Unilateral 47-66% R\>L (59-84%)

Question 369

What percent perinal hernias have bladder retroflexion?

Answer 369

* Bladder retroflexion 20-29%

Question 370

Surgical preparation of the perineal area. Incision A, traditional perineal herniorrhaphy; incision B, superficial gluteal transposition; 1, purse-string suture in the anus; 2, iliac crest; 3, greater trochanter of the femur; and 4, ischial tuberosity. The incision for the internal obturator muscle transposition should extend 2 to 3 cm ventral to the ischial tuberosity.

Answer 370

Question 371

What are surgical options for perineal hernia?

Answer 371

Surgical options: * Herniorrhaphy * Internal Obtrator Muscle Transposition * Do not go past caudal edge of foramen to avoid obturator n. damage * Superfical gluteal m. transposition * Tendon isolated below biceps m. and cut at insertion on the **trochanter tertius - reflected and sutures to external AS** * Must preserve n. and blood supply (still attached to sacrum, sacrotuberous lig. and gluteal fascia * Can include part of fascia lata * Modefication: tendon of insertion transected and roated 45 degrees – sutured to internal obturator, sacrotuberous, external anal sphincter * Combination of internal obturator and supficial gluteal (internal on bottom and sutured to tail, superficial to ischial fascia) * Semitendinosus m. transposition * Good as salvage or if ventral defect * Recommend _contralateral m._ for unilateral defect * Do not injure caudal gluteal a. = transect midbody/stifle * Prosthetic implants * Mesh: 92% success rate * Complication: suture sinsuses (resolved once suture removed) * PSIS * As strong as internal obturator m. trans. And normal diaphram * Porcine dermal collagen * Serosanguinous dc 33%, success rate 59% * Fascia Lata * Very good outcomes, lameness associated with donor site most common complication * Pexy * Colopexy * Cystopexy * Has been used to treat dysuria secondary to caudally displaced bladd * Vasopexy * Castration with ductus vigated separt from vasculature * Tunnel transverse abdominal m at level of apex empty bladder * Each passed through tunnel and sutured to self * Doesn’t prevent bladder retroflexion * Laparoscopic vasopexy: 66% free CS at 8m * Complications pexy: tenesmus most common, fever, constipation * Complications staged: urine dibbling (37,17% permanent), tenesmus (44%, 10% permant), wound complicaitons (17%), recurrence 10%

Question 372

How do you treat unusal perineal hernias?

Answer 372

Surgical options: * Herniorrhaphy * Internal Obtrator Muscle Transposition * Do not go past caudal edge of foramen to avoid obturator n. damage * Superfical gluteal m. transposition * Tendon isolated below biceps m. and cut at insertion on the **trochanter tertius - reflected and sutures to external AS** * Must preserve n. and blood supply (still attached to sacrum, sacrotuberous lig. and gluteal fascia * Can include part of fascia lata * Modefication: tendon of insertion transected and roated 45 degrees – sutured to internal obturator, sacrotuberous, external anal sphincter * Combination of internal obturator and supficial gluteal (internal on bottom and sutured to tail, superficial to ischial fascia) * Semitendinosus m. transposition * Good as salvage or if ventral defect * Recommend _contralateral m._ for unilateral defect * Do not injure caudal gluteal a. = transect midbody/stifle * Prosthetic implants * Mesh: 92% success rate * Complication: suture sinsuses (resolved once suture removed) * PSIS * As strong as internal obturator m. trans. And normal diaphram * Porcine dermal collagen * Serosanguinous dc 33%, success rate 59% * Fascia Lata * Very good outcomes, lameness associated with donor site most common complication * Pexy * Colopexy * Cystopexy * Has been used to treat dysuria secondary to caudally displaced bladd * Vasopexy * Castration with ductus vigated separt from vasculature * Tunnel transverse abdominal m at level of apex empty bladder * Each passed through tunnel and sutured to self * Doesn’t prevent bladder retroflexion * Laparoscopic vasopexy: 66% free CS at 8m * Complications pexy: tenesmus most common, fever, constipation * Complications staged: urine dibbling (37,17% permanent), tenesmus (44%, 10% permant), wound complicaitons (17%), recurrence 10%

Question 373

What are complicaitons of perineal hernias?

Answer 373

* Traditional: 28-61% * Internal: 19-45% * Gluteal: 15-58% * Incisional infection 6.4-45% * Other complications: rectal prolapse, urinary abnormalities, rectocutaneous fistula, anal sac fistulation, flatulence, pain on defecation * Incontinence \<15% * Sciatic n. injury \<5% * Use caudolateral approach to the hip * Bladder atony 15-29% with entrapment, dribbing can occur with or without (37%, 17% irreversible) * Mortality rate of 30% in one report * Tensmus: * Inflammation, severe rectal dilatation, tension on bilateral repair, suture rectal wall. * Incidence 44-50% with colopexy * Rectal prolapse 2-13% * Recurrence * 0-70%, traditional 10-48, internal 0-46, gluteal 36% * Factors related: surgeon experience (10 vs 70%), pervious repairs (83vs43%), type of suture, local tissue strength, amount of tension, ongoing predisposing factors, neutered vs intact * Sacculation associated with lack ventral diaphragm * 8/31 swelling, 11/31rectal sacculation, 9/31 lack ventral, 7 lack dorsal and ventral.

Question 374

uture placement for traditional herniorrhaphy (caudolateral view). 1, external anal sphincter; 2, coccygeal muscle; 3, superficial gluteal muscle; 4, ischial tuberosity; 5, internal obturator muscle elevated from ischial table; and 6, retractor penis muscle.

Answer 374

Question 375

emitendinosus muscle transposition for repair of recurrent bilateral perineal hernias in a Yorkshire terrier (also pictured in Figure 94-30). Previous bilateral internal obturator transpositions and subsequent unilateral prosthetic mesh placement had failed. A, The circumference of the semitendinosus muscle is isolated, taking care to avoid injury to the caudal gluteal artery and vein (visible at the tip of the electrocautery unit). B, The muscle is transected distal to the midbody and freed with gentle dissection as it is reflected dorsally. Lateral tendinous attachments can be incised to improve mobility. C, The muscle has been sutured to external anal sphincter medially, levator ani and coccygeus remnants dorsally, and superficial gluteal muscle laterally. D, Final appearance 1 day after surgery. The dog maintained a rounded appearance of the dorsal perineal region because of obesity and thickness of the transposed muscles; however, the hernias did not reoccur.

Answer 375

Question 376

Anatomic arrangement of the liver lobes and extrahepatic biliary tract. A, Diaphragmatic aspect of the liver. B, Visceral aspect of the liver. C, Liver lobes, gallbladder, and hepatic ducts, visceral aspect

Answer 376

Question 377

Ligaments of the liver?

Answer 377

**Coronary lig.** = liver to diaphram - 2 **right triangular ligaments:** larger = lateral, smaller = medial - **Left side trigangular lig** **Hepatorenal lig** = caudate to kidney Lesser omentum (surrounds papillary process) - **hepatogastic lig.** **- hepatoduodenal lig.** **- faliciform lig.**

Question 378

How long can the pringle manuver be performed?

Answer 378

20 min before liver necrosis

Question 379

Describe blood supply to liver

Answer 379

Hepatic a = 20% blood, 50% oxygen - 2-5 branches: R lat (caudate, R lat), R middle (R med, dorsal quadrate, L med), Left (L lat, L med, quadrate) - Cystic a. Portal V. = 80% blood, 50% oxygen - confluence cr. and cd. mesenteric v. at left pancreas - additional tribitaries: splenic, gastroduodenal (not in cats) - Right main br (caudate, R lat) - Left main br - L lat, L med, quadrate - - - Central br (R med, pap) Cats: 3 main branches: Right, central, left 6-8 hepatic vv. into cuadal vena cava - most cr. near diaphram

Question 380

Describe the flow of bile.

Answer 380

1. **Canaliculi** 1. **interlobular ducts** 1. **Lobar ducts** (inside parachyma) = **Hepatic ducts** (2-8 ducts) 1. **Common bile duct** (where 1st hepatic joins cystic) 1. **Sphincter of Oddi** (CBD enters duodenum) 2. Duodenum (major duodenal papilla)

Question 381

What are the differences between dogs and cats related to the major and minor duodenal papilla?

Answer 381

1. Ducts (pancreatic and CBD) separte in dogs and have sphincter of Oddi, but combined in cats 2. Minor duodenal papilla (acessory pancreatic duct) - major duct for pancreas in dogs, but absent in 80% cats - damage to the Major papilla can cause EPI in cats.

Question 382

What are the Vit K dependent coag facors?

Answer 382

2, 7, 9, 10

Question 383

Liver functions?

Answer 383

Synthesis/clearence plasma proteins Maintain carbohydrate/lipid metabolism Synthesis coag factors/anticoagulents Carboxylation Vit K dependent coag fators Modyfy immune fuction Production bile and synthesis hormones (gastrin) Storage VIt, fat glycogen, metals Clearence toxic metabolites Maintatin glucose conc Synthesis cholesterol

Question 384

What coag factors not produced by liver?

Answer 384

factor 8 and von wilbrands

Question 385

What clotting factors does the liver produce/

Answer 385

plasminogen, antithrombin 3, alpa2-macroglobulin, alpa2-antiplasmin

Question 386

What do Kuffer cells do?

Answer 386

Hepatic macrophages distributed througout hepatic sinusoids Primary reticuloendothelial celll endotoxemia, sepsis, drug sens may result if reticuloendothelial system compromised

Question 387

What is bile?

Answer 387

bile acids bilirubin cholesteral phospholipids water bicarb ions

Question 388

How is bilirubin produced?

Answer 388

80% hemoglobin breakdown 20% metabolism of proteins (myoglobin)

Question 389

Describe life cycle of bilirubin/bile?

Answer 389

Bilirubin bound to albumin → transported to liver In hepatocyte bilirubin conjugated to glycine/taurine (dogs) or taurine (cats) Conjugated biliribin and bile acids in gallbladder Cholecystolinin release from intestinal mucosa → GB contract, sphincter relax ---- Bile salts emulsify fats (aid digest and absorpotion), bind endotoxin, prevent absorption into portal circulation Bilirubin → urobilinogen (by bacteria) → urobilin or stercobilin (90% excreated, 10% resorbed) ----small amount urobilin excreated by kidneys, stercobilin give feces brown color

Question 390

How does the liver funciton in protein metabolism?

Answer 390

20% total body protein production 100%albumin, also alpha, beta, gama globulins and coag proteins

Question 391

How is cholesterol synthesized and fat stored in liver?

Answer 391

Cholesterol: chylomicrons and lipoproteins Stores fat as trigylcerides from FA

Question 392

How much liver can be removed in a normal dog?

Answer 392

65-70%, but not 84% - 28% survived 7d after 80% heptatecotmy - death due to portal hypertension Concurrent side-side portal caval shunt improved survival to 57%

Question 393

What portal pressure decreases survial and liver regeneration post heptatectomy?

Answer 393

16mmHg

Question 394

How much does liver volume increase after portal embolization in dogs?

Answer 394

25-33% Aids in contralateral liver hypertrophy prior to resection. Afer 70% heptaectomy - compensated hypertrophy as early as 6d may take 6-10w Can resect upto 95% liver if done as repeated partial heptectomy

Question 395

What factors contribute to liver regeneration?

Answer 395

cytokines (IL6, TNF alpha) Growth factors (Hepatic GF, epidermal GF, TGF beta) Vasoregulators (NO, PGE2) hormones (insulin, estrogen)

Question 396

What factors impede regeneration?

Answer 396

Billary obstruction → decrease blood flow DM Pancratectomy nonhepatic splanchnic eviscereation total nonhepaticc evisceration malnutrition male/old age

Question 397

What is the hepatic arterial buffer response?

Answer 397

Increase in hepatic arterial perfusion seconaday to lack of washout of senosince (vasodilator) via portal circulation (aka disruption in portal profusion)

Question 398

What happens with acute ligation of the CBD?

Answer 398

increased bilirubin and dilated CBD in 24-48hr dilation lobar and interlobular ducts at days 4-6 hypotension, decreased myocardial contractility, ARF, GI hemorrhage, coags, delayed healing - absence bile salts = bacteria overgrowth/endotoxin absorption = acute tubular necrosis, incaresed acid secreation, gastric ischemia, decrease fibroplasia, andiogensis

Question 399

What percent of choleliths are radiopaque?

Answer 399

50% dogs (calcium bilirubinate), 80% cats (calcium carbonate)

Question 400

What is the correlation between FNA and histopath for liver aspirates?

Answer 400

30-48% dogs, 51% cats

Question 401

What is contracst enhanced harmonic ultrsongraphy?

Answer 401

Detects harmonic signal produced by IV injection of gas microrbubbles to evalute perfusion patterns of different organs

Question 402

What is the noramal diameter of the CBD?

Answer 402

3-4mm

Question 403

How gallbladder emptying be tested?

Answer 403

Give IV sincalide (synthetic cholecystokinin) normal empty 40% GB in 1hr abnormal \<20%

Question 404

Methods of EHBO?

Answer 404

* *US** * *Hepatobiliary scinthigraphy -** IV tech99 - isolates in bilary tree, EHBO if not in SI by 3hr - doesn't differentiate functional from mechanical obstruction or site **CT** (=US for splenic metastatic HSA) **MRI** - 100%sens, 94% specific benign vs malignant hepatic lesions **Endoscopic retrograde cholangiopancrreatography** **- also allows stent placement**

Question 405

What procoagulents and anticoagulents does the liver produce?

Answer 405

Procoagulent: coag factors, fibrinogen, vit K, thrombopoetin Anticoagulent: protein C, proteinS Removes activated coag factors and fibrinogen degredation products

Question 406

What percent of dogs with liver disease have at least one coag abnormality?

Answer 406

57%

Question 407

What percent of dogs/cats with hepatobilliary disease had a positive culture?

Answer 407

dog: 5%, 50% single organism cat: 14%, 83% single organism Enteric most common: Clostridum, e coli, entercoccus, bacteroides) Billiary cultue more often positive (30% vs 7%)

Question 408

What are materials used for hemostasis of the liver?

Answer 408

gelatin sponge - smaller but present at 45d with fibrin layer ozidized regenerated cellulose - dissolved at 45d, no reaction cyanoacrylate glue fibrin glue

Question 409

What are methods for hepatic blood flow occulsion?

Answer 409

Inflow occulsion = Pringle maneuver Hepatic a. ligation - need abx (gangerous necrosis), cholecystectomy, lobar aa ideally - 95% blood supply to tumor vs 20% liver paranchyma Total inflow/outflow occulsion = Cr. and Cd. VC and inflow occlusion - w pringle gastroduodenal v, retrograde arterial flow through gastroduodenal a. and back bleeding through hepatic vv.

Question 410

What is the accuracy, complication rate and px factors of percutaneous liver biopsy?

Answer 410

43-83% accurate Complications: 22% minor (\>10% HCT no intervention), 6% major (transfusion, death) Complication factors: thrombocytopenia \<80K, prolonged PT/PTT Not reccomended in cats with EHBO = vagogenic shock

Question 411

What are methods for liver lobe biopsy?

Answer 411

Fracture/guillotine Punch Ultrasonically activated scapel (aka harmonic scapel) Laproscopic liver biopsy - biopsy forceps or loop ligature

Question 412

How does surgical ligation compare to stapler for hepatic lobe removal?

Answer 412

Dissection/ligation: slower, less complete, associated with more mircoscopic hemorrhage, necrosis and inflammaiton

Question 413

How can you deal with expected excessive portal hypertension from liver lobectomy?

Answer 413

Ipsilateral portal v. embolization create portocaval shunt

Question 414

What percent of the liver do the right, middle and left segments make up?

Answer 414

Right lateral/caudate = 28% Right medial/quadrate = 28% Left medial/latearl = 44%

Question 415

What are percutaneous tumor ablation techniques?

Answer 415

Radiofrequency Microwave laser thermal cryoablation ethanol ablation

Question 416

What percent of dogs and cats have a postive culture for EHBO, mucocele and bile peritonitis?

Answer 416

EHBO dogs: 17-39%, cats: 30-50% Mucocele: 23-60% bile peritonitis: **58-61%**

Question 417

What are surgical procedures of extrahepatic billary tract?

Answer 417

Cholecystocentesis Cholecystoduodenostomy Choledochoduodenostomy Billary stenting Cholcutostomy tube Cholecystectomy CHoledochal catheterizaiton

Question 418

What are indications for laproscopic cholecystectomy?

Answer 418

GB mucocele, cholelithiasis or cholecystitis not associated with EHBO, GB rupture,

Question 419

What were the outcomes in dogs and cats treated with choledochal stenting?

Answer 419

Dogs = no reobstruction Cats = 2/7 reobstruct within one week

Question 420

What are common bacteria reported for hepatic abcesses? And what are treatment options?

Answer 420

E.coli, staph, enterococcus, klebsiella, clostridium Medical alone, US drainage, sx resection Percutaneous US and alcholization

Question 421

What is the prognosis for hepatic abcsesses?

Answer 421

Dogs 50% euthanize, however those treated responded well Cats: 79% euthanized, 3/4 favorable response to treatment - 2 cases concurrent HCC, none of the cases in dogs had malignacy

Question 422

What is the most common liver lobe to have a torsion?

Answer 422

Left lateral Good px if treated quickly, associated with abscess, septic peritonitis, hernia, tumor, hepatitis, GDV - recommend pexy

Question 423

What is the underlying lesion of GB mucocele and what breed is predisposed?

Answer 423

Cause: cystic mucosal hyperplasia - hypersecreation of mucus - can cause EHBO or GB rupture Shetland sheep dogs

Question 424

What endocrinopathies are associated with GB mucocele?

Answer 424

Cushings = 29x higher, 21% of dogs with cushing's have mucoele (vs. 2%) Hypothyroidism = 3x higher, 14% of dogs with hypothyroidism have mucocele

Question 425

What is the sensativity of US for GB rupture?

Answer 425

85.7%

Question 426

What percent of GB mucoceles cultured positive and what type of bacteria?

Answer 426

Aerobes 9-75% Anaerobes 0-25% Enterococcus and E coli most common

Question 427

What percent of cases have a GB rupture and what percent have concurrent EHBO?

Answer 427

23-60% concurrent EHBO 30%

Question 428

What percent of dogs with choleliths have positive cultures?

Answer 428

70% aerobic 55% anaerobic some bacteria produce beta-glucoronidase = deconjugates soluble bilirubin = clcium bilirubinate

Question 429

What percent hepatocellular tumors are adenomas?

Answer 429

30%, hepatocellular carcinoma most common 50-70% of non-hemopoietic neoplasms

Question 430

What percent of HCA had mets?

Answer 430

61% are massive and have mets in 36% - 67% left lobe (20-80% with leasions other lobes), 12-20% central or right 30%/10% are nodular/diffuse and have mets in 93% mets ln (39%), lungs (38%), peritoneum (18%), also anywhere else

Question 431

What is the px for massive HCA?

Answer 431

MST 1460d with removal, 270d with medical management Periop mortality 5% Incomplete margins ~10%, not associated with recurrence Right side tumors poorer px

Question 432

List the tributaries to the portal v. (caudal to cr)

Answer 432

Cr. Mesenteric vessels Cd mesenteric vessels Splenic Gastroduodenal

Question 433

Hepatic veins

Answer 433

Question 434

Describe the embyronic deveolopment of the liver

Answer 434

vitelline vessels = hepatic sinusoids, cr. right becomes cd. vena cava in liver, right and left cd segements anastomos to become portal v. umbilical v = hepatic sinusoids cardinal = anastomse with vitelline to make cd vena cava, right suprecardinal = azygos, left supracardinal = hemiazygos Embryology of liver development. 1, Sinus venosus; 2, superior cardinal vein; 3, inferior cardinal vein; 4, left common cardinal vein. 5, right umbilical vein; 6, liver; 7, anastomosis between the left and right omphalomesenteric vein; 8, right umbilical vein (prehepatic); 9, left umbilical vein; 10, right omphalomesenteric vein; 11, umbilical vein (unpaired); 12, inferior vena cava; 13, ductus venosus; 14, portal vein; and 15, splenic vein.

Question 435

What congenital abnormality is associated with left sided intrahepatic shunts?

Answer 435

Patent ductus venosus Usually functional closure 2-6 d (wolfhounds 65% 4d, 23% 6d, all 9d) structural closure 3 weeks

Question 436

What causes ductus venosus contraction?

Answer 436

Cytochrome p450 and thromboxane = contract PGF1 alpha and PGE2 = relax Steroids → inhibit phospholipase A2 → decrease PG → increase acitivity alpha adrenoreceptors = contract

Question 437

What percentage of dogs have a single intrahepatic or extrahepatic shunt?

Answer 437

Intra = 25-33% (larger portion of blood shunting, CS eariler) Extra = 75-66%

Question 438

What percent have aquired shunts, where are they usually located and what are the common causes?

Answer 438

20% Portal tributary to renal v. or CVC, less common gonadal or internal thoracic Cirrhosis, PVH with portal hypertension, Hepatic arteriovenous malformations

Question 439

What is portal vein hypoplasia (PVH) without portal hypertension characterized by?

Answer 439

AKA microvascular dysplasia, 58% dogs, 87% cats also have macroscopic PSS ## Footnote - sm. intrahepatic portal vessels - portal endothelial hyperplasia - portal v. dilatation - random juvenile intralobular blood vessesl - central venous hypertrophy

Question 440

Types of PSS

Answer 440

Types of portosystemic shunts in dogs and cats. A, Portal vein to caudal vena cava. B, Portal vein to azygos vein. C, Left gastric vein to caudal vena cava. D, Splenic vein to caudal vena cava. E, Left gastric, cranial mesenteric, caudal mesenteric, or gastroduodenal vein to caudal vena cava. F, Combinations of the above.

Question 441

Toxins that cause hepatic encephalopathy and their MOAs.

Answer 441

**Ammonia** Increases brain tryptophan and glutamine; decreases ATP availability; increases neuronal and cellular excitability; increases glycolysis; can cause brain edema; decreases microsomal Na+,K+-ATPase in the brain Aromatic amino acids Decrease DOPA neurotransmitter synthesis; alter neuroreceptors; increase production of false neurotransmitters Bile acids Membranocytolytic effects alter cell membrane permeability; make the blood-brain barrier more permeable to other hepatic encephalopathic toxins; impair cellular metabolism because of cytotoxicity Decreased α-ketoglutaramate Diversion from Krebs cycle for ammonia detoxification; decreased ATP availability **Endogenous benzodiazepines** Neural inhibition through hyperpolarization of neuronal membrane False neurotransmitters Impair norepinephrine action Tyrosine → Octopamine Impair norepinephrine action Phenylalanine → Phenylethylamine Synergistic with ammonia and SCFA Methionine → Mercaptans Decreases ammonia detoxification in the brain urea cycle; gastrointestinal tract derived (fetor hepaticus breath odor in hepatic encephalopathy); decreases microsomal Na+,K+-ATPase GABA Neural inhibition by hyperpolarizing neuronal membrane; increases blood-brain barrier permeability to GABA Glutamine Alters blood-brain barrier amino acid transport Phenol (from phenylalanine and tyrosine) Synergistic with other toxins; decreases cellular enzymes; neurotoxic and hepatotoxic SCFAs Decrease microsomal Na+,K+-ATPase in brain; uncouple oxidative phosphorylation; impair oxygen utilization; displace tryptophan from albumin, increasing free tryptophan Tryptophan Directly neurotoxic; increases serotonin through neuroinhibition

Question 442

What metabolic derangements are associated with hepatic encephalopathy?

Answer 442

hypoglycemia, dehydration, hypokalemia, alkalemia

Question 443

What is the signalment for extra and intrahepatic PSS?

Answer 443

Intra = irish wolfhouns (left division, genetic assoc), Aussies (right division), retrievers Extra = sm breed (yorkie, havanese, maltese, dandie dinmont, pugs, schnauzers) = OR 20x - yorkies OR 36x Cats: DSH, siamese, persians, himalayans, burmese PVH-MVD = carins PVH hypertesion = Dobbies (27%), usually \<4y, \>10kg

Question 444

Why are PSS dogs PU/PD?

Answer 444

low BUN conc = poor medulary gradient INcreased renal blood flow Increased ACTH secretion Psycogenic HE

Question 445

What percent AV malformations have abdominal effusion?

Answer 445

75%

Question 446

What are common secondary problems with inta hepatic PSS that are less common with extrahepatic?

Answer 446

GI signs, especially gastic ulceration (30% with intrahepatic = GI protectents) IBD

Question 447

What percent of shunts have urinary calculi and why?

Answer 447

30% = ammonium urate decresed urea production increased renal ammonia decrased uric acid metabolism

Question 448

What are clinical signs more commonly seen in cats with PSS?

Answer 448

Ptyalism 75% copper colored eyes also cyrptorchid (30%), 50% dogs are cyrptorchid

Question 449

What common clin path findings associated with PSS?

Answer 449

Microcytosis - defective Fe transport Leukocytosis Mild increases in liver enzymes (ALP\>ALT) Low albumin (50%), Low BUN (70%), low cholesterol, low glucose Decreased Cre UA: low USG (\>50%), ammonium biurate crystalluria (26-57%, dog, 16-42% cat), hyperammonuria, proteinuria (100% severe glomerulopathy)

Question 450

What can effect bile acids testing?

Answer 450

timing GB contraction rate intestinal transport decrease BA deconjugation Rate/efficency absorption in ileum Portal blood flow functionality of epatocyte uptake and canalicular transport

Question 451

What cause false + and false - for bile acids testing?

Answer 451

False +: inappropriate sample timing, other hepatobillary disease, cholestasis, steriods, anticonvulsant therapy, trachal collapse, seizures, GI disease False - : Prolonged transport, lack GB contraction, inadequate food uptake, delayed gastric emptying, malabsorption/digestion

Question 452

What percent have abnormal ammonia conc? How can this be tested?

Answer 452

62-88% with PSS ## Footnote **Basal**, sens increased to 91% when 6hr post-prandial - basal affected by prolonged fasting, protein restriction, lactulose (not affected with ATT) **Ammonia tolerance test** (ammonium chloride), test 30min post giving (sample must be tested in 20min), sens =95-100% - hyperammonemia = methylmalonic acidemia, urea cycle enzyme deficientcy (cats, deficient ornithine transcarbamylase), urethral obstruction

Question 453

What coag factors are produced in the liver?

Answer 453

factors I (fibrinogen), II (prothrombin), V, VII, VIII (vascular endothelium), IX, X, XI, XIII, as well as protein C,protein S and antithrombin.

Question 454

How are PT and PTT affected by liver disease?

Answer 454

**65-80% factor loss** = prolonged PT or PTT Chronic disease - _increased PTT_ (common with PSS, factor deficiencies **common (2,5,10) and extrinsic (7))** Acute = increased PTT and PT Coag status returns to normal 6w postop if no persistent shunting

Question 455

What is protein C?

Answer 455

VitK dependent serine protease Activated by thrombin = anti-thrombotic, anti-inflammatory, antiapoptotic Normal dogs = 70% activity or greater Differentiates 95% MVD (\>70%) from 88% shunt (\<70%), doesn't differ MVD from normal

Question 456

What are common histopath findings with dogs with PSS, MVD, AV malformations, etc?

Answer 456

Increased/hypertrophied: Bile duct proliferation/hyperplasia (hx worse px), Arteriolar proligeration/duplicaiton, Smooth m. hypertrophy, Increased lymphatics around central v., Ito and Kupffer cell hypertrophy Hypoplasia/atrophy: Hypoplasia of intrahepatic portal tributaries, Hepatocellular atrophy Lipidosis/cytoplasmic vaculolar changes (lipogranulomas) - 55% dogs necrosis (hx worse px) fibrosis (hx worse px) None associated with px for intra or extra hepatic shunts

Question 457

Radiographic findings of PSS?

Answer 457

Microhepatica (60-100% dogs, 50% cats), bilateral renomegaly Not necessarily seen with portal v. hypoplasia

Question 458

What is the sens and specif of diagnosing extra and intra hepatic shunts on US?

Answer 458

Extrahepatic: Sens 75-95%, Spec 67-100% Intrahepatic: Sens 95-100% Distinciton intra vs extra: 92%

Question 459

What flow changes occur with various shunts on US? What is normal flow?

Answer 459

Normal portal flow 15cm/sec AV malformations = hepatofugal Extrahepatic PSS = hepatopedal flow, increased/variable velocity in 53% (92% with intrahepatic) Extrahepatic decrased portal v:arota size

Question 460

What is the 1/2 life of techntium pertechnetate?

Answer 460

6hr

Question 461

What are the methods for scintigraphic ID of shunts and what are the limitations?

Answer 461

Dx: arrives sooner and in higher conc. than expected to heart, PSS shunt fract \>60-80%, 52% cats **Transcolonic:** (99mTcPertechnetate) shunt fraction \<15% normal, false + if injected too caudal, heart visible 8-14sec, higer dose = isolate for 16-24hr **Transsplemic:** (99mTcO4-) lower shunt fraction, 100% sens/spec for PSS, in heart 2-4 sec, uptake poor with portal hypertension, cleared 30 min Increased shunt fraction with: PSS, aquired PSS, and AV malformations. **Doesn't distinguish** intra from extra or intra, single from multiple and MVD from normal...at least reliably for the first 2. Transsplenic scintigraphy. A, Extrahepatic portocaval shunt in a Labrador retriever. Blood flow from the spleen enters the heart at its caudodorsal aspect. B, Portoazygos shunt in a Yorkshire terrier. Blood flow from the spleen enters the heart at its craniodorsal aspect. C, Multiple acquired shunts in a Chihuahua. Blood flow travels caudally from the spleen before entering the caudal vena cava

Question 462

What methods for diagnosis of a PSS?

Answer 462

US Scintigraphy (transcolonic, transsplenic) CT angiogram (ideally duel phase, also trassplenic CT portography) MR angiogram (spec 97%, sens 67-79% w/o gadolinium) Portovenography - cr. to 13th rib = intrahepatic, sens = 85% dorsal, 91% right lat, 100% left lat) Percutanous US guided splenic portovenography Pretrograde tranjugular portography Cr. mesenteric arteriography (via femoral - alot of contrast, hard to interpet)

Question 463

How do you medically manage severe hepatic encephalopathy?

Answer 463

Warm water enema Oral/rectal lactulose Antibiotics → decrease in urease producing bacteria (metro, ampi, neo) Anticonvuslsants (benzos + maintance) Mannitol (HE = cerebral edema people) Lactulose (per os or high enema) - acidifiy lumen and binds ammonia, decreases bacteria numbers, also decreases fecal transit time If needed whole blood (packed rbcs have ammonia) Diet = milk/veg protein, 20% dogs, 30% cats Acid receptor blocker if intrahepatic (omeprazole life long) Ascites = diuertics (spironolactone), drugs that decrease connective tissue (pred, colchicine, D-penicillamine) Neutraceuticals: SAMe, ursidiol, Vit E, Milk thistle

Question 464

What is the px with medical managements liver shunts?

Answer 464

MST 10m, decreased TP, ALT, ALP (no other changes) 65% intra and 33% extra euthanized 50% med management survived long term, 88% sx survived long term - age no effect on survival MVD: 92% longterm survival HPV with hypertension - 40% long term survival but should be consisder favorable

Question 465

Side effects of overdose of Iohexol from portoveinography?

Answer 465

hypotension, arrhythmias, cardac arrest, renal failure dose 240mg I/ml 2-5ml/kg (not exceed 1200mg/kg)

Question 466

Additional interpretation of portovenogram

Answer 466

Cats: more arborixation after shunt ligation = less likely postop neuro comp and better response to sx Dogs: absence arborization prior to ligation = greater occurence postop complications - more portal branching, better able to withstand complete ligation - response to sx not correlated with preligation portal development

Question 467

How much of the ameroid constrictor diameter reduces?

Answer 467

Reduces by 32%, use ring larger than vessel (hydroscopic) Gas sterilized = do not use within 12-24 hours

Question 468

How do you determine the degree of shunt attenuation?

Answer 468

86% require partial ligation, (70% regain normal liver funct) ## Footnote Portal hypertension: pallor, cyanosis of intestines, increased GI peristalsis, cyanosis/edema of pancreas, incrased mesenteric vasular pulsations. Postligation pressure: max 17-24cmH20 (12.6-17.6mmHg), change P of 10cmH20 (7.35mmHg), max ecrease in CVP of 1cm H20 (0.74mmHg) Decrease arterial P max 5mmHg (\<15%) Shunt ligated to the point where shunt flow hepatopedal and cr. portal v. hepatopedal to avoid aquired shunts

Question 469

Intravascular hepatic shunt - left division

Answer 469

Venous dilatation at junct. left hepatic v. patent ductus venosus and left phrenic v = **ampulla** Usually ligate **shunt** (bwteen papillary process and L lat lobe before enters L hepatic v. ) OR **heptatic v.** If shunt can't be ID then left portal v. The left hepatic vein (LHV) enters the left side of the caudal vena cava (CVC) just cranial to the diaphragm. The central hepatic vein termination is indicated with an asterisk. B, The space between the CVC and LHV is gradually enlarged with right-angle forceps, which are advanced in a dorsolateral position

Question 470

Intravascular hepatic shunt - right division In dogs, the portal vein (PV) bifurcates approximately 1 cm distal to the termination of the gastroduodenal vein (GDV). The left hepatic vein (asterisk) is much smaller in this dog with a right intrahepatic portosystemic shunt

Answer 470

Ligate portal v. (see above) or intravascular technique If can't directly disect, then can do indirect suture passage Indirect suture passage for ligation of a right intrahepatic portocaval shunt. In a dog with a right-sided shunt, the portal vein would be much larger than the left

Question 471

Intravascular approach Portal venotomy

Answer 471

Need total inflow occlusion = pre/post hepatic cd. vena cava, thoracic aorta, and portal v./hepatic a. through epiploic foramen - mean arterial P = 30mmHg, mean CVC pressure = 25mmHg Intravascular repair of an intrahepatic portocaval shunt through a portal venotomy. A, The portal vein is exposed and the dilated prehepatic segment (star) is identified. B, After inflow occlusion, a venotomy is performed. The edges of the portal venotomy are retracted with stay sutures (arrows), and the shunt ostium is identified. C, A suture (5-0 prolene) is passed across the shunt ostium and though pledgets. D, The venotomy is closed with a simple continuous pattern, and inflow occlusion is released. The attenuating suture is subsequently tightened. CVC, Caudal vena cava; LL, left lateral; PV, portal vein; QU, quadrate; R, rumel; RHV, right hepatic vein; RL, right lateral; RM, right medial; S, shunt.

Question 472

Intravascular approach transcaval approach

Answer 472

Intravascular repair of an intrahepatic portocaval shunt, diaphragmatic view. The suture is passed through extraluminal and intraluminal Dacron pledgets in a mattress pattern

Question 473

How are platelets and clotting factors affected by acute ligation?

Answer 473

Plt. count decreases 27% Factors 2,5,7,9,10,11, fibrinogen decrease 10-16% PT increases 7% PTT no change 2-14% develop acute hypertension

Question 474

What percent have seizures?

Answer 474

Dogs: 3-18% Cats 8-22% upto 80 hr post-op

Question 475

What are potential causes of post-op seizures in PSS?

Answer 475

Decreases in endogenous inhbiory CNS benzos agonist levels Imbalance in excitatory and inhibitory NT Concurrent neurologic disease Hyponatermia = seizures/coma when \<120meq/L, increase slowly (1meq/h) or fatal cerbral edema and potine myelinosis

Question 476

What are the periop mortality rates and long term outcome for EH PSS

Answer 476

Periop mortality: suture 2-32%, AC, 7%, cellophane 6-9% Longterm: good 78-94% (any technique), 35% euthanized (mean 43m) after partial lig (recurrence), only 11% normal at 1yr with partial ligation.

Question 477

Mortality rate and long term outcome IH shunts?

Answer 477

Mortaliity: suture 6-23%, AC 0-9%, **Cellophane 27%** Good long term: 70-89% AC, 76-100% suture, 50% cellophane Proability of survial without recurrence: 60% 1yr, 55% 2-4yr Hydraulic occulder: immediate survival 100%, 30% require revision, 80% long term survival. complications recurrence, sinus tract development

Question 478

What factors have been associated with short term outcome for PSS

Answer 478

IH: \>10kg more favorable, Higher TP/albulmin = better survival, Increased BUN = decreased short term survival (not long term) Breeds not associated with PSS more likely to have unusual/inoperable PSS Acute ligation: - Non-encephalopathic dogs can tolerate complete occlusion more often - Greater liver size likely to tolerate acute ligation

Question 479

Factors associated with long term outcome for PSS in dogs.

Answer 479

POOR: anemia, leukocytosis/neutrophilia, albumin decrease by 1 = odds continued shuting increased 3.76x (EH/AC), greater increase in portal pressure GOOD: TP\>4 (IH), Every albumin increase 1 = unsucessful odds decreased 0.4 (EH/AC), better survial EH than IH one paper,

Question 480

Factors that have not effect on outcome in PSS for dogs.

Answer 480

Age at surgery Body weight Pre-op neuro signs Pre-op bile acids (EH) Pre-op histopathology Location of coil embolization

Question 481

What is the outcome in cats with PSS?

Answer 481

Periop mortality: 0-4% (AC, suture), 0-23% cellophane ## Footnote Post-op complications: upto 75% - neuro most common, seizure 8-28%, central blindness up to 44% (persisting neuro signs not associate with siezures, shunt location, degree attentuation, age Of surviving cats, good outcome 56-75% (suture), 33-75 (AC), cellophane 80% Persistent shunting = excellent outcome

Question 482

Where are hepatic AV malformations located?

Answer 482

Right or central divisional lobes Usually 1, 20% 2 Portal v. normal in size. Treat by lobe resection, periop survival 75-91%, longterm 38-57%, 75% still need medical management Complications: portal hypertension, systemic hypotension, braycardia, portal or mesenteric v. thrombus

Question 483

What is the Branham reflex?

Answer 483

reflex bradycarida with closure of hepatic AV fistula

Question 484

reveiw page on interventional rad for venous liver malformations

Question 485

What are the 4 poplypeptide secreting islet cell types and what do they secreate?

Answer 485

alpha → glucagon beta → insulin delta → somatostatin Fcells/PP cells → pancreatic polypeptide

Question 486

What is the blood supply to the pancreas?

Answer 486

Celiac → splenic → hepatic → cranial pancreaticoduodenal Cr. mesenteric → cd pancreaticoduodenal

Question 487

What is the innervation to the pancreas?

Answer 487

vessels: celiac and cr. mesenteric plexus acinar and islet cells: cholinergic nerurons that synapse with vagal fibers pancreatic juice secration: stimulated by parasympathetic, inhibited by sympathetic

Question 488

Describe pancreatic ducts

Answer 488

Dog: 68% single duct from each limb - accessory pancreatic duct (minor duodenal papilla) = duct of santorini (most important dogs) - pancreatic duct (major duodenal papilla) = duct of wirsung Cats: 80% only pancreatic duct, fuses with bile duct

Question 489

What does insulin and glucagon do?

Answer 489

Insulin: stimulates anabolic reactions (carbs, lipids, protein, nucleic acids), decrease blood conc of glucose, fatty acids, amino acids. Promote intracellular conversion into glycogen, triglycerides, protein. Controls glucose efflux from extracellular space into insulin-sens cells (adipocytes, monoctyes, hepatocytes) Glucogon: controls glucose inflex from hepatocytes, secreased in response to hypoglycemia, mobilizes energy stores by increasing glycogenolysis, gluconeogensis, lipolysis

Question 490

What are zymogens secreaeted from the pancreas?

Answer 490

Inactive zymogens: typsinogen, chymotrypsinogen, proelastases, procarboypeptidses, prophospholipases. Activated by enteropeptidase (duodenum) Enzymes: lipase (fats), amylase (starches) Inorganic components (ductal cells): water, na, K, Cl, bicarb, intrinsic factor (aborption B12)

Question 491

What are the 3 mechanisms that prevent autodigestion?

Answer 491

1) enzymes stored and secreated as inactive proenzymes/zymogens 2) Segregated storage of zymogens (packed as membrane bound granules in endoplasmic retriculum) 3) acinar cells synthesize panreatic secretory trypsin inhibitor (stored with enzymes to prevent premature activation)

Question 492

How do nervous and hormonal mechanisms cause pancreatic secreation?

Answer 492

smell food → vagal stimulation movement food into duodenum → secretin → bicrab rich fluid (second phase 8-11hr postprandial bicarb rich) → cholecystikinin → digestive enzymes (1-2hr post prandial)

Question 493

Bile duct anatomy near major duodenal papilla

Answer 493

Question 494

What are pancreatic biopsy techniques?

Answer 494

Distal right limb pancreas Tru-cut, wedge, suture fracture, blunt dissection and ligation, laproscopic Suture vs. blunt = no diff CS, amylas or lipase. Suture increase inflammation on histo Complications: swelling, pyrexia, abdominal pain, vomiting, Adhesion (common in cats)

Question 495

How much of the pancreas can be removed?

Answer 495

75-90% as long as ducts intact large regenerative capacity (5% left increased in weight by 50% in 6 w) potentially due to insulin like GF-1 (max levels 3 days postop)

Question 496

What are tests for EPI and pancreatitis?

Answer 496

EPI = TLI (typsin like immunoreactivity) = sens and spec EPI PLI = panraetic lipase immunoreactivity (82% sens and specific canine, feline 100% mod/severe, 54% sensitive for mild)

Question 497

What is the prognosis for surgical managment of pancreatitis?

Answer 497

overall survial 63% EHBO with cholecystoenterostomy = 80% necrosectomy 64% pancreatic abcess 40%

Question 498

For pancreatic abcess, what is the postive culture rate and what is the prognosis when treated with surgery as recommend.

Answer 498

In vet patients pancreatic abcess are often sterile Positve pancreatic culture ranged 0-27% (positive abdominal culture 58% in one study) Prognosis: 14-55% survival, another study 40% 62% surival rate with omentalization

Question 499

Where do the majority of pancreatic pseudocyst occur?

Answer 499

Left limb pancreas

Question 500

How to treat pancreatic peusdocyst?

Answer 500

may shrink on own (monitor if \<4cm) External drainage with US Internal drainage: cystoduodenostomy, cystojejunostomy, cystogastrostomy, omentalization Complete excision \>75% sucess/survival rate

Question 501

What lab finding is potentially indicative of pancreatic carcinoma?

Answer 501

lipase \> 25x upper limit Paraneoplastic alopecia noted in cats

Question 502

What percent of insulinomas are carcinomas?

Answer 502

60%

Question 503

What can insulinomas produce besides insulin?

Answer 503

glucagon, somatostatin, pancreatic polypeptide, gastrin

Question 504

What is the metastatic rate of insulinoma?

Answer 504

50% lymph nodes and liver most common

Question 505

What side effect can occur with prolonged exposure to glucose?

Answer 505

neuronal demyelination and axonal degeneration ataxia and weakness may not resolve

Question 506

How to diagnose insulinoma?

Answer 506

US: pancreatic mass 56%, mets 19% CT: increased diagnosis, however false positive results for mets screening common 71% - duel phase diagnosed 3/3 dogs Scintigraphy and single photon emission CT with radiolabled somatostatin = to other methods like US

Question 507

What are methods of treatment of post-op or recurrent hypoglycemia

Answer 507

streptozocin: nitrosura anitbiotic - kills beta cells = normoglycemia 163 d diazoxide: benzothiadiazine derivative = inhibits insulin secreation, stimulates gluconeogensis, stim glycolgenolysis, inhibits glucose use Octreotide: long acting synthetic somatostatin analogue - insulin synthesis Prednisone

Question 508

What is the prognosis for insulinoma?

Answer 508

surgery = more likely to become normocgylcemic, stay that way and survive longer Dogs with not met: 14m euglycemic, 18m MST Dogs with mets: 2m euglycemic, 7-9m MST Dogs with sx and treated with pred when recurrence = MST 1316 vs 785d with only surgery

Question 509

Where do gastrinomas arise from?

Answer 509

Pancreas most common, then duodenum, peripancreatic ln, and mesentary 70% metastatic disease (ln, liver) GI ulceration 80% Dx with elevated serum gastrin conc while fasting or abdominal explore, too small for imaging Px: 1w to 18m, isolated case 26m

Question 510

How to place pharyngostomy tube

Answer 510

Nerve damage, hemorrahge, if not caudal dorsal enough interfers with epiglotis = aspiration, cough, knking, dyspnea, etc. Indictor for oral disease

Question 511

Methods for esophagostomy tube placement

Answer 511

manual treanesophageal advancement needle=assited percutaneous placement tube assisted percutaneous placement Eld percutaneous feeding tube placement Esophageal feeding tube applicator

Question 512

Percutaneous tube esophagostomy. A, Stiff guide tube placed in midesophagus. B, Catheter passed through the skin and into the tube. C, Forceps placed in the catheter hub and advanced into the guide tube. D, Forceps pulls large feeding tube out through skin. E, The tip of a large feeding tube is sutured to tip of esophagostomy tube. F, The large feeding tube pulls esophagostomy tube into the mouth. A stylet is placed in the esophagostomy tube. G, The esophagostomy tube is withdrawn until it can be redirected distally. H, The tip of the esophagostomy tube is advanced to the distal esophagus.

Answer 512

Question 513

Percutaneous esophagostomy using an Eld applicator. A, The Eld applicator is placed in the esophagus, and the trocar is advanced through a small skin incision. B, The feeding tube is sutured to the eyelet of the Eld trocar. C, After the feeding tube is pulled into the oral cavity, a stylet helps to redirect the feeding tube into the esophagus

Answer 513

Question 514

What is this?

Answer 514

Feeding tube applicator

Question 515

What are methods of gastrostomy tube placement?

Answer 515

Surgical - mushroom tipped catheters, low profile (midline or left paracostal approach) Percutnaeous endoscopic gastrostomy tube non-endoscopic percutaneous tube placement (semi rigid orogastric tube, metal tube, Eld applicator)

Question 516

Placement of percutaneous endoscopic gastrostomy tube. A, An over-the-needle catheter is placed through the skin and into the air-distended stomach. B, A suture threaded through the catheter is grasped by endoscopic forceps and pulled out through the mouth (C). D, An over-the-needle catheter is threaded onto the suture, which is tied to the gastrostomy tube (E) and subsequently pulled into the stomach and out the gastric and body wall. F–G, The tube is pulled through the skin and secured with a flange. The mushroom-tipped end of the gastrostomy tube should press snugly against the gastric mucosa.

Answer 516

Question 517

Tube-assisted percutaneous nonendoscopic gastrostomy. The angled tube is inserted through the esophagus into the stomach at a level caudal to the last rib. Extending the patient's head over the end of the table facilitates palpation of the tube through the abdominal wall. A, The flared end of the tube in the stomach is pressed against the left abdominal wall, displacing other intra-abdominal organs. B, A needle is passed through the skin into the flared end of the tube, and a strand of heavy suture or wire is passed through the needle into the stomach and advanced out of the mouth. The remainder of the placement is the same as that for a percutaneous endoscopic gastrostomy tube.

Answer 517

Question 518

Percutaneous nonendoscopic gastrostomy with an Eld device. A, The device consists of a cannula with a handle and a trocar that is passed through the cannula after it is properly positioned. B, The device is advanced through the esophagus and into the stomach so it is beyond the last rib. The trocar is pushed through the cannula until the tip exits the skin, and a suture is tied onto the tip (inset). C, The trocar is retracted into the cannula (inset), and the device and attached suture are withdrawn through the animal's mouth. The remainder of the placement is the same as that for a percutaneous endoscopic gastrostomy tube.

Answer 518

Question 519

Low-profile gastrostomy device (arrowhead). Pressure on the obturator (solid arrow) elongates the mushroom tip for placement through the gastrocutaneous fistula (open arrow). The mushroom tip regains its conformation when the obturator is removed

Answer 519

Question 520

Enterostomy tube placement. A, An antimesenteric incision is made through serosa and muscularis, and the feeding tube is advanced through a mucosal perforation at the aboral end of the incision. B, Serosa and muscularis are sutured with an appositional pattern over the tube, and a purse-string or mattress suture is placed around the tube at its orad seromuscular exit site.

Answer 520

Question 521

Needle-assisted enterostomy. A, A needle is passed obliquely through the center of a purse-string suture, creating a subserosal tunnel in the antimesenteric intestinal wall. B, A feeding tube is passed through the needle and advanced 20 to 30 cm aborally. The needle is removed, and the purse string is tied

Answer 521

Question 522

What are enterostomy tube options?

Answer 522

Standard Needle assisted techniqque for tubes without catheter adaptors Needle assisted technique for tubes with catheter adaptors Gastroenterostomy tube (via PEG or open) Duodenostomy (limited approach with L block) Low profile enterostomy tube

Question 523

What is another name for a mushroom tip Gtube?

Answer 523

Pezzar tip

Question 524

What is the daily water requirements for dogs/cats

Answer 524

50-100ml/kg/day

Question 525

What is the most that can be fed?

Answer 525

22-30ml/kg

Question 526

What is refeeding syndrome?

Answer 526

Decreased potassium, phosphorus and magnesium Causes weakness, fluid retention, arrththmias, dyspnea, vomiting, diarrhea, illeus, renal dysfunction, tetany

Question 527

Examples of commercially available clamps designed for use with linear external skeletal fixation systems. A, Kirschner-Ehmer clamp; single and double clamps (IMEX Veterinary Inc., Longview, TX). B, SK clamp; single and double (IMEX Veterinary Inc.). C, Securos external skeletal fixator clamp (Securos, Sturbridge, MA). D, Titan external skeletal clamp (Securos). Black arrow, position for transfixation pin; white arrow, position for connecting bar

Answer 527

Question 528

How does adding a unilateral plate agumentation steel connecting plate or 2nd steel connecting bar add to the stiffness of a type 1a fixator?

Answer 528

Steel plate = 4.5x increase axial stiffnes and med/lat bending, 2x increased cr/cd bending and stiffness Double steel connecting bar = 80% stiffer in axial and 170% stiffer in med/lat beneing compared to external plate. = stiffness of IIb or 50% IIa

Question 529

Which is more important, bar diameter or pin number?

Answer 529

larger diameter bar to increase stiffness negated when 2 or more full pins used

Question 530

What factos improve stiffness type 1 fixators?

Answer 530

stonger frame hybrid design Tie-ins threaded pins

Question 531

At what point will pin number not increase stiffness?

Answer 531

\>4 per segment

Question 532

What size pins should be used and at what spacing for ESF?

Answer 532

no greater than 20-30% bone diameter = stress riser Evenly spaced, no closer than 3x pin diameter or 1/2 bone diameter from joint/fracture

Question 533

What can be done to decrease bone resorption around the pins?

Answer 533

reduce pin-bone interface stress smooth pins at 70 degrees to long axis position bar closer to the bone = stiffer construct Pin stiffness porportinal to the pin length^3 (shorter is stiffer) No chuck (wobbles), power drill \<150rpm 60 degree pin offset = 4-5x stiffness in 1a (acylics)

Question 534

What are the advantages of circular ESF?

Answer 534

1- increased stiffness in bending/shear and decreased stiffness in axial compression 2. small fragmenrs 1-1.5cm 3. adjustable after placement

Question 535

What are the 15 principles of ESF application?

Answer 535

1. Aseptic technique 2. Proper locaiton for pin insertion 3. Select most suitable ESF 4. Auxillary fixation when indicated 5. Maintain stabilization and reduction when applying frame 6. Insert pins without damaging soft tissues 7. proper pin insertion technique 8. Engage both corticies 9. insert smooth pins and neg. profile pins at 70 degree angle 10. Insert all pins in same plane when using bar 11. Even distribution - optimize mechanical stability 12. 3-4 pins in each fragment 13. Optimal size implants 14. Optimal distance between clamps and skin 15. Cancellous graft in sig cortical defects

Question 536

How does the use of ESF effect surgery time and healing time for comminuted tibia fractures?

Answer 536

Decreased surgery time 45% Decreased healing time 27%

Question 537

What is the incidence of mal/non-union in small breed dogs treated with exernal coaptation for radial fractures?

Answer 537

83%

Question 538

What are the guidelines for external coaptation?

Answer 538

Reduction = at least 50% contact of cotical fracture fragments Proper alignment Neural standing angle immobilize joints above and below

Question 539

What is this?

Answer 539

Robinson sling Other wierd slings = schroeder thomas

Question 540

What are grades of sprains?

Answer 540

Grade 1 = overstretch ligament Grade 2 = partial tear Grade 3 = complete tear

Question 541

What are types of orthoses?

Answer 541

Non-ridgid, semi-ridgid, Rigid Static vs. Dynamic Stifle braces: prophylactic, rehabilitative, funcitonal Contracture/assist type braces

Question 542

What are the types of non-unions?

Answer 542

Viable = mechanical issue (motion, fracture gap), biologically OK - Hypertrophic - Moderately hypertrophic - Oligotrophic - some biologic failure as well (loose implant at fracture- prevent bone proliferation and vascularization. Non-viable = biologically inactive - Dystrophic - compromised vasculature/non-viable bone 1 or both sides - Necrotic - infected dead bone = sequestrum - Defect - gap too large and filled with non-bone (fibrous or muscle) - Atrophic- result of above types, host removes bone but doesn't replace

Question 543

What are less conventional methods to deal with delayed/non-unions?

Answer 543

Extracorporeal shock wave - hypertrophic but not atrophic Pulse electromagnetic field Low intensity pulsed US