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Flashcards in Principles of small animal GIT surgery Deck (57):
1

What are the consequences of gastric vomiting (3)? How is this corrected prior to surgery (2)?

-Loss of gastric HCl (metabolic alkalosis, hypochloraemia)
-Dehydration (poor tissue perfusion --> metabolic acidosis)
-Insufficient food intake

CORRECTION:
-IV isotonic crystalloids
-IV K+ supplementation

2

What are the consequences of SI complete obstruction induced acute vomiting (4)? How is this corrected prior to surgery (2)?

-High intestinal obstruction - mimics gastric V
-Low intestinal obstruction - loss of pancreatic Na, HCO3 leading to metabolic acidosis and decreased Na
-Dehydration - poor tissue perfusion causing metabolic acidosis
-Insufficient food intake and deceased absorption leading to hypokalaemia.

CORRECT:
-IV isotonic crystalloids
-IV K+ supplementation

3

What are the consequences of SI partial obstruction induced chronic vomiting, diarrhoea and wt loss (3)? How is this corrected prior to surgery (2)?

-V--> dehydration and electrolyte loss
-Bacterial proliferation and nutrient metab -->maldigestion, malabsorption, intetinal mucosal damage
-Diarrhoea, wt loss, hypoalbuminaemia

CORRECTION:
-IV isotonic crystalloids
-IV K+ supplementation (can't correct hypoalbuminaemia but ensure normotensive)

4

What are the consequences of GIT bleeding causing haematemesis and melaena? (2) How is this corrected (2)?

-Anaemia - regenerative (acute bleeding) or non-regenerative (if blood loss is chronic as body loses ability to regenerate its RBCs)
-Hypoalbuminaemia

CORRECTION:
-Blood transfusion
-Iron supplementation

5

How do you check that an animal is fit for anaesthesia and surgery? (6)

-complete history
-complete PE
-check haematocrit and total protein (if anaemic)
-check electrolytes (K+ and Na+)
-check acid-base status
-complete haematology and biochem (if indicated)

6

How do the levels of bacteria within the GIT change? (2) Which bacteria most commonly causes infection after GIT surgery?

-Increased number and increased % of anaerobes the more caudally you travel
-E.coli

7

When might you want to use prophylactic ABs (2)? Why?

-When immune defences are compromised (debilitated animals from chronic V/D, GIT injury, extensive GIT resections, surgeries >90 minutes).
-Consider the location of the surgery (stomach - ABs aren't necesarily indicated in healthy young dog. SI and LI - ABs are always indicated).
-Septic peritonitis is fatal in 50% cases

8

What prophylactic AB might you use when indicated for stomach surgery?

Single broad spectrum with anaerobic coverage e.g. 2nd generation cephalosporin OR amoxycillin-clavulante

9

What prophylactic AB might you use when indicated for SI surgery?

Single broad spectrum with anaerobic coverage e.g. 2nd generation cephalosporin OR amoxycillin-clavulante

10

What prophylactic AB might you use when indicated for LI surgery?

Combination of 2 ABs including and AB specifically targeted to anaerobes. e.g. Metronidazole PLUS 2nd generation cephalosporin OR amoxycillin-clavulante

11

How can you decrease bacterial contamination? (6) How is it different for the LI?

-ABs
-Isolate the site of GI entry (swabs)
-Use a separate set of instruments for contaminated part of surgery
-Lavage GI wounds post-closure
-Change gloves
-Lavage abdomen (sterile saline)
-In the LI, there is no veterinary evidence that mechanical preparation of the bowels (i.e. enemas) decreases contamination risk. Liquid faeces may be more likely to bypass atraumatic clamps and purse string sutures. A low residue diet and at least 12-24hr starvation is recommended.

12

What is the strongest layer in the GIT wall? Why?

Submucosa because high collagen content (despite this layer not being the thickest).

13

What are the stages of intestinal wound healing?

Haemostasis (d1-4), Inflammation (d1-5), Proliferation or granulation (day 3 - weeks), remodelling or maturation (weeks to years)

14

When When is the chance of wound breakdown greatest?

Overlap between inflammation and proliferation

15

How does the rate of wound healing change along the GIT?

Stomach - rapid healing (many BVs) so healing rarely complicated
SI - by d14, 75-80% normal tensile strength returned
LI- by d14, 50% normal tensile strength returned. May be that there is increased collagenase production. Be SURE there is a real indication for entering the colon before performing colonic surgery.

16

What impacts negatively on intestinal wound healing?

-Compromise to BV
-Traumatic surgical technique (avoid electrocautery)
-Hypoproteinaemia (rarely correctable prior to surgery)
-Chemotherapy and radiation (delay chemo for 3 weeks post-surgery)
-Steroids - discontinue steroid therapy where possible)

17

Which surgical tools can you use for the GIT? (3)

Atraumatic debakey forceps
Atraumatic bowel clamps
Stay sutures (to handle stomach/intestines)
DON't use rat-tooth forceps

18

What are the aims of GIT sutures (2)? Which suture patterns do you use for GIT wounds (2)?

Aim = restore normal anatomy and promote rapid healing.
SUTURE = full thickness appositional. 2 types = simple interrupted and simple continuous.

19

Which suture material would you use?

Monofilament - yes
Multifilament - no (multiple fibres intertwined means grooves may support bacterial infection).

Must retain strength long enough to permit healing (> or equal to 5d)
Disappear after wound healing (absorbable).

Monocryl - no - loses 33% strength in 7 days
PDS 2 - yes for GIT - loses 26 % strength in 14 d

20

What would a staggered row of titanium staples do in terms of repairing a GIT wound?

Cause eversion or invesion (depending on how stapled). Not appositional healing. But the bursting strength) potential for wound to break down) will be less with staples vs. sutures.

21

Name 2 indications for exploratory laparotomy. What should be done if no discrete lesion is found?

Diagnose cause of intra-abdominal disease. OR correct the cause of intra-abdominal disease.

Next step: biopsy (stomach, SI +/-liver/pancrease/any enlared LNs).

22

How does the surgical approach for exp. lap. differ between males and females?

Both along linea alba between xiphisternum adn pubis. In males you perform a para-preputial approach and cut through the preputial muscle.

23

Name 2 types of retractor used in exp. lap.

Balfour retractors and Gossett retractors. Use moist swabs to prevent drying out.

24

Why do you need to know blood supply?

Know which BVs can be safely ligated when removing sections of the intestine. Avoid damaging the blood supply to vital organs.

25

How do you repair the stomach?

In two layers.
1.) Mucosa and submucosa (simple continuous)
2.)Serosa and muscularis (simple continuous or inverting lembert which is better at preventing leakage of the stomach contents).

26

Why should you be careful about biopsying LNs in the mesentery?

Could result in ligation of an important BV. Only biopsy if clinically indicated.

27

How do you do a SI biopsy? (7)

1.) Isolate SI
2.) Milk contents away and close with atraumatic clamps or assistant's fingers
3.) Incise along anti-mesenteric border
4.) Ellipse for biopsy cut with METZENABUM SCISSORS
5.) Trim excess mucosa to ensure sutures placed through submucosa
6.) Sutures 3-5mm apart, 3-5mm from cut edge
7.) Release clamps and assess enterotomy for leaks

28

When would you do a liver biopsy? (3) What else should be considered before this stage?

-clinical signs and blood test results suggestive of liver disease
-generalised abnormal appearance (ultrasound/usrgery)
-presence of liver nodules or masses
-first consider fine needle aspirates and trucut biopsy of the liver under ultrasound guidance.

29

How would you do a liver biopsy?

Biopsy along hte edge, crush with haemostats the cut. Stop the bleeding. Wait and see if bleeding has stopped or use haemostatic agents (e.g. sponges that act as a scaffold).

30

What must be considered when doing a pancreatic biopsy?

-Major duodenal papilla opens 2cm from pylorus
-common bile duct opening (you don't ideally want to have to re-route this)
-BVs shared between pancreas and descending duodenum

31

What history and clinical signs are associated with gastric FBs?

-any age, commoner in young
-previous FB ingestion
-known FB ingestion
-V
-lethargy (if chronic)
-abdominal pain
-depression
-anorexia
-dehydration (chronic)
-gastric distension
-malaena/haematemesis (if chronic -->ulceration)
-dyspnoea (if aspiration pneumonia present)

32

How do you diagnose gastric FBs?

xray (sometimes only seen dilation) and ultrasound

33

How do you treat gastric FBs?

Endoscopic retrieval (preferred becasue decreased infection risk) or gastrotomy

34

What post-op care is needed for gastrotomy?

Feed, antacids (if evidence of ulceration), gastric protectants. Then --> excellent prognosis.

35

What are some important questions to ask prior to surgery on gastric neoplasia? (3)

-Are there any obvious metastases? If there are then surgery isn't usually indicated because of the poor prognosis.

-Is tumour resection and reconstruction achievable? (a large proportion of stomach can be resected but cardia must be preserved)

-Can the common bile duct and pancreatic duct be preserved? If not you will have to reroute the biliary system and give pancreatic enzyme replacement therapy for rest of life.

36

What is the prognosis for gastric neoplasia?

-Complete resection of benign tumour (leiomyoma) = GOOD

-Malignant tumour (adenocarcinoma) = poor as clinical signs often reappear within weeks.

37

What are the repair techniques in partial gastrotomy?

Same prinicples as gastrotomy. Consider the use of staples.

38

When might you need to perform intestinal resection and anastomosis? (2)

When eneterotomy is not enough - i.e. ischaemic necrosis or neoplasia.

39

What assessments need to be made regarding GIT viability? (4)

-pulsations in the arterial BVs
-presence of peristaltic mm contractions
-normal colour
-normal wall thickness on palpation

40

What are the stages in intestinal resection? (5)

1.) milk out cntents
2.) isolate with atraumatic clamps
3.) ligate mesenteric vessels
4.) incise mesentery
5.)incise intestine close to clamps on intestine to be resected

41

What is luminal disparity? What is done about it?

When there is a difference in lumen diameter between the two parts of intestine.
ACTIONS= space sutures further apart on the large side. Transect the small side at an angle to match the diameter o the large side. Reduce small side with sutures. Or spaulate small size (i.e. cut along anti-mesenteric border)

42

What is an end-to-end anastomosis?

Use a simple interrupted or simple continuous stitch (i.e. suturing as for enterotomy). Place first suture in mesenteric border and 2nd suture in antimesenteric border. Repair defect in mesentery (to prevent intestinal strangulation).

43

How can you support a wound that has undergone end-to-end anastomosis?

Omentalisation
-Serosal patch (adjacent pieces of healthy intestine are tacked to intestinal wound).

44

What are the signs of an intestinal FB?

History - persistent V, possibly projectile, anrexia, depression, no defaecation
PE - dehydration, depression, abdominal pain, intraabdlominal mass, string around tongue (esp cats).

45

How would you correct an intestinal FB?

Enterotomy or multiple enterotomies (e.g. cat string)

46

What are the different types of intestinal neoplasia? (5)

-Adenoma/adenocarcinoma (local LN and liiver; siamese cats; median survival 12mo)
-Lymphoma (most common type in cats)
-Leiomyoma/leiomyosarcoma (smooth mm cnacer. local LN and liver. media survival is 10-21 mo)
-Mast cell
-Duodenal polyps.

47

What are the signs of intestinal neoplasia?

-Partial obstruction
-chronic intermittent V
-diarrhoea
-wt loss

48

What are the two parts to an intussusception?

Intussuscipiens (the bit that receives the GIT) and the intussusceptum (the bit that goes into another part of GIT). There is ischaemic necrosis of the intussusceptum

49

What are the clinical signs of intussusception?

-dehydration
-depression
-abdominal pain
-papable tubular mass
-protrusion of intussusceptum from anus (differentiate from rectal prolapse by ability to pass thermomemter up in this case but not prolapse).

50

How do you diagnose intussusception (2)?

Ultrasound (parallel lines or concentric rings)
Xray (gas distension of loops of SI)

51

What are the main treatment options for intussusception (2)? What are other treatment options (2)? What is the prognosis?

Reduction (push rather than pull, assess intestines)
Resection (if irreducible, ischaemic/injured, mass present)

OTHER: enteroplication (interrupted stitching of the GIT together to prevent telescoping), treat underlying diseases (i.e. always ask why - faecal bacteria?parasites? treat if in doubt), prognosis = good in young, 6-27% recurrence within 3d-3wks).

52

What are 4 potential complications of enterotomy and enterectomy?

-Persistent ileus
-stricture at anastomossi site (partial obstruction)
-short bowel syndrome (especially if >70% resected)
-intestinal incision dehiscence (7-16% for intestinal biopsies)

53

What are 3 ultimate consequences of intestinal wound breakdown causing septic peritonitis?

-Systemic inflammatory response syndrome (SIRS)
-Disseminated intravascular coagulation (DIC)
-Death

54

What is the prognosis for septic peritonitis?

Extremely guarded - 50% mortality

55

What are the clinical signs of septic peritonitis?

-Vomiting (especially within 3-5d post-surgery
-anorexia and depression
-abdominal pain
-abdominal enlargement
-hypovolaemic shock
-pyrexia
-discharge from abdominal wound
-diarrhoea
-haematochezia/melaena/haematemesis

56

How is septic peritonitis diagnosed?

Abdominocentesis - a hallmark is the presence of neutrophils with black dots (bacteria). Then perform an exp. lap. to determine cause of this.

57

What are the stages in treating septic peritonitis?

1.) Pre-op stabilisation (AB)
2.) Ex lap - find and correct leak
3.) Peritoneal lavage and drainage
4.) Intensive post-op case (maintenance of normovolaemia and blood pressure with fluids. nutrition is essential).