small intestine and appendix

Question 1

the duodenum

Answer 1

• extends from pylorus to ligament of treitz
• retroperitoneal
• 4 segments: duodenal bulb and descending duodenum which house major/minor duodenal papillae

Question 2

minor and major papilla

Answer 2

minor- drainage of dorsal pancreatic duct (accessory duct of Santorini)

major- drains common bile duct and main pancreatic duct (duct of wirsung)

Question 3

jejunum

Answer 3

more prominent plica circualres and longer vasa recta than ileum

Question 4

blood supply of small intestine

Answer 4

primarily the superior mesenteric artery (SMA)

duodenum also supplied by gastroduodenal artery, originating from celiac axis via common hepatic artery

Question 5

venous drainage of small intestine

Answer 5

superior mesenteric vein (SMV) which is joined by splenic and inferior mesenteric veins to constitute the portal vein

Question 6

lymphatic drainage of small intestine

Answer 6

lacteals and lymphatic channels paralleling the venous drainage, joining at the cisterna chyli in upper abd below the aortic hiatus of the diaphragm

Question 7

lymphatic tissue of terminal ileum

Answer 7

known as Peyer’s patches and terminates at ileocecal valve

Question 8

nerve supply of small intestine and appendix

Answer 8

autonomic nervous system

parasympathetic fibers from vagus nerve and traverse to gut via celiac plexus

sympathetic fibers travel via splanchnic nerves from ganglion cells in superior mesenteric plexus

intestinal distention- sympathetic visceral afferent fibers

Question 9

appendix

Answer 9

arises from the cecum at the confluence of the taenia coli and accompanied by an adjacent mesentery (mesoappendix) which courses the appendiceal artery as a terminal branch of ileocolic artery

Question 10

how is the primary function of digestion and absorption of the small intestine accomplished

Answer 10

intestinal motility, activity of digestive enzymes, secretion of digestive juices, and absorptive processes predicted on both simple diffusion and active transport

autonomic and endocrine regulation

Question 11

4 phases of migrating motor complex (MMC)

Answer 11

1. quiescent w no spikes or contractions
2. accelerating and intermittent spike and contractile activity
3. sequence of high amplitude spiking activity and corresponding strong, rhythmic gut contractions
4. brief migrate down the small intestine

total duration of cycle is 90-120m

Question 12

where is vit b12, a, d,e,k and bile salts, calcium and iron absorbed

Answer 12

b12,a,d,e,k,bile salts- terminal ileum

ca/fe- duodenum and proximal small bowel

Question 13

what does IgA for the gut immune system

Answer 13

suppress bacterial growth and adherence to epithelial cells

neutralizes bacterial toxins and viruses

Question 14

what happens with SBO

Answer 14

lumen of the small intestine is blocked causing small bowel effluent to back up resulting in abd distension, n, v

mesentery can be compromised causing strangulation of the intestine w resulting ischemia and potentially bowel necrosis

Question 15

closed loop bowel obstruction

Answer 15

complete obstruction where a portion of small intestine is obstructed both proximally and distally

high risk for strangulation and requires immediate surgery

Question 16

intraluminal causes of SBO

Answer 16

foreign bodies, barium inspissation (colon), bezoar, inspissated feces, gallstone, meconium (cystic fibrosis), parasites, intussusception, polypoid

Question 17

intramural causes of SBO

Answer 17

congenital (atresia, stricture, stenosis, web, meckels diverticulum)
inflammatory process (crohns, diverticulitis, ischemia, radiation enteritis, medication induced)
neoplasms (primary bowel, seconday)
trauma

Question 18

extrinsic causes of SBO

Answer 18

adhesions, congenital (ladd/meckels bands, postop, postinflammatory)
hernias (ext/int)
volvulus
external mass effect (abscess*, annular pancreas, carcinomatosis, endometriosis, pregnancy, pancreatic pseudocyst)

Question 19

MC SBO cause in industrialized and nonindustrialized

Answer 19

indust- postsurgical adhesions or scar tissue

nonind- inguinal or umbilical hernia

Question 20

SBO due to internal hernias after laparoscopic gastric bypass

Answer 20

small mesenteric defects can be created through which small bowel can herniate and cause obstruction and potentially strangulation

Question 21

metastatic peritoneal cancer as cause of extrinsic SBO

Answer 21

metastatic peritoneal implants, commonly from ovarian or colon cancer, may compress the small bowel lumen causing an intestinal obstruction

Question 22

how do instrinsic causes affect the small bowel

Answer 22

causes thickening of the bowel wall and causes lumen to compromise forming a stricture within the small intestine not allowing solids to pass through the narrow lumen causing abdominal crampy pain

Question 23

MC cause for benign stricture

Answer 23

Crohn’s disease

less common- radiation enteritis, ulcers from nsaids, previous small bowel resection

Question 24

is strangulation assoc w bowel obstructions caused by strictures

Answer 24

not likely since mesentery is not compromised

Question 25

how a foreign body (intraluminal cause) causes SBO

Answer 25

in some the ileocecal valve produces a slight narrowing that may form a barrier for some larger foreign bodies so they become impacted at the valve and an obstruction develops

Question 26

what is the most serious complication of SBO

Answer 26

strangulation of the involved intestine because the bowel becomes ischemic and eventually infarcts as edema and kinking of the mesentery impact mesenteric vascular patency

Question 27

indicators of a higher risk of strangulation

Answer 27

fever tachycardia leukocytosis localized abd tenderness

Question 28

pt w intermittent, intense, colicky pain relieved by vomiting of the epigastric region

Answer 28

proximal sbo (open loop)

Question 29

pt with intermittent to constant pain that is diffuse and progressive, moderate abd distention, obstipation, and mild vomiting

Answer 29

distal sbo (open loop)

Question 30

pt with progressive diffuse pain that was intermittent but rapidly worsened and is now constant, no abd distention

Answer 30

sbo closed loop

Question 31

pt w continuous diffuse pain, w intermittent vomiting, marked abd distention and obstipation

Answer 31

colon and rectum obstruction

Question 32

what should you be concerned about if pain and tenderness begin to localize in a more somatic pattern

Answer 32

bowel ischemia and peritonitis w attendant parietal peritoneal irritation

Question 33

in an obese pt what may be the only clue to bowel incarceration within an otherwise occult hernia

Answer 33

areas of focal contour change, erythema or tenderness near a surgical scar

Question 34

when will diffuse mild tenderness improve usually w sbo

Answer 34

after acute decompression via a nasogastric tube

Question 35

initial imaging studies for sbo

Answer 35

abd series- supine and upright abd films | upright chest radiograph

Question 36

imaging findings for sbo

Answer 36

bowel distention proximal to point of obstruction and collapse of bowel distal to same point

Question 37

what do air fluid levels on an upright film indicate

Answer 37

lack of normal propulsive activity in affected loops of intestine

Question 38

what represents closed loop obstruction on abd series

Answer 38

focal loops of intestine that are persistently abnormal

Question 39

if the bowel is massively distended with air and it is difficult to distinguish the small and large bowel what should be done

Answer 39

water soluble contrast enema to exclude the possibility of a large bowel obstruction mechanism

Question 40

when are contrast studies of the small intestine useful

Answer 40

pt w persistent partial obstructive symptoms or when it is difficult to distinguish paralytic ileus from mechanical obstruction

Question 41

lab tests for sbo

Answer 41

helpful in excluding other causes leukocytosis- if persists despite ng decompression and fluid resuscitation can mean progression toward ischemia electrolytes closely monitored hypokalemic- contraction of alkalosis w adv dehydration hyperamylasemia- sbo but w marked degree heighten suspicion for acute pancreatitis UA- excluding evidence for infection or stone lactic acidosis- bowel ischemia

Question 42

what is the most frequent ddx considered in setting of possible sbo

Answer 42

paralytic ileus

Question 43

process of paralytic ileus

Answer 43

bowel motility is suppressed as a consequence of systemic or inflammatory illness and bowel may become distended and pt obstipated ; no mechanical obstruction

Question 44

pt with minimal abd pain, n/v, obstipation, cant pass gas, abd distention, dec/absent bowel sounds, gas in small intestine and colon on xray

Answer 44

paralytic ileus

Question 45

pt with crampy abd pain, n/v, obstipation, abd distention, norm/inc bowel sounds, gas in small intestine on xray

Answer 45

sbo

Question 46

cause of POI

Answer 46

stress of surgery, fluid and electrolyte imbalances, pain management with narcotics

Question 47

fast tract protocol

Answer 47

used to try and minimize POI by avoiding ng tubes, early ambulation, avoidance of fluid overload and early intro of diet

Question 48

medication approved to dec length of POI

Answer 48

alvimopan- opioid antagonist that specifically targets the mu receptor responsible for the gi side effects of opioids doesnt cross bbb so selectively blocks the peripheral receptors contributing to POI wout sig altering central analgesic effects of opioids

Question 49

what does tx for sbo begin with

Answer 49

resuscitation, correction of fluid and electrolyte deficits

Question 50

what is the best tool for assessing adequacy of volume replacement

Answer 50

foley catheter to assess urine output | at least 0.5mL/kg

Question 51

what does an ng tube placement do

Answer 51

control emesis, relieve intestinal distention proximal to obstruction, lower risk of aspiration, allow monitoring of ongoing fluid and electrolyte losses

Question 52

reduction en mass

Answer 52

hernia sac is reduced w the contents as a unit and therefore the contents may remain compromised despite being internalized

Question 53

if there is question in regard to bowel viability what is an intraoperative assessment that is done

Answer 53

intraop assessment w fluorescein dye or doppler us to asses perfusion along with clinical evaluations of bowel viability such as color, bleeding, and peristalsis

Question 54

what should be done if intussusception if found in adults

Answer 54

resection because of high likelihood of a lead point lesion

Question 55

what are some complications that may complicate operative intervention for sbo

Answer 55

wound infection, anastomotic leak, abscess, peritonitis, and fistula formation

Question 56

features of crohns ds

Answer 56

involves segments of GI tract other than the colon sparing or skip lesions between affected areas transmural involvement and assoc tendency to dev fistulas noncaseating granulomata on histology

Question 57

gradual onset with progression of abd pain, diarrhea, and weight loss

Answer 57

crohns as progresses have malaise, fatigue, fever, weight loss, anorexia, n/v

Question 58

dx crohns

Answer 58

colonoscopy w visualization of terminal ileum or barium enema w inspection of terminal ileum and small bowel contrast studies

Question 59

biologies for crohns

Answer 59

infliximab adalimumab certolizumab

Question 60

indications for surgery w crohns disease

Answer 60

perforation fibrotic stricture- acute complete or chronic partial BO fistula

Question 61

what if a pt w a fistula fails to respond to medical management

Answer 61

resection of the communicating bowel and simple debridement or limited excision of the communicating cutaneous or nonenteric visceral tract

Question 62

how long does the small intestine have to be maintained in order for them to sustain oral intake

Answer 62

100cm

Question 63

complications of crohns

Answer 63

malnutrition, obstruction, fistulous ds, electrolyte distrubances medication se progression of ds resistant to medical therapy wound infx, short bowel syndrome, wound healing problems, fistulae anal incontinence

Question 64

4 major etiologies for acute mesenteric ischemia (AMI)

Answer 64

sma embolism sma thrombosis mv thrombosis nonocclusive mesenteric ischemia

Question 65

SMA embolism

Answer 65

- originate from heart and assoc w afib - thrombus forms win the heart and becomes dislodged, the clot passes downt he sma and lodges as the vessel narrows just distal to the take off of the middle colic artery completely occluding downstream flow

Question 66

sma thrombosis

Answer 66

- freq assoc w vascular ds like CAD,PVD, chronic renal insuff - chronic stenosis of the sma and if the vessel forms an acute thrombosis, ami may occur - usually begins at origin of SMA and more likely to lead to complete SB infarction

Question 67

smv thrombosis

Answer 67

- result of hypercoag state | - clot forms in smv obstructing venous outflow which results in venous htn, inc bowel wall edema and dec arterial flow

Question 68

nonocclusive mesenteric ischemia (NOMI)

Answer 68

- usually dx in ICu setting in critically ill pts - hx of toehr sig atherosclerotic ds - in severe shock, blood shunted away from GI tract and if process cont there can be sig vasospasm of the splanchnic circulation, resulting in ischemia of sm/lg intestine

Question 69

pt presents w severe rapid onset of pain, abd exam unimpressive

Answer 69

AMI pain out of proportion to PE

Question 70

presentation of SMV thrombosis and NOMI

Answer 70

smv- insidious onset, pain for several days or weeks, diffuse and nonspecific nomi- min abd pain that is overshadowed,**hemodynamic instability (primary cause)

Question 71

dx mesenteric ischemia

Answer 71

direct visualization of vascular tree via mesenteric arteriogram delayed films to obtain a venous phase to determine if smv is thrombosed CT is replacing

Question 72

initial tx for mesenteric ischemia

Answer 72

rapid resuscitation and correction of any metabolic abnorm abx rapidly restore blood flow to gut, resect necrotic bowel and min reperfusion injury

Question 73

tx for pt w sma embolism

Answer 73

immediate embolectomy via laparotomy sma isolated and arteriotomy is performed catheter placed directly into artery above clot and balloon inflated and catheter removed along with clot

Question 74

tx for sma thrombosis

Answer 74

revasc required since sma chronically narrowed by severe atherosclerotic ds sma bypass procedure or sma endovasc stent

Question 75

tx for smv thrombosis

Answer 75

supportive and prompt anticoag w iv heparin

Question 76

tx nomi

Answer 76

underlying pathology and aggressive resucitation efforts avoid alpha adrenergic vasopressors and digoxin since the induce spasm and vasospasm is major part of nomi

Question 77

mc benign lesion of small intestine

Answer 77

leiomyomas, which occur mc in jejunum but can occur anywhere in digestive tract are on the benign spectrum of mesenchymal tumors of the GI tract and now referred to as GI stromal tumors (GISTs)

Question 78

where do leiomyomas or GISTs arise from

Answer 78

interstitial cells of cajal

Question 79

other nonepithelial benign small bowel lesions

Answer 79

hemangiomas important potential cause of occult bleeding Osler Weber Rendu syndrome hamartomas- peutz jeghers syndrome lymphangiomas neurogenic tumors (schwannomas, neurofibromas)

Question 80

epithelial benign lesions of small intestine

Answer 80

tubular adenomas villous adenomas- more likely malignant so need to be excised brunner's gland adenomas- duodenum, asymp

Question 81

mc malignancy affecting individuals w familial polyposis after proctocolectomy

Answer 81

duodenal carcinoma of periampullary region

Question 82

adenocarcinomas of small intestine

Answer 82

mc in duodenum w dec incidence as move distally obstruction assoc w wl mc presentation occult bleeding and anemia endoscopic screening of periampullary region

Question 83

carcinoid tumors of small intestine

Answer 83

- arise from kulchitsky cells in crypts of lieberkuhn part of APUD - mc in ileum - obstruction is mc finding due to intense desmoplastic reaction that occurs in adjacent bowel mesentery, others inlcude anorexia, fatigue and wl - dx made laparotomy - tx wide excision of bowel and adjacent mesentery

Question 84

carcinoid syndrome

Answer 84

- episodic cutaneous flushing, bronchospasm, intestinal cramping/diarrhea, vasomotor instability, pellagre like skin lesions and right sided valvular heart ds - dx urinary measurement of 5-hiaa, serum measurement of serotonin or chromogranin a - tx resection

Question 85

lymphoma (small intestine mc site of extranodal lymphoma)

Answer 85

- ileum mce to peyers patches - nonspecific symp: vague abd pain, wl, fatigue, malaise - nodularity and thickening of wall on contrast studies or ct - surgical resection w subsequent chemo or radiation

Question 86

what is the mc congenital anomaly of small intestine

Answer 86

meckel's diverticulum- represents a remnant of the embryonic vitelline or omphalomesenteric duct

Question 87

rule of twos for meckels diverticulum

Answer 87

2% of population 2:1 male to female 2 types mucosae located within 2 ft of ileocecal valve

Question 88

anatomy of meckels diverticula, where does the diverticulum arise from, and blood supply

Answer 88

- evolve when there is incomplete obliteration of the viteline duct which arises from the midgut and typically closes between 8th and 10th week of gestation - arises from antimesenteric border of ileum usually within 60cm (2ft) of ileocecal valve - blood supply from vitelline vessels, arising from ileal blood supply

Question 89

what is the most common type of heterotopic mucosa found within the diverticulum

Answer 89

gastric-may cause ulceration of adjacent small intestinal mucosa and hemorrhage because of its capacity to produce acid in direct proximity to small bowel mucosa less freq is pancreatic and colonic

Question 90

what happens if there is a complete persistence of vitelline duct

Answer 90

sinus from the umbilicus to ileum may result presenting as an enteric fistula at the umbilicus itself

Question 91

what happens if the vitelline duct obliterates but leaves a fibrous cord remnant

Answer 91

remnant may act as a point of fixation of the small intestine to the abd wall and facilitate bowel obstruction

Question 92

clinical presentations in meckels diverticula

Answer 92

hemorrhage-bright red/maroon per rectum, painless, infants under 2 ileus intussusception diverticulitis perforation misc.- obstruction, inflammation, umbilical fistula

Question 93

how i hemorrhage related to meckels dx

Answer 93

radionuclide scanning using technetium-99m pertechnetate which is taken up by ectopic gastric mucosa enhanced by cimetidine or pentagastrin

Question 94

how does an intestinal obstruction occur in meckels

Answer 94

because of volvulus of the small bowel around the diverticulum or constrictive effect of a mesodiverticular band

Question 95

tx of meckels

Answer 95

resection of the diverticulum if outside of pediatric age- narrow base, when a mesodiverticular band is present, or when heterotopic tissue is evident base of diverticulum is closed transversely to minimize luminal narrowing

Question 96

intestinal malrotation

Answer 96

- 4th-10th weeks of gestation - 270deg rotation of proximal midgut places duodenum in retroperitoneum behind superior mesenteric vessels - 270deg rotation of distal midgut places cecum in rlq and transverse colon draped anterior to superior mesenteric vessels - if both turns are incomplete or not made at all abnorm exist

Question 97

what is the mc manifestation of malrotation

Answer 97

midgut volvulus in an infant w an incomplete rotation - the proximal midgut fails to rotate beyond the midline remaining to the right of sup mes vessels w the duodenum covered ant by Ladd's bands - distal midgut only rotates 90-180 and cecum becomes fixed to abd wall in ruq near duodenum - twisting becomes small bowel volvulus leading to ischemia and necrosis

Question 98

signs, dx and tx of midgut volvulus

Answer 98

- bilious emesis w progression to distention, tenderness/shock late findings - radiographic upper GI series - emergent laparotomy w detorsion of the bowel, division of Ladd's bands, broadening of the mesentery and placement of the small intestine on the right and colon on the left side of abdomen - also do appendectomy

Question 99

what is short bowel syndrome (short gut)

Question 100

vermiform appendix anatomy

Answer 100

- located in rlq at confluence of taenia coli on cecal apex - appendiceal artery travels in mesoappendix and originates from ileocolic artery - lined by columnar epithelium and rich in lymphatic follicles location determines the location of tenderness as ds progresses

Question 101

what causes acute appendicitis

Answer 101

- consequence of obstruction of appendiceal lumen - mc is lymphoid hyperplasia causing luminal obstruction - also accumulation of fecal material or fecalith

Question 102

what happens as the appendiceal lumen becomes compromised

Answer 102

-mucus secretion by the epithelium leads to distention of the appendix distal to the narrowed lumen w eventual compromise of venous outflow as the organ becomes increasingly turgid and ischemic

Question 103

what can progression of swelling, infection and ischemia assoc w acute appendicitis lead to

Answer 103

gangrene and perforation the resulting peritonitis may be walled off by omentum or other adjacent visceral structures if ifx not controlled, spread of infx into portal system via venous effluent (pylephlebitis)may result giving rise to air in portal system or liver abscesses

Question 104

mcburneys point

Answer 104

located 1/3 of distance from anterior superior iliac spine to the umbilicus (appendicitis)

Question 105

tx for appendicitis

Answer 105

- preop IV fluid resucitation coverage suitable for colonic flora - 2nd gen ceph, broad spectrum penicillin or fluroquinolone and anaerobic coverage w metronidazole (no perf=24hr, perf=afebrile,norm wbc, gi function) - surgery

Question 106

open appendectomy

Answer 106

open: muscle splitting incision centered on McBurneys pt, appendix mobilized into wound and mesoappendix taken down allowing isolation of base of appendix where it joins the cecum; appendix removed after ligature control of its base

Question 107

lap appy

Answer 107

less postop pain and lower wound infection rates allows inspection of peritoneal cavity before committing to given operative exposure

Question 108

complications of appy

Answer 108

wound infx, pelvic abscess, fecal fistula, appendiceal remnants

Question 109

appendiceal tumors

Answer 109

- carcinoid, carcinoma, mucocele | - 2cm in diameter, a right hemicolectomy to allow removal of lymphatic drainage pathway

Question 110

43yo w 3d hx abd distention, n, v, dec urine outpt. hx of total abd hysterectomy 5yrs ago for benign ds. no meds. pulse is 110beats/min. abd distended and mild diffuse tenderness. bowel sounds hyperactive. serum electrolytes are sodium 140, chloride 90, bicarb 32, potassium 4.0. most appropriate initial iv fluid to administer

Answer 110

normal saline K not added until volume restoration is achieved, lactated ringers may worsen metabolic alkalosis because lactate converted to bicarb in the liver, and colloidal solutions do not correct the hypochloremia and electrolyte imbalances and are not called for in resuscitating hypovolemic dehydrated pt

Question 111

what 3 segments is the small intestine composed of

Answer 111

duodenum- pylorus to ligament of treitz jejunum-first 40% of small bowel distal to duodenum ileum- remaining 60%

Question 112

A 38-year-old man has undergone four operations for Crohn’s disease in the last 10 years and recently underwent the last of these for treatment of recurrent disease proximal to a prior ileocolic anastomosis. Which of the following agents Is most useful for managing acute exacerbations rather than helping to maintain him in remission from active disease?

Answer 112

prednisone

Question 113

A 65-year-old woman comes to clinic with a vague history of diffuse abdominal discomfort over the past 3 weeks. She denies any history of trauma or prior abdominal surgery and has no known stigmata of peripheral vascular disease. She takes vitamin D and calcium supplements. On exam, she has diffuse mild to moderate subjective tenderness without guarding or peritoneal signs. She is In sinus rhythm on EKG. Which of the following is the most likely diagnosis?

Answer 113

mesenteric venous thrombosis

Question 114

A 63-year-old woman comes to clinic with symptoms of nonspecific abdominal pain. Her past medical history is unremarkable. She takes vitamins and calcium supplements. A recent CT scan shows a small bowel mass lesion. Laboratory evaluations show an elevated serum level of c-kit protein, with normal chromogranin A. Which of the following intestinal tumors is this consistent with?

Answer 114

gastrointestinal stromal tumor The elevated c-kit level is specific to gastrointestinal stromal tumor (GIST) tumors and Is the key information leading to this answer. The other small bowel lesions mentioned could present with similar vague symptoms but are not associated with the c-kit proto-oncogene mutation and associated serum protein marker. Carcinoid tumors may be associated with elevated levels of 5-HIAA (5-hydroxyindole acetic acid) on 24 urine testing. Osler-Weber-Rendu lesions are telangiectasias and may be associated with bleeding and characteristic visible telangiectasias in other mucosal areas including the oral cavity and skin. Hamartomas may be associated with Peutz-Jeghers syndrome. Brunner’s gland adenomas are seen In the proximal duodenum, where these glands are part of the mucus and alkaline mucosal protection mechanism of the proximal small Intestine.

Question 115

A 24-year-old female graduate student comes to the emergency department because of abdominal pain for the past 12 hours. Initially she had vague mid-abdominal pain that has localized to the RLQ about 3 hours ago. She is otherwise healthy and takes no medications. Her temperature is 37°C. There Is guarding and rebound tenderness in the right lower quadrant and a positive Rovsing’s sign. A CT scan shows fat stranding around a dilated appendix. At surgery, there is a 2.5-cm firm, smooth yellowish mass at the base of an inflamed appendix. There Is no evidence of perforation and no other abnormalities are found. Frozen section biopsy is consistent with a neuroendocrine tumor. Which of the following is the most appropriate management at this time?

Answer 115

right hemicolectomy This patient has a carcinoid tumor. A right hemicolectomy Is needed because of the heightened risk of lymph node metastases. A simple appendectomy would not be appropriate for a carcinoid at the base of the appendix but would be appropriate for a carcinoid tumor

Question 116

A 38-year-old man has undergone four operations for Crohn’s disease in the last 10 years and recently underwent the last of these for treatment of recurrent disease proximal to a prior ileocolic anastomosis. Which of the following agents Is most useful for managing acute exacerbations rather than helping to maintain him in remission from active disease?

Answer 116

prednisone

Question 117

A 65-year-old woman comes to clinic with a vague history of diffuse abdominal discomfort over the past 3 weeks. She denies any history of trauma or prior abdominal surgery and has no known stigmata of peripheral vascular disease. She takes vitamin D and calcium supplements. On exam, she has diffuse mild to moderate subjective tenderness without guarding or peritoneal signs. She is In sinus rhythm on EKG. Which of the following is the most likely diagnosis?

Answer 117

mesenteric venous thrombosis

Question 118

A 63-year-old woman comes to clinic with symptoms of nonspecific abdominal pain. Her past medical history is unremarkable. She takes vitamins and calcium supplements. A recent CT scan shows a small bowel mass lesion. Laboratory evaluations show an elevated serum level of c-kit protein, with normal chromogranin A. Which of the following intestinal tumors is this consistent with?

Answer 118

gastrointestinal stromal tumor The elevated c-kit level is specific to gastrointestinal stromal tumor (GIST) tumors and Is the key information leading to this answer. The other small bowel lesions mentioned could present with similar vague symptoms but are not associated with the c-kit proto-oncogene mutation and associated serum protein marker. Carcinoid tumors may be associated with elevated levels of 5-HIAA (5-hydroxyindole acetic acid) on 24 urine testing. Osler-Weber-Rendu lesions are telangiectasias and may be associated with bleeding and characteristic visible telangiectasias in other mucosal areas including the oral cavity and skin. Hamartomas may be associated with Peutz-Jeghers syndrome. Brunner’s gland adenomas are seen In the proximal duodenum, where these glands are part of the mucus and alkaline mucosal protection mechanism of the proximal small Intestine.

Question 119

A 24-year-old female graduate student comes to the emergency department because of abdominal pain for the past 12 hours. Initially she had vague mid-abdominal pain that has localized to the RLQ about 3 hours ago. She is otherwise healthy and takes no medications. Her temperature is 37°C. There Is guarding and rebound tenderness in the right lower quadrant and a positive Rovsing’s sign. A CT scan shows fat stranding around a dilated appendix. At surgery, there is a 2.5-cm firm, smooth yellowish mass at the base of an inflamed appendix. There Is no evidence of perforation and no other abnormalities are found. Frozen section biopsy is consistent with a neuroendocrine tumor. Which of the following is the most appropriate management at this time?

Answer 119

right hemicolectomy This patient has a carcinoid tumor. A right hemicolectomy Is needed because of the heightened risk of lymph node metastases. A simple appendectomy would not be appropriate for a carcinoid at the base of the appendix but would be appropriate for a carcinoid tumor

Question 120

what marks the end of the duodenum and start of the jejunum

Answer 120

ligament of treitz

Question 121

what provides blood supply to small bowel

Answer 121

branches of superior mesenteric artery

Question 122

what does the terminal ileum absorb

Answer 122

b12, fatty acids, bile salts

Question 123

pt w abd discomfort, cramping, n, abd distention, emesis, high pitched bowel sounds

Answer 123

sbo

Question 124

what labs are performed w sbo

Answer 124

electrolytes, cbc, type/screen, ua

Question 125

what are electrolyte/acid base findings w proximal obstruction

Answer 125

hypovolemic hypochloremic, hypokalemia, alkalosis

Question 126

what must be ruled out on pe in pts with sbo

Answer 126

incarcerated hernia

Question 127

what major axe findings are assoc w sbo

Answer 127

distended loops of small bowel air fluid levels on upright film

Question 128

what is the danger of complete sbo

Answer 128

close loop strangulation of the bowel leading to bowel necrosis

Question 129

initial manage of all pts w sbo

Answer 129

npo, ngt, ivf, foley

Question 130

abc's of sbo

Answer 130

adhesions bulge (hernia) cancer/tumors

Question 131

besides abc's what are other causes of sbo

Answer 131

``` gallstone ileus intussusception volvulus external compression sma syndrome ``` bezoars, bowel wall hematoma abscesses diverticulitis ``` crohns radiation enteritis annular pancreas meckels diverticulum peritoneal adhesions stricture ```

Question 132

what is sma syndrome

Answer 132

seen w wl, sma compresses duodenum causing obstruction

Question 133

tx for complete sbo

Answer 133

lap and lysis of adhesions (LOA)

Question 134

tx for incomplete sbo

Answer 134

conservative tx w close observation plus ngt decompression

Question 135

intraop how can level of obstruction be determined in pts w sbo

Answer 135

transition from dilated bowel proximal to decompressed bowel distal to obstruction

Question 136

mc cause abd surgery w crohns

Answer 136

sbo due to strictures

Question 137

after sb resection why should mesenteric defect always be closed

Answer 137

prevent internal hernia

Question 138

what may cause sob if pt is on coumadin

Answer 138

bowel wall hematoma

Question 139

what are the signs of strangulated bowel w sbo

Answer 139

fever, shock, peritoneal signs, acidosis severe/cont pain, hematemesis, gas in bowel wall or portal veing, abd free air

Question 140

absolute indication for operation w partial sbo

Answer 140

peritoneal signs, free air on axr

Question 141

what tumor classically causes sob due to mesenteric fibrosis

Answer 141

carcinoid tumor

Question 142

s/sx of sb tumor

Answer 142

abd pain, wl, obstruction, perforation

Question 143

mc benign sb tumor

Answer 143

leiomyoma

Question 144

mc malignant sb tumor

Answer 144

adenocarcinoma

Question 145

workup of small bowel tumor

Answer 145

ugi w small bowel follow through, enteroclysis, ct scan, enteroscopy

Question 146

tx for malignant sb tumor

Answer 146

resection and removal of mesenteric draining lymph nodes

Question 147

what malignancy is classically assoc w metastasis to small bowel

Answer 147

melanoma

Question 148

usual location of meckels diverticulum

Answer 148

within 2ft of ileocecal valve on anti mesenteric border of bowel

Question 149

major ddx assoc w meckels

Answer 149

appendicitis

Question 150

complications of meckels

Answer 150

intestinal hemorrhage, intestinal obstruction, inflammation

Question 151

s/sx meckels

Answer 151

lower gi bleed, abd pain, sbo

Question 152

meckels scan

Answer 152

scan for ectopic gastric mucosa in meckels diver; uses technetium pertechnetate iv which is taken up by gastric mucosa

Question 153

hernia assoc w incarcerated meckels diver

Answer 153

Littre's hernia

Question 154

mc cause small bowel bleeding

Answer 154

small bowel angiodysplasia

Question 155

what vessel provides blood supply to appendix

Answer 155

appendiceal artery- branch of ileocolic artery

Question 156

mesentery of appendix

Answer 156

mesoappendix

Question 157

how to locate appendix once find cecum

Answer 157

follow taenia coli down

Question 158

what is appendicitis

Answer 158

inflammation of appendix causes by obstruction of appendices lumen, producing closed loop w resultant inflammation that can lead to necrosis and perforation

Question 159

causes of appendicitis

Answer 159

lymphoid hyperplasia, fecalith

Question 160

s/sx appendidicitis

Answer 160

periumbilical pain n/v anorexia pain migrates to rlq

Question 161

valentines sign w append

Answer 161

rlq pain/peritonitis from succus drainage down to rlq from perforated gastric or duodenal ulcer

Question 162

labs for append

Answer 162

cbc- inc wbc w left shift | ua- look for pyelo or stones (can have hematuria/pyuria w append)

Question 163

in acute append what comes first pain or vomiting

Answer 163

pain

Question 164

radiographic signs of append on axr

Answer 164

fecalith, sentinel loops, scoliosis away from right because of pain, abscess, loss of psoas shadow, loss of pre peritoneal fat stripe, free air

Question 165

ct findings of append

Answer 165

periappendiceal fat stranding, appendiceal diameter >6mm, periappendiceal fluid, fecalith

Question 166

preop meds/prep

Answer 166

rehydration w iv fluids (LR) | abx

Question 167

tx for nonperf acute append

Answer 167

prompt appy, 24hrs of abx, discharge home POD 1

Question 168

tx for perf acute append

Answer 168

iv fluid resuscitation and prompt appy all pus is drained w postop abx cont for 3-7d wound left open in most cases of perf after closing fascia

Question 169

tx appendiceal abscess that is dx preop

Answer 169

percutaneous drainage of abscess abx elective appy 6 wks later

Question 170

duration abx for nonruptured append and what abx

Answer 170

24hrs | cefoxitin, cefotetan, unasyn, cipro, flagyl

Question 171

abx for perf appy

Answer 171

broad spectrum abx- amp/cipro/clinda or penicillin like zosyn until normal abc, afebrile, ambulating, eating reg diet

Question 172

complications of append

Answer 172

pelvic abscess, liver abscess, free perf, portal pylethrombophlebitis

Question 173

what bacteria assoc w mesenteric adenines closely mimic acute append

Answer 173

yersinia enterolytica

Question 174

complications of appy

Answer 174

sbo, enterocutaneous fistula, wound infx, infertility w perf, inc incidence of right inguinal hernia, stump abscess

Question 175

mc postop complication of appy

Answer 175

wound infx

Question 176

difference between mcburneys incision and rocky davis incision

Answer 176

mcburnerys is angled down (follows ext oblique fibers) | rocky straight across (transverse)

Question 177

layers of abd wall during mcburney incision

Answer 177

``` skin subq fat scarpai fascia ext oblique int oblique transversus muscle trasversali fascia pre peritoneal fat peritoneum ```

Question 178

steps in lap appy

Answer 178

1. id append 2. staple mesoappendix 3. staple and transect appendix at base 4. remove append from abdomen 5. irrigate and aspirate until clear

Question 179

which way should finger sweep trying to find appendix

Answer 179

lateral to medial along lateral peritoneum so don't tear mesoappendix

Question 180

how to get to retrocecal and retroperitoneal appendix

Answer 180

divide lateral peritoneal attachments of cecum

Question 181

why use electrocautery on exposed mucosa on appendices stump

Answer 181

kill mucosal cells so don't form mucocele

Question 182

if find crowns in terminal ileum, will you remove appendix

Answer 182

yes if cecal/appendiceal base is not involved

Question 183

mc appendiceal tumore

Answer 183

carcinoid tumor

Question 184

tx of appendices carcinoid

Answer 184

appy

Question 185

tx of appendices carcinoid >1.5cm

Answer 185

right hemicolectomy

Question 186

what type of appendices tumor can cause pseudomyxoma peritonea if appendix ruptures

Answer 186

malignant mucoid adenocarcinoma

Question 187

appendicitis definition

Answer 187

inflammation of the appendix caused by obstruction of the appendiceal lumen, producing a closed loop w resultant inflammation that can lead to necrosis and perforation