Stomach

Question 1

Blood supply of the stomach?

Answer 1

Greater curvature (L gastroepiploic via splenic artery, R gastroepiploic via GDA), lesser curvature (L gastric via celiac trunk, R gastric via common hepatic artery)

Question 2

Cells in the stomach? What do they secrete? (Mucus, chief, parietal, G cells, D cells)

Answer 2

Mucus, chief - pepsinogen (1st enzyme of proteolysis), parietal - H+, intrinsic factor, G cells - gastrin (inhibited by H+ in duodenum, stimulated by amino acids and Ach), D cells - somatostatin (inhibits gastrin and acid release)

Question 3

What stimulates acid secretion? What suppresses acid secretion?

Answer 3

stimulated by Ach via vagus nerve, gastrin, and histamine, suppressed by somatostatin, PGE1, secretin, CCK

Question 4

Mechanism of omeprazole?

Answer 4

Blocks H+/K+ ATPase in parietal cell membrane (final pathway for H+ release)

Question 5

Cellular pathway of acetylcholine, gastrin, histamine?

Answer 5

Acetylcholine and gastrin activate phospholipase (PIP -> DAG + IP3 to increase Ca+, which activates phosphorylase kinase, causing H+ release); histamine activates cAMP, activates protein kinase A which leads to H+ release

Question 6

What is intrinsic factor?

Answer 6

Helps with absorption of vitamin b12 by binding to it, produced by parietal cells; the complex is reabsorbed in the terminal ileum

Question 7

What are Brunner’s glands?

Answer 7

Located in the duodenum, they secrete alkaline mucus

Question 8

What are dieulafoy’s ulcers?

Answer 8

Congenital vascular malformation typically on lesser curvature, submucosal artery that is abnormally large and tortuous, can bleed - tx w/ endoscopy, cautery, sclerosing

Question 9

What is Menetrier’s disease?

Answer 9

Mucous cell hyperplasia, increased rugal folds, loss of parietal cells leading to achlorhydria, loss protein in stomach due to mucous hyper secretion, increased gastric Ca risk high protein diet, anticholinergic agents, Cetuximab (growth factor alpha blocker) is promising tx

Question 10

Gastric volvulus: primary/secondary, axis, symptoms, treatment?

Answer 10

Primary (idiopathic), secondary occurs in 2/3 due to anatomical problem like paraesophageal hernia / diaphragmatic hernia, etc; usually organoaxial volvulus (long axis) antrum antero-superior, fundus postero-inferior, often assoc. w/ anatomic problem – mesenteroaxial volvulus (short axis) usually not associated with secondary anatomic defect – Tx w/ NG, endoscopic detorsion, surgery (reduction/fundoplication) vs gastric fixation via G-tube

Question 11

Treatment for mallory-weiss tear

Answer 11

EGD with clips, tear usually on lesser curvature near GE junction

Question 12

What is the most common side effect after vagotomy and what is the pathophysiology?

Answer 12

Diarrhea (40% of patients), caused by sustained migrating motor complexes forcing bile acids into the colon

Question 13

Types of gastric ulcers?

Answer 13

type I = distal lesser curve (most common) - decreased/normal acid production, type II = 2 ulcers, lesser curve and duodenal - high acid production, type III = pre-pyloric ulcer - high acid production, type IV = lesser curve high/proximal/GE junction - normal/low acid production – impaired mucosal defense, V = associated with NSAIDs – “4+1 = 3+2 = 5” in order from proximal to distal

Question 14

Periop chemo regimen for gastric cancer?

Answer 14

Based off of MAGIC trial - ECF, epirubicin, cisplatin, and fluorouracil

Question 15

stomach GIST: dx, path, treatment?

Answer 15

most common benign gastric neoplasms, arises from mesenchymal / Cajal cells – not smooth muscle!, if malignant spreads hematogenously, usually asymptomatic, hyperechoic on ultrasound w/ smooth edges, dx w/ biopsy shows C-kit positive, +Cd117 stain – would be concerned if large (>5 cm or >5 mitoses/50 HPF), resect with 1 cm margins (microscopic positive margins do not affect survival), chemo w/ imatinib (Gleevec, tyrosine kinase inhibitor)

Question 16

MALT lymphoma: underlying problem? tx?

Answer 16

related to h. pylori, infection induces a lymphoid infiltrate, B cell proliferation occurs; usually regresses within 1 yr after treatment for H. pylori, XRT if fails after 1 yr (CHOP - cyclophosphamide, doxorubicin, vincristine, prednisone) – 11;18 translocation are unlikely to respond w/ just H. pylori eradication

Question 17

Gastric lymphoma: most common type? dx? tx?

Answer 17

most commonly B-cell NHL; dx w/ EGD w/ biopsy, chemo/XRT primary treatment modalities

Question 18

NIH criteria for bariatric surgery

Answer 18

BMI >40 (or BMI >35 w/ coexisting comorbidities), failure of nonsurgical methods, psychologic stability, absence of drug/EtOH use

Question 19

dumping syndrome: early vs late

Answer 19

occurs after gastrectomy or vagotomy/pyloroplasty, occurs from rapid entering of carbs into small bowel – early = hyperosmotic load causes fluid shifts into bowel (GI and cardiovascular symptomshypotension, diarrhea, dizziness) late = hypoglycemia from reactive increased insulin and decreased glucose – tx w/ small low fat low carb high protein meals, octreotide

Question 20

Post-gastrectomy complication: bile reflux in stomach with evidence of gastritis

Answer 20

alkaline reflux gastritis - HIDA scan can be helpful, more likely to occur after billroth 2 vs billroth 1 - if occurs in billroth 2, surgical procedure of choice to lengthen jejunal limb, i.e. convert o roux en Y gastrojejunostomy

Question 21

Post-gastrectomy complication (dx, tx): pain, steatorrhea, B12 deficiency, malabsorption

Answer 21

blind-loop syndrome caused by bacterial overgrowth from stasis in the afferent limb; dx w/ EGD aspirate/cx, tx w/ tetracycline and flagyl, reglan improve motility, consider shortening afferent limb

Question 22

Post-gastrectomy complication (dx, tx); RUQ pain, steatorrhea, non-bilious vomiting, pain relieved w/ bilious emesis

Answer 22

Afferent loop syndrome caused by mechanical obstruction of afferent limb, dx w/ CT scan, potentially tx w/ balloon dilation vs shortening afferent limb

Question 23

Areas of possible internal hernias after RXY gastric bypass?

Answer 23

1) Petersen’s defect (between Roux mesentery and transverse mesocolon), 2) mesenteric defect of the J-J / biliopancreatic limb 3) if retrocolic fashion, defect in transverse colon mesentery

Question 24

Causes of bowel obstruction in post-op RXY gastric bypass?

Answer 24

1) internal hernia, 2) roux compression due to mesocolon scarring, 3) adhesions

Question 25

Mechanism of sibutramine? Orlistat?

Answer 25

FDA approved medications for obesity; sibutramine blocks presynaptic uptake of serotonin, increases anorexic effect on CNS; orlistat inhibits pancreatic lipase which decreases dietary fat absorption

Question 26

Most common chemo regimen for diffuse B-cell NHL of the stomach?

Answer 26

R-CHOP (Rituximab, Cyclophosphamide, Hydroxydaunorubicin - aka doxorubicin or adriamycin, Oncovin - vincristine, and Prednisone)

Question 27

What is the first clinical manifestation of gastric leak after Roux-en-Y gastric bypass?

Answer 27

Tachycardia and fever

Question 28

Management of perforated duodenal ulcers?

Answer 28

Graham patch only in most patients followed by tx of H. pylori, also if pt unstable, extensive exudative peritonitis, or long duration – if h. pylori known to be negative, than ulcer surgery should be added – highly selective vagotomy is preferred, otherwise truncal vagotomy w/ pyloroplasty

Question 29

Postvagotomy syndrome: symptoms, treatment

Answer 29

diarrhea, gastric atony and incomplete vagotomy leading to recurrent ulcerations - not associated w/ cardiovascular manifestations; initial tx w/ dietary modifications, small frequent small meals, oral cholestyramine, loperamide, codeine, rare cases reversal of jejunal segment, octreotide is not helpful

Question 30

What to do w/ patient with Zollinger-Ellison syndrome that cannot be localized with somatostatin/octreotide scintigraphy, or with Kocher maneuver?

Answer 30

Blind proximal duodenotomy to examine wall of duodenum (in Gastrinoma triangle - cystic duct/CBD, D2/D3, and neck/body of pancreas)

Question 31

Gastric cancer staging general principles

Answer 31

T stage is depth (T1 invades lamina propria, T2 muscular prop or subserosa, T3 invades serosa, T4 adjacent structures), N1 is 1-6 regional nodes, N2 7-15 regional nodes, N3 more than 15 nodes; EUS best modality for assessing tumor depth and nodal disease (better for depth)

Question 32

R0 vs R1 Vs R2 resection

Answer 32

R0 removal of all gross/microscopic, R1 removal of all macroscopic but +microscopic margins, R2 gross residual disease left behind

Question 33

Risk factors for gastric Ca

Answer 33

dietary (smoked meats, pickled foods, nitrates), smoking, black race, H. pylori, chronic gastritis, blood type A, pernicious anemia; HNPCC, Li-Fraumeni, FAP, Peutz-Jeghers syndrome

Question 34

Definition of early gastric cancer

Answer 34

Adenocarcinoma limited to mucosa and submucosa (regardless of LN status - T1 any N)

Question 35

Best way to confirm eradication of H. pylori?

Answer 35

Urea breath test - serology not helpful; antral mucosal biopsy w/ histological examination is gold standard test however not practical

Question 36

How do you perform a highly selective vagotomy?

Answer 36

Divide vagal nerves of the proximal 2/3 of the stomach where parietal cells are located and preserve distal 1/3 to maintain antral function and thus not require drainage procedure (i.e. pyloroplasty)– spares main anterior/posterior vagal trunks, divides the nerves that directly innervate proximal stomach, Crow’s feet is spared (nerves in distal 7 cm), important to divide nerve of Grassi (criminal nerve because failure to divide leads to higher ulcer recurrence rate)

Question 37

most common nutrient deficiencies following gastrectomy

Answer 37

Iron (iron absorbed in duodenum, facilitated by acidic environment) B12 (less parietal cells means less intrinsic factor, less absorption in TI, fat malabsorption (inadequate mixing of food w/ bile and digestive enzymes), calcium (absorption facilitated by an acidic environment)

Question 38

most common functional neuroendocrine tumor?

Answer 38

insulinoma

Question 39

free air under the diaphragm, anemia, guaiac positive stool?

Answer 39

“kissing” duodenal ulcer = anterior duodenal ulcer w/ free peritoneal perforation, and posterior duodenal ulcer that erodes into the GDA and bleeds, manage w/ Graham patch and oversewing posterior ulcer

Question 40

Phytobezoar vs trichobezoars

Answer 40

Phytobezoars = undigested vegetable matter, enzyme therapy (cellulase), Coke; trichobezor = hair, girls young women, most have areas of alopecia, underlying psych disorder, large trichobezar likely to require surgery (not responsive to enzyme therapy)

Question 41

Greatest risk factors for rebleeding of gastric varies seen on EGD?

Answer 41

active spurting, > active oozing > non-bleeding visible vessel > adherent clot > flat pigment spot > clean visible ulcer base

Question 42

Hyperplastic polyps: most common location, associations, types, malignancy risk, indications for surgery

Answer 42

Most commonly gastric polyps (70-90%), associated with chronic atrophic gastritis (usually due to H. pylori), polypoid foveolar hyperplasia / typical hyper plastic polyps; polypoid foveolar hyperplasia no malignant potential, typical hyper plastic polyp has 2% chance of malignancy (adenomatous polyps have highest risk 10-20%); fundic gastric polyps associated w/ long term PPI, low risk of cancer - treat with endoscopic polypectomy, surgical resection for sessile, large polyps, symptomatic, or w/ areas of invasive tumor

Question 43

Antral vascular ectasia

Answer 43

watermelon stomach, leads to significantt acute/chronic GI loss

Question 44

What are the components of triple therapy?

Answer 44

PPI and antibiotics (clarithromycin and amoxicillin, metronidazole and amoxicillin, metronidazole and tetracycline)

Question 45

Most sensitive and specific test for Gastrinoma? How is it done

Answer 45

Secretin stimulation test - give pt bolus of secretin, check gastrin before and after, if gastrin increases 120 pg/mL or greater, highest sensitivity/specificity for Gastrinoma – octreotide scan best test for localizing the tumor

Question 46

management of a type I gastric ulcer failed to heal despite maximum medical therapy?

Answer 46

distal antrectomy (ulcer usually near angularis incisura), reconstruction w/ gastroduodenostomy (B1) or gastrojejunostomy (B2), vagotomy unnecessary (not acid hyper secretion)

Question 47

During lap Nissen, hypotension, increased end tidal co2, ventilation problems — dx/to

Answer 47

Tension hypercapnea- enlarge defect, red rubber to equalize pressure, needle Thoracostomy