Stomach and Bowel Flashcards
management of large mesenteric cysts?
excision and resection of associated bowel , high risk of recurrence if marsupialize
management of gastric cardia adenocarcinoma?
total gastrectomy
margins for gastric adenocarcinoma?
resection with at least 5cm margins (subtotal gastrectomy can be done win distal tumors but proximal tumors usually require total)
when do you give neoadjuvant chemotherapy in gastric adenocarcinoma?
lesions >T2 or any N
what are the recommendations for lymph node dissections for gastric adenocarcinoma?
D1 or D2 resection of at least 15 lymph nodes
what’s the difference between D1 and D2 dissection in lymph node dissection w gastric adenocarcinoma?
D1 = gastrectomy + the greater and lesser omental lymph nodes D2 = all that plus the omental bursa, leaf of the transverse mesocolon, and corresponding arteries
when is a splenectomy performed during resection of gastric adenocarcinoma?
for a D2 dissection for proximal gastric tumors
what is the cell of origin of a GIST?
interstitial cells of cajal: aka the pacemaker cells
what is the cell of origin of a carcinoid tumor?
enterochromaffin cells aka Kulchitsky cells
what is the cell origin of pheochromocytomas?
neuroectodermal cells of the adrenal medulla
what are th 3 different pattens of inflammation associated with H. Pylori infection?
- diffuse* MC, not assoc w PUD
- antral
- stomach-body related
how does gastrin stimulate acid secretion? (2 ways)
- stimulation of the synthesis and release of histamine from enterocrhomaffin-like cells which bind to H2 receptors on parietal cells
- from parietal cells via cholecystokinin B receptor
side effect of metoclopramide?
tardive dyskinesia
two different types of dumping syndrome and causes
- Early dumping: 30 min after eating and due to hyperosmotic load causing large fluid shift
- Late dumping: 2-3 hours after eating and due to large insulin release from large fluid bolus hitting the duo
what is the best test to determine a) diagnosis and b) eradication of h pylori?
a) serology: IgG
b) urea breath test
treatment of low versus high grade MALToma?
low = abx alone high = CHOP
what is triple therapy for H pylori?
PPI, clarithromycin, flagyl (metronidazole)
where is protein mostly absorbed?
mostly jejunum
what does the terminal ileum absorb?
bile salts, vitamin B12, fat soluble vitamins (ADEK)
where are the majority of small bowel adenocarcinomas found?
duodenum
what is the most common neoplasm of small bowel?
metastasis: MC melanoma, lung, breast, cervix, sarcoma, colon
most common PRIMARY small bowel neoplasm?
NET
UC or Crohns: Granulomas
Crohns
UC or Crohns: Rectal Involvement
UC
UC or Crohns: Cobblestone appearance
Crohns
UC or Crohns: Transmural involvement
Crohns
UC or Crohns: Patchy areas of bowel
Crohns
whats a finney stricturoplasty and when do you use it?
indicated for strictures 7-15cm, fold the diseased bowel on itself and create a large opening between the two loops
what is a Heineke-Mikulicz stricturoplasty and when is it used?
strictures <7cm, MC, make a longitudinal incision on the antimesenteric side of the bowel and close transversely
what are the different types of enterocutaneous fistulas?
Low output: <200mL/day
Moderate: 200-500mL/day
High output: >500mL/day
what are the sympathetic fibers for gastroduodenal pain?
afferent sympathetic fibers T5-10
cell type of mucosal lining of stomach?
simple columnar epithelium
where is the pacemaker (SA) node of the stomach?
Cardia
chief cells release what?
pepsinogen
Parietal cells release what?
H+ and intrinsic factor
what are 3 factors that stimulate H+ release from parietal cells of stomach?
- Acetylcholine (vagus nerve)
- Gastrin (from G cells in antrum)
- Histamine (from mast cells)
mechanism of how acetylcholine and gastrin increase H+
activate phospholipase which increases Ca (PIP -> DAG + IP3 to increase Ca), Ca-Calmodulin activates phosphorylase kinase -> increases H+
mechanism of how histamine increases H+
histamine activates adenylate cyclase -> cAMP -> activates protein kinase A -> increase H+ release
MOA omeprazole
blocks the H/K ATPase in parietal cell membrane (final pathway of H+ release)
what are 4 major inhibitors of parietal cells?
Somatostatin, prostaglandins (PGE1), secretin, CCK
intrinsic factor: released from? function? reabsorbed?
Released from parietal cells in gastric antrum
binds vitamin B12
reabsorbed in terminal ileum
what are brunner’s glands?
located in duodenum, secrete alkaline mucus
what is menetrier’s disease?
mucous cell hyperplasia, increase in rugal folds
tx of gastric volvulus?
reduction and Nissen fundoplication
where is the tear usually in Mallory-weiss?
lesser curvature of stomach near GE junction
truncal vagotomy versus proximal vagotomy?
truncal: divides vagus at level of esophagus, increases emptying of solids
proximal: highly selective, divides individual fibers, normal emptying of solids
most common problem following vagotomy, tx
diarrhea: caused by sustained MMCs (migrating motor complex) forcing bile into the colon and leading to osmotic diarrhea
tx: cholestyramine and loperamide
how do you diagnose gastroparesis?
gastric emptying study- normal should have <10% in stomach at 4 hours, if more then + gastroparesis
what are the biggest risk factors for rebleeding at time of EGD? like what do you see and assoc risk of rebleeding
- Spurting blood vessel (60% chance)
- Identifiable blood vessel (40% chance)
- Diffuse oozing (30% chance)
what is triple therapy for H. pylori?
bismuth salts, amoxicillin, metronidazole/tetracycline
BAM or BAT
what is ZES?
gastric acid hypersecretion, peptic ulcers, gastrinoma
what are 3 surgical options for acid-reducing surgery? assoc recurrence rate of ulcers?
- proximal vagotomy: 10-15% recurrence, 0.1% mortality
- Truncal vagotomy w pyloroplasty: 5-10% recurrence, 1% mortality
- truncal vagotomy w antrectomy: 1-2% recurrence, 2% mortality, reconstruct w RNYGB* v B1 v B2
how do you perform GDA ligation for bleeding duodenal artery?
3 suture ligation: proximal GDA, distal GDA and U stitch to transfix the pancreatic branch
best test for H pylori?
histiologic examination of biopsies from antrum
best test for h pylori eradication?
urea breath test
what are the 5 types of gastric ulcers?
type 1: lesser curvature, near antrum, nml acid
type 2: both gastric and duodenal, high acid
type 3: prepyloric, high acid
type 4: near GEjxn, nml acid
type 5: assoc w NSAIDs
cushing ulcer vs curling ulcer
cushing ulcer: head trauma and gastric ulcer
curling ulcer: burn patient and duodenal ulcer
where does a stress gastric ulcer appear first?
fundus
two types of chronic gastritis
type A: fundus, assoc w pernicious anemia and autoimmune disease
type B: antral, assoc w h pylori
40% of gastric cancers are located where?
antrum
what blood type increases risk of gastric cancer?
type A
risk of cancer in gastric adenoamtous polyp?
15%, tx: endoscopic resection
two types of gastric cancer?
intestinal type: japan, rare in US, histology shows glands, need 10cm margins, attempt subtotal gastrectomy
Diffuse gastric type: linitis plastica, MC in US, no glands on histology, tx total gastrectomy
MC benign gastric neoplasm
GIST (but can also be malignant)
what does biopsy of GIST show?
C-kit positive staining
when do you consider a GIST malignant?
> 5cm or >5 mitoses/50 HPF
tx of GIST
resection w 1 cm margin, no nodal dissection
tx: imatinib if malignant
MOA imatinib
gleevac: tyrosine kinase inhibitor
tx if MALT lymphoma doesnt regress w h pylori tx?
XRT
MC location for extra-nodal lymphoma?
stomach!
stomach lymphoma is usually what type?
non-hodgkins lymphoma, B cell
tx for gastric lymphoma?
chemotherapy and XRT
what comorbidity does NOT get better after bariatric surgery?
PAD
where is Fe absorbed?
duodenum
vitamin deficiencies after RNYGB?
B12 (intrinsic factor) and Fe (bypass duo)
MC cause of leak in RNYGB?
ischemia
why does dumping syndrome occur?
rapid entering of carbohydrates into the small bowel
what are 2 phases of dumping syndrome?
hyperosmotic load causes fluid shift into bowel (hypotension, diarrhea, dizziness), then (rare phase) hypoglycemia from reactive increase in insulin and decrease in glucose
what is blind loop syndrome? dx and tx?
- seen with B2 of RNYGB, caused by poor motility and bacterial overgrowth (GNR, Ecoli) from stasis in afferent limb
dx: EGD of afferent limb
tx: tetracycline or flagyl, reglan to improve motility, or can shorten afferent limb to 40cm
what is afferent loop obtsruction?
w B2 or RNYGB, mechanical obstruction of afferent limb
tx: dilation or reanastomosis w shorter afferent limb
what is efferent limb obstruction?
obstruction of efferent loop, can balloon dilate or reoperate
what is MOA of infliximab and one particular use?
TNF alpha inhibitor, shown to help close fistulas in Crohn’s disease
what’s triple therapy for H pylori?
PPI and 2abx: choose from amoxicillin, metronidazole, tetracycline, clarithromycin
which organ has the highest secretion of K?
colon
MC location of small bowel carcinoid?
ileum
where in the bowel are lymphoid follicles most prominent?
ileum (thats why small bowel lymphoma is most frequently there)
what is the Forest classification?
classification of risk for bleeding based on endoscopic findings in bleeding ulcers
High risk = active bleeding and visible vessel
medium risk = adherent clot
low risk = black spot or clean base
