Chapter 30 - Stomach+ Flashcards
What is the transit time of the stomach?
3-4h
What level of afferent sympathetic fibers sense gastroduodenal pain?
T5-10
What type of mucosa does the stomach have?
Simple columnar epithelium
What do the cardia glands secrete?
Mucus
What do Chief cells secrete? Location?
Pepsinogen; fundus and body
What do Parietal cells secrete? Location?
H+ and intrisic factor; fundus and body
What stimulates HCl release?
Gastrin, ACh, histamine
What mediator does ACh and gastrin work on to inc. HCl?
Phospholipase → PIP → DAG + IP3 → inc. Ca, activates phosphorylase kinase
Histamine acts on what mediator to inc. HCl?
Adenylate cyclase → cAMP → protein kinase A
What are inhibitors of parietal cells?
Somatostatin, PGE1, secretin, CCK
What does intrinsic factor do?
Binds B12 and the complex is reabsorbed in the terminal ileum
G cells release what? Location?
Gastrin; Antrum and pylorus
G cells inhibited by? Stimulated by?
Inhibited by H+ in duodenum; stimulated by amino acids, ACh
D cell secrete what? Location?
Somatostatin; antrum and pylorus
Response to somatostatin in the stomach?
Inhibit gastrin and acid release
Brunner’s glands secrete what? Location?
Pepsinogen and alkaline mucus; duodenum
DDx for elevated acid and gastrin?
ZES, antral cell hyperplasia, retained antrum, renal failure, gastric outlet obstruction, short bowel syndrome
DDx for elevated gastrin and normal/decreased acid?
Pernicious anemia, chronic gastritis, gastric ca, postvagotomy, medical acid suppression
DDx for rapid gastric emptying?
1 previous surgery, ZES, ulcers
DDx for delayed gastric emptying?
Opiates, anticholinergics, myxedema, hyperglycemia, diabetes
Components of Billroth I?
Antrectomy with gastroduodenal anastamosis
Components of Billroth II?
Antrectomy with gastrojejunal anastamosis
What is a trichobezoar? Treatment?
Hair, hard to pull out; EGD inadequate, likely need gastrostomy and removal
What is a phytobezoar? Treatment?
Fiber, often in diabetics with poor gastric emptying; enzymes, EGD, diet changes
What is Dieulafoy’s ulcer?
Vascular malformation
What is Menetrier’s disease?
Mucous cell hyperplasia, increased rugal folds
Gastric volvulus is associated with what condition?
Type II hiatal hernia
Symptoms of gastric volvulus? Treatment?
Nausea without vomiting, severe pain; usually organoaxial volvulus; reduction and Nissen
What is a Mallory-Weiss tear? Presentation?
Secondary to forceful vomiting; hematemesis following severe retching
Diagnosis of Mallory-Weiss? Treatment?
EGD; tear usually near lesser curve of stomach, PPE, transfusion; if continued bleeding, may need gastrostomy and oversewing of the vessel
Effects of all forms of vagal denervation?
Increased liquid emptying; vagally mediated receptive relaxation is removed; results in increased gastric pressure that accelerates liquid emptying
Where is the denervation in truncal vagotomy? Effect on solid emptying?
Divides vagal trunks at level of esophagus; decreased emptying of solids
Where is the level of denervation in selective vagotomy? Effect on solid emptying?
Divides nerves of Latarjet; decreased emptying of solids
Where is the level of denervation in highly-selective vagotomy? Effect on solid emptying?
Divides individual fibers, preserves “crow’s foot”; normal emptying of solids
What are the gastric effects of truncal vagotomy?
Dec. acid output by 90%, increased gastrin, gastrin cell hyperplasia
What are the nongastric effects of truncal vagotomy?
Decreased exocrine pancreas function, decreased postprandial bile flow, increased gallbladder volumes, decreased release of vagally mediated hormones
What is the most common problem following vagotomy?
Diarrhea (30-50%), caused by sustained MMCs forcing bile acids into colon
Risk factors for upper GI bleed?
Previous UGI bleed, PUD, NSAIDs, smoking, liver disease, esophageal varices, splenic v thrombosis, sepsis, burn injuries, trauma, severe vomiting
Risk factors for rebleeding at time of EGD for UGIB?
1 spurting blood vessel (60%), #2 visible blood vessel (40%), #3 diffuse oozing (30%)
Likely source of UGI bleed in liver failure patient? Treatment?
Bleeding from esophageal varices. Do EGD with sclerotherapy, TIPS, not OR
What is the cause of duodenal ulcers?
Increased acid production, decreased host defense
Most common location of duodenal ulcers?
1st part of duodenum, usually anterior
Most common presentation of anterior duodenal ulcers? Posterior?
Anterior: perforation, posterior: bleed
Treatment of duodenal ulcers?
H2 blockers, PPI, triple therapy for pts with H. pylori
Surgical indications for duodenal ulcer?
Perforation, protracted bleeding despite EGD therapy, obstruction, intractability despite medical therapy, inability to r/o cancer
Surgical options for duodenal ulcers?
Truncal vagotomy and pyloroplasty, truncal vagotomy and antrectomy with BI or BII. Highly selective vagotomy.
Ulcer surgery with lowest rate of recurrence?
Truncal vagotomy and antrectomy with BI/BII
Ulcer surgery with lowest rate of complications?
Proximal or highly selective vagotomy
What is the most frequent complication of duodenal ulcers?
Bleeding
What is the initial treatment of choice for obstruction secondary to duodenal ulcers?
Serial dilation
Surgical options for duodenal ulcer causing obstruction?
Near ampulla: gastroj (BII, bypasses obstruction), antrectomy, truncal vagotomy; proximal to ampulla: antrectomy with ulcer excision, BII, truncal vagotomy
% of patients with perforation that will have free air?
80%
Treatment of perforation in elderly, high risk patients?
Possibility that high risk patients can be safely observed with UGI to make sure perforation has sealed
Surgical option for perforated duodenal ulcer?
Graham patch and highly selective vagotomy (for pts on PPI); truncal vagotomy and pyloroplsty (include ulcer in pyloroplasty); truncal vagotomy and antrectomy with BI or BII (need to include ulcer)
What defines intractability with duodenal ulcers?
> 3mo without relief on PPI or recurrence <1y after medical therapy; based on EGD findings, not symptoms
Risk factors for gastric ulcers?
Male, tobacco, ETOH, NSAIDs, H. pylori, uremia, stress, steroids, chemo
Most common cause of gastric ulcers?
H. Pylori.
Most (type I/IV) have normal acid secretion, due to abnormal mucosal defense.
% of gastric ulcers on lesser curve of stomach?
70-80%
Where do biopsies for H. pylori need to be taken from?
Antrum
What type of blood is associated with type I ulcers?
Type A
What type of blood is associated with type II-IV ulcers?
Type O
Indications for surgery with gastric ulcers?
Perforation, bleeding, obstruction, cannot exclude malignancy, intractability
Location of type I gastric ulcer? Cause?
Lesser curvature; due to decreased mucosal protection
Treatment of type I gastric ulcer?
Distal gastrectomy including ulcer with BI/BII
Location of type II gastric ulcer? Cause?
Lesser curve and duodenal; high acid secretion
Treatment of type II gastric ulcer?
Distal gastrectomy with BI/BII and truncal vagotomy
Location of type III gastric ulcer? Cause?
Prepyloric; similar to duodenal, high acid secretion
Treatment for type III gastric ulcer?
Distal gastrectomy with BI/BII and truncal vagotomy
Location of type IV? Cause?
Lesser curve high along cardia of stomach; decreased mucosal protection
Treatment for type IV gastric ulcer?
Ulcer excision +/- vagotomy
Location of type V gastric ulcer? Cause?
Anywhere; NSAID-related
How many days after the event does stress gastritis occur?
3-5d
Where is type A chronic gastritis located? Associated with what conditions?
Fundus; pernicious anemia, autoimmune disease
Location of type B chronic gastritis? Associated conditions?
Antrum; H. pylori
Symptoms associated with gastric cancer?
Pain unrelieved by eating, weight loss
Where are the majority of gastric cancers located?
Antrum (40%)
Risk factors for gastric cancer?
Adenomatous polyps, tobacco, previous gastric operations, intestinal metaplasia, atrophic gastritis, pernicious anemia, type A blood, nitrosamines
Adenomatous polyps carry what % cancer risk? Treatment?
10-20% risk of cancer; endoscopic resection
What is Krukenberg tumor?
Metastases to ovaries
What is Virchow’s node?
Mets to supraclavicular node
What is intestinal gastric cancer associated with?
High risk populations, older men (rare in US); associated with chronic atrophy, dysplasia, blood invasion, glands on histology
Characteristics of diffuse gastric cancer (linitis plastica)?
Low risk populations, women, lymphatic invasion, NO glands
Surgical treatment of linitis plastica?
Total gastrectomy plus chemo
Options for palliation for gastric cancer causing obstruction? Bleeding or pain?
Obstruction: stenting; bleeding/pain: XRT or palliative gastrectomy
What is the most common benign gastric neoplasm?
Gastric leiomyomas (GIST)
US findings of GIST?
Hypoechoic, smooth edges