Fiser Chapter 30. STOMACH Flashcards
Stomach transit time
3-4 hours
Where in stomach does peristalsis occur?
Just antrum (distal stomach)
What sympathetic fibers does gastroduodenal pain get sensed?
T5-10
Blood supply of stomach
Celiac: left gastric, CHA, splenic (L gastroepiploic and short gastrics are branches of splenic)
Greater curvature: R and L gastroepiploics, short gastrics. (R gastroepiploic is a branch of GDA)
Lesser curvature: R and L gastrics, R is branch off CHA
Stomach mucosa hitso
Simple columnar epithelium
Cardia glands versus fundus and body glands
Cardia: mucus secreting
Fundus and body glands:
Chief cells pepsinogen
Parietal cells H+ and IF
Chief cells
Pepsinogen (1st enzyme in proteolysis)
Parietal cells
H+ and IF
What causes H+ release from parietal cells?
Ach (vagus)
Gastrin (G cells in antrum)
Histamine (from mast cells)
Phosphorylase kinase and protein kinase A
Achetylcholine and gastrin MoA to increase H+ release
Activates phospholipase (PIP) –> DAG + IP3 to increase calcium -> calcium-calmodulin activated phosphorylase kinase -> increased H+ relaease
Histamine MoA to increase H+ release
Histamine activates adenylate cyclase -> cAMP -> activates protein kinase A -> increased H+ release
Phosphorylase kinase and proteine kinase A MoA to increase H+ release
They phosphorylate H+/K+ ATPase to increase H+ secretion and K+ absorption
How does omeprazole work?
Blocks H+/K+ ATPase in parietal cell membrane (the final pathway for H+ release)
What are inhibitors of parietal cells (which release H+)?
Somatotatin
Prostaglandins (PGE1)
Secretin
CCK
What does intrinsic factor do?
Binds B12, and then the complex is reabsorbed in the TI
Fundus and body glands versus antrum and pylorus glands
Fundus and body: chief cells and parietal cells with pepsinogen and H+ and IF release
Antrum and pylorus: G cells (release gastrin in antrum) and mucus and HCO3- secreting glands; and D cells (secrete somatostatin)
Why is an antrectomy helpful for ulcer disease?
G cells release gastrin (taken out)
What inhibits and stimulates G cells
G cells release gastrin
Inhibited by H+ in duodenum
Stimulated by amino acids and acetylcholine
What do D cells do?
Secrete somatostatin, which inhibits gastrin and H+ release
What do Brunner’s glands do?
Secrete alkaline mucus
in duodenum
Antral and duodenal acidification causes what?
Somatostatin, CCK, and secretin release
MCC rapid and delayed gastric emptying
Rapid: previous surgery, ulcers
Delayed: DM, opiates, anticholinergics, hypothyroid
Trichobezoars and phytobezoars
Trychobezoars: Hair, hard to pull out, EGD generally inadequate and likely need gastrostomy and removal
Phytobezoars: Fiber, often in diabetics with poor gastric emptying, tx with enzymes, EGD and diet changes
Dieulafoy’s ulcer
vascular malformation that can bleed
Menetrier’s disease
Mucous cell hyperplasia, increased rugal folds
Nausea without vomiting, severe pains
Gastric volvulus, usually organoaxial
Associated with type 2 (paraesophageal) hernia
Tx: Reduction and Nissen
Hematemesis following severe retching
Mallory-Weiss tear
EGD with hemo-clips; Tear is usually on lesser curvature near GEJ
Bleeding often stops spontaneously, if continued bleeding may need gastrostomy and vessel oversewing
Truncal and proximal vagotomies
Both increase liquid emptying by removing vagally mediated receptive relaxation, causing increased gastric pressure that accelerates fluid emptying
Truncal (at level of esophagus): decreases solid emptying; add pyloroplasty to increase solid emptying
Proximal (high selective, divides individual fibers, preserves “crow’s foot”): Normal emptying of solids
Truncal vagotomy effects
decreased solid emptying (and increased liquid emptying like all vagotomies); decreases acid output by 90%, increases gastrin and gastrin cell hyperplasia; decreases exocrine pancreas function and postprandial bile flow; increases gallbladder volumes, and decreases release of vagally mediated hormons; diarrhea in 40% (most common problem after vagotomy) due to sustained MMCs forcing bile acids into colon
MCC problem after vagotomy
Diarrhea
Risk factors for UGIB
Prior UGIB, PUD, NSAIDs, smoking, liver dz, esophageal varices, splenic vein thrombosis, sepsis, burns, trauma, severe vomiting
Dx/Tx of UGIB
EGD, can potentially treat with hemo-clips, epi injection, cautery
Slow bleeding and having trouble localizing source?
Tagged RBCscan
Biggest risk factor for rebleeding at time of EGD
- Spurting blood vessel (60% chance)
- Visible vessel (40%)
- Diffuse oozing (30%)
HIghest risk factor for mortality with non-varicealm UGIB
Continued or rebleeding
Patient with liver failure MCC UGIB
Esophageal varices (NOT an ulcer)
Tx EGD with bands or sclerotherapy; TIPS if that fails
Duodenal ulcers cause
Increased acid production and less defese
Most common peptic ulcer
Duodenal
More common in men
Most common place for duodenal ulcer
Anterior, first part of duodenum
Anterior versus posterior duodenal ulcers
Anterior: Perforate
Posterior: Bleed from GDA
Epigastric pain radiating to the back, abates with eating but recurs 30 min after
Duodenal ulcer
Dx and Tx of duodenal ulcer
EGD; PPI, triple therapy for H pylori
Tripe therapy
Amoxicillin, Metronidazole/tetracyclene, PPI (PAM or PAT)
Surgery for ulcer?
Rarely indicated since PPIs
- Perforated
- Protracted bleeding despite EGD therapy
- Obstruction
- Intractability despite medical therapy
- Inability to rule out cancer (ulcer remains despite treatment) requires resection
- If a patient has been on a a PPI, an acid-reducing surgical procedure is required in addition to surgery for any complications
PUD mgt
Rule out gastrinoma in patients with complicated ulcer disease (ZES - gastric acid hypersecretion, peptic ulcers, and gastrinoma)
Surgical options for PUD (acid-reducing surgery)
Proximal vagotomy: lowest rate of complications, no need for antral or pylorus procedure; 10-15% ulcer recurrence and 0.1% mortality
Truncal vagotomy and pyloroplasty: 5-10% ulcer recurrence, 1% mortality
Truncal vagotomy and antrectomy: 1-2% ulcer recurrence (lowest rate of recurrence) and 2% mortality
Reconstruction after antrectomy: Roux-en-Y gastrojejunostomy is best: less dumping syndrome and reflux gastritis compared to Billroth I (gastroduodenal anastomosis) and Billroth II (gastrojejunal anastomosis)
Acid-reducing surgery with lowest rate of PUD recurrence?
Truncal vagotomy and antrectomy
Reconstruction after antrectomy with lowest rate of dumping syndrome and reflux gastritis
Roux-en-Y gastrojejunostomy
Most frequent complication of duodenal ulcers
Bleeding
Usually minor but can be life threatening
If > 6 units of blood in 24hr or hypotensive despite transfusion = major bleeding
Tx of duodenal ulcer bleeding
EGD 1st: hemoclips, cauterize, epi injection
- Surgery: duodenotomy and GDA ligation. Avoid hitting CBD (posterior). If patient has been on a PPI, need acid-reducing surgery too
Risk of duodenotomy and GDA ligation for duodenal ulcer bleed?
Hitting CBd (posterior)
PUD obstruction tx
PPI and serial dilation initially
Surgical options: antrectomy and truncal vagotomy (best); include ulcer in resection if located proximal to ampulla of Vater; need to bx area of resection to rule out Ca
Sudden sharp epigastric pain, generalized peritonitis, free air
PUD perforation: 80% will have free air
Pain can radiate to pericolic gutters with dependent drainage of gastric content
Tx of perforated PUD
Graham patch (place omentum over perforation)
Also need acite-reducing surgery if patient has been on a PPI
PUD intractability (no relief after >3 months of escalating PPI dose) tx
Based in EGD findings, not symptoms
Tx: Acid-reducing surgery
Gastric ulcers characteristics and risk factors
Older men, slow healing, 80% on lesser curvature
RF: male, tobacco, EtOH, NSAIDs, H pylori, uremia, stress (burns, sepsis, trauma), steroids, chemotx
GIB from stomach versus duodenal ulcer
Stomach hemorrhage associated with higher mortality
Epigastric pain radiating to back, relieved with eating but recurs 30 min later, melena or guaiac-positive stools
Stomach ulcer bleed?
Best test of H pylori
Histiologic examination of biopsies from antrum
Other: CLO test (rapid urease test): detects urease released from H pylori
Stomach ulcer types
I: lesser curve LOW along body of stomach, due to decreased mucosal protection
II: 2 ulcers (lesser curve and duodenal); similar to duodenal ulcer with high acid secretion
III: Pre-pyloric; similar to duodenal with high acid secretion
IV: lesser curve HIGH along cardia; decreased mucosal protection
V: ulcer associated with NSAIDs
Surgical indications for stomach ulcer
Perforation
Bleeding not controlled with EGD
Obstruction
Cannot exclude malignance
Intractability (> 3 months without relief; based on mucosal findings)
Surgical options for stomach ulcer disease
Truncal vagotomy and antrectomy best for complications; try to include the ulcer with resection (extended antrectomy); need separate ulcer excision if that is not possible (gastric ulcers are resected at time of surgery due to high risk of gastric Ca); omental patch and ligation of bleeding vessels are POOR OPTIONS for gastric ulcers due to high recurrence of symptoms and risk of gastric Ca in ulcer
Fundus ulcer 3-10 days after an event
Stress gastritis; tx PPI; EGD with cautery of specific bleeding point may be effective
Chronic gastritis types A and B
A: Fundus, associated with pernicious anemia; autoimnune disease; tx PPI
B: Antral, associated with H pylori; tx PPI
Pain UNRELIEVED by eating; weight loss
Gastric cancer
40% in antrum
Accounts for 50% of cancer-related deaths in Japan
Dx of gastric ca
EGD
Risk factors for gastric ca
Adenomatous polyps, tobacco, previous gastric operations, intestinal metaplasia, atrophic gastritis, pernicious anemia, type A blood, nitrosamines
Gastric adenomatous polyps and cancer risk?
15% cancer risk, tx with endoscopic resection
Krukenberg tumor
Gastric mets to ovaries
Virchow’s nodes
gastric mets to supraclavicular node
Intestinal type gastric Ca risk factors and tx
Increased in high risk populations, older men; Japan, rare in US
Tx: Try to perform subtotal gastrectomy (need 10 cm margins)
Diffuse gastric ca (linitis plastica)
In low-risk populations, woman; most common type in US
Diffuse lymphatic invascion; NO glands
Less favorable prognosis than intestinal type gastric ca (overall 5 YS of 25%)
Total gastrectomy because of diffuse nature of linitis plastica
Gastric ca chemotx
5-FU, doxorubicin, mitomycin C
Poor response
Contraindication to resection in gastric ca
Metastatic disease outside area of resection (unless it’s for palliation)
Palliation of obstructed gastric Ca
Stent proximal lesions
Gastrojejunostomy for distal lesions
Palliative of bleeding or painful gastric Ca
XRT
Palliative gastrectomy?
If other options for obstruction or bleeding fail
Most common benign gastric neoplasm
GISTS (though can be malignant)
GIST symptoms
usually asymptomatic, but obstruction and bleeding can occur
GISTS on US
Hypoechoid with smooth edges
GIST dx
Biopsy: C-KIT positive
GIST malignant characteristics
> 5 cm or > 5 mitoses/50 HPF
If malignant, chemo with imatinib (gleevec; tyrosine kinase inhibitor)
Treatment of GIST
Resect with 1cm margins
MALT lymphoma
Related to H pylori
Usually regresses after H pylori tx
Stomach most common location
Tx: triple therapy abx and surveillance; if MALT does not regress, need XRT
What if MALT lymphoma doesn’t regress after H pylori tx?
XRT
Most common location for extranodal lymphoma
Stomach; usually NHL (B cell); have ulcer symptoms
Dx of gastric lymphoma
EGD with biopsy
Tx of gastric lymphoma
Chemotx and XRT
Surgery for complications; possibly indicated only for stage I disease (tumor confined to stomach mucosa) and then only partial resection indicated
Gastric lymphoma prognosis
5YS of >50%
Bariatric surgery indications
- BMI>40 or BMI>35 with coexisting comorbidities
Failure of nonsurgical methods
Psychological stability
Absence of drug and alcohol abuse
Obesity worse prognoses
Central obesity
Bariatric operative mortality
~1%
What conditions get better after bariatric surgery?
DM
HLD
OSA
HTN
Urinary incontinence
GERD
VSU
Pseudotumor cerebri
Joint pain
Migraines
Depression
PCOS
NASH
Gastric bypass
Better weight loss than just banding
Risk of marginal ulcers, leak, necrosis, B12 deficiency (intrinsic factor needs acidic environment to bind B12), IDA (bypasses duodenum where Fe absorbed), gallstones from rapid weight loss
Perform chole during operation if stones present
UGI on POD2
10% failure rate due to high carb snacking
Gastric bypass leaks
MCC is ischemia
Increased RR, tachy, abd pain, fever, elevated WBCs after bypass
Leak; MCC is ischemia; dx with UGI; tx with re-op if early not-contained leak; percutaneous drain and abx if weeks out from surgery and likely contained
Marginal ulcer risk after RYGB
10%; tx with PP
Stenosis after RYGB
Usually responds to serial dilation
Hiccoughs and large stomach bubble after RYGB
Dilation of excluded stomach; Dx with AXR; Tx with G-tube
SBO after RYGB
Surgical emergency due to high risk of small bowel herniation, strangulation, infarction, and necrosis
Surgical exploration
Jejunoileal bypass
No longer done; associated with liver cirrhosis, kdieny stones, osteoporosis
Need to correct these patients and perform RYGB if ileojejunal bypasses are encountered
Postgastrectomy complications
Dumping syndrome
Alkaline reflux gastritis
Chronic gastric atony
Small gastric remnant
Blind-loop syndrome
Afferent-loop syndrome
Efferent-loop syndrome
Post-vagotomy diarrhea
Duodenal stump blow-out
PEG complications
Hypotension, diarrhea, and dizziness after gastrectomy
Dumping syndrome, hyperosomotic load causing fluid shift into bowel
Occurs from rapid entering of carbs into small bowel
Can occur after gastrectomy or after vagotomy and pyloroplasty
90% resolve with medical therapy
Hypglycemia after gastrectomy
Dumping syndrome, 2nd phase (rare); reactive increase in insulin and decrease in glucose
Tx of dumping syndrome
Small, low-fat, low-carb, high protein meals; no liquids with meals; no lying down after meals; octreotide
Dumping syndrome surgery (rarely needed)
Conversion of billroth I or II to RYGJ
Jejunal pouch or reversed jejunal loop to increase gastric reservoir or increase emptying time
Postprandial epigastric pain associated with N/V; pain not relieved with vomiting; after gastrectomy
Alkaline reflux gastritis
Ex: e/o bile reflux into stomach and histologic evidence of gastritis
Tx: PPI, cholestyramine, metoclopramide
Surgery: conversion of billroth I or II to RYGJ with afferent limb 60cm distal to gastroJ
SDelayedNausea, vomiting, pain, eraly satiety ater gastrectomy
Chronic gastric atony from delayed gastric emptying
Dx: Gastric emptying study
Tx: Metoclopramide, prokinetics
Surgery: Near-total gastrectomy with Roux-en-Y
Early satiety after gastrectomy
Small gastric remnant, actually want this for gastric bypass patients
Dx: EGD
Tx: Small meals
Surgery: jejunal pouch construction
Pain, steatorrhea, B12 deficiency, and malabsorption after gastrectomy
Blind-loop syndrome after Billroth II or Roux-en-Y
Caused by poor motility and bacterial overgrowth (E coli, GNRs) from stasis in afferent limb
Dx: EGD of afferent limb with aspirate and culture for organisms
Tx: Tetracycline and flagyl, metoclopramide to improve motility
Surgery: Re-anastomosis with shorter (40cm) afferent limb
RUQ pain, steatorrhea, nonbilious vomiting, pain relieved with bilious emesis after gastrectomy
Afferent-loop obstruction after billroth II or Roux-en-Y
Caused by mechanical obstruction of afferent limb (long afferent limb is a risk factor)
Dx: CT scan
Tx: Balloon dilation may be possible
Surgery: Re-anastomosis with shorter (40cm) afferent limb to relieve obstruction
Nausea, vomiting, abdominal pain after gastrectomy
Efferent-loop obstruction
Dx: UGI, EGD
Tx: Balloon dilation
Surgery: find site of obstruction and relieve it
Diarrhea after vagotomy
Secondary to non-conjugated bile salts in the colon (osmotic diarrhea), with sustained postprandial organized MMCs
Tx: cholestyramine, octreotide
Surgery: Reversed interposition jejunal graft
Duodenal stump blow out tx
Lateral duodenostomy tube and drains
PEG complications
Insertion into liver or colon
