GI Tract Flashcards
- What is secretin normally supposed to do to gastrin?
- Describe the secretin stim test
- What’s a positive test?
- Secretin normally inhibits gastrin
- 1) 1 week before the test, change the PPI to an H2 blocker
- 2) measure fasting serum gastrin
- 3) administer 0.4mcg/kg of secretin
- 4) measure serum gastrin @ 2, 5, 10 min
- Positive test: increase in gastrin >120pg/mL over basal fasting level
- What is a normal LES pressure high?
- What is normal LES pressure on relaxation?
- What pathology causes super high amplitude >200 on manometry?
- Achalasia has high or low amplitude?
- High > 24
- Relaxed > 5
- Super high amplitude >200: nutcracker esophagus. High amplitude >80: diffuse esophageal spasm
- Achalasia has low amplitude
Esophagus.
- What are primary, secondary, tertiary contractions?
- Tertiary contraction is pathognimonic for what?
- Primary: peristaltic
- Secondary: localized contraction without proximal contraction to clear things from the esophagus. Normal
- Tertiary: random contraction. Goes from bottom to top.
- Tertiary is pathognomonic for abnormal Diffuse esophageal spasm
- Low grade Barrett on initial EGD. When do you repeat? Follow-up?
- High grade Barrett on initial EGD. When do you repeat? Follow-up?
- Low grade: rpt EGD in 6mo then yearly until no dysplasia x2
- High grade: rpt EGD in 3mo then q3 mo. EMR
Thoracic duct leak.
- What’s high output vs low output? Treatment?
*
- High output > 500cc. OR. ligate it on the right side just above the diaphragm. Low output < 500cc. Npo, tpn, octreotide
- Most common site of esophageal perforation during endoscopy?
- Second most common?
- At the level of cricopharyngeus because it is a narrow opening into the esophagus
- Proximal to the lower esophageal sphincter
- What does the artery of Hyrtl supply?
- Where does it come from?
- It’s an aberrant left hepatic artery running alongside the hepatic branch of the vagus nerve. Provides the majority of arterial inflow to the left lateral segment of the liver
- Aberrant left: from left gastric Aberrant right: from SMA They’re supposed to branch off from proper hepatic.
Leiomyomas originate from what layer of the esophagus? Should all esophageal cysts be removed?
- Muscularis propria
- All esophageal cysts should be removed due to the risk of infection
What is the Siewert classification and how are they treated differently?
Anatomical classification for GE junction tumors
- Siewert I: within +1-5 cm above the GEJ - treat like esoph tumor. Esophagogastrectomy
- Siewert II: located within the cardia (between +1 and -2). Pretty much right at the GEJ - treat like esoph tumor. Eaophagogastrectomy
- Siewert III: subcardial tumor (between -2 and -5) - Treat like gastric tumor
Blood supply for:
- Cervical esophagus
- Thoracic aorta
- Abdominal aorta
- Cervical esophagus: inferior thyroid artery
- Thoracic aorta: bronchial arteries, branches directly from the aorta
- Abdominal aorta: left gastric and inferior phrenic
What is the Los Angeles classification?
Classification for esophagitis
- Class A: one or more mucosal break less than 5mm in length, not extending between the tops of two mucosal folds
- Class B: one or more mucosal breaks more than 5mm, not extending between two mucosal folds
- Class C: one or more mucosal break continuous between the tops of two or more mucosal folds but <75% circumference
- Class D: two mucosal breaks that involve at least 75% of the esophageal circumference
- Parietal cells produce what two things?
- Chief cells produce what?
- B12 gets absorbed where?
- Antrum makes what two things?
- Parietal: acid + intrinsic factor
- Chief cells: pepsin
- B12 in terminal ileum
- Antrum: mucous. also, G cells make gastrin
What are the gastric phases of acid stimulation?
- Cephalic phase: vagally mediated. Acetylcholine on parietal cells -> release acid
- Gastric phase: distention of stomach with food -> acid secretion
- Intestinal phase: release of gastrin from duodenal G cells
Gastric ulcers types.
Which ones are associated with increased acid production? Surgical options for each type?
- II and III - acid production
- Type V: NSAIDs. Diffuse ulcers
- I: vagotomy and antrectomy first. Billroth 2 or RNY acceptable
- II and III: truncal or selective vagotomy + Antrectomy including the ulcer, try Billroth 1 first
- IV: at GE junction. Goal is to preserve maximal healthy stomach. Pauchet (B1 or B2) and Csendes (RNY) procedure
- Truncal vagotomy must be accompanied with a drainage procedure
H. Pylori tests
- which one is used to test eradication? How long after treatment?
- culture vs. histology. Which one has 100% specificity?
- H. Pylori treatment
- carbon labeled urea breath test. >95% sensitive and specific. 4 weeks after treatment
- culture has 100% specificty
- treatment: PPI + Clarithromycin + Amoxicillin/flagyl
Dumping syndrome
- you get this after what?
- early vs. late. Timeframe?
- Treatment?
- after B1 or B2
- Early: < half an hr. hyperosmolar food bolus Late: 1-2hrs postprandial. rapid systemic insulin response
- Treatment: dry diet, separating solids from liquids. Octreotide may or may not help. Remedial surgery: convert to RNYGB
Afferent limb syndrome
- you get this after what?
- what is a major risk with this? treatment?
- What is Efferent loop syndrome?
- after Billroth II when you have a duodenal limb obstruction. May be due to excessive length. Then you get all the duodenal juice build up and build up and build up so you have pain. When it’s finally released, you get explosive bilious emesis and you get relief.
- major risk is the duodenal stump blowout. treatment: RNYGB or Braun enteroenterostomy -> basically make a side to side anastomosis between the duodenal afferent limb and the efferent SB
- Efferent loop: gastric outlet obstruction caused by kinking or herniation. More than half occurs in first post-op month.
Bile reflux
- you get this after what?
- in terms of symptoms how to distinguish between this and afferent limb syndrome?
- treatment?
- after B1 or B2 (when the pylorus is removed) or vagotomy and pyloroplasty
- bile reflux doesn’t have relief in symptoms after bilious vomiting because this is a gastritis. Afferent limb syndrome you get symptom relief.
- treatment: RNYGB with an intestinal limb of 50-60cm to prevent reflux of intestinal contents
Most common postgastrectomy syndrome requiring revision?
Bile alkaline reflux gastritis. Convert to RNY
Gastric stasis / Roux stasis
- what is it?
- treatment?
- difficulty in gastric emptying. Epigastric pain, vomiting, wt loss. Egd will show dilated remnant stomach or roux limb
- treatment: ngt, reglan or IV erythromycin. Surgery is rarely helpful. Reattempt rny
- What is a normal gastrin level?
- Two things you need to diagnose zollinger Ellison syndrome
- how long should they be off of PPI?
- describe the secretin stimulation test
- usual location of gastrinoma?
- pancreatic neuroendocrine tumor is primarily in the tail of the pancreas
- primarily in the head
- Evenly distributed?
- how do you rule out MEN 1?
- what % of MEN 1 pts have gastrinoma?
- Normal gastrin lvl < 110 oh/mL
- 1) elevated gastrin lvl 2) gastric aspirate pH < 2
- 72hrs before the test
- secretin 0.4 ug/kg given. Gastrin levels at 0, 2, 5, 10, 20 min. Increase in gastrin lvl > 200 pg/mL
- gastrinoma triangle (including duodenum) and throughout the pancreas
- tail: VIPoma and glucagonoma
- head: somatostatinoma
- evenly distributed: insulinoma +/- glucagonoma
- pituitary: prolactin lvl Parathyroid: PTH - 25% of MEN 1 have ZES
- up to 40% of MEN1 pts have gastrinoma. 2nd most common (parathyroid is #1)
Gastric adenocarcinoma.
- Margin and lymph nodes?
- LND. what’s d0, d1, d2? D3? D4?
- 5cm margin, 16 nodes
- D0: palliative
- D1: peri-gastric -> nodes along greater and lesser curvature
- D2: D1 + nodes along celiac axis, common hepatic artery, left gastric, splenic artery
- D3: D2 + hepatoduodenal ligament, root of the mesentery, retropancreatic
- D4: D3 + paraaortic, paracolic
- What tumor derives from interstitial cell of Cajal?
- Locations most common to least common?
CaJal: JIST.
gastric pacemaker cells Stomach (50-70%) > small bowel (25-35%) > colorectal (5-10%) > mesentery/omentum (7%) > esophagus (<5%) > duodenum
How is malignancy defined in GIST?
- < 2cm and < 5 mitoses per HPF -> benign
- >10cm and > 5 mitoses -> malignant
What do each of these hormones do and what does RNYGB do to their levels?
- Ghrelin:
- PYY:
- GLP-1:
- decreases Ghrelin: Decreased hunger
- increases PYY: delays gastric empting, increases satiety
- increases GLP-1: increase satiety, increases insulin production and sensitivity
tangent. GLP-2 improves nutrient absorption and nutritional status in short-bowel patients with no colon. this is gattex
% excess weight loss for
- RNYGB
- lap bands
- sleeve
- RNYGB: 70%
- lap bands: 40%
- sleeve: 60%
Most common type of gastric lymphomas?
What is the CHOP therapy?
Large B cell type (55%) MALToma (40%)
Cyclophosphamide
Hydroxydaunomycin (doxorubicin)
Oncovin (vincristine)
Prednisone
Appropriate length for
- afferent limb for B2 recon?
- for duodenal switch, where is the TI divided?
- B2 afferent limb: 20cm. As short as possible to prevent afferent loop syndrome. Longer -> higher risk
- divide the TI 250cm from the ileocecal valve and divide the duodenum at D1. make a duodenoileostomy. Make an ileoileostomy at 100cm from the ileocecal valve
- Most common nutrition abnormality after RNYGB?
- Nutrition deficiency in vomiting RNYGB?
iron deficiency anemia > hypocalcemia/megaloblastic anemia
Thiamine in vomiting rnygb
What are the three types of gastric Carcinoid tumors?
Higher the type: more aggressive
Type I: chronic atrophic gastritis, small (<1cm) and often multiple and polypoid. Slow growing, only rarely metastasize
Type II: associated with zollinger Ellison syndrome and MEN I. slow growing but more likely to met
Type III: most aggressive. Often large (>1cm), not associated with hypergastrinemia. Frequently met to nodes and liver