Path Ischemic and Vascular GI disorders Flashcards
SMA branches
Right & left colic
jejunal branches
ileal branches
ileocolic loop
how does vascular resistance increase in intramural vasculature?
precapillary sphincters
3 hormones that cause vasoconstrictions in GI & their sources
catecholamines, adrenal medulla
angiotensin II, Renal JGA
vasopressin Post. pituitary
3 hormones that cause vasorelaxation in GI & their sources
gastrin, G cells
CCK, I cells
Secretin, S cells
main intra-celular system responsible for vasodilation
NO
main mechanism for vasoconstriction
IP3 (phosphoinositol-inosotol triphosphate)
ileus-sepsis
infarction
edema of lamina propria
pain w/o ileus
necrosis of villi - presentation
bleeding
3 categories of vascular disorders
mucosal, mural, transmural
ischemic colitis
presentation, dx, tx, outcome, comments
Presentation: hematochezia, diarrhea, abdom pain (mild 2/10), abd tenderness
Dx: abdominal CT, colonoscopy
Tx: conservative
Outcome: benign
Comments: Look for splenic flexure in watershed region
ileus: early or late sign?
late
Acute mesenteric ischemia
presentation, dx, tx, outcome, comments
Presentation: early abdominal pain w/o ileus. peritoneal pain only in advanced disease. +/- hematochezia
Dx: abdominal CT, XR, MRI. Angiography (high Sn/Sp) Look for “Thumb indention” in XR
Tx: ICU mgmt, vasodilators, surg
Outcome: badness
Comments: medical/surgical emergency -> necrosis.
Bowel infarct
presentation, dx, tx, outcome, comments
Presentation: sequelae of ischemia
Dx: “dusky bowel” in surg.
Tx: resect
Outcome: bad. resect.
Comments: “dusky bowel” look for curtain of hemorrhage indicating edge of necrosis/indicating depth.
Chronic ischemia
presentation, dx, tx, outcome, comments
Presentation: abdominal pain after eating
Dx: CT, MRI, US, angiography
Tx: angioplasty/stent/surg
Outcome:
Comments: at least 2/3 splanchnic arteries usually have significant occlusive disease.
venous mesenteric ischemia
presentation, dx, tx, outcome, comments
Presentation: in several days
Dx: CT, MRI, angiography
Tx: stent/surg/anticoag meds
Outcome:
Comments: associated w/hypercoagulability status
GI bleeding (presentation types)
melena - above ligament of Treitz
hematochezia - below ligament of Treitz
Ischemic colitis vs acute mesenteric ischemia
Ischemic Colitis: <60 yo, acute cases rare, mild pain, tenderness, bleeding, colonoscopy.
Acute mesenteric ischemia: any age, acute cause, severe pain, tenderness not prominent early, bleeding uncommon, angiography
Acute upper GI bleeding
presentation, dx, tx, outcome, comments
Presentation: men/elderly,
Dx: scope
Tx: surg/scope to close
Outcome: 80% self-limiting. mortality dependent on cause. recurrence = 30% mortality risk.
Comments: most frequent GI bleed.
obscure overt bleeding
obscure occult bleeding
you see blood, but not source
you see no blood or source
low risk of rebleeding in ulcer on scope?
highest risk for rebleeding?
white base, away from large vessels lowest risk.
active bleeding highest risk. proximity to duodenal bulb bad b/c big vessels.
Esophageal Varices
presentation, dx, tx, outcome, comments
Presentation:
Dx:
Tx: banding
Outcome: mortality 30-50%. pressure, size, color are predictive.
Comments:
Mallory-Weiss tear
presentation, dx, tx, outcome, comments
Presentation: longitudinal tear at hiatal area
Dx: scope
Tx: hemodynamic stabilization and endoscopic treatment. Angiography or surgery are rarely required.
Outcome: resolves w/conservative mgmt. Bleeding stops spontaneously in 80-90%. 5% rebleed.
Comments: from retching.
acute lower GI bleed
outcome
acute causes
chronic causes
Outcome: mortality 3.6%
Chronic causes: hemorrhoids & neoplasia
Acute causes: Diverticulosis and angiodysplasia
Angiodysplasia
presentation, comments
Presentation: older, chronic renal failure, Ssler-Weber-Rendu, prior radiation therapy, watermelon stomach (GAVE) slow intermittent blood loss.
Comments:
primarily at cecum (37%)) & right colon (17%), sigmoid (18%)
appearance of esophageal ulcers: GERD pill-induced CMV herpes
GERD watermelon? red
pill-induced - spot anywhere
CMV - anywhere, large, same color as mucosa, ischemic
herpes - at GE junction
Define:
Osler-Weber-Rendu
Watermelon Stomach (GAVE)
autosomal dominant skin & mucosal disorder
gastric angiovascular ectasia/watermelon stomach