Ischemic and Vascular GI Flashcards
What artery supplies the small intestines?
Superior Mesenteric Artery
Atrial fibrillation often leads to what?
Development of thrombosis in the atrium which can travel to the SMA and lead to ischemic bowel
Connection between the Celiac artery and the SMA?
Pancrealicoduodenal arcade
Connection between the SMA and IMA
Arc of Riolan
Vasodilators in the GI?
Gastrin, CCK, Secretin
All released during feeding
Vasoconstrictors in teh GI
Catecholamines, Ang II, Vasopressin
How is the GI system affected by hypovolemia
Massive hemorrhage–> reduced blood volume–> decreased venous return to the heart –> Hypotension and low Cardiac Output—> Increased peripheral resistance –> Redistribution of blood flow to vital organs (heart, brain, lungs, kidneys) –> decreased splanchnic blood flow
Which part of the bowel will be injured first in response to low blood flow?
Tops of Villi, the necrosis proceeds downward from there.
Patients will have different symptoms depending on what level the infarction has reached
Know the different levels of infarction
Mucosal, Mural , Transmural
Ischemic colitis presentation
Bleeding but pain level may be low
Diarrhea may be present
In Ischemic Colitis, what area of the small bowel is most sensitive to ulcer development? KNOW
Splenic Flexure or between the sigmoid colon and rectum…Apparently areas where we have connections between the two big vessels
Acute Mesenteric Ischemia is what
First off, its a medical emergency because delaying treatment can lead to bowel necrosis
Clinical presentation of Acute Mesenteric Ischemia is what
Early abdominal pain without Ileus (obstruction)
How do you diagnose Ischemic colitis?
CT and colonscopy
How do you diagnose acute mesenteric ischemia
CT. NO ENDOSCOPY
Angiography is gold standard….injecting contrast in arteries and look on CT
Portal vein gas?
Usually associated with acute mesenteric ischemia…not a good sign because it usually represents complete necrosis of teh bowel wall
Tx of acute mesenteric ischemia
vasodilators via angiography. Surgery is the only possible cure but its very risky and outcome is poor