Ischemic Bowel Disease

Question 1

what are the 4 major causes of acute mesenteric ischemia?

Answer 1

SMA embolism, SMA thrombosis, nonocclusive ischemia, and mesenteric venous thrombosis

Question 2

Why is superior mesenteric artery commonly involved with ischemic bowel disease?

Answer 2

due to it’s angle off of the aorta

Question 3

Causes mesenteric (arterial) vasoconstriction and venous dilation. Reduces portal venous pressure in patients bleeding from portal hypertension

Answer 3

vasopressin

Question 4

Hallmark of mesenteric arterial embolism

Answer 4

Severe cramping abdominal pain, out of proportion of physical findings, poorly localized

Question 5

Where are the common origins of mesenteric arterial emboli?

Answer 5

Thrombus from L atrium, L ventricle or cardiac valves

Question 6

Is coagualopathy associated with mesenteric arterial thrombosis?

Answer 6

no, this is more common a culprit in venous thrombosis patients

Question 7

What is the usual site of blockage for mesenteric arterial thrombosis?

Answer 7

SMA or celiac axis

Question 8

Affects younger popn (48-60). Thrombosis of superior mesenteric vein or intestinal strangulation from hernia or volvulus

Answer 8

mesenteric venous thrombosis

Question 9

What is different about the presentation of mesenteric venous thrombois compared to mesenteric arterial thrombosis?

Answer 9

longer symptom presentation-Pain diffuse and nonspecific initially, but later becomes constant

Question 10

Major risk factor for mesenteric venous thrombosis

Answer 10

hypercoagulable states (75%)

Question 11

What is the etiology of nonocclusive mesenteric ischemia?

Answer 11

Result of splanchnic hypoperfusion & vasoconstriction

Question 12

What is a major risk factor for nonocclusive mesenteric ischemia?

Answer 12

atherosclerotic disease

Question 13

Mortality associated with nonocclusive mesenteric ischemia

Answer 13

70%

Question 14

Any patient with abdominal pain and metabolic acidosis has what condition until proven otherwise?

Answer 14

intestinal ischemia

Question 15

Critically important lab for intestinal ischemia

Answer 15

elevated serum lactate

Question 16

What might be present on a plain film in patients with mesenteric ischemia?

Answer 16

air fluid levels, dilated bowel loops, gasless abdomen

Question 17

Gas cysts in the bowel wall. Suggestive of necrotizing enterocolitis

Answer 17

Pneumatosis intestinalis

Question 18

Accumulation of gas in the portal vein and it’s branches. A variety of causes such as ischemic bowel, intra-abdominal sepsis

Answer 18

portal venous gas

Question 19

First step in the evaluation of the acute abdomen

Answer 19

plain abdominal xrays

Question 20

What is the preferred imaging study in the evaluation of the acute abdomen?

Answer 20

CT scan

Question 21

What is necessary for evaluatio of the mucosal thickening of the bowel wall?

Answer 21

oral contrast

Question 22

What can obscure the view of mesenteric vessel of a CT angiogram?

Answer 22

oral contrast

Question 23

Good study for evaluation of suspected intestinal ischemia but don’t do if planning on percutaneous angiography too (excessive contrast with 2 studies)

Answer 23

CT angiography

Question 24

Better at diagnosing venous occlusions

Answer 24

MR angiography

Question 25

If diagnosis is fairly certain and need consideration for percutaneous treatment or for surgical planning. Can’t be used for venous occlusions

Answer 25

mesenteric percutaneous arteriography

Question 26

Vasopressors that have less effect on mesentary

Answer 26

dobutamine, low dose dopamine, milrinone

Question 27

What can be given at angiography directly to relieve mesentaric vasoconstriction?

Answer 27

papaverine

Question 28

Gold standard diagnostic study for acute arterial ischemia

Answer 28

Mesenteric Angiography

Question 29

Treatment includes : Papaverine infusion during angiography. Reverse underlying conditions. Repeat angiography can be done in 24 hrs. Surgical exploration reserved for patients with peritoneal signs

Answer 29

Nonocclusive mesenteric ischemia

Question 30

Intestinal angina. Episodic or constant intestinal hypoperfusion. Secondary to atherosclerosis. Strongly associated with meals

Answer 30

Chronic mesenteric ischemia