Mesenteric ischemia

Question 1

Acute mesenteric ischemia causes:

Answer 1

1. embolic occlusion of artery
2. thrombosis of artery
3. intense splanchnic vasoconstriction (nonocclusive) - hypovolemia or low flow state
4. mesenteric vein occlusion

Question 2

most common cause of mesenteric ischemia

Answer 2

SMA thrombosis

Question 3

What type of mesenteric ischemia presents with acute onset abdominal pain in a patient with history of recent cardiac event or prior embolization?

Answer 3

embolism of SMA

Question 4

What type of mesenteric ischemia presents with acute onset abdominal pain in the setting of chronic abdominal pain associated with food aversion/weight loss and PVD?

Answer 4

SMA thrombosis

Question 5

What type of mesenteric ischemia presents with waxing and waning abdominal pain depending on HDS or abdominal distention in the setting of worsening acidosis in an unresponsive patient?

Answer 5

nonocclusive mesenteric ischemia (NOMI)

Question 6

What type of mesenteric ischemia presents with vague/nonspecific abdominal complaints (nausea, vomiting, diarrhea, nonspecific abdominal pain) that is not acute? Seen in patients with hx of PE, oral contraceptives, estrogen supplementation, hypercoagulable, hx of cancer

Answer 6

mesenteric vein thrombosis

Question 7

What is the fastest and most useful test to diagnose mesenteric ischemia?

Answer 7

CTA

Question 8

Medical treatment adjuncts of acute mesenteric ischemia:

Answer 8

resuscitated to correct acid/base abonormalities, anticoagulation with heparin, start antibiotics

Question 9

Surgical treatment of acute embolic mesenteric ischemia?

Answer 9

heparinize; expose the SMA: reflect transverse colon superiorly and retract small bowel to right upper quadrant, divide ligament of treitz, palpate SMA over the 3rd and 4th portions of duodenum

obtain proximal and distal control of SMA
transverse arteriotomy and embolectomy with balloon catheter

vein patch to close arteriotomy

Assess bowel viability, second look operation before definitive closure

Question 10

Surgical treatment of acute thrombotic mesenteric ischemia?

Answer 10

treatment consists of a bypass procedure

• antegrade or retrograde: supraceliac aorta, infrarenal aorta, or iliac artery
• conduit is reverse grater saphenous vein or dacron
• assess bowel viability

Question 11

antegrade bypass for acute thrombotic mesenteric ischemia steps:

Answer 11

divide gastrohepatic ligament and mobilize left lobe of liver
esophagus retract to left
divide diaphgragmatic crura and median arcuate ligament
vein graft is bypassed first to the celiac artery and then to the SMA by tunneling behind the pancreas

Question 12

steps of retrograde bypass for acute thrombotic mesenteric ischemia:

Answer 12

most proximal SMA segment that is patent is exposed

anastomois is completed and the bowel returned to anatomic position

Bypass graft is pulled and placed adjacent to the aorta to a soft spot on the infrarenal aorta or the iliac artery

Question 13

what other intervention besides surgery can be attempted for patients with acute embolic & thrombotic mesenteric ischemia who are poor surgical candidates?

Answer 13

mesenteric angiography with trials of lytic therapy, balloon angioplasty, stent placement

Question 14

Management of nonocclusive mesenteric ischemia ?

Answer 14

largely supportive; can also inject vasodilators such as papaverine as an adjunct with angiography

Question 15

Surgical management of mesenteric venous thrombosis:

Answer 15

evaluate for hypercoagulaable states; surgical exploration should be reserved for bowel ischemia and infarction; venous thrombectomy has not been shown to be effective; thrombolytics may be helpful

Question 16

Vasodilator agent used for NOMI that does not increase intestinal O2 uptake:

Answer 16

papaverine