Basic ScienceBasic Science

Mesenteric IschemiaMesenteric Ischemia

Visceral Artery AneurysmsVisceral Artery Aneurysms

3/1/20063/1/2006

What is the most common cause of acute What is the most common cause of acute mesenteric ischemia?mesenteric ischemia?

A. Embolism to SMAA. Embolism to SMA

B. Embolism to the celiac arteryB. Embolism to the celiac artery

C. Thrombosis of SMAC. Thrombosis of SMA

D. Low flowD. Low flow

E. Acute nonocclusive mesenteric E. Acute nonocclusive mesenteric insufficiencyinsufficiency

F. Mesenteric venous occlusionF. Mesenteric venous occlusion

What is the most common cause of acute What is the most common cause of acute mesenteric ischemia?mesenteric ischemia?

A. Embolism to SMAA. Embolism to SMA

B. Embolism to the celiac arteryB. Embolism to the celiac artery

C. Thrombosis of SMAC. Thrombosis of SMA

D. Low flowD. Low flow

E. Acute nonocclusive mesenteric E. Acute nonocclusive mesenteric insufficiencyinsufficiency

F. Mesenteric venous occlusionF. Mesenteric venous occlusion

Which of these statements about acute Which of these statements about acute mesenteric artery occlusion are truemesenteric artery occlusion are true– A. Most common cause of acute mesenteric A. Most common cause of acute mesenteric

artery occlusion is thrombosisartery occlusion is thrombosis– B. Most common vessel involved in embolic B. Most common vessel involved in embolic

acute mesenteric ischemia (AMI) is the SMAacute mesenteric ischemia (AMI) is the SMA– C. Most common location of embolic C. Most common location of embolic

occlusion within the vessel is at or within 2-3 occlusion within the vessel is at or within 2-3 cm of the origincm of the origin

– D. Patients usually present with peritonitis on D. Patients usually present with peritonitis on examexam

– E. After resuscitation, an arteriogram is E. After resuscitation, an arteriogram is necessary to identify the site of occlusion in a necessary to identify the site of occlusion in a patient with a peritoneal abdomen due to patient with a peritoneal abdomen due to suspected AMIsuspected AMI

Which of these statements about acute Which of these statements about acute mesenteric artery occlusion are truemesenteric artery occlusion are true– A. (FALSE) Most common cause of acute mesenteric A. (FALSE) Most common cause of acute mesenteric

artery occlusion is thrombosis (EMBOLUS)artery occlusion is thrombosis (EMBOLUS)– B. (TRUE) Most common vessel involved in embolic B. (TRUE) Most common vessel involved in embolic

acute mesenteric ischemia (AMI) is the SMAacute mesenteric ischemia (AMI) is the SMA– C. (FALSE) Most common location of embolic C. (FALSE) Most common location of embolic

occlusion within the vessel is at or within 2-3 cm of occlusion within the vessel is at or within 2-3 cm of the origin (6-8 cm)the origin (6-8 cm)

– D. (FALSE) Patients usually present with peritonitis D. (FALSE) Patients usually present with peritonitis on exam (pain out of proportion to exam)on exam (pain out of proportion to exam)

– E. (FALSE) After resuscitation, an arteriogram is E. (FALSE) After resuscitation, an arteriogram is necessary to identify the site of occlusion in a patient necessary to identify the site of occlusion in a patient with a peritoneal abdomen due to suspected AMI with a peritoneal abdomen due to suspected AMI (MAY DELAY OPERATIVE THERAPY)(MAY DELAY OPERATIVE THERAPY)

Most cases of embolic acute mesenteric Most cases of embolic acute mesenteric ischemia (AMI) are of cardiac origin.ischemia (AMI) are of cardiac origin.

A. TrueA. True

B. False B. False

Most cases of embolic acute mesenteric Most cases of embolic acute mesenteric ischemia (AMI) are of cardiac origin.ischemia (AMI) are of cardiac origin.

A. True - The clots causing embolic AMI A. True - The clots causing embolic AMI are overwhelmingly of cardiac origin, from are overwhelmingly of cardiac origin, from atrial fibrillation, mural thrombi following atrial fibrillation, mural thrombi following myocardial infarction, or valvular myocardial infarction, or valvular vegetations.vegetations.

B. False B. False

Which of these statements about chronic Which of these statements about chronic mesenteric ischemia are truemesenteric ischemia are true– A. Chronic mesenteric ischemia is almost A. Chronic mesenteric ischemia is almost

exclusively a problem in the older age groupexclusively a problem in the older age group– B. Because of abundant collaterals between B. Because of abundant collaterals between

the three main mesenteric arteries, in most the three main mesenteric arteries, in most cases all three must be severely cases all three must be severely compromised before symptoms arisecompromised before symptoms arise

– C. The most commonly affected arteries in C. The most commonly affected arteries in symptomatic CMI is the SMA and IMAsymptomatic CMI is the SMA and IMA

– Long-term patency of bypass grafts to the Long-term patency of bypass grafts to the celiac or SMA exceeds 90%celiac or SMA exceeds 90%

– E. Malabsorption is a significant problem E. Malabsorption is a significant problem leading to weight lossleading to weight loss

Which of these statements about chronic Which of these statements about chronic mesenteric ischemia are truemesenteric ischemia are true– A. (TRUE) Chronic mesenteric ischemia is almost A. (TRUE) Chronic mesenteric ischemia is almost

exclusively a problem in the older age group exclusively a problem in the older age group (ATHEROSCLEROSIS)(ATHEROSCLEROSIS)

– B. (FALSE) Because of abundant collaterals between B. (FALSE) Because of abundant collaterals between the three main mesenteric arteries, in most cases all the three main mesenteric arteries, in most cases all three must be severely compromised before three must be severely compromised before symptoms arise (USUALLY 2, SOMETIMES 3, symptoms arise (USUALLY 2, SOMETIMES 3, OCCASIONALLY 1)OCCASIONALLY 1)

– C. (FALSE) The most commonly affected arteries in C. (FALSE) The most commonly affected arteries in symptomatic CMI is the SMA and IMA (CELIAC/SMA)symptomatic CMI is the SMA and IMA (CELIAC/SMA)

– D. (TRUE) Long-term patency of bypass grafts to the D. (TRUE) Long-term patency of bypass grafts to the celiac or SMA exceeds 90%celiac or SMA exceeds 90%

– E. (FALSE) Malabsorption is a significant problem E. (FALSE) Malabsorption is a significant problem leading to weight loss (“FOOD FEAR” ABSTINENCE)leading to weight loss (“FOOD FEAR” ABSTINENCE)

Which of the following is a typical CT Which of the following is a typical CT finding in patients with chronic mesenteric finding in patients with chronic mesenteric ischemia?ischemia?

A. Clot in SMAA. Clot in SMA

B. Clot in SMVB. Clot in SMV

C. Atherosclerotic plaque involving the C. Atherosclerotic plaque involving the mesenteric arteries.mesenteric arteries.

D. Atherosclerotic plaque involving the D. Atherosclerotic plaque involving the mesenteric veins.mesenteric veins.

Which of the following is a typical CT Which of the following is a typical CT finding in patients with chronic mesenteric finding in patients with chronic mesenteric ischemia?ischemia?

A. Clot in SMAA. Clot in SMA

B. Clot in SMVB. Clot in SMV

C. Atherosclerotic plaque involving the C. Atherosclerotic plaque involving the mesenteric arteries.mesenteric arteries.

D. Atherosclerotic plaque involving the D. Atherosclerotic plaque involving the mesenteric veins.mesenteric veins.

Which of these statements about acute Which of these statements about acute nonocclusive mesenteric insufficiency are truenonocclusive mesenteric insufficiency are true– A. Normally associated with profound illness such as A. Normally associated with profound illness such as

sepsis, cardiovascular collapse, vasopressor usesepsis, cardiovascular collapse, vasopressor use– B. Arteriographic findings include sequential focal B. Arteriographic findings include sequential focal

vasospasm (“beading”), “pruned tree” appearance of vasospasm (“beading”), “pruned tree” appearance of distal vasculature, and presence of large vessel distal vasculature, and presence of large vessel occlusionocclusion

– C. Management includes fluid resuscitation, C. Management includes fluid resuscitation, withdrawal of vasoconstrictors, antibiotics, and withdrawal of vasoconstrictors, antibiotics, and selective infusion of papaverine into the SMA.selective infusion of papaverine into the SMA.

– D. Successful operative treatment of patients with D. Successful operative treatment of patients with clinical deterioration or peritonitis includes bypass clinical deterioration or peritonitis includes bypass grafting of the SMA and/or celiac arterygrafting of the SMA and/or celiac artery

Which of these statements about acute Which of these statements about acute nonocclusive mesenteric insufficiency are truenonocclusive mesenteric insufficiency are true– A. (TRUE) Normally associated with profound illness A. (TRUE) Normally associated with profound illness

such as sepsis, cardiovascular collapse, vasopressor such as sepsis, cardiovascular collapse, vasopressor use (LOW-FLOW, MESENTERIC use (LOW-FLOW, MESENTERIC VASOCONSTRICTION)VASOCONSTRICTION)

– B. (FALSE) Arteriographic findings include sequential B. (FALSE) Arteriographic findings include sequential focal vasospasm (“beading”), “pruned tree” focal vasospasm (“beading”), “pruned tree” appearance of distal vasculature, and presence of appearance of distal vasculature, and presence of large vessel occlusion (ABSENCE OF OCCLUSION)large vessel occlusion (ABSENCE OF OCCLUSION)

– C. (TRUE) Management includes fluid resuscitation, C. (TRUE) Management includes fluid resuscitation, withdrawal of vasoconstrictors, antibiotics, and withdrawal of vasoconstrictors, antibiotics, and selective infusion of papaverine into the SMA.selective infusion of papaverine into the SMA.

– D. (FALSE) Successful operative treatment of D. (FALSE) Successful operative treatment of patients with clinical deterioration or peritonitis patients with clinical deterioration or peritonitis includes bypass grafting of the SMA and/or celiac includes bypass grafting of the SMA and/or celiac artery (NO OCCLUSION – RESECT GANGRENOUS artery (NO OCCLUSION – RESECT GANGRENOUS BOWEL ONLY)BOWEL ONLY)

Which of these statements about mesenteric Which of these statements about mesenteric venous occlusion are truevenous occlusion are true– A. Commonly found in patients with portal A. Commonly found in patients with portal

hypertension, pancreatitis, systemic low-flow stateshypertension, pancreatitis, systemic low-flow states– B. CT and arteriography may demonstrate thickened B. CT and arteriography may demonstrate thickened

bowel walls and lack of prompt filling of the portal bowel walls and lack of prompt filling of the portal systemsystem

– C. Management includes hemodynamic support, C. Management includes hemodynamic support, anticoagulation, and fibrinolytic therapyanticoagulation, and fibrinolytic therapy

– D. Operative management for patients with peritonitis D. Operative management for patients with peritonitis include resection of necrotic bowel and surgical include resection of necrotic bowel and surgical thrombectomythrombectomy

– E. In general, overall prognosis is good E. In general, overall prognosis is good

Which of these statements about mesenteric Which of these statements about mesenteric venous occlusion are truevenous occlusion are true– A. (TRUE) Commonly found in patients with portal A. (TRUE) Commonly found in patients with portal

hypertension, pancreatitis, systemic low-flow stateshypertension, pancreatitis, systemic low-flow states– B. (TRUE) CT and arteriography may demonstrate B. (TRUE) CT and arteriography may demonstrate

thickened bowel walls and lack of prompt filling of the thickened bowel walls and lack of prompt filling of the portal systemportal system

– C. (FALSE) Management includes hemodynamic C. (FALSE) Management includes hemodynamic support, anticoagulation, and fibrinolytic therapy support, anticoagulation, and fibrinolytic therapy (LYSIS - HIGH RISK OF BLEEDING WITH (LYSIS - HIGH RISK OF BLEEDING WITH CONGESTED MUCOSA)CONGESTED MUCOSA)

– D. (FALSE) Operative management for patients with D. (FALSE) Operative management for patients with peritonitis include resection of necrotic bowel and peritonitis include resection of necrotic bowel and surgical thrombectomy (THROMBECTOMY RARELY surgical thrombectomy (THROMBECTOMY RARELY SUCCESSFUL)SUCCESSFUL)

– E. (TRUE) In general, overall prognosis is good E. (TRUE) In general, overall prognosis is good (FORMS VENOUS COLLATERALS, +/- (FORMS VENOUS COLLATERALS, +/- RECANALIZATION)RECANALIZATION)

A young healthy patient without any A young healthy patient without any obvious signs, symptoms, or risk factors of obvious signs, symptoms, or risk factors of atherosclerosis presents with chronic atherosclerosis presents with chronic history of postprandial pain, numerous history of postprandial pain, numerous evaluations by physicians, and evaluations by physicians, and dependency on pain medication. How will dependency on pain medication. How will you evaluate this patient and what might you evaluate this patient and what might you find?you find?

A young healthy patient without any A young healthy patient without any obvious signs, symptoms, or risk factors of obvious signs, symptoms, or risk factors of atherosclerosis presents with chronic atherosclerosis presents with chronic history of postprandial pain, numerous history of postprandial pain, numerous evaluations by physicians, and evaluations by physicians, and dependency on pain medication. How will dependency on pain medication. How will you evaluate this patient and what might you evaluate this patient and what might you find?you find?

– MRI/MRA or arteriography, celiac artery MRI/MRA or arteriography, celiac artery compression from the median arcuate compression from the median arcuate ligament of the diaphragmligament of the diaphragm

What is the treatment of celiac artery What is the treatment of celiac artery compression from the median arcuate compression from the median arcuate ligament of the diaphragm?ligament of the diaphragm?

What is the treatment of celiac artery What is the treatment of celiac artery compression from the median arcuate compression from the median arcuate ligament of the diaphragmligament of the diaphragm

– surgical release of median arcuate ligament, surgical release of median arcuate ligament, +/- patch angioplasty/short bypass if stenosed +/- patch angioplasty/short bypass if stenosed from fibrosis, +/- celiac nerve block (cause of from fibrosis, +/- celiac nerve block (cause of pain not always clear)pain not always clear)

Which of the following forms of acute Which of the following forms of acute mesenteric ischemia (AMI) typically has no mesenteric ischemia (AMI) typically has no indication for surgery other than resection indication for surgery other than resection of gangrenous bowel when present? of gangrenous bowel when present?

A. Embolic AMIA. Embolic AMI

B. Thrombotic AMIB. Thrombotic AMI

C. Nonocclusive mesenteric ischemia C. Nonocclusive mesenteric ischemia (NOMI)(NOMI)

D. Mesenteric venous thrombosis (MVT)D. Mesenteric venous thrombosis (MVT)

E. Arterial occlusive AMIE. Arterial occlusive AMI

Which of the following forms of acute mesenteric Which of the following forms of acute mesenteric ischemia (AMI) typically has no indication for ischemia (AMI) typically has no indication for surgery other than resection of gangrenous surgery other than resection of gangrenous bowel when present? bowel when present? A. Embolic AMIA. Embolic AMIB. Thrombotic AMIB. Thrombotic AMIC. Nonocclusive mesenteric ischemia (NOMI) - C. Nonocclusive mesenteric ischemia (NOMI) - NOMI has no vascular occlusion, so NOMI has no vascular occlusion, so revascularization is not indicated. MVT typically revascularization is not indicated. MVT typically does not need thrombectomy, but this operation does not need thrombectomy, but this operation may be indicated in certain patients with may be indicated in certain patients with localized clots diagnosed promptly. localized clots diagnosed promptly. Revascularization and embolectomy are surgical Revascularization and embolectomy are surgical options for thrombotic and embolic AMI.options for thrombotic and embolic AMI.D. Mesenteric venous thrombosis (MVT)D. Mesenteric venous thrombosis (MVT)E. Arterial occlusive AMIE. Arterial occlusive AMI

Which of the following types of acute Which of the following types of acute mesenteric ischemia (AMI) is more mesenteric ischemia (AMI) is more frequently found in young patients?frequently found in young patients?

A. Embolic AMIA. Embolic AMI

B. Thrombotic AMIB. Thrombotic AMI

C. Nonocclusive mesenteric ischemia C. Nonocclusive mesenteric ischemia (NOMI)(NOMI)

D. Mesenteric venous thrombosis (MVT) D. Mesenteric venous thrombosis (MVT) E. Arterial occlusive AMIE. Arterial occlusive AMI

Which of the following types of acute mesenteric Which of the following types of acute mesenteric ischemia (AMI) is more frequently found in ischemia (AMI) is more frequently found in young patients?young patients?A. Embolic AMIA. Embolic AMIB. Thrombotic AMIB. Thrombotic AMIC. Nonocclusive mesenteric ischemia (NOMI)C. Nonocclusive mesenteric ischemia (NOMI)D. Mesenteric venous thrombosis (MVT) - D. Mesenteric venous thrombosis (MVT) - Because hypercoagulability is the main risk Because hypercoagulability is the main risk factor, MVT occurs in patients of a much factor, MVT occurs in patients of a much younger age range compared to the typical younger age range compared to the typical patients with AMI. Some cases of embolic AMI patients with AMI. Some cases of embolic AMI are found in relatively young people with atrial are found in relatively young people with atrial fibrillation, but they are the exception, not the fibrillation, but they are the exception, not the rule.rule.E. Arterial occlusive AMIE. Arterial occlusive AMI

Angiographically infused papaverine is Angiographically infused papaverine is indicated for all types of acute mesenteric indicated for all types of acute mesenteric ischemia (AMI).ischemia (AMI).

A. TrueA. True

B. FalseB. False

Angiographically infused papaverine is Angiographically infused papaverine is indicated for all types of acute mesenteric indicated for all types of acute mesenteric ischemia (AMI).ischemia (AMI).A. TrueA. TrueB. False - While it has no effect on the B. False - While it has no effect on the course of mesenteric venous thrombosis course of mesenteric venous thrombosis (MVT), papaverine infused through the (MVT), papaverine infused through the angiogram catheter at the affected vessel angiogram catheter at the affected vessel is useful for all arterial forms of AMI. It is useful for all arterial forms of AMI. It relieves reactive vasospasm in occluded relieves reactive vasospasm in occluded arterial vessels, and it is the only treatment arterial vessels, and it is the only treatment for nonocclusive mesenteric ischemia for nonocclusive mesenteric ischemia other than resection of gangrenous bowel. other than resection of gangrenous bowel.

Heparin is indicated in all types of acute Heparin is indicated in all types of acute mesenteric ischemia (AMI).mesenteric ischemia (AMI).

A. TrueA. True

B. FalseB. False

Heparin is indicated in all types of acute Heparin is indicated in all types of acute mesenteric ischemia (AMI).mesenteric ischemia (AMI).

A. TrueA. True

B. False - Heparin is indicated in post-B. False - Heparin is indicated in post-revascularization arterial occlusion cases revascularization arterial occlusion cases and in mesenteric venous thrombosis and in mesenteric venous thrombosis (MVT). Heparin is not useful in (MVT). Heparin is not useful in nonocclusive mesenteric ischemia.nonocclusive mesenteric ischemia.

Angiographically infused thrombolytics are Angiographically infused thrombolytics are indicated in all cases of embolic acute indicated in all cases of embolic acute mesenteric ischemia (AMI).mesenteric ischemia (AMI).

A. TrueA. True

B. FalseB. False

Angiographically infused thrombolytics are Angiographically infused thrombolytics are indicated in all cases of embolic acute indicated in all cases of embolic acute mesenteric ischemia (AMI).mesenteric ischemia (AMI).

A. TrueA. True

B. False - Thrombolytics are noted to B. False - Thrombolytics are noted to cause potentially fatal bleeding. Their use cause potentially fatal bleeding. Their use is tempered by multiple contraindications. is tempered by multiple contraindications. Thrombolytics should be considered only Thrombolytics should be considered only in patients with no signs of peritonitis or in patients with no signs of peritonitis or other evidence of bowel necrosis.other evidence of bowel necrosis.

Which of these statements about visceral artery Which of these statements about visceral artery aneurysms are trueaneurysms are true– A. The arteries most commonly involved in A. The arteries most commonly involved in

descending order are splenic, SMA, hepatic, other descending order are splenic, SMA, hepatic, other arterialarterial

– B. Splenic artery aneurysms occur most commonly in B. Splenic artery aneurysms occur most commonly in women with a F:M ratio of 4:1women with a F:M ratio of 4:1

– C. Hepatic artery aneurysms occur most commonly in C. Hepatic artery aneurysms occur most commonly in women with a F:M ratio of 2:1women with a F:M ratio of 2:1

– D. One out of four patients with visceral artery D. One out of four patients with visceral artery aneurysms present as emergencies with a mortality aneurysms present as emergencies with a mortality rate of 10-35%rate of 10-35%

– E. Most patients without prohibitive risks factors E. Most patients without prohibitive risks factors should undergo elective repairshould undergo elective repair

Which of these statements about visceral artery Which of these statements about visceral artery aneurysms are trueaneurysms are true– A. (FALSE) The arteries most commonly involved in A. (FALSE) The arteries most commonly involved in

descending order are splenic (60%), SMA (5.5%), descending order are splenic (60%), SMA (5.5%), hepatic (20%), other arterial (EACH <5%)hepatic (20%), other arterial (EACH <5%)

– B. (TRUE) Splenic artery aneurysms occur most B. (TRUE) Splenic artery aneurysms occur most commonly in women with a F:M ratio of 4:1commonly in women with a F:M ratio of 4:1

– C. (FALSE) Hepatic artery aneurysms occur most C. (FALSE) Hepatic artery aneurysms occur most commonly in women with a F:M ratio of 2:1 (MOST commonly in women with a F:M ratio of 2:1 (MOST COMMON IN MEN M:F 2:1)COMMON IN MEN M:F 2:1)

– D. (TRUE) One out of four patients with visceral artery D. (TRUE) One out of four patients with visceral artery aneurysms present as emergencies with a mortality aneurysms present as emergencies with a mortality rate of 10-35%rate of 10-35%

– E. (TRUE) Most patients without prohibitive risks E. (TRUE) Most patients without prohibitive risks factors should undergo elective repairfactors should undergo elective repair