Mesentric Ischemia

Question 1

Mesenteric ischemia definition

Answer 1

Reduction in blood flow for intestinal circulation of
sufficient magnitude to compromise the viability of the affected portion, leading to ischemia cellular damage or even entire bowel wall necrosis.

Question 2

Classification of Mesenteric ischemia

Answer 2

Acute
Chronic

Question 3

Causes of acute Mesenteric ischemia

Answer 3

• SMA embolic occlusion
• SMA thrombotic occlusion
• non- occlusive Mesenteric ischemia
• Mesenteric vein thrombosis

Question 4

Embolic occlusion can originate from ?

Answer 4

the left atrium, as in atrial fibrillation

left ventricle if there is myocardial
dysfunction associated with poor
ejection fraction

cardiac valves due to endocarditis.

Occasionally emboli generated from
an atherosclerotic aorta with or without
aneurismal dilatation.

Question 5

Thrombotic occlusion occur in pre-existing stenosis due to ?

Answer 5

Atherosclerosis

Question 6

Affected vessels in thrombotic occlusion ?

Answer 6

Terminal branches and collateral arteries ( which is poorly developed)
Orpington of visceral arteries

Question 7

Mesenteric vein ischemia virchows triad ?

Answer 7

Hypercoagubility: congenital: as protein S deficiency, protein C deficiency, antithrombin
deficiency, and antiphospholipid syndrome.

Thrombophilia may also be acquired due to malignancies, hematologic disorders, and oral
contraceptives.

Stasis: Portal HTN

Question 8

Acute non occlusive Mesenteric ischemia

Answer 8

Ischemia NOMI occurs in approximately 20% of cases

Is usually a consequence of SMA vasoconstriction
associated with low splanchnic blood flow (as in
hypovolemic and cardiogenic shock specially with the use of vasoconstrictor drugs).

The compromised SMA blood flow often involves the
proximal colon as well due to involvement of the ileocolic artery.

Question 9

Clinical features
signs early

Answer 9

Minimal abdominal findings as slight distension with no tenderness
Pain out of proportion to abdominal signs must raise suspicion
(hallmark)

Question 10

Late signs

Answer 10

Late: with established severe ischemia ± perforation and peritonitis
• Systemic toxicity, septic shock
• Abdominal distention
• Generalized peritonitis
• Blood in stool

Question 11

Lab investigations

Answer 11

Question 12

Imaging CTA finding ?

Answer 12

• Arterial calcification, embolism, thrombosis
• Vein thrombosis
• Signs of bowel infarction: intestinal dilatation and thickness, absence of enhancement of the affected loops, pneumatosis intestinalis, and portal venous gas
• Perforation: free intraperitoneal air

Question 13

Sign of bowel infarction

Answer 13

intestinal dilatation and thickness, absence
of enhancement of the affected loops, pneumatosis intestinalis, and portal venous gas

Question 14

D.D of Mesenteric Ischemia

Answer 14

Acute pancreatitis
• Intestinal obstruction
• Peptic ulcer disease
• Gastroenteritis
• Perforated viscus

Question 15

Treatment of Mesenteric ischemia - ER Care

Answer 15

ABC
• Fluid resuscitation
• NGT decompression
• NPO
• Correct electrolyte disturbance
• ICU care
• Monitor vital signs
• Input output fluid chart

Question 16

Treatment- medication

Answer 16

Anticoagulation therapy with intravenous unfractionacted heparin.
• Antibiotics – broad spectrum
• Analgesia
• Antiemetic
• Control medical problems: Embolic? Thrombotic? NOMI? Venous?

Question 17

When NOMI is suspected, the focus is to?

Answer 17

correct the underlying
cause wherever possible and to improve mesenteric perfusion

Question 18

Indication of surgery

Answer 18

Signs of peritonitis
• CT signs of bowel infarction
Exploratory laparotomy
• Re-establishment blood supply to the ischemic bowel
• Resection of all non-viable regions

Question 19

Surgical option to Mesenteric arterial embolism ?

Answer 19

• Embolectomy then distal bypass graft
• Resect necrotic bowel

Question 20

Surgery of Mesenteric arterial thrombosis ?

Answer 20

Bypass graft or stenting
Resect necrotic bowel

Question 21

Surgery of NOMI

Answer 21

Treat the underlying cause
Fewer surgical options
Papaverine or glycerol infusion
Resect necrotic bowel

Question 22

Mesenteric venous thrombosis

Answer 22

Depends on extent of ischemia
Difficult for surgical management if diffuse thrombosis
Mild ischemia: treat with bowel resection of necrotic segment

Question 23

Endovascular options for Mesenteric vascular occlusion

Answer 23

percutaneous transluminal angioplasty and stent placement
• Remains controversial but may have a role with partial arterial occlusion

Question 24

Complications of Mesenteric ischemia

Answer 24

• Perforation • Septic shock • Multiple organ failure • Malnutrition • Short bowel syndrome • Complications of parenteral nutrition
• Mortality rates reach 80%

Question 25

Clinical features of intestinal angina

Answer 25

Recurrent abdominal postprandial pain with increasing frequency and severity
• Weight loss
Signs:
• Abdominal bruit

Question 26

Investigations of chronic ischemia

Answer 26

• Duplex u/s • CTA • MRA • Conventional angiography

Question 27

Treatment of chronic ischemia

Answer 27

• Surgical :
• Trans aortic endarterectomy
• Bypass
• Angioplasty
• Endovascular:
• PTA: percutaneous transluminal angioplasty
• Stent