What is the management of acute mesenteric ischemia?

Management of Acute Mesenteric Ischemia

Immediate CT angiography followed by prompt intervention is essential for managing acute mesenteric ischemia, with fluid resuscitation, broad-spectrum antibiotics, and anticoagulation as initial measures, followed by revascularization and/or bowel resection as indicated by the clinical presentation. 1

Initial Diagnosis and Management

• CT angiography is the first-line diagnostic tool for suspected acute mesenteric ischemia due to its high diagnostic accuracy 1
• Immediate fluid resuscitation with crystalloids should be initiated to enhance visceral perfusion 2
• Electrolyte abnormalities must be corrected and nasogastric decompression initiated 2
• Broad-spectrum antibiotics should be administered immediately to prevent infection due to loss of mucosal barrier 2
• Unless contraindicated, patients should receive intravenous unfractionated heparin for anticoagulation 2
• Vasopressors should be used with caution; dobutamine, low-dose dopamine, and milrinone are preferred if needed as they have less impact on mesenteric blood flow 2

Management Based on Clinical Presentation

Patients with Peritonitis

• Prompt laparotomy is mandatory for patients with overt peritonitis 2
• Goals of surgical intervention include:
  1. Re-establishment of blood supply to ischemic bowel
  2. Resection of all non-viable regions
  3. Preservation of all viable bowel 2
• Damage control surgery with temporary abdominal closure is recommended for patients requiring intestinal resection 1

Patients without Peritonitis

Arterial Occlusive Mesenteric Ischemia (Embolic or Thrombotic)

• Endovascular approaches should be considered as first-line treatment 1
• Options include:
  • Aspiration embolectomy
  • Thrombolysis
  • Percutaneous transluminal angioplasty with or without stenting 1
• These approaches are associated with decreased bowel resection, lower incidence of respiratory/renal failure, and reduced mortality 1

Non-Occlusive Mesenteric Ischemia (NOMI)

• Focus on correcting the underlying cause and improving mesenteric perfusion 1
• Treatment includes optimization of cardiac output, elimination of vasopressors, and intra-arterial administration of vasodilators (papaverine, nitroglycerin, or glucagon) 1
• High-dose intravenous prostaglandin E1 may be effective in improving mesenteric perfusion 1

Mesenteric Venous Thrombosis

• Continuous infusion of unfractionated heparin is the primary treatment 1
• Supportive measures including nasogastric suction, fluid resuscitation, and bowel rest 1
• Surgical intervention only if bowel infarction occurs 1

Surgical Considerations

• The superior mesenteric artery can be identified by placing fingers behind the root of the mesentery or by following the middle colic artery 2
• Revascularization is essential when relevant - mortality is significantly higher (62% vs 42%) in patients who do not undergo revascularization 2
• Planned second-look procedures are mandatory in patients with extensive bowel involvement to reassess bowel viability 1
• Decision to perform intestinal anastomosis should be delayed until bowel viability is confirmed 1
• In cases of massive gut necrosis, careful assessment of patient's comorbidities and advanced directives should guide treatment decisions 1

Postoperative Care

• Intensive care directed toward improving intestinal perfusion and preventing multiple organ failure 1
• Continued anticoagulation to prevent thrombosis recurrence 1
• Close monitoring for reperfusion injury and complications 1
• Antibiotic therapy should be administered for at least 4 days in immunocompetent stable patients 2

Prognostic Factors

• Age less than 60 years and appropriate bowel resection are associated with improved survival rates 3
• Time to diagnosis is the most important predictor of outcome 4
• Despite advances in diagnosis and treatment, mortality remains high (40-70%) 1
• Multiorgan failure is the most frequent cause of death 3