What is the management of superior mesenteric artery thrombosis?

Management of Superior Mesenteric Artery Thrombosis

In patients with acute thrombotic occlusion of the superior mesenteric artery, endovascular therapy should be considered as first-line therapy for mesenteric revascularization, followed by appropriate surgical intervention if signs of peritonitis or bowel infarction develop. 1

Diagnosis

• Urgent computed tomography angiography (CTA) is recommended as the first-line diagnostic tool for suspected superior mesenteric artery (SMA) thrombosis, with a diagnostic accuracy of approximately 94% sensitivity and 95% specificity 1
• D-dimer measurement should be considered to help rule out the diagnosis, with a pooled sensitivity of 96%, though specificity is only 40% 1
• Elevated lactate levels are not reliable early markers as they only rise after bowel gangrene has developed 1
• Plain abdominal X-rays have limited diagnostic value and should not delay definitive imaging 1

Initial Management

• Immediate fluid resuscitation is essential to enhance visceral perfusion 1, 2
• Correction of electrolyte abnormalities and acid-base disturbances 2
• Nasogastric decompression to reduce intestinal distention 2
• Broad-spectrum antibiotics administration to prevent infection 1, 2
• Intravenous unfractionated heparin should be initiated unless contraindicated 1, 2

Definitive Management Based on Clinical Presentation

For Patients Without Peritonitis:

• Endovascular therapy should be considered as first-line therapy for mesenteric revascularization 1, 2
• Options include:
  • Aspiration embolectomy 3
  • Catheter-directed thrombolysis 3
  • Percutaneous transluminal angioplasty with or without stenting 2
• Early endovascular intervention has shown promising results with a 30-day mortality rate of 9.5% in selected patients 3

For Patients With Peritonitis or Signs of Bowel Infarction:

• Emergency laparotomy is mandatory 1, 2
• Surgical options include:
  • Revascularization via embolectomy or bypass 1
  • Resection of necrotic bowel 1
  • Damage control techniques with temporary abdominal closure 1
• A second-look laparotomy 24-48 hours later is mandatory in patients with extensive bowel involvement to assess bowel viability 1, 2

For Embolic vs. Thrombotic Occlusion:

• For thrombotic occlusion: Endovascular therapy should be considered as first-line therapy 1
• For embolic occlusion: Both endovascular and open surgery therapy should be considered 1

Special Considerations

• In patients with acute thrombosis, revascularization should be attempted first, unless there is serious peritonitis and septic shock 1
• Hybrid approaches combining surgical and endovascular techniques may be beneficial in selected cases 1
• Intraoperative Doppler ultrasound can be used to confirm arterial flow and detect new thrombosis during repeated surgical procedures 4

Postoperative Care

• Intensive care directed toward improving intestinal perfusion and preventing multiple organ failure 2
• Continued anticoagulation to prevent thrombosis recurrence 2
• Close monitoring for reperfusion injury and complications 2

Pitfalls and Caveats

• Despite advances in diagnosis and treatment, mortality remains high (40-70%) 2
• Delayed diagnosis significantly worsens outcomes; maintain high clinical suspicion for patients with acute abdominal pain out of proportion to physical examination findings 1
• Lactate levels may be normal early in the disease process, even with significant ischemia, as the liver effectively metabolizes lactate until bowel gangrene develops 1
• Rebound tenderness and peritoneal signs indicate advanced disease that likely requires surgical intervention in addition to revascularization 3