What is the management of superior mesenteric artery occlusion?

Management of Superior Mesenteric Artery Occlusion

For patients with acute superior mesenteric artery occlusion, endovascular therapy should be considered as first-line treatment for mesenteric revascularization, particularly in cases of thrombotic occlusion, while both endovascular and open surgical approaches should be considered for embolic occlusion. 1

Diagnosis

• Urgent computed tomography angiography (CTA) is recommended as the first-line diagnostic tool with excellent diagnostic accuracy (94% sensitivity, 95% specificity) 1, 2
• D-dimer measurement should be considered to help rule out the diagnosis (96% sensitivity, 40% specificity) 1, 2
• 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 to enhance visceral perfusion 2
• Broad-spectrum antibiotics administration to prevent infection 2
• Intravenous unfractionated heparin should be initiated unless contraindicated 2

Management Algorithm Based on Occlusion Type

Thrombotic Occlusion

• Endovascular therapy should be considered as first-line therapy for mesenteric revascularization 1
• Recanalization can be performed retrograde from an exposed SMA, with guidewire snaring from femoral or brachial artery, followed by stenting 3
• Thrombolytic therapy can be effective relatively quickly and may obviate surgery in selected cases 4

Embolic Occlusion

• Both endovascular and open surgical approaches should be considered 1
• Open embolectomy followed by angiography is a traditional approach 3
• Catheter-directed thrombolysis via selective SMA cannulation has shown promising results in selected patients 5, 4

Surgical Management When Indicated

• Exploratory laparotomy is mandatory when peritoneal signs develop or bowel infarction is suspected 6, 3
• Revascularization should be attempted first, unless there is serious peritonitis and septic shock 1
• Bowel resections may be necessary for necrotic segments, with definitive bowel reconstructions often performed at a planned second-look laparotomy 3
• Hybrid approaches combining surgical and endovascular techniques may be beneficial in selected cases 1, 2

Minimally Invasive Approaches

• Combined approaches using arteriographic therapy and diagnostic laparoscopy for bowel viability assessment can avoid exploratory laparotomy in select patients 7
• Thrombolysis via an operatively placed mesenteric catheter has been reported as successful in cases of mesenteric venous thrombosis 6

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 2
• Remission of abdominal pain during the first few hours of treatment is an important indicator of therapeutic success for thrombolytic therapy 4
• Approximately 20-30% of patients with acute SMA occlusion can survive with bowel resection only, especially with distal embolism 1