Mesenteric Ischemia Second-Look Laparotomy

Acute mesenteric ischemia (AMI) is a vascular emergency caused by superior mesenteric artery (SMA) embolism (40-50%), SMA thrombosis (20-30%), nonocclusive mesenteric ischemia (20%), or mesenteric venous thrombosis (10%). Mortality remains 50-70% despite advances in diagnosis and revascularization. Second-look laparotomy is a strategic intervention when bowel viability remains uncertain at the index operation.

Indications for second-look include marginal bowel viability after revascularization, large bowel segments of unclear viability, primary bowel resection with viable margins requiring confirmation, nonocclusive ischemia with incomplete reperfusion, and damage control with deferred anastomosis. The decision is made intraoperatively at the first operation, with the abdomen left open with negative-pressure dressing or temporary closure to facilitate planned re-exploration.

At the second-look (typically 24-48 hours later), the bowel is reassessed for color, peristalsis, mesenteric pulse, and Doppler signal. Equivocal segments undergo additional resection, marginally viable bowel may now be clearly demarcated allowing anastomosis with primary or staged closure, and any new ischemic areas are addressed. Adjuncts include indocyanine green fluorescence angiography for perfusion assessment. Postoperatively, ICU care, anticoagulation (when not contraindicated), nutrition optimization, and short bowel syndrome management for extensive resections are critical. Long-term anticoagulation, antiplatelet therapy, and risk factor modification reduce recurrence.