Incidence and Natural History of Mesenteric Ischemia in Patients Already Hospitalized for Lower Extremity Bypass

Atherosclerosis is a systemic disease process and patients already hospitalized for lower extremity arterial reconstruction may have undiagnosed mesenteric artery disease that becomes symptomatic during the perioperative period. The purpose of this study is to analyze the incidence and outcomes in patients hospitalized for lower extremity revascularization who then developed acute mesenteric ischemia during the perioperative period. A retrospective review of a prospectively maintained surgery management system for a single academic center was queried for all patients who underwent mesenteric revascularization between 2012 and 2023. Charts were reviewed for demographics, indications, timing of leg and mesenteric revascularization, operative details, and outcomes. The results were tabulated and analyzed using standard statistical analysis. From 1/1/2012 to 9/30/2023, there was a total of 6179 infrainguinal bypasses and 155 mesenteric revascularizations performed. Nine (5.8%) mesenteric patients were already inpatient for lower extremity bypass (LEB). The LEB were mostly female (n = 7; 77.8%) and had median age 68.9 years (range, 52-83 years). The indications for lower extremity bypass were claudication (n = 1; 11.1%), rest pain (n = 4; 44.4%), thrombosis (n = 2; 22.2%), and gangrene (n = 2; 22.2%). One hundred forty-six patients underwent mesenteric bypass without antecedent leg revascularization (MES) and were mostly female (n = 99; 67.8%) and had a mean age of 66.2 years (range, 26-88 years) during that period. LEB trended more acute mesenteric ischemia than MES (n = 7; 77.7% vs n = 65; 44.5%; P = .052). LEB leg revascularizations were: two endovascular, one femoral endarterectomy, one femoral embolectomy, two axillary-bifemoral, two femoral-femoral, and one femoral-popliteal. Mesenteric bypass inflow was mostly supraceliac aorta in MES and LEB (n = 103; 70.6% vs n = 6; 66.6%; P = .804). Dual outflow for mesenteric bypass to superior mesenteric and celiac axis was similar for MEB and LEB (n = 85; 58.2% vs n = 6; 66.7%; P = .617). Patients in the LEB group had a mean prealbumin of 6, and admission BMI of 22.4. Mean estimated blood loss (EBL) in the LEB group was higher (1100 mL; range, 400-1500 mL vs 600 mL; range, 100-3000 mL; P = .014). Operative mortality was significantly higher in the LEB group (n = 36; 24.7% vs n = 6; 66.7%; P = .005). The systemic nature of atherosclerotic disease may become clinically relevant in patients being treated for lower extremity ischemic symptoms. Systemic hypotension or hypovolemia associated with anesthesia or blood loss from a lower extremity procedure may exacerbate a previously asymptomatic mesenteric artery stenosis. Vigilance is warranted for unexplained abdominal complaints in this subset of lower extremity ischemia patients.