Safety of transfer, type of procedure, and factors predictive of limb salvage in a modern series of acute limb ischemia.

OBJECTIVE: The primary objective was to evaluate the safety of transfer, type of procedure, and factors associated with limb salvage in patients with acute limb ischemia (ALI) treated at a quaternary referral center.

METHODS: A retrospective review of all patients with ALI secondary to thrombotic or embolic occlusion at a quaternary referral hospital from 2013 to 2016 was conducted. Patients were transferred from throughout Washington and Alaska by ambulance, helicopter, or fixed-wing modes of transportation. Demographics, transport and operative timing, Rutherford classification, level of occlusion, procedural information, and fasciotomy characteristics were reviewed. Outcomes measured included limb salvage rates, discharge disposition, and mortality.

RESULTS: One hundred twelve patients with ALI were identified, with 82% due to thrombosis and 18% due to arterial embolization. Fifty-seven percent of patients were transferred from a referring hospital with low mean transfer times (1.9 hours for embolic, 2.7 hours for thrombotic). Although the initial operative strategy varied according to the etiology, with 50% of thrombotic occlusions treated with endovascular therapies and 80% of embolic occlusions treated with open thrombectomy, the rates of limb salvage did not vary based on operative approach (92% endovascular first, 90% open first). Further, limb salvage rates were identical between transferred and nontransferred patients (77%). Limb salvage was successful in 91% of patients with Rutherford class 1 and 2 disease, but only 8% in patients with Rutherford class 3 disease. In-hospital and 30-day mortality rates were not different based on ischemic etiology (5%), although patients with Rutherford class 3 disease had significantly higher mortality rates (15%) compared with patients with class 1 (6%), class 2a (6%), and class 2b (2%) disease. Fasciotomy was performed in 29% of patients, with 59% of fasciotomy wounds closed primarily. Predictors of amputation include multiple attempts at limb salvage, higher Rutherford class, multilevel occlusion, more proximal levels of occlusion, and nonviable muscle seen after fasciotomy, with ischemic times trending toward higher amputation rates without statistical significance. There was no difference in discharge disposition based on ischemic etiology.

CONCLUSIONS: The modern treatment of patients with ALI is effective, with high rates of limb salvage and low mortality regardless of transfer status, etiology, or initial operation performed. In situations where compartment syndrome is unclear, fasciotomy should not be withheld because it provides valuable predictive information regarding limb salvage.