Society for Vascular Surgery femoral runoff score is associated with limb-based patency after aortofemoral bypass

Abstract

ObjectiveDespite advancements, aortofemoral bypass (AFB) remains the most durable option for aortoiliac occlusive disease. Although runoff has been shown to be associated with AFB patency, the association of the Society for Vascular Surgery (SVS) thigh runoff scoring system with patency has not been assessed. The aim of the present study was to evaluate the association between the SVS runoff scoring system and limb-based primary patency after AFB. MethodsInstitutional data for patients undergoing AFB with preoperative runoff imaging available from 2000 to 2017 were queried. Runoff scores were assigned according to the presence of occlusive disease in the superficial femoral artery and profunda femoris artery (minimum, 1; maximum, 10) as described by the 1997 SVS reporting standards for lower extremity ischemia. Limb-based patency was the primary endpoint. Kaplan-Meier analysis was used to compare the long-term limb-based patency and freedom from reintervention between limbs with runoff scores ≥6 and those with runoff scores <6. Propensity score-weighted Cox proportional hazards modeling was used to evaluate the association between a runoff score of ≥6 and primary patency loss, controlling for other factors associated with primary patency. ResultsIn 161 patients, 316 limbs had undergone revascularization. The mean patient age was 66.7 ± 11.3 years, and 51.6% were women. Most limbs had undergone revascularization for claudication (56.5%). Most (89.4%) had TransAtlantic InterSociety Consensus class D lesions, 27.3% had required suprarenal or higher clamping, and 11.2% had undergone concomitant mesenteric intervention. A femoral outflow adjunct and concurrent lower extremity bypass was required in 41.8% and 2.9% of limbs, respectively. Those with a runoff score of ≥6 had experienced greater rates of 30-day myocardial infarction (11% vs 1%; P = .005), respiratory failure (11% vs 1%; P = .005), and mortality (8% vs 0%; P ≤ .006). The median follow-up period was 4.0 years (interquartile range, 6.5 years). The 1-, 3-, and 5-year primary patency was 94.6% (95% confidence interval [CI], 91.9%-97.3%), 89.2% (95% CI, 85.4%-93.2%), and 81.4% (95% CI, 76.0%-87.1%), respectively. The 5-year primary-assisted patency, secondary patency, and freedom from reintervention were 84.9% (95% CI, 79.7%-90.5%), 91.7% (95% CI, 87.3%-96.3%), and 83.3% (95% CI, 78.3%-88.7%), respectively. Patients with a runoff score of ≥6 had lower primary (log-rank P < .01), primary-assisted (P < .01), and secondary patency (P = .01). The factors associated with the loss of primary patency included a high runoff score (runoff score of ≥6: hazard ratio [HR], 4.1; 95% CI, 2.1-8.0; P < .01), simultaneous mesenteric endarterectomy (HR, 13.5; 95% CI, 1.9-97.8; P = .01), and chronic kidney disease (HR, 4.6; 95% CI, 1.5-14.6; P = .01). Increasing age (HR, 0.94 per year; 95% CI, 0.91-0.97; P < .01) and hyperlipidemia (HR, 0.44; 95% CI, 0.23-0.85; P = .01) were protective. ConclusionsThe SVS femoral runoff score is an important factor associated with long-term AFB limb patency. Scores of ≥6 portend for worse limb outcomes and a greater incidence of operative complications. The SVS score can be determined from preoperative axial imaging studies and serve as a guide in decision-making and operative planning.