Objective Performance Goals for Surgical Treatment of Critical Limb Ischemia

Based on prospective vein bypass trials for lower leg ischemia, objective performance goals (OPG) were established by the Society for Vascular Surgery (SVS) and are used as a benchmark tool for open and endovascular treatments. This study aims to analyze OPG of all patients with critical limb ischemia (CLI) treated by open revascularization techniques at a tertiary care facility in routine practice.

From January 2005 to March 2013, 315 patients (mean age 72 years) with CLI were retrospectively included in this study. Inclusion criteria were patients with Fontaine stage III and IV, realized revascularization with open surgical procedures (bypass grafting or endarterectomy), or hybrid method (open + endovascular). Exclusion criteria were primary major amputations, patients with revascularization treatments of the index leg within the last 3 months, and missing aftercare. Primary end point was "amputation-free survival" (AFS), and secondary end point was "freedom from major adverse limb event + perioperative death (30 days)" (MALE + POD) according to the SVS. The technical end point was primary patency. Mean follow-up was 34 months. The following variables were studied: clinical stage (Fontaine), previous interventions, bypass material used, and site of the distal anastomosis. The statistical evaluation and preparation was carried out using the Kaplan-Meier estimator and the log-rank test. A multivariate analysis was performed using the Cox proportional hazards model. A P value ≤0.05 was considered to be statistically significant.

A total of 128 patients (31%) fulfilling the adjusted SVS OPG criteria showed significantly better results for AFS, MALE + POD, and primary patency (P = 0.013, P = 0.015, P = 0.002, respectively). Regarding the AFS (1 year: 74%), multivariate analysis displayed significant worse results for patients with end-stage renal disease (hazard ratio [HR] 2.90, 95% confidence interval [CI] 1.83-4.60, P < 0.001) and Fontaine stage IV (HR 1.69, 95% CI 1.11-2.57, P = 0.015). Regarding MALE + POD (1 year: 64%), male patients (HR 0.64, 95% CI 0.46-0.90, P = 0.011) showed a significantly better outcome and patients without previous interventions of the index leg (HR 1.51, 95% CI 1.09-2.09, P = 0.013) showed a significantly worse outcome.

In this study, we were able to show that it is possible to reach the efficacy of OPGs set by SVS in a surgically treated all-comers cohort of CLI patients. Nevertheless, patients who did not fulfill the SVS OPG criteria showed significantly worse results for AFS and MALE + POD.