Indirect Endovascular Revascularization via Collaterals: A New Classification to Predict Wound Healing and Limb Salvage

Abstract

In the setting of chronic limb ischemia, lower extremity (LE) wounds require revascularization of source arteries for wound healing and limb salvage. Direct revascularization of the source artery is preferred but cannot always be performed. Our objective was to analyze the influence of arterial-arterial connections on clinical outcomes after angiosome-directed endovascular revascularization. Consecutive LE wounds in patients with isolated infra-popliteal disease revascularized endovascularly from 2012 to 2016 within a single center were retrospectively reviewed. Treatment was classified as direct revascularization (DR) if the source artery supplying the wound angiosome was treated, indirect revascularization via collaterals (IR-C) if the source artery angiosome was revascularized by another major artery via arterial connections, or indirect revascularization (IR) if direct revascularization of the source artery angiosome was not possible. Demographics, comorbidities, and patient outcomes were collected. Of 105 patients with 106 LE wounds, there were 35, 38, and 33 patients in the DR, IR-C, and IR groups, respectively. The mean age was 65.8years old (standard deviation (SD) 11.9) with 81 males (77.1%) and 24 females (22.9%). Average follow-up was 21.0months (SD 14.0). Overall wound healing rates were 80.0%, 92.1%, and 63.6% for DR, IR-C, and IR, respectively (P=0.009). Significant differences were found between all 3 group comparisons, DR versus IR-C (P=0.010), DR versus IR (P=0.013), IR-C versus IR (P=0.008). Overall major amputation-free survival was 85.7%, 89.5%, and 69.7% in DR, IR-C, and IR groups, respectively, with statistically significant differences between the IR-C and IR groups (P=0.036). Treating diseased infra-popliteal arteries and improving blood flow via arterial-arterial connections as per the angiosome model improved wound healing and amputation-free survival in this cohort. Although DR is still the gold standard, revascularization using IR-C may give superior healing results even in highly comorbid patients. This offers an additional avenue for treatment, especially when DR is not possible.