Limb outcomes based on limb severity and anatomic complexity following infrapopliteal vein bypass for Japanese patients with chronic limb-threatening ischemia

Objective: The 2019 Global Vascular Guidelines recommend a suitable initial revascularization method with reference to limb severity (wound, ischemia, and foot infection [WIfI] stage) and anatomic complexity (Global Limb Anatomical Staging System [GLASS] stage). However, limb outcomes after revascularization among WIfI and GLASS stages have not been investigated fully after infrapopliteal vein bypass. The purpose of this study was to assess the four Global Vascular Guideline-recommended limb outcomes after infrapopliteal vein bypass in cases with different WIfI and GLASS stages. Methods: Patients who underwent infrapopliteal vein bypass for chronic limb-threatening ischemia at a single center were analyzed retrospectively. Medium-term limb outcomes were compared among WIfI and GLASS stages. The primary end points were limb salvage rate and major to minor amputation ratio, and the secondary end points were wound healing rate and wound healing time. Results: A total of 353 infrapopliteal vein bypasses were performed in 284 patients with tissue loss (male, 193 patients; median age, 77 years; diabetes, 71%; hemodialysis, 41%). A total of 111 limbs (31%) required only minor amputation and 38 limbs (11%) required major amputation. The major to minor amputation ratio was 0.34 with no significant differences among WIfI stages or GLASS stages. The 3-year limb salvage rate was 87%. This rate was significantly lower in WIfI stage 4 than in stage 2 (P = .049), but did not differ significantly among GLASS stages. The 12-month wound healing rate was 86%. This rate was also significantly lower in WIfI stage 4 than in stages 2 and 3 (both P < .001), but did not differ significantly among GLASS stages. The median wound healing time was 55 days (range, 32-110 days), and was significantly longer in WIfI stage 4 compared with stages 2 (P = .001) and 3 (P < .001), but showed no significant differences among GLASS stages. Conclusions: The limb salvage rate, wound healing rate, and wound healing time were associated with limb severity (WIfI stage), but not with anatomic complexity (GLASS stage). These findings suggest that an appropriate preoperative strategy and careful perioperative management are important for patients with greater limb severity.