Amputation-Free Survival, WIfI Stage, and GLASS Classifications in Distal Crural or Pedal Bypass for Chronic Limb-Threatening Ischemia.

Background: Chronic limb-threatening ischemia (CLTI) is a severe condition with high risks of amputation and mortality, especially in patients with distal crural or pedal artery disease. Despite advances in endovascular techniques, bypass surgery remains crucial for patients with CLTI. This study aimed to investigate amputation-free survival, Wound, Ischemia, and foot Infection (WIfI) staging, and Global Limb Anatomic Staging System (GLASS) classifications in patients undergoing distal crural or pedal bypass for CLTI. Methods: This retrospective study analyzed all patients who underwent distal crural or pedal bypass for CLTI in a tertiary vascular centre from January 2010 to December 2019. The data were collected from hospital records and preoperative imaging. WIfI stages and GLASS classifications were determined for each patient, and the primary endpoint was amputation-free survival. Secondary outcomes included bypass patency, 30-day morbidity, and mortality. Results: We identified 31 bypasses performed on 29 patients with a median age of 67 years (79% male). Preoperatively, 94% of limbs were staged GLASS III and 55% were classified WIfI stage 4. Failed endovascular revascularization preceded bypass surgery in 65% of the cases. Thirty-day mortality was 3% (n = 1) and 30-day major amputation rate was 10%. Primary patency was 87%, and secondary patency was 94% at 30 days. Median duration of follow-up for survival was 59 months with a mean follow-up index (FUI) of 0.99 ± 0.05, and for major amputation and bypass patency 54 months (mean FUI 0.9 ± 0.19 and 0.85 ± 0.28, respectively). At one year, amputation-free survival was 58%, decreasing to 45% at two years, 39% at three years, and 32% at five years. Most major amputations occurred in WIfI stage 4 patients, but 53% of WIfI stage 4 and 80% of WIfI stage 3 patients were alive without major amputation after one year. Conclusions: Distal crural and pedal bypasses are essential for limb salvage in high-risk CLTI patients, particularly those with failed prior revascularization. However, the procedure is associated with limited long-term amputation-free survival. WIfI and GLASS classifications are useful for stratifying risk and guiding treatment, but outcomes suggest the need for individualized care strategies. Further research into perioperative management and alternative interventions is warranted to improve long-term outcomes in this population.