Evaluation of autologous venous allograft for lower limb in the treatment of critical limb ischemia. The REVATEC (REVAscularisation par greffons veineux bioproTEC) study

Objective: Chronic limb-threatening ischemia (CLTI) requires revascularization whenever it is possible. The great saphenous vein represents the surgical conduit of choice. However, it is not always available, in particular in multi-operated patients. In such cases, alternative efficient biological conduits are needed but data remains limited. This study aims at evaluating the performance of cold stored venous allografts provided by Bioprotec® society.

Methods: Prospective multi-center cohort. The primary endpoint was limb salvage rate at one year following revascularization with cold stored venous allografts. Follow-up based on clinical examination and duplex-scan. Uni- and multivariate analyses were performed to analyze predictive factors of endpoints.

Results: Overall, 39 patients (40 limbs) were included between 2018 and 2021. Patients had a median of 2 [0-6] revascularizations prior to inclusion. A total of 97 grafts were used (median of 3 [1-4] grafts per procedure). In the postoperative period (30 days) no death and 4 major amputations were noted. The median length of follow-up was 13.4 [0.7-31.1] months. The six-months, one-year and two-year freedom from major amputation rates were 79% [95% CI: 68-93], 75% [95% CI 62-91] and 68% [95% CI: 51-90], respectively. The six months, one-year and two-year survival rates were 95% [88-100], 83% [95% CI: 71-98] and 79% [95% CI: 65-96], respectively. Primary patency rates were 77% [95% CI: 64-91] at six months, and 47% [95% CI: 32-70] at one and two years. Secondary patency rates were 82% [95% CI: 70-95] at 6 months and 50% [95% CI: 34-73] at one and two years. The analysis identified the number of previous revascularizations as a significant risk factor for graft patency (Hazard Ratio: 1.59; 95% Confidence Interval: 1.13-2.24).

Conclusion: Revascularization of CLTI patients with previous failed interventions is highly challenging. The use of cold stored venous allograft showed encouraging limb salvage rate despite modest patency rates and thus may represent an alternative to other substitute in some selected cases. More studies are necessary to identify the potential of CSVA in CLTI patients.