Facing Allograft Failure: A Systematic Review of Explantation and Retransplantation in Vascularized Composite Allotransplantation

Background: Vascularized composite allotransplantation (VCA) can restore form and function beyond conventional reconstruction, but acute (AR) and chronic rejection (CR) limit long-term allograft survival. When allograft failure becomes irreversible, explantation or retransplantation may be necessary. This review evaluates the indications, management, and operative considerations associated with explantation and retransplantation in VCA. Methods: A systematic review of PubMed, PubMed Central, MEDLINE, Scopus, and Web of Science was conducted to identify studies reporting patient-level data on VCA recipients who underwent allograft explantation or retransplantation. Extracted data included recipient demographics, immunologic characteristics, rejection history, and explantation or retransplantation outcomes. Results: Nineteen studies reporting 25 VCA recipients were included, comprising 22 explants and three retransplants (two face, one abdominal wall). The most common VCA types were uterus (32%), face (24%), and hand (16%). The leading indications for graft removal were CR (44%), perfusion-related complications (32.0%), medication non-compliance (24.0%), and patient request (12.0%). The median time to explant was 12.5 months, and to retransplant was 7.3 years. Management of CR included pulse steroids, increased immunosuppression, plasmapheresis, and biologic agents. Retransplantation was more technically challenging than the primary transplant due to scarring, distorted anatomy, and vessels affected by CR, requiring more proximal vascular anastomoses and nerve coaptations. Conclusion: Explantation and retransplantation in VCA are feasible but last-line interventions. The leading cause of graft loss was CR, though perfusion-related and patient-related factors also contributed. Earlier recognition and management of AR, clearer definitions of CR, and overall improved strategies to prevent progression to irreversible graft failure are needed.