Facial Subunit Transplantation: Current Concepts and Future Directions

Complex facial defects resulting from trauma, cancer, or congenital genital disorders present significant challenges for reconstructive surgery. Traditional methods, such as local flaps and grafts, often yield suboptimal aesthetic and functional outcomes. Facial vascularized composite allotransplantation (fVCA) has become a valid option for extensive facial defects. The isolated transplantation of facial subunits, however, potentially allowing for a targeted restoration of smaller defects of individual subunits, is currently not implemented in clinical practice.

This narrative review synthesizes findings from animal models, human cadaver studies, and clinical experiences to assess the feasibility, anatomical requirements, and immunosuppressive demands of facial subunit transplantation. We examined preclinical studies on vascular supply dynamics and rejection in transplanted tissues, particularly in animal models like nonhuman primates and rats, and cadaver studies focusing on vascularization strategies for facial subunits.

Our results indicate that subunit transplantation is anatomically feasible, with established pedicle options for specific regions. Immunosuppression protocols similar to full-face transplantation are required, with preclinical models showing a critical need for optimized immunosuppressive management to prolong graft survival. Cadaver studies reveal that adequate vascularization can be achieved in subunits with the facial artery as the main pedicle.

Facial subunit transplantation offers the potential for improved outcomes in selective facial reconstruction, particularly in functional and aesthetic-critical subunits. However, further advancements in immunosuppression and vascular planning are necessary for clinical application. Addressing these challenges could position subunit transplantation as a less invasive alternative for specific patient populations with tailored benefits regarding localized facial defects.