Prevalence and Distribution of Potential Vascularized Composite Allotransplant Donors, Implications for Optimizing the Donor-recipient Match.

Background: Vascularized composite allotransplantation (VCA) is an emerging and growing field. Little is known about the prevalence and distribution of the adult potential donor population in the United States now that it falls under the oversight of the United Network for Organ Sharing (UNOS).

Methods: We assessed the UNOS database from 2008 to 2015 to estimate the prevalence and distribution of adult potential vascularized composite allograft donors. Donor inclusion and exclusion criteria were developed in a way to minimize risk to recipients and were applied to the dataset. Donors were categorized by factors that influence vascularized composite allograft matching including ABO blood type, cytomegalovirus status, and ethnicity (correlate for skin color) and sorted by UNOS region.

Results: Just under half of all brain dead donors met the inclusion/exclusion criteria. Blood type O, cytomegalovirus+, White donors represented the most frequent donor profile while blood type AB, cytomegalovirus-, Asian donors were the least common. UNOS region 3 had the most and region 1 had the least potential VCA donors per year. Nearly all potential VCA donors were solid organ donors with the liver being the most commonly donated solid organ in this population.

Conclusions: A large portion of the solid organ donor pool would qualify as adult vascularized composite allograft donors in the current UNOS system. These data will assist transplant teams in determining the prevalence and distribution of vascularized composite allograft donors for their individual patients awaiting composite allografts based on relevant matching characteristics in addition to standard transplant criteria.