Introduction: Rate of organ donation per million population (pmp) in Japan from deceased donor remains low (0.99 pmp), though gradual improvement including increase in pediatric donors has been observed in the past years. Tissue donation activity, however, has not been well described in English literature.
Unlike organ donation, tissue donation is not clearly stated within the legal framework in Japan. It has been dealt with by donor coordination system independent from organ donation scheme under the guidance of Japanese Society of Tissue Transplantation. Tissue donation continues to require additional, separate consent process apart from organ donation.
University of Tokyo Tissue Bank function as the information hub for East Japan Tissue Transplantation Network (EJTTN) that covers all tissue categories in Eastern Japan (population 63.9 million). As the core facility, we here in present our experience.
Methods: Retrospective analysis of EJTTN donor registry data from 2017 to 2019 was conducted.
Results: Total number of donor information reported to EJTTN from 2017 to 2019 was 182 cases of which 136 cases (75%) were via organ donor coordinators.
Of the 182 cases, 138 (76%) met the initial medical screening criteria for donation, and were geographically identified within the designated recovery area. Family members were willing to discuss donation with tissue donor coordinators in 96 cases (53%), of which 65 (36%) resulted in obtaining consent for tissue donation. Actual recovery (including one or more tissue types; heart-valves, vessels, skin, musculoskeletal, pancreas islet) took place in 62 cases (34％). Thirty-six cases (58%) were with organ donation (21 under brain death, 15 after cardiac death), and 26 were tissue alone recovery.
Number of tissue donors were 21 cases (0.35 pmp), 18 cases (0.30 pmp), and 23 cases (0.38 pmp), while organ donors within the matched region were 44 cases (0.69 pmp), 41 cases (0.64 pmp), and 62 cases (0.97 pmp), for 2017, 2018, and 2019 respectively.
Discussion: Despite the lack of legal supportive framework, tissue donation and recovery system continues to provide valuable tissue transplant opportunities in Japan. Our study shows, however, that majority (75%) of donor information comes from network of organ donor coordinators, and most (58%) tissue recovery were carried out with organ donation. Consequently, parallel to organ donation, total number remains low. Cultivating public awareness on the characteristics of tissue donation, including request and donation after cardiac death, may provide appealing options considering the cultural back ground in Japan.
Conclusion: Our analysis suggests close cooperation with organ donation system is important for tissue donation activity. Considering the limited numbers of organ donor, however, efforts to increase donor for tissue recovery alone may be beneficial.