生体肺移植の現況と課題

Current Status and Problems of Living-donor Lobar Lung Transplantation

生体肺移植はドナー不足の一解決策として，1993年に南カリフォルニア大学により開発され，1998年に本邦に導入された1，2）．2010年7月の改正臓器移植法の施行以来，脳死肺移植数は増えたもののドナー不足の状況はかわらず，年間10〜20例の生体肺移植がコンスタントに行われている．本邦では2020年末までの23年間に251例の生体肺移植が行われており，生体肺移植は全肺移植835例の約30％を占める重要な治療法となっている（図1）．

Living-donor lobar lung transplantation （LDLLT） has become an important life-saving option for patients with severe respiratory disorders in order to address the current severe shortage of brain-dead donor organs. Although LDLLT candidates were basically limited to critically ill patients who would require hospitalization, the long-term use of steroids, and/or mechanical respiratory support before transplantation, LDLLT provided good post-transplant outcomes, comparable to brain-dead donor lung transplantation （BDLT）. In Kyoto University, the 1-, 5- and 10-year survival rates were 91％, 79％ and 62％ after LDLLT and 92％, 72％ and 65％ after BDLT, respectively. Various transplant procedures have recently been developed in LDLLT in order to deal with the issue of graft size mismatching. Native upper lobe-sparing and/or right-to-left inverted transplantation have been performed for undersized grafts, while single-lobe transplantation has been employed for oversized grafts. These new transplant procedures have provided favorable post-transplant outcomes.