Living-donor lobar lung transplantation

Abstract

Living-donor lobar lung transplantation (LDLLT) has become an important life-saving option for patients with severe respiratory disorders, since it was developed by a group in the University of Southern California in 1993 and introduced in Japan in 1998 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 prior to transplantation, LDLLT provided good post-transplant outcomes, comparable to brain-dead donor lung transplantation in the early and late phases. In Kyoto University, the 5- and 10-year survival rates after LDLLT were reported to be 79.0% and 64.6%, respectively. LDLLT should be performed under appropriate circumstances, considering the inherent risk to the living donor. In our transplant program, all living donors returned to their previous social lives without any major complications, and living-donor surgery was associated with a morbidity rate of <15%. Both functional and anatomical size matching were preoperatively performed between the living-donor lobar grafts and recipients. Precise size matching before surgery could provide a favorable pulmonary function and exercise capacity after LDLLT. Various transplant procedures have recently been developed in LDLLT in order to deal with the issue of graft size mismatching in recipients, and favorable post-transplant outcomes have been observed. Native upper lobe-sparing and/or right-to-left inverted transplantation have been performed for undersized grafts, while single-lobe transplantation has been employed with or without contralateral pneumonectomy and/or delayed chest closure for oversized grafts.

Keywords: Living donor; brain-dead donor; cadaveric lung transplantation; lobar lung transplantation; size matching.

Figure 1

The numbers of lung transplantation performed in Japan and newly registered patients in the Japan Organ Transplantation Network have been increasing since the Japanese organ transplant law was revised in July 2010.

Figure 2

By the end of 2019, lung transplantation had been performed in 760 patients and LDLLT had been performed in 234 patients (30.8%). CLT, cadaveric lung transplantation; LDLLT, living-donor lung transplantation.

Figure 3

Indications for CLT and LDLLT. CLT, cadaveric lung transplantation; LDLLT, living-donor lung transplantation; ILD, interstitial lung disease; PAH, pulmonary arterial hypertension; LAM, lymphangioleiomyomatosis; HSCT, hematopoietic stem cell transplantation; COPD, chronic obstructive pulmonary disease; BE, bronchiectasis; DPB, diffuse panbronchiolitis; CLAD, chronic lung allograft dysfunction; BO, bronchiolitis obliterans; LCH, Langerhans cell histiocytosis; CF, cystic fibrosis.

Figure 4

The 5- and 10-year survival rates after LDLLT and CLT in Kyoto University. LDLLT, living-donor lobar lung transplantation; CLT, cadaveric lung transplantation.

Figure 5

Date’s formula for functional size matching between a living-donor lobar graft and a recipient. FVC, forced vital capacity; PAH, pulmonary arterial hypertension.