(487) - How Donor Graft Lungs Behave in a Recipient Thorax After Living-Donor Lobar Lung Transplantation: 2-Year Follow-up

Abstract

Purpose: In living-donor lobar lung transplantation (LDLLT), there is a wide range of size discrepancies between donor and recipient. The aim of this study was to investigate how such donor grafts behave in the new recipient thorax after LDLLT. Methods: Twenty-six donor grafts in 13 bilateral LDLLT were enrolled in this study. The recipient's original diseases were bronchiolitis obliterans in 5 patients, pulmonary fibrosis in 5, bronchiectasis in 2, and pulmonary hypertension in 1. Pulmonary function tests and three-dimensional computed tomography (3D-CT) volumetry were performed before LDLLT and 3, 6, 12, and 24 months after LDLLT. Postoperative changes of pulmonary function and volume in the donor grafts were further investigated. Results: Donor graft volume ranged from 39 to 180% of the hemilateral tho- racic volume of the recipient. Only 2 recipients grew taller by 7cm and 11cm in 2 years. Graft forced vital capacities (FVC) increased over time, reaching 102 ± 39% and 109 ± 42% of preoperatively estimated values at 12 and 24 months after LDLLT, respectively. Graft volume also increased over time, reaching 122 ± 39% and 130 ± 39% of the original size at 12 and 24 months postoperatively. As for the association between postoperative donor graft volume ratio to the original value and preoperative 3D-CT volumetry size matching, there was a significant correlation between these parameters throughout postoperative timings (3, 6, 12, 24 months after LDLLT, p < 0.05). In contrast, there w as no significant correlation between postoperative donor graft FVC ratio to the preoperatively estimated value and preoperative 3D-CT volumetry size match- ing throughout postoperative timings. Furthermore, postoperative donor graft volume was significantly correlated with preoperative hemithorax volume of the recipient throughout postoperative timings (p < 0.01). Conclusion: We found that both lung function and volume in donor grafts significantly improved even 2 years after LDLLT. Furthermore, donor grafts adapted themselves to the recipient's thoracic cage by overinflating or under- inflating to the extent that they could maintain their own function in a new recipient environment.