Long-Term Outcome and the Radiological Evaluation of Lung Growth After Living-Donor Lobar Lung Transplantation in Pediatric Patients

Abstract

<h3>Purpose</h3> Living-donor lobar lung transplantation (LDLLT) is a valuable life-saving option for pediatric patients due to the scarcity of pediatric donor. The purpose of this study was to evaluate the long-term outcome and the lung growth of the transplanted adult lobe in growing pediatric recipients. <h3>Methods</h3> The clinical data of 30 pediatric LDLLTs (age<17) performed between June 2008 and December 2020 were reviewed. The annual pulmonary function test and CT scan data of the 12 recipients who were followed up for more than 5 years without significant complications were used for evaluating growth in height, graft function and radiological evidence of lung growth. Radiologic graft weight and air volume were calculated with CT value using 3D volume analyzer. <h3>Results</h3> Median age and height were 10 (3-15) and 125.3 cm (95-165), respectively. The procedures were unilateral transplantation of right lower lobe (n=12), bilateral transplantation of 2 lower lobes (n=13), and others including segmental and middle lobe transplantation (n=5). Ten-year overall survival and CLAD-free survival were 76.8% (Fig A) and 64.4%, respectively. In 12 recipients followed up for more than 5 years (median 6.5 years), the mean increase in height, vital capacity, and graft volume were 15.9%, 14.0%, and 55.4% (Fig B), respectively. Mean CT volumetric size matching (donor/recipient) at transplantation was 154% (53-367). The transplanted graft volume exceeded the original volume within the donor chest in 11 of 12 recipients (92%). During the median follow-up period of 3.0 years after the transplanted graft volume exceeded original one, the mean increase in radiologic graft weight was 6.6% and the radiologic graft weight was positively correlated with its air volume (r²=0.580, p<0.01, Fig C). <h3>Conclusion</h3> Pediatric LDLLT provided satisfactory long-term outcome with the radiological suggestion that the lung growth of transplanted mature lobe occurred in growing chest cavity.