Impact of Lung Allograft Oversizing on Pleural Cavity Expansion in Transplant Recipients with Idiopathic Pulmonary Fibrosis

Abstract

Purpose Due to parenchymal fibrosis and chest wall contraction in idiopathic pulmonary fibrosis (IPF), lung allografts are generally undersized to accommodate the smaller diseased chest cavity. We hypothesized that oversized allografts could be transplanted in recipients with IPF and result in thoracic cavity expansion. Methods We conducted a retrospective study on patients with IPF who underwent single or bilateral lung transplantation between 2014 and 2017 at our institution. Lung height was measured from lung apex to mid-diaphragm on donor and recipient chest radiographs. Donor lungs that were ≥10% larger than native recipient lungs were deemed oversized. Allograft lung height was measured monthly for the first postoperative year. Pulmonary function was assessed by FVC and FEV1. Data were analyzed by univariate analysis. Results 40 patients with IPF underwent lung transplantation. 7 were excluded due to lack of donor information. Of the remaining 23 bilateral and 20 single lung transplants, 21 were deemed oversized and 12 were similarly sized. There were no significant differences in donor and recipient characteristics or hospital length of stay between similarly sized and oversized groups (26.50 days ± 7.42 days vs 25.95 days ± 5.75 days, P= 0.9536). In the oversized group, a significant increase in right and left lung height was observed across all postoperative time points (Figure). In bilateral transplant recipients, no differences were evident at 12-month follow-up between similarly sized and oversized groups in FVC (66.80% ± 6.96% vs 69.90 ± 4.92%, P= 0.7218) or FEV1 (72.40% ± 9.24% vs 72.60% ± 25.05%, P= 0.9825). Conclusion Pleural cavities of patients with IPF expand to accommodate larger lung allografts over the first year post-transplant. Our data shows noninferiority in pulmonary function testing between oversized and similarly sized allografts. Thus larger allografts can be utilized in IPF, potentially increasing donor availability for these patients.