Oversizing lung allografts deteriorates outcomes in patients with pulmonary fibrosis

Lung transplantation is the only curative treatment for patients with end-stage pulmonary fibrosis. It is still under debate whether over- or undersizing of lung allografts is preferably performed regarding the postoperative outcome. We therefore analyzed our data using predicted total lung capacity to compare size mismatches.

Patient records were retrospectively reviewed. Three groups were formed, 1 including patients with a donor-recipients pTLC ratio (DRPR) of <1.0 (undersized group), the second with a DRPR of ≥1.0 and <1.1 (size-matched group), and the third group with a DRPR of ≥1.1 (oversized group). Outcomes were evaluated using chi-square test and Kruskall-Wallis test as well as Kaplan-Meier analysis, competing risk analysis, and multivariable analysis, respectively.

Between January 2010 and May 2023, among the 1501 patients transplanted at our institution, 422 (28%) patients were included, 26 (2%) patients forming the oversized group (median DRPR: 1.14), 101 (7%) patients forming the size-matched group (median DRPR: 1.03), and 296 (20%) patients forming the undersized group (median DRPR: 0.92). Patients from the oversized group had a higher PGD grade 3 rate at 24 (p < 0.001), 48 (p < 0.001), and 72 (p = 0.039) hours after transplantation as well as a higher in-hospital mortality compared to the undersized group (p = 0.033). The long-term survival was also better in the undersized group compared to the oversized group (p = 0.011) and to the size-matched group (p = 0.01).

Oversizing lung allografts more than 10% deteriorated early postoperative outcomes and long-term survival in patients with pulmonary fibrosis.