Is Lobar Size Reduction a Safe and Value Procedure Compared to Standard Lung Transplantation? A Cohort Study with Propensity Score

PURPOSE: Lung transplantation (LT) usually requires an optimal donor/recipient size matching to guarantee satisfactory results. In patients of small dimensions or with reduced thoracic cage the waiting time to receive a standard organ may be greater than their life expectancy. Lobar reduction is an important surgical option for these subjects but it is so far underutilized. In addition, lobar transplantation is suspected of high perioperative complications being technically demanding. This bicentric cohort study analyzed the impact of lobar lung transplantation on 1-year survival. Secondary end-point were common early and long-terms outcomes. METHODS: A retrospective study was performed on 619 consecutive LT between January 2006 and December 2018 (559 standard LT, group I and 60 lobar reduction, group II). A propensity score weighting approach was employed to account for potential confounding factors. The effect of the intervention on the post-operative outcomes of interest was assessed using a weighted regression approach. RESULTS: The propensity score was estimated on 571 patients (522 in group I and 49 in group II). Group I presented a higher percentage of single LT (29% vs 4%, p<0.001) and a lower donor/recipient height ratio (1.02 vs 1.08, p<0.001). One-year survival for group I and II were 72 and 73%, respectively. Considering early outcomes, group II presented a higher percentage of severe PGD (2-3) at 72 hours (52 vs 35%, p=0.022) and longer ICU stay (9 vs 6 days, p=0.014) compared to group I. No other differences in terms of morbidity, mortality, mechanical ventilation and hospital stay were observed. At long-terms, the two groups presented comparable 5-year survival (51 vs 57%) and pulmonary function (best post-operative percentage FEV1, 84 vs 78%). At the regression analysis, lobar lung transplantation was associated with severe PGD at 72 hours (p=0.01) and worse long-term pulmonary function (p=0.04). CONCLUSION: In our cohort, lobar transplantation did not affect 1-year survival. Although a higher rate of severe PGD at 72 hours and a slightly reduced respiratory function were observed in the lobar transplantation group, these factors did not affect the morbidity and long-term survival. Lobar transplantation could be positively considered to increase the donors' pool especially for recipients with small chest cavity.