Pulmonary Function Recovery and Displacement Patterns After Anatomic Segmentectomy vs Lobectomy

Background The functional benefit of segmentectomy compared with lobectomy remains controversial. This ambispective study characterizes the changes in pulmonary function as correlated to displacement patterns of residual lung after segmentectomies vs lobectomies. Methods Patients with normal preoperative pulmonary function and undergoing segmentectomy or lobectomy between 2017 and 2021 were considered. Pulmonary function testing was scheduled preoperatively and at least 3 months postoperatively. Differences in the proportions of the median forced expiratory volume in 1 second (FEV1) reduction between segmentectomy and lobectomy were calculated. Covariance analysis was used to estimate the adjusted postoperative FEV1 (apoFEV1) and compare the difference value (DV) in apoFEV1 between segmentectomy and lobectomy. Results The study enrolled 634 patients (334 lobectomies and 300 segmentectomies). Median difference in the proportions of the FEV1 reduction between segmentectomy and lobectomy was 4.58%, with maximal difference observed in right S6 (9.08%) and minimal difference in left S1+2+3 (2.80%). For resections involving the upper lobe, apoFEV1 was significantly higher after segmentectomy than after lobectomy (DV, 0.15-0.22 L), except for left S3 and S1+2+3 segmentectomies (DV, 0.08 L and 0.06 L, respectively). Compared with a lower lobe lobectomy, S6 segmentectomy conferred a higher apoFEV1, whereas S7+8 and S9+10 had a similar apoFEV1 (DV, 0.16-0.18 L, 0.07 L, and 0.00-0.06 L, respectively). Functional recovery after segmentectomy was associated with the number of intersegment planes (P < .01) and the presence of an adjacent nonoperated on lobe (P = .03). Conclusions Basilar and left S3 segmentectomies did not preserve more pulmonary function compared with their corresponding lobectomies, possibly due to the presence of multiple intersegmental resection planes.