Post-operative volume changes in residual lung lobes after VATS pulmonary segmentectomy for early stage non-small...

Pulmonary segmentectomy is a valid alternative to lobectomy in early-stage non-small cell lung cancer (NSCLC). However, limited data are available on post-operative compensatory volume changes following segmentectomy. The aim was to clarify the temporal patterns of lobar volume changes in the residual and contralateral lung at 6 and 12 months post-segmentectomy using 3D reconstruction.

We retrospectively reviewed patients who underwent video-assisted thoracoscopic surgery (VATS) segmentectomy for early-stage NSCLC from 2017 to 2022. Pre-operative lung lobe volumes were calculated from three dimensional (3D) reconstruction (Materialize^®) and compared with volumes at 6 and 12 months post-operatively.

A total of 30 patients (median age: 66, sex ratio M/F: 14/16) were included. On the right side (n = 15), median lobar volume loss reached 62.4% (p = 0.03) after upper S1 segmentectomy, 38.9% (p > 0.05) after S2 and 35.5% (p > 0.05) after S6 at 12 months. Compensatory expansion was predominant in the lower lobe for upper segmentectomies, respectively + 24.2% (p > 0.05) for S1 and + 22.2 (p > 0.05) for S2, whereas compensation in middle lobe was present for S1 segmentectomy (+ 17%, p = 0.03) and for S6 (+ 14.9%, p > 0.05). On the left side, median volume loss was 73.0% (p = 0.03) after upper trisegmentectomy, 34.8% (p > 0.05) after lingulectomy, and 37.4% (p = 0.03) after S6 resection. Compensatory expansion mainly involved the lower lobe for upper resections (+ 31.4%, p = 0.03), while the upper lobe increased by + 11.4% (p = 0.03) following lower-lobe segmentectomy. No volume difference was observed in the contralateral lobes over 12 months across resection types. Overall total lung volume was largely unchanged at 12 months across resection types, except for left S6 segmentectomy (a 6.6% decrease, p = 0.03).

Volume compensation mechanisms occur after VATS segmentectomy, with more pronounced volume reduction following upper-lobe resections compared to lower-lobe resections. The absence of contralateral volumetric compensation may allow subsequent compensatory responses to occur and potentially contribute to a better preservation of lung function in patients undergoing additional pulmonary resections. Characterizing these patterns is important for surgical planning and optimizing postoperative management in patients undergoing segmentectomy for early-stage NSCLC.