Effect of Inferior Pulmonary Ligament Management on Residual Lung Compensatory Function Following Thoracoscopic Upper Lobectomy

Background Compensatory lung expansion is crucial post-lobectomy. Inferior pulmonary ligament (IPL) division during thoracoscopic upper lobectomy is common but unproven for enhancement and may impair bronchial anatomy/function. Prospective studies using quantitative 3D functional lung volume (FLV) to evaluate IPL preservation versus division are lacking. This study assessed IPL management impact on postoperative pulmonary compensation using 3D FLV. Methods In this prospective randomized controlled trial, patients undergoing thoracoscopic upper lobectomy were intraoperatively assigned to IPL preservation (Group P) or division (Group D). Pulmonary function and residual bronchial angles were compared between groups at baseline and at 1, 3, and 6 months postoperatively. Results At 1 month postoperatively, Group P showed significantly smaller FLV and FEV₁ losses than Group D. From 1 to 3 months, Group P demonstrated significantly greater increases in FLV and FEV₁, particularly after right upper lobectomy. In right upper lobectomy, residual bronchial angle changes were significantly smaller in Group P at 1 and 3 months postoperatively. Group P also had significantly higher Leicester Cough Questionnaire scores at 1 and 3 months postoperatively. Conclusions IPL preservation during thoracoscopic upper lobectomy reduces early pulmonary function loss, enhances compensatory lung expansion, stabilizes bronchial anatomy, reduces cough, and accelerates recovery—particularly following right upper lobectomy.