The dynamic pulmonary functional change after thoracoscopic lower lobe segmentectomy

Background The advantages of segmentectomy over lobectomy in sparing pulmonary function remain controversial. Lower lobe segmentectomy is divided into simple segmentectomy, such as segment 6; and complex segmentectomy that includes the basal segments. Here, we compared residual lung function after thoracoscopic segmentectomy versus lobectomy in the lower lobe using the three-dimensional computed tomography volumetric method. Methods Between January 2012 and October 2020, 67 patients who underwent thoracoscopic segmentectomy of the lower lobe were matched to 67 patients who underwent thoracoscopic lower lobectomy during the same period using propensity score matching analysis. The postoperative decrease in the rate of forced expiratory volume in 1 s was compared between methods. The regional forced expiratory volume in 1 s of the residual lobe rescued by segmentectomy was measured using volumetric and spirometric analyses and compared to lower lobectomy. The ratio of the actual to predicted postoperative forced expiratory volume in 1 s in the residual lobe was defined as the preservation rate. Results Of the 67 thoracoscopic segmentectomies, 43 were S6, seven were S8, three were S8 + 9, seven were S10, and seven were S9 + 10. The percentage of postoperative/preoperative forced expiratory volume in 1 s was significantly higher in the segmentectomy versus lobectomy group (90.7% vs. 85.7%, p = 0.001). The preservation rates after simple segmentectomy (n = 43) and complex segmentectomy (n = 24) did not differ significantly (82.2% vs. 80.2%, p = 0.709). Conclusions Thoracoscopic lower lobe segmentectomy versus lobectomy preserves postoperative lung function. Even complex segmentectomy exhibited outcomes relevant to simple segmentectomy by sparing the residual lobe.