Differences in postoperative changes in pulmonary functions following segmentectomy compared with lobectomy

Abstract

OBJECTIVES: To clarify differences in postoperative changes in systemic and regional pulmonary functions between segmentectomy and lobectomy in patients with lung cancer, we compared the 2 procedures using lung perfusion scintigraphy with a fusion image of singlephoton emission computed tomography and computed tomography. METHODS: This study is a retrospective matched cohort study of consecutively acquired data. Pulmonary function tests and perfusion single-photon emission computed tomography/computed tomography were conducted before surgery and 6 months after surgery to measure changes in forced expiratory volume in 1 s of a whole lung, contralateral lung and a lobe. After exactly matching the site of the resected lobe between the 2 procedures, propensity scores for age, sex, smoking status and pulmonary function were used to match them. RESULTS: Of the 184 patients treated with segmentectomy and the 208 patients treated with lobectomy between 2013 and 2016, 103 patients were selected from each group after the matching. Whole lung function was significantly more preserved after segmentectomy than after lobectomy (P < 0.001). Segmentectomy preserved the function of the operated lobe with 48 ± 21% of the preoperative function. The function of the ipsilateral non-operated lobe increased after segmentectomy (P = 0.003) but not after lobectomy (P = 0.97). Contralateral lung function increased after both procedures (P < 0.001). CONCLUSIONS: Our data suggest that segmentectomy preserved whole lung function better than lobectomy, because it not only preserved the lobe but also increased the function of the ipsilateral non-operated lobe. Lobectomy did not result in an increase of ipsilateral non-operated lobe function. Contralateral lung function increased after both procedures. The postoperative increase in regional functions could be the result of compensatory lung growth.