Pulmonary function changes after different extent of pulmonary resection under video-assisted thoracic surgery

Background: Limited resections for early stage lung cancer have been of increasing interests recently. However, it is still unclear to what extent a limited resection could preserve pulmonary function comparing to standard lobectomy, especially in the context of minimally invasive surgery. The purpose of this study was to evaluate postoperative changes of spirometry in patients undergoing video-assisted thoracic surgery (VATS) lobectomy or limited resections. Methods: Spirometry tests were obtained prospectively before and 6 months after 75 VATS lobectomy, 34 VATS segmentectomy, 15 VATS wedge resection. Eleven VATS mediastinal procedures without lung resection were taken as a control group. Results were compared between groups of different resection extent. Results: Demographic characteristics and preoperative pulmonary function showed no differences among the four groups. Forced vital capacity (FVC) loss after lobectomy was significantly greater than after segmentectomy (P = 0.048), and much significantly greater than after wedge resection (P < 0.001). Forced expiratory volume in 1 second (FEV1) loss after lobectomy was similar to segmentectomy (P = 0.273), both significantly greater than after wedge resection (P < 0.01). Diffusing capacity of the lungs for carbon monoxide (DLCO) loss was similar among these three groups (P = 0.293). There was no significant difference in any spirometry index between wedge resection and mediastinal procedures (FVC: P = 0.856; FEV1: P = 0.671; DLCO: P = 0.057). When compared by average value per segment resected, pulmonary function loss was significantly less after lobectomy than after segmentectomy in all spirometry indexes (P < 0.001). On average, pulmonary function loss was around 5% per segment for VATS lobectomy and 10% per segment for VATS segmentectomy. Conclusions: In minimal invasive surgery, wedge resection best preserves pulmonary function with similar spirometry change with VATS mediastinal procedures without lung resection. Compared with VATS lobectomy, VATS segmentectomy may help minimize loss of FVC but not FEV1 or DLCO. Pulmonary function loss per segment resected is doubled after VATS segmentectomy than after lobectomy. These results should be taken into account when deciding the extent of resection for patients with early stage lung cancer.