The difference in postoperative pulmonary functional change between upper and lower thoracoscopic lobectomy

: OBJECTIVES: Through 3-dimensional lung volumetric and morphological analyses, we aimed to evaluate the difference in postoperative functional changes between upper and lower thoracoscopic lobectomy. METHODS: A total of 145 lung cancer patients who underwent thoracoscopic upper lobectomy (UL) were matched with 145 patients with lung cancer who underwent thoracoscopic lower lobectomy (LL) between April 2012 and December 2018, based on their sex, age, smoking history, operation side, and pulmonary function. Spirometry and computed tomography were performed before and 6 months after the operation. In addition, the postoperative pulmonary function, volume and morphological changes between the 2 groups were compared. RESULTS: The rate of postoperative decreased and the ratio of actual to predicted postoperative forced expiratory volume in 1 s were significantly higher after LL than after UL (P < 0.001 for both). The tendency above was similar irrespective of the resected side. The postoperative actual volumes of the ipsilateral residual lobe and contralateral lung were larger than the preoperatively measured volumes in each side lobectomy. Moreover, the increased change was particularly remarkable in the middle lobe after right LL. The change in the D-value, representing the structural complexity of the lung, was better maintained in the left lung after LL than after UL (P = 0.042). CONCLUSIONS: Pulmonary function after thoracoscopic LL was superior to that after UL because the upward displacement and the pulmonary reserves of the remaining lobe appeared more robust after LL.