Impact of pulmonary function on pulmonary complications after robotic-assisted thoracoscopic lobectomy

OBJECTIVES Percentage-predicted forced expiratory volume in 1 s (FEV1) and diffusing capacity for carbon monoxide (DLCO), and their predicted postoperative (ppo) values are established prognostic factors for postoperative pulmonary complications after thoracotomy. However, their predictive value for minimally invasive pulmonary resections remains controversial. This study assessed the incidence of pulmonary complications after robotic lobectomy for primary lung cancer and analysed the predictive significance of FEV1 and DLCO. METHODS This was a retrospective analysis of patients who underwent robotic lobectomy from 4 institutions. Descriptive and comparative analyses were performed for patients who experienced pulmonary complications versus patients who did not, in relation to FEV1 and DLCO values. To identify thresholds for increased complications, patients were categorized into groups of 10% incremental increases in FEV1 and DLCO, and their ppo values. RESULTS From November 2002 to April 2018, 1088 patients underwent robotic lobectomy. Overall, 169 postoperative pulmonary complications occurred in 141 patients. Male gender and Eastern Cooperative Oncology Group grade ≥1 were associated with increased pulmonary complications on univariable analysis. Patients who experienced pulmonary complications had increased mortality (2.1% vs 0.2%, P = 0.017) and longer hospitalizations (9 vs 4 days, P < 0.001). Pulmonary complications were associated when FEV1 ≤60% and DLCO ≤50%, and when ppo FEV1 or DLCO was ≤50%; ppo FEV1 ≤50% (P < 0.001) and ppo DLCO ≤50% (P = 0.031) remained statistically significant on multivariable analysis. CONCLUSIONS Both FEV1 and DLCO were shown to be significant predictors of pulmonary complications. Furthermore, thresholds of percentage-predicted and ppo FEV1 and DLCO values were identified, below which pulmonary complications occurred significantly more frequently, suggesting their predictive values are particularly useful in patients with poorer pulmonary function.