Risk factors of conversion in robotic- and video-assisted pulmonary surgery for non-small cell lung cancer.

BACKGROUND This study aimed to investigate risk factors of conversion to thoracotomy for patients with non-small cell lung cancer (NSCLC) underwent robotic- (RATS) or video-assisted thoracoscopic surgery (VATS). METHODS A retrospective review was conducted to included consecutive participants from January 2016 to December 2018. Three groups [mini-invasive, conversion, and up-front open thoracotomy (OT) groups] and two series of comparison (conversion versus mini-invasive, and conversion versus OT) were generated. Propensity score-matched analysis (1:1) was conducted to verify outcomes of complications and perioperative factors. Multivariate binary logistic regression analysis was used to identify potential risk factors of conversion. RESULTS 1177 patients (912 in mini-invasive group, 180 in conversion group, and 85 in OT group) were included. The overall conversion rate was 16.5%. Robotic approach resulted in dramatically lower conversion rate compared to VATS (2.4% vs 25.1%, p < 0.001). After propensity adjustment, no significant difference of complication rates was identified when comparing conversion group with mini-invasive and OT groups. Multivariate regression analyses shown that robotic approach (odd ratio (OR) = 0.037, 95% confidential interval (CI) 0.016-0.087), tumor size < 5 cm (OR = 0.274, 95% CI 0.152-0.493), no chief symptom(OR = 0.311, 95% CI 0.178-0.545), body mass index < 25 kg/m2 (OR = 0.537, 95% CI 0.343-0.842), and lobectomy (OR = 0.079, 95% CI 0.017-0.370) were independent protectors of conversion. CONCLUSIONS Seven demographic factors might be recognized as independent predictors of conversion. For patients with highly risk of conversion, robotic approach is recommended to perform mini-invasive pulmonary surgery over VATS.