Comparison between robot-assisted thoracoscopic surgery and video-assisted thoracoscopic surgery for mediastinal and hilar lymph node dissection in lung cancer surgery

OBJECTIVES: Lymph node dissection (LND) with robot-assisted thoracoscopic surgery (RATS) in lung cancer surgery has not been fully evaluated. The aim of this study was to compare LND surgical results between video-assisted thoracoscopic surgery (VATS) and RATS. METHODS: We retrospectively compared perioperative parameters, including the incidence of LND-associated complications (chylothorax, recurrent and/or phrenic nerve paralysis and bronchopleural fistula), lymph node (LN) counts and postoperative locoregional recurrence, among 390 patients with primary lung cancer who underwent lobectomy and mediastinal LND by RATS (n = 104) or VATS (n = 286) at our institution. RESULTS: The median total dissected LN numbers significantly differed between the RATS and the VATS groups (RATS: 18, VATS: 15; P< 0.001). They also significantly differed in right upper zone and hilar (#2R + #4R + #10L) (RATS: 12, VATS: 10; P=0.002), left lower paratracheal and hilar (#4L + #10L) (RATS: 4, VATS: 3; P = 0.019), aortopulmonary zone (#5 + #6) (RATS: 3, VATS: 2; P = 0.001) and interlobar and lobar (#11 + #12) LNs (RATS: 7, VATS: 6; P = 0.041). The groups did not significantly differ in overall nodal upstaging (P = 0.64), total blood loss (P = 0.69) or incidence of LND-associated complications (P = 0.77). CONCLUSIONS: In this comparison, it was suggested that more LNs could be dissected using RATS than VATS, especially in bilateral superior mediastinum and hilar regions. Accumulation of more cases and longer observation periods are needed to verify whether RATS can provide the acceptable quality of LND and local control of lung cancer.