Robot-assisted minimally invasive esophagectomy versus minimally invasive esophagectomy for thoracic lymph node dissection in patients with squamous cell carcinoma: a retrospective comparative cohort study.

Background: In Asia, esophageal squamous cell carcinoma (ESCC) accounts for more than 90% of esophageal cancer cases and can be treated with minimally invasive esophagectomy (MIE); however, MIE has certain technical limitations in resecting lymph nodes. The advantages of robot-assisted minimally invasive esophagectomy (RAMIE) surgery, such as the high-definition three-dimensional (3D) vision and the presence of the EndoWrist, facilitates movement in challenging anatomical regions. However, few studies have compared the postoperative outcomes between RAMIE with MIE for the lymph node dissection of patients with ESCC. Methods: We identified 285 patients with ESCC who underwent surgical resection between January 2019 and April 2023. Of these patients, 270 met the screening criteria and were enrolled in our study. These patients were then divided into two groups according to the thoracic approach: MIE (n=168) or RAMIE cohort (n=102). The aim of this study was to investigate the possible advantages in terms of postoperative outcomes of RAMIE over MIE for thoracic lymph node dissection. Results: Most patients were male (97.4%). According to the pathological-stage of esophageal cancer, 5 (1.9%), 99 (37.1%), 72 (27.0%), 82 (30.7%), and 9 (3.4%) patients were pathological-stage 0, I, II, III, and IV, respectively. The number of regional lymph node resections in the RAMIE cohort was significantly higher than that in the MIE group for the following regions: the left tracheobronchial lymph nodes (106tbL) (P<0.001), paratracheal lymph nodes [106pre] (P=0.011), the sub-longitudinal lymph nodes [107] (P<0.001), the left main bronchial lymph nodes [109L] (P<0.001), the right main bronchial lymph nodes [109R] (P<0.001), the sub-thoracic periesophageal lymph nodes [110] (P=0.004), and the supradiaphragmatic lymph nodes [111] (P<0.001). By comparing MIE cohort with RAMIE cohort, the transthoracic approach with RAMIE yielded a greater total number of thoracic lymph nodes dissected [MIE: mean 20.82, standard deviation (SD) 9.45; RAMIE: mean 26.07, SD 9.28; P<0.001] and a greater total number of lymph node groups that underwent thoracic lymph node dissection (MIE: mean 5.28, SD 1.94; RAMIE: mean 7.29, SD 1.77; P<0.001). Conclusions: Our study shows that RAMIE may be more effective than MIE in terms of the number thoracic lymph nodes dissected and the extent of dissection. Moreover, RAMIE may be not associated with additional surgical complications.