Clinical advantage of robot-assisted over conventional minimally invasive esophagectomy in patients with a narrow mediastinum.

BACKGROUND: Several studies have compared long-term outcomes between robot-assisted minimally invasive esophagectomy (RAMIE) and conventional minimally invasive esophagectomy (C-MIE). In C-MIE, patients with a narrow mediastinum present greater technical difficulty. This study compared long-term outcomes of RAMIE and C-MIE in this subgroup. METHODS: Between April 2017 and December 2023, we analyzed 272 patients with esophageal squamous cell carcinoma (ESCC) who underwent RAMIE or C-MIE at Kobe University Hospital. Mediastinal width was measured at the tracheal bifurcation using computed tomography; a narrow mediastinum was defined as a width ratio below the median. RESULTS: Baseline characteristics and preoperative treatments did not differ significantly between groups in the overall cohort or narrow-mediastinum subgroup. In the overall cohort, overall survival (OS) did not differ between RAMIE and C-MIE across disease stages. In the narrow-mediastinum subgroup, OS did not differ between RAMIE and C-MIE among patients with cT1N0 ESCC (p = 0.85). By contrast, among those with cT1N + or cT2 ≤ N any ESCC, the C-MIE group showed a trend toward poorer OS than the RAMIE group (p = 0.065). In patients with cT1N + or cT2 ≤ N any ESCC, patients with a narrow mediastinum undergoing C-MIE had significantly worse OS than those with a wide mediastinum (p = 0.028). In contrast, no such difference occurred in those undergoing RAMIE (p = 0.29). Multivariate analysis of the narrow-mediastinum subgroup showed that clinical tumor invasion (≥ cT2) and C-MIE were independent prognostic factors for OS (p = 0.0004 and 0.041, respectively). CONCLUSIONS: RAMIE may mitigate the adverse effects associated with narrow mediastinal anatomy.