Skeletonizing En Bloc Esophagectomy Revisited: Oncologic Outcome in Association with the Presence of Thoracic Duct Lymph Nodes

Background Skeletonizing en bloc esophagectomy (SEBE) involves the removal of the esophagus en bloc with locoregional soft tissues and lymph nodes, including the thoracic duct (TD); however, its oncologic benefits remain unclear. We evaluated the impact of SEBE on oncologic outcomes in patients with esophageal squamous cell carcinoma. Methods Patients undergoing McKeown esophagectomy without neoadjuvant therapy between 2013 and 2019 were evaluated. Outcomes after SEBE were compared with those after conventional esophagectomy (CE) using propensity score-matched analysis. Results Overall, 232 patients were identified, including 133 patients with SEBE and 99 patients with CE. Lymph node metastasis along the TD was identified in 7.5% (10/133) of the SEBE group, and the incidence was closely related with the tumor invasion depth (2.2% in pT1 and 19.0% in pT2-3). Based on the propensity score, 180 patients (90 pairs) were analyzed. Tumor recurrence was identified in 24.4% and 12.2% of CE and SEBE cases, respectively (p = 0.036). The observed difference was due to the higher incidence of locoregional recurrence in CE (10.5% vs. 2.2%; p = 0.024), while the incidence of systemic recurrence was similar (18.6% vs. 12.2%; p = 0.240). The 5-year disease-free survival rate was 83.6% and 62.4% in the SEBE and CE groups, respectively (p = 0.022). Multivariate analysis revealed that SEBE could significantly reduce the risk of recurrence or death in patients with pT2-3 tumors (hazard ratio 0.173, 95% confidence interval 0.048-0.628; p = 0.008). Conclusions SEBE could identify and eradicate lymphatic metastasis along the TD and positively impact disease-free survival, particularly in patients with pT2-3 tumors.