Thoracic Duct Resection During Esophagectomy Does Not Contribute to Improved Prognosis in Esophageal Squamous Cell Carcinoma: A Propensity Score Matched-Cohort Study

Purpose. Esophagectomy with extended lymphadenectomy remains the mainstay of treatment for localized esophageal squamous cell carcinoma (ESCC). Thoracic duct (TD) resection has been recommended as part of extended lymphadenectomy, although its merits are unclear. The aim of this two-institutional, matched-cohort study is to clarify whether TD resection improves prognosis in esophagectomy for ESCC. Patients and Methods. In this two-institutional, matched-cohort study of 399 patients with ESCC who underwent McKeown esophagectomy between 2010 and 2014, the primary outcomes were overall survival (OS), disease-free survival (DFS), and cause-specific survival (CSS). Secondary outcomes were perioperative results and recurrence patterns. Results. Based on a propensity score, 122 TD-resected or 122 TD-preserved patients in all stages were selected (median follow-up 4.5 years). The 5-year OS, DFS, and CSS rates in the TD-resected versus TD-preserved groups were 49% versus 60%, 53% versus 57%, and 58% versus 70%, respectively, without any significant differences. Operative time for the thoracic procedure was significantly longer and the number of retrieved mediastinal nodes was significantly higher in the TD-resected group (P = 0.009 and 0.005, respectively). The rates of chylothorax and left recurrent laryngeal nerve (RLN) palsy were significantly higher in the TD-resected group (P = 0.041 and 0.018, respectively). There were no significant differences in rates of local or distant metastases between the two groups. Conclusions. TD resection does not contribute to improve OS, DFS, or CSS in ESCC but increases incidence of chylothorax and left RLN palsy. Prophylactic TD resection should be avoided in esophagectomy for ESCC.