ObjectiveTo investigate the impact of thoracic duct ligation (TDL) on metabolism and postoperative complications during esophagectomy in patients with type-2 diabetes mellitus (T2DM).MethodsWe conducted a retrospective clinical data analysis of 230 esophageal carcinoma patients with T2DM who underwent esophagectomy in our hospital from January 2003 to December 2018. Patients were divided into a TDL+ group (n=112), including 78 males and 34 females aged 63.47±7.23 years, and a TDL– group (n=118), including 84 males and 34 females aged 64.38±7.57 years. We compared the blood glucose, liver function parameters and lipid metabolic parameters at different time points before and after surgery. In addition, we compared the postoperative major complications between the two groups. Propensity score-matched (PSM) was used to control the observed confounders.ResultsCompared with the TDL– group, patients in TDL+ group had higher blood glucose level (P<0.05, except the fourth postoperative day). The total protein and albumin levels on the first and fourth postoperative days in the TDL+ group were lower than those in the TDL– group (P<0.05). The alanine transaminase (P=0.027) and aspartate transaminase (P=0.007) levels on the fourth postoperative day in the TDL+ group were higher than those in the TDL– group. More pulmonary complications (P=0.014) and anastomotic leaks (P=0.047) were found in the TDL+ group.ConclusionGiven that TDL may aggravate metabolic disorders, increase anastomotic leaks and the pulmonary complications, it is cautious to perform TDL, and prophylactic TDL should not be performed routinely for patients with T2DM.