ObjectiveTo explore the application value of prognostic nutritional index (PNI) in the postoperative complications of McKeown surgery for da Vinci robotic esophageal cancer. MethodsThe clinical data of the patients who underwent da Vinci robotic McKeown surgery for esophageal cancer in the Department of Thoracic Surgery of the First Hospital of Lanzhou University from January 2019 to June 2022 were retrospectively collected. According to the receiver operating characteristic (ROC) curve, the optimal cut-off value of PNI for predicting postoperative complications was explored. The patients were divided into a high PNI group and a low PNI group according to the cut-off value, and the differences in basic characteristics, surgery-related indexes and postoperative complications between the two groups were analyzed. According to the occurrence of postoperative complications, the patients were divided into a non-complication group and a complication group. Univariate and multivariate analyses were used to explore the influence of relevant indicators on the occurrence of postoperative complications in da Vinci robotic McKeown surgery for esophageal cancer. ResultsFinally 120 patients were collected, including 95 males and 25 females, with an average age of 62.82 years. The preoperative hemoglobin content, preoperative blood lymphocyte count, preoperative serum albumin and preoperative blood total cholesterol in the high PNI group were higher than those in the low PNI group (P<0.05). There were statistical differences between the two groups in the incidences of postoperative overall complications, pulmonary infection, pleural effusion and poor incision healing (P<0.05). The relevant indicators that may cause postoperative complications were included in univariate analysis, and the results showed that age, operation time, intraoperative blood loss, preoperative blood lymphocyte count, preoperative hemoglobin content, preoperative blood mononuclear cell count, preoperative blood monocyte count, serum albumin level and PNI were possible influencing factors of postoperative complications after da Vinci robotic McKeown surgery for esophageal cancer. Incorporating these influencing factors into multivariate analysis, the results showed that age, PNI, operation time and intraoperative blood loss were independent influencing factors of postoperative complications. ConclusionPNI has certain predictive value in the postoperative complications of da Vinci robotic McKeown surgery for esophageal cancer. PNI is an independent factor affecting postoperative complications. Improving the level of PNI in esophageal cancer patient before surgery may help reduce the occurrence of postoperative complications.