Transpyloric optic navigation of tumor using a laparoscope during totally laparoscopic distal gastrectomy for gastric cancer.

Purpose: The purpose of this study was to describe the technique of intraoperative transpyloric optic navigation (TPON) and determine its efficacy and feasibility during totally laparoscopic distal gastrectomy (TLDG) in patients with gastric cancer. Methods: Seventy-nine patients who underwent laparoscopic gastrectomy with transpyloric optic localization of the tumor from January 2016 through December 2018 were enrolled in this study. After resecting the first portion of the duodenum, the distal part of the stomach was exteriorized through an extended supraumbilical trocar site, and a balloon trocar was introduced from the pylorus to determine the location of tumor and determine its resection margin. The clinicopathologic and surgical outcomes were analyzed. Results: The tumor was located in the lower third of the stomach in 39 cases, the middle third in 34 cases, and the upper-third in six cases. Tumor localization was successful in 67 patients. The mean proximal margin was 41.7 ± 26.8 mm. There was no morbidity related to the technique. By the fifth postoperative day, the average white blood cell count was within the normal range and the average level of C-reactive protein showed a decreasing pattern. Conclusion: TPON of the tumor during TLDG is an effective and feasible method to determine the tumor location and to obtain an adequate resection margin.