Clinical Significance of Intra-operative Gastroscopy for Tumor Localization in Totally Laparoscopic Partial Gastrectomy.

BACKGROUND Tumor localization during totally laparoscopic gastrectomy is challenging owing to the invisibility of tumors on the serosal surface. We aimed to evaluate the clinical significance of intra-operative gastroscopy in totally laparoscopic partial gastrectomy. METHODS We reviewed 1084 gastric cancer patients who underwent either intra- or extracorporeal partial gastrectomy between 2014 and 2018. The intracorporeal group with intra-operative gastroscopy (intra-operative gastroscopy group, n = 187), the intracorporeal group without intra-operative gastroscopy (non-intra-operative gastroscopy group, n = 267), and the extracorporeal group (n = 630) were evaluated for the adequacy of surgical resection margins. We assessed whether total gastrectomy could be avoided according to the performance of intra-operative gastroscopy if the tumor was located within 3-5 cm away from the gastroesophageal junction. RESULTS The proximal margin positivity was lesser in the intra-operative gastroscopy group than in the non-intra-operative gastroscopy group (0% versus 2.2%; P = 0.045) but similar to that in the extracorporeal group (0% versus 0.6%; P = 0.579). The number of cases with proximal resection margins < 1 cm was lower in the intra-operative gastroscopy group than in the non-intra-operative gastroscopy group (3.7% versus 9.4%; P = 0.025) but comparable with that in the extracorporeal group (3.7% versus 4.1%; P = 0.815). Among 94 patients with lesions located within 3-5 cm apart from the gastroesophageal junction, the intra-operative gastroscopy group (n = 47) had fewer patients who underwent total gastrectomy than the non-intra-operative gastroscopy group (n = 47) (12.8% versus 44.7%; P = 0.001). Intra-operative gastroscopy was the only independent factor that prevented total gastrectomy (P = 0.001). CONCLUSION Intra-operative gastroscopy can provide margin safety during intracorporeal partial gastrectomy, avoiding unnecessary total gastrectomy.