Introduction: The safety and efficiency of OGT-assisted method have not yet been compared with conventional overlap approach.

Methods Retrospectively analyses the data of 155 gastric/gastroesophageal junction (G/GEJ) cancer patients who underwent laparoscopic total gastrectomy by conventional(conventional group, n=83) or OGT-assisted (OGT group, n=72) overlap methods at Nanfang Hospital. The anastomotic efficiency and surgical outcomes were compared between two groups.

Although our previous multicenter randomized controlled trial (CLASS-01) has confirmed the safety and efficacy of laparoscopic distal gastrectomy for gastric cancer[1, 2], the feasibility of laparoscopic total gastrectomy (LTG) remains uncertain. The most challenging technical difficulty of LTG is esophagojejunostomy(ESJ)[3, 4]. At present, there is still no consensus on the ideal anastomosis method for EJ.

Since overlap esophagojejunostomy was first proposed in 2010[5], it has gradually gone mainstream because of its lower incidence of anastomotic-related complications and satisfactory short-term outcomes[6-10]. However, the overlap approach is technically-difficult and time-consuming, and might confront intraoperative construction complications, such as injuring esophagus caused by the repetition of inserting anvil fork into esophagus or developing esophageal submucosa pseudocanals(video 1 and 2). Therefore, we first designed an overlap guiding tube (OGT)-assisted method to overcame above limitations[11]. And the first reported about the application of OGT-assisted method preliminarily indicated that it is safe and feasible, with a satisfactory success rate of inserting anvil fork into esophageal lumen at first attempt and esophagojejunostomy time[11]. However, the safety and efficiency of OGT-assisted method have not yet been compared side-by-side with the conventional overlap approach. Therefore, this study aimed to compare the OGT-assisted and conventional overlap methods in terms of feasibility and safety in LTG for gastric/gastroesophageal junction (G/GEJ) tumors.

Methods Patients One hundred and fifty-five patients with G/GEJ cancer undergoing LTG via either the conventional overlap esophagojejunostomy(conventional group) or OGT-assisted overlap esophagojejunostomy (OGT group) in the Department of Gastrointestinal Surgery, Southern Medical University Nanfang Hospital, between June 2018 and February 2022 were initially eligible for the study. The inclusion criteria were as follows: (1)gastric cancer was confirmed by pathological examination; (2) tumor located in GEJ with involving esophagus no more than 2cm or the upper, upper to the middle, or entire stomach; (3) had no obvious operative contraindication; and (4) aged 18-85 years. The pathological staging was based on the TNM system of the 8th edition of the International Federation for the prevention and treatment of cancer[12]. This study meets the requirements of the Helsinki Declaration revised in 2013. Patients and their families signed informed consent forms before operation. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline. The data collection protocol was approved by the Ethics Committee of Nanfang Hospital, Southern Medical University. Written informed consent was obtained from all the patients in the study.

Inclusion Criteria:

• (1)gastric cancer was confirmed by pathological examination; (2) tumor located in GEJ with involving esophagus no more than 2cm or the upper, upper to the middle, or entire stomach; (3) had no obvious operative contraindication; and (4) aged 18-85 years.

Exclusion Criteria:

• Null.

All patients enrolled in our study underwent standard LTG with D2 lymphadenectomy according to the Japanese Gastric Cancer Association treatment guidelines

One hundred and fifty-five patients with G/GEJ cancer undergoing LTG via either the conventional overlap esophagojejunostomy(conventional group) or OGT-assisted overlap esophagojejunostomy (OGT group) in the Department of Gastrointestinal Surgery, Southern Medical University Nanfang Hospital, between June 2018 and February 2022 were initially eligible for the study. The inclusion criteria were as follows: (1)gastric cancer was confirmed by pathological examination; (2) tumor located in GEJ with involving esophagus no more than 2cm or the upper, upper to the middle, or entire stomach; (3) had no obvious operative contraindication; and (4) aged 18-85 years.

July,2022-December 2023.

All accessing are approved.