To compare the efficacy and safety of different sequences of lower mediastinal lymph node dissection in Siewert type II esophagogastric junction adenocarcinoma (AEG).

A total of 80 Siewert type II AEG patients undergoing surgical treatment from January 2021 to December 2022 were selected and divided into two groups using random number table method, with 40 patients in each group. Both groups underwent laparoscopic transesophageal hiatus (TH) approach to lower mediastinal lymph node dissection. Patients in group A were cleaned in the order of "ventral → dorsal → bilateral" with the esophagus as the center, and group B was cleaned in the order of "right → dorsal → ventral → left". SPSS 20.0 software was used to analyze the data. Perioperative indicators and lymph node dissection were represented by independent sample t test. Complications and other statistical data were represented by [cases (%)], χ² or Fisher or Rank Sum test; Survival analysis was performed by Kaplan-Meier method and Log-Rank test was used. P<0.05 was considered statistically significant.

All patients successfully completed the operation, esophagotomy margin was negative. The time and bleeding of lower mediastinal lymph node dissection in group B were better than those in group A (P<0.05). There was no significant difference in the number of lymph node dissection, postoperative recovery index, incidence of complications and prognosis survival between 2 groups (P>0.05).

The two sequences of lower mediastinal lymph node dissection by transabdominal TH approach are safe and feasible, and have similar sweeping effect and prognosis. Using the subcardiac sac as the anatomic marker, lower mediastinal lymph node dissection in the sequence of "right → dorsal → ventral → left" was beneficial to improve surgical safety and maneuverability, shorten the time of lower mediastinal lymph dissection and reduce bleeding.