Transhiatal lower mediastinal lymph node dissection for esophagogastric junction carcinoma by interconnecting four body cavities

Background: Due to the limited number of landmark structures, it is difficult to standardize the surgical procedures for advanced esophagogastric junction cancer such as Ivor Lewis esophagectomy that require transhiatal lower mediastinal lymph node dissection (TH-LMND). We demonstrate an easily reproducible procedure for THLMND, wherein four body cavities, namely, the abdominal cavity, infracardiac bursa (ICB), and left and right thoracic cavities are interconnected.Methods: First, the dissection between the right crus and the esophagus was used to connect the abdominal cavity to the ICB - a lower mediastinal cavity separated from the omental bursa during embryonic development [1,2]. Second, the right thoracic cavity was opened with the shortest distance by dissecting the cranial side of the ICB. The right pulmonary ligament was dissected from the right lung. Third, the dissection to the contralateral side while exposing the aorta and the pericardium connected the left and right thoracic cavities. Then, the left pulmonary ligament was dissected from the left lung. The dissected tissues, including the lymph nodes, were subsequently peeled from the esophagus.Results: Between April 2018 and August 2021, 14 patients underwent laparoscopic or robotic TH-LMND via the procedure above. The median time required to complete the dissection was 75 min. None of the procedures were converted to open surgery, and none of the patients experienced intraoperative complications such as pericardial injury, lung injury, or massive bleeding.Conclusion: The surgical concept of interconnecting four body cavities made the procedure more accessible and reproducible while achieving en bloc TH-LMND.