Thoracic cavity-to-cage ratio is a predictor of technical difficulties in minimally invasive esophagectomy.

Abstract

Technical difficulties are occasionally encountered when performing conventional minimally invasive esophagectomy and robot-assisted minimally invasive esophagectomy in patients with a narrow thoracic cavity. Thoracic cavity-to-cage ratio is an indicator of thoracic cavity length. We hypothesized that the thoracic cavity-to-cage ratio could be a predictor of technical difficulties in conventional minimally invasive esophagectomy and robot-assisted minimally invasive esophagectomy. We evaluated 340 patients who underwent minimally invasive esophagectomy for esophageal squamous cell carcinoma between April 2010 and March 2021. Thoracic cavity-to-cage ratio was calculated as the diameter of the thoracic cavity to that of the thoracic cage at the brachiocephalic vein, tracheal bifurcation, and inferior right pulmonary vein levels. Moreover, thoracic cavity-to-cage ratio score, which is an indicator of the whole thoracic cavity length based on the thoracic cavity-to-cage ratio at the 3 levels, was defined. The thoracic procedure time was considered an indicator of surgical difficulty. We divided the patients into the conventional minimally invasive esophagectomy (n = 295) and robot-assisted minimally invasive esophagectomy (n = 45) groups. The patients in each group were divided into 2 cohorts according to median thoracic procedure time. Based on multivariate analysis, body mass index (P = .0007), clinical N stage (P = .0191), and thoracic cavity-to-cage ratio score (P = .0005) were independent factors for thoracic procedure time in the conventional minimally invasive esophagectomy group. Moreover, thoracic cavity-to-cage ratio at the tracheal bifurcation level (P = .0331) was the only independent factor for thoracic procedure time in the robot-assisted minimally invasive esophagectomy group. Thoracic cavity-to-cage ratio could be a predictor of technical difficulties in both conventional minimally invasive esophagectomy and robot-assisted minimally invasive esophagectomy.