Mediastinal Adiposity Influences the Technical Difficulty of Thoracic Procedure in Minimally Invasive Esophagectomy

Obesity is considered to influence the difficulty of surgery. However, whether mediastinal adiposity influences the difficulty of the thoracic procedure in minimally invasive esophagectomy (MIE) remains unclear.

Computed tomography volumetry was performed in 142 patients who underwent MIE between 2012 and 2014. We measured abdominal visceral fat area (AVFA) at the umbilicus level and mediastinal fat area (MFA) at the tracheal carina level. The influence of MFA on the difficulty of the thoracic procedure was assessed using the thoracic procedure duration as a parameter, and the effect of MFA on morbidity after MIE was assessed.

MFA was significantly smaller than AVFA (p < 0.01). There was a positive correlation between them (p < 0.01). A significant positive correlation was observed between MFA and thoracic procedure duration (p < 0.01). Multivariate analysis revealed that MFA was independently correlated with prolonged thoracic procedure duration (p < 0.01). Regarding postoperative complications associated with the thoracic procedure, there were no significant differences in MFA between patients with or without pneumonia and those with or without chylothorax. Patients who experienced recurrent laryngeal nerve palsy (RLNP) had greater MFA than those who did not (p = 0.04). Multivariate analysis revealed that MFA was a significant predictor of the occurrence of RLNP (p = 0.04).

Although the extent of mediastinal adiposity was much lesser than that of abdominal visceral adiposity, it could be a predictor of the difficulty of the thoracic procedure as well as the risk of RLNP in MIE.