Preoperative computed tomography predicts the risk of recurrent laryngeal nerve paralysis in patients with esophageal cancer undergoing thoracoscopic esophagectomy in the prone position

Background: Recurrent laryngeal nerve paralysis (RLNP) after thoracoscopic esophagectomy for esophageal cancer (EC) is known to be a major complication leading to poor quality of life. RLNP is mainly associated with surgical procedures performed near the RLN. Therefore, with focus on the region of the RLN, we used preoperative computed tomography to investigate the risk factors of RLNP in patients with EC undergoing thoracoscopic esophagectomy. Methods: We retrospectively examined 77 EC patients who underwent thoracoscopic esophagectomy in the prone position at our department between January 2010 and December 2018. Bilateral cross-sectional areas (mm²) of the fatty tissue around the RLN at the level of the lower pole of the thyroid gland were measured on preoperative axial computed tomography (CT) images. Univariate and multivariate logistic regression analysis was used to evaluate the association between the incidence of RLNP and patient clinical factors, including the cross-sectional areas. Results: RLNP occurred in 24 of 77 patients (31.2%). The incidence of RLNP was significantly more frequent on the left side than on the right. (26% vs. 5.2%, respectively). Univariate analysis identified the following left RLNP risk factors: intrathoracic operative time (> 235 min), and area around the RLN (> 174.3 mm²). Multivariate analysis found that the area around the RLN was an independent risk factor of left RLNP. Conclusion: An increased area around the RLN measured on an axial CT view at the level of the lower pole of the thyroid gland was a risk factor of RLNP in EC patients undergoing thoracoscopic esophagectomy in the prone position.