Critical swallowing functions contributing to dysphagia in patients with recurrent laryngeal nerve paralysis after esophagectomy.

Abstract

Recurrent laryngeal nerve paralysis (RLNP) after esophagectomy can cause aspiration because of incomplete glottis closure, leading to pneumonia. However, patients with RLNP often have preserved swallowing function. This study investigated factors that determine swallowing function in patients with RLNP. Patients with esophageal cancer who underwent esophagectomy and cervical esophagogastric anastomosis were enrolled between 2017 and 2020. Videofluoroscopic examination of swallowing study (VFSS) and acoustic voice analysis were performed on patients with suspected dysphagia including RLNP. Dysphagia in VFSS was defined as score ≥ 3 of the 8-point penetration-aspiration scale VFSS and acoustic analysis results related to dysphagia were compared between patients with and without RLNP. Among 312 patients who underwent esophagectomy, 74 developed RLNP. The incidence of late-onset pneumonia was significantly higher in the RLNP group than in the non-RLNP (18.9 vs. 8.0%, P = .008). Detailed swallowing function was assessed by VFSS in 84 patients, and patients with RLNP and dysphagia showed significantly shorter maximum diagonal hyoid bone elevation (10.62 vs. 16.75mm; P = .003), which was a specific finding not seen in patients without RLNP. For acoustic voice analysis, the degree of hoarseness was not closely related to dysphagia. The length of oral intake rehabilitation for patients with and without RLNP was comparable if they did not present with dysphagia (8.5 vs. 9.0days). Impaired hyoid bone elevation is a specific dysphagia factor in patients with RLNP, suggesting compensatory epiglottis inversion by hyoid bone elevation is important for incomplete glottis closure caused by RLNP.