The Anastomoses of the Recurrent Laryngeal Nerve in the Larynx: A Meta-Analysis and Systematic Review

Abstract

Objectives: The recurrent laryngeal nerve and its branches form a great variety of anastomoses. These nerve communications can alter the innervation patterns of the laryngeal muscles and can affect both the diagnosis and treatment of paralyzed vocal cords. The aim of this study was to assess the prevalence and anatomical characteristics of the laryngeal nerve connections, and to review their function and clinical significance.

Study design: Meta-analysis and systematic review.

Methods: The major electronic databases were thoroughly searched to identify all studies reporting data on the anastomoses of the laryngeal nerves. Data on the prevalence of each type of anastomosis were extracted and pooled into a meta-analysis using MetaXL version 3.0 (EpiGear International Pty. Ltd., Wilston, Queensland, Australia).

Results: Twenty-two cadaveric studies (n = 1404 hemilarynges) were included in the meta-analysis. The two most common communications were Galen's anastamosis and the arytenoid plexus. The pooled prevalence estimate for Galen's anastamosis was 76.7% (95% confidence interval [CI]: 59.0-90.0), of which the single trunk type was most common (92.3%). The arytenoid plexus had a pooled prevalence estimate of 79.7% (95% CI: 41.1-100).

Conclusions: Owing to the high prevalences and variability of nerve connections in the larynx, detailed anatomical knowledge of these anastomoses can be crucial for the accurate interpretation of laryngoscopy results, reducing iatrogenic injury during surgical procedures, and facilitating the development of novel strategies for treating laryngeal paralyses.

Keywords: Innervation; Neural communications; Recurrent Laryngeal Nerve; Superior Laryngeal Nerve; Vocal cords.