Operative Procedure of Anterior Commissure for Type II Thyroplasty

Summary Objective We reviewed the clinical anatomy of the anterior commissure and examined the effectiveness of a specialized spreader developed for optimal, efficient spreading of the thyroid cartilage in type II thyroplasty. Study Design and Methods The present study was a multicenter retrospective study of patients with spasmodic dysphonia who underwent a primary operation either before or after the introduction of a specialized spreader (in 2008 or 2014, respectively). In these patients, we examined the size of the titanium bridge used, the presence of perforation of the mucosa directly superior to the anterior commissure, and postoperative glottic findings. Results The sample comprised 39 and 40 patients who underwent surgery in 2008 and 2014, respectively. The mean size of the titanium bridge used during surgery was significantly smaller in 2014 (2.9 mm) than in 2008 (3.81 mm). Perforation of the laryngeal mucosa occurred in 13 patients in 2008 but occurred in only one patient in 2014. Based on glottic findings, spreading the thyroid cartilage using the specialized spreader was deemed to yield an effective glottic gap. Conclusions In type II thyroplasty, the handling of the anterior commissure is the most important point. It is necessary to split the tendon and to spread the glottis while the tendon is joined with the cartilage. For this purpose, a specialized spreader was made. The use of a specialized spreader renders separation around the anterior commissure unnecessary, enabling minimally invasive spreading of the thyroid cartilage and thereby improving phonation.