External vocal fold medialization (thyroplasty type I): Surgical experience and modifications

Background: Despite a first report as early as 1915 by Payr, vocal fold medialization by an external approach did not gain general acceptance for many decades. Only when Isshiki took up these first attempts again in the 1970s, fundamentally revised them, and expanded the methods into the groups of Laryngeal Framework Surgery and Thyroplasty, did these techniques spread. Now they are increasingly performed. We have been using this technique since 1991. In a retrospective study we critically reviewed surgical experience with the original technique and several newly developed surgical modifications. Patients: An external vocal fold medialization was performed in 53 patients (22 male, 31 female). The underlying cause for the glottic insufficiency was in most of the cases unilateral laryngeal palsy, predominantly caused by thyroid surgery. Ten patients presented with an atrophy and/or scar of the vocal folds. In 7 out of these 10 cases the vocal folds were mobile. Most of the patients were operated on (n = 32) using the Isshiki technique. In the remaining 21 patients surgical modifications were used. In 7 cases new developed implants made out of glass ionomer cement were used, in 5 patients vocal fold medialization was performed using a 0.25 mm titanium sheet. Results: No intraoperative or postoperative complications could be observed. The surgical procedure was very well tolerated by all patients. The degree of glottic insufficiency was significantly reduced. There was also a statistically significant correlation between the preoperative and the postoperative degrees of glottic insufficiency. It was not always possible to close large glottic gaps completely in every case. Despite good overall results we experienced some limitations of the implant and the surgical technique as well. We therefore began to modify the implant and the surgical technique on the basis of anatomic and experimental studies. Conclusions: External vocal fold medialisation proved to be a safe and well tolerated surgical procedure. It is reversible and revisable, suitable for nearly all kinds of glottic insufficiencies, and can be combined with other phonosurgical procedures. Significant reduction of glottic insufficiency can usually be achieved, although large glottic gaps cannot be closed completely in every case. It should be possible to overcome certain limitations of the currently performed technique by developing new implants and modified surgical procedures. External vocal fold medialisation could then become established as a standard procedure providing even better and more stable functional results, at minimal risk to the patient.