Closure of the posterior glottis after thyroplasty type 1 was retrospectively evaluated with fiberscopic video recordings of patients treated at the Osaka Red-Cross Hospital. It was revealed that this surgery was not an effective treatment of posterior glottis incompetence.
Results of an experimental study with excised human larynges indicated that a posterior window, incision of the inner perichondrial membrane and a medial compression in 8 to 10 mm of the vocal process of the arytenoid cartilage were necessary for the mobilization of the posterior vocal cord to the midline of the larynx.
The modified thyroplasty type 1 described above was performed for a patient with unilateral recurrent laryngeal nerve paralysis and a large gap in the posterior glottis. Normal voice and complete closure of the posterior glottis were obtained after surgery. This method was inferred to be useful for the improvement of posterior glottis incompetence.
