These days, the main injection laryngoplasty technique is cricothyroid (CT) approach. However, patients who have previously undergone other neck treatments, such as thyroidectomy or neck dissection have distorted anatomical landmark makes this approach more difficult. The aim of this study is to determined the efficiency of transcartilaginous (TC) approah as compared with CT approach for unilateral vocal fold paralysis patients, especially for previously neck treated patients.
From March 2005 to February 2008, 137 consecutive injection laryngoplasties were performed in patients with unilateral glottic insufficiency. Percutaneous injection was performed under local anesthesia into the vocalis muscle, using disposable 25 G 4 cm long needles through the cricothyroid membrane or directly through the thyroid cartilage. Of the 137 patients, 124 completed acoustic, perceptual, stroboscopic, and subjective evaluations prior to the injection and at 3 months after the injection.
In the 124 patients, the CT and TC approaches were used in 94 and 30 patients, respectively. Acoustic and perceptual parameters (GRBAS, MPT, jitter, shimmer), voice handicap index, and grades of mucosal waves and glottic closure were significantly improved after the injection in both the CT and TC groups (P<0.05). Only two patients (6.6%) had penetration difficulties, because of ossification of the thyroid cartilage. The overall success rates of the CT and TC approaches were 86.2%, 93.3%, respectively. However, the success rate of the TC approach in patients who had previously undergone neck treatments was significantly higher than that of the CT approach (100% vs. 65% P<0.05).
Based on the preliminary results of this trial, injection laryngoplasty using a TC approach was an effective alternative to the CT approach, especially in patients who had previously undergone neck surgeries.