DiHA (dextranomers in hyaluronan) injections for treatment of insufficient closure of the vocal folds: early clinical experiences.

OBJECTIVE: To determine the clinical effects of injecting DiHA (a mixture of dextranomer molecules and 1% hyaluronan solution in equal proportions) as a "space filler" into the vocal folds of patients experiencing insufficient closure of the vocal folds resulting from either unilateral vocal fold paralysis or bowed vocal folds.

STUDY DESIGN: A consecutive series of patients with insufficient closure of the vocal folds treated with DiHA injections and prospectively followed up with videostroboscopy and voice recordings that were evaluated by expert panels.

METHODS: During a 21/2-year period, 14 patients with insufficient closure of the vocal folds were included. Six had a unilateral vocal fold palsy and 8 patients had "bowed" vocal folds. DiHA was injected into one vocal fold. Laryngoscopic examination and voice recordings were performed pre- and postoperatively. Expert panels did the evaluation of the stroboscopy examination and the perceptual voice analysis.

RESULTS: Three patients were operated on with local and 11 under general anesthesia. All patients with unilateral palsy improved their stroboscopic status regarding both the wave and the closure after injection. Also, their voice parameters were significantly improved. Among the patients with bowed vocal folds, all except 2 showed an improvement in the glottic wave, 5 of 8 improved in glottic closure, and 3 improved their voice parameters significantly.

CONCLUSION: This early clinical experience indicates that DiHA fulfills most of the requirements of an ideal "space-filling" substance for voice restoration in patients experiencing insufficient vocal fold closure.