Long-term effects of micronized Alloderm injection for unilateral vocal fold paralysis

Micronized Alloderm (Cymetra) is a relatively new product used for vocal fold augmentation. Previous studies evaluating possible long-term effectiveness of this product have shown mixed results. The objective of this present study is to reassess possible long-term results of Cymetra injection laryngoplasty in patients with unilateral true vocal fold paralysis.

Retrospective review of patients with unilateral true vocal fold paralysis who received Cymetra injection laryngoplasty between March 2001 and March 2004.

Preoperative voice samples and videostroboscopic findings were compared with the most recently available postoperative data to assess efficacy of the procedure. A panel of voice experts analyzed both vocal and vibratory function in these samples. In addition, pre- and postoperative voice-related quality of life measures and patients' self-ratings of voice outcomes were compared.

Twenty patients (7 male, 13 female; 14 with left-sided paralysis, 6 with right-sided paralysis) were identified in the study population. Cymetra injection was performed an average of 45.1 months after onset of vocal fold paralysis (range -216 months), and average follow-up postinjection was 11.2 (range -35) months. Comparing pre- and postoperative measures, voice quality (P < .0001), glottal closure (P < .0001), and degree of vocal fold bowing (P < .0001) were all improved by injection. Quality of life measures and patients' self-perceptions of vocal quality were also improved (P < .01). Fifteen (75%) patients showed long-lasting results. Eight patients showed improvement for more than 12 months after injection.

Cymetra injection laryngoplasty offers improved vocal and vibratory function to patients with unilateral true vocal fold paralysis. The benefits of such medialization may be longer lasting than previously reported, and further long-term study is warranted.