Cross-linked hyaluronan versus collagen for injection treatment of glottal insufficiency: 2-year follow-up.

OBJECTIVES: To evaluate the long-term (24 months) clinical performance (vocal fold function) and safety of hylan B gel as compared with bovine cross-linked collagen in the treatment of patients with glottal insufficiency. MATERIAL AND METHODS: In a prospective trial, 70 patients with glottal insufficiency due to unilateral vocal fold paresis (n =35) or atrophy (n =35) were randomized to received either hylan B gel (n =47) or collagen (n =23) injections into 1 vocal fold. Forty-two of the patients were examined 24 months after treatment. Evaluations were made based on patients' subjective ratings, digitized videostroboscopic measurements, maximum phonation time and phonation quotient. RESULTS: The patients' self-ratings were significantly improved in both the hylan B gel and collagen groups. Videostroboscopic measurements of glottal closure were significantly improved for both groups. The hylan B gel group showed a trend towards less resorption at the injected vocal fold edge in comparison with the collagen group (p =0.05). No serious adverse events were observed. Twenty-eight patients dropped out of the study after 12 months: 18 had been re-injected or operated on with medialization laryngoplasty due to insufficient voice and 10 had either died of causes unrelated to the study or refused to attend follow-up. CONCLUSIONS: No long-term side-effects were found for either the hylan B gel or collagen groups after injection treatment. Both treatments resulted in significantly improved voice as rated by the patients and significantly improved glottal closure. Some resorption was noted for both substances, and approximately 25%, of the patients chose re-treatment 2 years after the initial treatment.

Cross-linked hyaluronan used as augmentation substance for treatment of glottal insufficiency: safety aspects and vocal fold function.

OBJECTIVE: To examine safety aspects and vocal fold function after vocal fold augmentation with a cross-linked hyaluronan derivative (hylan B gel) as compared with bovine collagen. STUDY DESIGN; A prospective, randomized trial. METHODS: Eighty-three patients with glottal insufficiency were treated with injection augmentation with hylan B gel and bovine collagen and were examined at 1, 6, and 12 months after treatment. Seventy patients with unilateral vocal fold paresis (n = 35) or atrophy (n = 35) were randomly assigned to receive either hylan B gel (n = 47) or collagen (n = 23) injections into one vocal fold. Thirteen patients with glottal insufficiency caused by scar defects or paresis resulting from malignant disease were included in a nonrandomized group and were treated only with hylan B gel. Evaluations were made from patients' subjective ratings (visual analogue scales), digitized videostroboscopic measurements, phonetograms, maximum phonation time, and phonation quotients. RESULTS: Twelve months after injections, the patients' self-ratings were significantly improved for both the hylan B gel and the collagen groups. In addition, the videostroboscopic measurements showed significantly improved glottal closure for both groups. However, for the hylan B gel group, vibration amplitude and glottal area variations were preserved, and this group showed significantly less resorption at the injected vocal fold edge. Furthermore, maximum phonation time had increased significantly for the hylan B gel patients (collagen, nonsignificant). No serious adverse events were observed; three patients injected with hylan B gel had temporary inflammation at the injection site, which resolved without sequelae. CONCLUSIONS: The results showed that both hylan B gel and collagen can be safely used for injection treatment of glottal insufficiency. Both treatments resulted in significantly improved voice as rated by the patients. However, the patients treated with hylan B gel showed better vocal fold status and longer maximum phonation time at 12 months after treatment as compared with patients treated with collagen.