Initial long-term results of collagen injection for vocal and laryngeal rehabilitation.

The records of 14 patients who have benefited from intralaryngeal injections of ZCI collagen for at least 3-4 years were reviewed. All patients still living were evaluated. Qualitative phonatory measurements included laryngostroboscopy and frequency voice analysis, while quantitative studies included maximum phonation times and phonatory quotients. The absence of both local and general inflammatory reactions was observed in these patients, confirming the excellent host tolerance of ZCI collagen and the stability of the functional results achieved