Injection laryngoplasty with calcium phosphate cement

Abstract

Objective: To assess the feasibility of injection laryngoplasty with calcium phosphate cement (CPC), which is an injectable paste, self-hardening, and which recrystallizes to calcium hydroxylapatite after injection. Study Design: A case series with planned data collection. Methods: Fifty-six patients with unilateral vocal fold paralysis, who received injection laryngoplasty with CPC between August 2003 and August 2007 with a minimum follow-up period of six months, were enrolled in this study. Volumetric and migration analysis for injected CPC were performed using CT after surgery. Vocal function was also assessed by GRBAS subjective voice assessment scale and maximum phonation time (MPT), acoustic analysis including period perturbation quotient (PPQ), amplitude perturbation period (APQ), and noise-to-harmonics ratio (NHR). Results: No remarkable migration or absorption of injected CPC was observed on CT up to two years after surgery. The average remaining volume of CPC was 87.8% ± 5.3% two years after injection compared to immediately after injection. Significant improvements in GRBAS scales, MPT, PPQ, APQ, and NHR were observed postoperatively. No adverse effects were observed. Conclusions: Our clinical experience revealed that CPC was safe, nonabsorbable, and effective. Injection laryngoplasty with CPC may be a useful option in the treatment of glottic insufficiency.