Injection laryngoplasty with hyaluronic acid for unilateral vocal cord paralysis. Randomized controlled trial comparing two different particle sizes.

The objective was to determine if particle size affects durability of medialization in patients undergoing injection laryngoplasty (IL) with hyaluronic acid (HA) for unilateral vocal cord paralysis (UVCP). We hypothesized that large particle-size HA (LPHA) persists longer after injection to produce a more durable vocal result. The study design used was a prospective randomized controlled single-blind trial. Patients underwent IL with Restylane (small particle-size HA, SPHA) or Perlane (LPHA) (Q-Med AB, Uppsala, Sweden). Injections were performed transcutaneously in the outpatient clinic. The Voice Handicap Index (VHI) at 6 months postinjection was the primary outcome measure. Secondary outcomes included videostroboscopic findings, and objective acoustic and aerodynamic measures. Seventeen patients (eight SPHA, nine LPHA) were available for follow-up at 6 months. Normalized VHI scores at 6 months after IL were significantly lower in the LPHA group compared to the SPHA group when not adjusted for age and sex (P=0.027). After adjustment, the difference was not significant (P=0.053) but the LPHA group trended toward lower normalized VHI scores. The findings support the hypothesis that the larger particle-size of LPHA makes this material more durable than SPHA for IL. This material may be considered for temporary medialization in patients with UVCP in whom medium-term improvement of at least 6 months is desirable. The transcutaneous route can be used safely in the office setting in non-anticoagulated patients.