The usefulness of the transcricothyroid injection laryngoplasty via contralateral paramedian approach.

OBJECTIVE: Several laryngeal injection techniques are technically difficult and have limitations. In this study, we modified a transcricothyroid approach for injections to enhance needle visualization during procedures. The objective of this study was to investigate the efficacy of this alternative injection technique.

METHODS: We performed a retrospective analysis of 51 patients who had undergone injection laryngoplasty for unilateral vocal paralysis between March 2014 and February 2015. In total, 17 patients underwent a transcricothyroid injection laryngoplasty via the contralateral paramedian approach (ILC) and 34 patients underwent transcricothyroid injection laryngoplasty via the conventional approach (ipsilateral approach, ILI). Acoustic analyses, aerodynamic analyses, voice handicap index (VHI), and GRBAS scale were assessed pre-operatively and at 2 weeks and 3 months postoperatively.

RESULTS: From our acoustic and aerodynamic analyses, jitter, shimmer, noise-to-harmonic ratio (NHR), maximum phonation time (MPT), and mean flow rate (MFR) were all significantly improved in both groups after injection. VHI and GRBAS scales also improved postoperation. There were no significant differences between the pre-operative and postoperative subjective and objective parameters between both groups. The total injection volume used on the ILI group was larger than the volume given to the ILC group.

CONCLUSION: The transcricothyroid injection laryngoplasty via the contralateral paramedian approach is potentially more beneficial to performing injection laryngoplasty under local anesthesia. One important advantage of this approach to conventional approaches is its enhanced visualization of the needle during procedures.