Impact of Nonselective Laryngeal Reinnervation on Main Voice Characteristics

Abstract

The possibility and long-term results of non-selective surgical reinnervation by primary and delayed anastomosis of recurrent laryngeal nerve (RLN) with the one of the peripheral neck nerve (proximal RLN part, main part of ansa cervicalis, nerve-donor) in unilateral laryngeal paralysis have been investigated. At preoperative and postoperative stages we studied indirect laryngoscopy, videolaryngoscopy, spectral analysis of voice (fundamental frequency, intensity and harmonic-to-noise ratio (HNR), the maximum phonation time (MPT), patient's self-assessment of voice quality has been examined. Results. The anastomosis of the RLN was performed in 95 patients, who were in the main group (53 patients with anastomosis ansa cervicalis — RLN, 34 patients with anastomosis RLN — RLN and 8 with anastomosis RLN — nerve-donor — RLN).The postoperative average follow-up was 12.0 ± 1.8 months and the median time to the first indirect evidence of reinnervation —4.5 ± 2.9 months, which were observed in all patients of the main group: the emergence of vocal fold tone, reducing the size of the glottis during phonation (especially at the anastomosis ansa cervicalis — RLN) from 2.25 ± 0.86 mm to 0.35 ± 0.17 mm. Acoustic analysis showed the most effective reinnervation by the anastomosis ansa cervicalis — RLN, with change of HNR from 12.0 ± 3.7 dB to 24.0 ± 2.4 dB, MPT — from 7.00 ± 1.22 s to 16.00 ± 3.52 s (p < 0.01). The analysis of subjective psychosocial self-assessment of phonation showed the improvement in all subgroups of the main group.

Keywords

• postoperative laryngeal paralysis
• laryngeal reinnervation