Systematic review of laryngeal reinnervation techniques

To systematically review outcomes of reinnervation techniques for the management of unilateral vocal fold paralysis (UVFP).

Medline and Cochrane databases for English-language studies published between 1966 and 2009 on the surgical management of UVFP.

Studies were excluded if they reported on bilateral vocal fold paralysis, used nonhuman subjects, or did not assess clinical outcomes. Outcomes of interest were visual analysis, acoustic analysis, perceptual analysis, and electromyography.

Of 686 initial studies, 14 studies encompassing 329 patients were eligible for analysis. All studies had a case-series design. Of reported patients, 60.2 percent were men, with mean age of 51 years (range, 12-79 years). The most common reinnervation technique was ansa cervicalis-to-recurrent laryngeal nerve (RLN), which was most commonly performed after thyroidectomy (43.5%). Other techniques with reportable outcomes included primary RLN anastomosis, ansa-to-RLN combined with cricothyroid muscle-nerve-muscle pedicle, ansa-to-thyroarytenoid neural implantation, ansa-to-thyroarytenoid neuromuscular pedicle, and hypoglossal-to-RLN. Median postsurgical follow-up was 12 months, and mean time to first signs of reinnervation was 4.5 months (SD 2.9 months). Visual analysis of glottic gap showed the greatest mean improvement with ansa-to-RLN, from 2.25 (SD 0.886) to 0.75 (SD 0.886) mm (P < 0.01). Acoustic analysis showed greatest improvement with neural implantation, with a change in mean phonation time from seven (SD 1.22) to 16 (SD 5.52) seconds (P < 0.01). Perceptual analysis and electromyography demonstrated improvement in all studies.

Reinnervation is effective in the management of UVFP, although the specific method may be dictated by anatomical limitations. Prospective studies utilizing uniform and consistent outcome parameters are necessary.