• Recurrent laryngeal nerves;
  • vocal cord paralysis;
  • laryngeal reinnervation;
  • ansa cervicalis;
  • Level of Evidence: 4.



To evaluate the long-term efficacy of contralateral ansa cervicalis-to-recurrent laryngeal nerve (RLN) anastomosis for unilateral vocal fold paralysis (UVFP), when the ansa cervicalis on the side of the paralyzed vocal fold was absent or there was any question about its viability.

Study Design:

We retrospectively reviewed 56 consecutive cases of delayed laryngeal reinnervation with contralateral ansa cervicalis for UVFP.


Between January 1996 and January 2008, a total of 56 UVFP patients were enrolled in this study. All patients underwent contralateral ansa cervicalis-to-RLN anastomosis. Videostroboscopy, acoustic analysis, perceptual evaluation and maximum phonation time (MPT), and laryngeal electromyography (LEMG) were performed pre- and postoperatively.


Analysis of videostroboscopic findings indicated that the glottic closure, vocal fold edge, vocal fold position, phase symmetry, and regularity were significantly improved (P < .001, post- vs. preoperative). Perceptual evaluation of dysphonia severity showed that overall grade, roughness, breathiness, asthenia, and strain were also significantly decreased postoperatively (P < .001). Postoperative values of jitter (local), shimmer (local), and mean noise-to-harmonics ratio were significantly lower than the corresponding preoperative values (P < .001). The postoperative MPT value was significantly longer than the preoperative one (P < .001). LEMG showed that there was a significant postoperative improvement in voluntary motor-unit recruitment during phonation (P < .001).


In cases with a lack of viable ansa cervicalis on the side of a paralyzed vocal fold, contralateral ansa cervicalis-to-RLN anastomosis is a feasible and effective approach in the treatment of UVFP and can restore physiologic laryngeal phonatory function.