Effect of duration of denervation on outcomes of ansa-recurrent laryngeal nerve reinnervation.
OBJECTIVE
To investigate the efficacy of laryngeal reinnervation with ansa cervicalis among unilateral vocal fold paralysis (UVFP) patients with different denervation durations.


METHODS
We retrospectively reviewed 349 consecutive UVFP cases of delayed ansa cervicalis to the recurrent laryngeal nerve (RLN) anastomosis. Potential influencing factors were analyzed in multivariable logistic regression analysis. Stratification analysis performed was aimed at one of the identified significant variables: denervation duration.


METHODS
Videostroboscopy, perceptual evaluation, acoustic analysis, maximum phonation time (MPT), and laryngeal electromyography (EMG) were performed preoperatively and postoperatively. Gender, age, preoperative EMG status and denervation duration were analyzed in multivariable logistic regression analysis. Stratification analysis was performed on denervation duration, which was divided into three groups according to the interval between RLN injury and reinnervation: group A, 6 to 12 months; group B, 12 to 24 months; and group C, > 24 months.


RESULTS
Age, preoperative EMG, and denervation duration were identified as significant variables in multivariable logistic regression analysis. Stratification analysis on denervation duration showed significant differences between group A and C and between group B and C (P < 0.05)-but showed no significant difference between group A and B (P > 0.05) with regard to parameters overall grade, jitter, shimmer, noise-to-harmonics ratio, MPT, and postoperative EMG. In addition, videostroboscopic and laryngeal EMG data, perceptual and acoustic parameters, and MPT values were significantly improved postoperatively in each denervation duration group (P < 0.01).


CONCLUSIONS
Although delayed laryngeal reinnervation is proved valid for UVFP, surgical outcome is better if the procedure is performed within 2 years after nerve injury than that over 2 years.
Department of Otolaryngology-Head and Neck Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200433, People's Republic of China.
Meng
M
Li
Shicai
S
Chen
Wei
W
Wang
Donghui
D
Chen
Minhui
M
Zhu
Fei
F
Liu
Caiyun
C
Zhang
Yan
Y
Li
Hongliang
H
Zheng
D000293:Adolescent; D000328:Adult; D000368:Aged; D003714:Denervation / Q000379:methods*; D004576:Electromyography; D005260:Female; D006801:Humans; D007830:Larynx / Q000502:physiology; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D012009:Recurrent Laryngeal Nerve / Q000502:physiology / Q000601:surgery*; D012189:Retrospective Studies; D013997:Time Factors; D014826:Vocal Cord Paralysis / Q000601:surgery*; D055815:Young Adult
Vocal cord paralysis; ansa cervicalis; denervation duration; laryngeal reinnervation; recurrent laryngeal nerve