HSC Section 6 Nov2016 Green Book

atrophy and irreversible muscle fibrosis and degenera- tion of muscle endplates during long-term denervation may hinder successful reinnervation. 28 Even after rein- nervation, muscle fibers may fail to resume their normal size, possibly because of the progressive exhaustion of satellite cells whose activity and status may be the key determinant of skeletal muscle regeneration potential. Our previous work showed that the levels of myoD and myogenin, which are markers for activated satellite cells, were upregulated 6 to 12 months after denervation and then downregulated over time, ultimately becoming undetectable by 2 years after denervation. This indicates a decreased myogenic ability after a 2-year denervation duration, 22 which might explain the better surgical out- come of laryngeal reinnervation on patients with a denervation duration less than 2 years than on patients with a denervation duration longer than 2 years. There- fore, for UVFP patients with a denervation course of more than 2 years, it may be better to combine reinner- vation surgery with arytenoid adduction. 29,30 In addition, there are some other factors that may also affect the surgical outcome of laryngeal reinnerva- tion, such as the age of patients and the severity of nerve injury. 31–33 Crumley recommended that patients’ age should be less than 70 in order to ensure the effectiveness of laryngeal reinnervation, 2 while Paniello et al. revealed that patients under age 52 had significantly better voice recovery than those over age 52. 34 Stratification analysis on age in the present series of patients revealed that laryngeal reinnervation is less effective when patients are older than 60 years old. Details of further stratification analysis on these two identified influential factors will be presented in other reports (unpublished). CONCLUSION The data from this study indicate that surgical out- come of laryngeal reinnervation is affected by denerva- tion duration, the age of patients, and the severity of nerve injury. Although delayed reinnervation is effective, surgical outcome is better when the procedure is per- formed within 2 years after nerve injury than when the procedure is performed over 2 years. BIBLIOGRAPHY 1. Crumley RL. Unilateral recurrent laryngeal nerve paralysis. J Voice 1994; 8:79–83. 2. Crumley RL. Update: ansa cervicalis to recurrent laryngeal nerve anasto- mosis for unilateral laryngeal paralysis. Laryngoscope 1991;101:384– 387; discussion 388. 3. Zheng H, Li Z, Zhou S, Cuan Y, Wen W. Update: laryngeal reinnervation for unilateral vocal cord paralysis with the ansa cervicalis. Laryngoscope 1996;106:1522–1527. 4. Wang W, Chen D, Chen S, et al. Laryngeal reinnervation using ansa cervi- calis for thyroid surgery-related unilateral vocal fold paralysis: a long- term outcome analysis of 237 cases. PLoS One 2011;6:e19128. 5. Lee WT, Milstein C, Hicks D, Akst LM, Esclamado RM. Results of ansa to recurrent laryngeal nerve reinnervation. Otolaryngol Head Neck Surg 2007;136:450–454. 6. Lorenz RR, Esclamado RM, Teker AM, et al. Ansa cervicalis-to-recurrent laryngeal nerve anastomosis for unilateral vocal fold paralysis: experi- ence of a single institution. Ann Otol Rhinol Laryngol 2008;117:40–45.

7. Zheng H, Li Z, Zhou S, Cuan Y, Wen W, Lan J. Experimental study on reinnervation of vocal cord adductors with the ansa cervicalis. Laryngo- scope 1996;106:1516–1521. 8. Zheng H, Zhou S, Chen S, Li Z, Cuan Y. An experimental comparison of different kinds of laryngeal muscle reinnervation. Otolaryngol Head Neck Surg 1998;119:540–547. 9. Wang W, Chen S, Chen D, et al. Contralateral ansa cervicalis-to-recurrent laryngeal nerve anastomosis for unilateral vocal fold paralysis: a long- term outcome analysis of 56 cases. Laryngoscope 2011;121:1027–1034. 10. Mahieu HF, van Lith-Bijl JT, Groenhout C, Tonnaer JA, de Wilde P. Selec- tive laryngeal abductor reinnervation in cats using a phrenic nerve transfer and ORG 2766. Arch Otolaryngol Head Neck Surg 1993;119: 772–776. 11. van Lith-Bijl JT, Stolk RJ, Tonnaer JA, Groenhout C, Konings PN, Mahieu HF. Selective laryngeal reinnervation with separate phrenic and ansa cervicalis nerve transfers. Arch Otolaryngol Head Neck Surg 1997; 123:406–411. 12. Yumoto E, Sanuki T, Kumai Y. Immediate recurrent laryngeal nerve reconstruction and vocal outcome. Laryngoscope 2006;116:1657–1661. 13. Keilhoff G, Fansa H. Successful intramuscular neurotization is dependent on the denervation period. A histomorphological study of the gracilis muscle in rats. Muscle Nerve 2005;31:221–228. 14. van Lith-Bijl JT, Stolk RJ, Tonnaer JA, Groenhout C, Konings PN, Mahieu HF. Laryngeal abductor reinnervation with a phrenic nerve transfer after a 9-month delay. Arch Otolaryngol Head Neck Surg 1998; 124:393–398. 15. Maronian N, Waugh P, Robinson L, Hillel A. Electromyographic findings in recurrent laryngeal nerve reinnervation. Ann Otol Rhinol Laryngol 2003;112:314–323. 16. Chen D, Chen S, Wang W, Zhang C, Zheng H. Spontaneous regeneration of recurrent laryngeal nerve following long-term vocal fold paralysis in humans: histologic evidence. Laryngoscope 2011;121:1035–1039. 17. Woodson GE. Spontaneous laryngeal reinnervation after recurrent laryn- geal or vagus nerve injury. Ann Otol Rhinol Laryngol 2007;116:57–65. 18. Kupfer RA, Old MO, Oh SS, Feldman EL, Hogikyan ND. Spontaneous laryngeal reinnervation following chronic recurrent laryngeal nerve injury. Laryngoscope 2013;123:2216–2227. 19. Olson DE, Goding GS, Michael DD. Acoustic and perceptual evaluation of laryngeal reinnervation by ansa cervicalis transfer. Laryngoscope 1998; 108:1767–1772. 20. Miyamaru S, Kumai Y, Ito T, Yumoto E. Effects of long-term denervation on the rat thyroarytenoid muscle. Laryngoscope 2008;118:1318–1323. 21. Johns MM, Urbanchek M, Chepeha DB, Kuzon WM Jr, Hogikyan ND. Thyroarytenoid muscle maintains normal contractile force in chronic vocal fold immobility. Laryngoscope 2001;111:2152–2156. 22. Donghui C, Shicai C, Wei W, et al. Functional modulation of satellite cells in long-term denervated human laryngeal muscle. Laryngoscope 2010; 120:353–358. 23. Salonen V, Lehto M, Kalimo M, Penttinen R, Aro H. Changes in intramus- cular collagen and fibronectin in denervation atrophy. Muscle Nerve 1985;8:125–131. 24. Sunderland S, Bradley KC. Endoneurial tube shrinkage in the distal seg- ment of a severed nerve. J Comp Neurol 1950;93:411–420. 25. Bunge MB, Williams AK, Wood PM. Neuron-Schwann cell interaction in basal lamina formation. Dev Biol 1982;92:449–460. 26. Fu SY, Gordon T. Contributing factors to poor functional recovery after delayed nerve repair: prolonged denervation. J Neurosci 1995;15:3886– 3895. 27. Hydman J, Remahl S, Bjorck G, Svensson M, Mattsson P. Nimodipine improves reinnervation and neuromuscular function after injury to the recurrent laryngeal nerve in the rat. Ann Otol Rhinol Laryngol 2007; 116:623–630. 28. Anzil AP, Wernig A. Muscle fibre loss and reinnervation after long-term denervation. J Neurocytol 1989;18:833–845. 29. Chhetri DK, Gerratt BR, Kreiman J, Berke GS. Combined arytenoid adduction and laryngeal reinnervation in the treatment of vocal fold paralysis. Laryngoscope 1999;109:1928–1936. 30. Hassan MM, Yumoto E, Kumai Y, Sanuki T, Kodama N. Vocal outcome after arytenoid adduction and ansa cervicalis transfer. Arch Otolaryngol Head Neck Surg 2012;138:60–65. 31. Korte N, Schenk HC, Grothe C, Tipold A, Haastert-Talini K. Evaluation of periodic electrodiagnostic measurements to monitor motor recovery after different peripheral nerve lesions in the rat. Muscle Nerve 2011;44:63– 73. 32. Kovacic U, Sketelj J, Bajrovic FF. Chapter 26: Age-related differences in the reinnervation after peripheral nerve injury. Int Rev Neurobiol 2009; 87:465–482. 33. van Lith-Bijl JT, Mahieu HF, Stolk RJ, Tonnaer JA, Groenhout C, Konings PN. Laryngeal abductor function after recurrent laryngeal nerve injury in cats. Arch Otolaryngol Head Neck Surg 1996;122:393–396. 34. Paniello RC, Edgar JD, Kallogjeri D, Piccirillo JF. Medialization versus reinnervation for unilateral vocal fold paralysis: a multicenter random- ized clinical trial. Laryngoscope 2011;121:2172–2179.

Laryngoscope 124: August 2014

Li et al.: Denervated Duration on Reinnervation for UVFP

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