Barras Florian M, Kuntzer Thierry, Zurn Anne D, Pasche Philippe
Department of Otorhinolaryngology, CHU Vaudois and University of Lausanne, Lausanne, Switzerland.
Laryngoscope. 2009 May;119(5):846-55. doi: 10.1002/lary.20169.
OBJECTIVES/HYPOTHESIS: Facial nerve regeneration is limited in some clinical situations: in long grafts, by aged patients, and when the delay between nerve lesion and repair is prolonged. This deficient regeneration is due to the limited number of regenerating nerve fibers, their immaturity and the unresponsiveness of Schwann cells after a long period of denervation. This study proposes to apply glial cell line-derived neurotrophic factor (GDNF) on facial nerve grafts via nerve guidance channels to improve the regeneration.
Two situations were evaluated: immediate and delayed grafts (repair 7 months after the lesion). Each group contained three subgroups: a) graft without channel, b) graft with a channel without neurotrophic factor; and c) graft with a GDNF-releasing channel. A functional analysis was performed with clinical observation of facial nerve function, and nerve conduction study at 6 weeks. Histological analysis was performed with the count of number of myelinated fibers within the graft, and distally to the graft. Central evaluation was assessed with Fluoro-Ruby retrograde labeling and Nissl staining.
This study showed that GDNF allowed an increase in the number and the maturation of nerve fibers, as well as the number of retrogradely labeled neurons in delayed anastomoses. On the contrary, after immediate repair, the regenerated nerves in the presence of GDNF showed inferior results compared to the other groups.
GDNF is a potent neurotrophic factor to improve facial nerve regeneration in grafts performed several months after the nerve lesion. However, GDNF should not be used for immediate repair, as it possibly inhibits the nerve regeneration.
目的/假设：在某些临床情况下，面神经再生受到限制：在长移植体中、老年患者以及神经损伤与修复之间的延迟延长时。这种再生不足是由于再生神经纤维数量有限、其不成熟以及长时间去神经支配后施万细胞无反应性。本研究建议通过神经引导通道将胶质细胞源性神经营养因子（GDNF）应用于面神经移植体以改善再生。
评估了两种情况：即刻移植和延迟移植（损伤后7个月修复）。每组包含三个亚组：a）无通道移植，b）有通道但无神经营养因子的移植；以及c）有释放GDNF通道的移植。通过对面神经功能的临床观察和6周时的神经传导研究进行功能分析。通过计算移植体内以及移植体远端的有髓纤维数量进行组织学分析。通过荧光红逆行标记和尼氏染色进行中枢评估。
本研究表明，GDNF可增加延迟吻合中神经纤维的数量和成熟度以及逆行标记神经元的数量。相反，在即刻修复后，存在GDNF时再生神经的结果比其他组差。
GDNF是一种有效的神经营养因子，可改善神经损伤数月后进行的移植中面神经的再生。然而，GDNF不应立即用于修复，因为它可能抑制神经再生。
