SEMRA KARŞIDAĞ, Arzu ÖZCAN, Şevki ŞAHİN, SİBEL KARŞIDAĞ, FEVZİYE KABUKCUOĞLU, Kemal UĞURLU, Lütfi BAŞ

Farklı seviyelerde ve onarım tiplerindeki periferik sinir iyileşmesinin elektrofizyolojik ve histopatolojik olarak değerlendirilmesi

Amaç:Farklı seviyelerde yapılan sinir kesilerinin erken dönemde primer onarımı ile sinir grefti ile onarımının sonuçları elektrofizyolojik ve histopatolojik olarak karşılaştırıldı. Çalışma planı: Sprague-Dawley cinsi 22 erkek sıçan üç gruba ayrıldı. Sağ siyatik sinirler, distal kesi grubunda (n=8) sinirin dallanma noktasının hemen proksimalinden, proksimal kesi grubunda (n=7) ise 15 mm proksimalinden kesildi. Son grupta (n=7) ise sinir dallanmasının 5 mm ve 15 mm proksimalinden defekt oluşturuldu ve kesilen parça greft olarak kullanıldı. Tüm sinirler epiperinöral olarak onarıldı. Cerrahiden önce ve sonra elektrofizyolojik değerlendirmeler yapıldı. Üçüncü ayda, iki taraflı L4-5 kök gangliyonundan ve kesi distalinden alınan örnekler histopatolojik olarak incelendi, nöron ve akson sayıları hesaplandı. Sonuçlar: İkinci ayda, distal kesi grubunda latans değerleri diğer iki gruba göre anlamlı derecede düşük (p

Anahtar Kelimeler:

Sinirsel iletim, Sıçan, Sprague-Dawley, Siyatik sinir, Hayvanlar, Gangliyon, spinal, Sinir yenilenmesi, Rastgele seçim, Erkek, Elektrofizyoloji, Elektromiyografi, Hastalık modelleri, hayvan, Aksonlar, Nörocerrahi işlemleri, Periferal sinirler

Electrophysiologic and histopathologic evaluation of peripheral nerve regeneration at different nerve segments and with different repair techniques

Objectives: We compared the electrophysiologic and histopathologic results of early primary nerve repair and grafting of transections made at different levels. Methods: Twenty-two male Sprague-Dawley rats were divided into three groups. In one group (distal group, n=8), the right sciatic nerve was transected near the proximal segment of, and in another (proximal group, n=7) at 15 mm proximal to, its branching. In the graft group (n=7), the nerve was resected from 5 mm to 15 mm proximal to its branching and the defect was repaired with the removed segment. All the nerves were repaired using the epiperineural technique. Electrophysiologic studies were performed before and after surgery. In the third month, bilateral biopsies were taken from the L4-5 dorsal root ganglion and from distal nerve segments for histopathologic examination and neuron and axon counts. Results: At two months, the distal group exhibited significantly shorter latency (p=0.001) and higher amplitude (p=0.05) values. However, at three months, all the groups had similar values of latency, amplitude, and conduction velocity. At three months, the number of the dorsal root ganglion neurons was significantly greater in the distal group compared to the graft group (p<0.001), but this did not differ from the proximal group (p>0.05). Axon counts per square millimeter were similar (p>0.05), but axon diameter was greater in the distal group (p<0.05). In correlation analyses, increases in the number of L4-5 dorsal root ganglion neurons were significantly associated with increases in the percent changes in distal latency (p<0.05) and conduction velocity (p=0.018). Conclusion: Our findings suggest that distal injuries and primary repair of the sciatic nerve result in a faster and better recovery.

Keywords:

Neural Conduction, Rats, Sprague-Dawley, Sciatic Nerve, Animals, Ganglia, Spinal, Nerve Regeneration, Random Allocation, Male, Electrophysiology, Electromyography, Disease Models, Animal, Axons, Neurosurgical Procedures, Peripheral Nerves,

___

1. Lundborg G. A 25-year perspective of peripheral nerve surgery: evolving neuroscientific concepts and clinical significance. J Hand Surg [Am] 2000;25:391-414.
2 Terzis JK, Sun DD, Thanos PK. Historical and basic science review: past, present, and future of nerve repair. J Reconstr Microsurg 1997;13:215-25.
3. West CA, Davies KA, Hart AM, Wiberg M, Williams SR, Terenghi G. Volumetric magnetic resonance imaging of dorsal root ganglia for the objective quantitative assessment of neuron death after peripheral nerve injury. Exp Neurol 2007;203:22-33.
4. Cabaud HE, Rodkey WG, Nemeth TJ. Progressive ultrastructural changes after peripheral nerve transection and repair. J Hand Surg [Am] 1982;7:353-65.
5. Nichols CM, Myckatyn TM, Rickman SR, Fox IK, Hadlock T, Mackinnon SE. Choosing the correct functional assay: a comprehensive assessment of functional tests in the rat. Behav Brain Res 2005;163:143-58.
6. Terenghi G, Calder JS, Birch R, Hall SM. A morphological study of Schwann cells and axonal regeneration in chronically transected human peripheral nerves. J Hand Surg [Br] 1998;23:583-7.
7. Kanaya F, Firrell JC, Breidenbach WC. Sciatic function index, nerve conduction tests, muscle contraction, and axon morphometry as indicators of regeneration. Plast Reconstr Surg 1996;98:1264-71.
8. Rupp A, Dornseifer U, Fischer A, Schmahl W, Rodenacker K, Jutting U, et al. Electrophysiologic assessment of sciatic nerve regeneration in the rat: surrounding limb muscles feature strongly in recordings from the gastrocnemius muscle. J Neurosci Methods 2007;166:266-77.
9. Ko MH, Chen WP, Lin-Shiau SY, Hsieh ST. Age-dependent acrylamide neurotoxicity in mice: morphology, physiology, and function. Exp Neurol 1999;158:37-46.
10. Varejao AS, Meek MF, Ferreira AJ, Patricio JA, Cabrita AM. Functional evaluation of peripheral nerve regeneration in the rat: walking track analysis. J Neurosci Methods 2001;108:1-9.
11. Varejao AS, Melo-Pinto P, Meek MF, Filipe VM, Bulas-Cruz J. Methods for the experimental functional assessment of rat sciatic nerve regeneration. Neurol Res 2004;26:186-94.
12. Wilson AD, Hart A, Brannstrom T, Wiberg M, Terenghi G. Primary sensory neuronal rescue with systemic acetyl-Lcarnitine following peripheral axotomy. A dose-response analysis. Br J Plast Surg 2003;56:732-9.
13. McKay Hart A, Wiberg M, Terenghi G. Pharmacological enhancement of peripheral nerve regeneration in the rat by systemic acetyl-L-carnitine treatment. Neurosci Lett 2002;334:181-5.
14. Wilson AD, Hart A, Brannstrom T, Wiberg M, Terenghi G. Delayed acetyl-L-carnitine administration and its effect on sensory neuronal rescue after peripheral nerve injury. J Plast Reconstr Aesthet Surg 2007;60:114-8.
15. McKay Hart A, Brannstrom T, Wiberg M, Terenghi G. Primary sensory neurons and satellite cells after peripheral axotomy in the adult rat: timecourse of cell death and elimination. Exp Brain Res 2002;142:308-18.