Full length article The effect of in vivo created vascularized neurotube on peripheric nerve regeneration Abdul Kerim Yapici a, *, Yalcin Bayram a , Hakan Akgun b , Recep Gumus c , Fatih Zor a a Gulhane Military Medical Academy, Dept. of Plastic Surgery, Ankara, Turkey b Gulhane Military Medical Academy, Dept. of Neurology, Ankara, Turkey c Gulhane Military Medical Academy, Dept. of Histology, Ankara, Turkey A R T I C L E I N F O Article history: Received 17 December 2016 Received in revised form 5 May 2017 Accepted 9 May 2017 Keywords: Nerve regeneration Vascularized conduit Non-vascularized conduit Biologic conduit A B S T R A C T Introduction: Creating vascularized nerve conduits for treatment of nerve gaps have been researched, however, these methods need microsurgical anastomosis thereby complicating the nerve repair process. Thus, the concept of vascularized nerve conduits has not popularized up till now. The aim of this study is to evaluate the effects of vascularized and non-vascularized biological conduits on peripheral nerve regeneration. Material and methods: Following ethical board approval, 15 Sprague-Dawley rats were used in the study. The rats were equally divided into three groups. In group I, a silicon rod was inserted next to the sciatic nerve of the rat and connective tissue generated around this rod was used as a vascularized biological conduit. In group II, a silicon rod was inserted into the dorsum of the rat and connective tissue generated around this rod was used as a non-vascularized biological conduit. In group III, autogenic nerve graft was used to repair the nerve gap. The contralateral sciatic nerve is used as a control in all rats. Macroscopic, electrophysiological and histomorphometric evaluations were performed to determine the nerve regeneration. Results: There was no statistically significant difference between groups, in terms of latency. However, the mean amplitude of group I was found to be higher than other groups. The difference between group I and II was statistically significant. Myelinated axonal counts in group I was significantly higher than groups II and III. Conclusion: Our results showed that vascularized biological conduits provided better nerve regeneration when compared to autografts and non-vascularized biological conduits. Creation and application of vascularized conduits by using the technique described here is easy. Although this method is not an alternative to autogenic nerve grafts, our results are promising and encouraging for further studies. © 2017 Elsevier Ltd. All rights reserved. Introduction Autologous nerve grafts are the gold standard for repair of nerve gaps as they have critical elements for nerve regeneration such as basal lamina and Schwan cells. [1–3] However, the results following autologous nerve grafts are still suboptimal and cause donor site morbidity. Stemming from these disadvantages, there are many studies searching for alternative nerve conduits to autologous nerve grafts. [4] Vein grafts, collagen, basal lamina scaffolds, de-cellularized allografts and synthetic conduits are all considered as an alternative to nerve autografts. [3–11] Tissue engineered nerve conduits were also studied. These grafts included various growth factors, mediators and cellularization of the nerve conduit by Schwann or stem cells. [4] The effect of vascularization of the nerve graft was first mentioned by Kanaya et al., however, vascularized nerve grafts have not gained popularization due to surgical complexity and donor side morbidity. [12] Despite all these studies, autologous nerve grafts still remain the best option. Hunter et al. presented the histological features of pseudo- synovial sheath which is generated around a silicone rod. [13] They demonstrated that this pseudo-synovial sheath had three distinc- tive layers, namely intima, media and adventitia. The intimal cells contain a glycosaminoglycan substance and have a secretory capacity, the media cells have large amounts of collagen and provide structural and vascular support and the adventitia is a * Corresponding author at: General Dr. Tevfik Sa glam Cad. GATA Plastik, Rekonstrüktif ve Estetik Cerrahi Anabilim Dalı, Keçiören/Ankara, Turkey. E-mail address: drakyapici@gmail.com (A.K. Yapici). http://dx.doi.org/10.1016/j.injury.2017.05.014 0020-1383/© 2017 Elsevier Ltd. All rights reserved. Injury, Int. J. Care Injured xxx (2017) xxx–xxx G Model JINJ 7240 No. of Pages 6 Please cite this article in press as: A.K. Yapici, et al., The effect of in vivo created vascularized neurotube on peripheric nerve regeneration, Injury (2017), http://dx.doi.org/10.1016/j.injury.2017.05.014 Contents lists available at ScienceDirect Injury journal homepa ge: www.elsev ier.com/locate /injury