Research Report The effect of autogenous vein grafts on nerve repair with size discrepancy in rats: An electrophysiological and stereological analysis Murat Acar a , Ahmet Karacalar a , Mustafa Ayyildiz b , Bunyami Unal c , Sinan Canan d , Erdal Agar b , Suleyman Kaplan e, ⁎ a Department of Plastic, Reconstructive and Aesthetic Surgery, Ondokuz Mayis University School of Medicine, TR-55139 Samsun, Turkey b Department of Physiology, Ondokuz Mayis University School of Medicine, TR-55139 Samsun, Turkey c Department of Histology and Embryology, Ataturk University School of Medicine, TR-25100 Erzurum, Turkey d Department of Physiology, Başkent University School of Medicine, TR-06530 Ankara, Turkey e Department of Histology and Embryology, Ondokuz Mayıs University School of Medicine, TR-55139 Samsun, Turkey ARTICLE INFO ABSTRACT Article history: Accepted 3 January 2008 Available online 18 January 2008 Aside from anatomical repairs, the reestablishment of sensory and motor innervations for proper functional recovery is one of the fundamental objectives of reconstructive surgery. The heterotopic transfer of autologous tissues is likely to result in a size discrepancy between the donor and recipient nerves, which will have a negative influence on regeneration. Twenty Wistar albino female rats were used in a study that was divided into two main groups: tibial–peroneal (TP) and peroneal–tibial repair (PT). Both types of nerves were exposed on the hind legs with the nerves cut on the right side, while the proximal stump of the tibial nerve and distal stump of the peroneal nerve were sutured to each other. These groups are also called end-to-end neurorrhaphy groups (EtoE). On the left side, the tibial and peroneal nerves were cut on the same level as on the right side. After the end-to-end epineural suturing of the nerve, the vein graft was slid over to the repair zone under irrigation. These are called the vein graft group (VG). All processes mentioned above were also done for the PT group. On the 90th postoperative day, anesthetized animals were fixed prone on a board, with the nerves carefully dissected for electrophysiological recording. Stereological methods for an estimation of the total number of myelinated fiber, a mean axonal cross-section area and the thickness of the myelin sheet were used. In TP and PT groups, nerve conduction velocities were found to be higher within the VG group. Nevertheless; the difference was only significant in the PT group. In both TP and PT groups, the increase in the axon number, axon area and myelin thickness were statistically different in favor of the vein graft sides. An appearance of vacuoles and degenerated pertinacious material within the myelin sheath of EtoE sides was seen. A histomorphological examination of the sections proximal to, from, and distal to the repair zone over three months revealed less epineural scarring, a thinner epineurium, more regenerated axons and Keywords: Tibial nerve Peroneal nerve Vein graft Electrophysiology Stereology BRAIN RESEARCH 1198 (2008) 171 – 181 ⁎ Corresponding author. Department of Histology and Embryology, Ondokuz Mayıs University School of Medicine, TR-55139 Samsun, Turkey. Fax: +90 362 312 19 19x2265. E-mail address: skaplan@omu.edu.tr (S. Kaplan). 0006-8993/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.brainres.2008.01.013 available at www.sciencedirect.com www.elsevier.com/locate/brainres