THE EPINEURAL SLEEVE TECHNIQUE FOR NERVE GRAFT RECONSTRUCTION ENHANCES NERVE RECOVERY PRZEMYSLAW LUBIATOWSKI, M.D., Ph.D., 1,2 FAIK M. UNSAL, M.D., 1 DILEEP NAIR, M.D., 3 KAGAN OZER, M.D., 1 and MARIA SIEMIONOW, M.D., Ph.D. 1,4 * The purpose of the study was evaluation of nerve recovery following epineural sleeve technique for graft reconstruction in rat sciatic nerve. This technique provides the epineural sleeve to cover and separate the site of coaptation. Animals were divided into three groups: CNG- conventional nerve grafting, ESN-epineural sleeve from recipient nerve stumps, ESG-epineural sleeve from graft. Nerve regeneration was evaluated by pin-prick, toe-spread test, walking track analysis and somatosensory-evoked potentials (SEP), gastrocnemius index (GI), and histomorphometric evaluation. Most parameters (SFI, SEPs, and GI) showed significantly better nerve recovery for ESN group when com- pared to conventional CNG group. Also ESG group revealed better result for SFI. Better functional results for ESN and ESG groups were further confirmed by histomorphometric analysis: higher axon density and diameters as well as thicker myelin sheath. Epineural sleeve graft technique may be promising method with potential application for nerve reconstructive procedures. Better functional nerve recovery can be anticipated. V V C 2008 Wiley-Liss, Inc. Microsurgery 28:160–167, 2008. Nerve grafting is a well-accepted method of treatment for patients with inveterate nerve defects that cannot be bridged by simple epineural suture. Nerve grafting brings the issue of optimal coaptation, survival of the graft, and optimal restoration of fascicular pattern. 1 Nerve coapta- tion is of the utmost importance in successful nerve reconstruction. There are two coaptation sites when nerve grafts are applied so proper technique is essential. Differ- ent techniques for enhancement of nerve recovery after nerve suture have been applied previously. 2–9 Epineural sleeve technique for nerve repair was investigated recently in our laboratory. Technique described by Snyder in 1974 was introduced originally to minimize or to pre- vent neuroma formation at the repair site and to facilitate nerve regeneration. 10 Our previous studies on epineural sleeve repair reported both technical details and func- tional results using the rat sciatic nerve model. The sleeve technique improved functional recovery following repair of the sciatic nerve, as was shown by functional and histomorphometric results. 11,12 Epineural sleeve is created from the epineurium which covers coaptated nerve ends. Coaptation site becomes separated from the surrounding tissues, and thus is supplied with an optimal environment for nerve regen- eration. The sleeve prevents protrusion of fascicles out from the suture line and prevents nerve from contact with scar or fibrotic tissues around coaptation site facilitating axonal regrowth. In this study, the sleeve technique was applied to enhance recovery following nerve graft repair. MATERIALS AND METHODS Twenty-four Lewis rats were divided into 3 groups of 8 rats each. In Group I (Conventional Nerve Graft 5 CNG), nerve grafting using conventional epineural repair with 4 sutures at each site was performed. In the epineu- ral sleeve technique, a segment of epineurium from the nerve (or graft) stump is dissected as a sleeve into which the opposite nerve (or graft) stump is inserted. The sleeve is then anchored with 2 epineural sutures at the site 1808 apart. In Group II (Epineural Sleeve Graft 5 ESG), a sleeve was created from the graft epineurium and was pulled to cover the both stumps of recipient nerve. In Group III (Epineural Sleeve Nerve 5 ESN), a sleeve was created from both proximal and distal sciatic nerve stumps and was pulled over to cover the nerve graft ends. The right sciatic nerve was approached through a straight skin incision at the posterior surface of the upper thigh. Following dissection, a 10-mm fragment of the sci- atic nerve was excised by straight microscissors to create a nerve gap. Nerve isografts were harvested from the right sciatic nerves of donor animals. Surgical procedures were performed while the rats were under intraperitoneal pentobarbital anesthesia (40 mg/kg) by a single surgeon using standard microsurgical techniques under the operat- ing microscope (Zeiss OP-MI 6-SD; Carl Zeiss, Goettin- gen, Germany). All animals used in this experimental study received humane care in compliance with Guide for the Care and Use of Laboratory Animals published by the National Institutes of Health and guidelines of Cleveland Clinic Animal Research Committee. 1 Department of Plastic Surgery, The Cleveland Clinic, Cleveland, OH 2 Kosciuszko Foundation, NY-Warsaw 3 Department of Neurology, The Cleveland Clinic Foundation, Cleveland, OH 4 Department of Gastroenterology and Endocrinological Surgery, University of Medical Sciences, Poznan, Poland *Correspondence to: Maria Siemionow, M.D., Ph.D., Department of Plastic and Reconstructive Surgery, Cleveland Clinic Foundation, Desk A60, 9500 Euclid Ave., Cleveland, OH 44195. E-mail: siemiom@ccf.org Received 6 April 2007; Accepted 6 June 2007 Published online 19 February 2008 in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/micr.20472 V V C 2008 Wiley-Liss, Inc.