Nerve lengthening and subsequent end‐to‐end repair yield more favourable outcomes compared with autograft repair of rat sciatic nerve defects

Journal of Tissue Engineering and Regenerative MedicineVolume 13, Issue 12 p. 2266-2278 RESEARCH ARTICLE Nerve lengthening and subsequent end-to-end repair yield more favourable outcomes compared with autograft repair of rat sciatic nerve defects Holly M. Howarth, Holly M. Howarth orcid.org/0000-0002-3190-1464 Department of Bioengineering, University of California, San Diego, La Jolla, CASearch for more papers by this authorAdarsh Kadoor, Adarsh Kadoor Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CASearch for more papers by this authorRayeheh Salem, Rayeheh Salem Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CASearch for more papers by this authorBrogan Nicolds, Brogan Nicolds Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CASearch for more papers by this authorStephanie Adachi, Stephanie Adachi Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CASearch for more papers by this authorAchilles Kanaris, Achilles Kanaris Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CASearch for more papers by this authorRichard M. Lovering, Richard M. Lovering Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MDSearch for more papers by this authorJustin M. Brown, Justin M. Brown Department of Neurosurgery, Massachusetts General Hospital, Boston, MASearch for more papers by this authorSameer B. Shah, Corresponding Author Sameer B. Shah sbshah@ucsd.edu Department of Bioengineering, University of California, San Diego, La Jolla, CA Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA Research Service, VA San Diego Healthcare System, San Diego, CA Correspondence Sameer B. Shah, Department of Bioengineering, University of California, San Diego, 9500 Gilman Drive, MC 0863, La Jolla, CA 92093. Email: sbshah@ucsd.eduSearch for more papers by this author Holly M. Howarth, Holly M. Howarth orcid.org/0000-0002-3190-1464 Department of Bioengineering, University of California, San Diego, La Jolla, CASearch for more papers by this authorAdarsh Kadoor, Adarsh Kadoor Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CASearch for more papers by this authorRayeheh Salem, Rayeheh Salem Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CASearch for more papers by this authorBrogan Nicolds, Brogan Nicolds Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CASearch for more papers by this authorStephanie Adachi, Stephanie Adachi Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CASearch for more papers by this authorAchilles Kanaris, Achilles Kanaris Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CASearch for more papers by this authorRichard M. Lovering, Richard M. Lovering Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MDSearch for more papers by this authorJustin M. Brown, Justin M. Brown Department of Neurosurgery, Massachusetts General Hospital, Boston, MASearch for more papers by this authorSameer B. Shah, Corresponding Author Sameer B. Shah sbshah@ucsd.edu Department of Bioengineering, University of California, San Diego, La Jolla, CA Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA Research Service, VA San Diego Healthcare System, San Diego, CA Correspondence Sameer B. Shah, Department of Bioengineering, University of California, San Diego, 9500 Gilman Drive, MC 0863, La Jolla, CA 92093. Email: sbshah@ucsd.eduSearch for more papers by this author First published: 31 October 2019 https://doi.org/10.1002/term.2980Citations: 8Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract Outcomes of end-to-end nerve repairs are more successful compared with outcomes of repairs bridged by nerve grafts. However, end-to-end repairs are not always possible for large nerve gaps, as excessive tension may cause catastrophic failure. In this study, we built on previous nerve-lengthening studies to test the hypotheses that gradual lengthening of the proximal stump across a large nerve gap enables an end-to-end repair and such a repair results in more favourable regenerative outcomes than autografts, which represent the gold standard in bridging nerve gaps. To test these, we compared structural and functional outcomes in Lewis rats after repair of sciatic nerve gaps using either autografts or a novel compact internal fixator device, which was used to lengthen proximal nerve stumps towards the distal stump over 2 weeks, prior to end-to-end repair. Twelve weeks after the initial injury, outcomes following nerve lengthening/end-to-end repair were either comparable or superior in every measure compared with repair by autografting. The sciatic functional index was not significantly different between groups at 12 weeks. However, we observed a reduced rate of contracture and corresponding significant increase in paw length in the lengthening group. This functional improvement was consistent with structural regeneration; axonal growth distal to the injury was denser and more evenly distributed compared with the autograft group, suggesting substantial regeneration into both tibial and peroneal branches of the sciatic nerve. Our findings show that end-to-end repairs following nerve lengthening are possible for large gaps and that this strategy may be superior to graft-based repairs. CONFLICT OF INTEREST We report no conflicts of interest. Citing Literature Volume13, Issue12December 2019Pages 2266-2278 RelatedInformation