End-to side neurorrhaphy and bypass graft for peripheral injury: an experimental study and its clinical application

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 15591600
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Orthopaedic surgery
• Research Institution: Keio University
• Principal Investigator: NAKAMURA Toshiyasu Keio University, Department of Medicine, Instructor, 医学部, 助手 (70265859)
• Co-Investigator(Kenkyū-buntansha): NAKAO Yasushi Keio University, Department of Medicine, Assistant Professor, 医学部, 専任講師 (30188883) ; TOCHIGI Hirokazu Tokyo Dental University, Department of Dental Medicine, Instructor, 歯学部, 助手 (80306745)
• Project Period (FY): 2003 – 2004
• Keywords: Peripheral nerve / Bypass graft / end-to-side neurorrhaphv / axonal regeneration / electromyogram / nerve graft / complete laceration / partial laceration

Research Abstract

This experimental study demonstrates usefulness of end-to-side neurorrhaphy and bypass graft for the peripheral nerve injury. Its clinical application is also indicated.
We used the complete and incomplete laceration models of the peripheral nerve. In the complete laceration model, the rat's sciatic nerve was completely sectioned and the silicon tube was inserted not to regenerate. In the incomplete laceration model, the sciatic nerve was tightened up with 6-0 stitches. In the both model, damaged area of the peripheral nerve was bypass grafted by the autografted median nerve. Regeneration of the sciatic nerve was examined electomyographically and histologically in the complete and incomplete laceration models. BDA trace examination was also performed to analyze where the regenerative axon located.
M-wave was detected in 6 weeks after partial and complete laceration of the nerve with the bypass graft. Approximately 70% regeneration axons was noted in the bypass graft of incomplete laceration model 12 weeks after the surgery, while approximately 50% regeneration axons was found in complete laceration model, both of which indicated smaller number of regeneration of the axons in comparison with the conventional nerve graft model. Neurofilament staining and BDA trace examination indicated regenerative axons via the bypass graft.
In conclusion, the bypass graft using the end-to-side neurorrhaphy is useful method for augmentation of the damaged peripheral nerve, especially in continuous nerve damage, such as the incomplete brachial plexus injury.