Promoting nerve regeneration through long gaps using a small nerve tissue graft.

Saito Ikuo, Oka Yoshinori, Odaka Mitsuaki

Department of Orthopedic Surgery, Tokai University School of Medicine, Boseidai Isehara, Kanagawa, Japan.

Surg Neurol. 2003 Mar;59(3):148-54; discussion 154-5. doi: 10.1016/s0090-3019(02)01056-x.

BACKGROUND

If nerve tissue is capable of inducing regeneration, as suggested by the neurotropism theory, then even small pieces of nerve tissue should have the potential to induce nerve regeneration. Therefore, long gaps might presumably be bridged via the neurotrophic potential of small pieces of nerve tissue grafted into the middle of the nerve gap. It is necessary to confirm the validity of the neurotropism theory and to also explore the potential usefulness of small nerve grafting through long gaps.

METHODS

A small piece of nerve tissue was grafted into a silicone tube bridging a relatively long nerve gap in an attempt to promote nerve regeneration. A 15-mm gap was created in the left sciatic nerve of 31 Wistar rats (8 weeks of age). The experimental groups included one with nonvascularized nerve tissue grafted into a silicone tube with no distal nerve suturing (NV-A), another with vascularized nerve tissue grafted into a silicone tube with no distal nerve suturing (V-A), a third group with nonvascularized nerve tissue grafted into a silicone tube with distal nerve suturing (NV-P), a fourth group with vascularized nerve tissue grafted into a silicone tube with distal nerve suturing (V-P), and a group with no nerve segment grafted into the silicone tube (control). Electrophysiologic and histologic examinations were performed 10 weeks after the operation.

RESULTS

No regeneration was obtained in the control group. Nerve regeneration was evident at the proximal end of the tube in the NV-A, V-A, NV-P, and V-P groups, and at the distal end in the NV-P and V-P groups. The degree of distal regeneration was extremely slight in the NV-A and V-A groups. An electrophysiologic examination performed in the NV-P and V-P groups revealed better results in the latter group.

CONCLUSION

Small nerve grafts are capable of inducing nerve regeneration even over a long nerve gap, by grafting nerve tissue into the middle of the lesion using a silicone tube.