Intercostal nerve transfer in brachial plexus injuries: an experimental study.

Eighteen adult mongrel dogs underwent unilateral surgical disruption of the brachial plexus. Twelve animals (Group I) had as a second-stage procedure transfer of T4 and T5 intercostal nerves and their accompanying vascular bundles to the distal musculocutaneous nerve stump. Six animals (Group II) had restoration of musculocutaneous nerve continuity with conventional interpositional sural nerve cable grafts. Group I animals demonstrated significantly better electromyographic evidence of reinnervation and, comparing appearance and weight of operated and unoperated biceps muscles at the time of animal sacrifice, maintained greater gross weight and more normal overall appearance of muscle. Histologic study of muscle tissue showed no significant difference between the two groups whereas musculocutaneous nerve histology distal to all anastomoses revealed less fibrous tissue and a greater number of healthy-appearing axons in Group I. It is concluded that vascularized intercostal nerve transfer as performed in this study has theoretical advantages over conventional nonvascularized intercostal nerve transfer but additional investigation is required to make this determination. The superiority of vascularized intercostal nerve transfers over conventional interpositional sural nerve cable grafts has been demonstrated.