Regeneration of the vascular system in the experimental nerve heterografts was studied stereoscopically and histologically, using peroneal nerves of 27 mongrel adult dogs.
Comparison was made between radiated and nonradiated nerve grafts. Two types of arterial proliferation in and around the graft were found after nerve grafting: (1) extraneural proliferation of the vessels around the graft, most prominent at the third to sixth week after grafting and more extreme in nonradiated grafts, and (2) intraneural proliferation of the vessels, which began at the third week and became complete at the 24th week after grafting. In the radiated group, this type of proliferation traversed the graft longitudinally, forming regular bundles in the graft.
The evidence suggests that radiation of the nerve segments has the definite advantage of producing a regular pattern of the regenerating vascular system in the nerve heterografting.