Time course of alterations in muscle transfers with microneurovascular anastomoses. An experimental study in the rectus femoris muscle of the rabbit.

The time course of alterations in muscle transfers with microneurovascular anastomoses was studied in 17 rabbits. The left rectus femoris muscle was transferred to the right side. For comparison, in some animals the right rectus femoris muscle was transferred from the right to the left side, but without vascular repair. Two, seven, 14, 21, and 30 days after transfer, the electric excitability, macroscopic appearance, histology, histochemistry, ultrastructure, and activity of muscle enzymes were assessed. In the transfers with microneurovascular anastomoses, almost all muscle fibers survived. Alterations were limited to those typical of a denervation-reinnervation process. Contrary to this, only a few atrophic fibers survived in the periphery of the transfers without vascular repair. By far, the greater central part underwent necrosis. A considerable amount of connective tissue developed. These results clearly show the functional superiority of microsurgically vascularized muscle transfers over those without vascular anastomoses. Excellent functional recovery is possible because the process of complete degeneration and consecutive regeneration, with inevitable augmentation of connective tissue, is prevented by the performance of vascular anastomoses.