Purpose: We investigated whether sutures could guide regeneration across bifurcated nerve defects and how the number of sutures influenced regeneration.
Methods: Bilateral ten mm defects in the rat sciatic nerve were bridged by either two or six laps of longitudinal (8/0 polyglactin) sutures. Bilateral ten mm defects including the bifurcation of tibial and peroneal nerves were bridged by two laps to the tibial and four laps to the peroneal nerve on one side and vice versa on the other. Evaluation of tetanic force, weights of the gastrocnemius and caudal tibial muscles and morphometry of the nerves were performed at twelve weeks.
Results: Simple defects bridged by six laps yielded a significantly greater number of myelinated axons compared to two laps. In the bifurcated defects a well defined two branched nerve structure was formed in all cases between the sciatic nerve and its peroneal and tibial branches. However, in the bifurcated model the tibial nerve attracted more axons than the peroneal irrespective of the number of suture laps.
Conclusions: There is no simple correlation between the number of sutures and the number of regenerating axons but two suture laps may be insufficient for the repair of a rat sciatic nerve. Sutures supported reconstruction of new fascicles across bifurcated nerve defects.