Comparison of fascicular, interfascicular and epineural suture techniques in the repair of simple nerve lacerations.

Simple lacerations of dog anterior tibial nerves were repaired utilizing fascicular interfascicular, and epineural suture techniques. Two months following repair, the involved regions of the nerve were removed and stained with hematoxylin and eosin, Weil, Bielschowsky, and Masson trichrome stains. An independent, unbiased observer rated proximal and distal myelin, connective tissue responses, and proximal to distal axon counts. The proportion of proximal to distal axons revealed no significant difference between fascicular (77%) and epineural (67%) neurorrhaphy, but showed a significant beneficial effect of fascicular suture to the interfascicular (52%) repair (significance at less than 0.02). Masson stain revealed dense connective tissue responses, but the axon counts were adversely affected only when the separate fascicles showed internal disruption by connective tissue. In general, distal myelinization was mildly superior with the fascicular neurorrhaphy technique. It appears that in simple lacerations in nerves which are repaired via direct end-to-end suture, there is no significant advantages to fascicular over epineural repair; however, there is a definite deleterious effect of interfascicular neurorrhaphy. The theoretical and technical implications of these findings are discussed.