Effects of collagen nerve guide on neuroma formation and neuropathic pain in a rat model.

Background: Posttraumatic neuroma formation is a major cause of neuropathic pain that can occur after elective surgery, amputation, or trauma. This study examined the use of biosynthetic collagen nerve guides to prevent the development of posttraumatic neuromas.

Methods: Collagen nerve guides were applied after neurectomy in a rat sciatic nerve model in an effort to stimulate linear neuronal outgrowth and reduce random axon sprouting. Animals were monitored for evidence of neuropathic pain--autotomy scores were recorded for 8 weeks posttransection--after which proximal stumps were excised and processed for histologic analyses.

Results: Moderate to severe autotomy was observed in 88% (7 of 8) of the control (neurectomy) animals. In contrast, 13% (1 of 8) of animals receiving collagen nerve guides developed autotomy, which was significantly less than controls (P < .01). Qualitative analyses of neurofilament and Schwann cell-labeled nerve sections showed a significant enhancement in Schwann cell migration away from the proximal stump and advanced linear axonal regrowth in the collagen nerve guide-treated animals.

Conclusions: Collagen nerve guides alter the regrowth of transected nerves and reduce the severity of symptoms associated with neuropathic pain.