fibrin and Neuroma

The outcome of peripheral nerve injury is often impaired by neuropathic pain, which is resistant to most analgesics and presents a serious clinical problem. The mechanisms underlying post-traumatic neuropathic pain remain unclear, but they are likely associated with the regeneration processes. Brain-derived neurotrophic factor (BDNF) is known to enhance peripheral nerve regeneration and is also considered to be an endogenous modulator of nociceptive responses following spinal cord lesion. The aim of this work was to examine the local effect of BDNF in a neuropathic pain model. Sciatic nerves of adult male rats were transected and supplied with connective tissue chambers filled with (1) fibrin only, (2) fibrin with BDNF, or (3) fibrin with antibodies against BDNF. In control animals the nerve was transected and no chamber was applied. During follow-up, autotomy behavior was assessed. Seven weeks after the operation, the number of surviving and regenerating neurons in dorsal root ganglia was counted and the neuroma incidence was examined. We found that local inactivation of BDNF decreased the incidence as well as severity of autotomy and neuroma formation, but did not influence neuron regeneration into the chambers. These results indicate that BDNF plays a locally crucial role in neuropathic pain development after peripheral nerve injury.

Topics: Amputation, Traumatic; Animals; Antibodies, Blocking; Behavior, Animal; Brain-Derived Neurotrophic Factor; Fibrin; Fibrinogen; Ganglia, Spinal; Male; Nerve Regeneration; Neuroma; Neurons; Pain; Peripheral Nervous System Diseases; Peripheral Nervous System Neoplasms; Rats; Rats, Wistar; Sciatic Neuropathy; Thrombin

Animal experiments were performed in an attempt to prevent formation of amputation neuromas. For this purpose lyophilized homologous nerve transplants were used. Experiments were performed with the sciatic nerve of the rat. Results were compared with those achieved by using fresh autologous transplants and by covering the nerve ends with fibrin glue. Axons exhibited reduced growth within the empty spaces of the lyophilized transplant thus limiting uncontrolled growth of axons. Neuromas never occurred at the free end of this lyophilized transplant. Neuromas observed (13 out of 90) occurred at the juncture site. With respect to suture techniques epineural suture in combination with fibrin glue proved to be best.

Topics: Amputation, Surgical; Animals; Fibrin; Forelimb; Freeze Drying; Neuroma; Rats; Sciatic Nerve; Tissue Adhesives; Transplantation, Homologous