Peripheral nerve injury: a review and approach to tissue engineered constructs

Eleven thousand Americans each year are affected by paralysis, a devastating injury that possesses associated annual costs of $7 billion (American Paralysis Association, 1997). Currently, there is no effective treatment for damage to the central nervous system (CNS), and acute spinal cord injury has been extraordinarily resistant to treatment. Compared to spinal cord injury, damage to peripheral nerves is considerably more common. In 1995, there were in excess of 50,000 peripheral nerve repair procedures performed. (National Center for Health Statistics based on Classification of Diseases, 9th Revision, Clinical Modification for the following categories: ICD-9 CM Code: 04.3, 04.5, 04.6, 04.7). These data, however, probably underestimate the number of nerve injuries appreciated, as not all surgical or traumatic lesions can be repaired. Further, intraabodominal procedures may add to the number of neurologic injuries by damage to the autonomic system through tumor resection. For example, studies assessing the outcome of impotency following radical prostatectomy demonstrated 212 of 503 previously potent men (42%) suffered impotency when partial or complete resection of one or both cavernosal nerve(s). This impotency rate decreased to 24% when the nerves were left intact (Quinlan et al., J. Urol. 1991;145:380-383; J. Urol. 1991;145:998-1002).