Microsurgical management of old injuries of the peripheral nerve and brachial plexus

A prospective study was carried out in patients suffering from old peripher al nerve and brachial plexus injuries to attempt to validate that functiona l improvement was possible after microsurgical management. Fifty patients u nderwent operative procedures, of whom 35 were peripheral-nerve injury case s, from 1.2 to 50 years after injury, and 15 were brachial-plexus injury ca ses, from 1.2 to 12 years after injury. The patients were treated by extern al and interfascicular neurolysis and/or autogenous nerve grafts. In cases of preganglionic nerve injury, neurotization from C3, C4 roots was done for reinnervation of trunks or cords. During external and interfascicular neur olysis in 19 of the 35 peripheral-nerve injuries, significant improvement w as found in amplitude (p = 0.0001) and latency (p = 0.01) of compound muscl e action potentials (CMAPs) at the end of the surgery, compared to the onse t of surgery. Twenty (57 percent) of the 35 showed Functional motor improve ment up to M4-or M4. Electrophysiologic analysis of amplitude of CMAPs 1 ye ar after surgery showed statistically significant improvement (p = 0.0003). Five (33 percent) of the 15 patients with upper brachial-plexus injuries s howed functional motor improvement up to M4-(active movements against gravi ty and slight resistance) or M4 (active movements against gravity and moder ate resistance) after surgery and of these, 11 also had lower brachial-plex us injuries, with four (36 percent) showing antigravity function M3 (active movement against gravity). Statistical analysis of recruitment 1 year afte r surgery demonstrated the appearance of or significant voluntary muscle ac tivity in 45 percent of the muscles. Intraoperative electrophysiologic findings after external and interfascicul ar neurolysis confirmed that the viability of nerve tissue is of longer dur ation than previously considered. This study suggests that the use of micro surgical techniques results in the functional improvement of patients suffe ring from old injuries of the peripheral nerve and brachial plexus.