Use of bioabsorbable nerve conduits as an adjunct to brachial plexus neurorrhaphy

The use of bioabsorbable conduits in digital nerve repair has demonstrated increased efficacy compared to direct repair (for gaps ≤ 4mm) and nerve grafting (for gaps ≥ 8 mm) for sensory recovery in a level 1 human trial. Although nonhuman primate studies on mixed motor-sensory nerves have documented comparable efficacy of the bioabsorbable nerve conduits when compared to nerve repair or grafting, there is minimal human clinical data on motor recovery following bioabsorbable nerve conduit repair. This study investigates the outcomes of bioabsorbable nerve conduits in pure motor nerve reconstruction for adult traumatic brachial plexus injuries.

Over a 3-year period, 21 adult patients had 1 or more nerve-to-nerve transfers for traumatic brachial plexus palsy performed using the operative microscope. Ten nerve transfers were performed by advancing the nerve ends into a semi-permeable type I collagen conduit stabilized with 8-0 nylon sutures (conduit-assisted neurorrhaphy). Twenty-eight concurrent nerve transfers were performed using standard end-to-end neurorrhaphy and 8-0 or 9-0 nylon sutures. Clinical evaluation using the Medical Research Council grading system (MRC) was performed at 1 and 2 years postoperatively. Postoperative electromyographic studies were performed in 28 of 38 transfers at final follow-up.

Thirty transfers (17 patients) were available for 2-year follow-up evaluation. All 10 transfers performed with nerve conduits demonstrated clinical recovery and electromyographic reinnervation at 2 years. Eighteen of 20 transfers performed without conduits demonstrated clinical recovery.

Although no statistical difference in functional recovery was seen in nerve transfers performed with collagen nerve conduits or by traditional neurorrhaphy, this pilot series demonstrated clinical and electromyographic recovery in 10 of 10 motor nerve repairs performed using conduits. These findings warrant continued investigation into the efficacy of conduit-assisted repair for motor nerves, especially in regards to operative time, precision of repair, and speed of nerve recovery.

Therapeutic IV.