In Vivo Efficacy of a Novel, Sutureless Coaptation Device for Repairing Peripheral Nerve Defects.

Although microsuture neurorrhaphy is the accepted clinical standard treatment for severed peripheral nerves, this technique requires microsurgical proficiency and still often fails to provide adequate nerve approximation for effective regeneration. Entubulation utilizing commercially available conduits may enhance the technical quality of the nerve coaptation and potentially provide a proregenerative microenvironment, but still requires precise suture placement. We developed a sutureless nerve coaptation device, Nerve Tape®, that utilizes Nitinol microhooks embedded within a porcine small intestinal submucosa backing. These tiny microhooks engage the outer epineurium of the nerve, while the backing wraps the coaptation to provide a stable, entubulated repair. In this study, we examine the impact of Nerve Tape on nerve tissue and axonal regeneration, compared with repairs performed with commercially available conduit-assisted or microsuture-only repairs. Eighteen male New Zealand white rabbits underwent a tibial nerve transection, immediately repaired with (1) Nerve Tape, (2) conduit plus anchoring sutures, or (3) four 9-0 nylon epineurial microsutures. At 16 weeks postinjury, the nerves were re-exposed to test sensory and motor nerve conduction, measure target muscle weight and girth, and perform nerve tissue histology. Nerve conduction velocities in the Nerve Tape group were significantly better than both the microsuture and conduit groups, while nerve compound action potential amplitudes in the Nerve Tape group were significantly better than the conduit group only. Gross morphology, muscle characteristics, and axon histomorphometry were not statistically different between the three repair groups. In the rabbit tibial nerve repair model, Nerve Tape offers similar regeneration efficacy compared with conduit-assisted and microsuture-only repairs, suggesting minimal impact of microhooks on nerve tissue.

Biomechanical Testing of a Novel Device for Sutureless Nerve Repair.

Suboptimal nerve end alignment achieved with conventional nerve repair techniques may contribute to poor clinical outcomes. In this study, we introduce Nerve Tape®, a novel nerve repair device that integrates flexible columns of Nitinol microhooks within a biologic backing to entubulate, align, and secure approximated nerve ends. This study compares the repair strength of Nerve Tape with that of conventional microsuture repairs. Thirty small (2 mm) and 30 large (7 mm) diameter human cadaveric nerves were transected and repaired utilizing Nerve Tape or appropriate microsuture technique. Biomechanical testing was performed using a horizontal tensile tester. The repaired nerves were loaded until failure at a distraction rate of 40 mm/min, and the maximum failure load was determined. In the small nerve groups, the load-to-failure for Nerve Tape repairs (2.33 ± 0.66 N) was significantly higher than for suture repairs (1.22 ± 0.52 N; p < 0.05). In the large nerve groups, no significant difference in load-to-failure was found between Nerve Tape (7.45 ± 2.66 N) and suture repairs (5.82 ± 1.59 N: p = 0.12). Suture repairs tended to fail by rupture, whereas Nerve Tape failures resulted from microhook pullout. Nerve Tape is a novel nerve coaptation device that provides mechanical repair strength equal or greater to clinically relevant microsuture repairs.