A Multicenter, Prospective, Randomized, Pilot Study of Outcomes for Digital Nerve Repair in the Hand Using Hollow Conduit Compared With Processed Allograft Nerve

摘要

Although the standard for treatment of peripheral nerve injuries is tensionless primary nerve repair, the nature of the injury often necessitates extensive resection and debridement to obtain healthy nerve tissue, resulting in a gap in the nerve.16,17,20 Deficits that cannot be directly approximated require reconstruction with a material to bridge this gap.5,17,21 Current nerve gap bridging options include autograft nerve, autologous vein, and commercially available off-the-shelf alternatives such as processed nerve allograft or hollow tube conduits. Autografts are most often the standard of care, but required harvesting of donor nerves increases operative time and introduces the potential for a host of donor site complications, such as sensory loss, hypertrophic scarring, and painful neuroma formation.10,19Off-the-shelf nerve graft alternatives offer benefits over autograft techniques, including no donor deficit, avoidance of multiple suture lines, convenience, and proven effectiveness in the right situations. These include hollow conduits and, more recently, processed human nerve allograft. Hollow conduits are most commonly composed of polyglycolic acid, collagen, or poly(DL-lactide-ε-caprolactone).18,25 Conduits share the common characteristics that they are semirigid, to resist collapse and kinking; semipermeable, to allow the diffusion of oxygen and nutrients that support nerve regeneration; and absorbable. The entubulation technique provides an enclosed chamber to trap and collect fibrin, which provides a rudimentary scaffold for cellular migration during nerve regeneration.15Commercially available processed human nerve allograft (Avance? Nerve Graft; AxoGen Inc, Alachua, Florida, USA) mitigates concerns of donor site morbidity from nerve autografts while providing a 3-dimensional microstructural scaffolding and protein composition inherent to nerve tissue structure. Controlled decellularization protocols overcome issues with immune rejection while leaving the extracellular matrix intact. This process yields grafts with a preserved internal architecture of the epineurium, fascicles, and endoneurial tubes. The intact laminin in processed nerve allograft offers axon support and guidance cues not found in hollow conduit, and animal studies have reported several equivalent outcomes compared with autograft.9,12,22,26Early clinical data and outcomes reported from an ongoing registry on processed nerve allograft have demonstrated meaningful levels of recovery in nerve gaps up to 50 mm in length.2,4,7,13,23 The purpose of our study was to compare the outcomes for digital nerve gap reconstruction with hollow conduit versus allograft in a multicenter prospective, randomized, double-blind pilot study.