Early Clinical Outcomes with the Use of Decellularized Nerve Allograft for Repair of Sensory Defects within the Hand

Abstract

Nerve conduits have become an established option for repair of sensory deficits of up to 2 cm. More recently, decellularized nerve allograft has also been advocated as an option for nerve repair; however, no clinical studies have examined its efficacy for the treatment of sensory nerve defects. The aim of this study was to examine our early experience with the use of decellularized nerve allograft for repair of segmental nerve defects within the hand and fingers. From July 2007 to March 2008, seven patients who had ten nerve gaps were treated surgically using decellularized nerve allograft. Eight digital and two dorsal sensory nerves were repaired. The etiologies of the nerve defects were traumatic nerve transection in eight defects and neuroma resection and reconstruction in two defects. All of the affected nerves were pure sensory fibers. Functional recovery was evaluated by blinded hand therapist using moving and static two point discrimination tests. Implantation sites were also evaluated for any signs of infection, rejection, or graft extrusion. There were five men and two women with a mean age of 44 years (range 23-65). Mean nerve graft length was 2.23 cm with a range of 0.5-3 cm. Mean follow up time was 9 months (range 5-12). Average two point discrimination was 4.4 mm moving and 5.5 mm static at last recorded follow-up. There were no wound infections observed around the graft material and sensory improvement was observed in all of the patients despite this short-term follow-up. Re-exploration of two fingers was required for flexor tendon rupture in one and flexor tendon tenolysis in the other. In both cases, the nerve allograft was visualized and appeared well incorporated in the repair site. Decellularized nerve allografts were capable of returning adequate sensation in nerve defects ranging from 0.5 to 3 cm. There were no cases of infection or rejection. Decellularized nerve allograft may provide an option for segmental nerve gaps beyond 2 cm. Randomized comparative studies will be required to determine efficacy in comparison to collagen conduits or nerve autograft.

Decellularized grafts with axially aligned channels for peripheral nerve regeneration

“…Several studies have reported that decellularized allografts have consistently performed better than other commercially available grafts, which is most likely due to these grafts possessing the necessary architecture and guidance cues from nerve ECM components to promote axon regeneration (Karabekmez et al, 2009;Kehoe et al, 2012;Whitlock et al, 2009). A majority of protocols that decellularize nerve grafts are based on those developed by Sondell et al (Sondell et al, 1998) and Hudson et al(Hudson et al, 2004b) that predominantly use chemical decellularization agents.…”

Allograft Reconstruction for Digital Nerve Loss

“…(10,11,12) Several authors have reported success with processed nerve allografts. (1,2,13,14) One such allograft is the Avance® processed nerve graft (AxoGen, Inc., Alachua, FL). It consists of human nerve that has been decellularized, gamma irradiated, and subjected to enzymatic degradation of chondroitin sulfate proteoglycans with chondroitinase.…”

“…As a result, the allograft is rendered nonimmunogenic while its 3-dimensional structure is maintained. (14,15) Animal studies have shown this material to mimic autografts in macrostructure, 3-dimensional microstructural scaffolding, and protein composition. Theoretically, these qualities render 6 allograft an effective material to span peripheral nerve defects.…”

First human experience with autologous Schwann cells to supplement sciatic nerve repair: report of 2 cases with long-term follow-up

“…Although initial reports focused on short gap repairs, 5,18,26 several substrates have been studied for their potential to heal large gap defects when supplemented with AGCs, including purified SCs. 1,6,7,9,11,12,16,17,27,28,34,37,38,[40][41][42]44 Berrocal et al demonstrated that adding autologous SCs suspended in serum to AGCs significantly enhanced the ability to bridge larger gap distances in sciatic nerve repair in rats.…”