Nerve Gap Reconstruction.

In many nerve injuries, tissue destruction, scar, and other factors prohibit surgical reapproximation of the nerve ends without excessive tension. The resultant nerve gap has traditionally been bridged using autologous sensory nerve; however, the harvest of autologous nerve graft adds time and donor site morbidity. Over the past decades, a variety of commercially available hollow conduits designed for nerve gap reconstruction have been used.

More recently, commercially available processed human nerve allograft has been introduced with the promise of reconstruction whose success rivals the results of nerve autograft. In the case of digital nerve reconstructions, a number of studies indicate that for small nerve gaps (<15 mm) the recovery of sensation is the same for nerves repaired with nerve autograft, hollow nerve conduit, or processed nerve allograft. Although processed nerve allograft appears to outperform hollow conduits for slightly larger nerve gaps, it is unclear how it compares to nerve autograft across a variety of different nerve injuries.

Overall, the results of nerve reconstruction are often disappointing, regardless of whether by direct repair or by spanning an intervening nerve gap. Further work on the biology of nerve regeneration is needed, not only to improve existing nerve conduits, but to improve the results of all nerve repairs and reconstructions.