Floor plan - 2013 Annual Meeting - American Association for Hand ...

Regeneration in an Enzyme-Treated Decellularized Nerve Allograft
Institution where the work was prepared: Washington University School of Medicine, St. Louis, MO, USA
Sami H. Tuffaha, BA; Daniel A. Hunter; Ying Yan; Janina P. Luciano; Susan E. Mackinnon; Gregory H. Borschel;
Washington University in St. Louis
INTRODUCTION:
Peripheral nerve injuries are currently reconstructed using nerve autografts. The very limited supply of autologous nerve grafting material
combined with the morbidity associated with nerve autograft harvest, such as sensory loss and painful neuroma formation, necessitate
a suitable substitute to autografting. AxoGenô nerve allografts are manufactured by decellularizing human nerves with a process
that removes antigens and degrades molecules that inhibit neuroregeneration while leaving laminin intact. We designed a study to
compare the neuroregenerative capacities of the AxoGenô nerve graft to those of an autograft and the NeuraGenô conduit (the leading
hollow tube nerve conduit).
METHODS:
To obtain processed nerve grafts, sciatic nerves from Brown Norway rats were harvested and sent to AxoGenô for proprietary processing.
Three groups (Avanceô, NeuraGenô and isograft) were implanted into the sciatic nerve of Lewis rats at two different lengths (14mm
and 28mm). Grafts were harvested at either a 6 or 12 week endpoint and evaluated for neuroregeneration using histomorphometry.
Retrograde labeling, motor endplate staining, walking track analysis, and wet muscle mass were used to analyze functional recovery.
RESULTS:
Midgraft histomorphometric data of the 14mm grafts at 6 weeks showed significantly greater regeneration in AxoGenô processed
grafts, as compared to NeuraGenô conduits.† Fiber distribution patterns resembled those of an isograft as demonstrated by electron
micrographs of midgraft sections.
CONCLUSION:
The AxoGenô grafts were well-tolerated by all animals. The 6 week histomorphometric data suggest that the neuroregenerative capacities
of AxoGenô processed grafts are comparable to those of an isograft and significantly better than those of the leading biosynthetic
conduit. Pending functional outcome measures and data from the 12 week endpoint, it appears that AxoGenô grafts could provide
a much needed substitute for autografts.
Graft Type
Total fiber number ±
std dev
Percent Nerve
± std dev
* or †: significant difference between groups; p < 0.05 by ANOVA.
Fiber width (µm)
± std dev
120
Nerve density
(fibers/mm 2 )
± std dev
Isograft 13649 ± 4967*† 23.5 ± 11.0* 3.0 ± 0.2* 23191 ± 9616*
AxoGen TM
Processed
Nerve Graft
6041 ± 1515† 16.5 ± 3.4† 3.3 ± 0.2† 14749 ± 3512†
NeuraGen TM 1427 ± 2018* 1.3 ± 1.8*† 1.6 ± 2.2*† 1278 ± 1821*†