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

Suppression of Fibrous Scar Improves Peripheral Nerve Regeneration After Primary Nerve Suture
Institution where the work was prepared: University of Tuebingen and University of Duesseldorf, Tuebingen and
Duesseldorf, Germany
Nektarios Sinis, MD1; Philip Schoenle1; Tatjana Lanaras1; Frank Werdin, MD1; Armin Kraus, MD1; Max Haerle, MD2;
Timm Danker, PhD1; Elke Guenther, Phd1; Federica Di Scipio, Phd3; Stefano Geuna, MD3; Hans-Werner Mueller,
PhD4; Daniela Mueller5; Carmen Masannek5; Susanne Hermanns, Phd5; Hans-Eberhard Schaller, MD1; (1)University of
Tuebingen, (2)Orthopaedische Klinik Markgroeningen, (3)University de Torino, (4)Heinrich-Heine-University of
Duesseldorf, (5)Neuraxo Biopharmaceuticals GmbH
BACKGROUND:
Despite the progress of microsurgical techniques the outcome of repaired nerves after primary nerve suture remains incomplete in a
lot of cases. One reason that explains these results is the development of a fibrous collagen scar at the site of coaptation with expression
of different growth inhibiting substances. This collagen scar prevents axons from passing the lesion and reaching the end organ.
The aim of this study was to analyze the impact of a scar inhibiting substance, namely a potent iron chelator on peripheral nerves after
transection and primary nerve suture.
MATERIAL/ METHODS:
In a rat median nerve model four experimental groups were operated. Group I ñ transection of the median nerve and primary nerve
suture (N = 12). Group II ñ transection and venous ensheatment of the median nerve at the coaptation site (external jugular vein) (N =
12). Group III ñ transection of the nerve, venous ensheatment and filling the vein with a lipid carrier (N = 12). Group IV ñ transection,
venous ensheatment, filling of the vein with the iron chelator combined with the lipid carrier (N = 12). The observation† Axon number,
density, average diameter, nerve area and myelin thickness were measured. The gastrocnemius muscle was harvested and gene expression
of GAP-43, myogenin, MyoD, MYF5, MYF6 (MRF4) and the ?, ?, ?, ?, and ?-subunits of the nicotinic acetlycholinergic
receptor(nAChR) were examined.
RESULTS:
For control animals, 83% of Young showed evidence of regeneration vs. 50% of Aged. For IGF-1 treated animals, 100% of Young and
75% of Aged showed evidence of regeneration. Of regenerated animals, there was no difference in conduction delay or amplitude. In
aged animals, IGF-1 significantly increased a) axons per nerve (13025 vs. 3062; p