Objective—To determine the effect of a silicone dressing
on the rate and quality of repair of limb wounds and
compare microvascular occlusion and apoptosis in
wounds treated with the silicone dressing and those
treated with a conventional dressing in horses.
Procedure—Horses received two 6.25-cm2 wounds
on each metacarpus. Ten wounds were treated with a
silicone dressing; the other 10 were treated with a
control dressing. Quality of repair and wound size
were evaluated at each bandage change. Time to healing
and the number of excisions of exuberant granulation
tissue were recorded. Biopsy specimens taken
from healed wounds were evaluated semiquantitatively
via histologic examination, p53 immunohistochemical
analysis, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)
to quantify apoptosis, and electron microscopic examination
to measure microvessel luminal diameters.
Results—The silicone dressing surpassed the conventional
dressing in preventing formation of exuberant
granulation tissue and improving tissue quality.
Microvessels were occluded significantly more often
in wounds dressed with the silicone gel, which also
diminished the expression of mutant p53, an indirect
inhibitor of apoptosis, although greater apoptosis was
not confirmed quantitatively by use of TUNEL.
Conclusions and Clinical Relevance—Because the
silicone dressing inhibited the formation of exuberant
granulation tissue, it may be integrated in a management
strategy designed to improve the repair of limb
wounds in horses. (Am J Vet Res 2005;66:1133–1139)