Page 1336 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Wound management and infections of synovial structures 1311

VetBooks.ir apy (Fig. 13.21) by using a vacuum-assisted device is excessive motion at the wound bed not only pro-
The use of topical negative pressure (TNP) ther-
Wound immobility is also a crucial factor, and
becoming more popular in the treatment of wounds
by second-intention closure. The presumed mecha- motes dehiscence and delays wound healing but also
promotes exuberant granulation tissue. Inadequate
nisms of action are an increase in blood flow, pro- management of wound motion is one of the main
motion of angiogenesis, reduction of wound surface reasons for the exuberant granulation tissue forma-
area in certain types of wounds, modulation of the tion seen in clinical practice. Different degrees of
inhibitory contents in wound fluid and induction of immobilisation can be accomplished with an appro-
cell proliferation. In order to implement TNP ther- priately applied bandage with or without the use of
apy a commercial vacuum pump is required, plus a a splint or a cast (Fig. 13.22). A heavily layered ban-
piece of reticulated open-cell polyurethane foam, an dage or modified Robert Jones bandage will provide
occlusive dressing and a piece of evacuation tubing immobility directly related to the number of layers
with a flat end designed to be introduced through applied. It is important to maintain the conformation
the occlusive dressing and onto the top of the foam. and the uniform pressure of the bandage in order
It is important that the occlusive bandage surround- to avoid complications, such as pressure sores and
ing the wound is completely sealed and, for this, the undue wound irritation (Fig. 13.23). Splints should
region surrounding the skin should be completely be light, waterproof, easy to contour, strong, cheap
clipped as finely as possible and degreased. While and without sharp edges. PVC piping is an ideal
there is some controversy as to the magnitude of material. It is important to customise the splint so
negative pressure, currently the author uses –100 to that it has the appropriate length and width and con-
–125 mmHg. The dressing and foam are changed forms well to the individual horse. Inappropriately
every 2–3 days, or more frequently if the seal is lost placed or padded splints may produce large pres-
(identified by sudden loss of negative pressure) or sure sores, particularly in foals. Too little padding
the wound has excessive production of exudate. The can lead to pressure sores, while too much padding
antibacterial effect of TNP is controversial but it will allow the splint to move around the horse’s limb.
may have a positive effect. The use of splints allows the clinician access to the

13.21A 13.21B

Fig. 13.21 (A) Use of a
vacuum-assisted device on a
granulating wound of the caudal
thigh. (B) Detail of the use of
a vacuum-assisted device on a
granulating wound of the tarsus
covered in an occlusive dressing.