P. 630

An Urban Experience
J. Kirpensteijn1
1Hill’s Pet Nutrition, GPVA, Topeka, USA
Novel wound closure techniques
The companion animal skin consists of two main layers. The general composition of the outer layer, the epidermis, is of avascular keratinised strati ed squamous epithelium. The thicker vascular dermis lies underneath the epidermis and consists of tough  broelastic tissue with a supportive and nourishing function. The dermis rests on a layer of loose connective tissue known as the subcutis or hypodermis, composed of adipose tissue, the cutaneous trunci muscle (where present) and direct cutaneous arteries and veins. This layer is particularly abundant
in most dogs and cats, but the quantity and elasticity
of skin differs from breed to breed and on the physical condition of the animal. Variations in structure are present at different sites of the body surface. For instance the nose have a thick protective keratin layer. In addition, in most skin areas specialized epithelial appendages exist such as hair follicles and sebaceous glands.
Blood supply
In dogs and cats, direct cutaneous arteries are responsible for supplying large areas of skin. They run parallel to the skin in the hypodermis and arise from perforator arteries. Musculocutaneous arteries branch off the perforator arteries and supply small portions of the skin and run perpendicular to the surface of the skin.
The subdermal plexus in dogs and cats is of major importance in companion animal reconstructive
skin surgery and should always be preserved when undermining skin for local  aps, especially when no direct super cial arteries can be incorporated in the proposed  ap. Axial pattern  aps are  aps based on such direct cutaneous arteries and veins that supply a speci c region of dermal tissue. Since the terminal braches of these vessels supply the subdermal plexus, axial pattern  aps have better perfusion than local  aps and are widely used in veterinary reconstructive surgery.
Skin tension
Tension on the wound edges is the most common reason for skin reconstructions to fail and occurs when insuf cient skin is available to close the initial defect.
The elasticity of the canine and feline skin is primarily the result of the lack of  rm attachment of the subcutis to the
bone, muscle and fascia. The skin is loose and abundant on most parts of the body, particularly on the neck and trunk, but is less pliable on the limbs, tail and head, especially around the bridge of the nose, nasal planum and medial canthi. This is the result of linear alignment of  brous tissues within the skin in this area.
The tension lines of the head and neck region resemble the orientation of the underlying muscles. Generally speaking, incisions should always be made parallel to tension lines to minimize wound tension during closure. Incisions that are made in an angle or perpendicular to these lines may result in wound deformation, wound dehiscence and necrosis. If this is impossible, methods to reduce skin tension should be employed upon
closure. These include, from simple to more advanced, undermining the wound edges, selecting tension-relieving suture patterns, using tension-releasing incisions or skin stretching and tissue expansion techniques. If these methods do not allow primary closure of the wound, secondary intention healing or reconstruction with skin  aps or grafts have to be considered.
Reconstruction of the face
Reconstruction of the facial area can be challenging.
There are 3 major reasons for the challenge: 1. skin is less abundant than in other areas of the body, 2. There are major essential structures that make proper reconstruction more dif cult and 3. It is an obvious area, i.e. people immediately see if something is not completely right. Speci c facial reconstructive techniques include the caudal auricular axial pattern  ap, the crescentic nasojugal  ap, the facial artery axial pattern  ap.doc and the super cial temporal artery axial pattern  ap.
Reconstruction of the neck and trunk
Reconstruction of skin defects in the neck area is usually relatively easy in dogs and cats, because of
their considerable amount of loose skin in this area. In most cases defects can be closed using local skin  aps. However, after radical resection of tumours, for closure of large traumatic wounds, or for reconstruction in areas with compromised blood supply, other techniques have to be used. The axial pattern  aps that can be used for the reconstruction of large defects in the neck are the omocervical, and in some cases the thoracodorsal axial pattern  aps  aps.
Wound closure techniques
Most plastic and reconstructive techniques used in companion animals involve the creation of new surgical wounds. The general surgical principles of using aseptical techniques, proper instruments, and delicate tissue handling while creating a surgical wound apply here as well. In addition, appropriate suture materials

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