Reconstructive Surgery

Various skin flap and free grafting techniques can be used in the dog and cat to close wounds which are unamenable to simple apposition. Simple closure techniques, including undermining and tension -relieving patterns, should be considered first before more involved techniques are employed. Complex wounds involving large tissue defects and distal limb locations can be managed effectively in many cases with subdermal plexus or pedicle flaps and axial pattern flaps.

A pedicle graft, or skin flap, is a portion of skin and subcutaneous tissue with an intact vascular attachment that is transferred from one body area to another. Properly developed flaps survive because of their intact circulation. Flaps are versatile and have the following uses: covering defects with poor vascularity, improving regional circulation to an area, providing a full-thickness skin surface over areas where padding and durability are essential, giving immediate protection to nerves, vessels, tendons and other structures susceptible to exposure and injury and providing a skin surface with hair growth characteristics comparable to that of the donor area.

Pedicle Grafts

Pedicle grafts that incorporate a direct cutaneous artery and vein are termed axial pattern flaps. These flaps have an excellent blood supply and enable to surgeon to create large flaps of considerable dimension. A knowledge of regional anatomy is required to consistently incorporate the desired vasculature when creating the flap. Flaps can be transposed and rotated up to 180° into the recipient wound. For each of the described axial pattern flaps in common use, the donor defect is able to be closed primarily with minimal tension and loss of function. The two most versatile axial pattern flaps are the thoracodorsal and the epigastric flaps which can be used to reconstruct wounds of the trunk and proximal limb wiht their pedicle located at the caudal shoulder depression and inguinal area respectively. Compound or composite flaps are axial pattern flaps that involve two or more tissue types and can be use to provide more bulk than simple cutaneous flaps. Latissimus dorsi myocutaneous flaps have been used to close full-thickness chest wall defects and cover deep olecranon decubital ulcers.

Reconstructive Microsurgery

Reconstructive microsurgery refers to the use of an operating microscope and microvascular technique in facilitating reconstruction of difficult wounds. The premise of reconstructive microsurgery involves harvesting autogenous tissue from a body part distant to the wound, transferring that tissue into the wound bed for reconstruction, and reestablishing the transferred tissue’s blood supply by microvascular anastomosis of vessels feeding the flap to vessels adjacent to the wound bed. Tissue transferred in this manner are most commonly termed “free flaps”. The long-term patency rate of microsurgically anastomosed vessels in dogs is approximately 95% using well established techniques and appropriate instruementation. The major application in small animal surgery is to reconstruct difficult foot and paw wounds where skin flaps are unable to reach distally and for filling tissue defects on the face after ablative cancer surgery.