14 General Surgery

A surgical graft is the transfer of tissue without its blood supply to a new location, requiring a new blood supply to form.

Initially, the graft survives by plasmatic imbibition, or the absorption of transudate. Capillaries begin to form 48 hours following grafting, with full vascular flow developing 7 days postoperatively.

Surgical grafts are indicated when the patient experiences:

• Trauma

• Tumor removal

• Burns

• Poor approximation of wound edges

• Chronic ulcers

Split thickness skin grafts (STSG) include the epidermis and some of the dermis, and is usually 10/1000 to 18/1000 of an inch thick.

Full thickness skin grafts (FTSG) includes the epidermis and dermis. The donor location requires a surgical flap to repair the extraction site.

Full thickness skin grafts are used in locations where cosmetic appearance is important (e.g. the face) or in areas with increased mobility (e.g. around joints).

Split thickness skin grafts contract more than full thickness skin grafts, making them undesirable except when large grafts are required (e.g. large burns). They are used in cases of large grafts because of the simple healing process of the donor site.

Failure of a surgical graft may occur secondarily to:

• Graft movement

• Infection

• Poor neovascularization

• Diabetes mellitus

• Malnutrition

• Smoking

• Corticosteroid therapy

Graft failure may be treated depending on the extent of failure:

• Partial loss is managed with moist dressing

• Complete loss requires surgical assessment

Flap

A surgical flap is defined as the transfer of tissue with its original blood supply to a new location.

Surgical flaps are indicated when:

• The wound area is poorly vascularized

• The wound cannot be closed without high tension

• A large wound occurs in a cosmetically delicate location (e.g. breast reconstruction)

Surgical flaps may be categorized by location of original tissue such as:

• Simple flaps: skin that is adjacent to the wound

• Regional flaps: skin is found nearby, but not immediately adjacent to the wound

• Distant flaps: tissue taken from a distant region of the body

Surgical flaps may be categorized by route of vascularization:

• Free flaps have a blood supply that was reconnected microvascularly

• Prefabricated flaps have a blood supply connected from a distal site

Surgical flap failure is most commonly secondary to poor vascularization of the flap.

Surgical flaps that have become necrosed require surgical debridement.