More Than Skin Deep
Skin cancers are the most commonly diagnosed cancers in this country, with approximately 1 million cases annually. Most tumors are not aggressive and have an extremely low mortality rate. The majority of people treated for skin cancers, unlike many other types of cancer, have a minor, office-based surgical procedure and require no other therapy. Neglected or aggressive forms of skin cancer, however, may present a very different scenario. Treatment may involve complicated surgical removal of tissue or part or all of an organ followed by reconstructive procedures as well as chemotherapy or radiation therapy for control. Because of the potential risks involved, preventive measures, awareness of signs of skin cancer, and prompt attention to problem areas are extremely important.
The vast majority of true skin cancers are basal cell carcinomas and squamous cell carcinomas. When diagnosed early, these tend to be easily treatable. Melanoma is a more serious type of skin cancer. Though when caught early some melanomas are treated by simple excision, more than half the melanomas diagnosed are invasive and require wide and deep excision of the lesion as well as lymph node removal. Recurrent melanomas may require additional surgery, radiation, or chemotherapy.
Surgery and the Need for Reconstruction
Surgical treatment of skin cancer typically involves removal of the cancerous lesion along with a margin of surrounding skin. The entire affected area is excised, leaving a defect that extends into the deeper layers of skin. In some areas—such as around the eyes, nose, and mouth—there may be limits to the amount of skin that can be removed. In such cases, there are additional functional as well as aesthetic considerations, so Mohs micrographic surgery may be used.
Mohs surgery allows for serial excisions of sensitive areas and immediate examination of the tissue to ensure complete tumor removal while sparing as much normal tissue as possible. This is also a valuable technique with skin cancers that have recurred and with cancers with indistinct borders that have spread to the deeper layers of the skin. Mohs surgery can produce a higher chance of cure than standard resections in these types of cases.
Timing of Repair
Whenever possible, open surgical wounds are closed immediately. This reduces pain and discomfort, eliminates the need to care for an open wound, and speeds healing. There are some situations, however, when immediate closure may not be in a patient’s best interest.
At the time of the resection, surgeons use their clinical judgment or frozen section evaluation to ensure that the tumor has been completely removed. Frozen section examination of tissue gives immediate information but is not 100 percent accurate. Large tumors may make it more difficult to get a wide margin, and some tumors have indistinct borders, with fingers of tissue spreading under the skin that are not apparent on clinical examination. In these cases, it is in the patient’s best interest to have confirmation of clear margins before proceeding with reconstruction.
If immediate closure is performed when cancer has been left behind, previously cancer-free tissue may become contaminated. To achieve complete removal of the cancer, a significant amount of additional tissue along with the known positive margin must then be removed. If tissue rearrangement is done for closure, the exact location of the positive margin may not be clear, complicating effective treatment. To avoid this situation, closure of a skin cancer defect may be delayed until confirmation of clear margins is assured by the final pathology from permanent sections, which may take several days. Patients are generally treated with a dressing over the open wound.
The size and the location of the defect, the type of skin cancer, and the surgeon’s confidence of a clean resection determine which type of reconstruction is used. Options for treatment include simply allowing a wound to heal on its own (dressings only), direct closure, skin grafting, or flap closure (moving tissue around to allow for closure of complex wounds).
Allowing a wound to heal without surgical closure is called healing by secondary intention. This can be a good choice when a small wound is in an area where it will heal on its own with less scarring. The middle corner of the eye is one such area. Generally, however, surgical reconstruction will be completed after tumor resection. In many cases, the dermatologist or plastic surgeon who performed the tumor resection will also perform the reconstruction. In other cases, tumor resection is done by one physician, who then works with a plastic surgeon for the reconstruction.
Reconstruction with Direct Closure
The majority of skin cancers are small and well defined. In these cases, treatment may be simple. In areas of natural laxity, skin edges may be easily pulled together and closed, primarily after excision of a small skin cancer. Even in cases where the closure is not so easy, because of either a larger wound or less inherent laxity in the surrounding skin, the skin edges may be undermined and stretched to achieve a simple primary closure. This type of reconstruction is generally done with local anesthesia at the time of the cancer removal.
Reconstruction with Skin Grafts
The skin is the body’s largest organ. There is a lot of it, and it’s stretchy. It is also a multilayered organ that is able to heal itself when wounded, growing a new layer of outer skin to cover superficial defects. All these factors allow skin to be used as a graft (moved from one location to another, relying on the new location for survival and blood supply) to heal open wounds. When skin cancer treatment leaves a more complicated defect, skin grafting may also be used for closure.
There are two types of skin grafts: split-thickness skin grafts, which use only a partial layer of the skin, and full-thickness skin grafts, which use all layers. Split-thickness grafts are harvested by taking a thin shaving of the outer layer of skin. This leaves a raw spot (like a skinned knee) where the graft was harvested. In one to two weeks, a new outer layer of skin reforms over the deeper layer of skin. Any site on the body with a broad, flat expanse of skin can be used. Donor sites remain discolored for several months after healing and may have permanent alterations of texture or slightly raised scars. Full-thickness grafts are harvested by taking a complete piece of skin down to the underlying tissue layer. The resulting defect at the donor site is closed by simply pulling the skin edges together, leaving a linear scar. Full-thickness grafts are limited primarily by size—by what can be closed—and they are best taken from areas where there is natural laxity and skin excess and where the resulting scar can be best hidden.
When used for reconstruction of skin cancer defects, both split- and full-thickness grafts are useful. Small defects on the face are best treated with full-thickness grafts. For the best cosmetic result, the skin is taken from a nearby location that has similar color and thickness. Large defects in locations less prominent than the face are more easily addressed with split-thickness grafts, which provide simple, functional solutions when skin coverage is needed.
Reconstruction with Tissue Rearrangement
When a simple closure of a skin cancer defect cannot be done, reconstructive surgeons bring in tissue from elsewhere on the body. This follows the Robin Hood principle—taking from areas rich in tissue to give to areas that are deficient. Tissue moved from one location to another is called a flap. Flaps differ from grafts in that they have an inherent blood supply and therefore are not reliant on the new site for survival. Flaps can be designed from skin adjacent to the open wound (a local flap) or from distant areas (a regional flap). When no other good options are available for large complex wounds, tissue flaps may also be removed from a remote part of the body, moved to the site of the problem wound, and plugged in to a new blood supply. This is called a free flap.
Local flaps are frequently used on the face. Open wounds near the eyelid, nose, or mouth may cause distortion of these features if the skin is simply pulled together to close the wound. To prevent distortion, skin flaps can be designed to take advantage of areas with skin to spare as well as natural facial creases and contours. Tissue can be rearranged, spreading the tension over a large area, where it goes unnoticed. Whenever possible, flaps are designed to place the resulting scars into natural creases and shadowed areas of the face so that they are less noticeable. Local flaps are designed to take maximum advantage of areas of relative tissue excess. They may be designed as semicircular rotation flaps, rhomboid-shaped flaps, pennant-shaped flaps, and bilobed flaps.
Regional flaps recruit larger blocks of tissue from farther away to close more-complex wounds. For example, when a large portion of the nose needs resurfacing, the forehead skin can provide ideal coverage. The flap is elevated from the forehead and attached to a long leash of tissue that contains the blood vessels that feed it. These come from the area just above the central part of the eyebrow. This leash of tissue either bridges the intact skin to connect the flap to the open wound or is buried under the intact skin. If it is left external, the leash is divided after three weeks, once the flap has established a sufficient blood supply at its new location. The forehead has a large, broad surface and ample laxity when pulled in from the sides to the midline. This allows the majority of the donor site to be closed without significant deformity.
When a portion of the donor site cannot be closed, it is left to heal by itself. Because wounds contract as they heal, the resulting scar is much smaller than the initial wound; and when positioned at the top of the forehead adjacent to the hairline, the scar is minimally perceptible. If the surface of the nose were treated in the same way, it would severely distort the architecture of the nose and obliterate its natural contours. Wound contraction and scarring may also cause functional problems by narrowing the airway.
A free flap is a block of tissue that is removed from the body and attached to a length of artery and vein that supply it. This allows the tissue to be moved to a distant location, where tissue is needed. To ensure survival, an artery and a vein at the wound location must be recruited to plug in to the flap vessels to restore blood supply to the tissue. This type of solution for skin cancer defects is used when extensive coverage over a complex area is needed. It is also a valuable tool when there is no good-quality tissue nearby to close a skin cancer defect, such as when cancer arises in a bed of skin that has undergone radiation therapy or in an area of burn scars.
When skin cancer defects are reconstructed over broad, flat surfaces, skin grafts or single-layer flaps suffice. Areas of the body with three-dimensional architecture and critical functions, such as the eyelids and the nose, may require multilayered reconstructions. Layers for internal lining, structural stability, and external skin coverage—all may be required. Combinations of flaps and skin, cartilage, and bone grafts may be used. Composite grafts, which contain more than one tissue type, such as skin and cartilage, may also be helpful. A common example of this uses a portion of the ear rim, containing skin and cartilage, to reconstruct the border of the nasal aperture. The cartilage prevents the graft from collapsing and maintains the desired curvature.
Recovery After Reconstruction from Skin Cancer
Healing times after skin cancer reconstructive surgery vary depending on the site and the type of closure used. Procedures on the lower legs often involve grafts, and several weeks of immobilization and elevation of the extremity may follow. Lymph node dissections also significantly prolong the healing period. Small procedures on the face, including local flaps, may have little if any impact on daily activities and cause only minor discomfort.
One thing all procedures have in common is scarring. Scars take several months—even up to a year—to mature. During the various phases of healing, scars can become raised, thickened, and discolored. Over time scars fade, flatten, and soften. Small flaps on the face may appear puffy or pillowed for prolonged periods. This swelling is due to fluid buildup in the rearranged tissues, and it resolves gradually as new drainage channels are established. Surgeons may use surgical tapes, silicone gel sheeting, or compressive wraps to treat scars prophylactically, but keloid scars—red, raised formations of fibrous scar tissue—if they develop, likely require additional treatment. Given enough time, most people heal their surgical sites with acceptable scars without the need for any topical creams or scar treatments.