Mohs micrographic surgery is an advanced treatment process for skin cancer that offers the highest possible cure rate for many skin cancers and simultaneously minimizes the sacrifice of normal tissue. The Mohs surgical technique was developed by Dr. Frederic Mohs at the University of Wisconsin from the 1950's-1970's. His technique has been modified over the years to arrive at the technique used today. This treatment requires a highly specialized physician who serves as a pathologist, surgeon and reconstructive surgeon; as well as nurses and a histotechnological staff specializing in Mohs.
Some skin cancers are deceptively large and may be far more extensive under the skin than they appear from the surface. These cancers may have "roots" in the skin, along blood vessels, nerves, cartilage or along scars. Mohs surgery is specifically designed to remove these cancers by tracking and removing these cancerous "roots." The cure rate for Mohs micrographic surgery approaches 99% for primary (untreated) cancers and is slightly rates for secondary or recurrent (previously treated) skin cancers, while limiting sacrifice of uninvolved tissue. This provides the foundation for the best reconstructions and limits scarring and disfigurement. Mohs micrographic surgery remains the most effective method for curing non-melanoma skin cancers such as Basal Cell Carcinoma, Squamous Cell Carcinoma and others (Sebaceous Carcinoma, Dermatofibrosarcoma protuberans, Bowens Carcinoma, etc.) available in the world today.
Patients often want to know how a defect is going to be reconstructed, how long the process will take or how large the cancer is at the beginning of the day. Unfortunately, this information is not possible to give at this time. Mohs micrographic surgeons are often able to provide closure of the wound, following tumor removal, at the time of surgery. However, patients with larger defects or those affecting specialized anatomic structures following tumor removal may be referred to a plastic surgeon, otolaryngologist (ear, nose, and throat surgeon), ophthalmologist (oculoplastic surgeon) should the Mohs surgeon be unable to do so on the day of surgery.
It is important to note that Mohs surgery is not an appropriate treatment for all skin cancers. Cancers in areas such as the nose, ears, eyelids, lips, hairline, hands, feet, and genitals as well as previously unsuccessfully treated are great candidates. Most insurance policies cover the costs of Mohs surgery and the reconstruction of the surgical area. Please contact your insurance carrier directly for definitive information.
In the vast majority of cases, the wound can be dealt with on the same day as the Mohs procedure. The anesthesia used will usually continue to be local anesthetic or sometimes supplemented with an oral sedative. In more difficult cases where it is necessary for complicated reconstructive procedures to be performed, it may be necessary to send the patient through a hospital or surgery center where general anesthetic or deep sedation is used.
There is a wide range of options in dealing with wounds created by Mohs surgery. These include:
- "Granulation" - This is allowing the wound to heal on its own much as if a person who falls and scrapes his/her knee or elbow and treats it with local wound care of cleansing and applying topical ointment and bandages until it is allowed to heal.
- Grafting - This may include harvesting of skin from another site on the body or a xenograft, which is processed porcine, which serves as a biologic dressing temporarily until the body can take over the healing much as in granulation.
- Flap closure - This can involve very small sites up to massive sites and may be fairly simple and thin to multi-staged procedures which may include skin and muscle and cartilage as well.
- Tissue expansion - Tissue expansion is the last option, which is not used frequently. It involves inserting an inflatable reservoir or balloon under the skin at the first procedure then inflating it until the body produces additional skin, which can then be manipulated to close the wound.
Postoperative care is usually straight forward involving cleansing the wound area and doing dressing changes. More complicated situations such as grafting usually involve a dressing, which is allowed to stay on the wound for a few days since it assists in immobilization of the graft so that the body can grow blood vessels into it to nourish it and allow it to take. The number of postoperative visits depend on how complicated the wound is and how much oversight is required. In some areas it may be possible to place dissolving stitches, which require minimal if any care making the postoperative course less arduous for the patient.
Complications of surgery are typically standard and include blood loss, especially if a patient is on blood thinners in which case a discussion should be held with the surgeon as to the benefits or risks involved in stopping blood thinners. Infection is also a risk in approximately 4% to 6% of patients. Patients are not usually placed on antibiotics routinely unless they are considered at greater risk for infection, usually due to the location of the wound being near an orifice such as the mouth or ear canal, which has a higher number of bacteria. Scarring is a natural process of the body healing the wound. This is a lengthy progression, which incorporates multiple stages and types of collagen and actually takes many months even though the wound is closed. Instructions regarding optimal care of the wound postoperatively to minimize scarring are given to the patient. There may be tissue loss or loss of part of a flap or skin graft and these situations are handled on an individual basis. In most cases, the body will slough off the necrotic or dead tissue and heal the area again. Again, this will require additional care for the wound. Some patients have a tumor, which invades the area of a nerve, therefore requiring interruption of the nerve and resulting in what is usually limited to loss of sensation in an area. There are, however, a few superficial motor nerves that go to muscles, which can be injured or removed in the course of surgery. Depending on the situation location, these may or not be repaired at a later date. In some patients due to scar tissue and damaged nerves, the patient can have chronic pain in the area. Fortunately, this is a very rare complication of surgery.
Revisions of the surgical site are not often required. They are usually done in 6 to 12 months after the original surgery allowing the wound to mature and soften as well as improve as time goes by. Initially the surgical site does not appear pretty, but it usually improves significantly and satisfactorily as time progresses.