MOHS SURGERY INFORMATION
This process ensures total removal of the cancer preserving as much normal surrounding skin as possible, whilst achieving
the best cure rates for basal cell carcinomas. Following the surgery you will
have a pressure dressing and be on antibiotics for one week. If you are taking Warfarin, Aspirin or Clopidrogel it is very
important to tell us immediately.
The surgery is performed as follows: the skin is treated with a local anaesthetic so there is no pain: the tumour
is scraped using a semi-sharp instrument called a curette; a thin piece of tissue is then removed surgically around the scraped
skin and divided into pieces that will fit on a microscope slide; the edges are marked with coloured dyes; a map or diagram
of the tissue removed is made; and the tissue is frozen by the technician. A
pressure dressing is then applied and the patient is asked to wait while the slides are being processed. The doctor will then examine the slides under the microscope and be able to tell if any tumour is still
present. If cancer cells remain he is able to exactly locate them based upon
his map. Another layer of tissue is then removed and the procedure is repeated
until the doctor is satisfied that the entire base and sides of the wound have no cancer cells remaining.
The removal of each layer of
tissue takes approximately 1- 2 hours. Only 20 - 30 minutes is spent in the actual surgical procedure, the remaining time
being required for slide preparation and interpretation. It usually takes removal
of 1 - 3 layers of tissue (stages) to complete the surgery. Therefore, by beginning
in the morning, Mohs micrographic surgery is generally finished in one day. Sometimes,
however, a tumour may be extensive enough to necessitate continuing surgery a second day
At the end of Mohs micrographic surgery, you will be left with a surgical wound. This wound will be dealt with
in one of several ways. The possibilities explained below include:
Healing by itself (spontaneously or secondary intention)
Closing the wound or part of the wound with stitches
Using a skin graft
Using a skin flap
Rarely, if your Mohs Micrographic surgery is extensive
we may recommend you visit one of several consultant surgeons.
Healing by spontaneous granulation involves letting the wound heal by itself. This offers a good chance to observe
the wound as it heals after removal of a difficult tumour. Experience has taught
us that there are certain areas of the body where nature will heal a wound as nicely as any further surgical procedure. There are also times when a wound will be left to heal knowing that if the resultant
scar is unacceptable, some form of reconstruction can be performed at a later date.
Closing the wound with stitches is often performed on a small lesion. This
involves some adjustment of the wound and sewing the skin edges together. This
procedure speeds healing and can offer a good cosmetic result. For example, the
scar can be hidden in a wrinkle line.
Skin grafts involve covering a surgery site from another area of the body.
The most commonly used is a "full thickness graft" This graft provides
a thicker layer of skin to achieve better results. In this instance skin is usually
removed from behind the ear the inside of the arm or around the collar bone (the donor site) and stitched to cover the wound. The donor site is then sutured together to provide a good cosmetic result. A pressure dressing will be applied after the surgery which will usually stay in place for a week.
Skin flaps involve movement of
adjacent health tissue to cover a surgical site. Where practical they are chosen
because of the excellent cosmetic match of nearby skin. Again a dressing
is applied but this will be taken down generally after 24 hours.