Advanced dermatological surgery
Some dermatologists specialize in the field of skin surgery. All registrars and residents in dermatology are trained in these techniques. An outline of the subject is given here, including the use of flaps, grafts and Mohs’ surgery, along with mention of lasers and photodynamic therapy, and of some basic cosmetic procedures.
Simple plastic repairs
Simple plastic repairs are carried out by the following:
Dog-ear excision: dog-ears are redundant tissue at the end of an excision line. In sites of high elasticity or where tissue conservation is critical, circular excision of the lesion with appropriate margins is preferable to a predetermined ellipse excision. The redundant skin is lifted like a tent using a skin hook then excised each side (‘dog ears’), and the extended wound is sutured (Fig. 1).
Skin flaps
Advancement flap: in this, the skin flap is advanced in one direction over the defect. The flap of skin is created by making excision lines away from the defect to be covered, undermining to free the pedicle, advancing it into the defect and then suturing it in place (Fig. 2).
Rotation flap: a defect may be covered by rotating in skin from one side. One side of the excision wound is extended as an arc that is up to three times the length of the primary defect, depending on the elasticity of the skin at that body site (the scalp and dorsal hand are the least elastic). The pedicle is undermined, rotated in to the defect and sutured in place (Fig. 3).
Skin grafts
Mohs’ micrographic surgery
are of the morphoeic type (clinical assessment of margins is unreliable)
have recurred (scarring at site of previous excision can track tumour cells)
have developed in embryonic folds, e.g. nasolabial site
require tissue conservation as a priority (e.g. on the nose, around the eyes).
The bulk of the tumour is removed by curettage and then a saucer-like piece of skin is excised. This specimen is marked and flattened, and frozen sections are taken and read immediately by microscope, giving a ‘map’ that shows the extent of the tumour and the areas from which further excision is needed (Fig. 4). The defect is repaired conventionally, sometimes in collaboration with plastic surgeons. The cure rate is 98% for basal cell carcinoma.
Lasers and intense pulsed light (IPL)
The technology of lasers (light amplification by stimulated emission of radiation) has advanced rapidly, and lasers can be used to treat vascular or pigmented lesions, tumours and tattoos and for hair removal. The variation in absorption of different wavelengths of light means that a range of different lasers is needed (Table 1). Laser therapy is carried out in specialized centres. Treatment is usually painful and several visits are often required. IPL treatment can be used for some conditions such as hair removal, and treatment is similar to laser but is a cheaper alternative. Fractional laser therapy refers to treatment of small zones within the target area patterned like the holes in a watering can rose.
Cosmetic procedures
Botulinum toxins: injection of botulinum toxins into facial muscle paralyses the action of the muscle, thus reducing the prominence of frown lines. It is also used for axillary and sometimes palmar hyperhidrosis.
Advanced dermatological surgery
