Basic dermatological surgery

Instruments and methods

No one should attempt a procedure if unsure about it. Those with limited experience should remove only benign lesions. All procedures are ideally performed in an operating theatre with trained nurses and adequate lighting. Sterile instruments, an aseptic technique and sterile gloves are essential. The operator plans the procedure, explains it to the patient, discusses the scar and obtains written consent. The direction of crease marks is assessed: any excision is usually made parallel to these lines.

The basic instruments ( Fig. 63.1 ) include a #3 scalpel handle and #15 blade, a toothed Adson’s forceps, a small smooth-jawed needle holder, a pair of fine scissors, artery forceps and a Gillies skin hook. Curettes and skin punches come in various sizes. A solution of 1% lidocaine (Xylocaine) with 1/200 000 adrenaline (epinephrine) is usually satisfactory as the local anaesthetic , but plain lidocaine must be used on the fingers, toes and penis. The maximum safe dose for an 80-kg person using 1% lidocaine and adrenaline (1/200 000) is 40–50 mL. This volume is significantly reduced if higher concentrations of lidocaine or no adrenaline are used. The skin is prepared (but not sterilized) using, for example, 0.05% aqueous chlorhexidine (Unisept). Alcohol-based preparations are avoided as, if cautery is used, the solution may ignite. Sterile towels or a fenestrated sheet, placed around the operation site, reduces the chance of infection.

Absorbable subcutaneous sutures (e.g. polyglactin; Vicryl) are used for excisions where the wound may be deep or under tension. For cuticular stitches, monofilament nylon (e.g. Ethilon) and polypropylene (e.g. Prolene) are recommended. Use 5/0 or 6/0 sutures on the face, 3/0 on the back and legs, and 4/0 elsewhere. Stitches are preferably removed at 5–7 days on the face, 10–14 days on the legs or trunk and 7–8 days at other sites. Steristrips give extra support to a wound either in addition to sutures or when applied after their removal. An adherent tape or dressing (e.g. Micropore or Mepore) is used in most cases. For scalp biopsies, spray adhesive (e.g. Opsite spray) is useful.

Every biopsied lesion is sent for histology. If more than one specimen is taken from a patient, separate pots are used and each labelled before the biopsy is placed in it. The usual fixative is 10% formalin.

Basic surgical techniques