Quantification of wound oedema after dermatological surgery

Postoperative wound oedema causing increased suture tension is thought to be a possible cause of scars known as suture marks. Quantification of such oedema has not previously been reported in the literature. Measures to accommodate wound oedema may include the adoption of alternative suture techniques and the use of more elastic suture materials.

To quantify wound expansion after skin surgery and to identify any contributory factors, and to determine the ability of eight commonly used skin suture materials to stretch under increasing tension.

Forty consecutive adult patients attending a dermatology department for routine skin surgery in December 2002 were recruited. Details including body site, nature of the lesion excised and dimensions of the open wound were recorded. The distance between entry and exit points of an untied suture at the time of skin surgery was measured and then repeated 24 h postoperatively. The ability of eight different suture materials to stretch when an increasing force was applied was measured by hanging standard weights from the sutures and measuring the suture length for each force applied.

Thirty-nine patients completed the study. All wounds expanded postoperatively, with a mean lateral expansion of 1.0 mm. There was a strong association between the width of the unsutured wound after excision and the subsequent wound expansion. Commonly used sutures in skin surgery were found to be relatively inelastic at forces under 0.2 kg. The monofilament Novofil (Davis & Geck, Danbury, CT, U.S.A.) exhibited the greatest degree of stretch of those tested.

There is considerable oedema in the first 24 h after skin surgery, particularly with wider excisions. This needs to be considered when choosing suturing materials and techniques to avoid excessive suture tension.