How to draw the skin ellipse for a mastectomy.

The size of the skin ellipse for a mastectomy varies between patients and the accurate marking and tailoring of the skin flaps is often learnt by the surgical trainee only with increasing experience. Within the Breast Unit, a mathematical model was calculated to predict the required width of the skin ellipse for a successful mastectomy. Measurements of the straight-line distance from mid-clavicular point to the infra-mammary fold and maximum vertical height of the nipple above the infra-mammary fold were taken with the patient relaxed and supine. A close correlation (r = 0.85) was noted. Further analysis demonstrated a linear relationship between the pre-operative height to which the nipple could be suspended above the infra-mammary fold and the required maximum skin ellipse width (r = 0.87, P < 0.001). This linear relationship is easy to remember and is a useful check to ensure that the skin flaps intended will be just right. This same technique may be applicable to skin ellipses elsewhere.