Determinants of optimal mastectomy skin flap thickness

Background: There is a limited evidence base to guide surgeons on the ideal thickness of skin flaps during mastectomy. Here the literature relevant to optimizing mastectomy skin flap thickness is reviewed, including anatomical studies, oncological considerations, factors affecting viability, and the impact of surgical technique and adjuvant therapies. Methods: A MEDLINE search was performed using the search terms 'mastectomy' and 'skin flap' or 'flap thickness'. Titles and abstracts from peer-reviewed publications were screened for relevance. Results: A subcutaneous layer of variable thickness that contains minimal breast epithelium lies between the dermis and breast tissue. The thickness of this layer may vary within and between breasts, and does not appear to be associated with obesity or age. The existence of a distinct layer of superficial fascia in the breast remains controversial and may be present in only up to 56 per cent of patients. When present, it may not be visible macroscopically, and can contain islands of breast tissue. As skin flap necrosis occurs in approximately 5 per cent of patients, a balance must be sought between removing all breast tissue at mastectomy and leaving reliably viable skin flaps. Conclusion: The variable and unpredictable thickness of the breast subcutaneous layer means that a single specific universal thickness for mastectomy skin flaps cannot be recommended. It may be that the plane between the subdermal fat and breast parenchyma is a reasonable guide for mastectomy flap thickness, but this may not always correspond to a subcutaneous fascial layer.