MSFN ensues when the blood supply to the skin flaps is insufficient to meet their metabolic needs. It is therefore important to understand how blood is supplied to the breast and the overlying skin. Blood is supplied to the breast via perforating branches from the axillary artery, the internal thoracic artery and the second to fourth anterior intercostal arteries.16,17 Perforating cutaneous arterial and arteriolar branches deliver blood to the overlying breast skin, linking to form a continuous plexus. This plexus is best developed subdermally and on the undersurface of the subcutaneous fat.17 Interestingly, these subcutaneous vessels are found at a deeper level in breasts with a thicker layer of subcutaneous fat.18
There are inconsistencies in the literature as to precisely what is meant by MSFN. Fortunately, a validated scoring system to assess the severity of MSFN has recently been described by the Mayo Clinic called the SKin Ischemia and Necrosis (SKIN) score.19 A SKIN score is given based on the depth and area of skin necrosis visible, and this correlates strongly with the need for reoperation. Depth is assessed with a 4-point letter score, with “A” being no evidence of MSFN through to “D” being full-thickness skin flap necrosis. A 4-point numerical score is given for the surface area of the deepest necrosis, with “1” being assigned for 0% surface area through to “4” being assigned for >30% of breast skin (or nipple–areolar complex [NAC] in cases of NSM). This simplified scoring system should allow a more accurate and reproducible description and quantification of MSFN and facilitate comparisons between future studies.
MSFN and wound breakdown lead to a number of challenges. These are summarized in Figure 2 and include immediate and long-term wound management problems, delays to adjuvant therapy and esthetic compromise (particularly to a breast reconstruction) through scarring and distortion. If implants or expanders are used, there is a risk of infection and extrusion. In addition, the psychological morbidity to the patient from the resultant anxiety and distress from these complications should not be underestimated. Strikingly, women who lose their implant have high rates of undergoing no further reconstruction.20
The aim of this article was to review the challenges of MSFN, along with possible solutions to this problem.
A MEDLINE search was performed in March 2016 using the search term “mastectomy skin flap necrosis” (Figure 3). Abstracts were screened for relevance to the aims of the review. All directly relevant primary studies were included and referenced. Articles not relevant to the aims of the review were excluded, as were abstracts and reports from meetings not included in peer-reviewed publications. Additional potentially important references known to the authors, or cited within relevant papers, were also investigated. Only articles published in English were included.