Introducing the SKIN Score: A Validated Scoring System to Assess Severity of Mastectomy Skin Flap Necrosis

Background: With increasing use of immediate breast reconstruction (IBR), mastectomy skin flap necrosis (MSFN) is a clinical problem that deserves further study. We propose a validated scoring system to discriminate MSFN severity and standardize its assessment. Methods: Women who underwent skin-sparing (SSM) or nipple-sparing mastectomy (NSM) and IBR from November 2009 to October 2010 were studied retrospectively. A workgroup of breast and plastic surgeons scored postoperative photographs using the skin ischemia necrosis (SKIN) score to assess depth and surface area of MSFN. We evaluated correlation of the SKIN score with reoperation for MSFN and its reproducibility in an external sample of surgeons. Results: We identified 106 subjects (175 operated breasts: 103 SSM, 72 NSM) who had ≥1 postoperative photograph within 60 days. SKIN scores correlated strongly with need for reoperation for MSFN, with an AUC of 0.96 for SSM and 0.89 for NSM. External scores agreed well with the gold standard scores for the breast mound photographs with weighted kappa values of 0.82 (depth), 0.56 (surface area), and 0.79 (composite score). The agreement was similar for the nipple-areolar complex photographs: 0.75 (depth), 0.63 (surface area), and 0.79 (composite score). Conclusions: A simple scoring system to assess the severity of MSFN is proposed, incorporating both depth and surface area of MSFN. The SKIN score correlates strongly with the need for reoperation to manage MSFN and is reproducible among breast and plastic surgeons.