INTRODUCTION: Anatomical exclusion criteria for nipple-sparing mastectomy was defined as “not excessively large or ptotic breasts.” However, morphologic criteria such as ptosis and sternal notch to nipple have not been shown to predict ischemic outcome. In this presentation, we introduce a novel midclavicular-to-inframammary (MCI) fold measurement for nipple-sparing mastectomy (NSM) performed through an inframammary approach and demonstrate it to be predictive of mastectomy weight and ischemic outcomes.
METHODS: Retrospective review was performed on all NSM through an inframammary approach. Exclusion criteria include other mastectomy incisions, staged mastectomy, previous breast operation, and autologous reconstruction. Preoperative anatomical measurements for each breast, clinical course, and specimen weight were obtained.
RESULTS: One hundred forty breasts in 79 patients were reviewed. Mastectomy weight was strongly correlated with MCI fold measurement on linear regression (R2 = 0.651; P < 0.001) but neither ptosis nor sternal notch-to-nipple distance were. Twenty-five breasts (17.8%) had ischemic complications: 16 (11.4%) were nonoperative and 9 (6.4%) were operative. The average mastectomy specimen weight in patients with major ischemic complications was 498 g, significantly higher than mastectomy specimens without major complications (315 g; P = 0.001). Those with mastectomy weights ≥500 g were 9 times more likely to have operative ischemic complications than those with mastectomy weights <500 g (P = 0.0048). The average MCI fold measurement among breasts with major ischemic complications was 30.2 cm, significantly different from breasts without major ischemic complications (27.9 cm; P = 0.032). Those with MCI fold ≥30 cm had a 3.8 times increased incidence of any ischemic complication (P = 0.00547) and 9.2 times increase incidence of operative ischemic complications (P = 0.00376) compared with those <30 cm. The majority of patients with and without major ischemic complications had grade I ptosis (P > 0.05).
CONCLUSION: Breasts undergoing NSM with inframammary approach with MCI fold measurement ≥30 cm are at high risk for having ischemic complications. Previous anatomical measurements, such as sternal notch-to-nipple and ptosis, were not correlated with ischemic complications. Although our absolute contraindication to NSM remains MCI fold >34 cm, consideration for a staged approach or lateral incision is warranted in those ≥30 cm.