Mastectomy Flap or Subcutaneous Breast Thickness: What Is the Relevant Factor in Mastectomy Flap Necrosis? A Cohort Study on Preoperative Subcutaneous Breast Thickness Assessed by Mammography

Background One of the main causes of breast reconstruction failure is mastectomy flap necrosis. It is widely acknowledged that the vascularity of the mastectomy flap exhibits a direct correlation with its residual thickness. Previous studies demonstrated the possibility to measure preoperatively the thickness of breast subcutaneous tissue; however, its correlation with the risk of mastectomy skin flap necrosis has not been proved yet. This study aims to evaluate the predictive ability of mammography in identifying patients at risk of ischemic complications of mastectomy flaps. Methods A retrospective analysis of all patients undergoing mastectomy and implant-based immediate breast reconstruction between January 2015 and December 2022 at ASST-Sette Laghi was conducted. For each patient, breast subcutaneous thickness was assessed at preoperative mammography. The findings were then analyzed and combined with anamnestic, intraoperative, and postoperative data. Results Of all 647 patients reviewed, 398 (corresponding to 463 breasts) have been enrolled in the study, corresponding to those in which it was possible to evaluate the preoperative mammography. Mastectomy flap ischemia has been found in 57 patients (12.3%), of which 17 (29.8%) underwent reintervention. Heavy smoking, "conservative"mastectomy, higher mastectomy volume, and a preoperative subcutaneous thickness >17 mm were found to be risk factors for mastectomy flap ischemic complications (P > 0.000). Conclusions Mammography is a good tool to evaluate the preoperative thickness of the breast subcutaneous tissue. In our experience, especially in case of conservative mastectomies, patients with a thicker subcutaneous tissue have higher risk to develop ischemic complication of the mastectomy flap.