Internal Mammary Perforator Preserving Nipple-Sparing Mastectomy (IMP-NSM) to Reduce Ischemic Complications
Mardi R. Karin, MD; Arash Momeni, MD; Candice N. Thompson, MD
Stanford University School of Medicine

Nipple-Sparing Mastectomies (NSMs) with breast reconstruction are commonly performed for both breast cancer treatment or risk-reducing prophylactic mastectomies and have superior aesthetic results compared to total mastectomy or skin-sparing mastectomy. Preservation of the Nipple Areolar Complex (NAC) results in a more natural aesthetic appearance of the reconstructed breast, as well as greater patient satisfaction, as indicated by improved psychosocial and sexual well-being compared to total mastectomy. Preservation of vascular supply is of utmost importance for NAC and mastectomy skin flap viability after surgery, since postoperative ischemic complications can significantly undermine the aesthetic outcomes.

This report describes a contemporary NSM surgical technique developed by the senior author (MK), to preserve the dominant NAC vascular supply, and decrease postoperative ischemic complications. A total of 114 NSM were performed from 2018 to 2020 by the senior author. Based on preoperative breast MRI with contrast visualization of the vascular supply to the NAC, the Internal Mammary Perforator (IMP) vessels exiting the pectoralis major muscle at the sternal border were found to provide the dominant blood supply to the NAC in 92% and could be preserved in 89% of cases.

The Internal Mammary Perforator Preserving Nipple-Sparing Mastectomy (IMP-NSM) surgical technique was developed to preserve this important IMP blood supply to the NAC, resulting in decreased postoperative ischemic complications. Following implementation of this surgical technique, NAC necrosis requiring NAC removal occurred in 0.9%, and mastectomy skin necrosis requiring reoperation in 1.8% of cases, resulting in successful NAC preservation in the majority of patients. Furthermore, due to the consistent anatomical location of the IMP vascular supply to the NAC, this critical vascular supply can routinely be preserved even without preoperative MRI, thereby improving clinical outcomes. The IMP-NSM surgical technique is described in detail in this report with a case example.