"NACsomes": A new classification system of the blood supply to the nipple areola complex (NAC) based on diagnostic breast MRI exams.

Background: Breast MRIs have become increasingly common in breast cancer work-up. Previously obtained breast MRIs may facilitate oncoplastic surgery by delineating the blood supply to the nipple-areola complex (NAC). The aim of this study was to identify and classify the in vivo blood supply to the NAC using breast MRI exams.

Methods: Breast MRIs obtained over a one-year period were retrospectively reviewed. Patients with negative MRI findings (BI-RADS category 1) were included; patients with diagnoses of breast cancer or previous breast surgery were excluded. Twenty-six patients were evaluated. Dominant blood supply was determined by maximum filling at 70 s post-contrast. Blood supply to the NAC was classified into five anatomic zones: medial (type I), lateral (type II), central (type III), inferior (type IV) and superior (type V).

Results: Patient age ranged from 33 to 70 years. Fifty-two breasts were evaluated and 80 source vessels were identified (37 right, 43 left). Twenty-eight breasts had type I only blood supply, 22 breasts had multi-zone blood supply (type I + II, n = 20; type I + III n = 2), one breast had type II only blood supply, and a single breast had type III only blood supply. Anatomic symmetry was observed in 96% of patients.

Conclusion: This study utilized MRI to evaluate in vivo vascular anatomy of the NAC, classify NAC perfusion ("NACsomes"), and assess vascular symmetry between breasts. Superomedial source vessels supplying the NAC were predominant. Preoperatively defining NAC blood supply may aid planning for oncoplastic procedures.