Is minimal-accessed (endoscopic- or robotic-assisted) nipple-sparing mastectomy contraindicated for large breasts?

Background: In the developmental stage of minimal-accessed nipple-sparing mastectomy (MA-NSM), selecting patients with small to medium-sized breasts was common for better cosmetic outcomes and oncological safety. However, the suitability of MA-NSM for large, ptotic breasts remained uncertain. This retrospective study aim to assess MA-NSM outcomes in patients with large breasts.

Materials and methods: This retrospective study included patients receiving conventional NSM (C-NSM) and MA-NSM from January 2011 to September 2022, at a single institution. We analyzed perioperative parameters and clinical outcomes based on breast specimen size, classified as small (≤300 g), medium (>300-450 g), large (>450-600 g), and very large (>600 g).

Results: A total of 728 patients was enrolled. C-NSM was performed in 51% (371/728) of cases, while MA-NSM was done in 49% (357/728). The overall complication rate of MA-NSM was comparable to C-NSM (p = 0.573), but severe complications (Clavien-Dindo, CD III) was significantly reported more following C-NSM, regardless of breast size. During a median follow-up of 52 months, no significant difference in oncological outcomes was observed. Comparing MA-NSM and C-NSM outcomes in large-very large breasts (>450 g), MA-NSM demonstrated significantly less blood loss (p = 0.036) and lower incidence of severe complications (CD ≥ III) compared to C-NSM (p = 0.002).

Conclusion: MA-NSM is feasible for large breasts and offers benefits by reducing blood loss and decreasing the incidence of severe complications (CD ≥ III) in this patient group.