BackgroundNipple-sparing mastectomy (NSM) and skin-sparing mastectomy (SSM) are challenging for surgical training among fellow trainees. We developed a surgical training course with novel concept of breast modular resection (BMR) for NSM/SSM procedure, and performed this study to investigate whether BMR could improve surgical outcomes compared to classical procedure resection (CPR). MethodThe records of 105 breast cancer patients undergoing NSM/SSM with immediate reconstruction performed by fellow trainees were reviewed. Clinicopathological characteristics and surgical outcomes were compared between two groups. Laser speckle contrast imaging (LSCI) was performed to intra-operatively evaluate the blood supply of the NAC, and the absolute perfusion unit (PU) values and relative perfusion unit (rPU) values were further compared. ResultsSurgical training outcomes of BMR group (N=52) were insignificantly improved compared to CPR group (N=53). The rates of NAC necrosis, flap necrosis and implant removal all reduced respectively. Among the 60 NSM patients, the blood loss (p=0.011) and surgery time (p<0.001) was significantly reduced in BMR group (N=30) and all the other outcomes were insignificantly improved. Both the absolute PU values and rPU values were significantly higher among patients without NAC necrosis (p<0.001). The absolute PU values were significantly higher in BMR group (p=0.002). ConclusionCompared to CPR, the BMR-based surgical training course for NSM demonstrated the reduction in complications and operating time, offering a potential streamlined, efficient, and safe method for NSM procedure. LSCI was effective for intra-operative visualized evaluation of NAC blood supply and could provide effective real-time feedback for fellow trainees. MicroAbstractWe developed a surgical training course with novel concept of breast modular resection (BMR) for Nipple-sparing mastectomy (NSM) and skin-sparing mastectomy (SSM) procedure, and performed this study to investigate whether BMR could improve surgical outcomes compared to classical procedure resection (CPR). The records of 105 breast cancer patients undergoing NSM/SSM with immediate reconstruction performed by fellow trainees were reviewed. Compared to CPR, the BMR-based surgical training course for NSM demonstrated the reduction in complications and operating time, offering a potential streamlined, efficient, and safe method for NSM procedure.