Breast cancer is the most common cancer among women in the world. Although breast-conserving surgery is a viable option for patients, mastectomy remains the choice of treatment. Despite oncologic and surgical safety of nipple-sparing mastectomy(NSM) with immediate breast reconstruction(IBR) were amply demonstrated, a number of acute and late complications can occur. Surgical technique may play a role in the postoperative outcomes of mastectomy skin flap.Previous studies suggest that cold dissection with scissors or scalpel, may lead to decreasing blood loss and rates of skin necrosis, compared to electrocautery. A retrospective study by Troy Ng demonstrated that the use of cold dissection is likely to decrease the rate of partial-thickness necrosis (13.0%→33.3%, p=0.01) and full-thickness necrosis (1.3%→12.8%, p=0.02). The purpose of this study is to analyze whether cold dissection can decrease the rate of ischemia necrosis and other complications and then increase the aesthetic outcomes compared to electrocautery.