The day of surgery the patient will be randomized to right or left breast for stimulation. Following the mastectomy, the breast to be stimulated will be reconstructed with an implant first in the typical fashion. A percutaneous needle will be passed into the intercostal space alongside the 4th intercostal nerve, and a second needle will be inserted into the serratus anterior muscle . These needles will be attached to the anode and cathode respectively of our electrical stimulator, and the patient will receive 1 hour of intraoperative stimulation titrated to palpable contraction of the intercostal muscle. During this hour, the second breast will undergo reconstruction with no electrical stimulation. At the completion of the hour, the skin will be closed in the normal fashion. The laterality will be blinded to the patient as well as to the investigator who will perform all sensory testing.