Described as the "Angelina Jolie Effect", rates of prophylactic mastectomy with immediate implant-based reconstruction are increasing dramatically as more women with genetic predisposition towards breast cancer are seeking surgical prevention. Advances in surgical techniques allow for the creation of an aesthetically pleasing postoperative breast mound; however, a common complaint is the lack of sensation to the skin and nipple of the reconstructed breast due to injury and stretch of the sensory nerves. Numbness of the breast, nipple, and areola is an unnatural feeling for the patient, as well as a potential risk for injury or burns as the woman is unable to feel pain.

Our laboratory has previously shown that electrical stimulation (ES) is an effective way of improving nerve regeneration after injury to the nerves of the upper and lower extremities. Proven to improve motor outcomes following carpal and cubital tunnel release and sensation following injury to the digital nerves, this technique is a likely mechanism of restoring sensation of the breast as well.

In this study, we will follow thirty women undergoing prophylactic skin-sparing mastectomy with immediate implant-based reconstruction. At the time of surgery, patients will be randomly assigned ES to either the right or left breast. That breast will be reconstructed first and stimulated for one hour while the other breast is reconstructed. At the completion of the case, all wires will be removed. We will test sensation (tactile, temperature, 2-point discrimination, sharp/dull discrimination, and protective sensation) prior to surgery then again at 6, 12, 18, and 24 months following surgery to evaluate the effects of ES on sensory return. Patients will be provided with a survey to assess return of erogenous sensation.

Objective: To determine whether intraoperative electrical stimulation enhances sensory recovery following mastectomy with immediate implant reconstruction

Background: There is an increasing trend towards prophylactic mastectomy with immediate implant-based reconstruction for women with genetics predisposing to breast cancer (BRCA-1 and -2). Novel techniques such as fat grafting and nipple creation/tattooing have contributing towards creating an aesthetically pleasing breast mound; however, the majority of women experience non-recoverable significant sensory loss secondary to damage and stretch of the intercostal nerves that provide sensation to the skin, areola, and nipple. Most women will recover minimal sensation around the perimeter of the breast, indicating a potential for sensory return; however, particularly the nipple usually remains numb. An insensate breast feels unnatural to the woman and predisposes her to injury and burns of the reconstruction, which can require additional surgery or cause significant scarring.

Our laboratory has previously shown that electrical stimulation (ES) is safe and significantly improves postoperative outcomes in peripheral nerve injury in animal and human models. ES has been shown to improve return of median and ulnar nerve function following carpal and cubital tunnel release respectively, with improved motor outcomes. Sensory return following digital nerve laceration repair similarly is improved with immediate postoperative ES for one hour.

Methods: Thirty patients that will be undergoing bilateral prophylactic skin-sparing mastectomy with immediate implant-based breast reconstruction will be identified from the practice of two plastic surgeons. Preoperatively, women will be undergo sensory testing to the 4 quadrants of both breasts and the nipples, including testing for tactile sensation, cool detection, 2-point discrimination, heat-pain detection threshold, and sharp-blunt discrimination. A custom-made survey to evaluate erogenous sensation will be completed by the patient, as well as the validated BREAST-Q.

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.

Postoperatively, the patient will be evaluated at 1 week, 6 months, 12 months, 18 months and 24 months with the same sensory testing as described previously. Patients will serve as their own internal control, and the sensation of the right vs. left breast will be compared. At the completion of all 2-year evaluations, the study will be unblinded and the stimulated vs. non-stimulated breast outcomes will be compared.

Inclusion Criteria:

• Woman aged 18-60 undergoing bilateral, prophylactic nipple/skin-sparing mastectomy with immediate implant reconstruction

Exclusion Criteria:

• Smokers
• Preexisting peripheral neuropathy
• Prior breast surgery

Women undergoing prophylactic bilateral skin/nipple-sparing mastectomy with immediate implant-based breast reconstruction

IPD will be only used by the research team for this study. It will not be shared to other researchers.

Only the surgeon will be aware of the laterality of the intervention. The patient will not be performed. All outcomes will be assessed by the investigators, who will be masked to the laterality until the completion of the study when the surgeon will unmask.