Randomized Feasibility Trial for Mesh in Pre-Pectoral Reconstruction

University of Michigan, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Weill Medical College of Cornell University

Surgical mesh products, particularly acellular dermal matrices (ADM), are now used by the majority of plastic surgeons to assist with the nearly 100,000 prosthetic breast reconstruction procedures in the United States, despite never being approved by Food and Drug Administration (FDA) for this indication. As surgeons transition to placing breast implants above the chest muscle (pre-pectoral), there has been an increasing reliance on these often expensive mesh products without robust evidence to understand their risks and benefits. Our pilot study is a randomized multi-center trial to evaluate surgical mesh assistance in pre-pectoral tissue expander to breast implant reconstruction to address vital questions for women's public health.

One in eight women will develop breast cancer in her lifetime, causing both physical and psychological trauma due to invasive treatments and the distress associated with removal of a breast. Breast reconstruction after mastectomy has become a critical procedure for many women to restore psychological wellbeing, with implant-based reconstruction the most common approach. Nearly 100,000 patients undergo reconstruction with implants every year in the United States. Surgical mesh devices, particularly acellular dermal matrices, are now used off-label by most reconstructive surgeons performing prosthetic breast reconstruction. In the past decade, surgeons have advocated a transition from submuscular reconstruction (placement of the implant under the pectoralis muscle) to pre-pectoral (placement above the pectoralis) and often consider mesh to be necessary for this procedure. Surgical mesh has not been approved by the FDA for breast reconstruction for either anatomic location. These mesh devices are considered Class III medical devices and FDA recently prioritized the evaluation of these products during a panel meeting in 2019. No Level I randomized trial has been successfully performed to determine the actual risks and benefits of mesh devices in breast reconstruction. This study proposes a pilot study as the first ever randomized, multi-center trial for mesh assistance in two-stage prosthetic pre-pectoral breast reconstruction, across the major manufacturers. The goals are to demonstrate feasibility of such a study and to generate high level data toward the evaluation of safety and effectiveness of these products for the benefit of women's public health

Acellular dermal matrix will surgically implanted around the tissue expanders in patients in the ADM cohort.

Acellular dermal matrix will not be surgically implanted around the tissue expanders in patients in the control cohort.

Inclusion Criteria: Female patients age 22 to 75 undergoing unilateral or bilateral immediate pre-pectoral reconstruction with tissue expanders Prophylactic and oncologic mastectomies are both acceptable Nipple sparing and skin sparing mastectomy techniques are both acceptable Exclusion Criteria: Intraoperative assessment demonstrates unfavorable conditions (ie poor mastectomy skin flap thickness or viability) for immediate pre-pectoral reconstruction in any breast Bilateral reconstruction patients undergoing contralateral submuscular reconstruction Direct-to-implant reconstruction Pregnancy Delayed reconstruction

All our results will be published in peer-reviewed journals in a timely manner for reference by physicians, manufacturers, regulatory agencies, and patients. As part of the study consent, subjects will be asked whether they agree to share their data in de-identified format with researchers. Data privacy and protection is a top priority. All data made available for public use will be de-identified, i.e., stripped of personally identifiable information (pii) and personal health information (phi) that could be used to deduce the identity of individual subjects, according to the HIPAA Privacy Rule, to comply with the NIH Privacy Rule and Research guidance