Pre-pectoral breast reconstruction with tissue expander entirely covered by acellular dermal matrix: feasibility, safety and histological features resulting from the first 64 procedures

Background: Reconstructive options that can be used following conservative mastectomy, skin-, nipplesparing and skin-reducing mastectomies, allow a remarkable variety of safe methods to restore the natural shape and aesthetics of the breast mound. In case of two-stage breast reconstruction, tissue expanders (TEs) are usually placed in a subpectoral position. The purpose of this retrospective cohort study is to evaluate the feasibility and safety of two-step reconstruction with TE in pre-pectoral position covered by acellular dermal matrix (ADM). Methods: Between March 2021 and May 2023, at the Azienda Ospedaliero Universitaria Careggi, University of Florence, 55 patients with BRCA 1/2 mutations or early breast cancer underwent conservative mastectomy with immediate pre-pectoral reconstruction using TE covered with ADM, followed by a second surgery with replacement of the expander with definitive prosthesis. Demographic, oncological, and histological data along with surgical complications were recorded. Results: A total of 64 conservative mastectomies were performed. In 2 patients (3.1%) complications were found that required reintervention and, in both cases, the TE had to be removed. Two patients developed hematoma and one patient developed seroma. Two patients showed wound dehiscence, both healed after conservative treatment and without implant exposure. No case of necrosis of the skin or nipple-areola complex has been observed, neither of capsular contracture. Capsule formed around TE was populated with cells and blood vessels and showed a thin area of synovial metaplasia. Conclusions: In selected cases it may be more cautious to perform a two-stage breast reconstruction after radical breast surgery by means of TEs. The placement of TEs in pre-pectoral position combines the excellent aesthetic and functional results of the pre-pectoral philosophy with a quite safer and more prudent two-step approach. Our experience reports optimistic results: the ADM covering the TE is seen successfully integrating during tissue expansion and becoming a vascularised new self-tissue. Complications rates are low and such ADM-assisted two-stage pre-pectoral reconstructive technique is a safe, practical, and reproducible method.