Tissue Expander Based Breast Reconstruction

Expanders are used outside their intended use, due to two following facts: It is possible that expander implantation exceed the "approved" duration of 6 months (maximal 10 months). Additionally, some participants will receive after mastectomy/expander implantation an adjuvant radiotherapy according to standard of care, which is either a contraindication of the medical device or not yet tested in-vivo by the manufacturer. Requested answers: * how good is the aesthetic outcome of the breast with the expanders and the final implants, and whether any complications occurred during treatment, * how satisfied are subjects and doctors with the outcome of the breast reconstruction, and how the reconstruction affects health-related quality of life from participants, * how does the structural composition of the removed expanders looks like, in order to understand whether radiation therapy has caused changes in the material, * which key immunological factors lead to increased hardening of the tissue around the expander, especially during radiation therapy (capsule formation).

Infections after tissue expander breast reconstruction can lead to pain, additional surgeries, and loss of the reconstruction. This study will compare two types of antibiotic carriers used during surgery to help lower the risk of infection. One carrier is a non-absorbable PMMA disc, and the other is an absorbable antibiotic bead. Both release antibiotics directly into the breast pocket after surgery. About 100 patients will be randomly assigned to receive one of these two carriers at the time of tissue expander placement. After surgery, small samples of fluid around the tissue expander will be collected during routine clinic visits. These samples will be tested to measure how much antibiotic is present over time. The study will also track infections, tissue expander loss, and other complications during the first 90 days after surgery. The goal is to learn how much antibiotic each carrier delivers and whether one method is more effective at preventing infection.