The general objective of the study is to confirm the medium/long-term safety and clinical performance of the CELLIS Breast membranes used in breast reconstruction and to identify emerging risks in comparison to clinical data related to other treatment modalities.

The present study will be a prospective, multicentric, non-randomized and non-controlled trial involving 112 patients followed for 24 months. The study will be conducted in France in 7 investigational centres.

The study will be prospective, multicentric, single-arm observational (non-interventional) to evaluate the safety and performance of the CELLIS Breast membranes used in breast reconstruction following mastectomy.

All evaluations will be performed and products used according to the usual practice, without additional or unusual diagnostic, treatment and monitoring procedure.

The study will be conducted in France in 7 investigational centres including 112 patients scheduled for a breast reconstruction following mastectomy.

Each patient will participate in one assessment period including a preoperative visit, followed by the day of surgical procedure and a hospitalization period.

Patients will return for ambulatory visits on day 10 (+/- 5 days) and/or on day 30 (+/- 7 days), on month 3 (+/- 2 weeks), on month 12 (+/- 2 weeks) and on month 24 (+/-2 weeks) post-surgery.

CELLIS Breast is available in one thickness, in a variety of size and forms addressing multiple surgical techniques.

Inclusion Criteria:

• Patient aged ≥18 years,
• Patient with an indication of breast reconstruction after mastectomy (therapeutic or prophylactic),
• Patient being informed of her participation to the study and of the follow-up visits, and having no objection to the clinical data collection and medical file access,
• Patient being informed of the porcine origin of the device in advance of the procedure.

Exclusion Criteria:

• Patient with known hypersensitivity to porcine materials,
• Patient with an existing infection at the site of implantation,
• Patient having refused to participate to the study,
• Patient refusing to return for the follow-up visits,
• Patient who is pregnant.

Constitution and follow-up of a consecutive cohort of patients operated with the CELLIS Breast membranes based on the usual practices, the indication and the inclusion-exclusion criteria.