The goal of this feasibility randomised controlled clinical trial (RCT) is to compare mesh-assisted to no-mesh pre-pectoral implant based immediate breast reconstruction in women undergoing mastectomy for treatment of breast cancer or for risk reduction of an inherited breast cancer risk.

The main questions it aims to answer are:

• To determine the feasibility of a definitive RCT comparing the clinical and cost- effectiveness of no- mesh versus mesh- assisted pre-pectoral breast reconstruction.
• To determine if it is possible to collect data to inform a future economic analysis on the use of mesh in breast reconstruction.

Participants will be randomly allocated to have their breast reconstruction either with the use of mesh or without the use of mesh prior to the start of the operation. Participants will be blinded to their allocation until day 90 post operatively. Participants will be asked to have medical photography and to complete a short quality of life questionnaire before and after surgery at 90 days prior to finding out their allocation.

Trial Design:

Restore-B is a prospective, multicentre parallel 2-armed single-blinded randomised controlled feasibility trial comparing no-mesh to mesh- assisted immediate implant-based prepectoral breast reconstruction surgery.

Patients will be randomised 1:1 to either the intervention surgery (no- mesh) arm or the control arm surgery (mesh-assisted).

Planned Trial Period:

The overall period of the trial is:

12 months recruitment, 3 months follow-up and 6 months data analysis and final reporting of results.

Trial Participants:

Women over 18 years old eligible for elective immediate prepectoral implant-based breast reconstruction with mesh for cancer treatment or risk reduction surgery

Intervention:

Immediate prepectoral implant-based (implant or expander) breast reconstruction without surgical mesh (ADM or synthetic).

Comparator:

Immediate prepectoral implant- based (implant or expander) breast reconstruction with surgical mesh (ADM or synthetic) (standard of care).

Inclusion Criteria:

• Women > 18 years
• Participant is able and willing to give informed consent for participation in the trial
• Eligible for immediate prepectoral implant-based breast reconstruction with implant or expander with mesh (biologic or synthetic) for cancer treatment or risk reduction surgery.
• In the Investigator's opinion, can comply with all trial requirements.

Exclusion Criteria:

The participant may not enter the trial if any of the following apply:

• Participant is pregnant, lactating or planning pregnancy during the trial
• Patient refusal
• Delayed breast reconstruction post simple mastectomy

The study protocol will be published for reference. Study outcome data will be published at the end of the trial. Data will determine progression to full RCT.

3 months. Available long term

Open access publication of the protocol in British Medical Journal Open Scientific Journal.

Participants will be blinded to their surgical allocation (mesh or no mesh) and will be unblinded after completion of their post-operative questionnaire at day 90.