Literature Searches Database: Ovid MEDLINE; Epub Ahead of Print; In-Process & Other Non-Indexed Citations; Daily and Versions (710 results on August 7, 2019) Search: (exp mastectomy, subcutaneous/ or ((exp mammaplasty/ or exp mastectomy/ or (breast* adj5 reconstruct*).tw,kw) and (exp subcutaneous tissue/ or (prepector* or pre-pector* or subcutaneous*).tw,kw))) and (exp "prostheses and implants"/ or exp tissue expansion devices/ or (expander* or implant or implants or prosthe* or tissue expansion*).tw,kw) Database: Elsevier Embase (793 results on August 7, 2019) Search: ('subcutaneous mastectomy'/mj OR (('breast reconstruction'/exp OR mastectomy/exp/mj OR (breast* NEAR/5 reconstruct*):ti,ab,kw) AND ('subcutaneous tissue'/exp OR (prepector* OR 'pre-pectoral' OR subcutaneous*):ti,ab,kw))) AND ('breast prosthesis'/exp OR 'breast tissue expander'/de OR 'prostheses and orthoses'/de OR 'tissue expander'/de OR (expander* or implant OR implants OR prosthe* OR 'tissue expansion'):ti,ab,kw) Database: Wiley Cochrane Central Register of Controlled Trials (19 results on August 7, 2019) Search: ([mh "mastectomy, subcutaneous"] or (([mh mammaplasty] or [mh mastectomy] or (breast* near/5 reconstruct*):ti,ab) and ([mh "subcutaneous tissue"] or (prepector* or "pre-pectoral" or subcutaneous*):ti,ab))) and ([mh "prostheses and implants"] or [mh "tissue expansion devices"] or (expander* or implant or implants or prosthe* or "tissue expansion"):ti,ab) Database: Clarivate Web of Science (354 results on August 7, 2019) Search: TS=(breast* NEAR/3 reconstruct*) AND TS=(prepector* OR "pre-pectoral" OR subcutaneous) AND TS=(expander* OR implant OR implants OR prosthe* OR "tissue expansion")