Introduction <p>Reverse expansion (RE) is an innovative technique that enables the transfer of large volumes of autologous fat in breast reconstruction. This systematic review aims to assess the efficacy and safety of the RE, comparing hybrid and total autologous approaches.</p> Methods <p>A systematic search of Web of Science and PubMed identified 3117 records, of which 11 met inclusion criteria. To avoid duplication, the most recent and comprehensive studies from the same groups were analysed. Parameters such as the number of sessions, fat grafting volume, radiotherapy status, and complications were analysed. Comparisons were made between hybrid and total autologous reconstruction groups in terms of the number of fat grafting sessions, fat volume transferred, and complication rates. Additionally, the number of fat grafting sessions was compared between irradiated and non-irradiated patients.</p> Results <p>A total of 261 patients undergoing 568 fat grafting sessions were included. Both the mean fat volume transferred per session (288 mL vs. 105 mL) and the total volume per breast (742 mL vs. 228 mL), as well as the number of sessions (2.6 vs. 2), were significantly higher in the total autologous group. Complication rates were lower in total autologous group. Patients who had received radiotherapy required a significantly greater number of fat grafting sessions.</p> Conclusion <p>Although the total autologous RE technique required more fat volume and a greater number of sessions to achieve the desired outcome, the overall complication rate is lower. Radiotherapy is associated with an increased number of sessions and a higher-fat-volume requirement.</p> Level of Evidence I <p>This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors &#xa0;<a href="http://www.springer.com/00266">www.springer.com/00266</a>.</p>