BACKGROUND: Conversional surgery following sleeve gastrectomy (SG) is required in about 20 % of patients due to suboptimal outcomes. Single anastomosis duodenoileal bypass (SADI) has emerged as an option for such cases, though long-term outcomes remain unclear. This review analyzed available data on SADI as a conversional or second-stage procedure after SG. METHODS: A systematic search across PubMed, Web of Science, and Scopus included studies on adult patients who underwent SADI as a conversional or second-stage surgery following SG, with a minimum of 12 months' follow-up up to July 2024. RESULTS: Nineteen studies involving 867 patients examined weight loss, comorbidity resolution, postoperative complications, and nutritional deficiencies. Results showed a total weight loss (TWL) of 24 % in the first year post-revision, with a trend toward weight stabilization or regain over two years. Maximum TWL (27 %) occurred at 24 months, decreasing to 24 % at 60 months. Average follow-up of 27 months showed remission rates for type 2 diabetes, hypertension, and dyslipidemia at 68 %, 53 %, and 37 %, respectively. Short-term morbidity within 30 days was 8 %, including a 5 % rate of anastomotic leaks or fistulas and a 5 % reoperation rate. Overall mortality was 2 %. CONCLUSION: In conclusion, SADI shows promise as a safe and effective mid-term conversional surgery after SG with suboptimal results. However, further studies are needed to confirm its long-term safety and effectiveness.