Single Anastomosis Sleeve Ileal Bypass Could Be the Future of Redo Surgery? A Single-Center Cohort Study

Obesity is a leading global health challenge associated with increased morbidity and mortality from cardiovascular disease, type 2 diabetes, hypertension (HTN), and other metabolic comorbidities. Bariatric surgery is currently the most effective long-term treatment for severe obesity. However, 20-30% of patients may experience weight regain or unsatisfactory metabolic outcomes after primary surgery, requiring revisional (redo) procedures. The Single Anastomosis Sleeve Ileal Bypass (SASI) is an innovative bariatric technique, recently proposed as a redo option due to its favorable balance of restrictive and malabsorptive mechanisms and technical simplicity. SASI is still considered "experimental" in major international guidelines, and data on its efficacy as revisional surgery are limited.

This retrospective study included 30 patients (mean age 50.8 ± 10.75 years) undergoing SASI after failed primary bariatric procedures (sleeve gastrectomy, gastric plication, Bariclip) between 2023 and 2024. Parameters analyzed included weight, body mass index (BMI), percentage of excess weight loss (%EWL), percentage of total weight loss (%TWL), remission of type 2 diabetes (T2DM), HTN, obstructive sleep apnea (OSA), gastroesophageal reflux disease (GERD), surgical complications, nutritional status. Follow-up was conducted at 1, 6, and 12 months postoperatively.

Preoperatively, mean weight was 124 ± 29.1 kg and BMI 45.05 ± 5.4 kg/m². At 1, 6, and 12 months after SASI, mean BMI was 42.85 ± 7.69, 37.6 ± 6.3, and 32.7 ± 3.83 kg/m², respectively; mean weight was 113 ± 21.6, 99.25 ± 31.3, and 89.1 ± 18 kg. At 12 months, mean %EWL was 57.6 ± 19 and %TWL was 29.58 ± 8.16, exceeding standard benchmarks for bariatric success. Remission rates of T2DM, HTN, OSA and GERD all improved markedly, with nearly complete resolution of comorbidities at 12 months. No peri- or postoperative complications were observed. Considering the nutritional status at 12 months follow-up, no significant alterations were detected. In particular, we chose to analyze laboratory parameters such as serum albumin (3,7 ± 3), vitamin B12 (490 ± 250 pg/mL), folate (9 ± 6 ng/mL), iron (110 ± 32 ug/mL), ferritin (100 ± 35 ng/mL), and hemoglobin (12 ± 1,5).

The SASI procedure demonstrated significant efficacy and safety as a revisional bariatric surgery, producing substantial weight loss, favorable metabolic improvement, and no surgical complications in this single-center cohort. These findings support the use of SASI as a valid option for redo bariatric procedures. Further prospective studies with larger cohorts and longer follow-up are needed to assess long-term results and nutritional outcomes.