Outcomes of a Novel Surgery: Gastrojejunal–Ileal Interposition with Bipartition and Sleeve Gastrectomy for Type 2 Diabetes and Obesity

Background/Objectives: Gastrojejunal–ileal interposition with bipartition and sleeve gastrectomy (GJIB-SG) is a novel metabolic procedure developed to combine functional foregut exclusion with hindgut stimulation while preserving duodenal continuity and endoscopic biliary access. This study evaluated the medium-term glycemic, weight-loss, and nutritional safety outcomes of GJIB-SG in patients with obesity and long-standing type 2 diabetes (T2D). Methods: A retrospective single-center cohort of 30 consecutive patients with obesity and T2D who underwent GJIB-SG between January 2016 and August 2019 and reached at least 60 months of postoperative follow-up was analyzed at baseline and at 12, 24, 36, 48, and 60 months. Longitudinal data were analyzed by repeated-measures ANOVA with Greenhouse–Geisser correction and Bonferroni-adjusted pairwise comparisons. Diabetes remission was classified using the 2021 American Diabetes Association consensus definition (A1C < 6.5%, medication-free). Results: Mean body weight decreased from 102.4 ± 13.6 kg preoperatively to 73.5 ± 7.6 kg at 60 months (p < 0.001; mean %TWL 27.4%, mean %EWL 99.4%). Mean A1C decreased from 9.4 ± 1.6% to 6.0 ± 1.4% at 60 months (p < 0.001). Complete medication-free remission was achieved by 70.0% of patients at 12 months and 44.8% at 60 months; cumulatively, 25 of 30 (83.3%) achieved complete remission at one or more intervals, and 3 patients (10.0%) never achieved A1C < 6.5%. Triglycerides, total cholesterol, and LDL cholesterol decreased by 56%, 39%, and 35%, respectively. No protein–energy malnutrition or hypoalbuminemia occurred; however, a late rise in parathyroid hormone and a return of 25-OH vitamin D toward preoperative insufficient values by 60 months indicate the need for sustained micronutrient surveillance. One cardiovascular death at 24 months was not considered procedure related. Conclusions: In this single-center cohort, GJIB-SG was associated with durable weight loss, sustained glycemic improvement with cumulative complete remission in 83.3% of patients, and absence of severe nutritional complications over 60 months. Prospective comparative studies with longitudinal mixed-effects analysis are warranted to define the role of GJIB-SG within the metabolic–surgical armamentarium.