S2156 Therapeutic Potential of Gastro-Gastric Fistulas Created via Lumen-Apposing Metal Stents for Nutritional Deficiencies in Roux-en-Y Gastric Bypass Patients: A Multicenter Study

Introduction: Roux-en-Y gastric bypass (RYGB) is an effective long-term weight loss operation that improves metabolic diseases. Nutritional deficiencies, however, are highly prevalent despite supplementation, largely due to the exclusion of the proximal small bowel. In RYGB patients that require pancreaticobiliary access, the endoscopic ultrasound (EUS)-directed transgastric ERCP (EDGE) procedure provides a stable gastro-gastric (GG) fistula using a lumen-apposing metal stent (LAMS). The metabolic and nutritional effects of temporary food diversion remain unknown. Methods: We conducted a retrospective review of 60 consecutive RYGB patients from 2 tertiary centers who underwent EDGE. Nutritional (hemoglobin, vitamins B12, iron, albumin, magnesium, folate, ferritin) and metabolic (weight, body mass index, glucose, HbA1c, lipids) parameters were assessed before LAMS placement and after removal. Results: The mean age was 63.2 ± 11.05 years (23% were men). Significant improvements were observed in serum hemoglobin (mean difference [MD] = 1.1 g/dL; P = 0.004), vitamin B12 levels (MD = 204.4 pg/mL; P = 0.021), iron (MD = 57.9 mcg/dL; P = 0.017), albumin (MD = 0.4 g/dL; P = 0.013), and magnesium levels (MD = 0.24 mg/dL; P = 0.016). Additionally, serum folate (MD = 2.2 μg/mL; P = 0.873), and ferritin levels (MD = 315.5 μg/mL; P = 0.335), showed improvement trends, but these did not reach statistical significance. No significant changes were observed in total body weight, body mass index, serum glucose, hemoglobin A1c, serum triglycerides, LDL, and HDL (P > 0.05 for all). Conclusion: Temporary partial-reversal of RYGB via LAMS, is associated with significant improvement in key nutritional parameters without adversely affecting the metabolic benefits of RYGB. These findings support a therapeutic role for iatrogenic GG fistulas, as a minimally invasive option for RYGB patients with refractory nutritional deficiencies.