Therapeutic potential of gastro-gastric fistulas created via lumen-apposing metal stents for nutritional deficiencies after roux-en-y gastric bypass

Abstract

Background and study aims

Roux-en-Y gastric bypass (RYGB) is an effective long-term weight loss operation with improvements in metabolic diseases. Nutritional deficiencies, however, are highly prevalent despite supplementation, largely due to exclusion of the proximal small bowel. In RYGB patients who require pancreaticobiliary access, the 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 review of 60 consecutive RYGB patients from two tertiary centers who underwent EDGE. Nutritional and metabolic parameters were assessed before LAMS placement and after removal.

Results

Mean age was 63.2 ± 11.05 years; 23% were male. 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). In addition, 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, low-density lipoprotein, or high-density lipoprotein (P > 0.05 for all).

Conclusions

Temporary partial-reversal of RYGB using a LAMS improves key nutritional parameters without compromising metabolic benefits of RYGB. These findings may support a therapeutic role for iatrogenic GG fistulas as a minimally invasive option for RYGB patients with refractory nutritional deficiencies.

Keywords

Endoscopic ultrasonography - Intervention EUS - Endoscopy Lower GI Tract - Stenting

• References

• 1 Barberá-Carbonell B, Dayer-Jankechova A, Gaspar-Figueiredo S. et al. Laparoscopic Roux-en-Y gastric bypass: Evolution of weight loss and metabolic obesity-related complications after 15–20 years. Obesity Surgery 2025; 35: 2801-2811
• 2 Amin U, Huang D, Dhir A. et al. Effects of gastric bypass bariatric surgery on gut microbiota in patients with morbid obesity. Gut Microbes 2024; 16: 2427312
• 3 Saarinen I, Strandberg M, Hurme S. et al. Nutritional deficiencies after sleeve gastrectomy and Roux-en-Y gastric bypass at 10 years: secondary analysis of the SLEEVEPASS randomized clinical trial. Br J Surg 2025; 112
• 4 De Luca M, Shikora S, Eisenberg D. et al. Scientific evidence for the updated guidelines on indications for metabolic and bariatric surgery (IFSO/ASMBS). Obes Surg 2024; 34: 3963-4096
• 5 Clements RH, Katasani VG, Palepu R. et al. Incidence of vitamin deficiency after laparoscopic Roux-en-Y gastric bypass in a university hospital setting. Am Surg 2006; 72: 1196-1202 discussion 203–204
• 6 Lupoli R, Lembo E, Saldalamacchia G. et al. Bariatric surgery and long-term nutritional issues. World J Diabetes 2017; 8: 464-474
• 7 Stein J, Stier C, Raab H. et al. Review article: The nutritional and pharmacological consequences of obesity surgery. Aliment Pharmacol Ther 2014; 40: 582-609
• 8 Faintuch J, Matsuda M, Cruz ME. et al. Severe protein-calorie malnutrition after bariatric procedures. Obes Surg 2004; 14: 175-181
• 9 Skroubis G, Sakellaropoulos G, Pouggouras K. et al. Comparison of nutritional deficiencies after Roux-en-Y gastric bypass and after biliopancreatic diversion with Roux-en-Y gastric bypass. Obes Surg 2002; 12: 551-558
• 10 Parrott J, Frank L, Rabena R. et al. American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: Micronutrients. Surg Obes Relat Dis 2017; 13: 727-741
• 11 Gasteyger C, Suter M, Gaillard RC. et al. Nutritional deficiencies after Roux-en-Y gastric bypass for morbid obesity often cannot be prevented by standard multivitamin supplementation. Am J Clin Nutr 2008; 87: 1128-1133
• 12 Homan J, Schijns W, Janssen IMC. et al. Adequate multivitamin supplementation after Roux-en-Y gastric bypass results in a decrease of national health care costs: a cost-effectiveness analysis. Obesity Surgery 2019; 29: 1638-1643
• 13 Hage MP, El-Hajj Fuleihan G. Bone and mineral metabolism in patients undergoing Roux-en-Y gastric bypass. Osteoporos Int 2014; 25: 423-439
• 14 Kedia P, Shah-Khan S, Tyberg A. et al. Endoscopic ultrasound-directed transgastric ERCP (EDGE): A multicenter US study on long-term follow-up and fistula closure. Endosc Int Open 2023; 11: E529-e37
• 15 Kadkhodayan K, Pathak S, Chandan S. et al. EUS-guided rendezvous is a viable salvage technique for failed billiary cannulation in patients with Roux-en-Y gastric bypass undergoing BAE-ERCP. Endosc Int Open 2025; 13: a25097500
• 16 Mangiavillano B, Ramai D, Kahaleh M. et al. Outcomes of lumen apposing metal stent placement in patients with surgically altered anatomy: Multicenter international experience. Endosc Int Open 2024; 12: E1143-e9
• 17 Nunes R, Santos-Sousa H, Vieira S. et al. Vitamin B complex deficiency after roux-en-y gastric bypass and sleeve gastrectomy-A systematic review and meta-analysis. Obes Surg 2022; 32: 873-891
• 18 Lewis CA, de Jersey S, Seymour M. et al. Iron, vitamin B(12), folate and copper deficiency after bariatric surgery and the impact on anaemia: A systematic review. Obes Surg 2020; 30: 4542-4591
• 19 Pacana T, Sanyal AJ. Vitamin E and nonalcoholic fatty liver disease. Curr Opin Clin Nutr Metab Care 2012; 15: 641-648
• 20 Buchman AL, Ament ME, Sohel M. et al. Choline deficiency causes reversible hepatic abnormalities in patients receiving parenteral nutrition: proof of a human choline requirement: a placebo-controlled trial. JPEN J Parenter Enteral Nutr 2001; 25: 260-268
• 21 Buchman AL, Dubin MD, Moukarzel AA. et al. Choline deficiency: a cause of hepatic steatosis during parenteral nutrition that can be reversed with intravenous choline supplementation. Hepatology 1995; 22: 1399-1403
• 22 Tasabehji D, Saleh S, Mokadem M. Impact of bariatric surgery and endoscopic therapies on liver health in metabolic dysfunction-associated steatotic liver disease: A review. J Clin Med 2025; 14