[Postoperative long-term complications after intestinal bypass surgery : Internal hernia, anastomotic ulcer, choledocholithiasis].

The most frequent long-term complications following intestinal bypass procedures that require surgical treatment are internal hernia and treatment-refractory anastomotic ulcer. The risk of internal hernia after Roux-en‑Y gastric bypass ranges from 5-15% and, although it can be reduced by meticulous intraoperative closure of mesenteric defects, it cannot be entirely prevented. Internal hernia usually becomes clinically apparent after significant postoperative weight loss, typically within months to a few years and should ideally be managed by laparoscopic repositioning of the small bowel and closure of the mesenteric defect. Treatment-refractory anastomotic ulcer is most frequently associated with risk factors such as persistent nicotine use during a Helicobacter pylori infection and discontinuation of proton pump inhibitor (PPI) treatment. In addition, anatomical features such as a large gastric pouch or a circumferentially fashioned anastomosis predispose to ulcer formation. The reported incidence after gastric bypass varies considerably and ranges between 1% and 53%. Standard management consists of rigorous elimination of risk factors combined with PPI treatment. In cases of chronicity or (covered) perforation, surgical revision with resection and reconstruction of the anastomosis is required. Choledocholithiasis secondary to cholecystolithiasis represents a particular interdisciplinary challenge due to limited endoscopic access to the papilla of Vater. Established treatment options include endoscopic balloon enteroscopy, retrograde cholangiography via the gastric remnant, which is opened laparoscopically assisted, revision of the bile duct performed during laparoscopic cholecystectomy or percutaneous transhepatic cholangial drainage (PTCD). Management of these long-term complications should preferentially be carried out in certified centers for metabolic and bariatric surgery with appropriate specific expertise.