Risk Factors of Duodenobiliary Reflux-Related Dysfunction of Covered Biliary Metal Stents after Treatment of Duodenal Stricture in Patients with Malignant Biliary and Duodenal Obstruction

Duodenal obstruction is often accompanied with unresectable malignant distal biliary obstruction in patients who have undergone biliary self-expandable metal stent (SEMS) placement. Duodenobiliary reflux (DBR) is a major cause of recurrent biliary obstruction (RBO) after covered biliary SEMS placement. We analyzed the risk factors for DBR-related SEMS dysfunction following treatment for malignant duodenal obstruction. Sixty-one patients with covered SEMS who underwent treatment for duodenal obstruction were included. We excluded patients with tumor-related stent dysfunction (n = 6) or metal stent migration (n = 1). Fifty-four patients who underwent covered biliary SEMS placement followed by duodenal metal stenting or surgical gastrojejunostomy were included. Eleven patients had DBR-related biliary SEMS dysfunction after treatment of duodenal obstruction. There was no difference between the duodenal metal stenting group and the surgical gastrojejunostomy group. Duodenal obstruction below the papilla of Vater and a score of ≤2 on the Gastric Outlet Obstruction Scoring System after treatment for duodenal obstruction were associated with DBR-related covered biliary SEMS dysfunction. Thus, creating a reliable route for ensuring good oral intake and avoiding DBR in patients with duodenal obstruction below the papilla of Vater are both important factors in preventing DBR-related covered biliary SEMS dysfunction.

Design and evaluation of a novel anti-reflux biliary stent with cone spiral valve

Endoscopic placement of biliary stent is a well-established palliative treatment for biliary obstruction. However, duodenobiliary reflux after stent placement has been a common problem which may lead to dreadful complications. This paper designed a novel anti-reflux biliary stent with a cone spiral valve. Fluid-Structure Interaction (FSI) simulations were established to evaluate the efficiency of the anti-reflux stent comparing with a clinically applied standard stent. According to the stress distribution of the valve, the fatigue performance in the stress concentration area was analyzed. The results show that when the antegrade flow through the valve, the cone spiral valve could stretch and open to realize adequate drainage under the normal physiological pressure of biliary tract; When the duodenal reflux through the valve, the valve would be compressed and close with a result of nearly zero at the outlet flow rate. Furthermore, the anti-reflux stent achieved improved radial mechanical performance with 2.7 times higher radial stiffness than standard stent. Finite element analysis (FEA) also indicates that compared with the standard stent, the addition of the anti-reflux valve had little negative effect on flexibility of the stent. Fatigue analysis results showed that the valve was reliable. This research provides the new stent with a cone spiral valve and proves that it is technically feasible and effective for preventing the duodenobiliary reflux while ensuring the antegrade bile flow without compromising the other biomechanical performances.

Evaluation of choledochoduodenal anastomosis in benign biliary obstruction

Background/Aim. Choledochoduodenostomy has been reported as an effective treatment of benign biliary obstructions, but associated with a certain percentage of complications, (primarily cholangitis and the ?sump? syndrome), as the consequence of duodenobiliary reflux which may occur. The aim of our study was to evaluate the safety, effectiveness and technical feasibility of choledochoduodenostomy for the treatment of distal benign biliary obstruction and to present its minimal postoperative complications. Methods. This propective study included 50 operated patients who had choledochoduodenal anastomosis created for benign biliary obstructions. The symptoms, biochemical and echosonographic parameters of cholestasis, operative technique, recovery features and complications were analayzed and compared. Based on the analysis of obtained data, safety, efficacy and competence of choledochoduodenal anastomosis were determined. Results. Specific early anastomosis- related complications were observed in 12.0% of patients (mostly minor surgical complications). During the immediate postoperative course, aerobilia as an indirect sign of duodenobiliary reflux, occurred in 91.7% of patients, but it was reduced to 16.7% after 30 days (and was not always associated with symptomatology). Choledochoduodenostomy was associated with a low incidence of cholangitis (2%) and anastomosis dehiscence (2%). Transitory duodenogastric reflux was identified in 6% of patients. The rate of intrahospital mortality was very low, considering patients? very complex conditions (4%). During early postoperative period, the ?sump? syndrome was not identified. Conclusion. Choledochoduodenostomy is a simple and effective method in the management of certain types of biliary obstruction. Serious complications can be avoided by proper selection of patients and careful surgical technique. This type od anastomosis has to be included in basic skills of every general surgeon.