Endoscopic plastic stenting for bile duct stones: stent changing on demand or every 3 months. A prospective comparison study.

BACKGROUND AND STUDY AIMS: Endoscopic biliary sphincterotomy and stone removal is the standard of care for choledocholithiasis, with a success rate of > 90%. For stones ≤ 25 mm diameter, mechanical lithotripsy, extracorporeal shock wave lithotripsy, electrohydraulic lithotripsy, and laser lithotripsy can be used. In the case of failure, the next step is surgery. In elderly patients and in patients with an elevated surgical risk, stenting is the only treatment modality. In these cases the aim is to avoid the onset of acute obstructive cholangitis. The aim of the current study was to evaluate the best management of plastic stents in patients with biliary duct stones who were unfit for surgery and in whom previous endoscopic therapy had failed.

METHODS: Patients who were high surgical risks and in whom stone clearance was not possible due to the number and sizes of stones were included. Between March 2008 and September 2010 all patients were treated with endoscopic plastic biliary stenting at four tertiary care referral centers in Italy. Patients were randomly assigned to two groups: in Group A (n=39) plastic stents were changed every 3 months or sooner if symptoms appeared; in Group B plastic stents were changed on demand at the onset of symptoms, and ultrasonography and blood samples were performed every 3 months to check for signs of cholestasis and inflammation. The primary outcome was the rate of cholangitis. The secondary outcome was the rate of stone clearance after a period of stenting.

RESULTS: A total of 78 patients were included in the study (43 M/35F; mean age 76 years). Acute cholangitis occurred in 3 patients from Group A and in 14 patients from Group B (P=0.03). Mortality related to cholangitis occurred in one patient from Group A and three patients from Group B (P=n.s.). The mean follow-up was 13.5 months (range 2-23). Stone clearance after long term stenting occurred in 24 patients from Group A (61.5 %) and in 21 patients from group B (53.8%) (P=n.s.).

CONCLUSIONS: In patients with bile duct stones who were treated with biliary plastic stents, the best stent management to avoid cholangitis was stent changing at defined intervals (every 3 months in the current study). The data confirmed that plastic biliary stenting may decrease stone size with a high percentage of subsequent total stone clearance.