The Patency Period of the New Plastic Anti-reflux Biliary Stent

A Prospective Randomised Study on the Patency Period of the Plastic Anti-reflux Biliary Stent

The aim of this study is to determine the average patency period of the new anti-reflux biliary stent on patients with malignant bile duct strictures and to determine if this stent remains patent for a longer period of time comparing with the ordinary plastic Tannenbaum biliary stent.

Bile duct related cancer is a condition quite commonly seen among Asians. Predisposing conditions for primary bile duct cancer include recurrent infections and autoimmune diseases such as recurrent pyogenic cholangitis (RPC) and primary sclerosing cholangitis (PSC) as well as congenital problem such as choledochal cyst. Peri-ampullary tumour, pancreatic tumour and metastatic tumours with bile duct compression are other causes of bile duct obstruction. As many of these tumours are discovered at a late stage, curative treatment is usually not feasible. Palliative endoscopic stenting of the obstructed biliary system remains the treatment of choice for the majority.

The main problem with endoscopic stenting of the biliary system is the short stent patency period. There are some reports on modifications to plastic biliary stenting method in recent years including changes in stent designs, use of a different material or coating, administrating prophylactic antibiotics and the use of special drugs. All these have failed to show any conclusive effect on the stent patency period.

A preliminary study has demonstrated some promising results in the use of a stent with an anti-reflux property very similar to the stents the investigators are using in this study.

Inclusion Criteria:

• Age 18 years old
• Patients who have cholangiographic evidence (on ERCP) consistent with a malignant extrahepatic biliary stricture (below bifurcation of the common hepatic duct) who require plastic stenting
• Patients with peri-ampullary tumours, pancreatic tumours, gall bladder cancer and metastatic tumours with suspected extrinsic bile duct compression
• Patients with stent or nasobiliary drain in-situ without previous sphincterotomy will qualify for the study if they satisfy the above inclusion criteria.

Exclusion Criteria:

• Patients fit for surgery.
• Patients who have dominant biliary strictures involving the hilum or more proximal biliary segments.
• Previous sphincterotomy.
• Other medical conditions that will result in a life expectancy of less then 3 months (ASA class >4)
• Pregnancy