Palliative biliary stents for obstructing pancreatic cancer

The majority of patients with cancer of the pancreas are diagnosed only after blockage of the bile ducts has occurred. Surgical by-pass (SBP) or endoscopic stenting (ES) of the blockage are the treatment options available for these patients. This review compares 29 randomised controlled trials that used surgical by-pass, endoscopic metal stents or endoscopic plastic stents in patients with malignant bile duct obstruction. All included studies contained groups where cancer of the pancreas was the most common cause of bile duct obstruction. This review shows that endoscopic stents are preferable to surgery in palliation of malignant distal bile duct obstruction due to pancreatic cancer. The choice of metal or plastic stents depends on the expected survival of the patient; metal stents only differ from plastic stents in the risk of recurrent bile duct obstruction. Polyethylene stents and stainless-steel alloy stents (Wallstent) are the most studied stents.

Authors' conclusions: 

Endoscopic metal stents are the intervention of choice at present in patients with malignant distal obstructive jaundice due to pancreatic carcinoma. In patients with short predicted survival, their patency benefits over plastic stents may not be realised. Further RCTs are needed to determine the optimal stent type for these patients.

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Background: 

Palliative endoscopic stents or surgical by-pass are often required for inoperable pancreatic carcinoma to relieve obstruction of the distal biliary tree. The optimal method of intervention remains unknown.

Objectives: 

To compare surgery, metal endoscopic stents and plastic endoscopic stents in the relief of distal biliary obstruction in patients with inoperable pancreatic carcinoma.

Search strategy: 

We searched the databases of the Cochrane Upper Gastrointestinal and Pancreatic Group specialised register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CancerLit, Current Concepts Database and BIDS (September 2002 to September 2004). The searches were re-run in December 2005 and November 2008.

Selection criteria: 

Randomised controlled trials (RCTs) comparing surgery to endoscopic stenting, endoscopic metal stents to plastic stents, and different types of endoscopic plastic and metal stents, used to relieve obstruction of the distal bile duct in patients with inoperable pancreatic carcinoma.

Data collection and analysis: 

Two authors independently assessed trial quality and extracted data. Adverse effects information was collected from the trials.

Main results: 

Twenty-nine trials, that enrolled over 1,700 participants with pancreatic carcinoma, were included. Three eligible studies compared plastic stents to surgery. Endoscopic stenting with plastic stents was associated with a reduced risk of complications (RR 0.60, 95% CI 0.45 - 0.81), but with higher risk of recurrent biliary obstruction prior to death (RR 18.59, 95% CI 5.33 - 64.86) when compared with surgery. There was a trend towards lower risk of 30-day mortality with plastic stents (p=0.07, RR 0.58, 95% CI 0.32, 1.04). One published study compared metal stents to surgery and reported lower costs and better quality-of-life with metal stents.

Nine studies compared metal to plastic stents. Metal stents were associated with a lower risk of recurrent biliary obstruction than plastic stents (RR 0.48, 95% CI 0.38 - 0.62). There was no significant difference in risk of technical failure, therapeutic failure, complications or 30-day mortality by meta-analysis.

When different types of plastic stents were compared to polyethylene stents, only perflouro alkoxy plastic stents had superior outcomes in one trial. The addition of an anti-reflux valve improved the patency of Teflon stents.