RCT Steel (Wallstent®) vs Nitinol (Wallflex®) Bile Duct Stent for Palliation of Malignant Obstruction

Less than 20% of patients with malignant distal bile duct (BD) obstruction (often pancreatic cancer) are suitable for resection surgery.In the rest,palliation treatment comes into focus. Jaundice caused by BD obstruction gives pain, infection (cholangitis), often itching and increased weight loss, and the patient is stigmatized by the deep yellow colour of the skin.Therefore palliation with endoscopic stenting by ERCP-technique is important. Modern self-expanding metal stents (SEMS) are now widely used in this context. Comparison in a RCT between steel and nitinol SEMS has never been performed.

The steel stent (Wallstent®) is the "original",is widely used, and has more expanding power. Nitinol stents are softer and claimed to be easier to insert,and are more and more popular.A newly developed nitinol stent (Wallflex®)may have these advantages, but is some 120 Euros more expensive.

Regarding the most important outcome measure, time to stent failure (obstruction), no one knows if there is any difference.Our hypothesis is that there is no difference in this main outcome endpoint.

Secondary outcome measures (compare above) are complications caused by the stent or stent insertion and technical ease to insert the stent. To discover a 10% difference between the 2 groups, regarding patency, 400 patients must be included in the trial, alfa 0.05, beta 0.8. We know from previous trials (Single center trial South Hospital GIE 2006;63:986-995 and a newly finished similar swedish multicenter trial,prel data DDW- 09)that the 9 hospitals recruited will be able to include this no of patients in approximately 2.5 years.

We will have a shortest follow-up period of 10 months, followup will be by phone with standard questions connected to stent failure, which is defined clinically AND by a new ERCP with intervention because of an obstructed stent.

• Biliary Tract Neoplasms
• Pancreatic Neoplasms
• Stents

• Device: Patency of Steel Stent.
  ERCP procedure insertion of Metalic Steel Stent, Wallstent®
  Other Name: Wallstent
• Device: Patency of Nitinol Stent, Wallflex®.
  at ERCP, after Rx,a nitinol stent is inserted.
  Other Name: Wallflex

• Active Comparator: 1
  Insertion of Metalic Steel Stent, Wallstent® in malignant distal bile duct obstruction
  Intervention: Device: Patency of Steel Stent.
• Active Comparator: 2
  Nitinol Stent, Wallflex®.
  Intervention: Device: Patency of Nitinol Stent, Wallflex®.

Inclusion Criteria:

• pt more than 20yrs.
• BD stenosis at least 2cm distal of the hepatic hilum, with typical malignant exposure radiologically.
• Clinically in accordance with tumour.s-bilirubin more than 50 micromol per litre.
• Radical surgery probably not possible(temporary-1month-plastic stenting for further investigation and then exchange to SEMS if estimated non-operable, after Rx is allowed).
• The patient must be fully informed by his doctor orally and in writing prior to the procedure, and give her/his informed consent. Ultrasound or CT examination must be performed prior to Rx.

Exclusion Criteria:

• Informed consent not obtained.
• Significant multiple intrahepatic stenosis by multiple tumour growth, not suitable for ERCP stenting.
• Radical Surgery will probably take place. Suspicion of non-malignant obstruction-further investigation must be performed.
• Not possible by anatomical reasons to reach the papilla, i.e because of prior operations.

prior BD stent inserted (metal stent or plastic stent >1month).

• Previously included in this trial. Prothrombin index more than 1.5. (normal <1.1).