Covered Metal Stent for Benign Biliary Stricture Caused by Chronic Pancreatitis
Covered Metal Stent for Benign Biliary Stricture Caused by Chronic Pancreatitis
Benign biliary strictures caused by chronic pancreatitis can be endoscopically treated with
 covered self-expandable metal stents (cSEMS).The purpose of the prospective randomized study
 is to define the optimal duration of stenting and the diameter of the cSEMS.
All consecutive patients admitted for ERCP and treated for benign biliary stricture caused by
 chronic pancreatitis with or without acute pancreatitis are prospectively enrolled in the
 study. The age and gender of the patients and the aetiology of the pancreatitis will be
 recorded.

 At initial presentation, clinical and laboratory findings recorded include liver function
 tests, abdominal pain, jaundice and cholangitis. Pancreatic calcifications are documented in
 abdominal computed tomography. Patients with malignancies, cirrhosis, acute/chronic hepatitis
 or abnormal hepatic imaging studies are excluded. Patients with first attack of acute
 pancreatitis will be excluded.

 The approval of the ethics committee of the hospital has been obtained. An informed consent
 will be obtained from all patients.

 All patients are prepared and sedated for ERCP as per standard medical practice of the
 hospital. At the initial ERCP, an endoscopic sphincterotomy will be performed and the
 presence/absence of bile duct stones above the stricture and the treatment of stones are
 recorded. A pancreatic stent will be inserted if indicated. For the initial ERCP the patients
 will be randomized into two groups: those who receive 10 mm diameter cSEMS and those who
 receive 12 mm diameter cSEMS into the bile duct. For the randomization, sealed envelopes will
 be used. The length of the cSEMS is recorded.

 Further ERCP for stent removal will be performed after six months for the patients with 12 mm
 diameter cSEMS and after twelve months for the patients with 10 mm diameter cSEMS. In case of
 stent migration during the follow-up, the stent will be replaced by a similar new cSEMS. If a
 pancreatic stent will be placed, the removal or replacement will be handled according to the
 hospital practice.

 After each ERCP procedure, all patients will stay in hospital for monitoring the occurrence
 of primary complications such as acute pancreatitis and cholangitis, bile leak, bleeding or
 perforation. Plasma amylase activity is measured same day > 4h after ERCP. Post-ERCP
 pancreatitis is defined as the presence of abdominal pain attributable to acute pancreatitis
 and plasma amylase level at least three times above the upper limit of the reference
 interval. The treatment of primary complications is recorded.

 Follow-up

 Clinical response (adequate biliary drainage) and recurrent stricture formation are the
 primary endpoints of the study. Therefore, blood liver function tests (bilirubin, alkaline
 phosphatase) as well as the minimum diameter of the common bile duct in the area of the
 stricture, the maximum diameter of the common bile duct above the stricture and the length of
 the stricture are measured at ERCPs at the time of the initial ERCP and at removal of cSEMS.
 Blood liver function tests are measured in the morning before ERCPs; the exact widths and
 lengths in mm:s are obtained by comparison the widths and lengths with the diameter of the
 scope. In addition, blood liver function tests are measured and abdominal ultrasonography
 performed in the follow-up six months and two years after the stent removal.

 Morbidity and mortality are additional endpoints of the study. Therefore, complications
 (deaths, stent occlusions, dislodgements or migrations, cholangitis, hemobilia, stone
 formation above the stent), management of complications, admission times, surgical
 interventions and any additional care needed are monitored and recorded during the follow-up
 time. Patients are asked to contact the physician at any time if symptoms such as fever,
 abdominal pain or jaundice occur.
Inclusion Criteria:

 -  Benign biliary stricture caused by chronic pancreatitis

 Exclusion Criteria:

 -  Malignancy, cirrhosis, acute/chronic hepatitis or abnormal hepatic imaging. First
 attack of acute pancreatitis