Suspended Overlength Biliary Stents Preventing Duodenobiliary Reflux in Patients With Biliary Stricture

Study Overview
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Brief Summary
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Endoscopic insertion of plastic or metal stents in bile duct under endoscopic retrograde cholangiopancreatography is a well established treatment of distal malignant biliary obstruction.Biliary stents are widely used to relieve symptoms of malignant biliary stricture.Now, the mainly used biliary stents include plastic and metal stents. The main limitation of long time plastic stents is stents occlusion. Biliary plastic stents are changed every 2 to 3 months due to an expected median patency from 77 to 126 days.Metal stents present a lower risk of recurring biliary occlusion, yet high cost and stents occlusion are eventually inevitable. The mechanism of biliary stents occlusion include biliary sluge of the accumulation of bacteria and duodenal biliary reflux .The anti-reflux barrier of Oddi's sphincter disappears after the insertion of biliary stents and the presure in bile duct lowers the duodenals, which cause the retrograde flow of duodenal material into the biliary ducts. Besides, ordinary biliary plastic stent is short which can also shortens the length of duodenal biliary reflux . Therefore, trying to prevent the duodenal biliary reflux is very important in reducing biliary stents occlusion and it is gradually concerned by clinical researchers. Some studies have showed that plastic stents with antireflux valves can effectively reduce the biliary stent stricture and prolong the stents patency, which means reducing duodenobiliary reflux is surely useful for keeping biliary stent patency.So,we assume to explore an innovatively suspended overlength biliary stents (made from nasobiliary tube with length of 26cm or 30cm) as substitution for ordinary biliary plastic stent to prevent the duodenobiliary reflux by extending the length of duodenal content reflux and avoid the stents shift via suspending in intrahepatic duct. In this study,we will design a randomized controlled trial to compare the patency of different length of suspended overlength biliary stents and ordinary plastic biliary stents in patients with distal malignant biliary obstruction to evaluate the effect and safety of suspended overlength biliary stents for the prevention of duodenobiliary reflux and the effect of different length of the stents.

Detailed Description
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Endoscopic insertion of plastic or metal stents in bile duct under endoscopic retrograde cholangiopancreatography is a well established treatment of distal malignant biliary obstruction.Biliary stents are widely used to relieve symptoms of malignant biliary stricture.Now, the mainly used biliary stents include plastic and metal stents. The main limitation of long time plastic stents is stents occlusion. Biliary plastic stents are changed every 2 to 3 months due to an expected median patency from 77 to 126 days.Metal stents present a lower risk of recurring biliary occlusion, yet high cost and stents occlusion are eventually inevitable. The mechanism of biliary stents occlusion include biliary sluge of the accumulation of bacteria and duodenal biliary reflux .The anti-reflux barrier of Oddi's sphincter disappears after the insertion of biliary stents and the presure in bile duct lowers the duodenals, which cause the retrograde flow of duodenal material into the biliary ducts. Besides, ordinary biliary plastic stent is short which can also shortens the length of duodenal biliary reflux . Therefore, trying to prevent the duodenal biliary reflux is very important in reducing biliary stents occlusion and it is gradually concerned by clinical researchers. Some studies have showed that plastic stents with antireflux valves can effectively reduce the biliary stent stricture and prolong the stents patency, which means reducing duodenobiliary reflux is surely useful for keeping biliary stent patency .So,we assume to explore an innovatively suspended overlength biliary stents (made from nasobiliary tube with length of 26cm or 30cm) as substitution for ordinary biliary plastic stent to prevent the duodenobiliary reflux by extending the length of duodenal content reflux and avoid the stents shift via suspending in intrahepatic duct. In this study,we will design a randomized controlled trial to compare the patency of different length of suspended overlength biliary stents and ordinary plastic biliary stents in patients with distal malignant biliary obstruction to evaluate the effect and safety of suspended overlength biliary stents for the prevention of duodenobiliary reflux and the effect of different length of the stents. The investigators will recruit patients according to admission criteria and exclusion criteria. Eligible patients with distal malignant biliary obstruction will be randomly divided into 26cm suspended overlength biliary stents group (experimental group) 、30cm suspended overlength biliary stents group (experimental group) and ordinary plastic biliary stents group (control group).The test groups will be placed the 26cm or 30cm suspended overlength biliary stents in introhepatic bile duct in ERCP. The control group will be placed ordinary plastic biliary stents in ERCP. The primary endpoint is the duration of stent patency and the rate of stent occlusion.The secondary outcomes include the mortality of each group, adverse events and the rate of technical success.

Official Title
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Prevention of Duodenobiliary Reflux Via Suspended Overlength Biliary Stents in Patients With Biliary Stricture

Conditions
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Bile Duct Stricture

Intervention / Treatment
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* Procedure: 26cm suspended overlength biliary stents
* Procedure: 30cm suspended overlength biliary stents
* Procedure: ordinary plastic biliary stents


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Unresectable extrahepatic malignant biliary stricture,available for insertion of biliary stents in ERCP to alleviate biliary stricture. Exclusion Criteria: Patients agree with metal biliary stents; Patients with biliary stricture need double or multiple stents inserted; Patients with previous surgical drainage procedure; Patients with resectable biliary occlusion; A guidewire could not be passed through the stricture; Patients with duodenal obstruction and duodenal endoscopy could not be reached to papillary.; Patients with any contraindication to endoscopic procedures or refuse informed consent
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 26cm suspended overlength biliary stents group<br> | Procedure: 26cm suspended overlength biliary stents<br>* The test group will be placed 26cm suspended overlength biliary stents in introhepatic bile duct in ERCP<br>|
| Experimental: 30cm suspended overlength biliary stents group<br> | Procedure: 30cm suspended overlength biliary stents<br>* The test group will be placed 30cm suspended overlength biliary stents in introhepatic bile duct in ERCP<br>|
| Other: ordinary plastic biliary stents group<br> | Procedure: ordinary plastic biliary stents<br>* The control group will be placed ordinary plastic biliary stents in bile duct in ERCP<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| stent patency and stent occlusion rate | Patients with symptoms of cholangitis and worsening liver function tests suggestive of cholestasis are considered as premature stent occlusion. | 12 months after ERCP | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| mortality of each group | We will compare the mortality of each group after the insertion of biliary stents. | 12 months after ERCP | 
| adverse events | Adverse events include complications of post ERCP such as pancreatitis,biliary infection, bleeding, perforation and stent migration etc. | 12 months after ERCP | 
| the rate of technical success | Technical success is defined as successful insertion of the stent into the bile duct during ERCP. | 12 months after ERCP |