Bile Duct Procedures
Reopening bile tube without surgery
Biliary blockages are common. The ability to address them without surgery has been a boon to patients.
The biliary duct can become blocked as a
• disorders of the liver (including primary sclerosing cholangitis);
• long-standing anatomical obstructions;
• abnormal growths (including cancers in or around the duct, liver, pancreas, or surrounding areas);
• scarring in the duct;
• injury to the duct during surgery;
• and other causes.
|At its base, the common bile duct also drains digestive-enzyme fluids from the pancreas. Blockage at this juncture can cause pancreatitis (inflammation of the pancreas). Intervention radiologists can also use the procedures described above to open or otherwise address this location as well.|
When such problems cause a back-up of bile, the condition is called cholestasis. Bile in this case will build up in the bloodstream, causing a form of jaundice. Chronic compromise of bile duct function can cause life-threatening conditions such as infection and, over a longer period of time, liver failure that can lead to the need for liver transplantation.
Interventional radiologists are key specialists in addressing problems in the bile duct. Their interventions can help to prevent pain, complications, and liver failure, and can help prepare patients for surgery. In evaluating or treating the condition, these specialists can use catheter procedures to accomplish these steps:
• biliary drainage. In this procedure, the interventionalist places a fine needle through the skin of the abdomen and into the liver, advancing it into the bile duct. The team will use this access to place a drainage tube in the duct. This tube will drain bile to an external collection bag attached outside the body and placed against the skin or internally, returning the bile to the small intestine. The tube may need to stay in place for weeks and may need to be replaced during this time, if it becomes plugged. Interventionalists may also use the procedure to help heal an injury to the duct or in preparation for surgery, such as removal of a bile duct stone.
• stricture dilation. If the team should identify an area of narrowing or blockage in the duct, it may use the drainage access to insert a balloon catheter (like those that it uses in angioplasty) to correct this defect. The interventionalists will normally place a biliary drainage tube for a day or two prior to trying to dilate such strictures. The specialists can repeat these dilations as needed.
• stent placement. The interventional team can also use stent placement to maintain the opening of the biliary duct. Normally, the team will leave a biliary drainage tube in place for several weeks, across a narrowed area, as a kind of temporary stent. After this period, if the duct would revert to inadequate bile flow without the drainage tube, the specialists may attempt one or more stricture dilations. Should these steps prove inadequate to maintain the duct opening, the team may place a stent, in the form of a tiny metal-mesh tube matched to the length of the stricture, across the narrowed site. The stent preserves the opening of the duct and thus permits bile flow. (Interventionalists may also use this approach to maintain the competency of a bile duct that has a hole in it.) Several stents may be used together. The stents must be removed after several months but may be replaced with new stents as long as the patient requires relief from biliary obstruction.
• tissue sampling. The interventional team can also use the access created by the needle procedure or the drainage tube placement to take a sample of tissue (biopsy) or fluid from the bile system for evaluation in the laboratory.
• stone removal. Sometimes, despite the best surgical or endoscopic efforts, nodules or other calcifications from the bile system may be left behind in the body and require subsequent removal. These retained stones are a common problem.
For example, surgically inaccessible stones in the common bile duct are not unusual. One solution is for the interventional radiologist to remove them via the access provided by a drainage tube placed several weeks earlier. Once the opening provided by this tube has been well established, the interventionalist will insert a guidewire through the tube, remove the tube, pass a sheath over the guidewire, and advance a small snare or basket device through the sheath to acquire and draw out the stones. Other possible interventional steps include passing the stone into the small intestine or breaking up the stone for easier retrieval.
Sometimes stones may be inadvertently left behind in the abdominal cavity, after a patient has undergone gallbladder removal. These stones can cause abscesses. The interventional team can retrieve these stones, or even, rarely, stones within the appendix, with percutaneous catheter techniques.
Endoscopic specialists in gastroenterology also provide a key approach to biliary conditions, using endoscopic retrograde cholangiopancreatography (ERCP) techniques. Sometimes they collaborate with intervention radiologists to combine this approach with the techniques described above.