Percutaneous Biliary Drainage
Biliary duct obstruction is a serious problem, which may be related to benign or malignant causes. The mechanical obstruction of the biliary duct interrupts the flow of bile produced by the liver into the gut. Serious complications related to the obstruction may ensue, with changes in the liver function, development of infection, and other general symptoms. Regardless of the cause of biliary obstruction the technique is similar.
Using local anesthesia, a small needle is placed through the skin and into the liver. A bile duct is entered and under fluoroscopic (X-ray) guidance a cholangiogram (injection of dye in the bile ducts) is performed. The filling of the bile ducts with contrast solution allows the visualization of the site of obstruction, the assessment of the extension of the biliary dilatation (due to the obstruction) and in most instances the determination of the cause of the obstruction.
Once the level of obstruction in identified, a more peripheral bile duct is cannulated and using a wire with a special tip, the obstruction is crossed. A drain is placed into the bile duct across the point of stricture or total obstruction, reestablishing the communication between the duct above the obstruction and the gut (duodenum). The bile produced by the liver will reach the duodenum and the regular functions of digestion will retain. The catheter initially will be protruding from the skin, but replacement of the drain for an internal stents can be performed, with improvement in comfort for the patient.
Several different internal prosthesis or stents are available. Plastic tubing used to be the most common internal stent, but required exchange after relatively short periods of time (either through a new skin puncture or using an endoscopic procedure) therefore, new metal mesh stents were developed, providing larger diameters (better drainage) and the possibility to last longer.