1. Percutaneous stent implantation in patients with malignant liver extrahepatic biliary obstruction is reported as a useful preservation treatment. Biliary stents currently in use include metal stents (non-covered stents) and covered stents with a variety of materials. Successful stent implantation will improve the quality of life and allow patients to receive additional chemotherapy or radiation treatment without having to have a drain tube. However, a number of studies have been under way to prevent stent closures, as it can cause sepsis or systemic complications, and invasive treatments, such as percutaneous bile drainage, need to be re-treated.
2. The problem with the non-covered stent is the occlusion of the stent caused by the invasion of the tumor into the stent. covered stents have the advantage of effectively preventing stent closure due to tumor invasion, but they have the disadvantage of causing closure due to damage to covered materials or, in rare cases, tumor invasion. Another drawback of the covered stent is reported to be the movement of the stent due to covered material, but several previous studies have reported that the partial covered stent without covered material near the covered stent was effectively prevented.
3. Silicone, polyurethane, or polyetrafluoroethylene (PTFE) are used as covering substances in the covered stent, which can be damaged by gastric, bile, or pancreatic fluids, resulting in tumor invasion. However, PTFE is more biocompatible than silicon or polyurethane, and is widely used in percutaneous implantation because it has the advantage of no damage caused by chemical degeneration in biliary tract, and recent studies have reported higher opening rates for PTFE-based covered stents. It is also known that the occlusion of the pancreas or gallbladder tubes by covered stents may cause pancreatitis or gallbladder disease, but previous studies have found that the covered stents using PTFE cladding are not a risk factor for pancreatitis or gallbladder.
4. In most liver biliary tumors, stent ends must be installed to the duodenum, and if covered or non-covered stent is installed to the duodenum, food from the duodenum may flow back into the biliary tract, resulting in stent closure. Until now, various types of stents have been developed and used to prevent food backflow, but they have not effectively prevented backflow, and they still remain as research homework.
The 5.12mm diameter covered stent is expected to be effective in preventing stent closure by tumor invasion, 1.44 times wider than the existing 10mm diameter stent, which is expected to allow refluxed food to escape well back to the duodenum. In addition, it is intended to prevent stent movement by using partial PTFE covered stents, and to minimize pancreatic and gallbladder closure caused by covered materials and damage to the covered materials.
6. Due to the above-mentioned advantages, the newly designed 12mm diameter PTFE coverd
 stent is expected to contribute to improving the quality of life of patients by reducing complications and re-treatment after conventional stent implantation.

Treatment

Percutaneous transhepatic biliary drainage (PTBD) is performed prior to stent treatment, and the area to be performed is determined and treated by investigator. Stent implantation is performed without complications caused by PTBD. The biliary stent inserted depends on the degree of tumor invasion. A stent with at least 20 mm of proximal length from the tumor invasion site should be used to prevent proximal biliary occlusion due to tumor length growth to determine the treatment effect unique to the stent. The distal part of the stent must be installed with a duodenum. After stent insertion, remove the drain pipe without complications such as bile duct inflammation or acute stent occlusion. Acute stent occlusion is mainly caused by hematoma or food and can be solved by means of a stent wash using balloons or saline, and after several days of observation, the drain tube is removed if there is no re-occlusion of the stent.

Arm Label

Target Number of Participant

Arm Type

Arm Description

Percutaneous transhepatic biliary drainage (PTBD) is performed prior to stent treatment, and the area to be performed is determined and treated by investigator. Stent implantation is performed without complications caused by PTBD. The biliary stent inserted depends on the degree of tumor invasion. A stent with at least 20 mm of proximal length from the tumor invasion site should be used to prevent proximal biliary occlusion due to tumor length growth to determine the treatment effect unique to the stent. The distal part of the stent must be installed with a duodenum. After stent insertion, remove the drain pipe without complications such as bile duct inflammation or acute stent occlusion. Acute stent occlusion is mainly caused by hematoma or food and can be solved by means of a stent wash using balloons or saline, and after several days of observation, the drain tube is removed if there is no re-occlusion of the stent.

Gender

Age

Description

1) Adult patients aged 19 to under 80 years of age
2) Patients who are closed to malignancy, which is not surgical or resectable
3) Patients with obstructive obstruction caused by lymph node metastasis in the primary carcinoma other than the liver
4) Patients who cannot or fail endoscopic stent implantation
5) Patients who have not previously undergone bile duct surgery
6) Patients with an expected survival rate of at least 2 months (Eastern Cooperative Oncology Group Performance Status [ECOG-PS] less than 3 points)

1) Patients who had previously undergone endoscopic stent implantation or bile duct surgery
2) Patients with expansion of biliary tract in the liver or external biliary tract in the liver
3) Hemophilia patients
4) Patients with three or more ECOG points

Opening rate: Opening rate of 12mm diameter PTFE covered stent for treatment of malignant extrahepatic biliary obstruction.

CT is performed three months after treatment (measured based on patient symptoms and blood findings that may be observed in the event of bile duct inflammation due to stent obstruction) and additional CT is performed when these findings are observed.

Analysis of complications related to treatment

Follow-up up to 3 months

Analysis of survival rate of patients

Follow-up up to 3 months