Stent

Abstract

If smooth transportation of bile toward the duodenum is difficult due to cancerous cells growing in the bile duct or due to stricture of the bile duct, a cylindrical stent may be implanted into the stenosed site of the bile duct to enable smooth supply of bile. Conventional stents have no risk of slippage at an implanted position thereof, but suffer from invasively growing cancerous cells. Although a covered stent having a coating has been proposed to solve invasion of the growing cancerous cells, the covered stent may have a risk of slippage at an implanted position thereof and also, may cause pancreatitis and cholelithiasis. To solve the above described problems, disclosed herein is a stent to prevent backflow of food from the duodenum to the bile duct while assuring smooth transportation of bile without a risk of unwanted displacement caused by the transported bile. The stent includes a cylindrical outer stent, and a downwardly tapered inner stent covered with a polytetrafluoroethylene (PTFE) or silicone coating having biocompatibility. The inner and outer stents are coupled to each other to define a double structure.

Description

technical field [0001] The present invention relates to a stent, in particular to a stent with a double-layer structure, which is not affected by its slippage at the implantation site and invasion of the diseased site, such as cancerous tumors, and when it is implanted in the bile duct, it can To prevent reflux, for example, of food backing up from the duodenum into the bile ducts. Background technique [0002] Usually, in order to prevent the narrowing of a large number of blood vessels or organs of the body, or to solve the deterioration caused by food, blood movement or various enzymes, when, for example, cancerous tumors grow in the tubular organ and block or narrow the tubular organ, for example, food Or the smooth movement of blood, stents are often implanted in blocked or narrowed tube-like organs to forcibly expand the organ. [0003] Such stents are mainly made of shape memory alloys and have a cylindrical shape. Recently, stents of different shapes with different...

AI Technical Summary

Problems solved by technology

[0004] Traditional stents have no risk of slippage at their implantation site, but growing tumor cells can invade the inside of the stent

Even though the stent is covered with a membrane designed to address the invasion of growing cancer cells, the covered stent has the risk of slipping at its implantation site, leading to pancreatitis and gallstone disease

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