Tokyo Metropolitan Industrial Technology Research Institute and others develop new stent to alleviate pain of cancer patients

The Tokyo Metropolitan Industrial Technology Research Institute (TMITRI), in collaboration with Tokyo Medical University, the University of Fukui, and the Advanced Minimally Invasive Therapy Unit of the Cancer Center at the Keio University School of Medicine, announced on June 8 that they have developed the world's first functional stent that can be implanted in the bile duct for use as palliative therapy for advanced bile duct cancer and pancreatic cancer. The stent will enable long-term palliative therapy, which is expected to significantly reduce the burden on cancer patients and healthcare professionals.

A stent is a tubular medical device used to widen a tube (such as a blood vessel or digestive tract) in the human body from the inside. Its tubular shape inserted into similarly tubular areas in the body facilitates the flow of bile and other fluids that have slowed due to stones or tumors.

The stent developed will be used in bile ducts. When the bile duct become obstructed due to pancreatic cancer or other causes, jaundice develops as a result of the inability to expel bile. Since jaundice is accompanied by fever and nausea, palliative therapy is performed by endoscopically placing a stent into the bile duct to drain bile.

To date, plastic and metal stents have been widely used. Of these, plastic stents can be removed but become blocked prematurely, while metal stents have a large lumen and long-term patency, they cannot be removed as cancer can invade through the mesh. Therefore, the development of a new stent that combines the advantages of these stents and "shows long-term patency and is removable" has been a long-awaited development.

The new stent has unprecedented characteristics that combines the advantages of both conventional metal stents and plastic stents, in that it has long-term patency and removability. The use of a PVA hydrogel that swells when moistened as the material for the stent can ensure bile flow and help eliminate jaundice.

This self-expandable stent for bile duct drainage is made of a hydrogel, of which water is the main ingredient, and experiments have confirmed that it can dilate porcine bile ducts. Not only is this a new stent developed in Japan, but it is also expected to significantly reduce the burden on patients who need stenting and on healthcare professionals.

TMITRI is now seeking to compare the superiority of the stent with existing stents and to further improve the material. It is widely seeking joint research with small- and medium-sized companies involved in the development.

Journal Information
Publication: J. Mater. Chem. B
Title: Characterization and preliminary in vivo evaluation of a self-expandable hydrogel stent with anisotropic swelling behavior and endoscopic deliverability for use in biliary drainage
DOI: 10.1039/D2TB00104G