Biomaterial Database

Novel airway stent using a thermal shape-memory Ti-Ni alloy. 1991

T Nakamura, and Y Shimizu, and T Matsui, and N Okumura, and Y Takimoto

Department of Physiological Artificial Organs, Kyoto University, Japan.

An attempt was made to develop a tracheal or bronchial stent for nonsurgical implantation using a bronchoscope. Titanium-nickel alloy composed of 50% by weight of each metal has unique thermal shape-memory properties, with a transition temperature of 20 degrees C. Each stent consists of one wire with a diameter of 0.9 mm. It is 30 mm long with a cross-sectional profile resembling a horseshoe. The stent is designed to sustain the airway only at the cartilage rings. Tracheal cartilages of dogs were broken to make a tracheomalasia model, and 10 stents were implanted in 10 animals. The stents were made straight by cooling in liquid nitrogen and then inserted into the region of tracheomalasia. Once in place, they were warmed and recovered their initial shape. The animals were killed between 1 week and 6 months after implantation, and then examined. Nine of the ten stents were located in the implanted area. In one dog, the stent had been displaced into the bifurcation. Microscopic observation showed that the wires were gradually covered with epithelium. At 6 months, 58% were covered with epithelium.

UI	MeSH Term	Description	Entries
D009532	Nickel	A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.
D001999	Bronchoscopy	Endoscopic examination, therapy or surgery of the bronchi.	Bronchoscopic Surgical Procedures,Surgical Procedures, Bronchoscopic,Bronchoscopic Surgery,Surgery, Bronchoscopic,Bronchoscopic Surgeries,Bronchoscopic Surgical Procedure,Bronchoscopies,Surgeries, Bronchoscopic,Surgical Procedure, Bronchoscopic
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004848	Epithelium	The layers of EPITHELIAL CELLS which cover the inner and outer surfaces of the cutaneous, mucus, and serous tissues and glands of the body.	Mesothelium,Epithelial Tissue,Mesothelial Tissue,Epithelial Tissues,Mesothelial Tissues,Tissue, Epithelial,Tissue, Mesothelial,Tissues, Epithelial,Tissues, Mesothelial
D004867	Equipment Design	Methods and patterns of fabricating machines and related hardware.	Design, Equipment,Device Design,Medical Device Design,Design, Medical Device,Designs, Medical Device,Device Design, Medical,Device Designs, Medical,Medical Device Designs,Design, Device,Designs, Device,Designs, Equipment,Device Designs,Equipment Designs
D006097	Granulation Tissue	A vascular connective tissue formed on the surface of a healing wound, ulcer, or inflamed tissue. It consists of new capillaries and an infiltrate containing lymphoid cells, macrophages, and plasma cells.	Granulation Tissues,Tissue, Granulation,Tissues, Granulation
D000402	Airway Obstruction	Any hindrance to the passage of air into and out of the lungs.	Choking,Airway Obstructions,Obstruction, Airway,Obstructions, Airway
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013499	Surface Properties	Characteristics or attributes of the outer boundaries of objects, including molecules.	Properties, Surface,Property, Surface,Surface Property
D014025	Titanium	A dark-gray, metallic element of widespread distribution but occurring in small amounts with atomic number, 22, atomic weight, 47.867 and symbol, Ti; specific gravity, 4.5; used for fixation of fractures.