| 摘要 |
A stent is made of shape memory alloy which has an Austenite finished temperature ranging from 41 DEG C. to 43 DEG C. The stent is capable of adopting a first configuration at a temperature below the Af and a second expanded configuration at or above the Af. In the first configuration, the stent comprises a proximal cylindrical portion, a distal cylindrical portion. The two portion are connected with an interspace therebetween. At the Af temperature the stent is reoriented, and at and above the Af temperature the proximal portion flares into a funnel conical shape expanding in maximum diameter and decreasing in diameter toward the distal portion. The distal cylindrical portion also expands in diameter, and the two portions directly connect with each other without the interspace. A method of placing the stent in position comprises inserting the stent in the first configuration into a system and subsequently raising the temperature of the stent to or above its Af temperature so that the stent assumes the second expanded configuration. |
