| 摘要 |
PURPOSE:To again freely contract an inner diameter securing instrument even when said instrument is dilated in a tubular organ, by forming the inner diameter securing instrument into a cylindrical shape from a unidirectional shape memory alloy capable of being dimensionally changed in its diameter direction and making the diameter of the cylindrical body in a base phase smaller than the inner diameter of a tubular organ. CONSTITUTION:A stent 10 is deformed so as to have a diameter smaller than the inner diameter of a blood vessel 11 in a state equal to or less than the transformation temp. of a shape memory alloy and mounted to the leading end balloon 51 of a stay catheter 50 to be introduced so as to reach the desired position of the blood vessel 11 and subsequently dilated in its diameter by the action of the external force based on the dilation of the balloon 51 and stayed to secure the inner diameter of the blood vessel 11. Next, at the time of the recovery of the stent and at the time of the alteration of the stay position thereof, a recovery catheter 60 having a side hole 61 provided to the leading end part thereof is introduced so as to reach the stay position of the stent 10 to discharge a liquid having temp. equal to or more than the transformation temp. of the shape memory alloy from the side hole 61 to heat the stent 10 to the transformation temp. or more and the stent 10 is restored to the memory shape, that is, made smaller in its diameter than the inner diameter of the blood vessel 11. Then, the stent 10 is made movable along with the movement of the recovery catheter 60 in the state wound around the leading end part of the catheter 60. |
