| 摘要 |
<p>The invention provides an instrument made of a shape memory alloy cylinder for securing the inner diameter of the lumen of a tubular organ, said instrument being treated so as to enhance X-ray image contrast by plating with or vacuum evaporation of a metal with higher density than that of the shape memory alloy of at least part of the cylinder. Therefore, this instrument can be introduced into and left at the intended portion inside the tubular organ. This invention relates also to an apparatus for securing the inner diameter of the lumen for leaving in or recovering from the lumen the instrument for securing the inner diameter which is shaped substantially in a cylindrical form with a bi-directional shape memory alloy which can change its dimension in the radial direction with temperature change. This apparatus comprises a catheter capable of fitting the instrument for securing the inner diameter to the outer peripheral surface of an instrument fitting portion near the tip and a catheter sheath whose both ends are open, which can house the catheter having fitted thereto the contracted instrument in the lumen thereof, and whose inner diameter is equal to or smaller than the outer diameter of the expanded instrument for securing the inner diameter. Since the catheter sheath is used, the instrument for securing the inner diameter can be securely held in the sheath while being fitted to the catheter. Accordingly, it is not necessary to supply large quantities of cooling water so as to maintain a reduced diameter in order to wind the instrument around the catheter without any gap and the load to a patient can thus be reduced. Since the catheter sheath is used, the instrument for securing the inner diameter is neither exposed to the tubular organ, nor caught in the middle, nor undergoes deformation.</p> |
