| 主权项 |
1. An intravascular system comprising: with a double spiral stent component, and kits of components as means for delivering and for increasing and decreasing length and circumference of said double spiral stent comprising
a. an outer spiral having a distal end and a proximal end with a length of wire (Lw) therebetween wound in a clockwise direction in a circumference (C) and in a number of turns (N) and with a distance between said turns that results in a length of said outer spiral (Ls) between said distal end and said proximal end, and b. an inner spiral having a distal end and a proximal end with a length of wire (Lw) therebetween having dimensions approximately equal to those of said outer spiral with dimension differences that enable said inner spiral to be slidably located inside said outer spiral, with the length of wire of said inner spiral wound in a counter-clockwise direction in a circumference (C) and a number of turns (N) and with a distance between the turns that results in a length of spiral (Ls) between said distal end and said proximal end of said inner spiral which is the same as the length of said outer spiral (Ls) and, c. the distal ends of said outer spiral and said inner spiral being attached to each other and the proximal ends of said outer spiral and said inner spiral being attached to each other to produce said double spiral stent, and d. a distal balloon mounted on distal end of a distal catheter which has a proximal end, a distal end and a catheter body therebetween and said distal catheter being slidably received in a proximal catheter, and said distal and said distal catheter being configured with fluid lines and fluid ports to allow said distal balloon to be filled with chilled or normal inflation fluid, and said proximal catheter having a proximal end, a distal end and a catheter body there between being of a size to allow said distal catheter to be slidably received within said proximal catheter, and a proximal balloon mounted near said distal end of said proximal catheter, and said proximal catheter being configured with fluid lines and fluid ports to allow said proximal balloon to be filled with chilled or normal inflation fluid, whereby dimensions of said double spiral stent, are related according to the formula of C=(Lw−Ls)/N, wherein a maximum circumference of said double spiral stent is obtained when Ls is minimum because Lw and N remain the same regardless of said length (Ls) of said double spiral stent, and a minimum circumference is obtained when said length (Ls) is maximum and this is achieved by an operator making maximum a distance between said proximal balloon and said distal balloon while said double spiral stent is being delivered to its desired location in a vessel of the body because said proximal balloon and said distal balloon, are of a size such that when inflated to frictionally attach near said proximal end and said distal end of said double spiral stent and thus hold said double spiral stent at the maximum length and thus the minimum circumference, when operator chooses said length and when operator chooses to move said proximal and said distal catheters so as to bring said distal and said proximal balloons closer together, while adjusting inflation of said proximal and distal balloons sufficiently to maintain their frictional attachments to said spiral stent, and this causes said spiral stent to decrease in length and thus increase in circumference. |
