barriers 620 a and 620 b in the present embodiment the stents are of different lengths however they may also be of the same length each stent 206 bears a radio opaque annular marker 210 a 210 b and 210 c the catheter 600 is introduced into the vascular system and navigated to a stenosis by methods well known in the art fig8 shows the catheter 600 after having been navigated through the vascular system and positioned inside a blood vessel 202 the balloon is located within a stenotic region 204 of the blood vessel 202 the wire 116 is used to slide the cage 605 distally along the tube 102 so as to move the stents 206 distally the carriage 605 is pushed distally along the tube 102 until the balloon 104 is brought into the lumen of the stent 206 a and the marker 118 on the tube coincides with the marker 210 a as determined for example by x ray angiography in a similar manner the balloon may be slid within the carriage until it is positioned opposite the stent fig9 shows the stent 206 a surrounding the balloon 104 a fluid is then introduced into the tube 102 the fluid passes through the tube 102 and inflates the balloon 104 inflation of the tube 104 expands the portion of the carriage 605 surrounding the balloon 104 which in turn expands the stent 206 a onto the stenotic region of the blood vessel 202 as shown in fig1 the fluid is then withdrawn from the tube 102 into the syringe 130 withdrawal of the fluid from the tube 102 causes the balloon to deflate after deflation of the balloon the stent 206 a remains in its expanded state the catheter.