System and device for minimizing embolic risk during an interventional procedure

#The present invention relates to angioplasty procedures, and more particularly, to a system and device for preventing arterial plaque from dislodging from the arterial wall during procedures such as, for example, percutaneous transluminal coronary angioplasty (PTCA) or percutaneous transluminal angioplasty (PTA), especially carotid PTA, and entering into the bloodstream where the embolic debris can occlude the flow of oxygenated blood to vital organs, such as the brain, which can cause devastating consequences to the patient. The present invention also relates to methods for using such a system and device.

#In typical carotid PTA procedures, a guiding catheter or sheath is percutaneously introduced into the cardiovascular system of a patient through the femoral arteries and advanced through the vasculature until the distal end of the guiding catheter is in the common carotid artery. A guidewire and a dilatation catheter having a balloon on the distal end are introduced through the guiding catheter with the guidewire sliding within the dilatation catheter. The guidewire is first advanced out of the guiding catheter into the patient's carotid vasculature and is directed across the arterial lesion. The dilatation catheter is subsequently advanced over the previously advanced guidewire until the dilatation balloon is properly positioned across the arterial lesion. Once in position across the lesion, the expandable balloon is inflated to a predetermined size with a radiopaque liquid at relatively high pressure to radially compress the atherosclerotic plaque of the lesion against the inside of the artery wall and thereby dilate the lumen of the artery. The balloon is then deflated to a small profile so that the dilatation catheter can be withdrawn from the patient's vasculature and the blood flow resumed through the dilated artery. As should be appreciated by those skilled in the art, while the above-described procedure is typical, it is not the only method used in angioplasty.

#In angioplasty procedures of the kind referenced above, abrupt reclosure may occur or restenosis of the artery may develop over time, which may require another angioplasty procedure, a surgical bypass operation, or some other method of repairing or strengthening the area. To reduce the likelihood of the occurrence of abrupt reclosure and to strengthen the area, a physician can implant an intravascular prosthesis for maintaining vascular patency, commonly known as a stent, inside the artery across the lesion. Stents are usually delivered in a compressed condition to the target location and then are deployed into an expanded condition to support the vessel and help maintain it in an open position. The stent is usually crimped tightly onto a delivery catheter and transported in its delivery diameter through the patient's vasculature. The stent is expandable upon application of a controlled force, often through the inflation of the balloon portion of the delivery catheter, which expands the compressed stent to a larger diameter to be left in place within the artery at the target location. The stent also may be of the self-expanding type formed from, for example, shape memory metals or super-elastic nickel-titanum (NiTi) alloys, which will automatically expand from a compressed state when the stent is advanced out of the distal end of the delivery catheter into the body lumen.

#FIG. 1 is a perspective view of one particular embodiment of a plaque-trapping device made in accordance with the present invention.

#FIG. 2 is a side view, partially in section, of the end of a delivery catheter made in accordance with the present invention which shows the first mounting region for mounting the primary stent and a second mounting region for mounting a plaque-trapping device, such as the one shown in FIG. 1.

#FIG. 3 is a cross-sectional view, partially in section, depicting the delivery catheter of the present invention disposed within a blood vessel of the patient wherein the plaque-trapping device is partially expanded within the vessel.

#The present invention is directed to a system and device for minimizing embolic risk during the interventional procedure which helps prevent the release of any embolic debris created during an interventional procedure from being released into the bloodstream where the debris can lodge in critical arteries, cutting off blood flow to vital organs. While the present invention is described in detail as applied to the carotid artery of the patient, and the disclosed interventional procedure is directed to a stenting procedure, those skilled in the art will appreciate that it can also be used in other body lumens as well, such as the coronary arteries, renal arteries, saphenous veins and other peripheral arteries. Additionally, the present invention can be utilized while performing other interventional procedures, such as a balloon angioplasty procedure.

#FIG. 1 illustrates a plaque-trapping device 10 incorporating features of the present invention. In the particular embodiments shown in FIG. 1, the plaquetrapping device 10 comprises of a tubular net 12 with a proximal end 14 and a distal end 16, and defining an inner lumen 18 extending there between. An expandable member 20, which is shown in this particular embodiment as an expandable end ring, is attached to the proximal end 14 and distal end 16. The expandable member 20 also could be manufactured as an expandable arc (i.e., a portion of a ring) which opens the tubular net 12 once expanded. A longitudinal strut 22 is attached to each of the expandable members 20 located at the distal end 16 and proximal end 14 of the tubular net 12. As shown in FIG. 1, there are actually three or four longitudinal struts 22 attached to the expandable members 20 in this particular embodiment. More or less longitudinal struts can be implemented as well. Additionally, more expandable members 20 could also be spaced along the length of the tubular net 12, if desired. These longitudinal struts 22 are circumferentially positioned 120 or 90 degrees apart and help maintain a set longitudinal length between the expandable members 20 to maintain the entire length of the tubular net 12 in place over the area of plaque once deployed into the patient's vasculature. These longitudinal struts 22 also help maintain the expandable members 20 in proper alignment when deployed. These expandable members 20 are designed to expand radially outward from a contracted to an expanded position and contact the arterial wall to maintain the tubular net 12 in place after deployment. The plaque-trapping device 10, as depicted in FIG. 1, is shown in its expanded configuration.

#FIG. 2 illustrates a delivery catheter 24 also incorporating features of the present invention. In the particular embodiment shown in FIG. 2, the delivery catheter 24 includes an inner member 26 which has a first mounting region 28 and a second mounting region 30 formed therein. This first mounting region 28 is utilized for mounting a primary stent 32 which is to be deployed within the area of treatment in the patient's vasculature. The second mounting region 30 is designed for mounting a plaque-trapping device 10, such as the one shown in FIG. 1. This inner member 26 functions much like a stent holder in that the stent 32 and the plaque-trapping device 10 are placed in their contracted or collapsed position ready for deployment into the patient's vasculature. A restraining sheath 34 extends over the inner member 26, along with the stent 32 and plaque-trapping device 10. This restraining sheath 34 is designed to move axially in a longitudinal direction to first deploy the plaque-trapping device 10 within the area of plaque to be treated and then to deliver and place the primary stent 32 into the area of treatment for performance of the interventional procedure. The restraining sheath 34 should be sufficiently elastic to allow the sheath 34 to expand over the larger diameter inner member 26. Alternatively, the end portion of the sheath 34 which covers the plaque-trapping device 10 may be made from a material which is more elastic than the rest of the catheter, but strong enough to restrain the plaque trapping device 10.