MXPA98002364A - Assembly of endoprotesis and cateter and method to treat bifurcacio - Google Patents

Abstract

An apparatus and method for placing stents in bifurcated vessels are provided. A proximal stent is configured to be implanted into a lateral branching vessel wherein the proximal stent has an angled portion corresponding to the angle formed by the intersection of the lateral branching vessel and the main vessel, such that all portions of the vessel Lateral branch at the bifurcation are covered by the proximal stent graft. A main vessel stent is provided for implantation into the main vessel, wherein the main vessel stent has an opening or stent cell that aligns with the opening to the lateral branch vessel to allow unobstructed blood flow between the main vessel and the lateral branch vessel. The main vessel and lateral branching catheter structures are advanced over a pair of guidewires to properly supply, orient, and implant the near-angle stent and open endoprosthesis.

Description

ASSEMBLY OF ENDOPROTESIS AND CATHETER AND METHOD TO TREAT BIFURCATIONS BACKGROUND OF THE INVENTION The invention relates to assemblies for deployment of stents, for use in a bifurcation and more particularly to a catheter assembly for implanting one or more stents, for repairing bifurcations, the aorto-ostium, and diseased bifurcated blood vessels, and a method and apparatus for supply and implantation. Prior Art Stents conventionally repair blood vessels that are diseased and are generally hollow and cylindrical in shape and have terminal ends that are generally perpendicular to their longitudinal axis. In use, the conventional stent is placed in the diseased area of a vessel and after placement, the stent provides an unobstructed path for blood flow. The repair of vessels that are diseased at a bifurcation is particularly challenging since the stent must overlap the entire diseased area on the same occasion, however it must not compromise the flow itself compromising blood flow. Therefore, the stent should without compromising blood flow, superimpose the entire circumference of the ostium to a diseased portion and extend to a point within and beyond the diseased portion. When the endoprosthesis does not overlap the entire circumference of the ostium to the diseased portion, the stent fails to fully repair the bifurcated vessel. When the stent overlaps the entire circumference of the ostium to the diseased portion, however it extends to the junction comprising the bifurcation, the diseased area is repaired, but the blood flow can be compromised in other portions of the bifurcation. Unopposed endoprosthesis elements can promote lumen involvement during neointimalization and healing, producing restenosis and requiring further procedures. Furthermore, by spreading to the junction that compromises the bifurcation, the stent may block access to portions of the bifurcated vessel that require performance of additional interventional procedures. Similar problems are found when the vessels are diseased at their origin at an angle of the aorta, as in the ostium of a right coronary or a vein graft. In this circumstance, an endoprosthesis that superimposes the entire circumference of the ostium extends back to the aorta, creating problems, including those by repeated access of the catheter to the vessel involved in additional intervention procedures. Conventional endoprostheses are designed to repair areas of blood vessels that are removed from bifurcations and since a conventional endoprosthesis usually ends at right angles to its longitudinal axis, the use of conventional endoprostheses in the region of a bifurcation of a vessel may result in block blood flow to a lateral branch or fail to repair the bifurcation to the full extent necessary. The conventional stent may be positioned such that a portion of the stent extends in the blood flow path to a lateral branch of the bifurcation or extends so far as to completely cover the blood flow path in a lateral branch. The conventional endoprosthesis can alternatively be placed close to, but not totally overlapping the circumference of the ostium to the diseased portion. This position of the conventional stent results in a bifurcation that is not completely repaired. The only conceivable situation that the conventional endoprosthesis, with right-angled terminal ends, can be placed where the entire circumference of the ostium is repaired without compromising blood flow, is where the bifurcation is formed at right angles. In these scenarios, extremely accurate placement of the conventional stent is required, this extremely accurate placement of the conventional stent may result with the right-angled terminal ends of the conventional stent that overlaps the entire circumference of the ostium in the diseased portion, without extending to a lateral branch, thus completely repairing the bifurcation at right angles. To overcome or avoid the problems and limitations associated with conventional endoprostheses in the context of repairing diseased bifurcated vessels, an endoprosthesis can be used that consistently overlaps the entire circumference of the ostium in a diseased portion, but does not extend at the junction compromising the bifurcation. This stent would have the advantage of completely repairing the vessel at the bifurcation, without obstructing blood flow in other portions of the bifurcation. In addition, this endoprosthesis would allow access to all portions of the bifurcated vessel in case additional treatment with intervention is necessary. In a situation involving disease at the origin of an angled ostial aortic vessel, said stent would have the advantage of completely repairing the origin of the vessel without projecting into the aorta or complicating repeated access.

In addition to the problems encountered in using the prior art stents to treat bifurcations, the delivery platform for implanting these stents has presented numerous problems. For example, a conventional endoprosthesis is implanted in the main vessel, such that a portion of the stent is through the lateral branch, so that stenting of the lateral branch should occur through the stent grafts of the stent. main vessel In this method, commonly referred to in the art as the "monoclonal antibody" approach, the primary vessel stent columns should be separated to form an opening to the lateral branch vessel and then a catheter with a stent is delivered through the opening. The cell to be dispersed must be selected randomly and blindly upon re-crossing the deployed endoprosthesis with a cable. The disadvantage with this approach is that there is no way to determine or guarantee that the primary vessel stent columns are properly oriented with respect to the lateral branch or that the appropriate cell has been selected by the dilatation wire. The opening created often does not provide a free or clear opening and creates a major distortion in the surrounding stent columns. The disadvantage with this approach is that there is no way to discern whether the main vessel stent columns have been properly oriented and spaced apart to provide a clear opening for stent placement in the lateral branch vessel. In another method of the prior art for treating bifurcated vessels, commonly referred to as the "Culotte Technique", the lateral branch vessel is first stented, such that the stent is projected onto the main vessel. Dilation is then performed in the main vessel to open and stretch the stent columns extending through the lumen of the lateral branching vessel. Subsequently, the main vessel stent is implanted such that its proximal end superimposes with the lateral branch vessel. One of the disadvantages of this approach is that the orientation of the stent elements projecting from the lateral branching vessel to the main vessel is completely random. In addition, the deployed endoprosthesis must be crossed again with a wire in a blind and arbitrary manner, selecting a particular endoprosthesis cell. When dilating the main vessel by stretching the stent columns is therefore random, leaving the possibility of restricted access, incomplete lumen dilatation and major stent distortion. In another prior art device and method for implanting a stent, a "T" stent procedure includes implanting a stent in the lateral branched ostium of the bifurcation, followed by placing stent in the main vessel through the branching ostium. side. In another prior art procedure, known as "kissing" stents, an endoprosthesis is implanted in the main vessel with a lateral branching stent that extends partially into the main vessel creating a double barrel lumen of the two stents in the main vessel distant from the fork. Another approach in the prior art includes a "trouser seat and leg" approach, which involves implanting three stents, a stent in the lateral branching vessel, a second stent in a distal portion of the main vessel and a third stent or stent next in the main glass just next the fork. All structures for deployment of prior stents have the same problems and limitations. Typically, there are intimate surface segments not covered in the main vessel and lateral branching vessels between segments with endoprostheses. A fin or fold discovered on the plate or intimate will invite a "snow sweeper" effect, representing a substantial risk for subacute thrombosis, and the increased risk of the development of restenosis. Furthermore, when portions of stents remain unopposed within the lumen, the risk of subacute thrombosis or the development of restenosis again increases. Stents and prior art delivery assemblies for treating bifurcations are difficult to employ, making successful placement almost impossible. Furthermore, even when the placement has been successful, the lateral branching vessel may be "caged" or covered in such a manner that there is impaired access to the area with stent for subsequent intervention. The present invention solves these and other problems as will be shown. In addition to the problems encountered in treating bifurcations involving disease for vessel origins, there is also difficulty in treating disease confined to a vessel segment but extending very close to a distant branch point or bifurcation that is not diseased and does not require treatment. Under these circumstances, a very precise placement of a stent that covers the distant segment but does not extend to the ostium of the distant lateral branch may be difficult or impossible. The present invention also offers a solution to this problem. References to distant and close here will signify: the proximal direction moves away from or away from the patient and distant moves towards or to the patient. These definitions will be applied with reference to lumens and bodily appliances, such as catheters, guidewires and stents. SUMMARY OF THE INVENTION The invention provides stent designs and improved stent delivery assemblies for repairing a blood vessel and lateral branching vessels that form a bifurcation without compromising blood flow in other portions of the bifurcation, thereby allowing access to all portions of the bifurcated vessels should further intervention therapy be necessary. In addition, it provides a design of improved endoprosthesis and endothelial delivery system to repair disease confined to the aorta-ostium of a vessel without projection to the aorta. The endoprosthesis delivery assemblies of the invention all share the novel feature of containing in addition to a tracking guide wire, a second positioning wire that affects the rotation and precise placement of the deployment structure of the endoprosthesis.

The present invention includes a near-angle stent to implant a lateral branch vessel adjacent to a bifurcation. The cylindrical member can have substantially any exterior wall surface typical of conventional stents used, for example, in the coronary arteries. The cylindrical member of the proximal stent has a distal end that forms a first planar section that is substantially transverse to the longitudinal axis of the stent. The proximal end of the stent forms a second-plane section that is at an angle, preferably an acute angle to the longitudinal axis of the stent. The acute angle is chosen to coincide approximately with the angle formed by the intersection of the lateral branching vessel and the main vessel, such that no portion of the stented area in the lateral branching vessel remains uncovered, and no portion of the Stent at near angle extends to the main vessel. A second stent is provided for implantation into the main vessel adjacent a bifurcation, wherein a cylindrical member has distant and proximal ends and an outer wall surface therebetween, which typically can be similar to the outer wall surface of stents used in the coronary arteries. An opening is formed in the outer wall surface of the apertured stent and is dimensioned and positioned on the outer wall surface such that when the stent with aperture is implanted in the main vessel, the opening is aligned with the vessel. lateral branch and stent at close angle in the lateral branching vessel, providing unrestricted blood flow from the main vessel through the lateral branching vessel. The deployment of angled or open stent grafts is achieved by a novel stent delivery system, specifically adapted to treat bifurcated vessels. In a method for implanting the stent at a proximal angle, a lateral branching catheter is provided wherein a lumen with tracking guide wire extends into at least a portion of the lateral branch catheter, being designed either for an overlying catheter. The wire or fast exchange type. An expandable member is disposed at the distal end of the lateral branch catheter. A tracking guidewire is provided for slidable movement within the guidewire lumen. A placement guide wire lumen is associated with the catheter and the expandable member, such that a portion of the placement guidewire lumen is on the outer surface of the catheter and approaches the proximal end of the outer surface of the expandable member. . A stent delivery guidewire is provided for slidable movement within the placement lumen. The proximal ends of the stent delivery and tracking guide wires extend outward from the patient and can be manipulated simultaneously, such that the distal end of the stent placement guide wire is advanced into the main vessel distant to a blood vessel. lateral branch, and the distant end of the tracking guidewire is advanced to the lateral branch vessel distant from the target area. In a preferred embodiment, the stent guidewire lumen includes an angled section, such that the endoprosthesis positioning guide wire advances in the main vessel distant to the lateral branching vessel that results in rotation, causing the Near-angle stent acquires the correct position in the lateral branching vessel. The positioning lumen functions to orient the guide wire for stent placement, to rotate or apply torque to the lateral branch catheter, to properly align and position the stent at a proximal angle in the lateral branch vessel.

The lateral branching catheter assembly is capable of delivering the proximal angle stent mounted on the expandable member in the lateral branching vessel. The lateral branching catheter can also be configured to deliver a self-expanding proximal angle stent. The endoprosthesis delivery system of the present invention further includes a main vessel catheter for delivering a stent into the main vessel after the stent-graft vessel has been placed. The main vessel catheter includes a tracking guidewire lumen extending through a portion, and adapted to receive a tracking guidewire for slidable movement therein. An expandable member is positioned near the distal end of the main vessel catheter to deliver and implant a main vessel stent (with opening) in the main vessel. The main vessel stent includes an opening on its outer surface that aligns with the lateral branch vessel. A guidewire lumen is associated with the expandable member and is dimensioned to slidably receive the guide wire for stent placement. The guide wire for stent placement slides within the lumen of positioning guide wire, to orient the expandable member so that it is positioned adjacent to, but not in, the lateral branch vessel with the stent opening facing the ostium. of lateral branch. In a preferred embodiment, both main vessel catheter structures such as lateral branch catheter include the so-called rapid exchange catheter features, which are easily interchangeable by other catheters while the tracking and positioning guide wires remain located in the vessel. lateral branch and the main vessel, respectively. In an alternate modality, both catheters may be of the "over-the-wire" type. The present invention further includes a method for delivering the proximal angle and main vessel (with aperture) stent into the bifurcated vessel. In a preferred embodiment of the lateral branching catheter system (lateral branching catheter plus proximal approach stent), the distal end of the tracking guidewire is advanced to the lateral branching vessel and distant to the target area. The lateral branching catheter is then advanced over the tracking guidewire until the distal end of the catheter is just proximal to entering the lateral branch. The distal end of the integrated stent placement guidewire is then advanced by the physician pushing the guidewire from outside the body. The distal end of the stent delivery wire travels through the locating guidewire lumen and passes close to the proximal end of the proximal stent and expandable member and exits the lumen. The wire is advanced into the main vessel until the distal end of the lateral branching vessel. The catheter is then advanced to the lateral branch until resistance is felt from the stent guidewire that pushes up against the ostium of the lateral branching vessel, causing the proximal stent to rotate in position and slow its advance in the ostium. Subsequently, the near-angle stent mounted on the expandable member is aligned through the target area and the angled proximal end of the stent is aligned at the intersection of the lateral branching vessel and the main vessel (the ostium of the lateral branch vessel). ) so that the endoprosthesis completely covers the target area in the lateral branching vessel, however it does not extend to the main vessel, thus blocking blood flow. The expandable member expands, thereby expanding and implanting the proximal angle stent into the lateral branching vessel. The positioning wire prevents forward movement of the expandable member and the stent at a proximal angle during inflation. Later, the expandable member is deflated and the lateral branching catheter assembly will be removed from the patient in a known rapid exchange manner. In this modality, the lateral branching catheter is designed in such a way that both the lateral branching tracking wire and the main vessel positioning guidewire can be left in their respective vessels, in case balloon inflation is required. high sequential or simultaneous pressure in each of the vessels, in order to complete the stent placement procedure. In other words, the integrated positioning wire can be put into active service from the proximal 100 cm of the catheter, thus allowing it to act as a rapid exchange wire. Preferably, high-pressure balloons are simultaneously inflated in the main vessel and proximal angle stent in order to avoid deforming an endoprosthesis of the non-opposite balloon inflation within the other. This additional stage of balloon inflation with high pressure is a matter of physician selection. An additional advantage of this embodiment is that by waiting to advance the integrated stent placement wire out of the catheter only when the distal end of the catheter is near the target area, the wire wrap, which is in a mode using two guide wires not integrated, it is avoided. By using this preferred method, the lateral branching vessel can be stented without the need to place stents in the main vessel. In the aorto-ostial application of the lateral branch catheter assembly (lateral branch catheter plus near-angle stent), the placement wire is advanced to the aortic root, while the follow-up wire is advanced to the vein or coronary graft right whose angle origin is going to place stent. After advancement of the proximal angle stent mounted on the expansion member, it is aligned through the target area and the angled proximal end of the stent is aligned in the ostium. In the event that the main vessel is to be placed in the stent (with the stent positioned through the bifurcation site), the proximal end of the main vessel guidewire is inserted into the distal end of the guidewire lumen of the vessel catheter. principal. The lateral branching wire will be removed from the lateral branch at that time. The main vessel catheter will then be advanced into the body until the catheter is within approximately 1 cm of the target site. The distal end of the second guidewire (for integrated stent placement) which resides in the main vessel catheter during delivery to the main vessel, is then advanced when the doctor pushes the placement wire from outside the body. The distal end of the stent delivery wire travels through the locating wire guide lumen and passes under the proximal half of the stent until it exits at the stent opening site or a designated stent cell, where an opening can be formed. The catheter is then advanced distantly until resistance is felt from the stent-graft guidewire that pushes up against the ostium of the lateral branching vessel, indicating that the stent opening correctly faces the lateral branching vessel ostium and aligns with the proximal end of the stent at a proximal angle. Subsequently, the expandable member in the main vessel catheter is inflated, thereby expanding and implanting the main vessel stent in contact with the main vessel, with the opening in the stent providing a flow path for the vessel from the vessel main through the side branching vessel without any obstructions. The expandable member is deflated and the main vessel catheter is removed of the body. The main vessel catheter is designed in such a way that both the main vessel guide wire and the lateral branch wire can be left in their respective vessels in case sequential or simultaneous high pressure balloon inflation is required in each of the vessels in order to complete the stent placement procedure. The presence of the stent placement wire in the stent opening allows catheter access through this opening to the lateral branch vessel for balloon inflation, to smooth the opening in the main vessel stent. This additional stage is a matter of doctor selection. Using this preferred method, the stent can be fitted to the main vessel, without the need to place a stent in the lateral branch vessel. An advantage of this modality is that a main lateral branch, not diseased and requiring treatment, that leaves from a main vessel that requires placement of a stent, can be protected by the placement wire while the main vessel is fitted with a stent. If a "snow sweeper" compromise occurs, or closure of the lateral branching vessel with main vessel stent placement, then there is already present and guaranteed access to place the endovascular stent of the lateral branch vessel over the wire that is already in place in the manner described above. This will allow reliable stent placement of a main vessel segment that contains a major lateral branch. In this use, only if there is a compromise or occlusion of the lateral branch, additional stenting of the lateral branch will be required. In an alternate embodiment, a main vessel stent having no opening on its outer surface is mounted on the main vessel catheter and is implanted in the main vessel, such that the opening extends to the lateral branch vessel. Subsequently, a balloon catheter is inserted through an objective (non-random) stent cell of the main vessel stent, which is centered precisely against the laterally branching ostium, such that the balloon partially extends into the vessel. lateral branch. This balloon has been followed over the placement wire that has been left in place through the target stent cell during and after deployment of the main vessel stent. The balloon expands to form an opening through the stent columns corresponding to the opening of the lateral branching vessel, providing a blood flow path through the main vessel and the main vessel stent and into the lateral branch vessel . A proximal angle stent mounted on a lateral branch catheter is then advanced through the main vessel stent and the opening that is formed through the target stent cell to the lateral branch vessel. The proximal angle stent is expanded and implanted in the lateral branching vessel, such that all portions of the lateral branching vessel are covered by the stent in the area of the bifurcation. After the primary vessel stent and proximal stent of lateral branch vessel are implanted, a non-compromised flow path is formed from the main vessel through the main vessel stent and opened to the branch vessel. lateral and through the stent at close angle of the lateral branching vessel. In another alternate embodiment, an endoprosthesis having a distant angle is implanted in the main vessel. In major vessel portions having disease that are approximate and directly adjacent to the lateral branching vessel, a distant angle stent is implanted using the novel catheter of the present invention, such that the stent covers the diseased area, but does not cage or covers the opening to the lateral branching vessel.

In another alternate embodiment, a Y-shaped catheter and a Y-shaped stent are provided to place a stent into a bifurcated vessel. In this modality, a dual balloon catheter has a Y-shaped endoprosthesis mounted on the balloons and the balloons are placed side by side for easy delivery. The balloons are normally separated, but are restricted and held together to provide a low profile during delivery of the stent. A guidewire is first placed in the main vessel at a point distant from the fork. A second guidewire is retained in the catheter in a second guiding wire lumen, while the catheter is advanced over the tracking guidewire so that the balloons and the stent are distant from the bifurcation. The tracking guide wire is then removed next, thereby releasing the elastically separating balloons. The catheter is removed proximally until it is near the bifurcation. As the catheter is removed proximally, one of the two guide wires is left in the main vessel. The other guidewire is then advanced to the lateral branching vessel. The catheter is then advanced over both guide wires to the balloons and the stent is anchored at the bifurcation. The balloons are inflated and the endoprosthesis expands and implants at the bifurcation.

In another embodiment, two open stents are implanted to cover the bifurcated vessels. A main vessel stent has a cylindrical shape with a strong cell density in the distant half and slight cellular density in the proximal half and an opening in its outer surface at the junction in these two halves. A main vessel stent is first implanted in the main vessel, such that its opening aligns with the ostium of the lateral branching vessel, thereby covering the proximal main vessel with slight cell density and distant with strong cell density. A second main vessel stent is then implanted on the tracking wire to the lateral branch, such that the strong cell density portion of the stent is implanted in the lateral branch vessel, the light cell density is implanted in the vessel. Main vessel and overlaps the slight cell density of the proximal end of the main vessel stent and the opening faces the main vessel as it moves away from the lateral branch. Combined densities of portions of nearby light cells, close to the bifurcation, are similar to the strong cell densities at each extremity distant from the bifurcation. The respective openings of each of the two main vessel stents are aligned with the respective ostia of both ends of the bifurcation (main vessel and lateral branch). Other features and advantages of the present invention will be apparent from the following detailed description which is taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an elevation view of a bifurcation in which a prior art "T" stent is in a lateral branching ostium followed by stent placement of the main vessel through the ostium of branch. Figure 2 is an elevational view of a bifurcation in which prior art stents are "touched" where a stent is implanted in the lateral branch, a second stent is implanted in a proximal portion of the main vessel next of the branching stent, with interrupted placement of a third endoprosthesis implanted more distantly in the main vessel. Figure 3 is an elevation view of a bifurcation illustrating "kissing" stents wherein a portion of an endoprosthesis is implanted in both the lateral branch and the main vessel and is adjacent to a second endoprosthesis implanted in the main vessel creating a double-barrel lumen in the main vessel distant from the fork. Figure 4 is an elevation view of a "seat and legs of the pants" stent placement approach, illustrating an endoprosthesis implanted in the lateral branching vessel, a second endoprosthesis implanted in a proximal portion of the main vessel and a close deployment of a third endoprosthesis distant from the bifurcation leaving a small space between the three endoprostheses of an uncovered luminal area . Figure 5A is a perspective view of a stent of the present invention having an angled proximal end. Figure 5B is a side elevational view of the proximal angle stent of Figure 5A showing the end transverse to the longitudinal axis of the stent and the proximal end at an angle less than 90 °. Figure 5C is an elevation view of a bifurcation in which a prior art stent is implanted into the lateral branching vessel. Figure 5D is an elevation view of a bifurcation in which a prior art stent is implanted into the lateral branching vessel, with the proximal end of the stent extending to the main vessel. Figure 5E is an elevation view of a bifurcation in which the proximal angle stent of the present invention as illustrated in Figures 5A and 5B is implanted in the lateral branching vessel. Figure 6A is a perspective view illustrating the main vessel stent of the present invention wherein an opening is formed on the outer surface of at least a portion of the stent. Figure 6B is a side elevational view of the main vessel stent of Figure 6A. Figure 7A is an elevational view, partially in section, of a lateral branching catheter structure illustrating the distal end of the catheter with the expandable member and the second guide wire lumen connected to receive the stent placement guidewire integrated, while the tracking guide wire is received by the main guide wire lumen. Figure 7B is an elevational view, partly in section of the catheter structure of Figure 7A, wherein the guide wire for stent placement is advanced outside the catheter.

Figure 8 is an elevational view, partly in section, of a laterally branching catheter structure illustrating an expandable balloon having an angled proximal portion corresponding to the angle of the proximal stent. Figure 9A is an elevation view of a bifurcated vessel in which a lateral branching tracking wire has been advanced to the lateral branching vessel, with the stent placement wire remaining inside the catheter until the catheter structure is just next to the lateral branch vessel. Figure 9B is an elevational view of a bifurcation in which a lateral branching tracking wire has been advanced through the patient's vascular system to a lateral branch and stent guidewire that has been advanced through of the patient's vascular system and within the main vessel distant from the ostium of the lateral branching vessel. Figure 10A is an elevation view of a bifurcation in which the structure of the lateral branching catheter has advanced into the vasculature of the patient such that the proximal stent mounted on the expandable member is placed in the target area of the lateral branching vessel. Figure 10B is an elevational view of the lateral branching catheter structure of Figure 10A where the proximal stent has been expanded by the balloon portion of the catheter in the lateral branching vessel. Figures 11A-11D are partial elevation views where the lateral branching catheter structure of Figure 10A is employed to implant the near-angle stent into the lateral branching vessel, where the proximal stent is rotated to align properly to implant in the vessel. Figures 12A-12C illustrate an elevation view, partially in section, of a main vessel catheter structure wherein the main vessel stent has an opening on its outer surface. Figures 12D-12F illustrate an elevational view, partly in section of the main vessel catheter of Figures 12A-12C, with a ramp to assist in orienting and advancing the guidewire through the opening in the main vessel stent. Figure 12G-12I illustrate an elevation view, partially in section of an alternate embodiment of the main vessel catheter of Figures 12A-12C, wherein the guidewire lumen is angled to pass under the stent and exit through the stent. the stent opening. Figures 12J-12L illustrate an elevation view, partially in section, of an alternate embodiment of the main vessel catheter of Figures 12A-12C in a portion of the guidewire lumen passing under the stent. Figures 13A-13E are elevation views, partially in section illustrating the main vessel catheter structure of Figure 12A, and the main vessel stent, where two guidewires are used to correctly position the main vessel stent, such that the opening in the stent is aligned with the lateral branching vessel. Figure 14 is an elevation view of a bifurcated vessel, wherein the proximal stent is implanted in the lateral branching vessel and a main vessel stent is implanted in the main vessel. Figure 15 is a perspective view of the main vessel stent of the present invention for deployment in the main vessel, wherein an objective stent cell provides an opening through which a guide wire can pass.

Figures 16A-16D are elevation views, partially in section of a main vessel catheter having the main vessel stent of Figure 15 assembled, and its relation to the guidewire to advance through an objective stent cell. The figure 17 is an elevation view of a bifurcation in which a main vessel stent is placed in a main vessel such that it extends through the opening to the lateral branch vessel. Figure 18 is an elevation view of a bifurcation in which a main vessel stent is implanted in the main vessel and a balloon catheter is partially inserted into the lateral branch vessel to form an opening through the stent cell objective of the main endoprosthesis. Figures 19A-19C are elevational views of a bifurcation in which a primary vessel stent is first implanted in the main vessel and a catheter structure then deploys a proximal stent in a side branch vessel. Figures 19D-19E are cross-sectional views looking down the side branching vessel in a prior art endoprosthesis in an expanded primary vessel where a random suboptimal stent cell is accessed and expanded. Figure 19F is a cross-sectional view looking down the side branching vessel in an expanded main vessel stent of the invention where the appropriate target stent cell is accessed and expanded. Figure 20A is an elevation view, partially in section illustrating a main vessel catheter in which the main vessel stent is mounted on a guidewire lumen. Figure 20B is an elevation view, partially in section, of a main vessel catheter illustrating the main vessel stent mounted on a lumen section of positioning guidewire, with a distal portion of the guidewire lumen associated with the tip distant from the catheter. Figure 20C is an elevational view, partly in section of the catheter of Figure 20B, illustrating the advanced positioning guide wire outside the placement guidewire lumen. Figure 20D is an elevation view, partially in section, illustrating a main vessel stent implanted in the main vessel without caging or covering the lateral branch vessel.

Figure 20E is an elevation view, partially in section, illustrating the main vessel catheter of Figure 20A and having a ramp to assist in positioning the guide wire. Figure 20F is an elevation view, partially in section, of a stent of a distant angle that is implanted in the main vessel without caging the lateral branching vessel. Figures 21 and 22 are elevational views, partly in section, illustrating an alternate embodiment of the main vessel catheter of Figure 20B, wherein the distal end of the guidewire lumen springs away from the expandable balloon. Figures 23A-23B, 24A-24B, 25A-25B and 26A-26B are elevational views of various bifurcations that are indicated for receiving primary vessel and lateral branch vessel stent deployed by the catheters of the present invention. Figure 27A is an elevation view, partly in section illustrating an alternate embodiment wherein a Y-shaped catheter structure deploys a Y-shaped stent at the bifurcation. Figure 27B is an elevation view illustrating an alternate embodiment wherein a dual balloon catheter structure deploys a Y-shaped endoprosthesis at the bifurcation. Figure 28 is an elevation view illustrating the Y-shaped catheter structure of Figure 27A, where the stent is mounted in the balloon portions of the catheter. Figure 29A is an elevational view, partially in section of a bifurcation where the Y-shaped catheter of Figure 27A is delivered to the stent in the bifurcated area, tracking the wire joining the two tips together. Figure 29B is an elevation view, partially in section, of a bifurcation where the supplied Y-shaped balloon components have been detached and dispersed or separated upon removal of the tracking wire from the other balloon tip lumen. Figure 29C is an elevational view, partially in section, of the Y-shaped delivery catheter of Figure 27A, wherein the Y-shaped balloon has been withdrawn proximal to the bifurcation, leaving the first wire in the right branch. Figure 30 is an elevation, partially sectioned view of the Y-shaped delivery catheter of Figure 27A, wherein the second guidewire is advanced to the left branch.

Figure 31 is an elevation view illustrating the Y-shaped catheter of Figure 27A, wherein the Y-shaped stent is implanted into the main arms and lateral branch arms of the bifurcation. Figure 32 is an elevation view, partially in section, illustrating the Y-shaped catheter structure of Figure 27A, wherein the Y-shaped stent has been implanted and portions of the catheter balloon have deflated. Figure 33 is an elevation view illustrating a bifurcated vessel in which the catheter of Figure 27A has been removed after implantation of the Y-shaped stent. Figure 34 is an elevation view showing a modified stent having a stent. opening in its side wall and wherein half of the stent has a strong stent cell density while the other half of the stent has a light cell density of stent. Figure 35 is an elevation view illustrating the stent of Figure 34 combined to form an endoprosthesis having a strong stent cell density in all portions. Figure 36A is an elevation view illustrating the bifurcation, wherein the stent of Figure 35 has been implanted, such that the opening corresponds to the lateral branching vessel and the stent is implanted in the main vessel. Figure 36B is an elevation view illustrating a bifurcation vessel in which the stent of Figure 34 has been implanted such that the strong stent density is in the lateral branching vessel and light cell density is in the main vessel . The opening corresponds to the continuous lumen of the main vessel. Figure 36C is an elevation view illustrating a bifurcated vessel in which two stents of Figure 34 have been implanted into the lateral branching vessel and the main vessel respectively, in such a way that the light cell density of each endoprosthesis superimposes with the slight cellular density of the other, thus creating cell density close to the bifurcation similar to the strong cell density present in each extremity distant from the bifurcation. DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The present invention includes a structure and method for treating bifurcations, for example in the coronary arteries, veins, arteries, and other vessels in the body. Attempts at prior art to implant intravascular stents in a bifurcation have proven to be less than satisfactory. For example, Figures 1-4 illustrate prior art devices that include multiple stents implanted in both the main vessel and a side branch vessel. In Figure 1, a prior art "T" stent is implanted, such that a first stent is implanted in the lateral branch near the ostium of the bifurcation and a second stent is implanted in the main vessel through the stent. lateral branching ostium. With this approach, portions of the lateral branching vessel are uncovered, and blood flow to the lateral branching vessel must necessarily pass through the main vessel stent, causing possible obstructions or thrombosis. With reference to Figure 2, three stents of the prior art are required to place stents at the bifurcation. In Figure 3, the method of the prior art includes implanting two stents side by side, such that a stent is extended to the lateral branching vessel and the main vessel, and the second stent is implanted in the main vessel. This results in a double-barrel lumen that can present problems such as thrombosis, and turbulence in the blood flow. With reference to Figure 4 of the prior art device, a first endoprosthesis is implanted in the lateral branch vessel, a second endoprosthesis is implanted in a proximal portion of the main vessel and a third endoprosthesis is implanted distant to the bifurcation, leaving This way a small space between the endoprostheses and a discovered luminal area. All prior art devices illustrated in Figures 1-4 have several disadvantages that have been solved by the present invention. In a preferred embodiment of the present invention, as illustrated in Figures 5A, 5B and 5E, the proximal angle stent 10 is configured to deploy in the branch vessel 5. The proximal angle stent 10 includes a cylindrical member 11 that a longitudinal axis 12 which is an imaginary axis extending through the cylindrical member 11. The distal end 13 and the proximal end 14 define the length of the cylindrical member 11. The section of the first plane 15 is defined by a section of plane a through the distal end 13 of the cylindrical member, and the second plane section 16 is defined by a plane section through the proximal end 14 of the cylindrical member. The second plane section 16 defines an acute angle 18 which is the angle between the second plane section 16 and the longitudinal axis 12.

To treat the side branching vessel 5, if a stent of the prior art is employed where there is no acute angle at one end of the stent to correspond to the bifurcation angle, a condition will occur as illustrated in Figures 5C and 5D . That is, an endoprosthesis deployed in the lateral branching vessel 5 will leave a portion of the lateral branching vessel exposed, or as shown in Figure 5D, a portion of the endoprosthesis will be extended to the main vessel 6. As illustrated in the Figure 5E, the proximal angle stent 10 of the present invention has an acute angle 18 that approximates the angle formed by the bifurcation 4 of the side branching vessel 5 and the main vessel 6. In this way the acute angle 18 is intended to be approximate the angle formed by the intersection of the lateral branch 5 and the main vessel 6. The angle between the lateral branch 5 and the main vessel 6 will vary for each application and for purposes of the present invention, it should be less than 90 °. If there is a 90 ° angle between the lateral branching vessel and the main vessel, a conventional stent having ends transverse to the longitudinal axis of the stent will be suitable for stenting the lateral branching vessel.

The near-angle stent may be implanted in the lateral branching vessel to treat a number of angled ostial lesions, including but not limited to, the following: 1. The ostium of a left anterior descending artery (LAD = left anterior descending) where there is a circumflex or trifurcated vessel less than 90 ° in its separation from the LAD. 2. The ostium of the circumflex artery or a trifurcation in a situation similar to the number 1. 3. The ostium of a considerable diagonal. 4. The LAD just distant to, but freeing the origin of a diagonal. 5. The ostium of a circumflex marginal artery with angled separation. 6. Disease in the circumflex artery just distant to a marginal separation but overcoming that separation. 7. Aorta-ostium of a right coronary artery with an angled separation. 8. The origin of an angled posterior descending artery. 9. The origin of a branch of LV extension just and beyond the junction freeing the posterior descending artery. 10. The ostium of an origin of vein graft at an angle. 11. Any of the many previous locations in conjunction with the bifurcation and an alternate vessel. The proximal stent graft of the present invention can typically be used as a single device to treat the above indications, or it can be used in conjunction with the stent-graft stent described herein to place stent at the bifurcation. Following the invention, as illustrated in Figures 6A and 6B, the main vessel stent 20 is configured to deploy in the main vessel 6. The main vessel stent 20 includes the cylindrical member 21 having the distal end 22 and the proximal end 23. The main vessel stent 20 includes the outer wall surface 24 that extends between the distal end 22 and the proximal end 23 and incorporates the opening 25 in the outer wall surface 24. The opening 25 is configured in a manner that such that upon expansion, the diameter of the expanded proximal end 14 of the proximal angle stent 10 approaches. When the main vessel stent 20 is implanted and expanded in contact with the main vessel 6, the opening 25 is aligned with the vessel. lateral branch 5 and the proximal end 14 of the proximal angle stent, thereby providing an unrestricted blood flow path from the vessel of branch lateral to the main vessel. Unlike the previous technique, the main vessel catheter allows selection and placement of an opening in the lateral branch ostium. In addition, it allows the placement of a guide wire during the deployment of the stent in the main vessel, which can be used for additional intervention if necessary. In the prior art access to a lateral branch is through a select stent element in random form ("cell") and is only possible after deployment of the stent. The precise placement of the opening 25 is optional and the opening 25 can be positioned either closer to the proximal or distant end of the stent 20. The proximal stent 10 and the main vessel stent 20 can be formed from any one of a number of materials including but not limited to, alloys of stainless steel, nickel-titanium alloys (NiTi can either be shape memory or pseudo-elastic), tantalum, tungsten or any number of polymeric materials. These manufacturing materials are known in the art. In addition, the proximal stent 10 and the main vessel stent 20 can have virtually any pattern known to prior art stents. In a preferred configuration, the proximal stent 10 and the main vessel stent 20 are formed from a stainless steel material and have a plurality of cylindrical elements connected by connecting members, wherein the cylindrical elements have an undulating pattern or serpentine. This stent is described in U.S. Pat. No. 5,514,154 and is manufactured and sold in Europe only at this time by Advanced Cardiovascular Systems, Inc., Santa Clara, California. The stent is sold under the brand name MultiLink ™. These stents can be modified to include the novel features of the proximal angle stent 10 (the angulation) and the main vessel stent 20 (the opening). The proximal stent 10 and main vessel stent 20 are preferably globe expandable stent grafts, which are mounted on a portion of a catheter balloon and tightly folded over the balloon to provide a low profile delivery diameter. After the catheter is positioned so that the endoprosthesis and the portion of the catheter balloon are placed in either the lateral branch or the main vessel, the balloon expands, thereby expanding the stent beyond its elastic limit , in contact with the glass. Subsequently, the balloon is deflated and the balloon and catheter are removed from the vessel leaving the stent implanted. The deployment of angled and main vessel stent grafts is accomplished by a novel stent delivery system specifically adapted to treat bifurcated vessels. The near-angle stent and main vessel stent can be made to either expand by balloon or be self-expanding. In a preferred embodiment, to provide the novel endoprostheses of the present invention, as illustrated in Figures 7A and 7B, the stent delivery structure for lateral branch 30 is provided and includes the lateral branch catheter 31. The branch catheter side includes the distal end 32 that is configured to deliver into the vasculature of the patient and the proximal end 33 that is outside the patient. The first guidewire lumen 34A extends through at least a portion of the lateral branch catheter 31 depending on the type of catheter desired for a particular application. The first guide wire lumen 34A is preferably defined by the distal end 34B and the side port 34C, which is typical of the so-called rapid exchange type catheters. Typically, a slot (not shown) extends from the side port 34C, just proximal to the portion of the catheter balloon, such that the catheter can be rapidly exchanged during a medical procedure, as is known. The expandable member 35, which is typically a non-distensible balloon, has a first compressed diameter, to supply through the vascular system, and a second expanded diameter to implant a stent. An expandable member 35 is positioned near the distal end 32, in any case between the distal end 32 of the first catheter 31 and the lateral port 34C. With reference to Figures 7A and 7B, the tracking guide wire 36A, distal end 36B, and proximal end 36C all extend through the first guidewire lumen 34A. The tracking guide wire 36A is preferably a rigid wire having a diameter of .354 mm (.014 inch) but may have a different diameter and stiffness as required for a particular application. A particularly convenient guide wire may include those manufactured and sold under the brands SportMR and Ironman ™, manufactured by Advanced Cardiovascular Systems, Inc., Santa Clara California. The tracking guidewire 36A is dimensioned for slidable movement within the first guidewire lumen 34A. The stent delivery structure 30, further includes a second guide wire lumen 39A, which is associated with the expandable member 35. The second guidewire lumen 39A, includes the angled portion 39B and the straight portion 39C, and is connected firmly to the outer surface 40 of the catheter 31, at a point just proximal to the expandable member 35. The integrated stent guidewire 41A is dimensioned for slidable movement within the second guidewire lumen 39A. A slot 39D is formed in the lumen 39A near its distal end, such that the rigid guide wire 41A can bow outwardly as illustrated in Figure 7B. The portion of the guide wire 41A, which arcs outwardly from the slot 39D, will limit the advancement of the catheter 31 as will be described further below. The guide wire for integrated stent placement 41A has the distal end 41B, and the proximal end 41C extending out of the patient. Again, it is preferred that the guidewire for integrated stent placement 41A be a substantially rigid wire as previously described, for the reasons set forth below for supplying and implanting the stent at the bifurcation. In an alternate embodiment, the catheter 31 may have an expandable angle member 42 as illustrated in Figure 8. The proximal end of the expandable member is angled to coincide with the angle of the proximal angle stent 10 (not shown in FIG. Figure 8 for clarity). This embodiment is particularly useful for delivering the stent at an angle since the second guidewire lumen 39A, and its angled portion 39B, have the same angle as the stent and the proximal end of the expandable member. Further in accordance with the invention, as illustrated in Figures 9A-11D, the near-angle stent 10 is mounted to the lateral branch catheter 31 and implanted into the lateral branch vessel 5. The method for attaining angle stent implantation next is as follows. Following the preferred method of the invention, the proximal angle stent 10 is first folded tightly over the expandable member 35 for low profile delivery through the vascular system. In the preferred embodiment of the lateral branching catheter system 30 (lateral branching catheter plus near angle stent) the distal end 36B of the guidewire 36A is advanced into the lateral branching vessel 5 and distant to the target area, with the proximal end 36C that remains outside the patient. The lateral branching catheter 31 is then advanced into a guide catheter (not shown) on the tracking guidewire 36A, until the distal end 32 of the catheter is just proximal (approximately 1cm) entering the lateral branching vessel. Up to this point, the guide wire 41A resides in the second guide wire lumen 39A, such that the distant end 41B of the wire preferably is close, but not in, the angled portion 39B of the guidewire lumen 39A. This delivery method prevents the two guidewires from wrapping together, the guidewire 41A being protected by the catheter during delivery. The distal end 41B of the integrated stent placement wire 41A is then advanced when the doctor pushes the proximal end 41C from outside the body. The distal end 41B of the guidewire for integrated stent placement travels through the guidewire lumen 39A and the angled portion 39B and passes near the proximal end 14 of the angled stent 10 and expandable member 35 and exits the lumen 39B. As the guide wire 41A is advanced into, through and out of the lumen 39, the stiffness of the wire causes it to bow outwardly through the slot 39D in the distal portion of the lumen 39A. In this way, as can be seen for example in Figures 9B, 10A, 10B and 11B-11D, the positioning guide wire is buckled outwards and due to its rigidity, provide a stop against the ostium of the side branching vessel, for help in placing and deploying the stents. The guidewire for stent placement 41A is advanced into the main vessel until the distal end 41B is distant to the side branching vessel 5. The catheter is then advanced to the side branching vessel 5, until resistance of the guide wire of the stent is felt. stent placement 41A pushing up against the ostium of the lateral branching vessel 5. As previously described, the stent delivery wire 41A is relatively stiff, such as the tracking guidewire 36A, such that they can properly orient the catheter of lateral branch 31, as it advances to the side branching vessel 5. The angled portion 39B of the second guide wire lumen 39A is angled to assist in rotating the lateral branch catheter in proper placement within the lateral branch vessel. If the stent approaches the lateral branching vessel 5 in the wrong position, as illustrated in Figures 11A-11D, the stent delivery wire 41A will be forced to make a very sharp angle. The stiffness of the wire, however, prevents this from happening and causes the wire to acquire the lowest tension position. To alleviate this buildup of tension, the wire 41A creates a torque at the angled portion 39B, causing the guidewire lumen of 39A and the lateral branch catheter 31, with the proximal stent 10, to rotate to the correct position. Preferably, the slot 39D is formed on the outer surface of the catheter 31, near the angled portion 39B, such that the stent positioning guide wire 41A can buckle outwardly from the slot 39D, thereby increasing the ability to apply torque to a catheter and near-angle stent. Subsequently, the proximal angle stent mounted on the expandable member 35 is aligned through the target area, and seen under fluoroscopy, the acute angle 18 at the proximal end of the proximal stent is aligned at the intersection of the lateral branch vessel 5 and the main vessel 6 (the ostium of the lateral branching vessel), such that the near-angle stent completely covers the target area in the lateral branching vessel 5, however it does not extend to the main vessel 6, thereby compromising the blood flow . The expandable member 35, which is typically a non-distensible balloon, is expanded by known methods, thereby expanding the near-angle stent in contact with the lateral branch vessel 5, and thereby implanting the stent at a proximal angle in the branch / side vessel. Subsequently, an expandable member 35 deflates and the lateral branching catheter structure 31 is removed from the patient's vasculature. The lateral branching catheter 31 is designed such that both the tracking guidewire 36A and the endoprosthesis positioning guidewire 41A can be left in their respective vessels in the event that simultaneous or sequential high pressure balloon inflation is required. in each of the vessels in order to complete the stent placement procedure. In other words, the integrated positioning wire can be put into active service, through the slot (not shown) from the proximal 100 cm of the catheter, thereby allowing it to act as a rapid exchange wire. Preferably, high pressure balloons are inflated simultaneously in the main vessel and proximal angle stent to avoid forming a stent by balloon inflation unopposed within the other. This additional stage is the doctor's choice. Using this preferred method, the side branching vessel 5 can be stented, without need for stent placement in the main vessel, as illustrated in Figures 11A-11D. If necessary, stenting can also be placed in the main vessel 6 after the endoprosthesis is placed in the lateral branching vessel. In that regard, and continuing with the invention, the catheter structure of the main vessel 50 is provided to implant the main vessel stent 20, as illustrated in Figures 12A to 13E. In a preferred embodiment, as illustrated in Figures 12A-12C, the main vessel catheter 50 includes the distal end 51 that is configured to advance within the vasculature of the patient, and the proximal end 52 that is outside the patient. The main vessel catheter includes the guide wire lumen 53A having the distal end 53B and the lateral port 53C, which is proximate to the portion of the catheter balloon. The lateral port 53C is provided in a so-called rapid exchange catheter system, which includes a slot (not shown) as is known in the art. The expandable member 54 is located near the distal end 51 of the main vessel catheter 50. Typically, the expandable member 54 is a non-distensible balloon of a type known in the art for supplying and expanding stents.

Further in accordance with the invention, the guidewire lumen 55A is positioned partially on the catheter shaft and partially on the expandable member 54 and is configured to slidably receive the integrated stent guide wire 56A. Prior to delivery of the stent, the guide wire 56A resides in the guidewire lumen 55A and only during delivery of the stent is it advanced into and through the angled portion 55B of the lumen. Other preferred embodiments for implanting the main vessel stent 20 in the main vessel 6 are illustrated for example in Figures 12D-12F. This embodiment is identical to that illustrated in Figures 12A-12C, with the addition of the ramp 57 which is mounted on the balloon 35 and allows a slight tilt for the guidewire 56A as it exits the guidewire lumen 55A. As the guide wire slides on the ramp 57, the distal portion 56B of the guidewire will move radially outward, which helps to place the guidewire and orient it within the lateral branching vessel. In another preferred embodiment for implanting the main vessel stent in the main vessel, as illustrated in Figures 12G-121, the guidewire lumen 55A passes under the main vessel stent 20 and over the balloon 35. The end Distant 55B is curved over the balloon such that as the guidewire 56B advances out of the distal end 55B of the lumen, it will travel radially outwardly such that it can more easily locate and advance within the lateral branch vessel 5. Still in another preferred embodiment for implanting the main vessel stent 20 in the main vessel 6, as illustrated in Figures 12J-12L, the guidewire lumen 55A is placed under the stent 20 and terminates at the distal end 55B to the middle of the opening 25. The distal end 55A of the guide wire lumen will spring outward, which facilitates advancing the distal end of guide wire 41B to the side branching vessel. A remote guidewire lumen 58 is connected to the outer surface of the balloon 35 and extends from the opening 25 essentially to the distal end of the catheter. In a preferred method of implanting the main vessel stent 20 in the main vessel 6, as illustrated in Figures 12A-12I and 13A-13D, the guide wire 41A remains in position in the main vessel 6, while the guidewire lateral branch 36A is removed from the patient. The main vessel catheter 50 is backfilled or loaded from the back on the guide wire 41A by inserting the proximal end IB of the wire at the distal end of the catheter and into the guidewire lumen 53A. The main vessel catheter 50 is advanced over the guidewire 41A and viewed under fluoroscopy until the main vessel stent 20 is placed in the main vessel 6, just proximal to the side branch vessel 5. The distal end 56B of the guidewire for placement of integral stent 56A, then advanced by the physician pushing the proximal end 56C from outside the body. The distal end 56B of the wire 56A advances into and through the guide wire lumen 55A and passes under the proximal end of the main vessel stent 20 and exits at the angled portion 55B of the lumen and enters the lateral branch vessel 5. The main vessel catheter 50 is then advanced away from the main vessel until resistance is felt from the stent graft guidewire 56A pushing up against the ostium of the lateral branching vessel. The stiffness of stent placement guidewire 56A causes the main vessel catheter 50, with the main vessel stent 20, to rotate such that the opening 25 faces the main vessel ostium 5 and the near-angle stent 10 already implanted. The expandable member 54, which is typically a non-distensible expandable balloon, is thus inflated by expanding the main vessel stent 20 in contact with the main vessel 6. The opening 25 is correspondingly expanded and when properly aligned, it provides a blood flow path between the aperture 25 and the proximal angle stent implanted in the side branching vessel 5. As can be seen in Figures 12A-12I and 13A-13D, the guide wire lumen 55A is placed in the expandable member 54, such that when the expandable member is inflated, the placement guidewire lumen 55A does not interfere with stent-graft stent implantation 20. After the stent-graft stent is implanted into the main vessel , the expandable member 54 deflates, and the main vessel catheter 50 is removed from the patient. As seen in Figure 14, the bifurcated vessel has been completely covered by the endoprostheses, the lateral branching vessel 5 is covered by the proximal stent 10, and the main vessel 6 is covered by the main vessel stent 20, such that no portion of the bifurcation 4 is left uncovered and there is no overlap in implanted stents In an alternate method of implanting the main vessel stent 20 in the main vessel 6 as illustrated in Figures 12J-12L, the tracking guide wire 41A is advanced through the guidewire lumen 55A and the guidewire lumen 58 , such that it advances distantly from the distal end 51 of the catheter. In this manner, the distal end of the guide wire 41B is advanced to the main vessel, so that it is distant from the lateral branch vessel. The guide wire 56A, which up to this point has remained within the guidewire lumen 53A (see Figure 12K), is advanced distally as illustrated in Figure 12L and advanced to the main vessel distally of the lateral branch vessel. The guide wire 41A is then removed proximally through the guide wire lumen 58 until the distal end of the guide wire 41B is able to exit the distal end of the guide wire lumen 55B, as illustrated in Figure 12L. Since the guidewire lumen 55B is preformed and has a bypass, it will spring outwards. The guide wire 41A can then be advanced into the side branching vessel for additional placement. As the catheter 50 is advanced over the guide wires, the distal portion 41B of the guidewire will push against the ostium of the lateral branching vessel, thereby securing the location of the main vessel stent 20, and importantly the aligned aperture 25. with the opening to the lateral branching vessel 5. A stent without angle (see Figure 15) can be implemented using the catheter system of Figures 7A-11D, to place stent in a lateral branching vessel having an origin approaching 90 ° on its take-off or departure from the main glass. In this circumstance, the positioning wire only serves to slow down the forward movement of the endoprosthesis, precisely at the origin of the vessel for a more precise placement. However, the acute angle 18 is appropriate for a bifurcated vessel 4, wherein the angulation is the acute angle 18, or less than 90 °. In this way, consideration can be given to standard stent designs at an angle of 30 °, 45 ° and 60 ° for the proximal stent 10, which should provide sufficient luminal wall coverage when following the present invention. The near-angle stent 10 has a wide range of applicability and can be used to stent in lesions with ostial lateral branching, left anterior descending lesion (LAD = left anterior descending) or ostial circumflex, where the bifurcation is an acute angle, or less than 90 °, and ostial lesions involving the origin of angulation of a vein graft or right coronary artery. Importantly, the stents of the present invention provide full coverage of the intimal ostial, without projecting the main vessel or compromising subsequent access to the distal portion of the main vessel.

In order to assist in properly aligning both the proximal angle stent 10 and the main vessel stent 20, in the lateral branching vessel 5, and the main vessel 6, respectively, the guidewire lumen 39A, in the catheter of lateral branch 31, and the guide wire lumen 55A in the main vessel catheter 50, can be radiopaque or have the radiopaque marker associated in such a way that they are visible under fluoroscopy. In this way, when advancing the lateral branching catheter 31 and the main vessel catheter 50, the proper orientation can be more easily determined by viewing the position of the guide wire lumen 39A in connection with the main vessel 6 or the guidewire lumen 55, in connection with the alignment opening 25 with the side branching vessel 5. Additionally, the positioning guide wire 56A for positioning the main vessel stent 20 and placing the guidewire 41A for disposing the stent at angle 10, they are already radiopaque or have radiopaque portions such as gold markers, to assist in positioning and orienting the catheters and stents during implantation and deployment. While the above description includes implanting the proximal angle stent 10 in the side branching vessel 5 prior to implanting the main vessel stent 20 in the main vessel 6, in an alternate preferred embodiment, the implant procedure can be reversed. However, it will be understood that by implanting the main vessel stent 20 in the main vessel 6, and subsequently implanting the proximal stent 10 in the side branch vessel 5, the opening 25 must be carefully aligned with the side branch vessel. 5, such that the lateral branch catheter 31 can be advanced through the expanded main vessel stent 20 and the opening 25 and into the lateral branch vessel 5, to implant the proximal angle stent 10. While the catheter Lateral branching 31 and main vessel catheter 50 have been described herein as being of the rapid exchange type, they can also be of a conventional over-the-wire type catheter. In over-the-wire type catheters, the guide wire lumen extends from the distal end of the catheter to the proximal end without a side gate as found in the rapid exchange type catheters. The usual type of over-the-wire catheters is of the type illustrated in US Pat. Nos. 4,323,071 and Bl 4,323,071, which are incorporated herein by reference, and are commonly assigned and commonly owned by Advanced Cardiovascular Systems, Inc., Santa Clara, California. In a preferred embodiment of the invention as illustrated in Figure 15, the main vessel unmodified stent 60 can be configured without the lateral opening 25 of the stent 20. Upon expansion, the individual column members 61 of the unmodified stent 60 they expand sufficiently to allow a balloon catheter to be inserted through and expand to form an opening corresponding to the opening to the lateral branch vessel 5. In a preferred method of stenting the bifurcation, the lateral branch vessel 5 first it is placed in stents as described, for example, in the manner illustrated in Figures 9A to 11D. Subsequently, stent is placed in the main vessel 6, with the unmodified main vessel stent 60, which does not have an opening formed in the side of the stent. As illustrated in Figures 15-18, the unmodified stent 60 is mounted on the expandable portion 54 of the main vessel catheter 50. The main vessel catheter 50 is backfilled on the proximal end of the guide wire 41A which is already in position in the main vessel. The main vessel catheter 50 is advanced over the guide wire and viewed under fluoroscopy until the stent 60 is placed in the main vessel, approximately one centimeter close to the lateral branch vessel. The distal end 56B of the integrated stent delivery guide wire 56A is then advanced by the physician by pushing the proximal end 56C from outside the body. The distal end 56B of the wire 56 travels through the guide wire lumen 55A and passes under the proximal end of the unmodified stent 60 and exits the angled end of the lumen 55B and enters the lateral branching vessel 5. The catheter The main vessel 50 is then advanced distantly in the main vessel, until resistance is felt from the stent graft guidewire 56A pushing up against the ostium of the lateral branching vessel 5. The stiffness of the stent graft guidewire 56A , causes the main vessel catheter 50 to rotate with the unmodified stent 60, such that a stent cell 62 faces precisely the ostium of the lateral branch vessel 5. The expandable member 54 is expanded by known means, in such a manner that the unmodified stent 60 expands in contact with the main vessel 6. The expandable member 54 then deflates, the catheter 50 is withdrawn of the patient's vascular system, leaving the guidewire 56A at the lateral branch.

At this point, the proximal stent 10 is implanted into the lateral branching vessel and the unmodified main vessel stent 60 is implanted and extended through the side branching vessel 5. In order to provide an opening in the stent unmodified main vessel 60, aligns with the opening to the lateral branching vessel, the third catheter 65 which can be a standard PTCA catheter, is backfilled on the guide wire 56A, already in the side branching vessel 5, and advances into the Vascular system of the patient on the guide wire. As illustrated in Figure 18, the distal end 66 of the catheter 65 is advanced over the guide wire 56A, until the distal end 66 of the catheter 65 begins to pass through the cell 62 of the unmodified master vessel stent 60. and enters the side branching vessel 5. The catheter 65 may be of a known type used in angioplasty as described above, having a non-distensible member or balloon 67. Once the balloon 67 is placed through the cell stent 62 and in the opening of the side branching vessel 5, expands, thereby expanding some of the columns 61 comprising the unmodified stent 60 and forming a substantially circular opening of the main vessel 6 through the unmodified stent 60 and towards the side branching vessel 5. In essence, the balloon 67 detaches some of the columns of the unmodified stent 60, to form an opening in the stent 60 which corresponds to the opening of the lateral branching vessel 5, thereby providing a clear blood flow path between the main vessel and the side branching vessel. The unmodified main vessel stent 60 is positioned such that it crosses the opening to the lateral branching vessel 5. As stated above, a stent particularly well suited for this embodiment includes a stent distributed under the trade name MultiLink ™ Stent, manufactured by Advanced Cardiovascular Systems, Inc., Santa Clara, California. By implanting the unmodified main vessel stent 60 in the main vessel 6 with an appropriate stent cell precisely aligned with the lateral branch ostia, dilatation through this same cell on the wire 56A ensures a fully expanded and undistorted cell in the ostium of the lateral vessel 5. In an alternate modality, as illustrated in Figures 19A-19C, the unmodified stent 60 is first implanted, then the laterally branching stent 10 is implanted. In the preferred method of deploying the unmodified stent 60, the unmodified stent 60 can be mounted on the expandable portion 54 of the main vessel catheter 50. The main vessel catheter 50 is backfilled on the proximal end of the guide wire 41A. The main vessel catheter 50 is advanced over the guidewire 41A and viewed under fluoroscopy, until the unmodified stent 60 is placed in the main vessel 6, next to the lateral branch vessel 5. The distal end of the guidewire integral stent 56B, then advanced by the physician pushing the proximal end 56C from outside the body. The distal end 56B of the wire 56A travels through the second guidewire lumen 55A and passes under the proximal end of the unmodified stent 60 and exits the angled end of the lumen 55B and enters the lateral branching vessel 5. The catheter of main vessel 50 is then advanced distally to the main vessel until resistance is felt from stent graft guidewire 56A pushing up against the ostium of lateral branching vessel 5. The stiffness of stent graft guidewire 56A causes that the main vessel catheter 50 with the unmodified stent 60 rotate, such that a stent cell 62 precisely faces the lateral branching vessel ostium 5. The expandable member 54 expands by known means, such that the unmodified stent 60 expands in contact with the main vessel 6. The expandable member 54 is then deflated, and the catheter 50 is removed from the patient's vascular system, leaving the guidewire 56A at the lateral branch 5. Further with the preferred embodiment of stent placement, as illustrated in Figure 19B , the third catheter 65 which can be a standard PTCA catheter, is backfilled on the guidewire 56A already in the lateral branch vessel 5 and advances into the patient's vascular system on the guidewire. The distal end 66 of the catheter 65 is advanced over the guide wire 56A, until the distal end 66 of the catheter begins to pass through the columns 61 of the stent cell 62 of the unmodified main vessel stent 60 and enters the lateral branching vessel 5. The catheter 65 may be of a known type employed in angioplasty, as described above, having a non-distensible member or balloon 67. Once the balloon 67 is placed through a stent cell 62 , the opening of the lateral branching vessel 5 expands, thereby expanding some of the columns comprising the unmodified stent 50 and forming a substantially circular opening from the main vessel 6 through the unmodified stent 60 and into the vessel side branch 5. In essence, the balloon 67 is separated from the columns 61 of the unmodified stent 60, to form an opening in the non-modified endoprosthesis. This corresponds to the opening to the lateral branching vessel 5, thus providing a clear opening for placing additional stent to the lateral branching vessel 5. With the main vessel now positioned with stent as illustrated in Figures 19A-19C, Lateral branching vessel 5 is endotrophized in the same manner as described in Figures 9-11. The only difference is that in cell 19, the unmodified main vessel stent 60 is already implanted when the catheter 31 is advanced in the lateral branch vessel 5. The lateral branch catheter 31 is back-loaded on the guide wire 36A which already is located in the lateral branching vessel 5. The lateral branching catheter 31 is then advanced until the distal tip of the lateral branching catheter 31 just enters the ostium of the lateral branching vessel 5. The distal end 41B of the integrated guide wire 41A , then it is advanced by the doctor who pushes the proximal end 41C from outside the body. The distal end 41B of the integrated stent placement guidewire travels through the second guide wire lumen 39A and the angled portion 39B and passes close to the proximal end of the proximal stent 10 and expandable member 35 and exits the lumen. 39B. The guidewire for stent placement 41A is advanced until the distal end 41B is distant from the lateral branching vessel 5. The catheter is then advanced to the lateral branching vessel until resistance of the stent placement guidewire 41A is felt , pushing up against the ostium of the lateral branching vessel. As previously described, the stent delivery wire 41A is relatively rigid as is the follow guide wire 36A, such that it can properly orient the lateral branch catheter 31 as it advances to the lateral branch vessel. The angled portion 39B of the second guide wire lumen 39A is angled to assist in rotating the lateral branch catheter to the proper position within the lateral branch vessel 5. If the stent approaches the lateral branch vessel in the wrong position, the stent placement wire 41A will be forced to make a very sharp angle. The stiffness of the wire however prevents this from happening and causes the wire to acquire the position of minimum tension. To alleviate this buildup of tension, the wire 41A creates a torque at the angled portion 39B, causing the guidewire lumen 39A and the lateral branch catheter 31 with the proximal stent 10 to rotate to the correct position . Once the proximal angle stent is placed in the side branching vessel 5, the expandable member 35 expands such that the proximal stent is expanded in contact with the side branching vessel 5, ensuring that the proximal end 14 of the proximal stent 10 covers and is aligned with the side branching vessel 5 at the bifurcation 4. The proximal end 14 is aligned such that it coincides with the acute angle 18, thus ensuring that all portions of the side branching vessel 5 are covered by the proximal stent graft, where the side branching vessel 5 meets the main vessel 6. Now there is an unobstructed blood flow path between the expanded unmodified stent 60 and the vessel 6 through the previously formed opening and into the lateral branch vessel 5 and through the stent at proximal angle implanted or 10. Prior art devices that have attempted to first place stents in the main vessel and randomly choose a stents to expand by aligning with the lateral branch vessel have failed in general. One approach known as the "monoclonal antibody" approach as illustrated in Figures 19D and 19E illustrates what can happen when an inappropriate target stent cell is randomly selected and then expanded by a high pressure balloon. As illustrated in Figure 19D, which is a downward-facing view of the lateral branching vessel 5 in cross-section in a stent of the prior art 68, the doctor chooses alately stent cell 69 which is a sub-optimal cell for expand with the balloon portion of a catheter. As illustrated in Figure 19E, after balloon expansion in the sub-optimal cell 69, entry to the cell with a catheter may be impossible or if achieved, balloon expansion may be incomplete. The opening created will be inadequate and a major distortion may occur in the adjacent stent columns. Consequences may include sub-acute thrombosis or restenosis. With the present invention as illustrated in Figures 19A-19C, the objective stent cell 62 is the optimal cell for expansion, and is pre-selected with a wire in place before deployment of the stent (that same wire remaining in place). for subsequent access) and is oriented optimally with respect to the lateral branch ostium before deployment. The resulting expansion as illustrated in Figure 19F, guarantees an optimal opening where the stent columns have expanded to provide a blood flow path from the main vessel to the lateral branch vessel. In another alternative embodiment for positioning a stent of a bifurcation as illustrated in Figures 20A-20C, the main vessel catheter 70 includes the expandable member 71 near its distal end, while the proximal end of the catheter (not shown) is similar. to those previously described and may already be of the fast exchange or over-the-wire types. The catheter 70 includes the guide wire lumen 72 for slidably receiving the tracking guide wire 73, the lumen 72 extends at least partially through the catheter in the rapid exchange configuration and all the way through the catheter in the over-the-wire configuration. The catheter also includes a guidewire lumen 74 that is associated with the outer catheter surface and extends over and connects at least to a portion of the expandable member 71. As illustrated in Figure 20A, the guide wire lumen 74 extends over the expandable member and ends just in the taper away from the expandable member. As illustrated in Figures 20B and 20C, the positioning guide wire lumen 74 can be formed of two sections, i.e. the distal section 75 connected to the distal tip of the catheter, in the proximal section 76 which extends over and connects to the expandable member and the catheter. As previously described, the guide wires 73, 77 are intended to be relatively rigid wires, so that they can maneuver the catheter more easily. In these embodiments, the stent 78 is mounted on the expandable member and on the positioning guide wire lumen 74. The positioning guide wire 77 is configured for sliding movement within the placement lumen 7. In the preferred method of placing a stent in a vessel just proximal to a bifurcation using a main vessel catheter 70, the tracking guide wire 73 is first placed within the main vessel as previously described. The catheter is then back-loaded on the guidewire, by inserting the wire into the guidewire lumen 72 and advancing the catheter into the patient's vascular system. At this point, the positioning guide wire 77 receives inside the guide wire lumen 74 and is transported inside the main vessel where it will be released and advanced. Once the catheter has reached the target area, the positioning guide wire 77 is advanced distally out of the positioning wire guide lumen (for Figure 20A) or withdraws slightly outward from the remote section 75 of the guide wire lumen of the guide wire. placement (for Figures 20B and 20C). Once released by the removal of the guide wire, the distal section 75 will spring outwardly, such that the positioning guidewire can search and advance within the lateral branching vessel. Once the positioning guide wire is advanced into the lateral branching vessel, the catheter is again advanced and the stent is implanted into the main vessel in a manner similar to that described for other embodiments. The catheter of Figures 20A-20C is designed to allow deployment of a stent very close but not "snow swept" from a bifurcation or lateral branch and is configured to treat bifurcations as illustrated in Figures 23A-25B. A commonly encountered situation where the catheter 70 will be employed is an LAD that has a disease just and close to separation. After careful observation in multiple views, the doctor should be convinced that the diagonal is dispensed with, but the lesion is very close and immediately adjacent to the diagonal separation as illustrated in Figure 20D. It is very difficult to place a standard stent in the LAD and make sure that the lesion is completely covered and the diagonal is not barred like snow or cage. Catheter 70, with one cable in the LAD (main vessel) and the other in the diagonal (vessel with lateral branch) will allow precise definition of the bifurcation and will avoid these problems. Square stent 78A, which has both ends transverse to the stent axis, can be deployed just proximal to the carina, in which case the distal stent end may require a little flare, or more likely, backward relax to where the positioning guidewire 77 rests against the proximal aspect of the ostium, visually defining the ostium in relation to the stent and allowing accurate deployment. Several alternate embodiments of the main vessel catheter 70 illustrated in Figure 20A are shown in Figures 20E, 21 and 22. The catheter device illustrated in Figure 20E is similar to that shown in Figure 20A, except that the ramp 57 is employed just distant from the distal end of the guidewire lumen 74, so that the guidewire 77 leaves the lumen, will move outwardly on the ramp 57, so that it advances more easily in the lateral branch arm. Also, as illustrated in Figures 21 and 22, which are similar to the catheter described and illustrated in Figures 20B and 20C, the guidewire 77 is intended to move outward, so that it can be advanced more easily into the vessel. lateral branch. In this aspect, the distal end of the guide wire lumen 74 is drifted outwardly as illustrated in Figure 22, so that as the guidewire 77 retracts from the lumen 75, the distal end of the guidewire lumen 74 will spring. outwardly assisting the guidewire 77 in this manner by moving radially outward to be placed in the side vessel. In order to implant a square main vessel stent 78A into a main vessel, where the disease is at or just proximal to the lateral branch vessel, the catheter 70 is well suited as illustrated in Figures 21 and 22. For example , the catheter 70 is advanced over the wire 77 until the catheter is placed just next to the lateral branching vessel. The guidewire 73, which up to this point is contained within the catheter 70, is advanced to the main arm, in such a way that it is distant from the lateral branching vessel. The guidewire 77 is then withdrawn proximally such that its distal end 77A is removed from the lumen 75, whereby the wire 77 and the distal end of the guidewire lumen 74 spring outwardly thereby assisting the placement of the guidewire 77 to the lateral branch vessel. The wire is then advanced to the lateral branching vessel and the catheter 77 is advanced such that the wire 77 rests on the proximal ostium of the lateral branching vessel, where the square stent 78A can then be expanded to cover the diseased portion, but not to extend or cover (cage) the opening of the lateral branch vessel. If the diseased portion of a main vessel is directly adjacent to the opening of the lateral branching vessel, as illustrated in Figure 20F, then the catheter system as illustrated in Figure 20A, can be incorporated only by implanting the angled stent. distant 78B. As illustrated in Figure 20F, stent 78B has an angle at its distal end that coincides with the opening to the lateral branching vessel, such that the diseased portion of the main vessel is covered at the distal end of the stent, with the angle of the stent at a proximal angle, such that the lateral branch arm is not covered or caged. Dive alternatives of the square stent 78A and the distant angle stent 78B are used to treat various conditions as illustrated in Figures 23A to 26B. In another alternate modality, as illustrated in.

Figures 27-33, a dual globe Y-shaped catheter structure is provided to place stents in a bifurcation. In this modality, the Y-shaped stent is implanted to cover the bifurcation. The catheter 90 includes first and second expandable members 91, 92 that are configured to receive side by side (Y-shape) for low profile delivery and to spring spaced to implant the stents. The locking ring 93 can be used to assist in keeping the expandable members attached until just before use, at which time it is removed. A guidewire lumen 95 extends at least through a portion of the catheter and slidably receives the guidewire 96. The guidewire lumen 98 extends at least through a portion of the catheter and slidably receives the guidewire 99. The guidewire lumen 98 includes the remote sections 98A and 98B. A Y-shaped endoprosthesis 100 is mounted on the first and second expandable members 91, 92. In the preferred method of placing stent in the bifurcated vessels as illustrated in Figures 29 to 33, the guidewire 99, previously located remote from the bifurcation in a branch (probably the most vulnerable to problems due to cable recrossing) is loaded from the back in the lumens 98A and 98B and the catheter 90 is advanced over the wire 99, so that the catheter is advanced distally more beyond the bifurcation. The guidewire 96 which has been contained in the lumen 95 at this point is advanced over the guide wire 99. The wire 99 is then removed until its distal end is withdrawn from the distal section 98A. As the guide wire 99 is withdrawn (proximally), the first and second expandable members 91, 92, which are normally spaced apart, are released and now spring apart. The wire whose lumen is more distant (lateral) to the bifurcation (in this case wire 96) then advances to the distant vessel and the other wire (in this case 99) is removed as shown in Figure 29B. The catheter is then removed proximally, such that the expandable members 91, 91A, haora are close to the bifurcation as illustrated in Figure 29C and the other guide wire (in this case the wire 99) is advanced in the another branch of the bifurcation, as illustrated in Figure 30. The catheter 90 is then advanced distally over both guide 96 and 99, as illustrated in Figure 31, until the endoprosthesis 100 is placed at the bifurcation of the intersection of vessels 105, 106. Due to the appropriate wire selection, rotation not greater than 90 ° will be required. The stent 100 is implanted by inflating the expandable members 91, 92 in a known manner. The expandable members then deflate, and the catheter is removed from the patient. The novel structure of the guide wires 96 and 99 and their respective lumens allow the transport of simple unit from a stent Y to the distant target site without problems of wrapping or wire winding and allows minimum requirements of rotation of the device (less than 90 ° ) for optimum deployment (allowing minimal deformity due to twisting). The guide wires can be left in place for further intervention such as finishing the stent with simultaneous high-pressure balloon inflation. In an alternate embodiment of the invention, a pair of stents having variant endoprosthesis cell density are implanted in a bifurcated vessel, as illustrated in Figures 34-36C. As shown in Figure 34, open stent 115 is provided, wherein opening 116 is placed on its outer surface. Stent 115 includes strong stent cell density 117 and light stent cell density 118 on its outer surface. As can be seen in Figure 35, two stents 115 have been combined such that the light density of one overlap to the light density of the other, causing the combined stents to produce a relatively uniform strong cell density and thus provide a relatively uniform strong cell density over the entire wall of the bifurcated vessel. As illustrated in Figures 36A to 36C, two endoprostheses 115 are implanted to place stents at the bifurcation. For reasons of clarity, as illustrated in Figure 36A, the open endoprosthesis 115 shown to be implanted in the main vessel such that the opening 116 extends and provides an opening to the lateral branching vessel, while strong cellular density of Stent 117 provides complete coverage of the distant main vessel by stent 115. As shown in Figure 36B, the open stent 115 is partially implanted in the lateral branching vessel and partially implants in the main vessel, in this case with the opening 116. which faces the continuous lumen of the main vessel. More specifically, the strong cell density portion of stent 117 is implanted in the lateral branching vessel, while the light cell density of stent 118 is implanted in the main vessel, with opening 116 providing an opening for blood flow to through the main vessel. It is intended that the stent 115 is implanted first as seen in Figure 36A and that a second stent 115 is subsequently implanted as illustrated in 36B or, by doctor's preference, this sequence can be reversed. Thus, in Figure 36C, both stents 115 have been implanted and both openings 116 provide openings in such a way that the blood flow is not deteriorated, both through the main vessel and the side branching vessel and they are not allowed to deteriorate stent columns.

The light cell density portions of endoprosthesis 118 of both endoprostheses overlap close to the bifurcation, thus ensuring that there is complete coverage of the bifurcated area by strong stent cell density. Both stents 115 are implanted with the catheter delivery system described herein, which includes a positioning wire to precisely locate and implant the stents in the bifurcated vessels. While the present invention has been illustrated and described in terms of an apparatus and method for placing stents in bifurcated vessels, it will be apparent to those skilled in the art that the stents and delivery systems present may be employed in the coronary arteries, veins and arteries. other arteries through the patient's vascular system. Certain dimensions and materials of manufacture have been described herein, and may be modified without departing from the spirit and scope of the invention.

Claims (32)

1. CLAIMS 1. A structure for stent delivery, for treating bifurcated vessels having a lateral branching vessel and a main vessel, characterized in that it comprises: a side branching catheter having a proximal end and a distal end; an expandable member near the distal end of the catheter; a guidewire lumen extending within at least a portion of the lateral branching catheter; a tracking guide wire having a distal end and a proximal end dimensioned for slidable movement within the guidewire lumen; a positioning guide wire lumen associated with the expandable member and adapted to receive for sliding engagement a positioning guide wire, the positioning guide wire having a distal end and a proximal end; the proximal ends of the tracking and positioning guide wires extend outward from the patient and can be manipulated, such that the distal end of the positioning guide wire is advanced into the main vessel distant to the lateral branching vessel, the distal end of the Guide wire tracking is advanced to the lateral branching vessel.
2. 2. The stent delivery structure according to claim 1, characterized in that the placement guidewire lumen is connected to an outer surface of the catheter and extends just proximal to the expandable member.
3. 3. The stent delivery structure according to claim 1 or claim 2, characterized in that the positioning wire guide lumen includes an angled section.
4. 4. The stent delivery structure according to any preceding claim, characterized in that the placement guidewire lumen includes a straight portion and an angled portion.
5. 5. The stent delivery structure according to claim 4, characterized in that the angled portion is at an angle relative to the straight portion that is taken from the angle range of 5 to 90 degrees.
6. The stent delivery structure according to any preceding claim, characterized in that a stent is mounted on the expandable member and the stent includes a proximal end angled to mount on the expandable member and to deploy in the lateral branch vessel.
7. 7. The stent delivery structure according to claim 1, characterized in that the lateral branching vessel stent is removably mounted in the expandable member and configured to be implanted in the lateral branch vessel.
8. The stent delivery structure according to claim 7, characterized in that it further comprises: a main vessel catheter having a distal end and a proximal end and having a tracking guide wire lumen extending through at least a portion; The guidewire lumen of the main vessel catheter is sized to receive the tracking guidewire for slidable movement; an expandable member, positioned near the distal end of the main vessel catheter to deliver and implant a main vessel stent adjacent to the lateral branching vessel stent; and a placement guidewire lumen connected to the outer surface of the main vessel catheter and extending over at least a portion of the expandable member surface dimensioned to slidably receive the positioning guidewire, the guidewire placement lumen proceeds on the positioning guide wire to orient the expandable member adjacent to, but not in, the side branch vessel.
9. 9. The stent delivery structure according to any preceding claim, characterized in that the positioning guidewire comprises an integrated endoprosthesis placement guide wire., to accurately position a stent, and wherein the lateral branching catheter is configured for rapid exchange so that the catheter can be engaged in active service from the integrated stent placement wire, leaving the guidewire in place for additional interventions.
10. 10. The stent delivery structure according to any preceding claim, characterized in that the expandable member includes a tapered near-angled balloon to deploy a stent at a near angle at the bifurcation site.
11. The stent delivery structure according to any preceding claim, characterized in that the lateral branching catheter is a rapid exchange catheter and includes a distal end opening in the tracking guidewire lumen and a lateral port opening in an outer surface of the lateral branching catheter, such that the tracking guide wire extends through the lateral port opening through the tracking guide wire lumen and away from the distal end opening, and the catheter further includes a slot extending from the side port opening just proximal to the expandable member such that the tracking guide wire can be put into active service through the slot during catheter exchanges.
12. The stent delivery structure according to any preceding claim, characterized in that the lateral branch catheter is an over-the-wire catheter and includes a distal end opening in the lumen of tracking guidewire and a proximal opening in the tracking guide wire lumen, such that the tracking guide wire extends from the proximal end opening through the tracking guide wire lumen and out of the distal end opening.
13. The stent delivery structure according to claim 8, characterized in that the main vessel catheter is a rapid exchange catheter and includes a distal end opening in the tracking guide wire lumen and a lateral port opening in an outer surface of the main vessel catheter, such that the tracking guide wire extends through the lateral port opening on the outer surface of the main vessel catheter, through the tracking guide wire lumen and out of the distal end opening of the main vessel catheter, the catheter further includes a slot extending from the lateral port opening, such that the tracking guide wire can be pulled through the slot during a catheter exchange.
14. The stent delivery structure according to claim 8, characterized in that the main vessel catheter is an over-the-wire catheter and includes a distal end opening in the tracking guidewire lumen and a proximal opening in the lumen. the tracking guide wire lumen, such that the tracking guide wire extends from outside the proximal end opening through the tracking guide wire lumen and away from the distal end opening.
15. A proximal stent graft for implanting a lateral branching vessel adjacent a bifurcation between the lateral branching vessel and a main vessel, characterized in that it comprises: a cylindrical member having a longitudinal axis, the cylindrical member having a distal end and a near end; the distal end forms a foreground section substantially transverse to the longitudinal axis; and the proximal end forms a second-plane section having an acute angle with respect to the longitudinal axis, the acute angle being chosen to coincide approximately with an angle formed by the intersection of the lateral branching vessel and the main vessel.
16. 16. The proximal angle stent according to claim 15, characterized in that the stent is expandable from a smaller first diameter for delivery in a body lumen to a second expanded diameter, by plastically deforming the stent beyond the elastic limits. of the material that forms the endoprosthesis.
17. 17. The proximal stent graft according to claim 15, characterized in that the stent is formed from a self-expanding material, such that the stent is expanded from a smaller first diameter to deliver through a stent. body lumen to a second diameter implanted in the body lumen.
18. 18. A main vessel stent for implantation into a main vessel adjacent to a bifurcation, characterized in that it comprises: a cylindrical member having a distal end and a proximal end and an outer wall surface therebetween; and an opening in the outer wall surface that is dimensioned and positioned on the outer wall surface, such that when the stent is implanted in the main vessel, the opening is aligned with a lateral branch vessel, thereby allowing Unrestricted blood flow from the main vessel through the lateral branching vessel.
19. 19. A main vessel stent according to claim 18, characterized in that the stent is expanded from a smaller first diameter to deliver a second expanded diameter in a body lumen, by plastically deforming the stent beyond the elastic limits of the stent. material that forms the endoprosthesis.
20. 20. A main vessel stent according to claim 18, characterized in that the stent is formed of a self-expanding material, such that the stent is expanded from a smaller first diameter, to deliver through a body lumen to a second diameter implanted in the body lumen.
21. 21. A method for implanting a near-angle stent in a lateral branching vessel adjacent to a bifurcation with a main vessel, the method steps being characterized in that it comprises: providing a lateral branching catheter structure having a guide wire lumen of follow-up extending through at least a portion, an expandable member associated with the catheter and having the proximal angle stent therein mounted, a guide wire lumen for stenting associated with the expandable member, a guidewire dimensioned tracking for slidable movement within the lumen of tracking guidewire and a guidewire for stent placement dimensioned for slidable movement within the guidewire lumen of stent placement; advancing a remote end of the tracking guidewire into the lateral branching vessel and distant from a target area; advancing the lateral branching catheter on the tracking guidewire and simultaneously advancing the stent placement lumen connected to the proximal outer surface of the expandable member with the stent positioning guidewire contained therein, advancing the lateral branching catheter in the main vessel to a position just next to the lateral branch vessel; advancing a distal end of the endoprosthesis placement guidewire through the main vessel and away from the lateral branching vessel; further advancing the lateral branching catheter, such that the positioning guidewire creates rotation of the lateral branching catheter as the expandable member and the proximal stent advance into the lateral branching vessel and the lateral branching catheter is anchored in the lateral branching vessel. the lateral branching ostium; aligning the near-angle stent through the target area and aligning a proximal end of the near-angle stent with the intersection of the lateral branching vessel and the main vessel, such that the near-angle stent does not extend to the main vessel; inflating the expandable member, thereby expanding and implanting the stent at close angle in the target area in the lateral branching vessel; deflating the expandable member and removing the patient's lateral branch catheter; and removing guide wires for stent placement and patient tracking.
22. 22. The method according to claim 21, characterized in that it further comprises implanting a main vessel stent in the main vessel, including after the step of removing the lateral branch catheter and while the guide wire for stent placement remains in place. position in the main vessel: providing a main vessel catheter having a proximal end and a distal end and a lumen of tracking guide wire extending through at least a portion, an expandable member adjacent to the distal end of the catheter The main vessel and having the main vessel stent therein mounted, a placement guidewire lumen connected to the outer surface of the main vessel catheter and extending over at least a portion of the surface of the expandable member; providing a stent placement guide wire contained in the stent placement guide wire lumen; inserting the proximal end of the stent placement guide wire into the tracking guidewire lumen; advancing the main vessel catheter and the expandable member on the stent placement guidewire in the main vessel, until the distal end of the main vessel catheter is approximately one centimeter proximal to the lateral branch vessel; advancing the endoprosthesis placement guidewire out of the guidewire stent lumen, such that the distal end of guidewire positioning wire advances into the lateral branching vessel; manipulating and applying torque to stent delivery guide wires, until the expandable member and main vessel stent are in the main vessel and adjacent to the lateral branch vessel; inflating the expandable member to bring the main vessel stent into contact with the main vessel, thereby implanting the stent in the main vessel; deflating the expandable member and removing the patient's main vessel catheter; and removing the stent placement guide wires from the patient.
23. 23. The method according to claim 22, characterized in that providing the lumen stage of guide wire for stent placement, further comprises providing the stent placement lumen having a straight portion and an angled portion.
24. 24. A method for stenting a bifurcated vessel, the method steps are characterized in that they comprise: providing a main vessel catheter for delivering and implanting a primary vessel stent having a plurality of endoprosthesis cells formed by stent columns; implanting the main vessel stent in a main vessel of the bifurcation, the main vessel stent extends an opening to a lateral branching vessel and accurately orientates the main vessel stent cells with respect to the lateral branched ostium, so such that subsequent access to the lateral branching vessel is not compromised; remove the main vessel catheter from the patient; provide a balloon catheter and advance the balloon catheter through the main vessel and through the target stent cell and into the opening of the lateral branch vessel; expanding a balloon portion of the balloon catheter, such that the stent columns of the objective stent cell adjacent to the opening of the lateral branching vessel deform, thereby forming an aperture in the main vessel stent that substantially corresponds to the opening of the main vessel to the lateral branching vessel; providing a lateral branching vessel catheter having a proximal angle stent mounted on a balloon portion and advancing the lateral branching vessel catheter to the main vessel and through the opening in the main vessel stent, such that the Lateral branching catheter is advanced into the lateral branching vessel; expanding the balloon portion of the lateral branching vessel catheter, such that the proximal stent in the balloon portion expands in contact with the lateral branching vessel, thereby covering all portions of the lateral branching vessel immediately adjacent to the main vessel; and removing the lateral branching vessel catheter from the patient's vascular system.
25. 25. A stent delivery structure for treating bifurcated vessels having a lateral ramification vessel and a main vessel; characterized in that it comprises: a main vessel catheter having a proximal end and a distal end, - an expandable member proximate the distal end of the catheter, - a tracking guidewire lumen extending within at least a portion of the catheter main vessel; a tracking guidewire having a distal end and a proximal end and dimensioned for sliding movement within the tracking guidewire lumen, a lumen of positioning guidewire having a portion connected to the expandable member and adapted to receive for slidable coupling a positioning guide wire, the positioning guide wire has a distal end and a proximal end, the proximal ends of the tracking and positioning guide wires extend out of the patient and can be manipulated such that the distal end of the positioning guide wire is advanced into the main vessel distant to the lateral branching vessel, and the distal end of the tracking guide wire is advanced to the lateral branching vessel.
26. 26. The stent delivery structure according to claim 25, characterized in that the placement of the positioning guide wire connected to the expandable member extends over the expandable member with a stent mounted on the lumen portion of the positioning guide wire.
27. 27. The stent delivery structure according to claim 25, characterized in that the ramp is associated with a distal end of the positioning guide wire lumen, to assist in moving the positioning guide wire radially outwardly.
28. 28. The stent delivery structure according to claim 25, characterized in that the portion of the positioning wire guide lumen extends substantially over the entire expandable member.
29. 29. The stent delivery structure according to claim 25, characterized in that the lumen portion of the positioning guide wire includes a distal end section connected to the distal end of the catheter.
30. 30. The stent delivery structure according to claim 25, characterized in that the lumen portion of the positioning guide wire is angled and extends over the expandable member.
31. 31. The stent delivery structure according to claim 25, characterized in that the main vessel stent is mounted on the expandable member and on the lumen portion of placement guidewire connected to the expandable member.
32. 32. The stent delivery structure according to claim 29, characterized in that the lumen portion of positioning guide wire connected to the expandable member includes a distal section directed outwardly to spring away from the expandable member.