US20050209673A1 - Bifurcation stent delivery devices - Google Patents

Abstract

A stent delivery system for treating bifurcations is provided. The system has a low profile and provides substantially predictable translational and rotational positioning. In one embodiment, the system includes a fixed wire balloon catheter and a partially attached side branch lumen, wherein the side branch lumen is attached to the catheter at a crotch point. The location of the crotch point is predetermined so as to provide substantially predictable positioning. Several embodiments of the system are described for various types of bifurcations and vessels.

Description

• This application claims the benefit of U.S. Provisional Application No. 60/549,554, filed on Mar. 4, 2004, incorporated herein by reference in its entirety.
FIELD AND BACKGROUND OF THE INVENTION
• The present invention relates to stent delivery devices and methods and, more particularly, to stent delivery devices for positioning at a bifurcation, the devices having low profiles and predictable positioning capabilities, both rotationally and translationally.
• Several problems are associated with known prior art bifurcation stent delivery devices. First, they generally have large outer diameters, particularly since the known designs usually include two guidewire lumens—one for a main guidewire and one for a side branch guidewire. The relatively large profiles of currently known systems cause difficulties in maneuverability and access to the site. Furthermore, the presence of two guidewires often results in wire entanglement, making the procedure difficult to perform without multiple insertions and retractions. Another problem which persists in these devices is inaccurate positioning within the vessel. This problem has been addressed with the use of radiopaque markers placed in strategic locations. However, visualization is done in the two-dimensional plane, while the actual procedure takes place within the three-dimensional realm. As such, inaccurate deployment is commonplace, often resulting in either stent jailing or insufficient coverage.
• An example of a prior art bifurcation stent delivery system is disclosed in U.S. Pat. No. 6,048,361 to Von Oepen. The system includes a stent with an increased radial opening and a balloon catheter on which the stent is mounted, the balloon catheter having a hollow chamber for passage of a guiding wire so that it exits in a center of the increased opening. The system disclosed therein includes two passageways for guidewires, necessitating a relatively large outer diameter. Furthermore, the presence of two wires can lead to problems of wire entanglement.
• Other examples of prior art bifurcation stent delivery systems and methods are disclosed in U.S. Publication No. 2003/0028233 to Vardi et al. and U.S. Publication No. 2001/0049548 to Vardi et al. These include a balloon catheter having a main guidewire lumen and a flexible side sheath having a side branch lumen. The method disclosed aims to reduce wire entanglement by first inserting one of the guidewires, then advancing the system, and finally advancing the second guidewire. Alternatively, one of the guidewires is housed within the system and only released once the system is in place. However, problems of wire entanglement may also occur upon removal of the system. Furthermore, the system disclosed therein is prone to overshooting of the bifurcation, resulting in sub-optimal placement. Finally, the dual lumen configuration results in a relatively large profile for the overall system.
• Other similar examples of prior art bifurcation stent delivery systems are disclosed in U.S. Pat. No. 5,749,825 to Fischell et al. and U.S. Pat. No. 6,682,556 to Ischinger. The systems disclosed therein include balloon catheters with side branch tubes, and require two guidewires: one for the main vessel and one for the branch vessel. Similar to the aforementioned prior art, large profile, wire entanglement, and inaccurate positioning are potential problems.
• A prior art device which aims to provide improved rotational orientation while avoiding wire entanglement is disclosed in U.S. Publication No. 2003/0055483 to Gumm. Gumm discloses a catheter assembly having a rotatably mounted balloon, and further including a side branch hollow member attached to the catheter balloon. A noted feature of the device is the use of rotating members sealed to opposite ends of the balloon. Thus, the side branch hollow member, the balloon and the rotating members act as a unit which rotates freely relative to the main hypotube. This particular feature is considered an integral part of the design, providing improved orientation of the stent relative to the side branch at the bifurcation. However, this feature also results in an increased overall diameter of the system. Furthermore, it does not provide a way to accurately position the stent in the translational plane.
• Attempts have been made to reduce the profile of a single stent delivery device by using a fixed wire balloon catheter, such as is disclosed in U.S. Publication No. 2002/0147491 to Khan et al. The device disclosed therein includes either a short section of guidewire fixedly attached to the distal end of a balloon, or a core wire that extends within the system. This design reduces the profile of the system as compared to prior art devices by eliminating the inner guidewire lumen. However, the system disclosed therein does not teach or suggest the possibility of bifurcation stenting, nor does it provide rapid exchange capabilities.
• There is thus a widely recognized need for, and it would be highly advantageous to have, a bifurcation stent delivery system devoid of the above limitations.
SUMMARY OF THE INVENTION
• According the present invention there is provided a stent delivery system. The system includes a main elongated element having a proximal end, a distal end and a body connecting the proximal and distal ends, the main elongated element being for advancement within a main vessel, an auxiliary elongated element having a proximal and distal end, the auxiliary elongated element being for advancement within an auxiliary vessel. The auxiliary elongated element is at least partially attached to the main elongated element. The system also includes a crotch point, wherein at the crotch point, the body of the main elongated element is attached to the auxiliary elongated element, and wherein a location of the crotch point is configured to stop advancement of the system upon reaching a bifurcation.
• According to a further aspect of the present invention, there is provided a stent delivery device, including a catheter having a distal end and a proximal end, a balloon positioned on the catheter, the balloon having a distal end and a proximal end, wherein the balloon is immovable with respect to the catheter, a wire attached to the distal end of the balloon, and a side element having a distal end and a proximal end, the side element at least partially attached to the balloon.
• According to a further aspect of the present invention, there is provided a stent delivery system, including a catheter having a distal end and a proximal end, a balloon positioned on the catheter, the balloon having a distal end and a proximal end, a wire attached to the distal end of the balloon, a side element having a distal end and a proximal end, the side element at least partially attached to the balloon, and a crotch point, wherein at the crotch point, the side element and the balloon are attached, and wherein a location of the crotch point is configured to stop advancement of the system upon reaching a bifurcation.
• According to yet a further aspect of the present invention, there is provided a stent delivery system including a catheter having a distal end and a proximal end, a balloon positioned on the distal end of the catheter, the balloon having a distal end and a proximal end, and wherein the balloon is immovable with respect to the catheter, a stent positioned on the balloon, the stent having a side opening, wherein the side opening has a proximal end and a distal end, and a side branch lumen having a distal end and a proximal end, wherein the proximal end is attached to a proximal end of the balloon, and wherein the distal end is configured to exit through the side opening of the stent.
• According to yet a further aspect of the present invention, there is provided a stent delivery system including a catheter having a distal end and a proximal end, a stent positioned on the catheter, the stent having a distal end and a proximal end, an auxiliary elongated element having a distal end and a proximal end, the auxiliary elongated element positioned outside of the stent, and a crotch point located at the proximal end of the stent whereby the auxiliary elongated element is attached to the catheter at the crotch point.
• According to yet a further aspect of the present invention, there is provided a stent delivery system, including a catheter having a distal end and a proximal end, a distal balloon positioned on the distal end of the catheter, the distal balloon having a distal end and a proximal end, a proximal balloon positioned on the catheter proximal to the distal balloon, a stent positioned on the proximal balloon, the stent having a distal end and a proximal end, an auxiliary elongated element having a distal end and a proximal end, the auxiliary elongated element positioned inside of the stent and exiting at the distal end of the stent, and a crotch point located at the distal end of the stent wherein the auxiliary elongated element is attached to the balloon at the crotch point.
• According to a further aspect of the present invention, there is provided a catheter system including a catheter having a distal end, a proximal end and a body connecting the distal and proximal ends, a side branch lumen having a distal end, a proximal end and a body connecting the distal and proximal ends, wherein a first portion of the side branch lumen is positioned inside the body of said catheter, and a second portion of the side branch lumen is positioned outside the body of the catheter, and an exit point located on the body of said catheter wherein the first portion is proximal to the exit point and the second portion is distal to the exit point.
• According to yet a further aspect of the present invention, there is provided a method for treating a bifurcation, including introducing a side branch guidewire into a side branch vessel, providing a stent delivery system including a main elongated element, a side branch element, and a crotch point, wherein at the crotch point, the main and side branch elements are attached, and wherein a location of the crotch point is configured to stop advancement of the system when it reaches a bifurcation, and a stent positioned on the main elongated element, inserting a proximal end of the side branch guidewire into the distal end of the side branch lumen, advancing the stent delivery system over the side branch guidewire until a location at which the advancing automatically stops due to the crotch point reaching said bifurcation, and deploying the stent.
• According to yet a further aspect of the present invention, there is provided a method for treating a bifurcation, including providing a stent delivery system, wherein the system includes a catheter having a balloon at a distal end thereof, a fixed wire at a distal end of the balloon, and a side branch lumen at least partially attached to the catheter, wherein a point of attachment defines a stopping point, and advancing the stent delivery system through a main vessel until a location at which the advancing automatically stops due to the crotch point reaching the bifurcation.
• According to further features in preferred embodiments of the invention described below, the main elongated element is a catheter and the auxiliary elongated element is a side branch lumen. In a preferred embodiment, the catheter includes a balloon. The catheter may be a fixed wire balloon catheter, an over-the-wire catheter or a rapid exchange catheter. In one embodiment, the main elongated element is a catheter and the auxiliary elongated element is a positioning system. The positioning system includes at least one stopper, which may be a spring wire, for example, and an attachment mechanism, wherein in one embodiment, the attachment mechanism is a polymer jacket, and wherein the polymer jacket is configured to hold a proximal portion of the spring wire in place, and wherein a distal end of the polymer jacket defines a crotch point.
• In one embodiment, the system includes a stent with a side opening positioned on the main elongated element, and the crotch point is located at a distal portion of the side opening of the stent. In another embodiment, the system includes a stent having a proximal end and a distal end, the stent positioned on the main elongated element, and wherein the crotch point is located at the proximal end of said stent. In yet another embodiment, the system includes a proximal stent having a proximal end and a distal end and a distal stent having a proximal end and a distal end, the proximal stent positioned on the main elongated element and the distal stent positioned distal to the proximal stent on the main elongated element. In this embodiment, the crotch point may be located at the distal end of the proximal stent, and the two stents may be deployed separately. In one embodiment, proximal to the crotch point, the bodies of the main and auxiliary elongated elements are attached. In a preferred embodiment, an outer diameter of the system is less than 1 mm. In an exemplary preferred embodiment, the outer diameter of the system is approximately 0.5 mm.
• According to still further features in the described preferred embodiments, the stent delivery device includes a feature wherein the proximal end of the side branch lumen is positioned within the catheter, and wherein the distal end of the side branch lumen which is detached from the balloon is positioned outside of the catheter. According to still further features, the stent delivery system includes a distal connecting element at the distal end of the balloon. In one embodiment, the distal connecting element lies on a same side of the catheter as the side branch lumen, and is configured for receiving a side branch guidewire which is positionable through both the side branch lumen and the distal connecting element. In another embodiment, the distal connecting element lies on an opposite side of the catheter as the side branch lumen, and is configured for receiving a main guidewire which is positionable through the distal connecting element and outside of the stent.
• The present invention successfully addresses the shortcomings of the presently known configurations by providing a stent delivery system with a low profile and substantially predictable translational and rotational positioning.
• Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
• The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
• In the drawings:
• FIG. 1 is an illustration of a first type of vessel bifurcation with plaque buildup;
• FIG. 2 is an illustration of a prior art bifurcation stent delivery system;
• FIG. 3 is an illustration of a bifurcation stent delivery system in accordance with a preferred embodiment of the present invention;
• FIGS. 4a-dare illustrations of the system ofFIG. 3 shown without a stent;
• FIG. 5 is an illustration of the system ofFIG. 3 in position at a bifurcation;
• FIG. 6 is an illustration of a the system ofFIG. 3, shown without a stent, and further including a distal connecting element;
• FIG. 7 is an illustration of a bifurcation stent delivery system, shown without a stent, in accordance with another embodiment of the present invention;
• FIG. 8 is an illustration of a bifurcation stent delivery system, shown without a stent, in accordance with yet another embodiment of the present invention;
• FIGS. 9aand9bare illustrations of a bifurcation stent delivery system in accordance with another embodiment of the present invention;
• FIG. 10 is an illustration of a second type of vessel bifurcation with plaque buildup;
• FIG. 11a-care illustrations of a system for treating a bifurcation such as the one depicted inFIG. 10;
• FIG. 12 is an illustration of the system ofFIG. 11ain position at a bifurcation;
• FIG. 13 is an illustration of a third type of vessel bifurcation with plaque buildup;
• FIGS. 14aandbare illustrations of a system for treating a bifurcation such as the one depicted inFIG. 13;
• FIGS. 15aandbare illustrations of the system ofFIG. 14, further including a holder;
• FIGS. 16aandbare illustrations of the system ofFIG. 14, further including a holder, in an alternative embodiment;
• FIG. 17 is an illustration of the system ofFIG. 14 being introduced into a guiding catheter;
• FIGS. 18a-care illustrations of the system ofFIG. 14 during positioning and deployment;
• FIG. 19 is an illustration of a fourth type of vessel bifurcation with plaque buildup;
• FIG. 20 is an illustration of a system, shown without a stent, for treating a bifurcation such as the one depicted inFIG. 19;
• FIG. 21 is an illustration of the system depicted inFIG. 20, further including stents thereon;
• FIGS. 22a-dare illustrations of a method of deploying the system ofFIG. 20; and
• FIG. 23 is an illustration of a tapered balloon system with a side branch lumen, in accordance with another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
• The present invention is of a stent delivery system and method for delivery of a stent to a bifurcation area. Specifically, the present invention can be used to position a stent at a bifurcation with rotational and translational alignment. In addition to providing substantially predictable alignment, the devices and systems of the present invention have small outer diameters as compared with prior art bifurcation stent delivery systems, and reduce the possibility of wire entanglement.
• The principles and operation of a stent delivery system according to the present invention may be better understood with reference to the drawings and accompanying descriptions.
• Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
• Reference is now made toFIG. 1, which is an illustration of vessel bifurcation with plaque buildup. Amain vessel1 and abranch vessel2 are connected at abifurcation point3. A buildup ofplaque4 may be found anywhere within the vessels, but if there is plaque buildup located at or close tobifurcation point3, as shown inFIG. 1, the location presents a specific challenge with regard to accurate stent placement. Stents placed at bifurcations are typically deployed either slightly proximal or slightly distal to the bifurcation point, which can lead to stent jailing and/or insufficient coverage.
• Reference is now made toFIG. 2, which is an illustration of a prior art bifurcationstent delivery system5.System5 includes acatheter6 having astent7 with adedicated side hole8. Amain guidewire9 is positioned inmain vessel1 and passed through a main guidewire lumen incatheter6. A side branch guidewire11 is positioned within a second guidewire lumen, throughside hole8, and intobranch vessel2. As shown inFIG. 1, there is a tendency forsystem5 to overshootbifurcation point3 during placement. Additionally, prior art bifurcation stent systems are generally large in diameter due to the presence of two guidewire lumens—one formain guidewire9 and one for branch guidewire11. Furthermore, the two wires often become entangled with one another, causing a failure in delivery and/or removal of the system.
• The present invention seeks to address the limitations of prior art systems, by providing substantially predictable positioning and alignment, both translationally and rotationally within the vessel, while retaining a small profile and eliminating wire crossing so as to provide ease of delivery. Several different embodiments of the invention provide solutions for different types of bifurcations, as will be described in further detail hereinbelow.
• Bifurcation Type I:
• In a first embodiment, astent delivery system10 is designed to be delivered at a bifurcation, such as the one illustrated inFIG. 1, having amain vessel1 and abranch vessel2, wherein theplaque4 is located within the main vessel in the vicinity ofbifurcation point3.
• Reference is now made toFIG. 3 andFIGS. 4a-d, which are illustrations of a bifurcationstent delivery system10, shown with and without a stent respectively.System10 includes a main elongated element16, and an auxiliary elongated element34 aligned with main elongated element16. In a preferred embodiment, auxiliary elongated element34 is positioned within main elongated element16 proximal to anexit point37 and alongside main elongated element16 distal to exitpoint37, as depicted inFIG. 3. In an alternative embodiment, auxiliary elongated element34 is positioned alongside main elongated element16, as will be described hereinbelow with reference toFIG. 8.
• In a preferred embodiment, main elongated element16 is acatheter18 having adistal end20 and aproximal end22. Aballoon24 is positioned ondistal end20 ofcatheter18.Catheter18 includes ahypotube25 running along the length of the catheter, and an inflation lumen withinhypotube25 in communication withballoon24. The inflation lumen is designed for introducing a fluid, preferably a liquid, intoballoon24 for inflation ofballoon24 at the appropriate location. A port for inflation is positioned atproximal end22, in a configuration which is well known in the art.Catheter18 shown inFIGS. 3 and 4a-dmay be any commercially available balloon catheter. Optionally, a torquer device may be introduced toproximal end22 for improving torquability. Such torquer devices are well known in the art.
• In an exemplary preferred embodiment,balloon24 is a fixed wire balloon and as such, includes a fixedwire26 attached to a distal end ofballoon24 at abonding area28. A fixedwire skeleton30 runs along the interior ofballoon24 to provide rigidity. Fixed wire balloons are known in the art, and may be obtained from, for example, Boston Scientific Scimed [ACE balloon, catalog number 02071-04].
• System10 includes astent12 positioned on main elongated element16, thestent12 having aside opening14. In one embodiment,side opening14 is a dedicated side opening, and in another embodiment,side opening14 is any opening within the structure ofstent12. In a preferred embodiment, auxiliary elongated element34 is aside branch lumen36 for placement of a side branch guidewire therethrough.Side branch lumen36 has adistal end40 and aproximal end42 and is attached tocatheter18 atproximal end42 and unattached tocatheter18 atdistal end40. The point at which the detachment between main and auxiliary elongated elements (catheter18 andside branch lumen36 in the present embodiment) occurs is defined as acrotch point44. In an alternative embodiment,side branch lumen36 is unattached tocatheter18 both proximal and distal tocrotch point44, and is attached tocatheter18 only atcrotch point44.Balloon24 further includesfluorescent markers32 which can be visualized during a procedure under fluorescence. In a preferred embodiment,markers32 are located at both ends ofstent12 and at a location which is aligned withcrotch point44. In alternative embodiments, any configuration on markers which would enable viewing of key locations ofsystem10 can be used.
• Crotch point44 is preferably located close todistal end40 ofside branch lumen36. It should be noted that the depiction of crotch points in the figures is for indication purposes only, and that crotch points may not include an actual connecting element as shown. The length of the unattached portion is preferably less than 1 mm. In an exemplary preferred embodiment, the length of the unattached portion is approximately 0 mm, i.e. thedistal end40 ofside branch lumen36 is atcrotch point44. It should be noted that in this embodiment, a guidewire withinside branch lumen36 is configured to enter a side branch vessel, as will be described hereinbelow with reference toFIG. 5. This guidewire positioned withinside branch lumen36, and main elongated element16form crotch point44. In an alternative embodiment, the length of the unattached portion is approximately 1-5 mm, or more preferably approximately 2 mm.Side branch lumen36 may be as long or as short as necessary, both proximally and distally. In a preferred embodiment, the portion ofside branch lumen36 which is proximal tocrotch point44 is approximately 10-30 mm, and in an exemplary preferred embodiment is approximately 25 mm. By extendingside branch lumen36 proximally along at least a portion ofhypotube25, the rigidity ofsystem10 is increased, thus providing ease of rotation within the vessel. In an alternative embodiment, the portion ofside branch lumen36 which is proximal tocrotch point44 is approximately 5-15 mm.
• A cross-sectional view along lines A-A, B-B and C-C are depicted inFIGS. 4b,4cand4d, respectively. As shown inFIG. 4b, at a proximal location,side branch lumen36 is located withincatheter18.Fixed wire skeleton30 is in the center, andside branch lumen36 is between fixedwire skeleton30 and the edge ofcatheter18. As shown inFIG. 4c, atexit point37,side branch lumen36 is bonded tocatheter18. Distal to exitpoint37,side branch lumen36 is outside and adjacent to balloon24, as shown inFIG. 4d.
• Reference is now made toFIG. 5, which is an illustration ofsystem10 positioned at a bifurcation.Crotch point44 is a key element in positioning ofstent12 within the vessel. Withcatheter18 inmain vessel1 and a side branch guidewire38 withinside branch lumen36 positioned inbranch vessel2,system10 cannot be advanced beyond the point at whichcrotch point44 reaches bifurcationpoint3. Thus,system10 is substantially predictably aligned, and overshooting is prevented.
• In an exemplary preferred embodiment, a method for introducingsystem10 is as follows. First, a side branch guidewire38 is positioned withinbranch vessel2. A proximal end of side branch guidewire38 is introduced intodistal end40 ofside branch lumen36. With side branch guidewire38 positioned withinside branch lumen36,system10 is advanced throughmain vessel1.Fixed wire26 provides guidance as advancement occurs. In an alternative embodiment, side branch guidewire38 is not introduced initially, andsystem10 is advanced using only fixedwire26 as a guide. In either case,system10 is free to rotate without risk of entanglement. Whencrotch point44 reaches bifurcationpoint3, advancement ofsystem10 automatically stops. At this point,system10 is in place, with side branch guidewire38 inbranch vessel2, andstent12 in a correct position both translationally and rotationally.Balloon24 is then inflated, thus deployingstent12 within the vessel. Thus, the exact location ofcrotch point44 predetermines accuracy of positioning. After deployment,system10 is removed frombranch vessel2. A particular feature of the invention as described is the ability to provide rapid exchange of catheters via branch guidewire38, if necessary.
• It should be apparent that the specific features of the present invention allow for accurate positioning in both the rotational and the translational direction, while providing a small outer diameter overall. In a preferred embodiment, the overall outer diameter is 0.5-1.5 mm. Specifically, by attachingside branch lumen36 directly toballoon24, for example, and predetermining the location ofcrotch point44,side branch lumen36 acts as a guide in the translational plane. The use of a fixed wire provides torquability and ease of rotation, particularly since there is only one guidewire present (i.e. the branch guidewire). The configuration ofside branch lumen36 wherein adistal end40 thereof is unattached to main elongated element16, or wherein a guidewire placed therethrough is unattached to main elongated element16 allows for initial entry ofside branch lumen36 intobranch vessel2. These aspects allow for substantially predictable rotation of the system and substantially predictable rotational positioning, without wire entanglement.
• Reference is now made toFIG. 6, which is an illustration ofsystem10 in accordance with an alternative embodiment of the present invention. As shown inFIG. 6,system10 further includes a distal connectingelement46, attached to a distal end ofballoon24. In a preferred embodiment, distal connectingelement46 is attached atbonding area28 ofballoon24. In an alternative embodiment, distal connectingelement46 is attached at any other location onballoon24 which is distal toside branch lumen36. Distal connectingelement46 is configured to hold side branch guidewire38 in place untilsystem10 is in the vicinity ofbifurcation3. This prevents side branch guidewire38 from moving around within the vessel during delivery ofsystem10, possibly causing damage. Oncesystem10 is within the general vicinity ofbifurcation3, side branch guidewire38 is pulled proximally and released from distal connectingelement46, after which it is advanced intobranch vessel2.System10 is then advanced untilcrotch point44 prevents further advancement,balloon24 is inflated, andstent12 is deployed.
• Reference is now made toFIG. 7, which is an illustration ofsystem10 in accordance with yet another embodiment of the present invention. As shown inFIG. 7,side branch lumen36 is located internally withinballoon24, and includes anexit point37 at a location alongballoon24. The location ofexit point37 with respect tostent12 defines a crotch point, which coincides with the location ofcrotch point44 described in the earlier embodiments, and is functionally equivalent thereto. In one embodiment,side branch lumen36 ends atcrotch point44. In an alternative embodiment,side branch lumen36 extends distally beyondcrotch point44.
• Reference is now made toFIG. 8, which is an illustration ofsystem10 in accordance with yet another embodiment of the present invention.Side branch lumen36 is located external and adjacent to main elongated element16.Crotch point44 is located distal at an attachment point betweenside branch lumen36 andballoon24. The portion ofside branch lumen36 which lies betweenexit point37 andcrotch point44 may be attached or unattached to balloon24.
• Reference is now made toFIGS. 9aand9b, which are illustrations ofsystem10 in accordance with yet another embodiment of the present invention, shown with a stent thereon. In this depiction,side hole14 is not a dedicated side hole, but rather is any opening within the body ofstent12. It should be noted that this type of side hole may be found on any of the embodiments described herein.System10 includes amain guidewire39 rather than a fixed wire at the distal end ofballoon24. Amain guidewire lumen50 is located atbonding area28 ofballoon24. In a preferred embodiment,main guidewire lumen50 is relatively short, i.e. 1-5 mm. In alternative embodiments,main guidewire lumen50 extends proximally along a side ofballoon24. In a preferred embodiment,main guidewire39 is positioned outside ofstent12 so as to avoid wire crossing betweenmain guidewire39 and side branch guidewire38, as shown inFIG. 9a. In an alternative embodiment,main guidewire39 is positioned withinstent12, as shown inFIG. 9b. In a preferred embodiment,main guidewire lumen50 is positioned on an opposite side fromside branch lumen36, as depicted.
• In an alternative embodiment (not shown) of the present invention,system10 includes a main guidewire lumen in place of a fixed wire, and further includes acrotch point44 in accordance with the different embodiments described above.
• Bifurcation Type II:
• In a second embodiment, astent delivery system110 is designed to be delivered at a bifurcation as illustrated inFIG. 10, having amain vessel1 and abranch vessel2 at an angle with respect tomain vessel1, and whereinplaque4 is located inmain vessel1 at an area of abifurcation3. One example of such a location is the coronary artery, where blockage of, for example, the left anterior descending (LAD) artery is to be avoided while providing coverage to the plaque within the coronary artery. Other examples include renal arteries, the left main coronary artery, vein grafts, and others.
• Reference is now made toFIGS. 11a-c, which are illustrations of different embodiments of asystem110 for delivery of a stent at a bifurcation such as the one depicted inFIG. 10.System110 may be designed with a fixed wire, as shown inFIG. 11a, as on over-the-wire system, as shown inFIG. 11b, or as a rapid exchange system, as shown inFIG. 11c.
• Reference is now made toFIG. 11a, which is an illustration ofsystem110 designed as a single wire system.System110 includes a mainelongated element116 and an auxiliaryelongated element134. In a preferred embodiment, mainelongated element116 is acatheter118. In a preferred embodiment,catheter118 includes aballoon124 with a fixedwire126 at a distal end thereof. Astent112 is positioned onballoon124. In a preferred embodiment, auxiliaryelongated element134 is aside branch lumen136, and is attached tocatheter118 at acrotch point144.Side branch lumen136 has aproximal end142 and adistal end140. In a preferred embodiment,side branch lumen136 is positioned withincatheter118 proximally, exits at anexit point137, and is attached to mainelongated element116 atcrotch point144. The portion ofside branch lumen136 betweenexit point137 andcrotch point144 may be attached or unattached. In a preferred embodiment, a distal end ofside branch lumen136 is atcrotch point144, and a guidewire placed therethrough extends distally to provide a stopping point. In an alternative embodiment, the distal end of side branch lumen is located 1-5 mm distal tocrotch point144, and is unattached to thecatheter118 in this location.
• In an alternative embodiment,side branch lumen136 is located external to and positioned alongsidecatheter118 proximal tocrotch point144, and is unattached toelongated element116 distal tocrotch point144. In an alternative embodiment,side branch lumen136 is unattached tocatheter118 both proximal to and distal tocrotch point144.Crotch point144 is located at or near a proximal end ofstent112. In a preferred embodiment,crotch point144 is just proximal to the proximal end ofstent112.
• Reference is now made toFIG. 11b, which is an illustration ofsystem110′ designed as an over-the-wire, double rail system.System110′ is similar tosystem110 shown inFIG. 11a, except that in place of a fixed wire on the distal end ofballoon124′, amain guidewire lumen125 is present and runs the length ofcatheter118′. A main guidewire is positioned throughmain guidewire lumen125 for entry intomain vessel1.System110′ may be introduced to the site via a main guidewire located inmain guidewire lumen125 or via a branch guidewire located inside branch lumen136′.
• Reference is now made toFIG. 11c, which is an illustration ofsystem110″, designed as a rapid exchange dual wire system.System110″ is similar to bothsystems110 and110′ depicted inFIGS. 11aand11c, except that in place of a fixed wire or a main guidewire lumen running the length ofcatheter118″, a shortmain guidewire lumen127 is present and runs proximally until anexit point129. These types of systems are well known in the art, and are known to provide ease of catheter exchange. In the present invention, the location ofcrotch point144 allows for more accurate placement within the vessel.
• Reference is now made toFIG. 12, which is a depiction ofsystem110 positioned atbifurcation3. A side branch guidewire138 is introduced intobranch vessel2.System110 is guided over side branch guidewire138 and either fixedwire126 or a main guidewire139, depending on the type of system, untilcrotch point144 ofside branch lumen136 is atbifurcation point3. In a preferred embodiment,distal end140 is atcrotch point144, and only guidewire138 entersbranch vessel2. In an alternative embodiment,side branch lumen136 extends and intoside branch vessel2. System1110 is slowly advanced untilcrotch point144 reaches bifurcationpoint3, after whichsystem110 automatically stops advancing.Balloon124 is then inflated, deployingstent112. After deployment,balloon124 is deflated, andsystem110 is removed.
• Bifurcation Type III:
• In a third embodiment, astent delivery system210 is designed to be delivered at a bifurcation such as the one illustrated inFIG. 13, having amain vessel1 and abranch vessel2 at an angle with respect tomain vessel1, and whereinplaque4 is located inbranch vessel2 at an area of abifurcation3. In an exemplary preferred embodiment,main vessel1 is an aorta.
• Reference is now made toFIGS. 14aand14b, which are views of asystem210 in accordance with an embodiment of the present invention.System210 includes a main elongated element216 and an auxiliary elongated element234. In a preferred embodiment, main elongated element216 is acatheter218 having aproximal end222 and adistal end220.Catheter218 has aballoon224 atdistal end220, with astent212 positioned thereon. In one embodiment,balloon224 includes amain guidewire lumen227. In an alternative embodiment,balloon224 is a fixed wire balloon, such as described with reference to the first and second embodiments, and shown at least inFIGS. 4aand11a. In a preferred embodiment,main guidewire lumen227 extends only partially in the proximal direction alongcatheter218 and includes anexit point229 for rapid exchange. In an alternative embodiment,system210 is an over-the-wire system andmain guidewire lumen227 extends proximally to the proximal end ofcatheter218. In a preferred embodiment, auxiliary elongated element234 is a positioning system236, which will be described in further detail hereinbelow.
• In a preferred embodiment, positioning system236 includes astopper element250 and anattachment mechanism252. In a preferred embodiment,stopper element250 is separate fromattachment mechanism252 and comprises, for example, spring wires, flexible polymers, or any other material which can be extended in a first configuration and which can be folded, sprung or otherwise positioned to act as a stopper in a second configuration. In an alternative embodiment,stopper element250 is part ofattachment mechanism252, but can also be extended in a first configuration and positioned to act as a stopper in a second configuration. In one preferred embodiment,stopper element250 is comprised of a shape memory metal such as, for example, Nitinol. In the embodiment described herein, spring wires are used asstopper element250, which are designed to lay substantially horizontal tocatheter218 in their unextended positions and to coil or spring into a stopper upon release.Attachment mechanism252 attaches the spring wires to main elongated element216 to form crotch points244. In a preferred embodiment,attachment mechanism252 is a jacket having aproximal end256 and adistal end254.Attachment mechanism252 at least partially encloses stopper element250 (shown as spring wires), such that a proximal portion ofstopper element250 enclosed byattachment mechanism252 is relatively straight, and a distal portion ofstopper element250 is unenclosed and able to move freely.Attachment mechanism252 can comprise any biocompatible material, and is preferably comprised of a polymer. In a preferred embodiment, crotch points244 are located at a proximal end ofballoon224.
• Reference is now made toFIG. 14b, which is a cross-sectional view ofsystem210 along the lines A-A, in accordance with one embodiment.Catheter218 hasmain guidewire lumen227 for introduction of a main guidewire239. Surroundingcatheter218 isstopper element250, which is held in place byattachment mechanism252.
• Reference is now made toFIGS. 15a-b, which are illustrations ofsystem210 partially enclosed within aholder254. The purpose ofholder254 is to temporarily holdstopper element250 in a substantially straight configuration until the area ofbifurcation point3 is reached. In a preferred embodiment,holder254 is a peel-away device. Whenholder254 is in place,stopper element250 is enclosed and lies approximately along the plane of main elongated element216. In the embodiment shown inFIGS. 15aandb,stopper elements250 are straightened in the distal direction, such that they run alongsidestent212. The area proximal to crotch points244 is shown in cross section inFIG. 15b, and includes amain guidewire lumen227 withincatheter218,stopper elements250 enclosed withinattachment mechanism252, andholder254 surroundingattachment mechanism252.
• Reference is now made toFIGS. 16a-b, which are illustrations ofsystem210 partially enclosed withinholder254, in accordance with another embodiment of the present invention. In the illustration shown inFIGS. 16aandb,stopper elements250 are bent in a proximal direction, withholder254 surroundingstopper elements250 and holding them in place. That is,stopper elements250 are folded overattachment mechanism252. The area proximal to crotch points244 is shown in cross section inFIG. 16b, and includes amain guidewire lumen227 withincatheter218,stopper elements250 enclosed both within and outside ofattachment mechanism252, andholder254 surroundingattachment mechanism252 andstopper elements250.
• Reference is now made toFIG. 17, which is a depiction ofsystem210 within a guidingcatheter260. Guidingcatheter260 includes aproximal end262, through whichsystem210 is introduced, and adistal end264, which is open to a vessel. Assystem210 is guided intoproximal end262 of guidingcatheter260,holder254 is removed, sincestopper element250 will remain in place within guidingcatheter260. In a preferred embodiment,holder254 is a peel-away system, wherein the outer walls may be peeled away and removed from the system whilesystem210 is being introduced into guidingcatheter260. This introduction is performed outside of the body. In an alternative embodiment,holder254 is a sheath, which can be pulled back assystem210 is being introduced into guidingcatheter260.Holder254 can be any device for holdingstopper element250 in place untilsystem210 is within guidingcatheter260.
• Reference is now made toFIGS. 18aand18b, which are depictions of a method for introducingsystem210 to a bifurcation in accordance with an embodiment of the present invention. Guidingcatheter260 withsystem210 positioned therein is introduced throughmain vessel1 untilbifurcation point3.Distal end264 of guidingcatheter260 is visualized using methods currently known in the art, such as, for example, fluorescent markers. Oncedistal end264 of guidingcatheter260 is at the entrance to branchvessel2,system210 is advanced throughdistal end264 of guidingcatheter260, as shown inFIG. 18a. Assystem210 is advanced,stopper elements250 are no longer held in place by guidingcatheter260, and will spring or coil into their second configuration, acting as stoppers, as shown inFIG. 18b.System210 is then advanced untilstopper elements250 preventsystem210 from further advancement, as shown inFIG. 18c. At this point,system210 is properly positioned, andstent212 is deployed.
• Bifurcation Type IV:
• In a fourth embodiment, astent delivery system310 is designed to be delivered at abifurcation3 as illustrated inFIG. 19, having a Y-configuration.Main vessel1 branches into two branch vessels: afirst branch vessel2 and asecond branch vessel2′, andplaque4 is located in main and or branch vessels at the area ofbifurcation point3.
• Reference is now made toFIG. 20, which is an illustration of astent delivery system310, in accordance with one embodiment of the present invention.System310 includes a main elongated element316 and an auxiliary elongated element334. In a preferred embodiment, main elongated element316 is a catheter318. Catheter318 has aproximal end322 and adistend nd320.Proximal end322 includes ahub321 having a Y-valve for dual inflation.Distal end320 has two balloons: aproximal balloon324 and adistal balloon325. Each of proximal anddistal balloons324 and325 is in fluid communication with its own inflation channel. Anouter inflation channel335 communicates withproximal balloon324 and aninner inflation channel327 communicates withdistal balloon325.Outer inflation channel335 is coaxial withinner inflation channel327. Alternatively,outer inflation channel335 andinner inflation channel327 are positioned side by side. In either case, balloons324 and325 may be inflated separately. In an alternative embodiment, outer inflation channel communicates withdistal balloon325 andinner inflation channel327 communicates withproximal balloon324. In a preferred embodiment,distal balloon325 has a fixedwire326 at a distal end thereof. In alternative embodiments,system310 includes a main guidewire lumen or a short external guidewire lumen such as distal connectingelement50 shown inFIG. 6.
• In a preferred embodiment, auxiliary elongated element334 is aside branch lumen336 having aproximal end342 and adistal end340. In a preferred embodiment,side branch lumen336 is located internally within catheter318, and exits therefrom at anexit point337. Distal to exitpoint337,side branch lumen336 is adjacent toproximal balloon324 and attached thereto at acrotch point344. In an alternative embodiment,side branch lumen336 lies alongsideproximal balloon324.
• Reference is now made toFIG. 21, which is an illustration ofsystem310 with stents. In a preferred embodiment, two stents are included, as shown. Aproximal stent312 is positioned onproximal balloon324, and adistal stent313 is positioned ondistal balloon325. Each stent may be separately deployed by inflating its corresponding balloon.Proximal stent312 is positioned such that distal end ofside branch lumen336 is approximately aligned with a distal end ofproximal stent312. The distal edges ofside branch lumen336 andstent312 form acrotch point344. In an alternative embodiment,side branch lumen336 extends distallypast crotch point344. All of the embodiments described earlier in the present application may further be applied here.
• In alternative embodiments,system310 includes one, two or no stents, depending on the application. For example,system310 may be used for predilatation, with a stent only onproximal balloon324. Alternatively, a tapered vessel may require two different stent sizes, wherein one stent of a particular size is positioned ondistal balloon325, while another stent of a different size is positioned onproximal balloon324.
• Reference is now made toFIGS. 22a-d, which are illustrations of a method of deployingsystem310 within a Y-bifurcation. First, a side branch guidewire338 is introduced into afirst branch vessel2. A proximal end of side branch guidewire338 is then placed through a distal end ofside branch lumen336.System310 is advanced over side branch guidewire38 throughmain vessel1 and intosecond branch vessel2′. Whencrotch point344 reachesbifurcation3,system310 will not be advanceable, andsystem310 will be in place, as shown inFIG. 22a. As shown inFIG. 22b,distal balloon325 is inflated viainner inflation channel327, deployingdistal stent313 in a branch vessel, just distal to bifurcationpoint3. After deployment ofdistal stent313,proximal balloon324 is inflated viaouter inflation channel335, deployingproximal stent312. An alternate method is depicted inFIG. 22c, whereinproximal stent312 is deployed first, and thendistal stent313 is deployed. In an alternative embodiment, both stents are deployed simultaneously. The final result with both stents deployed and in position is shown inFIG. 22d.
• Reference is now made toFIG. 23, which is an illustration of atapered balloon system410, in accordance with an alternative embodiment of the present invention. Similar to the earlier embodiments,tapered balloon system410 includes a main elongated portion and an auxiliaryelongated element434. In a preferred embodiment, auxiliaryelongated element434 is a side branch lumen. A balloon has a proximal outer diameter and a distal outer diameter which is different from the proximal outer diameter. In a preferred embodiment, the distal outer diameter is smaller than the proximal outer diameter, although the reverse may be provided as well. This type of balloon system may be useful for introduction of a tapered stent into a vessel, so as to avoid over-expansion of a stent within a distal portion of the vessel.
• Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. For example, a self-expandable stent may be used in place of a balloon expandable stent, in which case the catheter would not necessarily be a balloon catheter. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

Claims (88)

1. A stent delivery system, the system comprising:

a main elongated element for advancement within a main vessel, said main elongated element comprising:

a proximal end;

a distal end; and

a body connecting said proximal and distal ends;

an auxiliary elongated element for advancement within an auxiliary vessel, said auxiliary elongated element comprising:

a proximal end; and

a distal end,

said auxiliary elongated element partially attached to said main elongated element; and

a crotch point, wherein at said crotch point, said body of said main elongated element is attached to said auxiliary elongated element, and wherein a location of said crotch point is configured to stop advancement of said system upon reaching a bifurcation.

2. The stent delivery system ofclaim 1, wherein said main elongated element is a catheter and said auxiliary elongated element is a side branch lumen.

3. The stent delivery system ofclaim 2, wherein said catheter includes a balloon.

4. The stent delivery system ofclaim 3, wherein said catheter is selected from the group consisting of a fixed wire balloon catheter, an over-the-wire catheter and a rapid exchange catheter.

5. The stent delivery system ofclaim 1, wherein said main elongated element is a catheter and said auxiliary elongated element is a positioning system.

6. The stent delivery system ofclaim 5, wherein said positioning system comprises at least one stopper and an attachment mechanism.

7. The stent delivery system ofclaim 6, wherein said at least one stopper is a spring wire.

8. The stent delivery system ofclaim 6, wherein said attachment mechanism is a polymer jacket, and wherein said polymer jacket is configured to hold a proximal portion of said at least one stopper in place, and wherein a distal end of said polymer jacket defines said crotch point.

9. The stent delivery system ofclaim 1, further comprising a stent with a side opening positioned on said main elongated element.

10. The stent delivery system ofclaim 9, wherein said side opening is a dedicated side opening.

11. The stent delivery system ofclaim 8, wherein said crotch point is located at a distal portion of said side opening of said stent.

12. The stent delivery system ofclaim 1, further comprising a stent having a proximal end and a distal end, said stent positioned on said main elongated element, and wherein said crotch point is located at said proximal end of said stent.

13. The stent delivery system ofclaim 1, further comprising a proximal stent comprising a proximal end and a distal end and a distal stent comprising a proximal end and a distal end, said proximal stent positioned on said main elongated element and said distal stent positioned distal to said proximal stent on said main elongated element.

14. The stent delivery system ofclaim 12, wherein said crotch point is located at said distal end of said proximal stent.

15. The stent delivery system ofclaim 1, wherein proximal to said crotch point, said bodies of said main and auxiliary elongated elements are attached.

16. The stent delivery system ofclaim 3, wherein said balloon is a tapered balloon.

17. The stent delivery system ofclaim 1, wherein said proximal end of said auxiliary elongated element is positioned within said main elongated element, and further comprising an exit point, wherein distal to said exit point said auxiliary elongated element is external to said main elongated element.

18. The stent delivery system ofclaim 1 wherein a distal end of said auxiliary elongated element is located distal to said crotch point, and wherein said distal end of said auxiliary elongated element is unattached to said main elongated element.

19. A stent delivery device, the device comprising:

a catheter having a distal end and a proximal end;

a balloon positioned on said catheter, the balloon having a distal end and a proximal end, wherein said balloon is immovable with respect to said catheter;

a wire attached to said distal end of said balloon; and

a side element having a distal end and a proximal end, said side element at least partially attached to said balloon.

20. The stent delivery device ofclaim 19, further comprising a stent with a side hole, said stent positioned on said balloon, said side hole having a distal end and a proximal end, and wherein said proximal end of said side element is attached to said catheter and said distal end of said side element is positioned alongside said balloon, and wherein a crotch point is defined at a location wherein at said crotch point, said side element is attached to said balloon, and wherein said crotch point is located at said distal end of said side hole.

21. The stent delivery device ofclaim 20, wherein said side hole is a dedicated side hole.

22. The stent delivery device ofclaim 19, wherein said proximal end of said side branch lumen is positioned within said catheter.

23. The stent delivery device ofclaim 20, wherein said distal end of said side element is located distal to said crotch point, and wherein said distal end of said side element is unattached to said catheter.

24. The stent delivery device ofclaim 19, wherein said balloon is a tapered balloon.

25. The stent delivery device ofclaim 19, further comprising a stent positioned on said balloon, wherein said proximal end of said side element is attached to said catheter, and wherein a crotch point is defined at a location wherein at said crotch point, said side element is attached to said balloon, and wherein said crotch point is located at said proximal end of said balloon.

26. The stent delivery system ofclaim 25, wherein said distal end of said side element is located proximal to said crotch point, and wherein said distal end of said side element is unattached to said catheter.

27. The stent delivery system ofclaim 19, wherein said side element is a side branch lumen.

28. The stent delivery system ofclaim 19, wherein said side element is a stopper.

29. The stent delivery device ofclaim 19, wherein said balloon is a proximal balloon, and further comprising a distal balloon positioned on said catheter distal to said proximal balloon.

30. The stent delivery device ofclaim 29, wherein said distal balloon and said proximal balloon may be inflated separately.

31. The stent delivery device ofclaim 29, further comprising a distal stent positioned on said distal balloon, said distal stent having a proximal end and a distal end, and a proximal stent positioned on said proximal balloon, said proximal stent having a proximal end and a distal end.

32. The stent delivery device ofclaim 31, wherein said side element is at least partially attached to said proximal balloon.

33. The stent delivery device ofclaim 32, wherein a crotch point is defined at a location wherein at said crotch point, said side element is attached to said proximal balloon, and wherein said crotch point is located at a distal end of said proximal balloon.

34. The stent delivery device ofclaim 19, wherein an outer diameter of said system is less than 1 mm.

35. A stent delivery system, the system comprising:

a catheter having a distal end and a proximal end;

a balloon positioned on said catheter, the balloon having a distal end and a proximal end;

a wire attached to said distal end of said balloon;

a side element having a distal end and a proximal end, said side element at least partially attached to said balloon; and

a crotch point, wherein at said crotch point, said side element and said balloon are attached, and wherein a location of said crotch point is configured to stop advancement of said system upon reaching a bifurcation.

36. The stent delivery system ofclaim 35, wherein said balloon is a tapered balloon.

37. The stent delivery system ofclaim 35, wherein said catheter is selected from the group consisting of a fixed wire balloon catheter, an over-the-wire catheter and a rapid exchange catheter.

38. The stent delivery system ofclaim 35, wherein said side element is a positioning system.

39. The stent delivery system ofclaim 38, wherein said positioning system comprises at least one stopper and an attachment mechanism.

40. The stent delivery system ofclaim 39, wherein said at least one stopper is a spring wire.

41. The stent delivery system ofclaim 39, wherein said attachment mechanism is a polymer jacket, and wherein said polymer jacket is configured to hold a proximal portion of said at least one stopper in place, and wherein a distal end of said polymer jacket defines said crotch point.

42. The stent delivery system ofclaim 35, further comprising a stent with a side opening positioned on said catheter.

43. The stent delivery system ofclaim 42, wherein said side opening is a dedicated side opening.

44. The stent delivery system ofclaim 42, wherein said crotch point is located at a distal portion of said side opening of said stent.

45. The stent delivery system ofclaim 35, further comprising a stent having a proximal end and a distal end, said stent positioned on said catheter, and wherein said crotch point is located at said proximal end of said stent.

46. The stent delivery system ofclaim 35, further comprising a proximal stent comprising a proximal end and a distal end and a distal stent comprising a proximal end and a distal end, said proximal stent positioned on said catheter and said distal stent positioned distal to said proximal stent on said catheter.

47. The stent delivery system ofclaim 46, wherein said crotch point is located at said distal end of said proximal stent.

48. The stent delivery system ofclaim 35, wherein proximal to said crotch point, said catheter and said side element are attached.

49. The stent delivery system ofclaim 35, wherein said proximal end of said side element is positioned within said catheter.

50. The stent delivery system ofclaim 35, wherein said distal end of said side element is located distal to said crotch point, and wherein said distal end of said side element is unattached to said catheter.

51. The stent delivery system ofclaim 35, wherein said side element is a side branch lumen.

52. The stent delivery system ofclaim 35, wherein said side element is a stopper.

53. The stent delivery device ofclaim 35, wherein said balloon is a proximal balloon, and further comprising a distal balloon positioned on said catheter distal to said proximal balloon.

54. The stent delivery device ofclaim 53, wherein said distal balloon and said proximal balloon may be inflated separately.

55. The stent delivery system ofclaim 35, wherein an outer diameter of said system is less than 1 mm.

56. A stent delivery system, the system comprising:

a catheter having a distal end and a proximal end;

a balloon positioned on said distal end of said catheter, the balloon having a distal end and a proximal end, and wherein said balloon is immovable with respect to said catheter;

a stent positioned on said balloon, said stent having a side opening, wherein the side opening has a proximal end and a distal end; and

a side branch lumen having a distal end and a proximal end, wherein said proximal end is attached to a proximal end of said balloon, and wherein said distal end is positioned at said side opening of said stent.

57. The stent delivery system ofclaim 56, wherein said balloon is a tapered balloon.

58. The stent delivery system ofclaim 56, wherein said proximal end of said side branch lumen is positioned within said catheter, and wherein said distal end of said side branch lumen which is detached from said balloon is positioned outside of said catheter.

59. The stent delivery system ofclaim 55, wherein said balloon comprises a fixed wire at a distal end thereof.

60. The stent delivery system ofclaim 55, further comprising a distal connecting element at said distal end of said balloon.

61. The stent delivery system ofclaim 60, wherein said distal connecting element lies on a same side of said catheter as said side branch lumen, and is configured for receiving a side branch guidewire, said side branch guidewire positionable through both said side branch lumen and said distal connecting element.

62. The stent delivery system ofclaim 60, wherein said distal connecting element lies on an opposite side of said catheter as said side branch lumen, and is configured for receiving a main guidewire, said main guidewire positionable through said distal connecting element and outside of said stent.

63. A stent delivery system, the system comprising:

a catheter having a distal end and a proximal end;

a stent positioned on said catheter, the stent having a distal end and a proximal end;

an auxiliary elongated element having a distal end and a proximal end, said auxiliary elongated element positioned outside of said stent; and

a crotch point located at said proximal end of said stent wherein said auxiliary elongated element is attached to said catheter at said crotch point.

64. The stent delivery system ofclaim 63, wherein said auxiliary elongated element is a side branch lumen.

65. The stent delivery system ofclaim 63, further comprising a fixed wire balloon at said distal end of said catheter.

66. The stent delivery system ofclaim 63, further comprising a tapered balloon at said distal end of said catheter.

67. The stent delivery system ofclaim 63, wherein said auxiliary elongated element is a positioning system.

68. The stent delivery system ofclaim 67, wherein said positioning system comprises at least one stopper and an attachment mechanism.

69. The stent delivery system ofclaim 67, wherein said at least one stopper is a spring wire comprising a shape-memory metal.

70. The stent delivery system ofclaim 63, wherein said attachment mechanism is a jacket for holding a proximal end of said at least one spring wire in place.

71. The stent delivery system ofclaim 63, further comprising a holder for holding a distal end of said at least one spring wire in place.

72. A stent delivery system, the system comprising:

a catheter having a distal end and a proximal end;

a distal balloon positioned on said distal end of said catheter, the distal balloon having a distal end and a proximal end;

a proximal balloon positioned on said catheter proximal to said distal balloon;

a stent positioned on said proximal balloon, the stent having a distal end and a proximal end;

an auxiliary elongated element having a distal end and a proximal end, said auxiliary elongated element positioned inside of said stent and exiting at said distal end of said stent; and

a crotch point located at said distal end of said stent wherein said auxiliary elongated element is attached to said balloon at said crotch point.

73. The stent delivery system ofclaim 72, wherein said auxiliary elongated element is a side branch lumen.

74. The stent delivery system ofclaim 72, wherein said distal balloon has a fixed wire at said distal end of said distal balloon.

75. The stent delivery system ofclaim 72, further comprising a distal stent positioned on said distal balloon.

76. The stent delivery system ofclaim 72, wherein said stent and said distal stent separately deployable.

77. The stent delivery system ofclaim 72, wherein said distal stent has a smaller outer diameter than said proximal stent.

78. The stent delivery system ofclaim 72, wherein said proximal end of said auxiliary elongated element is positioned within said catheter.

79. The stent delivery system ofclaim 72, wherein said distal end of said auxiliary elongated element is located distal to said crotch point and wherein said distal end of said auxiliary elongated element is unattached to said catheter.

80. A catheter system comprising:

a catheter having a distal end, a proximal end and a body connecting said distal and proximal ends;

a side branch lumen having a distal end, a proximal end and a body connecting said distal and proximal ends, wherein a first portion of said side branch lumen is positioned inside said body of said catheter, and a second portion of said side branch lumen is positioned outside said body of said catheter; and

an exit point located on said body of said catheter wherein said first portion is proximal to said exit point and said second portion is distal to said exit point.

81. The catheter system ofclaim 80, further comprising a crotch point, wherein at said crotch point said side branch lumen is attached to said catheter, and wherein said crotch point is located on said second portion of said side branch lumen.

82. The catheter system ofclaim 81, wherein said crotch point is located at said distal end of said side branch lumen.

83. The catheter system ofclaim 81, wherein said crotch point is located proximal to said distal end of said side branch lumen.

84. The catheter system ofclaim 80, further comprising a balloon on said distal end of said catheter.

85. The catheter system ofclaim 84, wherein said balloon is a fixed wire balloon.

86. The catheter system ofclaim 84, wherein said balloon is a tapered balloon.

87. A method for treating a bifurcation, the method comprising:

introducing a side branch guidewire into a branch vessel;

providing a stent delivery system, wherein the system comprises:

a main elongated element for advancement within a main vessel, said main elongated element having a proximal end, a distal end, and a body connecting said proximal and distal ends;

a side branch element for advancement within said side branch vessel, said side branch element having a body which is partially attached to said main elongated element;

a crotch point, wherein at said crotch point, said bodies of said main and side branch elements are attached, and wherein a location of said crotch point is configured to stop advancement of said system at a bifurcation; and

a stent positioned on said main elongated element;

inserting a proximal end of said side branch guidewire into said distal end of said side branch lumen;

advancing said stent delivery system over said side branch guidewire until a location at which said advancing automatically stops due to said crotch point reaching said bifurcation; and

deploying said stent.

88. A method for treating a bifurcation, the method comprising:

providing a stent delivery system, wherein the system comprises: a catheter having a balloon at a distal end thereof; a fixed wire at a distal end of said balloon; and a side branch lumen at least partially attached to said catheter, wherein a point of attachment defines a stopping point; and

advancing said stent delivery system through a main vessel until a location at which said advancing automatically stops due to said crotch point reaching said bifurcation.

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