Fully Crimped Stents for Treating Bifurcation

Abstract

A stent delivery system for treating bifurcated vessels includes a first elongate shaft with a first expandable member. A first stent having a side hole is disposed over the first expandable member. A second elongate shaft has a second expandable member. The second elongate shaft is slidably disposed under a proximal end of the first stent and extends out of the side hole. The first stent is fully crimped over the proximal and distal portions of the first expandable member and the proximal portion of the second expandable member to prevent axial movement of the first stent relative to the first or second elongate shafts during delivery. A portion of the first or second expandable member may be pillow-shaped to provide a protective barrier that prevents edges of the stent from catching on other objects.

Description

[Technical field]

[0001] (Priority Claim) This application is a nonprovisional application and claims the benefit of U.S. Provisional Patent Application No. 63 / 260,007 (Attorney Docket No. 5133.018PRV), filed August 6, 2021, the entire contents of which are incorporated herein by reference. (CROSS REFERENCE TO RELATED APPLICATIONS)

[0002] This patent application is also related to U.S. Patent Application No. 17 / 198,685, filed March 11, 2021 (Attorney Docket No. 5133.017US1), the entire contents of which are incorporated herein by reference. [Background technology]

[0003] The present invention relates to medical devices, and more particularly to the stenting and treatment of branched blood vessels. Stents are implantable scaffolds that are typically delivered percutaneously and deployed in veins, arteries, or other tubular body organs to treat occlusions, stenoses, aneurysms, collapsed, dissections, or weakened, diseased, or abnormally dilated blood vessels or vessel walls. Stents are radially expanded in situ, thereby expanding and / or supporting the blood vessel or body organ wall to help re-establish or maintain the patency of the blood vessel lumen or body cavity. In particular, stents are very commonly implanted in the coronary arteries, heart, lungs, neurovascular, peripheral vascular, kidneys, gastrointestinal tract, and reproductive system, and have been successfully implanted in the urinary tract, bile duct, esophagus, tracheobronchial tree, and brain to strengthen these body organs.

[0004] Stents are commonly used to restore vascular patency, thereby allowing blood to flow through blocked vessels. Stents are used to treat stenotic lesions in blood vessels, such as the coronary arteries, which supply oxygen-rich blood to the heart or other parts of the body. In addition, stents can help reduce symptoms such as angina and treat myocardial infarction. Stents are generally inserted percutaneously by catheter through an artery, such as the femoral, radial, or brachial artery, and upon reaching the site of deployment, the stent expands, reopening the vessel lumen and supporting the vessel wall, and the catheter is removed leaving the stent in place.

[0005] Conventional stent technology is relatively well developed. Conventional stent designs typically feature a straight, single type of porous structure, configuration, or pattern that is repetitive throughout translation along the longitudinal axis. In many stent designs, the repetitive structure, configuration, or pattern has struts and connecting balloon catheter sections that can impede blood flow in the vessel. Furthermore, the configuration of struts and connecting balloon catheter sections can interfere with the use of the device post-operatively to treat the vessel.

[0006] Thus, given the problems with current stent manufacturing processes and stent technologies used to treat vascular conditions, there exists a need for improved stent delivery systems, delivery methods, and processes. At least some of these objectives will be met by the present invention.

[0007] In the drawings, which are not necessarily drawn to scale, like numbers may describe similar components in different figures. Like numbers with different suffixes may represent different instances of similar components. Several embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. [Brief description of the drawings]

[0008] [Figure 1]FIG. 1 illustrates a side view of a delivery system having a mother catheter and a daughter catheter.

[0009] [Figure 2A] FIG. 2A illustrates a stent delivery system disposed within a guide catheter or introducer sheath.

[0010] [Figure 2B] FIG. 2B illustrates the stent edges hooking onto the edges of the introducer sheath or guide catheter of FIG. 2A.

[0011] [Figure 2C] FIG. 2C illustrates the stent edges contacting tissue upon delivery within a vessel.

[0012] [Figure 3A] FIG. 3A illustrates a side view of a radially expandable member positioned within a mold.

[0013] [Figure 3B] FIG. 3B illustrates a side view of FIG. 3A after radial expansion of the radially expandable member within the mold.

[0014] [Figure 3C] FIG. 3C illustrates a side view of FIG. 3B during processing of the radially expandable member within a mold.

[0015] [Figure 3D] FIG. 3D illustrates a side view of FIG. 3C after crushing of the radially expandable member within a mold.

[0016] [Figure 4A] FIG. 4A illustrates a side view of a stent loaded onto a radially expandable member with the pillows formed after processing in a mold.

[0017] [Figure 4B]FIG. 4B illustrates a side view of the pillows that protect the stent from engaging the edges of the sheath.

[0018] [Figure 5A] FIG. 5A illustrates a side view of a pillow on a proximal end of a radially expandable member.

[0019] [Figure 5B] FIG. 5B illustrates a side view of a pillow on a distal end of a radially expandable member.

[0020] [Figure 5C] FIG. 5C illustrates a side view of the pillows on the proximal and distal ends of the radially expandable member.

[0021] [Figure 5D] FIG. 5D illustrates another view of FIG. 5C after it has been removed from the mold.

[0022] [Figure 5E] FIG. 5E illustrates a side view of a stent loaded onto a first catheter having proximal and distal pillows.

[0023] [Figure 6A] FIG. 6A illustrates a distal portion of another stent delivery system.

[0024] [Figure 6B] FIG. 6B illustrates the stent of FIG. 6A partially crimped onto a delivery system.

[0025] [Figure 6C] FIG. 6C illustrates the stent of FIG. 6B further crimped onto a delivery system.

[0026] [Figure 6D] FIG. 6D illustrates pillowing of the radially expandable member in the stent delivery system of FIG. 6C.

[0027] [Figure 6E] FIG. 6E illustrates the insertion of a second catheter through the stent of FIG. 6D prior to additional stent crimping.

[0028] [Figure 6F] FIG. 6F illustrates a side view of FIG. 6E inserted into a die for additional crimping.

[0029] [Figure 7] FIG. 7 illustrates an example of a fully crimped stent delivery system.

[0030] [Figure 7A] FIG. 7A shows a flow chart illustrating an embodiment of a method of delivering the system of FIG. 7 to a treatment site.

[0031] [Figure 8-1] 8A-8C, 8C1, and 8D-8H illustrate a method for manufacturing a fully crimped stent delivery system with a pillow-like expandable member. [Figure 8-2] 8A-8C, 8C1, and 8D-8H illustrate a method for manufacturing a fully crimped stent delivery system with a pillow-like expandable member. [Figure 8-3] 8A-8C, 8C1, and 8D-8H illustrate a method for manufacturing a fully crimped stent delivery system with a pillow-like expandable member. [Figure 8-4] 8A-8C, 8C1, and 8D-8H illustrate a method for manufacturing a fully crimped stent delivery system with a pillow-like expandable member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Detailed Description of the Invention The present invention generally relates to improving stent delivery systems, delivery methods, and manufacturing techniques to make vascular treatment more precise and less likely to cause complications. For example, these systems and methods may be advantageous to reduce the risk of damaging surrounding tissue during distal advancement through a vessel or to facilitate retention of a prosthesis, such as a stent, on the delivery system. However, this is not intended to be limiting, and one of ordinary skill in the art will understand that the devices and methods described herein may be used to treat other areas of the body. Although the examples disclosed herein focus on stent delivery systems used to treat bifurcated vessels, this is not intended to be limiting, and the examples used herein may be used in other medical treatments or non-medical applications.

[0033] Aspects of the subject technology address some of the potential problems of conventional stent delivery systems, which may have limitations and challenges in stent retention during retraction of the stent-loaded catheter back into the introducer sheath or guide catheter, and during delivery of the stent delivery system through the vessel. For example, a potential challenge of conventional stent delivery systems may occur when the proximal edge of the stent catches on the distal edge of the introducer sheath or guide catheter as the stent is being retracted proximally, causing the stent to become dislodged and / or damaged. Furthermore, upon introduction of the catheter through the vessel, the distal edge of the stent may contact tissue during distal advancement, or the proximal edge of the stent may contact tissue during proximal retraction, thereby causing vessel injury or plaque exhumation. Tissue injury may occur around the curves of tortuous vessels. In still other situations, the proximal or distal end of the stent may scrape against contacting surfaces during delivery or other uses, such that the therapeutic agent carried by the stent may be scraped off or otherwise damaged. Examples of the stent delivery system disclosed herein may reduce the risk of the stent becoming caught in the introducer sheath or guide catheter or causing tissue damage while being introduced or otherwise manipulated. Similarly, the examples disclosed herein may also minimize or prevent unwanted damage to the therapeutic agent carried by the stent. These issues may be reduced with a stent delivery system having a "pillow" region on both sides of the stent. The pillow region is an enlarged protrusion (e.g., a ridge) that may be dumbbell shaped, which may protect the edges or any edges on both sides of the stent from becoming dislodged from the catheter or damaging the surrounding tissue upon insertion and retraction, as well as from scratching or otherwise damaging the therapeutic agent on the stent.

[0034] The proximal or distal edges of the stent, the edges of the stent, or therapeutic agents delivered by the stent may be protected from damage, dislodging, and tissue damage by the use of a radially expandable member. In any of the embodiments discussed herein, the radially expandable member may be a balloon. The balloon may have ridges on both ends of the stent or adjacent to any stent edges that may have shape memory. The shape memory may be induced by heat and pressure over time, and the shape may be retained after several cycles of expansion and contraction. In addition, the balloon may be deflated but still maintain a protective bulge (e.g., protrusion) that shields the proximal or distal edges, or any edges of the stent, due to the shape memory that provides protection from contacting the sheath or contacting tissue. Thus, the balloon or other radially expandable member may be deflated and re-inflated while still providing pillowing. The memory may last for 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, or more than 10 inflation / deflation cycles before the memory is lost. The radially expandable member in this or any embodiment may be another expandable member used in the deployment of a balloon or stent.

[0035] In general, the methods disclosed herein may provide protection to a stent or a therapeutic agent or another coating on a stent by inducing shape memory in the balloon. For example, inducing shape memory may be accomplished by the use of inserting the balloon into a mold. The mold may be made of metal, polymer, glass or ceramic, combinations thereof, or any other material known in the art. In any embodiment, all or a portion of the balloon is placed in the mold and a portion of the balloon may be expanded within the mold while another portion is constrained inside or outside the mold. The mold may be a hand crimper, an iris, or an elongated tubular shaft (e.g., made of metal, polymer, glass ceramic, etc.). The balloon may be treated during expansion (e.g., application of heat, pressure, etc.), which induces shape memory in the balloon.

[0036] Throughout this application, references to D refer to "distal" and references to P refer to "proximal," both of which are relative to the operator of the stent delivery catheter. Thus, proximal is closest to the operator and distal is furthest from the operator. The proximal end of the stent delivery catheter is often outside the human body, while the distal end is often inside the patient's body.

[0037] Reference will now be made in detail to specific embodiments of the present disclosure. In the following description, specific details are set forth to provide a thorough understanding of the subject matter. It will be understood that any embodiment may be practiced without some or all of these specific details, and that no specific feature is critical or limiting.

[0038] Stent retention

[0039] FIG. 1 shows a side view of a stent delivery system 100 for retaining a stent and delivering the stent to a target treatment area, according to any embodiment. The system includes a first catheter 120 (e.g., also referred to as a mother catheter or main branch catheter) with a first elongated shaft and hub 122, and a second catheter 110 (e.g., also referred to as a side branch catheter, daughter catheter) with a second elongated shaft and hub 112. The term "mother" may refer to a catheter, balloon, or stent in the main branch, while the term "daughter" may refer to a catheter, balloon, or stent in the side branch. Thus, the term "mother" may be substituted for the term "main branch" and the term "daughter" may be substituted for the term "side branch." The first catheter 120 has a first expandable member, here a balloon 130 (e.g., mother balloon), disposed on a distal portion of the first catheter 120, and the second catheter 110 has a second expandable member, here a balloon 140 (e.g., daughter balloon), disposed on a distal portion of the second catheter 110. A stent (not shown) may be disposed over the mother balloon, the daughter balloon, or a stent may be disposed over both balloons. Either catheter may be delivered to the treatment site over a guidewire.

[0040] FIG. 2A shows a side view of a stent delivery system 200 for retaining a stent 230, showing a proximal side P and a distal side D of the stent delivery system 200. The system for the stent comprises a delivery catheter 220, an expandable member, here a balloon 245, on a distal portion of the catheter 220, and a stent 230 disposed over the balloon. The balloon 245 has a working length that may match, be longer or shorter than the length of the stent 230. The balloon 245 may comprise proximal and distal shoulder regions that are connected to the catheter 220, which may be slidably disposed through a guide catheter 210 (e.g., a sheath) during delivery. An introducer sheath or guide catheter 210 is provided through which the catheter 220 and stent 230 may be retracted proximally such that the stent is protected by the guide catheter 210 during delivery.

[0041] FIG. 2B shows a side view of the catheter 220, balloon 245, and stent 240 of FIG. 2A being retracted proximally as indicated by arrow 247 through the sheath or guide catheter 210. The blunt proximal edge of the stent 240 may contact the distal edge of the sheath or guide catheter 210 and induce a compressive force on the stent 240. The stent may become distorted, deformed, and / or become partially or completely dislodged from the catheter. In addition, the stent may be damaged rendering it unusable. This may be particularly undesirable when the stent is carrying a therapeutic agent such as an anti-restenosis drug like paclitaxel or rapamycin or any other drug, because when the stent gets caught on the sheath edge, the drug may also come off the stent.

[0042] 2C shows a side view of catheter 260, balloon proximal portion 270 and balloon distal portion 282, and stent 280 being delivered through blood vessel 250. In some embodiments, blood vessel 250 may have an arcuate or tortuous region and blunt proximal end 290 of stent 280 may contact the wall of blood vessel 250 as the catheter is retracted proximally through the vessel, as indicated by arrow 252. The area of ​​contact of blunt proximal end 290 may cause tissue damage. Damage to tissue may also occur during distal advancement through the vessel, as indicated by arrow 284, where distal end 286 of stent 280 may contact blood vessel 250. Contact between the stent edge and tissue may also damage the stent or cause the stent to eject from the balloon.

[0043] Several embodiments are disclosed herein that protect one or more edges of a stent to form a protective barrier.

[0044] Shape memory function

[0045] 3A-3D show an example of a process for forming protection on the proximal portion of the balloon.

[0046] FIG. 3A shows a side view of a system 300 for forming a balloon to help protect and retain a stent on a stent delivery catheter. The stent delivery system includes a stent delivery catheter having a first catheter 330 and a folded balloon 340 on the first catheter 330. The balloon 340 may have pleats or creases 342 when the balloon 340 is in a neutral (e.g., unexpanded) state. The balloon is fixedly attached to the first catheter 330. The first catheter 330 and the balloon 340 are inserted into a mold 310. The mold 310 may be made of ceramic, glass, polymer, or metal, or a combination thereof, or any other material known in the art. In this or any embodiment, a portion of the balloon 340 may be restrained by the mold 310. The mold 310 includes a first cavity 380, a second cavity 395, and a transition region, such as a tapered portion 390, that may be disposed therebetween. The first cavity of the mold 310 is cylindrical and the second cavity of the mold 310 is also cylindrical, with the first cavity 380 having a larger diameter than the second cavity 395. The mold 310 may have the same length as the balloon 340 or a longer length than the balloon 340. The proximal portion of the balloon 340 may be disposed within the first cavity 380 and the distal portion of the balloon 340 may be disposed within the second cavity 395. In addition, a portion between the proximal portion of the balloon 340 and the distal portion of the balloon 340 may be disposed within the tapered portion 390. The distal portion of the balloon 340 is disposed within the second cavity of the mold 310, which is sized to fit closely with the balloon, such that the distal portion of the balloon is constrained by the mold and does not allow expansion of the distal portion of the balloon 340 (or does not allow substantially any expansion). The first cavity 380 has a diameter greater than the folded balloon 340 in its unexpanded state, allowing expansion of a proximal portion of the balloon. The first cavity 380 may have a diameter greater than the fully expanded balloon 340, which may allow the balloon 340 to fully expand.Alternatively, the first cavity 380 may have a smaller diameter than the balloon 340 in its fully expanded state, which prevents the balloon 340 from expanding further (e.g., the balloon does not fully expand) after the balloon 340 abuts the inner wall of the first cavity 380. The proximal portion of the balloon 340 may expand to create a pillow region. The pillow region creates a protective cover for the edges of the stent during introduction and retraction in and out of the vessel, as well as provides a protective edge that helps prevent therapeutic agents or other coatings on the stent from being scratched off the stent. The first cavity 380 is greater than or equal to the length of the pillow region on the proximal portion of the balloon 340. The second cavity 395 has a diameter sized to receive the distal portion of the balloon 340, however, it constrains the distal portion of the radially expandable portion and does not allow expansion when the balloon is heated and pressurized. The second cavity 395 is greater than or equal to the length of the distal portion of the balloon 340 .

[0047] FIG 3B shows a side view of the stent delivery system 300 of FIG 3A when the balloon is pressurized. The balloon 340 may be expanded within the mold 310. Expansion of the balloon 340 occurs when heat is applied to the mold 310 and pressure is applied, expanding the balloon 340. The heat, pressure, and dwell time in the mold will be discussed below. In one embodiment, a proximal portion of the balloon 340 is expanded within the mold 310 while a distal portion of the balloon 340 is restrained as described above.

[0048] The entire balloon 340 may be subjected to heat and pressure within the mold 310; however, only a proximal portion of the balloon 340 may expand, as a distal portion of the balloon 340 may be constrained and therefore unable to expand. In addition, an optional protective sheath 335, as shown in FIG. 4A below, may be applied to a portion of the balloon 340 within the mold to prevent expansion. The constrained portion of the balloon 340 has a smaller diameter than the unconstrained portion of the balloon 340, as shown in FIG. 4A.

[0049] In any embodiment, the proximal portion of the balloon 340 may be expanded under heat and pressure to contact the inner wall of the first cavity 380, and the distal portion of the balloon 340 is constrained and therefore remains unexpanded. The proximal portion of the balloon 340 may be fully expanded, which radially expands to the full diameter of the balloon 340, with or without contacting the inner wall of the first cavity 380. Alternatively, the balloon 340 may be partially expanded, and further expansion of the balloon 340 is prevented in response to contacting the inner wall of the first cavity 380. Alternatively, the balloon 340 may be partially expanded such that it does not reach its full diameter or contact the inner surface of the mold wall.

[0050] FIG. 3C shows a side view of the treatment of the balloon of FIG. 3B while being placed in a mold. In this example, the entire balloon 340 may be placed in the mold and undergoes treatment, but only the proximal portion of the balloon 340 expands to contact the larger proximal diameter of the mold, while the distal portion of the balloon 340 does not expand because it is constrained by the mold. Treatment may include adding heat 360, pressure 370, or both for a predetermined time. In any example, the added heat 360, pressure 370, or both may induce shape memory in the balloon 340. Once the stent is placed on the balloon 340, the shape memory may protect the edges of the stent. The shape memory may create ridges or dumbbells protruding from the edges of the stent that retain their shape after a series of expansions and contractions of the balloon 340. The heat 360, pressure 370, or both are applied for a predetermined time, which will induce shape memory in the balloon 340 within the mold. In any embodiment, the heat 360 may be between 40° C. and 80° C., or between 50° C. and 70° C., or between 55° C. and 65° C., or the heat may be at 60° C. In any embodiment, the pressure 370 applied to the balloon may be between 100 psi and 150 psi, or between 110 psi and 140 psi, or between 110 psi and 130 psi, or between 115 psi and 130 psi, or between 120 psi and 125 psi, or between 120 psi and 125 psi. The dwell time may be the amount of time that the heat 360 and / or pressure 370 is applied. In any embodiment, the dwell time may be between 15 seconds and 2 minutes, or between 15 seconds and 1 minute, or between 30 seconds and 1 minute, or between 1 minute and 1 minute and 30 seconds, or between 1 minute and 30 seconds, or between 1 minute and 2 minutes, or the dwell time may be 30 seconds, 45 seconds, 1 minute, 1 minute and 15 seconds, 1 minute and 30 seconds, 1 minute and 45 seconds, or 2 minutes. Any combination or permutation of time, temperature, or pressure ranges may be used to treat the balloon. Although heat 360 and pressure 370 are applied to the entire radially expandable component, only the expanded proximal portion of balloon 340 will undergo shape memory because the distal portion of balloon 340 remains constrained and unexpanded.The shape memory will allow the radially expandable portion 340 to retain the protruding pillow region even after it is fully expanded and fully deflated. The proximal portion of the balloon 340 that undergoes shape memory will be larger in diameter than the distal portion of the balloon 340 that is constrained. The shape memory added to the proximal portion of the balloon 340 can last for more than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 cycles. A cycle is identified by the inflation and deflation of the balloon during preparation or use on a patient.

[0051] 3D shows a side view of deflation of the stent delivery system 300. Here, the balloon 340 is fully deflated but has a shape memory that creates a bulge on the proximal portion of the balloon 340. In another embodiment, the balloon 340 is only partially deflated to retain a larger bulge on the edge of the stent (not shown) for insertion into the body. The first catheter 330 coupled to the balloon 340 may then be removed from the mold 310 and the stent may then be engaged to the delivery catheter.

[0052] 4A shows a side view of a stent delivery system 400 loaded with a stent 410 after forming a shape memory region or regions in the balloon according to any of the embodiments disclosed herein. In any embodiment, the stent 410 is loaded onto the balloon 340 in such a way that the proximal end of the stent abuts the pillow or dumbbell shaped protruding portion 344 of the proximal portion of the balloon 340. The "pillow effect" of the proximal portion of the balloon 340 has a larger diameter than the proximal edge of the stent 410, thereby creating a shielded edge of the stent. The sheath 335 is positioned over the balloon 340 such that the edges of the sheath pass over the balloon 340 without catching on the edges of the stent. The balloon 340 may be collapsed for removal through the sheath 335, or the balloon 340 will automatically collapse as it is removed through the sheath 335, however the shape memory remains intact. This minimizes or prevents damage to the proximal edge of the stent.

[0053] FIG. 4B illustrates continued proximal retraction 377 of the delivery catheter and stent 410 of FIG. 4A above into the sheath 335, with the protruding region 344 of the balloon 340 protecting the proximal blunt edge of the stent 410 as the stent is further retracted proximally, so the stent 410 does not get caught in the sheath 335 as the delivery catheter is being retracted into the sheath 335. The balloon 340 covers the proximal edge of the stent 410, preventing it from getting caught in the sheath 335, which helps to minimize or prevent distortion of the stent or expulsion of the stent from the balloon. This also helps to minimize scratching or other damage to any therapeutic agent or coating on the stent that is being delivered by the stent. Additionally, the proximal edge of the stent 410 is protected from dislodging or tissue damage during proximal retraction 377 through the vessel.

[0054] FIG. 5A shows a side view of the loading of the proximal portion 520 of the balloon into a mold 510 and a protective sheath 560. FIG. 5A is another example of imparting shape memory to the proximal portion 520 of the balloon similar to FIG. 4B above, with the main difference being the mold 510 and protective sheath 560 used during processing. In the stent delivery system 500, the mold 510 may be an elongated tube. The mold may be made of metal, polymer, or ceramic, combinations thereof, or any other material known in the art. Alternatively, the mold 510 may be a channel formed by a collapsible iris of a crimping system. Alternatively, the mold 510 may be a plastic tube. In the stent delivery system 500, the first catheter 530 has a distal radiopaque marker 540 and a proximal radiopaque marker 550. The distal radiopaque marker 540 and the proximal radiopaque marker 550 may provide assistance in positioning the stent between the radiopaque markers. The proximal portion 520 of the balloon may have portions that are constrained and portions that remain unconstrained. In this example, the proximal portion of the balloon remains unconstrained. The distal portion of the balloon may be constrained with a protective sheath 560. The protective sheath 560 may be made of metal, plastic, or any other material known in the art. The protective sheath 560 may restrict a portion of the balloon from expanding. Heat and pressure may be applied for a period of time to induce expansion of the unconstrained proximal portion 520 of the balloon using any of the process parameters previously described above. The proximal portion 520 of the balloon may expand until it reaches the wall of the mold 510. The diameter of the mold 510 may determine the diameter of the pillow portion of the proximal portion 520 of the balloon. Expansion of the proximal portion 520 induces a shape memory in the proximal portion 520. The shape memory may be a ridge protruding on the proximal end of the balloon or a pillow as described above in the shape of a dumbbell. The shape memory may withstand several cycles of expansion and contraction (as previously described above) of the proximal portion 520. The stent may be loaded onto the balloon such that the proximal edge of the stent abuts the pillow or at least partially covers the proximal edge of the stent.The shape memory of the proximal portion 520 of the balloon may protect the stent from becoming dislodged or damaged from retraction of the catheter or causing trauma to tissue, as previously explained above. Any therapeutic agent delivered by the stent or coating thereon is also protected by the protruding balloon portion.

[0055] FIG. 5B shows another embodiment similar to FIG. 5A, however, in this embodiment, the distal portion 525 of the balloon is endowed with shape memory. In the stent delivery system 500, a protective sheath 560 is loaded onto the proximal end of the first catheter 530 and over the distal portion 525 of the balloon, with a small gap in the balloon remaining unconstrained. Two radiopaque markers may be coupled to the first catheter 530. A proximal radiopaque marker 550 and a distal radiopaque marker 540 are placed on the distal portion of the first catheter 530, with the proximal radiopaque marker 550 being proximal to the distal radiopaque marker 540. In any embodiment, the protective sheath 560 may restrain the proximal portion 523 of the distal portion 525 of the balloon and leave the distal portion 527 of the distal portion 525 of the balloon unconstrained. In addition, the restraining sheath 532 may restrain a further distal portion 529 of the balloon distal portion 525 from expanding, while a more proximal portion of the balloon distal portion 525 is unconstrained and allowed to expand and form a pillow (in the gap area between the restrained portions of the balloon) distal to the distal radiopaque marker 540 where the distal edge of the stent would be. As explained above, heat may be applied to the mold 510 and pressure may be applied to the balloon distal portion 525 to inflate it, to induce shape memory in the balloon distal portion 525. As previously explained, the shape memory may be a bump or pillow, such as a dumbbell-shaped protrusion. The shape memory may withstand several cycles of expansion and contraction of the balloon distal portion 525. The stent may be loaded onto the balloon such that the distal edge of the stent abuts the balloon distal portion 525 or is covered by the protrusion. The shape memory of the balloon's distal portion 525, upon delivery, may protect the tissue of the vessel and protect the distal stent edges, as well as any therapeutic agents carried by the stent or coatings disposed over the stent.

[0056] FIG. 5C illustrates another embodiment of inducing shape memory. In FIG. 5C, shape memory is induced in both the proximal portion 520 of the balloon as described above in FIG. 5A and the distal portion 525 of the balloon as described above in FIG. 5B. In any embodiment, the pillow portion of the distal portion 525 of the balloon may be smaller in diameter than the pillow portion of the proximal portion 520 of the balloon. This may be due to a lower need for pillowing to protect the surrounding tissue. Alternatively, the pillow portion of the proximal portion 520 of the balloon may have a smaller diameter than the pillow portion of the distal portion 525 of the balloon. This may be due to less concern of tissue damage to the surrounding vessel upon insertion and retraction and more concern of dislodging the stent upon insertion and retraction. Alternatively, the pillow regions of the proximal portion 520 of the balloon and the distal portion 525 of the balloon may have the same size diameter. In this or any embodiment, a protective sheath 560 may be placed between the distal portion 525 of the balloon and the proximal portion 520 of the balloon to prevent the middle portion from expanding under heat and pressure. The heat, pressure, and dwell time ranges are discussed above. The sheath 560 may be made of any material discussed above. The first catheter 530 may have two or more radiopaque markers on the distal end of the shaft. The distal radiopaque marker 540 and the proximal radiopaque marker 550 may provide assistance in aligning the protective sheath 560 or the stent. The stent may be placed between each of the radiopaque markers. The distal and proximal portions of the balloons 525 and 520, respectively, may expand into contact with the mold 510 when heat and pressure are applied. This forms a dogbone-shaped or double dumbbell-shaped balloon with protective protrusions on the proximal and distal ends.

[0057] In another embodiment, when the protective sheath 560 is loaded into the mold 510 and placed between the distal portion 525 of the balloon and the proximal portion 520 of the balloon, the proximal portion 520 of the balloon or the distal portion 525 of the balloon may be fully expanded or partially expanded. When the distal portion 525 and the proximal portion 520 of the balloon are partially expanded, they may not contact the mold 510. Alternatively, the distal portion 525 of the balloon may contact the mold when it is fully expanded, while the proximal portion 520 of the balloon may not contact when it is partially expanded. Or conversely, the proximal portion 520 of the balloon may contact the mold 510 when it is fully expanded, while the distal portion 525 of the balloon may not contact when it is partially expanded. Whether the distal or proximal portions 525 and 520 of the balloon are fully or partially expanded may depend on the desired diameter size of the distal or proximal portions. For example, if a large proximal portion 520 is desired and a smaller distal portion 525 is desired, the proximal portion 520 may be fully expanded and the distal portion 525 may be partially expanded. In any embodiment, the distal and proximal portions 525 and 520 of the balloon may be expanded simultaneously. Alternatively, the proximal portion may be expanded before the distal portion. Alternatively, the distal portion may be expanded before the proximal portion.

[0058] 5D shows the example after the balloon has been removed from the mold 510 and the protective sheath 560 has been removed. Shape memory may be induced in the proximal and distal portions 520 and 525 of the balloon to withstand a series of inflations and deflations of the balloon as discussed above. After shape memory is induced, a stent may be loaded onto the first catheter 530. The stent may be placed between the distal radiopaque marker 540 and the proximal radiopaque marker 550 and disposed over the balloon. A sheath 570 may be inserted over the balloon.

[0059] 5E shows an example after a stent 580 has been loaded onto a first catheter 530 with a proximal portion 520 of the balloon and a pillow portion of a distal portion 525. The stent 580 is positioned between a proximal radiopaque marker 550 and a distal radiopaque marker 540.

[0060] Combined stent crimping and shape memory formation

[0061] 6A-6F show different steps in crimping a stent 610 as it is loaded over a balloon 620 that is attached to the distal end of a first catheter 630 for delivery using a delivery system 600. FIG.

[0062] FIG. 6A shows a system 600 that crimps a stent 610 and expands a balloon 620 to form one or more of the pillow regions previously described above. In FIG. 6A, the stent 610 is loaded over a balloon 620 that is attached to the distal end of a first catheter 630 for delivery. The working length of the balloon 620 matches the length of the stent 610, while the balloon shoulder 635 may extend slightly beyond the stent. In some embodiments, the balloon 620 may be longer than the stent 610 and may extend past the stent 610 on both sides. The stent 610 may have side holes 645, or in some embodiments where side holes are used, the spaces between the struts on the stent may be used as side holes. The first catheter 630 may have two or more radiopaque markers that may aid in stent alignment over the balloon 620. In this example, there are two radiopaque markers: a distal radiopaque marker 640 and a proximal radiopaque marker 650 that is more proximal than the distal radiopaque marker 640. Both markers may be on the distal portion of the first catheter.

[0063] In FIG. 6B, a first partial crimp may be applied to the distal portion 615 of the stent 610. The partial crimp provides alignment of the stent on the balloon 620 and prevents longitudinal movement of the stent 610 so that the stent remains positioned between the radiopaque markers 640, 650. In this or any embodiment, the distal crimp may extend from the distal-most end of the stent to the side hole 645 or any portion thereof. In any embodiment, the proximal portion 617 of the stent 610 may remain uncrimped. The distal crimp of the distal portion 615 may aid in alignment between the distal radiopaque marker 640 and the proximal radiopaque marker 650 by holding the stent in place. The distal crimp may be performed by light finger or hand crimping or with any other crimping tool. Alternatively, distal crimping may be performed by inserting the system 600 into a crimping iris which applies pressure and heat for a given time. A protective coating may be applied to the proximal portion 617 of the stent 610 to prevent expansion. Alternatively, or in addition, the proximal portion 617 is not inserted into the iris to be crimped.

[0064] In FIG. 6C, a full crimp is applied to the system 600, which embeds the stent 610 in the balloon 620. A full crimp may be applied to the distal portion 615 (the same portion that was partially crimped in the previous step). A full crimp embeds the stent 610 in the balloon 620, preventing migration or dislodgement of the stent 610. A full crimp may impart some shape memory to the distal portion 615 when heat and pressure are applied for a period of time (see operating parameters discussed above); however, full expansion may not occur because the dwell time is relatively short to crimp the stent. Embedding the stent in the balloon prevents any longitudinal movement of the stent 610 relative to the balloon 620. Additionally, a full crimp eliminates movement during delivery through the vessel and routine handling and manipulation of the device. A protective coating may be applied to the proximal portion 617 of the stent 610 to prevent expansion. Alternatively, or in addition, the proximal portion 617 may not be inserted into the iris to be crimped.

[0065] FIG. 6D is the system of FIG. 6C where the system 600 is inserted into a mold (as described above) and heat and pressure are applied for a dwell time to form a shape memory. The mold may be any of the materials or shapes discussed herein. Heat is applied to the mold and pressure is applied to the balloon, and in response, a portion of the balloon partially expands to form a protrusion such as the dumbbell shape shown. This may cause the proximal portion 670 of the balloon to expand as shown. Alternatively, this may cause the distal portion 660 of the balloon to expand. In this example, the heat in the mold and pressure on the balloon cause the proximal and distal portions 670 and 660 of the balloon to become pressurized and expand. The proximal portion 670 may be larger in diameter than the distal portion 660 (FIG. 6D shows the distal pillow having a smaller diameter, but large enough to protrude and form a protective barrier for the distal edge of the stent 610. FIG. 6E or FIG. 6F show the proximal and distal pillows more clearly). Alternatively, the distal portion 660 may be larger in diameter than the proximal portion 670. Alternatively, the distal portion 660 and the proximal portion 670 may have the same diameter. The heat, pressure, and dwell time imparting the shape memory may create ridges on the balloon that protrude to cover the proximal or distal or both ends of the stent 610. Alternatively, the ridges may be bulbous or dumbbell in shape. The ridges may be maintained even after several cycles of inflating and deflating the balloon.

[0066] FIG. 6E is a 90° rotated side view of FIG. 6D with a side hole at the top of the stent 610. A second catheter 690 (e.g., a daughter catheter or side branch catheter) is inserted into the side hole 645. The second catheter 690 may contain a second balloon 697. In some embodiments, the second catheter may contain a second stent (not shown) disposed over the second balloon 697. The first catheter may have a hollow exchange port tube 695 that aids in the alignment of the second catheter 690 with the side hole 645 and engages the two catheters together. The hollow exchange port 695 may be made of glass, plastic, rubber, or any suitable combination thereof. In this embodiment, the second catheter 690 has a distal end that exits out of the optional side hole 645 after being advanced through the hollow exchange port 695 and through the proximal end of the uncrimped proximal portion of the stent 610. Insertion of the second catheter 690 through the side hole 645 of the stent 610 can cause an overlap between the first catheter 630 and the second catheter 690. The second catheter 690 may be introduced through the stent 610 through existing openings between adjacent struts in the sidewall of the stent 610, or a separate side hole may be formed in the stent.

[0067] FIG. 6F shows the system 600 of FIG. 6E inserted into a protective tube 699 (which may then be crimped by a crimping machine or tool). Optional heat and pressure may be applied to the balloon during crimping. The heat and pressure applied to the system as discussed above serves to embed the stent in the balloon over the working length of the balloon on both the first catheter 630 (e.g., mother catheter) and the second catheter 690 (e.g., daughter catheter). The distal region 660 and the proximal region 670 may undergo a reduction in diameter as they will be reduced in size, however, the dumbbell shape will remain due to the shape memory imparted to these regions of the balloon. The various vertical arrows illustrate the compressive forces and movements applied by the crimping machine or tool that crimp the system 600 together.

[0068] Fully crimped stent

[0069] 7 shows an example of a fully crimped stent delivery system 700 that may be used to treat a bifurcated vessel. Here, the stent delivery system includes two catheters, one is a mother (i.e., main branch) catheter 702 having an elongate shaft with proximal and distal ends and an expandable member, such as a balloon, on the distal end of the elongate shaft. The second catheter is a daughter (i.e., side branch) catheter 704 also having an elongate shaft with proximal and distal ends and an expandable member, such as a balloon, on the distal end of each elongate shaft. A mother stent (i.e., main branch stent) 706 is placed over the mother expandable member, and the proximal and distal ends of the mother stent are marked with radiopaque markers on the mother elongate shaft adjacent to the proximal and distal ends of the mother stent.

[0070] The mother stent has a sidewall with side holes 708 extending therethrough. The stent geometry may be any of the stent geometries disclosed herein or otherwise known in the art. The stent may be self-expanding or balloon expandable.

[0071] The daughter catheter is placed under the proximal portion of the mother stent and exits out of the mother stent side hole 708 such that a portion of the daughter catheter extends along the outer surface of the stent. A radiopaque marker is used to mark the proximal end of the mother stent on the daughter extension shaft and a distal radiopaque marker marks the distal end of the daughter expandable member.

[0072] In this embodiment, the mother stent is fully crimped to both the mother and daughter expandable members, so the stent will not move axially relative to either the mother or daughter elongated shafts during delivery of the stent delivery system through the patient's vasculature toward the treatment area in the bifurcation. In addition, both catheters are in a steady state relative to each other and the mother stent. Thus, when both catheters are delivered in parallel toward the bifurcation, and once the mother catheter is positioned such that the side hole is adjacent the ostium to the side branch (i.e., daughter vessel) of the bifurcation, the daughter catheter may be partially inflated to radially expand the daughter balloon. This creates a small gap between the proximal portion of the mother stent and the daughter balloon, which in turn allows axial movement of the daughter catheter relative to the mother catheter, so that the daughter catheter may be accurately positioned within the daughter vessel of the bifurcation. Optionally, the mother expandable member may be inflated before the daughter expandable member to create a gap and allow movement of the daughter catheter. Once both the mother and daughter catheters are correctly positioned at the bifurcation, the mother catheter may be fully inflated, expanding the mother expandable member, which correspondingly expands the entire length of the mother stent into the treatment area, here the stenotic lesion at the bifurcation or dissection in the vessel wall. The side holes will align with the ports to the daughter catheter. The mother and daughter catheters may be inflated simultaneously (kissing balloons) to ensure that the stent is expanded to conform and engage with the native vessel wall. Once the procedure is complete, both balloons may be deflated and the delivery system may be removed from the patient.

[0073] Optionally, a second stent (daughter stent, not shown) may be placed over the daughter expandable member and deployed within the daughter vessel when the daughter catheter is fully expanded. The daughter catheter may be axially aligned with the mother catheter such that the proximal end of the daughter stent is adjacent or abuts a side hole in the mother stent.

[0074] An optional guidewire GW (shown in FIG. 7) may be used to aid in delivering both catheters, and thus both catheters may have a guidewire lumen. Optionally, the delivery system may also be advanced through a guide sheath or introducer catheter, as desired.

[0075] As discussed above, in some circumstances, the proximal edge of the stent, or the distal edge of the stent, or the edge of the side hole may get caught on the most distal edge of the guide sheath during proximal retraction of the delivery system into the guide sheath, or on the vessel wall during distal or proximal advancement of the delivery system through the vessel. Therefore, to avoid this, the proximal end of the mother expandable member, the proximal end of the daughter expandable member, the distal end of the mother expandable member, or the intermediate portion of either or both of the mother and daughter expandable members adjacent to the side hole may be pillow-shaped P to form a bulging barrier that will provide a protective barrier to the respective edges of the stent. Thus, the pillow proximal end of the mother or daughter expandable member provides a protective barrier that will protect and prevent the proximal edge of the mother stent from getting caught on anything. The pillow distal end of the mother catheter or daughter catheter will provide a protective barrier that will protect and prevent the distal edge of the mother stent from getting caught on anything. Similarly, the pillowing of the middle portion of the mother or daughter expandable member will provide a protective barrier that will protect and prevent the edges of the side holes from getting caught on anything. The middle portion of the mother or daughter expandable member is disposed between the proximal and distal ends of the respective expandable member. The pillowing, sometimes also referred to herein as dumbbells or protrusions, can be formed using any of the manufacturing techniques disclosed herein or otherwise known in the art.

[0076] In embodiments where a daughter stent is disposed over the daughter expandable member, the distal end of the daughter balloon may also be pillow-shaped to provide a protective barrier that helps protect and prevent the distal edge of the daughter stent from getting caught on anything.

[0077] FIG. 7A shows a flow chart illustrating an embodiment of a method of delivering the stent delivery system of FIG. 7 to a treatment area.

[0078] The method may use any of the stent delivery systems described herein (750). The stent delivery system is advanced to the target treatment site and, if optional pillowing is used as described herein, the stent edges are protected by the pillowing (752). The pillowing may protect the proximal, distal, or mid-edges of the stent during proximal advancement through the vessel or introducer or sheath. The pillowing may also protect the proximal, distal, or mid-edges of the stent during distal retraction through the vessel or sheath or introducer. The pillowing may also protect and prevent unwanted scraping or removal of a therapeutic agent carried by any coating disposed on the mother stent, daughter stent, or any stent, or any of the stents or stents. Pillowing may be included on the mother stent, optional daughter stent, or on both the mother stent and the daughter stent. The mother stent is aligned with the mother vessel treatment site. Optional repositioning may be required (754). The pillowing protects the stent edges and any coating or therapeutic agent delivered by the stent during repositioning. The daughter balloon may be partially inflated or the mother balloon may be partially inflated (756) to allow relative movement of the daughter catheter to the mother catheter. The daughter catheter is aligned with the daughter vessel treatment area (758). Optional pillowing protects the stent edges or any therapeutic agent or coating delivered by the stent or stents during optional repositioning. Once the mother and daughter catheters are properly positioned at the treatment site, the mother balloon may be fully inflated to radially expand the mother stent into the mother vessel (760). If the daughter catheter includes a daughter stent, the daughter balloon may be fully inflated to expand the daughter stent into the daughter vessel (762). Optionally, kissing balloons may be used where both the mother and daughter balloons are inflated simultaneously to hold both stents in place and ensure uniform radial expansion of the stent or stents (764). The stent delivery catheter may be removed from the patient once the procedure is complete (766).

[0079] 8A-8C, 8C1, and 8D-8H illustrate a method for manufacturing a fully crimped stent delivery system with a pillow-like expandable member, such as the system described above in FIG.

[0080] 8A shows the pre-crimping of a distal portion 802 of a mother stent 804 disposed over a mother balloon 806 on the distal end of a mother extension shaft 808. The stent 804 is disposed adjacent to proximal and distal radiopaque marker bands 810, 812 on the extension shaft 808 to mark the proximal and distal ends of the mother stent 804, which also mark the proximal and distal ends of the working length of the balloon. Here, the partial crimping is a loose crimping performed with fingers or a crimping tool or crimping fixture (e.g., a collapsible iris) to crimp the mother stent to the mother balloon enough to prevent it from easily falling off during processing, but not necessarily with enough retention force to stay in place during use (e.g., delivery through a vessel). The stent distal 802 at the side hole 814 is partially crimped to the mother balloon 806. A proximal portion 816 of the stent 804 proximal to the side hole 814 remains uncrimped. The side hole 814 may be left uncrimped or may be partially crimped.

[0081] 8B shows the distal portion 802 of the mother stent 804 fully crimped onto the mother balloon 806. Here, a constraining sheath 818 is placed over the stent 804, covering the side holes 814 and the proximal portion 816 of the stent 804. The distal portion 802 of the stent 804 is then placed into a crimping tool or machine (not shown) and fully crimped onto the balloon. Full crimping prevents the stent from moving axially along the mother elongated balloon 806 during delivery of the catheter through the vessel. As discussed above, heat and pressure may be applied to the balloon 806 and stent 804 to allow the balloon to pillow upwardly into the openings of the stent 804, thereby improving stent retention after crimping.

[0082] 8C shows a daughter catheter 820 with a daughter balloon 822 slidably advanced under the proximal end 816 of the mother stent 804 and out of the side hole 814. The proximal end 816 of the stent 804 remains uncrimped, allowing the daughter catheter 820 to be slidably advanced under the stent 804. Optionally, the daughter catheter 820 may include a daughter stent (seen in FIG. 8C1 ) that is fully crimped over the daughter balloon 822, although this will be omitted in this example for ease of illustration and discussion.

[0083] FIG. 8C1 is substantially identical to FIG. 8C, but in this embodiment, the optional daughter stent 824 is fully crimped onto the daughter balloon 822 (e.g., the stent will not slide or otherwise move relative to the daughter balloon 822 during use, such as delivery through a vessel). The daughter stent 824 may be of any length, but in some embodiments may be approximately half the length of the mother stent 804. The daughter stent 824 is positioned between a proximal radiopaque marker 826 and a distal radiopaque marker 828 on the daughter catheter 820 to mark the end of the stent 824. The daughter stent 824 may be distal to the mother stent 804 with little or no overlap between the two stents, such that the profile of the device is minimized during delivery. Other aspects of the elongated shaft 808 and the mother catheter with the mother stent 804 are generally identical to those disclosed above and previously in FIGS. 8A-8C.

[0084] 8D shows the formation of a distal pillow region 830 on a mother balloon 806 that is placed under a mother stent 804. Here, a first sheath 832, such as a polyimide tube, is placed over the distal crimped stent portion 802 to prevent it from expanding when pressurized and heated. A second sheath 834 having a larger inner diameter is placed over the mother stent 804 and mother balloon 806 (or, at a minimum, over the distal region 830 as pillow-like and the proximal region 836 as pillow-like) to allow the mother balloon 806 to expand slightly when inflated under pressure and heat, forming the proximal and distal pillow regions on the mother balloon.

[0085] Figure 8E shows the second sheath, removed from Figure 8D, with the proximal and distal pillowing 836, 830 on the mother balloon 806. The innermost sheath 832 remains positioned over the distal crimped region 802 of the mother stent 804. The proximal and distal ends of the daughter balloon that are not covered by the mother stent 804 remain relatively flat and unprotruding until the optional pillows on the daughter balloon are then formed.

[0086] FIG. 8F shows the formation of a daughter balloon pillow region 838 adjacent to the side hole 814 of the mother stent 804. Here, an inner sheath 840 is placed over the daughter balloon 822 and fits tightly over the distal portion of the daughter balloon, maintaining the original balloon pleats and folds and restraining the balloon 822 from expanding during expansion under heat and pressure. The inner sheath 840 does not cover the portion 838 of the daughter balloon 822 closest to the side hole 814 of the mother stent 804 (the area that should be pillow-like). A second, larger diameter sheath 842 is placed over the inner sheath 840 and the center or middle portion of the daughter balloon 822 is allowed to expand slightly during expansion under heat and pressure, which forms the pillow region 838 adjacent the edge of the side hole 814 in the stent. The proximal portion 844 of the daughter balloon 822 may be slightly pillow-like or remain generally flat.

[0087] 8G and 8H illustrate the pillowing 838 in the daughter balloon created around the side hole 814 of the mother stent 804 of FIG. 8F above, and also the proximal pillowing 836, 844 of the mother and daughter balloons formed in FIG. 8D. The sheath has been removed, and the pillowy daughter balloon proximal to the side hole and the pillowy mother and daughter balloons proximally are also visible. The pillowy areas provide a protective barrier adjacent to the respective stent edges, forming a raised layer of balloon material that prevents the stent edges from catching on other surfaces, which could cause the stent to bend, deform, or eject from the balloon. The pillowy edges also help prevent the therapeutic agent delivered by the mother or daughter stent or any coatings placed thereon from being scratched or otherwise damaged.

[0088] 8G and 8H also show that after formation of the middle pillow region 838, the proximal portion of the mother stent (the area proximal to the side hole) can be fully crimped onto both the mother and daughter balloons by placing it in a crimping tool or crimping machine where the stent is compressed onto both the mother and daughter proximal balloons. A sheath (not shown) may be placed over the proximal portion of the mother stent to restrain it and prevent it from expanding during the crimping process where the stent is crimped onto both the mother and daughter balloons while the balloons are partially expanded under heat and pressure. FIG. 8H shows a close-up view of the middle and proximal ends of the mother stent.

[0089] 8A-8H highlight the fabrication of a stent delivery system with only a mother stent. One skilled in the art will appreciate that if an optional daughter stent is crimped over the daughter balloon, the daughter stent will be fully crimped onto the daughter stent and therefore will not move during use (e.g., delivery through a vessel). The formation of the pillows around the daughter stent is substantially the same as described above in the preceding paragraphs, except that the daughter stent may be covered with a restraining sheath to prevent unwanted expansion of the daughter stent during pillow formation under the application of pressure and heat.

[0090] In addition, one skilled in the art will understand that any one or combination of stents (e.g., mother stent, daughter stent), any combination of balloons (e.g., mother balloon, daughter balloon), and any combination of pillowings (e.g., proximal mother balloon pillow, distal mother balloon pillow, mother balloon pillow around mother stent side hole, proximal daughter balloon pillow, distal daughter balloon pillow, daughter balloon pillow around mother stent side hole, etc.) may be used within any of the stent delivery systems described herein. Notes and Examples

[0091] The following non-limiting examples detail certain aspects of the present subject matter to, inter alia, solve the problems and provide the benefits discussed herein.

[0092] Example 1 is a stent delivery system for treating a bifurcated vessel, the system including: a first elongate shaft, the first elongate shaft having a proximal end, a distal end, and a first expandable member coupled to the distal end of the first elongate shaft; a first stent, the first stent having a proximal end, a distal end, and a sidewall with a side hole disposed therethrough, the side hole being disposed between the proximal and distal ends of the first stent, the first stent being disposed over the first expandable member; and a second elongate shaft. the second elongated shaft having a proximal end, a distal end, and a second expandable member coupled to the distal end of the second elongated shaft, the second elongated shaft being slidably positioned under the proximal end of the first stent and extending out of the side hole, the first stent being fully crimped over the proximal and distal portions of the first expandable member and the proximal portion of the second expandable member to prevent axial movement of the first stent along the first or second elongated shaft during delivery.

[0093] Example 2 is the system of example 1, wherein a distal portion of the first expandable member is pillow-shaped to provide a protective barrier to protect a distal edge of the first stent.

[0094] Example 3 is the system of any of Examples 1-2, wherein the proximal portion of the first expandable member is pillow-shaped to provide a protective barrier to protect the proximal edge of the first stent.

[0095] Example 4 is the system of any of Examples 1-3, wherein the proximal portion of the second expandable member is pillow-shaped to provide a protective barrier to protect the proximal edge of the first stent.

[0096] Example 5 is any of the systems of Examples 1-4, wherein an intermediate portion of the first expandable member is disposed between the proximal and distal ends of the first expandable member and is pillow-shaped to provide a protective barrier to protect the edges of the side hole.

[0097] Example 6 is any of the systems of Examples 1-5, wherein an intermediate portion of the second expandable member is disposed between the proximal and distal ends of the second expandable member and is pillow-shaped to provide a protective barrier to protect the edges of the side hole.

[0098] Example 7 is the system of any of Examples 1-6, wherein the first stent remains fully crimped onto the first expandable member such that the stent does not move axially relative to the first elongate shaft during delivery, while expansion of the second expandable member radially expands a proximal portion of the first stent, thereby allowing the second elongate shaft to slide relative to the first elongate member.

[0099] Example 8 is any of the systems of Examples 1 to 7, wherein expansion of the first expandable member radially expands the first stent, thereby enabling axial movement of the first and second elongate shafts relative to the first stent.

[0100] Example 9 is the system of any of Examples 1-8, further comprising a second stent disposed over the second expandable member, the second stent being fully crimped to the second expandable member, thereby preventing axial movement of the second stent relative to the second elongate shaft during delivery thereof.

[0101] Example 10 is a stent delivery system for treating a bifurcated vessel, the system including a first elongate shaft having a proximal end, a distal end, and a first expandable member coupled to the distal end of the first elongate shaft; a first stent, the first stent having a proximal end, a distal end, and a sidewall with a side hole disposed therethrough, the side hole being disposed between the proximal and distal ends of the first stent, the first stent being disposed over the first expandable member; and a second elongate shaft, the second elongate shaft having a proximal end, a distal end, and a second expandable member coupled to the distal end of the second elongate shaft, the second elongate shaft delivering the first stent to the first expandable member. and a second elongate shaft slidably disposed under the proximal end of the first expandable member and extending out of the side hole, wherein the first stent is fully crimped over the proximal and distal portions of the first expandable member and the proximal portion of the second expandable member to prevent axial movement of the first stent along the first elongate shaft or the second elongate shaft during delivery, the distal portion of the first expandable member is pillowed to provide a protective barrier protecting a distal edge of the first stent, the proximal portion of the first expandable member is pillowed to provide a protective barrier protecting a proximal edge of the first stent, and the proximal portion of the second expandable member is pillowed to provide a protective barrier protecting a proximal edge of the first stent.

[0102] Example 11 is the system of example 10, wherein an intermediate portion of the first expandable member disposed between the proximal and distal ends of the first expandable member is pillow-shaped to provide a protective barrier to protect edges of the side holes.

[0103] Example 12 is a system of any of Examples 10-11, wherein an intermediate portion of the second expandable member disposed between the proximal and distal ends of the second expandable member is pillow-shaped to provide a protective barrier to protect the edges of the side hole.

[0104] Example 13 is the system of any of Examples 10-12, wherein the first stent remains fully crimped onto the first expandable member such that the first stent does not move axially relative to the first elongate shaft during delivery, while expansion of the second expandable member radially expands a proximal portion of the first stent, thereby allowing the second elongate shaft to slide relative to the first elongate member.

[0105] Example 14 is any of the systems of Examples 10 to 13, wherein expansion of the first expandable member radially expands the first stent, thereby enabling axial movement of the first and second elongate shafts relative to the first stent.

[0106] Example 15 is any of the systems of Examples 10-14, further comprising a second stent disposed over the second expandable member, the second stent being fully crimped to the second expandable member, thereby preventing axial movement of the second stent relative to the second elongate shaft during delivery thereof.

[0107] Example 16 is a method for treating a branched vessel, the method including providing a stent delivery system comprising a first elongated shaft having a first expandable member, a first stent disposed across the first expandable member, and a second elongated shaft having a second expandable member; and advancing the stent delivery system through a vessel toward the branched vessel, wherein the first stent is fully crimped onto both the first and second expandable members and disposed across the first and second expandable members without movement of the first stent relative to the first or second elongated shafts during the advancement. radially expanding the second elongate shaft while the first stent remains coupled to the first expandable member without relative movement therebetween during the advancement, expanding the second elongate shaft radially to expand a proximal portion of the first stent and allowing axial movement of the second elongate shaft relative to the first elongate shaft, sliding the second elongate shaft axially under the first stent and through a side hole in the first stent to position the second expandable member at a desired location, and radially expanding the first expandable member to expand the first stent into engagement with a treatment area in the branch vessel.

[0108] Example 17 is the method of example 16, wherein advancing the stent delivery system includes protecting a distal edge of the first stent with a pillow distal region of the first expandable member providing a protective barrier in front of the distal edge of the first stent.

[0109] Example 18 is the method of any of Examples 16-17, wherein advancing the stent delivery system includes protecting the edges of the side hole with a pillow intermediate region of the first expandable member or the second expandable member, the pillow intermediate region being disposed between the proximal and distal ends of each of the first or second expandable members, and the pillow region providing a protective barrier in front of the edges of the side hole of the first stent.

[0110] Example 19 is the method of any of Examples 16-18, wherein advancing the stent delivery system includes protecting a proximal edge of the first stent with a pillow proximal region of the first expandable member or the second expandable member, the pillow region providing a protective barrier in front of the proximal edge of the first stent.

[0111] Example 20 is the method of any of Examples 16-19, further comprising radially expanding a second stent into the target treatment area of ​​the branched vessel, the second stent being disposed over the second expandable member and fully crimped thereto prior to radial expansion of the second stent.

[0112] Example 21 is a method of manufacturing a stent delivery system for treating a bifurcation, the method including: fully crimping a distal portion of a first stent onto a first expandable member; inserting a second expandable member under a proximal end of the first stent and out a side hole in a side wall of the first stent; forming proximal and distal pillow regions on the first expandable member that protect respective proximal and distal edges of the first stent; forming an intermediate pillow region on the second expandable member that protects edges of the side holes of the first stent; and fully crimping the proximal portion of the first stent onto the first and second expandable members.

[0113] Example 22 is the method of example 21, further comprising partially crimping a distal portion of the first stent to the first expandable member prior to fully crimping the first stent to the first expandable member.

[0114] Example 23 is the method of any of Examples 21-22, further comprising centering the first stent over the first expandable member prior to the partially crimping.

[0115] Example 24 is the method of any of examples 21-23, wherein forming the proximal or distal pillow region includes expanding the first expandable member under heat and pressure.

[0116] Example 25 is the method of any of examples 21-24, wherein forming the intermediate pillow region includes expanding the second expandable member under heat and pressure.

[0117] In Example 26, the apparatus or method of any one or any combination of Examples 1-25 can be optionally configured such that all of the elements or options listed are available for use or selection from.

[0118] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples." Such examples may include elements in addition to those shown or described. However, the inventors also contemplate examples in which only those elements shown or described are provided. The inventors also contemplate examples that use any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof) or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0119] In the event of inconsistency in usage between this document and any document so incorporated by reference, the usage in this document takes precedence.

[0120] The terms "a" or "an" are used herein to include one or more than one, as is common in patent documents, regardless of any other instance or usage of "at least one" or "one or more." The term "or" is used herein to refer to non-exclusive, or "A or B" to include "A but not B," "B but not A," and "A and B," unless otherwise indicated. The terms "including" and "in which" are used herein as the plain English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, i.e., a system, device, article, composition, formulation, or process that includes elements in addition to those recited after such term in the claim will still be considered to fall within the scope of the claim. Also, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

[0121] The above description is intended to be illustrative, not restrictive. For example, the embodiments described above (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be used, etc., by those of ordinary skill in the art upon review of the above description. The Abstract is provided to enable the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above detailed description, various features may be grouped together to streamline the disclosure. This should not be construed as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of the disclosed embodiments. Thus, the following claims are incorporated herein as examples or embodiments into the detailed description, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the present invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. 1. A stent delivery system for treating a bifurcated vessel, the system comprising: a first elongate shaft having a proximal end, a distal end, and a first expandable member coupled to the distal end of the first elongate shaft; a first stent having a proximal end, a distal end, and a sidewall with a side hole disposed therethrough, the side hole being disposed between the proximal and distal ends of the first stent, the first stent being disposed over the first expandable member; a second elongate shaft having a proximal end, a distal end, and a second expandable member coupled to the distal end of the second elongate shaft, the second elongate shaft being slidably positioned beneath the proximal end of the first stent and extending out of the side hole; Equipped with The system wherein the stent is fully crimped over the proximal and distal portions of the first expandable member and the proximal portion of the second expandable member to prevent axial movement of the first stent along the first elongate shaft or the second elongate shaft during delivery.

2. The system of claim 1 , wherein the distal portion of the first expandable member is pillow-shaped to provide a protective barrier that protects the distal edge of the first stent.

3. The system of claim 1 , wherein the proximal portion of the first expandable member is pillow-shaped to provide a protective barrier that protects the proximal edge of the first stent.

4. The system of claim 1 , wherein the proximal portion of the second expandable member is pillow-shaped to provide a protective barrier that protects the proximal edge of the first stent.

5. 2. The system of claim 1, wherein an intermediate portion of the first expandable member is disposed between the proximal and distal ends of the first expandable member, the intermediate portion being pillow-shaped to provide a protective barrier that protects the edges of the side hole.

6. 2. The system of claim 1, wherein an intermediate portion of the second expandable member is disposed between the proximal and distal ends of the second expandable member, the intermediate portion being pillow-shaped to provide a protective barrier that protects the edges of the side hole.

7. The system described in claim 1, wherein expansion of the second expandable member radially expands the proximal portion of the first stent, thereby allowing the second elongation shaft to slide relative to the first elongation member, while the stent remains crimped to the first expandable member so that the stent does not move axially relative to the first elongation shaft during delivery.

8. 10. The system of claim 1, wherein expansion of the first expandable member radially expands the first stent, thereby enabling axial movement of the first and second elongate shafts relative to the first stent.

9. 10. The system of claim 1, further comprising a second stent disposed over the second expandable member, the second stent being fully crimped onto the second expandable member, thereby preventing axial movement of the second stent relative to the second elongate shaft during delivery thereof.

10. 1. A stent delivery system for treating a bifurcated vessel, the system comprising: a first elongate shaft having a proximal end, a distal end, and a first expandable member coupled to the distal end of the first elongate shaft; a first stent having a proximal end, a distal end, and a sidewall with a side hole disposed therethrough, the side hole being disposed between the proximal and distal ends of the first stent, the first stent being disposed over the first expandable member; a second elongate shaft having a proximal end, a distal end, and a second expandable member coupled to the distal end of the second elongate shaft, the second elongate shaft being slidably positioned beneath the proximal end of the first stent and extending out of the side hole; Equipped with the stent is fully crimped over the proximal and distal portions of the first expandable member and the proximal portion of the second expandable member to prevent axial movement of the first stent along the first elongate shaft or the second elongate shaft during delivery, the distal portion of the first expandable member is pillowed to provide a protective barrier that protects the distal edge of the first stent, the proximal portion of the first expandable member is pillowed to provide a protective barrier that protects the proximal edge of the first stent, and the proximal portion of the second expandable member is pillowed to provide a protective barrier that protects the proximal edge of the first stent.

11. 11. The system of claim 10, wherein an intermediate portion of the first expandable member disposed between the proximal and distal ends of the first expandable member is pillow-shaped to provide a protective barrier that protects the edges of the side hole.

12. 11. The system of claim 10, wherein an intermediate portion of the second expandable member disposed between the proximal and distal ends of the second expandable member is pillow-shaped to provide a protective barrier to protect the edges of the side hole.

13. The system described in claim 10, wherein expansion of the second expandable member radially expands the proximal portion of the first stent, thereby allowing the second elongation shaft to slide relative to the first elongation member, while the stent remains crimped to the first expandable member so that the stent does not move axially relative to the first elongation shaft during delivery.

14. 11. The system of claim 10, wherein expansion of the first expandable member radially expands the first stent, thereby enabling axial movement of the first and second elongate shafts relative to the first stent.

15. 11. The system of claim 10, further comprising a second stent disposed over the second expandable member, the second stent being fully crimped onto the second expandable member, thereby preventing axial movement of the second stent relative to the second elongate shaft during delivery thereof.

16. 1. A stent delivery system for treating a bifurcated vessel, comprising: The system includes a first elongate shaft having a first expandable member, a first stent disposed over the first expandable member, and a second elongate shaft having a second expandable member; the stent delivery system is configured to be advanced through a blood vessel toward the branch vessel, the stent being fully crimped onto both the first and second expandable members and remaining disposed across the first and second expandable members without movement of the first stent relative to the first or second elongate shafts during the advancement; the second expandable member is configured to be radially expanded to expand a proximal portion of the first stent; the second elongate shaft is axially movable relative to the first elongate shaft; the second elongate shaft is axially slidable under the first stent and through a side hole in the first stent to position the second expandable member at a desired location; The system, wherein the first expandable member is configured to be radially expanded to expand the first stent into engagement with a treatment area within the branch vessel.

17. The system described in claim 16, wherein the first expandable member has a pillow-shaped distal region that provides a protective barrier in front of the distal edge of the first stent to protect the distal edge of the first stent.

18. The system described in claim 16, wherein the first expandable member or the second expandable member has a pillow-shaped intermediate region disposed between the proximal and distal ends of the respective first or second expandable member, and the pillow-shaped intermediate region provides a protective barrier in front of the edge of the side hole of the first stent to protect the edge of the side hole.

19. The system described in claim 16, wherein the first expandable member or the second expandable member has a pillow-shaped proximal region, the pillow-shaped region providing a protective barrier in front of the proximal edge of the first stent to protect the proximal edge of the first stent.

20. The system of claim 16, further comprising a second stent configured to be radially expanded into a target treatment area of the branch vessel, the second stent being positioned across the second expandable member and fully crimped thereto prior to radial expansion of the second stent.

21. 1. A method of manufacturing a stent delivery system for treating a bifurcation, the method comprising: fully crimping a distal portion of the first stent onto the first expandable member; inserting a second expandable member under the proximal end of the first stent and out a side hole in a side wall of the first stent; forming proximal and distal pillow regions on the first expandable member that protect respective proximal and distal edges of the first stent; forming an intermediate pillow-like region on the second expandable member that protects the edges of the side holes of the first stent; fully crimping a proximal portion of the first stent onto the first and second expandable members; A method comprising:

22. 22. The method of claim 21, further comprising partially crimping the distal portion of the first stent to the first expandable member prior to fully crimping the first stent to the first expandable member.

23. 23. The method of claim 22, further comprising centering the first stent over the first expandable member prior to the partial crimping.

24. 22. The method of claim 21, wherein forming the proximal or distal pillow-like region comprises expanding the first expandable member under heat and pressure.

25. 22. The method of claim 21, wherein forming the intermediate pillow-like region comprises expanding the second expandable member under heat and pressure.

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