Device used to expand the stent

Abstract

An apparatus for expanding a stent is provided, comprising: a tubular member including a proximal end; a distal end sized for introduction into a patient's body; and one or more lumens extending between the proximal and distal ends; and a balloon carried on the distal end, the balloon comprising: a first membrane including a first end and a second end attached to the distal end; a central region extending between a first tapered region and a second tapered region transitioning to the first and second ends, respectively; and a second membrane extending from the second tapered region partially toward the first tapered region to surround a first region of the central region to reinforce the first region, the central region further defining a second region that remains uncovered between the second membrane and the second tapered region, wherein the first membrane is formed of an elastic material and the second membrane is formed of a material having an elasticity equal to or less than that of the first membrane.

Description

[0001] This application is a divisional application of the Chinese national phase patent application with international application number PCT / US2018 / 024653, international application date March 27, 2018, and invention name “Balloon Catheter and Method of Use”, which entered the Chinese national phase on September 20, 2019 and has application number 201880019695.4. Field of the Invention

[0002] The present invention generally relates to devices and methods for treating stenoses, occlusions, or other lesions within a body lumen, such as an artery or other blood vessel, and more particularly to devices and methods for expanding or otherwise dilating a stent, artificial valve, or other prosthesis deployed within a body lumen, such as a branch vessel including an opening extending from a main vessel or trunk. Background Art

[0003] Tubular endoprostheses, or "stents," have been proposed for use in dilating or otherwise treating stenoses, occlusions, and / or other pathologies within a patient's vasculature or other body lumens. For example, a self-expanding stent can be maintained in a contracted state on a catheter, for example, by an overlying sheath or other restraining device, and delivered to a target location, such as a stenosis, within a blood vessel or other body lumen. Once the stent is positioned at the target location, the restraining device can be removed, whereupon the stent can automatically expand to dilate or otherwise line the vessel at the target location. Alternatively, a balloon-expandable stent can be carried on a catheter in a contracted state, for example, crimped or otherwise secured to a balloon. Once the stent is positioned at the target location, the balloon can be inflated to expand the stent and dilate the vessel. For example, a stenosis in an artery supplying the heart can result in low flow conditions within the vessel, which can cause ischemia and / or infarction in the organ supplied by the vessel, such as the heart. Sometimes, a stenosis or other pathology may occur at an opening or bifurcation, i.e., where a branch vessel extends from a main vessel or trunk. In such cases, it may be difficult to visualize the lesion and / or accurately position the stent within the ostium and / or branch vessel.

[0004] Typically, when a stent is deployed in such an anatomical structure, one end of the stent may extend from the opening into a major vessel, such as from a coronary artery, common carotid artery, or peripheral artery into the aorta. This positioning of the stent may create difficulties during future intraluminal interventions, such as re-entering a branch vessel, which may require re-traversing the stent. In addition, there may be a risk that the end of the stent extending from the opening may cause damage to adjacent structures, such as the aortic valve leaflets adjacent to the opening of the coronary vessel. In addition, there may be little or no contact between the stent and the wall of the opening, which may result in suboptimal treatment of the lesion.

[0005] To address these issues, it has been proposed to over-expand or flare the end of the stent that extends into the main vessel, for example to guide the end of the stent against or closer to the wall of the opening. Thus, in the event that future intravascular studies or interventions are required, it may be easier to re-cross the stent. Furthermore, in the case of coronary stents, flaring the end of the stent that extends into the aorta can also move the end further away from the aortic lumen and reduce the risk of damage to the aortic leaflets. Furthermore, direct contact or closer positioning of the stent relative to the wall of the opening can result in improved treatment of the lesion.

[0006] Therefore, devices and methods for deploying and / or otherwise expanding a stent or other prosthesis would be useful. Summary of the Invention

[0007] The present invention relates to devices and methods for treating stenosis, occlusion, or other pathology within a body lumen, such as an artery or other blood vessel. More particularly, the present invention relates to devices and methods for expanding and / or otherwise dilating a stent, artificial valve, or other prosthesis deployed within a body lumen, such as a stent deployed within a branch vessel that includes an opening extending from another main vessel or trunk.

[0008] According to one embodiment, a device for expanding a stent, artificial valve, or other prosthesis is provided, the device comprising: a tubular member comprising a proximal end; a distal end sized for introduction into a patient's body; and one or more lumens extending between the proximal and distal ends; and a balloon carried on the distal end. The balloon comprises: a first membrane comprising a first end and a second end attached to the distal end; and a central region extending between a first tapered region and a second tapered region transitioning to the first and second ends, respectively; and a second membrane partially surrounding the central region from the second tapered region toward the first tapered region to define a reinforced region of the balloon, wherein the first membrane is formed of an elastic material and the second membrane is formed of a material having an elasticity equal to or less than that of the first membrane.

[0009] According to another embodiment, a device for deploying a stent is provided, the device comprising: a tubular member comprising a proximal end; a distal end sized for introduction into a patient's body; and one or more lumens extending between the proximal and distal ends; and a balloon carried on the distal end. The balloon comprises: a first membrane comprising a first end and a second end attached to the distal end; a central region extending between first and second tapered regions transitioning to the first and second ends, respectively; and a second membrane surrounding a portion of the central region spaced apart from the first and second tapered regions to define a reinforced central region of the balloon, wherein the first membrane is formed of an elastic material and the second membrane is formed of a material having an elasticity equal to or less than that of the first membrane.

[0010] According to another embodiment, a method for expanding a prosthesis previously deployed in a patient's body is provided, the method comprising: providing an elongated member comprising: a proximal end, a distal end, a balloon on the distal end, the balloon comprising a first elastic membrane and a second membrane, the second membrane being on a reinforced region adjacent to an unreinforced region of the first membrane; introducing the distal end into a body cavity adjacent to the prosthesis with the balloon in a deflated state; positioning the balloon through the prosthesis such that the reinforced region is disposed within the prosthesis; initially inflating the balloon such that the unreinforced regions both expand to a first diameter such that the reinforced regions engage the prosthesis with the reinforced regions; and further inflating the balloon such that the unreinforced regions continue to expand to expand one end of the prosthesis while the reinforced region of the balloon remains at the first diameter.

[0011] Other aspects and features of the present invention will become apparent upon consideration of the following description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings illustrate exemplary embodiments of the present invention, in which:

[0013] Figure 1 is a side view of an exemplary embodiment of a catheter including a balloon having a first region and a second reinforced region to control expansion of the balloon.

[0014] Figure 2A and Figure 2B The balloon is shown to be made of a first film and a second film, such as Figure 1 An exemplary method of placing a balloon on a catheter.

[0015] Figure 2C It can be used to make balloons, such as Figure 1 Side view of an alternative embodiment of a first membrane of a balloon on a catheter.

[0016] Figures 3A to 3F is a cross-sectional view of a patient's body including an opening communicating between a main vessel and a branch vessel, illustrating the use of Figure 1 A method for expanding a previously deployed stent in a branch vessel using a device.

[0017] Figure 4 is a side view of another exemplary embodiment of a catheter including a balloon having a reinforced central region to control expansion of the balloon.

[0018] Figures 5A to 5C is a cross-sectional view of a patient's body illustrating an exemplary method of expanding a prosthetic heart valve implanted within a replaced portion of a native valve.

[0019] Figure 6 is a graph illustrating exemplary expansion profiles of unreinforced and reinforced regions of a balloon relative to the internal pressure within the balloon.

[0020] Figure 7 is a graph illustrating exemplary expansion profiles of unreinforced and reinforced regions of a balloon relative to the internal volume of the inflation medium within the balloon. DETAILED DESCRIPTION

[0021] Go to the attached figure, Figure 1 An exemplary embodiment of an apparatus 10 for deploying and / or otherwise expanding a stent or other prosthesis (not shown), for example, within or near an opening or other bifurcation between a main lumen and a branch lumen (also not shown), is shown. Generally speaking, the apparatus 10 includes a catheter or other elongated tubular member 12 having a proximal end 14, a distal end 16, and one or more lumens 18 extending therebetween, thereby defining a longitudinal axis 19 extending therebetween.

[0022] As shown, the catheter 12 can include a balloon or other expandable member 20 on the distal end 16, for example, including multiple areas for expanding and / or otherwise expanding a stent, artificial valve, or other tubular prosthesis previously deployed in a body cavity (not shown) as further described below. In addition, the distal end 16 can include one or more markers, such as one or more bands of radiopaque material (not shown), to help position the catheter 12 relative to the stent and / or the patient's body. Optionally, the device 10 can be provided as a kit or system that includes one or more additional components, such as a syringe, a guide catheter, and / or one or more guide wires (not shown).

[0023] Conduit 12 can be formed by one or more tubular bodies such as have variable flexibility along its length.For example, distal end 16 can be flexible substantially to help introduce through tortuous anatomical structure, for example, terminate at rounded, tapered and / or other substantially non-damaged distal tips 17. The size and / or shape of distal end 16 can be designed to be introduced into body cavity, for example, have between about one millimeter and seven millimeters (1 to 7mm), or be less than the diameter of 1.7 millimeters. Proximal end 14 can be flexible, semi-rigid or rigid substantially, for example, have enough breaking strength (column strength) to help make distal end 16 advance through patient's vascular system by pushing proximal end 14. Optionally, shaft support wire or other reinforcement (not shown) can be provided in proximal end 14 (if necessary), for example, to help promote conduit 12 from proximal end 14. Conduit 12 can be by plastics, metal or composite material, for example, have the plastic material of line, braid or coil core to form, and this can prevent conduit 12 from kinking or buckling during advancement.

[0024] like Figure 1 As shown, the catheter 12 can include a handle 50 on the proximal end 14, for example to assist in manipulating the catheter 12. As further described below, the handle 50 can include one or more ports 52 that are communicated with the corresponding lumen 18 in the catheter 12. The handle 50 can be molded, machined, or otherwise formed from plastic, metal, or a composite material, for example to provide a housing that can be contoured or otherwise shaped for ease of manipulation. The proximal end 14 of the catheter 12 can be attached to the handle 50, for example, by bonding, a mating connector, an interference fit, or the like. Optionally, if the device 10 includes any actuatable components (not shown) on the distal end 16, the handle 50 can include one or more actuators (also not shown), such as one or more sliders, dials, buttons, or the like, to actuate or otherwise manipulate the components from the proximal end 14.

[0025] exist Figure 1 In the exemplary embodiment shown, the catheter 12 includes at least two lumens 18 extending between the proximal end 14 and the distal end 16. For example, the catheter 12 can include an inflation lumen 18a that extends from a port 52a in the handle 50 through the catheter 12 to an opening (not shown) that communicates with the interior of the balloon 20. The opening 52a in the handle 50 can include a connector, such as a Luer lock connector (not shown), one or more seals (also not shown), etc. An inflation medium and / or vacuum source, such as a syringe (not shown) filled with saline or other inflation medium, can be connected to the port 52a, for example, directly or via tubing (also not shown), to expand and / or deflate the balloon 20.

[0026] In addition, the catheter 12 may include an instrument lumen 18b extending from a port 52b in the handle 50 to an opening 17a in the distal tip 17. As further explained below, the instrument lumen 18b may be of sufficient size to allow a guidewire or other guide rail or instrument (not shown) to be inserted therethrough, for example, to facilitate advancement of the catheter 12 over the guide rail. The handle 50 may include one or more seals (also not shown) that prevent fluid, such as blood, from flowing proximally from the port 52b while allowing one or more instruments to be inserted therethrough and into the instrument lumen 18b. Alternatively, a "quick exchange" instrument lumen may be provided in place of lumen 18b, extending from a side port (not shown) at an intermediate location on the catheter 12 to the opening 17a. The lumens 18a, 18b may be disposed adjacent to each other, for example, along the entire length of the catheter 12, or alternatively, disposed within the body of the catheter 12 in a concentric or other arrangement, or in different arrangements at different locations as desired.

[0027] Continue to refer Figure 1 , the balloon 20 generally includes a first or proximal region 20a and a second or distal region 20b. Generally speaking, as further described elsewhere herein, when fully inflated, the proximal region 20a of the balloon 20 can expand to a spherical or other shape, and the distal region 20b can expand to, for example, a substantially uniform cylindrical shape having a smaller diameter than the proximal region 20a.

[0028] Additional references Figure 2A and Figure 2B The balloon 20 may include a first membrane or layer 22 including a proximal end 24 and a distal end 26 that are bonded or otherwise secured to the distal end 16 of the catheter 12, such as by bonding with an adhesive, sonic welding, using an annular collar or sleeve, etc. In addition, the balloon 20 may include a second membrane or layer 32 that is bonded or otherwise attached to the first membrane 22, such as by bonding with an adhesive, sonic welding, using an annular collar or sleeve, etc.

[0029] exist Figure 2A and Figure 2B In the exemplary embodiment shown, the first membrane 22 can be formed from a compliant or semi-compliant polymer or other plastic material, such as polyethylene, polyurethane, nylon, silicone, low to medium hardness PEBAX, etc., using conventional methods, such as blow molding, dip molding, etc. The first membrane 22 can be formed into a desired shape, for example, including a tapered proximal region 25 and a tapered distal region 27 that expand from a proximal end 24 and a distal end 26 to a central region 28. The central region 28 can have a substantially uniform diameter in a relaxed state, for example after molding, and the central region 28 can expand from the relaxed state, for example, during inflation of the balloon 20. Optionally, as Figure 2CAs shown, the first membrane 22' may include a central region 28', wherein the central region 28' includes a first region 28a' proximal to a second region 28b'. The first region 28a' and the second region 28b' may have substantially uniform diameters, wherein the first region 28a' has a diameter greater than the second region 28b', for example, having a diameter difference of about one millimeter (1.0 mm). As shown, the first membrane 28 may include a proximal tapered region 25', which transitions from the first region 28a' to the proximal end 24'; and a distal tapered region 27', which transitions from the second region 28b' to the distal end 26'. The first membrane 22 may have a substantially uniform wall thickness, for example, between the proximal end 24 and the distal end 26, or the wall thickness may vary as desired, for example, being thinner in the proximal region than in the distal region (for example, corresponding to Figure 2C A first region 28a' and a second region 28b' are shown).

[0030] The second membrane 32 can be formed from a substantially inelastic polymer or plastic material, such as PET, nylon, medium to high durometer PEBAX, or the like, or can be formed from a substantially elastic material, such as silicone, polyurethane, or polyethylene, so that the balloon 20 can expand to various sizes depending on the volume and / or pressure of the fluid within. The second membrane 32 can have a substantially cylindrical shape between its proximal end 34 and distal end 36, e.g., having a substantially uniform diameter and / or wall thickness in a relaxed state.

[0031] During manufacture, the first and second films 22, 32 can be formed separately, for example, by blow molding, dip molding, etc., and then the second film 32 can be attached to the central portion 28 of the first film 22, for example, to define the second region 20b of the balloon 20. As best seen in Figure 2B , the second film 32 can have a length shorter than the central region 28 of the first film 22. For example, the second film 32 can be positioned immediately above the central region 28, adjacent to the distal tapered region 27, such that a portion of the central region 28 remains uncovered between the second film 32 and the proximal tapered region 25, i.e., to provide the first region 20a of the balloon 20. After being positioned above the central region 28, the second film 32 can be attached to the outer surface of the first film 22 (substantially continuously or intermittently), for example, by bonding with an adhesive, sonic welding, melting, etc. Alternatively, the second film 32 can be attached to the inner surface of the central region 28 of the first film (not shown).

[0032] In another alternative, the second membrane 32 can be formed directly on the central region 28 of the first membrane 22. For example, the material of the second membrane 32 can be applied to the first membrane 22, such as by dipping or spraying. For example, with the first membrane 22 on a mandrel or inflated to open the first membrane 22, the central region 28 can be dipped into the material a distance sufficient to cover the desired length of the central region 28 with the material. In an exemplary embodiment, the material can be the same material used to form the first membrane 22, or can be a slightly stronger and / or less compliant material.

[0033] In one embodiment, the second membrane 32 can be formed from, for example, a semi-compliant or non-compliant material having less elasticity than the material of the first membrane 22. Alternatively, the first membrane 22 and the second membrane 32 can be formed from the same material, such as a compliant or semi-compliant material, e.g., having substantially the same thickness as the first membrane 28. Alternatively, the second membrane 32 can be formed from the same base material as the first membrane 22, but have different mechanical properties, e.g., having a thickness greater than the first membrane 22, having a reinforcing element (not shown) embedded therein, etc.

[0034] In an exemplary embodiment, the first region 20a can have a length between about six and sixteen millimeters (6.0 to 16.0 mm), while the second region 20b can have a length between about 5.5 and 13.5 mm, for example, between 11.5 and 13.5 mm. Additionally, or in the alternative, the first region 20a can have a diameter in a relaxed state (i.e., after manufacture, but before full inflation) between about four and eight millimeters (4.0 to 8.0 mm), and the second region 20b can have a diameter between about three and seven millimeters (3.0 to 7.0 mm).

[0035] return Figure 1 The resulting balloon 20 can be attached to the distal end 16 of the catheter 12, for example, by attaching the distal end 26 adjacent to the distal tip 17 and attaching the proximal end 24 to the distal end 16 proximal to the distal tip 17. Figure 1 As shown, the reinforced second region 20b is located distally of the first region 20a, i.e., closer to the distal tip 17 of the catheter 12. Optionally, in some applications, the orientation of the first region 20a and the second region 20b can be reversed, i.e., the reinforced second region 20b is located proximal to the first region 20a. The balloon 20 can be rolled, folded, or otherwise compressed above the distal end 16 of the balloon 20, for example, to provide a delivery state for introduction into a patient's body. Additional information about methods and / or materials for manufacturing the balloon 20 and / or catheter 12 can be found in U.S. Patent Nos. 7,582,111, 7,862,601, and 9,034,025, the entire disclosures of which are expressly incorporated herein by reference.

[0036] Due to the resulting differences in the mechanical properties of the first and second regions 20a, 20b, the balloon 20 can expand to different diameters and / or shapes when inflated. For example, due to the compliance of the first membrane material and the individual material layers used for the first region 20a, the first region 20a of the balloon 20 can expand to a shape that is larger than the relaxed, formed shape, e.g., where the amount of expansion is proportional to the volume and / or pressure of the fluid introduced into the interior of the balloon 20. In contrast, given the additional support provided by the second membrane 32, the second region 20b of the balloon 20 can expand to a predetermined cylindrical diameter that is smaller than the maximum expanded size of the first region 20a.

[0037] For example, as further described below, if the balloon 20 is inflated to an initial pressure between about three and five atmospheres (3 to 5 ATM), both the first region 20a and the second region 20b can expand substantially simultaneously (i.e., with minimal delay between one region and the other), for example, to engage a prosthesis in which the balloon 20 is positioned. Also as further described below, thereafter, the pressure can be further increased to a maximum pressure, for example, between about eight and twenty atmospheres (8 to 20 ATM), whereby the second region 20b can resist further expansion while the first region 20a continues to expand, for example, to open or otherwise shape the prosthesis. For example, where the initial diameter is between about 4 and 8 mm, the first region 20a, when exposed to the maximum pressure, can expand to a substantially spherical shape having a maximum outer diameter between about 9.0 and 12.5 mm.

[0038] Figure 6 1 and 2. Exemplary expansion profiles of the balloon 20 are shown that may be experienced when an inflation medium is introduced into the interior of the balloon 20. As pressure increases from 0 to P1, the first region 20a and the second region 20b can rapidly expand to their formed (e.g., molded) diameters, for example, with the second region 20b expanding to a diameter Dai and the first region 20a expanding to a diameter Dbi. As pressure further increases, the diameters of the first region 20a and the second region 20b can remain substantially unchanged due to the pressurization of the balloon 20. Once the balloon 20 reaches a threshold pressure P2 ("burst pressure"), further inflation causes the first region 20a to further expand, while the second region 20b remains at substantially the same diameter (e.g., Daf = Dai). As additional pressure is applied, the first region 20a can continue to expand, for example, until a desired final pressure P3 and diameter Dbf are achieved.

[0039] Figure 7 The volume of fluid introduced into the interior of the balloon 20 is shown (rather than Figure 6Another exemplary expansion profile that the balloon 20 may undergo based on internal pressure is shown in FIG. In this embodiment, as the volume within the balloon 20 increases from 0 to V1 (the "burst volume"), the first region 20a and the second region 20b may expand substantially simultaneously, e.g., to their formed diameters Dai and Dbi. If additional inflation medium is introduced beyond V1, the first region 20a may further expand, e.g., to Dbf, while the second region 20b remains substantially the same (e.g., Daf = Dai).

[0040] Optionally, one or more outer surfaces, such as outer surface 38 of second membrane 32 and / or outer surface 29a of first membrane 22 defining first region 20a of balloon 20, can include one or more features thereon for enhancing traction, friction, or engagement with other structures, such as stents, artificial valves, or other prostheses (not shown), that are contacted by balloon 20 during expansion. For example, outer surface 38 of second region 20b of balloon 20 can be treated or textured, can include ribs or other protrusions, and the like for increasing friction or other engagement after expansion (not shown).

[0041] Optionally, the balloon 20 can include one or more diagnostic and / or therapeutic elements. For example, in one embodiment, the outer surfaces 29a, 38 can carry one or more therapeutic agents, as further described elsewhere in the applications incorporated herein by reference, which can be pressed against the wall of a blood vessel, such as at an opening, a lesion, or into a branch. In another embodiment, one or more electrodes, ultrasonic elements, or other components (not shown) can be provided on the balloon to deliver energy to tissue contacted by the balloon 20.

[0042] Go to Figures 3A to 3F , an exemplary method of using apparatus 10 to deploy and / or otherwise expand a stent 40 deployed within the body of a patient, for example, including an opening 90. As shown, opening 90 can be an opening in the wall of a first or main lumen or trunk 92 that communicates with a second lumen or branch 94. In an exemplary embodiment, the main lumen 92 can be the ascending aorta or the descending aorta, and the branch lumen can be a coronary artery, a common carotid artery, or a peripheral artery. A stenosis, occlusion, or other lesion 96 may be present at and / or near the opening 90, for example, extending at least partially into the branch 94. The lesion 96 can include an atherosclerotic plaque, or other substance that partially or completely occludes the flow of blood or other fluid between the trunk 92 and the branch 94.

[0043] Initially, as Figure 3AAs shown, conventional methods can be used, for example, to introduce a guide wire 98 or other guide rail from the trunk 92 through the opening 90 into the branch 94. For example, a percutaneous puncture or lower incision can be made at a peripheral position (not shown), such as the femoral artery, carotid artery, or other entry site, and the guide wire 98 can be advanced from the entry site through the patient's vascular system, for example, alone or with the aid of a guide catheter (not shown). For example, the distal end of the guide catheter (not shown) can be advanced into the trunk 92 over the guide wire 98, for example, until the distal end is adjacent to or close to the opening 90. A guide catheter can be used to advance one or more instruments (such as any one of a catheter or other device described herein) over the guide wire 98 and into the trunk 92 and / or branch 94.

[0044] If lesion 96 completely occludes branch 94, guidewire 98 can be introduced through the occlusion, or other devices (not shown) can be advanced over or otherwise in conjunction with guidewire 98 to create a pathway for guidewire 98 through lesion 96, for example using conventional methods.

[0045] After guiding the guidewire 98 in the branch 94 beyond the lesion 96, it may be desirable to at least partially dilate the lesion 96. For example, an angioplasty catheter (not shown) can be advanced into and through the lesion 96 in the guide catheter and / or over the guidewire 98, whereupon a balloon or other element on the catheter can be inflated to at least partially dilate the lesion 96. If desired, other procedures can also be performed at the lesion 96 before implanting the stent 40, such as to soften, remove, or otherwise treat plaque or other material forming the lesion 96. After any such procedures are completed, any instruments advanced over the guidewire 98 can be removed.

[0046] To deliver the stent 40, any delivery catheter and / or conventional procedure may be used. For example, the distal end of a delivery catheter (not shown) may be advanced from the entry site into the trunk 92 over the guidewire 98 and / or in the guide catheter. For example, with the distal end of the guide catheter abutting or adjacent the opening 90, the distal end of the delivery catheter may be advanced from the guide catheter through the opening 90 and into the branch 94. The delivery catheter may be positioned so that the stent 40 extends into and through the lesion 96 and / or the branch 94. The stent 40 may be expanded and / or otherwise deployed from the delivery catheter, for example, using conventional methods, to place the stent 40 across the lesion 96 and / or within the branch 94. For example, as Figure 3B As shown, the stent 40 may be deployed such that the first end 42 of the stent 40 extends at least partially into the opening 90 and / or trunk 92 , and the second end 44 of the stent 40 is positioned within the branch 94 beyond the lesion 96 .

[0047] As shown, the stent 40 can have a substantially uniform diameter cross-section after deployment. For example, the stent 40 can be expanded to enlarge and / or otherwise engage the lesion 96 and / or branch 94. Alternatively, as described below, the stent 40 can be partially expanded using a delivery catheter, thereby allowing the stent 40 to be further expanded by the device 10.

[0048] Go to Figure 3C , after which the distal end 16 of the catheter 12 (with the balloon 20 in its deflated state) can be introduced into the trunk 92 to deploy and / or otherwise expand the stent 40. For example, the delivery catheter can be removed and the distal end 16 of the catheter 12 can be advanced into the trunk 92 over the same guidewire 98. Figure 1 In the embodiment shown, the proximal end (not shown) of the guidewire 98 can be withdrawn into the opening 17a, through the instrument lumen 18b and out of the port 52b. The distal end 16 can then be advanced over the guidewire 98 into the patient's body over the guidewire 98.

[0049] like Figure 3C As shown, the distal end 16 can be advanced through the stent 40 and the opening 90 extending at least partially into the branch 94. For example, the distal end 16 can be positioned such that the second region 20b of the balloon 20 is positioned within the stent 40 and / or positioned beyond the stent, e.g., beyond the first end 42, and the first region 20a of the balloon 20 is positioned adjacent to the opening 90, e.g., within and / or proximate to the first end 42 of the stent.

[0050] Optionally, to aid in positioning, fluoroscopy or other external imaging can be used to monitor catheter 12, for example, to observe and monitor markings (not shown) on distal end 16. For example, markings can be located on distal end 16 to identify the ends of first region 20a and second region 20b of balloon 20. Thus, using the markings, second region 20b can be aligned with distal end 44 and / or the portion of stent 40 extending beyond opening 90 within branch 94, and first region 20a can be aligned with first end 42 of stent 40 and / or opening 90, as desired.

[0051] Go to Figure 3D With the catheter 12 positioned as desired, the catheter 12 can be opened, for example, by coupling a syringe or other device (not shown) to the port 52a (not shown). Figure 3D , see Figure 1) and delivering saline or other inflation medium into the interior of balloon 20 via inflation lumen 18a to expand balloon 20 to engage the walls of stent 40 and / or branches 94. For example, when inflated to an initial pressure, first region 20a and second region 20b of balloon 20 can expand to similar diameters substantially simultaneously to engage both stent 40 and the walls of branches 94 outside of stent 40 to prevent significant axial migration of stent 40.

[0052] After this, if Figure 3E As shown, the balloon 20 can be further inflated to a higher pressure, for example, by delivering additional inflation medium into the interior, to expand the first region 20a so as to expand the stent 40. For example, as the first region 20a further expands, the first end 42 of the stent 40 expands to, for example, an expanded configuration that can conform to the shape of the first region 20a and / or the opening 90.

[0053] If stent 40 is fully engaged by initial inflation, stent 40 and catheter 12 can remain substantially stationary during subsequent inflation and expansion. Otherwise, if second region 20b is not engaged with stent 40 and the wall of branch 94, stent 40 may tend to migrate distally into branch 94 rather than expanding properly, e.g., maintaining its substantially uniform diameter, which may shear or otherwise remove material from lesion 96 and / or the wall of branch 94 and potentially release such material within branch 94. Additionally or alternatively, if second region 20b is not expanded, distal end 16 of catheter 12 may tend to move proximally away from stent 40 and opening 90. Thus, second region 20b can provide an anchor that ensures first end 42 of stent 40 expands in a desired manner, with stent 40 and catheter 12 substantially fixed relative to each other and opening 90.

[0054] With the stent 40 fully deployed, the balloon 20 can be deflated or otherwise collapsed and the catheter 12 can be withdrawn from the branches 94 and trunk 92 and from the patient's body, e.g., into a guide catheter (not shown). The guide catheter and / or guidewire 98 can then be removed from the patient's body, allowing the stent 40 to be deployed as described above. Figure 3F One advantage of elastically expanding the first region 20a more than the second region 20b during final inflation is that the tension in the first region 20a can produce elastic recoil when the inflation medium is removed from the balloon 20. Thus, when the balloon 20 is deflated, the first region 20a can collapse quickly, which can shorten the overall deflation time of the balloon 20 before the catheter 12 can be removed.

[0055] In other embodiments, the devices and methods herein can be used to treat and / or deliver to other structures within the patient's body. For example, Figure 4 , shows another embodiment of a balloon device 110 comprising a catheter 112 including a distal end 116 carrying a balloon 120 having a reinforced central region 120b between two unreinforced outer regions 120a. The balloon 120 can be constructed similarly to the previous embodiments from a first film 222 including a first end 224 and a second end 226 and a central region 228 that is partially reinforced by a second film 232 to define the reinforced central region 220b.

[0056] exist Figures 5A to 5C In one exemplary embodiment shown, during use, the balloon 220 can be used to expand the ends of a prosthesis, such as an artificial heart valve, a stent, or other cylindrical prosthesis 140. Figure 5A As shown, an artificial valve prosthesis 140 has been deployed within an annulus 192 within a patient's heart 190, such as a replaced portion of an aortic valve. Prosthesis 140 may include a frame defining a first end 142 and a second end 144 and supporting one or more leaflets or other valve elements (not shown).

[0057] Go to Figure 5B , the distal end 116 of the catheter 112 can be introduced into the patient's body with the balloon 120 deflated, e.g., introduced into the patient's vasculature from a percutaneous access site and advanced into the aorta adjacent the annulus 192. The catheter 112 can be advanced to position the balloon 120 through the prosthesis 140, over the annulus 192, e.g., to position the reinforced central region 128b within the framework of the prosthesis 140. The central region 128b can have a length longer than the prosthesis 140, e.g., to provide a transition region at the ends 142, 144 of the prosthesis 140, or can have a length shorter than the prosthesis 140 as desired.

[0058] like Figure 5B As shown, once properly positioned, the balloon 120 can be inflated to an initial pressure, e.g., between one atmosphere and two atmospheres (1.0 to 2.0 ATM), whereby both the outer region 128a and the central region 128b expand substantially simultaneously, e.g., such that the central region 128b engages the frame of the prosthesis 140 to lock the relative positioning of the balloon 120 and the prosthesis 140. Optionally, the diameter of the central region 128b can be slightly larger than the deployed diameter of the prosthesis 140, e.g., such that the prosthesis 140 further expands after the initial inflation of the balloon 120.

[0059] Thereafter, the balloon can be further inflated to a pressure greater than, for example, five or six atmospheres, thereby causing the unreinforced outer region 128a to further expand while the central region 128b resists further expansion. Figure 5C The flared ends 142, 144 are shown flared outward, for example, to create a flange or other shape that secures the prosthesis 140 within the ring 192 without expanding and / or risking damage to the central region of the prosthesis 140 (e.g., which may host leaflets and / or other less durable components). Thus, the flared ends 142, 144 can resist subsequent migration of the prosthesis 140. Additionally, the flared ends 142, 144 can provide one or more other advantages, such as reducing the risk of thrombosis, for example, by minimizing exposure of bare metal on the prosthesis 140, engaging the ends 142, 144 into adjacent tissue to promote endothelialization, and the like.

[0060] Once the prosthesis 140 is sufficiently expanded and / or expanded, the balloon 120 may be deflated and the catheter 112 may be removed from the annulus 192 and the patient's body.

[0061] In other embodiments, Figure 4 The illustrated catheter 112 and balloon 120 can be used for other procedures. For example, tracheal and / or esophageal stents typically include flared ends, and the balloon 120 can be positioned over such deployed stents to further expand and / or shape the stent. Similarly, the balloon 120 can be used to expand the ends of stents deployed in the pulmonary artery, urinary or digestive tracts, or other body cavities. The balloon 120 can allow the ends of such stents to expand substantially simultaneously, thereby simplifying the delivery of such stents compared to conventional methods.

[0062] It will be appreciated that elements or components shown with respect to any embodiment herein are illustrative of a particular embodiment and can be used on or in conjunction with other embodiments disclosed herein.

[0063] While the invention is susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and herein described in detail. However, it should be understood that the invention is not limited to the particular forms or methods disclosed, but on the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the appended claims.

Claims

1. A device for expanding a stent, the device comprising: a tubular member comprising a proximal end and a distal end sized for introduction into a patient's body; and one or more lumens extending between the proximal end and the distal end; as well as a balloon carried on the distal end, the balloon comprising: a first membrane comprising a first end and a second end attached to the distal end; and a central region extending between first and second tapered regions transitioning to the first and second ends, respectively; and a second film extending from the second tapered region portion toward the first tapered region to surround a first region of the central region to reinforce the first region, the central region defining a second region remaining uncovered between the second film and the second tapered region, wherein the first film is formed of an elastic material and the second film is formed of a material having an elasticity equal to or smaller than that of the first film.

2. The apparatus of claim 1 , wherein the reinforced region defines a first region of the balloon and the uncovered length of the central region defines a second region of the balloon.

3. The apparatus of claim 1 or 2, wherein the balloon is expandable such that when the balloon is fully inflated, the second region of the balloon expands into a bulbous or other shape and the first region expands into a uniform cylindrical shape.

4. The apparatus of claim 1 or 2, wherein when the balloon is fully inflated, the diameter of the second region is smaller than the diameter of the first region.

5. The apparatus of claim 1 or 2, wherein the first membrane and the second membrane are formed of the same material.

6. The device of claim 1 or 2, wherein the first film and the second film have the same thickness.

7. The device of claim 1 or 2, wherein the second membrane is formed of an inelastic material.

8. The device of claim 1 or 2, wherein the second membrane is attached over an outer surface of the central region.

9. The apparatus of claim 8, wherein the second membrane is continuously attached over the outer surface by at least one of bonding, melting, and sonic welding.

10. The apparatus of claim 1 or 2, wherein the second film is formed over the central area by one of dip molding and spray molding.

11. The apparatus of claim 1 or 2, wherein the first membrane and the second membrane define a first diameter in a relaxed, formed state, and wherein the balloon is rolled or folded onto the distal end of the balloon in a delivery state.

12. A device as described in claim 1 or 2, wherein the materials of the first membrane and the second membrane are configured so that after the balloon is inflated to a first pressure, the first membrane and the second membrane simultaneously expand from a delivery state to a first diameter, and after the balloon is inflated to exceed the first pressure, the reinforced first region of the balloon remains at the first diameter while the remainder of the central portion of the first membrane continues to expand to a diameter greater than the first diameter.

13. The apparatus of claim 12, wherein a portion of the first membrane adjacent the reinforced region is formed into a shape configured to expand to a spherical shape when expanded to a diameter greater than the first diameter.

14. A device for expanding a stent, the device comprising: a tubular member comprising a proximal end and a distal end sized for introduction into a patient's body; and one or more lumens extending between the proximal end and the distal end; as well as a balloon carried on the distal end, the balloon comprising: a first membrane comprising a first end and a second end attached to the distal end; and a central region extending between first and second tapered regions transitioning to the first and second ends, respectively; and a second film that surrounds a first region of the central region from the second tapered region portion toward the first tapered region to reinforce the first region, the central region defining a second region that remains uncovered between the second film and the second tapered region, wherein the first film is formed of an elastic material and the second film is formed of a material having an elasticity equal to or smaller than that of the first film, and The materials of the first membrane and the second membrane are constructed so that when the balloon is inflated to a first pressure, the first membrane and the second membrane simultaneously expand from a delivery state to a first diameter along the first region, and when the balloon is inflated to exceed the first pressure, the first region of the central region remains at the first diameter, while the second region of the central region of the first membrane continues to expand to a diameter greater than the first diameter.

15. The apparatus of claim 14, wherein the first membrane and the second membrane are formed of the same material.

16. The apparatus of claim 15, wherein the first film and the second film have the same thickness.

17. An apparatus as claimed in any one of claims 14 to 16, wherein the second membrane is formed from an inelastic material.

18. The apparatus of any one of claims 14 to 16, wherein the second membrane is attached over an outer surface of the central region.

19. The apparatus of claim 18, wherein the second membrane is continuously attached over the outer surface by at least one of bonding, melting, and sonic welding.

20. The apparatus of any one of claims 14 to 16, wherein the second film is formed over the central region by one of dip molding and spray molding.

21. The apparatus of any one of claims 14 to 16, wherein the first and second membranes define a first diameter in a relaxed, formed state, and wherein the balloon is rolled or folded onto the distal end of the balloon in a delivery state.

22. The apparatus of any one of claims 14 to 16, wherein a portion of the first membrane adjacent the reinforced region is formed into a shape configured to expand to a spherical shape when expanded to a diameter greater than the first diameter.

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