WO2024118597A1

WO2024118597A1 - Catheter systems for treating blood vessels and associated systems and methods of use

Info

Publication number: WO2024118597A1
Application number: PCT/US2023/081336
Authority: WO
Inventors: John Anthony PHILLIPS; Michi E. Garrison
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-11-28
Filing date: 2023-11-28
Publication date: 2024-06-06
Anticipated expiration: 2025-05-28

Abstract

Devices for treating blood vessels are disclosed herein. According to some embodiments, the present technology includes a device for reduction and/or removal of an obstruction in a blood vessel. The device can comprise an elongate member, a penetration structure carried by a distal portion of the elongate member, and a dilatation balloon carried by the distal portion of the elongate member and positioned proximal of the penetration structure. The penetration structure can be configured to be positioned at least partially within the obstruction in the expanded state to engage and modify the obstruction, and the dilatation balloon can be configured to be expanded within the obstruction to create or enlarge an opening in the obstruction, thereby improving blood flow through the obstruction.

Description

CATHETER SYSTEMS FOR TREATING BLOOD VESSELS AND ASSOCIATED

SYSTEMS AND METHODS OF USE

CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] The present application claims the benefit of priority to U.S. Provisional Application No. 63/385,113, filed November 28, 2022, which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

[0002] The present technology relates to catheter systems for treating blood vessels and associated systems and methods of use.

BACKGROUND

[0003] An angioplasty is a type of minimally invasive procedure to open blocked blood vessels and restore blood flow to and from tissue, for example the heart muscle without undergoing open surgery. The procedure generally includes making an incision through the skin to a blood vessel, inserting a sheath into the blood vessel, inserting a treatment catheter with a penetration balloon through the sheath, guiding the catheter to one or more sites of obstruction (e g., a narrowed area of a blocked artery or vein), injecting contrast dye through the catheter to visualize the obstruction under fluoroscopic imaging, and inflating a balloon at the tip of the catheter such that the balloon presses against the sides of the blood vessel (which may be narrowed by plaque buildup, blood clots, etc ), thus increasing room for blood flow. The treatment catheter is typically placed over a guidewire to facilitate accessing the treatment site. The guidewire may be placed first across the treatment site and used as a rail to then advance the treatment catheter to and across the treatment site. Alternately, the guidewire and catheter may be advanced at the same time up to and across the treatment site.

[0004] Similarly, an atherectomy is another type of minimally invasive procedure wherein sharp blades, instead of balloon inflation, are used to cut away blockages from the walls of the blood vessel. Both procedures may further include stent placement, where a stent is placed into the newly opened area of the blood vessel to help keep the artery from narrowing again. [0005] The current tools used to remove/reduce blockages in blood vessels may be insufficient in cases where blockages are particularly severe, and it may be necessary to use different tools to advance across the blockage and then subsequently exchange these tools for one or more treatment catheters to perform the procedure. These exchanges add time and risk to the procedure. As a result, there is a need for improved tools for minimally invasive procedures and methods of producing and using the same.

SUMMARY

[0006] The subject technology is illustrated, for example, according to various aspects described below, including with reference to FIGS. 1 A-10C. Various examples of aspects of the subject technology are described as numbered examples (1, 2, 3, etc.) for convenience. These are provided as examples and do not limit the subject technology.

1. A device for reduction and/or removal of an obstruction in a blood vessel, the device comprising: an elongate member extending between a proximal portion and a distal portion, the distal portion configured to be intravascularly positioned at a treatment site within a blood vessel proximate an obstruction; a penetration structure carried by the distal portion of the elongate member and comprising an expandable structure, the penetration structure having a collapsed state for delivery to the treatment site and an expanded state in which an outer diameter of the penetration structure tapers in a distal direction, and wherein the penetration structure is configured to be positioned at least partially within the obstruction in the expanded state to engage and modify the obstruction; and a dilatation balloon carried by the distal portion of the elongate member and positioned proximal of the penetration structure along a longitudinal axis of the elongate member, wherein the dilatation balloon is configured to be expanded within the obstruction to create or enlarge an opening in the obstruction, thereby improving blood flow through the obstruction.

2. The device of Example 1, wherein the expandable structure comprises a balloon. 3. The device of Example 1 or Example 2, wherein, in the expanded state, a maximum outer diameter of the penetration structure is less than or equal to a maximum outer diameter of the dilatation structure.

4. The device of any one of the previous Examples, wherein the expandable structure has a proximal end, a distal end, and an intermediate portion extending therebetween, and wherein an outer diameter of the expandable structure is substantially constant along the intermediate portion.

5. The device of any one of the previous Examples, wherein the penetration structure includes a protrusion carried by the expandable structure, and wherein the protrusion is configured to penetrate the obstruction when the penetration structure is expanded.

6. The device of Example 5, wherein the protrusion comprises a blunt outer surface.

7. The device of Example 5 or Example 6, wherein the protrusion comprises a sharpened edge.

8. The device of any one of Examples 5 to 7, wherein the protrusion comprises a plurality of protrusions.

9. The device of Example 8, wherein the protrusions are spaced apart about the circumference of the expandable structure and/or spaced apart along a longitudinal dimension of the expandable structure.

10. The device of any one of Examples 5 to 9, wherein the protrusion has a first portion having a first length and a second portion having a second length different than the first length, and wherein the first and second portions are separated by a connecting region that is configured to bend when the penetration structure is expanded, thereby placing the first and second portions at an angle relative to one another. 11 . The device of Example 10, wherein the second length is greater than the first length.

12. The device of any one of Examples 5 to 11, wherein the protrusion has a proximal blunt portion and a distal sharpened portion.

13. The device of any one of Examples 5 to 12, wherein the expandable structure is a balloon, and wherein, when the penetration structure is in a collapsed state, the protrusion is positioned within a fold of the balloon such that the protrusion is not exposed to the vessel wall prior to expansion of the penetration structure.

14. The device of any one of the previous Examples, wherein the expandable structure comprises a balloon, and wherein the elongate member defines a single inflation lumen for both the expandable structure and the dilatation balloon.

15. The device of any one of the previous Examples, wherein the expandable structure comprises a balloon, and wherein the elongate member defines a first inflation lumen for the expandable structure and a second inflation lumen for the dilatation balloon.

16. The device of any one of the previous Examples, wherein the elongate member is a tubular structure configured to receive a guidewire therethrough.

17. A method for reduction and/or removal of an obstruction in a blood vessel, the method comprising: intravascularly delivering a distal portion of a treatment device at a treatment site within a blood vessel proximate an obstruction, the treatment device comprising an elongate member, a tapered penetration structure carried by a distal portion of the elongate member, and a dilatation balloon carried by the distal portion of the elongate member, proximal of the penetration structure; expanding the penetration structure within the obstruction to dilate at least a portion of the obstruction; and after dilating the obstruction with the penetration structure, advancing the dilatation balloon to a position within the obstruction and expanding the dilatation balloon within the obstruction to create or enlarge an opening in the obstruction, thereby improving blood flow through the obstruction.

18. The method of Example 17, further comprising positioning a guidewire at the treatment site and advancing the elongate member over the guidewire to the treatment site.

19. The method of Example 17 or Example 18, wherein dilating the obstruction comprises cutting the obstruction with one or more sharpened protrusions carried by the penetration member.

20. The method of any one of the previous Examples, wherein the penetration structure comprises a balloon, and wherein expanding the penetration structure comprises inflating the balloon.

21. The method of any one of the previous Examples, wherein, in the expanded state, an outer diameter of the penetration structure tapers in a distal direction.

22. The method of any one of the previous Examples, wherein the penetration structure comprises an expandable structure and a protrusion coupled to and extending away from the expandable structure.

23. The method of Example 22, wherein the protrusion comprises a blunt outer surface.

24. The method of Example 22, wherein the protrusion comprises a sharpened edge.

25. The method of any one of Examples 22 to 24, wherein the protrusion comprises a plurality of protrusions. 26. The method of Example 25, wherein the protrusions are spaced apart about the circumference of the expandable structure and/or spaced apart along a longitudinal dimension of the expandable structure.

27. The method of any one of Examples 22 to 26, wherein the protrusion has a first portion having a first length and a second portion having a second length different than the first length, and wherein the first and second portions are separated by a connecting region that is configured to bend when the penetration structure is expanded, thereby placing the first and second portions at an angle relative to one another.

28. The method of Example 27, wherein the second length is greater than the first length.

29. The method of any one of the previous Examples, wherein the penetration structure dislodges or displaces a portion of the obstruction.

30. The method of any one of the previous Examples, further comprising collapsing the penetration structure and moving the penetration structure distal to the obstruction prior to advancing and expanding the dilatation balloon.

31. The method of any one of the previous Examples, wherein expanding the penetration structure occurs at a first time, and the method further comprises collapsing the penetration structure and expanding the penetration structure within the obstruction a second time prior to advancement and expansion of the dilatation balloon.

32. The method of any one of the previous Examples, wherein the treatment device is a first treatment device, and wherein the method further comprises: (a) withdrawing the first treatment device from the treatment site, (b) advancing a second treatment device to the treatment site, the second treatment device comprising a stent, and (c) expanding the stent within the obstruction. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on illustrating clearly the principles of the present disclosure.

[0008] FIG. 1A is a side view of a treatment device in accordance with the present technology.

[0009] FIG. IB is an axial cross-sectional view of the treatment device taken along line 1B-1B in FIG. 1A.

[0010] FIGS. 2A-2D show a method of using the treatment devices of the present technology to treat a blood vessel.

[0011] FIGS. 3A-3D show another method of using the treatment devices of the present technology to treat a blood vessel.

[0012] FIG. 4A is a side view of a treatment device in accordance with the present technology.

[0013] FIG. 4B is an axial cross-sectional view of the treatment device taken along line 4B- 4B in FIG. 4A.

[0014] FIG. 5A is a side view of a treatment device in accordance with the present technology.

[0015] FIG. 5B is an axial cross-sectional view of the treatment device taken along line 5B- 5B in FIG. 5A.

[0016] FIGS. 6A and 6B are views of the distal portion of a treatment device configured in accordance with several embodiments of the present technology.

[0017] FIG. 6C is an enlarged view of a protrusion of the treatment device shown in FIGS. 6A and 6B.

[0018] FIG. 6D is an axial cross-sectional view of the penetration structure shown in FIGS. 6 A and 6B. [0019] FIGS. 7A and 7B are views of the distal portion of a treatment device configured in accordance with several embodiments of the present technology.

[0020J FIG. 7C is an axial cross-sectional view of the penetration structure shown in FIGS. 7A and 7B, taken along line 7C-7C. In FIG. 7C, only the penetration balloon and protrusions are depicted.

[0021 J FIG. 8 shows the distal portion of a treatment device configured in accordance with several embodiments of the present technology.

[0022] FIGS. 9A and 9B are views of the distal portion of a treatment device configured in accordance with several embodiments of the present technology, shown with the penetration structure in a collapsed state.

[0023] FIGS. 9C and 9D are views of the distal portion of a treatment device configured in accordance with several embodiments of the present technology, shown with the penetration structure in an expanded state.

[0024] FIGS. 10A and 10B are views of the distal portion of a treatment device configured in accordance with several embodiments of the present technology. In FIGS. 10A and 10B, the treatment assembly of the treatment device is shown in an expanded state.

[0025] FIG. 10C depicts the distal portion of the treatment device shown in FIGS. 10A and 10B, shown with the dilatation structure in an expanded state and the penetration structure in a collapsed state.

DETAILED DESCRIPTION

[0026] The present technology comprises an intravascular treatment device configured to engage an obstruction in a blood vessel for the purpose of creating or enlarging an opening through the obstruction, removing a portion of the obstruction, and/or crossing the obstruction. The obstruction may comprise, for example, plaque buildup, blood clots, etc. that effectively narrow the lumen of the vessel and limit blood flow. The treatment devices disclosed herein comprise an elongate shaft with a treatment assembly disposed at the distal portion of the elongate shaft. The treatment assembly includes both a dilatation structure for performing an angioplasty and a penetration structure for engaging and structurally modifying the obstruction prior to the angioplasty to facilitate the dilation. As the dilatation structure and penetration structure are carried by the same device, the devices of the present technology beneficially reduce the need for exchanging and using multiple devices during a procedure.

[0027] FIGS. 1 A and IB schematically depict a treatment device 100 (or “device 100”) for the reduction and/or removal of an obstruction in a blood vessel, configured in accordance with several examples of the present technology. The device 100 can comprise a proximal portion 100a configured to be extracorporeally positioned and manipulated by a clinician, a distal portion 100b configured to be intravascularly positioned at a treatment site within a blood vessel proximate an obstruction, and a longitudinal axis extending therebetween. The device 100 can comprise a hub 102 at the proximal portion 100a, an elongate shaft 104 extending distally from the hub 102 to the distal portion 100b of the device 100, and a treatment assembly 106 disposed at a distal portion of the elongate shaft 104.

[0028] The elongate shaft 104 can define one or more lumens therethrough. For example, as shown in FIG. IB, in some embodiments the elongate shaft 104 comprises a lumen 112 configured to receive a guidewire (not shown) or other device therethrough. The lumen 112 can extend from an opening at the proximal portion 100a of the device 100 to a distal opening 105 at the distal end portion of the elongate shaft 104. In some examples, the elongate shaft 104 is configured as a rapid-exchange-style catheter (not shown) in which the guidewire lumen extends along only a distal portion of the elongate shaft 104, for example the distal 20 to 30 cm of the elongate shaft 104 from a guidewire port (not shown) in the sidewall of the elongate shaft 104 to the distal opening 105. In any case, the elongate shaft 104 is configured to be slidably positioned over a guidewire having a diameter of at least 0.014 inches, 0.018 inches, or 0.035 inches. In addition to the guidewire lumen 112, the elongate shaft 104 may further define or include one or more inflation lumens, as detailed below. The elongate shaft 104 may be constructed from Pebax®, high-density polyethylene (HDPE), HDPE/low-density polyethylene (LDPE) blends, polyethylene terephthalate (PET), nylon, or a combination of materials to achieve the desired performance (trackability, flexibility, pushability, profile) and manufacturability. The working length of the elongate shaft 104 (e.g., the insertable length) may be between 80 cm and 200 cm, or 200 cm or more, depending on the location of the treatment site in relation to the vessel access site. [0029] The hub 102 can be coupled to the proximal end of the elongate shaft 104 and is configured to fluidly couple the one or more lumens of the elongate shaft 104 to additional tubing and/or facilitate passage of another device or fluid from an extracorporeal location to the lumen(s) of the elongate shaft 104. As described in greater detail below, the hub 102 can be configured to couple the elongate shaft 104 to one or more pressurized fluid sources as well as enable positioning of the elongate shaft 104 over a guidewire.

[00301 The treatment assembly 106 can be carried by a distal portion of the elongate shaft 104 and includes a dilatation structure 108 and a penetration structure 110 distal of the dilatation structure 108 along the longitudinal axis of the shaft 104. The penetration structure 110 comprises an expandable structure 11 1 configured to be positioned at least partially within the obstruction and expanded to penetrate the obstruction, thereby modifying the obstruction to ease the advancement of the dilatation structure 108 into the obstruction to enable a dilatation of the obstruction. As used herein, “penetrate” refers to cutting, separating, scoring, and/or otherwise modifying the obstruction to structurally weaken and/or displace a portion of the obstruction and/or widen an opening in the obstruction.

[0031 J In some embodiments the penetration structure 110 comprises a balloon. The balloon may taper distally, be substantially cylindrical, or have other shapes. In several of such embodiments, the penetration structure 110 optionally comprises one or more protrusions 114 (shown schematically in FIG. 1 A) affixed to the surface of the balloon. The protrusions are configured to extend radially away from the balloon when the penetration structure 110 is in an expanded state. The protrusions 114 can be blunt or sharpened.

[00321 In some examples, the penetration structure 110 comprises an expandable frame comprising a plurality of struts. The radially outermost edge of one, some, or all of the struts can be sharpened and/or may be blunt. According to some examples, the penetration structure 110 comprises an expandable frame positioned over a balloon and configured to be expanded by inflation of the balloon. In these and other embodiments, the expandable frame of the penetration structure 110 can be expanded by actuating a push/pull member coupled to a distal end of the expandable frame.

[0033J In those embodiments in which the penetration structure 110 includes a balloon, the elongate shaft 104 can define a first inflation lumen 120 (see FIG. IB) extending therethrough. The first inflation lumen 120 can have a first end at the proximal portion 100a of the device 100 and a second end at the distal portion of the shaft 104, coincident with an interior region of the balloon. The first inflation lumen 120 can be configured to be fluidly coupled to a fluid source (e.g., via one or more ports on the hub 102) to inflate/deflate the balloon. The balloon may be formed of a non-compliant or semi-compliant polymer material such as Nylon 12, PET, polyethylene, and the like.

[0034] The penetration structure 110 may have a diameter of about 0.5 mm to about 2.0 mm, and a length of about 5 mm to about 15 mm. In some embodiments, the penetration structure 110 has diameter of about 0.5 mm to about 1.5 mm, or about 1.0 mm to about 1.5 mm, or about 1.0 mm to about 2.00 mm. In those embodiments where the penetration structure 1 10 includes a tapered balloon, the tapered balloon maximum diameter of about 0.5 to about 2.0 mm, and then taper distally to the diameter of the distal tip.

[0035] The dilatation structure 108 can be positioned proximal of the penetration structure 110 along the longitudinal axis of the shaft 104. In some examples, the dilatation structure 108 comprises a balloon 109. As detailed herein, the dilatation structure 108 is configured to be expanded within the obstruction to create or enlarge an opening in the obstruction, thereby improving blood flow through the obstruction. In such embodiments, the elongate shaft 104 can define a second inflation lumen 118 (see FIG. IB) extending therethrough. The inflation lumen 118 can have a first end at the proximal portion 100a of the device 100 and a second end at the distal portion of the shaft 104, coincident with an interior region of the balloon 109. The second inflation lumen 118 can be configured to be fluidly coupled to a fluid source (e.g., via one or more ports on the hub 102) to inflate/deflate the balloon 109. In some embodiments, the dilatation balloon and the penetration balloon share a single inflation lumen (see, for example, FIGS. 4 A and 4B). The balloon 109 may be formed of a non-compliant or semi-compliant polymer material such as Nylon 12, PET, polyethylene, and the like.

[0036] For use in coronary and similarly sized vessels, the dilatation balloon 409 can have a diameter of about 2.0 mm to about 4.0 mm, and a length of about 25 mm to about 40 mm (for example for a coronary angioplasty). For use in peripheral vessels, the diameter and/or length of the dilatation balloon may be greater. [0037] The device 100 may optionally include radiopaque markers to aid in positioning of the device 100 using fluoroscopy. For example, the treatment device 100 may include one or more markers at the distal end of the penetration structure 110, one or more markers at the proximal end of the penetration structure 110, one or more markers along an intermediate portion of the penetration structure 110 (e.g., away from the ends), one or more markers at the proximal end of dilatation structure 108, one or more markers at the distal end of dilatation structure 108, and/or one or more markers along an intermediate portion of the dilatation structure 108 (e.g., away from the ends). The radiopaque markers may be constructed from radiopaque metals such as gold, platinum, tantalum, tungsten or alloys. The radiopaque markers may also be constructed from polymer such as Pebax®, which is impregnated with radiopaque material such as tungsten.

[0038] The device 100 may assist in opening blocked blood vessels and restoring sufficient blood flow. For example, the device 100 may remove at least some plaque and/or calcification contributing to blood vessel obstruction in the thigh of a patient wherein use of the device 100 may be antegrade with the direction of expected blood flow. In such an example, blood flow from the thigh and towards the foot of a patient may be restored. In other applications, the device 100 may assist in obstructions in other coronary or peripheral arteries or veins. The device 100 may also serve as a pre-dilatation step to a stent procedure in a peripheral or coronary artery or vein.

[0039] To treat a patient using the device 100 of the present technology, access to the vasculature is gained using standard interventional techniques, and angiographic imaging of the targeted vessel is performed to identify the obstruction site, determine the size of the vessel and the extent of the obstruction. Once the obstruction site is identified, the appropriately sized treatment device is selected. As shown in FIG. 2A, a guidewire GW is advanced through the vasculature and across the targeted obstruction in the vessel V. The distal portion 100b of the device 100 is then advanced over the guidewire GW to the treatment site with the treatment assembly 106 in a collapsed state. As shown in FIG. 2B, the treatment assembly 106 is advanced until all or a portion of the penetration structure 110 is positioned within the obstruction O with the dilatation structure 108 proximal of the obstruction O. A depicted in FIG. 2C, the penetration structure 110 is then expanded within the obstruction O. If the penetration structure 110 includes protrusions (e.g., rods, blades, etc.), the protrusions can engage, penetrate, and/or otherwise modify the obstruction O. As detailed herein, in some cases the penetration structure 110 may not include any protrusions, in which case the penetration structure 110 functions as a wedge or a smaller dilatation to pre-dilate the obstruction rather than scoring or weakening the obstruction. Such a penetration structure 110 thus still acts to ease the advancement of the dilatation balloon into the obstruction to perform a dilatation step.

[0040] While expanded, the penetration structure 110 may be moved proximally and distally within the obstruction and/or rotated within the obstruction O to further disrupt and/or dislodge obstructive material. The penetration structure 110 may be collapsed and expanded within the obstruction O as many times as needed to sufficiently reduce and/or weaken the obstruction O such that the dilatation structure can be advanced into the obstruction.

[0041] Once the obstruction O has been sufficiently pre-treated to allow advancement of the dilatation structure 108 across the obstruction, the treatment assembly 106 can be advanced distally, with at least the dilatation structure 108 in the collapsed state, until at least a portion of the dilatation structure 108 is aligned with the obstruction O and the penetration structure 110 is distal of the obstruction O. The penetration structure 110 may be collapsed and/or deflated prior to advancing the dilatation structure 108. The dilatation structure 108 can then be expanded within the obstruction O to enlarge the opening in the obstruction O, as shown in FIG. 2D. The dilatation structure 108 may be collapsed and expanded within the obstruction O as many times as needed in order to sufficiently reduce and/or weaken the obstruction O. In some cases, the penetration structure 110 may be positioned within the obstruction and expanded/collapsed in between dilations with the dilatation structure 108. At the completion of the dilation, the device 100 is removed from the patient, over the guidewire GW. In some cases, the device 100 and guidewire GW may be removed together.

[0042] Optionally, a stent delivery catheter may be inserted and advanced to the treatment site, and a stent can be deployed within and/or across the obstruction at the treatment site.

[0043] FIGS. 3A-3D show another method for using the device 100 of the present technology. As shown in FIG. 3A, a catheter C containing the treatment assembly 106 in a collapsed state is advanced over the guidewire GW to the treatment site. As shown in FIG. 3B, the treatment assembly 106 is advanced within the catheter C until all or a portion of the penetration structure 110 is positioned within the catheter C at a location that is longitudinally aligned with the obstruction O. In some cases, the treatment assembly 106 is pre-loaded at the distal end of the catheter C and the catheter C with the treatment assembly 106 therein is simply advanced to a location in which the treatment assembly 106 is longitudinally aligned with the obstruction O.

[0044] The catheter C is then withdrawn, as shown in FIG. 3C, and the penetration structure 110 is expanded within the obstruction O. The penetration structure 110 may be selfexpanding (and thus automatically expand upon withdrawal of the constraints of the catheter C), or mechanically expandable (as discussed herein), or both. In those cases in which the penetration structure 110 is at least partially self-expanding, the catheter C can be advanced and withdrawn to repeatedly to expand and collapse, repeatedly, the penetration structure 110. In some examples, the catheter C may progressively be advanced further into the obstruction O, until the desired weakening and pre-dilatation result is achieved. Regardless, while expanded, the penetration structure 110 may be moved proximally and distally within the obstruction and/or rotated within the obstruction O to further disrupt and/or dislodge obstructive material. The penetration structure 110 may be collapsed and expanded within the obstruction O as many times as needed to sufficiently reduce and/or weaken the obstruction O such that the dilatation structure can be advanced into the obstruction.

[0045] Once the obstruction O has been sufficiently pre-treated to allow advancement of the dilatation structure 108 across the obstruction, the treatment assembly 106 can be advanced distally, with at least the dilatation structure 108 in the collapsed state, until at least a portion of the dilatation structure 108 is aligned with the obstruction O and the penetration structure 110 is distal of the obstruction O. The penetration structure 110 may be collapsed and/or deflated (either mechanically or via constraint by the catheter C) prior to advancing the dilatation structure 108. The dilatation structure 108 can then be expanded within the obstruction O (e.g., mechanically, self-expansion in response to removal of the constraints of the catheter C, or both) to enlarge the opening in the obstruction O, as shown in FIG. 3D. The dilatation structure 108 may be collapsed and expanded within the obstruction O as many times as needed to sufficiently reduce and/or weaken the obstruction O. In some cases, the penetration structure 110 may be positioned within the obstruction and expanded/collapsed in between dilations with the dilatation structure 108. At the completion of the dilation, the device 100 is removed from the patient, over the guidewire GW. In some cases, the device 100 and guidewire GW may be removed together. [0046] Optionally, a stent delivery catheter may be inserted and advanced to the treatment site, and a stent can be deployed within and/or across the obstruction at the treatment site.

[0047] FIGS. 4A and 4B show a treatment device 400 (or “device 400”) configured in accordance with examples of the present technology. The device 400 can comprise a proximal portion 400a configured to be extracorporeally positioned and manipulated by a clinician, a distal portion 400b configured to be intravascularly positioned at a treatment site within a blood vessel proximate an obstruction, and a longitudinal axis extending therebetween. The device 400 can include an elongate shaft 404 extending from the proximal portion 400a of the device 400 to the distal portion 400b, and a treatment assembly 406 disposed at a distal portion of the elongate shaft 104. The treatment assembly 406 can include a dilatation structure 408 comprising a balloon409 and a penetration structure 410 also comprising a balloon 411.

[0048] The elongate shaft 404 can define one or more lumens therethrough. For example, as shown in FIG. 4B, in some embodiments the elongate shaft 404 comprises a lumen 412 configured to receive a guidewire (not shown) or other device therethrough. The lumen 412 can extend from an opening at the proximal portion 400a of the device 400 to a distal opening 405 at the distal end portion of the elongate shaft 404 (see FIG. 4A). In some examples, not shown, the elongate shaft 404 is configured as a rapid-exchange- style catheter in which the guidewire lumen runs along only a distal portion of the elongate shaft 104, as previously described.

[0049] The elongate shaft 404 may further comprise an inflation lumen 419 (FIG. 4B) extending from the proximal portion 400a of the device 400 to (a) an opening in the sidewall of the elongate shaft 404 coincident with an interior region of the balloon of the dilatation structure 408, and (b) an opening in the sidewall of the elongate shaft 404 coincident with an interior region of the balloon of the penetration structure 410. As seen in FIG. IB, the guidewire lumen 412 can be generally round to accommodate the guidewire, whereas the inflation lumen 419 may be crescent-shaped to allow passage of an inflation fluid without adding excessively to the overall diameter of the shaft 404. In other embodiments, the inflation lumen 419 is substantially round and/or circular.

[0050] The proximal portion 400a of the device 400 can includes a connector 440 configured to fluidly couple each of the guidewire and inflation lumens 412, 419 to a respective input tube. For example, in some embodiments the connector 440 comprises a Y-connector having a first port 430 configured to be fluidly coupled to a proximal end of the elongate shaft 404, a second port 432 configured to be fluidly coupled to a first tube 442, and a second port 434 configured to be fluidly coupled to a second tube 444. As such, the Y-connector places the first tube 442 in fluid communication with the inflation lumen 419 and the second tube 444 in fluid communication with the guidewire lumen 412. The first tube 442 can be configured to be coupled at its proximal end 446 to a pressurized fluid source for inflating/deflating the balloons of the treatment assembly 106, and the second tube 444 can be configured receive a guidewire through an opening at its proximal end 448.

[0051] The dilatation and penetration balloons 409, 411 can have different shapes and/or sizes. As shown in FIG. 4A, for example, the dilatation balloon 409 can be generally cylindrical while the penetration balloon 411 can have a diameter that tapers from the proximal portion of the balloon 411 to the distal portion. The tapered penetration balloon 411 may function as a wedge that can facilitate crossing an obstruction. In these and other embodiments, the maximum diameter of the penetration balloon 411 can be the same or less than the maximum diameter of the dilatation balloon 409, and the length of the penetration balloon 411 can be the same or less than the length of the dilatation balloon 409. The penetration balloon 411 thus encloses a volume, when inflated, less than or equal to the volume enclosed by the dilatation balloon 409.

[0052] The tapered penetration balloon 411 may have a maximum diameter of about 0.5 mm to about 2.0 mm, and a length of about 5 mm to about 15 mm. In some embodiments, the penetration balloon 411 has diameter of about 0.5 mm to about 1.5 mm, or about 1.0 mm to about 1.5 mm, or about 1.0 mm to about 2.00 mm. The angle formed by the taper (measured between the outer surface of the penetration balloon 411 and the longitudinal axis of the shaft 404) may be between 5 and 15 degrees, greater than 5 degrees, greater than 10 degrees, or greater than 15 degrees.

[0053] For use in coronary and similarly sized vessels, the dilatation balloon 409 can have a diameter of about 2.0 mm to about 4.0 mm, and a length of about 25 mm to about 40 mm (for example for a coronary angioplasty). For use in peripheral vessels, the diameter and/or length of the dilatation balloon may be greater.

[0054] Other configurations of the balloons 409, 411 are possible. For example, both the dilatation balloon 409 and the penetration balloon 411 can be tapered. In some embodiments, both the dilatation balloon 409 and the penetration balloon 411 can be substantially cylindrical. In certain examples, the dilatation balloon 409 is tapered while the penetration balloon is substantially cylindrical.

[0055] As previously mentioned, the dilatation and penetration balloons 409, 411 can be inflated by a single inflation lumen 419. In some cases, it may be desirable for the dilatation and penetration balloons 409, 411 to inflate to their respective functional volumes and/or pressures at different times. This can be achieved by varying the size and/or materials of the balloons 409, 411. For example, the dilatation and penetration balloons 409, 411 may be formed of materials with different elasticities such that upon inflation with a first fluid pressure, the penetration balloon 411 expands fully and the dilatation balloon 409 does not inflate or inflates only partially. When the treatment assembly 406 is inflated at a second fluid pressure, higher than the first fluid pressure, the dilatation balloon 409 then fully expands to its functional configuration.

[0056] Alternately, the two balloons 409 and 411 may be inflated independently with separate inflation lumens. FIGS. 5A and 5B show a treatment device 500 (or “device 500”) similar to the treatment device 400 shown and described with respect to FIGS. 4A and 4B, except the elongate shaft 504 of the treatment device 500 comprises two inflation lumens: a first inflation lumen 519 for the dilatation balloon 508 and a second inflation lumen 521 for the penetration balloon 511. The first and second inflation lumens 519, 521 can be generally crescent-shaped, substantially round and/or circular, ovular, or any other suitable shape. Independent inflation of the dilatation and penetration balloons 508, 511 provides several advantages, such as enabling the dilatation balloon 508 to remain relatively collapsed and/or low-profile while the penetration balloon 511 is expanded within the obstruction, and vice versa. Such independent control avoids unnecessary expansion of the vessel distal and/or proximal to the obstruction, which may be traumatic to the vessel wall.

[0057] To accommodate the additional inflation lumen, the connector 540 at the proximal portion 500a of the device 500 can include a third port 536 configured to be fluidly coupled to a third tube 550. As such, the connector 540 places the first tube 542 in fluid communication with the inflation lumen 519, the second tube 544 in fluid communication with the guidewire lumen 512, and the third tube in fluid communication with the third tube 550. The first tube 542 can be configured to be coupled at its proximal end 546 to a pressurized fluid source for inflating/deflating the dilatation balloon 509 (via the first inflation lumen 519), the second tube 544 can be configured receive a guidewire through an opening at its proximal end 548, and the third tube 550 can be configured to be coupled at its proximal end 552 to a pressurized fluid source for inflating/deflating the penetration balloon 511.

[0058] The use of separate inflation lines enables inflation of the penetration balloon 511 without inflation of the dilatation balloon 509, for example when the penetration balloon 511 is within or across the obstruction. Repeated inflations can be performed as required to advance the device 500 enough to position the dilatation balloon 509 across the obstruction, without inflating the dilatation balloon 509. Once the dilatation balloon 509 is positioned within the obstruction, the dilatation balloon 509 is inflated, without inflation of the penetration balloon 51 1, to dilate the obstruction.

[0059] FIGS. 6A and 6B show a portion of a treatment device 600 (or “device 600”) generally similar to the devices 400, 500 shown and described with reference to FIGS. 4A and 4B and 5 A and 5B, except the treatment device 600 shown in FIGS. 6 A and 6B includes one or more protrusions (labeled 614a-614c, referred to collectively as “protrusions 614”) affixed to the penetration balloon 611. The protrusions 614 can extend longitudinally along an outer surface of the penetration balloon 611 and may be spaced apart around the circumference of the penetration balloon 611. The penetration balloon 611 can include one, two, three, four, five, six or more protrusions 614.

[0060] Each protrusion 614 has a radially outermost edge 660 (FIG. 6C) when the penetration structure 610 is in an expanded state. In some embodiments, all or a portion of the radially outermost edge 660 of a given protrusion 614 can be sharpened such that at least a portion of the protrusion 614 comprises a blade. In some examples, the radially outermost edge 660 is blunt/not sharpened. One, some, or all of the protrusions 614 can have a sharpened edge 660, and one, some, or all of the protrusions 614 can have a blunt edge 660.

[0061] In some embodiments, one, some, or all of the protrusions 614 are divided into at least two segments 662, 664 separated longitudinally by a groove 665 or otherwise weakened portion of the protrusion 614 to improve the flexibility of the treatment device 600 along the penetration structure 610. In some embodiments, the distal most protrusion 664 has an angled leading edge 668, so as to complement the wedge configuration of the penetration structure 610 and improve the ability of the device 600 to be advanced across a severe obstruction.

[0062] As shown in detail in FIG. 6C, the protrusions 614 may be coupled to the penetration balloon 609 via holders 670 with slots for the protrusions 614. The holder 670 may be cast or molded flexible pads with a collective depth/thickness of about 0.02 mm to about 0.04 mm and secured to the penetration balloon 611 via adhesive bonds, thermal weld, or other means of fixation. Alternatively, the holders 670 may be insert molded into the penetration balloon 611 when the penetration balloon 611 is formed. Alternately, the protrusions 614 and the holders 670 are manufactured from one material and affixed directly to the surface of the penetration balloon 611. In some embodiments, the holder 670 can also be divided into multiple segments corresponding to the multiple protrusions 614. In some variations, one, some, or all of the protrusions 614 and/or holders 670 (if used) comprise a single continuous structure with one or more cuts along their respective lengths to provide bending flexibility.

[0063] Prior to insertion into the patient, the balloons of the treatment assembly 606 are in a deflated state, pleated, and “wrapped” radially around the shaft 604. A cross-sectional view of the penetration structure 610 in a collapsed state is shown in FIG. 6D. As shown, the penetration balloon 611 can be configured in a collapsed state such that the protrusions 614 are positioned within pleats or folds of the balloon 611 to prevent damage to the blood vessel by the protrusions 614 while the device 600 is being advanced through the vasculature. A penetration balloon 611 with three protrusions 614 would have three pleats, a penetration balloon 611 with four protrusions 614 would have four pleats, etc. When the penetration balloon 611 is inflated, the protrusions “stand” at their functional cutting height. In some embodiments, during this inflation step, the protrusions rotate between 80 to 100 degrees about the point at which the protrusions are coupled to the penetration balloon 611, with the rotation consistent with how the balloon pleats are wrapped around the shaft 604.

[0064] FIGS. 7A and 7B show a portion of a treatment device 700 (or “device 700”) generally similar to the device 600 shown and described with reference to FIGS. 6A and 6B, except the treatment device 700 shown in FIGS. 7A and 7B includes protrusions 714 (labeled individually as 714a-714d) in the form of rods configured to indent and weaken the obstruction to enable or facilitate dilatation with the dilatation structure 708. FIG. 7C is an axial cross-sectional view showing the penetration balloon 71 1 and the protrusions 714 isolated from the rest of the structures of the device 700. In contrast to the protrusions 614 comprising blades in FIGS. 6A-6C, the rods comprising the protrusions 714 of FIGS. 7A-7C have a blunt radially outermost surface and comprise a broader structure. In some embodiments, the rods may be round in cross section. In other embodiments, the rods may be square or triangular, in cross section to have a sharper contact point with the tissue. In some embodiments, one, some, or all of the rods may be disposed in a helical fashion (not shown) around the penetration balloon 711, which may facilitate advancement of the treatment assembly 706 through the obstruction, for example, by rotating the treatment assembly 706 as it is being advanced.

[0065] FIG. 8 shows a portion of a treatment device 800 (or “device 800”) configured in accordance with examples of the present technology. The device 800 can include an elongate shaft 804 extending from a proximal portion (not shown) of the device 800 to the distal portion 800b, and a treatment assembly 806 disposed at a distal portion of the elongate shaft 804. The treatment assembly 806 can include a dilatation structure 808 comprising a balloon 809 and a reinforced distal tip 870 which extends distally away from dilatation balloon 809. The distal tip 870 is reinforced in a manner which provides sufficient axial strength to enable pushing the treatment assembly 806 through tight obstructions while still maintaining sufficient flexibility to allow the device 800 to be advanced through tortuous anatomy. The distal tip 870 may be in the range of about 0.5 cm to about 2 cm in length. In some embodiments, the distal tip 870 is about 1 cm to about 1.5 cm. In some embodiments, the distal tip 870 is constructed with an inner and an outer polymer layer, with a reinforcement structure between the two layers. The reinforcement may be a wire or ribbon coil, or a wire or ribbon braid. The dimensions and material of the wire or ribbon and pitch of the braid or coil, as well as the wall thickness and durometer of the inner and outer layers, are selected to provide sufficient axial strength while maintaining desired flexibility of the tip. In another embodiment, the reinforcement structure may be a cut hypotube with a material, wall thickness, and cut pattern that provides the desired mechanical characteristics.

[0066] The reinforced structure may terminate proximally at a location distal to the dilatation balloon 808 or may extend proximally all or a portion of the length of the dilatation balloon 808. In some embodiments, the reinforced structure may extend proximally beyond the dilatation balloon 808. In certain examples, the entire shaft 804 may be reinforced. The flexibility of the reinforcement may vary along the length of the shaft 804. For example, the distal tip 870 or a distal portion of the distal tip 870 may be a relatively stiff section but then transition to a more flexible section as it moves proximally, such that the tip is able to cross the obstruction without causing the entire distal tip 870 to be overly stiff. The variable flexibility may be achieved, for example, by varying the pitch of the braid or coil, or by varying the cut pattern of the cut hypotube reinforcement structure. The variable flexibility may also be achieved by varying the durometer of the inner and/or outer layers of the shaft.

[0067] FIGS. 9A-9D show a portion of a treatment device 900 (or “device 900”) configured in accordance with examples of the present technology. The device 900 can comprise a proximal portion (not shown) configured to be extracorporeally positioned and manipulated by a clinician, a distal portion 900b configured to be intravascularly positioned at a treatment site within a blood vessel proximate an obstruction, and a longitudinal axis extending therebetween. The device 900 can include an elongate shaft 904 extending from the proximal portion of the device 900 to the distal portion 900b, and a treatment assembly 906 disposed at a distal portion of the elongate shaft 904. The treatment assembly 906 can include a dilatation structure 908 comprising a balloon 909 and a penetration structure 910 comprising an expandable structure 980.

[0068] FIGS. 9A and 9B show the expandable structure 980 in the collapsed or low-profile configuration and FIGS. 9C and 9D show the expandable structure 980 in the expanded configuration. As shown, the expandable structure 980 can comprise a plurality of struts (labeled 982a-982d, referred to collectively as “struts 982”), each of which have a flat, rounded, and/or otherwise blunt proximal portion 984 and a sharpened distal portion 986. The struts 982 are joined to one another at their respective proximal and distal ends. An additional inner member 988, seen most clearly in FIGS. 9C and 9D, is positioned inside of the struts and joined to distal tip 905. The inner member 988 extends proximally through a lumen of the elongate shaft 904 to a proximal portion of the device 900. To expand the expandable structure 980, the inner member 988 can be retracted relative to the elongate shaft 904, thereby shortening the expandable structure 908 and causing the struts 982 to bow out, as shown in FIGS. 9C and 9D. The sharpened edges of the distal struts 986 are configured to cut into and weaken the obstruction, thereby facilitating the subsequent crossing and dilation of the obstruction. In some embodiments, as shown in FIGS. 9A and 9B, the cutting edges 983 of struts 982 face radially outwardly when both collapsed and expanded. Alternatively, in some embodiments, the expandable structure 980 is configured such that the cutting edges 983 of the distal struts 986 lie flat and tangent to the shaft 904 when collapsed, but rotate outward when expanded, for example the struts are configured to be in a helical pattern. In several examples, the cutting edges 983 are tangent or slightly curved outwards to the shaft 904 when both collapsed and expanded, and when expanded, the distal end is rotated to cut tangentially into the obstruction to weaken the obstruction.

[0069] In some embodiments, the expandable structure 980 has a plurality of struts but no cutting edges. In this instance, the struts serve to score and weaken the obstruction material when the expandable structure 980 is expanded.

[0070] In any case, the expandable structure 980 can be constructed from a single hypotube with a cut pattern to form two or more struts comprising strut portions 984 and 986. The edges of one or more portions of one or more of the struts may be sharpened to create the cutting feature. The strut portions 984, 986 may also be twisted to create the desired cutting angle. Because the step of expanding the expandable structure 980 creates a compressive force on the shaft 904, it may be desirable to reinforce some or all of shaft 904. For example, the hypotube that forms the expandable structure 980 may be contiguous with a cut hypotube forming a reinforcement layer of shaft 904. In some embodiments, some or all of shaft 904 is a reinforced shaft with inner and outer polymer layers and a reinforcement layer comprised of a cut hypotube, up to and including the section of shaft 904 with the dilatation structure 908. Distal to that, the inner and outer layers terminate and the hypotube extends with a cut pattern configured to form expandable structure 980. In another embodiment, the shaft reinforcement structure is connected to but not continuous with expandable structure 980. In some examples, the shaft reinforcement structure is a braid or a coil, rather than a cut hypotube. The expandable structure 980 can comprise a first material, for example nitinol, while the reinforcement layer comprises a second material different than the first material, for example 304SS. In some examples, the expandable structure 980 and the reinforcement layer are the same materials.

[0071] FIGS. 10A-10B show a portion of a treatment device 1000 (or “device 1000”) configured in accordance with several examples of the present technology. The device 1000 can comprise a proximal portion (not shown) configured to be extracorporeally positioned and manipulated by a clinician, a distal portion 1000b configured to be intravascularly positioned at a treatment site within a blood vessel proximate an obstruction, and a longitudinal axis extending therebetween. The device 1000 can include an elongate shaft 1004 extending from the proximal portion of the device 1000 to the distal portion 1000b, and a treatment assembly 1006 disposed at a distal portion of the elongate shaft 1004. The treatment assembly 1006 can include a dilatation structure 1008 comprising a balloon 1009 and a penetration structure 1010. The treatment assembly 1006 is shown in an expanded state in FIGS. 10A and 10B.

[0072] The penetration structure 1010 can comprise a balloon 1011 and an expandable frame 1090 positioned over the balloon 1011. Expansion of the expandable frame 1090 is achieved by inflating the balloon 1011, rather than by shortening the frame 1090 by moving an inner member relative to the elongate shaft 1004 (as described in FIGS. 9A-9D). The configuration shown in FIGS. 10A and 10B may be beneficial as removal of the additional inner member eliminates the concomitant stresses of the inner member on the shaft 1004 during deployment/expansion of the penetration structure 1010, thus reducing the need for reinforcement of the shaft 1004.

[0073] FIG. 10C shows the treatment assembly 1006 with the dilatation structure 1008 in an expanded state and the penetration structure 1010 in a collapsed state, with the balloon 1011 removed to better view the expandable frame 1090. The expandable frame 1090 can comprise a plurality of struts (labeled 1092a-1092d, referred to collectively as “struts 1092”), each of which have a flat, rounded, and/or otherwise blunt proximal portion 1094 and a sharpened distal portion 1096 (only one strut labeled in FIGS. 10B and 10C for ease of the viewing the underlying structure). The struts 1092 are joined to one another at their respective proximal and distal ends. Each of the struts 1092 can include a bendable portion 1094 and a linear portion 1096 distal of the bendable portion 1094 and longer than the bendable portion when the expandable frame 1090 is in the collapsed state. Expansion of the tapered balloon 1011 causes the bendable portion 1094 to bend around the proximal edge of the penetration balloon 1011 (as shown in FIG. 10B) such that the bendable portion 1094 has a first region 1094a (labeled in FIG. 10B) extending radially away from the longitudinal axis and a second region 1094b, distal of the first region 1094a along the length of the strut 1092, extending substantially longitudinally in a distal direction. In the expanded state, the struts 1092 converge distally and radially inwardly at the distal end 1098 of the expandable frame 1090, thereby conforming to the tapered shape of the underlying balloon 1011. As described above with reference to FIGS. 9A-9D, the cutting edge of the struts 1092 can be facing outward from the surface, tangent to the surface, or configured to lie tangent when unexpanded and turn partially or fully outward when expanded. Conclusion

[0074] Although many of the embodiments are described above with respect to systems, devices, and methods for angioplasty, the technology is applicable to other applications and/or other approaches, such as atherectomy, a crossing procedure, etc. Moreover, other embodiments in addition to those described herein are within the scope of the technology. Additionally, several other embodiments of the technology can have different configurations, components, or procedures than those described herein. A person of ordinary skill in the art, therefore, will accordingly understand that the technology can have other embodiments with additional elements, or the technology can have other embodiments without several of the features shown and described above with reference to FIGS. 1 A-l 0C.

[0075] The descriptions of embodiments of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Where the context permits, singular or plural terms may also include the plural or singular term, respectively. Although specific embodiments of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein may also be combined to provide further embodiments.

[0076] As used herein, the terms “generally,” “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by those of ordinary skill in the art.

[0077] Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. Additionally, the term "comprising" is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and/or additional types of other features are not precluded. It will also be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.

Claims

CLAIMS I/We claim:

2. The device of Claim 1, wherein the expandable structure comprises a balloon.

3. The device of Claim 1 or Claim 2, wherein, in the expanded state, a maximum outer diameter of the penetration structure is less than or equal to a maximum outer diameter of the dilatation balloon.

4. The device of any one of the previous Claims, wherein the expandable structure has a proximal end, a distal end, and an intermediate portion extending therebetween, and wherein an outer diameter of the expandable structure is substantially constant along the intermediate portion.

5. The device of any one of the previous Claims, wherein the penetration structure includes a protrusion carried by the expandable structure, and wherein the protrusion is configured to penetrate the obstruction when the penetration structure is expanded.

6. The device of Claim 5, wherein the protrusion comprises a blunt outer surface.

7. The device of Claim 5 or Claim 6, wherein the protrusion comprises a sharpened edge.

8. The device of any one of Claims 5 to 7, wherein the protrusion comprises a plurality of protrusions.

9. The device of Claim 8, wherein the protrusions are spaced apart about the circumference of the expandable structure and/or spaced apart along a longitudinal dimension of the expandable structure.

10. The device of any one of Claims 5 to 9, wherein the protrusion has a first portion having a first length and a second portion having a second length different than the first length, and wherein the first and second portions are separated by a connecting region that is configured to bend when the penetration structure is expanded, thereby placing the first and second portions at an angle relative to one another.

11. The device of Claim 10, wherein the second length is greater than the first length.

12. The device of any one of Claims 5 to 11, wherein the protrusion has a proximal blunt portion and a distal sharpened portion.

13. The device of any one of Claims 5 to 12, wherein the expandable structure is a balloon, and wherein, when the penetration structure is in a collapsed state, the protrusion is positioned within a fold of the balloon such that the protrusion is not exposed to the vessel wall prior to expansion of the penetration structure.

14. The device of any one of the previous Claims, wherein the expandable structure comprises a balloon, and wherein the elongate member defines a single inflation lumen for both the expandable structure and the dilatation balloon.

15. The device of any one of the previous Claims, wherein the expandable structure comprises a balloon, and wherein the elongate member defines a first inflation lumen for the expandable structure and a second inflation lumen for the dilatation balloon.

16. The device of any one of the previous Claims, wherein the elongate member is a tubular structure configured to receive a guidewire therethrough.