TECHNICAL FIELD

This disclosure relates to medical stents and medical assemblies for introducing stents into the body of a patient.

BACKGROUND

Patient conditions associated with heart valves such as, but not limited to, calcification, can produce a stenosis and/or valvular insufficiency or regurgitation. Valvular insufficiency or regurgitation occurs when a valve in a heart of a subject does not close completely, allowing blood to flow backwards (e.g., from the left ventricle to the left atrium), which may adversely impact the functionality of the heart. In some cases, valvular stenosis can cause the valve to become narrowed and hardened, which may prevent the valve from opening fully, thereby reducing blood flow through the valve. This reduced blood flow may cause the heart to work harder to pump blood through the diseased valve.

Heart valve prostheses have been developed for repair and replacement of diseased and/or damaged heart valves. Some heart valve prostheses can be percutaneously delivered and deployed at the site of the diseased heart valve through a medical delivery system such as a catheter. An example of such a medical procedure is the transcatheter aortic valve replacement (TAVR) procedure. In some cases, a heart valve prostheses includes an expandable stent to which tissue defining valves are mounted. The heart valve prostheses can be delivered while the stent is in a low-profile or collapsed configuration so that the stent is in a low-profile state for advancement through the patient's vasculature. Once positioned at the target treatment site, the stent can be expanded to engage native tissue at a target treatment site and position the heart valve prostheses at the target treatment site.

SUMMARY

In some aspects, this disclosure describes example medical assemblies that include a medical stent including one or more electrodes carried by the stent and electrically coupled to an energy source via one or more electrical conductors. The stent is configured to be implanted in cardiovasculature of a patient and can be, for example, part of a heart valve prostheses or a stent configured to be implanted in a blood vessel of a patient to help improve patency of the vessel. The energy source may be configured to deliver an electrical signal between the electrode carried by the stent and a second electrode through a fluid in contact with the electrode of the stent to cause the fluid to undergo cavitation to generate a pressure pulse wave within the fluid.

The cavitation of the fluid may be used treat a condition in a heart of a patient or in the vasculature of a patient. For example, the cavitation may produce a high-energy pressure pulse wave that, when directed at a valvular stenosis, may be used to disrupt and fracture calcification partially or fully causing the valvular stenosis. The disruption and fracture of the calcification may allow a heart valve prosthesis (also referred to herein as an artificial heart valve or a prosthetic heart valve) to be more easily and/or fully expanded in place in the heart. In examples in which the cavitation is used to disrupt and fracture calcification in a blood vessel of a patient, the disruption and fracture of the calcification may allow a stent to easily and/or fully expanded in the vessel, e.g., to achieve better patency of the vessel and achieve better blood flow through the vessel. In some other aspects, the disclosure describes methods of delivering and using the medical stents described herein.

Clause 1: In one example, a medical assembly includes a stent including a primary electrode, where the stent is configured to expand from a collapsed configuration to an expanded configuration, a secondary electrode, and an energy source configured to deliver an electrical signal between the primary electrode and the secondary electrode through a fluid in contact with the primary electrode to cause the fluid to undergo cavitation to generate a pressure pulse wave within the fluid.

Clause 2: In some of the examples of the medical assembly of clause 1, the medical assembly further including an electrical conductor having a distal end electrically coupled to the primary electrode and a proximal end electrically coupled to the energy source.

Clause 3: In some of the examples of the medical assembly of clause 1or 2, the stent includes a nickel-titanium alloy.

Clause 4: In some of the examples of the medical assembly of any one of clauses 1 to 3, the stent is configured to self-expand from the collapsed configuration to the expanded configuration.

Clause 5: In some of the examples of the medical assembly of any one of clauses 1 to 3, the medical assembly further including a balloon configured to expand the stent from the collapsed configuration to the expanded configuration.

Clause 6: In some of the examples of the medical assembly of any one of clauses 1 to 5, the stent includes a plurality of electrodes including the primary electrode.

Clause 7: In some of the examples of the medical assembly of any one of clauses 1 to 6, the stent includes a metallic body and a dielectric coating over a portion of the metallic body, a surface of the metallic body defining the primary electrode.

Clause 8: In some of the examples of the medical assembly of clause 7, the stent further includes an electrically conductive coating on the dielectric coating, where the dielectric coating prevents direct contact between the electrically conductive coating and the metallic body, the electrically conductive coating defining the secondary electrode.

Clause 9: In some of the examples of the medical assembly of clause 8, the electrically conductive coating and the dielectric coating define an electrode aperture that extends through a thickness of the electrically conductive coating and the dielectric coating, the electrode aperture exposing the surface of the metallic body to the fluid.

Clause 10: In some of the examples of the medical assembly of clause 7, further including a band of electrically conductive material that defines the secondary electrode, where the band is attached to the stent such that the dielectric coating prevents direct contact between the band and the metallic body.

Clause 11: In some of the examples of the medical assembly of any one of clauses 1 to 7, the medical assembly further including a guidewire defining the secondary electrode.

Clause 12: In some of the examples of the medical assembly of clause 11, where the guidewire is electrically coupled to the energy source.

Clause 13: In some of the examples of the medical assembly of any one of clauses 1 to 7, the medical assembly further including a catheter including an inner elongated member including the secondary electrode, and an outer elongated member configured to be retracted relative to the inner elongated member, in which the stent is configured to be positioned between the inner and outer elongated members, where when the outer elongated member is retracted relative to the inner elongated member such that a distal end of the outer elongated member is proximal to a distal end of the stent and distal to a proximal end of the stent, the distal end of the stent is configured to expand to a partially expanded configuration, and where the catheter and the stent are configured to deliver the electrical signal between the primary electrode and the secondary electrode while the stent is in the partially expanded configuration.

Clause 14: In some of the examples of the medical assembly of clause 13, the secondary electrode defines an exterior surface of a distal tip of the inner elongated member.

Clause 15: In some of the examples of the medical assembly of clause 13 or 14, the secondary electrode includes an electrically conductive ring positioned around the inner elongated member.

Clause 16: In some of the examples of the medical assembly of any one of clauses 13 to 15, the catheter further includes an electrical contact defining a surface of either the inner elongated member or the outer elongated member, where, while in the partially expanded configuration within the catheter, the stent contacts the electrical contact to electrically couple the primary electrode to the energy source.

Clause 17: In some of the examples of the medical assembly of clause 16, the electrical contact includes an electrically conductive ring positioned over the inner elongated member.

Clause 18: In some of the examples of the medical assembly of any one of clauses 13 to 16, where when the outer elongated member is retracted relative to the inner elongated member such that the distal end of the outer elongated member is proximal to the proximal end of the stent, the stent is configured to expand to the expanded configuration.

Clause 19: In some of the examples of the medical assembly of any one of clauses 13 to 17, the medical assembly further including a balloon attached to the inner elongated member, where the balloon is configured to expand the stent to the expanded configuration.

Clause 20: In some of the examples of the medical assembly of any one of clauses 1 to 19, the primary electrode is at a distal end of the stent.

Clause 21: In some of the examples of the medical assembly of any one of clauses 1 to 20, where the stent includes an artificial heart valve member.

Clause 22: In some of the examples of the medical assembly of any one of clauses 1 to 21, the stent is a transcatheter heart valve.

Clause 23: In some of the examples of the medical assembly of any one of clauses 1 to 22, the stent is configured to be implanted within a body of a patient.

Clause 24: In one example, a medical assembly includes a catheter including an inner elongated member including a secondary electrode, and an outer elongated member configured to be retracted relative to the inner elongated member, and a stent including a primary electrode, where the stent is configured to be positioned between the inner and outer elongated members, the stent being configured to expand from a collapsed configuration to an expanded configuration, where the secondary electrode and the primary electrode are configured to be electrically coupled to an energy source configured to deliver an electrical signal between the primary electrode and the secondary electrode through a fluid in contact with both the primary electrode and the secondary electrode to cause the fluid to undergo cavitation to generate a pressure pulse wave within the fluid.

Clause 25: In some of the examples of the medical assembly of clause 24, the medical assembly further including the energy source electrically coupled to the catheter, the energy source configured to deliver the electrical signal via the catheter to the primary electrode and the secondary electrode to cause the fluid to undergo cavitation.

Clause 26: In some of the examples of the medical assembly of clause 24 or 25, where the catheter further includes an electrical contact defining a surface of either the inner elongated member or the outer elongated member, where, while in the collapsed configuration within the catheter, the stent contacts the electrical contact to electrically couple the stent to the energy source.

Clause 27: In some of the examples of the medical assembly of clause 26, the stent includes a metallic body and a dielectric coating over a portion of the metallic body, a first surface of the metallic body defining the primary electrode, and a second surface of the metallic body in direct contact with the electrical contact while the stent is in the collapsed configuration.

Clause 28: In some of the examples of the medical assembly of clause 27, the metallic body includes a nickel-titanium alloy.

Clause 29: In some of the examples of the medical assembly of any one of clauses 24 to 28, the stent includes a plurality of electrodes including the primary electrode, each electrode of the plurality of electrodes positioned at the distal end of the stent.

Clause 30: In some of the examples of the medical assembly of any one of clauses 24 to 29, the secondary electrode defines an exterior surface of a distal tip of the inner elongated member.

Clause 31: In some of the examples of the medical assembly of any one of clauses 24 to 30, the secondary electrode includes an electrically conductive ring positioned over the inner elongated member.

Clause 32: In some of the examples of the medical assembly of any one of clauses 24 to 31, the electrical contact includes an electrically conductive ring positioned over the inner elongated member.

Clause 33: In some of the examples of the medical assembly of any one of clauses 24 to 32, where when the outer elongated member is retracted relative to the inner elongated member such that a distal end of the outer elongated member is proximal to a distal end of the stent and distal to a proximal end of the stent, the distal end of the stent is configured to expand to a partially expanded configuration, and where the catheter and the stent are configured to deliver the electrical signal between the primary electrode and the secondary electrode while the stent is in the partially expanded configuration.

Clause 34: In some of the examples of the medical assembly of any one of clauses 24 to 33, where when the outer elongated member is retracted relative to the inner elongated member such that the distal end of the outer elongated member is proximal to the proximal end of the stent, the stent is configured to expand to the expanded configuration.

Clause 35: In some of the examples of the medical assembly of any one of clauses 24 to 34, the medical assembly further including a balloon attached to the inner elongated member, the balloon configured to expand the stent to the expanded configuration.

Clause 36: In some of the examples of the medical assembly of any one of clauses 24 to 35, where the stent is configured to self-expand from the collapsed configuration to the expanded configuration.

Clause 37: In some of the examples of the medical assembly of any one of clauses 24 to 36, the stent includes an artificial heart valve member.

Clause 38: In some of the examples of the medical assembly of any one of clauses 24 to 37, the stent is a transcatheter heart valve.

Clause 39: In some of the examples of the medical assembly of any one of clauses 24 to 38, the stent is configured to be implanted within a body of a patient.

Clause 40: In one example, a medical stent includes a metallic body defining a primary electrode, a dielectric coating positioned over a portion of the metallic body, and a secondary electrode on the dielectric coating, where the dielectric coating prevents direct contact between the secondary electrode and the metallic body, where the secondary electrode and the primary electrode are configured to be electrically coupled to an energy source configured to deliver an electrical signal between the primary electrode and the secondary electrode through a fluid in contact with both the primary electrode and the secondary electrode to cause the fluid to undergo cavitation to generate a pressure pulse wave within the fluid.

Clause 41: In some of the examples of the medical stent of clause 40, the stent further includes an electrically conductive coating on the dielectric coating, where the dielectric coating prevents direct contact between the electrically conductive coating and the metallic body, the electrically conductive coating defining the secondary electrode.

Clause 42: In some of the examples of the medical stent of clause 41, the electrically conductive coating and the dielectric coating define an electrode aperture that extends through a thickness of the electrically conductive coating and the dielectric coating, the electrode aperture exposing the primary electrode to an external environment of the stent.

Clause 43: In some of the examples of the medical stent of clause 40, the medical stent further including a band of electrically conductive material that defines the secondary electrode, where the band is attached to the stent such that the dielectric coating prevents direct contact between the band and the metallic body.

Clause 44: In some of the examples of the medical stent of any one of clauses 40 to 43, the medical stent further including an artificial heart valve member.

Clause 45: In some of the examples of the medical stent of any one of clauses 40 to 44, the stent is a transcatheter heart valve.

Clause 46: In some of the examples of the medical stent of any one of clauses 40 to 45, the stent is configured to be implanted within a body of a patient.

Clause 47: In one example, a method includes coupling a stent to an energy source, where the stent includes primary electrode, the stent is configured to expand from a collapsed configuration to an expanded configuration; electrically coupling a secondary electrode to the energy source; and delivering, using the energy source, an electrical signal between the primary electrode and the secondary electrode through a fluid in contact with the primary electrode to cause the fluid to undergo cavitation to generate a pressure pulse wave within the fluid.

Clause 48: In some of the examples of the method of clause 47, the secondary electrode is carried by a catheter includes an inner elongated member including the secondary electrode, and an outer elongated member configured to be retracted relative to the inner elongated member, where the stent is configured to be positioned between the inner and outer elongated members. The method further includes retracting the outer elongated member relative to the inner elongated member such that a distal end of the outer elongated member is proximal to a distal end of the stent and distal to a proximal end of the stent, where retracting the outer elongated member includes expanding the distal end of the stent to a partially expanded configuration within the fluid, where while in the partially expanded configuration the primary electrode is configured to be electrically coupled to the energy source via the catheter, and where delivering the electrical signal between the primary electrode and the secondary electrode includes delivering the electrical signal while the stent is in the partially expanded configuration.

Clause 49: In some of the examples of the method of clause 48, the method further includes collapsing the stent to the collapsed configuration; repositioning the catheter within the fluid; re-expanding the stent to the partially expanded configuration; and delivering, using the energy source, an additional electrical signal between the primary electrode and the secondary electrode, where delivery of the additional electrical signal causes the fluid to undergo cavitation that results in the generation of a pressure pulse wave within the fluid.

Clause 50: In some of the examples of the method of clause 49, where collapsing the stent to the collapsed configuration includes advancing the outer elongated member distal relative to the inner elongated member such the outer elongated member forces the stent into the collapsed configuration.

Clause 51: In some of the examples of the method of any one of clauses 48 to 50, the method further includes retracting the outer elongated member relative to the inner elongated member such that the distal end of the outer elongated member is proximal to the proximal end of the stent; and deploying the stent in the expanded configuration within the fluid; and removing the catheter from the fluid.

Clause 52: In some of the examples of the method of clause 51, where deploying the stent in the expanded configuration within the fluid includes deploying the stent adjacent a heart valve or across the heart valve.

Clause 53: In some of the examples of the method of any one of clauses 48 to 51, further including introducing a distal portion of the catheter through vasculature of a patient to a target treatment site containing a calcified lesion.

Clause 54: In some of the examples of the method of any one of clauses 47 to 53, where delivering the electrical signal includes delivering, using the energy source, a plurality of electrical pulses having a pulse width of between about 1 microsecond (μs) and about 200 μs.

Clause 55: In some of the examples of the method of any one of clauses 47 to 54, the method further includes deploying an embolic protection device downstream of the stent prior to delivering the electrical signal.

The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of examples according to this disclosure will be apparent from the description and drawings, and from the claims.

