Rotatable medical device

A rotational atherectomy device advanceable over a guidewire. The rotational atherectomy device includes a drive shaft rotatably extending through an outer tubular member to rotate a cutting member positioned at a distal end thereof. The rotational atherectomy device further includes an insert positioned within the cutting member for frictional contact with the guidewire.

TECHNICAL FIELD

The disclosure is directed to devices and methods for removing occlusive material from a body lumen. More particularly, the disclosure is directed to a rotational atherectomy device for forming a passageway through an occlusion of a body lumen, such as a blood vessel.

BACKGROUND

Many patients suffer from occluded arteries and other blood vessels which restrict blood flow. Occlusions can be partial occlusions that reduce blood flow through the occluded portion of a blood vessel or total occlusions (e.g., chronic total occlusions) that substantially block blood flow through the occluded blood vessel. Revascularization techniques include using a variety of devices to pass through the occlusion to create or enlarge an opening through the occlusion. Atherectomy is one technique in which a catheter having a rotatable cutting element thereon is advanced through the occlusion to form or enlarge a pathway through the occlusion. Typically, a guidewire is initially placed across the occlusion and then the atherectomy catheter is advanced over the guidewire as the atherectomy catheter is passed through the occlusion.

A need remains for alternative atherectomy devices to facilitate crossing an occlusion while being advanced along a guidewire.

BRIEF SUMMARY

The disclosure is directed to several alternative designs, materials and methods of manufacturing medical device structures and assemblies, and uses thereof.

Accordingly, one illustrative example is a rotational atherectomy device. The rotational atherectomy device includes an outer tubular member having a lumen extending therethrough, a cutting member rotationally positioned at a distal end of the outer tubular member, and a drive shaft extending through the lumen of the outer tubular member. The drive shaft is rotatable relative to the outer tubular member to rotate the cutting member. The rotational atherectomy device further includes an insert positioned within the cutting member, the insert including an opening extending therethrough for passing a guidewire therethrough.

Additionally or alternatively, a distal portion of the drive shaft extends into a bore of the cutting member.

Additionally or alternatively, the insert is positioned in the bore of the cutting member distal of a distal end of the drive shaft.

Additionally or alternatively, the drive shaft includes a guidewire lumen extending therethrough axially aligned with the opening of the insert.

Additionally or alternatively, the guidewire lumen has a diameter and the opening of the insert has a diameter less than the diameter of the guidewire lumen.

Additionally or alternatively, the insert includes an inner surface defining the opening of the insert, wherein at least a portion of the inner surface is nonparallel to a central longitudinal axis of the drive shaft.

Additionally or alternatively, the inner surface tapers radially outward from the central longitudinal axis in a distal direction.

Additionally or alternatively, the inner surface tapers radially outward in a distal direction from a mid region of the insert to a distal tip of the insert.

Additionally or alternatively, the inner surface tapers radially outward in a proximal direction from the mid region of the insert to a proximal end of the insert.

Additionally or alternatively, the bore has a diameter greater than the diameter of the opening of the insert.

Additionally or alternatively, the insert includes an inner surface defining the opening of the insert, the inner surface having a surface roughness Raof 0.4 micrometers or less.

Additionally or alternatively, the insert includes an inner surface defining the opening of the insert, the inner surface having a surface roughness Raof 0.2 micrometers or less.

Additionally or alternatively, the cutting member includes a distal opening axially aligned with the opening of the insert, the distal opening of the cutting member having a diameter greater than or equal to a diameter of the opening of the insert.

Additionally or alternatively, the insert is formed of a polymeric material.

Additionally or alternatively, the insert is formed of a polished metallic material.

An illustrative example that may optionally be used in conjunction with any of the above described characteristics is a rotational atherectomy device. The rotational atherectomy device includes an outer tubular member having a lumen extending therethrough, a cutting member rotationally positioned at a distal end of the outer tubular member, and a drive shaft extending through the lumen of the outer tubular member. The cutting member includes a central longitudinal bore extending therethrough. A distal end region of the drive shaft extends into the bore of the cutting member. The drive shaft is rotatable relative to the outer tubular member to rotate the cutting member. The rotational atherectomy device further includes an insert positioned within the bore of the cutting member. The insert includes an opening extending therethrough axially aligned with the bore of the cutting member.

Additionally or alternatively, the drive shaft includes a guidewire lumen extending therethrough axially aligned with the opening of the insert.

Additionally or alternatively, the guidewire lumen has a diameter and the opening of the insert has a diameter less than the diameter of the guidewire lumen.

Additionally or alternatively, the cutting member includes a distal opening axially aligned with the opening of the insert, the distal opening of the cutting member having a diameter greater than or equal to a diameter of the opening of the insert.

Additionally or alternatively, the insert includes an inner surface defining the opening of the insert, wherein at least a portion of the inner surface is nonparallel to a central longitudinal axis of the drive shaft.

Additionally or alternatively, the insert includes an inner surface defining the opening of the insert, the inner surface having a surface roughness Raof 0.4 micrometers or less.

Another illustrative example is method of creating or enlarging a passageway through an occlusion in a body lumen. The method includes advancing a guidewire through a body lumen to a location proximate an occlusion and then advancing a rotational atherectomy device through the body lumen over the guidewire to a location proximal of the occlusion in the body lumen. The rotational atherectomy device includes a rotatable drive shaft extending through an outer tubular member to rotatably drive a cutting member positioned at a distal end of the outer tubular member, and an insert positioned within the cutting member. The guidewire extends through an opening of the insert and a guidewire lumen of the drive shaft. The method further includes rotating the cutting member relative to the guidewire with the drive shaft while advancing the cutting member through the occlusion.

Additionally or alternatively, a coefficient of static friction between the insert and the guidewire is less than 0.25.

Additionally or alternatively, a coefficient of static friction between the insert and the guidewire is less than 0.10.

DETAILED DESCRIPTION

Definitions of certain terms are provided below and shall be applied, unless a different definition is given in the claims or elsewhere in this specification.

An exemplary rotational atherectomy system10is shown inFIG. 1. The rotational atherectomy system10may include a rotational atherectomy device12and a controller14for controlling the rotational atherectomy device12. The rotational atherectomy device12may include a housing16and an elongate shaft18extending distally from the housing16to a cutting member20located at a distal end of the elongate shaft18. The elongate shaft18may include a drive shaft24to provide rotational motion to the cutting member20. In some instances, the elongate shaft18may include an outer tubular member22having a lumen extending therethrough and the drive shaft24may extend through the lumen of the outer tubular member22. The drive shaft24, which may be fixed to the cutting member20, may be rotatable relative to the outer tubular member22to rotate the cutting member20. In some instances the axial position of the cutting member20relative to the outer tubular member22may be adjusted by moving the drive shaft24longitudinally relative to the outer tubular member22. For example, the atherectomy device12may include an advancer assembly26positioned in the housing16, or otherwise provided with the housing16, that is longitudinally movable relative to the housing16. The outer tubular member22may be coupled to the housing16while the drive shaft24may be coupled to the advancer assembly26. Accordingly, the drive shaft24(and thus the cutting member20) may be longitudinally movable relative to the outer tubular member22by actuating the advancer assembly26relative to the housing16.

The rotational atherectomy device12may include a prime mover (not shown) to provide rotational motion to the drive shaft24to rotate the cutting member20. For example, in some instances the prime mover may be a fluid turbine within the housing16, such as provided with the advancer assembly26. In other instances, however, the prime mover may be an electrical motor, or the like. The controller14may be used to control the prime mover. For example, the user may provide power to the prime mover and/or control the speed of rotation of the drive shaft24via the controller14. For example, the front panel28of the controller14may include a user interface including a power switch, speed control mechanism (e.g., a speed control knob and/or buttons), a display, and/or other features for controlling the rotational atherectomy device12. In some instances, the rotational atherectomy system10may include a remote control device30, such as a foot pedal, a hand control, or other mechanism which may be used to control the power and/or speed to the prime mover, for example.

In instances in which the prime mover is a turbine, the rotational atherectomy system10may also include a pressurized fluid source32providing a pressurized fluid to the turbine to rotate the drive shaft24. In some instances, as shown, the pressurized fluid source32may be a tank of pressurized fluid (e.g., compressed air), which may or may not include an air compressor. In other instances, the pressured fluid source32may be provided external of the rotational atherectomy system10, such as from a wall outlet at the medical facility. The pressured fluid source32may be coupled to the controller14via a fluid conduit34, which in turn is coupled to the rotational atherectomy device12via a fluid conduit36. The controller14may regulate the flow and/or pressure of fluid through the fluid conduit36to the rotational atherectomy device12to control the speed of rotation of the drive shaft24and cutting member20, for instance.

In instances in which the prime mover is an electric motor, the electric motor may be coupled to the controller14via an electrical connection to control the electric motor and/or provide electricity to the electric motor.

In some instances, the rotational atherectomy device12may include a speed sensor, such as an optical speed sensor, coupled to the controller14via a connector38, such as a fiber optic connector to provide speed data to the controller14. In other instances, an electronic sensor, such as a Hall Effect sensor, or other type of sensor may be used to sense the speed of the drive shaft24and cutting member20. The speed data may be displayed, such as on the front panel28and/or the controller14, and/or used to control the speed of the cutting member20, such as maintaining a desired speed of the cutting member20during a medical procedure.

In some embodiments, the rotational atherectomy system10may be configured to infuse fluid through the elongate shaft18to the treatment site and/or aspirate fluid through the elongate shaft18from the treatment site. For example, the rotational atherectomy system10may include a fluid supply40for providing a flow of fluid through a lumen of the elongate shaft18to a treatment site. As shown inFIG. 1, in some instances the fluid supply40may include a saline bag42which may be pressurized by a pressure cuff44to provide a pressurized fluid (e.g., saline) to the rotational atherectomy device12through a fluid supply line46. In other embodiments, an infusion pump, such as a peristaltic pump, may be used to deliver pressurized fluid to the rotational atherectomy device12. Additionally or alternatively, in some embodiments the rotational atherectomy system10may be configured to aspirate fluid from the treatment site. For example, the rotational atherectomy system10may include an aspiration pump, such as a peristaltic pump, to generate a vacuum to aspirate fluid through a lumen of the elongate shaft18to a fluid collection container (not shown), if desired.

In some instances, the elongate shaft18of the rotational atherectomy device12may be advanced over a guidewire48to a treatment site. For example, the drive shaft24may include a guidewire lumen through which the guidewire48may pass. Additionally or alternatively, the elongate shaft18may be advanced through a lumen of a guide catheter to a treatment site.

The distal region of the rotational atherectomy device12is shown inFIG. 2. As shown, the drive shaft24, which in some instances may include a coiled member, may extend through the lumen72of the outer tubular member22and be rotationally and/or longitudinally movable relative to the outer tubular member22. The drive shaft24may include the cutting member20mounted thereon. In some instances, the cutting member20may be a burr having an abrasive surface, such as a diamond coated abrasive surface. In other instances, the cutting member20may include one or more flutes having a cutting edge, or the cutting member20may be of another construction for abrading or cutting occlusive material.

A guidewire lumen60may extend through the drive shaft24and the cutting member20to a distal tip70of the cutting member20. As shown, the cutting member20may include a bore62extending therethrough with a distal end region of the drive shaft24extending into the bore62of the cutting member20.

The rotational atherectomy device12may also include an insert50positioned within the cutting member20. For example, the insert50may be positioned in the bore62of the cutting member20distal of a distal end25of the drive shaft24. The insert50may include an opening52extending therethrough for passing the guidewire48therethrough. In some instances, the opening52through the insert50may be axially aligned with the guidewire lumen60of the drive shaft24. In other words, the opening52may be coaxial with the guidewire lumen60in some instances.

The guidewire lumen60may have a diameter D1and the opening52through the insert50may have a diameter D2. In some instances, the diameter D1of the guidewire lumen60may be greater than the diameter D2of the opening52. Accordingly, there may be a closer tolerance between an inner surface of the insert50and the guidewire48than the tolerance between the guidewire48and the drive shaft24. In other words, there may be greater clearance between the guidewire48and the inner surface of the drive shaft24than the clearance between the guidewire48and the inner surface of the insert50defining the opening52. For example, to accommodate a guidewire having an outer diameter of 0.36 millimeter (0.014 inches), the guidewire lumen60may have a diameter D1of about 0.41 millimeters (0.016 inches) or more, or about 0.46 millimeters (0.018 inches) or more, while the diameter D2of the opening52of the insert50may be about 0.38 millimeters (0.015 inches).

The bore62, within which the insert50and/or the distal end region of the drive shaft24may be disposed, may have a diameter D3. The diameter D3of the bore62may be greater than the diameter D1of the guidewire lumen60through the drive shaft24and/or the opening52through the insert50. In some instances, the insert50may be inserted into the bore62of the cutting member20from the proximal opening of the cutting member20. Thereafter, the distal end region of the drive shaft24may be inserted into the bore62of the cutting member20from the proximal opening of the cutting member20. In some instances, the distal end25of the drive shaft24may face or abut the proximal end of the insert50within the bore62of the cutting member20.

The cutting member20may include a distal opening at the distal tip70of the cutting member20. The distal opening of the cutting member20may be axially aligned with the opening52of the insert50. In some instances, the distal opening of the cutting member20may have a diameter greater than or equal to the diameter D2of the opening52of the insert50. In some instances, the distal opening of the cutting member20may be configured to facilitate inserting the guidewire48into the opening52of the insert50and through the guidewire lumen62of the drive shaft24from the distal tip70of the cutting member20.

In some instances, the insert50may function as a spacer and/or bearing between the cutting member20and the guidewire48. For example, the insert50may provide a low friction interface with the guidewire48as the cutting member20is rotatably driven during a medical procedure.

In some instances, the inner surface of the insert50which defines the opening52of the insert50may have an average surface roughness Raof about 0.4 micrometers or less, about 0.3 micrometers or less, about 0.2 micrometers or less, or about 0.1 micrometers or less. Additionally or alternatively, in some instances the coefficient of static friction μsbetween the insert50and the guidewire48may be less than 0.25, less than 0.20, less than 0.15 or less than 0.10, for example.

The insert50may be made of any desired material, such as a low friction material, including a metallic material, a polymeric material, or a combination thereof. Some suitable metallic materials include stainless steel, such as highly polished stainless steel. Some suitable polymeric materials include polyamide (e.g., nylon), polytetrafluoroethylene (PTFE), high density polyethylene (HDPE), ultra-high molecular weight polyethylene (UHMWPE), or other polymeric material having a high molecular weight, for example.

Another embodiment of the distal region of the rotational atherectomy device12is shown inFIG. 3. The components and arrangement of the distal region may be similar in many respects to that shown inFIG. 2, and thus reference to those aspects discussed above is noted. As shown inFIG. 3, an insert150may be positioned within the cutting member20. For example, the insert150may be positioned in the bore62of the cutting member20distal of a distal end25of the drive shaft24. The insert150may include an opening152extending therethrough for passing the guidewire48therethrough. In some instances, the opening152through the insert150may be axially aligned with the guidewire lumen60of the drive shaft24. In other words, the opening152may be coaxial with the guidewire lumen60in some instances.

The insert150may include an inner surface defining the opening152of the insert150. As shown inFIG. 3, at least a portion of the inner surface of the insert150may be nonparallel to the central longitudinal axis X of the drive shaft24. For example, the inner surface of the insert150may taper radially outward from the central longitudinal axis in a distal direction (i.e., flare radially outward toward the distal tip70) along at least a portion of the longitudinal length of the opening152. For example, a proximal region and/or mid region of the opening152may have a diameter D2, while a distal region of the opening152may have a diameter D4greater than the diameter D2of the proximal region and/or mid region of the opening152.

The insert150may be similar to the insert50described above. For example, the insert150may function as a spacer and/or bearing between the cutting member20and the guidewire48. For example, the insert150may provide a low friction interface with the guidewire48as the cutting member20is rotatably driven during a medical procedure.

In some instances, the inner surface of the insert150which defines the opening152of the insert150may have an average surface roughness Raof about 0.4 micrometers or less, about 0.3 micrometers or less, about 0.2 micrometers or less, or about 0.1 micrometers or less. Additionally or alternatively, in some instances the coefficient of static friction μsbetween the insert150and the guidewire48may be less than 0.25, less than 0.20, less than 0.15 or less than 0.10, for example.

The insert150may be made of any desired material, such as a low friction material, including a metallic material, a polymeric material, or a combination thereof. Some suitable metallic materials include stainless steel, such as highly polished stainless steel. Some suitable polymeric materials include polyamide (e.g., nylon), polytetrafluoroethylene (PTFE), high density polyethylene (HDPE), ultra-high molecular weight polyethylene (UHMWPE), or other polymeric material having a high molecular weight, for example.

Also shown inFIG. 3, the distal opening of the cutting member20at the distal tip70may have a diameter D5greater than the diameter D4of the distal region of the opening152, and thus greater than the diameter D2of the proximal region and/or mid region of the opening152. The enlarged diameter of the distal opening of the cutting member20may facilitate inserting the guidewire48into the opening152of the insert150and through the guidewire lumen62of the drive shaft24from the distal tip70of the cutting member20.

Another embodiment of the distal region of the rotational atherectomy device12is shown inFIG. 4. The components and arrangement of the distal region may be similar in many respects to that shown inFIG. 2, and thus reference to those aspects discussed above is noted. As shown inFIG. 4, an insert250may be positioned within the cutting member20. For example, the insert250may be positioned in the bore62of the cutting member20distal of a distal end25of the drive shaft24. The insert250may include an opening252extending therethrough for passing the guidewire48therethrough. In some instances, the opening252through the insert250may be axially aligned with the guidewire lumen60of the drive shaft24. In other words, the opening252may be coaxial with the guidewire lumen60in some instances.

The insert250may include an inner surface defining the opening252of the insert250. As shown inFIG. 4, at least a portion of the inner surface of the insert250may be nonparallel to the central longitudinal axis X of the drive shaft24. For example, the inner surface of the insert250may taper radially outward from the central longitudinal axis in a distal direction (i.e., flare radially outward toward the distal tip70) along at least a portion of the longitudinal length of the opening252. For example, a mid region of the opening252may have a diameter D2, while a distal region of the opening252may have a diameter D4greater than the diameter D2of the mid region of the opening252. Furthermore, the inner surface of the insert250may taper radially outward from the central longitudinal axis in a proximal direction (i.e., flare radially outward toward the proximal end of the insert250) along at least a portion of the longitudinal length of the opening252. For example, a proximal region of the opening252may have a diameter D6greater than the diameter D2of the mid region of the opening252. In some instances the diameter D6of the proximal region of the opening252may be the same as the diameter D4of the distal region of the opening252, or the diameter D6may be different than (e.g., greater than or less than) the diameter D4.

The insert250may be similar to the insert50described above. For example, the insert250may function as a spacer and/or bearing between the cutting member20and the guidewire48. For example, the insert250may provide a low friction interface with the guidewire48as the cutting member20is rotatably driven during a medical procedure.

In some instances, the inner surface of the insert250which defines the opening252of the insert250may have an average surface roughness Raof about 0.4 micrometers or less, about 0.3 micrometers or less, about 0.2 micrometers or less, or about 0.1 micrometers or less. Additionally or alternatively, in some instances the coefficient of static friction μsbetween the insert250and the guidewire48may be less than 0.25, less than 0.20, less than 0.15 or less than 0.10, for example.

The insert250may be made of any desired material, such as a low friction material, including a metallic material, a polymeric material, or a combination thereof. Some suitable metallic materials include stainless steel, such as highly polished stainless steel. Some suitable polymeric materials include polyamide (e.g., nylon), polytetrafluoroethylene (PTFE), high density polyethylene (HDPE), ultra-high molecular weight polyethylene (UHMWPE), or other polymeric material having a high molecular weight, for example.

Also shown inFIG. 4, the distal opening of the cutting member20at the distal tip70may have a diameter D5greater than the diameter D4of the distal region of the opening252, and thus greater than the diameter D2of the mid region of the opening252. The enlarged diameter of the distal opening of the cutting member20may facilitate inserting the guidewire48into the opening252of the insert250and through the guidewire lumen62of the drive shaft24from the distal tip70of the cutting member20.

Another embodiment of the distal region of the rotational atherectomy device12is shown inFIG. 5. The components and arrangement of the distal region may be similar in many respects to that shown inFIG. 2, and thus reference to those aspects discussed above is noted. As shown inFIG. 5, an insert350may be positioned within the cutting member20. For example, the insert350may be positioned in the bore62of the cutting member20within the distal end region of the drive shaft24. The insert350may include an opening352extending therethrough for passing the guidewire48therethrough. In some instances, the opening352through the insert350may be axially aligned with the guidewire lumen60of the drive shaft24. In other words, the opening352may be coaxial with the guidewire lumen60in some instances.

The insert350may include an inner surface defining the opening352of the insert350. As shown inFIG. 5, at least a portion of the inner surface of the insert350may be nonparallel to the central longitudinal axis X of the drive shaft24. For example, the inner surface of the insert350may taper radially outward from the central longitudinal axis in a distal direction (i.e., flare radially outward toward its distal end) along at least a portion of the longitudinal length of the opening352and/or may taper radially outward from the central longitudinal axis in a proximal direction (i.e., flare radially outward toward its proximal end). For example, a mid region of the opening352may have a diameter D2, while a proximal region and/or a distal region of the opening352may have a diameter greater than the diameter D2of the mid region of the opening352.

The insert350may be similar to the insert50described above. For example, the insert350may function as a spacer and/or bearing between the cutting member20and the guidewire48. For example, the insert350may provide a low friction interface with the guidewire48as the cutting member20is rotatably driven during a medical procedure.

In some instances, the inner surface of the insert350which defines the opening352of the insert350may have an average surface roughness Raof about 0.4 micrometers or less, about 0.3 micrometers or less, about 0.2 micrometers or less, or about 0.1 micrometers or less. Additionally or alternatively, in some instances the coefficient of static friction μsbetween the insert350and the guidewire48may be less than 0.25, less than 0.20, less than 0.15 or less than 0.10, for example.

The insert350may be made of any desired material, such as a low friction material, including a metallic material, a polymeric material, or a combination thereof. Some suitable metallic materials include stainless steel, such as highly polished stainless steel. Some suitable polymeric materials include polyamide (e.g., nylon), polytetrafluoroethylene (PTFE), high density polyethylene (HDPE), ultra-high molecular weight polyethylene (UHMWPE), or other polymeric material having a high molecular weight, for example.

Also shown inFIG. 5, the distal opening of the cutting member20at the distal tip70may have a diameter D5greater than the diameter D2of the opening352. The enlarged diameter of the distal opening of the cutting member20may facilitate inserting the guidewire48into the opening352of the insert350and through the guidewire lumen62of the drive shaft24from the distal tip70of the cutting member20.

As shown inFIG. 5, the bore62of the cutting member20may include a stepped region between the diameter D3and the diameter D4. In some instances, the distal end25of the drive shaft24and/or the distal end of the insert350may be positioned adjacent to and/or abut the stepped region of the bore62.

Although the central longitudinal axis of the cutting member20and the central longitudinal axis of the insert50,150,250,350are shown inFIGS. 2-5as being coaxial with the central longitudinal axis X (i.e., the rotational axis) of the drive shaft24, in other instances, the central longitudinal axis of the cutting member20and/or the central longitudinal axis of the insert50,150,250,350may be non-coaxial with the central longitudinal axis X of the drive shaft24, allowing for eccentric rotation of the cutting member20while still providing a smooth bearing surface inside the cutting member20for the guidewire48.

Turning now toFIGS. 6-12, aspects of an exemplary method of traversing an occlusion in a blood vessel are shown. As shown inFIG. 6, a guidewire48may be advanced through the lumen94of the blood vessel90to a location proximate an occlusion92. For instance, the guidewire48may be advanced through the occlusion92such that the distal end of the guidewire48passes distally beyond the occlusion92.

Referring toFIG. 7, the rotational atherectomy device12may then be advanced through the lumen94of the blood vessel90over the guidewire48to a location proximate the occlusion92to create or enlarge a passageway through the occlusion92. For instance, the elongate shaft18of the rotational atherectomy device12may be advanced through a body lumen (e.g., blood vessel90) to a location proximal of the occlusion92in the body lumen. For example, the guidewire48may pass into the distal opening of the cutting member20, through the opening52,152,252,352of the insert50,150,250,350within the cutting member20, and through the guidewire lumen60of the drive shaft24, as shown inFIGS. 2-5. In some instances, the elongate shaft18may be advanced through a lumen of a guide catheter to the occlusion92while being advanced along the guidewire48.

Once positioned proximate the occlusion92, the rotational atherectomy device12may be used to create or enlarge a passageway through the occlusion92. For example, referring toFIG. 8, thereafter, rotation of the cutting member20(via rotationally driving the drive shaft24) may be initiated once the cutting member20has been advanced to the occlusion92. The rotatable drive shaft24extending through the outer tubular member22of the elongate shaft18of the rotational atherectomy device12may be rotatably driven to rotatably drive the cutting member20while advancing the cutting member20through the occlusion92. In some instances the drive shaft24may be advanced distally relative to the outer tubular member22to advance the cutting member20through the occlusion92, while in other instances the outer tubular member22may be advanced together with the drive shaft24. In some instances, fluid infusion and/or fluid aspiration through one or more lumens of the rotational atherectomy device12may be performed while advancing the cutting member20through the occlusion92.

The insert50,150,250,350may function as a bearing as the cutting member20rotates at a high rotational rate, e.g., 5,000 revolutions per minute (RPM) or more, 10,000 revolutions per minute (RPM) or more, or 20,000 revolutions per minute (RPM) or more) about the guidewire48. The insert50,150,250,350may maintain the guidewire48spaced away from directly contacting the cutting member20as the cutting member20is being rotated about its rotational axis. The frictional interaction between the guidewire48and the insert50may be less than that between the guidewire48and the cutting member20if permitted to frictionally contact one another. In some instances the coefficient of static friction μsbetween the insert50,150,250,350and the guidewire48may be less than 0.25, less than 0.20, less than 0.15 or less than 0.10, for example.

The cutting member20may be advanced through the occlusion92to form or enlarge a pathway96through the occlusion92to permit blood flow through the lumen94of the blood vessel90, as shown inFIG. 9. Thereafter, as shown inFIG. 10, the rotational atherectomy device12may be withdrawn, leaving the guidewire48in position across the occlusion92. Another intravascular device, such as a therapeutic or diagnostic medical device, may then be advanced over the guidewire48to a location proximate to or distal of the occlusion92, for example. For instance, as shown inFIG. 11, an angioplasty catheter100may be advanced over the previously positioned guidewire48to position an inflatable balloon120of the angioplasty catheter100across the occlusion92. The balloon120may then be inflated with an inflation media introduced into the balloon120from an inflation lumen extending through the elongate shaft110of the angioplasty catheter100to further enlarge the passageway through the occlusion92.

As described above, the same guidewire48may be used throughout the procedure without the need to exchange the guidewire48for one or more other guidewires. For example, the same guidewire48used to initially cross the occlusion92may also be used in advancing the rotational atherectomy device12distally through the occlusion92and/or in advancing one or more additional intravascular devices proximate to or distally through the occlusion92. The ability to utilize the same guidewire48without performing a guidewire exchange may save time during the procedure as well as reduce the number of medical devices needed to complete the procedure.

It is noted that the rotational cutting devices described herein may be used in other medical procedures, such as in orthopedic medical procedures, if desired. For example, the penetrating member may be penetrated into a bony structure to stabilize the cutting member prior to initiating engagement of the rotating cutting member with the bony structure.