A rotational atherectomy device for removing occlusive material

Abstract

A rotational atherectomy device for removing occlusive material from an interior of a blood vessel. The rotational atherectomy device comprises a rotatable drive shaft having a longitudinal axis, a rotatable head for cutting or abrading, the head being disposed at the distal end of the rotatable drive shaft, and a guide assembly. The guide assembly comprises a guide portion for contact with the wall of the blood vessel and for protecting the wall of the vessel. The guide assembly is transitionable between a radially contracted configuration and a radially expanded configuration. In the radially expanded configuration, the guide portion is disposed radially outward of the rotatable head.

Description

[0001] A ROTATIONAL ATHERECTOMY DEVICE FOR REMOVING OCCLUSIVE

[0002] MATERIAL

[0003] Technical Field

[0004] The present disclosure relates to a rotational atherectomy device for removing occlusive material such as plaque or lesions from an interior of a blood vessel, and a method of removing occlusive material using a rotational atherectomy device .

[0005] Background

[0006] Atherosclerosis is a condition where plaque deposits (e.g., calcified plaque deposits) or lesions in the walls of a blood vessel lead to narrowing of the blood vessel and increased blood pressure. In severe cases, this can result in peripheral artery disease, coronary artery disease, tissue death or stroke.

[0007] Atherosclerosis can be treated in a number of ways such as by angioplasty, where a balloon is used to force the expansion of the blood vessel to allow improved blood flow, a vascular bypass, where a surgical procedure is performed to redirect the blood flow to circumvent the diseased area of the blood vessel, or atherectomy.

[0008] Atherectomy is a non-surgical , minimally invasive procedure to open blocked blood vessels using a device at the distal end of a catheter to cut or abrade (grind) atherosclerotic plaque or lesions, i.e., occlusive material, from the walls of the blood vessel at an occlusion site. Atherectomy devices can generally be classified into four different types: orbital, rotational, laser and directional. A rotational atherectomy device uses a rotatable head to remove occlusive material by cutting or abrading atherosclerotic plaque or lesions from the walls of the blood vessel .

[0009] Conventional rotational atherectomy devices include a flexible drive shaft and a rotatable head for cutting or abrading, wherein a lumen extends through both the drive shaft and the rotatable head to allow passage of a guide wire .

[0010] In operation, the guide wire is inserted into a body lumen of a patient , advanced distally towards a desired occlusion site ( i . e . , an occlusion site to be treated) , and then advanced through and past the occlusion site . Accordingly, the distal end of the guide wire is positioned distally of the occlusion site .

[0011] The atherectomy device is then, via its lumen, slid over the guide wire and then advanced distally over the guide wire until it is positioned j ust proximal to the occlusion site .

[0012] In this state , the guide wire , which passes through the lumen of the atherectomy device , extends distally past the occlusion site , and, thus , the distal end of the guide wire is positioned distally of the atherectomy device .

[0013] A guide catheter may be used to assist in the positioning of the guide wire and the atherectomy device .

[0014] The proximal end of the drive shaft remains outside the body and is attached to an electric motor .

[0015] The motor rotates the rotatable head via the drive shaft while the atherectomy device is advanced distally through the occlusion site and the rotatable head removes the occluding material by cutting or abrading . Conventional rotational atherectomy devices require a guide wire for navigating the atherectomy device in the blood vessel . In particular, as noted above , conventional rotational atherectomy devices require the guide wire to be positioned distally of the occlusion site , to enable navigation and distal advancement of the atherectomy device through the occlusion site . However, there are cases in which is it di f ficult or impossible to advance the guide wire distally through and past the occlusion site , especially i f the plaque lesion ( s ) at the occlusion site are dense and / or plaque build-up has resulted in signi ficant narrowing of the blood vessel . Conventional rotational atherectomy devices may thus not be employed in those cases and have a limited range of application .

[0016] Furthermore , in conventional rotational atherectomy devices , the rotatable head is passed multiple times back and forth through the occlusion site to cut or abrade the plaque deposit ( s ) or lesion ( s ) from the wall of the blood vessel . Such multiple axial passes of the rotatable head are especially required i f the blood vessel to be treated is of larger diameter . This makes the treatment procedure longer and more complex .

[0017] There is hence a need in the art for a new type of rotational atherectomy device which has a wider range of application than conventional rotational atherectomy devices and facilitates safe removal of plaque .

[0018] There is further a need in the art for a new type of rotational atherectomy device which does not require a guide wire to navigate the atherectomy device through the occlusion site .

[0019] There is further a need in the art for a new type of rotational atherectomy device which makes it possible to treat larger vessels with fewer axial passes and thus simpli fies and shortens the treatment procedure .

[0020] Summary

[0021] In a first aspect of the present disclosure , there is provided a rotational atherectomy device for removing occlusive material from an interior of a blood vessel .

[0022] The atherectomy device comprises a rotatable drive shaft having a longitudinal axis ; a rotatable head for cutting or abrading, the head being disposed at the distal end of the rotatable drive shaft ; and a guide assembly .

[0023] The guide assembly comprises a guide portion for contact with the wall of the blood vessel and for protecting the wall of the vessel .

[0024] The guide assembly is transitionable between a radially contracted configuration and a radially expanded configuration .

[0025] In the radially expanded configuration, the guide portion is disposed radially outward of the rotatable head . That is , the guide portion is disposed further from the longitudinal axis in a radial direction than the rotatable head . In the radially expanded configuration, the maximum outer radial diameter of the atherectomy device may be defined by the guide portion .

[0026] Accordingly, in some embodiments , the guide assembly may stabili ze and guide the atherectomy device in a blood vessel , obviating the need for a guide wire to navigate the atherectomy device through the occlusion site . In some embodiments , the rotational atherectomy device may hence not use a guide wire . In some embodiments , the rotational atherectomy device may be employed in cases in which it is di f ficult or impossible to advance a guide wire ( of a conventional atherectomy device ) distally past the occlusion site .

[0027] In some embodiments , the rotational atherectomy device may allow treatment of larger vessels with fewer axial passes . In some embodiments , this may simpli fy and shorten the treatment procedure .

[0028] In some embodiments , the rotational atherectomy device may allow for a wider range of application while facilitating safe removal of plaque .

[0029] Throughout this disclosure , a direction along the longitudinal axis is referred to as an "axial direction" , and a direction perpendicular to the longitudinal axis is referred to as a "radial direction" .

[0030] In the radially contracted configuration of the guide assembly, the guide portion may be disposed radially inward of the rotatable head . That is , the guide portion may be disposed closer to the longitudinal axis in a radial direction than the rotatable head . In some embodiments , this may facilitate insertion of the atherectomy device into the blood vessel and delivery of the atherectomy device to the desired occlusion site ( treatment site ) .

[0031] Alternatively, in the radially contracted configuration of the guide assembly, the rotatable head and the guide portion may be disposed at substantially the same distance from the longitudinal axis in a radial direction . That is , the rotatable head and the guide portion may have substantially the same outer radial diameter . In some embodiments , this may facilitate insertion of the atherectomy device into the blood vessel and delivery of the atherectomy device to the desired occlusion site ( treatment site ) . The drive shaft may be flexible . This may allow insertion and navigation through a tortuous vessel anatomy .

[0032] The rotational atherectomy device may comprise a backstop arranged on the drive shaft and configured to be translatable along the longitudinal axis .

[0033] The backstop may comprise a bearing .

[0034] Distal movement of the backstop towards the rotatable head may cause the guide assembly to transition from the radially contracted configuration to the radially expanded configuration .

[0035] In some embodiments , this may allow the guide assembly to be expanded in a precise and simple manner .

[0036] Proximal movement of the backstop away from the rotatable head may cause the guide assembly to transition from the radially expanded configuration to the radially contracted configuration .

[0037] In some embodiments , this may allow the guide assembly to be contracted in a precise and simple manner .

[0038] The rotational atherectomy device may comprise a manipulating means configured to translate the backstop in a distal or proximal direction .

[0039] In some embodiments , this may allow the guide assembly to be manipulated in a precise and simple manner .

[0040] In some embodiments , this may allow control of the radial extent or degree of expansion in the radially expanded configuration in a precise and simple manner . The operator may hence adapt the radial extent or degree of expansion of the rotational atherectomy device to the vessel si ze , by increasing and decreasing the outer radial diameter as appropriate , while the rotational atherectomy device is advanced through the occlusion site . For example , the operator may increase the radial extent or degree of expansion of the atherectomy device such that the guide portion is in contact with the vessel wall .

[0041] The manipulating means may comprise a spring .

[0042] The guide assembly may be configured to rotate .

[0043] In some embodiments , this may allow the guide assembly to better stabili ze and guide the atherectomy device in the blood vessel .

[0044] The guide assembly may be configured to corotate with the rotatable drive shaft .

[0045] In some embodiments , this may allow the guide assembly to better stabili ze and guide the atherectomy device in the blood vessel .

[0046] Alternatively, the guide assembly may not be configured to corotate with the rotatable drive shaft .

[0047] The rotational atherectomy device may comprise a fluid inflatable balloon .

[0048] Inflation of the balloon may cause the guide assembly to transition from the radially contracted configuration to the radially expanded configuration .

[0049] In some embodiments , this may allow the guide assembly to be expanded in a precise and simple manner . Deflation of the balloon may cause the guide assembly to transition from the radially expanded configuration to the radially contracted configuration .

[0050] In some embodiments , this may allow the guide assembly to be contracted in a precise and simple manner .

[0051] The rotational atherectomy device may comprise means for inflating and deflating the fluid inflatable balloon .

[0052] In some embodiments , this may allow the guide assembly to be manipulated in a precise and simple manner .

[0053] In some embodiments , this may allow control of the radial extent or degree of expansion in the radially expanded configuration in a precise and simple manner . The operator may hence adapt the radial extent or degree of expansion of the rotational atherectomy device to the vessel si ze , by increasing and decreasing the outer radial diameter as appropriate , while the rotational atherectomy device is advanced through the occlusion site . For example , the operator may increase the radial extent or degree of expansion of the atherectomy device such that the guide portion is in contact with the vessel wall .

[0054] Furthermore , the balloon may be used to force expansion of the blood vessel to allow improved blood flow . In other words , the balloon may exhibit angioplasty capabilities for vessel dilation at the treatment site . In some embodiments , this may reduce the need for adj unct therapies or devices .

[0055] Moreover, one or more scoring wires , e . g . , made from Nitinol , may be provided on the outer surface of the balloon . The one or more scoring wires may be arranged in a manner that allows controlled expansion of balloon according to a predetermined shape . In other words , the balloon may exhibit scoring capabilities . In some embodiments , this may allow balloon to more easily score and / or crack plaque or lesions as well as dilate the vessel at the treatment site . In some embodiments , this may further reduce the risk of restenosis complications . In some embodiments , this may reduce the need for adj unct therapies or devices .

[0056] The rotatable head may form the distal end of the atherectomy device .

[0057] The rotatable head may be configured to corotate with the rotatable drive shaft .

[0058] The rotatable head may comprise a drill bit type cutting tip or a blunt tip or a ball point type tip .

[0059] In some embodiments , this may allow for better cutting or abrading of the occlusive material .

[0060] In the radially expanded configuration, the maximum outer radial diameter of the atherectomy device may be between 2 mm and 6 mm, preferably between 2 mm and 4 mm, more preferably between 2 mm and 2 . 5 mm .

[0061] The guide assembly may comprise at least two expandable structures , wherein each expandable structure comprises a proximal arm having a first end and a second end; a distal arm having a first end and a second end; a guide portion for contact with the wall of the blood vessel and for protecting the wall of the vessel .

[0062] In some embodiments , this may provide a guide assembly with a simple structure . The expandable structures may be arranged such that they have substantially rotational symmetry about the longitudinal axis of the drive shaft .

[0063] In some embodiments , this may allow for more stable positioning of the atherectomy device in the blood vessel .

[0064] In some embodiments , this may allow for more stable rotation and therefore better cutting or abrading of occlusive material .

[0065] The guide portions may be arranged such that they have substantially rotational symmetry about the longitudinal axis of the drive shaft .

[0066] In some embodiments , this may allow for more stable positioning of the atherectomy device in the blood vessel .

[0067] In some embodiments , this may allow for more stable rotation and therefore better cutting or abrading of occlusive material .

[0068] The guide assembly may comprise a collar which is arranged on the rotatable drive shaft at the proximal side of the rotatable head and at the distal side of the backstop, preferably adj acent to the rotatable head .

[0069] In each expandable structure , the first end of the distal arm may be pivotally connected to the collar ; the second end of the distal arm may be connected to the guide portion; the first end of the proximal arm may be pivotally connected to the backstop ; and the second end of the proximal arm may be connected to the guide portion .

[0070] In each expandable structure , the proximal arm, the distal arm, and the guide portion may be formed as a single piece . That is, the proximal arm, the distal arm, and the guide portion may be integrally formed.

[0071] In some embodiments, this may provide an expandable structure with a simple configuration.

[0072] In each expandable structure, the second end of the distal arm may be pivotally connected to the guide portion; and the second end of the proximal arm may be pivotally connected to the guide portion.

[0073] In some embodiments, this may provide an expandable structure with a simple configuration.

[0074] In each expandable structure, the distal arm may comprise a cutting edge for cutting or abrading. Accordingly, the distal arm may cut or abrade occlusive material in e.g., the radially expanded configuration of the guide assembly.

[0075] In some embodiments, this may allow a greater surface area to be cut or abraded in one axial pass. In some embodiments, this may promote smooth distal advancement of the atherectomy device through the occlusion site. In some embodiment, this may allow treatment of larger vessels with fewer axial passes. In some embodiments, this may reduce the overall treatment time and make the treatment procedure simpler.

[0076] In each expandable structure, the proximal arm may comprise a cutting edge for cutting or abrading. Accordingly, the proximal arm may cut or abrade occlusive material in e.g., the radially expanded configuration of the guide assembly.

[0077] In some embodiments, this may allow a greater surface area to be cut or abraded in one axial pass. In some embodiments, this may promote smooth movement of the atherectomy device through the occlusion site. In some embodiment, this may allow treatment of larger vessels with fewer axial passes. In some embodiments , this may reduce the overall treatment time and make the treatment procedure simpler .

[0078] The cutting edge of the distal arm may comprise a flute , and, optionally, the cutting edge of the distal arm may comprise Nitinol . The flute may exhibit a twisted shape . The flute may be configured to promote transportation of cut and / or abraded plaque proximally .

[0079] In some embodiments , this may promote better removal of cut and / or abraded plaque from the occlusion site .

[0080] The cutting edge of the proximal arm may comprise a flute , and, optionally, the cutting edge of the proximal arm may comprise Nitinol . The flute may exhibit a twisted shape . The flute may be configured to promote transportation of cut and / or abraded plaque proximally .

[0081] In some embodiments , this may promote better removal of cut and / or abraded plaque from the occlusion site .

[0082] In each expandable structure , the guide portion may comprise a protective material for the vessel wall . Optionally, the protective material may be a biomaterial such as silicone .

[0083] The biomaterial is not limited to silicone and any biomaterial that can protect the vessel wall may be used .

[0084] The protective material may be arranged on a radially outward facing part of the guide portion .

[0085] In some embodiments , this may promote better protection of the vessel wall and avoid trauma .

[0086] In each expandable structure , the guide portion may be arranged to be substantially parallel to the longitudinal axis of the drive shaft . In some embodiments , this may allow for more stable positioning of the atherectomy device in the blood vessel .

[0087] In some embodiments , this may allow for more stable rotation and therefore better cutting or abrading of occlusive material .

[0088] In each expandable structure , a cutting edge for cutting or abrading may be arranged at the distal end of the guide portion . Accordingly, the cutting edge at the distal end of the guide portion may cut or abrade occlusive material in e . g . , the radially expanded configuration of the guide assembly .

[0089] In some embodiments , this may allow a greater surface area to be cut or abraded in one axial pass while ensuring protection of the vessel wall to avoid trauma .

[0090] In some embodiment , this may allow treatment of larger vessels with fewer axial passes .

[0091] In some embodiments , this may promote smooth distal advancement of the atherectomy device through the occlusion site , especially i f the guide portion is in contact with the vessel wall .

[0092] In some embodiments , this may reduce the overall treatment time and make the treatment procedure simpler .

[0093] Moreover, the cutting edge at the distal end of the guide portion is oriented medially towards the longitudinal axis of the drive shaft . In other words , the cutting edge is oriented in a direction away from the vessel wall .

[0094] In some embodiments , this may avoid contact between the cutting edge and the vessel wall and avoid trauma . In each expandable structure , the cutting edge at the distal end of the guide portion may comprise a flute . The flute may exhibit a twisted shape . The flute may be configured to promote transportation of cut and / or abraded plaque proximally .

[0095] In some embodiments , this may promote better removal of cut and / or abraded plaque from the occlusion site .

[0096] In each expandable structure , the guide portion ( 31a, 31b ) may comprise a flute . The flute may exhibit a twisted shape . The flute may be configured to promote transportation of cut and / or abraded plaque proximally .

[0097] In some embodiments , this may promote better removal of cut and / or abraded plaque from the occlusion site .

[0098] The collar may be configured to corotate with the rotatable drive shaft .

[0099] The rotatable drive shaft may be configured to rotate relative to at least a portion of the collar .

[0100] The rotational atherectomy device may further comprise a rotational motor for providing rotation to the rotatable drive shaft , the rotatable head, and optionally the guide assembly .

[0101] The rotational atherectomy device may further comprise a rotation control unit for controlling the speed of rotation of the rotatable drive shaft .

[0102] In some embodiments , this may allow an operator to control the speed of rotation in a precise and simple manner .

[0103] The rotational atherectomy device may further comprise a position control unit for translating the atherectomy device in a distal or proximal direction in the vessel to thereby control the position of the atherectomy device in the vessel .

[0104] In some embodiments , this may allow an operator to accurately navigate the atherectomy device through the occlusion site .

[0105] The rotational atherectomy device may further comprise an expansion control unit for transitioning the guide assembly between the radially contracted configuration and the radially expanded configuration .

[0106] In some embodiments , this may allow an operator to transition the guide assembly between the radially contracted configuration and the radially expanded configuration in a precise and simple manner .

[0107] In some embodiments , this may also allow an operator to control , in a precise and simple manner, the radial extent or degree of expansion of the guide assembly in the radially expanded configuration . The operator may hence adapt the radial extent or degree of expansion of the rotational atherectomy device to the vessel si ze , by increasing and decreasing the outer radial diameter as appropriate , while the rotational atherectomy device is advanced through the occlusion site . For example , the operator may increase the radial extent or degree of expansion of the atherectomy device such that the guide portion is in contact with the vessel wall .

[0108] In a second aspect of the present disclosure , there is provided a method of removing occlusive material from an interior of a blood vessel using an atherectomy device .

[0109] The atherectomy device comprises a rotatable drive shaft having a longitudinal axis ; a rotatable head for cutting or abrading disposed at the distal end of the rotatable drive shaft ; and a guide assembly . The guide assembly comprises a guide portion for contact with the wall of the blood vessel and for protecting the wall of the vessel .

[0110] The method comprises introducing the atherectomy device into the blood vessel ; advancing the atherectomy device to a position in the blood vessel where occlusive material is to be cut or abraded; transitioning the guide assembly from a radially contracted configuration to a radially expanded configuration such that the guide portion is in contact with the wall of the blood vessel ; and rotating the rotatable head to cut or abrade the occlusive material .

[0111] Accordingly, in some embodiments , this may result in a method which allows the guide assembly of the atherectomy device to stabili ze and guide the atherectomy device in a blood vessel , obviating the need for a guide wire to navigate the atherectomy device through the occlusion site . In some embodiments , the method of removing occlusive material may hence not use a guide wire .

[0112] In some embodiments , this may allow the method to be employed in cases in which it is di f ficult or impossible to advance a guide wire ( of a conventional atherectomy device ) distally past the occlusion site .

[0113] In some embodiments , the method may allow treatment of larger vessels with fewer axial passes . In some embodiments , this may simpli fy and shorten the treatment procedure .

[0114] In some embodiments , the method may allow for a wider range of application while facilitating safe removal of plaque .

[0115] The method of removing occlusive material may further comprise advancing the atherectomy device without the use of a guide wire from a position that is proximal to the position in the blood vessel where occlusive material is to be cut or abraded ( i . e . , proximal to the occlusion or treatment site ) to a position that is distal to the position in the blood vessel where occlusive material is to be cut or abraded (i.e., distal to the occlusion or treatment site) .

[0116] In the method of removing occlusive material, the atherectomy device may be any one of the rotational atherectomy device as described above. That is, the atherectomy device may have any one of the configurations as described above.

[0117] Brief Description of the Drawings

[0118] To enable better understanding of the present disclosure, and to show how the same may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0119] FIG. 1 shows a schematic side view of a conventional rotational atherectomy device in a blood vessel;

[0120] FIG. 2 shows a schematic isometric view of an embodiment of the rotational atherectomy device according to the present disclosure ;

[0121] FIG. 3 shows a schematic side view of the rotational atherectomy device of FIG. 2 in a blood vessel;

[0122] FIG. 4A shows a schematic side view of the rotational atherectomy device of FIGS. 2 and 3 according to an embodiment of the present disclosure;

[0123] FIG. 4B is a sectional view taken along line A-A in FIG. 4A;

[0124] FIG. 5 shows a schematic side of the rotational atherectomy device of FIGS. 2 and 3 according to an embodiment of the present disclosure; FIG . 6 shows a schematic side view of an embodiment of the rotational atherectomy device according to the present disclosure ;

[0125] FIGS . 7A-7C show schematic side views of a rotatable head according to embodiments of the present disclosure ; and

[0126] FIG . 8 shows a schematic isometric view of a cutting edge according to an embodiment of the present disclosure .

[0127] Detailed Description

[0128] The embodiments herein are provided as exemplary and nonlimiting embodiments of the present disclosure . The invention is defined by the appended claims .

[0129] In the figures accompanying this application, dimensions and proportions are not necessarily to scale . Some elements and features may have been exaggerated, contorted, or adj usted for enhanced clarity and ease of understanding . The figures are provided for illustrative purposes only and should not be construed as limiting the scope of the invention .

[0130] FIG . 1 is a schematic drawing and shows a side view of a conventional rotational atherectomy device 1000 for removing occlusive material la from the interior of a blood vessel 1 .

[0131] The rotational atherectomy devices 1000 include a flexible drive shaft 1010 and a rotatable head 1020 for cutting or abrading the occlusive material la .

[0132] The drive shaft 1010 and the rotatable head 1020 are both shown in cross-section in FIG . 1 .

[0133] A lumen 1011 , 1021 extends through the drive shaft and the rotatable head to allow passage of a guide wire 1030 . In operation, the guide wire 1030 is inserted into a body lumen of a patient , advanced distally towards a desired occlusion site la, and then advanced through and past the occlusion site . Accordingly, the distal end 1031 of the guide wire is positioned distally of the occlusion site .

[0134] The atherectomy device 1000 is then, via its lumen 1011 , 1021 , slid over the guide wire 1030 and then advanced distally over the guide wire until it is positioned j ust proximal to the occlusion site .

[0135] In this state , which is depicted in FIG . 1 , the guide wire 1030 , which passes through the lumen 1011 , 1021 of the atherectomy device , extends distally past the occlusion site la, and, thus , the distal end 1031 of the guide wire is positioned distally of the atherectomy device 1000 .

[0136] A guide catheter 1070 may be used to assist in the positioning of the guide wire and the atherectomy device , as is known in the art .

[0137] The proximal end of the drive shaft (not shown) remains outside the body and is attached to an electric motor (not shown) .

[0138] The motor rotates the rotatable head via the drive shaft while the atherectomy device is advanced distally through the occlusion site and the rotatable head removes the occluding material by cutting or abrading .

[0139] FIG . 2 shows a schematic isometric view of an embodiment of the rotational atherectomy device according to the present disclosure .

[0140] FIG . 3 shows a schematic side view of the rotational atherectomy device of FIG . 2 in a blood vessel 1 of a patient . The rotational atherectomy device 100 , 200 for removing occlusive material from an interior of a blood vessel comprises a rotatable drive shaft 10 having a longitudinal axis 11 ; a rotatable head 20 for cutting or abrading occlusive material , the head being disposed at the distal end of the rotatable drive shaft ; and a guide assembly 30 .

[0141] The drive shaft 10 may be flexible so that it can be inserted and navigated through a tortuous vessel anatomy .

[0142] The guide assembly 30 comprises a guide portion 31a, 31b for contact with the wall of the blood vessel and for protecting the wall of the vessel .

[0143] The guide assembly 30 is transitionable between a radially contracted configuration and a radially expanded configuration . FIG . 2 shows the guide assembly 30 in the radially expanded configuration .

[0144] In the radially expanded configuration, the guide portion is disposed radially outward of the rotatable head . That is , the guide portion is disposed further from the longitudinal axis in a radial direction than the rotatable head . In the radially expanded configuration, as shown in FIG . 2 , the maximum outer radial diameter of the atherectomy device may be defined by the guide portion .

[0145] Accordingly, in some embodiments , the guide assembly may stabili ze and guide the atherectomy device in a blood vessel , obviating the need for a guide wire to navigate the atherectomy device through the occlusion site . In some embodiments , the rotational atherectomy device may hence not use a guide wire .

[0146] In some embodiments , the rotational atherectomy device may be employed in cases in which it is di f ficult or impossible to advance a guide wire ( of a conventional atherectomy device ) distally past the occlusion site .

[0147] In some embodiments , the rotational atherectomy device may allow treatment of larger vessels with fewer axial passes . In some embodiments , this may simpli fy and shorten the treatment procedure .

[0148] In some embodiments , the rotational atherectomy device may allow for a wider range of application while facilitating safe removal of plaque .

[0149] In the radially contracted configuration of the guide assembly, the guide portion may be disposed radially inward of the rotatable head . That is , the guide portion may be disposed closer to the longitudinal axis in a radial direction than the rotatable head . In some embodiments , this may facilitate insertion of the atherectomy device into the blood vessel and delivery of the atherectomy device to the desired occlusion site ( treatment site ) .

[0150] Alternatively, in the radially contracted configuration of the guide assembly, the rotatable head and the guide portion may be disposed at substantially the same distance from the longitudinal axis in a radial direction . That is , the rotatable head and the guide portion may have substantially the same outer radial diameter . In some embodiments , this may facilitate insertion of the atherectomy device into the blood vessel and delivery of the atherectomy device to the desired occlusion site ( treatment site ) .

[0151] The rotational atherectomy device 100 , 200 may include a backstop 40 arranged on the drive shaft and configured to be translatable along the longitudinal axis . Optionally, the backstop may comprise a bearing . Distal movement of the backstop towards the rotatable head may cause the guide assembly to transition from the radially contracted configuration to the radially expanded configuration . In some embodiments , this may allow the guide assembly to be expanded in a precise and simple manner .

[0152] Proximal movement of the backstop away from the rotatable head may cause the guide assembly to transition from the radially expanded configuration to the radially contracted configuration . In some embodiments , this may allow the guide assembly to be contracted in a precise and simple manner .

[0153] The rotational atherectomy device 100 , 200 may comprise a manipulating means 60 configured to translate the backstop 40 in a distal or proximal direction . Optionally, the manipulating means 60 may comprise a spring . In some embodiments , this may allow the guide assembly to be manipulated in a precise and simple manner . In some embodiments , this may allow control of the radial extent or degree of expansion in the radially expanded configuration in a precise and simple manner . The operator may hence adapt the radial extent or degree of expansion of the rotational atherectomy device to the vessel si ze , by increasing and decreasing the outer radial diameter as appropriate , while the rotational atherectomy device is advanced through the occlusion site .

[0154] The guide assembly 30 may be configured to rotate . The guide assembly 30 may be configured to corotate with the rotatable drive shaft 10 .

[0155] Alternatively, the guide assembly 30 may not be configured to corotate with the rotatable drive shaft 10 .

[0156] The rotatable head 20 may form the distal end of the atherectomy device . The rotatable head 20 may be configured to corotate with the rotatable drive shaft 10.

[0157] The rotatable head may comprise a drill bit type cutting tip 20a, a blunt tip 20b, or a ball point type tip 20c.

[0158] FIGS. 7A-7C show schematic side views of a rotatable head 20 according to embodiments of the present disclosure. Specifically, FIG. 7A shows a schematic side view of a rotatable head 20 having a drill bit type cutting tip 20a; FIG. 7B shows a schematic side view of a rotatable head 20 having a blunt tip 20b; and FIG. 7C shows a schematic side view of a rotatable head 20 having a ball point type tip 20c.

[0159] The operator or physician may select the tip according to the specific plaque lesion at the treatment site, i.e., depending on factors such as the degree of calcification, the size of the plaque lesion, and the vessel anatomy at the treatment site. In some embodiments, this may allow for better cutting or abrading of the occlusive material. For example, the drill bit type cutting tip 20a shown in FIG. 7A may have a tapered design, i.e., may be tapered towards its distal end, which may be helpful in initiating cutting / abrading of occlusive material .

[0160] Returning to FIGS. 2 and 3, the drive shaft 10 and the manipulating means 60 may be connected at their proximal ends to a hub (not shown) , which is located outside a patient's body .

[0161] The hub may include a rotational motor which can impart rotational motion to the rotatable drive shaft 10 and the rotatable head 20.

[0162] The hub may further include a rotation control unit to control, from outside a patient's body, the speed of rotation of the rotational motor and thereby the speed of rotation of the rotatable drive shaft 10 and the rotatable head 20 . In other words , the rotation control unit may be configured to control the speed of rotation of the rotatable head 20 . This may allow an operator to control the speed of rotation in a precise and simple manner .

[0163] The hub may also include a position control unit to control , from outside a patient ' s body, the position of the atherectomy device in a vessel of the patient , by translating the drive shaft ( and thereby the atherectomy device ) in a distal or proximal direction in the vessel . In other words , the position control unit may be configured to control the position of the atherectomy device in the vessel . This may allow an operator to accurately navigate the atherectomy device through the occlusion site .

[0164] The hub may also include an expansion control unit for transitioning the guide assembly 30 between the radially contracted configuration and the radially expanded configuration . The expansion control unit may be operatively connected to the manipulating means 60 to translate the backstop 40 in a distal or proximal direction . This may allow an operator to transition the guide assembly 30 of the atherectomy device between the radially contracted configuration and the radially expanded configuration from outside a patient ' s body in a precise and simple manner . This may also allow an operator to control , in a precise and simple manner, the radial extent or degree of expansion of the guide assembly in the radially expanded configuration . The operator may hence adapt the radial extent or degree of expansion of the rotational atherectomy device to the vessel si ze , by increasing and decreasing the outer radial diameter as appropriate , while the rotational atherectomy device is advanced through the occlusion site .

[0165] The guide assembly may comprise a collar 50 which is arranged on the rotatable drive shaft 10 at the proximal side of the rotatable head 20 and at the distal side of the backstop, preferably adj acent to the rotatable head .

[0166] The collar 50 may be configured to corotate with the rotatable drive shaft . For example , the collar 50 may be fixedly connected to the rotatable drive shaft so as to corotate with the drive shaft .

[0167] Alternatively, the rotatable drive shaft may be configured to rotate relative to at least a portion of the collar 50 .

[0168] In the radially expanded configuration, the maximum outer radial diameter of the atherectomy device may be between 2 mm and 6 mm, preferably between 2 mm and 4 mm, more preferably between 2 mm and 2 . 5 mm .

[0169] The guide assembly 30 may comprise at least two expandable structures , such as , but not limited to , two , three , four, five , six, seven, eight , or nine expandable structures . FIG .

[0170] 2 illustrates two expandable structures 30a, 30b, as an example .

[0171] Each expandable structure 30a, 30b comprises a proximal arm 32a, 32b having a first end 32al , 32bl and a second end 32a2 , 32b2 ; a distal arm 33a, 33b having a first end 33al and a second end 33a2 ; and a guide portion 31a, 31b for contact with the wall of the blood vessel and for protecting the wall of the vessel . In some embodiments , this may provide a guide assembly with a simple structure .

[0172] In each expandable structure 30a, 30b, the first end 33al , 33bl of the distal arm 33a, 33b may be pivotally connected to the collar 50 , and the second end 33a2 , 33b2 of the distal arm may be connected to the guide portion 31a, 31b .

[0173] Moreover, the first end 32al , 32bl of the proximal arm 32a, 32b may be pivotally connected to the backstop 40 , and the second end 32a2 , 32b2 of the proximal arm may be connected to the guide portion 31a, 31b .

[0174] In each expandable structure 30a, 30b, the proximal arm 32a, 32b, the distal arm 33a, 33b, and the guide portion 31a, 31b may be formed as a single piece . That is , the proximal arm, the distal arm, and the guide portion may be integrally formed . In some embodiments , this may provide an expandable structure with a simple structure .

[0175] In each expandable structure , the second end 33a2 , 33b2 of the distal arm 33a, 33b may be pivotally connected to the guide portion 31a, 31b, and the second end 32a2 , 32b2 of the proximal arm 32a, 32b may be pivotally connected to the guide portion 31a, 31b . In some embodiments , this may provide an expandable structure with a simple structure .

[0176] The expandable structures 30a, 30b may be arranged such that they have substantially rotational symmetry about the longitudinal axis 11 of the drive shaft 10 . In some embodiments , this may allow for more stable positioning of the atherectomy device in the blood vessel . In some embodiments , this may allow for more stable rotation and therefore better cutting or abrading of occlusive material .

[0177] The guide portions 31a, 31b may be arranged such that they have substantially rotational symmetry about the longitudinal axis 11 of the drive shaft 10 . In some embodiments , this may allow for more stable positioning of the atherectomy device in the blood vessel . In some embodiments , this may allow for more stable rotation and therefore better cutting or abrading of occlusive material .

[0178] In each expandable structure 30a, 30b, the distal arm 33a, 33b may comprise a cutting edge 35a, 35b for cutting or abrading . Accordingly, the distal arm 33a, 33b may cut or abrade occlusive material in e . g . , the radially expanded configuration of the guide assembly . In some embodiments , this may allow a greater surface area to be cut or abraded in one axial pass . In some embodiment , this may allow treatment of larger vessels with fewer axial passes . In some embodiments , this may promote smooth distal advancement of the atherectomy device through the occlusion site . In some embodiments , this may reduce the overall treatment time and make the treatment procedure simpler .

[0179] In each expandable structure 30a, 30b, the proximal arm may comprise a cutting edge 36a, 36b for cutting or abrading . Accordingly, the proximal arm 32a, 32b may cut or abrade occlusive material in e . g . , the radially expanded configuration of the guide assembly . In some embodiments , this may allow a greater surface area to be cut or abraded in one axial pass . In some embodiment , this may allow treatment of larger vessels with fewer axial passes . In some embodiments , this may promote smooth movement of the atherectomy device through the occlusion site . In some embodiments , this may reduce the overall treatment time and make the treatment procedure simpler .

[0180] The cutting edge 35a, 35b of the distal arm 33a, 33b may comprise a flute 37 . The flute 37 may exhibit a twisted shape . The flute may be configured to promote transportation of cut and / or abraded plaque proximally . Optionally, the cutting edge of the distal arm may comprise Nitinol . In some embodiments , this may promote better removal of cut and / or abraded plaque from the occlusion site .

[0181] The cutting edge 36a, 36b of the proximal arm 32a, 32b may comprise a flute 37 . The flute 37 may exhibit a twisted shape . The flute may be configured to promote transportation of cut and / or abraded plaque proximally . Optionally, the cutting edge of the proximal arm may comprise Nitinol . In some embodiments , this may promote better removal of cut and / or abraded plaque from the occlusion site . FIG . 8 shows a schematic isometric view of a cutting edge according to an embodiment of the present disclosure .

[0182] Speci fically, FIG . 8 exemplarily and schematically shows cutting edge 35a, 35b, 36a, 36b with flute 37 .

[0183] While FIG . 8 only shows one configuration of cutting edge for easier understanding, the shape and / or orientation of cutting edge 35a, 35b, 36a, 36b as well the shape and / or orientation of flute 37 may di f fer depending on whether the cutting edge is provided at proximal arm 32a, 32b or at distal arm 33a, 33b in order to promote transportation of cut and / or abraded plaque proximally . In this way, the cutting edge 35a, 35b, 36a, 36b may more ef fectively cut or abrade occlusive material and more ef fectively remove the cut or abraded occlusive material .

[0184] Returning to FIGS . 2 and 3 , in each expandable structure 30a, 30b, the guide portion 31a, 31b may comprise a protective material for the vessel wall . Optionally, the protective material may be a biomaterial such as silicone . The biomaterial is not limited to silicone and any biomaterial that can protect the vessel wall may be used . The protective material may be arranged on a radially outward facing part of the guide portion . In some embodiments , this may promote better protection of the vessel wall and avoid trauma .

[0185] In each expandable structure 30a, 30b, the guide portion 31a, 31b may be arranged to be substantially parallel to the longitudinal axis 11 of the drive shaft . In some embodiments , this may allow for more stable positioning of the atherectomy device in the blood vessel . In some embodiments , this may allow for more stable rotation and therefore better cutting or abrading of occlusive material . In each expandable structure 30a, 30b, a cutting edge 38a, 38b for cutting or abrading may be arranged at the distal end of the guide portion . Accordingly, the cutting edge 38a, 38b may cut or abrade occlusive material in e . g . , the radially expanded configuration of the guide assembly . In some embodiments , this may allow a greater surface area to be cut or abraded in one axial pass while ensuring protection of the vessel wall to avoid trauma . In some embodiment , this may allow treatment of larger vessels with fewer axial passes . In some embodiments , this may promote smooth distal advancement of the atherectomy device through the occlusion site , especially i f the guide portion 31a, 31b is in contact with the vessel wall . In some embodiments , this may reduce the overall treatment time and make the treatment procedure simpler .

[0186] The cutting edge 38a, 38b is oriented medially towards the longitudinal axis of the drive shaft . In other words , the cutting edge is oriented in a direction away from the vessel wall . Accordingly, the cutting edge at the distal end of the guide portion may cut or abrade occlusive material in e . g . , the radially expanded configuration of the guide assembly . In some embodiments , this may avoid contact between the cutting edge 38a, 38b and the vessel wall and avoid trauma .

[0187] In each expandable structure , the cutting edge 38a, 38b at the distal end of the guide portion may comprise a flute . The flute may exhibit a twisted shape . The flute may be configured to promote transportation of cut and / or abraded plaque proximally . In some embodiments , this may promote better removal of cut and / or abraded plaque from the occlusion site .

[0188] In each expandable structure , the guide portion 31a, 31b may comprise a flute . The flute may exhibit a twisted shape . The flute may be configured to promote transportation of cut and / or abraded plaque proximally . In some embodiments , this may promote better removal of cut and / or abraded plaque from the occlusion site.

[0189] As noted above, FIG. 3 shows a schematic side view of the rotational atherectomy device of FIG. 2 in a blood vessel 1 of a patient.

[0190] As shown in FIG. 3, the rotational atherectomy device 100, 200 is located proximal to the occlusion site or treatment site la. The occlusion or treatment site may be, for example, a heavily calcified section of the vessel 1 where the vessel is significantly narrowed or even fully blocked such that blood flow through the vessel is significantly reduced. The occlusion site may be of such nature that it is difficult or impossible to advance a guide wire of a conventional atherectomy device distally past the occlusion site; i.e., the occlusion site may not be treatable with conventional atherectomy devices.

[0191] In order to remove the plaque lesion la from a vessel 1 of a patient, first a suitable access site on the patient's body may be identified to deliver the atherectomy device 100, 200.

[0192] A delivery catheter or sheath 70 may be used to deliver the rotational atherectomy device 100, 200. That is, a delivery catheter 70, which houses the atherectomy device 100, 200 in its radially contracted configuration, may be introduced through the access site and advanced to a position proximal to the occlusion site. The atherectomy device 100, 200 may be positioned in the tip portion, i.e., the distal end portion, of the catheter 70.

[0193] Once the delivery catheter 70 has positioned or delivered the atherectomy device 100, 200 to the desired position, the operator can, e.g., through the position control unit, translate the atherectomy device 100, 200 distally out of the delivery catheter 70. Alternatively, a delivery guide wire may be used to facilitate delivery of the catheter or sheath 70 and the atherectomy device 100 , 200 . In this case , a lumen extends through the atherectomy device ( e . g . , the drive shaft and the rotatable head) to allow passage of the delivery guide wire through the atherectomy device (not shown) . The lumen may extend through the atherectomy device in essentially the same manner as described with respect to the conventional rotational atherectomy device 1000 in FIG . 1 above .

[0194] First , the delivery guide wire is introduced through the access site and advanced to a position proximal to the occlusion site . Then, the delivery catheter 70 and the atherectomy device 100 , 200 are slid over the delivery guide wire , introduced through the access site and advanced to a position proximal to the occlusion site , wherein the delivery catheter 70 houses the atherectomy device 100 , 200 in its radially contracted configuration and the delivery guide wire passes through the lumen of the atherectomy device . Once the delivery catheter 70 and the atherectomy device 100 , 200 are located at the desired position, the delivery guide wire is retracted and removed from the vessel via the access site . Moreover, the operator can, e . g . , through the position control unit , translate the atherectomy device 100 , 200 distally out of the delivery catheter 70 .

[0195] FIG . 3 depicts a state in which the atherectomy device 100 , 200 has been delivered to a position proximal to the occlusion site 1 and then moved distally out of the catheter 70 .

[0196] Furthermore , the operator may, e . g . , through the expansion control unit , cause the atherectomy device 100 , 200 to transition from the radially contracted configuration to the radially expanded configuration . The expansion control unit may cause the manipulating means 60 to translate the backstop 40 distally along the drive shaft 10 towards the rotatable head 20 , to thereby cause the guide assembly 30 to transition from the radially contracted configuration to the radially expanded configuration . The manipulating means 60 may comprise a spring, as illustrated for example in FIG . 3 .

[0197] As the guide assembly 30 transitions from the radially contracted configuration to the radially expanded configuration, the guide portion 31a, 31b, the proximal arm 32a, 32b, and the distal arm 33a, 33b of each expandable structure 30a, 30b move outward in a radial direction . As noted above , in the radially expanded configuration, the maximum outer radial diameter of the atherectomy device may be defined by the guide portion 31a, 31b .

[0198] The operator may, e . g . , through the expansion control unit , accurately adj ust the radial extent or degree of expansion of the guide assembly 30 . That is , the operator may adapt the radial extent or degree of expansion of the rotational atherectomy device to the vessel si ze , by increasing and decreasing the outer radial diameter as appropriate . The operator may adapt the extent or degree of expansion while the rotational atherectomy device is advanced through the occlusion site . For example , the operator may expand the guide assembly 30 to such a degree that the guide portion 31a, 31b contacts the wall of the vessel 1 , as shown in FIG . 3 . In this state , the protective material , e . g . , silicone , may contact the wall of the vessel 1 . The protective material ensures protection of the vessel wall and avoids trauma .

[0199] Each guide portion 31a, 31b may further include a radiopaque marker . This may allow the operator to determine and / or adj ust the radial extent or degree of expansion of the guide assembly 30 more accurately under fluoroscopy . The radiopaque marker may be made from any suitable radiopaque material, such as platinum-rhenium, platinum-iridium, tantalum, or gold, for example.

[0200] Moreover, the operator may activate the rotational motor to cause the drive shaft 10 and the rotatable head 20 to rotate. The speed of rotation of the rotatable head can be controlled e.g., through the rotation control unit. The rotation will cause the rotatable head 20 to cut or abrade occlusive material from the inside of the vessel wall.

[0201] As noted above, the rotatable head may comprise a drill bit type cutting tip 20a, a blunt tip 20b, or a ball point type tip 20c. The operator or physician may select the tip of the rotatable head according to the specific plaque lesion at the treatment site, i.e., depending on factors such as the degree of calcification, the size of the plaque lesion, and the vessel anatomy at the treatment site.

[0202] Furthermore, the operator may, e.g., through the position control unit, advance the atherectomy device distally towards and through the occlusion site la while the rotatable head 20 removes occlusive material.

[0203] Due to its arrangement at the distal end of the atherectomy device, the rotatable head 20 contacts and cut or abrades the occlusive material first when the atherectomy device is advanced distally through the occlusion site.

[0204] Moreover, as detailed above, the operator may adapt the radial extent or degree of expansion of the rotational atherectomy device to the vessel size, by increasing and decreasing the outer radial diameter as appropriate, while the atherectomy device is advanced through the occlusion site. In this manner, the rotational atherectomy device may cut or abrade (almost) the entirety of the plaque / blockage at the treatment site with one axial pass. As noted above , the guide assembly may stabili ze and guide the atherectomy device in the blood vessel , obviating the need for a guide wire to navigate the atherectomy device through the occlusion site . This allows use of the atherectomy device even in those cases in which it is di f ficult or impossible to advance a guide wire ( of a conventional atherectomy device ) distally past the occlusion site . Accordingly, the rotational atherectomy device may allow for a wider range of application while facilitating safe removal of plaque .

[0205] In each expandable structure 30a, 30b of guide assembly 30 , the distal arm 33a, 33b may comprise a cutting edge 35a, 35b for cutting or abrading . In each expandable structure 30a, 30b, the proximal arm 32a, 32b may comprise a cutting edge 35a, 35b for cutting or abrading . In the radially expanded configuration, as shown for example in FIG . 3 , the cutting edges 35a, 35b, 36a, 36b of the atherectomy device may cut or abrade occlusive material when the atherectomy device is moved through the occlusion site la . This may promote smooth movement of the atherectomy device through the occlusion site . Moreover, a greater surface area may be cut or abraded in one axial pass . This may allow treatment of larger vessels with fewer axial passes . Furthermore , the overall treatment time may be reduced, and the treatment procedure may be simpli fied .

[0206] In each expandable structure 30a, 30b of guide assembly 30 , a cutting edge 38a, 38b for cutting or abrading may be arranged at the distal end of the guide portion 31a, 31b . In the radially expanded configuration, as shown for example in FIG . 3 , the cutting edges 38a, 38b of the atherectomy device may cut or abrade occlusive material , in addition to e . g . the rotatable head 20 and the cutting edges 35a, 35b, when the atherectomy device is advanced distally through the occlusion site la . This may promote smooth distal advancement of the atherectomy device through the occlusion site , especially i f the guide portion 31a, 31b is in contact with the vessel wall . Moreover, a greater surface area may be cut or abraded in one axial pass . This may allow treatment of larger vessels with fewer axial passes . Furthermore , the overall treatment time may be reduced, and the treatment procedure may be simpli fied .

[0207] As also indicated for example in FIG . 3 , the cutting edge 38a, 38b at the distal end of guide portion 31a, 31b is , in a distal direction, oriented medially towards the longitudinal axis of the drive shaft . In some embodiments , this may avoid contact between the cutting edge 38a, 38b and the vessel wall and avoid trauma .

[0208] As further shown for example in FIG . 3 , in the radially expanded configuration, the cutting edges 38a, 38b at the distal end of the guide portions 31a, 31b may define the maximum cutting / abrading diameter of the atherectomy device .

[0209] As noted above , each cutting edge 35a, 35b of distal arm 33a, 33b, each cutting edge 36a, 36b of proximal arm 32a, 32b, and each cutting edge 38a, 38b at the distal end of guide portion 31a, 31b may comprise a flute . Each flute may exhibit a twisted shape to promote transportation of cut and / or abraded plaque proximally, towards the distal end of catheter or sheath 70 .

[0210] Moreover, the cut and / or abraded plaque may be aspirated through the catheter or sheath 70 for disposal . That is , a vacuum may be applied through the catheter or sheath 70 to remove cut and / or abraded plaque . The operator may control the level of vacuum from outside the patient ' s body, for example , via the hub .

[0211] As noted above , the guide assembly 30 may be configured to corotate with the rotatable drive shaft 10 . In this case , activation of the rotational motor will also cause guide assembly 30 to rotate . More speci fically, activation of the rotational motor will cause rotation of each expandable structure 30a, 30b, and thus each cutting edge 35a, 35b of distal arm 33a, 33b, each cutting edge 36a, 36b of proximal arm 32a . 32b, and each cutting edge 38a, 38b at the distal end of guide portion 31a, 31b .

[0212] This may allow the guide assembly to better stabili ze and guide the atherectomy device in the blood vessel .

[0213] Furthermore , rotation of each expandable structure 30a, 30b and the respective cutting edges 35a, 35b, 36a, 36b, 38a, 38b may even further promote smooth movement of the atherectomy device through the occlusion site ; cutting or abrasion of a greater surface area in one axial pass ; treatment of larger vessels with fewer axial passes ; reduction of overall treatment time ; and simpli fication of the treatment procedure .

[0214] Alternatively, as noted above , the guide assembly 30 may not be configured to corotate with the drive shaft 10 .

[0215] FIG . 4A shows a schematic side view of the rotational atherectomy device of FIGS . 2 and 3 according to an embodiment of the present disclosure . FIG . 4B is a sectional view taken along line A-A in FIG . 4A.

[0216] Speci fically, FIGS . 4A and 4B exemplarily and schematically show a rotational atherectomy device 100 in which the guide assembly 30 is configured to corotate with the rotatable drive shaft 10 .

[0217] The configuration of the rotational atherectomy device 100 corresponds to the rotational atherectomy device described with regard to FIGS . 2 and 3 , and only the aspect of corotation of guide assembly 30 and rotatable drive shaft 10 will be described with FIGS . 4A and 4B as illustrative and schematic examples .

[0218] As shown in FIG . 4a, the collar 50 is fixedly connected to the rotatable shaft 10 . In this manner, the collar 50 is configured to corotate with the rotatable drive shaft 10 .

[0219] The backstop 40 comprises a radially outer portion 40o and a radially inner portion 40i . A bearing 41 is arranged between the radially outer portion 40o and the radially inner portion 40i so as to allow for relative rotation between the inner portion 40i and the outer portion 40o .

[0220] The bearing 41 may be a ball bearing, as exemplarily and schematically shown in FIGS . 4A and 4B, or any type of bearing, such as , for example , cylindrical roller bearing or tapered roller bearing, that allows for relative rotation between the inner portion 40i and the outer portion 40o .

[0221] The manipulating means 60 is connected to the radially outer part 40o of backstop 40 .

[0222] The radially inner part 40i of backstop 40 is translatable along the longitudinal axis 11 of drive shaft 10 .

[0223] The radially inner part 40i of backstop 40 may be coupled to drive shaft 10 in a non-rotatable manner, via, for example , a keyed j oined or the like , to prevent relative rotation between inner part 40i of backstop 40 and drive shaft 10 but allow relative axial movement therebetween . Alternatively, the radially inner part 40i of backstop 40 may not be coupled to drive shaft 10 , to allow relative rotation and axial movement therebetween .

[0224] In each expandable structure 30a, 30b of guide assembly 30 , the first end 33al , 33bl of distal arm 33a, 33b is pivotally connected to the collar 50 , and the first end 32al , 32bl of proximal arm 32a, 32b is pivotally connected to the radially inner portion 40i of backstop 40 .

[0225] Manipulating means 60 can translate the backstop 40 in a distal or proximal direction, along longitudinal axis 11 of drive shaft 10 , to adapt the radial extent or degree of expansion of the guide assembly 30 , as detailed above .

[0226] Moreover, in the exemplary configuration of FIGS . 4A and 4B, rotation of the rotatable drive shaft 10 causes collar 50 , each expandable structure 30a, 30b of guide assembly 30 , and radially inner portion 40i of backstop 40 to corotate .

[0227] Accordingly, activation of the rotational motor will cause rotation of the rotatable drive shaft 10 , head 20 and ( co ) rotation of cutting edge 35a, 35b of distal arm 33a, 33b, cutting edge 36a, 36b of proximal arm 32a . 32b, and cutting edge 38a, 38b at the distal end of guide portion 31a, 31b .

[0228] FIG . 5 shows a schematic side of the rotational atherectomy device of FIGS . 2 and 3 according to an embodiment of the present disclosure .

[0229] Speci fically, FIG . 5 exemplarily and schematically shows a rotational atherectomy device 200 in which the guide assembly 30 is not configured to corotate with the rotatable drive shaft 10 .

[0230] The configuration of the rotational atherectomy device 200 corresponds to the rotational atherectomy device described with regard to FIGS . 2 and 3 , and only the aspect of the non- corotatable guide assembly 30 will be described with FIG . 5 as illustrative and schematic examples .

[0231] As shown in FIG . 5 , the collar 50 of the rotational atherectomy device 200 comprises a radially outer portion 50o and a radially inner portion 50i . A bearing 51 is arranged between the radially outer portion 50o and the radially inner portion 50i so as to allow for relative rotation between inner portion 50i and outer portion 50o of collar 50 . In this manner, the rotatable drive shaft 10 is configured to rotate relative to the outer portion 50o of the collar 50 .

[0232] The inner portion 50i of collar is fixedly connected to the rotatable drive shaft 10 , for example by securing element 52 .

[0233] The bearing 51 may be a ball bearing, as exemplarily and schematically shown in FIG . 5 , or any type of bearing, such as , for example , cylindrical roller bearing or tapered roller bearing, that allows for relative rotation between the inner portion 50i and the outer portion 50o of the collar 50 .

[0234] As further shown in FIG . 5 , the backstop 40 comprises a radially outer portion 40o and a radially inner portion 40i . A bearing 41 is arranged between the radially outer portion 40o and the radially inner portion 40i so as to allow for relative rotation between the inner portion 40i and the outer portion 40o .

[0235] The bearing 41 may be a ball bearing, as exemplarily and schematically shown in FIG . 5 , or any type of bearing, such as , for example , cylindrical roller bearing or tapered roller bearing, that allows for relative rotation between the inner portion 40i and the outer portion 40o .

[0236] The manipulating means 60 is connected to the radially outer part 40o of backstop 40 .

[0237] The radially inner part 40i of backstop 40 is translatable along the longitudinal axis 11 of drive shaft 10 .

[0238] The radially inner part 40i of backstop 40 may be coupled to drive shaft 10 in a non-rotatable manner, via, for example , a keyed j oined or the like , to prevent relative rotation between inner part 40i of backstop 40 and drive shaft 10 but allow relative axial movement therebetween . Alternatively, the radially inner part 40i of backstop 40 may not be coupled to drive shaft 10 , to allow relative rotation and axial movement therebetween . In both cases , the rotatable drive shaft 10 is rotatable relative to the outer portion 40o of the backstop 40 .

[0239] In each expandable structure 30a, 30b of guide assembly 30 , the first end 33al , 33bl of distal arm 33a, 33b is pivotally connected to the outer portion 50o of collar 50 , and the first end 32al , 32bl of proximal arm 32a, 32b is pivotally connected to the radially outer portion 40o of backstop 40 .

[0240] Manipulating means 60 can translate the backstop 40 in a distal or proximal direction, along longitudinal axis 11 of drive shaft 10 , to adapt the radial extent or degree of expansion of the guide assembly 30 , as detailed above .

[0241] Moreover, in the exemplary configuration of FIG . 5 , rotation of the rotatable drive shaft 10 does not cause corotation of the guide assembly 30 with the rotatable drive shaft 10 . That is , the guide assembly 30 is not configured to corotate with the rotatable drive shaft 10 .

[0242] In the exemplary configuration of FIG . 5 , the rotatable drive shaft 10 can rotate relative to the radially outer portion 50o of collar 50 and radially outer portion 40o of backstop 40 .

[0243] Accordingly, activation of the rotational motor will cause rotation of the rotatable drive shaft 10 and head 20 but will not result in corotation of guide assembly 30 .

[0244] FIG . 6 shows a schematic side view of an embodiment of the rotational atherectomy device according to the present disclosure . The rotational atherectomy device 300 shown in FIG . 6 essentially corresponds to the rotational atherectomy device described in connection with FIGS . 2 and 3 above .

[0245] Accordingly, a description of components and configurations that are identical to that of the rotational atherectomy device in FIGS . 2 and 3 will be omitted, and, in the following, only aspects that are speci fic to the rotational atherectomy device 300 of FIG . 6 will be described .

[0246] The main di f ference between the rotational atherectomy device 300 and the device in FIGS . 2 and 3 is that the rotational atherectomy device comprises a fluid inflatable balloon 350 . As shown in the schematic side view of FIG . 6 , the balloon 350 is arranged between the rotational shaft 10 and the guide ass e mb 1 y 30 .

[0247] Inflation of the balloon may cause the guide assembly 30 to transition from the radially contracted configuration to the radially expanded configuration .

[0248] In some embodiments , this may allow the guide assembly to be expanded in a precise and simple manner .

[0249] Deflation of the balloon may cause the guide assembly 30 to transition from the radially expanded configuration to the radially contracted configuration .

[0250] In some embodiments , this may allow the guide assembly to be contracted in a precise and simple manner .

[0251] The rotational atherectomy device may comprise means for inflating and deflating the fluid inflatable balloon 350 .

[0252] In some embodiments , this may allow the guide assembly to be manipulated in a precise and simple manner . In some embodiments , this may allow control of the radial extent or degree of expansion in the radially expanded configuration in a precise and simple manner . The operator may hence adapt the radial extent or degree of expansion of the rotational atherectomy device to the vessel si ze , by increasing and decreasing the outer radial diameter as appropriate , while the rotational atherectomy device is advanced through the occlusion site .

[0253] The rotational atherectomy device 100 , 200 may include a backstop 40 arranged on the drive shaft and configured to be translatable along the longitudinal axis . Optionally, the backstop may comprise a bearing .

[0254] Upon inflation ( deflation) of the balloon 350 , the backstop 40 may be translated along the longitudinal axis 11 of rotatable drive shaft , to facilitate radial expansion ( contraction) of the guide assembly 30 .

[0255] The guide assembly 30 is not configured to corotate with the rotatable drive shaft . The configuration of the backstop 40 and collar 50 may correspond to that of rotational atherectomy device 200 described with respect to FIG . 5 above .

[0256] The proximal end of drive shaft 10 may be connected a hub (not shown) , which is located outside a patient ' s body .

[0257] The hub may include the rotation control unit and the position control unit described above .

[0258] Furthermore , the fluid inflatable balloon 350 may be operatively connected to the hub .

[0259] The hub may also include an expansion control unit for transitioning the guide assembly 30 between the radially contracted configuration and the radially expanded configuration . The expansion control unit may be operatively connected to the means for inflating and deflating the fluid inflatable balloon 350 , to inflate and deflate the fluid inflatable balloon 350 . This may allow an operator to transition the guide assembly 30 of the atherectomy device between the radially contracted configuration and the radially expanded configuration from outside a patient ' s body in a precise and simple manner, by inf lating / def lating the balloon 350 . This may also allow an operator to control , in a precise and simple manner, the radial extent or degree of expansion of the guide assembly in the radially expanded configuration . The operator may hence adapt the radial extent or degree of expansion of the rotational atherectomy device to the vessel si ze , by increasing and decreasing the outer radial diameter as appropriate .

[0260] Furthermore , the balloon 350 may be used to force expansion of the blood vessel to allow improved blood flow . In other words , the balloon may exhibit angioplasty capabilities for vessel dilation at the treatment site la . In some embodiments , this may reduce the need for adj unct therapies or devices .

[0261] Moreover, one or more scoring wires , e . g . , made from Nitinol , may be provided on the outer surface of the balloon 350 (not shown) . The one or more scoring wires may be arranged in a manner that allows controlled expansion of balloon 350 according to a predetermined shape . In other words , the balloon may exhibit scoring capabilities .

[0262] In some embodiments , this may allow balloon 350 to more easily score and / or crack plaque or lesions as well as dilate the vessel at the treatment site la . In some embodiments , this may further reduce the risk of restenosis complications . In some embodiments , this may reduce the need for adj unct therapies or devices . As noted above , the embodiments herein are provided as exemplary and non-limiting embodiments of the present disclosure , and various modi fications will be apparent to those skilled in the art .

[0263] For example , while the rotational atherectomy device according to the above embodiments obviates the need for a guide wire to navigate the atherectomy device through the occlusion site , the rotational atherectomy device may nevertheless be used in conj unction with a guide wire . In this case , a lumen extends through the atherectomy device ( e . g . , the drive shaft and the rotatable head) to allow passage of the guide wire through the atherectomy device . The lumen may extend through the atherectomy device in essentially the same manner as described with respect to the conventional rotational atherectomy device 1000 in FIG . 1 above . The atherectomy device may be advanced through and past the occlusion site with the help of the guide wire in essentially the same manner as described with respect to the conventional rotational atherectomy device 1000 in FIG . 1 above .

Claims

CLAIMS1. A rotational atherectomy device (100, 200, 300) for removing occlusive material (la) from an interior of a blood vessel (1) , the device comprising: a rotatable drive shaft (10) having a longitudinal axis (11) ; a rotatable head (20) for cutting or abrading, the head being disposed at the distal end of the rotatable drive shaft; a guide assembly (30) comprising a guide portion (31a, 31b) for contact with the wall of the blood vessel and for protecting the wall of the vessel ; wherein the guide assembly is transitionable between a radially contracted configuration and a radially expanded configuration; wherein, in the radially expanded configuration, the guide portion is disposed radially outward of the rotatable head.

2. The rotational atherectomy device of claim 1, further comprising : a backstop (40) arranged on the drive shaft and configured to be translatable along the longitudinal axis, wherein, optionally the backstop comprises a bearing.

3. The rotational atherectomy device of claim 2, wherein distal movement of the backstop towards the rotatable head causes the guide assembly to transition from the radially contracted configuration to the radially expanded configuration .

4. The rotational atherectomy device of claim 2 or 3, wherein proximal movement of the backstop away from the rotatable head causes the guide assembly to transition from the radially expanded configuration to the radially contracted configuration .

5. The rotational atherectomy device of claim 3 or 4, further comprising a manipulating means (60) configured to translate the backstop in a distal or proximal direction, wherein, optionally the manipulating means (60) comprises a spring.

6. The rotational atherectomy device of any one of claims 1 to 5, wherein the guide assembly (30) is configured to rotate.

7. The rotational atherectomy device of claim 6, wherein the guide assembly (30) is configured to corotate with the rotatable drive shaft (10) .

8. The rotational atherectomy device of any one of claims 1 to 5, wherein the guide assembly is not configured to corotate with the rotatable drive shaft (10) .

9. The rotational atherectomy device of claim 1 or 2, further comprising a fluid inflatable balloon (350) , wherein inflation of the balloon (350) causes the guide assembly (30) to transition from the radially contracted configuration to the radially expanded configuration.

10. The rotational atherectomy device of claim 9, wherein deflation of the balloon (350) causes the guide assembly (30) to transition from the radially expanded configuration to the radially contracted configuration.

11. The rotational atherectomy device of any one of the preceding claims, wherein the rotatable head forms the distal end of the atherectomy device.

12. The rotational atherectomy device of any one of the preceding claims, wherein the rotatable head is configured to corotate with the rotatable drive shaft.

13. The rotational atherectomy device of any one of the preceding claims, wherein the rotatable head comprises a drill bit type cutting tip or a blunt tip or a ball point type tip.

14. The rotational atherectomy device of any one of the preceding claims, wherein, in the radially expanded configuration, the maximum outer radial diameter of the device is between 2 mm and 6 mm, preferably between 2 mm and 4 mm, more preferably between 2 mm and 2.5 mm.

15. The rotational atherectomy device of any one of the preceding claims, wherein the guide assembly (30) comprises at least two expandable structures (30a, 30b) , wherein each expandable structure (30a, 30b) comprises: a proximal arm (32a, 32b) having a first end (32al, 32bl) and a second end (32a2, 32b2) ; a distal arm (33a, 33b) having a first end (33al) and a second end (33a2) ; a guide portion (31a, 31b) for contact with the wall of the blood vessel and for protecting the wall of the vessel.

16. The rotational atherectomy device of claim 15, wherein the expandable structures are arranged such that they have substantially rotational symmetry about the longitudinal axis of the drive shaft.

17. The rotational atherectomy device of claim 15 or 16, wherein the guide portions are arranged such that they have substantially rotational symmetry about the longitudinal axis of the drive shaft.

18. The rotational atherectomy device of any one of the preceding claims, wherein the guide assembly comprises a collar (50) which is arranged on the rotatable drive shaft at the proximal side of the rotatable head (20) and at the distal side of the backstop, preferably adjacent to the rotatable head .

19. The rotational atherectomy device of claim 18 as dependent on any one of claims 15 to 17, wherein, in each expandable structure (30a, 30b) , the first end (33al, 33bl) of the distal arm is pivotally connected to the collar (50) ; the second end (33a2, 33b2) of the distal arm is connected to the guide portion; the first end (32al, 32bl) of the proximal arm is pivotally connected to the backstop; the second end (32a2, 32b2) of the proximal arm is connected to the guide portion.

20. The rotational atherectomy device of claim 19, wherein, in each expandable structure, the proximal arm, the distal arm, and the guide portion are formed as a single piece.

21. The rotational atherectomy device of claim 19, wherein, in each expandable structure, the second end (33a2, 33b2) of the distal arm is pivotally connected to the guide portion; and the second end (32a2, 32b2) of the proximal arm is pivotally connected to the guide portion.

22. The rotational atherectomy device of any one of claims 15 to 21, wherein, in each expandable structure (30a, 30b) , the distal arm (33a, 33b) comprises a cutting edge (35a, 35b) for cutting or abrading.

23. The rotational atherectomy device of any one of claims 15 to 22, wherein, in each expandable structure (30a, 30b) , the proximal arm (32a, 32b) comprises a cutting edge (36a, 36b) for cutting or abrading.

24. The rotational atherectomy device of claim 22 or 23, wherein the cutting edge of the distal arm and / or the cutting edge of the proximal arm comprises a flute (37) , wherein,optionally the cutting edge of the distal arm and / or the cutting edge of the proximal arm comprises Nitinol.

25. The rotational atherectomy device of any one of claims 15 to 24, wherein, in each expandable structure (30a, 30b) , the guide portion (31a, 31b) comprises a protective material for the vessel wall, wherein optionally the protective material is a biomaterial such as silicone.

26. The rotational atherectomy device of any one of claims 15 to 25, wherein, in each expandable structure, the guide portion is arranged to be substantially parallel to the longitudinal axis of the drive shaft.

27. The rotational atherectomy device of any one of claims 15 to 26, wherein, in each expandable structure (30a, 30b) , a cutting edge (38a, 38b) for cutting or abrading is arranged at the distal end of the guide portion; and wherein the cutting edge is oriented medially towards the longitudinal axis of the drive shaft.

28. The rotational atherectomy device of claim 27, wherein, in each expandable structure (30a, 30b) , the cutting edge at the distal end of the guide portion comprises a flute.

29. The rotational atherectomy device of any one of claims 15 to 28, wherein, in each expandable structure (30a, 30b) , the guide portion (31a, 31b) comprises a flute.

30. The rotational atherectomy device of any one of claims 18 to 29 as dependent on claim 7, wherein the collar (50) is configured to corotate with the rotatable drive shaft.

31. The rotational atherectomy device of any one of claims 18 to 29 as dependent on claim 8, wherein the rotatable drive shaft is configured to rotate relative to at least a portion of the collar (50) .32 . The rotational atherectomy device of any one of the preceding claims further comprising a rotational motor for providing rotation to the rotatable drive shaft ( 10 ) , the rotatable head ( 20 ) , and optionally the guide assembly ( 30 ) .33 . The rotational atherectomy device of any one of the preceding claims further comprising a rotation control unit for controlling the speed of rotation of the rotatable drive shaft ( 10 ) .34 . The rotational atherectomy device of any one of the preceding claims further comprising a position control unit for translating the atherectomy device in a distal or proximal direction in the vessel to thereby control the position of the atherectomy device in the vessel .35 . The rotational atherectomy device of any one of the preceding claims further comprising an expansion control unit for transitioning the guide assembly ( 30 ) between the radially contracted configuration and the radially expanded configuration .36 . A method of removing occlusive material from an interior of a blood vessel using an atherectomy device comprising : a rotatable drive shaft having a longitudinal axis ; a rotatable head for cutting or abrading disposed at the distal end of the rotatable drive shaft ; a guide assembly comprising a guide portion for contact with the wall of the blood vessel and for protecting the wall of the vessel ; wherein the method comprises : introducing the atherectomy device into the blood vessel ; advancing the atherectomy device to a position in the blood vessel where occlusive material is to be cut or abraded;transitioning the guide assembly from a radially contracted configuration to a radially expanded configuration such that the guide portion is in contact with the wall of the blood vessel ; and rotating the rotatable head to cut or abrade the occlusive material .37 . The method according to claim 36 , further comprising : advancing the atherectomy device without the use of a guide wire from a position that is proximal to the position in the blood vessel where occlusive material is to be cut or abraded to a position that is distal to the position in the blood vessel where occlusive material is to be cut or abraded .38 . The method according to claim 36 or 37 , wherein the atherectomy device is the rotational atherectomy device according to any one of claims 1 to 35 .

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