ATHERECTOMY DEVICE SUPPORTED BY FLUID BEARINGS

• US 20090312777A1
• Filed: 06/28/2007
• Published: 12/17/2009
• Est. Priority Date: 07/13/2006
• Status: Active Grant

• Current Assignee: Cardio Flow, Inc
• Original Assignee: Lela Nadirashvili
• Inventors: Shturman, Leonid
• Granted Patent: US 8,157,825 B2
• Time in Patent Office: Days
• US Class Current: 606/159
• CPC Class Codes: A61B 17/32037 for removing obstructions from inner organs or blood vessels, e.g. for atherectomy
• CPC Class Codes: A61B 17/320758 with a rotating cutting instrument, e.g. motor driven A61B17/320725, A61B17/32075 and A61B17/320783 take precedence; for removing intra-ocular material A61F9/00763; endoscopic rotatable cutting instruments A61B17/32002

Abstract

A rotational atherectomy device for removing a stenotic tissue (330, 360) from a vessel (300) of a patient comprises a flexible hollow drive shaft (2) and an abrasive element (101, 102) mounted to the drive shaft proximal to and spaced from a solid support element (10, 10s) mounted at the distal end (6) of the drive shaft, the solid support element having a rounded outer surface and an outflow channel (20, 20s) with an outflow opening in said rounded outer surface. The drive shaft comprises a torque transmitting coil (4) and at least one fluid impermeable membrane (3 ) forming a fluid impermeable lumen for the antegrade flow (FF) of fluid into the outflow channel such that, during rotation of the drive shaft, a flow of fluid out of said outflow opening forms a fluid bearing between the rotating solid support element and the wall of the treated vessel.

Claims

1. A rotational atherectomy device for removing a stenotic tissue from a vessel of a patient, the device comprising an abrasive element mounted to a rotatable, flexible, hollow drive shaft having a longitudinal axis and a distal end, the abrasive element being mounted to the drive shaft proximal to and spaced away from a distal solid support element which is mounted at the distal end of the drive shaft, the drive shaft comprising a torque transmitting coil and at least one fluid impermeable membrane forming a fluid impermeable lumen for an antegrade flow of fluid through the drive shaft the distal solid support element having a rounded outer surface and comprising an outflow channel which is in fluid communication with the fluid impermeable lumen of the drive shaft and which extends through the solid distal support element in a generally radially outward direction with respect to the longitudinal axis of the drive shaft, the outflow channel having an outflow opening in said rounded outer surface located such that, during rotation of the drive shaft, said outflow opening of the outflow channel is facing an inner surface of a vessel being treated so that a flow of fluid out of said outflow opening forms a fluid layer between the solid distal support element and a wall of the treated vessel, said layer of fluid forming a fluid bearing between the rotating solid distal support element and the wall of the treated vessel, the fluid bearing permitting safe rotation and back and forth movements of the drive shaft within the treated vessel.

2. A rotational atherectomy device according to claim 1, wherein the drive shaft is provided with a solid proximal support element located proximal to and spaced away from the abrasive element, the solid proximal support element having a rounded outer surface and comprising an outflow channel which is in fluid communication with the fluid impermeable lumen of the drive shaft and which extends through the solid proximal support element in a generally radially outward direction with respect to the longitudinal axis of the drive shaft, the outflow channel having an outflow opening in said rounded outer surface of the solid proximal support element located such that, during rotation of the drive shaft, said outflow opening of the outflow channel is facing the inner surface of the treated vessel and a flow of fluid out of said outflow opening forms a fluid layer between the solid proximal support element and the wall of the treated vessel, said layer of fluid forming a fluid bearing between the rotating solid proximal support element and the wall of the treated vessel.

3. A rotational atherectomy device according to claim 1, wherein the solid distal support element has a centre of mass which coincides with the longitudinal axis of the drive shaft, said distal support element having a plurality of outflow channels that extend through the distal support element in radially outward directions with respect to the longitudinal axis of the drive shaft, the outflow channels have their outflow openings spaced around the circumference of the solid distal support element such that, during rotation of the drive shaft, flows of fluid out of the outflow openings form a layer of fluid between the solid distal support element and the a wall of the treated vessel, said layer of fluid forming a fluid bearing between the rotating solid distal support element and the wall of the treated vessel, the fluid bearing permitting safe rotation and back and forth movements of the drive shaft within the treated vessel.

4. A rotational atherectomy device according to claim 2, wherein the solid proximal support element has a centre of mass which coincides with the longitudinal axis of the drive shaft, said proximal support element having a plurality of outflow channels that are in fluid communication with the fluid impermeable lumen of the drive shaft and extend through the solid proximal support element in radially outward directions with respect to the longitudinal axis of the drive shaft, the outflow channels have their outflow openings spaced around the circumference of the solid proximal support element such that, during rotation of the drive shaft, flows of fluid out of the outflow openings form a layer of fluid between the solid proximal support element and the wall of the treated vessel, said layer of fluid forming a fluid bearing between the rotating solid proximal support element and the wall of the treated vessel.

6. A rotational atherectomy device according to claim 2, wherein the abrasive element and each of the support elements have their individual centers of mass, the centres of mass of both the distal and proximal solid support elements being spaced radially away from a longitudinal axis of the drive shaft but in a direction diametrically opposite to the direction in which the abrasive element is spaced radially away from the longitudinal axis of the drive shaft so that the distal and proximal solid support elements act as counterweights to the abrasive element.

10. A rotational atherectomy device according to claim 1, wherein the fluid impermeable membrane lines the torque transmitting coil.

11. A rotational atherectomy device according to claim 1, wherein the fluid impermeable membrane is disposed around the torque transmitting coil.

12. A rotational atherectomy device according to claim 2, wherein the abrasive element and each of the support elements have their individual centers of mass, the center of mass of the abrasive element being spaced radially away from the longitudinal axis of the drive shaft while the center of mass of the distal support element and the centre of mass of the proximal support element each coincide with the longitudinal axis of the drive shaft.

13. A rotational atherectomy device according to claim 12, wherein both the distal and proximal solid support elements have multiple outflow channels which are in fluid communication with the fluid impermeable lumen of the drive shaft and which extend through each of the support elements in radially outward directions with respect to the longitudinal axis of the drive shaft, the outflow channels have their outflow openings spaced around the circumferences of the support elements such that, during rotation of the drive shaft, flows of fluid out of the outflow openings form layers of fluid between the solid support elements and the wall of the treated vessel, said layers of fluid forming fluid bearings between the rotating solid support elements and the wall of the treated vessel, the fluid bearings permitting safe rotation and back and forth movements of the drive shaft within the treated vessel.

14. A rotational atherectomy device according to claim 2, wherein the abrasive element and each of the support elements have their individual centers of mass, the center of mass of the abrasive element, the center of mass of the distal support element and the centre of mass of the proximal support element each coincide with the longitudinal axis of the drive shaft.

15. A rotational atherectomy device according to claim 2, wherein the abrasive element and each of the support elements have their individual centers of mass, the center of mass of the abrasive element being spaced radially away from the longitudinal axis of the drive shaft while the center of mass of the distal solid support element and the centre of mass of the proximal solid support element each coincide with the longitudinal axis of the drive shaft.

16. A rotational atherectomy device according to claim 1, wherein the fluid impermeable lumen of the drive shaft is configured for advancement of the drive shaft over a guidewire across a stenotic lesion to be treated and for transfer of pressurized fluid into the outflow channel of the distal solid support element after crossing the stenotic lesion and removing the guidewire from the drive shaft or withdrawing it into the drive shaft, the fluid bearing formed between the rotating solid distal support element and the wall of the treated vessel permitting safe rotation and back and forth movements of the drive shaft within the treated vessel after removing the guidewire from the drive shaft or withdrawing it into the drive shaft.

5. (canceled)

7. (canceled)

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9. (canceled)

17. A rotational atherectomy device for removing a stenotic lesion from within a vessel of a patient, the device comprising a rotatable, flexible, hollow drive shaft having a longitudinal axis of rotation and an abrasive element mounted proximal to and spaced away from a distal end of the drive shaft, the drive shaft including two solid support elements, a distal solid support element located at the distal end of the drive shaft and spaced away from the abrasive element and, a proximal solid support element located proximal to and spaced away from the abrasive element, the drive shaft having a fluid impermeable wall which defines a fluid impermeable lumen for an antegrade flow of fluid through the drive shaft, wherein the distal solid support elements has multiple outflow channels that are in fluid communication with the fluid impermeable lumen of the drive shaft and extend through the distal support element in generally radially outward directions with respect to the longitudinal axis of the drive shaft, the outflow channels have axes that form angles of about ninety (90) degrees with the longitudinal axis of the drive shaft and have outflow openings spaced around the circumference of the distal support element such that, during rotation of the drive shaft, flows of fluid out of the outflow openings form a layer of fluid between the distal solid support element and a wall of the treated vessel, said layer of fluid forming a fluid bearing between the rotating solid distal support element and the wall of the treated vessel, the fluid bearing permitting safe rotation and back and forth movements of the drive shaft within the treated vessel.

18. A rotational atherectomy device for removing a stenotic lesion from within a vessel of a patient, the device comprising a rotatable, flexible, hollow drive shaft having a longitudinal axis of rotation and an abrasive element mounted proximal to and spaced away from a distal end of the drive shaft, the drive shaft including two solid support elements, a distal solid support element located at the distal end of the drive shaft and spaced away from the abrasive element and, a proximal solid support element located proximal to and spaced away from the abrasive element, the drive shaft having a fluid impermeable wall defining a fluid impermeable lumen for an antegrade flow of fluid through the drive shaft, wherein both the distal and proximal solid support elements have multiple outflow channels that are in fluid communication with the fluid impermeable lumen of the drive shaft and extend through each of the support elements in generally radially outward directions with respect to the longitudinal axis of the drive shaft, the outflow channels have axes that form angles of about ninety (90) degrees with the longitudinal axis of the drive shaft and have outflow openings spaced around the circumferences of the support elements such that, during rotation of the drive shaft, flows of fluid out of the outflow openings form layers of fluid between the solid support elements and a wall of the treated vessel, said layers of fluid forming fluid bearings between the rotating solid support elements and the wall of the treated vessel, the fluid bearings permitting safe rotation and back and forth movements of the drive shaft within the treated vessel.

19. A rotational atherectomy device according to claim 18, wherein the fluid impermeable lumen of the drive shaft is configured for advancement of the drive shaft over a guidewire across a stenotic lesion to be treated and for transfer of pressurized fluid into the multiple outflow channels of both the distal and proximal solid support elements after crossing the stenotic lesion and removing the guidewire from the drive shaft or withdrawing it into the drive shaft, the fluid bearings formed between the rotating solid distal support elements and the wall of the treated vessel permitting safe rotation and back and forth movements of the drive shaft within the treated vessel after removing the guidewire from the drive shaft or withdrawing it into the drive shaft.