Atherectomy devices and methods

Abstract

The devices and methods generally relate to treatment of occluded body lumens. In particular, the present devices and method relate to removal of the occluding material from the blood vessels as well as other body lumens.

1 . A device for removing material from body lumens, the device comprising: 
 a catheter having a proximal end and a distal end and a catheter lumen extending therethrough;    a cutter assembly rotatably coupled to the distal end of the catheter, the cutter assembly including a cutter having at least one fluted cutting edge, the cutter located within a cylindrical housing and exposed at a distal opening in the cylindrical housing, where an edge of the distal opening forms a forward cutting surface, where the cylindrical housing and cutter rotate to remove tissue; and    a rotatable torque shaft extending through the catheter lumen and having a first end coupled to the cutter assembly and a second end adapted to couple to a rotating mechanism, an exterior surface of the torque shaft comprising a raised surface helically located thereon such that upon rotation, the raised surface conveys materials in a proximal direction.    
   
   
       2 . The device of  claim 1 , where the cutter and cylindrical housing rotate in a first direction.  
   
   
       3 . The device of  claim 1 , where the cutter rotates in a first direction and the cylindrical housing rotates in a second direction.  
   
   
       4 . The device of  claim 1 , where the cutter rotates at a first rate and the cylindrical housing rotates at a second rate.  
   
   
       5 . The device of  claim 4 , where the first and second rates are different.  
   
   
       6 . The device of  claim 1 , where the catheter does not rotate upon rotation of the torque shaft.  
   
   
       7 . The device of  claim 1 , where the cutter partially extends beyond the distal opening of the housing.  
   
   
       8 . The device of  claim 1 , where the cutter comprises a dome-shaped profile.  
   
   
       9 . The device of  claim 1 , where the cutter comprises a blunt nose at a distal end.  
   
   
       10 . The device of  claim 1 , further comprising a tube member linking the housing to a distal end of the catheter  
   
   
       11 . The device of  claim 1 , where the cutter comprises a steel material and is coated with titanium nitride.  
   
   
       12 . The device of  claim 1 , where the cutter comprises a tungsten carbide material.  
   
   
       13 . The device of  claim 1 , where the cylindrical housing comprises a steel material and where at least the forward cutting surface is coated with a titanium nitride.  
   
   
       14 . The device of  claim 1 , where forward cutting surface is made of tungsten carbide  
   
   
       15 . The device of  claim 1 , where the fluted cutting edge on the cutter is tangent to a helical path about the rotational axis of the cutter.  
   
   
       16 . The device of  claim 1 , further comprising a guidewire lumen extending through the torque shaft and through the cutter  
   
   
       17 . The device of  claim 16 , further comprising a guidewire extending through the guidewire lumen and distal to the cutter.  
   
   
       18 . The device of  claim 17 , where a distal portion of the guidewire includes an anchoring mechanism.  
   
   
       19 . The device of  claim 18 , where the anchoring mechanism comprises a structure selected from the group consisting of a self-expanding helical coil, a porous basket, a wire basket, a plurality of wires, and a pre-shaped section of the guidewire.  
   
   
       20 . The device of  claim 1 , where a distal portion of the catheter is more flexible than a remainder of the catheter.  
   
   
       21 . The device of  claim 20 , further comprising a sweep sheath located within the catheter lumen and exterior to the rotatable torque shaft, the sweep sheath being rotatable and axially moveable within the catheter, the sweep sheath also having a pre-set curved segment at a distal end thereof such that when the pre-set curve curved segment is in the flexible distal portion of the catheter, the cutter assembly deflects.  
   
   
       22 . The device of  claim 21 , where the sweep sheath is rotatable relative to the catheter such that upon rotation, the cutter assembly sweeps in an arc having a radius greater than a radius of the catheter.  
   
   
       23 . The device of  claim 21 , where a portion of the catheter lumen exterior to the sweep sheath permits delivery of fluid in a proximal to distal direction while the raised surface on the rotatable torque shaft permits simultaneous distal to proximal movement of material upon rotation of the torque shaft.  
   
   
       24 . The device of  claim 21 , where the sweep sheath is lockable relative to the catheter to fix the deflection of the cutter assembly.  
   
   
       25 . The device of  claim 21 , where the sweep sheath has sufficient friction against the catheter to fix the deflection of the cutter assembly.  
   
   
       26 . The device of  claim 1 , where the catheter comprises at least one opening near the cutter assembly, where the opening is fluidly coupled to the shaft lumen and configured to allow flush fluid to be emitted.  
   
   
       27 . The device of  claim 1 , where a port near the proximal end of the catheter is coupled to a fluid source.  
   
   
       28 . The device of  claim 1 , where the proximal end of the catheter is coupled to a vacuum source.  
   
   
       29 . The device of  claim 1 , further including a ferrule linking the cutter assembly to the catheter.  
   
   
       30 . The device of  claim 1 , where the raised surface on the rotatable torque shaft is wound in the same rotational sense as the helical flutes on the cutter.  
   
   
       31 . A device for removing material from body lumens, the device comprising: 
 a catheter having a proximal end and a distal end and a catheter lumen extending therethrough;    a cutter located at the distal end of the catheter body, the cutter comprising a housing having at least one opening and a cutter configured to rotate within the housing, the cutter includes least one fluted cutting edge that cuts in a first direction that is tangential to the rotational direction of the cutter, and where the cutter further includes at least one forward cutting surface that cuts in a second cutting direction when the catheter is moved in a distal or proximal direction and that is parallel to axis of the vessel, a torque shaft extending through the catheter lumen and having a first end coupled to the cutter assembly and a second end adapted to couple to a rotating mechanism, an exterior surface of the torque shaft comprising a raised surface helically located thereon such that upon rotation, the raised surface conveys materials in a proximal direction.    
   
   
       32 . The device of  claim 31 , further comprising a tube member linking the housing to a distal end of the catheter.  
   
   
       33 . The device of  claim 31 , where the cutter is cylindrically shaped, and a proximal portion of the housing is cylindrical and a distal portion of the housing is tapered.  
   
   
       34 . The device of  claim 31 , where forward cutting surface of the cutter is aligned approximately perpendicular to the rotational axis of the cutter.  
   
   
       35 . The device of  claim 31 , where the cutter further includes a rearward cutting surface that cuts in a third cutting direction when the catheter moves in a proximal direction and that is parallel to the rotational axis of the cutter.  
   
   
       36 . The device of  claim 35 , where rearward cutting surface of the cutter is aligned approximately perpendicular to the rotational axis of the cutter.  
   
   
       37 . The device of  claim 31 , where the cutter comprises a steel material coated with a titanium nitride.  
   
   
       38 . The device of  claim 31 , where the cutter comprises a tungsten carbide material.  
   
   
       39 . The device of  claim 31 , where the fluted cutting edge is tangent to a helical path about the rotational axis of the cutter.  
   
   
       40 . The device of  claim 31 , further comprising a guidewire lumen extending through the torque shaft and through the cutter.  
   
   
       41 . The device of  claim 40 , further comprising a guidewire extending through the guidewire lumen and distal to the cutter.  
   
   
       42 . The device of  claim 41 , where a distal portion of the guidewire includes an anchoring mechanism.  
   
   
       43 . The device of  claim 42 , where the anchoring mechanism comprises a structure selected from the group consisting of a self-expanding helical coil, a porous basket, a wire basket, a plurality of wires, and a pre-shaped section of the guidewire.  
   
   
       44 . The device of  claim 31 , where a distal portion of the catheter is more flexible than a remainder of the catheter.  
   
   
       45 . The device of  claim 44 , further comprising a sweep sheath located within the catheter lumen and exterior to the torque shaft, the sweep sheath being rotatable and axially moveable within the catheter, the sweep sheath also having a pre-set curved segment at a distal end thereof such that when the pre-set curve curved segment is in the flexible distal portion of the catheter, the cutter assembly deflects.  
   
   
       46 . The device of  claim 44 , where the sweep sheath is rotatable relative to the catheter such that upon rotation, the cutter assembly sweeps in an arc having a diameter greater than the diameter of the cutter assembly.  
   
   
       47 . The device of  claim 44 , where a portion of the catheter lumen exterior to the sweep sheath permits delivery of fluid in a proximal to distal direction while the raised surface on the rotatable torque shaft permits simultaneous distal to proximal movement of material upon rotation of the torque shaft.  
   
   
       48 . The device of  claim 44 , where the sweep sheath is lockable relative to the catheter to fix the deflection of the cutter assembly.  
   
   
       49 . The device of  claim 44 , where the has sufficient friction against the catheter to fix the deflection of the cutter assembly.  
   
   
       50 . The device of  claim 31 , where the catheter comprises at least one opening near the cutter assembly, where the opening is fluidly coupled to the shaft lumen and configured to allow flush fluid to be emitted.  
   
   
       51 . The device of  claim 31 , where the port near the proximal end of catheter is coupled to a fluid source.  
   
   
       52 . The device of  claim 31 , where the proximal end of the catheter is coupled to a vacuum source.  
   
   
       53 . The device of  claim 31 , further including a ferrule linking the cutter assembly to the catheter.  
   
   
       54 . The device of  claim 31 , where the raised surface on the rotatable torque shaft is wound in the same rotational sense as the helical flutes on the cutter.  
   
   
       55 . The device of  claim 31 , further comprising a burr rotatably located on a tip of the housing.  
   
   
       56 . The device of  claim 31 , where the cutter comprises a plurality of flutes having a plurality of fluted cutting edges.  
   
   
       57 . The device of  claim 56 , where the fluted cutting edges are helical.  
   
   
       58 . The device of  claim 57 , where each flute is arranged relative to the opening in the housing such that during operation, a total length of the fluted cutting edge exposed through the housing openings remains the same.  
   
   
       59 . The device of  claim 56 , where a portion of the housing comprises a curved surface and the opening forms a plane across the curved surface such that as the fluted cutting edge rotates across the opening, a portion of the fluted cutting edge extends out of the housing through the opening.  
   
   
       60 . A method for debulking material within a totally or partially occluded blood vessel, the method comprising: 
 inserting a catheter body having a cutter assembly near a distal end of the catheter body within the blood vessel;    rotating a cutter in the cutter assembly to form a first opening, where the cutter includes at least one fluted cutting surface and at least one forward cutting surface, where on rotation of the cutter the fluted cutting surface cuts tangential to a rotational direction of the cutter, and where the forward cutting surface cuts approximately parallel to the axis of the vessel;    deflecting a distal portion of the catheter relative to an axis of the catheter body; and    moving the cutter in an arc having a radius greater than a radius of the catheter body to form a second opening in the body lumen where the second opening is larger than the first opening.    
   
   
       61 . The method of  claim 60 , where moving the cutter in an arc comprises advancing a pre-curved sweep sheathSweep Sheath distally within the catheter body.  
   
   
       62 . The method of  claim 60 , where a distal portion of the catheter body includes at least one fluid port coupled to a fluid source, and further comprising delivering fluid through the fluid port.  
   
   
       63 . The method of  claim 62 , where delivering fluid comprises delivering a drug through the fluid port.  
   
   
       64 . The method of  claim 60 , further comprising providing a helical conveyor member within the catheter body and transporting the debris material out of the body via helical conveyor member.  
   
   
       65 . The method of  claim 60 , further comprising advancing a guidewire through the catheter body and cutter assembly.  
   
   
       66 . The method of  claim 65 , further comprising deploying an anchoring mechanism from the distal portion of the guidewire, where the anchoring portion comprises a structure selected from the group consisting of a self-expanding helical coil, a porous basket, a wire basket, a plurality of wires, and a pre-shaped section of the guidewire.