Material removal device and method of use

Abstract

An atherectomy catheter having an inner drive shaft which rotates a distal rotary tissue borer with a helical cutting surface which enables the catheter to cut through and cross a CTO. Additionally, the atherectomy catheter has a distal cutting element rotated by an outer drive shaft configured to cut material from the wall of a vessel at a treatment site as the catheter is pushed distally through the treatment site. The atherectomy catheter includes a collection chamber positioned proximally of the cutting element and rotary tissue borer. The atherectomy catheter may include means to direct material cut from the treatment site into the collection chamber, means to break down larger portions of material that may block or clog the collection chamber and means of transporting the material collected from the treatment site to a proximal opening in the atherectomy catheter.

1 - 20 . (canceled) 
     
     
         21 . A catheter for removing tissue from a body vessel, the catheter comprising:
 an outer elongate drive shaft having a longitudinal axis, the outer elongate drive shaft defining a drive shaft lumen extending longitudinally therethrough;   a tissue-removing element operatively connected to the outer elongate shaft, wherein the outer elongate drive shaft is selectively rotatable about its longitudinal axis to impart rotation to the tissue-removing element;   a bushing received in the tissue-removing element and coupled to the inner elongate shaft, the bushing defining a bushing lumen extending longitudinally therethrough configured to receive a guidewire therein, wherein the bushing has an enlarged circumferential outer portion enabling rotation of the tissue-removing element about the bushing and limiting longitudinal movement of the bushing relative to the tissue-removing element.   
     
     
         22 . The catheter set forth in  claim 21 , wherein the tissue-removing element includes an interior ledge, wherein the enlarged circumferential outer portion of the bushing is configured to engage the interior ledge. 
     
     
         23 . The catheter set forth in  claim 22 , further comprising a driver operatively coupled to the outer elongate drive shaft and configured to rotate the outer elongate drive shaft. 
     
     
         24 . The catheter set forth in  claim 23 , further comprising an elongate sheath, wherein the outer elongate drive shaft is received within the elongate sheath and configured to rotate relative to the elongate sheath. 
     
     
         25 . The catheter set forth in  claim 24 , further comprising a driver operatively coupled to the outer elongate drive shaft and configured to rotate the outer elongate drive shaft. 
     
     
         26 . The catheter set forth in  claim 25 , further comprising an elongate sheath, wherein the outer elongate drive shaft is received within the elongate sheath and configured to rotate relative to the elongate sheath. 
     
     
         27 . The catheter set forth in  claim 21 , wherein the enlarged circumferential outer portion of the bushing is captured longitudinally within the tissue-removing element. 
     
     
         28 . The catheter set forth in  claim 27 , further comprising a driver operatively coupled to the outer elongate drive shaft and configured to rotate the outer elongate drive shaft. 
     
     
         29 . The catheter set forth in  claim 28 , further comprising an elongate sheath, wherein the elongate outer drive shaft is received within the elongate sheath and configured to rotate relative to the elongate sheath. 
     
     
         30 . The catheter set forth in  claim 21 , further comprising an inner elongate shaft in the drive shaft lumen, the inner elongate shaft defining an inner lumen extending longitudinally within the drive shaft lumen and being configured to receive a guidewire therein. 
     
     
         31 . The catheter set forth in  claim 30 , wherein the bushing is coupled to the inner elongate shaft. 
     
     
         32 . The catheter set forth in  claim 21 , further comprising a driver operatively coupled to the outer elongate drive shaft and configured to rotate the outer elongate drive shaft. 
     
     
         33 . The catheter set forth in  claim 21 , further comprising an elongate sheath, wherein the elongate outer drive shaft is received within the elongate sheath. 
     
     
         34 . The catheter set forth in  claim 21 , wherein the elongate outer drive shaft comprises a helically wound wire. 
     
     
         35 . A method of removing tissue from a body vessel using the catheter set forth in claim  1 , the method comprising:
 advancing the catheter through the body vessel so that the tissue-removing element is adjacent a treatment site of the vessel; and   rotating, after said advancing the catheter, the elongate outer drive shaft to impart rotation of the tissue-removing element about the bushing and remove tissue at the treatment site.   
     
     
         36 . The method set forth in  claim 35 , further comprising moving distally, simultaneously with said rotating, the tissue-removing element at the treatment site. 
     
     
         37 . The method set forth in  claim 35 , further comprising introducing, before said advancing the catheter, a guidewire into the body vessel, wherein said advancing the catheter comprises advancing the catheter over the guidewire. 
     
     
         38 . The method set forth in  claim 35 , wherein the said rotating the elongate outer drive shaft comprises operating a driver coupled to the elongate outer drive shaft to drive rotation of the elongate outer drive shaft. 
     
     
         39 . The catheter set forth in claim  1 , wherein the catheter is sized and shaped to be received in a blood vessel, wherein the tissue-removing element is configured to remove tissue from the blood vessel. 
     
     
         40 . The catheter set forth in  claim 39 , wherein the catheter is sized and shaped to be received in an artery, wherein the tissue-removing element is configured to debulk plaque in the artery.