Intralumenal material removal using a cutting device for differential cutting

Abstract

Intralumenal material removal systems are provided using an advanceable and rotatable cutter assembly designed for differential cutting. The intralumenal material removal system includes a cutter assembly positionable in the body cavity of a mammalian subject. One embodiment of the cutter assembly comprises a cutter with blades that are designed and arranged to form an acute blade angle of attack with the matter-to-be-removed. The cutter assembly is axially advanceable by translating the drive shaft and rotatable by rotating the drive shaft. The occlusive material is scraped by the cutter assembly and may be aspirated to remove the material from the body cavity. The cutter assembly may provide aspiration ports positioned between facing surfaces of the blades.

1 . An intralumenal material removal system comprising:
 a rotatable drive shaft and a drive system operably coupled to the drive shaft for rotating the drive shaft; a cutter assembly coupled to the drive shaft for rotation with the drive shaft, the cutter assembly having a plurality of differential cutting blades, each differential cutting blade having an acute angle of attack formed as an angle between the leading face of the blade and a tangent to a circle formed by the circumference of the cutter assembly of greater than 30° and less than 90°; a catheter forming a sealed lumen with the cutter assembly; an aspiration component in proximity to the cutter assembly; and an infusion system providing infusion of liquid in proximity to the cutter assembly.   
   
   
       2 . The system of  claim 1 , wherein the acute angle of attack formed as an angle between the leading face of the blade and a tangent to a circle formed by the circumference of the cutter assembly is between about 45° and 75°. 
   
   
       3 . The system of  claim 1 , wherein the acute angle of attack formed as an angle between the leading face of the blade and a tangent to a circle formed by the circumference of the cutter assembly is greater than about 60° and less than 90°. 
   
   
       4 . The system of  claim 1 , wherein the cutting blades are raised cutting flutes provided on a fixed diameter cutter assembly. 
   
   
       5 . The system of  claim 1 , wherein the cutting blades are provided as cutting members of an expandable cutter assembly. 
   
   
       6 . The system of  claim 1 , additionally comprising a control unit designed to remain outside the body during a material removal operation, the control unit having an advancer system for axially displacing the rotating cutter assembly drive shaft and cutter assembly relative to the control unit. 
   
   
       7 . The system of  claim 1 , additionally comprising an automated guidewire braking system that is automatically actuated to brake during activation of the cutter assembly drive system, thereby releasably restricting axial and rotational movement of a guidewire. 
   
   
       8 . The system of  claim 1 , wherein the drive system is unidirectional and capable of rotating the cutter assembly at variable speeds ranging from 500 rpm to 150,000 rpm. 
   
   
       9 . The system of  claim 1 , wherein the drive system is bidirectional and capable of rotating the drive shaft selectively in both a clockwise and a counterclockwise direction. 
   
   
       10 . The system of  claim 1 , wherein the differential cutting blades have an abrasive surface. 
   
   
       11 . The system of  claim 1 , wherein the differential cutting blades are chamfered at least one of their proximal and distal ends. 
   
   
       12 . The system of  claim 1 , wherein the differential cutting blades are constructed from a material selected from the group consisting of: a stainless steel; vanadium steel; nickel-titanium; titanium-containing metals, and oxide ceramics. 
   
   
       13 . The system of  claim 1 , wherein the differential cutting blades have an asymmetrical curved profile. 
   
   
       14 . The system of  claim 1 , wherein the differential cutting blades have a symmetrical curved profile. 
   
   
       15 . An intralumenal material removal system comprising:
 a rotatable drive shaft and a drive system operably coupled to the drive shaft for rotating the drive shaft;   a sealed lumen formed between the rotatable drive shaft and a catheter;   a cutter assembly coupled to the drive shaft for rotation with the drive shaft, the cutter assembly having at least one differential cutting blade having an acute angle of attack formed as an angle between the leading face of the blade and a tangent to a circle formed by the circumference of the cutter assembly of greater than 30° and less than 90°; and   an aspiration source providing aspiration through at least one material removal port in proximity to the cutter assembly and withdrawal of material through the sealed lumen.   
   
   
       16 . The intralumenal material removal system of  claim 15 , wherein the acute angle of attack formed as an angle between the leading face of the blade and a tangent to a circle formed by the circumference of the cutter assembly is greater than about 60° and less than 90°. 
   
   
       17 . The intralumenal material removal system of  claim 15 , wherein the cutter assembly comprises multiple cutting members having different cutting characteristics. 
   
   
       18 . An intralumenal material removal system comprising:
 a rotatable drive shaft and a drive system operably coupled to the drive shaft for rotating the drive shaft;   a sealed lumen formed between the rotatable drive shaft and a catheter;   a cutter assembly coupled to the drive shaft for rotation with the drive shaft, the cutter assembly having at least one differential cutting blade having an acute angle of attack formed as an angle between the leading face of the blade and a tangent to a circle formed by the circumference of the cutter assembly of greater than 30° and less than 90°; and   a liquid infusion system providing infusion of liquid in proximity to the cutter assembly.   
   
   
       19 . The intralumenal material removal system of  claim 18 , wherein the acute angle of attack formed as an angle between the leading face of the blade and a tangent to a circle formed by the circumference of the cutter assembly is greater than about 60° and less than 90°. 
   
   
       20 . The intralumenal material removal system of  claim 18 , additionally comprising a control unit provided as a separate console incorporating displays for providing information concerning operating conditions and feedback from the material removal site to the operator.