Aspiration catheters

Abstract

Aspiration catheters may include parameters for facilitating aspiration of thrombi within blood vessels. For example, parameters of the catheters (e.g., inner lumen diameter, slot pitch) may be varied along a length of the catheter to cause changes in suction pressure, thereby resulting in improved thrombus aspiration. The aspiration catheters may include a balloon to temporarily occlude flow during an aspiration procedure.

1 . (canceled) 
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . A system for facilitating aspiration of thrombi comprising:
 a balloon catheter comprising a balloon configured to temporarily occlude a vessel proximal of a thrombus to be aspirated, the balloon catheter comprising a proximal end, a distal end, and a lumen;   a distal access microcatheter configured to be advanced within the lumen of the balloon catheter and beyond the distal end of the balloon catheter, the distal access microcatheter comprising a proximal end, a distal end and a lumen;   a microcatheter configured to be advanced within the lumen of the distal access microcatheter and beyond the lumen of the distal access microcatheter, the microcatheter comprising a proximal end, a distal end and a lumen,   wherein an inner diameter of the distal access microcatheter decreases from the proximal end to the distal end, thereby causing a change in suction pressure within the distal access microcatheter sufficient to affect blood velocity and facilitate thrombus aspiration,   wherein at least a portion of the distal access microcatheter comprises a hypotube within the lumen of the distal access microcatheter, thereby preventing collapse of the lumen of the distal access microcatheter during application of negative suction,   wherein the distal access microcatheter comprises an outer polymer coating radially outward of the hypotube and an inner polymer coating radially inward of the hypotube, and   wherein the negative suction is configured to be applied through a lumen of the distal access microcatheter for thrombus aspiration.   
     
     
         5 . The system of  claim 4 , wherein at least one parameter of the inner polymer coating varies along the longitudinal axis of the hypotube, the at least one parameter selected from the group consisting of material, thickness, and durometer. 
     
     
         6 . The system of  claim 5 , wherein the at least one varying parameter results in the decrease in the inner diameter of the distal access microcatheter from the proximal end of the microcatheter to the distal end of the distal access microcatheter. 
     
     
         7 . The system of  claim 4 , further comprising a thrombectomy device, wherein the thrombectomy device is configured to be delivered through the microcatheter. 
     
     
         8 . The system of  claim 4 , wherein the length of the distal access microcatheter is between 80 cm and 150 cm, wherein the inner diameter of the distal access microcatheter is between 4 Fr and 7 Fr, and wherein the wall thickness of the distal access microcatheter is between 0.02 mm and 1 mm. 
     
     
         9 . The system of  claim 4 , wherein the length of the microcatheter is between 150 cm and 210 cm, wherein the inner diameter of the microcatheter is between 0.014 inches and 0.027 inches, and wherein the wall thickness of the microcatheter is between 0.02 mm and 1 mm. 
     
     
         10 . The system of  claim 4 , wherein the lumen of the distal access microcatheter comprises a plurality of segments having decreasing inner lumen diameters from the proximal end to the distal end of the distal access microcatheter. 
     
     
         11 . The system of  claim 10 , wherein a first segment of the plurality of segments has a first length and wherein a second segment of the plurality of segments has a second length. 
     
     
         12 . A system for facilitating aspiration of thrombi comprising:
 a distal access microcatheter comprising a proximal end, a distal end and a lumen,   wherein the distal end of the distal access microcatheter comprises a balloon configured to provide temporary flow arrest within a blood vessel during an aspiration procedure,   a microcatheter configured to be advanced within the lumen of the distal access microcatheter and beyond the lumen of the distal access microcatheter, the microcatheter comprising a proximal end, a distal end and a lumen,   wherein an inner diameter of the microcatheter decreases from the proximal end to the distal end, thereby causing a change in suction pressure within the microcatheter sufficient to affect blood velocity and facilitate thrombus aspiration,   wherein at least a portion of the microcatheter comprises a hypotube within the lumen of the microcatheter, thereby preventing collapse of the lumen of the microcatheter during application of negative suction,   wherein the microcatheter comprises an outer polymer coating radially outward of the hypotube and an inner polymer coating radially inward of the hypotube, and   wherein the negative suction is configured to be applied through a lumen of the microcatheter for thrombus aspiration.   
     
     
         13 . The system of  claim 12 , wherein at least one parameter of the inner polymer coating varies along the longitudinal axis of the hypotube, the at least one parameter selected from the group consisting of material, thickness, and durometer. 
     
     
         14 . The system of  claim 13 , wherein the at least one varying parameter results in the decrease in the inner diameter of the microcatheter from the proximal end of the microcatheter to the distal end of the microcatheter. 
     
     
         15 . The system of  claim 12 , wherein the lumen of the distal access microcatheter comprises a plurality of segments having decreasing inner lumen diameters from the proximal end to the distal end of the distal access microcatheter. 
     
     
         16 . The system of  claim 15 , wherein a first segment of the plurality of segments has a first length and wherein a second segment of the plurality of segments has a second length. 
     
     
         17 . The system of  claim 12 , wherein at least one of the distal access microcatheter and the microcatheter comprises a plurality of radiopaque markers positioned at regular intervals along its length to facilitate visualization and measurements. 
     
     
         18 . The system of  claim 17 , wherein the regular intervals are between 8 mm and 10 mm. 
     
     
         19 . A system for facilitating aspiration of thrombi comprising:
 a microcatheter comprising a proximal end, a distal end and a lumen,   wherein the lumen of the microcatheter comprises a hypotube configured to provide proximal support and distal flexibility, and   wherein an inner lumen diameter of the microcatheter decreases from the proximal end to the distal end, thereby causing a change in suction pressure within the microcatheter sufficient to affect blood velocity and facilitate thrombus aspiration.   
     
     
         20 . The system of  claim 19 , further comprising a polymer coating radially inward of the hypotube, and wherein a parameter of the polymer coating varies to cause the decreasing inner lumen diameter of the microcatheter. 
     
     
         21 . The system of  claim 20 , wherein the varying parameter comprises at least one of durometer, thickness or material. 
     
     
         22 . The system of  claim 19 , wherein the hypotube comprises a parameter that varies across the length of at least a portion of the hypotube. 
     
     
         23 . The system of  claim 19 , wherein the lumen of the distal access microcatheter comprises a plurality of segments having decreasing inner lumen diameters from the proximal end to the distal end of the microcatheter.