Enhanced flexibility neurovascular catheter

Abstract

An enhanced flexibility catheter is provided, such as for distal neurovascular access or aspiration. The catheter includes an elongate flexible body, having a proximal end, a distal end, and a side wall defining a central lumen. The side wall is formed from a plurality of adjacent tubular segments. At least one segment has a first end face inclined at a non normal angle to a longitudinal axis of the catheter. An adjacent segment has a second end face inclined at a complementary angle to form an inclined junction at the transition between the two segments. The transition serves to provide superior bending characteristics along the length of the catheter shaft.

1 . (canceled) 
     
     
         2 . An enhanced flexibility catheter comprising:
 an elongate body comprising:
 a proximal end, 
 a distal end, and 
 a side wall at least partially defining a central lumen, the side wall comprising:
 a proximal zone comprising a tubular braid and a first helical coil; 
 a distal zone comprising a second helical coil, and 
 a transition between the distal zone and the proximal zone, the transition comprising a distal end of the tubular braid within 1 cm of a proximal end of the second helical coil, 
 
   wherein the first helical coil extends distally beyond the transition.   
     
     
         3 . The enhanced flexibility catheter of  claim 2 , wherein distal end of the tubular braid is within 5 mm of the proximal end of the second helical coil. 
     
     
         4 . The enhanced flexibility catheter of  claim 2 , wherein the first helical coil is formed from a wire having a first diameter, and wherein the second helical coil is formed from a second wire having a second diameter larger than the first diameter. 
     
     
         5 . The enhanced flexibility catheter of  claim 4 , wherein the first helical coil comprises stainless steel. 
     
     
         6 . The enhanced flexibility catheter of  claim 4 , wherein the second helical coil comprises Nitinol. 
     
     
         7 . The enhanced flexibility catheter of  claim 4 , wherein the first helical coil and the second helical coil are intertwined over a length of at least about 5 mm. 
     
     
         8 . The enhanced flexibility catheter of  claim 2 , wherein a distal section of the tubular braid has been heat annealed. 
     
     
         9 . The enhanced flexibility catheter of  claim 2 , wherein the side wall further comprises an inner liner and a tie layer being separated from the central lumen by the inner liner, wherein the second helical coil of the distal zone is adjacent the tie layer, and wherein the tubular braid of the proximal zone is adjacent the tie layer. 
     
     
         10 . The enhanced flexibility catheter of  claim 2 , wherein the elongate body further comprises an outer jacket being formed from a plurality of axially adjacent tubular segments, and wherein a proximal tubular segment of the plurality of axially adjacent tubular segments has a durometer of at least about 60D, and wherein a distal tubular segment of the plurality of axially adjacent tubular segments has a durometer of no more than about 35D. 
     
     
         11 . The enhanced flexibility catheter of  claim 2 , wherein the elongate body further comprises an axially extending filament within the side wall. 
     
     
         12 . The enhanced flexibility catheter of  claim 2 , further comprising a tubular support comprising:
 a proximal end surrounding a distal portion of the tubular braid, and   a distal end surrounding a proximal portion of the second helical coil.   
     
     
         13 . The enhanced flexibility catheter of  claim 12 , wherein the tubular support comprises a slotted metal tube. 
     
     
         14 . An enhanced flexibility catheter comprising:
 an elongate body comprising:
 a proximal end, 
 a distal end, and 
 a side wall at least partially defining a central lumen, the side wall comprising:
 a proximal tubular braid comprising a distal end adjacent a proximal end of a helical coil to form a junction, 
 a tubular metal support spanning the junction, and 
 an outer jacket surrounding the tubular metal support. 
 
   
     
     
         15 . The enhanced flexibility catheter of  claim 14 , further comprising an axial filament extending distally from beneath the tubular metal support. 
     
     
         16 . The enhanced flexibility catheter of  claim 14 , wherein the side wall further comprises an inner liner and a tie layer being separated from the central lumen by the inner liner, wherein the helical coil surrounds the tie layer, and wherein the proximal tubular braid surrounds the tie layer. 
     
     
         17 . The enhanced flexibility catheter of  claim 14 , wherein the elongate body further comprises an outer jacket being formed from a plurality of axially adjacent tubular segments extending coaxially about the helical coil, wherein a proximal tubular segment of the plurality of axially adjacent tubular segments has a durometer of at least about 60D, and wherein a distal tubular segment of the plurality of axially adjacent tubular segments has a durometer of no more than about 35D. 
     
     
         18 . A method of making an enhanced flexibility catheter, the method comprising:
 forming a catheter comprising a braid in a proximal zone of the catheter;   placing at least a portion of the braid over a mandrel;   annealing a distal section of the braid, annealing comprising induction heating the braid and the mandrel in a coil; and   visibly monitoring a parameter change of the braid.   
     
     
         19 . The method of  claim 18 , wherein induction heating the braid comprises placing the braid and the mandrel within an ERDO induction heater. 
     
     
         20 . The method of  claim 18 , wherein the parameter change comprises a color change of the braid. 
     
     
         21 . The method of  claim 18 , wherein the distal section of the braid has an axial length of no more than about 2 cm.