DUAL LUMEN HYPOTUBE CATHETER
A catheter includes a shaft having a proximal end, a distal end, and a central lumen extending continuously from the proximal end to the distal end. A hypotube forms a proximal region of the shaft, and a polymer tube forms a distal region of the shaft. A periphery of the hypotube is cut in a pattern which provides a decreasing stiffness in a proximal-to-distal direction, and in some embodiments the polymer tube is reinforced by a wire embedded over at least a portion of the polymer tube's length. A guidewire lumen is disposed at or near the distal end of the catheter and extends for a portion of the catheter's length. The catheter may be used for aspiration, device delivery, or other purposes in a patient's vasculature.
1 . A catheter comprising:
a shaft having a proximal end, a distal end, and a central lumen extending continuously from the proximal end to the distal end;
a hypotube forming a proximal region of the shaft; and
a polymer body formed over the hypotube and extending distally of the shaft;
wherein a periphery of the hypotube is cut in a pattern selected to provide a decreasing stiffness in a proximal-to-distal direction.
2 . The catheter of claim 1 , wherein the shaft has a guidewire lumen extending over a distal portion of the shaft.
3 . The catheter of claim 2 , wherein the shaft further comprises a guidewire tube having a distal tip and a proximal port, wherein the guidewire lumen is disposed in the guidewire tube and extends from the distal tip to the proximal port.
4 . The catheter of claim 3 , wherein the guidewire tube is attached to the shaft so that the guidewire lumen is parallel to and laterally offset from the central lumen.
5 . The catheter of claim 3 , wherein the distal tip of the guidewire tube extends distally beyond a distal opening of the central lumen by a distance in the range from 0.5 mm to 3 mm.
6 . The catheter of claim 3 , wherein the proximal port of the guidewire tube is located distally of the proximal end of the shaft to form a rapid exchange structure.
7 . The catheter of claim 6 , wherein the shaft has a length in the range from 65 cm to 165 cm and the proximal port of the guidewire tube is located proximally of the distal end of the shaft by a distance in the range from 5 cm to 80 cm.
8 . The catheter of claim 1 , wherein a distal end of the hypotube extends to within 5 mm of the distal end of the shaft and the portion of the polymer body distal to a distal end of the hypotube is free from reinforcement other than a radiopaque markerband.
9 . The catheter of claim 1 , wherein a distal end of the hypotube extends to more than 5 mm from the distal end of the shaft and the portion of the polymer body distal to a distal end of the hypotube is reinforced with a wire.
10 . The catheter of claim 9 , wherein the wire is configured in a manner to confer a stiffness to the device that decreases in a proximal-to-distal direction.
11 . The catheter of claim 1 , wherein the hypotube has a variable pitch and a consistent cut density to provide a decreasing stiffness in a proximal-to-distal direction.
12 . The catheter of claim 1 , wherein the hypotube has a variable cut density and a consistent pitch to provide a decreasing stiffness in a proximal-to-distal direction.
13 . The catheter of claim 1 , wherein the hypotube has variable cut density and a variable pitch to provide a decreasing stiffness in a proximal-to-distal direction.
14 . The catheter of claim 1 , wherein the polymer tube has a beveled end.
15 . The catheter of claim 14 , wherein the polymer tube has a generally planar opening disposed at an angle from 20° to 80° relative to the longitudinal axis of the catheter shaft at the distal end.
16 . The catheter of claim 9 , wherein a distal tip of the polymer tube is free from reinforcement from the wire.
17 . The catheter of claim 1 , further comprising a radiopaque marker near the distal end of the shaft.
18 . A method for aspirating thrombus, said method comprising:
providing a catheter as in claim 1 ;
advancing a distal end of the catheter to a region in a vasculature at least partially occluded by thrombus;
engaging a distal tip of the catheter against the thrombus to create a seal; and
applying a negative pressure to the proximal end of a central lumen of the shaft to aspirate thrombus through the central lumen.
19 . A method as in claim 18 , wherein the catheter is advanced over a guidewire.
20 . A method as in claim 19 , wherein the catheter is advanced through a guide catheter.
21 . A method as in claim 18 , wherein the distal end of the shaft is beveled to enhance the seal formed with the thrombus.
22 . A method as in claim 18 , wherein the vasculature is selected from the group consisting of coronary, peripheral, and neuro vasculature.
23 . A method as in claim 18 , wherein the vasculature comprises coronary vasculature.