Catheter

Abstract

Catheters and methods for supporting a guidewire or delivering a radiopaque, diagnostic or therapeutic agent through a vessel stenosis or other tortuous anatomy are disclosed. A catheter can comprise an elongate shaft body and a tip member disposed at a distal end of the shaft body. The shaft body can extend from a proximal end to the distal end and can define an inner lumen. The shaft body can include a liner, a braid member surrounding the liner, a multi-layer coil surrounding the braid member, and a polymer cover surrounding the multi-layer coil. The multi-layer coil can include first and second coil layers wound in opposing directions. An outer surface portion of the polymer cover can include one or more helical threads. The tip member can be made from a metal or a polymer and can also include one or more helical threads around its outer surface.

What is claimed is: 
     
         1 . A catheter, comprising:
 an elongate shaft body extending from a proximal end to a distal end and defining an inner lumen, the shaft body including a liner, a braid member and a coil member surrounding at least a portion of the liner, and an outer polymer cover; and   a tip member disposed at the distal end of the shaft body,   wherein a distal end of the liner and the coil member extend beyond the distal end of the shaft body and into a proximal end of the tip member.   
     
     
         2 . The catheter of  claim 1 , wherein the coil member includes one or more helically wound elongate strands composed of a same material composition at each of the proximal end of the shaft body, the distal end of the shaft body, and the proximal end of the tip member. 
     
     
         3 . The catheter of  claim 1 , wherein the coil member includes one or more helically wound elongate strands having a cross-sectional size that is the same at each of the proximal end of the shaft body, the distal end of the shaft body, and the proximal end of the tip member. 
     
     
         4 . The catheter of  claim 1 , wherein the coil member incudes multiple elongate strands having a fully-round transverse profile. 
     
     
         5 . The catheter of  claim 1 , wherein the coil member surrounds the braid member. 
     
     
         6 . The catheter of  claim 1 , wherein the braid member includes a plurality of interbraided, metallic elongate strands along its length that form multiple strand crossings. 
     
     
         7 . The catheter of  claim 6 , wherein the elongate strands are axially spaced apart to define multiple pics. 
     
     
         8 . The catheter of  claim 1 , wherein the braid member includes a plurality of elongate strands wound helically in opposite directions. 
     
     
         9 . The catheter of  claim 1 , wherein a distal end of the braid member extends beyond the distal end of the shaft body. 
     
     
         10 . The catheter of  claim 1 , wherein the braid member includes a plurality of elongate strands having a rectangular transverse profile. 
     
     
         11 . The catheter of  claim 10 , wherein the rectangular transverse profile includes a thickness directed radially, the thickness being in the range of 0.010 mm to 0.015 mm, inclusive. 
     
     
         12 . The catheter of  claim 1 , wherein a proximal portion of the shaft body is configured to be less flexible than a distal portion of the shaft body. 
     
     
         13 . The catheter of  claim 1 , wherein the tip member includes a polymer tip member. 
     
     
         14 . The catheter of  claim 1 , wherein the tip member includes a non-tapered proximal portion and a tapered distal portion. 
     
     
         15 . The catheter of  claim 1 , wherein a boundary marking the distal end of the shaft body and a proximal end of the tip member is defined by a change in radiopacity, the change in radiopacity due to a material of the tip member having greater radiopacity than any material proximal of the tip member. 
     
     
         16 . The catheter of  claim 1 , wherein the tip member comprises a smooth outer surface and has increased flexibility relative to the shaft body. 
     
     
         17 . The catheter of  claim 1 , wherein the inner lumen has a constant diameter that extends from the proximal end of the shaft body to the distal end of the shaft body. 
     
     
         18 . The catheter of  claim 1 , wherein the tip member includes a lumen that is coaxial with the inner lumen. 
     
     
         19 . The catheter of  claim 18 , wherein the inner lumen and the lumen are configured to receive a guidewire. 
     
     
         20 . The catheter of  claim 1 , wherein the proximal end of the shaft body is configured to connect to a luer hub.