Multi-Lumen Catheters for Small Body Vessel Applications

Abstract

Catheters adapted for use in small body vessels are described. A catheter includes an elongate shaft having a main body that defines first and second lumens. An inner tubular member is disposed in the second lumen and is formed of a material that has a stiffness that is greater than a stiffness of the material forming the main body.

We claim: 
     
         1 . A catheter, comprising:
 an elongate shaft having a proximal end, a distal end, a main body extending between the proximal end and the distal end, and a longitudinal axis, the main body formed of a first material and defining first, second, and third lumens;   an inner tubular member disposed in the second lumen and extending along an axial length of the elongate shaft, the inner tubular member formed of a second material and having a wall defining an inner lumen; and   a stiffening member disposed within the third lumen;   wherein the first material has a first stiffness, the second material has a second stiffness, and the second stiffness is greater than the first stiffness.   
     
     
         2 . The catheter of  claim 1 , wherein the elongate shaft has a distal portion disposed adjacent to the distal end of the elongate shaft; and
 further comprising a balloon disposed on the distal portion of the elongate shaft, the balloon defining an interior chamber in communication with the first lumen and having uninflated and inflated configurations.   
     
     
         3 . The catheter of  claim 2 , wherein the stiffening member extends through the distal portion of the elongate shaft. 
     
     
         4 . The catheter of  claim 1 , wherein the wall of the inner tubular member intersects the longitudinal axis of the elongate shaft. 
     
     
         5 . The catheter of  claim 1 , wherein the stiffening member is a rod. 
     
     
         6 . The catheter of  claim 1 , wherein the stiffening member has a solid cross-section. 
     
     
         7 . The catheter of  claim 1 , wherein the main body defines a fourth lumen. 
     
     
         8 . The catheter of  claim 7 , wherein the third lumen and the fourth lumen are positioned on the same side of the longitudinal axis of the elongate shaft in a cross-sectional plane. 
     
     
         9 . The catheter of  claim 7 , further comprising a second stiffening member disposed within the fourth lumen. 
     
     
         10 . The catheter of  claim 9 , wherein the stiffening member has a longitudinal axis;
 wherein the second stiffening member has a longitudinal axis; and   wherein the stiffening member and the second stiffening member are positioned on a cross-sectional plane such that an obtuse angle is formed between a first line segment connecting the longitudinal axis of the stiffening member and the longitudinal axis of the elongate shaft and a second line segment connecting the longitudinal axis of the second stiffening member and the longitudinal axis of the elongate shaft.   
     
     
         11 . The catheter of  claim 9 , wherein the second stiffening member is a rod. 
     
     
         12 . The catheter of  claim 1 , wherein one of the first material and the second material comprises a polyamide material. 
     
     
         13 . The catheter of  claim 12 , wherein one of the first material and the second material comprises a nylon material. 
     
     
         14 . The catheter of  claim 1 , wherein the second material has an elastic modulus greater than or equal to about 400 MPa. 
     
     
         15 . The catheter of  claim 1 , wherein the first lumen has a kidney cross-sectional shape. 
     
     
         16 . The catheter of  claim 1 , wherein the stiffening member comprises a metal. 
     
     
         17 . The catheter of  claim 1 , further comprising a reinforcement tubular member disposed over the inner tubular member and within the second lumen. 
     
     
         18 . The catheter of  claim 17 , wherein the reinforcement tubular member comprises a braided member. 
     
     
         19 . A catheter, comprising:
 an elongate shaft having a proximal end, a distal end, a main body extending between the proximal end and the distal end, a distal portion disposed adjacent to the distal end of the elongate shaft, and a longitudinal axis, the main body formed of a first material and defining first, second, third, and fourth lumens;   a balloon disposed on the distal portion of the elongate shaft, the balloon defining an interior chamber in communication with the first lumen and having uninflated and inflated configurations;   an inner tubular member disposed in the second lumen and extending along an axial length of the elongate shaft, the inner tubular member formed of a second material and having a wall defining an inner lumen;   a first stiffening member disposed within the third lumen and extending through the distal portion of the elongate shaft; and   a second stiffening member disposed within the fourth lumen;   wherein the first material has a first stiffness, the second material has a second stiffness, and the second stiffness is greater than the first stiffness.   
     
     
         20 . A catheter, comprising:
 an elongate shaft having a proximal end, a distal end, a main body extending between the proximal end and the distal end, a distal portion disposed adjacent to the distal end of the elongate shaft, and a longitudinal axis, the main body formed of a first material and defining first, second, third, and fourth lumens, the first lumen having a kidney cross-sectional shape;   a balloon disposed on the distal portion of the elongate shaft, the balloon defining an interior chamber in communication with the first lumen and having uninflated and inflated configurations;   an inner tubular member disposed in the second lumen and extending along an axial length of the elongate shaft, the inner tubular member formed of a second material and having a wall defining an inner lumen;   a first stiffening member disposed within the third lumen and extending through the distal portion of the elongate shaft, the first stiffening member comprising a solid cross-section; and   a second stiffening member disposed within the fourth lumen and having a solid cross-section;   wherein the first material has a first stiffness, the second material has a second stiffness, and the second stiffness is greater than the first stiffness.