Multi-lumen catheters for small body vessel applications

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, 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, and third lumens, the third lumen disposed between the first lumen and the second lumen;

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

a stiffening member disposed within the third lumen, extending through the distal portion of the elongate shaft, 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; and

wherein the second material has an elastic modulus greater than or equal to about 400 MPa.

2. The catheter of claim 1 , wherein one of the first material and the second material comprises a polyamide material.

3. The catheter of claim 2 , wherein one of the first material and the second material comprises a nylon material.

4. The catheter of claim 1 , wherein both of the first material and the second material comprise a polyamide material.

5. The catheter of claim 1 , wherein both of the first material and the second material comprise a nylon material.

6. The catheter of claim 1 , wherein the inner tubular member comprises a wall and the wall intersects the longitudinal axis of the elongate shaft.

7. The catheter of claim 1 , wherein the first lumen has a kidney cross-sectional shape.

8. The catheter of claim 1 , wherein the elongate shaft has a French Gauge of 4 or less than 4.

9. The catheter of claim 1 , wherein the stiffening member comprises a metal.

10. The catheter of claim 9 , wherein the stiffening member comprises stainless steel.

11. The catheter of claim 1 , wherein the stiffening member comprises a polymeric material.

12. The catheter of claim 1 , wherein the main body defines a fourth lumen.

13. The catheter of claim 12 , further comprising a second stiffening member disposed within the fourth lumen.

14. The catheter of claim 1 , further comprising a reinforcement tubular member disposed over the inner tubular member and within the second lumen.

15. The catheter of claim 14 , wherein the reinforcement tubular member comprises a braided member.

16. The catheter of claim 1 , wherein the stiffening member is a rod.

17. The catheter of claim 1 , wherein the stiffening member is a wire member.

18. The catheter of claim 1 , wherein the third lumen has a central axis; and

wherein a hypothetical plane extending orthogonally to a cross-section of the elongate shaft extends through the central axis of the third lumen and each of the first and second lumens.

19. The catheter of claim 18 , wherein the stiffening member intersects the longitudinal axis of the elongate shaft.

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 and third lumens, the third lumen disposed between the first lumen and the second lumen;

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

a stiffening member disposed within the third lumen, extending through the distal portion of the elongate shaft, and having a solid cross-section;

wherein the elongate shaft has a French Gauge of 5 or less than 5;

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; and

wherein the second material has an elastic modulus greater than or equal to about 400 MPa.

21. 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, and third lumens, the third lumen disposed between the first lumen and the second lumen;

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;

a braided member disposed over the inner tubular member and within the second lumen; and

a stiffening member disposed within the third lumen, extending through the distal portion of the elongate shaft, and having a solid cross-section;

wherein the elongate shaft has a French Gauge of 5 or less than 5;

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; and

wherein the second material has an elastic modulus greater than or equal to about 400 MPa.