Noncircular inner lumen guiding catheter with assisted variable support

1. A guiding catheter, comprising:

an elongated wall structure extending along a length of the catheter defining an inner lumen and an outer lumen, said inner lumen having a noncircular cross-sectional shape, the elongated wall structure defining the inner lumen including a plurality of torque transmittal guidance walls having a flat cross-sectional surface, said plurality of torque transmittal guidance walls being made of a different material than a remainder of said elongated wall structure, said plurality of torque transmittal guidance walls being substantially flexible in a dimension perpendicular to the flat cross-sectional surface of said plurality of torque transmittal guidance walls but substantially not flexible in a dimension parallel to the flat cross-sectional surface of said plurality of torque transmittal guidance walls, and said outer lumen substantially having a cross-sectional shape of at least a portion of a curved geometric figure; and

an elongated stiffener in said outer lumen, said elongated stiffener being formed of a polymeric material conforming to the shape of said outer lumen, and said elongated stiffener including a central wire.

2. The guiding catheter of claim 1 , wherein said noncircular cross-sectional shape of said inner lumen is defined by two parallel line segments connected at each end by two curved line segments.

3. The guiding catheter of claim 2 , wherein said two curved line segments are symmetric mirror images of each other.

4. The guiding catheter of claim 1 , wherein said noncircular cross-sectional shape is substantially at least a portion of an oval.

5. The guiding catheter of claim 1 , wherein an outer wall of said outer lumen varies in stiffness along its length.

6. The guiding catheter of claim 1 , further comprising:

an elongated longitudinal spring member disposed in an outer wall of said elongated wall structure.

7. The guiding catheter of claim 1 , wherein said cross-sectional shape of said inner lumen is substantially a complete oval.

8. The guiding catheter of claim 7 , wherein said outer lumen substantially has the cross-sectional shape of a portion of a circle and is disposed to one side of said inner lumen.

9. The guiding catheter of claim 8 , wherein said elongated wall structure further defines a second outer lumen having a cross-sectional shape of a portion of a circle disposed to another, opposite side of said inner lumen.

10. The guiding catheter of claim 1 , wherein a distal portion of said elongated wall structure is segmented and progressively compliant.

11. The guiding catheter of claim 1 , further comprising:

a free floating coil constrained in an outer wall of said elongated wall structure.

12. The guiding catheter of claim 1 , wherein said elongated stiffener varies in stiffness along its length.

13. The guiding catheter of claim 1 , wherein said elongated stiffener tapers along at least a portion of its length.

14. The guiding catheter of claim 13 , wherein said portion of the length of said elongated stiffener has a continuously changing taper angle.

15. The guiding catheter of claim 13 , wherein said portion of the length of said elongated stiffener has contiguous tapered segments having different taper angles.

16. The guiding catheter of claim 1 , further comprising a balloon disposed along an outside of the elongated wall structure of the guiding catheter, wherein the outer lumen is an inflation/deflation lumen for the balloon.

17. The guiding catheter of claim 1 , further comprising a metal cage disposed along an outside of the elongated wall structure of the guiding catheter, and control wires housed within the outer lumen that expand/collapse the metal cage.

18. The guiding catheter of claim 1 , wherein a layer or a segment of the elongated wall structure of the guiding catheter comprises a material that can be activated so that at least one characteristic of the material changes.

19. The guiding catheter of claim 18 , wherein the layer or the segment of the elongated wall structure is capable of changing in response to injection of a liquid into the outer lumen.

20. The guiding catheter of claim 18 , wherein the layer or the segment of the elongated wall structure is capable of changing in response to insertion of an electric heating element into the outer lumen.

21. A guiding catheter, comprising:

elongated wall structure extending along a length of the catheter, said elongated wall structure defining an inner lumen and an outer lumen, said inner lumen having a noncircular cross-sectional shape, and said outer lumen having a noncircular cross-sectional shape and a non-circular inner surface, said elongated wall structure defining the inner lumen including a plurality of torque transmittal guidance walls having a flat cross-sectional surface, said plurality of torque transmittal guidance walls being substantially flexible in a dimension perpendicular to the flat cross-sectional surface of said plurality of torque transmittal guidance walls but substantially not flexible in a dimension parallel to the flat cross-sectional surface of said plurality of torque transmittal guidance walls; and

an elongated stiffener in said outer lumen, said elongated stiffener being secured to said noncircular inner surface of said outer lumen and free to move throughout the length of the catheter, said elongated stiffener being formed of a polymeric material conforming to the shape of said outer lumen, and said elongated stiffener including a central wire.

22. The guiding catheter of claim 21 , wherein said noncircular cross-sectional shape of said inner lumen is defined by two parallel line segments connected at each end by two curved line segments.

23. The guiding catheter of claim 21 , wherein said stiffener varies in stiffness along its length.