Flexible sheath assemblies and interventional catheter systems incorporating them

1. A medical device comprising:

a sheath assembly including a lumen and an inner tubular member having a plurality of discontinuous slots along at least a portion of its length, wherein the plurality of slots includes a first slot having an enlarged aperture at a terminus and a flexible outer tubular member contacting and extending for at least a portion of the length of the inner tubular member;

a rotatable drive shaft disposed along the lumen, wherein the drive shaft includes a distal end region and a proximal end region;

a rotatable operating head coupled to the distal end region of the drive shaft; and

a control console coupled to the proximal end region of the drive shaft.

2. The medical device of claim 1 , wherein the inner tubular member has a plurality of sections having different arrangements of discontinuous slots along the length of at least two sections.

3. The medical device of claim 2 , wherein the inner tubular member has a plurality of sections having different lengths of discontinuous slots along the length of at least two sections.

4. The medical device of claim 3 , wherein at least one of the sections has slots having different slot lengths neighboring one another.

5. The medical device of claim 2 , wherein at least one of the sections has slots with slot lengths that vary over the length of the section, the slot lengths transitioning in a graduated fashion from a shorter length to a longer length.

6. The medical device of claim 2 , wherein the inner tubular member has a plurality of sections having different patterns of discontinuous slots along the length of at least two sections.

7. The medical device of claim 1 , wherein the first slot has a second aperture at a second terminus.

8. The medical device of claim 1 , wherein the first slot has a slot width and the enlarged aperture has an aperture width, and wherein the aperture width is at least twice the slot width.

9. The medical device of claim 1 , wherein the first slot has a slot width and the enlarged aperture has an aperture width, and wherein the aperture width is at least 4 times the slot width.

10. The medical device of claim 1 , wherein the at least some discontinuous slots extend for a length greater than the circumference of the inner tubular member.

11. The medical device of claim 1 , wherein the at least some discontinuous slots extend for a length greater than 360° around the circumference of the inner tubular member.

12. The medical device of claim 1 , wherein the at least some discontinuous slots extend for a length greater than 180° around the circumference of the inner tubular member and less than the circumference of the inner tubular member.

13. The medical device of claim 1 , wherein slot termini, or enlarged apertures provided at slot termini, are separated from neighboring slot termini or enlarged apertures by unslotted regions extending for a length of less than 90° around the circumference of the inner tubular member.

14. The medical device of claim 1 , wherein the inner tubular member comprises at least two tubular sections arranged end-to-end and joined to one another.

15. The medical device of claim 14 , wherein the tubular sections have different diameters.

16. A catheter system comprising the medical device of claim 1 , wherein the operating head is connected, directly or indirectly, at a distal end of the sheath assembly.

17. A catheter system of claim 16 , wherein the operating head rotates independently of and traverses the sheath assembly coaxially.

18. A catheter system of claim 16 , additionally comprising a control component associated with the control console.