System and methods for intracranial vessel access

1. A method of accessing vasculature of a patient, comprising:

advancing an intra cranial access system through the vasculature of the patient; the intra cranial access system comprising:

a distal access catheter having a lumen with an inner first diameter at its distal end;

an underlying wire; and,

an inner guide member having a proximal section with an outer second diameter that covers part of the underlying wire and having an expanded section with an outer third diameter that is larger than the outer second diameter;

the expanded section having proximal and distal surfaces that taper in diameter in a substantially uniform and substantially symmetrical manner;

the outer third diameter corresponding to the inner first diameter;

wherein the distal access catheter, the underlying wire, and the inner guide member are each proximally accessible to enable independent, manually actuated sliding relative to each other;

during advancement of the distal access catheter and the inner guide member, torsionally and coaxially moving the inner guide member relative to the underlying wire and the distal access catheter while maintaining the proximal surface within the distal access catheter and the distal surface outside of the distal access catheter so as to minimize a gap between the inner guide member and the distal access catheter.

2. The method of claim 1 , wherein the expanded section has a cylindrical surface.

3. The method of claim 1 , wherein the outer third diameter of the inner guide member is about 0.058-0.075 inches.

4. The method of claim 1 , wherein the proximal section has a diameter of about 0.035 inches.

5. The method of claim 1 , wherein the distal surface of the expanded section further includes a distal tip region that has a diameter of about 0.014-0.016 inches.

6. The method of claim 1 , wherein the distal access catheter has an outer diameter of 0.065-0.075 inches.

7. The method of claim 1 , wherein the expanded section, without the proximal and distal surfaces, has a length of about 6-10 cm.

8. The method of claim 7 , wherein the distal surface has an axial length of about 4-6 cm.

9. A method of accessing vasculature of a patient, comprising:

advancing an intra cranial access system through the vasculature of the patient; the intra cranial access system comprising:

a distal access catheter having a lumen with an inner first diameter at its distal end;

an underlying wire; and,

an inner guide member having a proximal support section with an outer second diameter and having an expanded section with an outer third diameter larger than the outer second diameter; the inner guide member covering a proximal portion of the underlying wire;

the expanded section having proximal and distal surfaces that taper in diameter in a substantially uniform and substantially symmetrical manner;

the outer third diameter corresponding to the inner first diameter;

wherein the distal access catheter, the underlying wire, and the inner guide member each proximally extend to enable independent, manually actuated sliding relative to each other by a physician;

during advancement of the distal access catheter and the inner guide member, torsionally and coaxially moving the inner guide member relative to the underlying wire and the distal access catheter while maintaining a distal edge of the distal access catheter between the proximal surface and the distal surface of the expanded section so as to minimize a gap between the inner guide member and the distal access catheter.

10. The method of claim 9 , wherein the expanded section has a length of about 12-15 cm.

11. The method of claim 9 , wherein a length between the proximal and distal surfaces that taper is about 8 cm.

12. The method of claim 9 , wherein the length of each of the proximal and distal surfaces that taper is about 2-4 cm.

13. The method of claim 9 , wherein the distal access catheter has an outer diameter of 0.065-0.075 inches.

14. The method of claim 9 , wherein the inner guide member has a lumen and a microwire positioned within the lumen.

15. The method of claim 9 , wherein the distal access catheter has a proximal fourth diameter through a proximal portion of the distal access catheter.

16. A method of accessing vasculature of a patient, comprising:

advancing an intra cranial access system through the vasculature of the patient;

the intra cranial access system comprising:

a distal access catheter having a lumen with an inner first diameter at its distal end;

an underlying wire; and,

an inner guide member having a proximal support section having an outer second diameter and an expanded section having an outer third diameter larger than the outer second diameter; the inner guide member configured to cover a proximal portion of the underlying wire;

the expanded section having a diametrically uniform portion, and proximal and distal surfaces that taper in diameter away from the uniform portion in a circumferentially substantially symmetrical manner;

the outer third diameter corresponding to the inner first diameter;

wherein the distal access catheter, the underlying wire, and the inner guide member each proximally extend to enable independent, manually actuated sliding relative to each other by a physician;

during advancement of the distal access catheter and the inner guide member, torsionally and coaxially moving the inner guide member relative to the underlying wire and the distal access catheter while maintaining a distal edge of the distal access catheter adjacent to the uniform portion of the expanded section so as to minimize a gap between the inner guide member and the distal access catheter.

17. The method of claim 16 , wherein the uniform portion of the expanded section has a length of about 6-10 cm; wherein the distal surface has an axial length of about 4-6 cm; wherein the outer third diameter of the expanded section of the inner guide member is about 0.058-0.075 inches.