Aspiration catheter systems and methods of use

1 . A method of performing a medical procedure in a cerebral vessel of a patient, the method comprising:

advancing a catheter system towards an embolus within a cerebral blood vessel, the catheter system comprising:

a first catheter comprising a first catheter portion having a lumen, a proximal opening into the lumen, a distal opening from the lumen, and a distal end and a first proximal extension coupled to the first catheter portion near the proximal opening, the first proximal extension being less flexible than the first catheter portion;

a second catheter comprising a second catheter portion having a lumen, a proximal opening into the lumen, a distal opening from the lumen, and a distal end; and a second proximal extension coupled to the second catheter portion near the proximal opening, the second proximal extension being less flexible than the second catheter portion; and

a guide sheath having a working lumen,

wherein an outer diameter of the second catheter portion near the proximal opening of the second catheter portion and an inner diameter of the first catheter portion are configured to provide a first seal within a proximal sealing zone;

applying aspiration pressure through the lumen of the second catheter portion for a time sufficient to anchor the embolus to the distal end of the second catheter portion; and

withdrawing the second catheter with respect to the first catheter,

wherein the first catheter portion and the second catheter portion each has a length and the proximal sealing zone has a location, wherein the lengths and the location are arranged such that withdrawal of the second catheter into the first catheter such that a proximal end of the second catheter portion is withdrawn through the proximal opening of the first catheter portion automatically at least partially releases the first seal and the automatic at least partial release of the first seal causes an automatic increase in the aspiration pressure at the distal end of the first catheter portion as the distal end of the second catheter portion passes into the distal end of the first catheter portion such that the embolus is captured at least partially within the lumen of the first catheter portion.

2 . The method of claim 1 , further comprising anchoring the distal end of the second catheter portion onto the embolus via the aspiration pressure.

3 . The method of claim 2 , wherein the step of withdrawing the second catheter with respect to the first catheter further comprises applying a proximally-directed force on the second catheter to reduce slack in the second catheter relative to surrounding anatomy while the distal end of the second catheter portion remains anchored onto the embolus.

4 . The method of claim 1 , wherein the catheter system further comprises a single aspiration source connected to the guide sheath.

5 . The method of claim 4 , wherein the single aspiration source provides the aspiration pressure within the second catheter that automatically increases at the distal end of the first catheter portion upon withdrawal of the second catheter into the first catheter.

6 . The method of claim 1 , wherein the aspiration pressure is applied through the lumen of the first catheter portion and the lumen of the second catheter portion from a single source of aspiration.

7 . The method of claim 1 , wherein an outer surface of the second catheter portion seals with an inner surface of the first catheter portion forming a contiguous lumen between the distal opening of the second catheter portion to a proximal end of the guide sheath.

8 . The method of claim 1 , wherein the system further comprises a connector having a single or two-headed rotating hemostatic valve, wherein both the first and second catheters are advanced through the connector.

9 . The method of claim 1 , wherein advancing the catheter system comprises advancing a distal opening of the guide sheath to a location in an internal carotid artery (ICA).

10 . The method of claim 1 , wherein the second catheter has an inner diameter that is between 0.054″ and 0.070″, the first catheter has an inner diameter between 0.072″ and 0.088″, and the guide sheath is between 6 Fr to 8 Fr.

11 . The method of claim 1 , further comprising a third catheter comprising a third catheter portion having a lumen, a proximal opening into the lumen, a distal opening from the lumen, and a distal end, the third catheter also comprising a third proximal extension coupled to the third catheter portion new the proximal opening of the third catheter,

wherein the third catheter portion has an outer diameter sized to extend through the lumen of the second catheter portion, and wherein the second catheter portion has an outer diameter sized to extend through the lumen of the third catheter portion.

12 . The method of claim 11 , wherein the third catheter portion has an inner diameter that is about 0.052″ to about 0.055″, the second catheter portion has an inner diameter that is about 0.070″ to about 0.073″, and the first catheter portion has an inner diameter that is about 0.087″ to about 0.089″.

13 . The method of claim 1 , wherein the embolus is not penetrated by a guidewire or a microcatheter during the method.

14 . The method of claim 1 , wherein the first catheter portion has an outer diameter that is larger than an outer diameter of the first proximal extension.

15 . The method of claim 14 , wherein the second catheter portion has an outer diameter that is larger than an outer diameter of the second proximal extension.

16 . The method of claim 14 , wherein the first proximal extension is a ribbon, spine or hypotube.

17 . The method of claim 14 , wherein the first proximal extension is solid.

18 . The method of claim 1 , wherein the step of withdrawing the second catheter with respect to the first catheter increases a minimum gap between the second catheter outer diameter and the first catheter inner diameter from less than 0.005 inches to greater than 0.005 inches.

19 . The method of claim 1 , wherein the outer diameter of the second catheter portion within the proximal sealing zone is greater than an outer diameter of a remainder of the second catheter portion.

20 . The method of claim 19 , wherein the proximal sealing zone has a length of less than 15 mm.

21 . The method of claim 1 , wherein the automatic at least partial release of the first seal occurs when the distal ends of the first and second catheters are substantially aligned.

22 . The method of claim 1 , wherein the automatic at least partial release of the first seal occurs when the distal ends of the first and second catheters are within 5 mm of each other.

23 . The method of claim 1 , wherein the automatic at least partial release of the first seal occurs when the distal end of the second catheter has been withdrawn into the first catheter at least 5 mm and no more than 20 mm proximal to the distal end of the first catheter.

24 . The method of claim 1 , wherein the second catheter further comprises a coupling band having a proximal end region and a distal end region, the proximal end region of the coupling band being sized and shaped to couple with a flattened distal end of the second proximal extension, the distal end region of the coupling band being coiled so as to intersperse with corresponding coils of a reinforcement layer of the second catheter,

wherein a polymer segment overlaying the coupling band forms an enlarged outer diameter section of the second catheter portion providing the first seal within the proximal sealing zone.

25 . A method of performing a medical procedure in a cerebral vessel of a patient, the method comprising:

advancing a catheter system towards an embolus within a cerebral blood vessel, the catheter system comprising:

a first catheter comprising a first catheter portion having a lumen, a proximal opening into the lumen, a distal opening from the lumen, and a distal end and a first proximal extension coupled to the first catheter portion near the proximal opening, the first proximal extension being less flexible than the first catheter portion;

a second catheter comprising a second catheter portion having a lumen, a proximal opening into the lumen, a distal opening from the lumen, and a distal end; and

a second proximal extension coupled to the second catheter portion near the proximal opening, the second proximal extension being less flexible than the second catheter portion; and

a guide sheath having a working lumen,

wherein an outer diameter of the second catheter portion near the proximal opening of the second catheter portion and an inner diameter of the first catheter portion are configured to provide a first seal within a proximal sealing zone;

applying aspiration pressure through the lumen of the second catheter portion for a time sufficient to anchor the embolus to the distal end of the second catheter portion; and

withdrawing the second catheter with respect to the first catheter,

wherein the first catheter portion and the second catheter portion each has a length and the proximal sealing zone has a location, wherein the lengths and the location are arranged such that withdrawal of the second catheter into the first catheter automatically at least partially releases the first seal wherein the automatic at least partial release of the first seal occurs due to the first seal moving out of the proximal opening of the lumen of the first catheter portion during withdrawal of the second catheter and the automatic at least partial release of the first seal causes an automatic increase in the aspiration pressure at the distal end of the first catheter portion as the distal end of the second catheter portion passes into the distal end of the first catheter portion such that the embolus is captured at least partially within the lumen of the first catheter portion.