METHODS AND SYSTEMS FOR TREATMENT OF ACUTE ISCHEMIC STROKE
Described are methods and systems for transcervical access of the cerebral arterial vasculature and treatment of cerebral occlusions, including ischemic stroke. The methods and devices may include methods and devices which may provide aspiration and passive flow reversal, those which protect the cerebral penumbra during the procedure to minimize injury to brain, as well as distal catheters and devices to remove an occlusion. The methods and devices that provide passive flow reversal may also offer to the user a degree of flow control. Devices and methods which provide a way to securely close the access site in the carotid artery to avoid the potentially devastating consequences of a transcervical hematoma are also described.
1 . A system of devices for performing a medical procedure at a treatment site in a cerebral vessel of a patient, the system comprising:
a catheter having a catheter lumen having an inner diameter and a distal end; and
an inner member sized to slide within the catheter lumen, wherein the inner member defines a lumen and has a distal portion and a distal-most end having a distal opening, the distal portion having a first outer diameter that tapers distally to a second outer diameter that is smaller than the first outer diameter,
wherein the inner member is constructed to have variable stiffness so that the distal portion is made from softer material, with increasingly harder materials towards more proximal sections, and
wherein the distal portion transitions in flexibility from a flexibility at the second outer diameter to a flexibility at the first outer diameter, and
wherein the system of devices is in an advancement configuration when the inner member is positioned coaxially in the catheter lumen with the distal portion positioned distal to the distal end of the catheter, and
wherein flexibility of the system of devices enables the catheter and the inner member to be advanced together distal to a petrous portion of an internal carotid artery to a treatment site in a cerebral vessel while the system of devices is held in the advancement configuration.
2 . The system of claim 1 , wherein the first outer diameter corresponds to the inner diameter of the distal end of the catheter.
3 . The system of claim 2 , wherein the inner diameter of the distal end of the catheter is 0.070″- 0.095″.
4 . The system of claim 2 , wherein the inner diameter of the distal end of the catheter is 0.035″- 0.060″.
5 . The system of claim 1 , wherein the lumen of the inner member is sized to receive a guidewire in a range of 0.014″- 0.018″.
6 . The system of claim 1 , wherein the lumen of the inner member is no more than 0.024″.
7 . The system of claim 1 , wherein the lumen of the inner member is sized to receive a guidewire up to 0.035″.
8 . The system of claim 1 , wherein the inner member further comprises a microcatheter tip.
9 . The system of claim 8 , wherein the microcatheter tip is a flexible tubular extension extending distally past the distal portion.
10 . The system of claim 9 , wherein a length of the flexible tubular extension has a uniform outer diameter and wherein the distal opening is at the distal-most end of the tubular extension.
11 . The system of claim 10 , wherein the uniform outer diameter of the tubular extension and the second outer diameter of the distal portion substantially correspond.
12 . The system of claim 1 , wherein, when the system of devices is positioned in the advancement configuration and a guidewire is positioned within the lumen of the inner member and extended out the distal opening, the second outer diameter of the inner member forms a smooth transition between an outer diameter of the guidewire and the inner diameter at the distal end of the catheter.
13 . The system of claim 12 , wherein a flexibility of the inner member creates a smooth transition in flexibility between a flexibility of the guidewire to a flexibility of the distal end of the catheter.
14 . The system of claim 1 , wherein, when the system of devices is positioned in the advancement configuration and a guidewire is positioned within the lumen of the inner member and extended out the distal opening, a flexibility of the inner member creates a smooth transition in flexibility between a flexibility of the guidewire to a flexibility of the distal end of the catheter.
15 . The system of claim 1 , wherein the first outer diameter reduces a step at the distal end of the catheter improving advancement of the system of devices past a location of a side-branch distal to the petrous portion of the internal carotid artery while held in the advancement configuration.
16 . The system of claim 1 , wherein the inner member comprises a radiopaque marker.
17 . The system of claim 16 , wherein the radiopaque marker comprises a platinum/iridium band, a tungsten, platinum, or tantalum-impregnated polymer.
18 . The system of claim 1 , wherein the catheter has an outer diameter sized to match a size of the cerebral vessel with an occlusion.
19 . The system of claim 1 , further comprising an arterial access device, the inner member and catheter being sized to advance through a hemostasis valve of the arterial access device.
20 . The system of claim 19 , further comprising an aspiration source.
21 . An inner member of a system of devices for performing a medical procedure at a treatment site in a cerebral vessel of a patient, the system comprising the inner member and a catheter having catheter lumen having an inner diameter and a distal end,
wherein the inner member is sized to slide within the catheter lumen, wherein the inner member defines a lumen and has a distal portion and a distal-most end having a distal opening, the distal portion having a first outer diameter than tapers distally to a second outer diameter that is smaller than the first outer diameter,
wherein the inner member is constructed to have variable stiffness so that the distal portion is made from softer material, with increasingly harder materials towards more proximal sections, and
wherein the distal portion transitions in flexibility from a flexibility at the second outer diameter to a flexibility at the first outer diameter, and
wherein the inner member is positionable coaxially in the catheter lumen with the distal portion positioned distal to the distal end of the catheter so that the system of devices is in an advancement configuration, and
wherein flexibility of the inner member enables the catheter and the inner member to be advanced together distal to a petrous portion of an internal carotid artery to a treatment site in a cerebral vessel while the system of devices is held in the advancement configuration.
22 . The inner member of claim 21 , wherein the first outer diameter corresponds to the inner diameter of the distal end of the catheter.
23 . The inner member of claim 21 , wherein the lumen of the inner member is sized to receive a guidewire in a range of 0.014″- 0.018″.
24 . The inner member of claim 21 , wherein the lumen of the inner member is no more than about 0.024″.
25 . The inner member of claim 21 , wherein the lumen of the inner member is sized to receive a guidewire up to 0.035″.
26 . The inner member of claim 21 , wherein the inner member further comprises a microcatheter tip, wherein the microcatheter tip is a flexible tubular extension extending distally past the distal portion.
27 . The inner member of claim 26 , wherein a length of the tubular extension has a uniform outer diameter and wherein the distal opening is at the distal-most end of the tubular extension.
28 . The inner member of claim 27 , wherein the uniform outer diameter of the tubular extension and the second outer diameter of the distal portion substantially correspond.
29 . The inner member of claim 21 , wherein the inner member comprises a radiopaque marker.
30 . The inner member of claim 29 , wherein the radiopaque marker comprises a platinum/iridium band, a tungsten, platinum, or tantalum-impregnated polymer.