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 for intracranial access through a patient's vasculature to access an intracranial occlusion, the system comprising:
a distal access catheter comprising a distal end forming a leading edge, the distal access catheter having an inner diameter of 0.070″-0.095″; and
an inner member for advancing the distal access catheter through a curved vessel at a location of a side-branch in a patient's vasculature, the inner member having a proximal section and a distal tip region having a tapered section, wherein an axis of the inner member passes centrally through the proximal section and through the distal tip region, wherein the proximal section, proximal to the distal tip region, has a cylindrical surface having an outer diameter greater than an outer diameter of the distal tip region, wherein the proximal section is configured to advance the inner member through the patient's vasculature, and wherein the distal tip region having the tapered section has a size and a flexibility to reach the intracranial occlusion, wherein the proximal section and the distal tip region form a single-lumen passage having a single distal opening,
wherein, in use, the cylindrical surface of the inner member is maintained at least partially distal of the distal end of the distal access catheter during advancement through the patient's vasculature, and
wherein the outer diameter of the cylindrical surface is sized to substantially correspond to the inner diameter of the distal access catheter to prevent diameter mismatch between the inner member and the leading edge of the distal access catheter while the distal access catheter is advanced through at least a curved portion of the patient's vasculature, and
wherein the cylindrical surface has a length to allow axial movements of the inner member relative to the distal access catheter while the distal access catheter is advanced through the patient's vasculature without diameter mismatch between the inner member and the inner diameter of the distal access catheter.
2 . The system of claim 1 , wherein the inner member is composed of a flexible material.
3 . The system of claim 1 , wherein the distal tip region of the inner member prevents a diameter mismatch between an outer diameter of a wire used with the system and passing through the single distal opening and the inner diameter at the distal end of the distal access catheter.
4 . The system of claim 3 , wherein the outer diameter of the wire is 0.014 inch-0.018 inch.
5 . The system of claim 1 , wherein the side-branch is an ophthalmic artery, and the curved vessel is an internal carotid artery.
6 . The system of claim 1 , wherein the single-lumen passage has a diameter that is no more than 0.024 inch.
7 . The system of claim 1 , wherein a distal end of the inner member comprises a radiopaque marker.
8 . The system of claim 7 , wherein the radiopaque marker is fabricated from a material selected from the group consisting of platinum/iridium, tungsten, platinum, and tantalum-impregnated polymer.
9 . The system of claim 1 , wherein the inner member is constructed with variable stiffness, wherein a distal segment of the inner member is constructed of a softer material with successively stiffer materials towards a proximal end of the inner member.
10 . The system of claim 1 , wherein a flexibility of the distal tip region of the inner member decreases proximally and creates a smooth transition between a flexibility of the inner member to a flexibility of the distal access catheter.
11 . The system of claim 1 , wherein the distal tip region having the tapered section further comprises a tubular extension located distally past the tapered section.
12 . The system of claim 11 , wherein the tubular extension has a uniform outer diameter.
13 . A method of accessing an intracranial occlusion through a patient's vasculature, the method comprising:
advancing an inner member through the patient's vasculature to reach the intracranial occlusion, the inner member having a proximal section and a distal tip region having a tapered section, the inner member having an axis passing centrally through the proximal section and through the distal tip region, wherein the proximal section, proximal to the distal tip region has a cylindrical surface having an outer diameter greater than an outer diameter of the distal tip region, wherein the proximal section is configured to advance the inner member through the patient's vasculature, and wherein the distal tip region having the tapered section has a size and a flexibility to reach the intracranial occlusion, wherein the proximal section and the distal tip region have a passage therethrough, and wherein the inner member is operatively connected to a distal access catheter having an inner diameter of 0.070″ -0.095″ and having a distal inner diameter substantially corresponding to the outer diameter of the cylindrical surface and wherein the distal access catheter is movable axially relative to the cylindrical surface;
maintaining the tapered section of the distal tip region at least partially outside of a distal end of the distal access catheter while the distal access catheter is advanced through at least a curved portion of the patient's vasculature and while causing axial movements of the inner member relative to the distal access catheter, the distal inner diameter of the distal access catheter and the outer diameter of the cylindrical surface being sized and having a length to prevent diameter mismatch between the inner member and a leading edge of the distal access catheter; and
manipulating the inner member and distal access catheter through the patient's vasculature using axial movements of the inner member relative to the distal access catheter to advance the distal access catheter through the curved portion of the patient's vasculature and without diameter mismatch between the cylindrical surface from the distal inner diameter of the distal access catheter and the leading edge of the distal access catheter.
14 . The method of claim 13 , wherein the inner member prevents the leading edge of the distal access catheter from catching on a side-branch within the curved portion.
15 . The method of claim 14 , wherein the side-branch is an ophthalmic artery.
16 . The method of claim 13 , further comprising advancing the inner member and the distal access catheter through the curved portion.
17 . The method of claim 13 , further comprising removing the inner member from the distal access catheter; and removing occlusive material while applying negative pressure to a lumen of the distal access catheter to capture occlusive material at, within, or through the distal end of the distal access catheter.
18 . An inner catheter of a system for intracranial access through a patient's vasculature to access an intracranial occlusion, the system comprising a distal access catheter comprising a distal end forming a leading edge; and the inner catheter, wherein the inner catheter comprises:
an elongate body adapted to advance the distal access catheter through a curved vessel at a location of a side-branch in the patient's vasculature, the elongate body having a proximal section and a distal tip region having a tapered section, wherein an axis of the elongate body passes centrally through the proximal section and through the distal tip region, wherein the proximal section, proximal to the distal tip region, has a cylindrical surface having an outer diameter greater than an outer diameter of the distal tip region, wherein the proximal section is configured to advance the elongate body through the patient's vasculature, and wherein the distal tip region having the tapered section has a size and a flexibility to reach the intracranial occlusion, wherein the proximal section and the distal tip region form a single-lumen passage having a single distal opening,
wherein, in use, the cylindrical surface of the elongate body is capable of being maintained at least partially distal of a distal end of the distal access catheter during advancement through the patient's vasculature, and
wherein the outer diameter of the cylindrical surface is sized to substantially correspond to an inner diameter of the distal access catheter to prevent diameter mismatch between the inner catheter and a leading edge of the distal access catheter while the distal access catheter is advanced through at least a curved portion of the patient's vasculature, and
wherein the cylindrical surface has a length to allow axial movements of the inner catheter relative to the distal access catheter while the distal access catheter is advanced through the patient's vasculature without diameter mismatch between the inner catheter and the inner diameter of the distal access catheter.
19 . The inner catheter of claim 18 , wherein the elongate body is composed of a flexible material.
20 . The inner catheter of claim 18 , wherein the distal tip region of the elongate body prevents a diameter mismatch between an outer diameter of a wire used with the distal access catheter and passing through the single distal opening and the inner diameter at the distal end of the distal access catheter.
21 . The inner catheter of claim 20 , wherein the outer diameter of the wire is 0.014 inch-0.018 inch.
22 . The inner catheter of claim 18 , wherein the side-branch is an ophthalmic artery, and the curved vessel is an internal carotid artery.
23 . The inner catheter of claim 18 , wherein the single-lumen passage has a diameter no more than about 0.024 inch.
24 . The inner catheter of claim 18 , wherein a distal end of the elongate body comprises a radiopaque marker.
25 . The inner catheter of claim 24 , wherein the radiopaque marker is fabricated from a material selected from the group consisting of platinum/iridium, tungsten, platinum, and tantalum-impregnated polymer.
26 . The inner catheter of claim 18 , wherein the elongate body is constructed with variable stiffness, wherein a distal segment of the elongate body is constructed of a softer material with successively stiffer materials towards a proximal end of the elongate body.
27 . The inner catheter of claim 18 , wherein a flexibility of the distal tip region of the elongate body decreases proximally and creates a smooth transition between a flexibility of the elongate body to a flexibility of the distal access catheter.
28 . The inner catheter of claim 18 , wherein the distal tip region having the tapered section further comprises a tubular extension located distally past the tapered section.
29 . The inner catheter of claim 28 , wherein the tubular extension has a uniform outer diameter.
30 . A system comprising the inner catheter of claim 18 , and further comprising the distal access catheter, the distal access catheter having an inner diameter of 0.070″-0.095″.