Methods and systems for treatment of acute ischemic stroke

Abstract

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, the inner member comprising:
 a single lumen having a distal opening; 
 a distal tapered portion comprising a first outer diameter that tapers distally to a second outer diameter that is smaller than the first outer diameter; and 
 a flexible tubular extension coupled to and extending distally past the distal tapered portion, wherein a length of the tubular extension has a uniform outer diameter and wherein the distal opening from the single lumen is at a distal-most end of the tubular extension. 
   
     
     
         2 . The system of  claim 1 , wherein the system is in an advancement configuration when the inner member is positioned coaxially in the catheter lumen with the distal tapered portion positioned distal to the distal end of the catheter and the inner member held fixed relative to the catheter, and wherein a flexibility of the distal tapered portion decreases smoothly from a flexibility at the second outer diameter to a flexibility at the first outer diameter when the system is in the advancement configuration. 
     
     
         3 . The system of  claim 2 , wherein the system of devices is sufficiently flexible that, when the system is in the advancement configuration, the catheter and the inner member are configured to be concurrently advanced distal to a petrous portion of an internal carotid artery while the system of devices is positioned in the advancement configuration. 
     
     
         4 . The system of  claim 2 , wherein, when the system of devices is positioned in the advancement configuration, a flexibility of the distal tapered portion of the inner member decreases proximally and creates a smooth transition in flexibility from the second outer diameter to the distal end of the catheter. 
     
     
         5 . The system of  claim 2 , wherein, when the system of devices is positioned in the advancement configuration and a guidewire is positioned within the single lumen and extended out the distal opening, the inner member creates a smooth transition from an outer diameter of the guidewire to an inner diameter at the distal end of the catheter. 
     
     
         6 . The system of  claim 5 , 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. 
     
     
         7 . The system of  claim 2 , wherein when the system of devices is positioned in the advancement configuration and a guidewire is positioned within the single lumen 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. 
     
     
         8 . The system of  claim 1 , wherein a stent retriever is positioned within the single lumen of the inner member. 
     
     
         9 . The system of  claim 1 , wherein the inner member at the second outer diameter is constructed of a material that is softer than a material at the first outer diameter. 
     
     
         10 . The system of  claim 1 , wherein the first outer diameter substantially corresponds to the inner diameter of the distal end of the catheter. 
     
     
         11 . The system of  claim 1 , wherein the uniform outer diameter of the tubular extension and the second outer diameter of the distal tapered portion substantially correspond. 
     
     
         12 . The system of  claim 1 , further comprising a second catheter having a catheter lumen having an inner diameter and a distal end, wherein the inner diameter of the catheter lumen of the second catheter is sized to slidably receive the catheter therein. 
     
     
         13 . The system of  claim 12 , wherein the second catheter further comprises a flexible distal luminal portion and a proximal tether element extending proximally from a point of attachment near a proximal end of the flexible distal luminal portion, the proximal tether element of the second catheter extending proximally to outside the body of the patient. 
     
     
         14 . The system of  claim 1 , wherein the single lumen has a diameter less than 0.024 inches. 
     
     
         15 . The system of  claim 1 , wherein the single lumen has a diameter less than 0.040 inches. 
     
     
         16 . The system of  claim 1 , further comprising a radiopaque marker disposed at a distal end region of inner member. 
     
     
         17 . The system of  claim 1 , wherein the first outer diameter tapers distally over a length sufficient to create a smooth transition between a flexibility of a guidewire and a flexibility of the distal end of the catheter. 
     
     
         18 . The system of  claim 1 , wherein the single lumen of the inner member a uniform inner diameter from the distal-most end to a proximal end of the single lumen. 
     
     
         19 . The system of  claim 1 , wherein the distal tapered portion of the inner member is more flexible than the distal end of the catheter. 
     
     
         20 . The system of  claim 1 , wherein a length of the distal tapered portion between the first outer diameter and the second outer diameter is longer than the first outer diameter. 
     
     
         21 . The system of  claim 1 , wherein the catheter and the inner member are advanceable together distal to a petrous portion of an internal carotid artery while the distal tapered portion extends distal to the distal end of the catheter. 
     
     
         22 . A system for intracranial access through a patient's vasculature to access an intracranial occlusion, the system comprising:
 an inner member for steering and advancing through the patient's vasculature, the inner member having a proximal section, a tapered section, and a flexible tubular extension coupled to and extending distally past the tapered section to a distal-most end of the inner member, wherein a length of the tubular extension has a uniform outer diameter,
 wherein an axis of the inner member passes centrally through the proximal section, the tapered section, and at least partially through the tubular extension, 
 wherein the proximal section, proximal to the tubular extension, has an outer diameter greater than the uniform outer diameter of the tubular extension, 
 wherein the proximal section is configured to advance the inner member through the vasculature, and wherein the proximal section, the tapered section, and the distal tip region have a single lumen therethrough configured for passage and relative movement of a wire; and 
   a distal access catheter operatively connected to the inner member and wherein the distal access catheter has a distal inner diameter substantially corresponding to a largest outer diameter of the proximal section,
 wherein the outer diameter of proximal section is maintained at least partially distal of a distal end of the distal access catheter during advancement through the patient's vasculature, and 
 wherein the distal inner diameter of the distal access catheter and the largest outer diameter of the proximal section are sized to prevent coaxial separation between the inner member and the distal end of the distal access catheter while being advanced through the curved vasculature and the proximal section has a length to allow torsional and coaxial movements of the inner member relative to the distal access catheter while being advanced through curved vasculature without causing separation of the inner member from the distal inner diameter of the distal access catheter. 
   
     
     
         23 . The system of  claim 22 , wherein a stent retriever is positioned within the single lumen of the inner member. 
     
     
         24 . The system of  claim 22 , wherein a length of the distal tapered portion between the first outer diameter and the second outer diameter is longer than the first outer diameter. 
     
     
         25 . The system of  claim 22 , wherein the inner member and the distal access catheter are advanceable together distal to a petrous portion of an internal carotid artery while the tapered section extends distal to a distal end of the distal access catheter. 
     
     
         26 . The system of  claim 22 , wherein the single lumen of the inner member is a uniform inner diameter from the distal-most end to a proximal end of the single lumen. 
     
     
         27 . The system of  claim 22 , wherein the tapered portion of the inner member is more flexible than the distal end of the catheter. 
     
     
         28 . The system of  claim 22 , wherein the tapered section has a first outer diameter which tapers distally to a second outer diameter over a length sufficient to create a smooth transition between a flexibility of a guidewire and a flexibility of the distal end of the catheter. 
     
     
         29 . The system of  claim 28 , wherein the inner member at the second outer diameter is constructed of a material that is softer than a material at the first outer diameter. 
     
     
         30 . The system of  claim 28 , wherein the first outer diameter substantially corresponds to the inner diameter of the distal end of the catheter. 
     
     
         31 . The system of  claim 22 , wherein the system is in an advancement configuration when the inner member is positioned coaxially in the catheter lumen with the tapered portion positioned distal to the distal end of the catheter. 
     
     
         32 . The system of  claim 31 , wherein the system of devices is sufficiently flexible that, when the system is in the advancement configuration, the catheter and the inner member are configured to be concurrently advanced distal to a petrous portion of an internal carotid artery while the system of devices is positioned in the advancement configuration. 
     
     
         33 . The system of  claim 31 , wherein, when the system of devices is positioned in the advancement configuration, a flexibility of the tapered portion of the inner member decreases proximally and creates a smooth transition in flexibility from the second outer diameter to the distal end of the catheter.