Cerebrovascular disease observation and treatment

Abstract

Devices and methods are provided that can help enable real-time, full-color, diagnostic-quality resolution, direct intravascular visualization of cerebrovascular lesions. [Solution] A sheath catheter (102) can be advanced toward a cerebrovascular lesion. A balloon at its tip can be inflated. An angioscope (104) can be inserted through its working lumen for observation. The sheath catheter can have a stepped lateral profile and can extend a working channel a distance beyond the balloon. The dual concentric lumen structure can include an inner body and an outer body defining an inflation lumen therebetween, and one or more portions of one or more layers can be stretched or cut, or both, to provide bending flexibility, etc. Reflow techniques can be used to help bond the layers together.

Description

[Technical Field]

[0001] This specification relates generally, but not by way of limitation, to intravascular imaging and therapy, and more particularly, but not by way of limitation, to cerebrovascular lesion monitoring and therapy. [Background technology]

[0002] Cerebrovascular lesions may include, among other things, thrombus (blood clot) or aneurysm (a partial widening or weakening of a blood vessel). Cerebrovascular thrombosis may be associated with ischemic stroke, which may further damage brain tissue. Cerebrovascular aneurysms may be associated with the risk of rupture and hemorrhagic stroke, which may also further damage brain tissue.

[0003] Fluoroscopic imaging from an imaging device location outside the patient's body can be used to guide intravascular devices within a patient's vasculature to cerebrovascular lesions, such as to perform treatments such as thrombectomy or aneurysm coil embolization. However, assessing the lesion or its composition or treatment using such external fluoroscopic imaging can be difficult or impossible, and external fluoroscopic imaging can also require the use of iodinated contrast agents, which must be introduced into the patient being imaged. This fluoroscopic image guidance of instrumentation has drawbacks. For example, the first-pass success rate for such fluoroscopically guided cerebrovascular thrombectomy procedures is low, with one study placing it at only 25.1%. Furthermore, radiation-induced complications for patients from such fluoroscopy can include skin burns and hair loss, which can occur at doses as low as 3 Gy. Furthermore, contrast-related nephropathy has been reported in approximately 20–30% of patients with preexisting renal disease and up to 5% of other low-risk patients. In addition to radiation risks to patients, there are also radiation risks to the operator of the fluoroscopic imaging device. Even with proper shielding and clothing, the radiation risk to the operator is not insignificant, with single cases reported of up to 254 Gy of radiation to the operator's hands and eyes. Furthermore, the dose to the operator is cumulative throughout the operator's career. Furthermore, this indirect visualization using fluoroscopic imaging equipment in difficult anatomical structures can lead to mispositioning of the treatment device, which in the case of cerebrovascular lesions can lead to thromboembolic and hemorrhagic complications for the patient. Summary of the Invention [Means for solving the problem]

[0004] The inventors have recognized an unmet need for devices and methods that can help enable, inter alia, real-time, full-color, diagnostic-quality resolution, direct intravascular visualization of cerebrovascular lesions, which may be located within the intracranial vasculature, such as before, during, or after endovascular treatment of the cerebrovascular lesion. This may enable direct intravascular visualization observation and treatment of cerebrovascular thrombus, e.g., before thrombectomy, such as to enable assessment of thrombus color or composition to guide treatment, during thrombectomy, such as to guide treatment, or after thrombectomy, such as to evaluate results or determine further treatment, which can help improve the efficacy or speed of treatment or help avoid one or more side effects. In another example, the present devices and methods can be useful for enabling endovascular observation and treatment of cerebrovascular aneurysms, such as before aneurysm treatment using a thrombolytic occluder (such as a coil, a thrombus-forming agent, or both), such as to plan or guide such treatment, during aneurysm treatment, such as to help guide the real-time administration or adjustment or adaptation of such treatment, or after aneurysm treatment, such as to help assess the efficacy of the delivered treatment or to guide further planning or treatment.

[0005] Cerebrovascular lesions located within the intracranial vasculature can present a particularly challenging environment due to one or more of the following: small vessel size, tortuous vessel morphology, or time constraints for diagnostic or therapeutic vascular instrumentation or intervention due to the risk of adverse effects on brain tissue due to reduced blood flow or perfusion from the cerebrovascular lesion or an intravascular diagnostic or therapeutic device introduced to diagnose or treat such a cerebrovascular lesion. Certain intravascular imaging techniques, such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT), can exhibit drawbacks in cerebrovascular lesion diagnostic or therapeutic applications, such as a lack of direct visualization and observation or a lack of sufficient miniaturization to be compatible for use within the small and tortuous intracranial vasculature. Other techniques, such as scanning fiber endoscopes (SFEs), can provide direct visualization compared to the indirect imaging of IVUS or OCT, but can be difficult to miniaturize to reach cerebrovascular lesions in intracranial locations, such as beyond the petrous portion of the carotid artery.

[0006] This specification describes a forward-looking fiber optic angioscope that may include an illumination fiber and a coherent fiber bundle (CFB) imaging fiber, such as may be suitable for, among other things, intravascular direct visualization at its tip of cerebrovascular lesions at intracranial locations beyond the petrous portion of the carotid artery in small and tortuous vessels. The angioscope may be used within the working lumen of a sheath catheter, such as for forward viewing and inspection of lesions using the angioscope. The sheath catheter may have an outer diameter of 1.17 mm (3.5 French) to 2.67 mm (8.0 French) and may define an inner diameter of the working lumen of the sheath catheter ranging from 0.99 mm (0.039 inch) to 2.08 mm (0.082 inch), inclusive, such as a nominal or preferred value of approximately 1.78 mm (0.070 inch). This allows both at least a portion of the cerebrovascular lesion treatment catheter and at least a portion of the angioscope to be positioned within the working lumen of the sheath catheter.

[0007] The Sheath Catheter can optionally include a distal balloon near its distal portion, such as retracted from the distal tip of the Sheath Catheter. The distal balloon can be inflated, such as by introducing a fluid into a port at the proximal end of the Sheath Catheter, which can be connected to the balloon via one or more inflation lumens extending from the proximal port to the distal balloon. Inflating the balloon can help stabilize the Sheath Catheter within the vasculature, such as in an intracranial location, such as over the petrous portion of the carotid artery near a cerebrovascular lesion.

[0008] The Sheath Catheter can have a stepped side profile and can extend the working channel a distance beyond the balloon. The dual concentric lumen structure can include an inner body and an outer body defining an inflation lumen therebetween, with one or more portions of one or more layers stretched and / or cut, such as to provide bending flexibility. Reflow techniques can be used to help bond the layers together.

[0009] This Summary is intended to provide an overview of the subject matter of this patent application. It is not intended to provide an exclusive or exhaustive description of the invention. The Detailed Description is included to provide further information regarding this patent application.

[0010] In the drawings, which are not necessarily drawn to scale, like numerals in different views may refer to like components. Like numerals with different letter suffixes may represent different instances of like components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. [Brief explanation of the drawings]

[0011] [Figure 1] 1 shows an example of a portion of a cerebrovascular or other intravascular lesion treatment kit or system. [Figure 2] 1 shows a more detailed example of a portion of a Sheath Catheter including an elongate body having a distal section and a proximal section. [Figure 3] An enlarged view of the "Detail A" area of ​​Figure 2 is shown. [Figure 4] FIG. 1 is a schematic diagram showing an example of a part of a vascular endoscope. [Figure 5A] 1 illustrates an example method of using one or more parts of the system for stent retriever thrombectomy under angioscopic visualization. [Figure 5B] 1 illustrates an example method of using one or more parts of the system for stent retriever thrombectomy under angioscopic visualization. [Figure 5C] 1 illustrates an example method of using one or more parts of the system for stent retriever thrombectomy under angioscopic visualization. [Figure 5D] 1 illustrates an example method of using one or more parts of the system for stent retriever thrombectomy under angioscopic visualization. [Figure 5E]1 illustrates an example method of using one or more parts of the system for stent retriever thrombectomy under angioscopic visualization. [Figure 5F] 1 illustrates an example method of using one or more parts of the system for stent retriever thrombectomy under angioscopic visualization. [Figure 5G] 1 illustrates an example method of using one or more parts of the system for stent retriever thrombectomy under angioscopic visualization. [Figure 5H] 1 illustrates an example method of using one or more parts of the system for stent retriever thrombectomy under angioscopic visualization. [Figure 5I] 1 illustrates an example method of using one or more parts of the system for stent retriever thrombectomy under angioscopic visualization. [Figure 6A] 1 illustrates an example of a method of using one or more parts of the system for aspiration-based thrombectomy under angioscopic observation. [Figure 6B] 1 illustrates an example of a method of using one or more parts of the system for aspiration-based thrombectomy under angioscopic observation. [Figure 6C] 1 illustrates an example of a method of using one or more parts of the system for aspiration-based thrombectomy under angioscopic observation. [Figure 6D] 1 illustrates an example of a method of using one or more parts of the system for aspiration-based thrombectomy under angioscopic observation. [Figure 6E] 1 illustrates an example of a method of using one or more parts of the system for aspiration-based thrombectomy under angioscopic observation. [Figure 6F] 1 illustrates an example of a method of using one or more parts of the system for aspiration-based thrombectomy under angioscopic observation. [Figure 6G] 1 illustrates an example of a method of using one or more parts of the system for aspiration-based thrombectomy under angioscopic observation. [Figure 7]FIG. 2 shows an example of a portion of a cerebrovascular or other endovascular lesion treatment kit or system similar to that shown in FIG. 1, but including an optional cerebrovascular or other endovascular lesion treatment catheter, which may include a thrombolytic occlusion device, such as a coil deployment catheter. [Figure 8A] 1 illustrates an example of a method of using one or more parts of the system for treating aneurysms under angioscopic visualization. [Figure 8B] 1 illustrates an example of a method of using one or more parts of the system for treating aneurysms under angioscopic visualization. [Figure 8C] 1 illustrates an example of a method of using one or more parts of the system for treating aneurysms under angioscopic visualization. [Figure 8D] 1 illustrates an example of a method of using one or more parts of the system for treating aneurysms under angioscopic visualization. [Figure 8E] 1 illustrates an example of a method of using one or more parts of the system for treating aneurysms under angioscopic visualization. [Figure 8F] 1 illustrates an example of a method of using one or more parts of the system for treating aneurysms under angioscopic visualization. [Figure 9A] Based on the description of the figures presented above, various views of portions of an example Sheath Catheter are shown. [Figure 9B] Based on the description of the figures presented above, various views of portions of an example Sheath Catheter are shown. [Figure 9C] Based on the description of the figures presented above, various views of portions of an example Sheath Catheter are shown. [Figure 9D] Based on the description of the figures presented above, various views of portions of an example Sheath Catheter are shown. [Figure 9E] Based on the description of the figures presented above, various views of portions of an example Sheath Catheter are shown. [Figure 9F] Based on the description of the figures presented above, various views of portions of an example Sheath Catheter are shown. [Figure 10A]FIG. 1 is a side view of an example inner body or inner sheath, along with an illustrative example of its layered structure along the length of the elongate body of the Sheath Catheter. [Figure 10B] 1 is a side cross-sectional view of an example inner body or inner sheath, along with an illustrative example of its layered structure along the length of the elongate body of the Sheath Catheter. FIG. [Figure 10C] 10C is a detailed cross-sectional side view taken along line 10C-10C of FIG. 10B showing an example of an inner body or inner sheath, along with an illustrative example of its layered structure along the length of the elongate body of the Sheath Catheter. [Figure 11A] FIG. 1 is a side view of an example outer body or outer sheath, along with an illustrative example of its layered structure along the length of the elongate body of the Sheath Catheter. [Figure 11B] 1 is a side cross-sectional view of an example outer body or outer sheath, along with an illustrative example of its layered structure along the length of the elongate body of the Sheath Catheter. FIG. [Figure 11C] 11C-11C is a detailed cross-sectional side view of an example outer body or outer sheath taken along line 11C-11C of FIG. 11B, showing an illustrative example of its layered structure along the length of the elongate body of the Sheath Catheter. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present devices and methods can be useful for enabling real-time, full-color, diagnostic-quality resolution, intravascular direct visualization of cerebrovascular lesions, such as before, during, or after endovascular treatment of the cerebrovascular lesion. This can enable endovascular observation and treatment of cerebrovascular thrombi, for example, before thrombectomy, such as to enable assessment of thrombus color or composition to guide treatment; during thrombectomy, such as to guide treatment; or after thrombectomy, such as to evaluate results or determine further treatment, which can help improve the efficacy or speed of treatment or avoid one or more side effects. In another example, the present devices and methods can be useful for enabling endovascular observation and treatment of cerebrovascular aneurysms, such as before aneurysm treatment using a thrombolytic occluder (e.g., a coil, a thrombus-forming agent, or both), such as to plan or guide such treatment; during aneurysm treatment, such as to help guide the real-time implementation, adjustment, or adaptation of such treatment; or after aneurysm treatment, such as to help assess the efficacy of the delivered treatment or to guide further planning or treatment. Although one study cites a 25.1% success rate for first-pass attempts of cerebral thrombectomy guided solely by external fluoroscopy, the present system, device, and technique, employing real-time visualization using an angioscope, was used in an animal model study in which 8 out of 8 first-pass thrombectomy attempts were successful, resulting in a 100% success rate for this limited animal model study.

[0013] An angioscope or other instrument can be used with the Sheath Catheter. The Sheath Catheter can optionally include a distal balloon near its distal end, such as retracted from the distal tip of the Sheath Catheter. The distal balloon can be inflated, such as by introducing a fluid into a port at the proximal end of the Sheath Catheter, which can be connected to the balloon via one or more inflation lumens extending from the proximal port to the distal balloon. Inflating the balloon can help stabilize the Sheath Catheter within the vasculature, such as in an intracranial location, such as over the petrous portion of the carotid artery near a cerebrovascular lesion. The Sheath Catheter can have a stepped lateral profile, and the working channel can extend a distance beyond the balloon. The dual concentric lumen structure can include an inner body and an outer body defining an inflation lumen therebetween, and one or more portions of one or more layers can be stretched or cut, or both, to provide bending flexibility, etc. Reflow techniques can be used to help bond the layers together.

[0014] 1 illustrates an example of a portion of a cerebrovascular or other endovascular lesion treatment kit or system 100 that may include a distal access balloon guide sheath catheter or other sheath catheter 102, a microangioscope 104, and an optional cerebrovascular or other endovascular lesion treatment catheter 106. The sheath catheter 102 may include an elongate body that may define an internal working lumen 108 that may extend from a proximal opening at a proximal end or portion of the sheath catheter 106 to a distal opening at a distal end or portion of the sheath catheter 106. As described further herein, the working lumen 108 of the sheath catheter 102 may define an inner diameter that may be sized to allow at least a portion of both the angioscope 104 and the treatment catheter 106 to be positioned together within the internal working lumen 108, which may allow simultaneous visualization using the angioscope 104 and endovascular treatment using the treatment catheter 106. Optionally, one or more other components may also be included in or used with system 100, such as a guidewire that may be used to aid in endovascularly directing the Sheath Catheter 102, the Treatment Catheter 106, or both, to a desired distal location within the body of a human patient or subject, such as to an intravascular location beyond the petrous portion of the subject's carotid artery. The lesion treatment catheter 106 or other devices or materials that may be used or housed within the working lumen 108 of the Sheath Catheter 108 may include, among others, one or more guidewires, a microcatheter, a stent retriever, saline (e.g., as a flushing agent to move opaque blood vessels to allow distal visualization via the angioscope 104), contrast media, aneurysm coils, or any combination thereof. For example, the lesion treatment catheter 106 may include a commercially available stent retriever catheter configured to engage and retrieve a clot at its distal end.Such a stent retriever catheter may include a guidewire lumen that allows the stent retriever catheter 106 to be inserted over the wire (OTW) to a desired location within the vasculature, such as to a thrombus that has been penetrated or crossed by the guidewire through which the stent retriever catheter 106 is introduced.

[0015] Figure 2 shows a more detailed example of a portion of the Sheath Catheter 102, including an elongate body having a distal section 202A and a proximal section 202B. Figure 3 shows an enlarged view of the "Detail A" area of ​​Figure 2. In the example of Figures 2 and 3, the elongate body also defines an internal working lumen 108, which in this example may include a nominal or preferred inner diameter of 1.78 millimeters (0.07 inches) and extends coaxially along the longitudinal axis of the elongate body from the distal end of the distal section 202A to the proximal end of the proximal section 202B. 2, the outer diameter of the elongate body may range from 1.17 millimeters (3.5 French) to 2.67 millimeters (8.0 French), inclusive, at the distal section 202A (e.g., a 2.0 millimeter (6 French) outer diameter), and may be the same or a slightly larger outer diameter (e.g., 2.0 millimeters (6 French) or slightly larger) at the proximal section 202A of the Sheath Catheter 102. The working length of the Sheath Catheter 102 from its proximal end to its distal end may be, in one example, 125 centimeters to 131 centimeters, inclusive.

[0016] The distal section 202A of the Sheath Catheter 102 can include an inflatable distal balloon 204 that can extend circumferentially around the elongate body of the distal section 202A of the Sheath Catheter 102. The balloon 204 can be attached to the elongate body of the distal section 202A, such as by a proximal cuff 206A at its proximal end and a distal cuff 206B at its distal end. In one example, the balloon cuffs 206A and 206B can be separated from each other by the working length of the balloon 204, such as a 10 millimeter working length. The cuffs 206A and 206B can be reinforced by being made from or including a metal or other radiopaque material that can assist or enhance fluoroscopy or other x-ray observation, as well as one or more other radiopaque markers at one or more other designated locations along the length of the Sheath Catheter 102, such as the distal tip of the Sheath Catheter 102.

[0017] When uninflated, the balloon 204 can be substantially flush with the outer diameter (e.g., 2 mm) of the distal portion 202A of the Sheath Catheter 102, but when inflated, can expand to a larger outer diameter, such as approximately 6 millimeters in the example shown in FIG. 2. When inflated, the balloon 204 can stabilize the distal portion 202A of the Sheath Catheter 102 at a desired location within the cerebral vasculature, such as an intracranial location beyond the petrous portion of the carotid artery. The balloon 204 can be made from a highly compliant material, such as polyurethane, to allow for rapid inflation and deflation, which can be useful for shortening or minimizing procedure time because occlusion of the balloon 204 in a blood vessel when inflated can impede blood flow through the vessel during such time, thereby temporarily reducing blood perfusion to areas of brain tissue that would normally be perfused by the unoccluded vessel unless the vessel was already completely occluded by a blood clot.

[0018] An annular or other dedicated inflation lumen 208 (which may be separate and distinct from the working lumen 108, for example) may extend from a proximal inflation port at the proximal end or portion 202B of the Sheath Catheter 102, such as via one or more inflation ports 300 ( FIG. 3 ) in the proximal cuff 206A, to a distal inflation port that leads into and allows fluid communication with the interior region of the balloon 204. In this manner, such as from the proximal port location, saline, contrast, or another liquid fluid (e.g., a 50 / 50 or other mixture of saline and liquid radiographic contrast) may be pumped or otherwise introduced into the balloon 204 under positive pressure, such as to inflate the balloon 204. One or more air purge vents or one-way valves may be provided in the distal cuff 206B of the balloon 204, the proximal cuff 206A of the balloon 204, or both, to expel air previously in the inflation lumen 207 or the balloon 204 when inflation fluid is introduced into the inflation lumen 208 at the proximal inflation port at the proximal end of the Sheath Catheter 102.

[0019] Similarly, the balloon 204 can be deflated by fluid exiting the proximal inflation port, such as under negative pressure or passively. The inflation lumen 208 can include one or more fluidly communicable passages in the elongate body of the Sheath Catheter 102, such as concentric ring cross-sectional passages that are coaxial with the working lumen 108 of the Sheath Catheter 102 and distal to the central longitudinal axis of the Sheath Catheter 102.

[0020] The inflation lumen 208 can be disposed between an outer sheath 210 portion of the elongate body of the Sheath Catheter 102 and an inner sheath 212 portion of the elongate body of the Sheath Catheter 102. The outer sheath 210 can extend from a proximal end of the proximal section 202B of the Sheath Catheter 102, for example, to the proximal cuff 206A, and to the proximal end of the balloon 204. The inner sheath 212 can extend from a proximal end of the proximal section 202B of the Sheath Catheter 102 to a distal end of the distal section of the Sheath Catheter 102. In one example, the outer sheath 210 can have an outer diameter of about 2.33 millimeters (about 7 French) and an inner diameter of about 2.26 millimeters (about 0.089 inches), and the inner sheath 212 can have an outer diameter of about 2.0 millimeters (e.g., about 6 French) and an inner diameter of about 1.78 millimeters (about 0.07 inches).

[0021] In one example, the inner sheath 212, the outer sheath 210, or both, can comprise a polymeric material (e.g., silicone or polyurethane) that can be reinforced with a stiffening material embedded therein, such as a metal or nylon braid or coil, or a combination thereof. Variations in stiffness of the inner sheath 212, the outer sheath 210, or both along the length of the Sheath Catheter 102 can be provided by varying the properties of the stiffening material along the length of the Sheath Catheter 102, such as by varying the inter-coil spacing between adjacent coils or the inter-braid spacing between adjacent braids. This can be used to provide greater flexibility at its distal end, as may be necessary for twisting through tortuous vessels, particularly small and tortuous in cerebrovascular intracranial locations beyond the petrous portion of the carotid artery, while providing greater stiffness toward the proximal end or portion 202B of the Sheath Catheter 102 compared to, for example, stiffness at the more distal end or portion 202A of the Sheath Catheter 102, which can aid in torqueing an intravascular device at or near its proximal end. Variable hardness or durometer of the outer sheath 210 can similarly be provided, such as by using different materials or constructions in different zones along the length of the Sheath Catheter 102 .

[0022] The distal end of the balloon 204 can include an atraumatic distal segment. In one example, this distal segment can include a soft distal tip, have an outer diameter of about 2.0 millimeters (about 6 French), and be 4 millimeters to 10 millimeters in length.

[0023] In one example, the stiffness of the Sheath Catheter, including the stiffness of its working lumen 108 extending from its proximal end to and through the atraumatic distal segment, is specified as sufficient to enable aspiration-based thrombectomy by applying aspiration (e.g., up to 300 psi) through the working lumen 108, such as by using a Direct Aspiration First Pass Technique (ADAPT) without distortion or rupture. This can include building up aspiration using an external vacuum / aspiration pump, such as by closing a valve between the external vacuum pump and the working lumen 108 to build up aspiration. The valve can also be opened, such as by creating a sudden suction force within the working lumen 108. Such a sudden suction force can cause clots located within the blood vessel and distal to the distal opening of the working lumen to be aspirated into (or plugged against) the distal opening of the working lumen 108. The clot can be removed by suction through the working lumen 108 and out the proximal end of the working lumen 108, or the clot can be removed by withdrawing the Sheath Catheter 102 from the vasculature while the clot is located within the working lumen 108 or plugging the distal opening of the working lumen 108, such as with suction still being applied during withdrawal of the Sheath Catheter 102 from the vasculature.

[0024] The outer sheath 210 may be provided with a biocompatible hydrophilic or lubricious material or coating, such as along its entire length or along a designated portion thereof (e.g., a distal portion), to help such portion of the Sheath Catheter 102 slide more easily to a desired location within the vasculature. Similarly, the inner working lumen 108 of the Sheath Catheter may be made lubricious, such as by appropriate selection of material or coating of the inner sheath 212, such as by providing a Teflon® or other polytetrafluoroethylene or other liner inside the inner sheath 212 along the wall of the working lumen 108 along all or a designated portion of the length of the inner sheath 212. This may help make it easier for the angioscope 104, cerebrovascular lesion treatment catheter 106, or one or more other instruments to be introduced into and slide within the working lumen 108 of the Sheath Catheter 102.

[0025] FIG. 4 is a schematic diagram illustrating an example of a portion of an angioscope 104. In the example of FIG. 4, the angioscope 104 can include a forward-looking fiber optic angioscope 104. The angioscope 104 can include one or more illumination fibers 402, such as in an annular bundle, that can concentrically surround a coherent fiber bundle (CFB) of imaging optical fibers 404, which can be centered along the longitudinal axis of the angioscope 104, such as behind a GRIN or other lens 406 located at the distal end of the angioscope 104. A polymer jacket 405 can concentrically surround and encapsulate the imaging optical fibers 404 and the lens 406, such as by being concentrically positioned between the imaging optical fibers 404 and the illumination fiber 402. The illumination fiber 402 can be configured to transmit light from an external light source that can be optically coupled to the proximal end of the angioscope 104 to the distal end of the angioscope 104. The light projected on the distal end can be used to illuminate forward into the vasculature into which the distal end of the angioscope 104 is inserted, or to illuminate forward within the working lumen 108 of the sheath catheter 102, or both, such as to enhance observation using the imaging optical fiber 404.

[0026] The coherent fiber bundle of imaging optical fibers 404 can extend between the proximal and distal portions of the angioscope 104, in one example, allowing the angioscope to have a working length of approximately 160 centimeters. In one example, the individual fibers of the imaging fibers 404 can have an outer diameter of approximately 2.5 micrometers. The group of imaging fibers 404 can include, for example, 3,000 imaging fibers, each of which provides a "pixel" observable proximally to the distal forward-looking imaging fiber 404 at the proximal end of the angioscope. The imaging fibers 404 can include a common cladding, which can be disposed between the individual fibers of the imaging fibers 404 or shared between the fibers. The illumination fiber 402 can include a claddingless arrangement of illumination fibers 404, which can be arranged in a circular, concentric configuration around the imaging fiber 404. In one example, the individual fibers of the illumination fiber 404 can have an outer diameter of 25 micrometers to 50 micrometers. In one example, the GRIN or other lens 406 can have a diameter of 250 millimeters or less and an axial length of 500 micrometers ±100 micrometers.

[0027] The GRIN or other lens 406 can include or be coated with an optically transparent (e.g., at the illumination and imaging wavelengths of the angioscope 104), anti-clotting or anti-coagulant material, such as a heparin-based coating. An outer sheath 408 made of silicone, polyurethane, or other polymer (e.g., Pebax® elastomer) can circumferentially surround an optics lumen (e.g., approximately 4.19 millimeters (0.0165 inches) in diameter) that supports the illumination fiber 404, lens 406, and imaging fiber 404. Such outer sheath 408 can provide an internal lumen that can optionally be coated with a hydrophilic or lubricious material, such as Teflon®, to, for example, allow easier insertion of optical components into such internal lumen. The outer sheath 408 can include different materials in different longitudinal zones, such as to provide greater flexibility in one or more distal regions (e.g., using 35D Pebax® elastomer material in such distal zones) than in one or more proximal regions (e.g., using 45D to 55D Pebax® elastomer material in such proximal zones with a proximal zone length of approximately 75 centimeters) or in one or more intermediate regions (e.g., using 45D Pebax® elastomer material in such intermediate regions).

[0028] The outer sheath 408 can optionally include an embedded microcoil stiffener structure to provide additional stiffness, such as by including an increasing coil pitch between the coils toward the distal end of the angioscope 104. This can help provide greater flexibility toward the distal portion of the angioscope 104 than more proximal regions, which can provide greater stiffness, pushability, trackability, and kink resistance. The stiffening coil can be omitted entirely at the distal end of the angioscope 104, leaving a softer, more flexible, and more atraumatic distal zone approximately 10 to 30 millimeters long that is useful for treating cerebrovascular lesions in deep and tortuous vascular locations within a subject's skull, including beyond the petrous portion of the carotid artery.

[0029] 4, the outer diameter of the angioscope 104 may be approximately 0.57 millimeters (approximately 1.7 French) at its soft, atraumatic distal end and approximately 0.80 micrometers (approximately 2.4 French) at the proximal end of the angioscope 104. The forward-looking fiber optic angioscope shown in FIG. 4 may be sized and shaped to be inserted into the working lumen 108 of the Sheath Catheter 102 from the proximal end of the Sheath Catheter 102, such as to (optionally) allow the distal portion of the angioscope 104 to extend beyond the distal opening of the working lumen 108 of the Sheath Catheter 102, such as to allow the angioscope 104 to be used to view and inspect cerebrovascular lesions from the front.

[0030] Figures 5A, 5B, 5C, 5D, 5E, 5F, 5G, and 51 show an example of how one or more portions of system 100 can be used for stent retriever thrombectomy under observation by an angioscope 104, such as to help provide better results than would otherwise be achieved if the stent retriever thrombectomy were performed under fluoroscopy alone, without the benefit or additional benefit of enabling simultaneous forward-looking intravascular observation using angioscope 104.

[0031] 5A , the distal end of the Sheath Catheter 102 has been introduced into the vasculature and advanced toward, but just short of, a cerebrovascular lesion (e.g., thrombus 502) at an intracranial location within the artery 504, such as beyond the petrous portion of the carotid artery. External fluoroscopic x-ray guidance can be used to guide this introduction of the Sheath Catheter 102, and the Sheath Catheter 102 can include one or more radiographically visible markers. Optionally, a guidewire can be first inserted into the artery 504, and the Sheath Catheter 102 can be inserted over-the-wire, such as by positioning the guidewire within the working lumen 108 of the Sheath Catheter 102 and steering it toward the thrombus 502 during introduction of the Sheath Catheter 102 into the artery 504. The balloon 204 can then be inflated, such as to stabilize the distal end of the Sheath Catheter 102 at a desired location within the artery 504, just short of the thrombus 502. The guidewire, if present, can then be withdrawn through the proximal opening of the working lumen 108 of the Sheath Catheter 102 .

[0032] 5B illustrates an example of a next or subsequent step, in which the distal end of the angioscope 104 may be inserted into the proximal opening of the working lumen 108 of the Sheath Catheter 102 and advanced toward the thrombus 502, such as by pushing the proximal portion of the angioscope 104. The distal end of the angioscope 104 may optionally be advanced beyond the distal opening of the working lumen 108 of the Sheath Catheter 102 for a forward view of the thrombus 502, or alternatively, optionally, such a forward view of the thrombus 502 may be performed while the distal end of the angioscope 104 remains slightly retracted within the working lumen 108 of the Sheath Catheter 102. Intravascular viewing of the thrombus 502 may be aided by gently introducing a clear saline flush through the working lumen of the Sheath Catheter 102 into the vasculature beyond the inflated balloon 204. This allows for the gradual flushing of more visually opaque red blood cells from the area between the tip of the angioscope 104 and the thrombus 502, allowing for a clearer visual assessment of the thrombus 502 using the angioscope 104.

[0033] Intravascular visual assessment of the thrombus 502 can be used to provide guidance for planning a method of treatment. The visualized color of the thrombus 502 can provide an indication of its composition and can be used to determine whether to place a stent within the vasculature, leaving the thrombus 502 in place, or to remove the thrombus 502 from the vasculature using a retriever stent or other technique.

[0034] 5C shows an example of a next or subsequent step, in which a guidewire 506 can be inserted through the proximal opening of the working lumen 108 of the Sheath Catheter 102. The distal end of the guidewire 506 can be advanced through the working lumen 108 of the Sheath Catheter 102, out the distal opening of the working lumen 108 of the Sheath Catheter 102, toward, into, or through the thrombus 502. During this step, a portion of the angioscope 104 can remain within the working lumen 108 of the Sheath Catheter 102, such as to allow for simultaneous observation of the insertion of the guidewire 506, such as from a position within the working lumen 108 of the Sheath Catheter 102 or from a position beyond the distal opening of the working lumen 108 of the Sheath Catheter 102.

[0035] 5D illustrates an example of a next or subsequent step, in which a cerebrovascular lesion treatment catheter, such as a stent retriever catheter 508, can be inserted through the proximal opening of the working lumen 108 of the sheath catheter 102. The distal portion of the stent retriever catheter 508 can be advanced over the guidewire 506, such as toward, into, or through the thrombus 502. At least the distal portion of the stent retriever catheter 508 can be retractable or include a retractable sheath such that it can be retracted from an external position through the proximal portion of the stent retriever catheter 508 to deploy a self-expanding stent retriever 510 or other similar thrombus engagement and retrieval device, such as after withdrawing the guidewire 506 from the stent retriever catheter 508 and replacing the withdrawn guidewire 506 with a stent retriever 510 inserted within the stent retriever catheter 508. The angioscope 104 may be left in place, such as with its tip positioned just outside the thrombus 502, to allow for observation of the thrombus during this portion of the procedure.

[0036] 5E shows an example of a next or subsequent step, in which the guidewire 506 can be retracted through and out of the working lumen 108 of the sheath catheter 102. A stent retriever 510 can then be inserted, such as through the working lumen of the stent retriever catheter 508. The stent portion of the stent retriever 510 can then self-expand outward to engage the thrombus 502. The expanded stent retriever 510 can then remain expanded for a period of time (e.g., 5 minutes) to penetrate into the thrombus 502. The angioscope 104 can be left in place, such as with its tip positioned just outside the thrombus 502, to allow observation of the thrombus during this portion of the procedure. The stent retriever catheter 508 and stent retriever 510 can then be retracted, such as with the expanded stent portion of the stent retriever 510 still in place engaging the snared thrombus 502. Again, the angioscope 104 may be left in place, such as with its tip positioned just short of the thrombus 502, to allow for observation of the thrombus during this portion of the procedure.

[0037] 5F shows an example of a next or subsequent step, in which the stent retriever catheter 508 and its distal stent retriever 510, along with the snared thrombus 502, can be retracted through and out of the working lumen 108 of the Sheath Catheter 102. Simultaneously or prior to this, the angioscope 104 can also be retracted through and out of the working lumen 108 of the Sheath Catheter 102, such as to allow observation of the snared thrombus 502 as it is withdrawn through the working lumen 108 of the Sheath Catheter.

[0038] 5G illustrates an example of a next or subsequent step, in which, optionally, the angioscope 104 can be reinserted into the proximal opening of the working lumen 108 of the Sheath Catheter 102. Optionally, the distal portion of the angioscope can be re-advanced toward or beyond the distal opening of the working lumen 108 of the Sheath Catheter 102, such as to allow endovascular observation of the vessel cleared of thrombus or the like from within or beyond the working lumen 108 of the Sheath Catheter 102. Such observation can help the physician determine whether any remnants of thrombus remain or whether any more distal emboli or other cerebrovascular lesions can be observed, which can further help determine the efficacy of the treatment or any need or strategy for further treatment. Such further treatment can include repeating the process of retrieving the thrombus using a stent retriever as described herein or using aspiration or another treatment technique for such further treatment. In experimental animal model studies, such post-treatment examination with angioscope 104 revealed no embolic remnants, which were therefore retrieved intravascularly via the working lumen 108 of the sheath catheter 102.

[0039] 5H shows an example of a next or subsequent step, in which, if the vessel is free of thrombus, the angioscope 104 can be retracted and removed from the body via the working lumen 108 of the Sheath Catheter 102. The balloon 204 can then be deflated, such as via the inflation lumen 208 of the Sheath Catheter 102. If thrombus 502 or portions thereof remain, further treatment can be applied as described with respect to FIG. 5G and elsewhere herein.

[0040] FIG. 5I illustrates an example of a desirable outcome, such as after various therapeutic devices have been removed from the lumen of a blood vessel, with reperfusion achieved through the artery from which a thrombus or the like has been removed. As described herein, performing one or more steps of such a procedure while allowing for intravascular observation, e.g., with an angioscope 104, in addition to fluoroscopic observation, can help improve the efficacy of the treatment, shorten the treatment time, or both. It can also help reduce or eliminate the time required for fluoroscopic observation, thereby reducing or minimizing radiation dose exposure to the patient, operator, or both. In particular, the ability to observe in real time when using an angioscope 104 allows the user to make real-time adjustments in the therapy being delivered. For example, if a user observes that the stent retriever 510 and its engaged clot 502 being retrieved are moving at different speeds as the stent retriever catheter 508 is being withdrawn toward or into the working lumen 108 of the Sheath Catheter 102, as viewed intravascularly via the angioscope 104, the user can infer that the stent retriever 510 is letting go of the clot 502 being retrieved, and the user can react to this visual feedback by pulling more gently on the proximal end of the stent retriever catheter 508, or by allowing the clot 502 to "snap" into engagement with the stent retriever 510 slightly longer before resuming pushing on the proximal end of the stent retriever catheter 508, or by otherwise manipulating or adjusting the stent retriever 510 to better engage the clot 502 being drawn by the stent retriever 510 toward or into the working lumen 108 of the Sheath Catheter 102. Such real-time visual feedback from the angioscope 104 can help improve the efficacy of such critical clot removal procedures.

[0041] 6A, 6B, 6C, 6D, 6E, 6F, and 6G illustrate an example of a method of using one or more portions of system 100 for aspiration-based thrombectomy under observation by an angioscope 104, such as to help provide better results than would otherwise be achieved if aspiration-based thrombectomy were performed under fluoroscopy alone, without the benefit or additional benefit of enabling simultaneous forward-looking endovascular observation using angioscope 104.

[0042] In the example of FIG. 6A , the distal end of the Sheath Catheter 102 has been introduced into the vasculature and advanced toward, but just short of, a cerebrovascular lesion (e.g., thrombus 502) at an intracranial location within the artery 504, such as beyond the petrous portion of the carotid artery. External fluoroscopic x-ray guidance can be used to guide this introduction of the Sheath Catheter 102, and the Sheath Catheter 102 can include one or more radiographically visible markers. Optionally, a guidewire can be first inserted into the artery 504, and the Sheath Catheter 102 can be inserted over-the-wire, such as by positioning the guidewire within the working lumen 108 of the Sheath Catheter 102 and steering it toward the thrombus 502 during introduction of the Sheath Catheter 102 into the artery 504. The balloon 204 can then be inflated, such as to stabilize the distal end of the Sheath Catheter 102 at a desired location within the artery 504, just short of the thrombus 502. The guidewire, if present, can then be withdrawn through the proximal opening of the working lumen 108 of the Sheath Catheter 102 .

[0043] 6B illustrates an example of a next or subsequent step, in which the distal end of the angioscope 104 may be inserted into the proximal opening of the working lumen 108 of the Sheath Catheter 102 and advanced toward the thrombus 502, such as by pushing the proximal portion of the angioscope 104. The distal end of the angioscope 104 may optionally be advanced beyond the distal opening of the working lumen 108 of the Sheath Catheter 102 for a forward view of the thrombus 502, or alternatively, optionally, such a forward view of the thrombus 502 may be performed while the distal end of the angioscope 104 remains slightly retracted within the working lumen 108 of the Sheath Catheter 102. Intravascular viewing of the thrombus 502 may be aided by gently introducing a clear saline flush through the working lumen of the Sheath Catheter 102 into the vasculature beyond the inflated balloon 204. This allows for the gradual flushing of more visually opaque red blood cells from the area between the tip of the angioscope 104 and the thrombus 502, allowing for a clearer visual assessment of the thrombus 502 using the angioscope 104.

[0044] Intravascular visual assessment of the thrombus 502 can be used to provide guidance for planning a method of treatment. The visualized color of the thrombus 502 can provide an indication of its composition and can be used to determine whether to place a stent within the vasculature, leaving the thrombus 502 in place, or to remove the thrombus 502 from the vasculature using a retriever stent or other technique.

[0045] 6C illustrates an example of a next or subsequent step, in which the angioscope 104 is slightly retracted so that its distal end is positioned within the working lumen 108 of the Sheath Catheter 102. The proximal end of the working lumen 108 of the Sheath Catheter can then be connected to an external suction source, such as a vacuum pump or another suction source, such as a syringe with a plunger that can be retracted to apply a vacuum, such as through a two-way or three-way valve or another valve. The valve can initially remain closed when the suction pump or other suction source is turned on or otherwise activated, such as to isolate the working lumen 108 from suction being built up by the suction pump on the other side of the valve. Once the operator or other person determines that sufficient suction has built up, the valve can be quickly opened, such as to apply suction to the working lumen 108 of the Sheath Catheter, thereby drawing the thrombus 502 toward, against, or into the working lumen 108 of the Sheath Catheter 102.

[0046] The larger inner diameter of the working lumen 108 can facilitate very rapid aspirating of the clot, especially if the clot is smaller than the inner diameter of the working lumen 108. When this is combined with a jerk technique (e.g., allowing a vacuum pump or other suction source to build up pressure before flipping an actuation switch to open a valve to apply vacuum to the working lumen 108), a scraping effect is created. The addition of the balloon 204 focuses the entire pressure on the clot, rather than simply applying suction to blood near the distal tip of the catheter 102, which flows toward the clot and then into the working lumen 108 of the catheter 102. These elements combine to help create balloon scraping, which can help provide optimal conditions for completely aspirating the clot rather than spiraling it, which is also much safer for the patient. The focused pressure draws blood from the distal region rather than the proximal region, which can help inhibit or prevent emboli from flowing distally.

[0047] By simultaneously viewing in real time through a slightly retracted angioscope 104, the user can observe the thrombus 502, and the user can see whether the thrombus 502 is being sucked into the working lumen 108 of the Sheath Catheter 102 under suction (provided by a suction pump, syringe, or other suction source) or alternatively, simply being sucked and "plugged" against the distal end of the working lumen 108 of the Sheath Catheter 102. In the latter case, suction can be maintained within the working lumen 108 of the Sheath Catheter (e.g., using a pump, syringe, or other suction source) to maintain the thrombus plugged against the distal end of the working lumen 108 of the Sheath Catheter 102. The balloon 204 can be deflated under suction, and the sheath catheter 102 and angioscope 104 can be withdrawn together with the embolized thrombus 502 while maintaining suction within the working lumen 108 of the sheath catheter 102 (e.g., using a pump, syringe, or other suction source) so as to hold the embolized thrombus 502 against the distal end of the working lumen 108 of the sheath catheter 102.

[0048] 6D illustrates an example of a next or subsequent step where a thrombus 502 has been aspirated into the working lumen 108 of the Sheath Catheter 102 so that it can be viewed intravascularly in real time by viewing through the angioscope 104. In some cases, it may be possible to use the angioscope 104 to view the thrombus 502 being aspirated into the working lumen 108 of the Sheath Catheter 102 and to view the thrombus 502 being aspirated beyond the angioscope to a more proximal location within the working lumen 108 of the Sheath Catheter 102.

[0049] 6E illustrates an example of a next or subsequent step in which the thrombus 502 has been completely removed from the body and from the working lumen 108 of the Sheath Catheter 102, and the aspiration pump has been disconnected from the working lumen 108 of the Sheath Catheter. As shown in the example of FIG. 6E, the angioscope 104 can be used to view the location of the vessel, such as to inspect for thrombus remnants or distal emboli. This can include extending the distal tip of the angioscope beyond the distal opening of the working lumen 108 of the Sheath Catheter 102, if desired. Optionally, a clear saline flush can be delivered through the working lumen 108 of the Sheath Catheter 102 to help improve visual observation by flushing red blood cells from the field of view of the angioscope 108.

[0050] 6F shows an example of a next or subsequent step, in which the blood vessel has been cleared of thrombus or other emboli. (If thrombus remains or other emboli are observed, aspiration or another thrombectomy procedure can be repeated.) The angioscope 108 can then be removed from the body via the working lumen 108 of the sheath catheter 102, such as by pulling on the proximal end of the angioscope 104 to retract the angioscope 104. The balloon 204 can then be deflated. The sheath catheter 102 can then be removed from the body, such as by pulling on the proximal end of the sheath catheter 102 to retract the sheath catheter 102.

[0051] 6G shows an example of a desired result, such as after various treatment devices have been removed from the lumen of a blood vessel, and reperfusion is achieved through the artery from which a thrombus or the like has been removed. As described herein, performing one or more steps of such a procedure while allowing for intravascular observation, for example, with an angioscope 104, in addition to fluoroscopic observation, can help improve the efficacy of the treatment, shorten the treatment time, or both. It can also help reduce or eliminate the time required for fluoroscopic observation, thereby reducing or minimizing radiation dose exposure to the patient, operator, or both.

[0052] While Figures 6A-6G highlight an aspiration-based thrombus removal procedure through the working lumen 108 of the sheath catheter 104, such an aspiration-based technique can be combined with a stent retriever thrombus removal technique as described with respect to Figures 5A-5I, or a separate aspiration catheter can be inserted through the working lumen 108 of the sheath catheter 104 (similar to the insertion of a stent retriever as described with respect to Figures 5A-5I), and the thrombus can be aspirated through the working lumen of such a separate aspiration catheter.

[0053] FIG. 7 illustrates an example of a portion of a cerebrovascular or other endovascular lesion treatment kit or system 100 similar to that shown in FIG. 1, but including an optional cerebrovascular or other endovascular lesion treatment catheter 106 that may include a thrombolytic occlusion device, such as a coil deployment catheter 710, that may be used to treat an aneurysm, such as by deploying an aneurysm coil to promote thrombus formation and occlusion within the aneurysm.

[0054] 8A, 8B, 8C, 8D, 8E, and 8F illustrate an example of a method of using one or more portions of system 100 for aneurysm treatment via occlusion under observation by an angioscope 104, such as to help provide better results than would otherwise be achieved if aspiration-based aneurysm occlusion treatment were performed under fluoroscopy alone, without the benefit or additional benefit of allowing simultaneous forward-looking endovascular observation using angioscope 104.

[0055] In the example of FIG. 8A , the distal end of the Sheath Catheter 102 has been introduced into the vasculature and advanced toward, but just short of, a cerebrovascular lesion (e.g., the basilar artery tip or other aneurysm 802) at an intracranial location within the artery 804, such as beyond the petrous portion of the carotid artery. External fluoroscopic x-ray guidance can be used to guide this introduction of the Sheath Catheter 102, and the Sheath Catheter 102 can include one or more radiographically visible markers. Optionally, a guidewire can be first inserted into the artery 504, and the Sheath Catheter 102 can be inserted over-the-wire, such as by positioning the guidewire within the working lumen 108 of the Sheath Catheter 102 and steering it toward the aneurysm 802 during introduction of the Sheath Catheter 102 into the artery 504. The balloon 204 can then be inflated, such as to stabilize the distal end of the Sheath Catheter 102 at a desired location within the artery 804, just short of the aneurysm 802. The guidewire, if present, can then be withdrawn through the proximal opening of the working lumen 108 of the Sheath Catheter 102 .

[0056] 8B illustrates an example of a next or subsequent step, in which the distal end of the angioscope 104 may be inserted into the proximal opening of the working lumen 108 of the Sheath Catheter 102 and advanced toward the aneurysm 802, such as by pushing the proximal portion of the angioscope 104. The distal end of the angioscope 104 may optionally be advanced beyond the distal opening of the working lumen 108 of the Sheath Catheter 102, such as for a forward view of the aneurysm 802, or alternatively, such a forward view of the aneurysm 802 may optionally be performed while the distal end of the angioscope 104 remains slightly retracted within the working lumen 108 of the Sheath Catheter 102. Intravascular viewing of the aneurysm 802 may be aided by gently introducing a clear saline flush through the working lumen of the Sheath Catheter 102 into the vasculature beyond the inflated balloon 204. This allows for the gradual flushing of more visually opaque red blood cells from the area between the tip of the angioscope 104 and the aneurysm 802, allowing for a clearer visual assessment of the aneurysm 802 using the angioscope 104.

[0057] Intravascular visual assessment of the aneurysm 802 can be used to provide guidance for planning a method of treatment. The visualized color or other characteristics of the aneurysm 802 can help determine the optimal method for reinforcing the aneurysm 802 to help prevent rupture of the aneurysm 802, for example, whether to insert aneurysm coils, liquid embolic material, or both to treat the aneurysm 802.

[0058] 8C illustrates an example of a next or subsequent step, in which a cerebrovascular lesion treatment catheter 110, such as an aneurysm coil deployment catheter 710, can be inserted through the proximal opening of the working lumen 108 of the sheath catheter 102. The distal portion of the coil deployment catheter 710 can be advanced (e.g., over a guidewire or otherwise) toward or into the aneurysm 802. At least the distal portion of the coil deployment catheter 108 can deliver one or more aneurysm coils to occlude the aneurysm 802, promote thrombus formation therein to enhance its structural integrity, help prevent its rupture, etc. The angioscope 104 can be left in place, such as with its distal portion positioned just outside the aneurysm 802 or extending within the aneurysm 802, to allow observation of the aneurysm 802 during this portion of the procedure.

[0059] 8D shows an example of a next or subsequent step, in which a cerebrovascular lesion treatment catheter 110, such as a coil deployment catheter 710, can be used to inject a thrombolytic agent or structure (such as one or more aneurysm coils, e.g., coil pack 808) that can be inserted through the working lumen of the coil deployment catheter 710. The angioscope 104 can be left in place, such as with its distal end positioned within or just short of the aneurysm 802, to allow observation of the aneurysm 802 during this portion of the procedure. In this manner, real-time visualization information can be provided to the user that can help the user determine whether and when coil introduction into the aneurysm 802 is sufficient, whether the coil packing is dispersed as desired within the aneurysm 802, etc.

[0060] 8E illustrates an example of a next or subsequent step in which the cerebrovascular lesion treatment catheter 110, such as the coil deployment catheter 710, can be removed while the angioscope 802 can optionally be temporarily left in place, such as to allow a user to optionally visually assess the treated aneurysm 802 or one or more nearby intravascular anatomical regions of interest. Such post-treatment intravascular visualization can be used to help determine whether the aneurysm 802 has been adequately packed with the coil 808 so that the coil 808 does not protrude outward from the aneurysm 802 into the main vessel, which could increase the risk of blood clot or thrombus formation within the main vessel. If the coil 808 does so, the distal end of the angioscope 104 can optionally be used to push such protruding portion of the coil 808 back into the aneurysm 802, such as to help reduce or avoid such risk.

[0061] 8F shows an example of a next or subsequent step, in which the balloon 204 can be deflated and the Sheath Catheter 102 and angioscope 104 can be removed together by retracting the instruments or pulling on their proximal portions. Alternatively, the angioscope 104 can be removed first, then the balloon can be deflated and the Sheath Catheter 102 can be removed.

[0062] 4 (including its small distal diameter dimensions and selected materials and their stiffness or other characteristics) can provide a bend radius at the distal portion of the angioscope 104 of 5 millimeters or less, which exceeds the capabilities of coronary or peripheral angioscopes, which have bend radii of 25 millimeters or more due to the use of thicker or stiffer polyamide sheaths. Providing the angioscope 104 with a bend radius of 5 millimeters or less enables access to other tortuous intracranial locations beyond the middle cerebral artery (MCA) or petrous portion of the carotid artery using the angioscope 104, such as to perform thrombectomy, aneurysm repair, or other cerebrovascular lesion treatment techniques described herein. In contrast, by using Pebax® or similar covering material on the outer sheath 408 of the angioscope 104, along with reinforcing coils or braids at one or more designated locations along the length of the angioscope 104, the angioscope 104 can be configured to provide sufficient distal flexibility and proximal stiffness, including sufficiently small diameters and bend radii, to permit use in the middle cerebral artery (MCA) or other intracranial locations beyond the petrous portion of the coronary arteries, including highly tortuous cerebrovascular locations and very small cerebrovascular lesions, such as within the basilar artery tip or other aneurysms, as described herein.

[0063] In the example described above with reference to FIG. 4 , the distal flexibility and maneuverability of the angioscope 104 may be limited primarily by the stiffness associated with the GRIN or other lens 406, which requires only an axial length of approximately 0.5 millimeters. In contrast, other imaging techniques, such as scanning fiber optic endoscopy (SFE), intravascular ultrasound (IVUS), optical coherence tomography (OCT), and complementary metal oxide semiconductor (CMOS) imaging, require longer stiff segments, limiting the usefulness of these techniques for cerebrovascular diagnosis or treatment, such as in intracranial locations beyond the petrous portion of the carotid artery. For example, SFE techniques have been reported to include stiff segments longer than 1.5 millimeters, which have difficulty bending around intravascular regions of the cerebrovascular system, such as the curves from the ophthalmic arch (C6) or petrous portion (C2). CMOS, IVUS, and OCT typically have stiff segments of 1 mm, which have difficulty bending around the ophthalmic arch (C6). In contrast, in the example of this approach as described with respect to Figure 4, by using an angioscope 104 having only a 0.5 mm long rigid segment, the distal portion of the angioscope 104 can be safely navigated through all of these intravascular portions of the brain without causing injury to the patient. This is very useful for enabling such constrained brain vascular diagnostics and imaging to extend beyond the constraints imposed in intravascular diagnostics or imaging in other parts of the human body.

[0064] Furthermore, peripheral or coronary angioscopes typically have an outer diameter of 1.67 millimeters (5 French) to 2.33 millimeters (7 French), which is too large for use in many neurovascular settings where thrombectomy, aneurysm repair, or other interventional treatment of cerebrovascular lesions is desired. Existing angioscopes also have very limited resolution, limiting their usefulness in the present intracranial applications where it is necessary to provide real-time, full-color visualization of cerebrovascular lesions, such as for intravascular assessment of their characteristics or composition or their treatment in real time, so that treatment can be modified or adjusted, such as to help improve the efficacy of the treatment. In contrast, the present angioscope 104 can be configured with imaging fiber bundles, lenses, and other features that can provide a very small outer diameter angioscope 104 (e.g., approximately 0.57 millimeters (1.7 French) at its tip) while still providing the user with adequate visual image resolution support for the cerebrovascular diagnostic and treatment techniques described herein. The size and flexibility of the present angioscope 104 are important not only to enable visualization of small and tortuous intracranial vascular regions, but also to its usefulness within the workflow described herein, in which the angioscope 104 can be inserted and at least partially positioned within the working lumen 108 of the Sheath Catheter 102, while another instrument, such as a coronary lesion treatment catheter 110, can also be inserted and at least partially positioned within the same working lumen 108 of the Sheath Catheter 102. This can help enable simultaneous real-time visualization and treatment, which can further help the user adjust the treatment and improve efficacy. If the angioscope is oversized, the physician or other user must insert it, view the lesion or vessel, then fully withdraw the oversized angioscope, then perform the treatment blindly, and then reinsert the oversized angioscope to observe the treatment location and assess efficacy. This is time-consuming and less useful because it does not provide real-time visualization feedback regarding the treatment, which could otherwise enable real-time adjustments of the treatment to improve its efficacy, as described herein.

[0065] One approach to adapting larger viewing instruments, such as GI endoscopes, for intravascular applications is to use a guidewire through the endoscope's lumen to track the viewing endoscope to the target intravascular location. However, over-the-wire (OTW) lumen or rapid exchange (RX) lumen techniques for these approaches both make the device's outer diameter too large for cerebrovascular interventions. Furthermore, angioscopes with polyamide sheaths lack the pushability and trackability to reach locations 150 cm inside the body. In contrast, the present small-diameter angioscope 104 can be housed within an outer sheath 408 that can include an embedded coil or braid, which can help improve one or more of kink resistance, pushability, and trackability. This allows the present angioscope 104 to be used within the working lumen 108 of an externally guided sheath catheter 102, enabling a smaller-diameter angioscope 104 to reach remote, tortuous, small-diameter cerebrovascular locations, such as using one or more of the workflows described herein. The Sheath Catheter 102 can be advanced to the target location using a guidewire, after which the angioscope 104 can be advanced quickly and safely (without the need for a separate guidewire) through the working lumen 108 of the Sheath Catheter 102 to the target cerebrovascular lesion to be diagnosed or treated. Another instrument, such as a cerebrovascular lesion treatment catheter 110, can then be advanced further through the angioscope 104, such as a moderate distance beyond the distal opening of the working lumen 108 of the Sheath Catheter 102, easily enough to allow real-time visualization by the user even when co-located, while also being advanced within the working lumen 108 of the Sheath Catheter 102.

[0066] In this manner, the Sheath Catheter 102 can be used to support the angioscope 104 during cerebrovascular interventions. The Sheath Catheter 102 can help guide or advance the angioscope 104 to the target location, and its balloon 204 can be inflated to occlude blood flow and to stabilize the vessel and create an observation window that aids user visualization using the angioscope 104. To do this safely, the balloon design must be more sophisticated, and it is within the peripheral vessels. The Sheath Catheter 102 includes a large inner diameter working lumen 108, but can also include a small outer diameter, which can help enable procedures using multiple instruments (e.g., the angioscope 104 and the cerebrovascular lesion treatment catheter 110) co-located within the working lumen 108 of the Sheath Catheter 102, while also allowing access to remote, small, and tortuous vascular locations, such as at or near the middle cerebral artery (MCA). The rapid inflation and deflation times of the balloon 204 can help a physician or other user quickly restore blood flow to the brain, avoiding brain tissue damage due to lack of blood perfusion. Such considerations are less important for non-cerebral vascular balloon catheters. However, in cerebral vascular applications, providing a large, concentric inflation lumen disposed around the working lumen 108 still allows for a reduced outer diameter distal to the balloon 204, thereby enabling distal access to smaller vessels beyond the balloon 240 (more distal to the balloon 204). This allows the distal end of the Sheath Catheter 102 to be advanced further into reduced-diameter cerebral vessels than approaches that did not provide such a step-down in outer diameter beyond the balloon 204, making it difficult or impossible to advance the distal end of the Sheath Catheter 102 to intracranial locations beyond the carotid artery. Illustrative Examples of Sheath Catheters 9A, 9B, 9C, 9D, 9E, and 9F illustrate various views of a portion of an example sheath catheter 102, which may include a distal access balloon catheter, based on the description of the previously presented figures and may include structural features that may be particularly useful for diagnosing and treating cerebrovascular lesions, such as intracranial locations beyond the petrous portion of the carotid artery. This is because such cerebrovascular lesions present particularly different challenges due to time constraints on intervention and treatment time resulting from possible brain tissue ischemia or damage from lack of blood perfusion while the vessel is compressed or occluded, such as due to vessel size and tortuosity, thrombus formation, or the use of partial or total occlusive treatment devices. However, the present systems, devices, and methods may also be useful for other endovascular diagnostic or therapeutic procedures at locations other than cerebrovascular locations, such that the present subject matter is not limited to cerebrovascular observation and interventional treatment.

[0067] FIG. 9A shows a top view of the Sheath Catheter 102, which can include an elongate body 904, such as having a distal portion 202A, a proximal portion 202B, and an intermediate portion therebetween. The proximal portion 202B can include a hub portion 902, from which the elongate body 904 can extend more distally. An inflatable balloon 204 can be disposed at or near the distal portion 202A of the elongate body 904. The elongate body 904 can include an outer body or outer sheath 210, such as can be seen by taking cross section AA in FIG. 9A, extending around an inner body or inner sheath 212, defining an annular inflation lumen 207 therebetween; an example cross section AA is shown in FIG. 9C. The inner body or inner sheath 212 can define a working lumen 108 therein, which combines with the annular inflation lumen 207 to provide a concentric dual lumen configuration.

[0068] The inner body or inner sheath 212 can extend beyond the distal end of the balloon 204, such as by an offset distance L, such that the distal end of the balloon 204 can be offset from the distal tip of the Sheath Catheter 102 by an offset distance L of at least 8 millimeters, which can help provide additional cerebrovascular access beyond the balloon 204 via the working lumen 108 of the inner body or inner sheath 212. In various examples, the offset distance L can be between 8 mm and 100 mm or more, such as 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, and 100 mm. Extending the inner body or inner sheath 212 and its working lumen 108 beyond the distal end of the balloon 204 can serve to provide additional diagnostic or therapeutic access capabilities beyond the balloon 204, which may be particularly useful for diagnosing or treating cerebrovascular lesions. The distal end of the Sheath Catheter 102 may be provided with a slightly outward flared or other atraumatic tip 910, as shown in FIG. 9A and in more detail in the detailed view of FIG. 9F. The working lumen 108 may likewise be flared, as may be useful for observing or applying suction or other therapy through the working lumen.

[0069] FIG. 9B is a side view illustrating one example of how hub 902 can provide separate access to working lumen 108 and inflation lumen 207, such as via working lumen access port 908 and inflation lumen access port 907, respectively, each of which can be in fluid communication with its lumen and each of which can include an external connector or other structure to which another instrument or other device can be mechanically coupled and optionally sealed.

[0070] 9A also illustrates an example of providing a laterally stepped inner body or inner sheath 212 that extends more distally beyond the balloon 204. For example, the inner body or inner sheath 212 can have an outer diameter or other circumference that is smaller than the outer diameter or other circumference of the outer body or outer sheath 210. The inflatable balloon 204 can be disposed toward the distal portion 202A of the elongate body 904 of the Sheath Catheter 102. The proximal end of the balloon 204 can be proximally attached to the elongate body 904 of the Sheath Catheter 102, such as via at least one of the outer diameter or other circumference of the outer body or outer sheath 210 or additionally or alternatively via a distal surface of the outer body or outer sheath 210. For example, the distal end of the outer body or outer sheath 210 can terminate at the proximal end of the balloon 204 with an optional proximal cuff that can be included to attach the proximal end of the balloon 204 to the outer body or outer sheath 210.

[0071] The balloon 204 may be distally attached to the elongate body 904 of the Sheath Catheter 102, such as via the outer diameter or circumference of the inner body or inner sheath 212, with an optional distal cuff or the like that may be included to attach the distal end of the balloon 204 to the inner body or inner sheath 212.

[0072] This method of attaching the proximal end of the balloon 204 to the outer body or outer sheath 210 and the distal end of the balloon 204 to the inner body or inner sheath 212 allows the elongate body 904 of the Sheath Catheter 102 to have a dimensional step-down laterally relative to the proximally attached portion of the balloon, the step-down occurring in the proximal-to-distal direction, such as beyond the proximal end of the balloon 204 and continuing beyond the distal end of the balloon. Optionally, the atraumatic distal tip 910 can again flare, such that the transverse dimensions of the periphery of the distal tip 910 can match the transverse dimensions of the outer body or outer sheath 210, allowing the periphery of the distal tip 910 to track within the lumen of another device that can similarly fit the periphery of the outer body or outer sheath 210. The detailed views of Figures 9D (side view) and 9E (side cross-sectional view) show the distal end of the balloon 204 attached to the periphery of the inner body or inner sheath 212.

[0073] 9C and 9E help illustrate that either or both of the inner body or inner sheath 212 or outer body or outer sheath 210 can include one or more layers forming the inner body or inner sheath 212 or outer body or outer sheath 210, respectively. Additionally, the number of layers or the particular nature of the materials can vary, such as along the length of the elongate body 904, such as to provide a desired bending flexibility or stiffness or other characteristic at that location along the length of the elongate body 904. For example, in FIG. 9C , the inner body or inner sheath 212 can include an inner layer 922, such as adjacent to and defining the working lumen 109 therein. An intermediate layer 924 can be included adjacent to and outward from the inner layer 922. An outer layer can be included adjacent to and outward from the intermediate layer 926. Again, these layers can vary along the length of the elongate body.

[0074] Figures 10A (side view), 10B (side cross-sectional view), and 10C (detailed side cross-section taken along line 10C-10C in Figure 10B) show an example inner body or inner sheath 212, along with an example layered structure thereof along the length of the elongate body 904 of the Sheath Catheter 102, such as at example cross-sections A, B, C, D, E, F, and G, proceeding from the distal portion 202A of the inner body or inner sheath 212 of the elongate body 904 of the Sheath Catheter 102 toward the proximal portion 202B of the inner body or inner sheath 212 of the elongate body 904 of the Sheath Catheter 102. Table 1 provides further explanation of Figures 10A and 10B, by way of example, but not by way of limitation.

[0075] [Table 1]

[0076] The inner layer 922 can include a PTFE or other liner, which can help provide a desired lubricity to the inner wall of the working lumen 108. One or more portions of the liner or other inner layer 922 can be stretched, for example, between 50% and 200%, inclusive, or another desired amount of stretch, such as to provide additional bending flexibility in the stretched region. The middle layer 924 can include a metal hypotube, such as a nitinol (e.g., a nickel-titanium alloy), or other structure, which can help provide structural rigidity, including beneath the balloon 204 or elsewhere during inflation, such as to help maintain patency of the inflation lumen 207 or working lumen 108, including during inflation of the balloon 204. One or more portions of the metal tubing or other middle layer 924 can be stretched, for example, between 50% and 200%, inclusive, or another desired amount of stretch, such as to provide additional bending flexibility in the stretched region. Additionally or alternatively, one or more portions of the metal tube or other intermediate layer 924 can be laser cut, e.g., at repeated intervals, to provide additional bending flexibility in the stretched region. If necessary, cutting before stretching can widen the cut and help provide additional bending flexibility. Portions of the intermediate layer 924 can include stainless steel or other metal or other braid, as desired. The outer layer 926 can include Pebax® or Nylon or other polymers of a desired hardness (e.g., a durometer hardness of 25D to 100D, inclusive) or hardness that can vary among different sections along the length of the inner body or inner sheath 212. One or more portions or all of the outer layer 926 can be heated and reflowed, e.g., after assembly of the intermediate layer 924 and inner layer 922, to reflow bond the outer layer 926 to the inner layer 922, e.g., through openings in the intermediate layer 924, such as provided by cuts or braid openings.

[0077] Figures 11A (side view), 11B (side cross-sectional view), and 11C (detailed side cross-section taken along line 11C-11C in Figure 11B) show an example outer body or outer sheath 210, along with an example layered structure thereof along the length of the elongate body 904 of the Sheath Catheter 102, such as at example cross-sections A, B, C, D, E, F, and G, proceeding from the distal portion 202A of the outer body or outer sheath 210 of the elongate body 904 of the Sheath Catheter 102 toward the proximal portion 202B of the outer body or outer sheath 210 of the elongate body 904 of the Sheath Catheter 102. Table 2 provides further explanation of Figures 11A and 11B, by way of example, but not by way of limitation.

[0078] [Table 2]

[0079] The inner layer 932 can include a PTFE or other liner that can be exposed to the inflation lumen 207. One or more portions of the liner or other inner layer 932 can be stretched, for example, between 50% and 200%, inclusive, or can be stretched by another desired amount, such as to provide additional bending flexibility in the stretched region, if desired. The middle layer 934 can include a metal (e.g., nickel-titanium alloy) coil or braid (e.g., stainless steel) or other structure that can help provide structural rigidity. One or more portions of the middle layer 934 can be stretched, for example, between 50% and 200%, inclusive, or can be stretched by another desired amount, such as to provide additional bending flexibility in the stretched region, if desired. Portions of the middle layer 934 can include stainless steel or other metal or other braid, if desired. Outer layer 936 may comprise Pebax® or Nylon or other polymers of a desired hardness (e.g., durometer hardness between 25D and 100D, inclusive) or hardness that may vary among different sections along the length of outer body or outer sheath 210. One or more portions or all of outer layer 936 may be heated and reflowed, such as after assembly with intermediate layer 934 and inner layer 932, such as to reflow bond outer layer 936 to inner layer 932, such as through openings in intermediate layer 934, such as provided by coil gaps or braid openings.

[0080] The stretching described herein can thin the resulting material. Stretching or thinning, alone or in combination with cutting or scoring (e.g., transverse to the longitudinal direction of the elongated body 904), can help provide additional bending flexibility in one or more desired regions of the elongated body. For example, stretching the PTFE liners 922, 932 can result in a thickness of 12.7 micrometers (0.5 thousandths of an inch), which can be much thinner than other available materials, such as non-stretched liner materials having a thickness of 19.05 micrometers (0.75 thousandths of an inch).

[0081] The above description has emphasized systems, devices, and methods for diagnosing and treating cerebrovascular lesions, such as at intracranial locations beyond the petrous portion of the carotid artery, because such cerebrovascular lesions present particularly different challenges due to time constraints on intervention and treatment time resulting from possible brain tissue ischemia or damage from lack of blood perfusion while the vessel is compressed or occluded, due to vessel size and tortuosity, thrombus formation, or the use of partially or totally occlusive treatment devices, etc. However, the present systems, devices, and methods may also be useful for other endovascular diagnostic or therapeutic procedures at locations other than cerebrovascular locations, such that the present subject matter is not limited to cerebrovascular observation and interventional treatment.

[0082] The above description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments, also referred to herein as "examples" or "aspects," an illustrative, non-limiting numbered list of which is set forth below.

[0083] Aspect 1 may include or use subject matter (e.g., an apparatus, a system, a device, a method, a means for performing an action, or a device-readable medium containing instructions that, when executed by a device, cause the device to perform an action, or an article of manufacture, etc.). The subject matter may include or use, for example, an apparatus for internally assisting a user in both the observation and treatment of cerebrovascular lesions. The apparatus may include a sheath catheter. The sheath catheter may include an elongate body defining an internal working lumen extending between a proximal portion and a distal portion of the elongate body of the sheath catheter. The sheath catheter may include an inflatable balloon, which may be disposed toward the distal portion of the elongate body of the sheath catheter. The sheath catheter may include an inflation lumen extending between the proximal portion of the elongate body of the sheath catheter and the balloon to provide fluid communication to the balloon, for example, to enable inflation and deflation of the balloon. For example, the distal portion of the elongate body of the Sheath Catheter can have an outer diameter between 1.17 millimeters (3.5 French) and 2.67 millimeters (8.0 French). For example, the elongate body of the Sheath Catheter can define a working lumen having an inner diameter ranging from 0.99 millimeters (0.039 inch) to 2.08 millimeters (0.082 inch), with a nominal or preferred value of at least 1.78 millimeters (0.070 inch), such as to enable cerebrovascular treatment via the working lumen with at least a portion of the angioscope remaining within the working lumen.

[0084] Embodiment 2 may include or use a forward-viewing fiber optic angioscope, or may optionally include or use a forward-viewing fiber optic angioscope in combination with the subject matter of Embodiment 1. The angioscope may be sized and shaped to be inserted into the working lumen of the Sheath Catheter from a proximal portion thereof, such as to allow a distal portion of the angioscope to extend beyond the distal opening of the working lumen of the Sheath Catheter, such as to allow a user to use the angioscope to view and inspect cerebrovascular lesions forward.

[0085] Aspect 3 may include or use, or may be optionally combined with one or more of the subject matter of Aspects 1 or 2, an angioscope that may include a coherent fiber bundle of imaging optical fibers, such as extending between a proximal end and a distal end of the angioscope. For example, each imaging fiber may have an outer diameter of approximately 2.5 micrometers. The cladding-less illumination fiber may be arranged concentrically around the imaging fiber. Each illumination fiber may have an outer diameter between 25 micrometers and 50 micrometers. In one example, the outer diameter of the angioscope 104 at its distal end may be 0.56 millimeters (1.7 French) or less. In one example, the outer diameter of the angioscope 104 at its proximal end may be 0.79 millimeters (2.4 French) or less.

[0086] Embodiment 4 can include or use an angioscope that can include a GRIN lens or other lens such as can be disposed at the tip of the angioscope, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 3 to include or use an angioscope. In one example, the lens can have a diameter of 250 micrometers or less.

[0087] Aspect 5 can include or use, for example, a polymeric sheath that can be positioned at the distal end of the angioscope to concentrically surround the illumination fiber, imaging fiber, and GRIN lens, or can be optionally combined with one or more of the subject matter of Aspects 1 through 4 to include or use such a polymeric sheath.

[0088] Embodiment 6 can include or use a blood-resistant coating material, such as may be disposed on a GRIN or other lens, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 5 to include or use said blood-resistant coating material.

[0089] Embodiment 7 can include or use a common cladding that can be disposed between or shared among each of the imaging fibers, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 6 to include or use such a cladding.

[0090] Embodiment 8 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 7 to include or use, a polymeric jacket that can provide one or more coatings or encapsulation of the imaging fiber.

[0091] Embodiment 9 may optionally be combined with one or more of the subject matter of Embodiments 1 through 8 to include or use a proximal portion of the Sheath Catheter that may be stiffer than the more distal portion of the Sheath Catheter.

[0092] Embodiment 10 can include or use a sheath catheter that includes at least two different portions (e.g., lengths) having different durometers or stiffnesses, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 9 to include or use such a sheath catheter.

[0093] Embodiment 11 can include or utilize, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 10, a Sheath Catheter including an elongate body of the Sheath Catheter including at least one of a braid or a coil. The braid or coil can be configured to be less stiff toward a distal portion of the elongate body than toward a more proximal portion of the elongate body.

[0094] Embodiment 12 can include or use at least one of a braid and a coil, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 11, to include or use at least one of a braid and a coil, comprising a metal or nylon material (e.g., a material that is more rigid and may provide reinforcement than a softer adjacent covering or encapsulating material).

[0095] Embodiment 13 can include or use at least one braid or coil that terminates short of the tip of the elongate body of the Sheath Catheter to allow for relatively greater flexibility in the distal portion of the elongate body, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 12 to include or use at least one of the braid or coil.

[0096] Embodiment 14 can include or use a working lumen of a sheath catheter that is coated with, filled with, or has a hydrophilic lubricious material (e.g., by providing a hydrophilic lubricious material, Teflon or other polytetrafluoroethylene or other liner), or can be optionally combined with one or more of the subject matter of Embodiments 1 through 13 to include or use a working lumen of the sheath catheter.

[0097] Embodiment 15 can include or utilize a valve that can be positioned toward the proximal portion of the Sheath Catheter, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 14 to include or utilize such a valve. The valve can be configured to allow a vacuum to be built behind the valve and applied to the working lumen of the Sheath Catheter when the valve opens, e.g., to allow for sudden suction to be applied to the tip of the working lumen of the Sheath Catheter.

[0098] Aspect 16 can include or use, or can be optionally combined with one or more of the subject matter of Aspects 1 through 15, to include or use, a cerebrovascular lesion treatment catheter, which can be sized and shaped to extend through the working lumen of the sheath catheter, for example, while allowing at least a portion of the angioscope to remain within the working lumen of the sheath catheter.

[0099] Embodiment 17 can include or use a cerebrovascular lesion treatment catheter, including a thrombus retrieval catheter (e.g., a stent retriever, etc.), or can be optionally combined with one or more of the subject matter of Embodiments 1 through 16 to include or use such a cerebrovascular lesion treatment catheter.

[0100] Embodiment 18 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 17, to include or use a thrombectomy catheter that includes a stent or other engagement mechanism at the tip of the thrombectomy catheter. In one example, the stent or other engagement mechanism can be configured to expand into or engage a thrombus such that it can be positioned in the vasculature beyond the distal opening of the working lumen of the sheath catheter.

[0101] Embodiment 19 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 18, to include or use a thrombectomy catheter that includes a longitudinal guidewire lumen, which can be sized and shaped to accommodate a guidewire, for example, to allow the thrombectomy catheter to be extended over the wire through the working lumen of the sheath catheter.

[0102] Embodiment 20 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 19, to include or use, a cerebrovascular lesion treatment catheter, including an aspiration catheter, such as one including an elongate body defining a longitudinal aspiration lumen.

[0103] Embodiment 21 may include or use, or may optionally be combined with one or more of the subject matter of Embodiments 1 through 20 to include or use, a method for internally observing and treating a cerebrovascular lesion. The method may include advancing a sheath catheter through a vasculature toward the lesion to be treated. A distal balloon of the sheath catheter may then be inflated to occlude a region of the vasculature to stabilize a distal portion of the sheath catheter. The distal tip of a forward-looking fiber optic angioscope may extend through the working lumen of the sheath catheter, such as to observe and inspect the lesion from the front using the angioscope. The cerebrovascular lesion may then be treated, such as through the working lumen of the sheath catheter, while allowing at least a portion of the angioscope to remain within the working lumen of the sheath catheter. Optionally, further observation may then be performed, such as through the distal tip of the angioscope, such as to observe a location beyond the distal opening of the working lumen of the sheath catheter. Such advancement into the vasculature may assist a user in assessing the cerebrovascular lesion treatment.

[0104] Aspect 22 can include or be used to insert, or can be optionally combined with one or more of the subject matter of Aspects 1 through 21, for example, a cerebrovascular treatment catheter that can be sized and shaped to extend through the working lumen of the sheath catheter while allowing at least a portion of the angioscope to remain within the working lumen of the sheath catheter.

[0105] Aspect 23 includes advancing a sheath catheter, which may include, use, or optionally combine one or more of the subject matter of aspects 1 through 22 to include or use an advancing sheath catheter, and the sheath catheter may have an outer diameter between 1.17 millimeters (3.5 French) and 2.67 millimeters (8.0 French). The inner diameter of the working lumen of the sheath catheter may be within the range of 0.99 millimeters (0.039 inch) to 2.08 millimeters (0.082 inch), with a nominal or preferred value of at least 1.78 millimeters (0.070 inch). This allows both at least a portion of the cerebrovascular lesion treatment catheter and at least a portion of the angioscope to remain within the working lumen of the sheath catheter.

[0106] Embodiment 24 may include or use inflating a distal balloon of a sheath catheter, which may include occluding blood flow using the inflated distal balloon, or may be optionally combined with one or more of the subject matter of Embodiments 1 through 23 to include or use inflating the distal balloon.

[0107] Embodiment 25 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 24, to include or use, injecting saline or other fluid (a clear fluid so that it can be observed using an angioscope) through the working lumen of the sheath catheter, such as after inflating the distal balloon of the sheath catheter.

[0108] Embodiment 26 may optionally be combined with one or more of the subject matter of Embodiments 1 through 25, where the cerebrovascular lesion includes a thrombus and inserting the cerebrovascular lesion treatment catheter includes or uses extending a thrombectomy catheter beyond the distal opening of the working lumen of the sheath catheter, or where the cerebrovascular lesion includes a thrombus and inserting the cerebrovascular lesion treatment catheter includes or uses extending a thrombectomy catheter beyond the distal opening of the working lumen of the sheath catheter. This may allow, for example, at least a portion of the thrombus to be retrieved and removed by retracting the thrombectomy catheter through the working lumen of the sheath catheter while allowing at least a portion of the angioscope to remain within the working lumen of the sheath catheter.

[0109] Embodiment 27 can include or utilize, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 26 to include or utilize, inserting a guidewire through the working lumen of the Sheath Catheter prior to inserting the thrombectomy catheter. The thrombectomy catheter can be inserted over-the-wire, such as with at least a portion of the angioscope remaining within the working lumen of the Sheath Catheter.

[0110] Embodiment 28 can include or use, or can be optionally combined with one or more of the subject matter of embodiments 1 through 27, to include or use, inserting a guidewire to cross the thrombus via the distal tip of the guidewire, e.g., before inserting a thrombectomy catheter, e.g., over-the-wire.

[0111] In embodiment 29, inserting the thrombectomy catheter over the wire can include or use, for example, inserting the tip of the thrombectomy catheter over the wire into or beyond the thrombus, or can be optionally combined with one or more of the subject matter of embodiments 1 through 28 to include or use such insertion.

[0112] Embodiment 30 can include or be used, or can be optionally combined with one or more of the subject matter of embodiments 1 through 29, for example, to include or be used to retract a guidewire through the working lumen of the sheath catheter, with at least a portion of the thrombectomy catheter and at least a portion of the angioscope remaining within the working lumen of the sheath catheter.

[0113] Embodiment 31 can include or be used to retract a thrombectomy catheter through the working lumen of the sheath catheter, for example, with at least a portion of the angioscope remaining within the working lumen of the sheath catheter, or can be optionally combined with one or more of the subject matter of embodiments 1 through 30 to include or be used to retract a thrombectomy catheter through the working lumen of the sheath catheter, for example.

[0114] Embodiment 32 can include or be used to, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 31 to include or be used to, reinsert a cerebrovascular lesion treatment catheter through the working lumen of the sheath catheter if evaluation of the cerebrovascular lesion treatment using an angioscopic approach indicates the need for further treatment.

[0115] In embodiment 33, reinserting the cerebrovascular lesion treatment catheter through the working lumen of the sheath catheter can include or be used to insert another cerebrovascular lesion treatment catheter, or can be optionally combined with one or more of the subject matter of embodiments 1 through 32 to include or be used to insert another cerebrovascular lesion treatment catheter.

[0116] In embodiment 34, reinserting the cerebrovascular lesion treatment catheter through the working lumen of the sheath catheter can include or be used to insert a different type of cerebrovascular lesion treatment catheter, or can be optionally combined with one or more of the subject matter of embodiments 1 through 33 to include or be used to insert a different type of cerebrovascular lesion treatment catheter.

[0117] Embodiment 35 can include or use suction through the working lumen of the sheath catheter, or can be optionally combined with one or more of the subject matter of embodiments 1 through 34, if evaluation of cerebrovascular lesion treatment using an angioscopic approach indicates the need for further treatment.

[0118] Embodiment 36 can include or utilize performing, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 35 to include or utilize performing, suctioning prior to deflating the distal balloon of the sheath catheter.

[0119] Embodiment 37 can include or utilize, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 36, to include or utilize inserting a guidewire through the working lumen of the Sheath Catheter prior to inserting the thrombectomy catheter. The cerebrovascular lesion treatment catheter can be inserted over-the-wire, with at least a portion of the angioscope remaining within the working lumen of the Sheath Catheter.

[0120] Embodiment 38 can include or be used where the cerebrovascular lesion comprises an aneurysm, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 37 to include or be used where the cerebrovascular lesion treatment catheter comprises an aneurysm. Inserting the cerebrovascular lesion treatment catheter can include inserting an aneurysm thrombolytic occluder into the aneurysm via the working lumen of the sheath catheter while allowing at least a portion of the angioscope to remain within the working lumen of the sheath catheter.

[0121] Embodiment 39 can include or use, or can optionally be combined with one or more of the subject matter of embodiments 1 through 38 to include or use, an aneurysm thrombolytic occluder used to place one or more aneurysm coils in an aneurysm while using an angioscope to endovascularly visualize the placement of the one or more aneurysm coils in the aneurysm.

[0122] Embodiment 40 can include or utilize, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 39 to include or utilize, inserting a guidewire through the working lumen of the Sheath Catheter prior to inserting the aneurysm thrombolytic occluder. The aneurysm thrombolytic occluder can be inserted over the wire, such as with at least a portion of the angioscope remaining within the working lumen of the Sheath Catheter.

[0123] Embodiment 41 can include or use inserting a guidewire prior to over-the-wire insertion of the aneurysm thrombolytic occluder, or can be optionally combined with one or more of the subject matter of embodiments 1 through 40 to include or use inserting a distal tip of the guidewire into the aneurysm.

[0124] Embodiment 42 can include or be used, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 41, for example, to include or be used to retract a guidewire through the working lumen of the sheath catheter, with at least a portion of the aneurysm thrombolysis occluder and at least a portion of the angioscope remaining within the working lumen of the sheath catheter.

[0125] Embodiment 43 can include or be used to retract an aneurysm thrombolysis occluder through the working lumen of the sheath catheter, for example, with at least a portion of the angioscope remaining within the working lumen of the sheath catheter, or can be optionally combined with one or more of the subject matter of embodiments 1 through 42 to include or be used to retract an aneurysm thrombolysis occluder through the working lumen of the sheath catheter.

[0126] Embodiment 44 can include or use, or can optionally be combined with one or more of the subject matter of embodiments 1 through 43 to include or use, an aneurysm thrombolytic occluder that introduces a liquid embolic agent or other thrombolytic agent into an aneurysm while using an angioscopic endovascular visualization of the placement of the thrombolytic agent into the aneurysm.

[0127] Embodiment 45 can be optionally combined with one or more of the subject matter of Embodiments 1 through 44, such that the aneurysm thrombolytic occluder comprises a fluid delivery catheter and further includes or can be used to introduce a thrombolytic agent into the aneurysm via a working lumen of the fluid delivery catheter with a distal tip disposed within the aneurysm, or the aneurysm thrombolytic occluder comprises a fluid delivery catheter and further includes or can be used to introduce a thrombolytic agent into the aneurysm via a working lumen of the fluid delivery catheter with a distal tip disposed within the aneurysm.

[0128] Embodiment 46 can include or be used to introduce a fluid delivery catheter over the wire to position the distal tip of the fluid delivery catheter within the aneurysm, or can be optionally combined with one or more of the subject matter of embodiments 1 through 45 to include or be used to introduce or use the fluid delivery catheter.

[0129] Embodiment 47 can include or use a fluid delivery catheter for introducing a thrombolytic agent into the aneurysm after the one or more aneurysm coils have been introduced into the aneurysm, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 46 to include or use such a fluid delivery catheter.

[0130] Embodiment 48 can include or be used where the cerebrovascular lesion includes a thrombus, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 47 to include or use where the cerebrovascular lesion treatment catheter includes. In one example, inserting the cerebrovascular lesion treatment catheter can include extending a thrombus aspiration catheter beyond the distal opening of the working lumen of the sheath catheter, e.g., to retrieve and remove at least a portion of the thrombus, e.g., by aspirating the thrombus, via the thrombus aspiration catheter disposed within the working lumen of the sheath catheter, e.g., while allowing at least a portion of the angioscope to remain within the working lumen of the sheath catheter.

[0131] Embodiment 49 can include or be used to aspirate thrombus, including thrombus caulking, such as through the distal tip of the thrombus retrieval catheter, such as with at least a portion of the angioscope remaining within the working lumen of the sheath catheter, before retracting the thrombus aspiration catheter through the working lumen of the sheath catheter, or can be optionally combined with the subject matter of one or more of Embodiments 1 through 48 to include or be used to aspirate thrombus, including thrombus caulking, such as through the distal tip of the thrombus retrieval catheter, such as with at least a portion of the angioscope remaining within the working lumen of the sheath catheter.

[0132] Embodiment 50 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 49, to include or use inserting a guidewire through the working lumen of the Sheath Catheter, such as before inserting the thrombus aspiration catheter. The thrombus aspiration catheter can be inserted over the wire, such as with at least a portion of the angioscope remaining within the working lumen of the Sheath Catheter.

[0133] Embodiment 51 can include or be used, for example, to retract a guidewire through the working lumen of the sheath catheter, with at least a portion of the thrombus aspiration catheter and at least a portion of the angioscope remaining within the working lumen of the sheath catheter, or can be optionally combined with one or more of the subject matter of embodiments 1 through 50 to include or be used to retract a guidewire through the working lumen of the sheath catheter, for example.

[0134] Embodiment 52 can include or be used to aspirate at least a portion of the thrombus into the thrombus aspiration catheter, and to draw the thrombus into the thrombus aspiration catheter via the working lumen of the sheath catheter, such as with at least a portion of the angioscope remaining within the working lumen of the sheath catheter, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 51 to include or use said aspirating and drawing.

[0135] Embodiment 53 can include or use retracting the thrombus aspiration catheter followed by re-aspiration through the working lumen of the sheath catheter while observing using the angioscope, or can be optionally combined with one or more of the subject matter of embodiments 1 through 52 to include or use said re-aspiration.

[0136] Embodiment 54 can include or utilize, or can be optionally combined with one or more of the subject matter of embodiments 1 through 53 to include or utilize, performing suction prior to deflating the distal balloon of the sheath catheter. The distal balloon of the sheath catheter can then be deflated.

[0137] Embodiment 55 may include or use, or may be optionally combined with one or more of the subject matter of Embodiments 1 through 54 to include or use, a method for internally observing and treating a cerebral thrombus. The method may include advancing a sheath catheter through a vasculature toward a thrombus to be treated. Next, a distal balloon of the sheath catheter may be deflated to occlude a predetermined region of the vasculature, such as to stabilize a distal portion of the sheath catheter. The distal tip of a forward-looking fiber optic angioscope may then be extended up to or beyond the distal opening of the working lumen of the sheath catheter to observe and inspect the thrombus from the front using the angioscope. Next, a thrombectomy catheter may be extended beyond the distal opening of the working lumen of the sheath catheter to retrieve and remove at least a portion of the thrombus, such as by retracting the thrombectomy catheter through the working lumen of the sheath catheter while allowing at least a portion of the angioscope to remain within the working lumen of the sheath catheter. The extended distal tip of the angioscope can then be used, such as from a position toward, near, or beyond the distal opening of the working lumen of the Sheath Catheter, to view forward into the vascular structure to assess retrieval and removal of at least a portion of the thrombus.

[0138] Embodiment 56 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 55 to include or use, a method for internally observing and treating a cerebral thrombus. The method can include advancing a sheath catheter through a vasculature toward a thrombus to be treated. A distal balloon of the sheath catheter can then be deflated to occlude a predetermined region of the vasculature, such as to stabilize a distal portion of the sheath catheter. A distal tip of a forward-looking fiber optic angioscope can extend through the working lumen of the sheath catheter, such as to observe and inspect the thrombus from the front using the angioscope. A vacuum can be applied, such as through a distal opening of the working lumen of the sheath catheter, such as to retrieve and remove at least a portion of the thrombus, such as while allowing at least a portion of the angioscope to remain within the working lumen of the sheath catheter during retrieval and removal. The distal tip of the angioscope may be positioned toward, near, or beyond the distal opening of the working lumen of the Sheath Catheter, such as to view forward into the vascular structure to assess retrieval and removal of at least a portion of the thrombus.

[0139] Embodiment 57 can include or use a sheath catheter advancement, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 56 to include or use such advancement. In one example, the sheath catheter can have an outer diameter between 1.17 millimeters (3.5 French) and 2.67 millimeters (8.0 French). In one example, the sheath catheter can define an inner diameter of the working lumen of the sheath catheter ranging from 0.99 millimeters (0.039 inches) to 2.08 millimeters (0.082 inches), such as a nominal or preferred value of at least 1.78 millimeters (0.070 inches), such as to enable retrieval of a thrombus via the working lumen of the sheath catheter, such as with at least a portion of the angioscope remaining within the working lumen of the sheath catheter.

[0140] Embodiment 58 can include or be used to occlude blood flow using the inflated distal balloon of the sheath catheter, or can be optionally combined with one or more of the subject matter of embodiments 1 through 57 to include or be used to occlude blood flow using the inflated distal balloon.

[0141] Embodiment 59 can include or utilize, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 58, to include or utilize injecting saline or other fluids through the working lumen of the Sheath Catheter after inflating the distal balloon of the Sheath Catheter. The fluid can be transparent so that it can be viewed using an angioscope.

[0142] Embodiment 60 can include or use, or can be optionally combined with one or more of the subject matter of embodiments 1 through 59 to include or use, retracting the distal tip of the angioscope into the working lumen of the sheath catheter, such as before applying vacuum through the distal opening of the working lumen of the sheath catheter.

[0143] Embodiment 61 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 60, to include or use observing using an angioscope that the thrombus has not been completely retracted into the working lumen of the sheath. In response, the balloon can be deflated and the sheath catheter can be slowly withdrawn, e.g., with vacuum still applied to the working lumen of the sheath catheter to maintain the thrombus against the tip of the sheath, for retraction of the thrombus under vacuum as the sheath catheter is withdrawn.

[0144] In embodiment 62, applying a vacuum can include or use increasing suction before opening the valve to apply the vacuum, or can be optionally combined with one or more of the subject matter of embodiments 1 through 61 to include or use increasing suction.

[0145] Embodiment 63 may include or use, or may be optionally combined with one or more of the subject matter of Embodiments 1 through 62 to include or use, a method for internally observing and treating a cerebral aneurysm. The method may include advancing a sheath catheter through a vasculature toward an aneurysm to be treated. A distal balloon of the sheath catheter may be inflated to plug a predetermined region of the vasculature, such as to stabilize a distal portion of the sheath catheter. A distal tip of a forward-looking fiber optic angioscope may extend through the working lumen of the sheath catheter, such as for forward observation and inspection of the aneurysm using the angioscope. An aneurysm thrombolysis occluder may be inserted, for example, into the aneurysm, such as through the working lumen of the sheath catheter, while allowing at least a portion of the angioscope to remain within the working lumen of the sheath catheter. The distal tip of the angioscope can be extended to, near, or beyond the distal opening of the working lumen of the sheath catheter, such as to view the vascular structure from the front, for example to evaluate the insertion of an occluder into an aneurysm.

[0146] Embodiment 64 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 63 to include or use, a cerebrovascular device, such as for at least partial insertion into the cerebrovasculature. The device can include a Sheath Catheter. The Sheath Catheter can include an elongate body. The elongate body can include an elongate outer body and an elongate inner body having an outer periphery smaller than the outer periphery of the outer body. An inflation lumen can be defined between the outer body and the inner body. An internal working lumen can be defined within the inner body. The working lumen can extend between a proximal portion and a distal portion of the elongate body of the Sheath Catheter. An inflatable balloon can be disposed toward a distal portion of the elongate body of the Sheath Catheter. The balloon can be proximally attached to the elongate body of the Sheath Catheter, such as via at least one of an outer periphery of the outer body and a distal surface of the outer body. The balloon can be distally attached to the Sheath Catheter elongate body, such as via at least the outer periphery of the inner body, such that the balloon is stepped in a lateral dimension relative to the proximally attached portion of the inflation balloon. An inflation lumen can extend between the proximal portion of the Sheath Catheter elongate body and the balloon, such as to provide fluid communication to the balloon to enable inflation of the balloon.

[0147] Embodiment 65 may include or utilize, or may optionally be combined with one or more of the subject matter of embodiments 1 through 64, a balloon tip that may be offset from the distal tip of the sheath catheter by an offset distance of, for example, at least 8 millimeters, to provide additional cerebrovascular access beyond the balloon, such as via a working lumen of the inner body.

[0148] Embodiment 66 can include or utilize an inner lateral dimension of the working lumen located at or near the distal tip of the Sheath Catheter that is larger in the more proximal region of the working lumen, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 65 to include or utilize such an inner lateral dimension.

[0149] Aspect 67 can include or utilize, or can be optionally combined with one or more of the subject matter of Aspects 1 to 66, so as to include or utilize, that the lateral outer periphery dimension of the distal tip of the Sheath Catheter is equal to the lateral outer periphery dimension of the outer body of the Sheath Catheter.

[0150] Embodiment 68 may include or use, or may be optionally combined with one or more of the subject matter of embodiments 1 through 67, a sheath catheter whose inner body may include a metal tube that may extend under the balloon to inhibit collapse and maintain patency of the working channel, such as when inflation pressure is applied to inflate the balloon.

[0151] Embodiment 69 can include or utilize a metal tube comprising a nickel-titanium alloy, or can be optionally combined with one or more of the subject matter of embodiments 1 through 68 to include or utilize such a tube.

[0152] Embodiment 70 may include or use a metal tube, such as may include laser cutting to enhance bending flexibility, or may be optionally combined with one or more of the subject matter of embodiments 1 through 69 to include or use such a tube.

[0153] Embodiment 71 can include or use laser cuts in the relatively distal portion of the tube that are more closely spaced apart than the laser cuts in the relatively proximal portion of the tube, such as to provide a relatively higher bending flexibility in the relatively distal portion of the tube than in the relatively proximal portion of the tube, or can be optionally combined with the subject matter of one or more of embodiments 1 through 70 to include or use such laser cuts.

[0154] Embodiment 72 can include or utilize, or can be optionally combined with the subject matter of one or more of Embodiments 1 through 71, to include or utilize a relatively distal portion of a metal tube that is stretched thinner than a relatively proximal portion of the tube, such as to create a wider laser cut in the relatively distal portion of the tube than in the relatively proximal portion of the tube.

[0155] Embodiment 73 may include or utilize a relatively distal portion of the tube that may be stretched relative to the relatively proximal portion of the tube, such as to provide a relatively greater bending flexibility to the relatively distal portion of the tube than to the relatively proximal portion of the tube, or may be optionally combined with one or more of the subject matter of embodiments 1 through 72 to include or utilize the relatively distal portion of the tube.

[0156] Embodiment 74 may include or be used with, or may be optionally combined with one or more of the subject matter of Embodiments 1 through 73 to include or be used with, a Sheath Catheter that may include an inner body that may further include a liner disposed within a metal tube, such as along at least a portion of the tube, such as to provide a desired lubricity to the inner working lumen of the Sheath Catheter.

[0157] Embodiment 75 can include or employ, or can optionally be combined with one or more of the subject matter of embodiments 1 through 74 to include or employ, a liner that is absent from at least a portion of the distal region of the tube distal to the balloon.

[0158] Embodiment 76 may include or use a relatively distal portion of the liner that may be stretched relative to the relatively proximal portion of the liner, such as to provide the relatively distal portion of the liner with a relatively higher bending flexibility than the relatively proximal portion of the liner, or may be optionally combined with one or more of the subject matter of embodiments 1 through 75 to include or use such a liner.

[0159] Embodiment 77 may include or use a sheath catheter in which the inner body may include at least one of a metal braid and a metal coil, such as in a region of the inner body more proximal than the tube, or may be optionally combined with one or more of the subject matter of embodiments 1 through 76 to include or use such a sheath catheter.

[0160] Embodiment 78 can include or use, or can be optionally combined with one or more of the subject matter of embodiments 1 through 77 to include or use, a sheath catheter in which the inner body can include a polymeric outer cover adjacent to a tube and adjacent to at least one of a metal braid and a metal coil.

[0161] Embodiment 79 may include or be used with, or may be optionally combined with the subject matter of one or more of Embodiments 1 through 78 for including or use with, a Sheath Catheter that may include an inner body that may further include a liner disposed within a tube along at least a portion of the tube, such as to provide desired lubricity to the inner working lumen of the Sheath Catheter. The polymeric outer cover may be reflowed to bond to the liner, such as through engagement of the liner, such as through a surface feature comprising at least one of a tube, a braid, and other intermediate layer between the liner and the outer cover.

[0162] Embodiment 80 may include or use, or may be optionally combined with one or more of the subject matter of embodiments 1 through 79, to include or use a sheath catheter that may include an inner body in which a relatively proximal portion of a polymeric outer cover may comprise a stiffer material than a relatively distal portion of the polymeric outer cover.

[0163] Embodiment 81 may include or use, or may be optionally combined with one or more of the subject matter of embodiments 1 through 80, a Sheath Catheter that may include or use an inner body in which a relatively proximal portion of a polymeric outer cover may comprise a harder material than a relatively distal portion of the polymeric outer cover.

[0164] Embodiment 82 may include or be used as a sheath catheter, or may be optionally combined with one or more of the subject matter of embodiments 1 to 81 to include or be used as a sheath catheter, for example, at least a portion of the outer body of the sheath catheter comprising an inner liner, an intermediate layer that may include one of a metal coil and a metal braid extending along and around the inner liner, and an outer layer such as a polymeric outer cover that extends along and around one of the coils and braids of the outer body.

[0165] Embodiment 83 may include or use a sheath catheter that may include an outer body that may include a polymeric outer covering that is reflowed to bond with the inner liner of the outer body, such as by engaging the inner liner of the outer body through at least one surface feature of the coil and braid of the outer body, or may be optionally combined with one or more of the subject matter of embodiments 1 through 82 to include or use the sheath catheter.

[0166] Embodiment 84 can be optionally combined with one or more of the subject matter of embodiments 1 through 83, e.g., so that the coil of the outer body includes or uses a nickel-titanium alloy.

[0167] Embodiment 85 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 84 to include or use, a cerebrovascular device, such as for at least partial insertion into the cerebrovasculature. The device can include a Sheath Catheter. The Sheath Catheter can include an elongate body. The elongate body can include an elongate outer body and an elongate inner body having an outer circumference smaller than the outer circumference of the outer body. An inflation lumen can be defined between the outer body and the inner body. An internal working lumen can be defined within the inner body. An inflatable balloon can be disposed toward a distal portion of the elongate body of the Sheath Catheter. The inflation lumen can extend between a proximal portion of the elongate body of the Sheath Catheter and the balloon, such as to provide fluid communication to the balloon to enable inflation of the balloon. The working lumen can extend between the proximal and distal portions of the elongate body of the Sheath Catheter, the working lumen further extending to the distal tip of the Sheath Catheter offset by an offset distance of at least 8 millimeters from the distal end of the balloon to provide additional cerebrovascular access beyond the balloon via the working lumen of the inner body.

[0168] Embodiment 85 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 84 to include or use, a cerebrovascular device, such as for at least partial insertion into the cerebrovasculature. The device can include a sheath catheter. The sheath catheter can include an elongate body. The elongate body can include an elongate outer body and an elongate inner body having an outer circumference smaller than the outer circumference of the outer body. An internal working lumen can be defined within the inner body, such as extending between a proximal portion and a distal portion of the elongate body of the sheath catheter. At least one of the inner body and the outer body can include at least a portion that is elongated relative to other portions of the at least one of the inner body and the outer body to provide greater relative bending flexibility in the elongated portion.

[0169] Embodiment 85 can include or use, or can optionally be combined with one or more of the subject matter of Embodiments 1 through 84 to include or use, a cerebrovascular device, such as for at least partial insertion into the cerebrovasculature. The device can include a Sheath Catheter. The Sheath Catheter can include an elongate body. The elongate body can include an elongate outer body and an elongate inner body having an outer circumference smaller than the outer circumference of the outer body. An internal working lumen can be defined within the inner body. The working lumen can extend between a proximal portion and a distal portion of the elongate body of the Sheath Catheter. At least one of the inner body and the outer body can include at least a portion that is elongated compared to other portions of the at least one of the inner body and the outer body, providing greater relative bending flexibility at the elongated portion compared to other portions.

[0170] Embodiment 86 can include or use, or can be optionally combined with one or more of the subject matter of Embodiments 1 through 85 to include or use, a cerebrovascular device, such as for at least partial insertion into the cerebrovasculature. The device can include a Sheath Catheter. The Sheath Catheter can include an elongate body. The elongate body can include an elongate outer body and an elongate inner body having an outer circumference smaller than the outer circumference of the outer body. An inflation lumen can be defined between the outer body and the inner body. An internal working lumen can be defined within the inner body. The internal working lumen can extend between a proximal portion and a distal portion of the elongate body of the Sheath Catheter. An inflatable balloon can be disposed toward the distal portion of the elongate body of the Sheath Catheter. The inflation lumen can extend between the proximal portion of the elongate body of the Sheath Catheter and the balloon, such as to enable inflation or deflation of the balloon, to provide fluid communication to the balloon, etc. The inner body may include a metal tube extending under the balloon to inhibit collapse when inflation pressure is applied to inflate the balloon, maintain patency of the working channel, etc.

[0171] Such examples may include elements in addition to those shown or described. However, the inventors also contemplate examples in which only the elements shown or described are provided. Moreover, the inventors also contemplate examples that use any combination or permutation of the elements shown or described (or one or more aspects of those elements) with respect to the particular example (or one or more aspects of that example) shown or described herein, or with respect to any other example (or one or more aspects of that example) shown or described herein.

[0172] In the event of inconsistent usage between this specification and a document incorporated by reference, the usage in this specification shall control. The terms "one" or "an" are used herein, as is common in patent documents, to include one or more, regardless of other instances or uses of "at least one" or "one or more." The term "or" is used herein to refer to a non-exclusive entity, unless otherwise specified, such that "A or B" includes "A but not B," "B but not A," and "A and B." The terms "including" and "in which" are used herein as the plain-English equivalents of the terms "comprising" and "wherein," respectively. Also, in the following claims, the terms "comprising" and "comprising" are open-ended, i.e., systems, devices, articles, compositions, formulations, or processes that include multiple elements in addition to those recited with such terms in the claims are still considered to be within the scope of the claims. Moreover, in the following claims, the terms "first," "second," and "third," etc., are used merely as labels and are not intended to impose numerical requirements on their objects.

[0173] Geometric terms such as "parallel," "orthogonal," "circular," and "square" are not intended to require absolute mathematical precision unless the context dictates otherwise. Instead, such geometric terms take into account variations due to manufacturing or equivalent functions. For example, if an element is described as "circular" or "nearly circular," parts that are not exactly circular (e.g., parts that are slightly elliptical or multi-sided polygonal) are also included in this description.

[0174] Examples of the methods described herein may be implemented at least partially on a machine or computer. Some examples may include a computer-readable medium or machine-readable medium encoded with instructions operable to configure an electronic device to perform the methods described in the examples. Implementations of such methods may include code such as microcode, assembly language code, high-level language code, etc. Such code may include computer-readable instructions for performing various methods. The code may form part of a computer program product. Further, in one example, the code may be tangibly stored on one or more volatile, non-transitory, or non-volatile tangible computer-readable media, such as during execution or at other times. Examples of these tangible computer-readable media may include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or memory sticks, random access memory (RAM), read-only memory (ROM), etc.

[0175] The above description is intended to be illustrative, not limiting. For example, the above-described examples (or one or more aspects thereof) can be used in combination with each other. Other embodiments will be apparent to those skilled in the art upon reviewing the above description. The Abstract is provided to comply with 37 CFR §1.72(b) to allow the reader to quickly ascertain the nature of the technical disclosure. The Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be construed as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Accordingly, it is contemplated that the following claims are incorporated into the Detailed Description as an example or embodiment, with each claim standing on its own as a separate embodiment, and that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

[Claim 1] The invention described in the specification and drawings.

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