Removal of thrombotic material

Abstract

A catheter for removal of thrombotic material from a head vessel is provided. The catheter includes a suction sheath (110) for removing thrombotic material (400) from a distal side to a proximal side of the catheter, an expansion sheath (120) for delivering an inflatable balloon (130) for occluding the vessel in an inflated state, and a tubular extension (140) extending beyond a distal end of the expansion sheath, the extension (140) being positioned such that when the distal end of the expansion sheath is positioned upstream of the eye, a distal tip of the extension is positioned downstream of the eye. A method for removal of thrombotic material from a head vessel is also provided.

Description

[Technical Field]

[0001] This application claims the benefit of European Patent Application No. EP21383118, filed December 9, 2021. The present disclosure relates generally to devices and methods for the removal of thrombotic material, and more particularly to catheters, methods and systems for the removal of thrombotic material from head vessels. [Background technology]

[0002] A stroke is a medical disorder in which the blood supply to a part of the brain is interrupted, causing that part of the brain to lose oxygen and nutrients. Stroke is a cerebrovascular disease that can cause serious health problems and even death. There are two types of stroke: ischemic stroke, where blood flowing to the brain through its supplying blood vessels is blocked, and hemorrhagic stroke, where bleeding occurs in the brain. Ischemic stroke can be caused by a blood clot or thrombotic material blocking or obstructing a blood vessel in the brain. Many ischemic strokes occur in the region of the middle cerebral artery. Thrombotic material, e.g., a thrombus, can be located within the middle cerebral artery. Treatment is based on the removal of the thrombus from the middle cerebral artery. In recent years, several methods have been developed, including the use of catheters that can be inserted through blood vessels into or advanced through the middle cerebral artery.

[0003] The catheter may have an inflatable device that temporarily blocks blood circulation upstream of the vessel to facilitate removal of thrombotic material downstream of the vessel. Although catheters offer a less traumatic solution than older surgical procedures, catheter inflatable devices can damage blood vessel walls and cause bleeding, the latter being particularly serious when brain regions are involved. Even if the catheterization procedure is performed by highly specialized personnel, the condition of the vessel wall may make it inadvisable to perform the procedure due to the risk of vessel damage. Therefore, a need remains for catheters, methods and systems for removing thrombotic material from head vessels that can address at least some of the above-mentioned problems. Summary of the Invention

[0004] In a first aspect, a catheter for removing thrombotic material from a cranial blood vessel is provided. The catheter includes a suction sheath for removing thrombotic material from the distal side to the proximal side of the catheter, and an inflation sheath for delivering an inflatable balloon for occluding the blood vessel in an inflated state, the inflatable balloon being disposed at the distal end of the inflation sheath. The suction sheath has a tubular extension extending beyond the distal end of the inflation sheath, the length of the extension being determined so that when the distal end of the inflation sheath is disposed upstream of the ophthalmic segment, the distal tip of the extension is disposed downstream of the ophthalmic segment of the internal carotid artery.

[0005] In this embodiment, a catheter is provided that allows for extraction (e.g., aspirating or removing) of thrombotic material from the downstream region of the eye, a particularly difficult region of the cerebral blood vessels, and for occluding the internal carotid artery in a region of the internal carotid artery excluding the subarachnoid space. An example of a region excluding the subarachnoid space would be the cavernous and intrapetrous regions of the internal carotid artery. On the other hand, if a secondary lesion, such as rupture, occurs in the wall of the cavernous and intrapetrous regions of the internal carotid artery, the lesion rarely causes intracranial hemorrhage. On the other hand, the lesion obstructs the passage of blood through the internal carotid artery, which may be compensated for intracranially by blood from the circle of Willis. Blood from the circle of Willis at least partially fills the brain, which may compensate for the obstruction of blood passage through the internal carotid artery caused by the lesion without clinical consequences.

[0006] Furthermore, lesions of the internal carotid artery wall upstream of the eye may not pose as high a risk as injuries downstream of the eye, which may be life-threatening and cause more serious damage, which may be associated with loss of the patient's ability to see, speak, hear, or lose partial or complete mobility.

[0007] Therefore, occlusion of the internal carotid artery upstream of the eye means occlusion of the internal carotid artery in a safer area than downstream of the eye.

[0008] In that embodiment, proximal occlusion of the inflatable balloon and distal aspiration or thrombus removal may be achieved through the use of the catheters disclosed herein.

[0009] In that embodiment, upstream occlusion with an inflatable balloon and downstream aspiration or removal of the thrombus may be achieved using the catheters disclosed herein.

[0010] The extension may protrude distally from the expansion sheath or toward the thrombotic material or tissue during use. The extension may extend beyond the distal end of the expansion sheath in the direction of the longitudinal axis of the catheter. The suction sheath and expansion sheath may be relatively coaxial, so that the extension may protrude from the extension distal end of the expansion sheath in the direction of the longitudinal axes of the suction sheath and expansion sheath.

[0011] The thrombotic material may be a so-called soft thrombus, especially a relatively new soft thrombus.

[0012] The tubular extension may have substantially the same inner cross-section as the suction sheath. Substantially the same inner cross-section may relate to size and / or shape. The tubular extension may have a substantially different cross-section than the suction sheath. The substantially different inner cross-section may relate to size and / or shape.

[0013] The expansion sheath may be disposed at least partially around the suction sheath. The ophthalmic segment includes the region of the internal carotid artery from which the ophthalmic artery arises, emerging from the internal carotid artery downstream of the carotid siphon.

[0014] In one embodiment, the length of the extension is determined so that when the distal end of the inflation sheath is positioned in the petrous or cavernous portion of the internal carotid artery, the distal tip of the extension is positioned in the middle cerebral artery. In this manner, thrombotic material can be removed or extracted from the middle cerebral artery through the distal tip of the extension. The balloon can be inflated in the petrous or cavernous portion. In this regard, a particularly difficult area of ​​the cerebral vasculature may be the middle cerebral artery, and an area of ​​enhancement of the internal carotid artery may be the cavernous or petrous portion of the internal carotid artery.

[0015] In some embodiments, the length of the extension is determined so that when the balloon is positioned to occlude the petrous or cavernous portion of the internal carotid artery, the distal tip of the extension is positioned in the middle cerebral artery.

[0016] In a further embodiment, the length of the extension is within the range of 25 mm to 60 mm, particularly 45 to 55 mm. Extensions having lengths within these ranges may allow for the removal of thrombotic material from a downstream segment of the eye when the upstream segment may be occluded by an inflatable balloon.

[0017] An extension having a length within these ranges may allow removal of thrombotic material from the middle cerebral artery when the internal carotid artery may be occluded at the cavernous or petrosal portion with an inflatable balloon.

[0018] The length of the extension according to any of the embodiments disclosed herein allows for the removal of thrombus from extremely difficult to access areas while simultaneously temporarily occluding upstream blood circulation in relatively more protected areas of the cranial circulatory system.

[0019] As used herein, the expression distal may be understood to mean the region furthest from the practitioner or the region that will be closer to the clot in use. For example, the distal end of a portion is intended to be closer to the thrombotic material in use than the proximal end. As used herein, the expression proximal may be understood to mean the area closest to the practitioner or the area furthest from the clot in use. For example, the proximal end of a portion is intended to be further from the thrombogenic material in use than the distal end. As used herein, the expression distal may be understood to mean closer to the thrombotic material or tissue in use. As used herein, the expression proximal may be understood to mean closer to the point of entry of the vessel in use. As used herein, the terms upstream and downstream may refer to the direction of blood flow through human blood vessels. For example, blood flows from an upstream region of the eye to a downstream region of the eye. Or, blood flows from the internal carotid artery to the middle cerebral artery.

[0020] In this disclosure, the phrase "an inflatable balloon disposed at the distal end of the expansion sheath" is understood to mean that the balloon can at least partially surround the distal end of the expansion sheath in the deployed or inflated state. In some embodiments, the balloon can completely surround the distal end of the expansion sheath in the deployed or inflated state.

[0021] The term "cranial vessels" refers to a single vessel, e.g., the internal carotid artery, or a set of vessels in fluid communication with one another that may define a blood pathway, e.g., the internal carotid artery and the middle cerebral artery. A set of vessels may include a first and a second vessel in fluid communication with one another. Any size or shape may be considered in this disclosure based on the average size or shape of an adult body.

[0022] Non-limiting examples of the present disclosure are described below with reference to the accompanying drawings. [Brief explanation of the drawings]

[0023] [Figure 1] 1A and 1B illustrate schematic diagrams of an embodiment of a system for retrieving thrombotic material from a blood vessel. [Figure 2]2A and 2B are schematic partial and cross-sectional views of the suction sheath and inflation sheath of the catheter of the system of FIG. 1; [Figure 3] 3A and 3B show schematic details of the distal ends of the suction sheath and expansion sheath according to the embodiment of FIG. 2; [Figure 4A] 1A-1C schematically illustrate partial views of the distal end of a catheter from different perspectives according to one embodiment. [Figure 4B] 1A-1C schematically illustrate partial views of the distal end of a catheter from different perspectives according to one embodiment. [Figure 5] 1A and 1B schematically illustrate a distal end of a catheter and a partial view of a deployable mesh according to one embodiment. [Figure 6] 3 shows a schematic partial view of the distal end of the catheter of FIG. 2 within a portion of a blood vessel. [Figure 7] 7A and 7B are schematic views of a partial view of the distal end of the catheter of FIG. 6 with the mechanical retriever in a deployed state; [Figure 8] 10A and 10B show schematic partial views of the distal end of a catheter aspirating thrombotic material. [Figure 9] 1 shows a schematic representation of an example blood vessel. [Figure 10] FIG. 1 is a block diagram of an embodiment of the method of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0024] FIG. 9 shows a schematic representation of an example blood vessel, specifically a portion of the internal carotid artery ICA and the middle cerebral artery MCA of the human body. In the present disclosure, the internal carotid artery ICA is considered to include, among other segments or portions: the cervical part CE, the petrous part PE, the corpus cavernosum CA, the carotid siphon CS, the eye OP, and the brain CB. In FIG. 9, the petrous part PB is also shown schematically.

[0025] FIG. 1 illustrates a schematic diagram of an embodiment of a system 100 for retrieving thrombotic material from a blood vessel. The system 100 includes a catheter 3 that is introduced through a human blood vessel. The catheter 3 may be according to any of the embodiments disclosed herein. The system 100 generally depicts an elongated structure having a distal side 1 and a proximal side 2. Portions of the present disclosure may be referred to as the distal side or the proximal side for convenience.

[0026] The catheter 3 can be introduced into the patient's body at a suitable location by puncture (not shown) to access the circulatory system, for example, a peripheral artery or a neurovascular artery. The catheter 3 can be advanced to a region of the circulatory system where the thrombotic material to be removed is expected to be present. This region can be referred to as the target site. The thrombotic material can be present in the head region, particularly in the blood vessels of the head. The distal side 1 is intended to be the first portion introduced into the patient's body and is the portion of the catheter 3 intended to be closest to the thrombotic material to be removed. To reach the target area, the catheter 3 may be advanced coaxially through a guiding catheter (not shown). Microcatheters and guidewires may be placed inside the catheter 3 to assist in distal navigation. The most distal portion of the catheter 3 may terminate in a rounded, atraumatic tip to avoid, or at least reduce, damage to the blood vessel during advancement. The distal portion of the catheter may be coated with a hydrophilic coating, which may aid in navigating the catheter through circuitous paths in the circulatory system. The catheter may be made of a suitable material or have a configuration that allows it to adapt to the shape of the blood vessel. The material of the catheter 3 that is intended to be in contact with the blood vessel may at least be biocompatible.

[0027] The system 100 of FIG. 1 includes a hub 20 for a receiver. The hub 20 may be a female luer lock connector that can mate with a male luer lock fitting (not shown). The male luer lock fitting may include an injection or withdrawal syringe or a hemostatic key. Male and female luer locks are a standardized system for small-scale fluid fittings used in medical and laboratory equipment to form a leak-tight connection between a male fitting and its female counterpart. The hub 20 in the embodiment of FIG. 1 is "Y" shaped and has two input ports 21, 22. The shape and number of ports can vary. In the system shown, the hub has a side port 22 and a straight port 21. The side port 22 can allow diluted contrast to enter for inflation and deflation of the inflatable balloon 130 of the catheter 3. The straight port 21 can be configured to allow the passage of devices such as microcatheters, stents, guidewires, retriever devices, fluids, suction, etc.

[0028] In one embodiment, the effective length of the catheter may be, but is not limited to, 125 cm. The overall length of the catheter may be, but is not limited to, 132 cm. The outer diameter of the catheter may fit into a 6F to 8F introducer sheath. The latter may mean that the catheter 3 can pass through the inside of such an introducer sheath.

[0029] 2 shows a partial and cross-sectional view of the suction sheath and expansion sheath of the catheter of the system of FIG. 1, and FIG. 3 shows a detailed view of the distal end of the suction sheath and expansion sheath according to the embodiment of FIG.

[0030] As previously mentioned, aspects of the present disclosure relate to a catheter 3 for removal of thrombotic material 400 from a cranial blood vessel 200. The catheter 3 includes a suction sheath 110 for removing thrombotic material 400 from a distal side 1 to a proximal side 2 of the catheter 3. The catheter also includes an expansion sheath 120 for delivering an inflatable balloon 130 that occludes the blood vessel 200 in an inflated state. The inflatable balloon 130 is disposed at a distal end 121 of the expansion sheath. The suction sheath 110 has a tubular extension 140 that extends beyond the distal end 121 of the inflation sheath. The length L of the extension is determined so that when the distal end 121 of the inflation sheath is positioned upstream 202 of the eye OP, the distal tip of the extension 141 is positioned downstream 201 of the eye OP of the internal carotid artery.

[0031] In some embodiments, the length L of the extension can be determined such that when the distal end 121 of the expansion sheath is positioned in the petrous portion PE or the cavernous portion CA of the internal carotid artery, the distal tip 141 of the extension can be positioned in the middle cerebral artery. Thus, when the distal end of the expansion sheath is positioned upstream of the eye OP, the distal tip 141 of the extension can be positioned downstream of the eye OP. In some embodiments, the length L of the extension can be determined so that when the balloon 130 is positioned to occlude the petrous or cavernous portion of the internal carotid artery, the distal tip 141 of the extension is positioned in the middle cerebral artery. The petrous or cavernous portion is positioned upstream of the ophthalmic portion. The petrous or cavernous portion can provide support to the vessel wall when the balloon 130 is inflated to occlude the vessel. In one embodiment, the length L of the extension can be in the range of 25 mm to 60 mm, particularly 45 to 55 mm, which may allow the distal tip 141 of the extension to be positioned downstream of the ophthalmic portion OP, for example, in the middle cerebral artery, when the distal end 121 of the inflation sheath is positioned in the cavernous or petrous portion of the internal carotid artery. The length L of the extension may be sufficient to be positioned along the carotid siphon in use.

[0032] In the embodiment of Figures 2 and 3, the expansion sheath 120 is disposed about the suction sheath 110 such that the expansion sheath 120 and the suction sheath 110 are coaxially disposed. In Figures 2 and 3, the longitudinal axis LA of the catheter 3 is shown. The coaxially disposed features may be relative to the longitudinal axis LA of the catheter 3, as shown in Figure 2. In one embodiment, the expansion sheath 120 can at least partially surround the suction sheath 110. In some embodiments not shown, the expansion sheath 120 and the suction sheath 110 are non-coaxially disposed within a third covering tube. In one embodiment, the suction sheath 110 may have several stiffness changes along its length, for example, 10. The proximal end may be stiffer than the distal end.

[0033] The extension 140 may have different mechanical characteristics than the remainder of the suction sheath 110. By way of non-limiting example, the extension 140 may be more flexible than the remainder of the suction sheath 110. The extension 140 is not surrounded by the inflation sheath 120 and may be better able to conform to particularly tricky vascular geometries, such as the middle cerebral artery and / or downstream regions of the eye.

[0034] In some embodiments, the expansion sheath 120 may have several stiffness changes along its length, for example, three stiffness changes. The proximal end may be stiffer than the distal end. The number and location of the changes in both the suction sheath and the expansion sheath may vary from case to case. The expansion sheath 120 and the suction sheath 110 may be removably coupled to one another. The expansion sheath 120 and the suction sheath 110 may be arranged such that there is substantially no relative movement therebetween in the direction of the longitudinal axis and / or relative rotation about the longitudinal axis LA. The expansion sheath 120 and the suction sheath 110 may be fixedly arranged relative to one another.

[0035] In some embodiments, the expansion sheath 120 can include a tubular body. In one embodiment, the expansion sheath 120 can have an outer diameter of 2.13 mm. This diameter and / or shape can vary depending on the situation. The tubular body of the expansion sheath 120 can be made, at least in part, from a reinforced material, such as a braided reinforcement material, which provides a relatively sturdy structure while allowing the outer contour of the expansion sheath 120 to conform to the shape of the vessel. Examples of suitable materials for the expansion sheath can include stainless steel, e.g., stainless steel 304V, nitinol, fabrics, fibers, or high-strength polymers.

[0036] Aspiration lumen 113 may be defined within suction sheath 110. Aspiration lumen 113 may be further defined within suction sheath extension 140. The aspiration lumen may have a cross-section having substantially the same shape and size in suction sheath 110 and extension 140. In some examples, the aspiration lumen may have a cross-section having a shape and size that may differ from that of suction sheath 110.

[0037] The suction sheath 110 may include a tubular body. In some embodiments, the tubular body of the expansion sheath 120 may at least partially and concentrically surround the tubular body of the suction sheath 110. The tubular body of the suction sheath 110 may have a reinforcing structure. The tubular body of the suction sheath 110 may include a braid, coil, or fiber-like structure. The tubular body of the suction sheath 110 may include a coil. The coil may be made of nitinol or any other suitable elastic material. The coiled configuration or structure may allow the suction sheath to conform to the shape of the blood vessel while at the same time having adequate mechanical strength. Examples of suitable materials for the suction sheath may include stainless steel, nitinol, fabric, fiber, or high-strength polymer.

[0038] The aspiration lumen 113 may be configured as a pathway that allows thrombotic material to be transported from the distal end to the proximal end of the catheter 3. The thrombotic material or thrombus may be transported through the aspiration lumen by aspiration and / or mechanical extraction.

[0039] In one embodiment of removing the thrombus by suction, a suitable vacuum may be generated within the suction lumen that may at least partially absorb the thrombus from the blood vessel. A vacuum source may be coupled to the proximal end of the catheter 3 to provide a vacuum within the suction lumen 3. The vacuum source may be in fluid communication with the hub 20.

[0040] In one example of removing thrombus by mechanical extraction, the aspiration lumen may allow for the passage of devices and tools to and from the region of the cranial vessel where thrombotic material is present. Examples of devices that may be employed for the removal of thrombotic material are described in this disclosure.

[0041] An inflation lumen 123 may be defined between the inflation sheath 120 and the suction sheath 110. The inflation lumen 123 may be configured as a pathway for a fluid employed to inflate or deflate the inflatable balloon 130. The fluid passage may be toward the distal end of the catheter when the balloon 130 is inflated, or toward the proximal end of the catheter when the balloon 130 is deflated. An inflation device, for example, a syringe, may be coupled at the proximal end of the catheter to deliver fluid to the inflation lumen 123.

[0042] The catheter may include inflation holes 125 disposed substantially at the distal end of the inflation sheath 121 such that the interior of the balloon 130 may be in fluid communication with the inflation lumen 123. The number of inflation holes 125 may vary. The holes 125 may be arranged to define a spiral or a straight line. The inflation orifices 125 allow a volume of fluid to enter or exit the inflatable balloon 130 from the inflation lumen 123. The inflatable balloon 130 may be pumped through one or more inflation holes 125.

[0043] In one embodiment, the inflatable balloons may have an inflation volume in the range of approximately 0.5 ml to 2.0 ml. The number of balloons 130 may vary from case to case.

[0044] In some embodiments, the suction sheath extension 140 may include a tubular body. The tubular body of the suction sheath extension 140 may have a reinforcing structure in the form of a braid, a coil, or a fiber-like structure. The tubular body of the extension 140 may include a coil. In this manner, the behavior of the extension 140 is substantially identical to that of a suction sheath. The extension can conform to the relatively complex shape of a cranial artery, such as the carotid siphon CS, while maintaining adequate mechanical strength. Examples of suitable materials for the extension may include stainless steel, nitinol, fabric, fiber, or a high-strength polymer or nitinol.

[0045] In some embodiments, extension 140 may have an inner diameter of at least 1.45 mm. Extension 140 may have an outer diameter of at least 1.60 mm. However, these details may depend on the illustrated shape and size.

[0046] In some embodiments, the inner diameter of the extension can be in the range of approximately 1.45 mm to 1.70 mm. In some embodiments, the extension 140 can have an outer diameter in the range of approximately 1.60 mm to 2.13 mm.

[0047] The suction sheath 110 may be made integral with the extension 140 or both components may be bonded to one another.

[0048] As shown in the embodiment of Figure 3, the distal tip 141 of the extension has an opening 144 for receiving the thrombotic material. The opening 144 can be an opening in the tubular body of the extension. 2-3, it can be seen that the expansion sheath 120 has a tapered end 124 on its distal side 1. The tapered end 124 may aid in the introduction of the catheter 3 into a blood vessel. The tapered end 124 may be defined between the outer surface of the expansion sheath 120 and the proximal tip 142 of the extension 140.

[0049] 4A and 4B schematically illustrate partial views of the distal end of a catheter from different perspectives according to one embodiment. In these figures, some hidden elements are shown for clarity. Thus, the structure of the elements according to one embodiment can be seen. As shown in FIGS. 4A and 4B, the suction sheath 110, the inflation sheath 120, and the extension 140 have a specific shape for at least a portion of their length. This specific shape may correspond to the shape of the blood vessel.

[0050] In the example of Figures 3 and 4B, suction sheath extension 140 is seen to include a first radiopaque marker element 143. First radiopaque marker element 143 may be disposed at distal tip 141. In the example of Figures 4A and 4B, inflatable balloon 130 is seen to include a second radiopaque marker element 133. While one example is shown having first and second radiopaque elements, examples are envisioned in which only one radiopaque element is present, or in which both radiopaque elements are absent.

[0051] 5 schematically illustrates a partial view of the distal end of a catheter and an expandable mesh according to one embodiment. The expandable mesh can be an example of a mechanical retriever or retrieval device. While the embodiment of FIG. 5 illustrates the catheter 3 in a normal straight state, the overall shape of the catheter 3 can be altered to accommodate the overall shape of the blood vessel.

[0052] The catheter 3 may include a device for mechanical removal of thrombotic material, as described above. In one embodiment, the catheter 3 includes an expandable mesh 150 that passes through the aspiration lumen 113 in the collapsed position and encapsulates at least a portion of the thrombotic material 400 in the expanded position. The expandable mesh 150 may be disposed inside a microcatheter 153 that is carried through the aspiration lumen 113. One embodiment of the microcatheter 153 is shown in FIG. 5. The microcatheter 153 and mesh may be introduced into the aspiration lumen through the straight port 21 of the hub 20 of FIG. 1. The expandable mesh 150 may include multiple wires 155 that interconnect to form a net. The expandable mesh 150 may be a stent retriever.

[0053] Although an embodiment of the expandable mesh 150 is described in this disclosure, the user may incorporate other mechanical retriever embodiments, which may vary in shape, material, or components. The mechanical retriever may capture or encapsulate thrombotic material to be removed from the vessel. Non-illustrated examples of mechanical retrievers may similarly pass through the aspiration lumen.

[0054] In some embodiments, the catheter 3 includes a guidewire (not shown for clarity) that guides placement of the catheter 3 through the blood vessel 200 along with the microcatheter 153. The diameter of the guidewire can be selected to pass through the microcatheter 153.

[0055] Examples of methods for removing thrombotic material according to the present disclosure are described below. Such methods may be performed using the catheters of the examples described herein. Examples of methods are described in relation to Figures 6-8. Figure 6 schematically shows a partial view of the distal end of the catheter of Figure 2 within a portion of a blood vessel. Figure 7 schematically shows a partial view of the distal end of the catheter of Figure 6 with a mechanical retriever in a deployed state. Figure 8 also shows a partial view of the distal end of the catheter aspirating thrombotic material. Figure 10 is a block diagram of one example of a method of the present disclosure. In an aspect of the present disclosure, a method 500 for removal of thrombotic material from a cranial vessel is disclosed. The method 500 includes the following steps: A step of preparing a catheter disclosed herein in a cephalic vessel 510 such that the distal end of the suction sheath is positioned downstream of the internal carotid artery OP when the distal end of the expansion sheath is positioned upstream of the eye OP. A guidewire with a microcatheter is placed inside the catheter 3, and the catheter 3 with the guidewire and microcatheter can be introduced through the patient's circulatory system until they reach the target site, i.e., an area near or containing the thrombotic material 400 to be removed. At least a distal portion of the catheter 3 can remain in the target vessel 200. FIG. 6 shows a schematic diagram of how the catheter 3 can be positioned within or inside the vessel 200 to remove the thrombus 400. In one embodiment, the distal tip of the extension 141 can be positioned downstream of the eye OP, while the distal end of the expansion sheath 121 can be positioned upstream of the eye OP. In FIG. 6, the inflatable balloon 130 is in its retracted or deflated position, allowing blood flow 203 to continue through the vessel 200; Inflating a balloon upstream of the eye 520. In FIG. 7, the balloon 130 is pumped with fluid 126. The fluid 126 passes through the inflation lumen 123 and exits the interior of the balloon 130 through the inflation hole 125. The catheter 3 is positioned in the patient's body so that the distal end 121 of the inflation sheath, and thus the balloon 130, is positioned substantially in the upstream region of the eye OP. As more fluid 126 enters the balloon 130, the volume of the balloon 130 increases, and more occlusion may be created against the blood vessel 200, and in particular against the inner surface 204 of the blood vessel 200. The flow of blood 203 is temporarily interrupted by the blocking action exerted by the inflated balloon 130; Extraction of thrombotic material from downstream of the eye 530. Thrombotic material 400 can be removed in a variety of ways. FIG. 7 illustrates an example of mechanical removal of thrombotic material using an expandable mesh 150. FIG. 8 illustrates an example of removal by aspiration or suction. In either case, the thrombus or a portion of the thrombus 400 can migrate along the aspiration lumen 113 in the direction indicated by arrow 114 to the proximal end of the catheter. In an aspiration example, the thrombus material can be aspirated or sucked by a vacuum generated, for example, by a vacuum source in fluid communication with the hub 20. In a mechanical retrieval example, a retriever is delivered from the distal end of the catheter 3 by a driver coupled to the hub 20 or by the user. The presence of the extension 140 of length L, as defined herein, allows for distal removal of the thrombus by proximal interruption of blood flow 203.

[0056] In some embodiments of the method 500, the step of providing a catheter disclosed herein in the head vessel 510 such that when the distal end of the expansion sheath is positioned upstream of the eye OP, the distal end of the suction sheath is positioned downstream of the eye OP of the internal carotid artery may include the step of providing the catheter such that when the distal end of the expansion sheath is positioned in the petrous or cavernous portion of the internal carotid artery, the distal tip of the extension is positioned in the middle cerebral artery; Inflating the balloon upstream of the ophthalmic portion may include inflating the balloon in the petrous portion PE or the cavernous portion CA of the internal carotid artery; The step of removing thrombotic material from downstream of the eye OP may include the step of aspirating thrombotic material from the middle cerebral artery MCA.

[0057] In some embodiments of the method 500, the distal tip of the extension may be positioned in the middle cerebral artery when the balloon 130 is positioned to occlude the petrous or cavernous portion of the internal carotid artery. The balloon 130 may be positioned relative to the inflation sheath 120 to block the internal carotid artery in this manner.

[0058] In some embodiments, the method 500 includes the following steps: deploying the deployable mesh 150 to at least partially encapsulate the thrombotic material 400. A practitioner may control the movement of the deployment mesh 150 through the hub 20; Dislodging the encapsulated thrombotic material prior to aspiration of the thrombotic material. The deployable mesh 150 can aid in the removal of the thrombotic material 400, which can be aspirated through the aspiration lumen. The thrombotic material 400 can include at least a portion of a soft thrombus. In some embodiments, the method may include the following steps: Passing a microcatheter through the suction sheath extension and carrying the deployable mesh 150. The microcatheter may pass along the suction lumen from the hub 20 to the distal tip 141 of the extension 140. The practitioner may control the movement of the deployment microcatheter through the hub 20.

[0059] For reasons of completeness, various aspects of the disclosure are described in the following numbered sections: Section 1. A catheter for removal of thrombotic material from a head vessel is provided, the catheter comprising: a suction sheath for extracting thrombotic material from the distal to the proximal side of the catheter; an expansion sheath for delivering an inflatable balloon for occluding the blood vessel in an inflated state, the inflatable balloon being disposed at a distal end of the expansion sheath; The suction sheath has a tubular extension that extends beyond the distal end of the expansion sheath, and the length of the extension is determined so that when the distal end of the expansion sheath is positioned upstream of the ophthalmic segment, the distal tip of the extension is positioned downstream of the ophthalmic segment of the internal carotid artery. Clause 2. The catheter of clause 1, wherein the length of the extension is determined such that when the distal end of the expansion sheath is positioned in the petrous or cavernous portion of the internal carotid artery, the distal tip of the extension is positioned in the middle cerebral artery. Clause 3. The catheter of clause 1, wherein the length of the extension is determined so that when the balloon is positioned to occlude the petrosal or cavernous portion of the internal carotid artery, the distal tip of the extension is positioned in the middle cerebral artery. Section 4. The catheter of any one of sections 1 to 3, wherein the length of the extension is in the range of 25 mm to 60 mm, particularly 45 to 55 mm. Clause 5. The catheter of any one of clauses 1-4, wherein the expansion sheath is disposed about the suction sheath such that the expansion sheath and the suction sheath are coaxially disposed. Clause 6. The catheter of any one of clauses 1-5, wherein the suction lumen is defined within the suction sheath. Clause 7. The catheter of clause 6, wherein the aspiration lumen is defined within the extension of the suction sheath. Clause 8. The catheter of any one of clauses 1-7, wherein the inflation lumen is defined between the inflation sheath and the suction sheath. Clause 9. The catheter of clause 8, including an inflation lumen disposed substantially at the distal end of the inflation sheath such that the interior of the balloon is in fluid communication with the inflation lumen. Clause 10. The catheter of any one of clauses 1-9, wherein the inflatable balloon is disposed at the distal end of the inflation sheath. Clause 11. The catheter of any one of clauses 1 to 10, wherein the extension of the suction sheath includes a tubular body. Clause 12. The catheter of clause 11, wherein the tubular body of the suction sheath extension has a reinforcing structure, preferably a coiled structure. Clause 13. The catheter of any one of clauses 1-12, wherein the suction sheath extension includes a first radiopaque marker element and the inflatable balloon includes a second radiopaque marker element. Clause 14. The catheter of any one of clauses 1 to 13, wherein the distal tip of the extension has an opening for receiving thrombotic material. Clause 15. The catheter of any one of clauses 6-7, including a deployable mesh that passes through the aspiration lumen in a collapsed position and encapsulates thrombotic material in a deployed position. Clause 16. A method for removal of thrombotic material from a head vessel is provided, the method comprising: providing a catheter according to any one of clauses 1 to 15 in a cephalic vessel such that a distal end of a suction sheath is positioned downstream of the ophthalmic portion of the internal carotid artery when a distal end of the inflation sheath is positioned upstream of the ophthalmic portion; inflating a balloon upstream of the eye; and removing thrombotic material from downstream of the eye. Clause 17. The step of providing a catheter in a cephalic vessel such that a distal end of a suction sheath is positioned downstream of the ophthalmic portion of the internal carotid artery when a distal end of an inflation sheath is positioned upstream of the ophthalmic portion includes the step of providing a catheter such that a distal tip of an extension is positioned in the middle cerebral artery when a distal end of the inflation sheath is positioned in the petrous or cavernous portion of the internal carotid artery; Inflating the balloon upstream of the eye includes inflating the balloon in the petrous or cavernous portion of the internal carotid artery; 17. The method of clause 16, wherein the step of removing thrombotic material from downstream of the eye comprises the step of aspirating thrombotic material from the middle cerebral artery. Clause 18. The catheter of clause 16, wherein the distal tip of the extension is positioned in the middle cerebral artery when the balloon is positioned to occlude the petrous or cavernous portion of the internal carotid artery. Clause 19. Deploying the expandable mesh to at least partially encapsulate the thrombotic material; 19. The method of any one of clauses 16-18, comprising expelling the encapsulated thrombotic material prior to extraction of the thrombotic material. Clause 20. The method of clause 19, including passing a microcatheter through an extension of the suction sheath to deliver the deployable mesh. Section 21. A catheter for the removal of thrombotic material from head vessels, a suction sheath for extracting thrombotic material from the distal to the proximal side of the catheter; an expansion sheath for delivering an inflatable balloon for occluding the blood vessel in an inflated state, the inflatable balloon being disposed at a distal end of the expansion sheath; The suction sheath has a tubular extension that extends beyond the distal end of the expansion sheath, and the length of the extension is determined so that when the distal end of the expansion sheath is positioned in the petrous or cavernous portion of the internal carotid artery, the distal tip of the extension is positioned in the middle cerebral artery. Section 22. A catheter for the removal of thrombotic material from head vessels, a suction sheath for extracting thrombotic material from the distal to the proximal side of the catheter; an expansion sheath for delivering an inflatable balloon for occluding the blood vessel in an inflated state, the inflatable balloon being disposed at a distal end of the expansion sheath; The suction sheath has a tubular extension extending beyond the distal end of the inflation sheath, and the length of the extension is determined so that when the balloon is positioned in the petrous or cavernous portion of the internal carotid artery, the distal tip of the extension is positioned in the middle cerebral artery. Section 23. A catheter for the removal of thrombotic material from head vessels, a suction sheath for extracting thrombotic material from the distal to the proximal side of the catheter; an expansion sheath for delivering an inflatable balloon for occluding the blood vessel in an inflated state, the inflatable balloon being disposed at a distal end of the expansion sheath; A catheter in which the suction sheath has a tubular extension that extends beyond the distal end of the inflation sheath, the extension having a length in the range of 25 mm to 60 mm, particularly 45 to 55 mm. Item 24. A method for the removal of thrombotic material from a head vessel, comprising: providing a catheter according to any one of clauses 1-15 and 33-35 such that when the distal end of the expansion sheath is positioned in the petrous or cavernous portion of the internal carotid artery, the distal tip of the extension is positioned in the middle cerebral artery; inflating a balloon in the petrous or cavernous portion of the internal carotid artery; removing thrombotic material from the middle cerebral artery. Section 25. A method for the removal of thrombotic material from a head vessel, comprising: Providing the catheter of any one of clauses 1-15 and 21-23 such that when the balloon is positioned to occlude the petrous or cavernous portion of the internal carotid artery, the distal tip of the extension is positioned in the middle cerebral artery; inflating a balloon in the petrous or cavernous portion of the internal carotid artery; removing thrombotic material from the middle cerebral artery. Clause 26. A system for removing thrombotic material from a head blood vessel, comprising the catheter according to any one of clauses 1 to 15 and 21 to 23, and a hub for a receiver.

[0060] While only a few embodiments have been disclosed herein, other alternatives, modifications, uses, and / or equivalents thereof are possible. Moreover, all possible combinations of the described embodiments are also encompassed. Therefore, the scope of the present disclosure should not be limited by specific embodiments, but should be determined solely by a proper reading of the claims. When reference signs relating to the figures are placed in parentheses in the claims, they are intended to enhance the understanding of the claims and should not be construed as limiting the scope of the claims.

Claims

1. A catheter for removing thrombotic material from a head blood vessel, comprising: a suction sheath for extracting the thrombotic material from the distal side to the proximal side of the catheter; an expansion sheath for delivering an inflatable balloon for occluding the blood vessel in an inflated state, the inflatable balloon being disposed at a distal end of the expansion sheath; A catheter wherein the suction sheath has a tubular extension extending beyond the distal end of the expansion sheath, the length of the extension being determined so that when the distal end of the expansion sheath is positioned upstream of the ophthalmic segment, the distal tip of the extension is positioned downstream of the ophthalmic segment of the internal carotid artery.

2. The catheter of claim 1 , wherein the expansion sheath and the suction sheath are capable of being fixedly positioned relative to one another.

3. The catheter of claim 1 , wherein the suction sheath is integrally fabricated with the extension.

4. 2. The catheter of claim 1, wherein the length of the extension is determined so that when the distal end of the expansion sheath is positioned in the petrous or cavernous portion of the internal carotid artery, the distal tip of the extension is positioned in the middle cerebral artery.

5. 2. The catheter of claim 1, wherein the length of the extension is determined so that a distal tip of the extension is positioned in the middle cerebral artery when the balloon is positioned to occlude the petrous or cavernous portion of the internal carotid artery.

6. The catheter of claim 1, wherein the extension has a length in the range of 25 mm to 60 mm, in particular 45 to 55 mm.

7. The catheter of claim 1 , wherein the expansion sheath is disposed about the suction sheath such that the expansion sheath and the suction sheath are coaxially disposed.

8. The catheter of claim 1 , wherein the expansion sheath has a tapered end relative to the distal end.

9. The catheter of claim 1 , wherein an aspiration lumen is defined within the suction sheath.

10. The catheter of claim 9 , wherein the aspiration lumen is further defined within an extension of the suction sheath.

11. The catheter of claim 9 including a deployable mesh that passes through the aspiration lumen in a collapsed position and encapsulates the thrombotic material in a deployed position.

12. The catheter of claim 11 , comprising a microcatheter for carrying the deployable mesh through the aspiration lumen.

13. The catheter of claim 11 , wherein the expandable mesh comprises multiple wires interconnected to form a net.

14. The catheter of claim 1 , wherein an inflation lumen is defined between the inflation sheath and the suction sheath.

15. The catheter of claim 14 including an inflation lumen disposed substantially at the distal end of the inflation sheath such that the interior of the balloon is in fluid communication with the inflation lumen.

16. The catheter of claim 1 , including a guidewire for guiding movement of the catheter through the blood vessel.

17. The catheter of claim 1 , wherein the suction sheath extension comprises a tubular body.

18. 18. The catheter of claim 17, wherein the tubular body of the suction sheath extension has a reinforcing structure, preferably a braided or coiled structure.

19. 18. The catheter of claim 17, wherein the extension has an inner diameter in the range of about 1.45 mm to 1.70 mm.

20. 18. The catheter of claim 17, wherein the extension has an outer diameter within the range of about 1.60 mm to 2.13 mm.

21. The catheter of claim 1 , wherein the expansion sheath comprises a tubular body.

22. 22. The catheter of claim 21, wherein the expansion sheath has an outer diameter that fits a 6F to 8F introducer sheath.

23. 22. The catheter of claim 21, wherein the tubular body of the expansion sheath is made from a reinforcing material such as braid.

24. The catheter of claim 1 , wherein the suction sheath extension includes a first radiopaque marker element.

25. The catheter of claim 1 , wherein the inflatable balloon includes a second radiopaque marker element.

26. The catheter of claim 1 , wherein the suction sheath comprises a tubular body.

27. 27. The catheter of claim 26, wherein the tubular body of the suction sheath has a reinforced structure, in particular a coiled or braided structure.

28. The catheter of claim 1 , wherein the distal tip of the extension has an opening for receiving thrombotic material.

29. The catheter of claim 1 , wherein the extension (140) has different mechanical characteristics than the remainder of the suction sheath (110).

30. A system for removing thrombotic material from a head blood vessel, comprising the catheter according to any one of claims 1 to 29 and a hub for a receiver.

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