Thrombus removal and stent implantation system

Abstract

To provide an improved system and a method for treating combined presence of clots and stenosis in a cerebral vasculature.SOLUTION: A design capable of both mechanical thrombectomy and stenting for treating occlusions in a cerebral vasculature provides a three-catheter setup. A first outer catheter has a largest diameter and can serve as a guide catheter while also being a sheath for the other catheters. A second deployment catheter can be configured for aspiration of occlusions and can include a stepped or recessed section proximal to a distal tip that can act as a housing for a braided expandable stent. The outer diameter of this stepped section can be lined with an inflation device on top of which the braided stent sits. Internal to the second deployment catheter is a microcatheter which can deliver mechanical thrombectomy devices to a target site to retrieve an occlusion in a vessel, after which the stent can be expanded and implanted in the vessel.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention generally relates to devices and methods used to remove occlusions and treat stenosis in cerebral blood vessels during endovascular medical procedures. More specifically, the present invention relates to a multi-catheter system for combining mechanical thrombectomy and stent placement procedures.

Background Art

[0002] Atherosclerosis results from lesions that narrow and reduce the space within the lumen of blood vessels in the vascular system. Such lesions typically consist of plaques that can be fat, cholesterol, calcium, or other components of blood. Severe occlusions or closures can impede the flow of oxygenated blood to different organs and parts of the body, leading to other cardiovascular disorders such as heart attacks or strokes. Narrowing of blood vessels, or stenosis, increases the risk that blood clots and other emboli can lodge in such locations, particularly within the neurovasculature where the diameter of the blood vessels is already small. Intracranial atherosclerotic disease (ICAD) is the narrowing of these arteries and blood vessels that supply blood to the brain and represents the most common proximate mechanism of ischemic stroke.

[0003] The treatment of vascular occlusions is well known in the art. The methods can include the use of drugs such as anticoagulants or antiplatelet agents, as well as medical procedures such as surgical endarterectomy, angioplasty, and stent placement. Many of the recent successes in endovascular revascularization treatment (ERT) have been in the further development of safe thrombectomy devices. Devices such as stent retrievers, direct aspiration systems, and other blood clot retrieval devices are strongly associated with better clinical outcomes. However, these devices are mainly designed to reopen blood vessels by removing and retrieving occluded emboli. If there is significant stenosis at the occlusion site, sufficient reopening may not occur, increasing the need for implanted stents.

[0004] Treatment methods for dealing with blood clots and lesions within the neurovasculature depend particularly on the degree of stenosis, the shape of the target occlusion site (i.e., the bevel, branches, etc.), and the overall condition of the patient. Mechanical procedures often involve using medical devices to retrieve occlusive blood clots and then opening the narrowed artery using balloons and stents. Following the use of a stent retriever or other blood clot retrieval device, a balloon is delivered to the target site and inflated to expand the stenosis. The balloon can then be removed and replaced via a catheter for the stent delivery device. If desired, once the stent is in place, the balloon can be inflated within the stent to firmly press the struts of the stent frame against the inner wall of the blood vessel.

[0005] However, there are various significant challenges in interpreting and diagnosing stenosis at the first location. This is particularly true for very small and tortuous blood vessels in the cerebrovascular system. During the treatment of a stroke or transient ischemic attack, it may be unknown whether an occlusion is the result of a blood clot only if stenosis is also present. Identifying stenotic lesions can be difficult because it is hard to distinguish them from blood clots and other embolic-related occlusions through baseline angiography. In many cases, the presence of stenosis is identified only after the initial treatment options have been selected and the ERT procedure is already underway, and the devices and methods used to remove the occlusion are often different from those used to treat stenosis and place a stent in the blood vessel.

[0006] When both a blood clot and stenosis are present, physicians may often need to replace the catheter, device, and often the guidewire after removing the blood clot. Thus, the need for multiple passes and device deliveries is cumbersome, and devices that provide flexibility in the procedure are highly useful because these mechanical procedures create an additional potential for releasing further fragments into the vasculature. Such fragments include, but are not limited to, blood clots, plaques, and other thrombus debris.

Summary of the Invention

Problems to be Solved by the Invention

[0007] In patients with ischemic stroke, it is always necessary for the time to treatment to be shorter in order to suppress long-term damage. Therefore, new systems and devices for addressing and continuously improving these treatments are still needed. The present design aims to provide an improved system and method for treating a condition in the cerebrovascular system that combines blood clots and stenosis to address the above-mentioned deficiencies.

Means for Solving the Problem

[0008] The object of the present design is to provide a system, device, and method that meet the above-mentioned needs. Generally, the proposed system provides three catheter configurations. The first catheter has a maximum diameter and can function as a guide catheter while also serving as a deployment sheath for other catheters. The second catheter can be configured for suction and can include a stepped or recessed section proximal to the distal tip that can act as a housing for a braided expandable stent. The outer diameter of this stepped section can be lined with a balloon or other expansion member on which a flexible stent is located. Inside the second catheter is a microcatheter that can deliver a mechanical thrombectomy device to the target site to retrieve intravascular occlusions.

[0009] An exemplary system for removing a blood clot from a blood vessel and implanting a stent in the blood vessel can include a sheath member, a deployment catheter, and a microcatheter. The three catheters can be substantially concentric. The source can be configured to aspirate the internal lumen of the sheath member and / or the deployment catheter. The deployment catheter can have a lumen and an outer surface and can be disposed within the lumen of the sheath member. The deployment catheter can have a flexible distal portion and a recessed region on its outer surface having an outer diameter smaller than the outer diameter of the deployment catheter in the region adjacent to the recessed region. The flexible region can improve deliverability and can surround the most distal region of the deployment catheter. For example, the flexible region can extend 15 to 30 centimeters proximal to the distal tip.

[0010] The inflation device and the stent implantation device can surround the recessed region of the outer surface of the deployment catheter. The recessed region can provide a seat for the inflation and stent implantation device on the outer surface and can provide a lower profile system. The stent implantation device can be self-expanding or can be expanded and implanted as a stent within a stenotic lesion using an inflation device, which is similar to the conventional methods of balloon angioplasty known in the art. Inflation can be achieved by utilizing an inflation lumen that can extend along the entire length of the deployment catheter. The inflation device can also be used to expand the blood vessel during any part of the stent implantation procedure.

[0011] For the retrieval of occlusions within blood vessels, the system can be used as an aspiration catheter that utilizes suction to remove occlusive blood clots. In situations where a blood clot is lodged within the region of a blood vessel or a constricted stenosis, the system can retrieve the blood clot by aspirating the blood clot into the lumen of the deployment catheter or by utilizing other mechanical thrombectomy techniques. For example, the third catheter of the system can be a microcatheter positioned within the lumen of the deployment catheter and configured to deliver a mechanical thrombectomy device to the target occlusion. The mechanical thrombectomy device can be any of a number of commercially available designs. In one example, it is an expandable blood clot retriever that has a folded configuration within the microcatheter but self-expands upon exiting the lumen at the distal tip to an expanded deployment configuration. The blood clot engaging portion of the device can have an expandable member that can form a flow lumen across the occlusion upon deployment, while also having a plurality of struts embedded to firmly grip the blood clot for an initial step of disengaging the blood clot from the blood vessel. Then, to remove the blood clot, the device can be retracted proximally into the deployment catheter using suction. Then, the device and the blood clot can either be withdrawn from the patient through the lumen of the catheter or retracted far enough to pack a more substantial blood clot into the tip of a larger catheter (withdrawn in series with the catheter).

[0012] In another example, a thrombectomy and stent deployment system for removing a blood clot from a blood vessel and deploying a stent in the blood vessel can include a sheath member, a deployment catheter positioned within the lumen of the sheath member, and a microcatheter positioned within the lumen of the deployment catheter. The sheath member, the deployment catheter, and the microcatheter can be concentric with each other and configured to move independently along the longitudinal axis of the system. An expandable stent deployment device can be coupled to the outer surface of the deployment catheter. The microcatheter can accommodate a blood clot retrieval device for capturing and removing the blood clot from the blood vessel.

[0013] The body of the stent delivery device can have a braided or interconnected pattern with a matrix of sufficient density to support the blood vessel wall when implanted. The mesh tube of the stent can be of a medical grade stainless steel such as 316SS, or of a cobalt or cobalt-chromium alloy. In other examples, the stent can be of a polymer or partially polymer structure. The mesh braid can also be made from a shape memory alloy so as to self-expand upon deployment. The stent can be bare metal, or the material can be coated with a non-pharmacological coating such as silicon carbide, carbon, and titanium-nitride-oxide. In other cases, the stent is coated with a biodegradable drug-eluting coating designed to inhibit restenosis. These coatings can be antiplatelet agents or anticoagulants that help prevent blood clot formation after the procedure.

[0014] In one example, a portion of the outer surface of the deployment catheter can include a recessed region having a dimension smaller than that of another region of the deployment catheter adjacent to the recessed region. The recessed region can be formed integrally with the body of the deployment catheter, such as a notch or groove cut into the outer surface of the deployment catheter. For example, if the support structure of the deployment catheter is formed from a hypo tube, the recessed region can be laser cut into the outer surface. Additional features can also be cut into the surface to improve the flexibility and tracking of the catheter. The expandable stent delivery member can be sized such that the member is positioned over or contained within the recessed region. In some cases, the system can also have an inflation device that circumscribes the stent delivery device on the outer surface of the deployment catheter. When the user desires to implant the stent within the stenotic region, the sheath member can be withdrawn to expose the stent delivery device. The inflation device can then be inflated to expand the stent delivery device scaffold and exert a radial force on the blood vessel wall.

[0015] Also provided is a method for using a system that provides flexibility for both mechanical thrombus removal and stent implantation procedures. The method can have some or all of the following steps and variations thereof, and the steps are listed in no particular order. The patient's vasculature is accessed using known prior art. A sheath member is positioned proximate to a stenotic lesion and an occlusive thrombus. A deployment catheter is disposed within the lumen of the sheath member. A microcatheter including a thrombus removal device is positioned within the lumen of the deployment catheter. A stent implantation device comprising an inflation device and a stent is positioned on the outer surface of the deployment catheter proximate to the distal end of the catheter. A suction source, such as a vacuum pump or syringe, is configured to direct suction through the lumen flow path of one or both of the sheath member and the deployment catheter. The suction can be utilized for blood clot retrieval and to prevent further embolization.

[0016] The microcatheter and thrombus removal device extend toward and across the occlusive clot while maintaining the sheath, deployment catheter, and stent implantation device proximate to the lesion. The blood clot can be aspirated through the lumen of the deployment catheter. The blood clot is captured by deploying the thrombus removal device from the microcatheter while maintaining the position of the thrombus removal device across the blood clot and retracting the microcatheter proximally. The microcatheter and thrombus removal device having the captured blood clot can then be withdrawn into the lumen of the deployment catheter. Alternatively, the sheath member, deployment catheter, and stent implantation device can be advanced over the thrombus removal device to intersect and align with the stenosis. Once in position, the sheath member can be retracted proximally of the lesion to expose the stent implantation device.

[0017] The stent delivery device can be inflated and can expand both the delivery device and the stent radially across the lesion. This radial expansion can increase the diameter of the first portion of the blood vessel containing the lesion to at least 75% of the diameter of the second portion of the blood vessel adjacent to the first portion. This process opens the blood vessel and reduces the stenosis / occlusion caused by stenosis. When the desired expansion is achieved, the stent can be released in place as an implant by contracting the delivery device. When the stent is in place, the rest of the system can be withdrawn from the patient.

[0018] By having the flexibility to perform mechanical thrombectomy and stent delivery procedures using a single system such as the current design, the treatment time can be significantly reduced, thus resulting in better clinical outcomes. This is particularly true in the case of stroke patients.

[0019] Other aspects and features of the present disclosure will be apparent to those skilled in the art by considering the following detailed description in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0020] The foregoing and further aspects of the present invention will be further considered in conjunction with the following description of the accompanying drawings, in which like numerals in the various drawings indicate like structural elements and features. The drawings are not necessarily to scale, and instead, emphasis is placed on illustrating the principles of the present invention. The figures depict one or more implementations of the apparatus of the present invention by way of example and not limitation. Those skilled in the art can envision and combine elements from the plurality of figures as may best suit the requirements of the user.

Figure 1A

Figure 1B

Figure 1C

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 3E

Figure 3F

Figure 3G

Figure 3H

Figure 3I

Figure 3J

Figure 4

[0021] Here, specific embodiments of the present invention will be described in detail with reference to the drawings, where like reference numerals indicate functionally similar or identical elements. The object of the present invention is to provide a system or device that gives a physician the advantage of operational flexibility to accommodate complications or unknown symptoms in endovascular procedures, such as when an occluded blood vessel has a blood clot and also has a stenotic region that was not detected during angiography. These improvements can lead to safe and more rapid access to complex regions of intracranial arteries to remove occlusions and shorten the treatment time.

[0022] Regardless of whether it is a coronary vessel, a pulmonary vessel, or a cerebral vessel, accessing various vessels within the vasculature involves well-known procedural steps and typically involves the use of a number of conventional commercially available accessory products. These products, such as angiographic materials, rotary hemostatic valves, and guidewires, are widely used in laboratories and medical procedures. When these products are used in conjunction with the systems and methods of the present invention in the following description, their functions and exact configurations are not described in detail. This specification is often related to the treatment of intracranial arteries, but the systems and devices may be used equally well in other body passages.

[0023] Referring to the figures, FIGS. 1A - 1C illustrate a system 100 capable of treating both occlusions and stenoses within a blood vessel. As illustrated, the system 100 can have a first outer guide catheter or sheath member 102 having an internal lumen 104. A second deployment catheter 106 can be disposed within the lumen 104 of the sheath member 102. The sheath member 102 can function as the guide catheter of the system 100. The sheath member can also function as a deployment sleeve for the deployment catheter and can protect the remainder of the system during delivery and deployment.

[0024] As illustrated in the cross-sectional view of FIG. 1C, the deployment catheter 106 can have a distal end 107, an outer diameter D2, an outer surface 110, an inner lumen 108, and a flexible portion 111 circumferentially disposed in an annular pattern around the outer surface proximate the distal end. The deployment catheter can also have a stepped or recessed region 120 immediately proximal to the distal end 107 of the catheter, where the recessed region outer diameter D1 is smaller than the nominal deployment catheter outer diameter D2. Thus, the recessed region 120 can represent a concave or grooved feature of the deployment catheter. The recessed region can adopt a trapezoidal shape with shallow corners or can be at least partially recessed from the outer surface of the deployment catheter 106 and can adopt a number of other shapes, such as a semi-ellipse, as long as it surrounds at least a portion of the outer periphery.

[0025] The expandable stent delivery device 112 can be disposed concentrically to surround the outer periphery of the non-expanded expansion device 122 and be close to the flexible portion 111 of the deployment catheter 106. The stent delivery device can be disposed within the flexible portion of the deployment catheter. In one example, the flexible portion 111 extends proximally over a length of approximately 20 cm from the distal end 107 of the deployment catheter 106.

[0026] Both the stent delivery device and the expansion device can surround the deployment catheter. In one example, the expandable stent delivery device 112 can be a stent having a plurality of elastic metal or plastic strands formed in a braided pattern. The stent delivery device may be self-expanding when deployed from the system or may be expanded with the aid of the expansion device 122. In one example, this braiding of the implantable stent of the stent delivery device can be of any of a number of stainless steel alloys, or cobalt or cobalt-chromium alloy structures. In other examples, the stent braiding can be made from polymer strands.

[0027] In still other cases, the braiding of the stent delivery device 112 can be manufactured from nitinol or a similar superelastic alloy having shape memory properties of a tubular structure having a predetermined outer diameter. The self-expanding stent delivery device can be actuated by retracting the outer sheath member 102 and may not require a separate expansion device 122 for deployment, although the balloon can be used for pre-dilation or post-dilation of the blood vessel during the implantation process. This tubular structure can be heat-treated to a suitable temperature on a mandrel to anneal the structure and conform the tube to the shape of the mandrel. In these methods, the elastic properties of the stent braiding can be controlled such that the stent can self-expand and assist in the implantation process. The properties are also important so that the stent can maintain rigidity and strength over the desired lifespan of the implant. The winding of the braided strands can also be sufficiently dense to provide a stable configuration that can support the entire inner circumference of the blood vessel when implanted.

[0028] In another example, the strands or struts of the stent can be woven in a substantially helical configuration that extends longitudinally and is coaxial with the central axis or centerline 130 of the resulting tubular structure. A first set of strands can be wound in one direction while being axially displaced from each other. A second group of strands may be wound in a direction opposite to the first group and may also be axially displaced relative to each other.

[0029] The stent delivery device may also be bare metal or may be coated in a number of ways. The coating may be hydrophilic or may have additives effective to enhance the lubricity of the mesh braiding of the stent delivery device 112 to enable more atraumatic navigation of the vasculature. In another example, the coating may be a hydrogel or may contain soluble particles in a polymer matrix that can soften or completely dissolve when exposed to an aqueous medium such as blood. In a further example, the coating may have an embedded pharmaceutical formulation such as an antiplatelet agent, an anticoagulant, an anti-inflammatory agent, or an antibacterial agent. These agents serve to elute the coating from the matrix when exposed to an aqueous medium and prevent the implanted stent from forming potential foci for future blood clot formation.

[0030] The inflation device 122 can be connected, adhered, or welded to the outer surface 110 of the deployment catheter. The inflation device 122 can have one or more balloons or inner-tube type members of various structures, and an expanded state configured to expand and embed the stent delivery device 112. The inflation of the inflation device can be achieved through an inflation lumen or tube 124 extending along the entire length of the deployment catheter 106. The inflation tube may sometimes be an independent member, but more often may be a hollow lumen incorporated into the internal structure of the deployment catheter. The expandable stent delivery device and the inflation device can together surround the recessed region 120 of the deployment catheter 106, and together can have a nominal radius dimension similar to the nominal outer diameter D2 of the deployment catheter. The recessed region 120 within the flexible distal portion 111 of the deployment catheter 106 can be a housing for the inflation device 122 and the stent delivery device 112 during delivery of the system 100. The longitudinal length of the recessed region 120 can be such that this region can accommodate the size of the most common neurovascular stents.

[0031] The balloon can be constructed of any of a number of materials such as Chronoprene, polyurethane, nylon, PBx, or another thermoplastic elastomer. These materials can make the balloon durable and thin. The final shape of the balloon(s) can be altered and adjusted to the shape of the stent delivery device 112. In one example, the balloon can have a substantially tubular profile with conical ends.

[0032] It should be noted that when an element is described and visualized in the drawings as having a tubular structure and is generally illustrated as having a substantially straight cylindrical structure, the terms "tubular" and "tube" as used herein should be construed broadly. This does not mean that they are limited to a straight cylindrical structure, or a structure with a strictly circular cross-section, or a structure with a uniform cross-section over its length.

[0033] FIG. 1C also illustrates a microcatheter 114 that can be disposed within the lumen 108 of the deployment catheter 106. The microcatheter can be concentric with both the guide / sheath member 102 and the deployment catheter 106 about the longitudinal central axis 130 of the system 100. The sheath member, the deployment catheter, and the microcatheter can be movable independently of each other. The deployment catheter can be used to first aspirate the occlusive blood clot 50, and then, if necessary, the microcatheter can be used for the delivery and deployment of the mechanical thrombectomy device 118. The mechanical thrombectomy device can be any of a number of commercially available products. The device can have a delivery configuration folded within the microcatheter and can have a clot retriever with a self-expanding clot engagement portion that expands to an expanded deployment configuration when it exits the distal tip 115 of the microcatheter. The engagement portion can have a network of expandable struts for gripping the clot and removing it from the blood vessel. The shape of the network can be designed such that when the device 118 is retracted, the struts exert a force on the clot in a direction substantially parallel to the direction in which the clot 50 is pulled from the blood vessel (i.e., a direction substantially parallel to the longitudinal axis 130 of the system). This limits the outward radial force applied to the blood vessel, meaning that the action of the thrombectomy device does not act to increase the force necessary to actually remove the clot from the blood vessel. This non-traumatic function is important for the often fragile blood vessels of the neurovasculature 40.

[0034] It is beneficial for the microcatheter 114 and the thrombectomy device 118 to deploy and retract from within the lumen 108 of the deployment catheter 106 so that the clot retrieval process can be isolated from and kept from interfering with the stent implantation process. Similarly, the thrombus can be aspirated and retrieved through the inner lumen of the deployment catheter without using the thrombectomy device.

[0035] In some situations, a physician may desire to reverse the flow of blood within a target vessel. Retrograde flow prevents any emboli from moving downstream in the vessel. Suction can be directed through either the lumen 104 of the deployment catheter 106, the sheath member 102, or both. A seal can be formed between the inner and outer surfaces of the catheter to isolate any one of the catheter lumens for suction purposes. For example, if the suction source is connected to lumen 104 at the proximal end of the guide sheath 102, it can be directed at the mouth at the distal end 107 of the deployment catheter 106 by utilizing a hydrogel seal between the outer surface 110 of the deployment catheter and the inner wall of the sheath member. In another example, an expandable member or frame can be used as a flow restriction between the surfaces. Thereby, a low pressure region can be transferred to the distal end 107 of the deployment catheter 106. In some cases, it may be possible to directly suction a blood clot or debris into the lumen 108 of the deployment catheter without the need to use the microcatheter 114 and thrombus removal device 118.

[0036] In another example, a thrombus removal and stent placement system 100 for removing a blood clot from a neurovascular 40 vessel and placing a stent in the neurovascular 40 vessel can include a sheath member 102, a deployment catheter 106 disposed within the lumen 104 of the sheath member, a microcatheter 114 oriented within the lumen 108 of the deployment catheter, and a thrombus removal device 118 disposed within the lumen 116 of the microcatheter. The sheath member 102, the deployment catheter 106, and the microcatheter 114 can be substantially concentric and configured to move independently of each other along the longitudinal axis A1. Suction for a supported procedure can be directed at the mouth at the distal end 107 of the deployment catheter. The thrombus removal device can have an expandable framework of struts or crowns configured to grip and remove an occlusive blood clot 50.

[0037] The outer surface 110 of the deployed catheter 106 can also have a recessed region 120. The recessed region can have a first radial dimension D1 that is smaller than a second radial dimension D2 of another region of the outer surface adjacent to the recessed region. The deployed catheter 106 can have an expandable stent retention device 112 coupled to the outer surface 110 of the deployed catheter. The stent retention device can surround the recessed region 120 such that the recessed region 120 is substantially in the same radial plane as the outer surface 110. An inflation device 122 configured to expand the stent retention device 112 can also be included and coupled to the outer surface of the deployed catheter. In one example, the inflation device is an outer balloon that can be inflated with a contrast agent. At least a portion of the stent retention device 112 can surround the inflation device 122.

[0038] Figure 2 shows a composite system 100 navigated through the internal carotid artery 30 to a target site within the neurovascular 40. The target site can be an occluded blood vessel having an occlusive clot remaining in a region of intracranial stenosis in the form of a lesion 60 caused by the accumulation of atherosclerotic plaque, as shown. An advantage provided by the system seen in Figure 2 is that the guide catheter or sheath member 102 of the system can function as a sleeve that can protect the internal components of the system during navigation to the site. Other designs of balloon-expandable coronary stents can have a risk of the stent slipping off the balloon due to the tortuosity and various diameters of the cerebrovascular system before reaching the target lesion. This is one of the reasons why a significant amount of effort has been made in the development of low-profile balloon catheters. The recessed section or stepped section 120 as described herein can allow for the adoption of a smaller system 100 because it enables the use of a smaller diameter outer sheath member 102 while still shielding the system.

[0039] Figures 3A - 3J show cross - sectional views illustrating exemplary steps of one method of using the system of the present invention to perform mechanical thrombus removal and subsequent stent placement procedures. When the system 100 is advanced to a position immediately proximal to the target lesion 60 and the occlusive clot 50, the deployment catheter 106 can be used as a suction catheter to aspirate and remove the occlusion into the lumen 108 of the deployment catheter. For more sticky and stubborn occlusions, as shown in Figure 3A, the micro - catheter 114 can be advanced across the clot beyond the distal end 107 of the deployment catheter 106 and until the distal end 115 is distal to the clot. A guide wire can also be used to position the micro - catheter. In many cases, radiopaque markers or coils are also added to various parts of the device and / or catheter to assist the user in determining when the device is properly positioned across the clot. For example, coils of radiopaque materials such as tungsten and / or platinum can be attached to the distal end of the thrombus removal device, such that the distal end can be easily visualized during the treatment procedure. Once in the appropriate position, when the micro - catheter 114 is withdrawn proximally, the thrombus removal device 118 can be made sheath - less, allowing the thrombus removal device to expand within and on both sides of the clot 50, as shown in Figure 3B. The scaffold of the capture portion of the device expands to grip the portion of the clot.

[0040] When the user is confident that the thrombus removal device 118 is firmly gripped on the clot 50, the device can be withdrawn proximally back into the deployment catheter 106, as shown in Figure 3C. This can help maintain a firm grip on the clot with the aid of suction through the deployment catheter 106 and avoid loss and movement of fragments. If desired, the user can then completely remove the thrombus removal device and the micro - catheter from the system 100 and the patient to allow for more efficient suction during subsequent steps. Multiple passes with the micro - catheter and the thrombus removal device may also be necessary to adequately clear the blood vessel.

[0041] After the occlusive clot is securely fixed and withdrawn, the remaining portion of the system 100 within the sheath member 102 can be advanced across the stenosis, whereby the stent delivery device 112 and the inflation device 122 are aligned with the lesion 60 as seen in FIG. 3D. Good alignment can ensure that when the stent delivery device is expanded, the radial force exerted on the blood vessel is dispersed as uniformly as possible along the longitudinal length of the device. Similar to the thrombus removal procedure of FIG. 3B, proper alignment can be achieved by the placement of radiopaque markers or coatings. Once aligned across the lesion, the sheath distal end 109 can return proximal to the stenosis and the sheath member 102 can be retracted to expose the stent delivery device 112 as seen in FIG. 3E.

[0042] Once exposed, the stent delivery device 112 is self-expandable and can be expanded radially by the inflation device 122. The inflatable member of the inflation device 122 can be filled with an operating fluid, typically a contrast agent, via the inflation lumen or tube 124. Once inflation begins, the inflation device can expand the stent delivery device 112 radially, as illustrated in FIG. 3F. As the inner diameter of the target blood vessel is constricted by the stenosis, the outer surface of the stent delivery device can first contact the plaque or fatty deposits of the lesion 60. FIG. 3G shows that as the outer diameter of the stent delivery device continues to increase, this contact can gently exert a compressive radial force on the lesion by squeezing between the stent delivery device and the blood vessel wall. When the lesion is no longer further compressed, continued inflation can expand and enlarge the lumen diameter until the desired implant diameter D3 of the blood vessel is reached, as shown in FIG. 3H. In one example, this desired diameter is achieved when the first contracted diameter of a portion of the blood vessel accommodating the lesion increases to 75% of a second diameter in a portion of the blood vessel adjacent to the first diameter.

[0043] In an alternative process, the stent delivery device 112 can be a self-expanding structure configured to assume a predetermined outer diameter when deployed without the need for an inflation device 122. The outer diameter of the device can be selected such that a desired radial force is applied to the blood vessel, and the implant diameter D3 can be selected to be sufficient to allow flow to re-permeate.

[0044] After the dilated occluded neurovascular 40 is reopened, by contracting the inflation device 122, the stent delivery device 112 can remain in place as an implanted stent. This can be accomplished by attaching a suction source to the proximal end of the inflation tube 126. Suction can continue until the inflation device contracts to a diameter approximating the diameter D2 of the outer surface 110 of the deployment catheter 106. Alternatively, as shown in FIGS. 3I and 3J, suction can continue until the inflation device contracts to a diameter smaller than the inner diameter of the sheath member 102 and allows the deployment catheter to be retracted into the lumen 104 of the sheath member 102. Once no longer fixed by the inflation device, the expanded stent delivery device 112 remains in place as a stent to ensure patency of the target vessel lumen.

[0045] FIG. 4 is a flowchart including method steps for performing an intravascular procedure involving thrombus removal and stent placement using a system such as the example described herein. Referring to method 400 outlined in FIG. 4, in step 410, access to the patient's blood vessel is obtained via a conventionally known technique, and three catheter systems are positioned proximate to a lesion and occlusive thrombus within an occluded blood vessel in the neurovasculature. The first catheter may be a guide catheter or sheath member as described herein, or alternatively may be one known to those skilled in the art. The second catheter can be a delivery catheter having an inflation device and a stent delivery device as described herein. The delivery catheter can be further configured as a suction catheter. The third catheter may be a microcatheter having a lumen and a thrombus removal device therein as described herein, or alternatively may be one known to those skilled in the art.

[0046] In step 420, the distal portions of the microcatheter and the thrombus removal device are advanced from the deployment catheter toward and across the occlusive clot in the neurovascular vessel while maintaining the deployment catheter, the dilation device, the stent delivery device, and the sheath in proximity to the lesion. In step 430, the thrombus removal device is deployed to capture the occlusive clot as exemplified and described herein or to capture the occlusive clot by other means such as direct suction. Step 430 can also include the step of retracting the captured clot, the thrombus removal device, and the microcatheter proximally back into the lumen of the deployment catheter. The captured clot, the thrombus removal device, and the microcatheter can be completely removed from the system and the patient if desired by the user at this stage.

[0047] In step 440, the sheath member, the deployment catheter, the dilation device, and the stent delivery device are advanced distally across the lesion. The stent delivery device can be aligned with the lesion. In step 450, the sheath member is retracted proximally to the lesion to expose and enable the expansion of the stent delivery device.

[0048] In step 460, the dilation device expands to expand the stent delivery device, expand the lesion, and increase the diameter of the vessel lumen. The stent delivery device can expand until it reaches the desired stent implant diameter. In step 470, the dilation device contracts to relieve the pressure on the implanted stent delivery device and allow the deployment catheter to be retracted into the sheath member. In step 480, the stent remains in the vessel as an implant. Step 480 can further include the step of removing the remainder of the system from the patient.

[0049] The present invention is not necessarily limited to the described examples, which may vary in composition and detail. The terms "distal" and "proximal" are used throughout the foregoing description and are meant to refer to the position and direction relative to the treating physician. Thus, "distal" or "distally" refers to a position away from or a direction away from the physician. Similarly, "proximal" or "proximally" refers to a position near to or a direction toward the physician. Further, unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" include plural referents.

[0050] "Comprising" or "containing" or "including" means that at least the specified compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if they have the same function as the specified ones.

[0051] In describing exemplary embodiments, technical terms are used for clarity. Each term is intended to have the broadest meaning understood by those skilled in the art and is intended to include all technical equivalents that act in a similar manner to achieve a similar purpose. It should also be understood that reference to one or more steps of a method does not exclude the presence of additional method steps or method steps intervening between those explicitly identified. Some steps of a method can be performed in an order different from that described herein without departing from the scope of the disclosed technology. Similarly, reference to one or more components of an apparatus or system does not exclude the presence of additional components or components intervening between those explicitly identified. Not all possible combinations are listed for the sake of clarity and brevity.

[0052] As used herein, the term "about" or "approximately" with respect to any numerical value or range of numerical values indicates a tolerance of suitable dimensions that enables a component part or a set of components to function in accordance with its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of values that are ±20% of the recited value. For example, "about 90%" can refer to a range of values from 71% to 99%.

[0053] The descriptions contained herein are examples of embodiments of the present invention and do not limit the scope of the present invention in any way. Although specific embodiments of the present invention are described, various modifications can be made to the apparatus and method without departing from the scope and spirit of the present invention. For example, the embodiments described herein refer to specific components, but the present invention can utilize various combinations of components to achieve the described functionality, utilize alternative materials to achieve the described functionality, combine components from various embodiments, and combine components from various embodiments with known components, among other embodiments. The present invention contemplates replacing the component parts illustrated herein with other well-known commercially available products. To those skilled in the art related to the present invention, these modifications are often obvious and are intended to be within the following "claims".

[0054] 〔Embodiments〕 (1) A thrombus removal and stent implantation system for removing a blood clot from a blood vessel and implanting a stent into the blood vessel, the system comprising a sheath member having a sheath lumen; a deployment catheter oriented within the sheath lumen and having a deployment catheter lumen and an outer surface of the deployment catheter; a stent implantation device surrounding the outer surface of the deployment catheter; a microcatheter oriented within the deployment catheter lumen and having a microcatheter lumen; A system comprising a thrombus removal device, at least a portion of the thrombus removal device being oriented within the microcatheter lumen. (2) The deployment catheter of having an outer diameter of the deployment catheter and a recessed region outer diameter configured to be smaller than the outer diameter of the deployment catheter, on the outer surface of the deployment catheter and proximate the distal end of the deployment catheter, the system of Embodiment 1 further comprising a recessed region. (3) The system of Embodiment 2, wherein the stent delivery device surrounds the recessed region of the deployment catheter. (4) Further comprising an inflation device coupled to the outer surface of the deployment catheter, a portion of the stent delivery device surrounding the inflation device, the inflation device having an expanded state configured to expand the stent delivery device, the system of Embodiment 1. (5) The system of Embodiment 1, wherein the sheath lumen, the deployment catheter lumen, and the microcatheter lumen are substantially concentric.

[0055] (6) The system of Embodiment 1, wherein the thrombus removal device comprises an expandable blood clot retriever that is foldable to fit within the microcatheter lumen and self-expandable when exiting the microcatheter lumen. (7) The system of Embodiment 1, wherein the deployment catheter comprises a flexible portion proximate the stent delivery device. (8) A method of using a thrombus removal and stent delivery system comprising a sheath member, a deployment catheter, a stent delivery device comprising an inflation device and a stent, a microcatheter, and a thrombus removal device, the method comprising positioning the system in proximity to a lesion, While maintaining the deployment catheter, the stent delivery device, and the sheath in proximity to the lesion, extending the distal portions of the thrombus removal device and the microcatheter toward an occlusive thrombus within the vasculature; Capturing the occlusive thrombus with the thrombus removal device; Extending the sheath member, the deployment catheter, and the stent delivery device to intersect the lesion; Retracting the sheath member from the lesion; Expanding the expansion device of the stent delivery device across the lesion; Releasing the stent of the stent delivery device to intersect the lesion, the method comprising. (9) The method according to embodiment 8, further comprising retracting the occlusive thrombus into the deployment catheter. (10) The method according to embodiment 8, further comprising positioning the deployment catheter within the sheath lumen.

[0056] (11) The method according to embodiment 8, further comprising positioning the microcatheter within the deployment catheter. (12) The method according to embodiment 8, further comprising positioning the thrombus removal device within the microcatheter. (13) The method according to embodiment 8, further comprising disposing the stent delivery device on an outer surface of the deployment catheter. (14) Expanding the stent delivery device includes increasing the diameter of a first portion of the vasculature region including the lesion to at least 75% of the diameter of a second portion of the vasculature adjacent to the first portion. The method according to embodiment 8. (15) The method according to embodiment 8, further comprising releasing the stent of the stent delivery device in proximity to the lesion by contracting the expansion device.

[0057] (16) Crossing the occlusive thrombus with the microcatheter and the thrombus removal device; The method according to embodiment 8, further comprising: retracting the microcatheter while maintaining the thrombus removal device across the occlusive thrombus. (17) A thrombus removal and stent implantation system for removing a thrombus from a blood vessel and implanting a stent in the blood vessel, the system comprising: A sheath member having a sheath lumen; A deployment catheter disposed within the sheath lumen and having a deployment catheter lumen and a deployment catheter outer surface; A stent implantation device coupled to the deployment catheter outer surface; A microcatheter disposed within the deployment catheter lumen and having a microcatheter lumen; A thrombus removal device, at least a portion of the thrombus removal device being disposed within the microcatheter lumen; The system, wherein the sheath member, the deployment catheter, and the microcatheter are substantially concentric and configured to move independently of each other along an axis. (18) The system according to embodiment 17, wherein the deployment catheter further comprises a recessed region on the deployment catheter outer surface, the recessed region having a dimension smaller than a dimension of another region of the deployment catheter outer surface adjacent to the recessed region. (19) The system according to embodiment 18, wherein the stent implantation device surrounds the recessed region of the deployment catheter. (20) The system according to embodiment 17, further comprising an inflation device coupled to the deployment catheter outer surface, wherein a portion of the stent implantation device surrounds the inflation device.

Claims

1. A thrombus removal and stent implantation system for removing a blood clot from a blood vessel and implanting a stent in the blood vessel, the thrombus removal and stent implantation system comprising: a sheath member having a sheath lumen; a deployment catheter oriented within the sheath lumen, the deployment catheter having an inner surface defining a deployment catheter lumen and an outer surface; a stent deployment device surrounding the outer surface of the deployment catheter; a microcatheter oriented within the deployment catheter lumen, the microcatheter having a microcatheter lumen; a thrombus removal device, at least a portion of the thrombus removal device being oriented within the microcatheter lumen; and the deployment catheter further having a recessed region, the recessed region having a dimension of the outer surface of the deployment catheter that is smaller than a dimension of another region of the outer surface of the deployment catheter adjacent to the recessed region, and a dimension of the inner surface of the deployment catheter that is smaller than a dimension of another region of the inner surface of the deployment catheter adjacent to the recessed region; the stent deployment device surrounding the recessed region of the deployment catheter; the deployment catheter further comprising an inflation device surrounding the recessed region of the deployment catheter; the inflation device surrounding only the recessed region in the deployment catheter and not surrounding regions other than the recessed region in the deployment catheter; a portion of the stent deployment device surrounding the inflation device; and the inflation device having an expanded state configured to expand the stent deployment device, the entire inflation device expanding in a longitudinal direction in the expanded state of the inflation device, the thrombus removal and stent implantation system.

2. The thrombus removal and stent implantation system according to claim 1, wherein the sheath lumen, the deployment catheter lumen, and the microcatheter lumen are substantially concentric.

3. The thrombus removal and stent implantation system according to claim 1, further comprising an expandable blood clot retriever, the thrombus removal device being foldable to fit within the microcatheter lumen and self-expandable when exiting the microcatheter lumen.

4. The thrombus removal and stent implantation system according to claim 1, wherein the deployment catheter comprises a flexible portion proximate to the stent implantation device.

5. A thrombus removal and stent implantation system for removing a blood clot from a blood vessel and implanting a stent in the blood vessel, the thrombus removal and stent implantation system comprising a sheath member having a sheath lumen; a deployment catheter oriented within the sheath lumen, the deployment catheter having an inner surface defining a deployment catheter lumen and an outer surface; a stent implantation device coupled to the outer surface of the deployment catheter; a microcatheter oriented within the deployment catheter lumen, the microcatheter having a microcatheter lumen; a thrombus removal device, at least a portion of the thrombus removal device being oriented within the microcatheter lumen; wherein the sheath member, the deployment catheter, and the microcatheter are substantially concentric and configured to move independently of one another along an axis; wherein the deployment catheter further comprises a recessed region having a dimension of the outer surface of the deployment catheter that is smaller than a dimension of the outer surface of another region of the deployment catheter adjacent to the recessed region, and a dimension of the inner surface of the deployment catheter that is smaller than a dimension of the inner surface of the another region of the deployment catheter adjacent to the recessed region; wherein the stent implantation device surrounds the recessed region of the deployment catheter; further comprising an inflation device surrounding the recessed region of the deployment catheter; wherein the inflation device surrounds only the recessed region in the deployment catheter and does not surround regions other than the recessed region in the deployment catheter; wherein a portion of the stent implantation device surrounds the inflation device; the inflation device having an expanded state configured to expand the stent implantation device, and in the expanded state of the inflation device, the entire length of the inflation device in the longitudinal direction expands, the thrombus removal and stent implantation system.

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