Apparatus, system, and method for removing blood clots

Abstract

To provide systems, devices and methods for more effectively treating stroke by removing blood clots during a catheter procedure.SOLUTION: The present invention provides systems, devices and methods for removing a blood clot 10 from a blood vessel 12. Various uses of suction pressure and positive pressure proximal and / or distal to the blood clot 10 assist with clot dislodgement and removal. The pressures may be constant and / or cycled / pulsed to assist with clot dislodgement and / or removal. Various further devices assist with separating the blood clot 10 from the blood vessel 12.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] Cross-Reference to Related Applications This application claims priority to U.S. Provisional Patent Application Nos. 62 / 621,776, 62 / 654,693, and 62 / 775,510, filed on January 25, 2018, April 9, 2018, and December 5, 2018, respectively, the entire disclosures of which are incorporated herein by reference.

Background Art

[0002] Stroke is a medical event that causes sudden, often severe disability for many people. Stroke can cause sudden death, and even for those who survive, they may lose the ability to speak, walk, eat, and care for themselves. These patients often require long-term care and have a limited life expectancy.

[0003] The most common cause of stroke is occlusion of an artery in the brain caused by blockage of a blood clot. The clot or embolus dislodges from a source such as the heart or a carotid artery, and travels to an artery in the brain. As the artery narrows, the clot eventually becomes stuck or lodged in place. Flow to the region of the brain beyond the occlusion stops, often resulting in severe damage. The brain has a very narrow tolerance for loss of blood flow. Many regions are supplied by only a single blood source, and brain functions are not redundant. When a motor or language area is lost, the ability of other parts of the brain to take over the lost function is limited.

[0004] Common treatment for stroke has been conservative, expectant therapy. Outcomes are often inadequate with this approach. Another form of therapy involves the use of thrombolytic agents. However, these agents can only provide limited benefits.

[0005] More recently, significant advances have been made in catheter-based blood clot removal techniques. Currently, if stroke patients are transported to a catheterization lab immediately after a clot blockage occurs, the clot can be removed, restoring blood flow more quickly. In such cases, the survival and functional status of these patients can dramatically improve. Instead of most patients dying or being transferred to nursing facilities, the majority survive and are able to live independently.

[0006] The tools currently developed and available for removing blood clots in the brain are still in their early stages of development. A key aspect of treatment may involve using constant suction pressure proximal to the clot, coupled with a stent-like clot retrieval device ("stent-type retrieval device") that physically captures and allows for removal of the clot. These devices still have considerable room for improvement. Furthermore, a significant percentage of patients who enter a catheterization lab for clot removal do not regain blood flow. More effective systems, devices, and methods are needed to treat these individuals.

[0007] One of the main challenges concerns small blood vessels containing blood clots. These vessels can have an inner diameter of approximately 2 mm or less. These vessels are often located deep within the brain, and the pathways leading to them are winding. These realities present significant challenges. However, the rewards of solving these problems are immense for those who have unfortunately suffered a stroke.

[0008] Most strokes are treated using constant suction pressure proximal to the clot. Suction is performed by a catheter placed near or proximal to the clot. If this is insufficient, or if the interventionist chooses, a guidewire is advanced adjacent to or through the clot, and then distally beyond it. This guidewire is then used to guide the delivery of a stent-type retrieval device within a small catheter. The stent-type retrieval device is deployed adjacent to the clot and used to capture and physically remove it. The stent-type retrieval device breaks up the blood clot into fragments, which may travel distally or downstream and enter smaller cerebral blood vessels, potentially causing complications. This can lead to distal vascular occlusion, potentially causing further brain damage and physical disability to the patient. It is beneficial to remove the clot while minimizing the further risk of such additional injury to the patient.

[0009] The stent retrieval device involves further steps. A guidewire must be introduced into the blood vessel proximal to the blood clot. The stent retrieval device is then advanced through the guidewire to the site of the clot. It is advantageous to provide a device that simplifies this procedure.

[0010] Excessive suction of blood vessels can collapse them, making clot removal even more difficult. Therefore, physicians using current systems, devices, and methods based on constant suction fluid pressure must balance the need to use sufficient pressure to dislodge blood clots with the need to avoid vascular collapse. Unfortunately, blood clots can often be firmly attached to and / or block the inner wall of blood vessels, making removal using current techniques extremely difficult or impossible. Aggressive use of current techniques to remove tightly attached or blocked clots can lead to harmful complications for the patient. [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] For these and other reasons, it is desirable to provide systems, devices, and methods for more effectively treating stroke by removing blood clots during catheterization procedures. [Means for solving the problem]

[0012] In a first exemplary embodiment, a system is provided for removing blood clots from a patient's blood vessels. The system comprises a catheter having a distal end portion. A fluid pressure delivery device operates to apply transvascular aspiratory fluid pressure through the distal end portion of the catheter to the proximal side of the blood clot. A clot retrieval element captures the blood clot within the blood vessel. A control device is operably coupled with the fluid pressure delivery device and / or catheter to repeatedly circulate the intravascular aspiratory fluid pressure between different pressure levels to assist in the release and removal of the blood clot.

[0013] In some cases, the system may further include a radially expandable distal seal that is deployable from the distal end of the catheter. The radially expandable seal includes a proximal end portion and a distal end portion and is configured to expand radially during use and engage with the inner wall surface of the blood vessel. The seal has an open proximal end portion. Alternatively, the distal radially expandable seal may automatically adjust its size to accommodate blood vessels of different diameters. For example, this automatic adjustment may occur when the blood clot is pulled proximal during removal and the blood vessel expands. In that case, the expandable seal will also expand in size to maintain the seal. A fluid pressure delivery device may then apply positive fluid pressure transvascularly to the region of the blood vessel enclosed by the radially expandable seal. A control device is operably coupled with the fluid pressure delivery device to repeatedly circulate positive fluid pressure within the blood vessel between different pressure levels distal to the blood clot in order to assist in the release and removal of the blood clot.

[0014] In another exemplary embodiment, a system is provided for removing blood clots from a patient's blood vessel, the system comprising a catheter having a distal end portion, a radially expandable seal, a fluid pressure delivery device, and a blood clot retrieval element. The radially expandable seal is deployable from the distal end portion of the catheter and is configured to expand radially during use and engage with the inner wall surface of the blood vessel. The fluid pressure delivery device applies fluid pressure transvascularly through the catheter to the region of the blood vessel between the radially expandable seal and the blood clot. The blood clot retrieval element captures the blood clot within the blood vessel. In this embodiment, the seal may be deployed proximal or distal to the blood clot, and in various embodiments, two seals may be deployed, one deployed proximal to the blood clot and the other deployed distal to the blood clot. As another option, one or both radially expandable seals may automatically adjust their size to accommodate blood vessels of different diameters. For example, this automatic adjustment may occur when the blood clot is pulled proximally during removal, causing the vessel to dilate, and the seal may also expand in size to maintain engagement with the inner wall surface of the vessel.

[0015] In another exemplary embodiment, a system is provided for removing a blood clot from a patient's blood vessel, the system comprising a catheter having a distal end portion, a radially expandable seal, a fluid pressure delivery device, and a control device. The radially expandable seal is deployable from the distal end portion of the catheter and comprises a proximal end portion and a distal end portion. The radially expandable seal is configured to expand radially during use distal to the blood clot and engage with the inner wall surface of the blood vessel. The seal has an open proximal end portion. The fluid pressure delivery device applies transvascular positive fluid pressure to the region of the blood vessel between the radially expandable seal and the blood clot. To assist in the release and removal of the blood clot, the control device is operably coupled with the fluid pressure delivery device to repeatedly circulate positive fluid pressure within the blood vessel between different pressure levels distal to the blood clot.

[0016] In another exemplary embodiment, a system is provided for removing blood clots from a patient's blood vessels, the system comprising a catheter, a fluid pressure delivery device, a clot retrieval element, and a radially expandable thrombus capture element. The catheter has a distal end portion. The fluid pressure delivery device applies transvascular fluid suction pressure through the distal end portion of the catheter to the location of the blood clot proximal to the blood vessel. The clot retrieval element captures the free blood clot within the blood vessel. The radially expandable thrombus capture element is expandable from the distal end portion of the catheter and comprises a proximal end portion and a distal end portion. The radially expandable thrombus capture element is configured to expand radially during use and engage with the inner wall surface of the blood vessel. The thrombus capture element has an open proximal end portion, which expands radially distal to the blood clot to capture the thrombus and prevent the thrombus from moving distally through the blood vessel. Alternatively, the radially expandable thrombus-catching element may automatically adjust its size to accommodate vessels of different diameters. For example, this automatic adjustment may occur when the blood clot is pulled proximally during removal, causing the vessel to dilate. In this case, the expandable thrombus-catching element would also expand to prevent the clot from escaping distally.

[0017] In another exemplary embodiment, an intravascular device for removing blood clots from a blood vessel is provided. The device includes an elongate intravascular element that is sized and configured to be introduced into a blood vessel. The elongate intravascular element includes a distal end portion. A radially expandable seal is held in the distal end portion of the elongate intravascular element. The radially expandable seal includes a proximal end portion and a distal end portion, and is configured to expand radially during use so that at least the proximal or distal end portion of the seal forms a fluid pressure seal against the inner wall surface of the blood vessel. In various embodiments, the elongate intravascular element may further comprise a catheter, such as a small-diameter catheter, or what may be referred to herein as a “microcatheter.” A guidewire may be used to guide the microcatheter to the proximal position of the blood clot. In other embodiments, the elongate intravascular element is a guidewire. As another option, the radially expandable seal may auto-adjust its size to accommodate blood vessels of different diameters. For example, this automatic adjustment may occur when the blood clot is pulled proximally during removal, causing the blood vessel to dilate. In that case, the expandable seal would also expand in size to maintain the seal.

[0018] In some embodiments, various options are available depending on the patient's clinical needs and / or the physician's desired surgical procedure. For example, a radially expandable seal may have an open distal end, which may be sized and configured to provide a fluid pressure seal against the inner wall of a vessel to allow suction to be applied to the proximal side of the blood clot. In other embodiments, a radially expandable seal may have an open proximal end, which may be sized and configured to provide a fluid pressure seal against the inner wall of a vessel to allow positive fluid pressure to be applied to the distal side of the blood clot. As will be understood from further description below, the physician may choose a system that applies either suction pressure or positive pressure, or both, to the proximal and / or distal side of the blood clot to assist in its release and removal. As will be further described herein, the suction and / or positive fluid pressure may be a constant pressure, a circulating or pulsating pressure, or a combination of both during the clot release and removal procedure.

[0019] A radially expandable seal may take many possible forms depending on the desired properties and surgical procedure. For example, a radially expandable seal may have the shape of an elongated tube to cover an opening to one or more side vessel branches of a blood vessel. The radially expandable seal may be further configured to retract radially to allow delivery through a delivery catheter, and may be retracted into the delivery catheter or folded for removal. At least one tether may connect the radially expandable seal to the elongated intravascular element. The radially expandable seal may have a proximal end portion of various configurations for use at a distal location of a blood clot. For example, the proximal end portion may be oriented perpendicular to or nearly acute to the longitudinal axis of the elongated intravascular element when the radially expandable seal is expanded. Various shapes, such as an S-shape or other curves or straight lines, may define the proximal end portion. The radially expandable seal may be formed in a separate, longitudinally extending portion. A radially expandable seal may be configured to unroll along the longitudinal axis of the elongated intravascular element during deployment and radial expansion of the seal. A radially expandable seal may also expand in the opposite direction from its location on the elongated intravascular element to at least partially enclose the blood clot between the blood clot and the inner wall of the vessel.

[0020] In particular, when the elongated intravascular element is a standard catheter, the radially expandable seal may be detachable from the elongated intravascular element. This form of detachable seal may be advanced to the distal end portion of the elongated intravascular element and fixed in place at the distal end portion. In other embodiments, the radially expandable seal is fixed to the elongated intravascular element, such as by being integrally formed with the elongated intravascular element, for delivery together with the elongated intravascular element, for example, a catheter.

[0021] The radially expandable seal may further include reinforcing structures, such as radially expandable stent structures. When the radially expandable seal is led out of the delivery catheter, the radially expandable seal may self-expand radially. Alternatively, the radially expandable seal may auto-adjust its size to accommodate blood vessels of different diameters. For example, this auto-adjustment may be achieved by adding a spring bias or elastic property to the seal, such as one or more superelastic wire elements, which maintain and adjust the radial expansion so that the seal engages with the inner wall surface of the vessel even as the vessel diameter changes. Depending on the application, the material forming the radially expandable seal may take many forms. If the radially expandable seal must provide a robust fluid pressure seal, the seal may be formed from a highly flexible but non-porous membrane material. In other applications where the fluid pressure seal does not need to be extremely robust, or when the seal is used as a thrombus trapping element, a mesh or stent-like structure may be used to serve the purpose.

[0022] Many embodiments of the system and apparatus may further include other optional components and / or features. For example, a guide may be positioned at the distal end of an elongated intravascular element. The guide may include at least one guide portion that guides a second elongated intravascular element laterally toward the periphery of the blood clot. The apparatus may further include an inflatable balloon element that holds the guide. The elongated intravascular element may include at least one channel for transmitting fluid pressure changes in the vessel proximal and / or distal to the blood clot. The elongated intravascular element may further include a plurality of punched holes at the distal end portion communicating with at least one channel. The punched holes may be included in the region of a radially expandable seal to expand the radially expandable seal by guiding positive fluid pressure through the punched holes. The apparatus may further include a radially expandable clot retrieval element for engaging with the blood clot proximal in the vessel and retrieving the clot. The device may further comprise a plurality of expandable projections held by elongated intravascular elements to engage with the blood clot and assist in its removal. The elongated intravascular elements may further comprise nonlinear portions to engage between the blood clot and the inner wall surface of the vessel. The nonlinear portions may further comprise sinusoidal or helical portions overall. The device may further comprise a positive pressure tube to deliver positive fluid pressure proximal to the blood clot, thereby assisting in its removal. Elongated clot-releasing elements may be provided and configured to extend between the blood clot and the inner wall surface of the vessel to release the blood clot from the inner wall surface. Guides may be provided and configured to guide the elongated clot-releasing elements laterally, generally toward the periphery of the blood clot.

[0023] Other embodiments and exemplary models provide methods for removing blood clots from a patient's blood vessels. For example, in one common method, suction fluid pressure is applied into the blood vessel proximal to the blood clot. The suction fluid pressure is repeatedly circulated between different pressure levels proximal to the blood clot to assist in its release and removal using a pulling force. The blood clot is released from the inner wall of the blood vessel and removed from the blood vessel using a catheter.

[0024] Various secondary features and steps of the method may be provided. For example, the aspirated fluid pressure may be circulated at a frequency greater than 1 Hz. The amplitude or difference between high and low pressure may be greater than, for example, 20 mmHg. Generally, the fluid pressure may be used according to any level that is deemed not harmful to the patient. This may include the fluid pressure above, below, or within the patient's normal blood pressure range. The method may further include a step of using a tool to help dislodge the blood clot from the inner wall surface of the blood vessel. The method may further include a step of using a retrieval tool to remove the blood clot from the blood vessel. The aspirated fluid pressure may be circulated repeatedly at a pressure below the patient's normal blood pressure range. The step of removing the blood clot may further include a step of guiding the blood clot into and through the catheter. Alternatively, the step of removing the blood clot may further include a step of retaining the blood clot in the distal end portion of the catheter and then withdrawing the catheter from the blood vessel.

[0025] Another method according to an exemplary embodiment includes the step of deploying a radially expandable seal by engaging with the inner wall surface of a blood vessel proximal to the blood clot. Fluid pressure is then applied to the region of the blood vessel between the radially expandable seal and the blood clot to assist in separating the blood clot from at least the inner wall surface. The blood clot is then removed from the blood vessel using a catheter.

[0026] In a secondary or optional step of the method, any of the other features described herein may be employed. For example, the step of deploying a radially expandable seal and the step of applying fluid pressure may each further comprise the step of engaging the expanded seal proximally of the clot and the step of applying suction fluid pressure, respectively. In another optional aspect, the step of applying suction fluid pressure may further comprise applying a constant fluid pressure and / or a circulating or pulsating suction fluid pressure. When circulating the suction fluid pressure, the suction fluid pressure may be circulated within a range below a patient's normal blood pressure. Alternatively or additionally, the step of deploying a radially expandable seal and the step of applying fluid pressure may each further comprise the step of engaging the expanded seal distally of the clot and the step of applying positive fluid pressure, respectively. Again, the positive fluid pressure may consist of a constant fluid pressure and / or a circulating or pulsating fluid pressure. When circulating the positive fluid pressure, the circulating fluid pressure may be within a range above a patient's normal blood pressure.

[0027] Another method according to an exemplary embodiment comprises deploying a radially expandable thrombus capturing element by engaging the inner wall surface of a blood vessel distal to a clot. Although this element may not provide a fluid sealing function, it may alternatively still be referred to as a "seal" even when it seals the blood vessel distal to the clot to prevent the thrombus from moving distally and causing an additional stroke. Suction fluid pressure is applied to a region of the blood vessel proximal to the clot to assist in at least releasing the clot from the inner wall surface. The clot is then removed from the blood vessel using a catheter. In this embodiment, the radially expandable thrombus capturing element is used to capture thrombus that may move distally during the method or procedure. Any of the secondary or other optional features or steps described above or in the detailed description below may be used in this method as well as any other disclosed method.

[0028] Various other aspects, advantages, features, combinations of features, and / or steps will be understood from the following detailed description of exemplary embodiments taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] [Figure 1A] It is a longitudinal sectional view schematically showing a system according to an exemplary embodiment used for releasing and removing a thrombus. [Figure 1B] It is a view similar to FIG. 1A, showing the next step in a method for releasing and removing a thrombus. [Figure 1C] It is a view similar to FIG. 1B, showing the next step in this method. [Figure 1D] It is a view similar to FIG. 1C, showing the optional use of a stent-like retrieval device for removing a thrombus. [Figure 2A] It is a longitudinal sectional view schematically showing a system according to another embodiment used for releasing and removing a thrombus. [Figure 2B] It is a view similar to FIG. 2A, showing the next step in a method for releasing and removing a thrombus. [Figure 2C] It is a view similar to FIG. 2B, showing withdrawal of an elongated intravascular element at the end of the procedure. [Figure 3A] It is a longitudinal sectional view schematically showing a system according to another embodiment used for releasing and removing a thrombus. [Figure 3B] It is a view similar to FIG. 3A, showing the next step in a method for releasing and removing a thrombus. [Figure 3C] It is a view similar to FIG. 3A, showing the next step in a method for releasing and removing a thrombus. [Figure 3D] It is a view similar to FIG. 3C, showing the next step including withdrawal of an elongated intravascular element at the end of the procedure. [Figure 3E] It is a view similar to FIG. 3B, showing another embodiment of a radially expandable seal. [Figure 3F] This figure shows another embodiment of a radially expandable seal, similar to Figure 3C. [Figure 3G] This figure shows a similar configuration to Figure 3E, but represents another embodiment of the system. [Figure 3H] This figure shows a similar configuration to Figure 3G, but represents another embodiment of the system. [Figure 4A] This is a schematic longitudinal cross-sectional view showing a system according to another embodiment for freeing and removing blood clots. [Figure 4B] This figure is similar to Figure 4A, but shows the next step in this method. [Figure 5A] This is a schematic longitudinal cross-sectional view showing a system according to another embodiment for freeing and removing blood clots. [Figure 5B] This figure is similar to Figure 5A, but shows the next step in this method. [Figure 5C] This figure is similar to Figure 5A, but shows the next step in this method. [Figure 6A] This is a schematic longitudinal section illustrating another embodiment of a system for releasing and removing blood clots. [Figure 6B] This figure is similar to Figure 6A, but shows the next step in this method. [Figure 7A] This is a schematic longitudinal section illustrating another embodiment of a system for releasing and removing blood clots. [Figure 7B] This figure is similar to Figure 7A, but shows the next step in this method. [Figure 7C] This figure is similar to Figure 7B, but shows the next steps in this method. [Figure 7D] This figure is similar to Figure 7C, but shows the next steps in a method that involves withdrawing an elongated intravascular element. [Figure 7E] This is a cross-sectional view along the line 7E-7E in Figure 7B. [Figure 7F] Figure 7E is a perspective view of the guide. [Figure 8A]This is a schematic longitudinal section illustrating another embodiment of a system for freeing and removing blood clots. [Figure 8B] This figure is similar to Figure 8A, but shows another step in this method. [Figure 8C] This figure is similar to Figure 8B, but shows another step in this method. [Figure 9A] This is a schematic longitudinal section illustrating another embodiment of a system for freeing and removing blood clots. [Figure 9B] This figure is similar to Figure 9A, but shows another step in this method. [Figure 9C] This figure is similar to Figure 9B, but it is an enlarged view showing a different embodiment. [Figure 10A] This is a longitudinal section schematically showing another exemplary embodiment of a system for freeing and removing blood clots. [Figure 10B] This figure is similar to Figure 10A, but shows the next step in this method. [Figure 10C] This figure is similar to Figure 10B, but shows another step in this method. [Figure 10D] This figure is similar to Figure 10C, but shows another step in this method. [Figure 10E] This figure is similar to Figure 10D, but shows another step in this method. [Figure 11A] This is a longitudinal section schematically showing another exemplary embodiment of a system for freeing and removing blood clots. [Figure 11B] This figure is similar to Figure 11A, but shows the next steps in this method. [Figure 12A] This is a longitudinal section schematically showing another exemplary embodiment of a system for freeing and removing blood clots. [Figure 12B] This figure is similar to Figure 12A, but shows the next step in this method. [Figure 12C]This figure is similar to Figure 12B, but shows another step in this method. [Figure 12D] Figures 12A to 12C are enlarged cross-sectional views showing the system. [Figure 13A] This is a longitudinal section schematically showing another exemplary embodiment of a system for freeing and removing blood clots. [Figure 13B] This figure is similar to Figure 13A, but shows the next steps in this method. [Figure 13C] This figure is similar to Figure 13B, but shows another step in this method. [Figure 13D] This figure is similar to Figure 13C, but shows another step in this method. [Figure 14A] This is a longitudinal section schematically showing another exemplary embodiment of a system for freeing and removing blood clots. [Figure 14B] This figure is similar to Figure 14A, but shows the next steps in this method. [Figure 14C] This figure is similar to Figure 14B, but shows another step in this method. [Figure 14D] This figure is similar to Figure 14C, but shows another step in this method. [Figure 15] This is a schematic longitudinal cross-sectional view showing another exemplary embodiment of a blood clot removal or extraction system. [Figure 16A] This is a schematic longitudinal cross-sectional view showing another exemplary embodiment of a blood clot removal or extraction system. [Figure 16B] This figure is similar to Figure 16A, but shows the next steps in this method. [Figure 16C] This figure is similar to Figure 16B, but shows the next steps in this method. [Figure 16D] This is a cross-sectional view showing a radially expandable seal before deployment. [Figure 16E] This is a cross-sectional view similar to Figure 16D, showing the deployment of a radially expandable seal. [Figure 16F] This is a side view of a radially expandable seal. [Figure 17A] This is a schematic longitudinal cross-sectional view showing another exemplary embodiment of a blood clot removal or extraction system. [Figure 17B] This figure is similar to Figure 17A, but shows the next steps in this method. [Figure 17C] This is a cross-sectional view showing the deployment of a radially expandable seal. [Figure 17D] This is a cross-sectional view similar to Figure 17C, but showing another embodiment of a radially expandable seal. [Figure 18A] This is a top view showing another embodiment of an elongated intravascular element and a radially expandable seal or clot extraction element. [Figure 18B] Figure 18A is a top view showing the complete deployment of the radially expandable element. [Figure 18C] Figure 18B is a longitudinal cross-sectional view showing a radially expandable element. [Figure 19A] This is a longitudinal cross-sectional view showing an elongated intravascular element and another embodiment of a radially expandable seal or clot extraction element. [Figure 19B] Figure 19A is a side view showing the complete deployment of the radially expandable element. [Figure 19C] Figures 19A and 19B show schematic longitudinal cross-sectional views of the apparatus used to loosen and remove blood clots. [Figure 20A] This is a schematic longitudinal section showing another exemplary embodiment of a blood clot release and removal element used to extract blood clots. [Figure 20B] This figure is similar to Figure 20A, but shows the next step in this method. [Figure 21A] This is a schematic longitudinal section showing another exemplary embodiment of a blood clot release and removal element used to extract blood clots. [Figure 21B] This figure is similar to Figure 21A, but shows the next steps in this method. [Figure 21C]Figure 21B is a cross-sectional view showing the fully unfolded blood clot release and removal elements. [Figure 22A] This is a schematic longitudinal section showing another exemplary embodiment of a blood clot release and removal element used to extract blood clots. [Figure 22B] This figure is similar to Figure 22A, but shows the next steps in this method. [Figure 23A] This is a schematic longitudinal cross-sectional view showing another exemplary embodiment of a blood clot removal or extraction system. [Figure 23B] This figure is similar to Figure 23A, but shows the next step in this method. [Figure 23C] This is a cross-sectional view showing the initial development of a radially expandable clot extraction element. [Figure 23D] This is a cross-sectional view similar to Figure 23C, but showing a further development of the radially expandable extraction element. [Figure 24A] This is a schematic longitudinal section showing another exemplary embodiment of a blood clot release and removal element used to extract blood clots. [Figure 24B] This figure is similar to Figure 24A, but shows the next step in this method. [Figure 25A] This is a schematic longitudinal section showing another embodiment of an elongated intravascular element used to excise and remove blood clots. [Figure 25B] This figure is similar to Figure 25A, but shows the next step in this method. [Figure 26A] This is a schematic longitudinal section showing another embodiment of an elongated intravascular element used to excise and remove blood clots. [Figure 26B] This figure is similar to Figure 26A, but shows the next step in this method. [Figure 26C] This figure is similar to Figure 26B, but shows the next step in this method. [Figure 27A] This is a schematic longitudinal section showing another embodiment of an elongated intravascular element used to excise and remove blood clots. [Figure 27B] This figure is similar to Figure 27A, but shows the next step in this method. [Figure 28A] This is a schematic longitudinal section showing another embodiment of an elongated intravascular element used to excise and remove blood clots. [Figure 28B] This figure is similar to Figure 28A, but shows the next step in this method. [Figure 28C] This figure is similar to Figure 28B, but shows the next step in this method. [Figure 28D] This figure is similar to Figure 28C, but shows the next step in this method. [Figure 28E] This figure is similar to Figure 28D, but shows the next step in this method. [Figure 29A] This is a schematic longitudinal section showing another embodiment of an elongated intravascular element used to excise and remove blood clots. [Figure 29B] This figure is similar to Figure 29A, but shows the next step in this method. [Figure 29C] This figure is similar to Figure 29B, but shows the next steps in this method. [Figure 30A] This is a schematic longitudinal section showing another embodiment of an elongated intravascular element used to excise and remove blood clots. [Figure 30B] This figure is similar to Figure 30A, but shows the next step in this method. [Figure 30C] This figure is similar to Figure 30B, but shows the next step in this method. [Modes for carrying out the invention]

[0030] The detailed descriptions herein serve to illustrate non-limiting embodiments or examples, including various inventive concepts, and reference numbers are used to facilitate understanding of these examples. Common reference numbers between figures refer to common features and structures having the same or similar function, as is understood. Various figures have common reference numbers that point to such common features and structures, but for the sake of brevity, the descriptions of later figures do not necessarily repeat the descriptions of these features and structures.

[0031] Figures 1A and 1B Figures 1A and 1B show an occlusion, or blood clot, 10 within a blood vessel 12 having an inner wall surface 12a. The blood vessel 12 may include a proximal portion 11 and a distal portion 13, and the blood clot 10 may be located in the blood vessel between portions 11 and 13. As used herein, the term “blood clot” means any occluding or clot material that obstructs the flow of blood within the blood vessel 12, regardless of the material forming the occlusion. An exemplary embodiment or example of a clot removal system is shown, including an elongated intravascular element in the form of a suction catheter 14. The suction catheter 14 may have a distal end 15, which may have a mouth or seal 16. The distal end 15 of the suction catheter 14 is circular. The mouth or seal 16 may be funnel-shaped and radially expandable by having a stent-like structure that can self-expand when led out of a delivery catheter (not shown). During the procedure to remove the blood clot 10, the user inserts the distal end 15 of the aspiration catheter into the blood vessel 12 through the proximal portion 11 in its unexpanded form. The mouth or seal 16 can touch the inner wall 12a of the blood vessel 12 and expand radially to create a seal against the fluid flow on the proximal side of the blood clot 10. Next, a guidewire 18 may be advanced through the length of the aspiration catheter 14, exiting the mouth or seal 16 and being guided distally beyond the blood clot 10 (Figure 1B). The guidewire 18 may have a thin, radially expandable distal seal membrane 20 at its distal end portion 18a. The guidewire 18 may have a wire core made of a small hollow tube with one or more slots or slits (not shown) cut into at least the distal end portion 18a to allow the guidewire 18 to bend or curve easily. The hollow tube may also include a solid core wire that fills the lumen or void of the tube. In some embodiments, the wire core may be solid but flexible, with a thin flexible wire spirally wound around it. The guidewire 18 may have a U-shaped tip (see Figures 30A and 30B) which also has a wire wrap around the inner wire. This prevents the distal tip 18a of the guidewire 18 from penetrating the wall of the blood vessel 12.In some embodiments, the hollow guidewire 18 is not filled with a solid core wire, but instead is open to allow the delivery of a fluid such as CO2 to create a pressure change within the blood vessel 12. In some embodiments, the outer surface of the guidewire 18 can be coated with a low-friction material that helps guide the wire and prevent coagulation.

[0032] Figure 1C As shown in Figure 1C, the system may include a guidewire 18 connected to a pressure source 22. The guidewire 18 is passed through the mouth 16 of the suction catheter 14 and can be stopped distal to the blood clot 10. The mouth or seal 16 can be expanded to create a seal against the vessel wall proximal to the blood clot 10. The guidewire 18 may have a distal seal or membrane 20 and punched holes 23 of any desired number, shape, and / or configuration at its distal end portion 18a. For example, the punched holes 23 may be replaced by one or more slits or slots in the distal end portion 18a of the guidewire within the expansion or widening area of ​​the seal 20. The punched holes 23 are located proximal to the attachment point of the distal seal 20 to the guidewire 18 or other elongated intravascular element. The seal 20 can include many embodiments. In some embodiments, the distal seal or membrane can be expanded radially to create a seal distal to the blood clot 10. The proximal end of the seal may be open to the blood clot 10.

[0033] The pressure source 22 can release CO219 from the punched hole 23 on the guidewire to apply positive pressure to the distal seal or membrane 20 due to the pressure distal to the clot 10. Applying positive pressure rather than suction into the blood vessel 12 can avoid collapse of the blood vessel 12 and allow for easier removal of the blood clot 10. Applying positive pressure distal to the clot 10 into the blood vessel 12 can radially expand the blood vessel 12, freeing the clot 10 from where it was lodged on the inner wall surface 12a of the blood vessel 12, and pushing the clot 10 proximal back towards the suction catheter 14, which can provide relative negative pressure at its own funnel-shaped distal end 16.

[0034] One or more pressure sources and control devices 22 are provided, as schematically shown in Figure 1C, to provide and control suction and / or positive fluid pressure as disclosed herein, and / or to provide other control and operating functions. For brevity, the pressure sources / control devices 22 are not shown in all embodiments, but it will be understood that all embodiments of the systems disclosed herein include components for providing negative and / or positive pressure, and one or more control devices 22 associated with the supply source (e.g., one or more pumps) and / or elongated intravascular elements (e.g., catheters and / or guidewires) that deliver the pressure. The control devices 22 may also provide other capabilities. Ischemic vessels may be prone to spasm. Positive fluid pressure can help dilate the vessel 12, potentially increasing the chances of clot removal. Applying pressure to the blood vessel 12 distal to the clot 10 and aspirating or suctioning the clot 10 proximal to the clot 10 can create a large pressure gradient, and therefore may be a successful combination of actions to remove the clot 10.

[0035] As used herein, the term “fluid” means a liquid, a gas, or a combination of a liquid and a gas. The liquid may be any desired biocompatible liquid. Gases such as air, CO2, O2, anesthetic gases, or any other biocompatible gas can be used to protect against brain injury. CO2 is absorbed very quickly into the body and can be a very good gas to use for pressurization. CO2 can be non-toxic and is often available in hospital tanks and / or other gas sources. CO2 can also be produced locally by adding an acid to bicarbonate. Nitric oxide is a potent vasodilator gas. Pressurizing blood vessels and widening them physically and chemically may be effective. Drugs can also be delivered in spray form. These may be used to widen blood vessels 12 and protect the brain. In some examples shown or described herein, a fluid containing a drug may be introduced into blood vessels 12.

[0036] The distal guidewire membrane 20 seals along its entire length, but in this embodiment, its proximal end is open. The gas or other fluid delivered through the punched hole 23 may be continuous (constant) or pulsate (circulate) at one or more desired frequencies and amplitudes of pressure, such as being controlled by the pressure source / controller 22. The fluid pressure may be introduced slowly to prevent over-distention and rupture of the vessel. Slow pressurization can prevent these undesirable effects. Since the pressure is generally equal at both ends of the guidewire 18, it is safe to add the gas or fluid slowly. The fluid widens or radially expands the vessel 12 at the location of the applied pressure, thereby releasing the agglutinous mass 10 from the vessel wall 12a, or at least loosening it, and its funnel-shaped distal end 16 This helps to push the clot 10 proximal back towards the suction catheter 14, which is providing relative negative pressure. Either or both of the suction and positive fluid pressure levels and / or type (e.g., constant pressure and / or pulsating or circulating pressure) may be adjusted during the procedure as requested or deemed necessary by the physician, or according to an algorithm.

[0037] Figure 1D Figure 1D illustrates the removal of a blood clot 10 from a blood vessel 12 using a system including a stent-type retrieval device 24. In some embodiments, the system may further include a pressure source 22 that provides positive pressure in addition to the negative pressure or suction provided by the catheter. In some embodiments, the pressure source may not provide positive pressure. The stent-type retrieval device 24 may comprise a guidewire 18 and a mesh 17 proximal to the distal end of the guidewire 18. When deployed, the guidewire 18 can advance through the catheter 14 to the distal side of the blood clot 10, and the mesh 17 can be positioned near the site of the blood clot 10. When the pressure source 22 performs suction through the catheter 14 to release the blood clot 10, the mesh 17 can physically capture the blood clot 10, allowing for easier removal. In some embodiments, positive pressure may be applied from the pressure source 22 through the guidewire 18 to help release the blood clot 10. The guidewire 18 may further comprise a seal 20. The seal 20 can include many embodiments. In some embodiments, the seal may be proximal and flexible. The seal may be expandable to help prevent the agglutinating mass 10 or thrombus fragments from traveling distally, such as entering the patient's brain.

[0038] Figures 2A, 2B, and 2C Here, a balloon-shaped or more spherical radially expandable seal 20a is shown with an annular hole or opening 21 at its proximal end. The balloon membrane 20a or seal may have one or more holes 21, particularly proximal. The end of the membrane 20a near the punch hole 23 may expand first (for example, by being more flexible (compliant)), while the other, more proximal portion with the holes 21 may expand later or afterward. A balloon-shaped membrane 20a can seal the vessel 12 where it touches the vessel wall 12a (Figure 2B). The membrane 20a can help prevent fragments of the blood clot 10 from moving distally. Aspiration is performed through the catheter 14 to release and remove the blood clot 10. When the user removes the guidewire 18 after the procedure, the membrane 20a may invert so that the membrane touches or does not touch the inner wall 12a of the vessel, allowing for easier removal of the guidewire 18 (Figure 2C).

[0039] Figures 3A and 3B These figures show that the distal seal or membrane 20b may be elongated or tubular so as to cover or overlap the intersection or opening of the lateral vascular branches 12b communicating with the main vessel 12 containing the agglutination 10. This prevents the fluid 19 from leaking through the side branches 12b and causing the main vessel 12 to lose positive pressure. Morphological variations of the distal seal 20b or membrane, such as being cylindrical or other shapes, may provide further assistance. Also, differences in the thickness and flexibility or compliance of the membrane 20b may help ensure that the membrane 20b inflates first near one or more holes 23 of the fluid source, and then the rest of the membrane 20b inflates or expands.

[0040] Figures 3C and 3D Here, a blob 10 is shown pushed into the distal end of a suction catheter 14 for removal. The membrane or seal 20b can be depressurized and inverted for removal. If the gas used to apply positive pressure is CO2, it will be absorbed over a short period of time. When the blob 10 is removed, there is no longer a closed space around the membrane 20b, and gas or other fluids may leak out. For example, since CO2 can be seen as a lucent area on X-rays, it is effective to image the blob 10 using CO2 on one side and a dye on the other. This may highlight the distal end of the blob 10, with the dye indicating the proximal end.

[0041] Figure 3E Here, an inflated or expanded distal membrane 20c is shown, where the elongated tube also acts as a piston against the distal end of the mass 10. For example, a tubular membrane 20c may be used that continuously expands in the direction toward the mass 10 (proximal) and pushes the mass 10 proximal toward the aspiration catheter 14. This will be better illustrated and explained below. The membrane or seal 20c may be constructed to impart force to the mass 10 in a manner similar to that of a piston. The open proximal end of the seal 20c is attached to the guidewire 18 by one or more tethers 25.

[0042] Figure 3F As shown in this figure, the membrane 20c may not invert for removal. Here, the tether 25 allows the seal 20c to be drawn proximal into the aspirator catheter 14. A non-inverting membrane may be beneficial because it can continue to prevent the agglutinating material from migrating into the downstream cerebral blood vessels during removal.

[0043] Figure 3G Here, the proximal open end 27 of the radially expandable distal seal 20d is oriented at a substantially acute angle with respect to the longitudinal axis of the elongated endovascular element, such as the guidewire 18. In other words, the proximal open end 27 is bevel-shaped. The bevel shape may be a linear or straight cut end, or it may be any curve or other shape. The radially expandable seal or tubular element 20d of this embodiment is shown attached to the elongated endovascular element guidewire 18 by a single tether 25. In some cases, multiple tethers 25 may be used. In any case, the tether 25 may be formed integrally with the membrane or seal 20d, or it may be separate and thus appropriately attached to the seal 20d and the elongated endovascular element or guidewire 18 with an adhesive or the like. The elongated tubular seal 20d may be formed by cutting a tube to form an opening at the proximal end 27 of the desired shape. The tubular seal may have a suitable flexible frame, such as one formed by a superelastic wire element (see, for example, Figure 3H). This facilitates radial support and auto-adjustable expansion to adapt to blood vessels 12 of different sizes. The substantially obliquely shaped proximal end 27 helps to automatically fold and withdraw the seal / tube 20d into the catheter 14 at the end of the procedure.

[0044] Figure 3H In this embodiment, as generally described with respect to Figure 3G, the open proximal end 27 has an overall beveled shape, but the shape is curved or S-shaped. The tether 25 is integrally formed from the seal 20e during manufacturing to simplify the manufacturing process. In addition, a flexible frame is provided on the seal / tube structure 20e and includes a ring-shaped support element 28 that is attached to the open proximal end 27. The ring-shaped structure 28 may be formed from, for example, a superelastic wire. When the ring-shaped wire 28 is inside a blood vessel 12 having a typical circular cross-sectional shape, the ring-shaped wire 28 is positioned at an angle, and its diameter is larger than the inner diameter of the blood vessel 12. However, as the inner diameter of the blood vessel increases, the wire 28 is repositioned so as not to be too angled, maintaining engagement with the inner wall surface 12a of the blood vessel 12. The opposite happens when the blood vessel diameter decreases. This constitutes an auto-adjusting function for the distal seal 20e.

[0045] Figures 4A and 4B Here, a double membrane 20f is shown, continuously occluding the blood vessel 12. For example, there may be a first, more spherical distal balloon portion 20f1, followed by a second elongated tubular or overall cylindrical proximal portion 20f2 that expands by introducing fluid through a punch hole 23. Other shapes may be used for a “piston effect” to remove the agglutination 10.

[0046] Figures 5A, 5B, and 5C These figures show that the balloon or membrane seal 20g may unravel at its open proximal end so that it can be used as a “piston.” Unraveling may be modifiable. The length of the mass 10 is generally unknown, and therefore, as the guidewire 18 advances distally beyond the mass 10, the unraveling balloon may expand to adjust the distance to the mass 10.

[0047] Figures 6A and 6B Figures 6A and 6B show another embodiment of a tubular distal seal 20g that can open or expand proximal. The folded seal may expand proximal as the guidewire 18 advances distally beyond the clot 10, allowing one or more unraveling proximal end portions of the seal 20g to come into contact with the clot 10 and push it proximal to aid in its release and / or removal.

[0048] Figures 7A, 7B, 7C, and 7D The guidewire 18 may have a J-shaped tip. This is to prevent the distal end of the guidewire 18 from puncturing the blood vessel 12 or vascular structure when it is guided through the patient's blood vessel 12 or vascular structure. However, the guidewire 18 must advance around the clot 10. Sometimes, the physician may be unable to advance the wire distally past the clot 10 because the clot 10 has been pushed further and further into the lumen of the blood vessel where the blood flow is tapering. The blood vessel 12 may also become constricted. Therefore, when the clot 10 is tightly lodged in the blood vessel 12, it is useful to be able to stabilize and guide the guidewire 18 to allow for more accurate guidance between the blood vessel wall 12a and the clot 10. In this embodiment, a guide 30, which may be a mechanical device, a balloon-type structure, or a combination of both, is provided at the distal end of the suction catheter 14 to help guide the wire past the clot 10. The guidewire 18 and guide 30 are such that the guidewire 18 can advance between the catheter and the guide 30 and be positioned together within the catheter 14 (Figure 7B). The guide 30 includes a guide portion, which may be a channel 32, for receiving the guidewire 18 and guiding it laterally toward the periphery of the atrophy 10. The guide 30 further includes an inflatable portion 34 that inflates for use as shown and deflates for delivery and removal through the catheter 14. Figures 7C and 7D show, respectively, that positive pressure pushes the atrophy 10 and negative pressure aspirates the atrophy 10 to the distal end of the aspiration catheter 14, and subsequently removes the atrophy 10 and distal seal 20 or membrane through the aspiration catheter 14.

[0049] Figures 7E and 7F These diagrams better illustrate the use of guide 30. Guide 30 may be passed through the suction catheter 14 in a deflated state, then inflated for use at the site of the atrophy 10, then deflated again and removed. Guide 30 may have the U-shaped or J-shaped distal end of the guidewire 18 straightened and placed directly adjacent to the atrophy 10 so that the distal end of the guidewire 18 can find a space between the atrophy 10 and the inner wall surface 12a of the blood vessel 12. Channels 32, or other guiding parts such as indentations, may be used to help guide the guidewire past the atrophy 10. This may be used when the guidewire 18 does not pass through the atrophy 10 or between the atrophy 10 and the blood vessel wall surface 12a, or it may be used in all cases. A radiopaque marker 32a may be placed adjacent to channel 32.

[0050] Figures 8A, 8B, and 8C These figures illustrate the use of an alternative guide 30' having a guide channel 32' defined by a rail or other structure to receive and guide an elongated intravascular element in the form of a distal guidewire 18. The guide 30' is best removed before aspiration is performed by the catheter 14, as it may interfere with the effect of aspiration. The guide 30' may be mechanically folded for proper delivery and removal through the catheter. The guide 30' may use a funnel-shaped seal 16 as part of the channel 32'.

[0051] Figure 9A The previous figure shows an elongated intravascular element in the form of a guidewire 18 with an added distal membrane to provide various desirable, but merely illustrative, forms of seals. The distal end of the seal can be attached to a microcatheter 26, while the proximal end remains unattached and can be partially opened by the unattached end when the membrane is expanded. Guidewires are generally made of steel, and it can be difficult to reliably puncture the side of the guidewire 18 to deliver fluid. It may be more effective to configure one or more systems generally described above with a catheter instead of or in addition to the guidewire 18.

[0052] Catheters are generally made of polymer material. This allows for better formation of suitable fluid openings in the catheter wall. Also, catheters generally have a larger diameter than the guidewire 18, but the catheter is usually guided past the mass when the stent-type retrieval device 24 is delivered through the catheter.

[0053] Figure 9A shows a microcatheter 26 with a radially expandable seal membrane 20b attached to its distal end. It will be understood that any other configuration of the seal 20b may be used instead. For injecting fluids such as gas, the microcatheter 26 has a hole or opening 35 beneath or inside the expanded membrane 20b. Figure 9A also shows a small guidewire tip 36 extending beyond the distal end of the microcatheter 26 to help deliver the microcatheter 26 over the agglutination 10. This may be a guidewire portion appropriately attached to the distal end of the microcatheter, or it may be a more traditional guidewire tip portion that extends the length of the microcatheter 26. To avoid a “step up” at the junction of the guidewire tip and the catheter, it may be necessary to place a filler material such as glue or polymer at the junction to smooth the transition. Also, the guidewire tip 36 and / or the distal end 26a of the microcatheter may have a tapered shape adapted to have the smallest transition. The microcatheter 26 is inserted and extends distally beyond the mass 10, as already illustrated and described.

[0054] Figure 9B Figure 9B shows that the microcatheter 26 has been advanced distally beyond the clot 10. Fluid is injected through the transverse holes 35 to expand the membrane 20b, creating a seal against the inner wall surface 12a of the blood vessel 12, allowing positive pressure to be applied proximal to extract the clot 10. The number of transverse holes 35 can be changed. Additional holes (not shown) may also be placed in the microcatheter 26 between the clot 10 and the blood vessel wall surface 12a to help release the clot 10 from strong adhesion to the blood vessel wall surface 12a. It may be effective to rotate the microcatheter 26 to help separate the clot 10 circumferentially so that the clot 10 is released for removal. When rotating the catheter 26, the catheter 26 may be made with a gentle spiral, twist, or bend along its length to encourage the catheter 26 to surround the clot 10. Vibrations applied to the catheter 26 may also assist in the separation of the clot. Pressure oscillation and fluid injection may help separate the clot 10 from the vessel wall 12a. Positive pressure is applied distal to the clot 10 (e.g., gas injection indicated by the arrow), and suction is performed through the suction catheter 14 (vacuum). The clot 10 can then be removed. As previously described, fluctuations and oscillations in the pressure (positive pressure and / or suction) on each side of the clot 10 (i.e., circulating or pulsating the pressure) may help remove the clot 10.

[0055] Figure 9C This figure shows a device similar to those shown in Figures 9A and 9B. This microcatheter 26 has a guidewire 38 that is advanced through the length of the device. The guidewire 38 also helps to seal the distal end 26a of the catheter 26 so that positive pressure can be generated inside the catheter 26 to pressurize the sealing membrane 20b. Between the guidewire 38 and the inside of the catheter 26 there is a space 40 for injecting a fluid, such as gas, to expand and pressurize the membrane 20b. The injected gas allows the radially expandable membrane 20b to press against the vessel wall 12a, creating a seal and generating pressure to push the agglutination 10 proximal. When performing the procedure, the guidewire 38 may first be guided distally beyond the agglutination 10. Then the catheter 26 may be advanced distally beyond the agglutination 10 through the guidewire 38. Then the gas may be injected at the distal location of the agglutination 10 as shown and described.

[0056] Figure 10A The configuration of a system for removing the agglutination 10, in which a guidewire-type or catheter-type element is part of the system, is difficult, costly, and in some cases can be unstable in certain situations. Optionally, the elongated intravascular element may be a standard microcatheter 26, and the lumen of the standard microcatheter 26 may be used as a channel to inflate or radially expand the distal seal or membrane 20h and apply positive pressure to the area between the membrane 20h and the agglutination 10. Attaching the membrane 20h to a guidewire 18 and advancing it beyond the agglutination 10 may be less costly and easier. This is a relatively simple device to fabricate. A relatively cylindrical seal or membrane 20h is attached to the guidewire 18, near its distal end, and sealed to the guidewire 38. The guidewire 38 with the attached membrane 20h is contained within the microcatheter 26, as shown in this figure, and delivered from there. The guidewire 38 and microcatheter 26 are further contained within the aspiration catheter 14 and proximal to the agglutination 10, and delivered from there. It should be understood that, instead of inserting and manipulating the microcatheter 26, any other suitable delivery components and methods may be used.

[0057] Figure 10B This diagram shows a guidewire 38 (with an attached seal or membrane 20h) inside a microcatheter 26. These devices are guided distally beyond the agglutination 10. The membrane 20h is inside the microcatheter 26 during delivery to facilitate insertion distally beyond the agglutination 10.

[0058] Figure 10C The guidewire 38 with the attached seal or membrane 20h is pushed out of the microcatheter 26 at the distal location of the agglutination 10. The membrane 20h is constructed such that its open proximal end is stiffer than its distal end and springs out radially or opens once outside the microcatheter 26. To encourage the proximal end of the membrane 20h to open, a small hyperelastic spring element (not shown) may be attached to the proximal end of the membrane 20h to help the membrane 20h maintain the shape shown in the figure. The previous figure shown and described herein shows a tether 25 used to close the membrane 20h, which may be used similarly in this embodiment. The tether 25 may be made from a thin wire that is stiff and is pushed or otherwise moved to open the membrane 20h.

[0059] Figure 10D Next, the microcatheter 26 is pushed toward the end of the guidewire 38 under the membrane or seal 20h to further open the seal and engage with the inner wall surface 12a of the blood vessel 12.

[0060] Figure 10E Next, a fluid, such as CO2 gas or another fluid, is injected through the microcatheter 26 from its distal end to more completely expand the membrane 20h radially, forming a fluid seal between the membrane 20h and the inner wall surface 12a and applying positive pressure to the distal region of the mass 10. There is sufficient space between the wire 38 and the inside of the catheter 26 for injecting the gas or other fluid. The advantage of this alternative configuration is that no lateral hole is required in the catheter or guidewire. The guidewire 38 can be made with an attachment membrane or seal 20h, as shown in the figure. The membrane 20h can be compressed and folded to deliver the membrane 20h from inside the microcatheter 26.

[0061] Figure 11A This figure illustrates an alternative method for deploying a membrane or seal 20. This system comprises a guidewire 18 with an attachment membrane 20 folded or folded over a microcatheter 26. The tip of the microcatheter 26 is advanced using the guidewire 38, under the membrane 20, near the point where the membrane 20 is attached. At this point, the membrane 20 is radially outward of the microcatheter 26. The microcatheter 26 and guidewire 38 are pushed distally beyond the agglutination 10. In common situations, there is a sudden change in diameter where the guidewire 38 passes through the microcatheter 26, which can make guiding the catheter 26 more difficult. The membrane or seal 20 is positioned to smooth the passage of the microcatheter 26 by covering this transition. The advantage of this configuration is that the microcatheter 26 does not need to be advanced inside the seal or membrane 20. The membrane configuration is simpler and eliminates the risk of the microcatheter 26 failing to grasp the inside of the membrane 20 in order to expand the membrane 20.

[0062] Figure 11B This diagram shows that a gas or other fluid is injected through the microcatheter 26. The gas exits from the distal tip 26a of the microcatheter 26, which is deep inside the membrane 20. This expands the membrane 20 and forms a distal seal 20. The pressure on the system then prompts the clot 10 to break free from the blood vessel 12.

[0063] Once the membrane 20 is deployed by injecting CO2 or other fluids, the microcatheter 26 may be moved toward the agglutination 10, and the tip of the microcatheter 26 may be returned into the agglutination 10, i.e., between the agglutination 10 and the vessel wall 12a. CO2 or other fluids may be injected to help separate the agglutination 10 from the vessel wall 12a. As previously described, CO2 can be pulsated using pressure fluctuations to help separate the agglutination 10 from the vessel wall 12a. As with all other embodiments, the pressure may instead be constant or nearly constant, or a combination of pulsating and constant pressure may be used between different parts of the procedure. Vibrations may also be applied to the wire 38 or catheter 26 to move the agglutination 10 and the vessel wall 12a rapidly and help release the agglutination 10. A combination of fluid injection, pressure fluctuations, and / or pulsations may be extremely effective.

[0064] As described herein, positive pressure and suction can be applied proximal to the clot 10 through the suction catheter 14. Pulsation under vacuum and positive pressure may enhance the effectiveness of this clot removal system. The microcatheter 26 and / or guidewire 38 may include one or more sections. In this case, as the catheter 26 is rotated, it moves around the clot 10, helping to separate the clot 10 from the vessel wall 12a.

[0065] The microcatheter 26 may have a slightly meandering shape or a U-shaped turning motion. The configuration is generally designed to deviate from the line of the central axis of the catheter 26. For example, the deviation alternates between left and right or side to side, similar to the teeth of a saw. As a result, the microcatheter 26 is rotated and / or moved in other ways relative to the agglutination 10, and by gradually pushing the catheter 26 between the agglutination 10 and the vessel wall 12a during rotation, the agglutination 10 helps to separate from the vessel wall 12a. An example is further described herein.

[0066] The microcatheter 26 may also be moved back and forth over the lumps 10 to help release or detach the lumps 10. A combination of negative or suction pressure, positive pressure, suction and / or positive pressure oscillating or pulsating, and / or vibration may be used. Additionally, rotating one or more components around the lumps 10 may help the guidewire 38 or catheter move around the lumps 10 and help remove the lumps 10.

[0067] A control device 22 (as shown in Figure 1B) may be provided for various purposes in any and / or all embodiments. For example, the control device 22 may provide pressure level changes, frequency and amplitude variations in pressure pulsation and / or oscillation, pressure type (suction and / or positive pressure), vibration supply, and / or other aspects directly related to the clot removal technique. Additional or alternative, the control device 22 may measure blood loss to ensure that the patient does not lose too much blood during the procedure, and / or the control device 22 may measure pressure in the system to monitor the state of the clot 10. In this latter regard, zero pressure may indicate that the clot 10 is fixed at the distal end of the suction catheter 14, and a constant level of continuous suction pressure may indicate that the clot 10 is moving proximal through the suction catheter 14 during removal. Vibration may be applied to any device near the clot 10, namely the suction catheter 14, the microcatheter 26, and / or the guidewire 38.

[0068] CO2 is rapidly absorbed. However, some gas may remain beneath the membrane 20 where it does not come into contact with the tissue that absorbs it. To remove the catheter system after clot removal, suction can be applied to the end of the microcatheter 26 to remove the gas beneath the membrane 20. This flattens the membrane 20, making removal easier. Suction can be applied to any of the described variants of the microcatheter 26 to fold the membrane 20 and help remove it.

[0069] Figures 12A to 12D These figures show the lateral hole 35 of the microcatheter 26. The microcatheter 26 can be pulled proximal so that the lateral hole 35 is at the location of the agglutination 10. Alternatively, the microcatheter 26 can be designed, as shown in Figure 12A, so that it is not necessary to move the microcatheter 26 proximal to align the hole 35a with the location of the agglutination between the agglutination 10 and the vessel wall 12a. This allows for the injection of gas or other fluid between the agglutination 10 and the vessel wall 12a.

[0070] As further shown in Figure 12B, inflatable blades or fins 44 may be fabricated on the side of the microcatheter 26. They can be inflated by an additional lateral hole in the microcatheter 26 located beneath the fin or blade 44. These fins or blades can be made of a small membrane that is flattened to the catheter 26 for insertion. Hole 35a can communicate with hole 35 of the microcatheter 26 distally beyond the mass 10. When the distal hole 35 applies pressure to the distal area beyond the mass 10, the fin or blade 44 begins to expand. The fin or blade 44 may be about 1 mm to 3 mm in size. The fin or blade 44 may be positioned around the catheter 26 like a shoelace. The fin or blade 44 may also form a structure such as a screw or helix that helps engage with the mass 10, allowing the mass 10 to be drawn proximal when the catheter 26 is withdrawn. The fins or blades 44 may also be filled with separate channels (not shown) so that they do not depend on or involve the use of the distal hole 35 beyond the clot 10. The projections, such as the fins or blades 44, may have any useful shape so that the microcatheter 26 can help capture the clot 10. The projections 44 may also help separate the clot 10 from the vessel wall 12a.

[0071] Figure 13A This figure shows a proximal seal membrane 16 delivered on a microcatheter 26. The microcatheter 26 is located inside the aspiration catheter 14. A wire 38 with a membrane 20g for distal sealing is advanced over the agglutination 10. The membrane seal 20g may be expanded by a superelastic frame that opens the seal. The membrane seal 20g can be expanded by positive pressure, i.e., by injecting fluid through the microcatheter 26. For delivery, the membrane 20g or seal may be inverted inside the microcatheter 26 and pushed out of the microcatheter 26 together with a guidewire or stylet (not shown).

[0072] Figure 13B As shown in this figure, the proximal seal or membrane 16 forms a seal against the inner wall surface 12a of the blood vessel 12, as previously illustrated and described.

[0073] Figure 13C As further shown in this figure, the distal seal 20g or membrane is folded in itself as previously illustrated. When gas or other fluid is introduced from inside the wire 38, the membrane 20g expands and begins to spread. The membrane 20g eventually touches the agglutination 10 and pushes the agglutination 10 proximal toward the aspiration catheter 14.

[0074] Figure 13D As shown in the figure, the agglutination 10 is pushed into the receiving end of the proximal membrane 16. The proximal membrane 16 encloses the agglutination 10 and helps to keep the agglutination 10 intact when it is aspirated or pulled into the vacuum catheter 14. This reduces the risk of the agglutination breaking and fragments forming an embolism further distal to the brain. Having a longer proximal membrane 16 can also be beneficial. The agglutination 10 is often at least 10 mm in length. The membrane 16 that completely contains the agglutination 10 and is sealed at the ends by an open distal seal membrane 20 g is completely contained and there is no concern about embolism during removal.

[0075] Figure 14A As shown in this figure, the proximal seal 16 is attached to the aspiration catheter 14. It will be understood that the proximal seal or membrane 16 can take many different shapes and sizes. For example, the proximal seal 16 may be longer than shown and may be inverted inside the aspiration catheter 14 for delivery and then extruded for sealing. This figure also shows the aggregate 10 and the wire 38 that holds the distal membrane seal 20g before unfolding, for example, coiled or possibly folded.

[0076] Figure 14B The proximal membrane seal 16 is activated. A small amount of pressure may be required to expand or widen this seal 16 radially.

[0077] Figure 14C A microcatheter 26 is advancing along a wire with a folded membrane 20g attached. CO2 or other fluid may be used to inflate the membrane 20g, which is expanded as shown in the figure.

[0078] Figure 14D As in the previous series 13 diagram, the distal membrane 20g pushes the lumps 10 into the proximal membrane 16, or at least toward the proximal membrane 16. Alternatively, combining the proximal suction force and the distal pushing force can cause the proximal movement of the lumps 10, which can then be removed.

[0079] To help push the mass 10 proximal, positive pressure can also be applied distal to the mass 10, i.e., proximal. A combination of distal positive pressure on the mass 10 and proximal suction can also be extremely effective in mass extraction.

[0080] Suction and / or positive pressure can be varied by means of circulation or pulsation, etc. The change in suction may be gradual or abrupt. It may be used in repetitive cycles or variable cycles or any variation in suction and / or positive pressure to help release the lumps 10. Suction and / or positive pressure may be applied in any pressure pattern. Positive pressure and suction may be adjusted simultaneously or as needed (circulation or pulsation, pressure level or other variation) to create the best configuration for removing the lumps 10.

[0081] Applying positive pressure to both the proximal and distal aspects of the abscess 10 can also be beneficial. This can dilate the blood vessel 12 and help separate the abscess 10 from the wall 12a of the blood vessel 12. Abscesses 10 inside the blood vessel 12 tend to adhere to the wall 12a. By stretching the blood vessel 12 using positive pressure, the blood vessel 12 can be dilated, and at least part or even all of the abscess 10 can be separated from the wall 12a.

[0082] A device that can be advanced through an existing or more traditional suction catheter is advantageous, having a radially expandable seal, such as the illustrated funnel-shaped distal end 16, which helps to bring the seal into place at the end of the suction catheter 14. The funnel-shaped seal 16 can be made of a shape-memory or superelastic material that folds for insertion and opens for sealing. The shape-memory or superelastic material, such as nitinol, may include a sealing membrane or cover material to create a complete seal. The sealing material may be plastic, such as ePTFE. Such a separate device allows radiologists and neurologists to use an existing suction catheter and then add a seal separately after the suction catheter 14 has been brought into place.

[0083] Figure 15 This figure shows a microcatheter 26 having a nonlinear portion 50, which in this exemplary embodiment is spiral or helical. Rotation of the microcatheter 26, such as while the microcatheter 26 is guided distally past the agglutination 10, helps to separate the agglutination 10 from the inner wall surface 12a of the blood vessel 12, making the removal of the agglutination 10 easier.

[0084] Figure 16A The preceding figure in the application incorporated above shows a seal 20g from an inflatable or optionally radially expandable membrane or seal 20 that provides a seal to apply positive pressure distal to or beyond the agglutination 10 within a blood vessel 12. The distal membrane or seal may be delivered on an elongated intravascular element, such as a guidewire-type or catheter-type structure.

[0085] When a distal membrane or seal is pressurized, one risk is that fluid may leak distally, preventing a proper seal from forming. Several options to avoid this, such as double membranes and molded membranes with small proximal openings, are described herein.

[0086] Another option shown in this series of figures is to use the clot 10 to close the open proximal end of the distal membrane or seal 20i. Here, the membrane 20i is advanced so that the proximal (open) end of the membrane 20i is trapped between the medial vessel wall 12a and the clot 10. This closes the proximal end of the membrane 20i, and as the membrane 20i is inflated by the fluid, the membrane 20i expands to form a seal.

[0087] Figures 16A to 16C also show a suction catheter 14 with an attached or integrated funnel-shaped seal 16 to create a seal with the blood vessel 12 and improve suction for removing the clot 10. Another way to create this proximal seal 16 is to use a conventional off-the-shelf cylindrical suction catheter and add the funnel-shaped seal 16 during a surgical intervention. This option will be discussed in more detail below. The proximal seal 16 can be attached to a long wire and advanced through the suction catheter 14. The seal 16 may be made of an expandable frame of nitinol or other shape memory material. A membrane cover may be added to reinforce the seal. The shape memory mesh itself may be suitable for sealing if the mesh is dense, but the addition of a solid or fluid-impermeable covering may form a more robust fluid pressure seal. As shown, the distal seal membrane 20i is folded into the microcatheter 26 so that it can be delivered distally beyond the clot 10 in the patient's blood vessel 12.

[0088] Figure 16B This figure shows the fluid being injected into the membrane 20i. The fluid fills the membrane 20i distal to the clot 10, expands the membrane 20i against the vessel wall 12a, creates a seal, and ensures that the membrane 20i is fully expanded and that the fluid does not leak distally to a significant extent.

[0089] As the membrane seal 20i fills distal to the agglutination 10, additional fluid is introduced. The membrane 20i begins to envelop the agglutination 10. This is important because the movement of the membrane 20i around the agglutination 10 helps separate the agglutination 10 from the vessel wall 12a. As previously explained, separating the agglutination 10 from the vessel wall 12a is crucial because it breaks the adhesion between the agglutination 10 and the vessel wall 12a, facilitating agglutination removal. This increases the likelihood of extracting the agglutination 10. The arrows in the figure indicate the course the membrane 20i takes as it encircles the agglutination 10.

[0090] Figure 16C The membrane 20i occludes the distal vessel 12 of the clot 10. The membrane 20i encloses the clot 10, separating it from the wall 12a in at least part of its pathway around the vessel 12. The membrane 20i is shown with its proximal end open. In practice, the membrane 20i can be closed or partially closed at its proximal end (as shown in the figure) to help ensure that it encloses the clot 10 as much as possible before fluid begins to leak proximal.

[0091] It may also be effective to fully expand the membrane 20i and maintain fluid injection. The injected fluid can help separate the clot 10 that is not in contact with the membrane 20i. As previously described, positive pressure may be applied from the suction catheter 14 proximal to the clot 10, or, in some cases, radially expand the blood vessel 12 to help separate the clot 10 from the vessel wall 12a. The membrane 20i enclosing the clot 10 may be wide enough to completely enclose the clot 10. Also, pulsating / varying / circulating the positive pressure and / or suction applied to each side of the clot 10 may be effective in extracting the clot 10.

[0092] Another way to ensure that the membrane 20i fills and occludes the distal portion of the blood vessel 12 is to deliver the membrane 20i from the microcatheter 26 so that only a portion of it is deployed (for example, half-deployed). This captures the fluid and expands the membrane 20i. After the membrane 20i has expanded, the remainder of the membrane 20i can be pushed out from the microcatheter 26. The microcatheter 26 can be slowly withdrawn, allowing the membrane 20i to continuously wrap around the agglutination 10 as the microcatheter 26 is withdrawn. In other words, an initial amount of fluid is introduced, which fills or expands the membrane 20i at the distal end of the device. The catheter 26 is then withdrawn a few millimeters, and an additional amount of fluid is introduced into the area contained in the membrane 20i. The membrane 20i then envelops further agglutination. This process is repeated until all agglutination 10 is separated from the blood vessel wall 12a.

[0093] Figure 16D This figure is a cross-sectional view showing the initial insertion of the microcatheter 26 laterally into the agglutination 10 and the initial deployment of the annular seal membrane 20i.

[0094] Figure 16E This figure is a cross-sectional view of the membrane 20i enclosing the lumps 10 during further development, compared to Figure 16D. As more fluid is introduced, the membrane 20i expands and continuously extends around the lumps 10. The shape of the membrane 20i can be made such that it completely surrounds and encloses the lumps 10. This separates the lumps 10 circumferentially from the vessel wall 12a. Also, the lumps 10 will be completely surrounded by the membrane 20i. This allows the lumps 10 to be removed inside the “cocoon”-like membrane enclosure, and the lumps 10 are maintained as a single unit for removal, thus preventing fragmentation of the lumps 10. The dotted line shows the deformation of the membrane 20i that can completely enclose the lumps 10.

[0095] The membrane 20i is shown attached to the microcatheter 26. To attach the membrane 20i, a guidewire-type structure or other types of elongated intravascular elements may be used instead to manufacture a similar device. The arrows in Figures 16A and 16C indicate that when the aspiration 10 is partially or completely released from the vessel wall 12a, suction is performed from the aspiration catheter 14 to remove the aspiration 10. In this case as well, the funnel-shaped seal 16 adjacent to the distal end of the aspiration catheter 14 may be integrated with the aspiration catheter 14 for delivery, or optionally attached, or delivered as a separate component, in which case the aspiration catheter 14 itself may be of a conventional type.

[0096] Figure 16F This shows the overall shape of the membrane seal 20i. The distal end 52 is tapered. The distal end 52 can have any useful shape, such as a sharper tip, a rounded tip, or a bullet shape. In the proximal portion 54, the membrane 20i is rather cylindrical. Proximal to the surface, it may be effective for the membrane 20i to have a wider cylinder to enclose more aggregates 10.

[0097] Figures 17A and 17B These figures show a device similar to the previous configuration, where the membrane 20j encloses the agglutination 10, but the membrane 20j is closed at its ends. The membrane 20j enclosing the agglutination 10 is coupled to, or possibly held by, a microcatheter 26, a guidewire 38, or other form of elongated intravascular element. In this regard, with respect to all embodiments, the form of the elongated intravascular element may exhibit many variations. To expand the membrane 20j, the guidewire or catheter has an opening 35 that communicates with the internal space of the membrane 20j, allowing fluid to be introduced through the catheter or guidewire.

[0098] In Figure 17B, the membrane 20j is expanded, enveloping and surrounding the aggregate 10. The aggregate 10 is shown inside the membrane 20j by a dashed line. The ends of the membrane 20j are shown open. It is also possible to close the expanded membrane 20j at one or both ends of the aggregate 10 to prevent any part of the aggregate 10 from escaping.

[0099] Figure 17C This figure shows a cross-sectional view of the membrane seal 20j enclosing the aggregate 10.

[0100] Figure 17D In this variant of Figure 17C, the membrane 20j has “welds” or attachments 56 that maintain the membrane 20j in a flat shape when the membrane 20j expands. This helps the membrane 20j to reliably enclose the agglomerate 10 in the circumferential direction. These attachments 56 can be point attachments, or lines, or circles, or any effective shape to achieve this result. In the figure, the “weld points” 56 are shown as dashed lines.

[0101] Figure 18A This shows a top view of a microcatheter 26 or guidewire 60 in a form that allows it to be inserted into a patient's body. The inflatable membrane 20k has a junction with the lumen, which allows the membrane 20k to expand once it enters the patient's blood vessel (not shown).

[0102] Figure 18B This figure shows the membrane 20k expanded. The membrane 20k forms a closed space in which the introduced fluid can be retained. The membrane 20k communicates with the lumen of the microcatheter to be filled with fluid. The figure shows welding points 62 of various shapes that maintain the membrane 20k from expanded to more spherical. Generally, this membrane 20k expands in a plane that can be used to separate the agglutination 10 from the vessel wall 12a (see other figures herein).

[0103] The weld shape can be altered to help maintain the shape of the expanded membrane 20k. It may be effective for the membrane 20k to expand into a cylindrical shape so that it expands overall along the inner wall surface 12a of the blood vessel 12 and grasps the internal atrophy 10. This can be achieved by making one side of the membrane 20k shorter than the other, or by adjusting the weld to guide the expanded structure into a cylindrical or other tubular shape. Once the atrophy 10 is contained within the membrane 20k, the membrane 20k helps prevent the thrombus from traveling distally and causing a stroke or injury downstream of the brain. In this respect, the membrane 20k acts as a radially expandable seal.

[0104] Figure 18C This figure shows a cross-sectional view of the expanded membrane 20k. The welding point 62 helps control the expanded shape of the membrane 20k, i.e., the overall cylindrical shape for enclosing the aggregate 10.

[0105] Figure 19A This figure also shows a folded clot extraction device or membrane 20l, ideal for insertion into a patient. An elongated intravascular element, such as a guidewire or microcatheter 60, provides a channel for filling the membrane 20l with fluid. The elongated intravascular element, for example, the guidewire 60, communicates with one or more internal cavities or spaces within the membrane 20l in order to inflate the membrane 20l, which is initially closed or folded.

[0106] Figure 19B The previous Figures 18A and 18B show a membrane 20k designed to enclose the agglutination 10. Folding this expansive membrane 20k for insertion can be difficult due to the large volume of membrane 20k to be folded. Figure 19B shows a membrane 20l with numerous sealed cutouts separated by a series of fluid-connected link elements 64 that expand from the central lumen of a guidewire or microcatheter 60. The expandable link elements 64 may be three-dimensionally shaped to form a tube or cylinder that encloses the agglutination 10. Although pentagonal and hexagonal shapes are shown here, any shape of this type of lattice structure may be used. The advantage of an open lattice is that material is reduced and crimping for delivery is possible.

[0107] It should be noted that this same shape of the device can be constructed without requiring fluid expansion. The grid can be constructed from a foldable material, such as nitinol or other superelastic material. The grid can fold inside the catheter for delivery and may self-expand to this shape when released from the catheter.

[0108] Figure 19C This figure shows a device inside a blood vessel 12 that has expanded and enclosed the agglutination 10. The device is attached to a connected guidewire and microcatheter 26. The attachment of the catheter 26 to the guidewire 38 at its distal tip 26a creates a seal that prevents the fluid introduced at the tip from leaking.

[0109] The microcatheter 26 is hollow, allowing a fluid to fill the membrane 20l that encloses the agglutination 10. The membrane 20l is fluid-coupled to the lumen of the microcatheter 26 in such a manner that it allows the fluid to fill, i.e., expand, the membrane 20l, as generally described herein.

[0110] The membrane 20l enclosing the aggregate 10 can form a casing at either the proximal or distal end, or both. This further helps to keep the small pieces of aggregate 10 from escaping.

[0111] The figure also shows an arrow indicating that a microcatheter 26 is withdrawn to remove the agglutination 10 inside the enclosed inflated membrane structure.

[0112] There is a suction catheter 14 with a funnel-shaped proximal seal 16 or opening. The assemblies 20l, 26, and 38 can be pulled through the suction catheter 14 if necessary. The arrows indicate the direction in which the microcatheter 26 moves to remove the clump 10 inside the lattice structure. Alternatively, as in all other embodiments, the clump 10 may adhere to the distal tip or end of the suction catheter 14, and the suction catheter 14 may then be withdrawn together with the attached clump 10.

[0113] Figure 20A This figure illustrates another method for removing a clot 10 from a blood vessel 12. A suction catheter 14 with a funnel opening 16 is shown proximal to the clot 10 and configured as in any of the methods described herein. The clot 10 is lodged in the blood vessel 12. A microcatheter tip 26a is advanced distally beyond the clot 10. This microcatheter 26 has a guidewire tip 36. The microcatheter 26 has a hollow lumen to fill the clot extraction or removal device 70 with fluid. Note that the core or spine of the device may consist entirely of a microcatheter without a guidewire tip or without a guidewire tip. An inflatable structure is shown and may comprise an annular inflatable membrane 20m. The membrane 20m can capture and / or surround the clot 10.

[0114] Figure 20B This figure shows an annular, expandable membrane 20m expanded. Upon expansion, the membrane 20m encloses the agglutination 10, forming a “finger” 72 that encompasses the agglutination 10. The finger 72 expands toward the agglutination 10, enclosing and encompassing it as shown. Alternatively (not shown), the finger 72 may be inserted so as to enclose the agglutination 10 upon expansion and fully expand along the length of the spine or core of the microcatheter. The proximal or distal membrane segments 74, 76 may be connected (i.e., joined proximal and distal finger segments). Upon expansion, the finger 72 completely covers and captures the agglutination 10 for sealing. The figure shows an arrow indicating that the agglutination 10 is being pulled out.

[0115] Figure 21A This figure shows a variation of the inflatable finger structure shown in the previous figure. The agglutinator 10 is located inside the blood vessel 12, and the funnel-shaped seal 16 and suction catheter 14 are located proximal to the agglutinator 10 as previously described. A core or spine is shown, consisting of a hollow, fillable microcatheter 26 with a guidewire tip 36. A slender rod 80, most likely composed of a polymer gas-fillable tube or a polymer such as polypropylene (e.g., a wire or suture material), extends between the inflatable bulbous ends 82, 84. At their ends, the rod 80 engages with or adheres to the inflatable bulbous ends 82, 84. To help expand the rod 80, the rod 80 may wrap around the distal ends of the inflatable bulbous ends 82, 84. The rod 80 folds into the spine provided by the catheter 26.

[0116] Figure 21B The inflatable ends 82, 84 are expanded. The rod 80 sweeps the inside periphery of the blood vessel 12, scraping the clot 10 from the blood vessel wall 12a. The inflatable ends 82, 84 may also expand the blood vessel wall to help the rod 80 enclose the clot 10. The rod 80 surrounds the clot 10 and is shown internally, grasping the clot 10 for extraction. The rod 80 is moved into place by the expansion of the inflatable bulbous ends 82, 84. The expansion carries the rod 80 around the clot 10. The clot 10 may be extracted at the distal end of the suction catheter 14, or it may be attached to the distal end.

[0117] Figure 21C This cross-sectional view shows one of the inflatable bulbous ends 82 to which the microcatheter 26 is attached. The rod 80 is shown in a position where it is radially expanded to surround the mass 10. The rod 80 may be located on or coiled over the ends 82, 84.

[0118] Figures 22A and 22B This variant of the membrane 20o shows inflatable bulbous ends 86, 88 that do not enclose the microcatheter 26. The inflatable bulbous ends 86, 88 move a wire or rod 90 that may be inflatable or simply composed of a metal wire or polymer wire to enclose the agglutination 10. Between the catheter 26 and the bulbous ends 86, 88 is a fluid connection that allows them to be filled with fluid and expanded at the illustrated positions to seal the blood vessel 12 at both proximal and distal ends of the agglutination 10.

[0119] Figures 23A and 23B The rod enclosing the atrophy 10 can be actuated by means other than fluid expansion. In these figures, the atrophy extraction device is shown to include a rod 92, which encloses the atrophy 10 and is held inside a microcatheter 26 with a guidewire tip 36. The rod 92 is attached to stents 94, 96, each end of which is foldable (there is one stent at each end of the rod). The proximal stent 94 and distal stent 96 are folded inside the microcatheter 26 for insertion. The microcatheter 26 can be withdrawn, allowing the stents 94, 96 to self-expand. In this regard, any stents or stent-like structures described herein may be self-expanding. The stents 94, 96 and their attachments to the rod 92 expand, wrapping the rod 92 around the atrophy 10. The stents 94, 96 can be made from a shape-memory material such as nitinol, or any other superelastic material, which automatically expands to the desired shape when released from the catheter.

[0120] This separates the clot 10 from the vessel wall 12a, and then the rod 92 captures the clot 10 internally. Open stents 94, 96 can also be used to aid in clot removal. Open stents 94, 96 may have tapered ends that allow the stent to be pulled posteriorly to easily remove the clot 10. Stents 94, 96 may have different shapes. Any stent deformation that allows the rod 92 to move around the stent is also good. Once the stent is deployed, the microcatheter 26 can be removed. The stent / rod device can then be pulled to remove the clot 10. A pull wire for pulling out the captured clot 10 is not shown in the figure. Ideally, the proximal end of the proximal stent 94 would have a wire (not shown) attached to its end, which would travel through the suction catheter 14, allowing the interventionist to pull the wire to retrieve the clot 10.

[0121] Figures 23C and 23D It is beneficial that the stents 94 and 96 at both ends of the atrophy 10 expand along the curved wall of the vessel 12, following the inner lumen of the vessel 12. Since these stents 94 and 96 hold the rod 92, this ensures that the atrophy 10 is separated from the vessel wall surface 12a by the rod 92 and that the rod 92 captures the atrophy 10. These cross-sectional views show that stent 94 opens in a circumferential pattern to hold the rod 92 so as to surround the atrophy 10.

[0122] Figures 24A and 24B Using a rod (wire, polymer, etc.) that encloses the atrophy 10 helps to separate and capture the atrophy 10 from the wall 12a of the blood vessel 12 for removal. The figure in the previous series 23 shows a pair of expandable stents 94, 96 that hold the rod 92 so that the rod 92 encloses the atrophy 10. Figures 24A and 24B show alternative forms of stents or fluid inflation. This system uses two loops 100, 102 separated by a rod or wire 104, respectively, at proximal and distal positions. Once the system is released from inside the microcatheter 26 or other elongated intravascular element, the loops 100, 102 can actuate on their own. Alternatively, the loops 100, 102 may be actuated by a bull wire (not shown) to move the loops 100, 102 into the actuated position. The loops 100, 102 may be formed from a wire such as stainless steel, or from a shape memory material such as nitinol or other superelastic material.

[0123] In Figure 24B, the macrocatheter 26 is stationary in place. The microcatheter 26 may be removed if the system is delivered from inside the microcatheter 26 rather than being held by the microcatheter 26. Loops 100, 102 perform the same or similar functions as the stents 94, 96. Loops 100, 102 guide the rod 104 around the agglutination 10 to separate and extract the agglutination 10. An optional distal membrane or seal 20 is also shown, such as a bag-like component attached to the distal loop 102 to ensure that fragments or agglutination material do not advance downstream from the agglutination 10.

[0124] Figures 25A and 25B These figures show an alternative funnel-shaped distal end configuration 16 for the suction catheter 14. Instead of stent action, there is a wire loop or hoop 110 that inverts and takes position to open the funnel opening or proximal seal 16. In this embodiment, the seal 16 is a separate component from the suction catheter 14 and is advanced into position at the distal end of the suction catheter 14, and the wire loop 110 is actuated to secure the proximal membrane or seal 16 to the distal end portion of the suction catheter 14. This transition of the seal is shown in these figures. The funnel-shaped seal 16 then performs the function described herein.

[0125] Figure 26A This diagram shows a clot 10 trapped in a blood vessel 12. A conventional cylindrical aspiration catheter 14 is advanced proximal to the clot 10. When aspiration is performed with a standard catheter, some of the aspiration is lost because there is no occlusion of the blood vessel 12. 1) Seal the blood vessel 12 so that all suction can be performed. 2) In order to apply more suction force to the clot 10, increase the surface area of ​​the catheter tip. This is extremely effective. Conventional suction catheters are designed with great care to be extremely thin yet able to withstand suction without collapsing. Furthermore, these catheters must be easily manipulated by the surgeon over long distances through small blood vessels. Interventional surgeons have become highly skilled at manipulating these catheters, and the custom fabrication of suction catheters 14 with funnel-shaped distal ends 16 can sometimes hinder the deliverability of the suction catheters 14. Therefore, adding a funnel-shaped, radially expandable seal tip 16 to existing catheters may be a better alternative.

[0126] This figure shows a folded tube 112, comprising a cylindrical body and a radially expandable seal 16 or funnel opening, formed from a shape-memory material such as nitinol or other suitable material. The figure shows a membrane or covering material over the funnel portion or opening 16. This covering material is optional but can improve the seal. A thin layer of Gortex® / ePTFE may be a good choice, but other materials may be used, such as biomaterials (pericardium) or other polymers. A push wire 114 is attached to the stent structure 112 to allow the stent structure 112 to be inserted and removed. The stent structure or tube 112 is shown inside a catheter 116 (dotted line). It may be possible to insert this device without a catheter, such as directly from inside a suction catheter 14.

[0127] Figure 26B The funnel tip 16 is pushed out from the end of the suction catheter 14. More specifically, the funnel tip 16 extends from the microcatheter 26. It may be possible to deliver this funnel tip 16 directly from the suction catheter 14. The funnel-shaped seal 16 forms or takes the illustrated shape in a manner of self-expansion by a pre-formed shape, made possible by the use of a shape memory material. The membrane is shown on top of the shape memory material stent, although the membrane may be inside the stent or between the wires of the stent.

[0128] Figure 26C The funnel-shaped stent seal 16 is fully deployed. The arrow indicates the suction being performed by the suction catheter 14. The funnel opening 16 forms a seal by engaging with the inner wall surface 12a of the blood vessel 12 and expanding radially. The funnel-shaped seal 16 thereby increases the suction surface area, allowing for greater tensile force on the atrophy 10. The funnel-shaped seal 16 may also slightly stretch the blood vessel wall during this step, helping to separate the atrophy 10 from the blood vessel wall surface 12a. The funnel-shaped seal 16 may be retracted into the suction catheter 14. Alternatively, the funnel tip 16 may remain in place inside the suction catheter 14, and the entire catheter system may be withdrawn together.

[0129] The distal end of the funnel-shaped seal 16 is positioned flat, for example, perpendicular to the longitudinal axis of the catheter 14. The distal end of the seal 16 may instead include any other desired shape, such as being flat but angled with respect to the vertical, and / or including any other shape or distal end configuration. For example, the distal end may have one or more indentations, such as one or more U-shaped indentations. Such shapes may allow the distal end to wrap better between the agglutinous mass 10 and the vessel wall 12a, or possibly engage. One or more U-shaped or other preferred shaped indentations or recesses that are open distally may allow at least a portion of the funnel-shaped seal 16 to separate the agglutinous mass 10 from the wall 12a, with another portion of the agglutinous mass 10 located inside the seal 16.

[0130] Figures 27A and 27B These figures illustrate the use of positive pressure between the clot 10 and the vessel wall 12a (e.g., by injecting a fluid) to separate the clot 10 from the vessel wall 12a. This positive pressure is delivered through a microcatheter 26. The positive pressure catheter 26 may then be extended beyond the clot 10, as shown in Figure 27B, to deploy a distal funnel-shaped or tubular seal 20. Further positive pressure and / or aspiration applied proximal to the clot 10 moves the clot 10 proximal, where it is captured and extracted. One or more physically acting tools (as opposed to fluid-acting) may be used to assist in the separation and / or extraction of the clot from the vessel wall 12a. One example is to rotate the distal end portion of the positive pressure tube or catheter 26 (i.e., distal to the clot 10) alongside the clot 10 and form it into an S-shape or other non-linear shape as it moves proximal, which helps separate the clot 10 from the vessel wall 12a. A wire 118 or similar element may be used to rotate the catheter 26 around the agglutination 10 in order to separate the agglutination 10 from the blood vessel wall 12a.

[0131] Figures 28A to 28E These figures illustrate exemplary methods for removing a blood clot 10. As shown in Figure 28A, an aspiration catheter 14 is inserted into the patient's venous system to the site of the blood clot 10, as shown. The aspiration catheter 14 includes a radially expandable seal 16 at its distal end, as shown, by attaching the seal 16 to it or forming it integrally with it, or the seal 16 is advanced separately through the catheter 14 and secured in place by the previously described method or another preferred method, etc. As shown in Figure 28B, the distal seal 20 is advanced distal to the clot 10 and pressurized with fluid, as shown, and the seal 20 expands radially and adjusts to autoconform to seal the inner wall surface 12a of the blood vessel 12. Positive fluid pressure is guided proximal by a microcatheter 26 to push the clot 10 and also radially expands or widens the blood vessel 12 to stretch the vessel wall away from the clot 10. Refer to Figures 28B, 28C, and 28D. For example, the abscess 10 may be 7 mm long and 2.5 mm wide, and may block a blood vessel 2.5 mm wide. The blood vessel 12 should extend to a width of 3.0–3.5 mm, and the abscess 10 can be separated from the inner wall surface 12a of the blood vessel over most of the circumferential direction. As shown in Figure 28E, the abscess 10 may be removed proximal using suction in combination with positive fluid pressure, as needed or desired. As with all embodiments, the fluid suction and pressure may be constant, variable (circulating or pulsating), or both, as required in the case.

[0132] Figures 29A, 29B, and 29C These figures illustrate exemplary methods for removing a blood clot 10, similar to those shown in Figures 28A–28E, except that a mechanical clot release device 120 is further used to help separate the clot 10 from the inner wall surface 12a of the blood vessel. As shown in Figure 29A, an aspiration catheter 14 is inserted into the patient's venous system to the site of the blood clot 10 as shown. The aspiration catheter 14 may be configured in one of the methods described above with respect to Figure 28A, or in any other preferred method. As shown in Figures 29A–29C, a distal seal 20 is advanced distal to the clot 10 and pressurized with fluid as shown, and the distal seal 20 expands radially and adjusts to seal the inner wall surface 12a of the blood vessel 12. The positive fluid pressure is then directed proximal to the clot 10 and also expands or widens the blood vessel 12 radially to stretch the blood vessel wall away from the clot 10, as generally described above with respect to the Figure 28 series. To further assist in separating the atrophy 10 from the inner wall surface 12a, a circular or partially circular tipped element, such as a wire 120, is advanced back and forth along the periphery of the atrophy 10, as shown in Figures 29A and 29B, while suction and / or positive fluid pressure is continuously applied, preferably as illustrated. A curved wire or element 120 may have a radius of curvature larger than the radius of curvature inside the vessel 12 to ensure that the wire or element 120 does not slightly compress the inner wall surface 12a and not damage the vessel 12. As shown in Figure 29C, the atrophy 10 may be removed proximal to the vessel using suction in combination with positive fluid pressure, if necessary or desired.

[0133] Figures 30A, 30B, and 30C This series of figures is similar to the series of figures 28 and 29, and therefore no repeated explanation is needed regarding the common steps that can be taken, which are consistent with the examples. The difference in Figures 30A–30C is that the guide 122 is provided on the aspiration catheter 14. This guide 122 may instead be provided on any other component used in this method, and the placement of the guide 122 on the aspiration catheter 14 is therefore only an example. The guide 122 includes a channel provided at the distal end of the catheter 14, more specifically in a radially expandable element or seal 16. The guide 122 receives the elongated intravascular element, such that the distal end of the element 18 is guided laterally toward the periphery of the blood clot 10. The distal end of the guidewire 18 ideally generally travels between the periphery of the clot 10 and the inner wall surface 12a of the blood vessel 12, exiting distal to the clot 10 with the radially expandable seal 16 ready to deploy. The radially expandable seal 16 is then deployed in one of the methods described earlier as an example. The elongated intravascular element or guidewire 18 may then be used to inject a positively pressurized fluid in the methods and for the purposes described earlier, or the element may instead be used as a component to capture the thrombus released from the clot 10 during the removal method.

[0134] The descriptions herein refer to and describe aspiration decongestants that utilize pressure generated by gases and / or other fluids such as liquids. The gas may be air or any other effective gas. Helium is used in medical applications because of its low density and ease of injection through small catheters with small, long channels for injection. Intra-aortic balloon pumps use this gas because its low viscosity allows it to be transported very quickly in and out of the balloon inside the patient. Mixtures of gases such as CO2 and helium may help maximize tissue absorption (CO2) and increase injectability.

[0135] To apply pressure to the membrane seal illustrated and described herein, a fluid such as saline or dye may be injected distal to the clot 10.

[0136] One alternative way to operate the device is that a positive fluid pressure may be applied distal to the mass 10. The positive fluid pressure may be pulsating or oscillating distal to the mass 10, or the pressure may be constant overall, or a combination of pulsating / oscillating fluid pressure and constant pressure may be used as desired by the physician.

[0137] The clot 10 may adhere to the intima (internal) wall 12a of the blood vessel 12. Positive fluid pressure can be applied proximal to the clot 10 to help stretch the blood vessel 12 and / or, in some cases, release the clot 10. Combined positive pressure proximal and distal to the clot 10 can potentially help release the clot 10 from the blood vessel wall 12a and aid in its removal. A clot 10 located inside an artery can adhere completely to the blood vessel wall 12a in a short time. To loosen the clot 10 for removal, it may be effective to oscillate / pulsate / circulate pressure distal to the clot 10. Alternatively, suction performed proximal to the clot 10 may be alternated with circulating / pulsating positive fluid pressure distal to release and remove the clot. Suction may also be used proximal to the clot 10 to remove it. The suction may be oscillating / pulsating / circulating or constant, depending on the combination of features used in accordance with this disclosure.

[0138] A combination of proximal and distal pressure manipulation (positive and negative, as well as pressure fluctuations) can certainly improve lumps removal. The pressure may be constant or oscillated on each side of the lumps 10 to help release them.

[0139] A control unit 22 may also be added to the system to control the pressure proximal to the aggregate 10 and the positive pressure distal to the aggregate 10. This control unit 22 may consist of a pump and a vacuum chamber that can be used to supply ideal pressure and pressure fluctuations.

[0140] Actively injecting gas or other fluids around the clot 10 may also be effective. A hole in the pressure-inflating catheter advanced distal to the clot 10 may include a hole adjacent to or proximal to the clot 10 to impart force to the clot 10. This may help separate the clot 10 from the vessel wall 12a and aid in clot removal. When surgically removing a clot, the surgeon has a spatula-like tool to separate the clot from the vessel wall. Injecting gas or other fluids around the clot 10 may be advantageous with similar effects but without a similar risk of vessel damage.

[0141] To maintain ideal clot removal conditions, it may be beneficial to add pressure sensors to the control unit 22. These sensors may be attached to or included in the catheter located inside the control unit or distal to the clot aspiration catheter 14 and clot 10. Small microtransducers may be added to the catheter at beneficial locations to help monitor the pressure inside the patient. High pressure may lead to vascular rupture. Pressure that is too low may not provide sufficient force to remove the clot 10. A constant pressure level may indicate that the clot 10 has blocked the aspiration catheter 14 or that the clot 10 is moving proximal through the aspiration catheter 14 during removal.

[0142] As previously explained, CO2 is an excellent contrast agent in radiology. When CO2 is injected, it provides a negative image, as opposed to a positive image (generally containing iodine) from a dye. Since the dye stops at the clot 10, the length of the clot 10 is often unknown. By advancing the catheter distally beyond the clot 10 and injecting CO2 beyond the clot 10, the distal side of the clot 10 can be imaged. This combination of imaging with dye on one side of the clot 10 (proximal) and CO2 on the other side (distal) of the clot 10 can provide useful information regarding the length of the clot 10. This can help position the catheter and device to optimize the removal of the clot 10.

[0143] The following table includes some of the features illustrated and / or described herein. Combinations of systems, apparatus, and methods of the invention may be assembled by using at least one of the features listed in the table and / or by combining two or more features from the table. Note that “RES” refers to a “radially expandable seal,” such as the wide variety of proximal and distal membranes or seals illustrated and described herein. “EIE” refers to an “elongated intravascular element,” such as the aspiration catheter 14, guidewire 18, microcatheter 26, or other EIEs contemplated herein.

[0144] A non-limiting table of features according to some embodiments of this disclosure is provided below. Some of the features relate to non-structural items, such as the delivery and control of suction and / or positive pressure. These features are described throughout this specification with respect to most embodiments. For example, some embodiments include only suction pressure on the proximal side of the clot 10. As one option, the structure in Figure 1C may still use suction through the catheter 14, but without positive pressure supplied through the guidewire 18. In this case, the distal seal 20 is used as a thrombus capture element to capture the thrombus before it can travel further downstream into the brain. Other combinations of one or more pressure options from column 1 may be utilized for beneficial effects depending on the case. As also described throughout this specification, the user may choose from a variety of fluid options to deliver positive pressure proximal to the clot 10. Some options are listed in column 2 and may be used by the user alone or in combination for a desired effect. Distal RES options are listed in column 3 and are illustrated and described, for example, throughout this specification as various forms of seals or membranes. One or more distal seals may, in this case, be combined with or not combined with other features listed in the table. Proximal RES options are listed in column 4 and are illustrated and described, for example, as various forms of seal 16 throughout this specification. One or more of these proximal seal configurations 16 may, in this case, be combined with or not combined with other features listed in the table. Column 5 describes options for devices or components specifically configured to assist in agglutination and removal. For example, several specific examples are illustrated and described with respect to Figures 12B, 12C, 12D, and Figure Series 16 to 24, which illustrate and describe several configurations of the distal membrane 20. Column 6 describes various options for guiding an EIE, such as a guidewire 18 or microcatheter 26, to a position near the periphery of the agglutination 10, so that the EIE can be guided past the agglutination 10 adjacent to the vessel wall 12a.Specific examples are illustrated and described with respect to Figures 7A to 7F, Figures 8A to 8C, and Figures 30A to 30C. Column 7 describes various control options that may be used alone or in combination with each other, and with one or more of the other features / options listed in the table. According to the concept of the present invention, the features of the following given columns (1-7) may be used alone or in combination, or one feature or multiple features from two or more columns may be used in combination to liberate and remove the aggregate 10.

[0145] [Table 1]

[0146] The present invention has been illustrated by the description of one or more embodiments thereof, and the embodiments have been described in considerable detail, but they are not intended to limit the scope of the appended claims to such detail or in any way. Further advantages and modifications will readily come to mind for those skilled in the art. In its broader embodiment, the present invention is therefore not limited to specific details, representative products and methods, as well as the illustrated and described exemplary examples. Thus, developments may be made from such details without departing from the scope of the general concept of the invention. For example, any of the individual features or embodiments described herein may be used alone or in any combination, depending on the desired results and associated advantages. [Explanation of Symbols]

[0147] 10 Blood clot, clot 11 Proximal part 12 Blood vessels 12a Inner wall surface 12b Lateral vascular branches 13. Distal portion 14. Suction catheter 15. Distal end 16. Mouth or seal, proximal membrane, proximal seal, funnel-shaped distal end 17 mesh 18 Guidewire 18a Distal end portion, distal tip 19 CO2, fluid 20 Distal seal or membrane, seal, distal guidewire membrane 22 Pressure source, control device 23 punched holes 24 Stent-type recovery device 25 Tether 26 Microcatheters 27 Proximal end, open end, open proximal end 28 Ring-shaped support element, ring-shaped structure, ring-shaped wire 30 Guides 32 channels 34 Expandable parts 35 holes, openings 36 Guidewire tip 38 Guidewire 40 space 44 fins, blades, protrusions 50 Nonlinear portion 52 Distal end 54 Proximal portion 56 Welded parts, attached parts 60 Guidewires, Microcatheters 62 Welding point 64 Wheel Elements 70 Removal device 72 Fingers 74 Proximal membrane portion 76 Distal membrane portion 80 rods 82,84,86,88 bulbous end 90 rods 92 rods 94 stents 96 Stents 100,102 loops 104 wire 110 loops, hoops 112 Stent structure, tube 114 Push Wire 116 Catheter 120 wire 122 Guide 201 Clot extraction device or membrane

Claims

1. This is a system that visualizes blood clots within blood vessels. An elongated body having a radially expandable distal seal, wherein the distal seal is introduced into the blood vessel and configured to extend beyond the blood clot such that the distal seal is positioned distal to the blood clot, the distal seal defines an opening at its proximal end, the distal seal is a membrane, and the elongated body defines a lumen and at least one punched hole located distal to the proximal end of the distal seal and proximal to the distal end of the distal seal, A fluid delivery device is configured to deliver a fluid contrast agent through the lumen and at least one punched hole of the elongated body to a region between the blood clot and the distal end of the distal seal, thereby increasing the pressure in the region to expand the distal seal and forming a fluid pressure seal against the inner wall surface of the blood vessel distal to the blood clot, wherein, when the contrast agent is located in the region, the contrast agent is visible through an imaging modality so as to be able to identify at least a portion of the blood clot in the blood vessel, the blood vessel distal to the blood clot is radially expanded by the contrast agent flowing out through the opening, thereby releasing the blood clot from the blood vessel wall in its original state, or at least loosening it, and the contrast agent generates enough force to move the blood clot in its original state proximal toward a recovery system. A system equipped with these features.

2. The system according to claim 1, wherein the contrast agent comprises a radiopaque dye, the imaging modality comprises fluoroscopy, and the contrast agent does not have a thrombolytic effect, thereby promoting the detachment of the blood clot.

3. The system according to claim 1, wherein the contrast agent is visible via a fluoroscopic image when the contrast agent is placed in a region that can identify the distal end of the blood clot and the blood vessel distal to the blood clot.

4. The system according to claim 1, wherein the position of the elongated body and the position of the distal seal are adjustable based on the identification of the portion of the blood clot within the blood vessel.

5. The system according to claim 1, further comprising the recovery system including a catheter configured to be introduced into the blood vessel proximal to the blood clot, wherein the elongated body is slidably positioned within the lumen of the catheter.

6. The system according to claim 5, wherein the catheter is configured to apply aspirated fluid pressure to the proximal side of the blood clot, thereby pushing the blood clot forward in the direction of the catheter within the blood vessel.

7. The system according to claim 6, further comprising a control device operatively coupled with the fluid delivery device to repeatedly circulate the aspirated fluid pressure proximal to the blood clot between different pressure levels in order to assist in the release and removal of the blood clot.

8. The system according to claim 1, wherein the distal seal has a distal end connected to the elongated body and an opening between the most proximal end of the distal seal and the elongated body.

9. The system according to claim 1, wherein a portion of the circumference of the distal end and the proximal end of the distal seal is attached to the elongated body.

10. The system according to claim 1, wherein the contrast agent is a radiopaque dye, the fluid delivery device is configured to deliver the radiopaque dye through the at least one punched hole and generate sufficient pressure to move the blood clot proximally within the blood vessel, and only a portion of the most proximal end of the distal seal is connected to the elongated body, forming an incomplete seal between the distal seal and the elongated body.

11. The system according to claim 1, further comprising a wire mesh type retrieval device coupled to the elongated body proximal to the radially expandable distal seal, positioned at least partially distal to the blood clot, and configured to capture the blood clot and facilitate its removal from the blood vessel.

12. The system according to claim 1, wherein the membrane is highly flexible and the radially expandable distal seal is configured to automatically adjust to seal against the inner wall surface of the blood vessel.

13. This is a system that visualizes blood clots within blood vessels. An elongated body having a radially expandable distal seal, wherein the distal seal is introduced into the blood vessel and configured to extend beyond the blood clot such that the distal seal is positioned distal to the blood clot, and the elongated body defines a first punch hole located between the proximal end and the distal end of the distal seal, and a second punch hole located proximal to the proximal end of the distal seal, A fluid delivery device is configured to (1) expand the distal seal through a first punch hole to form a fluid pressure seal on the inner wall surface of the blood vessel distal to the blood clot, and (2) deliver the fluid contrast agent through a second punch hole to a region between the blood clot and the proximal end of the distal seal to generate sufficient force to move the blood clot proximally while maintaining its original state, and when the contrast agent is located within the region, the contrast agent is visible via a fluoroscopic image so as to be able to identify at least a portion of the blood clot in the blood vessel. Fluid delivery device, Equipped with, The distal seal has a proximal end sealed around the elongated body of the system.

14. The system according to claim 13, wherein the contrast agent is a radiopaque dye.

15. The system according to claim 13, wherein the position of the elongated body and the position of the distal seal are adjustable based on the identification of the portion of the blood clot within the blood vessel.

16. The system according to claim 13, wherein the distal seal is a membrane.

17. The system according to claim 13, wherein the contrast agent is a radiopaque dye, and the fluid delivery device is configured to deliver the radiopaque dye through the first punched hole and the second punched hole.

18. The system according to claim 13, further comprising a catheter, wherein the catheter is configured to apply suction to the proximal side of the blood clot, thereby pushing the blood clot proximal toward the catheter within the blood vessel.

19. The system according to claim 18, wherein the elongated body is slidably positioned within the lumen of the catheter.

20. The system according to claim 18, further comprising a control device operatively coupled with the fluid delivery device to repeatedly circulate the aspirated fluid pressure proximal to the blood clot between different pressure levels in order to assist in the release and removal of the blood clot.

21. The system according to claim 13, wherein the elongated body is configured such that the fluid delivery device simultaneously delivers the fluid contrast agent through the first punched hole and the second punched hole.

22. The system of claim 13, further comprising a wire mesh type retrieval device coupled to the elongated body proximal to the radially expandable distal seal, positioned at least partially distal to the blood clot, and configured to capture the blood clot and facilitate its removal from the blood vessel.

23. The system according to claim 13, wherein a portion of the circumference of the distal end and the proximal end of the distal seal are attached to the elongated body.

24. The system according to claim 13, wherein the expandable distal seal is formed of a highly flexible membrane and is configured to self-adjust to seal against the inner wall surface of the blood vessel.

25. The system according to claim 1 or 13, configured to maintain, image, and remove the blood clot without damage.

26. The system according to claim 1 or 13, configured to image without removing the blood clot.

27. The system according to claim 1 or 13, wherein the length of the blood clot is determined by using a first contrast agent distal to the blood clot and a second contrast agent proximal to the blood clot.

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