Conduit funnel extension

Abstract

The invention is entitled "Catheter funnel extension." The present disclosure includes a system for retrieving a blood clot in a blood vessel using a clot retrieval device having an expandable funnel capable of engaging the blood clot. The present disclosure also includes a clot retrieval device having an expandable frame capable of engaging the blood clot. The expandable funnel and expandable frame are capable of expanding from a collapsed delivery state to an expanded deployed state, thereby increasing the cross-sectional area of the clot retrieval device engaging the blood clot. The increased cross-sectional area of the clot retrieval device can increase the extraction force, thereby providing for effective removal of the clot from the patient.

Description

Technical Field

[0001] The present invention relates generally to systems and methods for removing acute blockages from blood vessels during intravascular medical treatment. Background Technology

[0002] In patients with conditions such as acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE), clot retrieval catheters and devices are frequently used in mechanical thrombectomy involving endovascular intervention. The hours immediately following these life-threatening events are critical, as intravascular clots must be removed as quickly as possible to prevent long-term disability, brain damage, or death. Accessing the neurovascular bed using conventional techniques can be challenging because the target blood vessel is small in diameter, located distally relative to the insertion site, and is highly tortuous. Conventional devices are often too large, lack the deliverability and flexibility required to navigate tortuous blood vessels, or fail to completely and effectively remove the clot upon delivery to the target site. Furthermore, tissue plasminogen activator (“tPA”) is a conventional FDA-approved treatment for removing blood clots in the brain; however, tPA may become less effective when the blood clot is located in the main blood vessel. This limitation has spurred the need for devices that can effectively and rapidly remove blood clots from the main blood vessel.

[0003] The clot itself can further complicate the process by exhibiting a variety of complex morphologies and consistencies, ranging from simple tubular structures resembling blood vessels to long, chain-like arrangements that can simultaneously span multiple blood vessels. The age of the clot can also affect its compliance, with older clots tending to be more incompressible than fresh ones. Experience has also shown that the mechanical properties of the clot can be significantly influenced by the nature of its interaction with the clot removal device. Additionally, several mechanisms can play a role in strongly adhering the clot to the blood vessel wall. Breaking these adhesions without damaging the fragile neurovascular structures can be a significant challenge.

[0004] Delivering effective devices to the small and highly branched cerebral arterial system remains challenging, and conventional clot retrieval devices can have several drawbacks. The retrieval device must also be flexible enough to navigate the vascular system and withstand high strain, while also possessing axial stiffness to provide smooth advance along the route. Once the target site is reached, the typical size of the object to be retrieved from the body is significantly larger than the device, making it more difficult to retrieve the object back to the distal end. For example, tight, fibrin-rich clots can often be difficult to extract because they can aggregate at the ends of conventional fixed-orifice catheters and devices. Furthermore, this aggregation can lead to the shearing of softer portions from the tighter areas of the clot.

[0005] Small diameter and fixed-end size are also less effective for aspiration required to remove blood and thrombus material during guided procedures. Aspiration must be strong enough to keep any fragmentation that may occur due to aspiration or the use of mechanical thrombectomy devices stationary, thus preventing fragments from migrating and clogging distal vessels. However, when aspirating with a fixed-end catheter or device, a significant portion of the aspiration flow ultimately comes from vascular fluid near the catheter or device tip, where no clots are present. This can significantly reduce aspiration efficiency, thereby decreasing the success rate of clot removal.

[0006] Therefore, the applicant recognizes the need for improved methods, devices, and systems that incorporate an expandable funnel deployed externally to the catheter, thereby allowing for efficient and rapid thrombus retrieval due to the increased thrombus removal force resulting from the increased area of ​​the thrombus. Additionally, there is a need for improved methods, devices, and systems incorporating a stent retrieval device with an expandable frame, which serves as an extension to the funnel catheter tip to provide efficient and rapid blood clot retrieval. Summary of the Invention

[0007] Generally, a system is provided for retrieving blood clots from a blood vessel using a clot retrieval device having an expandable funnel that engages with the blood clot. This disclosure also includes a clot retrieval device having an expandable frame that engages with the blood clot. The expandable funnel and expandable frame can expand from a collapsed delivery state to an expanded unfolded state, thereby increasing the cross-sectional area through which the clot retrieval device engages with the blood clot. The increased cross-sectional area of ​​the clot retrieval device increases the suction force, thereby providing effective removal of the clot from the patient.

[0008] An exemplary system for retrieving emboli from a blood vessel may include an external catheter that facilitates the introduction of a microcatheter, guidewire, or any of a number of commercially available products into a target site within a vascular system. The external catheter may be one or both of a guide catheter and an intermediate catheter. A clot retrieval device may be located within the external catheter. The clot retrieval device may include: an elongated flexible delivery line having a distal end; an expandable tube having a lumen and attached to the distal end of the elongated flexible line; and an expandable funnel attached to the expandable tube. The expandable funnel may be capable of expanding from a collapsed delivery state to an expanded deployment state, wherein in the collapsed delivery state, the expandable funnel may have a circumference approximately the size of the lumen of the external catheter, and in the expanded deployment state, the circumference of the expandable funnel may be larger than the circumference of the lumen of the external catheter. The expandable funnel may include: a fluid-impermeable flexible tube; an open distal port located at the distal end of the flexible tube; and a first and a second support ring attached to and structurally supported by the flexible tube. The fluid-impermeable flexible tube may include a lumen in fluid communication with the lumen of the expandable funnel. The second support ring may be positioned close to the first support ring. A suction source may be attached to the system to apply suction through the fluid channels of the external conduit and the clot retrieval device.

[0009] When the expandable funnel is in the expanded, extended state, approximately half of the clot retrieval device can be positioned within the lumen of the external catheter, while approximately half of the clot retrieval device can be positioned within the blood vessel.

[0010] When the expandable funnel is in the expanded, unfolded state and the expandable tube is positioned within the lumen of the external conduit, the outer wall of the expandable tube can abut against the lumen of the external conduit to form a seal.

[0011] When the expandable funnel is in the expanded, extended state, it can be expanded to circumferentially juxtapose the lumen of the blood vessel.

[0012] When the expandable funnel is in the collapsed delivery state, a portion of the expandable funnel and the expandable tube may have a common circumferential dimension.

[0013] When the expandable funnel is in the collapsed delivery state and positioned within the lumen of the external conduit, the lumen of the flexible tube, the lumen of the expandable tube, and the lumen of the external conduit can be coaxially aligned about the longitudinal axis.

[0014] The fluid-impermeable flexible tube provides unique structural support for the expandable funnel between the first and second support rings. The fluid-impermeable flexible tube may be stitched and / or adhered to the first and second support rings. The fluid-impermeable flexible tube may comprise a flexible polymer material.

[0015] Another exemplary system may include an external catheter that facilitates the introduction of a microcatheter, guidewire, or any of many commercially available products into a target site within a vascular system. The external catheter may be one or both of a guide catheter and an intermediate catheter. A stent retrieval device may be located within the lumen of the external catheter. The stent retrieval device may include: an elongated, flexible delivery line; an expandable frame; and a fluid-impermeable membrane. The expandable frame can engage and capture emboli within a blood vessel by expanding from a collapsed delivery configuration to an expanded, deployed configuration. A proximal end of the expandable frame may be attached to a distal end of the delivery line. The expandable frame may include a tubular portion that has an elongated tubular shape when expanded. The expandable frame may taper proximally from the tubular portion to the distal end of the delivery line. The fluid-impermeable membrane may be attached to the expandable frame near the proximal end of the frame such that the fluid-impermeable membrane has a funnel shape when the expandable frame is in the expanded configuration.

[0016] The tubular portion of the scalable frame may have multiple unit openings, the size of which is set to pass through the embolus as the scalable frame expands from the collapsed delivery configuration.

[0017] The system may include a scalable frame, the scalable frame including a closed distal end portion extending distally from the tubular portion and radially inward toward a central axis.

[0018] When the expandable frame is in the expanded configuration, the tubular portion can expand to have a circumference approximately the same as that of the blood vessel, thereby allowing full engagement with the embolism.

[0019] The system may include a microcatheter whose size is configured to traverse the lumen of the external catheter. The scalable frame may be configured to traverse the lumen of the microcatheter when in the collapsed delivery state.

[0020] When the vascular expansion is part of a treatment, the fluid-impermeable membrane may include a first outer circumference approximately equal to the inner circumference of the lumen of the external catheter and a second outer circumference approximately equal to the inner circumference of the blood vessel. When the expandable frame is in the expanded configuration, a portion of the proximal portion of the expanded frame may be positioned within the lumen of the external catheter. This configuration provides external force on the lumen of the external catheter, thereby forming a fluid-impermeable seal between the fluid-impermeable membrane and the lumen of the external catheter. This configuration also provides force between the fluid-impermeable membrane and the wall of the blood vessel, thereby forming a fluid-impermeable seal between the fluid-impermeable membrane and the wall of the blood vessel.

[0021] An exemplary method for retrieving an embolus from a blood vessel may include one or more steps presented in a non-specific order. The exemplary method may include additional steps as will be understood and appreciated by those skilled in the art. The exemplary method may be performed by exemplary systems as disclosed herein, variations thereof, or alternatives thereof as will be understood and appreciated by those skilled in the art.

[0022] The method may include: inserting an external catheter into a patient's artery; positioning the distal end of the external catheter close to an embolism; advancing a microcatheter and an expandable frame having a fluid-impermeable membrane through the lumen of the external catheter in a collapsed delivery configuration; passing the microcatheter and the expandable frame in the collapsed configuration through the embolism; retracting the microcatheter into the lumen of the external catheter while the expandable frame remains in contact with the embolism; extending a portion of the expandable frame through the embolism; extending the distal and proximal portions of the membrane to circumferentially juxtapose the lumen of the external catheter; and performing aspiration through a fluid channel.

[0023] The method may include advancing the external catheter to a distance of approximately three millimeters from the embolism.

[0024] The method may include: retracting a portion of the expandable frame into the lumen of the external catheter during aspiration, thereby causing the expandable frame with the embolus to be removed from the patient.

[0025] The method may include: injecting a contrast agent into the lumen of the external catheter to assess the extent of embolism remaining in the blood vessel. Attached Figure Description

[0026] The foregoing and other aspects of the invention will be further discussed with reference to the following description and the accompanying drawings, in which similar numbers indicate similar structural elements and features in various figures. The drawings are not necessarily drawn to scale; rather, the focus is on illustrating the principles of the invention. The drawings depict one or more specific embodiments of the device of the invention by way of example only and not by way of limitation. It is expected that those skilled in the art will be able to conceive of and combine elements from the various drawings to better meet the needs of the user.

[0027] Figure 1A This is an illustration of a system for retrieving an embolus using an expandable funnel, according to various aspects of the present invention.

[0028] Figure 1B For the purposes of various aspects of the present invention Figure 1A A cross-sectional view of the interior of the expandable tube.

[0029] Figure 2 This is an illustration of an expandable funnel comprising a first support ring and a second support ring according to various aspects of the present invention.

[0030] Figure 3 A view of a system for retrieving an embolus using an expandable funnel comprising a fluid-impermeable flexible tube, according to various aspects of the invention, is shown.

[0031] Figure 4 This is an illustration of a system for retrieving emboli using a stent retrieval device according to various aspects of the present invention.

[0032] Figure 5 A view of a system comprising a fluid-impermeable membrane on a stent retrieval device and a scalable frame, according to various aspects of the invention, is shown.

[0033] Figure 6 This is an illustration of a stent retrieval device with a fluid-impermeable membrane according to various aspects of the present invention.

[0034] Figures 7A to 7D A series of views illustrating a stent retrieval device for removing emboli from a blood vessel according to various aspects of the present invention.

[0035] Figures 8A to 8H A series of views illustrating methods for removing emboli from blood vessels using a first catheter, an external catheter, a microcatheter, and a stent retrieval device according to various aspects of the present invention.

[0036] Figures 9A to 9B The increased embolism removal force provided by the disclosed technology, according to various aspects of the invention, is shown compared to the embolism removal force provided by commercially available products.

[0037] Figure 10The diagram illustrates, graphically, the embolization removal force provided by the disclosed technology compared to that provided by commercially available products, according to various aspects of the invention.

[0038] Figure 11 A flowchart outlining the steps for removing an embolus from a blood vessel, as described in various aspects of the present invention. Detailed Implementation

[0039] Specific examples of the invention will now be described in detail with reference to the accompanying drawings, wherein like reference numerals indicate functionally similar or identical elements.

[0040] A key success factor in endovascular treatments (such as aneurysm treatment) involves embolization removal force, defined as the product of vacuum pressure and catheter cross-sectional area. In some treatments, mechanical clot removal devices, commonly referred to herein as “stent retrievers,” are also used in conjunction with aspiration. To increase embolization removal force, either the vacuum pressure or the catheter cross-sectional area can be increased. The disclosed technology relates to clot retrieval devices comprising an expandable funnel that increases the cross-sectional area through which the device can contact the embolus. Alternatively, the disclosed technology relates to stent retrievers comprising an expandable frame having a membrane thereon that provides a sealing opening to the catheter lumen, providing a cross-sectional area larger than the catheter cross-sectional area for contact with the embolus. Due to the increased cross-sectional area, the embolus removal force can be increased, resulting in improved removal of the embolus from the patient compared to aspiration alone via the catheter.

[0041] Approaching various blood vessels within the vascular system (whether coronary, pulmonary, or cerebral) involves well-known surgical procedures and the use of many routinely available commercially available accessory products. These products, such as angiography materials, rotary valves, and guidewires, are widely used in laboratory and medical procedures. Their function and exact construction when used in conjunction with the systems and methods of the present invention described below are not described in detail.

[0042] Figure 1A A system 10 for retrieving the embolus (T) is shown. Figure 1B As shown Figure 1A A cross-section of system 10 is shown. (Common Reference) Figure 1A and Figure 1BThe system 10, as shown in the figure, includes a clot retrieval device 100 and an external catheter 200. The clot retrieval device 100 is slidably translatable within the lumen 202 of the external catheter 200 and is expandable such that as the distal funnel 106 portion slides distally away from the external catheter 200, the distal funnel 106 portion of the device 100 expands into the vessel (BV) wall, and the proximal portion 104 of the device expands into the wall of the lumen 202 of the external catheter 202. The system 10 can be configured to perform aspiration through the catheter 200 and the expansion device 100 to dissociate and / or remove emboli (T) including occlusive clots or thrombi, debris, and / or other foreign matter within the patient's vessel (BV).

[0043] Figure 2 An end perspective view of a system 10a including a clot retrieval device 100a and an external conduit 200 is shown. Figure 2 The device 100a shown can be configured according to Figure 1A and Figure 1B The principle of the device 100 shown works. Figure 2 The system 10a shown can be configured to be positioned within a blood vessel (BV) and similar to... Figure 1A The system 10 shown retrieves the embolus (T). As... Figure 2 The distal funnel portion 106 of the illustrated device 100a includes a fluid-impermeable flexible tube 110a attached to a strut frame 116a. The strut frame 116a includes a first distal strut ring 112 and a second strut ring 114 positioned proximally (PD) relative to the first strut ring 112. The first strut ring 112 and the second strut ring 114 may be disposed close to the open distal opening 108 of the expandable funnel 106. In some examples, the device 100a may include one or more additional strut rings positioned proximally (PD) relative to the first strut ring 112 and the second strut ring 114. In some examples, the strut frame 116a may extend into the lumen 105 of the expandable tube 104. In some examples, the first strut ring 112 and the second strut ring 114 are separate, such that the flexible tube 110a structurally supports each strut ring 112, 114. The distal end of the fluid-impermeable flexible tube 110a may define an open distal port 108 of the device 100a. In some examples, the cover 110a may be a fluid-impermeable flexible tube fixed to the strut frame 116a. The fluid-impermeable flexible tube 110a may be sewn to the strut frame 116a, such as... Figure 2 As shown.

[0044] Figure 3 A side view of a system 10b, including a clot retrieval device 100b and an external conduit 200, is shown. Figure 3 The device 100b shown can be configured according to Figure 1A and Figure 1BThe principle of the device 100 shown works. Figure 3 The system 10b shown can be configured to be positioned within a blood vessel (BV) and similar to... Figure 1A The system 10 shown retrieves the embolus (T). Figure 3 The expandable tube 104 and distal funnel 106 of the illustrated device 100b may include a support frame 116b and a fluid-impermeable tube, coating, or membrane 110b. Figure 2 Compared to the frame 116a shown, Figure 3 The frame 116b shown can be adjacent. Figure 3 The frame 116b shown may be shaped, made of a suitable material, and otherwise configured to structurally support the fluid-impermeable cover 110b. In some examples, the cover 110b may include a fluid-impermeable flexible tube, and the tube 110b may be adhered to the strut frame 116b. The fluid-impermeable flexible member 110 may be adhered to the strut frame 116a by applying heat.

[0045] Common Reference Figure 1A , Figure 1B , Figure 2 and Figure 3 The size and configuration of the external catheter 200 can be set and otherwise configured to navigate the blood vessel (BV) to the treatment site and facilitate the introduction of the clot retrieval devices 100, 100a, 100b across the embolism (T). In one example, the external catheter 200 may be an aspiration catheter. The aspiration catheter may be of the rapid exchange (RX) type. The external catheter 200 may include a lumen 202 extending across its length. The lumen 202 may be sized to receive the clot retrieval devices 100, 100a, 100b and to provide sufficient space for the clot retrieval devices 100 to move along the longitudinal axis through the lumen 202 when the system 10 approaches and engages the embolism (T). The systems 10, 10a, 10b may include an aspiration source (AS) configured to apply aspiration through a fluid channel within the lumen 202 of the external catheter 204. The aspiration source (AS) provides sufficient aspiration for engaging the clot retrieval devices 100, 100a, 100b with the embolus (T) to effectively remove the embolus (T) from the patient's blood vessel (BV). In one example, the aspiration source (AS) may first be applied to the lumen 202 of the external catheter 200 and then guided to the expandable funnel 106 of the clot retrieval devices 100, 100a, 100b.

[0046] Clot retrieval devices 100, 100a, and 100b may include a flexible delivery member 102 (also generally referred to herein as a “delivery line”), an expandable tube 104, and an expandable funnel 106. The expandable tube 104 may be attached to the distal end of the delivery line 102, and the expandable funnel 106 may extend distally from the expandable tube 104. The size of the clot retrieval device 100, including the delivery line 102, expandable tube 104, and expandable funnel 106, may be configured to fit within the lumen 202 of an external conduit 200. Devices 100, 100a, and 100b may include, but do not necessarily include, a defined transition between the expandable tube 104 and the expandable funnel 106.

[0047] During delivery of systems 10, 10a, and 10b through the vascular system, devices 100, 100a, and 100b can be completely retained within the lumen 202 of the external catheter 200 as the catheter 200 is translated through the vascular system. Once the distal end of the catheter 200 is positioned near the embolus (T), the delivery line 102 can be pushed distally to move the expandable funnel 106 distally out of the lumen 202 of the catheter 200. The expandable funnel 106 can be expandable to circumferentially juxtapose the vessel wall proximal to the embolus (T) while the expandable tube 104 remains positioned within the lumen 202 of the catheter 200. The circumference 210 of the distal opening 108 of the expandable funnel 106 as it expands within the vessel (BV) can be approximately equal to the circumference 212 of the vessel (BV). Therefore, the expandable funnel 106 can be extended to an expanded, deployed state having an outer circumference 210 larger than the circumference 208 of the lumen 202 of the external conduit 200. The expandable funnel 106 can provide a fluid passage to the lumen 105 of the expandable tube 104. The lumen 105 of the expandable tube 104 can be in fluid communication with the lumen 202 of the conduit 200, such that when a suction source (AS) is applied, the suction force can sufficiently reach the embolus (T). The expandable tube 104 can be extended to have an outer circumference approximately equal to the circumference 208 of the lumen 202 of the external conduit 200.

[0048] An expandable tube 104 may be disposed near the distal end of the delivery line 102. The expandable tube 104 may be attached to a plurality of connecting struts 120 disposed on the distal end of the delivery line 102. The expandable tube 104 can be expanded and retracted to accommodate delivery conduits of different diameters.

[0049] Common Reference Figure 1A , Figure 1B , Figure 2 and Figure 3The delivery line 102 may be coated with a hydrophilic and / or hydrophobic lubricating polymer (including polyvinylpyrrolidone, polytetrafluoroethylene, or siloxane) to reduce friction between components of systems 10, 10a, 10b and blood vessels (BV). The delivery line 102 may possess sufficient flexibility for a physician to manipulate the clot retrieval devices 100, 100a, 100b through the blood vessel (BV), and sufficient rigidity to effectively guide the clot retrieval devices 100, 100a, 100b to the target site. In one example, the delivery line 102 may be solid steel. In another example, the delivery line 102 may be a nitinol wire. In one example, the distal end 103 of the delivery line 102 may include a plurality of connecting struts 120. The connecting struts 120 may include the same material as the delivery line 102. The connecting strut 120 can connect the distal end 103 of the delivery line 102 to the expandable tube 104, such as... Figure 1B As shown.

[0050] An expandable funnel 106 may be attached to the distal end of an expandable tube 104. The expandable funnel 106 may expand from a collapsed delivery state to an expanded unfolded state. In the collapsed delivery state, the expandable funnel 106 is sized to traverse the lumen 202 of the outer conduit 200. In this configuration, the expandable funnel 106 may fold or collapse itself to fit adequately within the lumen 202 of the outer conduit 200. The expandable funnel 106 may fold or collapse radially inward toward the longitudinal axis. In the collapsed delivery state, at least a portion of the expandable funnel 106 and the expandable tube 104 may share a common circumference. In the collapsed delivery state, the lumen 111 of the fluid-impermeable flexible tube 110, the lumen 105 of the expandable tube 104, and the lumen 202 of the outer conduit 200 may be coaxially aligned about the longitudinal axis (LA). In this configuration, catheters of different diameters can be used to deliver the clot retrieval device 100 through the body until the clot retrieval device 100 approaches the embolus (T) in the blood vessel (BV).

[0051] The expandable funnel 106 can be configured to extend radially outward from its longitudinal axis as it exits the distal end of the external catheter 200. In an example where the expandable funnel 106 can be folded or compressed, when in a collapsed delivery state, the expandable funnel 106 provides a spring-like force that facilitates its self-expansion as it exits the external catheter 200. In its expanded, deployed state, the expandable funnel 106 expands such that it has an outer circumference 210 greater than the circumference 208 of the lumen 202 of the external catheter 200. In one example, the circumference 210 of the expandable funnel 106 in its expanded, deployed state may be approximately equal to the circumference 212 inside the blood vessel (BV). Therefore, the expandable funnel 106 can be sealed to the blood vessel (BV) or form sufficient restriction such that, when aspiration is applied, blood and clots distal to the distal opening 108 of the expandable funnel 106 will be drawn into the clot retrieval devices 100, 100a, 100b rather than into the blood proximal to the expandable funnel 106. In the expanded, deployed state, at least a portion of the clot retrieval device 100 can be positioned within the lumen 202 of the external catheter 200. In one example, in the expanded, deployed state, approximately half of the clot retrieval devices 100, 100a, 100b can be positioned within the lumen 202 of the external catheter 200. The clot retrieval devices 100, 100a, 100b can be coaxially positioned within the lumen 202 of the external catheter 202 along the longitudinal axis (LA). In the expanded, deployed state, at least a portion of the clot retrieval devices 100, 100a, 100b can be positioned within the lumen of the blood vessel (BV). In one example, in the extended deployed state, approximately half of the clot retrieval devices 100, 100a, 100b can be positioned within the lumen of the blood vessel (BV).

[0052] The expandable funnel 106 may include a distal port 108. In its expanded, deployed state, the distal port 108 can be opened and configured to engage the embolism (T). The circumference of the open distal port 108 may be approximately equal to the circumference 212 of the blood vessel (BV). The circumference of the distal port 108 may be approximately equal to or larger than the circumference of the embolism (T). Because the circumference of the open distal port 108 is approximately equal to or larger than the circumference of the embolism, the distal port 108 of the expandable funnel 106 can engage and receive the embolism (T). When an aspiration source is connected and aspiration begins, the embolism expandable funnel 106 can further receive the embolism (T) such that the embolism (T) can be drawn into the expandable funnel 106 and specifically into the lumen 111 of the fluid-impermeable flexible tube 110. The expandable funnel 106 can be gradually compressed to a small diameter during retrieval of the embolus (T) so that it can be completely received within the expandable tube 104 of the clot retrieval devices 100, 100a, 100b. The embolus (T) can then be safely and effectively removed from the patient. If the embolus (T) does accumulate in the distal orifice 108, the opening 108 will protect the embolus (T) and prevent it from disintegrating while aspiration is maintained and the clot retrieval devices 100, 100a, 100b are retracted into the sheath or external catheter 200.

[0053] The large distal port 108 of the clot retrieval devices 100, 100a, and 100b of the systems 10, 10a, and 10b shown herein provides improved performance compared to conventional fixed-port designs. Conventional fixed-port catheters can be obstructed by the accumulation of tight, fibrin-rich clots at the catheter tip or by the shearing away of softer portions of the clot. When aspirating through a fixed-port catheter, a significant portion of the aspirated fluid is directed proximal to the tip, reducing the aspiration of the clot and decreasing the success rate of clot removal. When the diameter of the expandable distal port 108 is close to that of the blood vessel, clot shearing at the catheter tip is reduced, and the volume of fluid and clot distal to the tip is fixed. However, the expandable funnel 106 of the disclosed technology increases the amount of aspiration force by increasing the cross-sectional area of ​​the connection between the expandable funnel and the embolus, thereby removing the embolus(T) more effectively.

[0054] Figure 1B This is a cross-sectional view of the interior of the expandable tube 104 when the clot retrieval device 100 is in the expanded, deployed state. Figure 1BAs shown, delivery line 102 may include connecting strut 120. Connecting strut 120 may be secured to the wall of expandable tube 104. Fluid-impermeable flexible tube, membrane, coating, or other covering 110 may cover at least a portion of the outer wall of expandable tube 104. When the outer wall of expandable tube 104 applies force to the inner wall of outer conduit 200, a seal 118 may be formed against the inner wall of outer conduit 200. Seal 118 may direct the suction source to the embolus (T) and ensure that clot retrieval device 100 can capture the embolus (T). Cover 110 may be attached to or integrated with expandable tube 104 and otherwise configured to extend to form a seal between the outer surface of membrane 110 and the inner wall of lumen 202 of outer conduit 200. The lumen 105 of the expandable tube 104 is in fluid communication with the lumen 202 of the conduit 200, such that when a suction source (AS) is applied, the suction force can reach the embolus (T) sufficiently, while the flow between the membrane or cover 110 and the inner wall of the lumen 202 is minimal or nonexistent.

[0055] Figure 2 and Figure 3 The clot-catching devices 100a and 100b shown may similarly include a cover 110 above the proximal portion 104 of the devices 100a and 100b. Figure 2 The external flexible tube 110a shown can extend to cover the proximal portion of the device 100a to form Figure 1B The cover 110 shown. Figure 2 The fluid-impermeable flexible tube 110a of the illustrated device 100a may include a lumen 111. The lumen 105 of the proximal expandable tube 104 may be in fluid communication with the lumen 111 of the fluid-impermeable flexible tube 110a, such that when a suction source (AS) is applied, the suction force can sufficiently reach the plug (T). Alternatively, Figure 2 The proximal expandable tube 104 of the illustrated device 100a may include a separate cover, coating, membrane, or seal to guide aspiration through the funnel 106 and the catheter lumen 202.

[0056] same, Figure 3 The cover 110b (a fluid-impermeable flexible tube, membrane, coating, or other cover) of the illustrated device 100b may extend over the funnel 104 and tube 104 portions of the device 100b, or the funnel 106 and tube 104 may be unevenly covered. The cover 110b may extend within the expandable tube 104. The cover 110b may cover at least a portion of the inner wall of the expandable tube 104.

[0057] Common Reference Figure 1A , Figure 1B , Figure 2 and Figure 3Devices 100, 100a, and 100b may include a distal end 122. The distal end 122 may correspond to the distal end of the cover 110, 110a, and 110b of the funnel 106 of devices 100, 100a, and 100b. In an example where the cover 110, 110a, and 110b extend to the proximal expandable tube 104 of devices 100, 100a, and 100b, when the clotting retrieval devices 100, 100a, and 100b are in their extended, deployed state, the distal end 122 of the cover 110, 110a, and 110b may have a larger circumference 210 than the proximal end of the cover 110, 110a, and 110b. The distal end 122 may have a circumference at least the size of the embolus (T), thereby allowing the expandable funnel 106, including the covers 110, 110a, 110b, to receive the embolus (T) when a suction source (AS) is applied. The covers 110, 110a, 110b may comprise a flexible polymer material. For example, the covers 110, 110a, 110b may be formed of a stretchable elastomer that is soft and flexible, and resistant to tearing and perforation caused by high failure strain. In one example, the covers 110, 110a, 110b may comprise a urethane or other similar material. The covers 110, 110a, 110b may provide advantageous properties for the clot retrieval devices 100, 100a, 100b, such as high tensile strength, degradation resistance, biocompatibility, and flexibility. The fluid-impermeable flexible tube 110 can also be configured to minimize friction between the covers 110, 110a, 110b and the blood vessel (BV), thereby reducing strain on the blood vessel (BV). The flexible nature of the covers 110, 110a, 110b allows them to stretch as the expandable funnel 106 expands from a collapsed delivery state to an extended unfolded state. When the covers 110, 110a, 110b stretch, they can follow the contour of the underlying support frame 116. In some examples, such as Figure 2 As shown, the cover 110a may include a flexible tube that structurally supports the strut frame 116a to maintain the position of the first strut ring 112 and the second strut ring 114 relative to each other. The cover 110a may also include a construction with sufficient structural integrity to allow the strut frame 116a to be sewn to the cover 110a. Therefore, the funnel 106 portion of the device 100a may also include sutures or other stitches for attaching the cover 110a to the frame 116a, such as… Figure 2 As shown.

[0058] The support frames 116a and 116b may have Figure 1A , Figure 1B , Figure 2 or Figure 3Various configurations are not shown. The strut frames 116a and 116b may be configured such that the outline of the expandable funnel 106 in its extended, unfolded state is radially outwardly hinged to have a portion juxtaposed with the circumference 212 of the blood vessel (BV). The strut frames 116a and 116b may include multiple obturators, rings, or undulations. In one example, the strut frames 116a and 116b may include multiple distal coronal portions. In one example, the strut frames 116a and 116b may have petal-shaped units with rounded edges. These petal-shaped units can open in the extended, unfolded state to present their maximum radial size.

[0059] In one example, the covers 110, 110a, 110b may include fluid-impermeable flexible tubes that provide the sole structural support for the expandable funnel 106. Figure 2 As shown, the fluid-impermeable flexible tube 110a provides the sole structural support for the expandable funnel 106 in the region between the first support ring 112 and the second support ring 114. Figure 3 As shown, the strut frame 116 provides support for the expandable funnel 106.

[0060] The ideal diameter of the clot retrieval devices 100, 100a, and 100b depends on the location of the target embolus and the diameter of the external catheter 200 through which the clot retrieval devices 100, 100a, and 100b can be delivered. For retrieving clots from cerebral vascular beds where the vessel diameter is typically about 3 to 6 mm, a suitable system may have an external catheter 200 with an inner diameter of about 0.070 inches (1.8 mm) and a clot retrieval device 100 with an inner diameter of about 0.062 inches (1.6 mm). When deployed from the external catheter 200, the maximum diameter of the expandable funnel 106 may be at least 3 mm (but in some cases about 5-6 mm), allowing it to seal against the wall of the vessel (BV) and provide an opening at the distal orifice as large as the vessel (BV) itself.

[0061] Figures 4 to 6 Illustration of an alternative system 10c for retrieving an embolus (T) from a blood vessel (BV). System 10c may include a catheter 200 and a funnel stent retrieval device 300, the stent retrieval device including an expandable frame 304 for engaging the embolus (T), the frame 304 having a fluid-impermeable membrane, cover, or tube attached to its proximal portion. The embolus (T) may include an occlusive clot within a patient's blood vessel (BV). The embolus may include debris or other foreign bodies or substances within the blood vessel (BV). The external catheter 200 may include a lumen 202 whose size, shape, and other configuration are slidably configured to receive the funnel stent retrieval device 300. The size and configuration of the catheter 200 may be otherwise configured, as shown and disclosed elsewhere herein. Figure 4A system 10c is shown that extends the embolus (T) through the blood vessel (BV). Figure 5 As shown Figure 4 The extended system 10c shown illustrates the struts of the scalable frame 304. Figure 6 A funnel stent retrieval device 300 that can be extended without being restricted by the catheter 200 or blood vessel (BV) is shown.

[0062] Common Reference Figures 4 to 6 During device delivery, the funnel support retrieval device 300 can be positioned within the lumen 202 of the external conduit 202. When the system 10c approaches and engages with the embolus (T), the funnel support retrieval device 300 can move along the longitudinal axis.

[0063] The funnel-shaped stent retrieval device 300 may include an elongated flexible member 102, which is generally referred to herein as a "delivery line". The delivery line 102 may facilitate positioning the stent retrieval device 300 close to the embolus (T). The delivery line 102 may be coated with a hydrophilic and / or hydrophobic lubricating polymer (including polyvinylpyrrolidone, polytetrafluoroethylene, or siloxane) to reduce friction between components of the system 10c and between components of the system 10c and the blood vessel (BV). The delivery line 102 may not only have sufficient flexibility for a physician to manipulate the stent retrieval device 300 through the blood vessel (BV), but also sufficient rigidity to effectively guide the stent retrieval device 300 to the target site. In one example, the delivery line 102 may be solid steel. In another example, the delivery line 102 may be a nitinol wire. In one example, the distal end 103 of the delivery line 102 may include a plurality of connecting struts 120. The connecting struts 120 may include the same material as the delivery line 102. The connecting strut 120 can connect the distal end 103 of the delivery line 102 to the expandable tube 104, such as... Figures 4 to 6 As shown. The delivery line 102 and the connecting support can be constructed as shown and described otherwise herein.

[0064] The stent retrieval device 300 may include an expandable frame 304 configured to engage and capture an embolus (T). The frame 304 is shown having a structure similar to that disclosed in U.S. Patent No. 9,445,829, which is incorporated herein by reference as set forth herein. Alternatively, based on the teachings of this disclosure, the expandable frame 304 may have a structure similar to other known frames or variations thereof of stent retrieval device as understood by one of ordinary skill in the art. As an incomplete list of such frames for stent retrieval device, U.S. Patent Nos. 10,292,723, 8,852,205, 9,301,769, 10,229,881, 10,420,570, 10,201,360, and 10,363,054 and U.S. Patent Publication No. 2017 / 0071614 are incorporated herein by reference as set forth herein.

[0065] The scalable frame 304 may be made of a material (such as a shape memory material) capable of self-expanding into an extended configuration once released from a collapsed delivery state. Alternatively, the scalable frame 304 may be made of a hyperelastic material. In one example, the superlattice alloy may be nitinol or an alloy with similar properties. In one example, the hyperelastic alloy may contain nickel and titanium. The scalable frame 304 may have various forms. The scalable frame 304 may be manufactured by laser-cutting a nitinol tube and then applying heat and electropolishing to form the desired frame. The scalable frame 304 may include radiopaque markings that allow the scalable frame 304 to be visible using a fluorescent microscope for inspection.

[0066] When the expandable frame 304 is in its extended, unfolded configuration, it may have a substantially tubular shape. In the extended, unfolded configuration, the expandable frame 304 may include a tubular portion 310, a proximal portion 306, and a distal portion 312. The tubular portion 310 may extend distally from the proximal portion 306. The proximal portion 306 of the expandable frame 304 may be secured to the distal end 103 of the delivery line 102. In one example, the proximal portion 306 may be secured to the distal end 103 of the delivery line 102 via a snap ring connector 316, such as... Figure 6 As shown. The retaining ring connector 316 may include one or more features and functions of retaining ring connectors disclosed elsewhere (e.g., in U.S. Patent Applications Nos. 16 / 150,024 and 16 / 667,454), each of which is incorporated herein by reference as set forth herein in its entirety.

[0067] In an alternative example, the proximal portion 306 may be welded to the distal end 103 of the delivery line 102. When the expandable frame 304 is in an extended, deployed configuration, the proximal portion 306 of the expandable frame 304 may be tapered, such that the proximal portion 306 narrows from the tubular portion 310 to the point where the expandable frame 304 can be secured to the delivery line 102. The tapering of the proximal portion 306 may form a funnel shape, such as... Figures 4 to 6 As shown. The distal portion 312 may extend distally from the tubular portion 310. When the expandable frame 304 is in an expanded, deployed configuration, the distal portion 312 may taper, narrowing from the tubular portion to the distal joint 326. The distal portion 312 may be closed, having unit openings small enough to prevent clumping material from traveling distally through the distal portion 312 from the interior of the frame 304. Alternatively, the funnel support retriever may not include a tapered or closed distal portion 312; for example, the distal end of the frame 304 may be open.

[0068] The tapering of the distal portion 312 can form a conical or funnel-shaped form, such as Figures 4 to 6 As shown. The distal portion 312 may include a distal coil 328, such as Figure 6 As shown. The distal coil 328 and the distal portion 312 can be attached to the distal joint 326. The distal joint 326 can be a retaining ring connector.

[0069] The ideal diameter of the expandable frame can depend on the location of the target embolism and the diameter of the external catheter through which the expandable frame 304 is delivered. For retrieving a clot within an internal carotid artery where the vessel diameter can be between approximately 3 mm and 6 mm, the suitable system 10c may include an expandable frame 304 between approximately 3 mm and 6 mm. In one example, the expandable frame 304 may be slightly larger than the diameter of the vessel (BV) to form a seal with the inner wall of the vessel. The ideal length of the expandable frame 304 can depend on the location of the target and the characteristics of the embolism (T). In one example, the length of the expandable frame 304 may be approximately 30 mm. In another example, the length of the expandable frame may be approximately 40 mm.

[0070] like Figure 6As shown, in one example, the expandable frame 304 may include an inner body 318 and an outer body 320. The inner body 318 may be disposed within the outer body 320. The inner body 318 may have a substantially longitudinal tubular shape and extend across the length of the tubular portion 310 of the expandable frame 304. The inner body 318 and the outer body 320 may be connected to the distal end 103 of the delivery line 102. The inner body 318 may include a distal portion 324 adjacent to the distal portion 312 of the expandable frame 304. The distal portion 324 of the inner body 318 may have a specific line configuration that facilitates engagement with the embolus (T) and prevents fragments of the embolus from escaping from the expandable frame 304. The specific line configuration may have a substantially vertically oriented elliptical shape. The specific line configuration may be attached to the inner body 318, the outer body 320, or both.

[0071] The stent retrieval device 300 may include a fluid-impermeable membrane 308. The fluid-impermeable membrane 308 may be attached to the proximal portion 306 of an expandable frame 304. The fluid-impermeable membrane 308 may also be attached to the expandable frame 304 extending into a lumen 202 of the external catheter 200. The fluid-impermeable membrane 308 may be made of a porous material. The porous material may include pores sized to be smaller than the size of blood molecules, thereby preventing blood molecules from passing through the fluid-impermeable membrane 308. The flexible nature of the fluid-impermeable membrane 308 allows it to stretch as the expandable frame expands from a collapsed delivery state to an extended deployment state. When the fluid-impermeable membrane 308 stretches, it may follow the contour of the underlying expandable frame 304. In one example, the fluid-impermeable membrane 308 may cover at least a portion of the proximal portion 306 of the expandable frame 304. In another example, the fluid-impermeable membrane 308 may cover the entire proximal portion 306 of the expandable frame. A fluid-impermeable membrane 308 may cover the proximal portion 306 of the expandable frame 304 extending into the lumen 202 of the external conduit 200. When the fluid-impermeable membrane 308 covers at least a portion of the proximal portion 306 of the expandable frame 304 and the expandable frame 304 extending into the lumen 202 of the external conduit 200, a funnel shape may be formed. The fluid-impermeable membrane 308 may include a proximal opening sized to allow aspiration. In an expanded configuration, the circumference of the proximal opening may be approximately equal to the circumference 208 of the lumen 202 of the external conduit 200. When a suction force is applied, the proximal opening allows aspiration through the funnel-shaped fluid-impermeable membrane, thereby facilitating the retrieval of the embolus (T).

[0072] The expandable frame 304 can have a collapsed delivery configuration and an expanded deployment configuration. In the collapsed delivery configuration, system 10c may include a microcatheter 204. The size of the microcatheter 204 can be configured to traverse the lumen 202 of the outer catheter 200. In the collapsed delivery configuration, the expandable frame 304 can collapse into itself, such that the expandable frame 304 can be positioned within the lumen 205 of the microcatheter 204.

[0073] In the collapsed delivery state, the first outer circumference 212 and the second outer circumference 214 of the fluid-impermeable membrane 308 may be approximately equal. The first circumference 212 and the second circumference 214 may be approximately equal to the circumference 220 of the lumen 205 of the microcatheter 204. In the collapsed delivery state, the first circumference 212, the second outer circumference 214, the circumference 330 of the tubular portion 310 of the expandable frame 304, and the circumference 220 of the lumen 205 of the microcatheter 204 may be approximately equal.

[0074] In its extended, unfolded state, the tubular portion 310 of the expandable frame 304 can be expanded such that the circumference 330 of the tubular portion 310 is substantially equal to the circumference 212 of the blood vessel (BV). In one example, the funnel stent retrieval device 300 can be configured to treat an embolism (T) whose circumference is substantially equal to the circumference of the blood vessel (BV). In another example, the funnel stent retrieval device 300 can be configured to treat an embolism (T) whose circumference is smaller than the circumference of the blood vessel (BV). Because the tubular portion 310 can be expanded such that its circumference is substantially equal to the circumference of the blood vessel (BV), the expandable frame 304 can fully engage with the embolism (T).

[0075] In its expanded, deployed state, the fluid-impermeable membrane may include a first outer circumference 212 and a second outer circumference 214. The first outer circumference 212 may be approximately equal to the circumference 208 of the lumen 202 of the external conduit 200, such as... Figure 5 As shown. The second outer circumference 214 can be approximately equal to the inner circumference 212 of the blood vessel (BV), as... Figure 5 As shown. The difference between the circumferences 212 and 214 of the fluid-impermeable membrane 308 allows the membrane 308 to have a substantially funnel shape in an expanded configuration.

[0076] In the extended, deployed state, the portion of the proximal portion 306 of the expandable frame 304 extending into the lumen 202 of the external conduit 200 can generate an outward force on the inner wall of the external conduit 200. This outward force is sufficient to form a fluid-impermeable seal 332 between the fluid-impermeable membrane 308 covering the proximal portion of the expandable frame 304 extending into the lumen 202 of the external conduit 200 and the lumen 202 of the external conduit 200, such as... Figure 5As shown. The fluid-impermeable seal 332 facilitates aspiration and therefore facilitates the removal of the embolus (T) from the blood vessel (BV) as the aspiration is directed to the embolus (T).

[0077] Figures 7A to 7D and 8A to Figure 8H A method for removing an embolus (T) from a blood vessel (BV) is shown using a system 10c that includes a stent retrieval device 300 with an expandable frame 304. Figures 7A to 7D The illustration at the target site shows the delivery of the stent retrieval device 300 to the target site and the capture of the embolism (T). Figures 8A to 8H The accompanying diagram shows the delivery of the stent retrieval device 300 to the target site, the capture of the embolism (T), and the removal of the stent retrieval device 300 from the patient's body. Figures 8A to 8H The accompanying image is a photograph based on prototype system 10c, which retrieves agglomerates (T) from an organosilicon model of a vascular system near Wilshire Circle.

[0078] Figure 9A and Figure 9B The significant improvements offered by the clot recovery devices 100a, 100b, and 300 compared to other commercially available products are demonstrated. Figure 9A It shows that it will be similar to Figure 2 and Figure 3 The data compare the dimensions and operation of the prototype clotting retrieval devices constructed by the devices 100a and 100b shown. Figure 9B It shows that it will be similar to Figures 4 to 8H The prototype clotting device 300 shown is used to compare the dimensions and operation of the clotting recovery device.

[0079] Optimal retrieval of the embolus (T) from the blood vessel (BV) can depend on the embolization removal force. The embolization removal force can be defined as the product of the applied vacuum pressure and the cross-sectional area of ​​the clot retrieval device attached to the embolus (T). When the embolization removal force is high, the embolus (T) is held firmly to the clot retrieval device, thus effectively removing the embolus (T). Increasing the applied vacuum pressure is one way to increase the embolization removal force. However, the vacuum pressure can only be increased to practical limits (e.g., based on design constraints understood by those skilled in the art). Furthermore, increasing the inner diameter of the catheter and thus the cross-sectional area can be challenging, as a larger catheter may be more difficult to track and may increase the likelihood of vessel injury.

[0080] Therefore, compared to commercially available products, the clot retrieval devices 100a, 100b, and 300 disclosed herein are configured to significantly increase the cross-sectional area of ​​the embolus (T), and thus increase the embolus removal force. For example, Figure 9A and Figure 9B As shown, the expandable funnel 106 and funnel stent retriever 300 of the clot retrieval devices 100a and 100b can each expand to a distal inner diameter approximately equal to the inner diameter of the blood vessel in which the devices 100a, 100b, and 300 are deployed. Assuming the blood vessel has an inner diameter of 0.16 inches, or approximately 4 millimeters, regardless of the specific implementation of the devices 100a, 100b, and 300, the devices can be expanded to have a distal inner diameter of approximately 4 millimeters and can have a diameter of approximately 0.030 square inches, or 2.0 × (10⁻⁶) mm. -5 The cross-sectional area is approximately 1.2 square meters. When a vacuum pressure of approximately 29 Hg (98,000 Pascals) is applied, regardless of the specific implementation of devices 100a, 100b, or 300, the resulting embolism removal force at the expandable funnel is approximately 1.2 Newtons (approximately 127 gf). In contrast, as... Figure 9A As shown, when it has a distal inner diameter of approximately 0.070 inches or 1.8 mm and approximately 0.003 square inches or 2.0 × (10) -6 When a commercially available catheter with a cross-sectional area of ​​approximately 1,000 square meters is subjected to a vacuum pressure of approximately 98,000 Pascals, the resulting embolization removal force at the catheter tip can be approximately 0.21 to approximately 0.26 Newtons (approximately 21 to 27 gf). In this case, the clot retrieval devices 100a, 100b, and 300 can provide a cross-sectional area at the tip that is approximately 1,000% larger than that of other commercially available products, resulting in an embolization removal force that is approximately 500% higher than that of other commercially available products.

[0081] Figure 10 The significantly increased embolism removal force provided by clot retrieval devices 100a, 100b, and 300 compared to commercially available products is illustrated graphically. In the illustrated examples, EMBOVAC exhibits a maximum thrombus retention force of approximately 26 g / L and a 2.6 × (10⁻⁶) g / L force compared to the commercially available devices tested. -6 The maximum end cross-sectional area is 100 square meters. The clot retrieval devices 100a, 100b, and 300 of this disclosure have an end cross-sectional area and holding force that are 4 times (almost 5 times) greater than that of EMBOVAC. Furthermore, the cross-sectional area (and therefore the holding force) of the clot retrieval devices 100a, 100b, and 300 is limited in this illustration by a vessel diameter of 4 mm, so the end cross-sectional area and holding force can be even greater in vessels with larger diameters.

[0082] Figure 11This is a flowchart illustrating a method 400 for delivering a system including a funnel-shaped stent retrieval device 300 to a target site, capturing the embolus, and removing the stent retrieval device 300 from the patient's body. The method may include one or more of the steps presented in a non-specific order. This exemplary method 400 may include additional steps as understood and appreciated by those skilled in the art. The exemplary method may be performed by exemplary devices as disclosed herein, variations thereof, or alternatives thereof as understood and appreciated by those skilled in the art.

[0083] A long guidewire 216 can be used to enter a cerebral artery. Once the distal end of the guidewire 216 reaches the target site, it can act as a guide for a larger catheter to be followed and delivered to the target site. The guidewire 216 can be constructed of solid steel, nitinol core, or other suitable materials. In one example, a guiding catheter such as a balloon catheter can be used to access the vascular system.

[0084] In step 402, a first catheter 206 including a lumen 207, an aspiration catheter 200 including a lumen 202, and a microcatheter 204 including a lumen 205 can be used to enter the patient's arterial blood vessels. Figure 7A and Figure 8A As shown, the first catheter 206 may have the maximum diameter of the catheter delivery system. The first catheter 206 may be the initial catheter for entry into the patient's blood vessel (BV). The aspiration catheter 200 may be disposed within the lumen 207 of the first catheter 206. The aspiration catheter 200 may be the second catheter for entry into the patient's blood vessel (BV). The microcatheter 204 may be disposed within the lumen 202 of the aspiration catheter 200. The microcatheter may have the minimum diameter of the delivery catheter system, and its size may be configured to receive the stent retrieval device 300 within its lumen 205. Catheters 206, 200, and 204 may be advanced over a guidewire 216 that passes through the entire embolization (T) positioning, as... Figure 7A and Figure 8A As shown.

[0085] In step 404, the aspiration catheter 200 can be advanced through the lumen 207 of the first catheter 206 and toward the proximal end of the embolus (T) using conventionally known techniques, such as... Figure 7A and Figure 8B As shown. In one example, the external catheter 200 is advanced through the lumen 207 of the first catheter 206 until the external catheter 200 is approximately three millimeters from the embolus (T).

[0086] In step 406, the microcatheter 204, in which the collapsed expandable frame 304 is present, can be advanced through the lumen 202 of the external catheter 200 and toward the proximal end of the embolus (T), as... Figure 7A and Figure 8AAs shown. The expandable frame 304 may include a fluid-impermeable membrane 308 attached thereto, which collapses within the lumen 207 of the microcatheter 204 when the microcatheter 204 is advanced. The guidewire 216 and the external catheter 200 can be manipulated as needed while advancing the microcatheter 204 toward the embolism (T).

[0087] In step 408, the microcatheter 204, having an expandable frame 304 that collapses within the lumen 207 of the microcatheter 204, can be passed through the embolus (T), as... Figure 7B and Figure 8C As shown. The guidewire 216 can then be removed from system 10c. The extension frame 304 can be advanced through the microcatheter 204 until the distal end of the extension frame 304 punctures the distal end of the microcatheter 204, as shown. Figure 8D As shown.

[0088] In step 410, the microcatheter 204 can be retracted into the lumen 202 of the external catheter 200, while most of the expandable frame 304 remains through the embolus (T), as... Figure 7C , Figure 7D , Figure 8E and Figure 8F As shown.

[0089] In step 412, at least a portion of the expandable frame 304 is used to engage the plug (T), as... Figure 7C , Figure 7D , Figure 8E and Figure 8F As shown. When the microcatheter 204 is retracted into the lumen 202 of the outer catheter 200 in step 410, the expandable frame 304 can self-expand. Alternatively, when the expandable frame 304 is within the lumen 205 of the microcatheter 204, the expandable frame 304 can exhibit a spring force that facilitates spring-like expansion when the expandable frame 304 is removed from the lumen 205 of the microcatheter 204.

[0090] In step 414, the distal portion of the fluid-impermeable membrane 308 can expand, as... Figure 8E and Figure 8F As shown. In one example, the distal portion of the fluid-impermeable membrane 308 can be extended to circumferentially juxtapose a blood vessel (BV). In this configuration, the fluid-impermeable membrane 308 is adjacent to the inner wall of the blood vessel (BV).

[0091] In step 416, the proximal portion of the fluid-impermeable membrane 308 can expand, as... Figure 7D , Figure 8E and Figure 8FAs shown. In one example, the proximal portion of the fluid-impermeable membrane 308 can be extended to circumferentially juxtapose the lumen 202 of the external conduit 200. In this configuration, the fluid-impermeable membrane 308 can form a seal 332 against the inner wall of the external conduit 200.

[0092] In step 418, an aspiration source may be connected to system 10c. The aspiration source may generate a vacuum pressure that can be aspirated through a fluid channel defined by the fluid-impermeable membrane 308 and the lumen 202 of the aspiration conduit 200. The aspiration may be sufficient to engage the stent retrieval device 300 and the embolus (T) during embolization removal.

[0093] In step 420, at least a portion of the expandable frame 304 may be retracted into the lumen 202 of the external conduit 200, such as Figure 8G As shown. The expandable frame 304 can be retracted into the lumen 202 of the external catheter 200 until the physician can feel significant tactile force. Significant tactile force indicates that the embolism (T) has been successfully positioned within the distal end of the external catheter 200. At this point, the aspiration source can be substantially restricted or eliminated.

[0094] In step 422, the stent retrieval device 300 can be removed from the patient along with the captured embolus (T), as... Figure 8H As shown.

[0095] In one example, a contrast agent may be injected into the lumen 202 of an external catheter 200 to assess the extent of embolism remaining in the blood vessel (BV). The contrast agent may contain iodine-based contrast material.

[0096] This invention is not limited to the described examples, the construction and details of which may vary. The terms “distal” and “proximal” are used throughout the foregoing description and refer to position and orientation relative to the treating physician. Similarly, “distal” or “towards distal” refers to a position away from the physician or in a direction away from the physician. Likewise, “proximal” or “towards proximal” refers to a position close to the physician or in a direction toward the physician.

[0097] In describing exemplary embodiments, terminology is used for clarity. It is intended that each term be contemplated for its broadest meaning as understood by one of those skilled in the art, and includes all technical equivalents that operate in a similar manner to achieve similar purposes. It should also be understood that reference to one or more steps of a method does not exclude the presence of additional method steps or intermediate method steps between those expressly identified steps. The steps of a method may be performed in an order different from that described herein without departing from the scope of the disclosed technology. Similarly, it should be understood that reference to one or more components in an apparatus or system does not exclude the presence of additional components or intermediate components between those expressly identified components.

[0098] As discussed herein, a “patient” or “individual” can be a person or any animal. It should be understood that an animal can be any applicable type, including but not limited to mammals, veterinary animals, livestock, or pets. For example, an animal can be a laboratory animal specifically selected to have certain characteristics similar to humans (e.g., rats, dogs, pigs, monkeys, etc.).

[0099] As used herein, the term “about” or “approximately” for any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or components to achieve the intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of ±20% of the enumerated values, for example, “about 90%” may refer to a range of values ​​from 71% to 99%.

[0100] "Comprising," "containing," or "including" means that at least the named compound, element, particle, or method step is present in the composition, article, or method, but does not exclude the presence of other compounds, materials, particles, or method steps, even if the other such compounds, materials, particles, or method steps have the same function as the named ones.

[0101] It should also be noted that, unless the context clearly indicates otherwise, the singular forms “a” and “the” used in this specification and the appended claims include plural references. A range may be expressed herein as “about” or “approximately” a particular value and / or “about” or “approximately” another particular value. When expressing such a range, other exemplary embodiments include from one particular value and / or to another particular value.

[0102] The description contained herein is an example of embodiments of the invention and is not intended to limit the scope of the invention in any way. While specific examples of the invention have been described, various modifications may be made to the apparatus and methods without departing from the scope and spirit of the invention. For example, while the examples described herein relate to specific components, the invention includes other examples such as implementing the function using various combinations of components, implementing the function using alternative materials, combining components of the various examples, combining components of the various examples with known components, etc. The invention contemplates replacing the components shown herein with other well-known and commercially available products. Modifications recognized by those skilled in the art to which this invention pertains are intended to fall within the scope of the following claims.

Claims

1. A system for retrieving an embolus from a blood vessel, the system comprising: An external conduit, the external conduit including a lumen passing through it, the lumen including a circumference; as well as A clot retrieval device, positioned within the lumen of the external conduit and capable of translationally passing through the lumen of the external conduit, the clot retrieval device comprising: An elongated flexible delivery member, the elongated flexible delivery member including a distal end; An expandable tube, the expandable tube including a lumen therethrough, the expandable tube being attached to the distal end of an elongated flexible delivery member; and An expandable funnel, attached to the expandable tube, capable of expanding from a collapsed delivery state to an expanded deployment state, wherein in the collapsed delivery state, the size of the expandable funnel is set to traverse the lumen of the external conduit, and in the expanded deployment state, the expandable funnel includes an outer circumference larger than the circumference of the lumen of the external conduit, the expandable funnel comprising: A fluid-impermeable flexible tube includes a lumen passing through it, the lumen of the flexible tube communicating with the lumen of the expandable tube. An open distal port is provided at the distal end of the flexible tube. A first support ring is disposed near the open distal end, the first support ring is attached to the flexible tube and is structurally supported by the flexible tube, and A second support ring is disposed in the proximal direction relative to the first support ring, and the second support ring is attached to the flexible tube and structurally supported by the flexible tube. A suction source configured to apply suction through the lumen of the external conduit, the lumen of the fluid-impermeable flexible tube, and the open distal port.

2. The system of claim 1, wherein the flexible tube is configured to provide the sole structural support for the expandable funnel between the first support ring and the second support ring.

3. The system of claim 1, wherein when the expandable funnel is in the expanded, extended state, approximately half of the clot retrieval device is coaxially positioned along the longitudinal axis within the lumen of the external conduit.

4. The system of claim 1, wherein when the expandable funnel is in the expanded, extended state, the expandable tube is positioned within the external conduit and abuts against the lumen of the external conduit to form a seal.

5. The system of claim 1, wherein when the expandable funnel is in the collapsed delivery state, at least a portion of the expandable funnel and the expandable tube have a common circumferential dimension.

6. The system of claim 1, wherein when the expandable funnel is in the expanded, unfolded state, the expandable funnel is capable of expanding to circumferentially juxtapose the lumen of the blood vessel.

7. The system of claim 1, wherein the fluid-impermeable flexible tube is stitched and / or adhered to the first support ring and the second support ring.

8. The system of claim 1, wherein the fluid-impermeable flexible tube comprises a flexible polymer material.

9. The system of claim 1, wherein when the expandable funnel is in the collapsed delivery state and positioned within the lumen of the external conduit, the lumen of the fluid-impermeable flexible tube, the lumen of the expandable tube, and the lumen of the external conduit are coaxial about a longitudinal axis.

10. A system for retrieving an embolus from a blood vessel, the system comprising: An external conduit, the external conduit including a lumen passing through it; as well as A clot retrieval device, wherein the clot retrieval device is disposed within the external conduit and is capable of translating through the lumen of the external conduit, the clot retrieval device comprising: An elongated flexible member, the elongated flexible member including a distal end; An expandable frame configured to engage the embolus and extend from a collapsed delivery configuration to an extended configuration, the expandable frame including a proximal portion attached to the distal end of the elongated flexible member and a tubular portion extending distally from the proximal portion, wherein the tubular portion comprises an elongated tubular shape when the expandable frame is in the extended configuration, and the proximal portion tapers proximally from the tubular portion to the distal end of the flexible member when the expandable frame is in the extended configuration; and A fluid-impermeable membrane is attached to the proximal portion of the scalable frame, the membrane comprising a funnel shape when the scalable frame is in the extended configuration.

11. The system of claim 10, wherein a majority of the tubular portion of the scalable frame includes a unit opening sized to pass through the embolus as the scalable frame expands from the collapsed delivery configuration to the extended configuration.

12. The system of claim 10, wherein the expandable frame further includes a closed distal end portion extending distally from the tubular portion and radially inwardly to the central axis of the tubular portion.

13. The system according to claim 10, further comprising: A microcatheter, the size of which is configured to traverse the lumen of the external catheter. The size of the scalable frame is set to traverse the lumen of the microcatheter when the scalable frame is in the collapsed delivery configuration.

14. The system of claim 10, wherein when the expandable frame is in the expanded configuration, the tubular portion is capable of expanding to circumferentially juxtapose the lumen of the blood vessel.

15. The system of claim 10, wherein when the scalable frame is in the extended configuration, the fluid-impermeable membrane comprises a first outer circumference approximately equal to the inner circumference of the lumen of the external conduit and a second outer circumference approximately equal to the inner circumference of the blood vessel.

16. The system according to claim 10, When the expandable frame is in the expanded configuration, at least a portion of the proximal portion of the expandable frame is positioned within the lumen of the external conduit, thereby providing an outward force to the lumen of the external conduit. The force thereon is capable of effectively forming a fluid-impermeable seal between the fluid-impermeable membrane and the lumen of the external conduit.

Images