Blockage recovery device

Abstract

The present invention provides a retrieval assembly configured to capture an obstruction located within a patient's body conduit. [Solution] A recovery assembly is provided, comprising a distal collar 21 stationary and fixed on an elongated wire, a proximal collar 22 slidable along a portion of the length of the elongated wire, and a plurality of elongated shape-memory blood clot capturing elements 23, each of the plurality of elongated shape-memory blood clot capturing elements having a proximal end connected to the proximal collar and a distal end connected to the distal collar. The recovery device is configured to automatically transition from a radially constrained state to an expanded rest state, in which case the proximal collar is located near the distal collar. When the recovery device transitions from a radially constrained state to an expanded rest state, the proximal portions of the blood clot capturing elements invert around the proximal collar.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application relates to U.S. Application No. 16 / 555,745, filed on April 9, 2019, and claims the benefit and priority thereof.

[0002] The present invention relates to devices, assemblies, and methods for removing obstructions from a patient's body conduit, such as removing a blood clot located within a patient's vasculature.

Background Art

[0003] Existing blood clot retrieval devices are based on the concept of passing a guide wire through or near the center of a blood clot until the guide wire extends beyond the clot, passing a delivery catheter over the guide wire across the clot, and then replacing the guide wire with a retriever. Thereby, the delivery catheter is withdrawn, and the retriever is exposed to the blood clot, enabling capture after the retriever is expanded. Subsequently, the retriever device containing the blood clot is withdrawn into a suction catheter positioned proximal to a blood clot of sufficient diameter, enabling retrieval of the device while holding the blood clot. One such retrieval device is the Solitaire (trademark) vascular recanalization device.

[0004] Most blood clot capture elements of current retrieval devices are made of nitinol and passively expand within and through the blood clot using the device - specific radial force before the device contracts to remove the blood clot. This radial force is due to the thermally induced martensitic transformation of the nitinol elements of the device by a predetermined shape change in the geometry of the nitinol. Inevitably, this expansion creates shearing and fragmentation of the blood clot because the blood clot capture element cannot expand through the blood clot such that it contacts the vessel wall without creating linear defects within the blood clot. Next, this shearing and fragmentation of the blood clot may increase the risk of distal embolism.

[0005] An estimated 700,000 people in the United States and 950,000 in Europe experience ischemic stroke annually, the majority of which are large vessel occlusions (LVOs). Several of the important randomized prospective clinical trials to date have established the superiority of radially expandable retrieval devices over drug therapy alone for LVOs in the precerebral circulation. These clinical trials include MR CLEAN (published analysis in the New England Journal of Medicine 2015), SWIFT PRIME (published analysis in the New England Journal of Medicine 2015), ESCAPE (published analysis in the New England Journal of Medicine 2015), EXTEND IA (published analysis in the New England Journal of Medicine 2015), REVASCAT (published analysis in the New England Journal of Medicine 2015), and THRACE (published analysis in Lancet Neurology 2016).

[0006] Published analyses of these trials do not emphasize the number of new ischemic strokes in the interventional arm of these studies compared to standard medical care. These new strokes are attributed to distal embolism, vasospasm, or vascular dissection. In the MR CLEAN study, 5.6% of patients (13 out of 233) in the retrieval arm had clinical signs of new ischemic stroke in a different vascular domain, compared to 0.4% (1 out of 267) in the control group, representing a 14-fold relative risk. In the REVASCAT study, 4.9% of patients had distal embolism to a new vascular domain, compared to none in the control group, and 12.7% had local arterial complications attributable to the passage of the retrieval device (3.9% dissection, 4.9% perforation, and 3.9% vasospasm requiring treatment), compared to none in the control group. In the THRACE study, 6% had distal embolism in a new domain, and 26% experienced vasospasm, dissection, or perforation. None of these events occurred in the control group.

[0007] Clinical trials of these devices to date have not emphasized the number of additional passes (withdrawal of the retrieval device across segments containing the initial blood clot in the vessel). To enable repeated delivery / deployment of the retrieval device, each pass requires manipulation and advancement of the catheter and guidewire across the arterial segment containing the thrombus, thereby creating potential vascular damage in the form of vasospasm, dissection, or perforation. A recent study (REVIVE 2018) required as many as five separate retrieval device passes for intended thrombectomy, with an average of 2.2 passes. The Instructions for Use (IFU) for the Solitaire® thrombectomy device (sold by Medtronic) instruct physicians to perform up to three retrieval attempts within the same vessel. The IFU for the Trevo® thrombectomy device (sold by Stryker) instructs physicians to exercise caution when withdrawing the device through site or arterial vasospasm. The 3D blood vessel regeneration device (sold by Penumbra) allows the retrieval device to be passed through up to five times, with each pass requiring the re-crossing of the target vessel (e.g., the M1 segment of the middle cerebral artery) using a catheter and guidewire. [Overview of the project]

[0008] Obstruction retrieval devices, assemblies, and methods are disclosed herein, along with methods for manufacturing the retrieval devices. While the exemplary implementations disclosed herein concern the removal of blood clots located within a patient's arteries, it is understood that the devices, assemblies, and methods are applicable to the retrieval of other types of obstructions located within other body conduits in a patient.

[0009] According to several implementations, a blood clot recovery assembly is provided, comprising an elongated wire and a recovery device mounted on the elongated wire. According to several implementations, the recovery device includes a distal collar stationary and fixed on the elongated wire and a proximal collar slidable along a portion of the length of the elongated wire. Extending between the proximal and distal collars are a plurality of elongated shape-memory blood clot-catching elements, each of which has a proximal end connected to the proximal collar and a distal end connected to the distal collar. According to several implementations, the recovery device is configured to take on radially constrained, expanded resting, and expanded stressed states. When the recovery device is in the radially constrained state, the proximal collar is located at a first axial position on the elongated wire proximal to the distal collar and separated from the distal collar by a first distance. When the recovery device is in an expanded-rest state, the proximal collar is located at a second axial position on the elongated wire proximal to the distal collar, and is separated from the distal collar by a second distance less than the first distance. When the recovery device is in an expanded-stress state, the proximal collar is located at a third axial position on the elongated wire proximal to the distal collar, and is separated from the distal collar by a third distance less than the second distance.

[0010] When the recovery device is radially constrained and the constraining force is removed, the shape memory properties of the elongated blood clot capturing element cause the recovery device to transition from the radially constrained state to an expanded resting state. The recovery device is configured such that during the transition from the radially constrained state to the expanded resting state, the elongated blood clot capturing element inversion occurs in the proximal section of the recovery device, resulting in the elongated blood clot capturing element taking on an arched configuration. During the inversion, the proximal collar transitions to a second axial position on the elongated wire and, after the inversion, is at least partially surrounded by the arched blood clot capturing element.

[0011] When a distal force is applied to the proximal side of the recovery device or to the proximal end of the proximal collar, the recovery device transitions from an expanded resting state to an expanded stress state. By shortening the distance between the proximal and distal collars, the arched clot-catching element is biased to expand radially outward and / or the shape-memory elongated clot-catching element bends more noticeably, resulting in an increase in the stiffness of the elongated clot-catching element forming the arch. In either event, the recovery device's clot-catching ability is enhanced by the increase in radial force applied by the arched clot-catching element and / or by the increase in the stiffness of the arched clot-catching element.

[0012] According to some implementations, the elongated shape-memory blood clot-capturing elements are independent elements, fixed to the proximal collar at their proximal ends and to the distal collar at their distal ends. According to other implementations, the proximal collar, distal collar, and elongated shape-memory blood clot-capturing elements are integrally formed (i.e., made from a single piece of material).

[0013] According to some implementations, the retrieval device is delivered to the site of the blood clot inside the delivery catheter, while being radially constrained. According to some implementations, the retrieval device is deployed inside the patient's vascular structure at a distal position to the blood clot. During deployment, the proximal end portion of the clot-capturing element inverts around the proximal collar as described above. After deploying the retrieval device inside the patient's artery, the elongated wire is pulled out proximal by the clinician so that the proximal end portion of the retrieval device engages with the blood clot. This results in a distal force being applied to the proximal side of the retrieval device, moving the proximal collar distally closer to the distal collar. After the retrieval device is deployed, the radial force exerted by the arched clot-capturing element may change during the retrieval process as a result of the proximal collar's ability to slide distally on the elongated wire. This variable radial force characteristic enhances the clot-capturing ability of the retrieval device as described above.

[0014] These and other implementation examples, along with their advantages and features, will become clear when considering the drawings and detailed descriptions. [Brief explanation of the drawing]

[0015] [Figure 1A] This describes a blockage recovery assembly using one implementation example, where the recovery device is in an extended state. [Figure 1B] Figure 1A illustrates an enlarged view of the recovery device shown, where the distal cover has been removed and the proximal collar is positioned at a first distance from the distal collar. [Figure 1C] Figure 1A illustrates an enlarged view of the recovery device, where the distal cover has been removed and the proximal collar is located at a second distance from the distal collar that is less than the first distance. [Figure 1D] A blockage recovery assembly, such as the one shown in Figure 1A, which has multiple recovery devices, will be described. [Figure 2A] Figure 1A shows a side view of the occlusion retrieval assembly, in which the retrieval device is positioned at the distal end of the delivery catheter in a radially constrained state. [Figure 2B] Figure 2A is a cross-sectional side view of the distal end of the delivery catheter, showing the retrieval device which is radially constrained inside the delivery catheter. [Figure 3] Figure 2A shows a side view of the occlusion retrieval assembly, with the delivery catheter being withdrawn proximally to deploy the retrieval device. [Figure 4A-B] The proximal end view and cross-sectional side view of the distal collar of the recovery device in one implementation example are shown. [Figure 5A-C] The proximal end view, distal end view, and cross-sectional side view of the proximal color of the recovery device in one implementation example are shown. [Figure 5D] This is a cross-sectional side view of the proximal collar of a recovery device having a non-invasive proximal end. [Figure 6]Describe a plurality of independent blood clot capture elements having proximal and distal ends configured to be present within radially dispersed apertures of a proximal color and a distal color as shown in FIGS. 5B and 4A, respectively. [Figure 7A] Show the components of FIGS. 4B, 5D, and 6 in a first assembled state. [Figure 7B] Show the recovery device of FIG. 7A when there is an axial force applied to one or both of the proximal collar and the distal collar to invert the proximal end portion of the recovery device. [Figure 7C] Show a proximal end view of the recovery device of FIG. 7B when one or both of the proximal collar and the distal collar rotate relative to the other. [Figure 8A] Describe a tubular member for integrally fabricating a recovery device according to one implementation example. [Figure 8B] Show the tubular member of FIG. 8A cut along its axial length and placed flat on a surface. [Figure 8C] Show a recovery device having an inverted proximal end portion formed when there is an axial force applied to one or both of the proximal collar and the distal collar. [Figure 8D] Show an end view of the recovery device of FIG. 8C after rotating one or both of the proximal collar and the distal collar relative to each other to cause each of the elongated capture elements to take an arched configuration. [Figure 8E] Show a tubular member such as that of FIG. 8B having proximal and distal end sections of blood clot capture elements with different widths. [Figure 9A] Describe a Nitinol tube having a wall section that thins along a portion of its length. [Figure 9B] Describe a flattened view of the tube of FIG. 9A after the formation of the slot therein. [Figure 9C] Show a cross-sectional view of a blood clot capture element having a curved recess formed therein. [Figure 10A] Describe a tubular member for integrally fabricating a recovery device according to another implementation example. [Figure 10B] Figure 10A shows a tubular member that has been cut along its axial length and laid flat on a surface. [Figure 10C] Figure 10A shows a tubular member when an axial force is applied to one or both of the proximal and distal collars to invert the proximal end portion of the tubular member. [Figure 10D] Figure 10A shows an isometric view of the recovery device formed from the tubular member. [Figure 10E] Figure 10D is a proximal end view of the recovery device. [Figure 11] This describes inserts for placement inside the annular openings of the proximal and distal collars. [Figure 12] This shows a tubular member that has been cut and laid flat on a surface, from which a recovery device can be manufactured. [Figure 13A] A tubular member for centrally manufacturing a recovery device will be described according to another implementation example. [Figure 13B] Figure 13A shows a tubular member that has been cut along its axial length and laid flat on a surface. [Figure 14A] This section describes a tubular component used to centrally manufacture a recovery device, following one implementation example. [Figure 14B] Figure 14A shows a tubular member that has been cut along its axial length and laid flat on a surface. [Figure 15A] This section describes a tubular component used to centrally manufacture a recovery device, following one implementation example. [Figure 15B] Figure 15A shows a tubular member cut along its axial length and laid flat on a surface. [Figure 15C] Figure 15B shows a tubular member having a proximal and distal end section of a blood clot-capturing element with different widths. [Figure 16A] This section describes a tubular component used to centrally manufacture a recovery device, following one implementation example. [Figure 16B] Figure 16A shows a tubular member that has been cut along its axial length and laid flat on a surface. [Figure 17A] This section describes a tubular component used to centrally manufacture a recovery device, following one implementation example. [Figure 17B] Figure 17A shows a tubular member that has been cut along its axial length and laid flat on a surface. [Figure 18A] This section describes a tubular component used to centrally manufacture a recovery device, following one implementation example. [Figure 18B] Figure 18A shows a tubular member that has been cut along its axial length and laid flat on a surface. [Figure 19A-D] This document presents a method for detecting blockages in a patient's body conduits using one implementation example. [Figure 20A] An occlusion recovery assembly having a proximal recovery device and a distal recovery device is described. [Figure 20B] Figure 20A shows enlarged views of the proximal and distal retrieval devices. [Figure 20C] This is a cross-sectional side view of the distal end of the delivery catheter, showing the proximal and distal retrieval devices, which are radially constrained inside the delivery catheter. [Figure 21] This describes an obstruction recovery assembly with another implementation example in which the proximal recovery device is movable axially along the length of an elongated member. [Figure 22] Figure 22 is a side view of the occlusion retrieval assembly, where the proximal and distal retrieval devices are located inside the delivery catheter. [Figure 23] Figure 22 is a cross-sectional side view of the distal end of the delivery catheter, showing the proximal and distal retrieval devices, which are radially constrained inside the delivery catheter. [Figure 24] This shows the distal retrieval device after deployment from the delivery catheter. [Figure 25A] The diagram shows the proximal and distal retrieval devices after deployment from the delivery catheter, with the proximal retrieval device separated from the distal retrieval device by a distance of 1. [Figure 25B]The diagram shows the proximal and distal retrieval devices after deployment from the delivery catheter, with the proximal retrieval device separated from the distal retrieval device by a second distance, and the second distance being less than the first distance. [Modes for carrying out the invention]

[0016] Figure 1A illustrates an assembly useful for removing occlusions located within a patient's body conduits, such as the removal of blood clots located within the anatomical structures of the cerebrum. According to several implementations, the assembly includes a retrieval device 20 attached to an elongated wire 10. During use, the retrieval device 20 is delivered to the site of the occlusion while remaining radially constrained inside the delivery catheter 30, as shown in Figure 2B. A method for delivering the retrieval device to the occlusion site and subsequently retrieving the occlusion is disclosed in more detail below.

[0017] As discussed above, the exemplary implementations disclosed herein concern the removal of blood clots located within a patient's vascular structure, but it is understood that the apparatus, assemblies, and methods are applicable to the retrieval of other types of obstructions located within other body conduits in a patient.

[0018] According to some implementations, the recovery device 20 includes a distal collar 21 stationary and fixed to an elongated wire 10, and a proximal collar 22 that is slidable on the elongated wire 10. Extending between the proximal and distal collars are multiple shape-memory elongated blood clot capturing elements 23, which are configured to engage with the occlusion when the recovery device 20 is in an expanded / unfolded state, as shown in Figures 1A to 1C. When the recovery device is in the expanded / unfolded state, the elongated shape-memory blood clot capturing element 23 may have a curved structure, such as or different from that shown in the figure. Hereafter, the elongated shape-memory blood clot capturing element 23 will be referred to as an “arch,” or having an “arched configuration” or “arched structure” when in its expanded / unfolded state. As used herein, the terms “arch” and “arched” do not mean any particular curvature of the blood clot capturing element 23. Notwithstanding the foregoing, when the recovery device 20 is in the unfolded / unfolded state, the blood clot capturing element 23 has a curved configuration sufficient to engage with the occlusion in a manner that facilitates at least partial removal of the occlusion during the occlusion removal process.

[0019] In some implementations, each of the shape-memory elongated blood clot-retaining elements 23 has a proximal end fixed to the proximal collar 22 and a distal end fixed to the distal collar 21. As shown in the figure, the proximal end of the shape-memory elongated blood clot-retaining element 23 may be attached to the distal end 22b of the proximal collar 22, and the distal end of the shape-memory elongated blood clot-retaining element 23 may be attached to the proximal end 21a of the distal collar 21. As will be discussed in more detail below, the shape-memory elongated blood clot-retaining elements 23 may include independent elements fixed to the proximal and distal collars by a binder (e.g., adhesive, solder, etc.) and / or by a bonding process (e.g., welding). The distal collar 21, the proximal collar 22, and the shape-memory elongated blood clot-retaining elements 23 may also be formed from a single piece of material, as will be discussed in more detail below.

[0020] According to several implementation examples, the retrieval device 20 includes a proximal inverted portion 24 and a distal non-inverted portion 25 when deployed from the delivery catheter 30 and in an expanded state. The proximal inverted portion 24 may be characterized by the fact that, when the retrieval device is in the deployed state, elongated shape-memory blood clot-capturing elements 23 are dispersed around the outer surface 22k of the proximal collar 22. The proximal inverted portion 24 may be characterized by the fact that, when the retrieval device is in the deployed state, at least some portions 23c of the elongated shape-memory blood clot-capturing elements 23 are located proximal to their proximal ends 23a, with the proximal ends 23a being connected to the distal end portion 22b of the proximal collar 22 or located inside the distal end portion 22b of the proximal collar 22. The proximal inverted portion 24 may be characterized by the fact that, when the retrieval device is in the deployed state, the proximal end 22a of the proximal collar 22 is located distal to the nearest end 20a of the retrieval device 20. The proximal inversion portion 24 may be characterized by a zigzag configuration of the elongated shape-memory clot-capturing elements 23 within the inversion portion. That is, as most clearly shown in Figure 1B, a portion of the elongated shape-memory clot-capturing elements 23 initially extends distally D from the distal end 22b of the proximal collar 22, then changes course to extend proximal P, and then changes course again to extend distally D. The proximal inversion portion 24 may have one or any combination of the above characteristics.

[0021] As shown in Figure 1A, according to some implementations, the distal non-inverting portion 25 of the recovery device is equipped with a cover 27 made of a permeable biocompatible material that can capture occluding fragments that may be removed during the recovery process. According to some implementations, the biocompatible material is encapsulated polytetrafluoroethylene (ePTFE) with a thickness of 0.0008 to 0.016 inches. According to some implementations, the elongated blood clot capturing element 23 portion of the shape memory within the non-inverting portion 25 of the recovery device 20 extends continuously from the proximal end 21a of the distal collar 21 toward the proximal direction P, rather than in a zigzag pattern.

[0022] According to several implementation examples, when the recovery device 20 is in its extended resting state, the elongated shape-memory blood clot capturing elements 23 form multiple arch structures, as shown in Figures 7C, 8D, and 10E, which, when viewed from the proximal end of the recovery device, preferably adjacent arch structures but not necessarily overlapping each other.

[0023] Figure 2A shows a side view of the occlusion retrieval assembly, where the retrieval device 20 is located inside the distal end portion of the delivery catheter 30. Figure 2B is a side cross-sectional view of the distal end portion of the delivery catheter 30 in Figure 2A, showing the retrieval device 20 radially constrained inside the delivery catheter. In the radially constrained state of the retrieval device 20, the proximal collar 22 is located in a first axial position on an elongated wire, and the distal end 22b of the proximal collar 22 is separated from the proximal end 21a of the distal collar 21 by a first distance d1. According to some implementation examples, as shown in the figure, the distal collar 21 includes a curved / rounded non-invasive end 21b.

[0024] When the retrieval device 20 is in an unrestrained resting position as shown in Figures 1A and 1B, the proximal collar 22 is located at a second axial position on the elongated wire 10, and the proximal end 21a of the distal collar 21 is located at a second distance d2 from the distal end 22b of the proximal collar 22, where the second distance d2 is less than the first distance d1. When the retrieval device is in an extended resting position, the proximal collar 22 is movable along the length of the elongated wire 10 to a third axial position such that the proximal end 21a of the distal collar 21 is located at a third distance d3 from the distal end 22b of the proximal collar 22, where the third distance d3 is less than the second distance d2. By shortening the distance between the proximal and distal collars from the second distance d2 to the third distance d3, the arch structure 28 is biased to expand radially outward and / or the stiffness of the clot-catching element 23 increases as the clot-catching element bends more noticeably. During the removal of blood clots from the patient's vascular structure, distal movement of the proximal collar 22 on the elongated wire 10 is particularly advantageous. This, as a result, biases the arch structure 28 to expand radially, and consequently, the arch structure 28 can be firmly pressed against the arterial wall during the blood clot retrieval process. Rigidity of the clot-catching element 23 increases its rigidity, making it more difficult for the arch structure 28 to detach during the blood clot retrieval process. In either case, the blood clot-catching capacity of the retrieval device is enhanced.

[0025] According to some implementation examples, one or both of the distal color 21 and the proximal color 22 are made of or coated with radiopaque material, thereby allowing the location of the color to be observed by fluorescence fluoroscopy.

[0026] Figure 3 shows the retrieval device 20 in its deployed state. During use, the retrieval device 20 can be deployed from the distal end of the delivery catheter 30 by either pulling out the delivery catheter proximally while fixing and holding the elongated wire 10, or by fixing and holding the delivery catheter 30 while advancing the elongated wire 10 distally.

[0027] As discussed above, the distal collar 21, proximal collar 22, and elongated shape-memory blood clot capturing element 23 of the recovery device 20 may comprise an assembly of parts assembled together or may be formed from a single piece of material. Figures 4A to 7C illustrate a recovery device consisting of an assembly of parts, while Figures 8A to 19B illustrate a recovery device with a unified structure (i.e., made from a single piece of material).

[0028] Figures 4A and 4B show the proximal end and cross-sectional side view, respectively, of the distal collar 21 according to one implementation example. The distal collar 21 includes a central through-opening 21c through which the elongated wire 10 passes when the distal collar is fixed to an elongated wire. According to some implementation examples, the proximal end portion 21d of the collar includes a plurality of apertures 21e-j arranged radially around the central opening 21c. The apertures 21e-j may be blind apertures as shown in Figure 4B, or they may have through-apers with a distal opening. According to some implementation examples, the apertures 21e-j are equidistant around the central opening 21c, as shown in Figure 4A. According to some implementation examples, the outer surface of the distal end 21b of the distal collar is curved to minimize tissue damage when the retrieval device 20 is maneuvered through the patient's vascular structure.

[0029] Figures 5A, 5B, and 5C show the proximal end, distal end, and cross-sectional side view of the proximal collar 22 according to several implementation examples, respectively. The proximal collar 22 includes a central through-opening 22c through which the elongated wire 10 passes when the proximal collar is mounted on an elongated wire in a slidable manner. According to some implementation examples, the distal end portion 22d of the collar includes a plurality of apertures 22e-j arranged radially around the central opening 22c. The apertures 22e-j may be blind apertures as shown in Figure 5C, or they may have through-apers extending throughout the entire length of the collar. According to some implementation examples, the apertures 22e-j are equidistant around the central opening 22c, as shown in Figure 5B. According to some implementation examples, the proximal end 22a of the proximal collar 22 is curved as shown in Figure 5D for the purpose of minimizing tissue damage when the retrieval device 20 is maneuvered through the patient's vascular structure.

[0030] In the embodiments shown in Figures 4A and 4B and Figures 5A to 5D, the proximal collar 22 and distal collar 21 each carry six apertures 22e-j and 21e-j, respectively, and the six apertures 22e-j and 21e-j are configured to receive the proximal ends 23a and distal ends 23b, respectively, of six elongated shape-memory blood clot-retaining elements 23e-j, as shown in Figure 6. According to some implementation examples, as discussed above, the elongated shape-memory blood clot-retaining elements are fixed inside the apertures of the proximal and distal collars by using adhesive or other means.

[0031] Throughout this disclosure, exemplary retrieval devices are shown to carry five or six elongated shape-memory blood clot-capturing elements. It is important to note that retrieval devices may have fewer or more than five, or fewer or more than six, elongated shape-memory blood clot-capturing elements.

[0032] Figure 7 shows elongated shape-memory blood clot-capturing elements 23e-j fixed to distal collar 21 and proximal collar 22 as depicted in Figures 4B and 5D. According to some implementations, the elongated shape-memory blood clot-capturing elements 23-j are made of nitinol and are shaped into their respective resting state configurations, as shown in Figures 1A and 1B, by heating the blood clot-capturing elements above their thermally induced martensitic transformation temperatures. Subsequently, the blood clot-capturing elements 23 are radially constrained and, once unconstrained, automatically aim to assume an expanded resting state.

[0033] Shaping the clot-capturing element 23 to assume these expanded resting states may involve applying a distal force DF to the proximal collar 22 and / or a proximal force PF to the distal collar 21, as shown in Figure 7A, while rotating one or both of the distal and proximal collars clockwise or counterclockwise relative to each other. Alternatively, or in conjunction with the shaping method described above, the clot-capturing element 23 may be constrained to these expanded resting configurations using specially designed fixtures. In either case, as considered above, the clot-capturing element 23 may be heat-treated to lock it in the expanded resting configuration.

[0034] As shown in Figure 7B, when a distal force DF is applied to the proximal collar 22 and / or a proximal force PF is applied to the distal collar 21, inversion occurs as the proximal collar 22 moves closer to the distal collar 21, and as a result, the outer peripheral surface 22k of the proximal collar 22 is at least partially surrounded by the curved portion of the clot-retaining elements 21e~j. According to one implementation example, during or after inversion, one or both of the distal collar 21 and the proximal collar 22 are rotated relative to the other, so that the clot-retaining elements take on an arched configuration as shown in Figure 7C, with at least a portion of the adjacent arched structures overlapping each other.

[0035] According to several implementation examples, the retrieval device 20, when in its expanded resting state, is attached to an elongated wire 10 and then stored radially constrained inside, for example, a peel-away sheath. During the subsequent blood clot removal process, the retrieval device 20 is loaded into the delivery catheter 30 in its radially constrained state and is ready to be deployed outside the delivery catheter into the patient's vascular structure.

[0036] Figures 19A to 19D illustrate a method for removing a blood clot 52 from a patient's arterial passage 50. The process typically involves delivering a guidewire across the blood clot 52 so that the distal end portion of the delivery catheter is distal to the blood clot 52, followed by the subsequent advancement of the delivery catheter 30 on the guidewire. With the delivery catheter in place, the retrieval device 20 is loaded into the delivery catheter 30 as described above. According to some implementations, as shown in Figure 19A, the retrieval device 20 is positioned within the distal end portion of the delivery catheter 30 so that only its distal curved end 21b protrudes from the distal end 35 of the delivery catheter 30. The retrieval device 20 is then deployed from the delivery catheter 30 as shown in Figure 19B. As discussed above, the retrieval device 20 can be deployed from the distal end of the delivery catheter 30 by either pulling out the delivery catheter proximally while fixing and holding the elongated wire 10, or by fixing and holding the delivery catheter 30 while advancing the elongated wire 10 distally.

[0037] When deployed inside the patient's passage 50, the arched clot-capturing element 23 of the retrieval device 20 is pressed against the arterial wall 54 of the blood vessel. (Note that the retrieval device is sized so that when deployed inside the patient's arterial passage, it does not reach its expanded resting state as a result of its maximum resting diameter being larger than the diameter of the arterial passage.) After the retrieval device 20 is deployed inside the passage 50, the delivery catheter 30 is withdrawn, as shown in Figure 19C, and the retrieval device 20 is ready to be pulled proximal to engage with the clot 52. Immediately before the retrieval device 20 engages with the clot 52, as shown in Figure 19C, the distal end 22b of the proximal collar 22 is separated by a distance A from the proximal end 21a of the distal collar 21. According to some implementations, as shown in Figure 19D, when the retrieval device 20 is pulled proximal to the blood clot 52, the proximal collar 22 moves distally closer to the distal collar 21 such that the distal end 22b of the proximal collar 22 is separated from the proximal end 21a of the distal collar 21 by a distance B less than a distance A. The advantages associated with the distal movement of the proximal collar 22 on the elongated wire 10 during blood clot capture are discussed above.

[0038] When capturing the blood clot 52 with the recovery device 20, the removal of the blood clot can be achieved at least partially by pulling the elongated wire 10 proximal to move the blood clot into the mouth of the aspiration catheter or into the delivery catheter 30.

[0039] In some implementations, the blood clot capturing element 23 of the recovery device 20 is configured to sweep along the arterial wall 54 to which the blood clot is attached during the removal process, moving the blood clot or the remainder of the blood clot towards the center of the affected blood vessel 50.

[0040] In the implementation examples shown in Figures 1A and 19A-19D, the blood clot recovery assembly includes a single recovery device 20. According to other implementation examples, the recovery assembly includes multiple recovery devices spaced apart along the axial length of the elongated wire 10. During use, two or more recovery devices each deploy distal to the blood clot 52. By using two or more recovery devices, any remaining blood clot 52 not captured by the recovery device positioned proximal can be captured by the recovery device positioned distally. Figure 1D shows an exemplary recovery assembly having three recovery devices 31, 32, and 33 positioned along the length of the distal end portion of the elongated wire 10 in an expanded and resting state. According to several implementations, the retrieval devices 31, 32, and 33 are spaced apart, and when the retrieval devices 31, 32, and 33 are housed inside the sheath or inside the delivery catheter 30 while being radially constrained, the slidable proximal collar 33a of retrieval device 33 is located distal to the fixed distal collar 32b of retrieval device 32, and the slidable proximal collar 32a of retrieval device 32 is located distal to the fixed distal collar 31b of retrieval device 31. In the embodiment of Figure 1D, retrieval device 32 is spaced equidistant from retrieval device 31 and retrieval device 33. According to another implementation, retrieval device 32 is located closer to retrieval device 31 than to retrieval device 33. According to yet another implementation, retrieval device 32 is located closer to retrieval device 33 than to retrieval device 31.

[0041] According to several implementations, the elongated wire 10 has a length of approximately 200 centimeters and a diameter of approximately 0.01 to 0.014 inches. The term "approximately" is used in conjunction with other terms used herein to describe dimensional characteristics, and indicates a tolerance of ±10% of the stated dimensions. (For example, the description of the elongated wire 10 having a length of approximately 200 centimeters means a length of 180 to 220 centimeters.) According to several implementations, the delivery catheter 30 has a length of approximately 150 centimeters and an inner diameter of approximately 0.027 inches. According to several implementations, the retrieval device 20 has a radially constrained length of approximately 16 to 30 millimeters and a length of approximately 8 to 15 millimeters when the retrieval device is in an expanded resting state. When the retrieval device 20 is in an expanded resting state, the maximum diameter dimension of the expanded device is approximately 3 to 6 millimeters. According to several implementations, the shape-memory elongated blood clot capture element 23 has a diameter of approximately 0.0002 to 0.0008 inches. (It is important to note that the attached figures are not drawn to scale.)

[0042] As discussed above, according to some implementations, the recovery device 20 has a unified structure, and the proximal collar 22, distal collar 21, and blood clot capturing element 23 are made from a single material piece. According to some implementations, the single material piece is a nitinol tube.

[0043] Figures 8A to 8D illustrate a method for fabricating a recovery device according to one implementation example. According to several implementation examples, the method involves laser cutting a nitinol tube 60 to form multiple spaced elongated blood clot capturing elements 62 that extend continuously (i.e., without any breaks or interruptions) along the substantial length L1 of the tube 60, forming multiple spaced elongated blood clot capturing elements 62. Figure 8B shows the slotted tube 60 of Figure 8A as if it had been cut along its length and laid flat on a surface.

[0044] Slot 61 has a proximal end 63, which is separated from the proximal end 65 of the tube 60 by a certain distance to form a proximal collar 22. Similarly, slot 61 has a distal end 64, which is separated from the distal end 66 of the tube 60 by a certain distance to form a distal collar 21. Thus, the length distance L2 between the proximal end 63 and the distal end 64 of the slot is less than the length L1 of the tube 60. Each of the length distances L1 and L2 is a straight-line distance running parallel to the longitudinal axis 164 of the tube 160, as shown in Figure 8B. According to some implementations, length L2 is at least 50% of length L1, and preferably at least 70% of length L1.

[0045] After the formation of the slot 61, the tube 60 may be polished to remove slag (oxide) formed during the laser cutting process. The apparatus can then be operated as described above in conjunction with the implementation examples in Figures 7A and 7C to cause the clot-catching element 62 to assume a curved configuration as shown in Figures 8C and 8D. In one method, the recovery apparatus is formed by inverting the clot-catching element 62 at the proximal end of the apparatus by applying a distal force DF to the proximal collar 22 and / or a proximal force PF to the distal collar 21, as shown in Figure 8A. Simultaneously with or after the application of one or both of the distal force DF and the proximal force PF, one or both of the distal collar 21 and the proximal collar 22 can be rotated clockwise or counterclockwise relative to the other to cause at least some of the clot-catching elements 62a to e to assume an arched configuration. Figure 8D is a proximal end view of the recovery apparatus, showing the clot-catching element 62 in an arched configuration. According to some implementations, at least some of the arched structures 72 overlap each other, as shown in Figure 8D. According to some implementations, the length of the recovery device 20 in the extended resting state is 40% to 70% of the length of the pipe 60 before inversion.

[0046] As shown in Figures 8C and 8D, in order to shape the clot-capturing elements 62 into their respective extended resting state configurations, the clot-capturing elements are heat-treated in the resting state configurations of the clot-capturing elements such that they are radially constrained and then, once unconstrained, automatically bias toward the extended resting state of the clot-capturing elements. As discussed above, shaping the clot-capturing elements 62 may involve applying a distal force DF to the proximal collar 22 and / or a proximal force PF to the distal collar 21, while simultaneously or afterward rotating one or both of the distal and proximal collars clockwise or counterclockwise relative to each other. Alternatively, or in conjunction with the shaping method described above, the clot-capturing elements 62 can be constrained to these extended resting state configurations using specially designed fixtures. In either case, the clot-capturing elements 62 are heat-treated to lock them in the extended resting state configurations of the clot-capturing elements 62.

[0047] According to some implementations, a cylindrical collar 70, such as that shown in Figure 11, is fitted into one or both of the annular openings 67 and 68 of the distal collar 21 and the proximal collar 22. The cylindrical collar 70 includes a central through-opening 71 having a diameter smaller than the diameters of the annular through-openings 67 and 68. The smaller diameter opening 71 allows the recovery device 20 to be positioned more centrally on the elongated wire 10, and allows for smoother, more controlled sliding of the proximal collar 22 on the elongated wire 10 when the recovery device transitions from its radially constrained state to an expanded rest state, and also when the recovery device transitions from its expanded rest state to an expanded stress state. According to some implementations, the central through-opening 71 of the collar 70 has an inner diameter 5% to 20% larger than the outer diameter of the elongated wire 10. Figure 8D shows a cylindrical collar 70 positioned within the annular through-opening 68 of the proximal collar 22. Collar 70 may be located in one or both of the proximal and distal collars of all recovery devices disclosed and intended herein, which are made from slotted tubing.

[0048] According to other implementations, the slot 61 is cut such that the proximal end section 62a and distal end section 62b of the clot capture element 62 have different widths, with the width of the distal end section 62b being greater than the width of the proximal end section 62a, as shown in Figure 8E. (The proximal end section 61a of the slot 61 has a greater width than the width of the distal end section 61b of the slot 61.) Providing a distal end section 62b with a greater width results in a smaller gap existing between the proximal end section 61a and the distal end section 61b when the resulting retrieval device is in an expanded / unfolded state. This is advantageous as it significantly prevents removed clot fragments from passing through the retrieval device during the clot retrieval procedure.

[0049] For the reversal portion of the recovery device to form, the blood clot capturing element 62 must first dent or bend outward somewhere along the length of the blood clot capturing element 62. As shown in Figures 9A and 9B, the slotted tube 60 may have a reduced wall thickness region 69 somewhere along the length of the slotted tube 60 to control where the first dent or bend occurs. The reduced wall thickness region 69 may take on any of a variety of shapes that cause the tube to first dent or bend along the reduced wall thickness region when a distal force DF and / or a proximal force PF are applied to the proximal and distal ends of the tube 60, as shown in Figure 8A.

[0050] Figure 9A shows the nitinol tube 60 before the slot 61 is formed inside. The tube 60 is cut to form a cylindrical recess 76 on its outer cylindrical surface 75. The slot 61 is then formed inside the tube, as shown in Figures 8A and 8B. Figure 9B shows the tube 60 of Figure 9A in a flattened state (as if the cut of the tube were along the length of the tube and placed flat on the surface) after the formation of the slot 61. As shown in Figure 9B, each of the blood clot trapping elements 62 carries a zone 69 with reduced wall thickness. Figure 9B shows an implementation example in which the recess 76 formed within the blood clot trapping element 62 has a rectangular profile, and Figure 9C shows an implementation example in which the recess 76 formed within the blood clot trapping element 62 has a curved profile, such as a semicircular or U-shaped profile.

[0051] According to some implementation examples, the reduced wall thickness zone 69 is located closer to the distal end 66 of the slotted pipe than to the proximal end 65, as shown in Figure 9B.

[0052] According to some implementation examples, the recess 76 is cut within the pipe 60 such that the pipe wall thickness in the recess area is reduced by 5-30%, preferably 10-20%.

[0053] In the implementation examples shown in Figures 8A-8D and 9A-9C, the slots 61 are cut to form clot-retaining elements 62, each of which is arranged parallel to the longitudinal axis 77 of the tube 60 along its entire length. As will be disclosed in more detail below, the slots 61 may, however, be cut to form clot-retaining elements having different geometric shapes and / or different orientations.

[0054] Figures 10A to 10E illustrate a method for creating a recovery device using another implementation example. According to several implementations, the method involves laser cutting a nitinol tube 80 to form a plurality of circumferentially spaced longitudinal slots 81. Formed between the slots 81 are a plurality of elongated blood clot-catching elements 82 that extend continuously (i.e., without any breaks or interruptions) along the substantial length of the tube 80. According to some implementations, the blood clot-catching elements 82 have a length L2 that exceeds 50% of the length L1 of the slotted tube 80. According to other implementations, the blood clot-catching elements 82 have a length L2 that exceeds 70% of the length L1 of the slotted tube 80. Each of the length distances L1 and L2 is a straight-line distance running parallel to the longitudinal axis 145 of the tube 80.

[0055] The proximal end 86 of the slot 81 is separated by a certain distance from the proximal end 83 of the tube 80, and the distal end 87 of the slot 81 is separated by a certain distance from the distal end 84 of the tube 80, so as to form the proximal collar 22 and the distal collar 21, respectively. Figure 10B shows the slotted tube 80 from Figure 10A as if it had been cut along its length and laid flat on a surface.

[0056] As discussed above, the slots 81 are cut to form multiple clot-capturing elements 82 between them. The entire length of the slots 81 is not cut into a single straight path. Instead, each slot is cut to produce a clot-capturing element 82 having a straight proximal section 82a and a straight distal section 82b that are circumferentially offset from each other. According to some implementations, as shown in Figure 10B, the clot-capturing element 82 includes a bend 85 that connects the distal end of the straight proximal section 82a to the proximal end of the straight distal section 82b. According to some implementations, the bend 85 comprises straight segments arranged at a certain angle to each of the proximal section 82a and distal section 82b of the clot-capturing element 82, as shown in Figure 10B. According to other implementations, the bend 85 comprises curved segments that can bend in a clockwise or counterclockwise direction. The slot 81, the blood clot capture element 82, and the bend 85 are configured and arranged such that when a distal force DF is applied to the proximal collar 22 and / or a proximal force PF is applied to the distal collar 21, the tube 80 begins to bulge at or around the bend 85, as shown in Figure 10C. According to some implementations, the bend 85 is configured to rotate the proximal collar 22 relative to the distal collar 21 (for example, when the bend 85 bends spirally) as the proximal and distal collars move closer to each other, as shown in Figure 10D.

[0057] As shown in Figure 10D, as the distal force DF and / or proximal force PF continue to be applied to the tube, the inversion of the clot-capturing elements 82 occurs within the proximal end portion of the tube, while simultaneously, each of the clot-capturing elements 82 continues to bend to form an arched configuration, as shown in Figure 10E. If necessary, one or both of the distal collar 21 and the proximal collar 22 can be rotated relative to the other during or after the inversion process so that the clot-capturing elements form an arched configuration of clot-capturing elements, as shown in Figure 10E, with adjacent arches 74 preferably overlapping each other. Alternatively, or in conjunction with the shaping method described above, the clot-capturing elements 82 can be constrained to these desired expanded resting states using specially designed fixtures. Once the clot-capturing elements 82 and the collars 21 and 22 are properly oriented relative to each other, the unit is heat-treated to shape the resulting recovery device to its expanded resting state. According to some implementation examples, the length of the recovery device 20 obtained as a result of being in an extended resting state is 50% to 70% of the length of the pipe 80 before inversion.

[0058] According to some implementations, a reduced wall thickness zone, as considered above, may be formed along a section of the clot-catching element 82 to assist in inducing the inversion of the proximal end portion of the pipe 80. According to some implementations, each of the bends 85 includes a reduced wall thickness zone. In such examples, the reduced wall thickness zone may span the entire length of the bend, or less. In the latter case, the reduced wall thickness zone may be located within the central section, proximal end section, or distal end section of the bend.

[0059] Figure 12 depicts a Nitinol tube 90 that has been cut and laid flat on a surface. The tube 90 has a length L1 and includes a plurality of circumferentially spaced longitudinal slots 91 that are cut into the tube 90 and form a plurality of elongated blood clot-capturing elements 92 that extend continuously along the substantial length of the tube 90. According to some implementations, the blood clot-capturing elements have a length L2 that is greater than 50% of the length L1 of the slotted tube 90. According to other implementations, the blood clot-capturing elements have a length L2 that is greater than 70% of the length L1 of the slotted tube 90. The proximal end 88 of the slot 91 is spaced a certain distance from the proximal end 93 of the tube 90, and the distal end 89 of the slot 91 is spaced a certain distance from the distal end 94 of the tube 90, so as to form a proximal collar 22 and a distal collar 21, respectively.

[0060] In the embodiment of Figure 12, each of the slots 91 includes a flared portion 95 within each of the blood clot capturing elements 92, creating a reduced-width zone 96. On each side of the reduced-width zone 96, the blood clot capturing element 92 includes a proximal section 92a and a distal section 92b, the proximal section 92a and the distal section 92b having the same width W1 in the embodiment of Figure 12. In the embodiment of Figure 12, each of the reduced-width zones 96 has an area of ​​minimum width W2 located within its central section. According to some implementations, the width W2 is 5 to 25 percent smaller than the width W1.

[0061] According to some implementations, the proximal end section 92a and distal end section 92b of the blood clot capture element 92 have different widths, with the width of the distal end section 92b being greater than the width of the proximal end section 92b. According to some implementations, the width of one or both of the proximal section 92a and distal section 92b may vary along their lengths, with the proximal section having a maximum width dimension along its length, and the maximum width dimension of the distal section 92b being greater than the maximum width dimension of the proximal section 92a.

[0062] The slot 91, the clot-capturing element 92, and the reduced-width zone 96 are configured and arranged such that when a distal force DF is applied to the proximal collar 22 and / or a proximal force PF is applied to the distal collar 21, the tube 90 begins to bulge at or around the location of the reduced-width zone 96 to assist in the inversion of the clot-capturing element within the proximal end portion of the tube 90. According to other implementations, one or both of the first section 92a and the second section 92b of the clot-capturing element may not be aligned parallel to the longitudinal axis of the tube 90, but instead curve around the longitudinal axis of the tube 90 (e.g., aligned in a spiral pattern), as shown in Figures 15A to 17B below.

[0063] In the embodiment shown in Figure 12, the width of the flared portion varies linearly along the length of the flared portion as a result of the flared portion being bounded by inclined straight wall segments 98a, 98b, 98c, and 98d. According to other implementations, the flared portion is bounded by curved wall segments, resulting in a nonlinear variation in width along the length of the flared portion. In the implementation shown in Figure 12, the proximal wall segments 98a and 98c diverge distally from each other, while the distal wall segments 98b and 98d converge distally from each other. According to some implementations, the flared portion 95 of the slot 91 is shaped such that the resulting clot-catching element 92 exhibits an hourglass shape along a portion of its length, as shown in Figure 12.

[0064] According to some implementations, the reduced-width zone 96 of the blood clot capture element 92 is located closer to the proximal end 93 of the slotted tube 90 than to the distal end 94, as shown in Figure 12. According to other implementations, the reduced-width zone is located closer to the distal end 94 of the slotted tube 90 than to the proximal end 93.

[0065] Similar to the previously disclosed implementation example, during or after the inversion of the proximal end portion 92a of the blood clot capturing element 92 around the proximal collar 21, one or both of the distal collar 21 and the proximal collar 22 can be rotated relative to the other to cause the formation of a recovery device similar to that depicted in Figures 8C and 8D.

[0066] Alternatively, or in conjunction with the shaping method described above, the blood clot capturing element 92 can be constrained to these desired expanded resting states using specially designed fixtures. In either case, if the resulting recovery device is formed to assume its desired expanded resting state, a defined heat treatment for shaping the resulting blood clot recovery device to its expanded resting state follows the manufacturing process. According to some implementation examples, the length of the resulting recovery device in the expanded resting state is 50% to 70% of the length of the tube 90 before inversion.

[0067] Figures 13A and 13B illustrate variations of the slotted tube of Figure 12. Figures 13A and 13B show, respectively, slotted nitinol tubes 100 having a number of slots 101. Blood clot trapping elements 102 are interposed between the slots 101. Figure 13A shows the tube 100 in a cylindrical configuration. Figure 13B shows the slotted tube 100 as if it had been cut along its length and laid flat on a surface. Similar to the embodiment in Figure 12, one or more of the slots 101 have flared portions 105 along a portion of the length of the blood clot trapping elements 102, resulting in the formation of a reduced-width zone 106. The flared portions 105 in Figures 13A and 13B differ from the flared portions 96 in Figure 12 in both size and shape, being shorter in length and having a more rectangular shape.

[0068] Figures 14A and 14B show slotted nitinol tubes 120 used to construct a recovery device similar to those depicted in Figures 10D and 10E. Figure 14A shows the tube 120 in a cylindrical configuration. Figure 14B shows the tube 120 as if it had been cut along its length and laid flat on a surface. The tube 120 has a length L1 between its proximal end 130 and distal end 131.

[0069] The slotted pipe 120 includes a plurality of circumferentially spaced slots 121 that extend continuously over the substantial length of the pipe 120. According to some implementations, each of the slots 121 has a length L2 which is at least 50% of the length L1 of the pipe 120, and preferably a length L2 which is at least 70% of the length of the pipe 120. As shown in Figure 12, each of the length distances L1 and L2 is a straight-line distance running parallel to the longitudinal axis 129 of the pipe 120.

[0070] Each of the slots 121 includes a proximal segment 121a and a distal segment 121b, which are circumferentially offset from each other and joined together by a transverse passage 128 at their overlapping distal ends 123 and proximal ends 124. Adjacent circumferential slots 121 form a clot-catching element 122 between them, which includes a circumferentially offset proximal segment 122a and distal segment 122b of a first width W1, which are joined by a segment 127 of reduced width having a width W2 smaller than width W1. According to some implementations, width W2 is 5-50% of width W1, and according to other implementations, width W2 is 5-20% of width W1.

[0071] According to some implementation examples, the segment 127 with reduced width is located closer to the distal end 131 of the slotted tube 120 than to the proximal end 130.

[0072] The proximal end 123 of the slot 121 is separated by a certain distance from the proximal end 130 of the tube 120, and the distal end 126 of the slot 121 is separated by a certain distance from the distal end 131 of the tube 120, so as to form the proximal collar 22 and the distal collar 21, respectively.

[0073] As shown in Figure 14B, each of the blood clot-capturing elements 122 includes a zone 140 in which a segment 127 of reduced width coincides with the change in the trajectory of the blood clot-capturing element. As a result of the configuration of the blood clot-capturing elements, when the initial distal force DF is applied to the proximal collar 22 and / or when the initial proximal force PF is applied to the distal collar 21, the tube 120 begins to bulge in or around the location of zone 140.

[0074] As the distal force DF and / or proximal force PF continue to be applied to the tube 120, the clot-catching element 122 inversion occurs within the proximal end portion of the tube, similar to that shown in Figure 10D. If necessary, during or after the inversion, one or both of the distal collar 21 and the proximal collar 22 can be rotated relative to the other to cause the clot-catching element 122 to assume a desired arched configuration, such that adjacent arches preferably overlap each other, as shown in Figure 10E.

[0075] Alternatively, or in conjunction with the shaping method described above, the blood clot capturing element 122 can be constrained to these desired expanded resting states using specially designed fixtures. In either case, if the resulting recovery device is formed to assume its desired expanded resting state, a defined heat treatment for shaping the resulting blood clot recovery device to its expanded resting state follows the manufacturing process. According to some implementation examples, the length of the resulting recovery device in the expanded resting state is 50% to 70% of the length of the tube 120 before inversion.

[0076] Figures 15A and 15B illustrate a slotted tube 150 that can be used to fabricate a recovery device like the one depicted in Figures 10D and 10E. Figure 15A shows the slotted tube in a cylindrical configuration, and Figure 15B shows the tube 150 as if it had been cut along its length and laid flat on a surface. The tube has a length L1 between its proximal end 156 and distal end 157.

[0077] The tube 150 includes a plurality of circumferentially spaced slots 151, which form a plurality of circumferentially spaced clot-capturing elements 152 between them. The tube 150 includes a proximal end portion 150a and a distal end portion 150b, each having internally cut slots 151 between circumferentially adjacent slots for generating clot-capturing elements 152. In the proximal end portion 150a of the tube 150, the clot-capturing element includes a proximal end section 152a that curves, for example, in a spiral manner around the longitudinal axis 154 of the tube 150. In the distal end portion 150b of the tube 150, the clot-capturing element includes a distal end section 152b that is arranged substantially parallel to the longitudinal axis 154.

[0078] According to some implementations, the slot 151 includes a flared portion 155, which creates a reduced-width zone 153 within the clot-capturing element 152, joining the proximal section 152a and the distal section 152b. According to some implementations, the reduced-width zone 153 is arranged non-parallel to the longitudinal axis 154 of the tube 150 and also non-parallel to each of the proximal section 152a and distal section 152b of the clot-capturing element 152, as is most commonly seen in Figure 15B.

[0079] According to some implementation examples, the reduced-width zone 153 is located closer to the distal end 157 of the slotted tube 150 than to the proximal end 156.

[0080] According to several implementations, each of the helical proximal end section 152a and the straight distal end section 152b of the clot-capturing element 152 has the same first width W1, and the reduced width zone 153 has a second width W2 that is smaller than the first width W1. According to some implementations, the width W2 is 5-50% of the width W1, and according to other implementations, the width W2 is 5-20% of the width W1.

[0081] According to other implementations, the slot 151 is cut such that the proximal end section 152a and distal end section 152b of the clot capture element 152 have different widths, with the width W3 of the distal end section 152b being greater than the width W4 of the proximal end section 152a, as shown in Figure 15C. Providing a distal end section 152b with a larger width results in a smaller gap existing between the proximal end section 152a and the distal end section 152b when the resulting retrieval device is in an expanded / unfolded state. This is advantageous as it significantly prevents removed clot fragments from passing through the retrieval device during the clot retrieval procedure.

[0082] Continuing to refer to Figures 15A and 15B, slot 151 has a proximal end 151a, which is separated from the proximal end 156 of pipe 150 by a certain distance to form a proximal collar 22. Similarly, slot 151 has a distal end 151b, which is separated from the distal end 157 of pipe 150 by a certain distance to form a distal collar 21. Thus, the length distance L2 between the proximal end 151a and the distal end 151b of the slot is less than the length L1 of pipe 150. Each of the length distances L1 and L2 is a straight-line distance running parallel to the longitudinal axis 154 of pipe 150. According to some implementation examples, length L2 is at least 50% of length L1, and preferably at least 70% of length L1.

[0083] As disclosed above, according to some implementation examples, the clot-catching element 152 includes a reduced-width zone 153 that coincides with the change in the trajectory of the clot-catching element. Due to the configuration of such a clot-catching element, when the initial distal force DF is applied to the proximal collar 22 and / or when the initial proximal force PF is applied to the distal collar 21, the tube 150 begins to bulge in or around the reduced-width zone 153. Due to the helical nature of the proximal end section 152a of the clot-catching element 152, as the distal collar 21 and proximal collar 22 move closer to each other by applying proximal and / or distal forces, the proximal collar 22 rotates relative to the distal collar 21.

[0084] As the distal force DF and / or proximal force PF continue to be applied to the tube 150, the inversion of the blood clot-capturing elements 152 occurs at least within the proximal end portion 150a of the tube, as shown in Figure 10D, while at the same time, each of the blood clot-capturing elements 152 continues to bend, as shown in Figure 10E, to create arched elements such as those shown in Figure 10D, where adjacent arches preferably overlap each other.

[0085] Alternatively, or in conjunction with the shaping method described above, the blood clot capturing element 152 can be constrained to these desired expanded resting states using specially designed fixtures. In either case, if the resulting recovery device is formed to assume its desired expanded resting state, a defined heat treatment for shaping the resulting blood clot recovery device to its expanded resting state follows the manufacturing process. According to some implementation examples, the length of the resulting recovery device in the expanded resting state is 50% to 70% of the length of the tube 150 before inversion.

[0086] Figures 16A and 16B illustrate a slotted tube 160 that can be used to fabricate a recovery device like the one depicted in Figures 10D and 10E. Figure 16A shows the slotted tube in a cylindrical configuration, and Figure 16B shows the tube 160 as if it had been cut along its length and laid flat on a surface. The tube has a length L1 between its proximal end 166 and distal end 167.

[0087] The tube 160 includes a plurality of circumferentially spaced slots 161, the plurality of circumferentially spaced slots 161 forming a plurality of circumferentially spaced blood clot trapping elements 162 between them. The tube 160 includes a proximal end portion 160a and a distal end portion 160b, each of which has internally cut slots 161 between circumferentially adjacent slots for generating blood clot trapping elements 162. In the proximal end portion 160a of the tube 160, the blood clot trapping element 162 includes a proximal end section 162a that curves in a first direction (e.g., counterclockwise) around the longitudinal axis 164 of the tube 160, and a distal end section 162b that curves in a second direction (e.g., clockwise) opposite to the first direction around the longitudinal axis 164 of the tube 160.

[0088] According to some implementations, the slot 161 includes a flared portion 165, which creates a reduced-width zone 163 within the clot-capturing element 162, joining the proximal section 162a and the distal section 162b. According to some implementations, the reduced-width zone 163 is aligned parallel to the longitudinal axis 164 of the tube 160.

[0089] According to some implementation examples, the reduced-width zone 163 is located closer to the distal end 167 of the slotted tube 160 than to the proximal end 166.

[0090] According to some implementations, each of the proximal end section 162a and distal end section 162b of the blood clot capturing element 162 has the same first width W1, and the reduced width zone 163 has a second width W2 that is smaller than the first width W1. According to some implementations, the width W2 is 5-50% of the width W1, and according to other implementations, the width W2 is 5-20% of the width W1.

[0091] According to other implementations, the slot 161 is cut such that the proximal end section 162a and distal end section 162b of the clot capture element 162 have different widths, with the width of the distal end section 162b being greater than the width of the proximal end section 162a. Providing a distal end section 162b with a larger width results in a smaller gap between the proximal end section 162a and the distal end section 162b when the resulting retrieval device is in an expanded / unfolded state. This is advantageous as it significantly prevents removed clot fragments from passing through the retrieval device during the clot retrieval procedure.

[0092] Continuing to refer to Figures 16A and 16B, slot 161 has a proximal end 161a, which is separated from the proximal end 166 of pipe 160 by a certain distance to form the proximal collar 22. Similarly, slot 161 has a distal end 161b, which is separated from the distal end 167 of pipe 160 by a certain distance to form the distal collar 21. Thus, the length distance L2 between the proximal end 161a and the distal end 161b of the slot is less than the length L1 of pipe 160. Each of the length distances L1 and L2 is a straight-line distance running parallel to the longitudinal axis 164 of pipe 160. According to some implementation examples, length L2 is at least 50% of length L1, and preferably at least 70% of length L1.

[0093] As disclosed above, according to some implementation examples, the clot-catching element 162 includes a reduced-width zone 163 that coincides with the change in the trajectory of the clot-catching element. Due to the configuration of such a clot-catching element, when the first distal force DF is applied to the proximal collar 22 and / or when the first proximal force PF is applied to the distal collar 21, the tube 160 begins to bulge at or around the location of the reduced-width zone 163. Due to the curved nature of the proximal end section 162a of the clot-catching element 162, as the distal collar 22 and proximal collar 22 approach the distal collar 21 axially, one or both of the proximal collar 22 and distal collar 21 rotate relative to the other.

[0094] As the distal force DF and / or proximal force PF continue to be applied to the tube 160, the inversion of the blood clot-capturing elements 162 occurs at least within the proximal end portion 160a of the tube, as shown in Figure 10D, while at the same time, each of the blood clot-capturing elements 162 continues to bend to create arched elements, where adjacent arches preferably overlap each other.

[0095] Alternatively, or in conjunction with the shaping method described above, the blood clot capturing element 162 can be constrained to these desired expanded resting states using specially designed fixtures. In either case, if the resulting recovery device is formed to assume its desired expanded resting state, a defined heat treatment for shaping the resulting blood clot recovery device to its expanded resting state follows the manufacturing process. According to some implementation examples, the length of the resulting recovery device in the expanded resting state is 50% to 70% of the length of the tube 160 before inversion.

[0096] Figures 17A and 17B illustrate a slotted tube 170 that can be used to fabricate a recovery device like the one depicted in Figures 10D and 10E. Figure 17A shows the slotted tube in a cylindrical configuration, and Figure 17B shows the tube 170 as if it had been cut along its length and laid flat on a surface. The tube has a length L1 between its proximal end 176 and distal end 177.

[0097] The tube 170 includes a plurality of circumferentially spaced slots 171, which form a plurality of circumferentially spaced clot-capturing elements 172 between them. The tube 170 includes a proximal end portion 170a and a distal end portion 170b, each having internally cut slots 171 between circumferentially adjacent slots for generating clot-capturing elements 172. In the proximal end portion 170a of the tube 170, the clot-capturing element 172 includes a curved proximal end section 172a, as shown in Figure 17B, which has a single bend. In the distal end portion 170b of the tube 170, the clot-capturing element 172 includes a curved distal end section 172b, which has a plurality of bends, as also shown in Figure 17B.

[0098] According to some implementation examples, the slot 171 includes a flared portion 175, which creates a reduced-width zone 173 within the clot-capturing element 172, joining the proximal end section 172a and the distal end section 172b of the slot 172. According to some implementation examples, the reduced-width zone 173 is located closer to the distal end 177 of the slotted tube 170 than to the proximal end 176.

[0099] According to some implementations, each of the proximal end section 172a and distal end section 172b of the blood clot capture element 172 has the same first width W1, and the reduced width zone 173 has a second width W2 that is smaller than the first width W1. According to some implementations, the width W2 is 5-50% of the width W1, and according to other implementations, the width W2 is 5-20% of the width W1.

[0100] According to other implementations, the slot 171 is cut such that the proximal end section 172a and distal end section 172b of the clot capture element 172 have different widths, with the width of the distal end section 172b being greater than the width of the proximal end section 172a. Providing a distal end section 172b with a larger width results in a smaller gap between the proximal end section 172a and the distal end section 172b when the resulting retrieval device is in an expanded / unfolded state. This is advantageous as it significantly prevents removed clot fragments from passing through the retrieval device during the clot retrieval procedure.

[0101] Continuing to refer to Figures 17A and 17B, the slot 171 has a proximal end 171a, which is separated from the proximal end 176 of the tube 170 by a certain distance to form the proximal collar 22. Similarly, the slot 171 has a distal end 171b, which is separated from the distal end 177 of the tube 170 by a certain distance to form the distal collar 21. Thus, the length distance L2 between the proximal end 171a and the distal end 171b of the slot is less than the length L1 of the tube 170. As shown in Figure 17B, each of the length distances L1 and L2 is a straight-line distance running parallel to the longitudinal axis 174 of the tube 170. According to some implementations, the length L2 is at least 50% of the length L1, and preferably at least 70% of the length L1.

[0102] The reduced-width zone 163 within the clot-catching element 172 coincides with the change in the trajectory of the clot-catching element as a result of being located within the curved portion of the clot-catching element. Due to the configuration of the clot-catching element, when the initial distal force DF is applied to the proximal collar 22 and / or when the initial proximal force PF is applied to the distal collar 21, the tube 170 begins to bulge at or around the location of the reduced-width zone 173. Due to the curved nature of the proximal end section 172a of the clot-catching element 172, as the distal collar 21 and proximal collar 22 move closer to each other by applying a proximal force and / or distal force, one or both of the proximal collar 22 and distal collar 21 rotate relative to the other.

[0103] As the distal force DF and / or proximal force PF continue to be applied to the tube 170, the inversion of the blood clot capturing elements 172 occurs at least within the proximal end portion 170a of the tube, as shown in Figure 10D, while simultaneously, each of the blood clot capturing elements 172 continues to bend to create an arched element in which adjacent arches preferably overlap each other. Alternatively, or in conjunction with the shaping method described above, the blood clot capturing elements 172 can be constrained to these desired expanded resting states using specially designed fixtures. In either case, if the resulting recovery device is formed to assume its desired expanded resting state, a defined heat treatment for shaping the resulting blood clot recovery device to its expanded resting state follows the manufacturing process. According to some implementation examples, the length of the resulting recovery device in the expanded resting state is 50% to 75% of the length of the tube 170 before inversion.

[0104] Figures 18A and 18B illustrate a slotted tube 200 that can be used to fabricate a recovery device like the one depicted in Figures 10D and 10E. Figure 18A shows the slotted tube in a cylindrical configuration, and Figure 18B shows the tube 200 as if it had been cut along its length and laid flat on a surface. The tube has a length L1 between its proximal end 206 and distal end 207.

[0105] The tube 200 includes a plurality of circumferentially spaced slots 201, which form a plurality of circumferentially spaced clot-retaining elements 202 between them. The tube 200 includes a proximal end portion 200a and a distal end portion 200b, each having an internally cut slot 201 between circumferentially adjacent slots for generating clot-retaining elements 202. The slots 201 are cut such that the width of the slot 201 constantly changes along the length of the slot 201. As a result, the clot-retaining elements 202 arranged between the slots 201 also have a width that constantly changes along the length L2 of the slot 201.

[0106] In the implementation examples shown in Figures 18A and 18B, the clot-capturing element 202 includes a proximal end section 204 having a proximal end 204a and a distal end 204b. The clot-capturing element 202 also includes a distal end section 205 having a distal end 205b and a proximal end 205a that coincides with the distal end 204b of the proximal end section 204. Each of the distal end section 205 and the distal end section of the clot-capturing element is defined by curved wall segments 204c, 204d, and 205c, 205d, respectively. According to some implementation examples, the curved wall segments are shaped such that the location W1 of the maximum width of the proximal section 204 and the distal section 205 is located at each of the proximal ends 204a / b and distal ends 205a / b of the respective sections. According to some implementations, the curved wall segments are shaped to produce a single minimum width location W2 along the respective lengths of the proximal end section 204 and the distal end section 205. According to some implementations, the minimum width locations W2 of the proximal end section 204 and the distal end section 205 are equidistant from the respective proximal ends 204a, 204b and the distal ends 205a, 205b of the section.

[0107] According to some implementations, width W2 is 30-90% of width W1, while according to other implementations, width W2 is 25-80% of width W1.

[0108] According to some implementations, the distal end 204b of the proximal end section 204 of the blood clot-capturing element 202 merges with the proximal end 205a of the distal end section 205 at a point where it is located closer to the distal end 208 of the tube 200 than to the proximal end 207 of the tube. According to other implementations, the distal end 204b of the proximal end section 204 of the blood clot-capturing element 202 merges with the proximal end 205a of the distal end section 205 at a point where it is located equidistant from the proximal end 207 and the distal end 208 of the tube 200.

[0109] Continuing to refer to Figures 18A and 18B, slot 201 has a proximal end 201a, which is separated from the proximal end 207 of pipe 200 by a certain distance to form a proximal collar 22. Similarly, slot 201 has a distal end 201b, which is separated from the distal end 208 of pipe 200 by a certain distance to form a distal collar 21. Thus, the length distance L2 between the proximal end 201a and the distal end 201b of the slot is less than the length L1 of pipe 200. As shown in Figure 18B, each of the length distances L1 and L2 is a straight-line distance running parallel to the longitudinal axis 209 of pipe 200. According to some implementations, length L2 is at least 50% of length L1, and preferably at least 70% of length L1.

[0110] Similar to the implementation examples of slotted tubes disclosed above, the formation of a blood clot recovery device structurally similar to those depicted in Figures 10D and 10E can be achieved by applying a distal force DF to the proximal collar 21 and / or a proximal force PF to the distal collar 21 to induce inversion of at least the proximal end section 204 of the blood clot capture element 202. Alternatively, as disclosed above, during or after the inversion, one or both of the proximal collar 22 and the distal collar 21 can be rotated relative to each other to achieve the desired arched configuration of the blood clot capture element 202. Alternatively, or in conjunction with the shaping method described above, the blood clot capture element 202 can be constrained to these desired expanded resting states using specially designed fixtures. In any case, if the resulting recovery device is formed to assume its desired expanded resting state, a defined heat treatment for shaping the resulting blood clot recovery device to its expanded resting state follows the manufacturing process. According to several implementation examples, the length of the recovery device resulting from the extended resting state is 50% to 75% of the length of pipe 200 before inversion.

[0111] Figures 20A–20C illustrate a clot recovery assembly 300, which includes a distal clot recovery device 320 and a proximal clot recovery device 340 mounted on an elongated wire 310. During use, the recovery devices 320 and 340 are delivered to the site of occlusion while remaining radially constrained inside the delivery catheter 360, as shown in Figure 20C.

[0112] In some implementations, the distal retrieval device 320 includes a distal collar 321 stationary and fixed to an elongated wire 310, and a proximal collar 322 slidable on the elongated wire 310. Extending between the proximal and distal collars are multiple shape-memory elongated blood clot-capturing elements 323, configured to engage with the occlusion when the distal retrieval device 320 is in an expanded / unfolded state, as shown in Figures 20A and 20B. When the distal retrieval device 320 is in an expanded / unfolded state, the shape-memory elongated blood clot-capturing elements 323 take on a curved configuration, which may be similar to or different from those shown in Figures 20A and 20B.

[0113] In some implementations, the proximal retrieval device 340 includes a proximal collar 342 stationary and fixed to an elongated wire 310, and a distal collar 341 slidable on the elongated wire 310. Extending between the proximal collar 342 and the distal collar 341 are multiple shape-memory elongated clot-capturing elements 343, configured to engage with the occlusion when the proximal retrieval device 340 is in an expanded / deployed state, as shown in Figures 20A and 20B. When the proximal retrieval device 340 is in an expanded / deployed state, the shape-memory elongated clot-capturing elements 343 take on a curved configuration similar to, or different from, those shown in Figures 20A and 20B.

[0114] According to some implementations, each of the distal retrieval device 320 and the proximal retrieval device 340 is constructed from an assembly of independent parts, as shown in Figures 4A to 6. According to other implementations, each of the distal retrieval device 320 and the proximal retrieval device 340 is fabricated from a slotted tube, as discussed above in conjunction with Figures 8A to 18B.

[0115] The distal retrieval device 320, when deployed from the delivery catheter 360 and in an expanded state, includes a proximal inverted portion 324 and a distal non-inverted portion 325. The distal retrieval device 340, when deployed from the delivery catheter 360 and in an expanded state, includes a distal inverted portion 344 and a proximal non-inverted portion 345. As shown in Figure 20A, according to some implementations, the distal non-inverted portion 325 of the distal retrieval device 320 is equipped with a permeable cover 327 made of a biocompatible material. The purpose of the permeable cover 327 is to capture any fragments of the blood clot that may be removed during the blood clot retrieval process. According to some implementations, the biocompatible material is encapsulated polytetrafluoroethylene (ePTFE) with a thickness of 0.0008 to 0.016 inches.

[0116] According to several implementation examples, as shown in Figures 20A and 20B, when the distal retrieval device 320 is in its unrestrained extended resting state, the elongated shape-memory blood clot capturing elements 323 form multiple arch structures, as shown in Figures 7C and 8D, which are preferably adjacent arch structures but do not necessarily overlap each other, when viewed from the proximal end of the distal retrieval device 320.

[0117] According to several implementation examples, as shown in Figures 20A and 20B, when the proximal retrieval device 340 is in its unrestrained extended resting state, the elongated shape-memory blood clot capturing elements 343 form multiple arch structures, as shown in Figures 7C and 8D, which are preferably adjacent arch structures but do not necessarily overlap each other, when viewed from the distal end of the distal retrieval device 340.

[0118] Figure 20C is a side cross-sectional view of the distal end of the delivery catheter 360, showing the distal retrieval device 320 and the proximal retrieval device 340, which are radially constrained inside the delivery catheter. The distal retrieval device 320 functions like the retrieval device 20 discussed above in conjunction with the explanation in Figures 1A to 3, and transitions between a radially constrained state, an expansion rest state, and an expansion stress state. The proximal retrieval device 340 functions similarly to the distal retrieval device 320, but in the opposite way.

[0119] According to some implementation examples, one or both of the distal color 321 and proximal color 322 of the distal retrieval device 320, and / or one or both of the distal color 341 and proximal color 342 of the proximal retrieval device 340, are made of or coated with radiopaque material, so that the location of the color can be observed by fluorescence fluoroscopy.

[0120] During use, the distal end of the delivery catheter 360 is delivered distal to the site of the blood clot via a guidewire, as shown in Figure 19A. With the delivery catheter in place, as shown in Figure 20C, the retrieval devices 320 and 340 are loaded onto the delivery catheter 360, constrained in their radial directions. Subsequently, the distal and proximal retrieval devices are deployed distal to the blood clot by either withdrawing the delivery catheter proximally while fixing and holding the elongated wire 10, or by fixing and holding the delivery catheter 30 while advancing the elongated wire 10 distally.

[0121] When deployed inside the patient's passage, the arched structures of the retrieval devices 320 and 340 are pressed against the arterial wall of the blood vessel. After the retrieval devices 320 and 340 are deployed, the retrieval devices pull the elongated wire 310 to which they are attached proximal, first engaging the proximal retrieval device 340 with the blood clot and trapping at least a portion of the clot between the clot-capturing elements 343. After at least a portion of the blood clot is trapped within the proximal retrieval device 340, the elongated wire 310 advances further proximal, engaging the distal retrieval device 320 with any remaining portion of the blood clot. In some implementations, the clot-capturing element 323 of the distal retrieval device 320 is configured to sweep along the arterial wall to which the blood clot is attached, moving the blood clot or the remainder of the clot towards the center of the affected blood vessel.

[0122] In some implementations, the distal collar 341 of the proximal retrieval device 340 and the proximal collar 322 of the distal retrieval device 320 move distally along the elongated wire 310 as the retrieval device is pulled proximal to the blood clot. In some implementations, the proximal retrieval device 340 can be positioned proximal to the blood clot and pressed against or pushed into the blood clot during the clot removal process. In such examples, its distal collar 341 moves proximal along the elongated wire 310 as the retrieval device is pushed distally into the blood clot. As discussed above, the movement of the collar along the elongated wire during the clot capture process puts stress on the clot capture element, enhancing the collar's ability to contain the blood clot.

[0123] When capturing the blood clot with one or both of the recovery devices 320 and 340, the removal of the blood clot can be achieved at least partially by pulling the elongated wire 10 proximal to move the blood clot into the mouth of the aspiration catheter or into the delivery catheter 360.

[0124] Figure 21 shows a blood clot capture assembly including a distal retrieval device 320 and a proximal retrieval device 340, which may be fabricated by any of several methods, including the method disclosed above. The blood clot capture assembly differs from the assemblies in Figures 20A–20C in that the proximal retrieval device 340 is axially movable along the length of the elongated wire 310, and as a result, the distance separating the proximal retrieval device 340 from the distal retrieval device 320 can vary. In all other respects, the distal and proximal retrieval devices function as described above.

[0125] Similar to the implementation examples in Figures 20A to 20C, the distal retrieval device 320 is mounted on an elongated wire 310, with the distal collar 321 of the distal retrieval device 320 being stationary and fixed to the elongated wire, and the proximal collar 322 being slidable on the elongated wire. On the other hand, both the distal collar 341 and proximal collar 342 of the proximal retrieval device 340 are slidable on the elongated wire 310, and the proximal collar 342 is fixed to the distal end 371 of an elongated hypo tube 370 through which the elongated wire 310 passes. The proximal end portion of the hypo tube 370 is attached to a sliding tab 381 located inside the user handle 380. The user handle 380 is configured such that when the handle is grasped by the user, the user's thumb can act on the sliding tab 381 to move the tab forward F or backward R. With the elongated wire 310 stationary, moving the tab 381 forward in direction F causes the hypo tube 370 to advance distally, moving the proximal recovery device 340 distally along the elongated wire 310 closer to the distal recovery device 320. Conversely, moving the tab 381 backward in direction R causes the hypo tube 370 to advance proximal, moving the proximal recovery device 340 proximally along the elongated wire 310 away from the distal recovery device 320.

[0126] The retrieval devices 320 and 340 are typically delivered to the site of the blood clot through a previously positioned delivery catheter 360. Figure 22 shows a side view, and Figure 23 shows a cross-sectional side view of the retrieval devices 320 and 340 radially constrained inside the lumen of the delivery catheter 360. As shown in Figure 21, when the sliding tab 381 of the user handle 380 is in the center position, the distal retrieval device 320 and the proximal retrieval device 340 are separated by a distance D inside the lumen of the delivery catheter 360. Before deploying one or both of the retrieval devices 320 and 340 from the delivery catheter 360, the user can increase or decrease the distance D between the retrieval devices by moving the sliding tab 381 backward R or forward F, respectively. Once the proximal retrieval device 340 is positioned in the desired location relative to the distal retrieval device 320, the sliding tab 381 locks into place to prevent any axial movement of the hypotubule 370. Subsequently, the distal retrieval device 320 is deployed outside the delivery catheter 360, as shown in Figure 24, and in some examples, the proximal retrieval device 340 is deployed outside the delivery catheter, as shown in Figure 25A. One or both of the retrieval devices 320 and 340 may be deployed from the distal end of the delivery catheter 360 by either pulling the delivery catheter proximally while fixing and holding the elongated wire 310, or by fixing and holding the delivery catheter while advancing the elongated wire 310 distally.

[0127] Figure 25A shows the distal retrieval device 320 and proximal retrieval device 340 deployed outside the delivery catheter 360, separated by a first distance D1. Figure 25B shows the distal retrieval device 320 and proximal retrieval device 340 deployed outside the delivery catheter 360, separated by a second distance D2, which is less than the first distance.

[0128] According to several implementation examples, the hypo tube 170 has a length of approximately 180 centimeters and an inner diameter of approximately 0.010 to 0.016 inches.

[0129] The following provisions in groups A through E disclose additional implementation examples in an unrestricted manner.

[0130] Group A clauses: Clause 1. Blood clot recovery assembly, A long, slender wire having length and a longitudinal axis, The system comprises a first recovery device, and the first recovery device is A distal collar fixed and stationary on a long, thin wire. A proximal collar that is slidable along a portion of the length of a long, slender wire, and It comprises multiple elongated shape-memory blood clot-capturing elements, each of which has a proximal end connected to a proximal collar and a distal end connected to a distal collar, and each of which has a proximal end portion and a distal end portion. A blood clot recovery assembly comprising a first recovery device configured to automatically transition from a radially constrained state to an expanded rest state, wherein in the radially constrained state, none of the multiple elongated shape-memory clot-capturing elements are located proximal to the proximal collar, the proximal collar is located at a first axial position on an elongated wire proximal to the distal collar and separated from the distal collar by a first distance, and in the expanded rest state, the proximal collar is located at a second axial position on an elongated wire proximal to the distal collar and separated from the distal collar by a second distance less than the first distance, at least some of the proximal portions of the multiple elongated shape-memory clot-capturing elements are inverted around the proximal collar, and at least some of the proximal portions of the multiple elongated shape-memory clot-capturing elements are positioned proximal to the proximal collar.

[0131] Clause 2. The blood clot recovery assembly according to Clause 1, wherein when the first recovery device is in an extended resting state, the proximal collar is movable distally to a third axial position on an elongated wire proximal to the distal collar, and is separated from the distal collar by a third distance less than a second distance.

[0132] Clause 3. The blood clot recovery assembly according to Clause 2, wherein the first recovery device is in an expanded stress state when the proximal collar of the first recovery device is at a third axial position on the elongated wire.

[0133] Clause 4. The blood clot recovery assembly according to Clause 1, wherein when the first recovery device is radially constrained, none of the portions of each of the multiple shape-memory elongated blood clot capturing elements are folded back.

[0134] Clause 5. A blood clot recovery assembly as described in any one of the preceding clauses, wherein the second length is 30% to 60% of the first length.

[0135] Clause 6. A blood clot recovery assembly according to any one of the preceding clauses, wherein, when the first recovery device is in an extended resting state, at least some of a plurality of elongated shape-memory blood clot capturing elements exhibit a zigzag path from a proximal collar to a distal collar, with a first portion of the path extending proximal and a second portion of the path extending distally.

[0136] Clause 7. A blood clot recovery assembly according to any one of the preceding clauses, wherein when the first recovery device is in an extended resting state, the first recovery device includes a proximal inverted portion in which a shape-memory elongated blood clot capturing element is inverted around a proximal collar, and a distal non-inverted portion, the distal non-inverted portion comprising the distal end portion of the shape-memory elongated blood clot capturing element.

[0137] Clause 8. The blood clot recovery assembly according to Clause 2, wherein when the proximal collar is in a second axial position, one or more of the elongated shape-memory blood clot capturing elements have a first stiffness, and when the proximal collar is in a third axial position, one or more elongated shape-memory blood clot capturing elements have a second stiffness greater than the first stiffness.

[0138] Clause 9. The blood clot recovery assembly according to Clause 7, wherein the distal non-inverting portion of the first recovery device includes a permeable cover.

[0139] Clause 10. A blood clot recovery assembly according to any one of the preceding clauses, wherein each of a plurality of elongated shape-memory blood clot-catching elements has a proximal end and a distal end, the proximal end and distal end being attached to a proximal collar and a distal collar, respectively, by adhesive.

[0140] Clause 11. A blood clot recovery assembly according to any one of the preceding clauses, wherein each of a plurality of elongated shape-memory blood clot capturing elements has a proximal end and a distal end, the proximal end and distal end being attached to a proximal collar and a distal collar, respectively, by solder.

[0141] Clause 12. A blood clot recovery assembly according to any one of the preceding clauses, wherein each of a plurality of elongated shape-memory blood clot-catching elements has a proximal end and a distal end, the proximal end and the distal end are welded to a proximal collar and a distal collar, respectively.

[0142] Clause 13. A blood clot recovery assembly according to any one of the preceding clauses, wherein multiple elongated shape-memory blood clot capturing elements, as well as a proximal collar and a distal collar, are formed from a single piece of material.

[0143] Clause 14. A blood clot recovery assembly as described in any one of the preceding clauses, wherein the distal collar has a non-invasive distal tip.

[0144] Article 15. The system further comprises a second recovery device located on an elongated wire distal to the first recovery device, the second recovery device being A distal collar fixed and stationary on a long, thin wire. A proximal collar that is slidable along a portion of the length of a long, slender wire, and It comprises multiple elongated shape-memory blood clot capturing elements, each of which has a proximal end connected to a proximal collar of a second recovery device and a distal end connected to a distal collar of a second recovery device, and each of which has a proximal end portion and a distal end portion. The blood clot recovery assembly according to any one of the preceding clauses, wherein the second recovery device is configured to transition from a radially constrained state to an extended resting state, in the radially constrained state, the proximal collar of the second recovery device is located at a first axial position on an elongated wire proximal to the distal collar of the second recovery device and is separated from the distal collar of the second recovery device by a first distance, and in the extended resting state, the proximal collar of the second recovery device is located at a second axial position on an elongated wire proximal to the distal collar of the second recovery device and is separated from the distal collar of the second recovery device by a second distance less than the first distance.

[0145] Clause 16. The blood clot recovery assembly according to Clause 15, wherein when the second recovery device is radially constrained, none of the multiple elongated shape-memory blood clot capturing elements are located proximal to the proximal collar, and when the second recovery device is radially extended, at least some of the proximal portions of the multiple elongated shape-memory blood clot capturing elements are inverted around the proximal collar, and at least some of the proximal portions of the multiple elongated shape-memory blood clot capturing elements are positioned proximal to the proximal collar.

[0146] Clause 17. The blood clot recovery assembly according to Clauses 15 and 16, wherein when the second recovery device is in an extended resting state, the proximal collar is movable distally to a third axial position on an elongated wire proximal to the distal collar, and is separated from the distal collar by a third distance less than the second distance.

[0147] Article 18. The system further comprises a second recovery device located on an elongated wire near the first recovery device, wherein the second recovery device is A proximal collar fixed and stationary on a long, thin wire. A distal collar that is slidable along a portion of the length of a long, slender wire, and It comprises multiple elongated shape-memory blood clot capturing elements, each of which has a proximal end connected to a proximal collar of a second recovery device and a distal end connected to a distal collar of a second recovery device, and each of which has a proximal end portion and a distal end portion. The blood clot recovery assembly according to Clause 1, wherein the second recovery device is configured to transition from a radially constrained state to an expanded resting state, in the radially constrained state, the distal collar of the second recovery device is located at a first axial position on an elongated wire proximal to the proximal collar of the second recovery device and is separated from the proximal collar of the second recovery device by a first distance, and in the expanded resting state, the distal collar of the second recovery device is located at a second axial position on an elongated wire distal to the proximal collar of the second recovery device and is separated from the proximal collar of the second recovery device by a second distance less than the first distance.

[0148] Clause 19. The blood clot recovery assembly according to Clause 18, wherein when the second recovery device is radially constrained, none of the multiple elongated shape-memory blood clot capturing elements are located distal to the distal collar, and when the second recovery device is in an extended resting state, at least some of the distal portions of the multiple elongated shape-memory blood clot capturing elements are inverted around the distal collar, and at least some of the distal portions of the multiple elongated shape-memory blood clot capturing elements are positioned distal to the distal collar.

[0149] Group B clauses: Clause 1. Blood clot recovery assembly, A long, slender wire having length and a longitudinal axis, The system comprises a first recovery device, and the first recovery device is A distal collar fixed and stationary on a long, thin wire. A proximal collar that is slidable along a portion of the length of a long, slender wire, and It comprises multiple elongated shape-memory blood clot-capturing elements, each of which has a proximal end connected to a proximal collar and a distal end connected to a distal collar. A blood clot recovery assembly comprising a first recovery device configured to transition from a radially constrained state to an expanded rest state, and from the expanded rest state to an expanded stress state, wherein in the radially constrained state, the proximal collar is located at a first axial position on an elongated wire proximal to the distal collar and is separated from the distal collar by a first distance, in the expanded rest state, the proximal collar is located at a second axial position on an elongated wire proximal to the distal collar and is separated from the distal collar by a second distance less than the first distance, and in the expanded stress state, the proximal collar is located at a third axial position on an elongated wire proximal to the distal collar and is separated from the distal collar by a third distance less than the second distance.

[0150] Clause 2. The blood clot recovery assembly according to Clause 1, wherein when the first recovery device is radially constrained, none of the portions of each of the multiple shape-memory elongated blood clot capturing elements are folded back.

[0151] Clause 3. The blood clot recovery assembly according to Clause 1, wherein when the first recovery device is radially constrained, none of the multiple elongated shape-memory blood clot capturing elements are located proximal to the proximal collar.

[0152] Clause 4. A blood clot recovery assembly as described in any one of the preceding clauses, wherein the second length is 30% to 60% of the first length.

[0153] Clause 5. A blood clot recovery assembly according to any one of the preceding clauses, wherein, when the first recovery device is in an extended resting state, at least a portion of several elongated blood clot capturing elements of a plurality of shape memory elements extends proximal to the proximal collar.

[0154] Clause 6. A blood clot recovery assembly according to any one of the preceding clauses, wherein, when the first recovery device is in an extended resting state, at least some of a plurality of elongated shape-memory blood clot capturing elements form a path from a proximal collar to a distal collar, with a first portion of the path extending proximal and a second portion of the path extending distally.

[0155] Clause 7. The blood clot recovery assembly according to Clause 1, wherein when the first recovery device is in an extended resting state, the first recovery device includes a proximal inverted portion and a distal non-inverted portion, wherein the proximal inverted portion is composed of the proximal end portion of a shape-memory elongated blood clot capturing element, and the distal non-inverted portion is composed of the distal end portion of a shape-memory elongated blood clot capturing element.

[0156] Clause 8. The blood clot recovery assembly described in Clause 7, wherein there is no proximal inversion portion when the first recovery device is in a radially constrained state.

[0157] Clause 9. A blood clot recovery assembly according to any one of the preceding clauses, wherein when the proximal collar is in a second axial position, one or more elongated shape-memory blood clot-retaining elements have a first stiffness, and when the proximal collar is in a third axial position, one or more elongated shape-memory blood clot-retaining elements have a second stiffness greater than the first stiffness.

[0158] Clause 10. The blood clot recovery assembly according to Clause 7, wherein the distal non-inverting portion of the first recovery device includes a permeable cover.

[0159] Clause 11. A blood clot recovery assembly according to any one of the preceding clauses, wherein each of a plurality of elongated shape-memory blood clot-catching elements has a proximal end and a distal end, the proximal end and distal end being attached to a proximal collar and a distal collar, respectively, by adhesive.

[0160] Clause 12. A blood clot recovery assembly according to any one of the preceding clauses, wherein each of a plurality of elongated shape-memory blood clot capturing elements has a proximal end and a distal end, the proximal end and distal end being attached to a proximal collar and a distal collar, respectively, by solder.

[0161] Clause 13. A blood clot recovery assembly according to any one of the preceding clauses, wherein each of a plurality of elongated shape-memory blood clot-catching elements has a proximal end and a distal end, the proximal end and distal end being welded to a proximal collar and a distal collar, respectively.

[0162] Clause 14. A blood clot recovery assembly according to any one of the preceding clauses, wherein multiple elongated shape-memory blood clot capturing elements, as well as a proximal collar and a distal collar, are formed from a single piece of material.

[0163] Clause 15. A blood clot recovery assembly as described in any one of the preceding clauses, wherein the distal collar has a non-invasive distal tip.

[0164] Article 16. The system further comprises a second recovery device located on an elongated wire distal to the first recovery device, the second recovery device being A distal collar fixed and stationary on a long, thin wire. A proximal collar that is slidable along a portion of the length of a long, slender wire, and It comprises multiple elongated shape-memory blood clot capturing elements, each of which has a proximal end connected to a proximal collar of a second recovery device and a distal end connected to a distal collar of a second recovery device. The blood clot recovery assembly according to Clause 1, wherein the second recovery device is configured to transition from a radially constrained state to an expanded resting state, in the radially constrained state, the proximal collar of the second recovery device is located at a first axial position on an elongated wire proximal to the distal collar of the second recovery device and is separated from the distal collar of the second recovery device by a first distance, and in the expanded resting state, the proximal collar of the second recovery device is located at a second axial position on an elongated wire proximal to the distal collar of the second recovery device and is separated from the distal collar of the second recovery device by a second distance less than the first distance.

[0165] Clause 17. The blood clot recovery assembly according to Clause 16, wherein when the second recovery device is in an extended resting state, the proximal collar is movable distally to a third axial position on an elongated wire proximal to the distal collar, and is separated from the distal collar by a third distance less than the second distance.

[0166] Article 18. The system further comprises a second recovery device located on an elongated wire near the first recovery device, wherein the second recovery device is A proximal collar fixed and stationary on a long, thin wire. A distal collar that is slidable along a portion of the length of a long, slender wire, and It comprises multiple elongated shape-memory blood clot capturing elements, each of which has a proximal end connected to a proximal collar of a second recovery device and a distal end connected to a distal collar of a second recovery device. The blood clot recovery assembly according to Clause 1, wherein the second recovery device is configured to transition from a radially constrained state to an expanded resting state, in the radially constrained state, the distal collar of the second recovery device is located at a first axial position on an elongated wire proximal to the proximal collar of the second recovery device and is separated from the proximal collar of the second recovery device by a first distance, and in the expanded resting state, the distal collar of the second recovery device is located at a second axial position on an elongated wire distal to the proximal collar of the second recovery device and is separated from the proximal collar of the second recovery device by a second distance less than the first distance.

[0167] Group C clauses: Clause 1. A method for preparing a blood clot recovery assembly, wherein the method is The objective is to obtain a first collar having a proximal end, a distal end, a central longitudinal through-opening extending between the proximal and distal ends and through the proximal and distal ends, and a plurality of longitudinal channels located within the proximal end around the central longitudinal through-opening, wherein the central longitudinal through-opening has a central axis. The objective is to obtain a second collar having a proximal end, a distal end, a central through-opening extending between the proximal and distal ends of the second collar and through the proximal and distal ends, and a plurality of channels located within the distal end of the second collar around the central through-opening of the second collar, wherein the central longitudinal through-opening of the second collar has a central axis. The objective is to obtain multiple elongated elements, each of which has a proximal end, a distal end, and a length. The first end of each of the multiple elongated elements is fixed inside one of the multiple channels within the first color, The second end of each of the multiple elongated elements is fixed inside one of each of the multiple channels in the second color, Aligning the central axes of the central through-openings of the first and second collars in the axial direction, After axially aligning the central axes of the central through-openings of the first and second collars, one or both of the first and second collars are moved axially toward the other by applying an axial force to one or both of the first and second collars so that multiple elongated elements are inverted around the second collar. Shaping multiple elongated elements while inverting them around a second color, A method comprising mounting the proximal and distal collars onto the distal end portion of an elongated wire, such that the distal collar is stationary and fixed on the elongated wire, and the proximal collar is slidable on the elongated wire.

[0168] Clause 2. The method according to Clause 1, further comprising rotating one or both of the first and second colors relative to the other while inverting a plurality of elongated elements around a second color.

[0169] Clause 3. The method according to Clause 1, further comprising rotating one or both of the first and second colors relative to the other after a plurality of elongated elements have been inverted around a second color.

[0170] Clause 4. The method of any one of the preceding clauses, wherein one or both of the first color and the second color are made of a radiopaque material.

[0171] Clause 5. The method according to any one of the preceding clauses, wherein one or both of the first color and the second color are coated with a radiopaque material.

[0172] Clause 6. The method described in any one of the preceding clauses, wherein multiple elongated elements are made of nitinol.

[0173] Clause 7. The method of any one of the preceding Clauses, further comprising attaching a permeable cover to one or more of a plurality of elongated elements, wherein the permeable cover extends circumferentially around a portion of the plurality of elongated elements.

[0174] Clause 8. The method of any one of the preceding clauses, further comprising shaping multiple elongated elements by using a fastener before shaping the multiple elongated elements.

[0175] Clause 9. The method described in any one of the preceding clauses, wherein multiple elongated elements include a wire.

[0176] Clause 10. The method described in any one of the preceding clauses, in which multiple elongated elements include a ribbon.

[0177] Clause 11. The method according to Clause 9, wherein some of the wires have a first diameter and some of the wires have a second diameter smaller than the first diameter.

[0178] Clause 12. The method according to Clause 10, wherein some of the ribbons have a first width and some of the elongated elements have a second width smaller than the first width.

[0179] Clause 13. The method described in any one of the preceding clauses, wherein the first collar has a non-invasive tip.

[0180] Clause 14. The method according to any one of the preceding clauses, wherein the first collar has a non-invasive tip and the second collar has a non-invasive tip.

[0181] Clause 15. The method of any one of the preceding clauses, further comprising radially restraining the recovery device inside the sheath.

[0182] Clause 16. The method according to Clause 15, wherein the recovery device is radially constrained inside the sheath, so that no portion of the elongated blood clot capturing element of shape memory is located proximal to the proximal collar.

[0183] Group D clauses: Article 1. A method for preparing a blood clot recovery device, wherein the method is The objective is to obtain a cylindrical tube, wherein the cylindrical tube has a proximal end, a distal end, a length, and a central longitudinal axis, the tube has a plurality of circumferentially spaced continuous elongated slots, each of the plurality of circumferentially spaced continuous elongated slots extending along a portion of the length of the tube, and between each adjacent set of spaced elongated slots are elongated blood clot capturing elements, each of the elongated slots has a proximal end and a distal end, the proximal end and distal end being spaced apart from the proximal and distal ends of the tube, the tube includes a proximal collar disposed between the proximal end of the elongated slot and the proximal end of the tube, the tube includes a distal collar disposed between the distal end of the elongated slot and the distal end of the tube, and each of the elongated blood clot capturing elements has a proximal end portion and a distal end portion. By applying a force directed distally to the proximal collar and / or distal collar, at least some of the proximal portions of the elongated blood clot-capturing elements are inverted around the proximal collar, A method that includes shaping multiple elongated elements while inverting them around a proximal color.

[0184] Clause 2. The method according to Clause 1, further comprising rotating one or both of the proximal and distal colors relative to the other while inverting a plurality of elongated elements around a second color.

[0185] Clause 3. The method according to Clause 1, further comprising inverting a plurality of elongated elements around a second color, and then rotating one or both of the proximal and distal colors relative to the other.

[0186] Clause 4. The method according to any one of the preceding clauses, wherein one or both of the proximal and distal collars are coated with a radiopaque material.

[0187] Clause 5. The method described in any one of the preceding clauses, wherein the tube is made of nitinol.

[0188] Clause 6. The method according to any one of the preceding Clauses, further comprising attaching a permeable cover to one or more of the blood clot-capturing elements, wherein the permeable cover extends circumferentially around the distal end portion of the elongated blood clot-capturing element.

[0189] Clause 7. The method of any one of the preceding clauses, further comprising shaping multiple elongated blood clot-catching elements by using a fixing device before shaping the elongated blood clot-catching elements.

[0190] Clause 8. The method of any one of the preceding clauses, wherein each elongated blood clot-capturing element includes an area of ​​reduced thickness.

[0191] Clause 9. The method according to Clause 8, wherein the area of ​​reduced thickness is configured to cause the first indentation of the elongated blood clot-catching element in the area of ​​reduced thickness when a distal force is applied to the proximal collar and / or when a proximal force is applied to the distal collar.

[0192] Clause 10. The method according to any one of the preceding clauses, wherein the proximal end portion of the elongated blood clot-capturing element has a first width, and the distal end portion of the elongated blood clot-capturing element has a second width different from the first width.

[0193] Clause 11. The method according to Clause 10, wherein the second width is greater than the first width.

[0194] Clause 12. The method according to any one of the preceding clauses, wherein the proximal end portion of an elongated blood clot-catching element is curved about the longitudinal axis of the tube before a distal force is applied to the proximal collar and / or before a proximal force is applied to the distal collar.

[0195] Clause 13. The method according to any one of the preceding clauses, wherein the proximal ends of the elongated blood clot-capturing elements are arranged spirally with respect to the longitudinal axis of the tube.

[0196] Clause 14. The method according to any one of the preceding clauses, wherein the distal end portion of the elongated blood clot-capturing element is straight.

[0197] Clause 15. The method according to Clause 14, wherein the straight distal end portions of the elongated blood clot-capturing elements are arranged parallel to the longitudinal axis of the tube.

[0198] Clause 16. The method according to Clause 12, wherein the distal end portion of the elongated blood clot-capturing element is curved.

[0199] Clause 17. The method according to Clause 12, wherein the proximal end portion of the elongated trapping element has a first length, and the distal end portion of the elongated trapping element has a second length shorter than the first length.

[0200] Clause 18. The method according to Clause 1, wherein each of the elongated blood clot-capturing elements includes an area of ​​reduced width.

[0201] Clause 19. The method according to Clause 18, wherein the area of ​​reduced width is configured to cause the first indentation of the elongated blood clot-catching element in the area of ​​reduced width when a distal force is applied to the proximal collar and / or when a proximal force is applied to the distal collar.

[0202] Clause 20. The method according to Clause 1, wherein the elongated blood clot-capturing element includes an intermediate portion located between a proximal end portion and a distal end portion, the proximal and distal ends of the elongated capture element being arranged offset from each other in the circumferential direction and joined by the intermediate portion.

[0203] Clause 21. The method according to Clause 1, wherein, before a distal force is applied to the proximal collar and / or before a proximal force is applied to the distal collar, each of the circumferentially spaced continuous elongated slots has a length of 70% or more of the length of the cylindrical tube.

[0204] Group E clauses: Article 1. A method for preparing a blood clot recovery device, wherein the method is The objective is to obtain a cylindrical tube, wherein the cylindrical tube has a proximal end, a distal end, a length, and a central longitudinal axis, the tube has a plurality of circumferentially spaced continuous elongated slots, each of the plurality of circumferentially spaced continuous elongated slots extending along a portion of the length of the tube, and between each adjacent set of spaced elongated slots are elongated blood clot capturing elements, each of the elongated slots has a proximal end and a distal end, the proximal end and distal end being spaced apart from the proximal and distal ends of the tube, the tube includes a proximal collar disposed between the proximal end of the elongated slot and the proximal end of the tube, the tube includes a distal collar disposed between the distal end of the elongated slot and the distal end of the tube, and each of the elongated blood clot capturing elements has a proximal end portion and a distal end portion. By applying a force directed distally to the proximal collar and / or distal collar, at least some of the proximal portions of the elongated blood clot-capturing elements are inverted around the proximal collar, While inverting multiple elongated elements around a proximal color, shaping multiple elongated elements, A method comprising mounting the proximal and distal collars onto the distal end portion of an elongated wire, such that the distal collar is stationary and fixed on the elongated wire, and the proximal collar is slidable on the elongated wire.

[0205] Clause 2. The method according to Clause 1, further comprising rotating one or both of the proximal and distal collars relative to the other while inverting a plurality of elongated blood clot-capturing elements around a second collar.

[0206] Clause 3. The method according to Clause 1, further comprising rotating one or both of the proximal and distal collars relative to the other while inverting a plurality of elongated blood clot-capturing elements around a second collar and before shaping the plurality of elongated blood clot-capturing elements.

[0207] Clause 4. The method according to any one of the preceding clauses, wherein one or both of the proximal and distal collars are coated with a radiopaque material.

[0208] Clause 5. The method described in any one of the preceding clauses, wherein the tube is made of nitinol.

[0209] Clause 6. The method according to any one of the preceding Clauses, further comprising attaching a permeable cover to one or more elongated blood clot-capturing elements, wherein the permeable cover extends circumferentially around the distal end portion of the elongated blood clot-capturing elements.

[0210] Clause 7. The method of any one of the preceding clauses, further comprising shaping multiple elongated blood clot-catching elements by using a fixing device before shaping the elongated blood clot-catching elements.

[0211] Clause 8. The method of any one of the preceding clauses, wherein each elongated blood clot-capturing element includes an area of ​​reduced thickness.

[0212] Clause 9. The method according to Clause 8, wherein the area of ​​reduced thickness is configured to cause the first indentation of the elongated blood clot-catching element in the area of ​​reduced thickness when a distal force is applied to the proximal collar and / or when a proximal force is applied to the distal collar.

[0213] Clause 10. The method according to Clause 1, wherein the proximal end portion of the elongated blood clot-capturing element has a first width, and the distal end portion of the elongated blood clot-capturing element has a second width different from the first width.

[0214] Clause 11. The method according to Clause 10, wherein the second width is greater than the first width.

[0215] Clause 12. The method according to any one of the preceding clauses, wherein the proximal end portion of an elongated blood clot-catching element is curved about the longitudinal axis of the tube before a distal force is applied to the proximal collar and / or before a proximal force is applied to the distal collar.

[0216] Clause 13. The method according to any one of the preceding clauses, wherein the proximal ends of the elongated blood clot-capturing elements are arranged spirally with respect to the longitudinal axis of the tube.

[0217] Clause 14. The method according to Clause 12, wherein the distal end portion of the elongated blood clot-capturing element is straight.

[0218] Clause 15. The method according to Clause 14, wherein the straight distal end portions of the elongated blood clot-capturing elements are arranged parallel to the longitudinal axis of the tube.

[0219] Clause 16. The method according to Clause 12, wherein the distal end portion of the elongated blood clot-capturing element is curved.

[0220] Clause 17. The method according to Clause 12, wherein the proximal end portion of the elongated trapping element has a first length, and the distal end portion of the elongated trapping element has a second length shorter than the first length.

[0221] Clause 18. The method described in any one of the preceding clauses, wherein each elongated blood clot-capturing element includes an area of ​​reduced width.

[0222] Clause 19. The method according to Clause 18, wherein the area of ​​reduced width is configured to cause the first indentation of the elongated blood clot-catching element in the area of ​​reduced width when a distal force is applied to the proximal collar and / or when a proximal force is applied to the distal collar.

[0223] Clause 20. The method according to Clause 1, wherein the elongated blood clot-capturing element includes an intermediate portion located between a proximal end portion and a distal end portion, the proximal and distal ends of the elongated capture element being arranged offset from each other in the circumferential direction and joined by the intermediate portion.

[0224] Clause 21. The method according to Clause 1, wherein, before a distal force is applied to the proximal collar and / or before a proximal force is applied to the distal collar, each of the circumferentially spaced continuous elongated slots has a length of 70% or more of the length of the cylindrical tube.

Claims

1. A device for collecting blood clots from a patient's body conduits: A slender wire having a longitudinal axis, a proximal end portion that is located outside the patient's body conduit while retrieving the blood clot from the body conduit, and a distal end portion that is located inside the patient's body conduit while retrieving the blood clot from the body conduit; A recovery device mounted on the aforementioned elongated wire, having a central longitudinal axis, and capable of transitioning from a state of not expanding radially to a state of expanding radially, wherein in the state of not expanding radially, the recovery device is delivered to a distal position of the blood clot inside the patient's body conduit, and in the state of expanding radially, the recovery device is configured to recover the blood clot. A distal collar having a first opening through which the first portion of the distal end of the elongated wire passes, A recovery device comprising: a proximal collar located proximal to the distal collar, having a second opening through which a second portion of the distal end of the elongated wire passes; when the recovery device is not expanded radially, the proximal collar and the distal collar are separated by a first distance; when the recovery device is expanded radially, the proximal collar and the distal collar are separated by a second distance shorter than the first distance; and at least one of the proximal collar and the distal collar is slidable along the longitudinal axis of a portion of the elongated wire, allowing the recovery device to transition from a state where it is not expanded radially to a state where it is expanded radially; A recovery device comprising a plurality of elongated blood clot capturing elements, wherein each set of adjacent elongated blood clot capturing elements is circumferentially separated from one another by an elongated slot continuously extending between the proximal collar and the distal collar, each of the plurality of elongated blood clot capturing elements has a proximal end connected to the proximal collar and a distal end connected to the distal collar, each of the plurality of elongated blood clot capturing elements has a proximal end section and a distal end section, the proximal end section of the elongated blood clot capturing element is bent around the longitudinal axis of the recovery device when the recovery device is not expanded radially, and the distal end section of the elongated blood clot capturing element is parallel to the longitudinal axis of the recovery device when the recovery device is not expanded radially; Device.

2. The proximal end section of the elongated blood clot capturing element is arranged in a spiral pattern around the longitudinal axis of the recovery device when the recovery device is not extended; The apparatus according to claim 1.

3. When the recovery device is expanded radially, the entire portion of the elongated blood clot capturing element extends proximal to the proximal collar; The apparatus according to claim 1.

4. One or both of the proximal and distal collars rotate around the longitudinal axis of the recovery device while the recovery device transitions from a state where it is not radially expanded to a state where it is radially expanded; The apparatus according to claim 1.

5. When the recovery device is not expanded in the radial direction, none of the multiple elongated blood clot capturing elements are folded back; The apparatus according to claim 1.

6. When the recovery device is not expanded in the radial direction, none of the multiple elongated blood clot capturing elements are located proximal to the proximal collar; The apparatus according to claim 1.

7. The plurality of elongated blood clot-capturing elements and the proximal and distal collars are formed from a single piece of material; The apparatus according to claim 1.

8. The distal collar is fixed in place on the elongated wire; The apparatus according to claim 1.

9. The distal end sections of the elongated blood clot capturing elements overlap each other when viewed along the longitudinal axis of the recovery device when the recovery device is extended, and do not overlap each other when viewed along the longitudinal axis of the recovery device when the recovery device is not extended; The apparatus according to claim 1.

10. The distal section has a first width at a first point on the longitudinal axis that is tangent to the proximal section, a second width at a second point on the longitudinal axis, and a third width at a third point on the longitudinal axis, the second and third points being located proximal and distal to the first point, respectively, the first width being greater than the second and third widths, and each of the first, second, and third widths being measured around the longitudinal direction of the recovery device; The apparatus according to claim 1.

11. The proximal sputum and distal ends of the elongated blood clot capturing element are located proximal and distal to the second and third points, respectively; The apparatus according to claim 10.

12. The proximal and distal ends of the elongated blood clot-capturing element each have a width greater than the second width and the third width, respectively; The apparatus according to claim 11.

13. The proximal and distal ends of the elongated blood clot capturing element each have the same width as the first width; The apparatus according to claim 12.

14. A device for collecting blood clots from a patient's body conduits: A slender wire having a longitudinal axis, a proximal end portion that is located outside the patient's body conduit while retrieving the blood clot from the body conduit, and a distal end portion that is located inside the patient's body conduit while retrieving the blood clot from the body conduit; A recovery device mounted on the aforementioned elongated wire, having a central longitudinal axis, and capable of transitioning from a state of not expanding radially to a state of expanding radially, wherein in the state of not expanding radially, the recovery device is delivered to a distal position of the blood clot inside the patient's body conduit, and in the state of expanding radially, the recovery device is configured to recover the blood clot. A distal collar having a first opening through which the first portion of the distal end of the elongated wire passes, A recovery device comprising: a proximal collar located proximal to the distal collar, having a second opening through which a second portion of the distal end of the elongated wire passes; when the recovery device is not expanded radially, the proximal collar and the distal collar are separated by a first distance; when the recovery device is expanded radially, the proximal collar and the distal collar are separated by a second distance shorter than the first distance; and at least one of the proximal collar and the distal collar is slidable along the longitudinal axis of a portion of the elongated wire, allowing the recovery device to transition from a state where it is not expanded radially to a state where it is expanded radially; A plurality of elongated blood clot capturing elements, wherein each set of adjacent elongated blood clot capturing elements is circumferentially separated from one another by an elongated slot extending continuously between the proximal and distal collars, each of the plurality of elongated blood clot capturing elements has a proximal end connected to the proximal collar and a distal end connected to the distal collar, each of the plurality of elongated blood clot capturing elements has a proximal end section and a distal end section, the elongated blood clot capturing element has a first width at a first point on the longitudinal axis where the distal section is tangent to the proximal section, a second width at a second point on the longitudinal axis, and a third width at a third point on the longitudinal axis, the second and third points being located proximal and distal to the first point, respectively, the first width being greater than the second and third widths, and each of the first, second and third widths being measured around the longitudinal direction of the recovery device; Device.

15. The proximal and distal ends of the elongated blood clot-capturing element are located proximal and distal to the second and third points, respectively; The apparatus according to claim 14.

16. The proximal and distal ends of the elongated blood clot-capturing element each have a width greater than the second width and the third width, respectively; The apparatus according to claim 15.

17. The proximal and distal ends of the elongated blood clot capturing element each have the same width as the first width; The apparatus according to claim 16.

Images