Plug filter catheter

Abstract

An embolic substance capture catheter, as well as related devices and methods, restrain a distal end portion of an embolic substance filter assembly in an insertion configuration. A method of deploying the embolic substance filter assembly includes advancing the embolic substance filter assembly in an insertion configuration through a blood vessel. To reconfigure the embolic substance filter assembly to a deployed configuration via self-expansion of the embolic substance filter assembly and release the distal end portion of the embolic substance filter assembly, a pull wire is retracted.

Description

Technical Field

[0001]

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 337,340, filed May 2, 2022, the entire disclosure of which is incorporated herein by reference for all purposes.

Background Art

[0002]

[0002] Transcatheter aortic valve replacement (TAVR) is a proven strategy for the treatment of severe aortic valve stenosis that has been validated for use in patients who are not eligible for surgical aortic valve replacement (SAVR) due to patient frailty or associated high surgical risk. TAVR, with the use of self-expanding or balloon-expandable bioprosthetic valves, is FDA approved for commercial use in the United States in selected patients. TAVR is rapidly becoming an alternative method of treating aortic valve stenosis in patients who are considered to be at high risk of death if traditional surgical aortic valve replacement is performed. However, patients currently selected for TAVR are most often elderly with frailty and some comorbidities. The femoral artery is generally the first choice for access to the aortic valve. However, in patients with severe arterial occlusive disease, significant tortuosity of the iliofemoral system and / or significant atherosclerotic plaque within native aorta and / or aneurysm disease can present significant risk for femoral access, so alternative access TAVR is preferred. An alternative route in the form of a trans-apical (TA) approach through the apex of the left ventricle exposed by left thoracotomy was proposed several years ago. However, the TA approach requires opening the left chest in patients with potential pulmonary insufficiency, and the rate of hemorrhagic complications can be higher than that observed after the conventional trans-femoral (TF) approach. In the search for yet another alternative to compromised peripheral arterial access, a direct trans-aortic (TAo) route has been reported in a limited number of cases since 2010. In recent reports, cases performed via the TAo route were only 4% of the TAVR cases performed by 2013.

[0003]

[0003] The results are promising for TAVR, but it has been demonstrated that the risk of stroke is significantly higher with TAVR compared to SAVR. Clinically observed stroke (CVA) underestimates the prevalence of embolization events specific to TAVR. During TAVR, the stent and balloon-expandable valve (with or without the use of a balloon) cause compression of the native valve and displacement of the radially oriented valve leaflets, resulting in the release of tissue and particulate matter that migrates distally in the arterial tree. Some of the debris lodges in the terminal branches of the cerebral vasculature, as evidenced by newly developed strokes. Other debris released during TAVR lodges in the vessels of the peripheral, renal, coronary, and mesenteric circulations. These patients may present with a clinical scenario of renal failure, mesenteric ischemia, peripheral ischemia, and / or myocardial infarction. Other patients may not have an acute clinical deterioration but may suffer sequelae due to impairment of functional reserve associated with silent embolization events. The occurrence of embolization events during TAVR significantly hinders the provision of this technology to large low-risk groups of patients.

[0004]

[0004] Several different approaches have been developed for embolization protection. Existing embolization protection devices are mainly configured to either allow embolic material to escape from the brachiocephalic vessels or to capture embolic material within the brachiocephalic vessels. These existing embolization protection devices have several problems. First, deployment of the device requires additional time and may conflict with the performance of the valve implantation procedure. Second, deployment of the device can result in additional vascular trauma and the release of embolic material. Third, deployment of the device is difficult and the stability of deployment may reduce the reliability of protection. Fourth, the device may not protect the brain from all sources of blood flow, and in particular, posterior cerebral blood flow is not filtered. Fifth, systemic embolization that can result in ischemic bowel, renal dysfunction, and / or peripheral symptoms of the bowel, kidneys, and / or periphery may still occur. Sixth, coronary embolization and myocardial infarction may occur due to proximal embolization.

Summary of the Invention

[0005]

[0005] In the following, to provide a basic understanding of the present invention, a simplified overview of some embodiments of the present invention is presented. This overview is not a broad overview of the present invention. It is not intended to identify important / critical elements of the present invention or to clarify the scope of the present invention. Its sole purpose is to present some embodiments of the present invention in a simplified form as a prelude to the detailed description presented later.

[0006]

[0006] In many embodiments, the embolic material filter catheter includes an embolic material filter assembly deployable within a blood vessel downstream of a treatment site to capture embolic material released from the treatment site. In many embodiments, deployment of the embolic material filter assembly is achieved via a deployment sequence in which a distal end portion of the embolic material filter assembly is held in a folded configuration while a proximal end portion of the embolic material filter assembly advances distally toward the distal end portion of the embolic material filter assembly, thereby expanding an intermediate portion of the embolic material filter assembly. In many embodiments, subsequent to expansion of the intermediate portion of the embolic material filter assembly, the distal end portion of the embolic material filter assembly is released and self-expands to engage the blood vessel. In some embodiments, the embolic material filter assembly is constrained in the insertion configuration by an axial tension applied to the embolic material filter assembly, such that the retention sheath is not required to hold the embolic material filter assembly in the insertion configuration, thereby allowing the embolic material filter catheter to have a reduced diameter and / or high flexibility. The embolic material filter catheter can be configured for use in any suitable procedure. For example, the embolic material filter catheter can be used during implantation of an artificial aortic valve, where the embolic material filter assembly is deployed within the patient's aorta downstream of the patient's aortic valve to capture embolic material released during implantation of the artificial aortic valve. In many embodiments, the embolic material filter catheter includes a lumen through which a delivery catheter for an artificial valve can be inserted to advance the artificial valve to an implantation site upstream of the deployed embolic material filter assembly. In many embodiments, the lumen is configured to accommodate extraction of embolic material captured by the embolic material filter assembly. In some embodiments, such as embodiments sized to be inserted through the femoral artery, it is often not possible to remove embolic material through the lumen of the embolic material filter catheter while the delivery catheter for the artificial valve is housed within the lumen. In such embodiments, removal of embolic material through the lumen of the embolic material filter catheter can be achieved after removing the delivery catheter for the artificial valve from the lumen of the embolic material filter catheter.Embolic substance filter catheters, as well as related therapeutic catheters, devices, and methods, are particularly suitable for use in TAVR via any suitable access (including but not limited to femoral artery, direct aortic access, brachiocephalic artery, subclavian artery, axillary artery, or carotid artery) that enables accurate positioning of the artificial aortic valve.

[0007]

[0007] Thus, in one aspect, the embolic substance filter catheter includes an introducer sheath, an inner sheath, an embolic substance filter assembly, and a dilator assembly. The introducer sheath defines an introducer sheath lumen. The inner sheath is slidably disposed within the introducer sheath lumen and defines an inner sheath lumen. The embolic substance filter assembly has a proximal end portion and a distal end portion. The proximal end portion is attached to the distal end portion of the inner sheath. The embolic substance filter assembly is reconfigurable between an insertion configuration and a deployed configuration. The embolic substance filter assembly is configured to engage the inner surface of a blood vessel in the deployed configuration. The embolic substance filter assembly is configured to filter embolic substances from the blood flowing through the embolic substance filter assembly. The dilator assembly has a holding configuration and a non-holding configuration. The dilator assembly includes a dilator shaft, a dilator distal end member, and a dilator pull wire. The dilator shaft is configured to extend through the inner sheath lumen. The dilator distal end member is attached to the distal end of the dilator shaft. The distal end portion of the embolic substance filter assembly is constrained in the insertion configuration in the holding configuration via engagement with the dilator pull wire and the dilator distal end member. The dilator pull wire is configured to translate proximally relative to the dilator distal end member to reconfigure the dilator assembly from the holding configuration to the non-holding configuration, releasing the distal end portion of the embolic substance filter assembly from engagement with the dilator pull wire and the dilator distal end member to reconfigure the embolic substance filter assembly to the deployed configuration. The dilator assembly is removable from the inner sheath lumen while the embolic substance filter assembly is in the deployed configuration by proximal retraction of the dilator assembly relative to the inner sheath.

[0008]

[0008] In many embodiments, the dilator assembly is configured to suppress the induction of trauma to the patient's vasculature. For example, the dilator distal end member can include a dilator pull wire recess. Each of the dilator pull wires can include a respective dilator pull wire distal end portion disposed within a corresponding one of the dilator pull wire recesses when the dilator assembly is in the retained configuration. Each of the dilator pull wire distal end portions is withdrawn from a corresponding one of the dilator pull wire recesses during reconfiguration of the dilator assembly from the retained configuration to the non-retained configuration.

[0009]

[0009] In many embodiments, the embolic material filter catheter is operable to capture the embolic material filter assembly within the introducer sheath before removing the embolic material filter assembly from the patient. For example, the embolic material filter assembly can be reconfigurable from a deployed configuration to a capture configuration in which the embolic material filter assembly is disposed within the introducer sheath lumen by proximal retraction of the inner sheath relative to the introducer sheath.

[0010]

[0010] In many embodiments, the embolic material filter assembly can be maintained in an insertion configuration when disposed distally of the introducer sheath. The embolic material filter assembly can be constrained to conform to the outer surface of the dilator shaft from the proximal end portion of the embolic material filter assembly to the distal end portion of the embolic material filter assembly when the embolic material filter assembly is in the insertion configuration. The embolic material filter assembly can have an outer surface extending between the proximal end portion of the embolic material filter assembly and the distal end portion of the embolic material filter assembly. The outer surface of the embolic material filter assembly is disposable distally of the introducer sheath while the embolic material filter assembly is in the insertion configuration. The embolic material filter assembly can be configured to be at least partially retained in the insertion configuration by axial tension applied to the embolic material filter assembly via the dilator assembly and the inner sheath.

[0011]

[0011] In many embodiments, the inner sheath is sized to accommodate a treatment catheter. For example, the inner sheath can be sized to accommodate the insertion of a treatment catheter into the inner sheath lumen and the advancement of the distal portion of the treatment catheter to a position distal to the distal end portion of the embolic material filter assembly in the deployed configuration. The distal end portion of the treatment catheter can be configured to achieve a surgical operation.

[0012]

[0012] In some embodiments, the embolic material filter assembly is configured for use in a patient's aorta. For example, the embolic material filter assembly can be configured to engage the patient's aorta in the deployed configuration and substantially block the flow of embolic material through the patient's aorta passing through the embolic material filter assembly. The treatment catheter can be configured to deploy an artificial aortic valve.

[0013]

[0013] In some embodiments, the embolic material filter assembly includes an outer scaffold and an inner filter attached to the outer scaffold. The inner filter can be configured to filter embolic material from the blood flowing through the inner filter.

[0014]

[0014] In some embodiments, the embolic material filter catheter is configured to be coupled to an embolic material extraction device. The embolic material extraction device can be operable to draw embolic material through the inner sheath lumen while the embolic material filter assembly is in the deployed configuration.

[0015]

[0015] In some embodiments, the embolic material filter assembly includes an outer scaffold and an inner filter attached to the outer scaffold. The outer scaffold can be configured to expand radially to contact a blood vessel and prevent the transverse passage of embolic material along the blood vessel. The inner filter can be configured to prevent the passage of emboli larger than a particular size through the inner filter. The outer scaffold can include a distally extending loop of wire configured for non-invasive engagement of the blood vessel.

[0016]

[0016] In some embodiments, an intermediate portion of the embolic material filter assembly has an intermediate portion outer diameter in a deployed configuration. A distal end portion of the embolic material filter assembly has a distal end portion outer diameter in a deployed configuration. In some embodiments, the intermediate portion outer diameter is smaller than the distal end portion outer diameter.

[0017]

[0017] In many embodiments, the embolic material filter assembly includes an outer scaffold and an inner filter. The inner filter can be separated from the outer scaffold by an intervening annular space in a deployed configuration along the length of the inner filter.

[0018]

[0018] In some embodiments, a proximal end portion of the outer scaffold is formed by proximally extending an unbraided outer scaffold wire segment coupled to an outer surface of an inner sheath. Each of the unbraided outer scaffold wire segments can have a reduced diameter produced by electropolishing.

[0019]

[0019] In another aspect, a method of deploying an embolic filter assembly within a blood vessel includes restraining a proximal end portion of the embolic filter assembly via attachment to a distal end portion of an inner sheath having an inner sheath lumen. A distal end portion of the embolic filter assembly is restrained in an insertion configuration of the embolic filter assembly via restraint of the distal end portion of the embolic filter assembly by a dilator assembly extending through the inner sheath lumen. The dilator assembly has a retention configuration and a non-retention configuration. The dilator assembly includes a dilator shaft, a dilator distal end member, and a dilator pull wire. The embolic filter assembly advances in an insertion configuration through the blood vessel. The dilator pull wire is retracted proximally relative to the dilator distal end member to reconfigure the embolic filter assembly from an insertion configuration to a deployed configuration by self-expansion of the embolic filter assembly, releasing a distal end portion of the embolic filter assembly from engagement with the dilator pull wire and the dilator distal end member, and reconfiguring the dilator assembly from a retention configuration to a non-retention configuration.

[0020]

[0020] In many embodiments, the method includes capturing the embolic filter assembly prior to removing the embolic filter assembly from the patient. For example, the method can include capturing the embolic filter assembly by retracting the inner sheath proximally relative to the introducer sheath to retract the embolic filter assembly into the introducer sheath lumen of the introducer sheath.

[0021]

[0021] In many embodiments of the method, the embolic material filter assembly has an outer surface that extends between a proximal end portion of the embolic material filter assembly and a distal end portion of the embolic material filter assembly. When the embolic material filter assembly advances through a blood vessel in an insertion configuration, the outer surface of the embolic material filter assembly may be disposable distal to the introducer sheath. When the embolic material filter assembly is in the insertion configuration, the embolic material filter assembly can conform to the outer surface of the dilator assembly from the proximal end portion of the embolic material filter assembly to the distal end portion of the embolic material filter assembly. The embolic material filter assembly can be held in the insertion configuration at least partially by an axial tension imparted to the embolic material filter assembly via the dilator assembly and the inner sheath.

[0022]

[0022] In many embodiments, the method includes advancing, in a deployed configuration, a distal portion of a treatment catheter through the inner sheath lumen to a position distal to a proximal end portion of the embolic material filter assembly. Surgical procedures can be accomplished distal to the proximal end portion of the embolic material filter assembly in a deployed configuration via the treatment catheter.

[0023]

[0023] In many embodiments, the method includes joining an embolic material filter assembly in a deployed configuration to a patient's aorta. The method can further include blocking the flow of embolic material through the patient's aorta that passes through the embolic material filter assembly. The method can further include deploying an artificial aortic valve via the treatment catheter.

[0024]

[0024] In many embodiments, the method includes reconfiguring the embolic material filter assembly from an insertion configuration to an intermediate deployment configuration. For example, the embolic material filter assembly can be reconfigured from the insertion configuration to the intermediate deployment configuration by advancing the inner sheath distally toward the distal end portion of the embolic material filter assembly constrained by the expander assembly, thereby expanding an intermediate portion of the embolic material filter assembly disposed between the proximal end portion of the embolic material filter assembly and the distal end portion of the embolic material filter assembly.

[0025]

[0025] In many embodiments, the method includes drawing embolic material through the inner sheath lumen while the embolic material filter assembly is in the deployed configuration. The embolic material can be drawn through the inner sheath lumen by an embolic material extraction device fluidly coupled to the inner sheath lumen.

[0026]

[0026] In many embodiments of the method, the embolic material filter assembly includes an outer scaffold and an inner filter attached to the outer scaffold. The outer scaffold can be configured to expand radially to contact the blood vessel, and the inner filter prevents transverse passage of embolic material along the blood vessel. The inner filter can be configured to prevent passage of emboli larger than a particular size through the inner filter. The outer scaffold can include a distally extending loop of wire configured for non-invasive engagement of the blood vessel.

[0027]

[0027] In many embodiments of the method, the embolic material filter assembly includes suture loops. Each of the suture loops can pass through each of the distally extending loops of wire and engage one of each of the expander pull wires in the insertion configuration, within each respective set of distally extending loops of wire.

[0028]

[0028] In many embodiments of the method, the middle portion of the embolic material filter assembly has, in the deployed configuration, an outer diameter of the middle portion. The distal end portion of the embolic material filter assembly can have, in the deployed configuration, an outer diameter of the distal end portion, and the outer diameter of the middle portion can be smaller than the outer diameter of the distal end portion.

[0029]

[0029] In many embodiments of the method, the embolic material filter assembly includes an outer scaffold and an inner filter. The inner filter can be separated from the outer scaffold by an intervening annular space in a deployed configuration along the length of the inner filter.

[0030]

[0030] In many embodiments of the method, the embolic material filter assembly includes an outer scaffold and an inner filter. The proximal end portion of the outer scaffold can be formed by extending, in the proximal direction, an unbraided wire segment of the outer scaffold that is coupled to the outer surface of the inner sheath. Each of the unbraided wire segments extending in the proximal direction of the outer scaffold can have a reduced diameter produced by electropolishing.

[0031]

[0031] In another aspect, the embolic material filter catheter includes an introducer sheath, an inner sheath, an embolic material filter assembly, and a dilator assembly. The introducer sheath defines an introducer sheath lumen. The inner sheath is slidably disposed within the introducer sheath lumen and defines an inner sheath lumen. The embolic material filter assembly is coupled to the distal portion of the inner sheath. The embolic material filter assembly includes an outer scaffold and an inner filter. The embolic material filter assembly is reconfigurable from an insertion configuration to a deployed configuration. The insertion configuration accommodates insertion of the distal portion of the inner sheath and the embolic material filter assembly into a patient's blood vessel and positions the embolic material filter assembly downstream of the treatment site. In the deployed configuration, the outer scaffold has an outer perimeter configured to engage the blood vessel and positions the inner filter to filter embolic material from the blood flowing through the embolic material filter assembly. The outer scaffold undergoes a reduction in length during reconfiguration of the embolic material filter assembly from the insertion configuration to the deployed configuration. The inner filter includes body pleats in the deployed configuration configured to correspond to the reduction in length of the outer scaffold during reconfiguration of the embolic material filter assembly from the insertion configuration to the deployed configuration. The dilator assembly has a holding configuration and a non-holding configuration. In the holding configuration, the dilator assembly restrains the distal end portion of the embolic material filter assembly in the insertion configuration. Reconfiguration of the dilator assembly from the holding configuration to the non-holding configuration releases the distal end portion of the embolic material filter assembly and corresponds to reconfiguration of the embolic material filter assembly to the deployed configuration.

[0032]

[0032] In the insertion configuration, the outer scaffold can extend distally at least 1 inch from the distal portion of the inner sheath. In some embodiments, during reconfiguration of the embolic material filter assembly from the insertion configuration to the deployed configuration, the reduction in length of the outer scaffold is at least 0.5 inch.

[0033]

[0033] The body pleats can have any suitable configuration. For example, in some embodiments, the body pleats are arranged axially symmetrically with respect to the central axis of the embolic material filter assembly. In other embodiments, the body pleats extend helically around the central axis of the embolic material filter assembly. In some embodiments, the inner filter does not include body pleats in the inserted configuration.

[0034]

[0034] In some embodiments, the distal end of the inner filter has distal end segments arranged in a zigzag pattern in the deployed configuration. In some embodiments, the distal end segments are aligned with and woven into the braid of the outer scaffold to secure the inner filter to the outer scaffold, suppress passage of emboli around the inner filter, and minimize the resulting combined thickness of the embolic material filter assembly at the distal end of the inner filter.

[0035]

[0035] In many embodiments, the embolic material filter assembly is configured to be at least partially retained in the inserted configuration by an axial tension applied to the embolic material filter assembly via the dilator assembly and the inner sheath. In many embodiments, the inner filter is formed to have body pleats when not subjected to the axial tension applied to the embolic material filter assembly via the dilator assembly. In some embodiments, the body pleats are formed in the inner filter by heat setting.

[0036]

[0036] In many embodiments, the embolic material filter assembly can be captured via an introducer sheath prior to removal of the embolic material filter assembly from the patient. For example, the embolic material filter assembly may be reconfigurable from the deployed configuration to a capture configuration by proximal retraction of the inner sheath relative to the introducer sheath.

[0037]

[0037] In many embodiments, the embolic material filter assembly has a configuration intended to reduce the diameter size of the embolic material filter assembly during insertion into a patient's vasculature. For example, in many embodiments, the embolic material filter assembly is disposable distal to the introducer sheath when the embolic material filter assembly is in the insertion configuration. In many embodiments, when the embolic material filter assembly is in the insertion configuration and is disposed distal to the introducer sheath, the embolic material filter assembly is conformable to the outer surface of the dilator assembly.

[0038]

[0038] In many embodiments, the inner sheath accommodates insertion of a treatment catheter into the inner sheath lumen and advancement of the distal portion of the treatment catheter to a position distal to the distal end portion of the embolic material filter assembly in the deployed configuration. The treatment catheter can have any suitable configuration. For example, the distal end portion of the treatment catheter can be configured to accomplish a surgical operation. In some embodiments, the embolic material filter assembly is configured to engage the patient's aorta in the deployed configuration and substantially block the flow of embolic material through the patient's aorta passing through the embolic material filter assembly. In some embodiments, the treatment catheter is configured to deploy an artificial aortic valve.

[0039]

[0039] The embolic material filter can be configured to be coupled to an embolic material extraction device. The embolic material extraction device can be operable to draw embolic material through the inner sheath lumen while the embolic material filter assembly is in the deployed configuration.

[0040]

[0040] In some embodiments, the embolic material filter assembly includes an outer scaffold and an inner filter attached to the outer scaffold. The outer scaffold can be configured to radially expand to contact a blood vessel and prevent the transverse of embolic material along the blood vessel. The inner filter can be configured to prevent the passage of emboli larger than a particular size through the inner filter. The outer scaffold can include a distally extending loop of wire configured for non-invasive engagement of the blood vessel.

[0041]

[0041] In some embodiments, an intermediate portion of the embolic material filter assembly has an intermediate portion outer diameter in a deployed configuration. A distal end portion of the embolic material filter assembly has a distal end portion outer diameter in a deployed configuration. In some embodiments, the intermediate portion outer diameter is smaller than the distal end portion outer diameter.

[0042]

[0042] In many embodiments, the embolic material filter assembly includes an outer scaffold and an inner filter. The inner filter can be separated from the outer scaffold by an intervening annular space in a deployed configuration along the length of the inner filter.

[0043]

[0043] In some embodiments, a proximal end portion of the outer scaffold is formed by proximally extending an unbraided outer scaffold wire segment coupled to an outer surface of an inner sheath. Each of the unbraided outer scaffold wire segments can have a reduced diameter produced by electropolishing.

[0044]

[0044] In another aspect, the embolic material filter catheter includes an inner sheath, an embolic material filter assembly, a dilator assembly, and an introducer sheath. The inner sheath defines an inner sheath lumen. The embolic material filter assembly is coupled to the distal portion of the inner sheath. The embolic material filter assembly is reconfigurable from an insertion configuration to a deployed configuration. The insertion configuration accommodates insertion of the distal portion of the inner sheath and the embolic material filter assembly into a patient's blood vessel and positions the embolic material filter assembly downstream of the treatment site. In the deployed configuration, the embolic material filter assembly has an outer perimeter configured to engage the blood vessel. The dilator assembly is configured to advance and retract through the inner sheath lumen. The dilator assembly has a holding configuration and a non-holding configuration. The dilator assembly in the holding configuration restrains the distal end portion of the embolic material filter assembly in the insertion configuration. Reconfiguration of the dilator assembly from the holding configuration to the non-holding configuration releases the distal end portion of the embolic material filter assembly and corresponds to reconfiguration of the embolic material filter assembly to the deployed configuration. The introducer sheath defines an introducer sheath lumen configured to accommodate advancement of the embolic material filter assembly, the inner sheath, and the dilator assembly. The introducer sheath includes a tapered distal end portion having a longitudinal length and an outer diameter, and the outer diameter tapers distally from a proximal outer diameter at the proximal end of the tapered distal end portion to a distal outer diameter at the distal end of the tapered distal end portion.

[0045]

[0045] The tapered distal end portion of the introducer sheath can have any suitable configuration. For example, in an exemplary embodiment, the diameter ratio of the distal outer diameter to the proximal outer diameter is in the range of 0.80 to 0.95. In an exemplary embodiment, the length ratio of the longitudinal length to the distal outer diameter is in the range of 1.0 to 4.0.

[0046]

[0046] In many embodiments, the distal end of the tapered distal end portion of the introducer sheath, and the dilator assembly, are configured to have an interference fit between the distal end of the tapered distal end portion of the introducer sheath and the dilator assembly. The tapered distal end portion of the introducer sheath, and the dilator assembly, can have any suitable configuration for creating an interference fit. For example, in some exemplary embodiments, the inner diameter of the distal end of the tapered distal end portion is in the range of 0.97 to 0.99 times the outer diameter of the dilator assembly.

[0047]

[0047] In many embodiments, the tapered distal end portion of the introducer sheath includes a strain relief mechanism configured to reduce circumferentially directed strain at the distal end of the tapered distal end portion of the introducer sheath due to the interference fit between the distal end of the tapered distal end portion of the introducer sheath and the dilator assembly. The strain relief mechanism can have any suitable configuration. For example, in some exemplary embodiments, the strain relief mechanism includes a thickness-through slit extending proximally from the distal end of the tapered distal end portion. In some other exemplary embodiments, the strain relief mechanism includes a thickness-through slot extending proximally from the distal end of the tapered distal end portion. In some embodiments, the tapered distal end portion includes an outer surface having a non-traumatic shape that extends from and surrounds the thickness-through slot.

[0048]

[0048] For a complete understanding of the nature and advantages of the present invention, reference should be made to the following detailed description and the accompanying drawings.

Brief Description of the Drawings

[0049]

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DETAILED DESCRIPTION OF THE INVENTION

[0050]

[0079] For a complete understanding of the nature and advantages of the present invention, reference should be made to the following detailed description and the accompanying drawings.

[0051]

[0080] Hereinafter, various embodiments of the present invention will be described. For the purpose of the description, specific configurations and details are set forth in order to provide a complete understanding of the embodiments. However, it will be apparent to those skilled in the art that the present invention can be practiced without specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the described embodiments.

[0052]

[0081] Referring now to the drawings, like reference numerals represent like parts throughout the several views, and FIG. 1 shows an embolic material filter catheter 10 in an insertion configuration for insertion into a patient's vasculature and advancement therethrough. The filter catheter 10 includes an introducer sheath assembly 12, an inner sheath assembly 14, and a dilator assembly 16. The introducer sheath assembly 12 includes an introducer sheath 18 and an introducer sheath proximal end assembly 20 attached to the introducer sheath 18. The introducer sheath 18 is a flexible tube having an introducer sheath lumen extending therethrough. The introducer sheath proximal end assembly 20 remains outside the patient and can be used to advance the introducer sheath 18 distally through a blood vessel and to retract the introducer sheath 18 proximally along and / or from the vasculature. The inner sheath assembly 14 includes an inner sheath 22, an inner sheath proximal end assembly 24 attached to the inner sheath 22, and an embolic material filter assembly 36 (shown in FIG. 2) attached to the distal end of the inner sheath 22. The inner sheath 22 is a flexible tube having an inner sheath lumen extending therethrough. The inner sheath 22 is slidably disposed within the introducer sheath lumen of the introducer sheath 18. In many embodiments, the introducer sheath proximal assembly 20 includes a seal that engages the outer surface of the inner sheath 22 to inhibit and / or prevent leakage of body fluid (e.g., blood) from the annular space between the inner sheath 22 and the introducer sheath 18. The inner sheath proximal end assembly 24 remains outside the patient and can be used to advance the inner sheath 22 distally through the introducer sheath 18 and the vasculature and to retract the inner sheath 22 proximally along and / or from the introducer sheath 18 and the vasculature. While initially advancing the filter catheter 10 into and through the patient's vasculature, the configuration shown in FIG. 1 where the embolic material filter assembly 36 is disposed within the introducer sheath lumen of the introducer sheath 18 can be utilized.Subsequently, the inner sheath 22 can be advanced distally relative to the introducer sheath 18 during a stage subsequent to the advancement of the embolic material filter assembly 36 through the vasculature.

[0053]

[0082] The dilator assembly 16 is used to constrain the distal end of the filter assembly 36 in the insertion configuration of the filter assembly 36. The dilator assembly 16 includes a dilator shaft 26, a dilator distal end member 28, and a dilator pull wire 30. The dilator shaft 26 includes a lumen for each of the dilator pull wires 30. The dilator pull wires 30 are coupled to a pull wire actuating member 32 operable to retract the dilator pull wires 30 proximally relative to the dilator distal end member 28. The dilator distal end member 28 is attached to the distal end of the dilator shaft 26. The dilator shaft 26 extends through the inner sheath lumen of the inner sheath 22 and is slidably disposed within the inner sheath lumen. As described herein, when the filter assembly 36 is in the insertion configuration, the dilator distal end member 28 and the dilator pull wires 30 constrain the distal end portion of the embolic material filter assembly 36.

[0054]

[0083] During deployment of the embolic material filter assembly 36, the pull wire actuating member 32 retracts the dilator pull wires 30 proximally relative to the dilator distal end member 28 to release the distal end portion of the embolic material filter assembly 36 from engagement with the dilator distal end member 28 and the dilator pull wires 30, thereby enabling self-expansion of the distal end portion of the embolic material filter assembly 36 as described herein. In many embodiments, the embolic material filter catheter 10 is configured to deploy over a guide wire 106 (shown in FIG. 8). For example, the dilator assembly 16 can include a guide wire lumen 39 (shown in FIG. 6) extending therethrough.

[0055]

[0084] Figure 2 shows the distal portion of the plugging substance filter catheter 10 in the insertion configuration. The illustrated portion of the catheter 10 includes the distal end portion of the introducer sheath 18, the distal end portion of the inner sheath 22 that extends distally beyond the lumen of the introducer sheath 18, the plugging substance filter assembly 36 in the folded insertion configuration, the distal end portion of the dilator shaft 26, the dilator distal end member 28, and the dilator pull wire 30. In the illustrated insertion configuration, the suture loops 38 are attached to the distal end portion of the plugging substance filter assembly 36. Each of the suture loops 38 passes through each set of the distal end loops of the outer scaffold 44 of the filter assembly 36 and through each passage formed between each of the dilator pull wires 30 and the dilator distal end member 28 in the insertion configuration. By the suture loops 38 being constrained by the engagement of the dilator distal end member 28 and the dilator pull wires 30 with the proximal end portion 40 of the plugging substance filter assembly 36 attached to the distal end of the inner sheath 22, an appropriate position of the inner sheath 22 relative to the dilator distal end member 28 can be maintained to hold the plugging substance filter assembly 36 in the folded insertion configuration. For example, in some embodiments, in the illustrated folded insertion configuration, the plugging substance filter assembly 36 is under axial tension induced by opposing axial forces applied to the plugging substance filter assembly 36 by the dilator assembly 16 and the inner sheath 22. In some embodiments, when the plugging substance filter assembly 36 is in the insertion configuration, from the proximal end portion to the distal end portion of the plugging substance filter assembly 36, the plugging substance filter assembly 36 at least partially conforms to the outer surface of the dilator shaft 26. In many embodiments, during distal advancement of the catheter 10 through the vasculature, the dilator distal end member 28 has a non-traumatic shape to protect the vasculature. In the illustrated configuration, the inner sheath 22 is positioned relative to the introducer sheath 18 such that the proximal end of the plugging substance filter assembly 36 is disposed distally of the distal end of the introducer sheath 18 and is maintained in the folded insertion configuration without using a sheath surrounding the plugging substance filter assembly 36.

[0056]

[0085] Figures 3 and 4 show the progressive expansion of the embolic material filter assembly 36 from the insertion configuration shown in FIG. 2 to the intermediate deployment configuration shown in FIG. 4 by the distal advancement of the inner sheath 22 relative to the dilator assembly 16 while the suture loop 38 of the embolic material filter assembly 36 remains constrained by the dilator distal end member 28 and the dilator pull wire 30. As shown, the intermediate portion of the embolic material filter assembly 36 expands radially from the insertion configuration to the intermediate deployment configuration.

[0057]

[0086] When the suture loop 38 is released by retraction of the dilator pull wire 30, the distal end of the embolic material filter assembly 36 self-expands from the intermediate deployment configuration to the deployment configuration shown in FIG. 5. In many embodiments, the embolic material filter assembly 36 includes an outer scaffold 44 (shown in FIGS. 13 and 14), and the outer scaffold 44 is configured to self-expand from the insertion configuration to a deployment configuration in which the outer surface of the embolic material filter assembly 36 engages the blood vessel.

[0058]

[0087] FIG. 6 shows an enlarged end view of the distal portion of the expander assembly 16 in the intermediate deployment configuration of the plugging material filter catheter 10 (shown in FIG. 4). In both the insertion configuration and the intermediate deployment configuration, each of the suture loops 38 of the plugging material filter assembly 36 is captured within the proximal recess 45 of the expander distal end member 28 and retained within the proximal recess 45 via respective ones of the expander pull wires 30. Any suitable number of expander pull wires 30, such as two, three, four, five, six, seven, or more, and a corresponding number of suture loops 38 can be utilized. For example, in the illustrated embodiment, there are six circumferentially distributed expander pull wires 30 and a corresponding six circumferentially distributed suture loops 38. Each of the suture loops 38 can pass through a suitable number of end loops of the outer scaffold 44. For example, the outer scaffold 44 can have 24 end loops, and each of the six suture loops 38 can pass through each of four respective sets of the end loops of the outer scaffold 44. By passing each of the suture loops 38 through each of two or more respective sets of the end loops of the outer scaffold 44, due to the tension within each of the suture loops in the insertion configuration, the suture loops 38 function like drawstrings to gather each of the respective sets of the end loops of the outer scaffold 44, thereby strengthening the fixation of the end loops of the outer scaffold 44 around the expander shaft 26 in the folded insertion configuration of the plugging material filter assembly 36. Retraction of the expander pull wires 30 in the proximal direction is used to release the suture loops 38, thereby releasing the distal end of the plugging material filter assembly 36.

[0059]

[0088] From the configuration shown in FIG. 5, the dilator assembly 16 is removed through the inner sheath lumen of the inner sheath 22, making the inner sheath lumen available for insertion of a treatment catheter through the inner sheath lumen of the inner sheath 22, and surgical operations can be performed upstream of the embolic material filter assembly 36 in the fully deployed configuration. FIG. 7 shows an embolic material filter catheter 10 having an embolic material filter assembly 36 in a deployed configuration with the dilator assembly 16 removed. To deploy the embolic material filter assembly 36, the inner sheath 22 advances distally relative to the introducer sheath assembly 12, so that when the embolic material filter assembly 36 is in the deployed configuration, the inner sheath proximal end assembly 24 can be close to the introducer sheath proximal end assembly 20, thereby enabling the use of an existing length of treatment catheter.

[0060]

[0089] In many embodiments, the embolic material filter assembly 36 includes an outer scaffold 44 and an inner filter 46 attached to the outer scaffold. The outer scaffold 44 can include one or more members that expand radially to contact the wall of the blood vessel and prevent the transverse passage of embolic material along the blood vessel. The inner filter 46 can include a filtering device or a filtering membrane configured to prevent the passage of emboli or a filtering membrane that exceeds a particular size. For example, to capture emboli having a size of 200 microns or greater, the inner filter 46 can have openings having a size of 200 microns or less. To provide an appropriate pressure drop across the inner filter 46 during use, the inner filter 46 can have openings between an appropriate minimum size (e.g., 50 microns) and an appropriate maximum size (e.g., 200 microns) for capturing emboli having a size of 200 microns or greater. In some embodiments, the inner filter 46 has openings of 140 microns to provide an appropriate balance between the size of the captured emboli and an appropriate pressure drop across the inner filter 46 during use. The outer scaffold 44 is configured to provide a framework and stability for the inner filter 46 to function.

[0061]

[0090] The embolic material filter catheter 10 can be configured for use in any suitable blood vessel and for use with any suitable therapeutic catheter. For example, FIG. 8 shows one embodiment of an embolic material filter catheter 10 deployed within a patient's aorta 42 to capture embolic material released during the implantation of an artificial aortic valve. FIG. 9 shows an embolic material filter catheter 10 with an aortic valve replacement deployment catheter 100 inserted through the inner sheath lumen of an inner sheath 22 and positioned to deploy an aortic valve replacement 102. The replacement valve deployment catheter 100 includes an expandable member 104 that expands to deploy the valve 102. FIG. 9 also shows an expandable member 104 (and an artificial valve 102 attached to the expandable member 104 in a folded configuration) positioned for implantation of the artificial valve 102 after advancing along a guidewire 106 through the inner sheath lumen of the inner sheath 22. With the embolic material filter assembly 36 deployed downstream of the patient's native aortic valve 108, the embolic material filter assembly 36 is positioned to capture embolic material released during the deployment of the artificial aortic valve 102.

[0062]

[0091] FIG. 10 shows the deployment of the artificial valve 102 at the implantation site by expansion of the expandable member 104. Expansion of the expandable member 104 expands the artificial aortic valve 102 to its deployed configuration covering the native aortic valve 108. The expandable member 104 can expand during rapid pacing of the patient's heart. Embolic material released during the deployment of the artificial aortic valve 102 is captured by the embolic material filter assembly 36. In some embodiments, the embolic material filter catheter 10 can be in fluid communication with an external embolic material removal device operable to remove embolic material collected by the embolic material filter assembly 36 from the patient. After implantation of the artificial aortic valve 102, the replacement valve deployment catheter 100 can be removed from the embolic material filter catheter 10 by retraction in the proximal direction through the inner sheath lumen of the inner sheath 22.

[0063]

[0092] In many embodiments, prior to withdrawing the embolic material filter catheter 10 from the patient, the embolic material filter catheter 10 can be reconfigured to capture the embolic material filter assembly 36. For example, in the illustrated embodiment, the embolic material filter catheter 10 can be reconfigured from the configuration shown in FIG. 8 in which the embolic material filter assembly 36 is in the deployed configuration to the configuration shown in FIG. 11, which configuration is a capture configuration in which the embolic material filter assembly retracts the inner sheath assembly 14 proximally relative to the introducer sheath assembly 12, thereby drawing the embolic material filter assembly 36 into the introducer sheath lumen of the introducer sheath 18.

[0064]

[0093] FIG. 12 is a simplified block diagram of the operation of a method 200 for deploying an embolic material filter assembly intravascularly, according to many embodiments. The method 200 can be implemented using one or more any suitable devices, including the embolic material filter catheter 10 described herein. The method 200 can be used to provide embolic protection in conjunction with any suitable treatment, including the treatments shown herein.

[0065]

[0094] The method 200 includes (operation 202) constraining a proximal end portion of the embolic material filter assembly via attachment to a distal end portion of an inner sheath having an inner sheath lumen. For example, as shown in FIG. 2, the proximal end 40 of the embolic material filter assembly 36 is attached to the distal end of the inner sheath 22 within the embolic material filter catheter 10.

[0066]

[0095] The method 200 further includes (operation 204) constraining the distal end portion of the embolic material filter assembly in an insertion configuration and an intermediate deployment configuration of the embolic material filter assembly by constraining the distal end portion with an expander assembly extending through the inner sheath lumen. For example, in the insertion configuration shown in FIG. 2 and the intermediate deployment configuration shown in FIG. 4, the suture loop 38 of the embolic material filter assembly 36 is constrained to the expander distal end member 28 via the expander pull wire 30.

[0067]

[0096] Method 200 further includes advancing an introducer sheath through which an embolic material filter assembly is disposed through the patient's vasculature (operation 206). For example, the configuration of the filter catheter 10 shown in FIG. 1 can be used during the introduction and initial advancement of the embolic material filter assembly 36 through the patient's vasculature.

[0068]

[0097] Method 200 further includes advancing an inner sheath and a dilator assembly relative to the introducer sheath to advance the embolic material filter assembly in an insertion configuration through the patient's vasculature to a position distal to the introducer sheath (operation 208). For example, operation 208 can be achieved by advancing the inner sheath assembly 14 distally relative to the introducer sheath assembly 12 to reconfigure the filter catheter 10 from the insertion configuration shown in FIG. 1 to the insertion configuration shown in FIG. 2.

[0069]

[0098] Method 200 further includes reconfiguring the embolic material filter assembly from an insertion configuration to an intermediate deployment configuration by advancing the inner sheath distally toward the distal end portion of the embolic material filter assembly constrained by the dilator assembly to expand an intermediate portion of the embolic material filter assembly disposed between the proximal end portion and the distal end portion of the embolic material filter assembly (operation 210). For example, operation 210 can be achieved by reconfiguring the embolic material filter catheter 10 from the insertion configuration shown in FIG. 2 to the intermediate deployment configuration shown in FIG. 4, as described herein.

[0070]

[0099] Method 200 further includes (operation 212) reconfiguring the embolic material filter assembly from an intermediate deployment configuration to a deployed configuration via reconfiguration of the dilator assembly to disengage the distal end portion of the embolic material filter assembly from engagement with the dilator assembly and self-expansion of the distal end portion of the embolic material filter assembly. For example, operation 212 can be achieved by reconfiguring the embolic material filter catheter 10 from the intermediate deployment configuration shown in FIG. 4 to the fully deployed configuration shown in FIG. 5, as described herein.

[0071]

[0100] Method 200 further includes (operation 214) capturing the embolic material filter assembly within the introducer sheath before proximally retracting the embolic material filter assembly from the patient's vasculature. For example, operation 214 can be achieved by retracting the inner sheath assembly 14 proximally relative to the introducer sheath assembly 12 to reconfigure the filter catheter 10 from the deployed configuration shown in FIG. 7 to the captured configuration shown in FIG. 11.

[0072]

[0101] In many embodiments, the embolic material filter assembly 36 is flexible such that the distal end of the embolic material filter assembly 36 conforms to the inner surface of the blood vessel (e.g., aorta 42) and has a deployed shape that conforms to the shape of the blood vessel. For example, in many embodiments, the embolic material filter assembly 36 is configured to conform to the shape (e.g., curvature) of the blood vessel (e.g., the curvature of the aorta 42) between the distal end portion and the proximal end portion 40 of the embolic material filter assembly 36.

[0073]

[0102] Configuration of the embolic material filter assembly

[0074]

[0103] The plugging material filter assembly 36 can have any suitable configuration. For example, FIG. 13 shows a side view of an embodiment 36a of the plugging material filter assembly 36 in a deployed configuration. FIG. 14 shows a side cross-sectional view of an embodiment 36a of the plugging material filter assembly 36 in a deployed configuration. An embodiment 36a of the plugging material filter assembly 36 includes an outer scaffold 44 and an inner filter 46.

[0075]

[0104] The outer scaffold 44 includes a helical length between one or more braids of a suitable wire 44w (e.g., a wire having a diameter of 0.006 to 0.010 inches made from a suitable nickel-titanium shape memory alloy). In many embodiments, the strands of wire 44w are woven alternately (e.g., passing under after passing over) so as to cross portions of the strands of wire 44w. From the insertion configuration shown in FIG. 2 to the fully deployed configuration shown in FIGS. 13 and 14, the pitch between adjacent positions on wire 44w decreases from a suitable initial pitch to a suitable deployed pitch (DP), and the diameter of the outer scaffold 44 increases from a suitable insertion configuration diameter to a suitable fully deployed configuration diameter, thereby resulting in a corresponding decrease in the length of the outer scaffold 44. The wire 44w of the outer scaffold 44 has shape memory such that, in response to the distal advancement of the inner sheath 22 and the release of the distal end portion of the first configuration 36a of the embolic material filter assembly 36, the outer scaffold 44 automatically reconfigures from the insertion configuration to the fully deployed configuration. Retracting the first configuration 36a of the embolic material filter assembly 36 into the introducer sheath 18 increases the pitch between adjacent positions on wire 44w and decreases the diameter of the outer scaffold 44, thereby resulting in a corresponding increase in the length of the outer scaffold 44. In the illustrated embodiment, the outer scaffold 44 has a non-traumatic leading edge 50 formed by a loop of wire 44w. In some embodiments, the outer scaffold 44 includes a capture loop that engages a suture loop 38, and the capture loop is constrained in contact with the dilator distal end member 28 via the dilator pull wire 30 while the embolic material filter assembly 36 is in the insertion configuration. In some embodiments, the maximum expanded diameter of the embolic material filter assembly 36 is sized to ensure engagement with the patient's aortic arch.

[0076]

[0105] In many embodiments, the inner filter 46 has an appropriate porosity that results in capture of embolic material by the inner filter 46 while accommodating blood flow through the inner filter 46. The inner filter 46 can be made of any suitable material. For example, in some embodiments, the inner filter 46 includes a helically braided polyethylene terephthalate (PET) filter. In some embodiments, the inner filter 46 includes a helically braided polymer filter made of suitable polymer yarns such as ultra-high-molecular-weight polyethylene (UHMWPE), PET, nylon, polypropylene, polytetrafluoroethylene (PTFE), and liquid crystal polymer (LCP). In some embodiments, the inner filter 46 includes a laser cut polymer filter made of a suitable polymeric material (e.g., an elastomeric material such as silicone, polyurethane, and copolymers). In some embodiments, the inner filter 46 includes a woven fabric filter having a diameter less than or equal to that of the braided outer scaffold 44 and having a target porosity that allows blood flow through the inner filter 46 and captures embolic material. Such a woven fabric filter can be made of suitable polymer yarns such as UHMWPE, PET, nylon, polypropylene, PTFE, and LCP. The inner filter 46 can have any suitable configuration. For example, in many embodiments, the inner filter 46 can have an outer diameter in a fully deployed configuration that is less than or equal to the inner diameter of the outer scaffold 44 in a fully deployed configuration. In many embodiments, the inner filter 46 has a longitudinal length and / or longitudinal flexibility that corresponds to a change in the length of the outer scaffold 44 between an insertion configuration and a fully deployed configuration.

[0077]

[0106] The inner filter 46 can have any suitable configuration. For example, the inner filter 46 can include a non-pleated distal member 48 made of nylon and a pleated body member formed from a suitable polyester material that can be attached to the distal member 48 and have pleats formed by heat setting.

[0078]

[0107] In the deployed configuration, the embolic material filter assembly 36a has a stepped outer diameter shape configured to enhance deployment from the insertion configuration to the deployed configuration by substantially separating the contact between the outer scaffold 44 and the blood vessel with respect to the distal end portion 64 of the embolic material filter assembly 36a. In the deployed configuration, the intermediate portion 66 of the embolic material filter assembly 36a has an intermediate portion outer diameter 68, and the distal end portion 64 has a distal end portion outer diameter 70. In many embodiments, the distal end portion outer diameter 70 is sized to provide an appropriate amount of engagement with the target blood vessel. For example, in the deployed configuration, when the distal end portion 64 is deployed within the target blood vessel, the distal end portion outer diameter 70 can be sized to be an appropriate increment larger than the inner diameter of the target blood vessel (e.g., the aorta) so as to apply an appropriate engagement pressure to the target blood vessel. In many embodiments, the intermediate portion outer diameter 68 is appropriately smaller than the inner diameter of the target blood vessel, whereby an annular gap exists between the intermediate portion 66 and the inner wall of the target blood vessel, and with respect to the distal end portion 64, substantially separates the contact between the outer scaffold 44 and the blood vessel, corresponding to the longitudinal contraction of the embolic material filter assembly 36a during deployment from the insertion configuration to the deployed configuration. The annular gap between the intermediate portion 66 and the inner wall of the target blood vessel helps to avoid the interaction between portions of the embolic material filter assembly 36a proximal to the distal end portion 64 that can suppress the contraction of the embolic material filter assembly 36a during deployment from the insertion configuration to the deployed configuration. The intermediate portion outer diameter 68 can be any suitable amount smaller than the inner diameter of the target blood vessel or the distal end portion outer diameter 70 in the deployed configuration. For example, in the illustrated embodiment, the intermediate portion outer diameter 68 is about 50% of the distal end portion outer diameter 70.

[0079]

[0108] In the illustrated embodiment 36a of the plugging material filter assembly 36, the inner filter 46 includes a proximal portion 47 that connects to the distal end of the inner sheath 22. In many embodiments, the proximal portion 47 has a shape (e.g., conical) that provides a smooth transition to the distal end of the inner sheath 22. The proximal portion 47 can be attached to the inner sheath 22 using any suitable approach. For example, the proximal end portion of the proximal portion 47 can be coupled to the outer surface of the distal end portion of the inner sheath 22.

[0080]

[0109] In some embodiments of the plugging material filter assembly 36, the inner filter 46 has pleats in the deployed configuration that correspond to the contraction of the outer scaffold 44 during deployment of the plugging material filter assembly 36 from the insertion configuration to the deployed configuration. FIG. 15 shows a side cross-sectional view of one embodiment of the plugging material filter assembly 36 including an inner filter 46p having pleats 49 in the deployed configuration as shown. The inner filter 46p can be configured to have pleats 49 in the deployed configuration using any suitable approach. For example, in the insertion configuration, when no axial tension is applied to the inner filter 46p by the outer scaffold 44, the pleats 49 can be formed in the inner filter 46p using heat setting so that the inner filter 46p has an unconstrained configuration including the pleats 49. FIG. 16 is a view of a prototype of the pleated inner filter 46p in the unconstrained configuration. FIG. 17 shows a side cross-sectional view of one embodiment of the plugging material filter assembly 36 including an inner filter 46p-h having spiral pleats 49h in the deployed configuration as shown. The inner filter 46p-h can be configured to have spiral pleats 49h in the deployed configuration using any suitable approach. For example, in the insertion configuration, when no axial tension is applied to the inner filter 46p-h by the outer scaffold 44, the spiral pleats 49h can be formed in the inner filter 46p-h using heat setting so that the inner filter 46p-h has an unconstrained configuration including the spiral pleats 49h. FIG. 18 is a view of a prototype of the spiral-pleated inner filter 46p-h in the deployed configuration of the plugging material filter assembly 36.

[0081]

[0110] FIG. 19 is a view of one embodiment of a plugging material filter assembly 36 including an outer scaffold 44 and one embodiment of an inner filter 46 having a zigzag-shaped distal end 51. The zigzag-shaped distal end 51 is aligned and braided with the braiding of the outer scaffold 44 to secure the distal end 51 to the outer scaffold 44 so as to suppress the passage of plugs around the inner filter 46 and minimize the resulting combined thickness of the plugging material filter assembly 36 at the distal end 51 of the inner filter 46. In some embodiments, the inner filter 46 includes a non-pleated distal end member 48 including the distal end 51, and the non-pleated distal end member 48 further includes a pleated member attached to the proximal end of the non-pleated distal end member 48 and extending to the inner sheath 22.

[0082]

[0111] FIG. 20 shows an enlarged side view of one embodiment of a plugging material filter catheter 10, the proximal end of the outer scaffold 44 having a wire segment 52 at the proximal end coupled to the outer surface of the inner sheath 22. The wire segment 52 is processed to be thinner in thickness relative to the wire segments of the outer scaffold 44 distal to the distal end of the inner sheath 22 at the proximal end 40 of a plugging material filter assembly 36a coupled to the distal end of the inner sheath 22 to reduce the diameter of the inner sheath assembly 14. For example, in some embodiments, the outer scaffold 44 is formed from braided wire 0.009 inches in diameter, and the proximal end segment forming the wire segment 52 is electropolished down to a reduced diameter (e.g., 0.0055 - 0.006 inches).

[0083]

[0112] FIG. 21 shows an enlarged side view of one embodiment of the embolic material filter catheter 10, where the proximal end of the outer sheath 44 has an unbraided wire segment 54 coupled to the outer surface of the inner sheath 22. In the embodiment shown in FIG. 21, the unbraided wire segments 54 are each arranged in parallel, although any suitable routing of the unbraided wire segments 54 can be employed. The unbraided wire segments 54 do not cross over or under each other, thereby reducing the thickness of the proximal portion of the outer sheath 44 coupled to the inner sheath 22 due to the lack of stacking of the unbraided wire segments 54 at the intersection. Further, in some embodiments, the unbraided wire segments 54 are processed to be thinner at the proximal end 40 of the embolic material filter assembly 36a coupled to the distal end of the inner sheath 22, relative to the wire segments of the outer sheath 44 distal to the distal end of the inner sheath 22, in order to further reduce the diameter of the inner sheath assembly 14. For example, in some embodiments, the outer sheath 44 is formed from braided wire having a diameter of 0.009 inches, and the proximal end segments forming the unbraided wire segments 54 are electropolished down to a reduced diameter (e.g., 0.0055 - 0.006 inches).

[0084]

[0113] Tapered distal end of the introducer sheath

[0085]

[0114] Figures 22, 23, and 24 show the tapered distal end portion 56 of the introducer sheath 18. The tapered distal end portion 56 has a longitudinal length 58, and the outer diameter is tapered distally from the proximal outer diameter 60 at the proximal end of the distal end portion 56 to the distal outer diameter 62 at the distal end of the distal end portion 56. The distal outer diameter 62 can be made smaller than the proximal outer diameter 60 by any suitable length. For example, in many embodiments, the ratio of the distal outer diameter 62 to the proximal outer diameter 60 is in the range of 0.80 to 0.95. The distal end portion 56 can have any suitable longitudinal length 58. For example, in some embodiments, the ratio of the longitudinal length 58 to the distal outer diameter 62 is in the range of 1.0 to 4.0. The tapered distal portion 56 has an inner diameter that is tapered distally from the proximal inner diameter 64 at the proximal end to the distal inner diameter 66 at the distal end. In many embodiments, in the insertion configuration of the embolic material filter catheter 10 shown in FIGS. 1, 22, and 24, the distal inner diameter 66 is less than or equal to the maximum outer diameter 68 of the dilator distal end member 28 such that the inner surface of the distal end portion 56 at the distal end of the distal end portion 56 conforms to the outer surface of the dilator distal end member 28. In many embodiments, the distal inner diameter 66 is smaller than the maximum outer diameter 68 of the dilator distal end member 28 by a suitable amount to create a proper interference fit between the introducer sheath 18 and the dilator distal end member 28 at the distal end of the tapered distal end portion 56. For example, in some embodiments, the distal inner diameter 66 is 0.98 times the outer diameter 68. In the insertion configuration shown in FIGS. 1, 22, and 24, the combination of the dilator distal end member 28 and the tapered distal end portion 56 of the introducer sheath 18 provides a smooth tapered outer shape that helps reduce tissue trauma induced during the advancement of the embolic material filter catheter 10 through the patient's vasculature. FIG. 25 shows another side view of the tapered distal end portion 56 of the introducer sheath 18 of the embolic material filter catheter 10 in an expanded configuration created by the radial expansion generated by the interaction between the dilator distal end member 28 and the tapered distal end portion 56 of the introducer sheath 18. FIG. 26 shows the cross-sectional view BB defined in FIG. 25 and an enlarged view of the distal end of the tapered distal end portion 56 that joins the outer annular recess 72 of the dilator distal end member 28.FIG. 27 shows a side view of the distal end portion of the dilator assembly 16 including the dilator distal end member 28. The outer annular recess 72 is configured to receive and accommodate the distal end of the tapered distal end portion 56 (as shown in detail at section C of FIG. 26) to shield the distal end of the tapered distal end portion 56 from front contact with tissue during advancement of the occluding substance filter catheter 10 within the patient. The outer annular recess 72 can have any suitable configuration. For example, in the illustrated embodiment, the dilator distal end member 28 has a major diameter 74 of 0.236 inches, and the outer annular recess 72 has a recess length 76 of 0.05 inches and a recess diameter 78 of 0.218 inches, thereby creating a recess depth of 0.009 inches.

[0086]

[0115] In some embodiments, a strain relief mechanism is included in the distal end portion of the introducer sheath 18 that is configured to increase compliance to accommodate a diametrical expansion of the distal end portion of the introducer sheath 18, thereby reducing the longitudinal frictional force during relative longitudinal movement between the introducer sheath 18 and the dilator assembly 16. In the embodiment shown in FIG. 28, the strain relief mechanism takes the form of longitudinal strain relief slits 80 in the tapered distal end portion 56 of the introducer sheath 18. In the embodiment shown in FIG. 29, the strain relief mechanism takes the form of longitudinal strain relief slots 82 in the tapered distal end portion 56 of the introducer sheath 18. FIG. 30 shows a photograph of a prototype of an introducer sheath having longitudinal strain relief slots 82 in the tapered distal end portion 56 of the introducer sheath 18. During diametrical expansion of the distal end of the tapered distal end portion 56, the longitudinal strain relief mechanisms 80, 82 expand circumferentially, thereby reducing the circumferential strain that occurs in the distal end portion of the tapered distal end portion 56, and thus reducing the diametrical engagement force and associated frictional force between the distal end of the tapered distal end portion 56 and the dilator distal end member 28. As shown in FIG. 30, the prototype of the introducer sheath 18 includes an outer surface having a non-traumatic contour shape that extends from and surrounds the longitudinal strain relief slots 82. Although the distal end portion 56 of the introducer sheath is shown with one longitudinal strain relief mechanism 80, 82, any suitable number (e.g., 1, 2, 3, 4, or more) and length of strain relief mechanisms 80, 82 can be included in the distal end portion of the introducer sheath 18.

[0087]

[0116] The devices and methods described herein are expected to provide a substantial benefit in terms of substantially enhancing the safety and effectiveness of surgical treatments with a high potential for the generation of embolic materials, such as aortic valve replacement. As a result, such surgical treatments can be performed on a substantially increased number of patients with improved outcomes and reduced recovery times. Specifically, the amount of embolic material carried within the circulatory system is reduced, thereby decreasing the incidence of each of clinical stroke, silent stroke, silent cerebral embolization, renal embolism, mesenteric embolism, and peripheral embolism, as well as related clinical syndromes.

[0088]

[0117] The embolic material filter catheter 10 is suitable for use in procedures involving the deployment of covered or uncovered stents in arteries for the capture and extraction of embolic material that may be released during their implantation for the treatment of aneurysms, dissections, stenoses or thrombi. The embolic material filter catheter 10 is suitable for preventing injury resulting from embolic events occurring during balloon aortic valvuloplasty. The embolic material filter catheter 10 is suitable for preventing tissue damage resulting from the performance of mitral balloon valvuloplasty or replacement. In the case of mitral valve procedures, the embolic protection provided by the embolic material filter catheter 10 may be separate from the delivery catheter. In this situation, there may be a separate transvenous or transapical implantation system of sheaths and catheters for valve delivery and deployment, and the embolic material filter catheter 10 can be deployed in the ascending aorta for the capture and removal of material released from the mitral valve procedure.

[0089]

[0118] Other variations are also within the spirit of the invention. Accordingly, while the invention is susceptible to various modifications and alternative constructions, specific exemplary embodiments thereof have been shown in the drawings and described in detail above. However, it is not the intention to limit the invention to the one or more specific forms disclosed, and on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents within the spirit and scope of the invention as defined by the appended claims.

[0090]

[0119] The use of the terms "a", "an", and "the" and similar referents in the context of describing the present invention (particularly in the context of the following claims) should be construed to include both the singular and the plural unless otherwise indicated herein or clearly contradicted by the context. The terms "comprising", "having", "including", and "containing" should be construed as non-limiting terms (i.e., meaning "including but not limited to") unless specifically stated otherwise. The term "connected" should be construed to mean attached, joined together, either in part or whole, even if there are intervening elements. The recitation of a range of values herein is merely intended to serve as a convenient method of referring individually to each separate value falling within the range, and each separate value is incorporated herein as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or clearly contradicted by the context. The use of any and all examples or exemplary language (e.g., "such as") provided herein is merely intended to better illuminate embodiments of the present invention and, unless otherwise claimed, does not limit the scope of the present invention. No language in this specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0091]

[0120] Preferred embodiments of the present invention are described herein, including the best mode known to the inventors for carrying out the present invention. Variations of these preferred embodiments will be apparent to those skilled in the art upon reading the foregoing description. The inventors expect those skilled in the art to appropriately use such variations, and the inventors intend for the present invention to be practiced otherwise than as specifically described herein. Accordingly, the present invention includes all modifications and equivalents of the subject matter recited in the appended claims as permitted by applicable law. Further, unless otherwise indicated herein or clearly contradicted by context, any combination of the above-described elements in all possible variations thereof is included in the present invention.

[0092]

[0121] All references, including publications, patent applications, and patents, cited herein are incorporated by reference herein to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

Claims

1. The introducer sheath defines the lumen of the introducer sheath, The inner sheath is slidably positioned within the lumen of the introducer sheath and defines the lumen of the inner sheath. An embolic material filter assembly having a proximal end portion and a distal end portion, wherein the proximal end portion is attached to the distal end portion of the inner sheath, the embolic material filter assembly is reconfigurable between an insertion configuration and an deployment configuration, the embolic material filter assembly is configured to connect with the inner surface of a blood vessel in the deployment configuration, and the embolic material filter assembly is configured to filter embolic material from the blood flowing through the embolic material filter assembly, An expander assembly having a retaining configuration and a non-retaining configuration, wherein the expander assembly comprises an expander shaft, an expander distal end member, and an expander pull wire, wherein the expander shaft is configured to extend through the inner sheath lumen, the expander distal end member is attached to the distal end of the expander shaft, and the distal end portion of the embolic material filter assembly is constrained in the insertion configuration by the engagement between the expander pull wire and the expander distal end member in the retaining configuration, and the expander pull wire is attached to the expander distal end member The expander assembly is configured to translate proximal to the member, reconfiguring the expander assembly from the retaining configuration to the non-retaining configuration, releasing the distal end portion of the embolic material filter assembly from engagement between the expander pull wire and the expander distal end member, thereby reconfiguring the embolic material filter assembly to the deployed configuration, and while the embolic material filter assembly is in the deployed configuration due to the proximal retraction of the expander assembly relative to the inner sheath, the expander assembly is removable from the inner sheath lumen. An embolic material filter catheter equipped with the following features.

2. The distal end member of the expander is provided with an expander pull wire recess, When the expander assembly is in the retaining configuration, each of the expander pull wires comprises a distal end portion of the expander pull wire that is positioned in one of the corresponding recesses of the expander pull wire. The embolic material filter catheter according to claim 1, wherein each of the distal end portions of the expander pull wire is drawn out from the corresponding one of the expander pull wire recesses during the reconstruction of the expander assembly from the retaining configuration to the non-retaining configuration.

3. The embolic material filter catheter according to claim 1, wherein the embolic material filter assembly is reconfigurable from the deployed configuration to a capture configuration in which the embolic material filter assembly is positioned in the lumen of the introducer sheath by the proximal retraction of the inner sheath relative to the introducer sheath.

4. The embolic material filter catheter according to claim 1, wherein when the embolic material filter assembly is in the insertion configuration and positioned distal to the introducer sheath, the embolic material filter assembly can be restrained to fit the outer surface of the expander shaft from the proximal end portion of the embolic material filter assembly to the distal end portion of the embolic material filter assembly.

5. The embolic material filter assembly has an outer surface that extends between the proximal end portion of the embolic material filter assembly and the distal end portion of the embolic material filter assembly, The embolic substance filter catheter according to claim 1, wherein the outer surface of the embolic substance filter assembly is disposable distal to the introducer sheath while the embolic substance filter assembly is in the insertion configuration.

6. The embolic material filter catheter according to claim 1, wherein the embolic material filter assembly is configured to be at least partially held in the insertion configuration by axial tension applied to the embolic material filter assembly via the expander assembly.

7. The inner sheath accommodates the insertion of the treatment catheter into the inner sheath lumen and the advancement of the distal portion of the treatment catheter to a position distal to the distal end portion of the embolic material filter assembly in the deployed configuration. The embolic material filter catheter according to claim 1, wherein the distal end portion of the therapeutic catheter is configured to perform surgical procedures.

8. The embolic material filter assembly is configured to connect to the patient's aorta in the deployed configuration and substantially block the flow of embolic material through the patient's aorta that passes through the embolic material filter assembly. The embolic material filter catheter according to claim 7, wherein the treatment catheter is configured to deploy an artificial aortic valve.

9. The embolic substance filter catheter according to claim 1, wherein the embolic substance filter assembly comprises an outer scaffold and an inner filter, which is attached to the outer scaffold and configured to filter embolic substances from blood flowing through the inner filter.

10. The embolic material filter catheter according to claim 1, wherein the embolic material filter assembly is configured to be connected to an embolic material extraction device that is operable to draw embolic material through the inner sheath lumen while the embolic material filter assembly is in the deployed configuration.

11. The embolic material filter assembly comprises an outer scaffold and an inner filter attached to the outer scaffold, The outer scaffold is configured to expand radially to contact the blood vessel, thereby preventing the embolic material from crossing along the blood vessel. The embolic material filter catheter according to claim 1, wherein the inner filter is configured to prevent embolus exceeding a certain size from passing through the inner filter.

12. The embolic material filter catheter according to claim 11, wherein the outer scaffold comprises a distally extending loop of wire configured for non-traumatic engagement of the blood vessel.

13. The intermediate portion of the embolic material filter assembly has an intermediate outer diameter in the unfolded configuration, The distal end portion of the embolic material filter assembly has the outer diameter of the distal end portion in the deployed configuration. The embolic material filter catheter according to claim 1, wherein the outer diameter of the intermediate portion is smaller than the outer diameter of the distal end portion.

14. The embolic material filter assembly comprises an outer scaffold and an inner filter, The embolic material filter catheter according to claim 1, wherein the inner filter is separated from the outer scaffold by an intervening annular space in the unfolded configuration along the length of the inner filter.

15. The embolic material filter assembly comprises an outer scaffold and an inner filter, The embolic material filter catheter according to claim 1, wherein the proximal end portion of the outer scaffold is formed by extending a non-braided wire segment of the outer scaffold, which is bonded to the outer surface of the inner sheath, in the proximal direction.

16. The embolic material filter catheter according to claim 15, wherein each of the non-braided wire segments extending proximal to the outer scaffold has a reduced diameter produced by electropolishing.

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