WO2019036047A1

WO2019036047A1 - Concentric aortic arch filter and methods for use thereof

Info

Publication number: WO2019036047A1
Application number: PCT/US2018/000343
Authority: WO
Inventors: Thomas HALDIS; Alexander DROFA
Original assignee: Sanford Health
Current assignee: Sanford Health
Priority date: 2017-08-18
Filing date: 2018-08-20
Publication date: 2019-02-21
Anticipated expiration: 2020-02-18

Abstract

The present disclosure provides a catheter system including: (a) a first catheter having a first end and a second end, the first catheter defining a first lumen, (b) a second catheter having a first end and a second end, the second catheter defining a second lumen, where the first catheter is positioned at least partially within the second lumen of the second catheter, and the second catheter and the first catheter are moveable with respect to each other, and (c) a filter coupled to the first catheter, where the filter comprises an expandable frame and a semipermeable membrane coupled to the expandable frame, and where the expandable frame has shape memory and is movable from a compressed position to an expanded position in response to the second catheter being retracted relative to the first catheter and/or the first catheter being advanced relative to the second catheter.

Description

Concentric Aortic Arch Filter and Methods for Use Thereof

Related Applications

[1] This application claims the benefit of priority to U.S. Provisional Application No.

62/547,283 entitled "Concentric Aortic Arch Filter and Methods for Use Thereof," filed on August 18, 2Q17, the contents of which are hereby incorporated by reference in its entirety.

Background the Invention

[2] Cardiovascular surgery has traditionally been performed with open surgical techniques that involve invasive procedures to surgically excise the diseased structure before sewing in an artificial replacement often requiring prolonged clamping to halt blood flow through the diseased segment. These open surgical techniques are effective and durable but they can only be performed on relatively healthy patients and often result in relatively long recovery periods. Recently, minimally invasive techniques have been developed and used with endovascular or catheter-directed methodologies. These minimally invasive approaches can make the procedures more broadly applicable to patients with more comorbidities. It can also reduce recovery times and reduce the risk of certain complications. However, minimally invasive techniques can create a new set of complications that need to be dealt with. For instance, embolus formation is one such example.

Summary of the Invention

[3] In several diseased states the cardiovascular system may develop thrombus buildup. One area where thrombus buildup is troublesome is the aortic arch. Atheroma in the aortic arch can be a nidus for clot. If blood flow from the heart is not hemodynamically normal it can result in thrombus deposition in the arch. Alternatively, thrombus deposition in the arch could be caused by aneurysmal dilation which causes slower than normal velocities as well as regions along the curvature of the bulge where recirculating zones and stagnation develop which lead to further thrombus formation.

[4] In order to repair the large cardiovascular structures near the heart, relatively large catheter systems often need to be advanced across the aortic arch. These larger catheter systems are relatively stiff so they may require additional force to advance around the curvature of the arch. The relative stiffness of the catheter will bias the catheter toward the outer curvature of the arch and the forces generated can break emboli free if the catheter is advanced through thrombotic regions of the arch.

[5] Further, over time calcified deposits can form on the leaflets of the native aortic valve. Then, when a large structural heart prosthetic such as an aortic valve is deployed, the prosthetic can knock calcified particles off of the native aortic valve leaflets. If these break free they form emboli which can also travel distally including into the great vessels.

[6] If emboli form in the aortic arch or the aortic valve, this can be especially problematic as the emboli will travel distally causing complications in the bloodstream. There are three main outlets through which they may travel: the great vessels, the visceral branch vessels, or to the distal/lower extremities. If the emboli travel through the great vessels they could travel to the arms that can lead to ischemia, limb necrosis and amputation. But the emboli could also travel to the brain that may cause stroke that is very problematic. If the emboli travel to the branch vessels of the visceral segment, this can cause bowel ischemia or infarction that can be deadly. Finally if the emboli travel to the distal extremities, this may lead to ischemia, limb necrosis and amputation.

[7] As the diameter and number of emboli increase, the emboli become more problematic. For instance, emboli having a diameter of less than 100 micrometers are less problematic. Emboli having a diameter greater than 100 micrometers should be trapped in a filtration system. [8] The risk of stroke during transcatheter aortic valve replacement (TAVR) is substantial; close to 5% based on recent analyses. However, the risk of cerebral embolic phenomena has been documented to be much higher with an incidence of 40-80%. The current patient population best served by TAVR are those who are non-operative, of high surgical risk or intermediate surgical risk. Typically the higher risk patients are elderly and have significant comorbidities that may predispose them to cerebral embolism and stroke. Non-paradoxic stroke as a result from transcatheter aortic valve implantation (TA.VI) can be traced to aortic atheroma, valve debris, air or ventricular or atrial, aortic or valvular thrombus. Atheroma can be scraped and carried proximal to the great vessels from descending aortic arch segments. Atheroma can be dislodged during valve transit around the arch and embolize primarily. Valve debris can be dislodged during valve crossing or during valve deployment. Air can be introduced into the aorta from the TAVI system or from balloon rupture. Ventricular thrombus can be dislodged with wire in the left ventricle. Atrial appendage thrombus can be dislodged during rapid pacing. After TAVR, thrombus can form in situ in the aorta or on the valve stent or leaflets leading to a later event. In fact, many strokes occur after all of the TAVR equipment has been removed when a patient is recovering.

[9] In a TAVR, the catheter is brought from a groin access, through the aorta, over the arch, and into the native valve before deployment. The large size of the valve on the stent necessitates a catheter having a larger diameter. Finally, in an ascending aortic aneurysm or dissection a stent graft is brought again from the same approach. The stent graft is then deployed above the sinotubular junction and below the braciocephalic artery. Again, this is a relatively large stent graft necessitating a large catheter being advanced up and over the aortic arch potentially breaking loose thrombus thereby forming dangerous emboli.

[10] Thus, in a first aspect, a catheter system is disclosed including (a) a first catheter having a first end and a second end, the first catheter defining a first lumen, (b) a second catheter having a first end and a second end, the second catheter defining a second lumen, wherein the first catheter is positioned at least partially within the second lumen of the second catheter, and wherein the second catheter and the first catheter and moveable with respect to each other, and (c) a filter having a first end and a second end such that the first end of the filter is coupled to the first catheter, wherein the filter comprises an expandable frame and a semipermeable membrane coupled to the expandable frame, and wherein the expandable frame has shape memory and is movable from a compressed position to an expanded position in response to the second catheter being retracted relative to the first catheter and/or the first catheter being advanced relative to the second catheter.

[lij in a second aspect, a method is provided that includes: (a) introducing a guidewire into an arterial configuration via arterial access, (b) loading the catheter system according to the first aspect onto the guidewire, (c) advancing the catheter system along the guidewire into the arterial configuration, and (d) retracting the second catheter relative to the first catheter thereby permitting the filter to transition from the compressed position to the expanded position.

[12] These as well as other aspects, advantages, and alternatives, will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings.

Brief Description of the Drawings

[13] Figure 1A is a perspective view of a catheter system in a compressed position, according to an example embodiment.

[14] Figure IB is a perspective view of the catheter system of Figure 1A in an expanded position, according to an example embodiment.

[15] Figure 2 is a perspective view of the catheter system of Figure 1 A in an expanded position in an aortic arch, according to an example embodiment. [16J Figure 3 is a perspective view of an example catheter system, according to an example embodiment.

[17] Figure 4 is a perspective view of another example catheter system, according to an example embodiment.

[18] Figure 5 is a perspective view of another example catheter system, according to an example embodiment.

[19] Figure 6 is a flow chart depicting functions that can be carried out in accordance with example embodiments of the disclosed methods.

Detailed Description of the Invention

[20] The description of the different advantageous arrangements are presented for purposes of illustration and description, and are intended to be exhaustive or limited to the examples in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Further, different advantageous examples may provide different advantages as compared to other advantageous examples. The example or examples selected are chosen and described in order to best explain the principles of the examples, the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various examples with various modifications as are suited to the particular use contemplated.

[21] As used herein, with respect to measurements, "about" means +/- 5 %.

[22] As used herein, "coupled" means associated directly, as well as indirectly. For example, a member A may be directly associated with a member B, or may be indirectly associated therewith, e.g., via another member C. It will be understood that not all relationships among the various disclosed elements are necessarily represented.

[23] Unless otherwise indicated, the terms "first," "second," etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to, e.g., a

\ "second" item does not require or preclude the existence of, e.g., a "first" or lower-numbered item, and/or, e.g., a "third" or higher-numbered item.

[24] Reference herein to "one embodiment" or "one example" means that one or more feature, structure, or characteristic described in connection with the example is included in at least one implementation. The phrases "one embodiment" or "one example" in various places in the specification may or may not be referring to the same example.

[25] As used herein, apparatus, element and method "configured to" perform a specified function is indeed capable of performing the specified function without any alteration, rather than merely having potential to perform the specified function after further modification. In Other words, the apparatus, element, and method "configured to" perform a specified function is specifically selected, created, implemented, utilized, programmed, and/or designed for the purpose of performing the specified function. As used herein, "configured to" denotes existing characteristics of an apparatus, element, and method which enable the apparatus, element, and method to perform the specified function without further modification. For purposes of this disclosure, an apparatus, element, and method described as being "configured to" perform a particular function may additionally or alternatively be described as being "adapted to" and/or as being "operative to" perform that function.

[26] As used herein, a "catheter" is an apparatus that is connected to a deployment mechanism and is configured to house a prosthetic device that can be delivered over a guidewire. The catheter may include a guidewire lumen for over-the-wire guidance and may be used for delivering the medical device to a target lumen.

[27] As used herein, a "guidewire" is an elongated cable comprised of one or more biocompatible materials including metals and polymers. Guidewires may be used for selecting target lumens and guiding catheters to target deployment locations. Guidewires are typically definecj as wires used independently of other devices that do not come as part of an assembly.

[28] As used herein, a "stent" is a device that is advanced through emboli or a clot in the form of an occlusion and configured to expand and embed in the clot. Once embedded in the occlusion, the stent may then be retracted to restore blood flow and aid thrombectomy in acute embolic stroke.

[29] As used herein, "target vessel" refers to the blood vessel or artery in which the apparatus is deployed. The target vessel may further include artificial lumens used, for example, as teaching aids.

[30] As used herein, the "filter" reters to a material that may effectively permit blood flow through the filter but prevent particles having a diameter greater than about 100 micrometers from passing therethrough.

[31] As used herein, the "frame" refers to a structure capable of having shape memory that comprises a bio-compatible material.

[32] As used herein, a "membrane" is a thin pliable sheet of material.

[33] As used herein, "lumen" refers to a passage within an arterial or tubular structure, such as the pulmonary arteries or a passage within the tubular housings or catheters through which the guidewire may be disposed.

[34] As used herein, "first end" refers to a proximal end of the device or component thereof, and "second end" refers to a distal end of the device or component thereof.

[35] As used herein, "distal" with respect to a portion of the apparatus means the end of the device (when in use) nearer the treatment zone (e.g., the pulmonary artery) of the subject and the term "proximal" means the portion of the device (when in use) further away from the targeted lumen of the subject and nearer the access site and the operator. [36] During an aortic valve replacement or an ascending aortic aneurysm stent graft placement, cerebral embolic protection may be helpful. To perform this procedure, a guidewire would first be advanced via a femoral access through the iliac artery and aorta, and over the aortic arch. Then, the catheter carrying the filter device would be advanced over the guidewire and positioned within the aortic arch. The radiopaque marker on the catheter may aid in positioning. Next, the second catheter can be retracted relative to the first catheter and/or the first catheter can be advanced relative to the second catheter until the filter is deployed. If the filter is not positioned properly along the axis of the aorta, the operator can advance the second catheter to recapture, reposition, and redeploy the filter.

[37] When the filter is deployed, a prosthetic device (i.e., aortic valve or stent graft) can be deployed via balloon inflation through the first catheter or by releasing a self- expanding prosthetic device via movement of the first catheter relative to a third catheter, as discussed in detail below. This allows the same groin access to be utilized to deploy the aortic valve or stent graft as was used to deploy the filter. The prosthetic device can be a part of the first catheter. Alternatively, the prosthetic device can be a separate device which is brought through the first catheter after the filter is deployed.

[38] Once the aortic valve or stent graft is placed, the filter can be removed. First the second catheter is re-advanced retracting the first catheter back into the second catheter, thereby trapping the embolic particles contained within the filter. Once the filter and any ensuing emboli are in the first catheter and second catheter, the emboli can be removed along with the first catheter and the second catheter from the body.

[39] Various other features of the example systems discussed above, as well as methods for using these systems, are also described hereinafter with reference to the accompanying figures. Illustrative, non-exhaustive examples of the subject matter according the present disclosure are provided below. [40] With respect to the Figures, Figures 1A-1B illustrate a catheter system 100 according to an example embodiment. The catheter system 100 includes a first catheter 102 having a first end 104 and a second end 106 opposite the first end 104. The first catheter 102 defines a first lumen 108. The catheter system 100 also includes a second catheter 110 having a first end 112 and a second end 114 opposite the first end 112. The second catheter 110 defines a second lumen 116. As shown in Figures 1A-1B, the first catheter 102 is positioned at least partially within the second lumen 116 of the second catheter 110. The second catheter 110 and the first catheter 102 are moveable with respect to each other. The catheter system 100 also includes a filter 118 having a first end 120 and a second end 122 such that the first end 120 of the filter 118 is coupled to the first catheter 102. The filter 118 comprises an expandable frame 124 and a semipermeable membrane 126 coupled to the expandable frame 124. The expandable frame 124 has shape memory and is movable from a compressed position (as seen in Figure 1A) to an expanded position (as seen in Figure IB) in response to the second catheter 1 10 being retracted relative to the first catheter 102 and/or the first catheter 102 being advanced relative to the second catheter 110.

[41] The first end 120 of the filter 118 may be coupled to the first catheter 102 at a distance proximal to the second end 106 of the first catheter 102, as shown in Figure IB. A longitudinal axis of the first lumen 108 may be parallel to a longitudinal axis of the second lumen 116, as shown in Figure 1A. The second end 106 of first catheter 102 and the second end 114 of the second catheter 1 10 may each include a radio-opaque marker 128, 130. In addition, one or more of the first catheter 102, the second catheter 110, and the expandable frame 124 may include a hydrophilic coating.

[42] In another embodiment, the second end 122 of the filter 118 is coupled to the first catheter 102 at the second end 106 of the first catheter 102. Such a coupling may be in place of or in addition to the coupling of the first end 120 of the filter 118 to the first catheter 102. In one example, as shown Figure IB, the second end 122 of the filter 1 18 may include one or more struts 131 extending from the second end 122 of the filter 1 18 to the exterior surface 140 of the first catheter 102. The one or more struts 131 may have shape memory to move from the compressed position to the expanded position. The one or more struts 131 may provide an outward force to radially bias the expandable frame 124 in the expanded position such that the second end 122 of the filter 1 18 is configured to conform to a lumen 132 of a target vessel 134 in the expanded position, as shown in Figure 2. In another example, the expandable frame 124 itself provides the outward force such that the expandable frame is radially biased outward in the expanded position without the need for the one or more struts 131.

[43] The expandable frame 124 may be coupled to the semipermeable membrane 126 along a perimeter of the second end 122 of the filter 1 18. In one example, the expandable frame 124 has a cone-shape in the expanded position such that the second end 122 has a larger diameter than the first end 120. In particular, the tapered first end 120 of the filter 1 18 permits the expandable frame 124 and the filter 1 18 to form an outward expanding cone- shape at the first end 120 to capture emboli in the filter 1 18 when the filter 1 18 is advanced back into the first catheter 102. This capability may beneficially capture particles that break away from the filter during re-sheathing of the cone-shaped second end 122 of the filter 1 18 into the second lumen 116 of the second catheter 1 10. In another example, the expandable frame 124 has an elongated sleeve shape in the expanded position. In such an example, the expandable frame 124 and filter 1 18 may taper slightly from the second end 122 that is free to the first end 120 that is coupled to the first catheter 102.

[44] The semipermeable membrane 126 should be of sufficient porosity to capture particles that are large enough to create dangerous levels of ischemia. In one example, the semipermeable membrane 126 is configured to prevent the passage therethrough of particles having a diameter greater than about 100 μηι. The semipermeable membrane 126 may include a polyethylene terephthalate (PET) knit fabric, dacron, polyester, polycaprolactone, polyethylene, polypropylene, polyvinylchloride, polyethersulfone, polylactide, polyglycolide, polyethersulfone, polyetrafluoroethylene, polyetheretherketone, polysulfone, polypropylene and combinations thereof.

[45] In one example, a length of the filter 1 18 from the first end 120 to the second end 122 may range from about 10 mm to about 500 mm. In another example, a diameter of the second end 122 of the filter 1 18 in the expanded position may range from about 5 mm to about 100 mm. Further, the filter 1 18 may have a thickness ranging from about 0.001 mm to about 0.5 mm.

[46] In one example, the semipermeable membrane 126 may include a plurality of shape memory wires. Such shape memory wires may comprise nitinol, titanium, titanium alloys, or copper-aluminum-nickel alloys as examples. In such an example, the shape memory wires may be woven together in a cross-hatch pattern to form the semipermeable membrane 126. In another example, the semipermeable membrane 126 further includes a filter media having the plurality of shape memory wires disposed therein, and the filter media is porous, cross-hatched or multi-layered. In yet another example, the plurality of shape memory wires are curved radially outward to bias the expandable frame 124 to the expanded position.

[47] As shown in Figure 1A, the first catheter 102 has an outer diameter 136, and the second catheter 1 10 has an inner diameter 138 that is greater than the outer diameter 136 of the first catheter 102. In one example, the outer diameter 136 of the first catheter 102 ranges from about 0.5 mm to about 3 mm. In another example, the inner diameter 138 of the second catheter 1 10 ranges from about 0.5 mm to about 8 mm. [48] The filter 1 18 may be positioned at least partially between an exterior surface 140 of the first catheter 102 and an interior surface 142 of the second catheter 1 10 in the compressed position, as shown in Figure 1A. In such an example, as shown in Figure 3, the first catheter 102 may have a first outer diameter 144 for a first portion 145 of the first catheter 102, and the first catheter 102 may have a second outer diameter 146 for a second portion 147 of the first catheter 102. The first outer diameter 144 is greater than the second outer diameter 146. As such, the outer diameter of the first catheter 102 is reduced in the area in which the filter 118 is positioned prior to deployment. In such an example, the first catheter 102 may have a third outer diameter Γ48 for a third portion 149 of the first catheter 102, where the second portion 147 is positioned between the first portion 145 and the third portion 149. The third outer diameter 148 may be equal to the first outer diameter 144.

[49] In another example, as shown in Figure 4, the catheter system 100 may further include a third catheter 150 having a first end 152 and a second end 154 opposite the first end 152. The third catheter 150 is positioned at least partially within the first lumen 108 of the first catheter 102, and the third catheter 150, the second catheter 1 10, and the first catheter 102 are with respect to each other. The movement of the third catheter 150 with respect to the first catheter 102 may thereby unsheath a self-expanding stent valve 158. In such an example, the outer diameter of the third catheter 150 ranges from about 0.5 mm to about 2 mm, for example. The third catheter 150 upon which the self-expanding stent valve 158 is mounted may be a wire or a catheter. The third catheter 150 may include mounting brackets 162 for the self-expanding stent valve 158.

[50] In another example, as shown in Figure 5, the filter 1 18 may be detachable from the first catheter 102 via a coupling mechanism 164. The coupling mechanism 164 may take a variety of forms. In one example, the coupling mechanism 164 may include male and female mating threads. The male and female portions of the mating threads may be made from a bio-compatible metal such as titanium, nitinol or a hard bio-compatible polymer, as examples. Once the filter 1 18 is deployed, the first catheter 102 can be twisted in order to detach the first catheter 102 from the filter 1 18. In another example, the coupling mechanism 164 may include a releasable pull cord within the first catheter 102. In another example, the coupling mechanism 164 may include wiring configured to impart an electric charge to a coupling between the second end 122 of the filter 1 18 and the first catheter 102. In yet another example, the coupling mechanism 164 may include an inflatable balloon configured to fracture the connection between the first catheter 102 and the filter 118 upon inflation. Other example coupling mechanisms are possible as well.

[51] In one embodiment, the first end 120 of the filter 1 18 may include one or more snarable features 168, which may be snared by a guidewire from the descending aorta to remove the filter 1 18 from the target vessel after completion of a procedure. Other snarable features 170 can be added to the second end 122 of the filter 118, thereby enabling the operator to pull on a snare wire effectively bending the second end 122 of the filter 1 18 in the direction of the first end 120 of the filter 1 18 while the first end 120 of the filter 1 18 is at least partially positioned within the first lumen 108 of the first catheter 102, thereby trapping the emboli in the filter 118 for safe removal from the patient. In another embodiment, as discussed above in relation to Figure 4, the filter 1 18 may be detached from the first catheter 102 via the coupling mechanism 164 and left in the target vessel to continue filtering after a procedure is completed. In a further embodiment, the filter 1 18 may be dissolved or be absorbed by a patient's body after a period of in vivo exposure.

[52] In yet another embodiment, as shown in Figure 5, the catheter system 100 may include a second coupling mechanism 174 positioned between the second end 122 of the filter 1 18 and an implanted prosthetic device 172, such as a valve as shown in Figure 5. The second coupling mechanism 174 may comprise any of the examples of the coupling mechanism described above. In such an example, the operator has the option of detaching the connection of the implanted prosthetic device 172 via the second coupling mechanism 174 to detach the implanted prosthetic device 172, or detaching the filter 1 18 from the first catheter 102 via the coupling mechanism 164 to leave the filter 1 18 and/or the implanted medical prosthetic device 172 permanently in vivo.

[53] Figure 6 is a simplified flow chart illustrating a method 200 according to an exemplary embodiment. Although the blocks are illustrated in a sequential order, these blocks may also be performed in parallel, and/or in a different order than those described herein. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and/or removed based upon the desired implementation.

[54] At block 202, the method 200 involves introducing a guidewire 176 into an arterial configuration via arterial access. At block 204, the method 200 includes loading the catheter system 100 according to any one of the embodiments described above onto the guidewire 176. At block 206, the method 200 includes advancing the catheter system 100 along the guidewire 176 into the arterial configuration. At block 208, the method 200 includes retracting the second catheter 110 relative to the first catheter 102 thereby permitting the filter 118 to transition from the compressed position to the expanded position. In another example, the first catheter 102 advanced relative to the second catheter One of skill in the art would appreciate that other arrangements are possible as well, including some arrangements that involve more or fewer steps than those described above, or steps in a different order than those described above.

[55] In one embodiment, the method 200 may further include conforming the second end 122 of expandable frame 124 of the filter 118 to the arterial configuration in which the filter 1 18 is deployed. In another embodiment, the method 200 may further include advancing a prosthetic device 172 coupled to the first catheter 102 to a position distal to the second end 122 of the filter 118. In one example, the prosthetic device 172 comprises a stent mounted on the first catheter 102. In another example, the prosthetic device 172 comprises a valve mounted on the first catheter 102, such as a self-expanding stent valve 158. Other prosthetic device 172 are possible as well.

[56] In another embodiment, the method 200 may further include capturing at least one particle on the semipermeable membrane 126 of the filter 118. In one example, the at least one particle includes embolic material. In another embodiment, the method 200 may further include advancing the second catheter 1 10 toward the second end 122 of the filter 1 18 and thereby transitioning the filter 118 from the expanded position to the compressed position in which the filter 1 18 is positioned within the second lumen 116 of the second catheter 1 10. In another embodiment, the method 200 may further include retaining at least one particle between an exterior surface 140 of the first catheter 102 and the semipermeable membrane 126 of the filter 1 18. In another embodiment, the arterial configuration is an aortic arch, and the method 200 may further include positioning the second end 106 of the first catheter 102 proximal to the innominate artery prior to retracting the second catheter 110. In yet another embodiment, the method 200 may further include advancing the third catheter 150 relative to the first catheter 102, thereby permitting a self-expanding stent valve 158 coupled to the third catheter 150 to transition from a compressed position to an expanded position.

[57] In yet another example, the method 200 may further include detaching the first end 120 of the filter 1 18 from the first catheter 102. In yet another example, the method 200 may further include snaring the second end 122 of the filter 1 18 via a snarable feature 170 coupled to the second end 122 of the filter 1 18, and pulling the second end 122 of the filter 1 18 towards the first end 120 of the filter 1 18 while the first end 120 of the filter 118 is at least partially positioned within the first lumen 108 of the first catheter 102. In such an example, the second end 122 of the filter 1 18 can be snared and pulled toward the first catheter 102, thereby pulling the second end 122 of the filter 1 18 in the direction of the first end 120 of the filter 1 18, essentially trapping the embolic material in the filter 1 18 prior to safely removing from the patient.

[58] In the above description, numerous specific details are set forth to provide a thorough understanding of the disclosed concepts, which may be practiced without some or all of these particulars. In other instances, details of known devices and/or processes have been omitted to avoid unnecessarily obscuring the disclosure. While some concepts were described in conjunction with specific examples, it will be understood that these examples are not intended to be limiting.

Claims

1. A catheter system comprising:

a first catheter having a first end and a second end, the first catheter defining a first lumen;

a second catheter having a first end and a second end, the second catheter defining a second lumen, wherein the first catheter is positioned at least partially within the second lumen of the second catheter, and wherein the second catheter and the first catheter are moveable with respect to each other; and

a filter having a first end and a second end such that the first end of the filter is coupled to the first catheter, wherein the filter comprises an expandable frame and a semipermeable membrane coupled to the expandable frame, and wherein the expandable frame has shape memory and is movable from a compressed position to an expanded position in response to the second catheter being retracted relative to the first catheter and/or the first catheter being advanced relative to the second catheter.

2. The catheter system of claim 1, wherein the expandable frame is radially biased outward in the expanded position such that the second end of the filter is configured to conform to a lumen of a target vessel in the expanded position.

3. The catheter system of claim 1 or 2, wherein the expandable frame has a cone- shape in the expanded position such that the second end of the filter has a diameter larger than the first end of the filter in the expanded position.

4. The catheter system of any one of claims 1-3, wherein the expandable frame has an elongated sleeve shape in the expanded position.

5. The catheter system of any one of claims 1-4, wherein the expandable frame is coupled to the semipermeable membrane along a perimeter of the second end of the filter.

6. The catheter system of any one of claims 1 -5, wherein a length of the filter from the first end to the second end ranges from about 10 mm to about 500 mm.

7. The catheter system of any one of claims 1-6, wherein a diameter of the second end of the filter in the expanded position ranges from about 5 mm to about 100 mm.

8. The catheter system of any one of claims 1-7, wherein a longitudinal axis of the first lumen is parallel to a longitudinal axis of the second lumen.

9. The catheter system of any one of claims 1-8, wherein the filter has a thickness ranging from about 0.001 mm to about 0.5 mm.

10. The catheter system of any one of claims 1-9, wherein the semipermeable membrane comprises a plurality of shape memory wires.

1 1. The catheter system of claim 10, wherein the plurality of shape memory wires are woven together in a cross-hatch pattern.

12. The catheter system of claim 10, wherein the semipermeable membrane further comprises a filter media having the plurality of shape memory wires disposed therein, and wherein the filter media is porous, cross-hatched or multi-layered.

13. The catheter system of claim 10, wherein the plurality of shape memory wires are curved radially outward to bias the expandable frame to the expanded position.

14. The catheter system of any one of claims 1-13, wherein the semipermeable membrane is configured to prevent the passage therethrough of particles having a diameter greater than about 100 μηι.

15. The catheter system of any one of claims 1-14, wherein the semipermeable membrane comprises at least one of a polyethylene terephthalate (PET) knit fabric, dacron, polyester, polycaprolactone, polyethylene, polypropylene, polyvinylchloride, polyethersulfone, polylactide, polyglycolide, polyethersulfone, polyetrafluoroethylene, polyetheretherketone, polysulfone, polypropylene and combinations thereof.

16. The catheter system of any one of claims 1-15, wherein the second end of one or more of the first catheter and the second catheter includes a radio-opaque marker.

17. The catheter system of any one of claims 1-16, wherein one or more of the first catheter, the second catheter, and the expandable frame have a hydrophilic coating.

18. The catheter system of any one of claims 1-17, wherein the filter is positioned at least partially between an exterior surface of the first catheter and an interior surface of the second catheter in the compressed position.

19. The catheter system of any one of claims 1-18, wherein the first catheter has an outer diameter, and wherein the second catheter has an inner diameter that is greater than the outer diameter of the first catheter.

20. The catheter system of claim 19, wherein the outer diameter of the first catheter ranges from about 0.5 mm to about 3 mm.

21. The catheter system of claim 19 or 20, wherein the inner diameter of the second catheter ranges from about 0.5 mm to about 8 mm.

22. The catheter system of any one of claims 1 -21 , wherein the first catheter has a first outer diameter for a first portion of the first catheter, and wherein the first catheter has a second outer diameter for a second portion of the first catheter, wherein the first outer diameter is greater than the second outer diameter.

23. The catheter system of any one of claims 1-22, further comprising:

a third catheter having a first end and a second end, wherein the third catheter is positioned at least partially within the first lumen of the first catheter, and wherein the third catheter, the second catheter, and the first catheter are moveable with respect to each other.

24. The catheter system of claim 23, wherein an outer diameter of the third catheter ranges from about 0.5 mm to about 2 mm.

25. The catheter system of any one of claims 1-24, wherein the first catheter is detachable from the filter via a coupling mechanism.

26. The catheter system of any one of claims 1-25, wherein the first end of the filter includes one or more snarable features.

27. A method comprising:

introducing a guidewire into an arterial configuration via arterial access;

loading the catheter system according to any one of claims 1-26 onto the guidewire; advancing the catheter system along the guidewire into the arterial configuration; and retracting the second catheter relative to the first catheter thereby permitting the filter to transition from the compressed position to the expanded position.

28. The method of claim 27, further comprising:

conforming the second end of the filter to the arterial configuration in which the filter resides.

29. The method of claim 27 or 28, further comprising:

advancing a prosthetic device coupled to the first catheter to a position distal to the second end of the filter.

30. The method of any one of claims 27-29, further comprising:

capturing at least one particle via the semipermeable membrane of the filter.

31. The method of any one of claims 27-30, further comprising: advancing the second catheter toward the second end of the filter and thereby transitioning the filter from the expanded position to the compressed position in which the filter is positioned within the second catheter.

32. The method of any one of claims 27-31, further comprising:

retaining at least one particle between an exterior surface of the first catheter and the semipermeable membrane of the filter.

33. The method of any one of claims 27-32, wherein the arterial configuration is an aortic arch, the method further comprising:

positioning the second end of the first catheter proximal to the innominate artery prior to retracting the second catheter.

34. The method of any one of claims 27-33, the method further comprising:

advancing the third catheter relative to the first catheter thereby causing a self- expanding stent valve to transition from a compressed position to an expanded position.

35. The method of any one of claims 27-34, the method further comprising:

detaching the first end of the filter from the first catheter.

36. The method of any one of claims 27-35, the method further comprising:

snaring the second end of the filter via a snarable feature coupled to the second end of the filter; and

pulling the second end of the filter towards the first end of the filter.