WO2018200566A1

WO2018200566A1 - Systems and methods for embolic protection

Info

Publication number: WO2018200566A1
Application number: PCT/US2018/029196
Authority: WO
Inventors: David M. LOOK; Bradley S. Culbert
Original assignee: Incuvate, Llc
Priority date: 2017-04-24
Filing date: 2018-04-24
Publication date: 2018-11-01

Abstract

A system for catching or filtering embolic material in the vascular system of a patient includes an elongate shaft having a proximal end, a distal end, and a longitudinal axis and configured to extend through the lumen of an elongate tube, the proximal end of the shaft configured to be manipulated by a user, the distal end of the shaft configured for placement within the vasculature of a subject, and a blocking member carried on the distal end of the shaft and having a substantially linear elongated state and an expanded state having a planar spiral shape defined by a series of winds.

Description

SYSTEMS AND METHODS FOR EMBOLIC PROTECTION

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The field of the invention generally relates to distal embolic protection devices or flow control devices for vascular catheter-directed therapies.

Description of the Related Art

[0002] A treatment method for removing undesired matter such as thrombus from a blood vessel of a patient involves use of an aspiration catheter having elongate shaft formed with an aspiration lumen extending therein. An aspiration catheter may also include a guidewire lumen for placement of a guidewire, which is used to guide the aspiration catheter to a target site in the body. By applying a vacuum (i.e. negative pressure) to a proximal end of the aspiration lumen, for example, with a syringe having a hub that is connected to the proximal end of the aspiration catheter, the matter can be aspirated into an aspiration port at the distal end of the aspiration catheter, into the aspiration lumen, and thus be removed from the patient.

[0003] Thrombus aspiration and other catheter-directed therapies such as stenting, angioplasty, atherectomy, may disrupt thrombus residing in or near the target area of treatment. Catheter-deliverable distal protection devices have been developed to attempt to catch emboli or potential emboli, such as pieces of thrombus, in order to prevent downstream embolization, which may induce severe consequences including stroke or myocardial infarction. Besides creating a physical barrier to downstream embolization, the blood flow itself may be decreased or stopped, for example, by the use of a balloon.

SUMMARY OF THE INVENTION

[0004] In one embodiment of the present disclosure, a system for catching or filtering embolic material in the vascular system of a patient includes an elongate shaft having a proximal end, a distal end, and a longitudinal axis and configured to extend through the lumen of an elongate tube, the proximal end of the shaft configured to be manipulated by a user, the distal end of the shaft configured for placement within the vasculature of a subject, and a blocking member carried on the distal end of the shaft and having a substantially linear elongated state and an expanded state having a planar spiral shape defined by a series of winds.

[0005] In another embodiment of the present disclosure, a system for catching or filtering embolic material in the vascular system of a patient includes an elongate shaft having a proximal end, a distal end, and a longitudinal axis and configured to extend through the lumen of an elongate tube, the proximal end of the shaft configured to be manipulated by a user, and a blocking member carried by the distal end of the shaft and having a substantially linear elongated state and an expanded state having a planar spiral shape.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 is a perspective view of a spiral barrier device in a first state according to an embodiment of the present disclosure.

[0007] FIG 2 is a perspective view of the device of FIG. 1 in a second state.

[0008] FIG. 3 is a detail view of FIG. 1 taken within circle 3.

[0009] FIG. 4 is a perspective view of a spiral barrier device according to an embodiment of the present disclosure.

[0010] FIG. 5 is a perspective view of a spiral barrier device in use, according to an embodiment of the present disclosure.

[0011] FIG. 6 is a perspective view of a spiral barrier device according to an embodiment of the present disclosure.

[0012] FIG. 7 A is a perspective view of a spiral barrier device according to an embodiment of the present disclosure.

[0013] FIG. 7B is a perspective view of a spiral barrier device according to an embodiment of the present disclosure.

[0014] FIG. 8 is a perspective view of a system for performing a vascular procedure in a first delivery state, according to an embodiment of the present disclosure.

[0015] FIG. 9 is a perspective view of the system of FIG. 8 in a second delivery state.

[0016] FIG. 10 is a perspective view of the system of FIG. 8 in a third delivery state.

[0017] FIG. 11 is a perspective view of a system for performing a vascular procedure in a first delivery state, according to an embodiment of the present disclosure.

[0018] FIG. 12 is a perspective view of a system for performing a vascular procedure in a first delivery state, according to an embodiment of the present disclosure. [0019] FIG. 13 is a detail view of a spiral barrier device in a first state according to an embodiment of the present disclosure.

[0020] FIG. 14 is a detail view of a spiral barrier device in a first state according to an embodiment of the present disclosure.

[0021] FIG. 15 is a perspective view of a system for performing a vascular procedure after manipulation, according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODFMENTS

[0022] The present invention relates to systems for catheter-directed therapy which include elongate devices having a spiral feature for blocking the migration of thromboemboli or other emboli, or for modifying the flow of blood through a blood vessel. Medical applications for the elongate devices include arteriovenous (AV) fistula, for example AV fistula that are created in arms or legs of hemodialysis patients; temporary vena cava filtering applications; flow control applications; and distal arterial protection.

[0023] Mechanical elimination of thromboembolic material for the treatment of ischemic stroke has been attempted using a variety of catheter-based transluminal interventional techniques. One such interventional technique involves deploying a coil into a thromboembolism (e.g. via corkscrew action) in an effort to ensnare or envelope the thromboembolism so it can be removed from the patient. Such coil-based retrieval systems have only enjoyed modest success overcoming ischemic stroke. This may be due, in part, to thromboembolic material slipping past or becoming dislodged by the coil. In the latter case, the dislodgement of thromboembolic material may lead to an additional stroke in the same artery or a connecting artery.

[0024] Another interventional technique involves deploying a basket or net structure distally (or downstream) from the thromboembolism in an effort to ensnare or envelope the thromboembolism so it can be removed from the patient. This technique may suffer a significant drawback in that the act of manipulating the basket or net structure distally from the occluded segment without angiographic roadmap visualization of the vasculature increases the danger of damaging the vessel. In addition, removing the basket or net structure may permit if not cause thromboembolic material to enter into connecting arteries. As noted above, this may lead to an additional stroke in the connecting artery.

[0025] A still further interventional technique for treating ischemic stroke involves advancing a suction catheter to the thromboembolism with the goal of removing it via aspiration (i.e. negative pressure). To augment the effectiveness of aspiration techniques, a rotating blade has been employed, to sever or fragment the thromboembolism, which may thereafter be removed via the suction catheter. This technique nonetheless increases the danger of damaging the vessel due to the rotating blade.

[0026] FIG. 1 illustrates an elongate wire device 100 having a proximal end 102 and a distal end 104, and configured for placement within a blood vessel, in the vasculature of a patient. The wire device 100 comprises a shaft 106 and a distal blocking feature 108 comprising a spiral. The distal blocking feature 108 is a substantially planar spiral that approximates a plane 118 (see FIG. 3) that is generally perpendicular to the longitudinal axis 110 of the elongate wire device 100 (and shaft 106). The distal blocking feature 108 and the shaft 106 are formed from a wire 112, which may comprise a superelastic or shape-memory alloy, such as a nickel -titanium alloy, or Nitinol. In a particular embodiment, the distal blocking feature 108 is wound into a desired shape and heat set into the substantially planar spiral shape. FIG. 1, thus, illustrates the distal blocking feature 108 in a first, expanded, relaxed (unstressed) state. FIG. 2 illustrates the elongate wire device 100 with a distal portion 108a of the wire 112 that forms the distal blocking feature 108 in a straightened, stressed second state. The second state may be achieved by applying a tensile force between the proximal end 102 and distal end 104 of the elongate wire device 100, or by forcing the distal blocking feature 108 within a substantially small lumen (not shown), such as a catheter lumen. As will be described in further detail, the single linear configuration of the elongate wire device 100 allows it to be inserted through a relatively small lumen of a catheter or sheath. For example, a 0.014 inch (0.35 mm) diameter elongate wire device 100 may be placed through a 0.015 inch (0.38 mm) inner diameter lumen, or a 0.016 inch (0.40 mm) inner diameter lumen, or a 0.017 inch (0.43 mm) inner diameter lumen, or larger, thus allowing very low profile delivery. In an alternative embodiment, the distal portion 108a is set in the shape shown in FIG. 2, and takes the shape of the distal blocking feature 108 of FIG. 1 upon exposure to an elevated temperature (e.g., human blood temperature of about 37°C), thus harnessing the shape-memory characteristics of a shape-memory alloy.

[0027] The wire 112 may have a circular or non-circular cross-section and may have a single transverse dimension or diameter or a varying or tapered transverse dimension or diameter. For example, the shaft 106 may have a diameter of between about 0.008 inches (0.20 mm) and about 0.040 inches (1.02 mm), or between about 0.012 inches (0.30 mm) and about 0.019 inches (0.48 mm), or about 0.014 inches (0.35 mm). The shaft 106 may have a constant diameter, or may taper from its proximal end 1 14 to its distal end 116. In some embodiments, the shaft 106 has a 0.014 inch (0.35 mm) diameter and the wire 112 of the distal blocking feature 108 has a 0.014 inch (0.35 mm) diameter. In other embodiments, the shaft 106 has a 0.014 inch (0.35 mm) diameter, and the wire 112 of the distal blocking feature 108 tapers from 0.014 inches (0.35 mm) to a lesser diameter. As shown in FIGS. 1 and 2, the shaft 106 and the distal blocking feature 108 may comprise a single, continuous wire 112. In other embodiments, the shaft 106 and the distal blocking feature 108 may be formed from two or more different wires, and may be coupled to each other by welding, soldering, brazing, thermal bonding, swaging, tying, braiding, winding, adhesive bonding, or epoxy bonding, or any combination thereof. The shaft 106 may comprise stainless steel (e.g., 304 stainless steel), and be coupled to a distal portion 108a that comprises a superelastic alloy such as nitinol.

[0028] The elongate wire device 100 as depicted in FIGS. 1 and 2 comprises a bare wire 112. In alternative embodiments, the wire 112 may serve as a core wire, and may have a helical coil surrounding it, as is well known within the medical guidewire art. In some embodiments, only the shaft 106 may be covered with a coil, in other embodiments, only the distal blocking feature 108 may be covered with a coil, and in other embodiments, both the shaft 106 and the distal blocking feature 108 may be covered with a coil. In some embodiments, the shaft 106 is surrounded with a less-radi opaque or significantly non- radiopaque coil, such as a stainless steel coil, which may comprise 304 stainless steel. In some embodiments, the distal blocking feature 108 is surrounded with a radiopaque coil, such as a platinum coil, or a platinum alloy coils, such as a 92% platinum/8% tungsten coil. The coils may be secured to the wire 112 by any combination of mechanical assembly, adhesive, or soldering/brazing/welding, at one or both ends of the coil, or even at one or more intermediate portions of the coil. It can be appreciated that a blocking feature 108 whose entire distal portion 108a of wire 112 is either coated (e.g., plated or ion-implanted) with a radiopaque material, or whose entire distal portion 108a of wire 112 is covered with a radiopaque coil, has radiopacity not only at its outer diameter, but at a number of areas along the spiral. The radiopaque portion follows a spiraled cylinder. Thus, visibility of the distal blocking feature 108 in its expanded state on radiography or fluoroscopy can demonstrate not only the effective diameter the distal blocking feature 108 (e.g., in relation to the blood vessel diameter) but also the extent that the distal blocking feature 108 maintains a planar configuration, or strays from the planar configuration (e.g., if it is pulled into a conical or funnel shape). In some embodiments, the radiopacity can even be varied along the length of the distal portion 108a of wire 112. For example, multiple coils may be secured over the wire 112 along the distal portion 108a, such as alternating stainless steel coils and radiopaque (e.g., platinum, etc.) coils, in order to somewhat limit the overall "brightness" of the radiopacity, while still allowing an image that suggests the overall presence of the distal blocking feature 108. In other embodiments, a coil having a varying outer diameter, or a coil would from a tapered diameter wire may be utilized, so that the radiopacity either increases toward the distal end of the distal portion 108a or decrease toward the distal end of the distal portion 108a. In other embodiments, only the first inner wind 135 and last outer wind 137 are covered with a radiopaque coil (see FIG. 4) while the intermediate length 139 may be covered with a coil having low or virtually no radiopacity. Thus, the inner and outer diametric portions of the distal blocking feature 108 are clearly indicated. Alternatively, the first inner wind 135 and last outer wind 137 are covered with a radiopaque coil, with no coil in between them.

[0029] FIG. 3 shows in more detail that the planar spiral shape of the distal blocking feature 108 is an Archimedean spiral 120 having a free distal end 122. The free distal end 122 has a tapered-down portion 124, which serves to increase the flexibility of the free distal end 122, making it more atraumatic (e.g., when being moved against a blood vessel wall, etc.). The Archimedean spiral 120 has windings with a pitch P equal to or greater than the diameter of the wire 112 at the distal blocking feature 108. Thus, there is a gap G of greater than or equal to zero. In some embodiments, the gap G is between about 1 mm and about 6 mm, or between about 3 mm and about 5 mm. The pitch P and the wire diameter can be configured such that the gap G is within a desired range to allow desired performance characteristics, including: the capture of thromboemboli/emboli, the filtering of blood, and the control of blood flow. The size of the gap G, for example, can be configured (via winding geometry and wire diameter) in order to set the size (e.g., diameter) of emboli that are allowed to pass through the gap G and size of those that cannot. In inner hole 126 with inner diameter d can likewise be configured (via winding geometry and wire diameter) to allow a certain amount of blood flow through it. For example, it may be desired that a device configured for use in coronary arteries, allows enough blood flow to avoid elevation of ST- segments, or angina, or even myocardial infarction. Multiple models of the elongate wire device may include the same overall diameter D of the distal blocking feature 108, but different gaps G, or different inner diameters d, so that, for example, if a first model fits in the blood vessel of choice, but does not allow enough blood flow, it may be removed, and a second model having the same overall diameter D, but either a larger gap G and/or a larger inner diameter d may be placed. An similar strategy may be used in a blood vessel that feeds any other critical organ, such major vessels (vena cavae, aorta) or cerebral, carotid, or vertebral arteries, or even renal arteries, to avoid stroke or kidney failure, for example. The inner hole 126 may even be configured to allow a guidewire or catheter to be passed through it. For example, the inner diameter d may be between 0.5 mm and 5 mm, or about 1 mm to 3 mm.

[0030] FIG. 4 illustrates an elongate wire device 130 comprising a shaft 132 and a distal blocking feature 134. The distal blocking feature 134 includes a wire portion (not visible) that is a tapered down, smaller diameter extension of the shaft 132. The wire portion is covered by a distal radiopaque coil 141, a proximal radiopaque coil 143, and an intermediate stainless steel coil 145. A free distal end 136 includes a ball end 138 having a hemispherical shape, for improved atraumatic characteristics. The ball end 138 may comprise a weld of an end of the wire portion to an end of the distal radiopaque coil 141. Alternatively, the ball end 138 may comprise solder, braze, adhesive, or epoxy that secures an end of the distal radiopaque coil 141 to and end of the wire portion.

[0031] FIG. 5 illustrates an elongate wire device 140 comprising a shaft 142 and a distal blocking feature 144. A free distal end 146 includes a distal section 148 that is curved out of the plane of the distal blocking feature 144. As depicted in FIG. 5, the distal section 148 curves slightly toward the distal 149 and away from the proximal 160. As will be described in further detail, the free distal end 146 is the first portion of the elongate wire device 140 that will exit the distal end of a catheter lumen (when delivered), and thus, by placing a particular curve (J-tip, etc.) on the distal section 148, some orientation can be induced during the delivery of the distal blocking feature 144 (as it moves to its expanded state within a blood vessel).

[0032] FIG. 6 illustrates an elongate wire device 150 comprising a shaft 152 and a distal blocking feature 154. Like the distal section 148 of the elongate wire device 140 of FIG. 5, the elongate wire device 150 of FIG. 6 includes a distal section 156, having a free distal end 158, which, when the distal blocking feature is in its expanded state, is curved slightly curved out of the plane of the distal blocking feature 154. However, the distal section 156 is curved toward the proximal 160 and away from the distal 149. A configuration such as the distal blocking feature 144 of FIG. 5 may be chosen so that thrombus 162 at its distal extremity 164 sits as flush as possible with the plane of the distal blocking feature 144. A configuration such as the distal blocking feature 154 of FIG. 6 may be chosen so that the distal section 156 provides some "searching" or "finding" utility, like a j -tip guidewire, when the distal blocking feature 154 is being delivered from a catheter lumen. But, additionally, the curve of the distal section 156 "tucks" it out of the way, behind the distal blocking feature 154 when the distal blocking feature 154 is in its expanded state. This may be desirable if there is atherosclerotic plaque, distal sidebranches or ostia, an aneurysm, or sensitive (e.g., spasm prone) vessel wall or other tissue that should be contacted as little as possible.

[0033] FIG. 7 A illustrates an elongate wire device 170 comprising a shaft 172 and a distal blocking feature 174. Unlike the elongate wire devices 100, 130, 140, 150 of FIGS. 3- 6, whose shafts 106, 132, 142, 152 are coupled to (or continue on to) an inner extreme 166 (FIG. 6) of the spiral, the elongate wire device 170 of FIG. 7 A comprises a reverse configuration. The spiral may be configured with a variety of radii of curvature at its most proximal portion, adjacent to the distal end of the shaft. A larger radius of curvature may facilitate the delivery and recapture of the distal blocking feature 174 within a catheter lumen. A smaller radius of curvature may allow the distal end of a catheter to be placed closer to the distal blocking feature 174 with the distal blocking feature 174 is in its expanded state, and/or more centered in relation to the distal blocking feature 174. As shown in FIG. 7A, the shaft 172 couples to (or continues on to) an outer extreme 176 of the distal blocking feature 174. Thus, the elongate wire devices 100, 130, 140, 150 of FIGS. 3-6 may be chosen in certain cases in which the shaft 106, 132, 142, 152 is desired to reside generally coaxial with a catheter or lumen (e.g., within the catheter lumen). The elongate wire device 170 of FIG. 7 A may be chosen in certain cases in which the shaft 172 is to extend either in a non-central lumen of a catheter, or to extend outside of (next to) the catheter, or even up against the vessel wall. A distal section 178 having a curve 180 and a flattened portion 182 (to increase flexibility) is atraumatic, and extends distally (out of the plane of the distal blocking feature 174. Alternatively, a free distal end may terminate within the plane in the center 184 of the distal blocking feature 174. Though the spirals in the elongate wire devices 100, 130, 140, 150 of FIGS. 3-6 follow the right-hand rule (looking from proximal to distal) and the elongate wire device 170 of FIG. 7 A follows the left-hand rule, embodiments comprising the opposite-handed winding are possible in each case. Embodiments are even possible that include both directions (left and right) of winding within a single distal blocking feature (see FIG. 14).

[0034] FIG. 7B illustrates an elongate wire device 190 comprising a shaft 192 and a distal blocking feature 194. The elongate wire device 190 has a similar construction as the elongate wire device 170 of FIG. 7 A, except the shaft 192 is co-linear with a central axis 196 that passes through the center 198 of the distal blocking feature. Thus, the elongate wire device 190 shares the generally central axis location of the elongate wire devices 100, 130, 140, 150 of FIGS. 1-6, but also shares the interface with and extension to an outer extreme device 170 of FIG. 7 A.

[0035] FIG. 8 illustrates a system for performing a vascular procedure 200 comprising a catheter 202 and the elongate wire device 100 of FIGS. 1-3, in use within a blood vessel 199, shown longitudinally sectioned. The catheter 202 has a distal end 204 which may include a radiopaque marker band 206. The distal end 204 is configured to be inserted (e.g., via the Seldinger approach, via femoral, brachial, radial, jugular, etc. veins or arteries) into a target area 197 within the blood vessel 199. The catheter 202 has a lumen 208 extending therethrough and may include a hub or connector 210 coupled to its proximal end 212. The connector 210 may have a valve 222, such as a Touhy-Borst or spring-loaded seal, for sealing over a device placed therethrough, such as the elongate wire device 100. Alternatively, the catheter 202 may be placed through another catheter, such as a guiding catheter and/or a sheath. The lumen 208 may include an end hole 214 and/or one or more sideholes 216 which communicate to the interior 195 of the blood vessel 199. In one embodiment, the catheter 202 is an aspiration catheter, and the lumen 208 is an aspiration lumen. A vacuum source 218 may be coupled to a hub 220 (e.g., luer) of the connector 210. The vacuum source 218 may include a vacuum pump, a vacuum bottle, or a syringe, such as a syringe with a locking plunger. Suitable systems for aspiration are described by Look et al. in U.S. Patent No. 9,883,877, issued February 6, 2018, and titled Systems and Methods for Removal of Blood and Thrombotic Material, which is hereby incorporated by reference in its entirety for all purposes. In other embodiments, the catheter 202 may be an angioplasty catheter, a stent delivery catheter, an energy-application catheter (radiofrequency, laser, ultrasound, infra-red, near infra-red, etc.), or an infusion catheter, such as a catheter for infusion of an agent, including a drug.

[0036] As shown in FIG. 9, by grasping the elongate shaft 106 of the elongate wire device 100, and by grasping the connector 210 of the catheter 202, the user may place a substantially axially-directed force F on the shaft 106 to move the elongate wire device 100 distally, such that the distal end 104 of the elongate wire device 100 begins to exit the distal end 204 of the catheter 202. In FIG. 10, the shaft 106 has been pushed substantially forward distally such that the distal blocking feature 108 is delivered into the interior 195 of the blood vessel 199. The shaft 106 may be pushed or pulled to adjust the difference in longitudinal locations between the distal blocking feature 108 and the distal end 204 of the catheter 202. Any radiopaque element on the blocking feature 108 or at the distal end 104 of the elongate wire device 100 may be visualized in relation to the radiopaque marker 206 of the catheter 202. Though the radiopaque marker 206 of the catheter 202 is shown spaced a small distance from the extreme of the distal end 204 of the catheter 202, in other embodiments, the radiopaque marker band 206 may be flush with the extreme of the distal end 204. It is contemplated to produce the elongate wire device 100 with a variety of models, some having different distal blocking feature 108 diameters. A small annular gap 224 is shown between the wall 193 of the blood vessel 199 and the distal blocking feature 108. An annular gap 224, if it is small enough, because of the flow profile of blood, may be sufficient to stop flow around the diameter of the distal blocking feature 108 (e.g., if being used in a flow control application), or may be sufficient to stop the passage of emboli around the diameter of the distal blocking feature 108 (e.g., if being used in a distal protection/filter application). However, if a larger diameter model of the distal blocking feature 108 is chosen (i.e., larger than the inner diameter of the blood vessel 199), the outer perimeter of the distal blocking feature 108 may push against and substantially seal against the wall 193 of the blood vessel 199 around the outer perimeter. If the blood vessel 199 is relatively non-compliant (e.g., if it is diseased), and if it has an oval or other non-circular cross-section at or near the target area 197, by a user oversizing or slightly oversizing the diameter of the distal blocking feature 108 in relation to the minor inner diameter of the blood vessel 199, a circular shaped distal blocking feature 108 may be changed to a more oval or non-circular shape, to better conform to the blood vessel 199. Two opposing inward (or even outward) radial forces on the distal blocking feature 108 can serve to change it from a circular to an oval or elliptical shape. A certain amount of oversizing may be acceptable in some cases, even for the purpose of disrupting (e.g., scraping or squeegeeing) the inner wall of a blood vessel, to remove thrombus or material from it. The linear backbone of the spiral shape of the distal blocking feature 108 makes it a relatively safe implement when being pulled, and may safely navigate over, for example, a valve of a vein, or over atherosclerotic plaque, or over a fibrous cap without damaging them. In many cases, this can avoid the distal blocking feature 108 getting caught, as there is always a single, linear portion available to be pulled into a catheter, or to unwrap from a spiral shape.

[0037] FIG. 11 illustrates a system for performing a vascular procedure 230 comprising a catheter 232 and the elongate wire device 100 of FIGS. 1-3, in use within the interior 195 of a blood vessel 199, shown longitudinally sectioned. The catheter 232 includes a lumen 234 extending from a distal end 236 to a proximal end 238, and having a connector 240 coupled thereto. The catheter 232 also includes a guidewire lumen 242 within a side tube 244 carried by the catheter 232. The elongate wire device 100 may be used as a guidewire and placed through the guidewire lumen 242, so that it can be used to track (guide) the catheter 232 while also being able to perform its function as a distal protection device and/or flow control device, when desired. The shaft 106 of the elongate wire device 100 may be backloaded into the guidewire lumen 242 and delivered with the catheter 232, or the elongate wire device 100 may be tracked to the target site 197 first, with the catheter 232 subsequently tracked over it. In some embodiments, a straightening sheath 246 may be carried over the shaft 106 and distal blocking feature 108 to straighten the distal blocking feature 108 during delivery to the target area 197. The straightening sheath 246 may be pulled back and removed, or peeled off and removed from the elongate wire device 100, to allow the distal blocking feature 108 to expand in the desired location within the blood vessel 199. The straightening sheath 246 may comprise ultra-thin walled polyester, such as PET (polyethylene terephthalate). The distal end of the straightening sheath may comprise a more flexible material or may include spiral scores to increase its flexibility. The distal end of the straightening sheath may include metal helical coil reinforcement (e.g., stainless steel, platinum) in order to facilitate flexibility, while also straightening out the wire 112 of the distal blocking feature 108. The catheter 232 may include any of the functions described in relation to the catheter 202 of FIGS. 8-10.

[0038] FIG. 12 illustrates a system for performing a vascular procedure 250 comprising a catheter 232 and the elongate wire device 170 of FIG. 7A, in use within the interior 195 of a blood vessel 199, shown longitudinally sectioned. The catheter 232 includes a lumen 234 extending from a distal end 236 to a proximal end 238 having a connector 240 (as in FIG. 11). The catheter 232 also includes a guidewire lumen 242 within a side tube 244 carried by the catheter 232. A standard guidewire 252 is used through the guidewire lumen 242 to track the catheter 232. In both FIGS. 11 and 12, though a short, single operator exchange guidewire lumen 242 is illustrated, alternatively, a longer or even full catheter length guidewire lumen may be incorporated. The shaft 172 of the elongate wire device 170 is configured to extend along the interior 195 of the blood vessel 199, outside of the catheter 232. A straightening sheath or catheter 246, or simply a standard microcatheter, may be used to deliver the elongate wire device and then removed upon delivery. The blocking feature 174 is shown expanded within the interior 195 of the blood vessel 199, with the elongate wire device 170 completely outside of and separate from the catheter 232. The shaft 172 extends substantially parallel to and adjacent the shaft of the catheter 232.

[0039] FIG. 13 illustrates an elongate wire device 260 having a shaft 262 and a distal blocking feature 264 having a wavy spiral shape. The blocking feature 264 spirals substantially within a plane and, as depicted in FIG. 13, the wave elements 266a-d are also substantially within the plane. In alternative embodiments, the wave elements 266a-d may also or alternatively extend proximally and distally (longitudinally) instead of radially. As shown in FIG.13, the wave elements 266a-d provide for a plurality of openings 268a-d which may be configured to allow a controlled amount of blood flow, and/or to trap a particular minimum size of emboli (e.g, thromboemboli). The openings 268a-d may additionally be sized to allow the passage of a guidewire that may be used in conjunction with the elongate wire device 260. A radiopaque band 269 is shown attached to the distal end 267 of the wire 265 that forms the distal blocking feature 264. The radiopaque band 269 may be crimped, swaged, welded, soldered, brazed or adhesively, hot melt or epoxy bonded to the wire 265. The elongate wire device 260 may comprise any of the materials, dimensions, and constructions previously described herein in relation to the other embodiments.

[0040] FIG. 14 illustrates an elongate wire device 270 having a shaft 272 and a distal blocking feature 274. The distal blocking feature 274 extends substantially within a plane and includes a left-hand spiral portion 276 and a right-hand spiral portion 278. A transition portion 280 between the left-hand spiral portion 276 and the right-hand spiral portion 278 provides for an opening 282 which may function in the same manner as any one of the openings 268a-d of the elongate wire device 260 of FIG. 13. The alternation of the left- hand spiral portion 276 and a right-hand spiral portion 278 can aid in the deployment of the distal blocking feature 274 into a blood vessel, as well as the removal of the distal blocking feature from a 274 from a blood vessel because of the added complexity or randomness of the motion. The motion tends to avoid the device being "wound-up" or tightened, and tends to promote unwinding. The elongate wire device 270 may comprise any of the materials, dimensions, and constructions previously described herein in relation to the other embodiments.

[0041] There are many advantages to the elongate wire devices 100, 130, 140, 150, 170, 190, 260, 270 and systems 200, 230, 250 described herein. The substantially planar distal blocking features allow for a flow control device or distal embolic protection device/filter with a significantly low longitudinal profile. In other words, they do not "stick out" too far either in a distal sense or a proximal sense. Thus, the extreme distal portion of a thrombus can be held or protected, without touching or damaging vascular tissue or other tissue that resides just distal to the target area. This may also be important because blood vessels may taper down in size, such that traditional devices would not even fit in the space required, while elongate wire devices 100, 130, 140, 150, 170, 190, 260, 270 described herein, with their low longitudinal profile are able to fit. The low longitudinal profile also makes it easier to judge, whether via fluoroscopy, x-ray, or other imaging modalities, a precise distance between the distal blocking feature and other radiopaque elements or vascular features. In the case of an embodiment having a fully radiopaque distal blocking feature, the spaces between the spirals may even be identifiable at particular imaging projections. This may allow the user to adjust the device into its most preferable orientation.

[0042] The elongate wire devices 100, 130, 140, 150, 190, 170, 260, 270 described herein may be used by themselves as a stand-alone device, such as a filter or thrombus retrieval device. Or, the elongate wire devices 100, 130, 140, 150, 190, 170, 260, 270 may be used in conjunction with other devices such as stents, balloons, microcatheters, aspiration catheters, infusion catheters, or energy application devices. As described, the continuous linear construction of the elongate wire devices 100, 130, 140, 150, 190, 170, 260, 270 described herein allows greater ease of delivery or deployment out of a catheter lumen or retraction into a catheter lumen. By their linear nature, they have a very small profile (diameter) when pulled into or delivered through a catheter lumen. This greatly aids the delivery of the elongate wire devices 100, 130, 140, 150, 170, 190, 260, 270 into small diameter, distal, and/or tortuous blood vessels. Nevertheless, the large cross-sectional coverage of the blocking features allows for utility in a variety of blood vessel diameters or geometries. Also, as described, the elongate wire devices 100, 130, 140, 150, 170, 190, 260, 270 may be used themselves as a guidewire, to track catheters through blood vessels, thus simplifying and speeding up procedures and reducing their overall cost and complexity. The shaft diameter of the elongate wire device 100, 130, 140, 150, 170, 190, 260, 270 may be sized to match standard guidewire sizes (0.014 inch, 0.018 inch, 0.035 inch, 0.038 inch, etc.).

[0043] The elongate wire devices 100, 130, 140, 150, 170, 190, 260, 270 described herein may be sized such that the distal blocking features are appropriate for flow control or filtering/distal embolic protection in a variety of different blood vessels (veins, arteries) and even other cardiovascular features (patent foramen ovale or other heart septal defect, or an opening created in the ventricular septum). The distal blocking feature diameters may range from 2 mm to 30 mm, and used in vessels as small as minor cerebral or coronary arteries, to the inferior vena cava. The elongate wire devices 100, 130, 140, 150, 170, 190, 260, 270 may even be used as temporary vena cava filters. Though the distal blocking features of the elongate wire devices 100, 130, 140, 150, 170, 190, 260, 270 are described with a linear primary shape that is formed into a secondary spiral shape (simple or complex), in other embodiments, an additional mesh or fabric structure may be used over part or all of the distal blocking features. Though the distal blocking features are described as being substantially planar, it should be understood that some slight variations are substantially the same, for example devices with a slight convex or concave distal blocking feature. During use, a substantially planar spiral shape may slightly deform longitudinally to have a slight distally- pointing or proximally-pointing conical shape, having a significantly smaller longitudinal height than outer diameter.

[0044] FIG. 15 illustrates a system for performing a vascular procedure 300 comprising a catheter 302 and the elongate wire device 100 of FIGS. 1 -3, in use within a blood vessel 199, shown longitudinally sectioned. The catheter 302 includes a lumen 304 extending from a distal end 306 to a proximal end 308 having a connector 310. The catheter 302 also includes a guidewire lumen 312 within a side tube 314 carried by the catheter 302, configured for passage of a guidewire 316. In use, a user deploys the distal blocking feature 108 within the blood vessel 199, and, as shown, may pull on the shaft 106 of the elongate wire device 100 with a tensile force FTI which is transmitted (minus frictional forces) to the to the distal blocking feature 108 as tensile force FT₂. With the distal blocking feature 108 sufficiently expanded within the blood vessel 199 or against a portion of thrombus to impart a frictional holding force at the outer perimeter of the distal blocking feature 108, the tensile force FT₂ increases the spacing (e.g., longitudinal pitch) between each wind of the spiral, thus forming a conical or conical like coil structure having length L. When the elongate wire device 100 is used for flow control purposes, the increase of the spacing between winds increases flow (lessens flow resistance) by allowing blood to flow through the larger interstices. Thus, by pulling or pushing on the shaft 106, a user can manually, and actively, adjust the amount of flow in the blood vessel. As an alternative strategy, the longitudinal adjustment may even be done in an opposite direction (e.g., by pushing, rather than pulling on the shaft 106) to form an inverted cone shape with the distal blocking feature 108.

[0045] In addition, or alternatively to the radiopaque materials (coils, markers, etc.) which may be coupled to the elongate wire devices 100, 130, 140, 150, 170, 190, 260, 270, a coating or coverage of a radiopaque material may be achieve, for example, by ion implantation of radiopaque materials.

[0046] The ranges disclosed herein also encompass any and all overlap, subranges, and combinations thereof. Language such as "up to," "at least," "greater than," "less than," "between," and the like includes the number recited. Numbers preceded by a term such as "approximately", "about", and "substantially" as used herein include the recited numbers (e.g., about 10%= 10%), and also represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms "approximately", "about", and "substantially" may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1%> of, within less than 0.1%> of, and within less than 0.01%> of the stated amount.

Claims

WHAT IS CLAIMED IS:

1. A system for catching or filtering embolic material in the vascular system of a patient comprising:

an elongate shaft having a proximal end, a distal end, and a longitudinal axis and configured to extend through the lumen of an elongate tube, the proximal end of the shaft configured to be manipulated by a user, the distal end of the shaft configured for placement within the vasculature of a subject; and

a blocking member carried on the distal end of the shaft and having a substantially linear elongated state and an expanded state having a planar spiral shape defined by a series of winds.

2. The system of claim 1, wherein the planar spiral shape comprises an

Archimedean spiral.

3. The system of claim 1, wherein the proximal end of the blocking member is integral to the distal end of the shaft.

4. The system of claim 1, wherein the proximal end of the blocking member is coupled to the distal end of the shaft.

5. The system of claim 4, wherein the proximal end of the blocking member is secured to the distal end of the shaft by at least one of welding, soldering, brazing, thermal bonding, swaging, tying, braiding, winding, adhesive bonding, or epoxy bonding.

6. The system of claim 1, wherein the blocking member in its expanded state has a generally circular perimeter.

7. The system of claim 6, wherein the blocking member in its expanded state has a diameter of between about 2 mm and about 30 mm.

8. The system of claim 7, wherein the blocking member in its expanded state has a diameter of between about 2 mm and about 4 mm.

9. The system of claim 1, wherein the blocking member comprises a wire.

10. The system of claim 9, wherein the wire comprises a nickel -titanium alloy.

11. The system of claim 9, further comprising an elongate helical coil carried on the wire.

12. The system of claim 1, wherein the blocking member in its expanded state resides substantially within a plane that is generally perpendicular to the longitudinal axis of the shaft.

13. The system of claim 1, wherein adjacent winds of the planar spiral shape are separated by a gap of between about 1 mm and about 6 mm.

14. The system of claim 1, wherein a free distal end of the blocking member comprises a blunt tip.

15. The system of claim 1, wherein a free distal end of the blocking member comprises a flattened end.

16. The system of claim 1, wherein at least some of the winds of the blocking member include wavy increases and decreases in radial dimension.

17. The system of claim 16, wherein the wavy increases and decreases in radial dimension form one or more openings.

18. The system of claim 1, wherein the blocking member in its expanded state is configured to be adjustable by rotation of the elongate shaft, when at least a portion of an exterior of the blocking member is at least partially constrained.

19. The system of claim 1, wherein the longitudinal axis of the elongate shaft is substantially centered in relation to the outer boundary of the blocking member.

20. The system of claim 1, wherein the longitudinal axis of the elongate shaft is offset such that it is at an outer radial portion of the blocking member.

21. A system for catching or filtering embolic material in the vascular system of a patient comprising:

an elongate shaft having a proximal end, a distal end, and a longitudinal axis and configured to extend through the lumen of an elongate tube, the proximal end of the shaft configured to be manipulated by a user; and

a blocking member carried by the distal end of the shaft and having a substantially linear elongated state and an expanded state having a planar spiral shape.

22. The system of claim 21, wherein the planar spiral shape comprises an Archimedean spiral.

23. The system of either one of claims 21 or 22, wherein the blocking member comprises a coiled elongate member having a proximal end extending from the distal end of the shaft and a free distal end.

24. The system of claim 23, wherein the proximal end of the elongate member is integral to the distal end of the shaft.

25. The system of claim 23, wherein the proximal end of the elongate member is coupled to the distal end of the shaft.

26. The system of claim 25, wherein the proximal end of the elongate member is secured to the distal end of the shaft.

27. The system of claim 26, wherein the proximal end of the elongate member is secured to the distal end of the shaft by at least one of welding, soldering, brazing, thermal bonding, swaging, tying, braiding, winding, adhesive bonding, or epoxy bonding.

28. The system of any one of claims 21-27, wherein the blocking member in its expanded state has a generally circular perimeter.

29. The system of claim 28, wherein the generally circular perimeter may be transformed into a generally elliptical perimeter by the application of opposing radial forces on an outer periphery of the blocking member.

30. The system of any one of claims 23-27, wherein the coiled elongate member comprises a wire.

31. The system of claim 30, wherein the wire comprises a shape-memory alloy.

32. The system of claim 31, wherein the wire comprises Nitinol.

33. The system of any one of claims 30-32, wherein the wire comprises a superelastic material.

34. The system of any one of claims 23-33, further comprising an elongate helical coil carried on the wire.

35. The system of claim 34, wherein the elongate helical coil is secured to the wire at a distal end of the coiled elongate member.

36. The system of any one of claims 21-35, wherein the blocking member in its expanded state resides substantially within a plane that is generally perpendicular to the longitudinal axis of the shaft.

37. The system of any one of claims 21-36, wherein the blocking member in its expanded state has a diameter of between about 2 mm and about 30 mm.

38. The system of claim 37, wherein the blocking member in its expanded state has a diameter of between about 2 mm and about 8 mm.

39. The system of claim 38, wherein the blocking member in its expanded state has a diameter of between about 2 mm and about 4 mm.

40. The system of any one of claims 21-36, wherein adjacent winds of the planar spiral shape are separated by a gap of between about 1 mm and about 6 mm.

41. The system of claim 40, wherein adjacent winds of the planar spiral shape are separated by a gap of between about 3 mm and about 5 mm.

42. The system of any one of claims 23-35, wherein the free distal end of the coiled elongate member comprises a blunt tip.

43. The system of any one of claims 23-35, wherein the free distal end of the coiled elongate member comprises a ball end.

44. The system of any one of claims 23-35, wherein the free distal end of the coiled elongate member comprises a flattened end.

45. The system of any one of claims 23-35, wherein the free distal end of the coiled elongate member comprises a taper to a decreased dimension.

46. The system of any one of claims 23-35, wherein the free distal end of the coiled elongate member comprises a J-tip.

47. The system of any one of claims 21-46, wherein the system is configured to guide an elongate catheter having a lumen sized for placement of the system.

48. The system of claim 43, wherein the ball end comprises a radiopaque material.

49. The system of claim 35, wherein the elongate helical coil comprises a radiopaque material.

50. The system of any one of claims 23-27, wherein the coiled elongate member has a continuously increasing angle of curvature as a diameter of the blocking member increases.

51. The system of any one of claims 23-27, wherein the coiled elongate member includes wavy increases and decreases in radial dimension.

52. The system of claim 51, wherein the wavy increase and decreases in radial dimension form one or more openings.

53. The system of any one of claims 21-52, wherein the blocking member in its expanded state is configured to reduce blood flow.

54. The system of any one of claims 21-53, wherein the blocking member in its expanded state is configured to trap thromboemboli.

55. The system of any one of claims 21-54, wherein the blocking member in its expanded state is configured to be adjustable in order to increase or decrease the amount of blood flow.

56. The system of claim 54, wherein the blocking member in its expanded state is configured to be adjustable in order to increase or decrease the size of thromboemboli that are trapped.

57. The system of either one of claims 55 or 56, wherein the blocking member is adjustable by manipulation of the elongate shaft.

58. The system of claim 57, wherein rotation of the elongate shaft in a first direction causes a first change in a performance characteristic, and therein rotation of the elongate shaft in a second direction, opposite the first direction, causes a second change in the performance characteristic, that is contrary to the first change.

59. The system of any one of claims 21-58, wherein the longitudinal axis of the elongate shaft is substantially centered in relation to the blocking member.

60. The system of any one of claims 21-58, wherein the longitudinal axis of the elongate shaft is offset such that it is substantially even with an outer portion of the blocking member.