Intravascular occlusion device

Abstract

The present invention relates to an intravascular occlusion device for occluding a lumen of an intravascular system to treat certain medical conditions, such as vascular malformation, vascular hemorrhage or occluding a blood vessel to cause tissue ischemia or necrosis, the occlusion device comprising: a deformable cannula, the deformable sleeve is displaceable between a contracted state and an expanded state; and a tapered array of cantilevers extending from a distal end of the cannula and converging toward a distal tip defining a first hemostasis valve around the distal end of the cannula. The distal end of the cannula will be at least partially covered by a polymer fluid impermeable film to provide a seal to prevent fluid flow through the occlusion device. The internal valve will be hemostatic regardless of the initial direction of blood flow and will allow distal intravascular delivery of a surgical instrument, such as a catheter, that can be manipulated and used to deliver a therapeutic agent, such as a liquid or small particle embolism.

Description

Technical Field

[0001] The present invention relates to an intravascular occlusion device, in particular to an occlusion device for occluding the lumen of an intravascular system to treat certain medical conditions, and more particularly to an occlusion device for treating vascular malformations, vascular bleeding or occluding a blood vessel to cause tissue ischemia or necrosis. Background Art

[0002] There are many clinical situations where occlusion of blood vessels such as arteries and veins is desirable. For example, inducing compensatory hyperplasia in an untreated, non-embolized liver in the weeks before liver surgery is attempted. Inducing necrosis or tissue ischemia is a desirable effect in certain medical conditions, such as uterine fibroids, prostatic hyperplasia, benign or malignant renal tumors and liver parenchyma. The number of indications and procedures for distal embolization to induce ischemia and necrosis is increasing.

[0003] Certain cancer treatments also require drug delivery to arteries and veins. Proximal occlusion of blood flow can redirect blood flow (blood flow redistribution) from distal vessels toward the tumor. If drug delivery is performed from the proximal artery of the occlusion, such as by delivering drugs through an occlusion catheter (bTACE) in transarterial chemoembolization (TACE), more distal and more complete drug delivery penetration can be achieved.

[0004] Endoluminal occlusion has been performed for more than sixty years. In recent decades, significant technological advances have improved the techniques used, and different devices have been developed for different conditions and an increasing number of indications. Early embolic materials included glass particles, thermal contrast agents, paraffin, fibrin, and tissue fragments such as muscle fibers and blood clots. Current occlusive materials include metal devices, small particles, and liquid materials, which can be indicated for proximal or distal occlusion, high-flow and low-flow situations, and large-caliber and small-caliber vessels based on need.

[0005] Metal devices: Coils are one of the most commonly used embolic devices. They consist of a spiral of different materials, such as stainless steel, platinum, alloys of these or other materials, and can be covered / coated with synthetic materials to promote clotting. One of the main issues with coils is their proximal occlusion. If coils are used in a bleeding situation, the proximal occlusion may hinder access to the bleeding site in the presence of a distal vascular network. The size of the coil is critical, as a coil that is too small may migrate, while a coil that is too large will stretch and therefore may not adequately occlude the vessel. Coils that are too large are also prone to dislodging and result in non-targeted embolization.

[0006] The AVP (AGA Medical, Golden Valley, MN, USA) is a braided nickel-titanium alloy device that can be used to achieve permanent vascular occlusion. It is a type of embolic occluder. The main advantage is that the AVP can be recaptured and repositioned. This allows for precise placement with a low risk of mispositioning or migration. If the size is incorrect, the occluder can be withdrawn and replaced. However, a major disadvantage of all such occluders is that they rely on effective coagulation of the patient. If a severe coagulopathy occurs, the occluder may not be able to achieve occlusion. The occlusion time may also be unpredictable in cases of larger vessels with higher flow. Embolization of distal small vessels distal to a deployed intravascular occluder cannot be ensured, and although the occluder is safe, rapid, and easy to deploy, it cannot induce ischemia of distal small vessels.

[0007] Coils and vaso-occlusive occluders do not allow for distal small vessel embolization and are therefore not suitable for use alone if ischemia or necrosis is desired.

[0008] Liquid embolic agents: Liquid embolic agents are becoming increasingly popular because they are easy to use, result in reduced radiation dose, and they allow for distal small vessel occlusion and thus good induction of ischemia and necrosis. It is a non-viscous liquid embolic material that consists of three main elements: ethylene and vinyl alcohol copolymer (EVOH) responsible for occlusion, dimethyl sulfoxide (DMSO) as a solvent, and tantalum powder for radiopaque visualization. On the other hand, N-butyl cyanoacrylate (NBCA) is a rapid embolic agent; therefore, radiation exposure during intervention can be reduced. One of the main disadvantages is that reflux caused by too rapid injection or inappropriate injection volume may cause non-targeted embolization. Migration of coagulated material may also occur when retracting the catheter due to stripping of the material attached to the catheter tip. Other reasons for migration include premature polymerization and insufficient relationship between polymerization speed and blood flow in high-flow vascular malformations.

[0009] Small particle embolic agents: Polyvinyl alcohol (PVA) is a synthetic, nonabsorbable embolic agent used for permanent vascular occlusion. Acrylic microspheres (polytriacrylic acid gelatin) are nonabsorbable microspheres with a precisely calibrated particle size and uniform shape. Their smooth surface structure prevents particle aggregation, which allows better penetration of the particles into distal arteries. Both agents are good at inducing distal tissue necrosis but rely on the direction of blood flow to achieve safe embolization and are prone to reflux when blood flow slows in the vessel to which they are administered.

[0010] Current vascular occlusive occluders and coils do not allow for catheter placement distally for further embolization. Increasingly, clinical scenarios recognize the need to embolize distal small vessels to the level of the capillary bed. This includes liver and portal vein embolization (used to induce contralateral liver lobe hypertrophy prior to surgery), portal hypertension hemorrhagic varicose vein embolization (the entire length of the varicose vein needs to be occluded rather than occluding the capillary bed), transarterial chemoembolization, and prostatic artery embolization. If liquid or small particles are used for embolization and ischemia is induced, the risk is non-targeted embolization and serious patient complications. In addition, if concentrated drugs or particles that release radiotherapy (such as Yttrium90) need to be administered intravascularly for locoregional treatment, the risk of reflux or non-targeted embolization may mean that the delivered dose is not optimal.

[0011] In some cases, liquids or small particles cannot be safely administered. For example, if hepatic vein embolization is being performed, distal vein embolization is essential to prevent the formation of veno-venous collaterals, which would render the procedure ineffective. However, a catheter placed in the hepatic vein from a jugular or femoral access point cannot be used to safely infuse liquids or small particles, because these agents would immediately travel in the direction of the bloodstream out of the liver and into the heart and lungs.

[0012] An occlusion balloon catheter can be used to temporarily occlude the hepatic vein and allow fluid or small particles to be infused through its central lumen, but once the balloon is deflated, the liquid embolic agent may migrate into the heart. In addition, the occlusion balloon may become lodged in the liquid embolic agent. Similarly, if liquid embolic agents or small particles are used in the artery or portal vein, once stasis or slow flow is achieved, there is an increased risk of reflux of the liquid embolic agent, small particles, or drug into another vessel and resulting non-targeted embolization / therapy.

[0013] Therefore, an object of the present invention is to provide an improved occluding device to solve the above problems. Summary of the invention

[0014] According to the present invention, there is provided an intravascular occlusion device comprising: a deformable sleeve which is displaceable between a contracted state and an expanded state; and a conical array of cantilevers which extend from a distal end of the sleeve and converge toward a distal tip, thereby defining a first hemostatic valve around the distal end of the sleeve.

[0015] Preferably, the resilience of the array of cantilevered arms is used to bias the first hemostatic valve into a closed state.

[0016] Preferably, the array of cantilevers is sufficiently elastically deformable to allow the tips to radially separate to facilitate the passage of surgical instruments.

[0017] Preferably, the array of cantilevered arms is sufficiently elastically deformable to apply a radial compressive force to a surgical instrument protruding through the first hemostasis valve sufficient to maintain hemostasis between the instrument and the first hemostasis valve.

[0018] Preferably, the cross-sectional area of ​​one or more of the cantilevers varies along the length of the cantilever.

[0019] Preferably, one or more of the cantilevers comprises a living hinge.

[0020] Preferably, the distal tips of the cantilevers are configured to cooperate with each other to establish a hemostatic seal at the distal tips.

[0021] Preferably, one or more of the distal tips are longitudinally offset relative to one or more of the other distal tips.

[0022] Preferably, one or more of said cantilever arms comprises a radially inwardly extending portion proximal to said distal tip of the respective cantilever arm.

[0023] Preferably, the occluding device comprises an annular support connecting the sleeve and the cantilever arms, the annular support having a proximal side fixed to the distal end of the sleeve and a distal side from which the tapered array of cantilever arms extends.

[0024] Preferably, the annular support is configured to substantially isolate or decouple the cantilever from deformation or displacement of the sleeve.

[0025] Preferably, said occluding device comprises an array of elastically deformable spokes connected between said distal end of said sleeve and said proximal side of said annular support.

[0026] Preferably, the annular support is substantially resistant to radial deformation.

[0027] Preferably, the annular support defines a flexible region at a connection with one or more of the cantilever arms and / or one or more of the deformable spokes.

[0028] Preferably, the proximal side and / or the distal side of the annular support comprises a wavy edge.

[0029] Preferably, the sleeve comprises a plurality of interconnected annular sinusoidal ribs defining a web-like cylindrical side wall.

[0030] Preferably, the cylindrical side wall comprises a plurality of protrusions extending radially outwardly.

[0031] Preferably, the occluding device comprises a remotely operable actuator arranged to effect displacement of the sleeve between the expanded state and the contracted state.

[0032] Preferably, the occluding means comprises a membrane enclosing the cantilever and at least a portion of the distal end of the cannula.

[0033] Preferably, said membrane surrounds said distal tip of at least one of said cantilevers.

[0034] Preferably, the membrane is dimensioned to accommodate relative displacement between at least two adjacent cantilevers.

[0035] Preferably, the occluding device comprises one or more elements disposed at the proximal end of the cannula and configured to facilitate recapture of the occluding device.

[0036] Preferably, the occlusion means comprises a second hemostatic valve around the proximal end of the cannula.

[0037] Preferably, the second hemostatic valve comprises a tapered array of cantilevered arms extending from the proximal end of the cannula and converging toward a tip to define the second hemostatic valve.

[0038] Preferably, the first hemostatic valve and / or the second hemostatic valve are operable to maintain bidirectional hemostasis regardless of the original direction of flow through the body lumen in which the occluding device is deployed.

[0039] According to another aspect of the present invention, a method for delivering a therapeutic agent into a lumen of an intravascular system is provided, comprising: positioning an occluding device in a contracted state into the lumen, the occluding device comprising a deformable sleeve and a conical array of cantilevers, the cantilevers extending from a distal end of the sleeve and converging toward a distal tip; expanding the sleeve to anchor the occluding device within the lumen such that the cantilevers define a first hemostatic valve; and passing a surgical instrument through the array of cantilevers to deliver the therapeutic agent distal to the occluding device.

[0040] Preferably, the method includes deforming the tips of at least some of the cantilever arms radially outwardly in response to pressure applied by the surgical instrument to facilitate passage of the surgical instrument.

[0041] Preferably, the method includes biasing at least some of the cantilever arms against an exterior of the surgical instrument so as to maintain hemostasis between the surgical instrument and the first hemostasis valve.

[0042] Preferably, the method comprises at least partially isolating the hemostatic valve from deformation or displacement of the cannula by providing the occluding device with an annular support between the first hemostatic valve and the cannula.

[0043] Preferably, the method includes passing the surgical instrument through the first hemostasis valve in a first axial direction while maintaining hemostasis between the surgical instrument and the first hemostasis valve.

[0044] Preferably, the method includes passing the surgical instrument through the first hemostasis valve in a second axial direction while maintaining hemostasis between the surgical instrument and the first hemostasis valve.

[0045] Preferably, the method comprises pulling back the surgical instrument through the hemostatic valve and closing the hemostatic valve by radially inward elastic deformation of the array of cantilever arms.

[0046] Preferably, the method includes clearing the therapeutic agent from the exterior of the surgical instrument while simultaneously pulling the surgical instrument back through the hemostasis valve.

[0047] As used herein, the term "surgical instrument" refers to any tool or instrument used during deployment / retrieval of an occlusive device that can be passed through the central lumen of the device, including but not limited to conventional guidewires for delivering the device to the deployment site and catheters for dispensing embolic agents, etc. to the distal side of the device during deployment.

[0048] As used herein, the term "annular" is intended to refer to any generally circular or ring-shaped element, which may be cylindrical or conical, may have solid or open sidewalls, and may have varying degrees of rigidity.

[0049] As used herein, the terms "axial" and "radial" are intended to refer to a generally cylindrical sleeve of an occluder device having a longitudinal axis along which an "axial" direction extends and radial directions extend perpendicular to the longitudinal axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The present invention will now be described with reference to the accompanying drawings, in which:

[0051] Figure 1 shows a side elevation view of an intravascular occlusion device according to an embodiment of the present invention;

[0052] Figure 1a Shows Figure 1 A schematic diagram of an intravascular occlusive device is shown to illustrate possible angle variations of different sections of the device;

[0053] Figure 2 Shows Figure 1 A side elevation view of a distal end of an occluding device;

[0054] Figure 3 Shows Figure 2 a perspective view of the distal end shown;

[0055] Figure 4 Shows Figures 1 to 3 A perspective view of an occluding device;

[0056] Figure 5 Shows Figures 1 to 4 An alternative partial perspective view of an occlusion device;

[0057] Figure 6 Shows Figures 1 to 5 an occlusive device in an expanded state;

[0058] Figure 7 Shows Figure 6 An occluding device in a partially retracted state;

[0059] Figure 8 Shows Figure 6 and Figure 7 The occlusive device is in a fully retracted state;

[0060] Fig. 9 Shows Figures 1 to 8 An occluding device and showing a membrane-forming portion of the device;

[0061] Fig.10 Shows Fig. 9 An occluding device having a distal end open to allow a surgical instrument to pass therethrough;

[0062] Fig.11 Shows Fig.10 and showing surgical instruments passing through the occluding device;

[0063] Fig.12 An annular support forming part of an occluding device is shown;

[0064] Fig.13 Shows Fig.12 An alternative to the annular support shown;

[0065] Fig.14 Shows Fig.12 Another alternative to the annular support shown;

[0066] Fig.15 Shows Figure 2 Alternative form of distal end shown;

[0067] Fig.16 Shows Figure 2 Additional alternatives to the distal end shown;

[0068] Fig.17 Shows Figure 2 Yet another alternative to the distal end shown;

[0069] Fig.18Shows Figure 2 Additional alternatives to the distal end shown;

[0070] Fig.19 Shows Figure 2 A perspective view of another alternative form of the distal end is shown;

[0071] Fig. 20 Shows Fig.19 a front view of the distal end shown;

[0072] Fig.21 Shows Figures 1 to 11 An occluding device, wherein a second hemostatic valve is provided around the proximal end of the occluding device;

[0073] Fig. 22 shows a side elevation view of an intravascular occlusion device according to a second embodiment of the present invention;

[0074] Fig.23 shows a side elevation view of an intravascular occlusion device according to a third embodiment of the present invention;

[0075] Fig.24 shows a side elevation view of an intravascular occlusion device according to a fourth embodiment of the present invention;

[0076] Fig.25 shows a side elevation view of an intravascular occlusion device according to a fifth embodiment of the present invention; and

[0077] Fig.26 A side elevation view of an intravascular occlusion device according to a sixth embodiment of the present invention is shown. DETAILED DESCRIPTION

[0078] Now refer to the accompanying drawings Figures 1 to 11 , an intravascular occlusion device, generally indicated at 10, is shown according to an embodiment of the present invention for occluding the lumen of an intravascular system to treat vascular malformations, vascular bleeding, or to occlude a vessel to cause tissue ischemia or necrosis. As described in detail below, the occlusion device 10 is used to hinder blood flow from the distal portion of the device 10 to the proximal side, and vice versa, before, during, and after delivery of an embolic or other therapeutic material at the distal side of the device 10. The occlusion device 10 also induces coagulation.

[0079] The occluding device 10 includes a sleeve 12, which preferably has an axisymmetric cross-section, is more preferably cylindrical, and is most preferably a mesh-like structure. As described in detail below, the sleeve 12 can be Figure 1 The expansion state shown and Figure 8In the expanded state, the sleeve 12 has a radial dimension that can engage and be held against the interior of the wall of the vessel (not shown) in which the intravascular device 10 is to be deployed, and its diameter when expanded can be, for example, in the range of between 4 mm and 20 mm. In the expanded state, the sleeve 12 defines an internal lumen that provides the occlusion device 10 with the functions described below, particularly allowing a guide wire to pass through the occlusion device 10 to facilitate deployment, and allowing a catheter to pass through to deliver emboli to the distal side of the occlusion device 10. In the contracted state, the sleeve 12 has a significantly reduced radial dimension so that it can be delivered to the deployment site and / or allow the device 10 to be repositioned or removed.

[0080] The occluding device 10 also includes an annular support 14, which is axially spaced from the distal side or distal end of the sleeve 12 and is connected to the distal end via an array of spokes 16, which together define a shoulder or transition zone between the sleeve 12 and the annular support 14. The annular support 14 and the sleeve 12 are preferably but not necessarily arranged coaxially. Unlike the sleeve 12, the annular support 14 is preferably substantially resistant to radial deformation, but may have controlled flexibility as described below. The annular support 14 has a significantly reduced diameter relative to the expanded sleeve 12, and in an exemplary embodiment its inner diameter may be in the range of between 0.5 mm and 4 mm. The outer diameter of the annular support 14 may correspond approximately to the outer diameter of the sleeve 12 when in a contracted state, for example as Figure 8 shown.

[0081] The occluding device 10 also includes a first hemostatic valve 18, which is defined by a tapered array of cantilever arms 20 extending from the distal end of the annular support 14 and converging and terminating at a distal tip 22. The cantilever arms 20 can be elastically deformed or otherwise displaced to allow surgical instruments such as catheters or guidewires to pass therethrough, and in particular to allow the tips 22 to be reversibly separated from each other by elastic outward deformation of the arms 20. In a preferred arrangement, the cantilever arms 20 are elastically deformable and / or are provided with a flexible or elastically deformable connection to the annular support 14. However, it should be understood that any other mechanism can be used to achieve this function, such as one or more hinges can be provided on or around one or more of the cantilever arms 20. As described below, the geometry of the arms 20 and the tips 22 can be varied to vary the operation of the hemostatic valve 18, such as by tapering the arms 20 to define sharp tips 22 that effectively converge completely to form a hemostatic seal, or the tips 22 can be rounded or otherwise contoured to reduce friction with a surgical instrument (such as a guidewire or catheter) passing therethrough.

[0082] Figure 1aThe occluder device 10 is schematically shown, highlighting the angular inclination α (α) of the transition zone defined by the spokes 16 relative to the longitudinal axis, the angular inclination β (β) of the annular support 14, and the angular inclination γ (γ) of the arm 22. Each of these angles can vary between 0 and 90 degrees, and for example Figure 1 In the case of Figure 1a The angle selected will affect the mechanical properties of the various parts of the occluding device 10, allowing for fine tuning to achieve the desired performance characteristics.

[0083] In the first embodiment shown, the sleeve 12 is formed of a biocompatible self-expanding material (such as a nickel-titanium alloy) and may be at least partially covered with a polymer fluid-impermeable membrane 24 (such as Figures 9 to 11 The sleeve 12 is provided with a plurality of annular rings 26 arranged axially adjacent to each other and connected to each other, each ring 26 comprising a sinusoidal or wavy element that facilitates displacement of the sleeve 12 between an expanded state and a contracted state by relative articulation and / or flexure of adjacent segments to provide an accordion-like action. The number of rings 26 can be varied as desired, for example to vary the overall length of the sleeve 12. In the illustrated embodiment, each ring 26 defines sixteen peaks and valleys, and adjacent rings 26 are secured to each other via a plurality of struts 28 that extend between aligned peaks of adjacent rings 26. In one embodiment, this arrangement will create an open cell configuration such that every two cells create a closed cell. The open cell design will promote intimal hyperplasia and allow the vascular endothelium to protrude through the sleeve 12. This configuration will allow tissue to prolapse between the interstices of the sleeve 12, thereby providing an anti-migration anchoring feature to prevent accidental movement of the occlusive device 10 after deployment. In an exemplary but non-limiting embodiment, the width of the defining element of the ring 26 is 50-400 μm and the thickness is 50-400 μm.

[0084] The cannula 12 can be crimped onto a delivery system (not shown) before delivery and deployment into the target vessel. In the neutral position, once out of the delivery system, the cannula 12 will expand to a desired size (e.g., between 4 mm and 20 mm). Once deployed in the vessel, the outer diameter of the cannula 12 will be reduced from the thermal profile diameter to a reduced diameter due to the radial resistance exerted by the vessel wall, and due to the elasticity of the cannula 12, the cannula will tend to exhibit a long-term outward force on the wall to prevent migration. The position and arrangement of the polymer film 24 are configured not to inhibit this mechanical action, such as not covering the entire length of the cannula 12.

[0085] It should be understood that the number, size, and precise geometry of the rings 26 can be varied as desired. For example, one or more of the peaks can be raised from the cylindrical surface of the sleeve 12 to provide additional anchoring in the vessel. Additionally or alternatively, the cross-sectional profile of the sleeve 12 can be modified to reduce the effective radius of curvature at one or more locations on the surface of the sleeve 12, thereby enhancing stress concentration and anchoring in the wall of the vessel. As a further modification, the alternative rings 26 can be heat-formed to different diameters to increase stress concentration and anchoring when the occluding device 10 is deployed.

[0086] The spokes 16 provide a transition between the relatively larger diameter and flexible sleeve 12 (in the deployed or expanded state) and the relatively stiff or incompressible annular support 14. The occluding device 10 preferably includes four to eight spokes 16, and the spokes may have a width of 50-400 μm and a thickness of 50-400 μm, and are covered by the membrane 24. The spokes 16 may have a different cross-sectional profile than the ring 26, and their geometry may be selected to at least partially isolate displacement of the sleeve 12 from the rest of the occluding device 10 (particularly the annular support 14 and the hemostatic valve 18).

[0087] The spokes 16 can be formed of the same biocompatible material as the ring 26 of the sleeve 12, and in the illustrated embodiment have a sinusoidal profile in the radial direction. This profile facilitates controlled deformation of the spokes 16 as the sleeve 12 is displaced between the expanded and contracted states, again minimizing the transmission of any deformation or movement of the sleeve 12 to the rest of the occlusion device 10 during use. The sinusoidal profile of the spokes 16 holds the annular support 14 and the hemostatic valve 18 centered within the vessel and prevents the device from rotating, deforming, or bending regardless of the diameter of the vessel. This is an important aspect of the operation of the occlusion device 10, maintaining the central lumens of the annular support 14 and the hemostatic valve 18 axially aligned to allow a vascular catheter to pass through the central lumen of the occlusion device 10.

[0088] Of course, it is understood that the number and configuration of the spokes 16 can be changed. The spokes 16 can be shaped, for example, to define a curve in the axial direction so that one end of the spoke 18 connected to the sleeve 12 can be axially offset to the opposite end of the spoke 18 connected to the annular support 14. Such a profile can provide flexibility for the rotational displacement of the sleeve 12, thereby further isolating the rotational displacement from the annular support 14 and the hemostatic valve 18. A plurality of radial elements or spars (not shown) connected between two or more adjacent spokes 16 can also be provided. These will provide additional rotational stability during use. Additionally or alternatively, one or more of the spokes 16 and / or the connecting struts (not shown) may have a wavy profile similar to the ring 26 to facilitate bending and thus absorb the distortion transmitted from the sleeve 12.

[0089] Special References Figure 12 to Figure 14 , in which various alternative configurations of the annular support 14 are shown separately. The annular support 14 has two primary functions, the first of which is to isolate the hemostatic valve 18 from movement or twisting of the cannula 12 as described above. The second is to provide a stable platform or base from which the cantilever 20 of the hemostatic valve 18 extends and can be displaced relative to the platform or base to accommodate the passage of surgical instruments while providing a hemostatic seal at the distal end of the occluding device 10. As described above, the annular support 14 is preferably but not necessarily resistant to radial compression to resist deformation transmitted from the cannula 12 during use, thereby providing a stable platform for the cantilever 20 to ensure consistent operation of the occluding device 10 during use. The annular support 14 may define a substantially solid sidewall, such as Fig.12 and Fig.13 As shown, but it can also be honeycomb or mesh, for example Fig.14 The annular support 14 may provide a low level of compressibility or crushability, thereby undergoing expansion during deployment. However, it is also contemplated that the occlusion device 10 may be configured without the annular support 14, whereby the array of cantilevers 20 would extend directly from the spokes 16, but such an arrangement would not provide the isolation of the hemostatic valve 18 from the cannula 12 described above.

[0090] refer to Fig.12, the annular support 14 may be provided with holes 30 adjacent its proximal end at which the spokes 16 are connected. These holes 30 provide locally increased flexibility, thereby reducing stress concentrations at these areas, which effectively act as hinges between the spokes 18 and the annular support 14. Corresponding holes 30 are provided adjacent the distal end to provide the same function relative to the cantilever 20. The annular support 14 is preferably also provided with a serrated or sawtoothed proximal and distal edge. The spokes 16 and cantilever 20 are connected to corresponding valleys of the corresponding serrated edges. This helps to shorten the overall length of the occluder 10. The contoured edges also provide flexibility and prevent circumferential / rotational forces that may be transmitted by the spokes 16 and / or cantilever 20. The valleys or troughs of the distal edge are preferably offset or out of phase with the valleys / troughs of the proximal edge. This serves to further avoid the transmission of displacement or distortion between the spokes 16 and the arms 20, again further stabilizing the occluder device 10 to ensure consistent performance during use. In Fig.14 In the arrangement of, the holes 30 are configured to define a lattice-type or open frame-type arrangement for the annular support 14. It should be understood that more or fewer frame annular rows can be used to achieve the desired mechanical properties, thereby changing the overall or local flexibility of the support 14.

[0091] Extending distally from the annular support 14 is a hemostatic valve 18, which is preferably composed of four to eight cantilevers 20. In an exemplary embodiment, the width (circumferential dimension) of the cantilever 20 is between 50 and 400 μm and the thickness (radial dimension) is between 50 and 400 μm. The cantilever 20 is preferably set at an angle of between 20 and 60 degrees to the center or longitudinal axis of the occlusion device 10. The cantilever 20 is preferably formed of a biocompatible and elastically deformable material, and can be formed of the same material as the sleeve 12 and / or spokes 18. The cantilever 20 is configured to converge at a distal tip 22 to provide a closed end, which establishes a hemostatic seal, particularly when the valve 18 is wrapped by a membrane 24. However, the cantilever 20 is elastically deformable, and thus the tips 22 can be forced away from each other to provide a cannulation / through-the-lumen lumen, thereby allowing surgical instruments to pass through the hemostatic valve 18. In addition, when the guidewire G (see Fig.11 ) or a vascular catheter is pushed through the lumen of the occluding device 10, the cantilever 20 will deform to open the hemostatic valve 18, thereby allowing the guidewire G or catheter to pass through the lumen and enter the distal side of the occluding device 10 in the blood vessel where the device 10 is deployed. The tip 22 of the cantilever 20 can be contoured or otherwise configured to produce low friction with the guidewire / catheter, thereby allowing the cantilever 20 to be easily opened when the guidewire / catheter is introduced. The size of the membrane 24 (particularly between adjacent cantilevers 20) is set to allow such relative movement during the opening and closing of the hemostatic valve 18, thereby ensuring that a seal is established around the guidewire or catheter to prevent fluid from leaking through the occluding device 10.

[0092] The cantilever 20 can be configured to adjust its flexibility and movement during use. For example, the cross-section of the cantilever 20 is preferably square or rectangular at the connection with the annular support 14, and then the thickness tapers toward the distal tip 22. The tapered cross-section provides enough space for the cantilever 20 to converge at the vertex that defines the most distal part of the occlusion device 10. Such a configuration establishes a hemostatic seal. The profile of the cantilever 20 and / or the tip 22 can be varied to provide a certain function. For example, the cross-section of the cantilever 20 is tapered to have a sharp distal tip 22, while in an alternative configuration, the distal tip 22 has a rounded taper to provide lower friction between the tip 22 and the guidewire / catheter. Preferably, the aspect ratio of the cantilever 20 is selected to minimize the risk of off-axis bending during the displacement of the cantilever 20, which may impair the function and symmetry of the hemostatic valve 18.

[0093] refer to Fig.15 The cantilever 20 may be provided with a notch 32 or equivalent localized reduction in thickness to define a living hinge or region of increased flexibility to allow the cantilever 20 to deform radially outwardly to facilitate passage of a guidewire / catheter. Fig.16 A modification of the cantilever 20 is shown to provide a radially inwardly extending abutment 34 that the advancing guidewire / catheter will contact, thereby forcing the cantilever 20 to move radially outward. A similar function can be achieved, but the cantilever 20 has a curved or arcuate shape in the radial direction so that the cantilever 20 converges toward each other along a curved path. When the guidewire / catheter passes through the hemostatic valve 18, it will first engage those curved or converging portions, opening the hemostatic valve 18 and eliminating any engagement between the distal tip 22 and the guidewire / catheter. This will avoid potential damage to the guidewire / catheter and will also prevent the cantilever 20 from bending inwardly when the guidewire / catheter is pulled out, which may otherwise occur due to excessive friction between them. Fig.17 A similar arrangement is shown, but instead of being curved, the cantilever 20 defines a converging / diverging configuration. Fig.18 The cantilever 20 is shown when the distal tip 22 is sharpened to a fine point to ensure complete convergence. Fig.19 and Fig. 20 In the embodiment, two pairs of opposing cantilevers 20 are connected together via corresponding flexible couplings 20a, which are located between the annular support 14 and the distal tip 22, or at the distal tip 22, so as to adjust the mechanical properties of the plurality of cantilevers 20 again. It should be understood that more or fewer cantilevers 20 can be fixed together in this way.

[0094] The hemostatic valve 18 may also be configured such that every other cantilever 20 is reduced in length and / or oriented further radially inwardly so that the membrane 24 between each of two adjacent longer cantilever arms 20 folds inwardly at the distal portion, thereby providing a complete seal at the distal tip 22 .

[0095] A portion of fabric material, such as Dacron or other polymer / fiber, may be attached to the distal tip 22 of the cantilever 20 to act as a thrombogenic fiber, but may also additionally act as a scraping seal or brush to remove embolic or other liquids / particles from the outer surface of the injection catheter as the embolic injection catheter is withdrawn. This will prevent inadvertent proximal backflow of glue or other materials as the catheter is withdrawn through the lumen / channel of the occluding device 10. The above variations may be combined with any of the embodiments disclosed herein in various permutations and combinations to achieve the necessary performance or use characteristics.

[0096] Reference now Fig.21 , shows an occlusion device 10 in which a second hemostatic valve 40 having the same configuration and operation as the first hemostatic valve 18 is provided, but the second hemostatic valve is located at the opposite end of the cannula 12, and therefore located on the proximal side of the occlusion device 10. This arrangement provides an additional level of hemostatic sealing and facilitates recapture of the occlusion device 10 after initial deployment from a delivery sheath or system (not shown) if the operator determines that the deployment position is not optimal. A similar tapered geometry can also be used to facilitate recapture of the device without incorporating a second hemostatic valve 40.

[0097] Now turn to Fig. 22 , shows an intravascular occlusion device generally indicated as 110 according to the present invention, for occluding the lumen of the intravascular system to treat vascular malformations, vascular bleeding, or to occlude a vessel to cause tissue ischemia or necrosis. In this second embodiment, similar components are given similar reference numerals and perform similar functions unless otherwise specified. The occlusion device 110 also includes a retractable sleeve 112, an annular support 114, a shoulder or transition zone defined by spokes 116, and a hemostatic valve 118. The proximal end of the sleeve 112 (defined by one of the annular rings in the array of annular rings 126) is radially outwardly flared so that the ring 26 forms a circular array of protrusions that will engage with the vessel wall to which the device 110 is deployed when in use, thereby providing additional anchoring to keep the device 110 in place.

[0098] Fig.23 A third embodiment of an occluding device, generally designated 210, according to the present invention is shown. In this third embodiment, similar components are given similar reference numerals and perform similar functions unless otherwise specified. The occluding device 210 also includes a flared proximal end defined by one of the array of annular rings 226, the one annular ring forming an array of circular protrusions that, in use, will engage the vessel wall into which the device 210 is deployed to provide additional anchoring. The protrusions ( Fig.23Each of the cantilevers 220 (shown in enlarged form on the left side of the figure) defines a hole 226a, which may contain a radiopaque marker to allow imaging of the proximal end of the occluding device 210 during deployment or subsequent surgery. Similarly, one or more cantilevers 220 may define an opening 220a, which may also contain a radiopaque marker to allow imaging of the distal end of the device 210, wherein Fig.23 One such arm 220 is shown enlarged in the right side of FIG.

[0099] Fig.24 A fourth embodiment of an occluder device, generally designated 310, according to the present invention is shown. In this fourth embodiment, similar components are given similar reference numerals and perform similar functions unless otherwise specified. The occluder device includes a retractable sleeve 312, an annular support 314, a transition zone or shoulder defined by spokes 316, and a hemostatic valve defined by cantilever 320. Unlike the previous embodiments, the annular support 314 is positively inclined relative to the longitudinal axis, such as having a positive angle β, as described above with reference to Figure 1a The annular support 314 is also a simple lattice or frame configuration having a simple sawtooth shape with arms 320 extending from the peaks of the sawtooth and spokes 316 connected to the valleys of the sawtooth. This arrangement allows the overall length of the occluding device 310 to be shorter and the isolation function of the support 314 to be adjusted.

[0100] Fig.25 A fifth embodiment of the occluding device is shown, generally indicated as 410 and having a construction similar to the fourth embodiment, but with the spokes 416 and cantilever 420 connected to the same location on the annular support 414, namely, the sawtooth peaks of the support 414, which again provides alternative adjustment for the flexibility of the components of the device 310.

[0101] Fig.25 A sixth embodiment of an occluding device is shown, generally indicated at 510 and similar in construction to the fourth embodiment, but the spokes 516 are greater in number and thus connected to both the peaks and valleys of the wavy or zigzag annular support 514. An array of cantilevered arms 520 for a hemostatic valve, one arm 520 extending from each peak of the support 514.

[0102] In use, the occluding device 10; 110; 210; 310; 410; 510 is initially Figure 8The collapsed state shown is provided, and is preferably intended for delivery through a vascular catheter or sheath or custom delivery system (not shown), and most likely along a pre-installed guidewire G, over which the occluding device 10; 110; 210; 310; 410; 510 can be passed, as previously described. Upon reaching the deployment site, the occluding device 10; 110; 210; 310; 410; 510 is displaced outwardly from the vascular catheter. The occluding device 10; 110; 210; 310; 410; 510 may include a remotely operable actuator (not shown) that may be triggered to allow the sheath to expand outwardly to a deployed or expanded state. Without such an actuator, the sheath would simply expand once removed from the vascular catheter. The occluding device 10; 110; 210; 310; 410; 510 would then press against the wall of the vessel to anchor in place.

[0103] After the occlusion device 10; 110; 210; 310; 410; 510 is deployed, the relative rigidity of the annular support 14; 114; 214; 314; 414; 514 can be used as a stop by the delivery catheter / sheath (not shown) to help disengage the introducer / pusher (not shown) from the deployed occlusion device 10; 110; 210; 310; 410; 510.

[0104] At this point, the angiocatheter may be withdrawn, or the angiocatheter may be used to advance the injection catheter to the deployment site. The injection catheter is then advanced axially into the lumen of the occluding device 10; 110; 210; 310; 410; 510 and then engages with the inner surface of the cantilever 20; forcing the cantilever 20 to elastically deform radially outward, as shown in FIG. Fig.10 and Fig.11 The resiliency of the cantilever arms 20 ensures that they remain engaged against the outside of the injection catheter and in combination with the surrounding membrane 24 (if provided) prevent any fluid from flowing through the occluding device 10;110;210;310;410;510 from either direction.

[0105] Once the tip of the injection catheter is in the proper position distal to the occluding device 10; 110; 210; 310; 410; 510, a liquid embolic agent or other substance or therapeutic material can be injected from the catheter into the blood vessel. The injection catheter can then be removed, whereupon the cantilever 20 will deform back together to establish a suitable seal to prevent the embolism or other substance from flowing back. It should therefore be understood that the elasticity and orientation of the cantilever 20 ensure hemostasis, and therefore the occluding device 10; 110; 210; 310; 410; 510 does not rely on the blood pressure within the blood vessel to close the hemostatic valve 18; 118. Therefore, whether blood or fluid flows from the proximal side to the distal side or vice versa, the occluding device 10; 110; 210; 310; 410; 510 provides hemostasis.

[0106] Therefore, the occluding device 10; 110; 210; 310; 410; 510 of the present invention can achieve immediate proximal permanent embolization and occlude the blood vessel at the same time. After positioning, before final release and deployment, the occluding device 10; 110; 210; 310; 410; 510 can also be repositioned and / or withdrawn and replaced. Unlike current coils or vascular occluders, a catheter can be passed through the occluding device 10; 110; 210; 310; 410; 510 to access its distal side. This allows safe and effective distal small blood vessel embolization with liquid embolics or small particles without the risk of liquid or small particle reflux or proximal flow. Alternatively, it allows high-dose distal drug infusion or small particle radiation therapy through the proximally occluded blood vessel without the risk of reflux. The device 10;110;210;310;41;510 allows for a variety of embolic agents, including but not limited to microparticles, to be delivered distally to the deployed device 10;110;210;310;410;510 via commercially available angiocatheters and microcatheters (not shown), regardless of the delivery system (not shown) used to deploy the device 10;110;210;310;410;510. Such catheters and microcatheters can be manipulated and directed distally to the device 10;110;210;310;410;510, thereby allowing for more distal and targeted delivery of these forms of embolic agents.

Claims

1. An intravascular occlusion device, comprising: a deformable sleeve, the deformable sleeve being displaceable between a contracted state and an expanded state; and a tapered array of cantilever arms extending from the distal end of the cannula and converging toward a distal tip to define a first hemostatic valve about the distal end of the cannula.

2. The intravascular occlusion device according to claim 1, wherein the elasticity of the array of cantilevers is used to bias the first hemostatic valve to a closed state.

3. An intravascular occlusion device according to any preceding claim, wherein the array of cantilevers is sufficiently elastically deformable to allow the tips to radially separate to facilitate the passage of surgical instruments.

4. An intravascular occlusion device according to any preceding claim, wherein the cantilever array is capable of being sufficiently elastically deformed to apply a radial compression force to a surgical instrument protruding through the first hemostatic valve sufficient to maintain hemostasis between the instrument and the first hemostatic valve.

5. An intravascular occlusive device according to any preceding claim, wherein the cross-sectional area of ​​one or more of the cantilevers varies along the length of the cantilever.

6. An intravascular occlusion device according to any preceding claim, wherein one or more of the cantilevers comprises a living hinge.

7. An intravascular occlusion device according to any preceding claim, wherein the distal tips of the cantilevers are configured to cooperate with each other to establish a hemostatic seal at the distal tips.

8. An intravascular occlusion device according to any preceding claim, wherein one or more of the distal tips are longitudinally offset relative to one or more of the other distal tips.

9. An intravascular occlusion device according to any preceding claim, wherein one or more of the cantilevers include a radially inwardly extending portion located proximal to the distal tip of the respective cantilever.

10. An intravascular occlusion device according to any preceding claim, comprising an annular support connecting the sleeve and the cantilever, the annular support having a proximal side fixed to the distal end of the sleeve and a distal side from which the tapered array of cantilevers extends.

11. The intravascular occlusion device according to claim 10, wherein the annular support is configured to substantially isolate or decouple the cantilever from deformation or displacement of the sleeve.

12. An intravascular occlusive device according to claim 10 or 11, comprising an array of elastically deformable spokes connected between the distal end of the sleeve and the proximal side of the annular support.

13. The intravascular occlusion device according to any one of claims 10 to 12, wherein the annular support is substantially resistant to radial deformation.

14. The intravascular occlusive device according to any one of claims 10 to 13, wherein the annular support defines a flexible region at a connection with one or more of the cantilevers and / or one or more of the deformable spokes. 15 . The intravascular occlusion device according to claim 10 , wherein the proximal side and / or the distal side of the annular support comprises a wavy edge.

16. An intravascular occlusion device according to any preceding claim, wherein the sleeve comprises a plurality of interconnected annular sinusoidal ribs defining a web-like cylindrical sidewall.

17. The intravascular occlusion device of claim 16, wherein the cylindrical sidewall comprises a plurality of protrusions extending radially outward.

18. An intravascular occlusion device according to any preceding claim, comprising a remotely operable actuator arranged to effect displacement of the sleeve between the expanded and contracted states.

19. An intravascular occlusion device according to any preceding claim, comprising a membrane enclosing the cantilever and at least a portion of the distal end of the sleeve.

20. The intravascular occlusion device of claim 19, wherein the membrane surrounds the distal tip of at least one of the cantilevers.

21. The intravascular occlusive device according to claim 19 or 20, wherein the membrane is dimensioned to accommodate relative displacement between at least two adjacent cantilevers.

22. An intravascular occlusive device according to any preceding claim, comprising one or more elements disposed at the proximal end of the cannula and configured to facilitate recapture of the occlusive device.

23. An intravascular occlusion device according to any preceding claim, comprising a second hemostatic valve around the proximal end of the cannula.

24. The intravascular occlusion device of claim 23, wherein the second hemostatic valve comprises a tapered array of cantilevered arms extending from the proximal end of the cannula and converging toward a tip to define the second hemostatic valve.

25. An intravascular occlusion device according to any preceding claim, wherein the first hemostatic valve and / or the second hemostatic valve are operable to maintain hemostasis regardless of the original flow direction through the body lumen in which the occlusion device is deployed.

26. A method of delivering a therapeutic agent into a lumen of an intravascular system, comprising: positioning an occluding device in a collapsed state into the lumen, the occluding device comprising a deformable sleeve and a tapered array of cantilevers extending from a distal end of the sleeve and converging toward a distal tip; expanding the cannula to anchor the occluding device within the lumen such that the cantilever arms define a first hemostatic valve; and passing a surgical instrument through the array of cantilever arms to deliver the therapeutic agent distal to the occluding device.

27. The method of claim 26, comprising deforming the tips of at least some of the cantilevers radially outwardly in response to pressure applied by the surgical instrument to facilitate passage of the surgical instrument.

28. The method of claim 26 or 27, comprising biasing at least some of the cantilever arms against an exterior of the surgical instrument so as to maintain hemostasis between the surgical instrument and the first hemostasis valve.

29. A method according to any one of claims 26 to 28, comprising at least partially isolating the haemostatic valve from deformation or displacement of the cannula by providing the occluding device with an annular support between the first haemostatic valve and the cannula.

30. The method of any one of claims 26 to 29, comprising passing the surgical instrument through the first hemostasis valve in a first axial direction while maintaining hemostasis between the surgical instrument and the first hemostasis valve.

31. The method of any one of claims 26 to 30, comprising passing the surgical instrument through the first hemostasis valve in a second axial direction while maintaining hemostasis between the surgical instrument and the first hemostasis valve.

32. A method according to any one of claims 26 to 31, comprising pulling back the surgical instrument through the haemostatic valve and closing the haemostatic valve by radially inward elastic deformation of the array of cantilevered arms.

33. The method of any one of claims 26 to 32, comprising manipulating a surgical instrument in a plurality of non-axial directions distal to the occluding device to achieve optimal therapeutic delivery of the therapeutic agent.

34. The method of claim 32, comprising clearing a therapeutic agent from an exterior of the surgical instrument while the surgical instrument is being drawn back through the hemostasis valve.

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