WO2018118706A1

WO2018118706A1 - Clot retrievers and methods for deployment

Info

Publication number: WO2018118706A1
Application number: PCT/US2017/066789
Authority: WO
Inventors: Omar M. Lattouf
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-12-20
Filing date: 2017-12-15
Publication date: 2018-06-28
Anticipated expiration: 2019-06-20

Abstract

Methods and devices for catheter-based removal of unwanted tissue or occlusive matter from blood vessels and other body lumens rely on a wire advanced from a tube to deploy a capture net that can be drawn over the clot. Apparatus include simple and reliable mechanisms for deployment of nets, funnels, and other clot capturing mechanisms for retrieving clot material from inside a blood vessel.

Description

CLOT RETRIEVERS AND METHODS FOR DEPLOYMENT

CROSS-REFERENCE TO RELATED APPLICATION

[001] This application claims the benefit of US Provisional Application No. 62/436,920 (Attorney Docket No. 51116-703.101), filed on December 20, 2016, the full disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[002] 1. Field of the Invention. The present invention relates generally to medical devices and methods, and more particularly, to devices and methods for mechanically removing unwanted occlusive material from a blood vessel.

[003] Coronary vessels can become narrowed or occluded by plaque or thrombus causing myocardial infarction, angina, and other conditions. For example, a coronary stenosis can be formed by an atheroma, which is typically a harder, calcified substance that forms on the lumen walls of a blood vessel. A stenosis can also be formed of a thrombus material, which is typically much softer than an atheroma, but can nonetheless cause restricted blood flow in the lumen.

[004] A number of medical procedures have been developed to effect removal or displacement of plaque or thrombus from vessel walls to open a channel restoring blood flow. Conventional catheter-based removal techniques include enzymatic dissolution of the stenotic lesion, such as with streptokinase, and energy-based ablation, for example, by radio frequency signals and lasers. Removal of a stenosis has also been achieved by thrombectomy or atherectomy. During thrombectomy and atherectomy, the stenosis is mechanically cut or abraded away from the vessel.

[005] Complications can arise from stenosis removal procedures. Stenotic debris, once separated from the stenosis, can flow from the treatment site though the vessel and compromise blood flow at a location removed from the treatment site. Various protection systems have been developed to prevent such debris from embolizing in a vessel following treatment. One such technique includes shredding the debris into sufficiently small fragments such that they will not occlude vessels within the vasculature. However, it can be difficult to control the size of severed fragments, particularly for thrombi, which tend to dislodge in larger fragments than atheroma. Another technique includes introducing negative pressure into the vessel during treatment to vacuum up dislodged stenotic debris. However, excessive negative pressure can cause the vasculature to collapse.

[006] Yet another technique for eliminating incidental stenotic debris during treatment includes introducing a vascular filter distal from the stenosis before removal. The filter can catch dislodged fragments of the stenosis as they flow downstream from the treatment site. Later, the vascular filter can be retrieved along with the caught debris after the removal of the stenosis at the treatment site is complete.

[007] Such filters include various configurations of nets, baskets, and other capture mechanisms for grabbing stenotic debris. However, low-profile delivery to and deployment of captures devices at a treatment site in a blood vessel can be difficult to achieve. Many conventional designs are hindered by complex and cumbersome actuation mechanisms.

Moreover, captured stenotic debris can become loose again during extraction and retrieval of the capture device, again posing a risk of becoming dangerous emboli.

[008] 2. Description of Background Art. Devices related to removal of occlusive material from blood vessels are described in U.S. Patent Nos. 9,402,708; 9,351,749; 7,695,491; and 6,001,118; and U.S. Patent App. Pub. Nos. 2016/0220346; 2016/0192956; and 2016/0143722.

SUMMARY OF THE INVENTION

[009] The present invention provides medical devices and methods for removing harmful occlusive material, such as soft plaque, calcified plaque, thrombus, fibrin, clot, fatty tissue, etc., (generally referred to herein as "clot" material) from blood vessels and other body lumens

[010] Blood vessels, including the coronary, pulmonary, and peripheral vasculature are often treated with catheter-based thrombectomy or atherectomy procedures. Aspects of the present invention improve the reliability and efficacy of such procedures by enabling low-profile delivery of clot retrieval devices inside a blood vessel, and providing simple and reliable mechanisms for deploying and retrieving the same. Various configurations of clot capture mechanisms are described herein for capturing and extracting clot material. Generally, the present invention provides a set of catheters or tubes containing a collapsed or compressed clot capture net, funnel, and/or other clot capture mechanisms which may be advanced distally through a blood vessel and past a clot region by a deployment wire. Once in place, the deployment wire is retracted proximally, deploying the expanding clot capture mechanism which then entrains and captures clot material as the device is removed from the vasculature.

[011] In a first aspect, the present invention provides a method for retrieving clot from a blood vessel. In one example, the method includes advancing a wire delivery tube or catheter in a distal direction through a blood vessel or other body lumen toward and past a clot region in the blood vessel. The blood vessel is a typically a coronary artery, peripheral vein, or peripheral artery, but can also be other types of vasculature such as renal, carotid, pulmonary artery, or the like. [012] With the wire delivery tube or catheter past the clot region, the method further includes advancing a deployment wire in a distal direction from a distal end of the wire delivery tube or catheter, causing a collapsible hoop integrally formed in the distal end of the deployment wire to deploy laterally relative to a longitudinal axis of the deployment wire as the collapsible hoop emerges from the wire delivery tube.

[013] The method further includes drawing or retracting the deployment wire in a proximal direction to pass the deployed hoop over and past the region of clot. The deployed hoop pulls an attached clot collection net other capture mechanism which entrains and moves the clot from the region as the deployment wire is drawn proximally.

[014] In a further embodiment, advancing the deployment wire in a distal direction further deploys a funnel attached to the deployment wire. The funnel is aligned on a proximal side of the clot collection net and configured to direct the clot into the clot collection net as the deployment wire is drawn in the proximal direction.

[015] In yet a further embodiment, the wire delivery tube is initially disposed inside a main delivery tube during delivery. The method includes advancing the main delivery tube in a distal direction through the blood vessel, carrying the wire delivery tube past the clot region.

[016] In still yet a further embodiment, the main delivery tube carries a net delivery tube in addition to the wire delivery tube, the net delivery tube carrying at least a portion of the clot collection net. The method includes pulling the clot collection net from the net delivery tube by drawing the deployment wire in a proximal direction. In some embodiments, one or more the hoop and funnel are deployed from the wire delivery tube before the clot collection net is drawn from the net delivery tube. The method may also include retracting the main delivery tube to expose the wire delivery tube and net delivery tube before deployment of the clot capture mechanisms.

[017] In still yet a further embodiment, the net delivery tube carrying at least a portion of the clot collection net includes a secondary wire attached to the distal end of the net. The wire allows for the distal end of the net to be directionally controlled, and potentially retracted into the net delivery tube if necessary.

[018] In still yet a further embodiment, the net delivery tube carrying at least a portion of the clot collection net includes a catheter with a "J" shaped tip known in the art as an angiographic catheter, attached to the distal end of the net. The catheter allows for the distal end of the net to be directionally controlled, and potentially retracted into the net delivery tube if necessary. The use of a catheter also allows for the infusion of clot busting drugs into the net surrounding the clot, thus dissolving clots that may be too large, or too hard for extraction. The catheter could also be used to aspirate the portions of the clot that dissolve for easy removal.

[019] In a second aspect, the present invention provides a clot retriever. In one example, the clot retriever includes a deployment wire having a distal end and a proximal end. A resiliently collapsible hoop is integrally formed in the distal end of the deployment wire, and a clot collection net is coupled to the resiliently collapsible hoop. A wire delivery tube is configured to translatably receive the deployment wire so that the resiliently collapsible hoop can be moved from a retracted position where the hoop is constrained within the lumen of the wire delivery tube to an advanced position where the hoop is deployed by releasing from constraint. Once released from constraint, the hoop is configured to deploy laterally outwardly from a main body of the wire to unfurl the clot collection net.

[020] In a further embodiment, the deployment wire comprises a shape memory metal such as nitinol formed into the resiliently collapsible hoop and the main body.

[021] In a still further embodiment, the clot retriever includes a collapsible funnel. The funnel is attached to the main body at a location proximal to the resiliently collapsible hoop. The funnel, when free from constraint and deployed, is tapered to have a clot receiving opening at its proximal end which is larger than a clot directing opening at its distal end.

[022] In yet a further embodiment, the funnel has curved sides. The curved sides are configured to interleave when the funnel is collapsed, pre-deployment, in the wire delivery tube. When deployed, the funnel can expand or unfold to a preselected dimension, or to the extent of the lumen of the blood vessel.

[023] In another embodiment, the clot retriever includes a main delivery tube. The main delivery tube has a lumen configured to translatably receive the wire delivery tube.

[024] In a further embodiment, the clot collection net everts from a distal end of the wire delivery tube. The clot collection net and wire delivery tube are stowed in parallel within the main delivery tube prior to deployment.

[025] In yet a further embodiment, a net delivery tube has a lumen and a distal opening which receives the clot collection net. The net delivery tube is stowed in parallel to the wire delivery tube within the main delivery tube.

[026] In yet a further embodiment, the net is made from a mesh like material such as Nylon or polyester with mesh porosity sufficient for capture and retainment of clot material.

[027] In yet a further embodiment, the net is made from a compliant plastic material such as polyurethane with a pattern of holes cut or punched in it sufficient for capture and retainment of clot material. [028] In yet a further embodiment, the clot capture net is shaped such that is can enclose and retain the clot, such shape to be cylindrical, conical, or a combination thereof.

[029] In various embodiments, the deployment wire has a length in the range from 10 cm to 250 cm. In one embodiment, the clot collection net is a short net having a length with a length in the range from 0.1 cm to 20 cm. In an alternate embodiment, the net is a long net having a length in the range from 0.1 cm to 20 cm. In another embodiment, the funnel is a short funnel having a length in the range from 0.1 cm to 20 cm. In another embodiment, the funnel comprises a long funnel having a length in the range from 0.1 cm to 20 cm. It will be obvious to those of skill in the art that various configurations of the deployment wire, clot collection net, funnel, and other components may be assembled based on the parameters of the delivery catheter or tube and to suit the characteristics of the blood vessel and clot to be removed.

[030] Other objects and advantages of the present invention will become apparent from the detailed description to follow, together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[031] The foregoing and other objects, features and advantages of embodiments of the present inventive concepts will be apparent from the more particular description of preferred embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same or like elements. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the preferred embodiments.

[032] FIG. 1 illustrates a first clot retrieval device 100, pre-deployment, according to an example embodiment.

[033] FIG. 2 illustrates the first clot retrieval device 100, mid-deployment, according to an example embodiment.

[034] FIG. 3 also illustrates the first clot retrieval device 100, mid-deployment, according to an example embodiment.

[035] FIG. 4 illustrates the first clot retrieval device 100, post-deployment, according to an example embodiment.

[036] FIG. 5 illustrates the first clot retrieval device 100 entraining a clot 190 in a blood vessel 180, according to an example embodiment.

[037] FIG. 6 illustrates the first clot retrieval device 100 capturing the clot 190 in the blood vessel 180, according to an example embodiment.

[038] FIG. 7 illustrates the first clot retrieval device 100 retrieving the clot 190 in the blood vessel 180, according to an example embodiment. [039] FIG. 8 illustrates the first clot retrieval device 100 capturing a clot 190 in a left pulmonary artery 850, according to an example embodiment.

[040] FIG. 9 illustrates a second clot retrieval device 200, pre-deployment, according to an example embodiment.

[041] FIG. 10 illustrates a second clot retrieval device 200, post-deployment, according to an example embodiment.

[042] FIG. 11 illustrates a third clot retrieval device 300, post-deployment, according to an example embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[043] FIGs. 1-4 illustrate a first clot retrieval device 100 throughout various stages of deployment. Clot retrieval device 100 comprises a deployment wire 130 with a resiliently collapsible hoop 125 formed integrally in a distal end. A clot collection net 145 is coupled to the collapsible hoop 125. Also at a distal end of the deployment wire 130 but proximal from the hoop 125 is a collapsible funnel 165. The funnel 165 has curved sides configured to interleave while the funnel is collapsed inside the wire delivery tube.

[044] In the pre-deployment configuration of the clot retrieval device 100, as shown in FIG. 1, the hoop 125 is initially collapsed and disposed within the wire delivery tube 120. The deployment wire 130 is also translatably received by the wire delivery tube 120. Similarly, the clot collection net 145 is initially disposed at least partially in within a net delivery tube 140. The funnel 165 is also collapsed within the wire delivery tube 120. Both the wire delivery tube 120 and net delivery tube 140 are disposed within a main delivery tube 110. There may also be included a wire or tube 146 distally attached to the clot collection net such that the net can be positioned therefrom, or retrieved into the net delivery tube. In it' s tube configuration, the tube can be used also to infuse or aspirate into and from the net enclosed space.

[045] During deployment of the clot retrieval device 100, as shown in FIG. 2, the main delivery tube is retracted to expose the wire delivery tube and net delivery tube 140. The wire delivery tube is itself retracted (or the deployment wire 130 otherwise advanced in a distal direction through the wire delivery tube 120) allowing the resiliently collapsible hoop 125 to emerge from the distal end of the wire delivery tube 120. As shown in FIG. 4, once a critical portion of the resiliently collapsible hoop 125 is no longer constrained by wire delivery tube, the hoop 125 expands laterally relative to a longitudinal axis of the deployment wire 130. As the deployment wire continues to advance, the funnel 165 may also emerge from the wire delivery tube. As the funnel emerges, it expands or unfurls. [046] After deployment of the clot retrieval device 100, as shown in FIG. 4, the funnel has expanded to a stable configuration for entraining and directing occlusive material to the clot collection net 145. In some configurations, a proximal opening of the funnel can be larger than a distal opening of the funnel to more effectively guide clot material into the clot collection net 145. In another configuration the distal opening of the funnel can be smaller than the opening of the deployed hoop 125.

[047] FIGs. 5-7 illustrate removal of a clot 190 in a blood vessel 180 with the clot retrieval device. After the clot retrieval device is introduced to the blood vessel 180, the main delivery tube is advanced past a clot region. The hoop 125 and funnel of the clot retrieval device are then deployed and the deployment wire is retracted to advance the funnel 165 and hoop 125 in a proximal direction of the blood vessel back towards the clot region.

[048] As shown in FIG. 5, a first portion of the clot 190 is entrained by the funnel as the deployment wire is retracted in a proximal direction. The funnel guides the clot into the resiliently collapsible net 145 as shown in FIG. 6. As the deployment wire continues to retract, the clot passes through the funnel and into the net 145. The deployment wire is further retracted until the net 145 and clot are pulled out of the blood vessel. In some embodiments, the net 145 may completely emerge from the net delivery tube 140, as shown in FIG. 7. The net delivery tube 140 may then be retracted before the clot is engaged by the funnel 165 and/or hoop 125. There may also be included a wire or tube 146 distally attached to the clot collection net such that the net can be positioned therefrom, or retrieved into the net delivery tube. The addition of the wire or tube provides the user the option of retracting the net into the delivery tube, or of infusing drugs into the net space, which could include clot busting drugs to soften hard clots.

[049] FIGs. 9-10 illustrates a second clot retrieval device 200 before and after deployment. Like the first clot retrieval device 100, the second clot retrieval device comprises a deployment wire 230 with a resiliently collapsible hoop 225 formed integrally in a distal end. A clot collection net 245 is coupled to the collapsible hoop 225. Also at a distal end of the deployment wire 230 but proximal from the hoop 225 is a collapsible funnel 265. The funnel 265 has curved sides configured to interleave while the funnel is collapsed inside the wire delivery tube.

[050] In the pre-deployment configuration of the clot retrieval device 200, as shown in FIG. 9, the hoop 225 and funnel 265 are initially collapsed and both disposed within the wire delivery tube 265 along with the clot collection net 245. Accordingly, in one embodiment, the second clot retrieval device has only a single catheter or tube for carrying the capture mechanisms. In the post-deployment configuration of the clot retrieval device 200, as shown in FIG. 10, the net 245, hoop 225, and funnel 265 each emerge from the deployment tube as the deployment wire 230 is retracted in a proximal direction. Once deployed, the second clot retrieval device 200 entrains and retrieves a clot in a similar manner as the first clot retrieval device 100.

[051] FIG. 11 illustrates a third clot retrieval device 300. The clot retrieval device comprises a resiliently collapsible hoop 325 coupled to a clot collection net 345 which are both disposed in a single tube until deployment. The hoop 325 and net 345 are deployed by advancing a deployment wire 330 in a distal direction. Although the third clot retrieval device 300 omits a funnel for guiding a clot 390 into the clot collection net 345, the clot may still be entrained and retrieved by the clot collection net when the deployment wire is retracted in a proximal direction after deployment.

[052] It will be obvious to those of skill that additional embodiments comprising various configurations of catheters, funnels, nets, and other components beyond those described in detail above are contemplated and within present invention. For example, the long clot collection net of the first clot retrieval device 100, as shown in FIG. 7, may be substituted for the short net of the second clot retrieval device, as shown in FIG. 10, and vice versa. Ranges of suitable sizes for various components are described hereinabove.

[053] The method comprises advancing a wire delivery tube in a distal direction through a blood vessel and past or through a clot region. A deployment wire is then advanced in a distal direction from a distal end of the wire delivery tube to deploy the collapsible hoop on the distal side of the clot region. The deployment wire is then drawn in a proximal direction to pass the deployed hoop over and past the region to direct the clot into the clot collection net. Optionally. The clot is directed into the net by the funnel.

[054] While the preferred embodiments of the devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the present inventive concepts. Modification or combinations of the above- described assemblies, other embodiments, configurations, and methods for carrying out the invention, and variations of aspects of the invention that are obvious to those of skill in the art are intended to be within the scope of the claims. In addition, where this application has listed the steps of a method or procedure in a specific order, it may be possible, or even expedient in certain circumstances, to change the order in which some steps are performed, and it is intended that the particular steps of the method or procedure claim set forth herebelow not be construed as being order-specific unless such order specificity is expressly stated in the claim.

Claims

WHAT IS CLAIMED IS:

1. A clot retriever comprising;

a deployment wire having a distal end, a proximal end, and a resiliently collapsible hoop integrally formed in the distal end;

a clot collection net coupled to the resiliently collapsible hoop; and a wire delivery tube having a lumen configured to translatably receive the deployment wire so that the resiliently collapsible hoop can be moved from a retracted position wherein the hoop is constrained within the lumen to an advanced position wherein the hoop is released from constraint and deploys laterally outwardly from a main body of the wire to unfurl the clot collection net.

2. A clot retriever as in claim 1, wherein the deployment wire comprises a shape memory metal formed into the resiliently collapsible hoop and the main body.

3. A clot retriever as in claim 1, further comprising a collapsible funnel attached to the main body at a location proximal to the resiliently collapsible hoop, wherein the funnel, when deployed and free from constraint, is tapered to have a clot receiving opening at its proximal end which is larger than a clot directing opening at its distal end.

4. A clot retriever as in claim 3, wherein the funnel has curved sides which are configured to interleave when the funnel is collapsed within the wire delivery tube.

5. A clot retriever as in claim 1, further comprising a main delivery tube having a lumen which translatably receives the wire delivery tube.

6. A cloth retriever as in claim 5, wherein the clot collection net everts from a distal end of the wire delivery tube and wherein the clot collection net and wire delivery tube are stowed in parallel within the main delivery tube prior to deployment.

7. A clot retriever as in claim 6, further comprising a net delivery tube having a lumen and a distal opening which receives the clot collection net, wherein the net delivery tube is stowed in parallel to the wire delivery tube within the main delivery tube.

8. A clot retriever as in claim 1, further comprising a wire distally attached to the clot collection net which allows for the distal end of the net to be controlled, positioned, and retrieved into the delivery tube.

9. A clot retriever as in claim 1, further comprising a tube distally attached to the clot collection net which allows for the distal end of the net to be controlled, positioned, and retrieved into the delivery tube, and also provides for a means of aspiration and infusion of fluids into the clot collection net.

10. A clot retriever as in claim 1, wherein the deployment wire has a length in the range from 10 cm to 250 cm.

11. A clot retriever as in claim 6, wherein the net comprises a short net with a length in the range from 0.1 cm to 10 cm.

12. A clot retriever as in claim 6, wherein the net comprises a long net with a length in the range from 10 cm to 20 cm.

13. A clot retriever as in claim 6, wherein the funnel comprises a short funnel having a length in the range from 0.1 cm to 10 cm.

14. A clot retriever as in claim 6, wherein the funnel comprises a long funnel having a length in the range from 10 cm to 20 cm.

15. A method for retrieving clot from a blood vessel, said method comprising; advancing a wire delivery tube in a distal direction through a blood vessel and past a region of clot;

advancing a deployment wire in a distal direction from a distal end of the wire delivery tube, wherein a collapsible hoop integrally formed in a distal end of the deployment wire deploys laterally relative to a longitudinal axis of the deployment wire as the collapsible hoop emerges from the wire delivery tube; and

drawing the deployment wire in a proximal direction to pass the deployed hoop over and past the region of clot wherein the deployed hoop pulls a clot collection net which collects clot from the region of clot as the wire is drawn proximally.

16. A method as in claim 15, wherein advancing the deployment wire in a distal direction further deploys a funnel attached to the wire, wherein the funnel is aligned on a proximal side of the clot collection net and configured to direct clot into the clot collection net as the deployment wire is drawn in the proximal direction.

17. A method as in claim 16, further comprising advancing a main delivery tube in a distal direction through the blood vessel, wherein the main delivery tube carries the wire delivery tube as the main delivery tube is advanced.

18. A method as in claim 17, wherein the main delivery tube further carries a net delivery tube which carries the clot collection net, wherein the deployment wire is drawn proximally to pull the clot collection net from the net delivery tube.

19. A method as in claim 15, wherein the blood vessel is a coronary artery.

20. A method as in claim 15, wherein the blood vessel is a Superior Vena Cava, an Inferior Vena Cava or a peripheral vein.

21. A method as in claim 15, wherein the blood vessel is an aorta, a carotid artery or a peripheral artery.