Implantable medical device disconnection system with flexible braid segment

Abstract

The invention is entitled "Implantable medical device detachment system with flexible braid segment." The disclosed technology includes a detachment system for delivering an implantable medical device to a target location in a body vessel, the detachment system including a proximal delivery tube, a distal delivery tube, and a braid segment disposed therebetween. The distal tube includes a proximal end, a distal end, and a compressible portion of the tube itself between the proximal end and the distal end, the compressible portion being axially movable from a compressed state to an elongated state. The proximal tube has a proximal end and a distal end. The braid segment is formed from a plurality of wires. An engagement system engages and deploys the implantable medical device engaged at the distal end of the distal tube.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to interventional medical device systems capable of navigating through the vasculature of a human subject. More particularly, the present invention relates to a decoupling system for delivering and deploying an implantable medical device to a target location of a body vessel and methods of using the decoupling system. BACKGROUND

[0002] The use of catheter delivery systems to position and deploy therapeutic devices such as inflatable balloons, stents, and embolic coils in the vasculature of the human body has become a standard procedure for treating intravascular disease. Such devices have been found to be particularly useful in treating areas where traditional operating procedures are not possible or pose a great risk to the patient, for example, in the treatment of aneurysms in intracranial vessels. Because the tissue surrounding intracranial vessels, particularly, for example, brain tissue, is relatively fragile, it is very difficult and often risky to surgically treat defects in intracranial vessels. In such cases, improvements in catheter deployment systems provide an alternative treatment option. Some advantages of catheter delivery systems are that they provide a way to treat blood vessels in a manner that has been found to reduce the risk of trauma to surrounding tissue, and they also allow for the treatment of blood vessels that were previously considered inoperable.

[0003] Generally, a procedure for treating an aneurysm using a catheter deployment system involves inserting a distal end of a delivery catheter into the vasculature of a patient and guiding the delivery catheter through the vasculature to a predetermined delivery site. A vascular occlusion device such as an embolic coil can be attached to an implant engagement / delivery system at a distal end of a delivery member (e.g., a microcatheter) that pushes the coil through the delivery catheter and out of the distal end of the delivery catheter into the delivery site. Exemplary delivery members and engagement / delivery systems are described in U.S. Patent Publication No. 2019 / 0192162 Al, U.S. Patent Publication No. 2019 / 0328398 Al, and U.S. Patent Publication No. 2021 / 0001082 Al, each of which is incorporated herein by reference.

[0004] Many catheter-based implant delivery systems can include one or more internal elongate members that extend through the catheter, which can be manipulated by a physician at the proximal end to deploy the implantable device. The internal elongate members can hold the implantable device in the catheter until the time for releasing the implant. These systems can be actuated by retracting or pulling the elongate members relative to the catheter. Some challenges associated with proper execution of such aneurysm treatment procedures include ensuring that the delivery member and the engagement system remain in a stable position throughout the treatment. For example, in some aneurysm treatment applications, as the aneurysm is increasingly filled with embolic material, the delivery member can tend to shift due to increased pushback from the implanted embolic material. If the delivery member shifts during treatment, the physician can not accurately control the placement of the embolic material and can choose to stop filling the aneurysm. In such examples, the aneurysm can not be adequately filled, which can result in recanalization. Additionally, excessive movement or stretching of the delivery member and / or the engagement system thereon can result in premature detachment of the embolic coils. Some examples of methods to reduce the likelihood of premature release can result in a mechanical release system that is less flexible.

[0005] Additionally, catheter deployment systems can be used to treat intravascular lesions associated with intracranial atherosclerotic disease (ICAD). In some cases, the intravascular lesion can not be soft enough for a stentrievers to effectively engage the vessel and remove the lesion from the vessel. In such cases, it can be desirable to deploy a stent so that the intravascular lesion can be treated by stenting. Prior to delivery of either device, the physician can not know whether the lesion is better treated by a stent or a stentriever. Since stentrievers are retractable and stents are generally not, in such cases, the stentrievers are generally deployed on the first pass and then the stent is deployed on the second pass, if appropriate. Multiple passes through the vasculature can increase trauma to the vasculature and increase treatment time, increasing the likelihood of complications.

[0006] Accordingly, there is a need for systems, devices, and methods that can reduce the likelihood of premature deployment of intravascular treatment devices while also providing a flexible mechanical release system. SUMMARY

[0007] It is a general object of the present invention to provide a split system for delivering an implantable medical device to a target location in a blood vessel of a body, the split system including a proximal delivery tube, a distal delivery tube, and a braid segment disposed therebetween. The braid segment provides stability during deployment of the implantable device in an aneurysm while maximizing flexibility of the split system.

[0008] An exemplary detachment system for delivering an implantable medical device to a target location of a blood vessel can include a generally hollow proximal tube, a generally hollow distal tube, a braid segment, and an engagement system. The proximal tube can include a proximal end and a distal end. The distal tube can include a proximal end, a distal end, and a compressible portion of the distal tube that is axially movable from a compressed state to an elongated state. The braid segment can be disposed between the proximal end of the distal tube and the distal end of the proximal tube. The braid segment can be formed of a plurality of wires. The engagement system can be configured to engage and deploy an implantable medical device disposed at the distal end of the distal tube.

[0009] The braid segment can be disposed concentrically about a polymer liner.

[0010] The polymer sleeve can be positioned over at least a portion of the proximal tube, the braid segment, and the distal tube.

[0011] The polymer sleeve can include one or more hydrophilic coatings.

[0012] The polymer sleeve can have a wall with a thickness between about 0.02 millimeters and about 0.08 millimeters.

[0013] The braid segment can include between about 8 and about 16 wire segments.

[0014] The braid segment can be configured to have between about 50 and about 100 wefts per inch.

[0015] The compressible portion of the distal tube can be a spiral cut portion of the distal tube.

[0016] The engagement system can be configured to move the compressible portion to the compressed state when the implantable medical device is engaged and deploy the implantable medical device when the compressible portion is released to the elongated state.

[0017] The compressible portion can be adapted to automatically move to the elongated state when the engagement system is disengaged from the implantable medical device.

[0018] In one example, the implantable medical device can be a stent retriever with a proximal end collapsed by the engagement system and a distal end collapsed by the engagement system when engaged to the engagement system. The implantable medical device can be a stent with an open proximal end and an open distal end when disengaged from the engagement system.

[0019] An exemplary method of detaching an implantable medical device can include one or more of the following steps presented in no particular order. The method can also include additional steps as would be appreciated and understood by one of ordinary skill in the art in light of the teachings of this disclosure.

[0020] The method may include forming a compressible portion on the distal tube; forming a flexible portion on the proximal tube; attaching a braided segment to the distal end of the proximal tube and the proximal end of the distal tube; and engaging the implantable medical device with the engagement system.

[0021] The method may also include sliding the polymer sleeve on at least a portion of the proximal tube, the braided section, and the distal tube.

[0022] The method may also include attaching a polymer cannula to an implantable medical device.

[0023] The method may also include coating the polymer sleeve with one or more hydrophilic coatings.

[0024] The method may include wrapping a woven section around a polymer liner and then attaching the woven section to the distal end of the proximal tube and the proximal end of the distal tube.

[0025] The engagement step may include using a loop with a locking member to engage the implantable medical device, and applying force to the loop to move the compressible portion into a compressed state.

[0026] The method may also include applying force to the locking member to disengage the implantable medical device and allowing the compressible portion to return to its elongated state.

[0027] The method may include deploying the attached implantable medical device by moving the compressible portion to an elongated state.

[0028] In one example, the implantable medical device could be a stent thrombectomy device configured to deploy upon deployment to juxtapose the vessel wall. Attached Figure Description

[0029] The foregoing and other aspects of the invention will be further discussed with reference to the following description and the accompanying drawings, in which similar numbers indicate similar structural elements and features in various figures. The drawings are not necessarily drawn to scale; rather, the emphasis is on illustrating the principles of the invention. The drawings depict one or more specific embodiments of the apparatus of the invention by way of example only and not by way of limitation.

[0030] FIG. 1A This is an illustration of an exemplary separation system having woven sections according to various aspects of the present invention, and FIG. 1B According to various aspects of the present invention FIG. 1A A cross-sectional view of an exemplary separation system;

[0031] FIG. 2A This is an illustration of another exemplary separation system having woven sections according to various aspects of the present invention;

[0032] FIG. 2Bis a cross-sectional view of an exemplary separation system according to aspects of the present application; FIG. 2A is a cross-sectional view of an exemplary separation system according to aspects of the present application;

[0033] FIG. 3A is a cross-sectional view of an exemplary separation system according to aspects of the present application;

[0034] FIG. 3B is a cross-sectional view of an exemplary separation system according to aspects of the present application; FIG. 3A is a cross-sectional view of an exemplary separation system according to aspects of the present application;

[0035] FIG. 4A is a side perspective view of an example of a loop according to aspects of the present application;

[0036] FIG. 4B is a plan view of an example of a loop according to aspects of the present application;

[0037] FIG. 4C is a rear perspective detail view of an opening of a loop in an upturned state according to aspects of the present application;

[0038] FIG. 5A to FIG. 5D is a series of illustrations of an exemplary implanted medical device in dissection according to aspects of the present application;

[0039] FIG. 6A to FIG. 6C is a series of illustrations of deployment of an exemplary stentriever as an implanted medical device according to aspects of the present application;

[0040] FIG. 7A to FIG. 7B is a series of illustrations of an exemplary stentriever in dissection according to aspects of the present application;

[0041] FIG. 8A to FIG. 8C is an illustration of another exemplary stentriever according to aspects of the present application attached to a deployment system (A), in cross-section (B), and in dissection (C); FIG. 8A FIG. 8B FIG. 8C

[0042] FIG. 9 is a side view of an example of a distal tube in compressed and expanded states according to aspects of the present application; and

[0043] FIG. 10 is a flowchart outlining steps of dissection of an implanted medical device according to aspects of the present application. DETAILED DESCRIPTION

[0044] ​​​A key factor for success in endovascular treatments such as aneurysm treatment is the stability of a detachment device (e.g., microcatheter) during deployment of an implant or other medical treatment device. During endovascular treatment, a lack of flexibility in the distal portion of the detachment device as the implant is placed in an aneurysm or other treatment site can result in the detachment device being pulled back or otherwise moved out of position from the treatment site. Thus, a detachment device with a more flexible distal portion can provide a stabilization system for delivering medical devices in neurovascular anatomical structures and for other applications facing similar challenges. However, flexible structures can tend to deform, elongate, or expand when navigating tortuous anatomical structures. Deformation of the detachment system can inhibit the ability of the detachment system to navigate to the treatment site and / or effectively deploy the medical device. Elongation of the detachment system can result in premature deployment of the medical device. It is an object of the present invention to provide a detachment system with a highly flexible braided segment that is resistant to stretching and structurally stable during the delivery and deployment of a medical treatment device.

[0045] While example implementations of the disclosed technology are explained in detail herein, it should be understood that other implementations can be contemplated. Thus, it is not intended that the scope of the disclosed technology be limited to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The disclosed technology is capable of other implementations and of being practiced or carried out in various ways.

[0046] It should also be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. By way of example, reference to "a compound" includes a combination of two or more compounds, and vice versa. So as not to exclude any possible embodiment, reference to "comprising" or "containing" or "including" means "including but not limited to."

[0047] In describing example implementations, terminology will be used that will be understood by those skilled in the art. Each term is intended to encompass its broadest meaning, as understood by those with ordinary skill in the art, and includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. It should also be understood that reference to one or more steps of a method does not exclude the presence of additional method steps or intervening method steps between those explicitly identified. The steps of the method can be performed in a different order than described herein without departing from the scope of the disclosed technology. Similarly, it should also be understood that reference to one or more components in an apparatus or system does not exclude the presence of additional components or intervening components between those explicitly identified.

[0048] As discussed herein, the vasculature can be that of any "subject" or "patient," including any human or animal. It should be appreciated that the animal can be of any applicable type, including but not limited to a mammal, a veterinary animal, a farm animal, or a pet class animal, etc. For example, the animal can be an experimental animal specifically selected to have certain characteristics similar to humans (e.g., a rat, a dog, a pig, a monkey, etc.). It should be appreciated that the subject can be, for example, any applicable human patient.

[0049] As discussed herein, the term "about" or "approximately" with respect to any numerical or range of values indicates suitable dimensional tolerances that allow the parts or components to function for their intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of values ±20% of the recited value, for example "about 90%" can refer to a range of values from 71% to 99%.

[0050] The drawings illustrate generally hollow or tubular structures in accordance with the present application. As used herein, the terms "tubular" and "tube" are to be interpreted broadly and are not limited to structures that are right cylinders or have a complete circular cross-section or have a uniform cross-section throughout their length. For example, tubular structures or systems are generally shown as structures that are substantially right cylinders. However, the tubular systems can have tapered or curved outer surfaces without departing from the scope of the present application.

[0051] FIG. 1A to FIG. 3B An example of a separation system 10 is shown, where the separation system addresses the shortcomings of previous methods and other shortcomings disclosed herein. The separation system 10 can include a proximal delivery tube 100 and a distal delivery tube 300. Braided sections 200a, 200b, 200c can be disposed between the proximal delivery tube 100 and the distal delivery tube 300. The braided sections 200a, 200b, 200c can be formed from a plurality of wires 202. The braided section 200b can be wrapped around a polymer liner 204 to minimize friction and protect the braided section 200b when delivering the separation system 10. A polymer sleeve 206 can be disposed over the braided section 200c to further minimize friction and protect the braided section 200c. The braided sections 200a, 200b, 200c enable the separation system 10 to remain stable during deployment of the implantable medical device 12 while also providing sufficient flexibility that minimizes the likelihood of moving or pulling back the separation system 10 when the implantable medical device is positioned in the aneurysm.

[0052] An example of a separation system 10 of the present application (as FIG. 1A to FIG. 3BThe illustrated) can have a proximal elongate delivery tube 100, braid segments 200a, 200b, 200c, and a distal delivery tube 300. The implantable medical device 12 can be engaged at a distal end 304 of the distal delivery tube 300. The implantable medical device 12 can be an embolic coil. The implantable medical device 12 can be a stentriever 612 (as FIG. 6A 、 FIG. 6B 、 FIG. 7A 、 FIG. 7B 、 FIG. 8A to FIG. 8C The illustrated) can have a proximal elongate delivery tube 100, braid segments 200a, 200b, 200c, and a distal delivery tube 300. The implantable medical device 12 can be engaged at a distal end 304 of the distal delivery tube 300. The implantable medical device 12 can be an embolic coil. The implantable medical device 12 can be a stentriever 612 (as

[0053] The proximal delivery tube 100 can have a proximal end portion 102, a distal end portion 104, and a flexible portion 106. The flexible portion 106 can be disposed between the proximal end portion 102 and the distal end portion 104. The proximal delivery tube 100 can have an axial lumen therein. The distal delivery tube 300 can have a proximal end portion 302, a distal end portion 304, and a compressible portion 306. The compressible portion 306 can be disposed between the proximal end portion 302 and the distal end portion 304. The compressible portion 306 can be closer to the distal end portion 304. The distal delivery tube 300 can have an axial lumen formed therein.

[0054] The delivery tubes 100, 300 can be made of a biocompatible material such as stainless steel. The tubes 100, 300 can have a diameter between about 0.25 millimeters (0.010 inch) and about 0.46 millimeters (0.018 inch). In one example, the delivery tubes can have a diameter of about 0.37 millimeters (0.0145 inch). These examples of tube size are suitable for delivering and deploying embolic coils to a target location (typically an aneurysm) within the neurovasculature. It is contemplated that different sizes of tubes 100, 300 composed of other materials can be used for different applications and are within the scope of the present disclosure.

[0055] The flexible portion 106 of the proximal delivery tube 100 can allow the proximal delivery tube 100 to bend and flex. This ability can facilitate tracking of the detachment system 10 through a catheter and through the tortuous pathways of the human vasculature. The flexible portion 106 can be formed with interference helical cuts. These cuts can allow for gaps to allow bending, but in one example, do not act as helical cut springs. In this configuration, the interference helical cuts can bend and flex, but do not compress.

[0056] The compressible portion 306 is axially adjustable between an elongated state and a compressed state. The compressible portion 306 can be formed from a helical cut portion of the distal tube 300 formed by a laser cutting operation. However, it is contemplated that any other arrangement that allows for axial adjustment (e.g., a wrapped wire or a helical ribbon) is also suitable for use with the detachment system according to the present application. Unless otherwise limited, the compressible portion 306 can be in the elongated state when at rest and automatically or elastically return to the elongated state from the compressed state. The detachment device 10 can include a loop wire 400 that, along with the locking member 140, is configured to secure the implant 12 to the detachment device 10. When the loop wire 400 and the locking member 140 are engaged to the implant 12, the compressible portion 306 can be held in the compressed state by tension in the loop wire 400. The loop wire 400 can be attached to the distal tube 300 near the proximal end 302 of the distal tube 300.

[0057] The braid segments 200a, 200b, 200c can be disposed between the proximal end 302 of the distal tube 300 and the distal end 104 of the proximal tube 100. The braid segments 200a, 200b, 200c can be attached to the proximal end 302 of the distal tube 300 and the distal end 104 of the proximal tube 100. The braid segments 200a, 200b, 200c can be attached to the proximal end 302 of the distal tube 300 and the distal end 104 of the proximal tube 100 using any attachment mechanism, including but not limited to adhesive, welding, etc. The proximal tube 100 can extend a majority of the length of the detachment system 10, while the braid segments 200a, 200b, 200c and the distal tube 300 can extend over the most distal portion of the detachment system. In one example, the braid segments 200a, 200b, 200c and the distal tube 300 can extend over the most distal 500 millimeters of the detachment system 10.

[0058] The braid segments 200a, 200b, 200c can be formed from a plurality of wires 202. The plurality of wires 202 can be made from a biocompatible material such as stainless steel or nitinol. The plurality of wires 202 can include round wires. Alternatively or additionally, the plurality of wires 202 can include flat wires. The plurality of wires 202 can include between about 6 wires to about 20 wires. The braid segments 200a, 200b, 200c can be configured to have various picks per inch. In one example, the braid segments 200a, 200b, 200c can be configured to have between about 50 picks / inch to about 100 picks / inch. The number of wires in the plurality of wires 202 and the picks per inch can result in the braid segments 200a, 200b, 200c having a reduced cross-sectional dimension before kinking when the hollow member is bent. By reducing the cross-sectional dimension, the braid segments 200a, 200b, 200c can be substantially elliptical. The number of wires in the plurality of wires 202 and the picks per inch can facilitate elongation of the braid segments 200a, 200b, 200c such that the braid segments 200a, 200b, 200c can resist stretching when the detachment system 10 is withdrawn in the blood vessel BV while the implant 12 is held in the aneurysm by friction. Additionally, the elongation of the braid segments 200a, 200b, 200c can inhibit the braid segments 200a, 200b, 200c from collapsing axially or radially when the compressible portion 106, 206, 306 is in the compressed configuration prior to deployment.

[0059] When the detachment system 10 is assembled, the braid segments 200a, 200b, 200c can be more flexible than the proximal tube 100 and the distal tube 300. One way to measure flexibility is to perform a three-point bend test in which a portion of the detachment system 10 is held fixed at two end points, a force is applied perpendicular to the detachment system 10 at a location intermediate the points, and flexibility is quantified by the deflection length of the detachment system 10 caused by the force. When measured in this way, in some examples, the braid segments 200a, 200b, 200c can be more flexible than the distal tube 300 and more flexible than the proximal tube 100. In other words, when a three-point test is performed on the three segments 100, 200a, 200a, 200c, 300 in the same manner, the braid segments 200a, 200b, 200c can deflect a length that is greater than the deflection length of the distal tube 300 and greater than the deflection length of the proximal tube 100. As will be appreciated by one of ordinary skill in the art, flexibility can be measured in other ways.

[0060] The flexible braided sections 200a, 200b, and 200c are more flexible than the relatively rigid proximal tube 100 and the relatively flexible distal tube 300. The relatively rigid proximal tube 100, which extends the length of the dissection system 10, resists kinking when pushed through the microcatheter. The flexible braids 200a, 200b, 200c and the distal tube 300 can each be sufficiently flexible to reduce pushback when the implantable medical device 12 is placed in the aneurysm. Because the flexible braided sections 200a, 200b, and 200c do not need to be as compressible as the distal tube, they can be more flexible than the distal tube 300. The compressibility and elongation of the separation system 10 (including flexible braided sections 200a, 200b, 200c) can be precisely manipulated and / or controlled by changing the number of wefts per inch, the number of segments, and / or the size of each segment in the multiple threads 202.

[0061] like FIG. 1A and FIG. 1B As shown, a braided section 200a may be disposed between the proximal tube 100 and the distal tube 300. A locking member 140 may be disposed within the lumen of the braided section 200a. The locking member 140 may translate relative to the distal end 304 of the distal tube 300, at least in the proximal direction. Multiple threads 202 of the braided section 200a may be exposed. In this configuration, the braided section 200a is not covered by the polymer sheath 206 or any other protective covering. In this configuration, the multiple threads 202 may be exposed to the inner wall of the blood vessel during delivery of the dissection system 10 to the desired location within the patient.

[0062] FIG. 2A A separation system 10 is shown having a braided section 200b concentrically arranged around a polymer liner 204. The polymer liner 204 may be a polytetrafluoroethylene (PTFE) liner. The polymer liner 204 may provide stability to the braided section 200b and reduce friction between the braided section 200b and a locking member 140 disposed within the lumen of the braided section 200b. The braided section 200b may be wrapped around the polymer liner 204 before the braided section 200b and the polymer liner 204 are attached to the proximal tube 100, and the distal tube 300 or the polymer liner 204 may be a separate entity placed along the entire length of the device, the entire length of the device including at least a portion of the proximal tube 100, at least a portion of the distal tube 300, and at least a portion of the braided section 200b.

[0063] FIG. 2BA cross-sectional view of the braid segment 200b wrapped around the polymer liner 204 is shown. The polymer liner 204 can have substantially the same shape as the proximal tube 100 and the distal tube 300. The polymer liner 204 can be generally tubular and can have a lumen disposed therethrough. The locking member 140 can be slidably disposed within the lumen of the polymer liner 204.

[0064] FIG. 3A A separation system 10 is shown having a braid segment 200c encircled by a polymer liner 204 and a polymer sleeve 206 positioned over at least a portion of the proximal tube 100, the braid segment 200c, and at least a portion of the distal tube 300. After the separation system 10 is assembled, the polymer sleeve 206 can be slidably disposed over at least a portion of the proximal tube 100, the braid segment 200c, and at least a portion of the distal tube. In one example, the polymer sleeve 206 can be positioned over at least a portion of the flexible segment 106 of the proximal tube 100 to inhibit deformation of the flexible segment and / or reduce friction with the vasculature and the flexible segment 106 during intravascular navigation. In one example, the polymer sleeve 206 can be positioned over the entire distal tube 300 such that the polymer sleeve 206 can be attached proximate to the implantable medical device 12. In one example, the polymer sleeve 206 can be glued to the distal tube 300 and / or the proximal tube 100. Alternatively or additionally, the polymer sleeve 206 can be fused over the braid segment 200c such that the polymer sleeve 206 can be incorporated into the braid segment 200c. The polymer sleeve 206 can be attached to the implantable medical device 12 using attachment mechanisms including adhesives, fusions, welds, and the like. The polymer sleeve 206 can be a thermoplastic elastomer sleeve. The polymer sleeve 206 can include one or more additives to increase lubricity such that the sleeve can easily slide through the body vasculature.

[0065] The polymer sleeve 206 can provide stability to the braid segment 200c and reduce friction while the separation system 10 is delivered to a desired location within the patient. The polymer sleeve 206 can protect the braid segment 200c as the separation system 10 is conveyed through the vasculature and to the desired location within the patient.

[0066] FIG. 3B A cross-sectional view of the braid segment 200b wrapped around the polymer liner 204 is shown. The polymer liner 204 can have substantially the same shape as the proximal tube 100 and the distal tube 300. The polymer liner 204 can be generally tubular and can have a lumen disposed therethrough. The locking member 140 can be slidably disposed within the lumen of the polymer liner 204. FIG. 3AA cross-sectional view of the separation system 10 is shown. The polymer jacket 206 can have a wall 210 with a thickness between about 0.02 millimeters and about 0.08 millimeters. In one example, one or more hydrophilic coatings 208 can be applied to the polymer jacket 206. The one or more hydrophilic coatings 208 can include hyaluronic acid, polyalkylene glycol, alkoxylated polyalkylene glycol, poly(saccharide), poly(vinylpyrrolidone), poly(vinyl alcohol), poly(acrylic acid), poly(acrylamide), poly(maleic anhydride), copolymers thereof, and mixtures thereof. The one or more hydrophilic coatings 208 can also minimize friction that can occur when the separation system 10 is delivered through the vasculature and to a desired location within the patient.

[0067] As shown in FIGS. 2A and FIG. 2B The braid segment 200c can include a polymer liner 204. The braid segment 200c can be disposed concentrically around the polymer liner 204. The polymer liner 204 can provide stability to the braid segment 200c and reduce friction between the braid segment 200c and the locking member 140.

[0068] As shown in FIGS. 2A and FIG. 3B The locking member 140 is capable of translation through the lumens of the proximal delivery tube 100 and the braid segment 200c. The locking member 140 is also capable of translation through the lumen of the distal delivery tube 300, as shown in FIG. 2B. FIG. 3A

[0069] Although FIG. 3A and FIG. 3B The separation system 10 is shown with the braid segment 200c disposed concentrically around the polymer liner 204 and the polymer jacket 206 disposed over at least a portion of the proximal tube 100, the braid segment 200c, and at least a portion of the distal tube after the separation system 10 is assembled, it is contemplated that in some cases the braid segment 200c is not disposed around the polymer liner 204.

[0070] FIG. 4A to FIG. 4C An example of a looped wire 400 is shown. In some examples, the looped wire 400 can be relatively small, having the thickness of a hair. Due to the small size of the looped wire 400, the looped wire 400 can be completely shielded by the distal end 304 of the distal delivery tube 300 to prevent damage from accidental contact. The looped wire 400 can be an elongated wire in a loop, as shown in FIG. 4A. The looped wire 400a can also be a single elongated wire with an opening 405, as shown in FIG. 4B. FIG. 4A FIG. 4B ​​The opening 405 can be formed by loosely bending the loop wire 400a in half. In an alternative example, the loop wire 400b can include a flattened band defining an opening 405b at a distal portion, and the opening 405b can be in an upturned state adapted to engage an end of the implanted medical device 12. The examples of the loop wire 400, 400a, 400b can be elastically deformable to the upturned state such that it will return to a substantially flat state when not otherwise constrained. The loop wire 400, 400a, 400b can be formed of any of a variety of materials, including nitinol and stainless steel.

[0071] To load the detachment system 10, the locking member 140 can be axially inserted within the lumens of the proximal tube 100, the braid sections 200a, 200b, 200c, and the distal tube 300. The distal end 404 of the loop wire 400 can be inserted into the distal delivery tube 300 through the anchor portion located proximal of the proximal end 302 of the distal tube 300. The loop wire 400 can pass through the lumen of the distal tube 300 to the distal end 304. The distal end 404 of the loop wire 400 can then be looped to form the opening 405. The opening 405 can be passed through the locking portion 18. The locking member 140 can be passed through the opening 405 to engage the medical device 12.

[0072] FIG. 5A to FIG. 5D The detachment of the implanted medical device 12 is shown, where the implanted medical device 12 is a stent. FIG. 5A The detachment system 10 is shown, where the implanted medical device 12 is engaged and the compressible portion 306 of the distal tube 300 is in a compressed state. To reach the compressed state, the loop wire 400 can be pulled at the proximal end, and the continued force can compress the compressible portion 306. The amount of compression can be controlled by the amount of force applied to the proximal end of the loop wire 400 after the medical device 12 is mounted to the distal end 304 of the distal tube 300. Once the distal tube 300 is compressed by the appropriate amount, the loop wire 400 can be anchored at a solder point proximal to the proximal end 302 of the distal tube 300 or proximal to the anchor portion of the distal tube 300.

[0073] In FIG. 5A The engagement system, including the locking member 140 and the loop wire 400, is locked within the locking portion 18 of the medical device 12. The opening 405 of the loop wire 400 can be inserted through the locking portion 18. When the locking member 140 is inserted through the opening 405, the implanted medical device 12 can be securely in the desired position.

[0074] FIG. 5B The locking member 140 is shown being pulled proximally to begin the release sequence of the implanted medical device 12, as indicated by the arrow.

[0075] FIG. 5CThe instant the locking member 140 exits the opening 405 and is pulled out of the loop line 400 is shown. At this point, the distal end 404 of the loop line 400 can return to its initial pre-shaped shape and can exit the locking portion 18. Once the loop line exits the locking portion 18, there are no components holding the implantable medical device 12 to the detachment system 10.

[0076] FIG. 5D The end of the release sequence is shown. The compressible portion 306 can expand and return to its initial elongated state. As the compressible portion 306 returns to its initial elongated state, the compressible portion 306 can "spring forward." The distal end 304 of the distal tube 300 can apply a spring force E to the implantable medical device 12 to "push it away," thereby ensuring that the medical device 12 is fully detached and delivered to the desired location.

[0077] FIG. 6A to FIG. 6C An exemplary treatment method for a thrombus T or lesion within a blood vessel BV using the same detachment device 10 as FIG. 1A to FIG. 3B shown and a stentriever 612 as the medical implant 12 is shown. The stentriever 612 can have a proximal end 614 and a distal end 616. The proximal end 614 of the stentriever 612 can be attached to the detachment device 10. The locking member 140 can extend through the distal end 616 of the stentriever 612 as FIG. 6A shown. During delivery through the vasculature, the detachment device 10 and the stentriever 612 can be disposed within a microcatheter 610. The microcatheter 610 can prevent the strut frame 620 of the stentriever 612 from self-expanding. In some cases, the microcatheter 610 can be passed through the thrombus T or lesion within the blood vessel BV. The microcatheter 610 can be sized to keep the stentriever 612 collapsed thereon as the microcatheter 610 and the stentriever 612 are positioned over the thrombus T. The stentriever can remain in place as the microcatheter 610 is retracted proximally to allow the stentriever 612 to expand to appose the walls of the blood vessel BV.

[0078] FIG. 6B and FIG. 6CThe microcatheter 610 can be pulled proximally to allow the strut frame 620 of the stentriever 612 to begin to deploy. The strut frame 620 can self-deploy to appose the walls of the blood vessel BV. The stentriever 612 can include loops 618 disposed at the distal end 616 and the proximal end 614. The locking member 140 extending through the distal end 616 of the stentriever 612 can engage with the loops 618 such that the distal end 616 and the proximal end 614 of the stentriever 612 remain closed. By maintaining the distal end 616 and the proximal end 614 in a closed configuration via the loops 618 engaged with the locking member 140, the stentriever 612 can form a generally conical or tubular shape as it deploys. Upon deployment, the strut frame 620 can engage and deploy through the soft material of the thrombus T. The detachment device 10 attached to the proximal end 614 of the stentriever 612 can then be used to facilitate removal of the stentriever 612, including the captured thrombus T, from the blood vessel BV. The detachment device 10 and the stentriever 612 with the captured thrombus T can be retracted proximally such that the thrombus T can be effectively removed from the blood vessel BV.

[0079] Upon crossing the affected region including the thrombus T and / or lesion, in some treatments, the thrombus material can be soft enough to pass through the strut frame 620 of the stentriever, as shown in FIG. 6B and FIG. 6C In this case, as the captured thrombus T, the stentriever 612, and the detachment device 10 are pulled proximally from the patient, the stentriever 612 can remain attached to the detachment device 10. Removal of the stentriever 612 and the thrombus T from the patient can be performed with the aid of an auxiliary suction through a larger diameter intermediate catheter positioned over the microcatheter with the tip of the microcatheter immediately proximal to the proximal end 614 of the stentriever 612. Alternatively, the thrombus material can not be soft enough to pass through the strut frame 620 or there can be a potential narrowing (stenosis) of the blood vessel BV after the thrombus T is removed, continuing to restrict flow outside the lesion, in which case the affected region can be better treated with a stent implantation.

[0080] FIG. 7A and FIG. 7B Another method of treatment using the detachment device 10 and the stentriever 612 is shown, which can be applied in appropriate cases of stent implantation. As FIG. 7AAs shown, when the microcatheter 610 is pulled proximally, the stent retrieval device 612 can begin to deploy. As the stent retrieval device 612 deploys, it can press against the thrombus T, thereby causing the thrombus T to press against the wall of the vessel BV. The distal end 616 and / or the proximal end 614 of the stent retrieval device may include a ring 618, which is sized to allow the locking member 140 to pass through. The ring 618 may be circumferentially positioned around the stent retrieval device 612 at intervals such that when the locking member 140 extends through the ring, the distal end 616 and / or the proximal end 614 have a tapered shape extending inward toward the locking member 140 as shown. As the locking member 140 is pulled proximally, the closed distal end 616 of the stent retrieval device 612 can be released as the ring 618 disengages from the locking member 140. Once released, the distal end 616 can open, allowing it to be juxtaposed against the wall of the vessel BV. As the locking member 140 is pulled further proximally, the closed proximal end 614 of the stent retrieval device 612 can also be released. The proximal end 614 can then be opened, allowing it to be juxtaposed against the wall of the vessel BV. In this configuration, the stent retrieval device 612 is converted into a permanent implantable stent that can continue to press the thrombus T against the vessel BV and apply a chronic force to the wall of the vessel BV, with or without subsequent angioplasty balloon dilation, to open any potential stenosis.

[0081] like FIG. 7B As shown, the stent retrieval device 612 can be detached from the separation device 10. Once detached, the stent retrieval device 612 can no longer be retrieved from the body, therefore it is essentially a stent. The method of detachment of the stent retrieval device 612 can be... FIG. 5A to FIG. 5D The same separation method is shown. Once deployed, the stent thrombectomy device (stent) 612 can be held on the blood vessel BV.

[0082] FIG. 8A to FIG. 8C Deployment and optional separation of a stent retrieval device 612 using a separation method and separation device 10 similar to those shown in 5A to 5D are illustrated. The stent retrieval device 612 may have a proximal end 614 and a distal end 616. The proximal end 614 may be attached to the separation device 10, and more specifically, to the distal end 304 of the distal tube 300. When the stent retrieval device 612 is attached to the separation device 10 prior to deployment, the compressible portion 306 of the distal tube 300 may be in a compressed state.

[0083] like FIG. 8A As shown, engagement systems 140, 400 can engage with stent retrieval device 612. Locking member 140 can extend to the distal end 616 of stent retrieval device 612 such that locking member 140 extends through opening 405 of loop 400. Stent retrieval device 612 may include a ring 618, which is similar to...FIG. 7A and FIG. 7B the ring shown and described. The stent retriever 612 can include, but is not necessarily limited to, a locking portion 18 having a geometry as shown in FIG. 5A and FIG. 5B shown. As shown in FIG. 8A the loop wire 400 can be fed through the stent retriever 612 near the proximal end of the stent retriever 612 such that the junction between the loop wire 400, the locking member 140, the distal tube 300, and the stent retriever 612 is configured to secure the stent retriever to the detachment device 10. The stent retriever 612 can also include eyelets 622 configured to maintain the compression of the body of the stent retriever 612 during delivery. The eyelets 622 can be similar in shape to the loops 618. The eyelets 622 and the loops 618 can include openings sized to allow the locking member 140 to pass therethrough. The one or more eyelets 622 can be attached to the deployable frame 620 and positioned at least partially around the locking member 140, thereby preventing the premature deployment of the deployable frame 620 and the secure engagement of the stent retriever 612 with the junction system 140, 400. In this configuration, the deployable frame 620 can be prevented from deploying even without the use of a catheter. In one example, the one or more eyelets 622 can be disposed along the entire stent retriever 612. Alternatively, the one or more eyelets can be disposed along a portion of the stent retriever 612. By way of example, the one or more eyelets 622 can be disposed along a distal portion of the stent retriever 612. FIG. 8B a cross-sectional view of an example stent retriever 612 as shown in FIG. 8A The stent retriever 612 can be attached to the distal tube 300 such that the stent retriever 612 is in junction with the detachment system 10. The locking member 140 can be translated through the distal tube 300 and can extend through the stent retriever 612. The deployable frame 620 of the stent retriever 612 can include one or more eyelets 622. As shown in FIG. 8B the eyelets 622 can be attached at least partially around the locking member 140 and to the deployable frame 620, thereby preventing the premature deployment of the stent retriever 612.

[0084] FIG. 8CThe locking member 140 can be pulled proximally to initiate the release sequence of the stentriever 612, as shown by the arrow. As the locking member 140 is pulled proximally, the loop 618 at the distal end 616 is released, and then the eyelet 622 is released. As the loop 618 and eyelet 622 are released, the expandable frame 620 of the stentriever 612 can begin to expand. By way of example, as the locking member 140 is pulled proximally, the eyelet 622 disposed near the open distal end 616 of the stentriever 612 can be released first, such that the open distal end 616 of the stentriever 612 can begin to expand. As the locking member 140 is pulled further proximally, the eyelet 622 disposed near the proximal end 614 of the stentriever 612 can be released, such that the open proximal end 614 of the stentriever 612 can expand.

[0085] At the instant the locking member 140 exits the opening 405 and is pulled away from the loop wire, the distal end 404 of the loop wire 400 can return to its initial pre-shaped shape. At this point, in the release sequence, no component is holding the stentriever 612 to the detachment system 10, as all eyelets 622 attached to the expandable frame 620 are released.

[0086] After the stentriever 612 is released, the compressible portion 306 can expand and return to its initial elongated state. As the compressible portion 306 returns to its initial elongated state, the compressible portion 306 can “spring forward.” The distal end 304 of the distal tube 300 exerts a spring force on the stentriever 612 to “push it away,” thereby ensuring that the stentriever 612 is fully detached and delivered to the desired location. Upon detachment, the stentriever 612 can fully expand, such that the stentriever 612 can appose the vessel wall.

[0087] FIG. 9 The distal tube 300 without the implantable medical device 12 in the compressed and elongated states is shown. The axial length of the compressible portion 306 can be shortened to the compressed state. The compressible portion 306 can shorten by a distance D in axial length when moving from the elongated state to the compressed state. This compression can occur along the axis A.

[0088] FIG. 10 is a flowchart showing a method 1000 of detaching an implantable medical device. The implantable medical device can comprise a device 12, 612 such as shown and described herein, variations thereof, or alternatives as appreciated by one of skill in the art from the teachings contained herein. The method can include one or more of the following steps presented in no particular order. The example method 1000 can include additional steps as appreciated by one of ordinary skill in the art. The example method can be performed by an example detachment system 10 as disclosed herein, variations thereof, or alternatives as appreciated by one of ordinary skill in the art.

[0089] In step 1005, a compressible portion 306 on the distal tube 300 can be formed. The compressible portion 306 on the distal tube 300 can be formed by spiral cutting a portion of the distal tube 300.

[0090] In step 1010, a flexible portion 106 on the proximal tube 100 can be formed. The flexible portion 106 on the proximal tube 100 can be formed by interference cutting along at least a portion of the proximal tube 100.

[0091] In step 1015, the braid segments 200a, 200b, 200c can be attached to the distal end 104 of the proximal tube 100 and the proximal end 302 of the distal tube 300.

[0092] In step 1020, the implantable medical device 12 can be engaged with the engagement system 140, 400. The engagement system 140, 400 can include a locking member 140 and a loop wire 400.

[0093] The method can include engaging the implantable medical device 12 with the loop wire 400 with the locking member 140 and applying a force to the loop wire 400 to move the compressible portion 306 to the compressed state.

[0094] The method can include wrapping the braid segment 200b around the polymer liner 204 before attaching the braid segment 200b to the distal end 104 of the proximal tube 100 and the proximal end of the distal tube 300.

[0095] The method can include sliding the polymer sleeve 206 over at least a portion of the proximal tube 100, the braid segment 200c, and the distal tube 300. The polymer sleeve 206 can be engaged to the implantable medical device.

[0096] The method can include engaging the polymer sleeve 206 to the implantable medical device 12.

[0097] The method can include coating the polymer sleeve 206 with one or more hydrophilic coatings 208.

[0098] During detachment, the method can include applying a force to the locking member 140; disengaging the implantable medical device 12; and allowing the compressible portion 306 to return to the elongated state. By moving the compressible portion 306 to the elongated state, the implantable medical device 12 can be deployed.

[0099] The description contained herein is exemplary of the embodiments of the application and is intended to be limiting in any way. As described herein, the present application contemplates many variations and modifications of the delivery and release system of the present application for vascular occlusion devices, including a variety of configurations, a variety of stiffness characteristics, and methods of delivery thereof. In addition, there are many possible variations of configurations of materials and release mechanisms. These modifications will be apparent to those of ordinary skill in the art and are intended to be within the scope of the following claims.

Claims

1. A detachment system for delivering an implantable medical device to a target location of a body vessel, comprising: a generally hollow, relatively rigid proximal tube having a proximal end and a distal end; a generally hollow, relatively flexible distal tube comprising: a proximal end; a distal end; and a compressible portion of the distal tube itself, the compressible portion being axially movable from a compressed state to an elongated state; a flexible braid segment disposed between the proximal end of the distal tube and the distal end of the proximal tube, the braid segment being formed of a plurality of wires, the braid segment being more flexible than the relatively rigid proximal tube and the relatively flexible distal tube; a polymeric sheath positioned over at least a portion of the flexible segment of the proximal tube, the braid segment, and the entire distal tube, the polymeric sheath being attached to the implantable medical device and coated with one or more hydrophilic coatings; and an engagement system configured to engage and deploy the implantable medical device disposed at the distal end of the distal tube.

2. The detachment system of claim 1, wherein the braid segment is disposed concentrically around a polymeric liner.

3. The detachment system of claim 1, wherein the polymeric sheath has a wall with a thickness of between about 0.02 millimeters and about 0.08 millimeters.

4. The detachment system of claim 1, wherein the braid segment includes between about 8 and about 16 wires.

5. The detachment system of claim 1, wherein the plurality of wires have a weft count of between about 50 and about 100 per inch.

6. The detachment system of claim 1, wherein the compressible portion of the distal tube is a spiral cut portion of the distal tube.

7. The detachment system of claim 1, wherein the engagement system is configured to: move the compressible portion to the compressed state when the implantable medical device is engaged; and deploy the implantable medical device when the compressible portion is released to the elongated state.

8. The detachment system of claim 1, wherein the compressible portion is adapted to automatically move to the elongated state when the engagement system is disengaged from the implantable medical device.

9. The detachment system of claim 1, wherein the implantable medical device is a stent retriever when engaged to the engagement system, has a proximal end collapsed by the engagement system and a distal end collapsed by the engagement system, and wherein the medical device is a stent when disengaged from the engagement system, has an open proximal end and an open distal end.

Images