This application claims priority under 35 U.S.C. § 119 to European application No. 22210053.9 filed Nov. 28, 2022 entitled An Introducer Assembly For Minimally Invasive Deployment Of A Medical Device In A Vessel, which is hereby incorporated herein by reference in its entirety.
This disclosure pertains in general to introducer assemblies for minimally invasive deployment of a medical device in a vessel, e.g. cerebral embolic protection assemblies to prevent emboli from entering arteries branching from the aorta, e.g., arteries that lead to the brain. In particular, the disclosure relates to improvements of cerebral embolic protection assemblies.
Particles such as emboli may form, for example, as a result of the presence of particulate matter in the bloodstream. Particulate matter may originate from for example a blood clot occurring in the heart. The particulate may be a foreign body, but may also be derived from body tissues. For example, atherosclerosis, or hardening of the blood vessels from fatty and calcified deposits, may cause particulate emboli to form. Moreover, clots can form on the luminal surface of the atheroma, as platelets, fibrin, red blood cells and activated clotting factors may adhere to the surface of blood vessels to form a clot.
Various medical procedures may perturb blood vessels or surrounding tissues. When this occurs, potentially harmful particulates, such as emboli, may be released into the blood stream. These particulates can be damaging, e.g., if they restrict blood flow to the brain. Since emboli are typically particulate in nature, various types of filters have been proposed in an attempt to remove or divert such particles from the bloodstream before they can cause damage to bodily tissues. As intravascular devices and procedures, such as Transcatheter Aortic Valve Implantation (TAVI), become more advanced, there is an emerging need for features that provide these devices with improved ease of use, intravascular stability, and embolic protection. Devices to block or divert particulates from flowing into particular regions of the vasculature have been proposed but may not eliminate the risks associated with the release of potentially harmful particulates into the blood stream during or after particular medical procedures.
Possible areas of improvements of such devices and procedures include prevention of “windsailing” of devices with pulsatile blood flow, leakage of fluid and/or particulate matter at peripheral portions of devices during use thereof, secure positioning in a patient during use and/or retrievability, etc.
Hence, an improved intravascular device, system and/or method would be advantageous and in particular allowing for increased flexibility, cost-effectiveness, and/or patient safety would be advantageous.
An object of the invention is to define a cerebral embolic protection assembly that further increases patient safety.
Accordingly, embodiments of the present invention preferably seek to mitigate, alleviate or eliminate one or more deficiencies, disadvantages or issues in the art, such as the above-identified, singly or in any combination by providing devices, assemblies, kits, systems and methods according to the appended patent claims. The present invention is defined by the appended claims only, in particular by the scope of appended independent claim(s). Reference(s) to “embodiments” throughout the description which are not under the scope of the appended claims merely represents possible exemplary executions and are therefore not part of the present invention.
The aforementioned objects are achieved according to the disclosure.
In a broad aspect of the disclosure, an introducer assembly is provided for minimally invasive deployment of a medical device in a vessel. The assembly generally includes a handle, and a locking mechanism for locking a guidewire relative said handle.
In an aspect of the disclosure, an embolic protection assembly is provided comprising an embolic protection device, a hypotube running through a catheter or sheath and a handle. The embolic protection assembly further comprises a locking mechanism that is configured to be able to positionally lock a guidewire in relation to for example either the hypotube, the sheath, the catheter or the handle. In some embodiments the handle comprises the locking mechanism. In further embodiments the locking mechanism of the embolic protection assembly may comprise a dampening function.
In one aspect of the disclosure, a cerebral embolic protection assembly is provided comprising an embolic protection device comprising a filter unit, a sheath or catheter, and a tube directly or indirectly attached to the embolic protection device. The sheath or catheter may for example be a part of a delivery system, the tube may for example be a hypotube. During use a guidewire is drawn through the tube and the tube is drawn through the sheath or catheter. The assembly further comprises a locking mechanism comprising a lockable passage. The lockable passage may be structured in many different ways, a first example is using a screw that can squeeze/lock a guidewire within the lockable passage when turned in a first direction and create an open passage in the lockable passage when turned in a second direction. Another example is to have a lever that can be flipped between two positions, where in a first position of the lever a guidewire is squeezed/locked within the lockable passage and in a second position of the lever leaves an open passage in the lockable passage. The locking mechanism is arranged in the assembly such that during use a guidewire drawn through the tube is also drawn through the lockable passage. During use the locking mechanism in a first state is configured to positionally lock a guidewire that is going through the lockable passage, positionally locked in relation to the lockable passage. The locking mechanism in a second state is configured to let a guidewire move freely through the lockable passage, suitably by an open passage through the lockable passage.
In some embodiments the locking mechanism is further configured in the first state to subject a guidewire through it in use to a predetermined friction so that for as long as a guidewire is subjected to a force in relation to the locking mechanism that is below a first predetermined force level, it is positionally locked. When a guidewire is subjected to a force in relation to the locking mechanism that is above the first predetermined force level, then the predetermined friction is overcome, and a guidewire can thus slide through the lockable passage.
In some embodiments the locking mechanism is further configured in the first state to change to the second state if a guidewire through it in use is subjected to a force in relation to the locking mechanism that is above a second predetermined force level.
In some embodiments the locking mechanism may further comprise a dampening function. Then advantageously, when the locking mechanism is in the first state, the dampening function is configured when in use to enable to displace the lockable passage in relation to a first end of the locking mechanism. The displacement is preferable up to a predetermined maximum length when a guidewire that is positionally locked in the lockable passage is subjected to at least a third predetermined force level. It is often suitable that the third predetermined force level is a function of the displacement of the lockable passage. Preferably the dampening function comprises one or more springs and/or one or more spring mechanisms. The one or more springs and/or one or more spring mechanisms can suitably be either linear, progressive, or a mix of both. The dampening function may be symmetrical or asymmetrical in relation to the lockable passage.
In some embodiments the embolic protection assembly further comprises a handle. Then the locking mechanism may positionally lock a guidewire in relation to the handle.
The different additional enhancements of the embolic protection assembly according to the invention can be combined in any desired manner as long as no conflicting features are combined.
The aforementioned object is also achieved by an embolic protection assembly comprising an embolic protection device, a tube such as a hypotube running through a catheter or sheath, and possibly a handle. The embolic protection assembly further comprises a locking mechanism that is configured to, in use, be able to positionally lock a guidewire in relation to for example either the sheath, the catheter, or the handle. In some embodiments the handle comprises the locking mechanism. In further embodiments the locking mechanism of the embolic protection assembly comprises a dampening function.
A primary purpose is to provide a means to be able to perform an operation with improved safety when using a cerebral embolic protection assembly. This is obtained by having a locking mechanism positionally locking a guidewire, thus avoiding to manually hold the guidewire. Other advantages will become apparent from the detailed description.
Some examples will now be described in more detail for explanatory, and in no sense limiting, purposes, with reference to the following figures, in which
Specific embodiments of the invention will now be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements.
In order to clarify the assembly according to some examples and of their use will now be described in connection with
The present disclosure focuses on examples of the present invention defining an improved introducer assembly, such as an embolic protection assembly for example comprising an embolic protection device with a deflection-filter. The embolic protection device, suitably a collapsible embolic protection device, is in examples configured for delivery to an aortic arch of a patient and keeping it there in place for protection of side branch vessels of the aortic arch from embolic material. In particular, an embolic protection device having a deflection-filter membrane with a two- or three-dimensional structure. The embolic protection device is preferably delivered transvascularly, for instance in a trans-femoral approach. In some alternative examples, the device may be configured to be delivered through side branch vessels of the aortic arch.
Examples of embolic protection devices are disclosed in WO 2019/081689 A1 or WO 2018/206160A1 which are incorporated herein by reference in their entirety for all purposes.
The deflection-filter 142 membrane is arranged to separate a first fluid volume of the aortic side branch vessels from a second fluid volume in the aortic arch when the protection unit is positioned in the aortic arch and maintained by a hypotube. The deflection-filter 142 membrane may be a 3-dimensional structure, such as a dome-shape. This may create space underneath the embolic protection device 140 and also may provide optimized filtering due to a larger filter area in relation to a flat or near flat deflection-filter 142 membrane.
The embolic protection device 140 can for example suitably comprise a self-positioning nitinol support frame without stabilizers with a PEEK mesh as a deflection-filter 142 or for example a nitinol frame with stabilizers and a nitinol mesh.
The deflection-filter 142 may suitably be made of an elastic and atraumatic material such as a polymer, e.g. a mesh made from a plurality of fibers made of polymer, nylon, nitinol, or metal, or a combination thereof. The mesh may be made from woven fibers. Fibers may be from about 20 to 50 μm in thickness. Alternatively, the deflection-filter 142 may be a perforated film. When a perforated film is present, the pores formed in the perforated film may include pores of varied or unvaried shape (e.g., rectilinear or rhomboid pores), have a varied or constant density across the film, and/or have a constant or varied size. The size of the pores of the filter allows passage of blood cells (e.g., red blood cells (erythrocytes), white blood cells (leukocytes), and/or platelets (thrombocytes)) and plasma, while being impermeable to particles (e.g., emboli) larger than the pore dimensions. Emboli filtered by the mesh of the filter of the present disclosure are typically particles larger in one or more dimensions than an aperture of the mesh of the filter. The deflection-filter 142 is further advantageously configured for collapsibility and/or crimpability of the embolic protection device 140.
The deflection-filter 142 of the embolic protection device is coupled to a distal part of the hypotube 130 via a device-tail/connection-mechanism 144 with a connector 146. The connection-mechanism 144 may in some embodiments have an integrated connector 146 and/or an integrated coupling to the deflection-filter. In other embodiments the connector 146 and/or the coupling to the deflection-filter 140 may be at least partly comprised of separate parts in relation to the connection-mechanism 144. In some embodiments the coupling to the deflection-filter may pivot. The connection-mechanism 144 can for example be a twisted wire suitably made of nitinol for a flexible connection-mechanism 144. Alternatively, the connection-mechanism 144 may be more or less rigid, for example made from a laser cut tube.
At a proximal end of the proximal part of the handle 114, there is a port 116 for a guide wire 150. A proximal part of the guidewire 150 will stick out here during use. A distal end of the hypotube 130 suitably comprises an atraumatic tip 132, from which a distal part of the guidewire 150 appears during use.
During use of this embolic protection assembly 100, after deployment of the embolic protection device there will be one person holding the handle 110 to make sure that the hypotube 130 is pushed up towards the deflection-filter 140 with a suitable force and making sure that it is in the correct place. A further person will ensure that the guidewire 150 is kept in place.
To improve ease of use and relieve one person or at least one hand of one person to hold the guidewire in place, according to the invention a locking mechanism is applied to the guidewire to replace manually holding the guidewire. The locking mechanism should preferably be activated to lock a guidewire first when the embolic protection device is deployed and in place, and unlocked when readjustment is necessary. The locking mechanism movably locks the guidewire in relation to an entry point into the body or in relation to the handle, or in relation to a catheter or sheath in which the guidewire is running.
The locking mechanism 260 can be a part of the handle 211 or be a separately applicable locking mechanism 260 attached to the handle 211. The locking mechanism 260 may comprise a dampening spring function especially when the locking mechanism is incorporated with or attached to the handle 211. The dampening spring function is further described below in relation to
The clamping of a guidewire in a clamping box may be frictionally limited to allow a guide wire to move in relation to the clamping box if the guidewire is subjected to a force in relation to the clamping box that is above a first predetermined level. Alternatively, or additionally the locking mechanism may comprise a release mechanism, that releases a guidewire that is in a locked state into an unlocked state, when a guidewire is subjected to a force in relation to the clamping box that is above a second predetermined level. These additions are to prevent bodily harm from a distal end of a guidewire when a guidewire is in a locked state and the handle is moved intentionally or by accident.
Just like the locking mechanism according to
In contrast to the embodiment of
The two springs 487, 488 may be the same length and type, which would then position the clamping box 482 in the middle between the first end 485 and the second end 486 when in rest. This would result in a symmetrical dampening locking mechanism 480, which is suitable for a dampening mechanism 480 that is not integrated with a handle or does not comprise a connection element for attachment on only one correct/intended side, or for example keyed attachment connection elements. A symmetrical dampening locking mechanism cannot be turned in the wrong direction, working equally well in both directions. Preferably with an integrated or with a keyed attachment connection element to a handle, the dampening locking mechanism is asymmetrical having a longer stroke toward a proximal end of the dampening locking mechanism than a distal end towards a distal end of a guidewire. This is a safety mechanism to avoid the distal end of a guidewire being pushed into somewhere that could cause bodily harm.
In addition, as also described as an addition for the embodiment according to
In the illustrated example the second end 596 comprises a tubular external extension 591 that reaches the first end 595 where the first end 595 and the extension 591 are attached with threads. By turning the first end 595 and the second end 596 in relation to each other, the first end 595 and the second end 595 will either move apart or move closer together depending on the threads and how the ends 595, 596 are turned in relation to each other. Internally the first end 595 is coupled to a first tubular extension 597 with a distal end that is externally tapered, and the second end 596 is coupled to a second tubular extension 598 with a distal end that is internally tapered. The tapered end of the first extension is inside the tapered end of the second extension, and at this place inside the first extension is where the lock unit is located. When the ends are turned such that the two ends come closer together then the lock unit becomes more and more squeezed positionally locking the guidewire to the lock unit. At the same time the friction also increases between the lock unit and the inside of the distal end of the first tubular extension. This increases a necessary force on the guide wire in relation to the locking mechanism before the lock unit will move. Once the lock unit moves out of the squeezed region, the guidewire becomes positionally unlocked from the lock unit.
To improve the function of the embolic protection device even further, a filter cleaning mechanism can be incorporated in cooperation with the filter. A particle might stick to the filter or get stuck in a crease of the embolic protection device. These potential sticky or stuck particle(s) might become dislodged during removal of the embolic protection device and flow somewhere unwanted. The cleaning mechanism may comprise one or more of:
To improve this cleaning mechanism even further, it is beneficial if the cleaning mechanism function is synchronized with the heartbeat, for example by means of EKG. Suitably the function is initiated at the beginning of the ventricular ejection and stopped before the ventricular ejection ends (ventricular systole, second phase). This to ensure that any particles that are dislodged by the cleaning mechanism are transported away from the area of the embolic protection device.
To improve the function of the embolic protection device still further, an embolic protection device removal synchronizer function can be incorporated in cooperation with the embolic protection device. As mentioned above, a particle might stick to the filter or get stuck in a crease of the embolic protection device. These potential sticky or stuck particle(s) might dislodge during removal of the embolic protection device and flow somewhere unwanted. The embolic protection device removal synchronizer function synchronizes the removal of the embolic protection device with the heartbeat, suitably by means of EKG or other suitable means. The removal of the embolic protection device should suitably be done during the interval when the blood pressure starts to increase since anything that is then dislodged will be flushed downstream. Otherwise, dislodged particles might just instead float about when the embolic protection device is folded and pulled away and then be flow up the previously filtered entrances when the pressure returns. A removal of an embolic protection device from its place of protection might thus take several heartbeats to complete.
The invention is based on the basic inventive idea of keeping an embolic protection device safely in place without less continuous manual intervention. The invention is not restricted to the above-described embodiments, but may be varied within the scope of the appended claims.
Some additional or alternative examples include:
1. An embolic protection assembly (201) comprising:
2. The embolic protection assembly according to example 1, wherein the locking mechanism comprises a lock unit (372, 382) and wherein a guidewire is positionally locked in relation to the lock unit.
3. The embolic protection assembly according to example 2, wherein that the lock unit (372, 382) is configured to clamp a guidewire in the first state.
4. The embolic protection assembly according to example 2 or 3, wherein the locking mechanism (480, 590) further comprises a dampening function.
5. The embolic protection assembly according to example 4, wherein the dampening function comprises one or more springs and/or one or more spring mechanisms.
6. The embolic protection assembly according to example 5, wherein the one or more springs and/or one or more spring mechanisms are linear.
7. The embolic protection assembly according to example 5, wherein the one or more springs and/or one or more spring mechanisms are progressive.
8. The embolic protection assembly according to any one of examples 4 to 7, wherein the dampening function is symmetrical in relation to the lock unit.
9. The embolic protection assembly according to any one of examples 4 to 7, wherein the dampening function is asymmetrical in relation to the lock unit.
10. The embolic protection assembly according to any one of example 4 to example 9, wherein when the locking mechanism is in the first state the dampening function is configured to enable to displace the lock unit in relation to a first end of the locking mechanism up to a predetermined maximum length when a guidewire that is positionally locked is subjected to at least a third predetermined force level in relation to the locking mechanism.
11. The embolic protection assembly according to example 10, wherein the third predetermined force level is a function of the displacement of the lock unit.
12. The embolic protection assembly according to any preceding example, wherein the locking mechanism is further configured in the first state to subject a guidewire to a predetermined friction so that as long as a guidewire is subjected to a force in relation to the locking mechanism that is below a first predetermined force level, it is positionally locked.
13. The embolic protection assembly according to any preceding example, wherein the locking mechanism is further configured in the first state to change to the second state if a guidewire is subjected to a force in relation to the locking mechanism that is above a second predetermined force level.
14. The embolic protection assembly according to any preceding example, wherein the embolic protection device (240) comprises a filter (242) or a deflector unit (242).
15. The embolic protection assembly according to any preceding example, wherein the tube is directly or indirectly attached to the embolic protection device.
16. The embolic protection assembly according to any previous example, wherein the assembly further comprises a handle.
Number | Date | Country | Kind |
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22210053.9 | Nov 2022 | EP | regional |