Patent Application
20210085332
An aneurysm is a blood bulge formed in a wall of an artery and can develop in any artery, including brain, aorta, legs, and spleen. Various aneurysms are typically formed in a saccular form and if the saccular aneurysm ruptures, a stroke, also known as a subarachnoid hemorrhage, may occur. Open surgery to clip or seal the aneurysm is an option for treating and removing an aneurysm; however, the surgery often carries risks and may be inappropriate or dangerous for larger sizes of aneurysms and/or aneurysms in more sensitive locations. Therefore, treating, reducing, and/or removing aneurysms is important to the long-term health of patients.
As an alternative to open surgery, a surgeon may perform a minimally invasive procedure whereby an occlusion embolic device is placed within an artery in an effort to treat the developed aneurysm. In such a procedure, the occlusion embolic device (e.g., a blocking device) is placed into the saccular aneurysm at a position to isolate or block the saccular aneurysm from a blood vessel. The placement of the occlusion embolic device is typically accomplished using a catheter carrying the occlusion embolic device such that the device may be inserted into a blood vessel and steered through the blood vessel to treat the aneurysm.
Conventional embolic device deployment systems exhibit difficulties with respect to embolic device placement as maneuvering, placing and releasing the embolic device within an artery inside a patient's body and are proven to be cumbersome. This is especially true for brain aneurysms as the deployment procedure requires accurate placement of the embolic device and any error during the procedure may result in significant damage to the brain.
Aspects and many of the attendant advantages of the claims will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
Note that the same numbers are used throughout the disclosure and figures to reference like components and features.
The subject matter of embodiments disclosed herein is described here with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described.
Embodiments will be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, exemplary embodiments by which the systems and methods described herein may be practiced. The embolic device delivery system 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 such that this disclosure will satisfy the statutory requirements and convey the scope of the subject matter to those skilled in the art.
By way of an overview, the subject matter disclosed herein may be directed to an embolic device delivery system, method, and device. In an embodiment, e.g., an embolic device delivery system comprises a delivery catheter having an embolic device coupler disposed at one end, a locking tube disposed about the delivery catheter, a protective sheath, and a sheath outer component disposed about the protective sheath configured to unsheathe and resheathe the delivery catheter. In one embodiment, the coupler may be an elongated shape having a loop portion for engaging the coil toward the distal end of the delivery catheter. The loop portion of the coupler may be an elastic material or a shape-memory alloy, such as Nitinol or nickel titanium, such that the loop portion is bendable at various angles. Together, the delivery catheter and coupler may be inserted into an artery and carry an embolic device to an aneurysm for placement near and treatment of the aneurysm.
The embolic device may be coupled by a retaining mechanism (e.g. an aperture) to the distal end of the coupler. Until the embolic device is delivered to a certain location within an artery, the embolic device may be secured to the coupler that is disposed within the delivery catheter by interlocking the loop portion of the coupler with the retaining mechanism of the embolic device. Thus, when unsheathing the delivery catheter from the reusable sheath, the locking tube and the sheath outer component may be used to bias the protective sheath to reveal the delivery catheter for inserting into an artery. Similarly, when being retrieved, the locking tube and the sheath outer component may be used to bias the protective sheath to a closed position that encloses the delivery catheter for subsequent use. In some embodiment, the undelivered embolic device may still be attached to the coupling mechanism.
The proximal end of the coupler is coupled to an actuator such that the coupler is maneuverable by a surgeon. The actuator has a handler for a surgeon to manipulate the coupler with a mechanism to release the embolic device. When the delivery catheter reaches the desired location in the artery, the embolic device may be released from the delivery catheter by simply pulling the coupler via the actuator proximally such that the U-shaped curve portion of the coupler and the loop portion of the coupler first become disengaged from the locking windows and then the coupler releases the embolic device by disengaging the retaining mechanism. During the pulling, the loop portion of the coupler, which does not have a hook or curved end, does not pose a great risk of bumping, pulling or moving the embolic device after placement because the flexible loop end of the coupler has been at least partially straightened by the edge of the implant's retaining mechanism with or without cross bar and is more easily maneuvered from the locking windows and retaining mechanism. Further, the straightened coupler can be easily pulled through the tube of the delivery catheter. This is advantageous over conventional embolic device delivery systems that use hooks or other non-flexible engagement/delivery components to easily dislodge or move the embolic device once placed. In addition, the simple structure of the embodiments discussed herein are more efficiently manufactured with costs that are more reasonable and the reusable nature of resheathing the delivery catheter allows for multiple subsequent uses. These and other advantages will become more apparent in the detailed descriptions below with respect to
Depending on the location or nature of the aneurysm 30, the embolic device 70 is placed inside of the saccular aneurysm 30 as shown in
However, the interlocking mechanisms in conventional embolic device deployment systems require many components or features to achieve reliability, such as firmly holding the embolic device until the deployment catheter 70 reaches a desired location for effectively releasing the embolic device 70. Many conventional interlocking mechanisms require an additional locking component to interlock the deployment catheter 50 and embolic device 70 in a fixed manner. Further, if the interlocking mechanism fails to release the embolic device in the desired location, retrieving the embolic device along with the catheter for a second use is not possible with conventional embolic device delivery systems. Thus, as the catheter is removed from the artery and the patient (with or without the embolic device still attached), the catheter cannot be easily resheathed and reused with conventional systems.
In specific, this view in
Turning to the locking tube 196 first, the locking tube 196 is slidably disposed about the catheter 110. The locking tube 197 includes a tubular cavity surrounded by a conical body that tapers at a proximal end (e.g., an end closer to the sheathe/unsheathe point). The locking tube 196 facilitates the unsheathing and resheathing of the catheter during a respective unsheathing or resheathing procedure. The locking tube 196 comprises an asymptotically decreasing conical shape (similar to the shape of a vuvuzela) wherein the shape further includes a central tubular orifice that in centered about the delivery catheter 110. In this respect, when resheathing the catheter 110, the locking tube aligns the catheter 110 to be resheathed in the protective sheath 195 in conjunction with the sheath outer component 197 that “zips” the sheath 195 up around the catheter 110 when the catheter 100 and sheath 195 enter the orifice of the sheath outer component 197 (described in more detail with respect to
Together, the locking tube 196 and the outer component 197 facilitate the unsheathing of the catheter at a point that is separate form and outside of any actuation handle (discussed below with respect to
In a first feature, the cylindrical body of the sheath outer component 197 comprises a distal end that includes a first surface 198 and a second surface 199. The surfaces are disposed at planar angle with respect to each other such that the first surface 198 is disposed in a first plane and the second surface 199 is disposed in a second plane different from the first plane. Further, the sheath outer component 197 comprises a notch 192 disposed protruding into the tubular. In an embodiment, the notch is disposed along the entire longitudinal axis of the tubular aperture. In another embodiment, the notch is only disposed at the distal end of the sheath outer component adjacent to the second surface 199. The notch 192 biases the sheath 195 into a resheathed or “zipped up” state while also preventing the locking tube 196 from locking up movement at the zipperlike resheathing of the catheter 110 (and perhaps a still attached embolic device).
As mentioned previously, the sheath 195 may be zippered and unzippered due the presence of biases crescent-shaped notches 191 that are shown in a blow-up bubble in
The elongated cylinder of the delivery catheter 110 further includes a coupler 130 disposed along a central axis of the delivery catheter 110. The coupler 130 may have a proximal end 132 and distal end 140. In one embodiment, the proximal end 132 of the coupler 130 may be a linear member that extends through the proximal end 112 of the delivery catheter 110. The proximal end 132 may further include a mechanism for a surgeon to actuate the coupler 130 by moving the coupler 130 backward inside the delivery catheter 110, further discussed below in
The embolic device 160 coupled to the delivery catheter 110 may include an embolic device 160 configured to expand once placed at the appropriate location inside the artery or near the aneurysm. In some embodiments, the embolic device 160 may be a platinum coil. The embolic device 160 may also include a proximal end 172 and a distal end 174 and a retaining mechanism 180 may be formed at the proximal end 172 of the embolic device 170 to securely couple with the delivery catheter 110. In various embodiments, the retaining mechanism 180 may be formed as a closed ring, loop, hoop, or eyelet separately formed from the embolic device 160 and affixed at the proximal end 172 of the embolic device 160. In a further embodiment, the retaining mechanism 180 may be formed integrally with the embolic device 160. With such a proximal end 172 suited to engage a coupler 130, the retaining mechanism 180 forms an aperture 190 by which the proximal end 172 of the coupler may engage and penetrate. The retaining mechanism 180 may be made of polypropylene or a platinum filament from the primary wind of the coil. During embolic device placement and delivery, the retaining mechanism 180 (and at times, the entire embolic device 160) may be disposed inside the delivery catheter 110 near the distal end 120. Thus, the diameter of the aperture 190 and the width of the embolic device 160 may be narrower than the inside diameter of the delivery catheter 110 such that the retaining mechanism 180 and embolic device 160 are held inside the distal end 120 of the delivery catheter 110 while being maneuvered through an artery.
When the delivery catheter 110 engages with the embolic device 160, the maneuverable engagement member 140 of the coupler 130 engages with the retaining mechanism 180 at the distal end 120 of the delivery catheter 110 by extending the maneuverable engagement member 140 into the aperture 190 of the retaining mechanism 180. For this configuration, the inside diameter of the aperture 190 may be slightly wider than the diameter of the maneuverable engagement member 140 such that the retaining mechanism 180 allows a small amount of movement for the maneuverable engagement member 140 to move around the inside of the aperture 190 of the retaining mechanism 180. In one embodiment, the maneuverable engagement member 140 may be extended upwardly through the aperture 190 by taking an upwardly curved shape. The maneuverable engagement member 140 may be extended downwardly or sideways instead of upwardly in response to rotation of the delivery catheter 110 due to manipulation of the delivery catheter by a surgeon such that a person having an ordinary skill in the art would change the direction of the curves accordingly. In a further embodiment, the maneuverable engagement member 140 maneuver away from the axis of the delivery catheter 110. Due to the super elasticity and shape memory characteristics of the maneuverable engagement member 140, the maneuverable engagement member 140 is capable of deforming its shape, such as from a straight configuration to an upwardly curved shape. In a further embodiment, the maneuverable engagement member 140 may be bent vertically at one portion to extend through the aperture 190 of the retaining mechanism 180.
As discussed briefly above, the delivery catheter 110 forms an upper locking window 150 on one side of the interior wall of the hollow tube near the distal end 120 of the delivery catheter 110 and a lower locking window 152 on the other side of the interior wall of the hollow tube near the distal end 120 of the delivery catheter 110. In one embodiment, the maneuverable engagement member 140 may form a U-shaped curve 154 and the downward curve 154 of the maneuverable engagement member 140 may be maintained with the locking features by the upper locking window 150 and the lower locking window 152. In this configuration, the bottom of the downward curve 154 of the maneuverable engagement member 140 may be maintained within the lower locking window 152 and the tip 200 of the maneuverable engagement member 140 may be maintained within the upper locking window 150 within the delivery catheter 110 while navigating the delivery catheter 110 into an artery. In another embodiment, the upper locking window 150 is located nearer to the distal end 120 of the delivery catheter 110 than the lower locking window 152 is to the distal end 120 of the delivery catheter 110 such that the maneuverable engagement member 140 is locked with the upper locking window 150 and the lower locking window 152 at the distal end 120 of the delivery catheter 110.
When the tip 200 of the maneuverable engagement member 140 passes through the lower locking window 152 and reaches the upper locking window 150, the maneuverable engagement member 140 further curves up such that the tip 200 of the maneuverable engagement member 140 extends through the upper locking window 150. In a further embodiment, the maneuverable engagement member 140 may bend vertically to extend through the upper locking window 150 as well. Once the maneuverable engagement member 140 is shaped in the upwardly curved position, the maneuverable engagement member 140 maintains its shape until any physical force is applied to the maneuverable engagement member 140. The upwardly curved shape of the maneuverable engagement member 140 may be formed by physically bending the maneuverable engagement member 140, such as by hand, or by maneuvering the distal end 120 of the coupler 130 to extend the maneuverable engagement member 140 through the aperture 190 such that the straight original configuration is deformed into the curved shape. In various embodiments, the upper locking window 150 and lower locking window 152 may be formed as a rectangular shape, elliptical shape, oval shape, or round shape. In a still further embodiment, the width of the locking window 150 may be slightly wider than the width of the tip 200 of the maneuverable engagement member 140. As such, the inside of the locking window 150 allows limited movement of the tip 200 to move around such that the tip 200 is secured in the locking window 150.
In addition to the locking mechanisms by the upper and lower locking windows 150, 152, a cross bar 156 extending perpendicular to the axis of the hollow tube of the delivery catheter 110 may further limit the movements of the coupler 130 both in the distal direction 140 and proximal direction 132. When the embolic device 160 is in a position coupled to the delivery catheter 110 (see
Referring back to
When the delivery catheter 110 reaches the desired location, a physician may determine at step 438 whether or not the embolic device is located in a proper position for deployment. If YES, then the proximal end of the coupler 130 is pulled proximally (step 440). By pulling, the maneuverable engagement member 140 of the coupler 130 is withdrawn from the upper locking window 150 and lower locking window 152 (step 450). By further proximally pulling, the maneuverable engagement member 140 is further withdrawn from the aperture 190 of the retaining mechanism 180 (step 460). When the tip 200 of the maneuverable engagement member 140, especially the curved shape of the maneuverable engagement member 140 contacts a cross bar 156, the cross bar 156 pushes the maneuverable engagement member 140 down, such that the tip 200 is not dragged or scratched within the delivery catheter 110 (step 470). Once the tip 200 of the maneuverable engagement member 140 is completely withdrawn from the aperture 190, the embolic device 160 is released from the delivery catheter 110 and the delivery catheter is withdrawn from the artery (step 480).
If, however, at step 438, the embolic device is not properly placed according to a physician's opinion (e.g., the NO branch), the embolic device may be retrieved while still attached to the coupling mechanism at the distal end of the catheter 110 and the catheter 110 may be resheathed along with the embolic device for another use. Such a resheathing process at step 490 may be accomplished by securing the outer sheath component 197 in a fixed position while maneuvering a catheter 110 in a proximal direction. This will facilitate the nesting of the first V-shaped portion (see
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and/or were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the specification and in the following claims are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “having,” “including,” “containing” and similar referents in the specification and in the following claims are to be construed as open-ended terms (e.g., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value inclusively falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments and does not pose a limitation to the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to each embodiment of the present disclosure.
Different arrangements of the components depicted in the drawings or described above, as well as components and steps not shown or described are possible. Similarly, some features and sub-combinations are useful and may be employed without reference to other features and sub-combinations. Embodiments have been described for illustrative and not restrictive purposes, and alternative embodiments will become apparent to readers of this patent. Accordingly, the present subject matter is not limited to the embodiments described above or depicted in the drawings, and various embodiments and modifications can be made without departing from the scope of the claims below.
