Rotatable ultrasound catheter for detecting leaks in left atrial appendage closure devices

Abstract

Implanting a left atrial appendage closure (LAAC) device in a patient's left atrial appendage (LAA) can include advancing an assembly to a position proximate the patient's LAA. The assembly includes a LAAC device releasably secured to a LAAC delivery catheter and one or more ultrasound transducers positioned relative to the LAAC delivery catheter. Once the LAAC device is deployed, the ultrasound transducers can be rotated relative to the LAAC device to locate leaks between the LAAC device and the LAA. In some cases, if excessive leaks are detected by ultrasound, the LAAC device can be repositioned relative to the LAA.

Description

[Technical Field]

[0001] The present disclosure relates generally to medical devices, and more particularly to medical devices adapted to detect leaks around left atrial appendage closure devices. [Background technology]

[0002] The left atrial appendage is a small organ attached to the left atrium of the heart. When the heart is functioning normally, the left atrial appendage contracts to pump blood into the left atrium as the left atrium contracts to pump blood into the left ventricle. The contractile ability of the left atrial appendage helps improve the filling of the left ventricle, thereby maintaining cardiac output. However, in patients with atrial fibrillation, the left atrial appendage may not contract properly or empty, resulting in the accumulation of stagnant blood within it, which can lead to the formation of undesirable blood clots within the left atrial appendage.

[0003] A blood clot formed within the left atrial appendage can break off from this area and enter the bloodstream. A blood clot traveling within a blood vessel can eventually block smaller blood vessels downstream, thereby causing a stroke or heart attack. Clinical studies have shown that the majority of blood clots in patients with atrial fibrillation originate in the left atrial appendage. As a treatment, medical devices have been developed that are placed to occlude the left atrial appendage. Each of the known medical devices and methods has certain advantages and disadvantages. There is a continuing need to provide alternative medical devices and methods for manufacturing and using medical devices. Summary of the Invention

[0004] The present disclosure provides alternatives for medical device design, materials, manufacturing methods, and uses. One example is a method for implanting a left atrial appendage closure (LAAC) device into a patient's left atrial appendage (LAA). The method includes advancing an assembly including a LAAC device releasably secured to a LAAC delivery catheter and one or more ultrasound transducers positioned relative to the LAAC delivery catheter to a position adjacent to the patient's LAA. The method includes deploying the LAAC device within the LAA and then rotating the ultrasound transducer relative to the LAAC device to locate gaps and / or leaks between the LAAC device and the LAA.

[0005] Alternatively or additionally, the method may further include repositioning the LAAC device in response to detection of gaps and / or leaks. Alternatively or additionally, the one or more ultrasound transducers may be part of an ultrasound catheter.

[0006] Alternatively or additionally, the ultrasound catheter may be steerable. Alternatively or additionally, the method may further include steering the ultrasound catheter to better observe any leaks that may exist between the LAAC device and the LAA.

[0007] Alternatively or additionally, rotating the one or more ultrasound transducers may include rotating the ultrasound catheter around the LAAC delivery catheter.

[0008] Alternatively or additionally, rotating the one or more ultrasound transducers may include rotating the ultrasound catheter in place relative to the LAAC delivery catheter.

[0009] Alternatively or additionally, the one or more ultrasound transducers may be disposed on the LAAC delivery device. Alternatively or additionally, rotating the one or more ultrasound transducers may include rotating the LAAC delivery device.

[0010] Another example includes an assembly adapted to implant a left atrial appendage closure (LAAC) device in a patient's left atrial appendage (LAA), the assembly including a LAAC device releasably secured to a LAAC delivery catheter and one or more ultrasound transducers positioned relative to the LAAC delivery catheter.

[0011] Alternatively or additionally, the one or more ultrasound transducers may be part of an ultrasound catheter. Alternatively or additionally, the ultrasound catheter may be steerable.

[0012] Alternatively or additionally, the ultrasound catheter may be adapted to rotate around the LAAC delivery catheter. Alternatively or additionally, the ultrasound catheter may be adapted to rotate in place relative to the LAAC delivery catheter.

[0013] Alternatively or additionally, the one or more ultrasound transducers may be disposed on the LAAC delivery catheter. Alternatively or additionally, the LAAC delivery device may have a releasable connection between the LAAC delivery catheter and the LAAC device, and the releasable connection may be adapted to allow relative rotation therebetween without releasing the LAAC device.

[0014] Another example includes an assembly adapted to implant a left atrial appendage closure (LAAC) device in a patient's left atrial appendage (LAA), the assembly including a LAAC device releasably secured to a LAAC delivery catheter and a steerable ultrasound catheter rotatably disposed relative to the LAAC delivery catheter.

[0015] Alternatively or additionally, the assembly may further include a tubular member through which both the LAAC delivery catheter and the steerable ultrasound catheter extend.

[0016] Alternatively or additionally, the steerable ultrasound catheter may be adapted to rotate around the LAAC delivery catheter within the tubular member. Alternatively or additionally, the steerable ultrasound catheter may be adapted to rotate in place relative to the LAAC delivery catheter within the tubular member.

[0017] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The figures and the detailed description that follow more particularly exemplify these embodiments. [Brief explanation of the drawings]

[0018] The present disclosure can be more fully understood from the following detailed description considered in conjunction with the accompanying drawings. [Figure 1] This is a partial cross-sectional view of the LAA (left atrial appendage). [Figure 2] FIG. 1 is a side view of an exemplary left atrial appendage closure (LAAC) device delivery catheter, with the LAAC device shown in a collapsed configuration. [Figure 3] FIG. 3 is a side view of the exemplary LAAC device delivery catheter of FIG. 2, with the LAAC device shown in an expanded configuration. [Figure 4]1 is a perspective view of an exemplary expandable framework forming part of a LAAC device. [Figure 5] FIG. 1 is a perspective view of an exemplary LAAC device. [Figure 6] FIG. 1 is a perspective view of an exemplary assembly including a LAAC device delivery catheter and an ultrasound catheter. [Figure 7] FIG. 1 is a schematic diagram illustrating a portion of an exemplary assembly including a LAAC device delivery catheter and an ultrasound catheter. [Figure 7A] FIG. 1 is a cross-sectional view showing a portion of an exemplary assembly including a LAAC device delivery catheter and an ultrasound catheter. [Figure 7B] FIG. 1 is a cross-sectional view showing a portion of an exemplary assembly including a LAAC device delivery catheter and an ultrasound catheter. [Figure 8] FIG. 1 is a schematic diagram of an exemplary assembly including a LAAC device delivery catheter and an ultrasound catheter. [Figure 9] FIG. 1 is a schematic diagram of an exemplary assembly including a LAAC device delivery catheter and an ultrasound catheter. [Figure 10] FIG. 1 is a schematic diagram of an exemplary assembly including a LAAC device delivery catheter including an ultrasound transducer disposed on the LAAC device delivery catheter. DETAILED DESCRIPTION OF THE INVENTION

[0019] While the present disclosure is susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that it is not intended to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure.

[0020] Detailed Description The following description should be read with reference to the drawings, which are not necessarily to scale, and in which like reference numerals refer to like elements throughout the several views. The detailed description and drawings are intended to illustrate, but not limit, the present disclosure. Those skilled in the art will recognize that the various elements described and / or shown can be arranged in various combinations and configurations without departing from the scope of the present disclosure. The detailed description and drawings illustrate exemplary embodiments of the present disclosure. However, for clarity and ease of understanding, not all features and / or elements may be shown in each drawing, although it can be understood that such features and / or elements are present unless otherwise specified.

[0021] For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification. As used herein, all numerical values, whether explicitly stated or not, are deemed to be modified by the term "about." The term "about" generally refers to a range of numerical values ​​that one of ordinary skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term "about" may include numbers that are rounded to the nearest significant figure.

[0022] The recitation of numerical ranges by upper and lower limits includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). As used in this specification and the appended claims, the singular forms "a," "the," and "said" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is used in its general sense including "and / or" unless the content clearly dictates otherwise.

[0023] As used in this specification and the appended claims, the singular forms "a," "an," "the," and "said" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is used in its general sense including "and / or" unless the content clearly dictates otherwise. For ease of understanding, it should be noted that certain features of the present disclosure may be described in the singular even if they are multiple or repeated within a disclosed embodiment. Each instance of a feature may comprise and / or be encompassed by a single disclosure unless expressly stated to the contrary. For purposes of simplicity and clarity, not every element of the present disclosure is necessarily shown in every figure or described in detail below. However, it will be understood that the following description may apply equally to any and / or all of a plurality of components unless expressly stated to the contrary. Moreover, for clarity, not every instance of some element or feature may be shown in every figure.

[0024] Relative terms such as “proximal,” “distal,” “advance,” “retract,” and variations thereof generally refer to the positioning, orientation, and / or operation of various elements relative to a user / operator / manipulator of a device. Here, “proximal” and “retract” indicate or refer to being closer to or toward the user, and “distal” and “advance” indicate or refer to being further from or away from the user. In some cases, the terms “proximal” and “distal” may be arbitrarily assigned to facilitate understanding of the present disclosure, and such examples will be readily apparent to those skilled in the art. Other relative terms, such as “upstream,” “downstream,” “inflow,” and “outflow,” refer to the direction of fluid flow within a lumen, such as a body lumen, blood vessel, or device. Still other relative terms, such as “axial,” “circumferential,” “longitudinal,” “lateral,” “radial,” and / or variations thereof, generally refer to directions and / or orientations relative to a central longitudinal axis of the disclosed structure or device.

[0025] The terms "monolithic" and "single" shall generally refer to an element made of or consisting of a single structure or basic unit / element. Monolithic and / or single element shall not include structures and / or features made by assembling or joining multiple individual elements.

[0026] References herein to "one embodiment," "some embodiments," "other embodiments," etc., indicate that the described embodiment may include a particular feature, structure, or characteristic, but note that not all embodiments necessarily include that particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, if a particular feature, structure, or characteristic is described in connection with one embodiment, unless expressly stated to the contrary, it is within the knowledge of one skilled in the art to use that particular feature, structure, or characteristic in connection with other embodiments, whether explicitly described or not. That is, it is contemplated that various individual elements described below, even if not explicitly shown in specific combinations, can be combined or arranged with one another to form other or additional embodiments, or to supplement and / or enrich the described embodiments, as would be understood by one skilled in the art.

[0027] For purposes of clarity, certain distinguishing numerical nomenclature (e.g., first, second, third, fourth, etc.) may be used throughout this specification and / or claims to name and / or distinguish various features described and / or claimed. It should be understood that the numerical nomenclature is not intended to be limiting, but is merely exemplary. In some embodiments, variations and departures from previously used numerical nomenclature may be made for brevity and clarity. That is, a feature identified as a "first" element may later be referred to as a "second," "third," etc., or may be omitted entirely, and / or a different feature may be referred to as the "first" element. The meaning and / or name in each instance will be apparent to one of ordinary skill in the art.

[0028] The following figures illustrate selected components and / or arrangements of an implant for occluding a left atrial appendage, a system for occluding a left atrial appendage, and / or a method of using the implant and / or system. Note that in any of the figures, some features may not be shown or may be shown diagrammatically for simplicity. Additional details regarding some components of the implant and / or system may be shown in greater detail in other figures. While described for occlusion of a left atrial appendage, the implant and / or system may also be used for other interventional and / or percutaneous medical procedures in a patient. Similarly, devices and methods described herein with respect to percutaneous deployment may be used for other types of surgical procedures, if desired. For example, in some instances, the devices may be used in non-percutaneous procedures. Devices and methods according to the present disclosure may also be adapted and configured for other uses within anatomical structures.

[0029] FIG. 1 is a partial cross-sectional view of a left atrial appendage 10. In some embodiments, the left atrial appendage (LAA) 10 may have a complex shape and / or an irregular surface area. It will be understood that the illustrated LAA 10 is only one of many possible shapes and sizes of the LAA 10 and will vary from patient to patient. One skilled in the art will also recognize that the medical devices, systems, and / or methods disclosed herein may be adapted to various sizes and shapes of the LAA 10, as needed. The left atrial appendage 10 may include a generally longitudinal axis 12 disposed along the depth of a body 20 of the left atrial appendage 10. The body 20 may include a sidewall 14 and an ostium 16 forming a proximal ostium 18. In some instances, the lateral extent of the ostium 16 and / or the sidewall 14 may be less than the depth of the body 20 along the longitudinal axis 12; i.e., the depth of the body 20 may be greater than the lateral extent of the ostium 16 and / or the sidewall 14. In some instances, the LAA 10 may narrow rapidly along the depth of the body 20, or the left atrial appendage may maintain a substantially constant lateral extent along most of the depth of the body 20. In some instances, the LAA 10 may include a distal-most region formed or arranged as a tail associated with a distal portion of the body 20. In some instances, the distal-most region may protrude radially or laterally from the longitudinal axis 12.

[0030] 2 and 3 illustrate selected components and / or configurations of a LAAC device delivery catheter 22 adapted to deliver a LAAC device for occluding the LAA 10. Note that in either figure, for the sake of brevity, some features of the LAAC device delivery catheter 22 may not be shown or may be shown only diagrammatically. Additional details regarding some components of the LAAC device delivery catheter 22 may be shown in greater detail in other figures.

[0031] The LAAC device delivery catheter 22 may include a delivery sheath 40 having a lumen 42 extending from a proximal opening to a distal opening, a core wire 30 slidably disposed within the lumen 42, and a LAAC device 100 for occluding the LAA 10. The LAAC device 100 may include an expandable skeleton 110 (e.g., FIG. 4) configured to transition between a fully constrained configuration (e.g., FIG. 2 ), in which the LAAC device 100 is disposed within the lumen 42 proximal to the distal opening in a delivery configuration, and a fully unconstrained configuration (e.g., FIG. 3 ), wherein the LAAC device 100 and / or the expandable skeleton 110 are configured to transition between the fully constrained configuration and the fully unconstrained configuration as the LAAC device 100 translates relative to the delivery sheath 40. In at least some embodiments, the expandable skeleton 110 may be self-biased toward the fully unconstrained configuration.

[0032] The LAAC device 100 may be disposed on and / or releasably secured to the distal portion of the core wire 30. The core wire 30 may be slidably and / or rotatably disposed within the lumen 42 of the delivery sheath 40. In some embodiments, the proximal end of the core wire 30 may extend proximally beyond the proximal end of the delivery sheath 40 and / or the proximal opening of the lumen 42 for manual manipulation by a clinician or practitioner. In some embodiments, the LAAC device 100 may be removably attached, bonded, fixed, or otherwise connected to the distal end of the core wire 30. The core wire 30 may be configured and / or movable to move the LAAC device 100 axially relative to the delivery sheath 40. In one example, the core wire 30 may be advanced distally while the delivery sheath 40 is held in a fixed position. In another example, the core wire 30 may be advanced distally while the delivery sheath 40 is retracted proximally. In yet another example, the core wire 30 can be held in a fixed position while the delivery sheath 40 is retracted proximally relative to the core wire 30 and / or left atrial appendage closure device 100. Other configurations are contemplated. The delivery sheath 40 and / or core wire 30 can have a selected level of axial stiffness and / or pushability characteristics, while also having a selected level of flexibility that allows navigation through the patient's vasculature.

[0033] Set forth below are some suitable, but non-limiting, examples of materials for the LAAC device delivery catheter 22, core wire 30, delivery sheath 40, and / or LAAC device 100. It is contemplated that any of the exemplary LAAC devices disclosed herein may be used in accordance with and / or in association with the exemplary LAAC device system 10 described above.

[0034] The LAAC device 100 may include an expandable framework 110 configured to transition axially and / or radially along a central longitudinal axis between a fully constrained configuration and a fully unconstrained configuration. In the fully constrained configuration, the expandable framework 110 may be axially elongated and / or radially compressed. In the fully unconstrained configuration, the expandable framework 110 may be axially shortened and / or radially expanded.

[0035] As seen in FIG. 4 , which illustrates selected features of the LAAC device 100 in a fully unconstrained configuration, the expandable framework 110 can have multiple struts arranged about a central longitudinal axis. In some embodiments, the multiple struts can define multiple compartments. In some embodiments, the multiple compartments can be multiple closed compartments. In some embodiments, the multiple compartments can be multiple open compartments. In some embodiments, the multiple compartments can include multiple open compartments and multiple closed compartments in various combinations and / or arrangements.

[0036] The expandable framework 110 may include a proximal hub 112 and a distal hub 114. In some embodiments, the proximal hub 112 and / or the distal hub 114 may be centered on and / or coaxial with the longitudinal axis. Multiple struts may be coupled to each other at the proximal hub 112 and / or the distal hub 114 and / or fixedly attached to the proximal hub 112 and / or the distal hub 114. The proximal hub 112 may be configured to releasably connect, secure, and / or attach the LAAC device 100 and / or the expandable framework 110 to the core wire 30. In some embodiments, the proximal hub 112 may include female threads configured to rotatably engage and / or threadably engage with the male-threaded distal end of the core wire 30. Other configurations for removably securing the LAAC device 100 to the core wire 30 are also contemplated. As described herein, some figures may not show certain features for clarity.

[0037] The expandable skeleton 110 and / or multiple struts may be formed and / or cut from a tubular member. In some embodiments, the expandable skeleton 110 and / or multiple struts may be integrally formed and / or cut from a single member. In some embodiments, the expandable skeleton 110 and / or multiple struts may be integrally formed and / or cut from a single tubular member, and then formed and / or heat set into the desired shape in the fully unconstrained configuration. In some embodiments, the expandable skeleton 110 and / or multiple struts may be integrally formed and / or cut from a single flat member or sheet, and then rolled or formed into a tubular structure, and then formed and / or heat set into the desired shape in the fully unconstrained configuration. Some exemplary means and / or methods of creating and / or forming the expandable skeleton 110 and / or multiple struts include laser cutting, machining, punching, stamping, electrical discharge machining (EDM), chemical dissolution, etc. Other means and / or methods are also contemplated.

[0038] As will be appreciated by those skilled in the art, the size and / or shape of anatomical features can vary. In some embodiments, the left atrial appendage can have an irregular (e.g., elongated and / or rectangular) cross-sectional shape. In some embodiments, the expandable framework 110, when deployed and / or expanded within the left atrial appendage, is compliant, substantially conforms to, and / or sealingly engages with the contour and / or surface shape of the sidewall of the LAA 10. In some embodiments, the LAAC device 100 can expand to a size, extent, or shape that is smaller than or different from its fully unconstrained configuration, as determined by the surrounding tissue and / or the sidewall of the LAA 10. In some embodiments, the expandable framework 110 can be configured to mold and / or stretch the tissue of the LAA 10 such that the sidewall of the LAA 10 substantially conforms to the contour of the expandable framework 110. Other configurations are also contemplated.

[0039] In some embodiments, the expandable skeleton 110 may include at least one fixation member 116 extending radially outward therefrom in a fully unconstrained configuration. In some embodiments, the expandable skeleton 110 may include at least one fixation member 116 extending radially outward from the expandable skeleton 110. In some embodiments, the expandable skeleton 110 may include at least one fixation member 116 extending radially outward from the expandable skeleton 110 near a proximal shoulder of the expandable skeleton 110. In some embodiments, the expandable skeleton 110 may include at least one fixation member 116 extending radially outward from the expandable skeleton 110 near a central portion of the expandable skeleton 110. In some embodiments, the at least one fixation member 116 may be configured to engage a sidewall of the body of the left atrial appendage. In some embodiments, at least one fixation member 116 may be formed as a J-shaped hook having a free end extending and / or oriented proximally relative to the central longitudinal axis of the left atrial appendage closure device 100 and / or the expandable framework 110. Other configurations are also contemplated.

[0040] In some embodiments, the LAAC device 100 may optionally include an occlusion element 120 connected to, disposed in contact with, disposed on, disposed around, and / or disposed radially outward of the expandable skeleton 110 and / or at least a portion of the plurality of struts, as seen in FIG. 5 . In some embodiments, the occlusion element 120 may be attached to the proximal hub 112 and / or attached to the expandable skeleton at the proximal hub 112. In some embodiments, the occlusion element 120 may extend radially outward from the proximal hub 112 and / or extend distally from the proximal hub 112. In some embodiments, the occlusion element 120 may be attached to and / or anchored to the expandable skeleton 110 at multiple discrete locations. In some embodiments, one, some, and / or all of the at least one anchoring member 116 may extend through the occlusion element 120 (if present).

[0041] In some embodiments, occlusion element 120 may comprise a membrane, a fabric, a mesh, a tissue component, or another suitable structure. In some embodiments, occlusion element 120 may be porous. In some embodiments, occlusion element 120 may be non-porous. In some embodiments, occlusion element 120 may be permeable to selected gases and / or fluids. In some embodiments, occlusion element 120 may be substantially impermeable to selected gases and / or fluids, such as blood, water, etc. In some embodiments, occlusion element 120 may be designed, sized, and / or configured to prevent thrombus and / or embolic material from exiting the left atrial appendage into the left atrium and / or the patient's bloodstream. In some embodiments, occlusion element 120 may be configured to promote endothelialization after implantation, thereby effectively excluding the target site (e.g., the left atrial appendage) from the patient's circulatory system. Some suitable, but non-limiting, examples of materials for occlusion element 120 are described below.

[0042] The LAAC device delivery catheter 22 described above can be used to deliver and deploy the LAAC 100. It will be understood that not all implants are perfect, as one patient's LAA 10 will likely differ from another patient's LAA 10. Depending on how the LAAC device 100 is deployed relative to the LAA 10, one or more gaps may form between the LAAC device 100 and the LAA 10. In some cases, leakage or blood flowing through one or more of these gaps may limit the effectiveness of the LAAC device 100 and should be minimized, if not eliminated. In some cases, ultrasound may be used in conjunction with the LAAC device delivery catheter 22 to check for gaps and / or leaks in the LAAC device delivery catheter 22 before withdrawing the LAAC device delivery catheter 22. If gaps and / or leaks are found, the LAAC device 100 can be repositioned. Repositioning the LAAC device 100 may include re-sheathing the LAAC device 100 to collapse the LAAC device 100 into a collapsed configuration, and then repositioning the LAAC device delivery catheter 22 before redeploying the LAAC device 100.

[0043] 6 is a perspective view of an exemplary assembly 150 including a LAAC device delivery catheter 152 and an ultrasound catheter 154. In some cases, for example, the ultrasound catheter 154 is an intravascular cardiac echography (ICE) catheter. The assembly 150 includes the LAAC device 100 secured to the LAAC device delivery catheter 152 via the proximal hub 112 of the LAAC device 100. The LAAC device delivery catheter 152 is considered to be an example of the LAAC device delivery catheter 22, for example. In some cases, the LAAC device delivery catheter 152 may include or otherwise represent the core wire 30 shown with respect to FIGS. 2 and 3 . Any features attributed to the LAAC device delivery catheter 22 are considered applicable to the LAAC device delivery catheter 152 as well.

[0044] The ultrasound catheter 154 is shown as including an ultrasound transducer 156. While a single ultrasound transducer 156 is shown, this is merely exemplary, and the ultrasound catheter 154 may include any number of different ultrasound transducers 156. FIG. 6 schematically illustrates a field 158 representing what could potentially be seen by the ultrasound transducer 156. It can be seen that the field 158 extends radially enough to be able to see beyond the periphery of the LAAC device 100. Consequently, this means that the field 158 must extend into any space or void that exists between the LAAC device 100 and the LAA 10 in which it is implanted. Rotating the ultrasound transducer 156 360 degrees allows for viewing of the entire periphery of the LAAC device 100, thereby identifying any gaps and / or leaks that may exist. Ultrasound may be able to visualize gaps and / or leaks that may exist between the LAAC device 100 and the LAA 10, and in some cases, Doppler may be used to identify potential leaks.

[0045] In some cases, a gap may be found between the LAAC device 100 and the tissue of the LAA 10. In some cases, blood flowing through the gap between the LAAC device 100 and the tissue of the LAA 10 may be visible via ultrasound. If a leak and / or gap is found, various measures may be taken. As an example, the physician may decide to implant the LAAC device 100 in its current location or may decide to reposition the LAAC device 100 before releasing it. In some cases, the physician may decide to discontinue the procedure. In some cases, the physician may decide to remove the LAAC device 100 and implant a different sized device. In some cases, the physician may decide to add an additional device, such as an embolic coil or foam plug, to resolve the leak.

[0046] The assembly 150 includes a tubular member 160 that serves to hold the LAAC device delivery catheter 152 and the ultrasound catheter 154 in close proximity. In some cases, the tubular member 160 can be a short element that fits snugly around the LAAC device delivery catheter 152 and the ultrasound catheter 154, as shown in FIG. 6 for example. In some cases, the tubular member 160 is a longer tubular element and / or does not fit snugly around the LAAC device delivery catheter 152 and the ultrasound catheter 154. In some cases, the tubular member 160 can be an extruded member with two or more lumens extending therethrough, with the LAAC device delivery catheter 152 extending through one lumen and the ultrasound catheter 154 extending through another lumen. The tubular member 160 can take on a variety of shapes so long as the ultrasound catheter 154 can rotate relative to the LAAC device delivery catheter 152.

[0047] 7A is a schematic cross-sectional view showing the LAAC device delivery catheter 152 and the ultrasound catheter 154 within a tubular member 162. As shown in FIG. 7A, the ultrasound catheter 154 can rotate around the LAAC device delivery catheter 152 by planetary motion within the tubular member 162. FIG. 7B is a schematic cross-sectional view showing the LAAC device delivery catheter 152 and the ultrasound catheter 154 within the tubular member 162. As shown in FIG. 7B, the ultrasound catheter 154 does not rotate around the LAAC device delivery catheter 152, but rotates in a fixed position next to the LAAC device delivery catheter 152. It will be understood that with either type of motion of the ultrasound catheter 154, the ultrasound catheter 154 can "see" the entire periphery of the LAAC device 100, except for areas that may be at least partially blocked by parts or portions of the LAAC device delivery catheter 152 that may be at least partially radiopaque.

[0048] 8 and 9 are schematic diagrams of an exemplary assembly 164. The exemplary assembly 164 includes a LAAC device delivery catheter 166 and a steerable ultrasound catheter 168. The LAAC device delivery catheter 166 and the steerable ultrasound catheter 168 are coupled to one another via a tubular member 170. The steerable ultrasound catheter 168 includes an ultrasound transducer 172. While a single ultrasound transducer 172 is shown, this is merely exemplary, and the steerable ultrasound catheter 168 may include any number of different ultrasound transducers 172. FIGS. 8 and 9 also schematically illustrate a field 174 representing what may be seen by the ultrasound transducer 172. It can be seen that the field 174 extends radially enough to be visible beyond the perimeter of the LAAC device 100. Consequently, this means that the field 174 must extend into any space or void that exists between the LAAC device 100 and the LAA 10 in which the LAAC device 100 is implanted. The ultrasound transducer 152 can be rotated 360 degrees to view the entire circumference of the LAAC device 100, allowing for confirmation of any leaks that may exist. Ultrasound may be able to visualize gaps that exist between the LAAC device 100 and the LAA 10, and in some cases, Doppler may be used to confirm possible leaks. The LAAC device delivery catheter 166 and the steerable ultrasound catheter 168 extend through the guide catheter 176.

[0049] The steerable ultrasound catheter 168 has a steerable distal region 178 to provide improved imaging. In some cases, the field 174 shown in FIG. 8 may be insufficient to fully visualize the gap between the LAAC device 100 and the LAA 10 in which the LAAC device 100 is implanted. In some cases, bending the distal region 178 effectively changes the direction in which the ultrasound transducer 172 is pointed, resulting in a field 174' that provides a better view, as shown in FIG. 9. In some cases, the steerable ultrasound catheter 168 may include an elongate member extending proximally from the distal region 178 within the steerable ultrasound catheter 168, which can be manipulated to bend or curve the distal region 178.

[0050] FIG. 10 is a schematic diagram of an exemplary assembly 180. The exemplary assembly 180 includes a combination catheter 182 having not only an ultrasound transducer 184 but also a threaded engagement portion 186 configured to releasably engage the proximal hub 112 of the LAAC device 100. In other words, the combination catheter 182 combines the functions of a LAAC device delivery catheter and an ultrasound catheter into a single device. In some cases, the threaded engagement portion 186 is adapted to allow the combination catheter 182 to rotate at least 360 degrees relative to the LAAC device 100 without disengaging the LAAC device 100. As a result, the ultrasound transducer 184 generates a field 188, allowing the LAAC device 100 to rotate at least 360 degrees therearound without prematurely disengaging the LAAC device 100. In some cases, the LAAC device 100 may be intentionally disengaged by rotating the combination catheter 182 multiple times.

[0051] Although a single ultrasound transducer 184 is shown, this is by way of example only, and the combination catheter 182 may include any number of different ultrasound transducers 184. By rotating the ultrasound transducer 184 360 degrees, the entire circumference of the LAAC device 100 can be viewed to identify any leaks that may be present. Ultrasound may be able to visualize gaps that exist between the LAAC device 100 and the LAA 10, and in some cases, Doppler may be used for confirmation.

[0052] Materials that can be used in the devices described herein can include those commonly associated with medical devices. The devices described herein or components thereof can be made from metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, and the like, or other suitable materials. Examples of suitable metals and alloys include stainless steels, e.g., 304V, 304L, and 316LV stainless steel; mild steel; nickel-titanium alloys, e.g., linear elastic and / or superelastic nitinol; other nickel alloys, e.g., nickel-chromium-molybdenum alloys (e.g., UNS: N06625, e.g., INCONEL® 625, UNS: N06022, e.g., HASTELLOY® C-22, UNS: N10276, e.g., HASTELLOY® C-22, UNS: N10276, e.g., HASTELLOY® C-22, UNS: N10276, ) C276, other HASTELLOY® alloys, etc.), nickel-copper alloys (e.g., UNS: N04400, e.g., MONEL® 400, NICKELVAC™ 400, NICORROS® 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, e.g., MP35-N, etc.), nickel-molybdenum alloys (e.g., UNS: N10665, e.g., HASTELLOY® ALLOY B2, etc.), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, e.g., ELGILOY®, PHYNOX®, etc.); high platinum stainless steels; titanium; combinations thereof; etc.; or other suitable materials.

[0053] As alluded to herein, there is a category of commercially available nickel-titanium or Nitinol alloys referred to as "linear elastic" or "non-superelastic." These may be chemically similar to traditional shape memory or superelastic varieties, but may exhibit unique and useful mechanical properties. Linear elastic and / or non-superelastic Nitinol can be distinguished from superelastic Nitinol in that its stress-strain curve does not exhibit a substantial "superelastic plateau" or "flag region" like superelastic Nitinol. Instead, in linear elastic and / or non-superelastic Nitinol, as recoverable strain increases, stress continues to increase in a substantially or somewhat linear relationship (not necessarily a perfectly linear relationship), or at least a relationship that is more linear than the superelastic plateau and / or flag region seen in superelastic Nitinol, until plastic deformation begins. Therefore, for purposes of this disclosure, linear elastic and / or non-superelastic Nitinol may also be referred to as "substantially" linear elastic and / or non-superelastic Nitinol.

[0054] In some cases, linear elastic and / or non-superelastic nitinol may also be distinguished from superelastic nitinol in that linear elastic and / or non-superelastic nitinol can accommodate strains of up to about 2-5% while remaining substantially elastic (e.g., before plastically deforming), whereas superelastic nitinol can accommodate strains of up to about 8% before plastically deforming. Both of these materials may be distinguished from other linear elastic materials, such as stainless steel (which may also be distinguishable based on composition), which can only accommodate strains of about 0.2-0.44 percent before plastically deforming.

[0055] In some embodiments, linear elastic and / or non-superelastic nickel-titanium alloys are alloys that do not exhibit any martensite / austenite phase change detectable by differential scanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA) over a wide temperature range. For example, in some embodiments, linear elastic and / or non-superelastic nickel-titanium alloys may not exhibit any martensite / austenite phase change detectable by DSC and DMTA analysis over a range of about -60 degrees Celsius (°C) to about 120°C. Thus, the mechanical bending properties of such materials may generally be temperature-independent over this very wide temperature range. In some embodiments, the mechanical bending properties of linear elastic and / or non-superelastic nickel-titanium alloys at ambient or room temperature are substantially the same as those at, for example, body temperature, and do not exhibit a superelastic plateau and / or flag region at that temperature. In other words, over a wide temperature range, linear elastic and / or non-superelastic nickel-titanium alloys maintain their linear elastic and / or non-superelastic properties and / or characteristics.

[0056] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy may be in the range of about 50 to about 60 weight percent nickel, with the remainder essentially titanium. In some embodiments, the composition ranges from about 54 to about 57 weight percent nickel. One example of a suitable nickel-titanium alloy is FHP-NT alloy, commercially available from Furukawa Techno Material Co., Ltd., Kanagawa Prefecture, Japan. Some examples of nickel-titanium alloys are disclosed in U.S. Patent Nos. 5,238,004 and 6,508,803, which are incorporated herein by reference. Other suitable materials include ULTANIUM™ (available from Neo-Metrics) and GUM METAL® (available from Toyota). In some other embodiments, a superelastic alloy, such as superelastic nitinol, can be used to achieve the desired properties.

[0057] In at least some embodiments, the devices disclosed herein or components thereof may be doped with, made of, or otherwise include a radiopaque material. A radiopaque material is understood to be a material capable of producing a relatively bright image on a fluoroscopy screen or other imaging technique during a medical procedure. Some examples of radiopaque materials include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials loaded with radiopaque fillers, and the like. Additionally, other radiopaque marker bands and / or coils can be incorporated into the design of the guidewire 10 to achieve the same results.

[0058] In some embodiments, a degree of magnetic resonance imaging (MRI) compatibility is imparted to the devices described herein or components thereof. For example, the devices described herein or components thereof may be made of materials that do not substantially distort images or cause substantial artifacts (e.g., gaps in the images). For example, certain ferromagnetic materials may not be suitable because they may cause artifacts in MRI images. The devices described herein or components thereof may be made of materials that can be imaged by MRI machines. Some materials that exhibit these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, such as ELGILOY®, PHYNOX®), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035, such as MP35-N™), nitinol, and others.

[0059] A sheath or cover (not shown) can be disposed over some or all of the devices described herein to define a generally smooth outer surface. However, in other embodiments, such a sheath or cover may not be present. The sheath can be made from a polymer or other suitable material. Some examples of suitable polymers include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block esters, polyurethanes (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyetheresters (e.g., ARNITEL® available from DSM Engineering Plastics), ether- or ester-based copolymers (e.g., butylene / poly(alkylene ether) phthalates and / or other polyester elastomers, e.g., HYTREL® available from DuPont), polyamides (e.g., DURETHAN® or Elf® available from Bayer), and the like. CRISTAMID™ available from Atochem), elastomeric polyamides, block polyamide / ethers, polyether block amides (PEBA, available, for example, under the trade name PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), MARLEX® high density polyethylene, MARLEX® low density polyethylene, linear low density polyethylene (e.g., REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon-12 (EMS AmericanExamples of suitable materials include GRILAMID® (available from Grillon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefins, polystyrene, epoxies, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites, and the like. In some embodiments, the sheath can be blended with a liquid crystal polymer (LCP). For example, the mixture can include up to about 6 percent LCP.

[0060] In some embodiments, the exterior surfaces of the devices described herein may be sandblasted, bead-blasted, sodium bicarbonate-blasted, electropolished, or the like. In these and other embodiments, a coating, such as a lubricious, hydrophilic, protective, or other type of coating, may be applied. Alternatively, the sheath may include a lubricious, hydrophilic, protective, or other type of coating. Hydrophobic coatings, such as fluoropolymers, improve guidewire handling and device exchange by providing dry lubricity. Lubricious coatings improve steerability and lesion crossing capabilities. Suitable lubricious polymers are well known in the art and include hydrophilic polymers, such as silicones, hydrophilic polymers, such as high-density polyethylene (HDPE), polytetrafluoroethylene (PTFE), polyarylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, hydroxyalkyl cellulose, algin, sugars, caprolactone, and the like, as well as mixtures and combinations thereof. Hydrophilic polymers can be mixed by themselves or with blended amounts of water-insoluble compounds, including some polymers, to produce coatings with suitable lubricity, adhesion, and solubility. Some other examples of such coatings and the materials and methods used to make such coatings are described in U.S. Pat. Nos. 6,139,510 and 5,772,609, which are incorporated herein by reference.

[0061] Portions of the devices described herein can be formed, for example, by coating, extrusion, coextrusion, interrupted layer coextrusion (ILC), or by fusing several segments end-to-end. The layers may have uniform stiffness or may have a gradual decrease in stiffness from the proximal to distal end. The gradual decrease in stiffness may be continuous, as in ILC, or stepwise, as in the fusion of separately extruded tubular segments. The outer layer may be impregnated with a radiopaque filler material to enhance radiographic visibility. Those skilled in the art will recognize that these materials may vary widely without departing from the scope of this disclosure.

[0062] It will be understood that this disclosure is in many respects merely illustrative. Changes may be made in details, particularly in matters of shape, size, and order of steps, without exceeding the scope of the disclosure. This may include, to the extent appropriate, using any of the features of one illustrative embodiment in other embodiments. The scope of the invention is, of course, defined in the language of the appended claims.

Claims

1. 1. A method of implanting a left atrial appendage closure (LAAC) device in a left atrial appendage (LAA) of a patient, comprising: advancing an assembly to a position adjacent to the patient's LAA, the assembly comprising: a LAAC device releasably secured to a LAAC delivery catheter; and one or more ultrasound transducers positioned relative to the LAAC delivery catheter. Deploying the LAAC device within the LAA; and Rotating the ultrasound transducer relative to the LAAC device to locate gaps and / or leaks between the LAAC device and the LAA. A method comprising:

2. The method of claim 1 , wherein the one or more ultrasound transducers are part of an ultrasound catheter.

3. The method of claim 2 , wherein the ultrasound catheter is steerable.

4. The method of claim 3, further comprising steering the ultrasound catheter to better view any leaks that may exist between the LAAC device and the LAA.

5. The method of any one of claims 2 to 4, wherein rotating the one or more ultrasound transducers comprises rotating the ultrasound catheter around the LAAC delivery catheter.

6. The method of any one of claims 2 to 4, wherein rotating the one or more ultrasound transducers comprises rotating the ultrasound catheter in position relative to the LAAC delivery catheter.

7. The method of claim 1 , wherein the one or more ultrasound transducers are disposed on the LAAC delivery device.

8. The method of claim 7 , wherein rotating the one or more ultrasound transducers comprises rotating the LAAC delivery device.

9. 1. An assembly adapted to implant a left atrial appendage closure (LAAC) device within a left atrial appendage (LAA) of a patient, comprising: a LAAC device releasably secured to a LAAC delivery catheter; one or more ultrasound transducers positioned relative to the LAAC delivery catheter; Including the assembly.

10. The assembly of claim 9 , wherein the one or more ultrasound transducers are part of an ultrasound catheter.

11. The assembly of claim 9 , wherein the one or more ultrasound transducers are disposed on the LAAC delivery catheter.

12. 1. An assembly adapted to implant a left atrial appendage closure (LAAC) device within a left atrial appendage (LAA) of a patient, comprising: a LAAC device releasably secured to a LAAC delivery catheter; a steerable ultrasound catheter rotatably positioned relative to the LAAC delivery catheter; Including the assembly.

13. The assembly of claim 12, further comprising a tubular member, the LAAC delivery catheter and the steerable ultrasound catheter both extending through the tubular member.

14. The assembly of claim 13 , wherein the steerable ultrasound catheter is adapted to rotate within the tubular member around the LAAC delivery catheter.

15. The assembly of claim 13 , wherein the steerable ultrasound catheter is adapted to rotate in place relative to the LAAC delivery catheter within the tubular member.

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