DIELECTRIC COATING FOR CARDIAC ABLATION DEVICE

A medical device includes an elongate hollow shaft having a shaft proximal end, a shaft distal end, and a lumen extending along the elongate hollow shaft. A handle is disposed at the shaft proximal end. A connector assembly having a connector assembly proximal end and a connector assembly distal end, the connector assembly proximal and distal ends being opposite ends of the connector assembly. An expandable frame is detachably disposed at the connector assembly distal end, the expandable frame including a plurality of interconnected members formed of an electrically conductive material, wherein the interconnected members in a first portion of the expandable frame are coated with a dielectric layer, and wherein the interconnected members in a second portion of the expandable frame are uncoated and configured as an electrode region of the expandable frame.

TECHNICAL FIELD

The present disclosure generally relates to devices, systems, and methods for ablating and occluding a body lumen or cavity and, more particularly, to devices, systems, and methods for occluding the left atrial appendage of the heart and ablation of tissue by electroporation.

BACKGROUND

Atrial fibrillation (AF) is a common sustained cardiac arrhythmia affecting people worldwide. Serious consequences may come to those affected by AF. AF is the irregular, chaotic beating of the upper chambers of the heart where electrical impulses discharge so rapidly that the atrial muscle quivers or fibrillates. Episodes of AF may last a few minutes or several days. A serious consequence of AF is ischemic stroke. Most AF patients, regardless of the severity of their symptoms or frequency of episodes, require treatment to reduce the risk of stroke.

In patients with AF, blood tends to pool and form clots in an area of the heart called the left atrial appendage (LAA). The LAA is a pouch-like extension located in the upper left chamber of the heart. A blood clot that breaks loose from this area may migrate through the blood vessels and eventually plug a smaller vessel in the brain or heart resulting in a stroke or heart attack. It is known that a majority of blood clots in patients with AF are found in the LAA.

Treatment of AF may include surgically closing the LAA, epicardial LAA ligation, or delivering a device or mechanism across or into the LAA in order to occlude it. Occlusion devices for addressing AF typically utilize a metallic “cage” and/or fabric graft, which, when deployed, form a circular shape across and/or within the LAA. They are delivered to the treatment site via a catheter system.

InFIG.1, a cross-sectional view of the human heart is shown.FIG.1also depicts a common technique whereby a catheter is threaded through the vasculature and into the heart to deliver an occlusion device to the LAA. Ideally, when the device is properly positioned within the LAA the occlusion device forms a seal with the wall of the LAA in order to prevent emboli or blood clots from passing back into the blood stream. Many known occlusion devices, however, are equipped with expandable frames that while sufficient to support a filter or membrane, have insufficient circumferential and/or radial strength to resist the distortive forces that the LAA exert on the occlusion device. As a result, the seal such devices form with the interior wall of the LAA is compromised as the expandable frame is bent into a more elliptical shape by the LAA. As a consequence, such devices may allow some material to exit the LAA and re-enter the blood stream.

Unexpected pericardial adhesions can delay or prevent successful occlusion operations. Known in the art are self-expanding nitinol frame structures with fixation barbs and a permeable polyterephthalate membrane that covers the atrial surface. These occlusion devices can be useful in hybrid ablation procedures. For examples, implantation of occlusion devices in a hybrid AF ablation setting (i.e., combination of thoracoscopic epicardial surgical and endocardial catheter ablation) can be a reliable option in cases where surgical LAA occlusion methods cannot be applied.

SUMMARY

Example 1 is a medical device comprising an elongate hollow shaft having a shaft proximal end, a shaft distal end, and a lumen extending along the elongate hollow shaft; a handle disposed at the shaft proximal end; a connector assembly having a connector assembly proximal end and a connector assembly distal end, the connector assembly proximal and distal ends being opposite ends of the connector assembly; and an expandable frame that is detachably disposed at the connector assembly distal end, the expandable frame comprising a plurality of interconnected members formed of an electrically conductive material, wherein the interconnected members in a first portion of the expandable frame are coated with a dielectric layer, and wherein the interconnected members in a second portion of the expandable frame are uncoated and configured as an electrode region of the expandable frame. The connector assembly is operatively connected to the expandable frame and configured to facilitate moving the expandable frame between a plurality of deployment positions.

Example 2 is the medical device of Example 1, wherein the expandable frame comprises a threaded socket and the connector assembly comprises a threaded wire that is receivable within the threaded socket such that the expandable frame is attached by threading the connector assembly into the expandable frame and is detached by unthreading the connector assembly from the expandable frame.

In Example 3, in the medical device of Examples 1 and 2, the connector assembly includes a hypotube that extends through the handles and a threaded wire that is attached to the hypotube and the expandable frame.

In Example 4, in the medical device of any of Examples 1-3, the handle includes a housing and a deployment assembly arranged together with the housing such that actuating the handle thereby moves the expandable frame between the plurality of deployment positions.

In Example 5, in medical device of Example 4, the deployment assembly includes a switch and a translator that is operatively connected to both the switch and the connector assembly such that actuating the handle comprises actuating the switch, the translator facilitating movement of the connector assembly relative to the elongate hollow shaft to thereby move the expandable frame between the plurality of deployment positions.

In Example 6, in the medical device of any of Examples 4 and 5, the deployment assembly comprises a torque knob with which to detach the expandable frame from the ablation catheter.

In Example 7, in the medical device of any of Examples 1-6, a biocompatible covering disposed over at least a part of the expandable frame.

In Example 8, in the medical device of any of Examples 1-7, the expandable frame comprises an electrode that facilitates delivering ablative energy to generate a volume of ablated tissue having a shape and size that corresponds to a deployment position of the expandable frame.

In Example 9, in the medical device of any of Examples 1-8, the expandable frame is formed as a closed basket with an ablation electrode positioned at a distal end of the expandable frame.

In Example 10, The medical device of any of Examples 1-9, the first portion of the expandable frame includes a proximal end to a proximal border.

In Example 11, in the medical device of Example 10, the second portion of the expandable frame extends from the proximal border to a distal end of the expandable frame.

In Example 12, in the medical device of Example 10, the second portion of the expandable frame extends from the proximal border to a distal border proximal from the distal end.

In Example 13, in the medical device of Example 12, the expandable frame includes a third portion coated with insulation, wherein the third portion extends from distal border to the distal end.

In Example 14, in the medical device of Example 13, the second portion extends between the proximal ring of anchors on the expandable frame and a distal ring of anchors on the expandable frame.

In Example 15, in the medical device of any of Examples 1-14, the interconnected members are axially surrounded by the dielectric layer in the first portion.

Example 16 is a medical device comprising: an elongate hollow shaft having a shaft proximal end, a shaft distal end, and a lumen extending along the elongate hollow shaft; a handle disposed at the shaft proximal end; a connector assembly having a connector assembly proximal end and a connector assembly distal end, the connector assembly proximal and distal ends being opposite ends of the connector assembly; and an expandable frame that is detachably disposed at the connector assembly distal end, the expandable frame comprising a plurality of interconnected members formed of an electrically conductive material, wherein the interconnected members in a first portion of the expandable frame are coated with a dielectric layer, and wherein the interconnected members in a second portion of the expandable frame are uncoated and configured as an electrode region of the expandable frame. The connector assembly is operatively connected to the expandable frame and configured to facilitate moving the expandable frame between a plurality of deployment positions.

In Example 17, in the medical device of Example 16, the expandable frame comprises a threaded socket and the connector assembly comprises a threaded wire that is receivable within the threaded socket such that the expandable frame is attached by threading the connector assembly into the expandable frame and is detached by unthreading the connector assembly from the expandable frame.

In Example 18, in the medical device of Example 16, the connector assembly includes a hypotube that extends through the handles and a threaded wire that is attached to the hypotube and the expandable frame.

In Example 19, in the medical device of Example 16, the handle includes a housing and a deployment assembly arranged together with the housing such that actuating the handle thereby moves the expandable frame between the plurality of deployment positions.

In Example 20, in the medical device of Example 16, wherein a biocompatible covering disposed over at least a part of the expandable frame.

In Example 21, in the medical device of Example 16, the expandable frame comprises an electrode that facilitates delivering ablative energy to generate a volume of ablated tissue having a shape and size that corresponds to a deployment position of the expandable frame.

In Example 22, in the medical device of Example 16, the expandable frame is formed as a closed basket with an ablation electrode positioned at a distal end of the expandable frame.

In Example 23, in the medical device of Example 16, the first portion of the expandable frame includes a proximal end to a proximal border.

In Example 24, in the medical device of Example 23 the second portion of the expandable frame extends from the proximal border to a distal end of the expandable frame.

In Example 25, in the medical device of Example 23, the second portion of the expandable frame extends from the proximal border to a distal border proximal from the distal end.

In Example 26, in the medical device of Example 16, the expandable frame includes a third portion coated with insulation, wherein the third portion extends from distal border to the distal end.

In Example 27, in the medical device of claim 16, wherein the second portion extends between the proximal ring of anchors on the expandable frame and a distal ring of anchors on the expandable frame.

In Example 28, in the medical device of Example 16, wherein the interconnected members are axially surrounded by the dielectric layer in the first portion.

Example 29, is a method for occluding portions of a heart, the method comprising delivering an ablation catheter into the heart such that an intracardial portion of the ablation catheter is positioned adjacent a portion of the heart that is to be ablated The ablation catheter comprises an elongate hollow shaft having a shaft proximal end, a shaft distal end, and a lumen extending along the elongate hollow shaft; an expandable frame that is detachably disposed at the shaft distal end, the expandable frame comprising a plurality of interconnected members formed of an electrically conductive material, wherein the interconnected members in a first portion of the expandable frame are coated with a dielectric layer, and wherein the interconnected members in a second portion of the expandable frame are uncoated and configured as an electrode region of the expandable frame. The ablation catheter also comprises a handle that is disposed at the shaft proximal end and operatively connected to the expandable frame such that actuation of the handle moves the expandable frame between the plurality of deployment positions. The ablation catheter is configured to direct energy to the expandable frame so as to ablate tissue at or around the second portion of the expandable frame; and deploys the expandable frame into the portion of the heart that is to be ablated.

In Example 30, the method of Example 29 further comprises positioning a deployed portion of the expandable frame to be adjacent tissue that is to be ablated, and generating ablative energy at the expandable frame to ablate tissue at or around the second portion of the expandable frame.

In Example 31, the method of Example 30 further comprises moving the expandable frame into at least one of the focal arrangement and the wide area arrangement.

In Example 32, in the method of Example 31, the ablation catheter further includes a connector assembly that extends from the handle to the expandable frame so as to operatively connect the handle to the expandable frame; and a deployment assembly that is arranged at the handle to correspond actuating the handle with directing the expandable frame to move between the plurality of deployment positions. The deployment assembly includes a switch and a translator that is operatively connected to both the switch and the connector assembly such that actuating the handle comprises actuating the switch, the translator facilitating movement of connector assembly relative to the elongate hollow shaft to thereby move the expandable frame between the plurality of deployment positions; and moving the expandable frame into at least one of the focal arrangement and the wide area arrangement comprises actuating the handle.

In Example 33, the method of Example 30 deploys the expandable frame into a portion of the heart that is to be ablated comprises detaching the expandable frame into a portion of the heart that is to be occluded.

In Example 34, in the method of Example 29, the expandable frame includes a third portion coated with insulation, wherein the third portion extends from distal border to the distal end.

In Example 35, in the method of Example 29, the interconnected members are axially surrounded by the dielectric layer in the first portion.

DETAILED DESCRIPTION

For purposes of promoting an understanding of the principles of the present disclosure, reference is now made to the examples illustrated in the drawings, which are described below. The illustrated examples disclosed herein are not intended to be exhaustive or to limit the disclosure to the precise form disclosed in the following detailed description. Rather, these exemplary embodiments were chosen and described so that others skilled in the art may use their teachings. It is not beyond the scope of this disclosure to have a number (e.g., all) the features in a given example used across all examples. Thus, no one figure should be interpreted as having any dependency or requirement related to any single component or combination of components illustrated therein. Additionally, various components depicted in a given figure may be, in examples, integrated with various ones of the other components depicted therein (and/or components not illustrated), all of which are considered to be within the ambit of the present disclosure.

The terms “couples,” “coupled,” “connected,” “attached,” and the like along with variations thereof are used to include both arrangements wherein two or more components are in direct physical contact and arrangements wherein the two or more components are not in direct contact with each other (e.g., the components are “coupled” via at least a third component), but yet still cooperate or interact with each other.

Throughout the present disclosure and in the claims, numeric terminology, such as first and second, is used in reference to various components or features. Such use is not intended to denote an ordering of the components or features. Rather, numeric terminology is used to assist the reader in identifying the component or features being referenced and should not be narrowly interpreted as providing a specific order of components or features.

For purposes of this disclosure, like reference numerals in the figures shall refer to like features unless otherwise indicated. For example, reference numeral100refers to an expandable frame inFIG.2Aand also refers to an expandable frame inFIGS.3and4.

Generally, disclosed herein are devices, systems, and methods for treatment of heart conditions related to fibrillations such as left atrial appendage fibrillation (LAAF). In this regard, examples of the present disclosure include occlusive implant delivery systems. These systems can perform hybrid ablation procedures using a single device. Such systems can include an ablation catheter as shown herein such as those with a detachable ablative, occlusion device (e.g., an occlusive implant) with an expandable frame that can be manipulated during operation to perform hybrid ablation procedures using different forms of ablation depending on the operation. For instance, the device can assume several arrangements, including a focal arrangement (see configuration A inFIG.2A) and an expanded arrangement (e.g., a wide-shot arrangement at configuration B inFIG.2A) that corresponds to a deployment position of the occlusion device. At least one of these arrangements can use one or more ablation techniques, such as radiofrequency (RF) ablation and pulsed field ablation (PFA). In this regard, the system also includes a generator (not shown) that is operatively connected to the ablation catheter10to cause the ablation catheter10to generate ablative energy at and/or around the device. These generators can be similar to those known in the art, such as those configured to perform PFA and RF ablation. These and more examples of principles of the present disclosure are discussed below.

In one or more aspects of the present disclosure, an occlusion device may include an expandable frame and a biocompatible covering disposed over at least a part of the expandable frame. Such an occlusion device of the present disclosure may be used to, for example, occlude the left atrial appendage (LAA) of the heart for the treatment of, for example, sustained cardiac arrhythmia (e.g., atrial fibrillation). When an occlusion device of the present disclosure is properly positioned within the LAA, the occlusion device may have sufficient circumferential and/or radial strength to form a seal with the wall of the LAA (and resist the distortive forces that the LAA may exert on the occlusion device) in order to, for example, prevent emboli or blood clots from passing back into the blood stream.

More detail about the ablation catheter10will be discussed with reference toFIGS.2A and2B. As shown here, the ablation catheter10includes an elongate hollow shaft12having a shaft proximal end14, a shaft distal end16, and a lumen18extending along the elongate hollow shaft12; an expandable frame100that is detachably disposed at the shaft distal end16; and a handle110that is disposed at the shaft proximal end14. The expandable frame100has a plurality of deployment positions, which can include a first deployed position in which the expandable frame100is in a focal (e.g., narrow) arrangement (e.g., configuration A) and a second deployed position in which the expandable frame100is in a wide area arrangement (e.g., configuration B). Other deployment positions (such as those between or just beyond configurations A and B) are also contemplated and within the scope of this disclosure. As discussed further below, in examples, the ablation catheter10is configured to direct energy to the expandable frame100so as to ablate tissue at or around the expandable frame100. Optionally, when the expandable frame100is formed as an occlusion device (see, e.g.,FIGS.7and8), the ablation catheter10is further configured to deploy the occlusion device by detaching it from the ablation catheter10as discussed in more detail below.

A connector assembly120operatively connects the expandable frame100to the handle110. In examples, the connector assembly120extends from the handle110to the expandable frame100to thereby operatively connect the handle110to the expandable frame100. The expandable frame100is disposed at a distal end of the connector assembly120, and the handle110is disposed at a proximal end of the connector assembly120. As discussed below, the connector assembly120can include one or more connector components (e.g., tubes, wires, or other connectors) that are interconnected. Under these circumstances, the connector assembly120can perform various functions, such as assisting with a deployment operation of the ablation catheter10as further discussed below. Of course, the one or more connector components can be integrally formed.

With reference toFIGS.2A,2B,3, and4, operation of the ablation catheter10can be facilitated via a deployment assembly130that is included with the handle110. More specifically, as shown in the illustrated example inFIGS.2A and2B, the handle110includes a housing with the deployment assembly130arranged therein. The deployment assembly130includes a switch132and a translator134that is operatively connected to both the switch132and the connector assembly120. The switch132is disposed within a corresponding slot136in the housing. Illustratively, the translator134is formed as an extension of the switch132that is connected to the connector assembly120via a bearing138. In this regard, actuating the handle110may include actuating the switch132(e.g., proximally and/or distally relative to the housing). The translator134facilitates movement of the connector assembly120relative to the elongate hollow shaft12to thereby move the expandable frame100between the plurality of deployment positions. In this regard, actuating the handle110moves the expandable frame100between the plurality of deployment positions.

To facilitate deployment of the expandable frame100when it is an occlusion device, the deployment assembly130can be manipulated. For instance, with continued reference toFIGS.2A and2B, the expandable frame100may include a threaded socket141and the connector assembly120may include a connector143with a threaded portion145(e.g., at a distal end of the connector143). As such, this connector143is receivable within the threaded socket141such that the expandable frame100is attached by threading the connector143(e.g., using the threaded portion145) into the expandable frame100and is detached by unthreading the connector143from the expandable frame100. The deployment assembly130may include a torque knob147with which to detach the expandable frame100from the ablation catheter10. In examples, the connector143is formed at least partially as a hypotube that extends through the handle110and a threaded connector143or threaded portion145that is attached to the hypotube and the expandable frame100so as to be coupled between the hypotube and the expandable frame100.

As discussed above, the ablation catheter10can generate electrical energy in the expandable frame100for ablation procedures. In this regard, illustratively, the expandable frame100is made of plurality of interconnected members formed of an electrically conductive material. Thus, in various embodiments, the entirety of the expandable frame is capable of functioning as an ablation electrode.

In various embodiments, the expandable frame includes an electrode149(e.g., an ablation electrode149). The generator is configured to facilitate delivering ablative energy to generate a volume of ablated tissue having a shape and size that corresponds to the deployment position of the expandable frame100. The expandable frame100is formed as a closed basket with an ablation electrode149positioned at a distal end of the expandable frame100. In an ablation system, the ablation catheter10can be connected to a generator via a coupler150at the proximal end of the handle110. Together, the ablation catheter10and generator are configured to generate energy to perform pulsed field ablation, for example. A flex connector152can ensure that the coupler150is in communication with the expandable frame100(e.g., via the connector143and/or wires extending from the expandable frame100to the flex connector152) even during actuation of the connector assembly120(e.g., via movement of the switch132and/or translator134).

Multiple electrodes can be disposed in the ablation catheter10to perform multipolar ablation. In examples, the electrode149can be a subcomponent of an electrode assembly. In this regard, the electrode assembly can include first and second ablation electrodes149,153. Illustratively, one of the first and second electrodes149,153is disposed at a distal end of the expandable frame100and the other is disposed proximal to the ablation electrode149(e.g., on the expandable frame100, the elongate hollow shaft12, or the connector143). Of course, other arrangements of electrodes in the electrode assembly are also contemplated. For instance, there are examples where the ablation electrode is disposed at the proximal end of the expandable frame100.

Certain design considerations are useful when constructing an expandable frame for use during operation, for instance during a cryoablation procedure. Visualization in an electroanatomical mapping system can be performed via a navigation sensor integration as are known in the art. Some implementations can use fluoroscopy and TEE/ICE for visualization. Further, the expandable frame can be constructed from rigid materials that are navigable through body lumens and do not have any negative effects on long term LAAO.

More details about the expandable frame100will now be discussed with reference toFIGS.5-8. In particular,FIG.5is a side view of one or more embodiments of an expandable frame100of the present disclosure having closed proximal and distal ends. Illustratively, the ends are defined by an inverted proximal hub and an inverted distal hub.FIG.6is a side view of one or more embodiments of an expandable frame100of the present disclosure having closed proximal and distal ends. Illustratively, the ends are defined by an external proximal hub and an inverted distal hub (or vice versa).FIGS.7and8are similar toFIGS.5and6respectively except that the expandable frame100is implantable as an occlusive device.

As shown, an occlusion device may include an expandable frame100formed from, for example, a sheet. The expandable frame100may be suitable for use as a component of an occlusion device, which may also include covering590(e.g., a filter graft, membrane, etc.). Such a covering590may be supported by the expandable frame100(e.g., the covering590may extend over and from the proximal end of the expandable frame100toward the distal end of the expandable frame100). The occlusion device (including the expandable frame100and covering590) may include other components and may be combined with a delivery system for delivering the occlusion device to the LAA or other body lumen. In the one or more examples, the expandable frame100is depicted after manufacture, but before being loaded onto a catheter or deployed.

In the present disclosure, a beam530of expandable frame100may include a number of segments. For example, each beam530may include a first segment532extending from the first hub520to the first circumferentially extending column540of strut pairs542and a second segment538extending from the first circumferentially extending column540of strut pairs542to another (e.g., a second, third, fourth, etc.) circumferentially extending column540of strut pairs542.

Illustratively, the expandable frame100includes a first hub520(e.g., a proximal cap or ring) from which a plurality of beams530(e.g., support beams530) extend longitudinally therefrom. The first segment532(e.g., the proximal portion) of each beam530may also be considered as a radial component of the beam530because when the expandable frame100is expanded the predominant length of the first segment532may extend radially outward from first hub520. When collapsed, the expandable frame100can be substantially flat or significantly compacted relative to the expanded state.

As shown inFIGS.5-7, the first segment532of the beam530may include a first longitudinally extending region534that is immediately adjacent to the first hub520. The first longitudinal extending region534may transition to the radially extending region536at interior curve535. In one or more examples, the radially extending region536may then transition or turn back to the longitudinal direction at exterior curve537. One or more examples of the present disclosure may include an expandable frame100including a plurality of beams530that terminate at a second hub570(e.g., a distal cap or ring). In at least one example the distal end of the expandable frame100may include a second hub570(e.g., the end may be closed), such that the longitudinally extending beams530turn radially inward near the distal end of the device to a distal cap or ring. In examples, the expandable frame100can be a self-expanding frame while in other examples the expandable frame100is a mechanically expanding frame. These examples are just some of many examples disclosed herein.

In some examples, in a deployed or expanded state, the first hub520(e.g., proximal ring) may be longitudinally adjacent (external) to the entire length of the beams530, such that the beams530extend longitudinally away from the first hub520in a single longitudinal (distal) direction. In one or more examples, the first hub520may be inverted (internal) such that the beams530initially extend in a first (proximal) longitudinal direction away from the first hub520and then as the beams530turn and extend radially outward the beams530curve back over the first hub520in the opposite (distal) longitudinal direction. In one or more examples where the device has a second hub570(e.g., a distal ring), the second hub570may be configured with an internal (see, e.g.,FIGS.5and7) or external configuration (see, e.g.,FIGS.6and8). The internal or external positioning of the first hub520and second hub570may be the same or different. That is, in one or more examples, at least one of the first and second hubs520,570may be inverted. For example, the first hub520and second hub570may be internally positioned (inverted) such as in the example shown inFIGS.5and7. One hub (for example, first hub520) may be externally positioned while the other hub (for example, second hub570) may be inverted, such as in the example depicted inFIGS.6and8. At least a portion of the beams530may be hooked (e.g., be J-shaped or C-shaped).

In examples wherein both the proximal end and distal end are closed, such as in the manner described herein, the columns540of strut pairs542may have a uniform orientation (all peaks “point” in the same direction) or, as shown, have opposing orientations relative to one or more other columns540. In still other examples, an expandable frame100can include closed ends, and also include engagement anchors in the form of protrusions, indents, or other features of the expandable framework100. For example, the framework may include one or more radially extending anchors (e.g., engagement barbs or other features) for improved securement of the framework into the surrounding tissue (e.g., the interior wall of the LAA) when the device is deployed.

Examples of the present disclosure include an expandable framework100that includes a biocompatible covering590disposed over at least a part of the expandable frame100. In one or more examples, the covering590may take any of a wide variety of forms known to one of skill in the art. For example, a covering590may include a graft and/or a membrane and may include one or more layers. In one or more examples, a membrane or other covering590may be disposed over and about most of the proximal end of expandable frame100. For example, a covering590may be substantially bowl-shaped, with an opening that extends around the portion of the occlusion device having the greatest diameter in the second configuration. In the one or more examples that include anchors as discussed above, the anchors may penetrate the covering590in both the first and second configurations (e.g., unexpanded and expanded states) to secure the covering590on the expandable frame100. The covering590may be any of a wide variety of biocompatible fabric, membrane, or material known to one of skill in the art. For example, the covering590may be constructed of one or more layers of polyethylene terephthalate (PET). It should be recognized that the coverings described herein may be suitable for use with any of the examples of the expandable frame100shown or described herein.

FIGS.10A and10Bshow an expandable frame100having an electrically insulative covering600disposed on conductive struts602, such as nitinol struts, extending between a proximal threaded socket603to receive a connector assembly603to a distal puck605. The delivery of PFA energy (or RF energy, as well) to a relatively large conductive frame, as well as a conductive frame with a relatively large distance between struts, can result in low impedance at the generator, which can result in relatively less favorable lesions in the myocardial tissue from ablation. The partially insulated expandable frames concentrate delivered energy to the exposed portions of the frame to achieve more favorable lesions. While an external hub configuration (see, e.g.,FIG.6), the concepts described apply similarly to an expandable frame having an internal hub configuration (see, e.g.,FIG.5). In various embodiments, portions of the expandable frame100are covered with an outer coating, thereby insulating a portion of the outer surface of the expandable frame100. In other embodiments, a portion of the struts and columns are coated with an insulative material. In various embodiments, the insulative material is a dielectric material. In some embodiments, the partially insulated frame can further include a covering (such as that illustrated and described with respect toFIGS.7-8). The application of the electrically insulative covering600at locations on the conductive struts602serves to reduce the exposed or bare conductive surface area of the frame acting as an electrode. The electrically insulative covering600concentrates ablation energy to the exposed portions of the of the frame100.

FIG.10Aillustrates an embodiment having an expandable frame100including a proximal portion604extending from a proximal end608to a border610as a plane bisecting the frame100and a distal portion606extending from the border610to a distal end612. The proximal portion604of the frame100includes electrically insulated struts614and a distal portion606with exposed conductive struts616. Embodiments are contemplated including a distal portion of the expandable frame including insulated struts and a proximal portion having exposed struts. The frame100of the particular embodiment shown inFIG.10Aincludes a substantial majority of the proximal portion604with struts602covered or coated with the insulative material600. For example, the embodiment ofFIG.10Aillustrates the border610distal to a ring of proximal anchors630, such as hooks on the frame100, and the border610near a ring of distal anchors632, such as hooks on the frame100with the exposed struts616disposed around the frame100distal the proximal anchors630and the proximal the distal anchors632.

FIG.10Billustrates an embodiment having an expandable frame100including a proximal portion654extending from a proximal end658to a proximal border660as a plane extending through the frame100, and a distal portion656extending from a distal end662to a distal border664as a plane extending through the frame100. The proximal portion654and distal portion656include insulated struts666,668, respectively, i.e., the conductive struts602in the proximal and distal portions654,656, are covered in insulative material600. The expandable frame100further includes a medial portion670extending from the proximal border660to the distal border664with electrically exposed conductive struts672, i.e., the conductive struts602in the medial portion670are not covered with insulative material600. Embodiments are contemplated having exposed distal and proximal portions with an electrically insulated medial portion. The frame100of the particular embodiment shown inFIG.10Bincludes a substantial majority of the proximal and distal portions654,656with struts602covered or coated with the insulative material600. For example, the embodiment ofFIG.10Billustrates the proximal border660near a ring of proximal anchors680, such as hooks on the frame100, and the distal border664near a ring of distal anchors682, such as hooks on the frame100with the medial portion670of exposed struts672disposed around the frame100between the proximal anchors680and the distal anchors682.

The insulator600is an electrical insulator that resists delivery of electrical energy on the expandable frame100through the insulator600. In some embodiments, the insulator600completely surrounds the conductive struts on which the insulator600is disposed. For example, the insulator600extends completely around the strut axial element in the embodiment and does not provide radial gaps of insulation to expose the conductor of the strut. In other embodiments, the insulator600extends around the strut axial element on the regions of the strut602that will contact tissue. In some embodiments, the exposed portions of the frame can include insulator on the axial portions of the struts that do not contact tissue, such as the inner frame facing an internal cavity. In some embodiments, the insulator600does not include longitudinal gaps to expose the conductor of the strut until reaching the insulation border640,642,644with exposed struts614,636. In some embodiments, the insulator600is constructed from a polymer applied to the frame100such as via a dip coating or spray coating the frame100. In some embodiments, the insulator600is tubular polymer such as a shrink fit polymer disposed about the frame100and attached in place. In some embodiments, the insulator600is a metal oxide formed by a manufacturing process—such as physical vapor deposition or physical vapor transport (or type of vacuum deposition), sputtering, or an electrochemical process—to deposit a thin film or coating on the frame. Portions of the conductive struts that are intended to remain uncoated, or exposed, can be masked prior to coating, and the masking is removed to expose the uncoated conductive material of the finished frame. For example, the medial portion670of struts672can be masked prior to coating or covering the frame with insulative material, and the mask can later be removed to expose uncovered struts672.

According to principles of the present disclosure, ablation and occlusion methods are also disclosed herein. Each of these methods can use ablation catheters similar to those disclosed elsewhere herein. For instance, as shown inFIG.9, a method900for performing a hybrid ablation procedure and related methods are disclosed. At step910, the method900can include advancing a distal end of the catheter through a patient's vasculature to an area of interest, such as into the heart to deliver an occlusion device to the LAA. In this regard, continuing with this heart example, the ablation catheter can be positioned adjacent heart tissue that is to be ablated. In one embodiment, the exposed or uncoated portion of the ablation catheter is positioned adjacent heart tissue that is to be ablated, and an insulated or coated portion of the ablation catheter is positioned adjacent to heart tissue that is not to be ablated. At step920, the method900can include creating scar tissue inside the heart via one or more ablation techniques (e.g., RF and/or PFA ablation). When deploying an occlusion device is desirable, the method900can include advancing an occlusion device to the LAA at step930and deploying the device therein at step940. When the device is properly positioned within the LAA, the occlusion device forms a seal with the wall of the LAA to prevent emboli and/or blood clots from passing back into the blood stream.

Using the ablation catheters disclosed elsewhere herein, the expandable frame employed in these methods can be used for ablation, occlusion, or both. For instance, as discussed above, an operator can have the option to use both narrow and wide-area ablation with the expandable frame. Ablation typically occurs before the expandable frame is deployed depending on the application. Transitioning between the narrow and expanded states of the expandable frame (or from one state to the other) can corresponded to actuating a connector assembly of the ablation catheter. In this regard, distal-to-proximal translation (e.g., of a switch) can move the expandable frame from a pre-expansion state within an elongate shaft of the ablation catheter to the narrow state just outside the elongate shaft, and further advancement in the same direction can move the expandable frame to the wide-area state further still outside the elongate shaft. Of course, there are examples where other movements (e.g., distal to proximal, rotations, etc.) of the connector assembly similarly advance the expandable frame. Deploying the device at step940can include detaching the occlusion device from the ablation catheter using a deployment assembly. In this regard, this step940can include unthreading the occlusion device from a connector that is in threaded engagement with the occlusion device. The connector can be in the form of a hypotube that is operatively connected to a torque knob at a proximal end of the ablation catheter for easy access such that rotating the torque knob rotates the connector to thereby thread/unthread the occlusion device. Other attachment/detachment methods, such as those known in the art and disclosed elsewhere herein, are also contemplated.

It is well understood that methods that include one or more steps, the order listed is not a limitation of the claim unless there are explicit or implicit statements to the contrary in the specification or claim itself. It is also well settled that the illustrated methods are just some examples of many examples disclosed, and certain steps may be added or omitted without departing from the scope of this disclosure. Such steps may include incorporating devices, systems, or methods or components thereof as well as what is well understood, routine, and conventional in the art.

In the detailed description herein, references to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art with the benefit of the present disclosure to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments.