Patent Description:
Heart failure is a common and potentially lethal condition affecting humans, with sub-optimal clinical outcomes often resulting in morbidity and/or mortality, despite maximal medical treatment. In particular, "diastolic heart failure" refers to the clinical syndrome of heart failure occurring in the context of preserved left ventricular systolic function (ejection fraction) and in the absence of major valvular disease. This condition is characterized by a stiff left ventricle with decreased compliance and impaired relaxation, which leads to increased end-diastolic pressure.

Symptoms of diastolic heart failure are due, at least in large part, to an elevation in pressure in the left atrium. Elevated left atrial pressure (LAP) is present in several abnormal heart conditions, including heart failure (HF). In addition to diastolic heart failure, a number of other medical conditions, including systolic dysfunction of the left ventricle and valve disease, can lead to elevated pressures in the left atrium. Both heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) can exhibit elevated LAP.

It may be beneficial to reduce elevated pressure in the left atrium. One way to do this is to shunt blood from the left atrium to the coronary sinus. By creating an opening between the left atrium and the coronary sinus, blood will flow from the higher pressure left atrium to the lower pressure coronary sinus. Examples of methods to shunt blood from the left atrium to the coronary sinus are disclosed in <CIT> entitled "Expandable Cardiac Shunt".

Using catheter-based instruments, the surgeon creates a puncture hole between the left atrium and the coronary sinus and places an expandable shunt within the puncture hole. To do this, one or more catheters are used to create the puncture hole, to deliver the expandable shunt along a guidewire, and to deploy the expandable shunt in the puncture hole. Once expanded, the shunt defines a blood flow passage that allows blood to flow from the left atrium to the coronary sinus when the LAP is elevated.

Methods for surgery are not claimed.

For purposes of summarizing the disclosure, certain aspects, advantages and novel features have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular example. Thus, the disclosed examples may be carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

Some implementations of the present disclosure relate to a guidewire delivery catheter used to implant a shunt between the coronary sinus and the left atrium. The catheter includes a needle housed within the catheter in a delivery configuration, the needle configured to extend out of the catheter to puncture a vessel wall in a deployment configuration. The catheter includes a needle port through which the needle extends out of the catheter to transition from the delivery configuration to the deployment configuration. The catheter includes a securing mechanism housed within the catheter in a delivery configuration, the securing mechanism comprising a compliant wire configured to be advanced out of the catheter in a deployment configuration so that a distal portion of the wire comes into contact with the vessel wall to provide wall apposition for the needle to puncture the vessel wall. The catheter includes a wire port through which the wire of the securing mechanism extends out of the catheter to transition from the delivery configuration to the deployment configuration.

In some examples, a distal portion of the wire of the securing mechanism is configured to coil upon exiting the wire port.

In some examples, the catheter further includes a second wire port, wherein the securing mechanism further comprises a second wire configured to exit the catheter at the second wire port. In further examples, each of the wires of the securing mechanism is configured to curve away from the catheter in the deployment configuration. In further examples, an azimuth angle between the needle port and each of the two wire ports is at least <NUM> degrees and less than <NUM> degrees. In further examples, an azimuth angle between the needle port and each of the two wire ports is at least <NUM> degrees. In further examples, an azimuth angle (θ1) between the two wire ports is less than or equal to <NUM> degrees.

In some examples, the securing mechanism further includes a curved endcap at a distal end of the wire. In further examples, the curved endcap is configured to contact the vessel wall in the deployment configuration. In further examples, the curved endcap is configured to cover the wire port in the delivery configuration. In further examples, the curved endcap is configured to follow a contour of the vessel wall.

In some examples, the wire is configured to run along a length of the catheter such that the wire is configured to be advanced by manipulating a component of the securing mechanism from outside of an operative site.

In some examples, the wire comprises a shape memory metal. In further examples, the wire is shape set to curve away from the catheter. In further examples, the wire is shape set to coil outside of the catheter. In further examples, the wire is shape set to exit the catheter at an exit angle. In further examples, a distal end of the catheter is coated with a material to reduce a likelihood of damaging the vessel wall.

In some examples, the wire is configured to be withdrawn to transition from the deployment configuration back to the delivery configuration. In some examples, the wire port is positioned opposite the needle port so that the wire exits the catheter on an opposite side from where the needle exits the catheter. In some examples, wire port is positioned more distally along the catheter relative to the needle port.

Various examples are depicted in the accompanying drawings for illustrative purposes and should in no way be interpreted as limiting the scope of the disclosed subject matter. In addition, various features of different disclosed examples can be combined to form additional examples, which are part of this disclosure. Throughout the drawings, reference numbers may be reused to indicate correspondence between reference elements. However, it should be understood that the use of similar reference numbers in connection with multiple drawings does not necessarily imply similarity between respective examples associated therewith. Furthermore, it should be understood that the features of the respective drawings are not necessarily drawn to scale, and the illustrated sizes thereof are presented for the purpose of illustration of inventive aspects thereof. Generally, certain of the illustrated features may be relatively smaller than as illustrated in some examples or configurations.

The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed subject matter.

Symptoms of diastolic heart failure arise from elevated pressure in the left atrium, or elevated left atrial pressure (LAP). Other heart conditions may manifest elevated LAP as well. To reduce the pressure in the left atrium, a pathway can be created between the left atrium and the coronary sinus. This allows blood to flow from the higher pressure left atrium to the lower pressure coronary sinus. The pathway can be created by puncturing a hole between the left atrium and the coronary sinus. Once the hole has been created, a shunt can be placed in the hole to keep it open.

For example, catheter-based instruments can be used to create the hole and to deliver and deploy a shunt within the puncture hole. The catheter can be referred to as a guidewire delivery catheter (GDC) and can be used to puncture through the coronary sinus into the left atrium and to place a guidewire in the left atrium. To puncture through the tissue, the catheter has wall apposition to get the needle directly against the coronary sinus-left atrium wall. Prior GDCs used an "anchor balloon" (a saline-inflated balloon) to anchor the catheter when creating the puncture hole. The anchor balloon solution has the potential to burst or to slip out of position, which may harm the patient.

Accordingly, described herein are materials and mechanisms for securing the GDC in place to enable the GDC to puncture the wall from the coronary sinus to the left atrium. These materials and mechanisms serve as an alternative to the anchor balloon.

The term "catheter" is used herein according to its broad and ordinary meaning and may include any tube, sheath, steerable sheath, steerable catheters, and/or any other type of elongate tubular delivery device comprising an inner lumen configured to slidably receive instrumentation, such as for positioning within an atrium or coronary sinus, including for example delivery catheters and/or cannulas. In some cases, a securing mechanism may be composed of a shape-memory alloy (e.g., Nitinol) and/or may have a predefined shape and/or structure. The securing mechanism may be configured to be shaped and/or compressed to fit into and/or around a catheter. In some cases, a securing mechanism may have an elongated shape in a delivery configuration to extend at least partially along the catheter and to change shape in a deployed configuration to provide wall apposition.

Some examples described herein provide methods and/or systems for securing a guidewire delivery catheter, or other similar delivery device, to provide wall apposition for puncturing a vessel wall. While some examples may be directed to securing a catheter within the coronary sinus to puncture the wall between the coronary sinus and the left atrium, the devices described herein may be applicable to other areas of the body. For example, some devices described herein may advantageously be configured for securing catheters to provide wall apposition for puncturing vessels in vessels other than the coronary sinus.

The following includes a general description of a method for delivering a guidewire delivery catheter to a targeted location in the coronary sinus. It is to be understood that the disclosed securing mechanisms can be used in conjunction with such a guidewire delivery catheter in this or similar methods to provide wall apposition for puncturing the coronary sinus. <FIG> illustrates several access pathways for maneuvering guidewires and catheters in and around the heart to deploy shunts. For instance, access may be from above via either the subclavian or jugular veins into the superior vena cava (SVC), right atrium (RA) and from there into the coronary sinus (CS). Alternatively, the access path may start in the femoral vein and through the inferior vena cava (IVC) into the heart. Other access routes may also be used, and each typically utilizes a percutaneous incision through which the guidewire and catheter are inserted into the vasculature, normally through a sealed introducer, and from there the physician controls the distal ends of the devices from outside the body.

<FIG> depicts an example method for deploying an expandable shunt, wherein a guidewire <NUM> is introduced through the subclavian or jugular vein, through the superior vena cava and into the coronary sinus. Once the guidewire provides a path, an introducer sheath (not shown) may be routed along the guidewire and into the patient's vasculature, typically with the use of a dilator. <FIG> shows a deployment catheter <NUM> extending from the superior vena cava to the coronary sinus of the heart, the deployment catheter <NUM> having been passed through the introducer sheath which provides a hemostatic valve to prevent blood loss.

In some examples, the deployment catheter <NUM> may be about <NUM> long, and the guidewire <NUM> may be somewhat longer for ease of use. In certain examples, the deployment catheter <NUM> may function to form and to prepare an opening in the wall of the left atrium, and a separate placement or delivery catheter may be used for delivery of an expandable shunt. In various examples, the deployment catheter may be used for both puncture preparation and shunt placement. In the present application, the terms "deployment catheter" or "delivery catheter" are used to represent a catheter or introducer with one or both of these functions.

Since the coronary sinus is largely contiguous around the left atrium, there are a variety of possible acceptable placements for a stent. The site selected for placement of the stent may be made in an area where the tissue of the particular patient is less thick or less dense, as determined beforehand by non-invasive diagnostic means, such as a CT scan or radiographic technique, such as fluoroscopy or intravascular coronary echo (IVUS).

<FIG> are schematic views of steps in making a puncture hole through a wall of the coronary sinus, as seen looking down on a section of the heart with the posterior aspect down. Initially, <FIG> shows a guidewire <NUM> being advanced from the right atrium into the coronary sinus through its ostium or opening. A puncture catheter <NUM> is then advanced over the guidewire <NUM>, as seen in <FIG>. The puncture catheter <NUM> is introduced into the body through a proximal end of an introducer sheath (not shown). As is customary, an introducer sheath provides access to the particular vascular pathway (e.g., jugular or subclavian vein) and may have a hemostatic valve therein. While holding the introducer sheath at a fixed location, the surgeon manipulates the puncture catheter <NUM> to the implant site.

In certain implementations, a distal end of the puncture catheter <NUM> has a slight curvature, with a radially inner and a radially outer side, to conform to the curvature of the coronary sinus. A securing mechanism <NUM> is exposed along the radially outer side of the catheter <NUM> adjacent an extreme distal segment <NUM> that may be thinner than or tapered narrower from the proximal extent of the catheter. Radiopaque markers <NUM> on the catheter <NUM> help the surgeon determine the precise advancement distance for desired placement of the securing mechanism <NUM> within the coronary sinus. In some instances, the radiopaque markers <NUM> are C-shape bands that flank the proximal and distal ends of the securing mechanism <NUM>.

<FIG> shows outward deployment of the securing mechanism <NUM>, which is to be considered a generic structure that is replaced by any of the securing mechanisms disclosed herein and described with reference to <FIG>. Deployment of the securing mechanism <NUM> presses the radially inner curve of the catheter against the luminal wall of the coronary sinus to provide wall apposition. Again, the securing mechanism <NUM> is located adjacent the distal segment <NUM> of the puncture catheter <NUM>. In some examples, the securing mechanism <NUM> extends opposite a needle port <NUM> formed in the radially inner side wall of the catheter. Consequently, the needle port <NUM> abuts the luminal wall and faces toward a tissue wall <NUM> between the coronary sinus and the left atrium. Preferably, guided by visualizing the radiopaque markers <NUM>, the surgeon advances the catheter <NUM> so that the needle port <NUM> is located within about <NUM>-<NUM> into the coronary ostia. This places the subsequent puncture approximately above the "P2" portion of the posterior leaflet of the mitral valve (when looking at the inflow side of the valve the posterior leaflet has P1-P2-P3 cusps in a CCW direction, as seen in <FIG>). The securing mechanism <NUM> may be centered diametrically across the catheter <NUM> from the needle port <NUM>, or as shown may be slightly offset in a proximal direction from the needle port <NUM> to improve leverage.

The curvature at the distal end of the puncture catheter <NUM> aligns to and "hugs" the anatomy within the coronary sinus and orients the needle port <NUM> inward, while the securing mechanism <NUM> holds the catheter <NUM> in place relative to the coronary sinus. Subsequently, as seen in <FIG>, a puncture sheath <NUM> having a puncture needle <NUM> with a sharp tip advances along the catheter <NUM> such that it exits the needle port <NUM> at an angle from the longitudinal direction of the catheter and punctures through the wall <NUM> into the left atrium. The puncture sheath <NUM> has a built-in curvature at the end that "aligns" with the curvature of the anatomy ensuring that the needle <NUM> is oriented inward toward the left atrium. The securing mechanism <NUM> provides rigidity to the system and holds the needle port <NUM> against the wall <NUM> (e.g., the securing mechanism <NUM> provides wall apposition). Preferably, the puncture needle <NUM> has a flattened configuration to form a linear incision and is mounted on the distal end of an elongated wire or flexible rod (not shown) that passes through a lumen of the puncture sheath <NUM>.

Described herein are mechanisms for securing a catheter within a vessel to facilitate puncturing a wall of the vessel with a needle that extends from the catheter. The securing mechanisms described herein can be implemented in a catheter, such as the catheter <NUM> described herein with respect to <FIG>. Additionally, the securing mechanisms described herein are configured to provide the functionality of the generic securing mechanism <NUM> described herein with respect to <FIG>. In other words, the securing mechanisms described below can be used in place of the securing mechanism <NUM> and/or to provide the functionality of the securing mechanism <NUM>, as described herein with respect to <FIG>.

The disclosed securing mechanisms are variations of the securing mechanism <NUM> that is used to secure the guidewire delivery catheter in place to facilitate puncturing the wall between the coronary sinus and the left atrium. The disclosed example securing mechanisms represent an improvement over other securing mechanisms, such as a saline-filled anchor balloon, because there is no risk of balloon burst and there is potential for better catheter securement. If the balloon bursts before the needle is deployed, the needle could deploy into the wrong space potentially causing severe damage to the patient. Moreover, a ruptured balloon could result in an embolism in the patient. The disclosed examples eliminate this risk. Furthermore, the disclosed examples eliminate the need to deflate the balloon, thereby providing a more streamlined puncturing procedure.

The disclosed securing mechanisms include mechanically releasing arms that are actuated to press against the coronary sinus wall to provide apposition for the guidewire delivery catheter, thereby ensuring that the needle punctures properly through the coronary sinus wall and into the left atrial space. The disclosed securing mechanisms comprise a compliant wire that extends outward from the catheter. The wire can be made from a shape memory material such as a nickel titanium alloy (e.g., Nitinol). The securing mechanisms can be activated by pushing the wire (e.g., at a proximal end of the catheter) to extend the securing mechanism out of the catheter. The securing mechanism can be configured to curve outward toward the coronary sinus wall. As the securing mechanism extends out of the catheter, the distal portion of the securing mechanism contacts the coronary sinus wall to secure the distal end of the catheter in place. The more the mechanically releasing arms are advanced, the closer the approach to the wall and the more force placed against the wall to anchor the catheter in place. The mechanically releasing arms can include a plurality of wires that angle or curve toward the vessel wall when deployed, one or more wires that coil away from the catheter to contact the vessel wall when deployed, or a stopper arm with a curved endcap that contacts the vessel wall when deployed. The securing mechanisms can extend from one side of the catheter or from a plurality of sides of the catheter.

The disclosed securing mechanisms are configured for use with a catheter, such as a guidewire delivery catheter. Disclosed herein are guidewire delivery catheters that have a securing mechanism (or anchor member) that includes one or more mechanically releasing arms. A first example securing mechanism includes two or more wires that advance out of a distal portion of the catheter to curve toward and contact the wall of the coronary sinus. A second example securing mechanism includes a wire that advances out of a distal portion of the catheter and coils toward and contacts the wall of the coronary sinus. A third example securing mechanism includes a wire that is advanced out of a distal portion of the catheter and includes a curved endcap at the end of the wire, the wire angled toward the wall of the coronary sinus.

<FIG> illustrate a first example securing mechanism <NUM>. The securing mechanism <NUM> includes two or more wires <NUM> housed along a length of the catheter <NUM> in a delivery configuration, as shown in <FIG>. The two or more wires <NUM> can be advanced out of a distal portion of the guidewire delivery catheter, at wire ports <NUM>, to press against the wall of the coronary sinus to assume a deployment configuration, as shown in <FIG>. The securing mechanism <NUM> can be guided into place as part of the catheter <NUM> to where the needle <NUM> is to puncture the wall of the coronary sinus <NUM>. Once in place, the wires <NUM> are pushed or advanced so that distal portions <NUM> of the wires <NUM> extend out of the distal portion of the catheter <NUM> and curve away from the catheter <NUM>. Continued advancement of the wires <NUM> causes a distal portion <NUM> of each wire <NUM> to contact the wall of the coronary sinus <NUM>, thereby securing the distal end of the guidewire delivery catheter <NUM> in place, as shown in <FIG>. The wires <NUM> can extend along a length of the catheter to a proximal portion of the catheter <NUM> to allow a user to advance the wires <NUM> from outside an operative site. <FIG> illustrate the wire ports <NUM> as being positioned distally to the needle port <NUM>. However, it is to be understood that the wire ports <NUM> can be positioned proximally to the needle port <NUM> or approximately even with the needle port <NUM>. Similarly, although the wire ports <NUM> are positioned at a same distal distance, it is to be understood that each wire port <NUM> can be positioned with different distal distances. The wires <NUM> can be pulled or withdrawn to retract the wires <NUM> into the catheter <NUM> to resume the delivery configuration.

The securing mechanism <NUM> material can be a compliant, wire material such as a nickel titanium alloy (e.g., Nitinol). In some examples, the distal portions <NUM> of the wires <NUM> can include protective material to reduce the likelihood that the distal portions <NUM> cause damage to the wall <NUM>. In certain examples, the distal portions <NUM> of the wires <NUM> are curved to reduce the likelihood that the distal portions <NUM> cause damage to the wall <NUM>.

<FIG> illustrates the wires <NUM> on opposite sides of the catheter <NUM> from one another. However, it is to be understood that the wires <NUM> can be positioned closer together, as shown in <FIG>. In addition, <FIG> illustrates the wires <NUM> such that one wire port <NUM> is on or near the same side of the catheter <NUM> as the needle port <NUM>. In some instances, this may be undesirable due to the wire <NUM> on the same side of the needle <NUM> pushing the catheter <NUM> away from the wall <NUM> that is nearest the needle <NUM>. Thus, in some examples, the wires <NUM> are configured so that the distal portions <NUM> of the wires push the wall <NUM> so that the resulting force is in a direction to provide wall apposition for the catheter <NUM> to push the catheter <NUM> against the wall <NUM> nearest the needle <NUM>. In such examples, the wire ports <NUM> are positioned in a portion of the catheter <NUM> that is opposite to the portion of the catheter <NUM> that includes the needle port <NUM>, an example of which is shown in <FIG> (which represents a cross-section of the catheter <NUM>). For example, the azimuth angles θ2 and θ3 between the needle port <NUM> and the wire ports <NUM> can be at least <NUM> degrees and less than <NUM> degrees. It should be understood that reference to the azimuth angle is a reference to cylindrical coordinates, the azimuth angle measured within a cross-section of the catheter, the cross-section forming a surface perpendicular to a longitudinal axis of the catheter. In some examples, the azimuth angles θ2 and θ3 between the needle port <NUM> and the wire ports <NUM> can be at least <NUM> degrees. In some examples, the azimuth angle θ1 between the two wires <NUM> can be less than <NUM> degrees, between <NUM> degrees and <NUM> degrees, or between <NUM> degrees and <NUM> degrees. In some examples, the wire ports <NUM> are on a radially outer side of the catheter <NUM> while the needle port <NUM> is on a radially inner side of the catheter <NUM>. Some example securing mechanisms <NUM> may include more than two wires and more than two corresponding wire ports. Such wire ports may be distributed on a radially outer side of the catheter <NUM> and/or may be distributed around the catheter <NUM>.

<FIG> illustrate a second example securing mechanism <NUM>. The securing mechanism <NUM> can be a wire that advances out of a wire port <NUM> at a distal portion of the guidewire delivery catheter <NUM>. In a delivery configuration, the wire <NUM> is housed within the catheter <NUM>, as shown in <FIG>. As the wire <NUM> is advanced, a distal portion <NUM> of the wire <NUM> exits the wire port <NUM> and coils to assume a deployment configuration, as shown in <FIG>. The coiled distal portion <NUM> is configured to press against the wall of the coronary sinus <NUM>, as shown in <FIG>. The securing mechanism <NUM> can be guided into place as part of the catheter <NUM> to where the needle <NUM> is to puncture the wall of the coronary sinus <NUM>. Once in place, the wire <NUM> is pushed or advanced (e.g., from a proximal end of the catheter <NUM>) so that a distal portion <NUM> of the wire <NUM> extends out of the wire port <NUM> of the catheter <NUM> and curves away from the catheter <NUM>. Continued advancement of the wire <NUM> causes a distal portion <NUM> of the wire to coil and to contact the wall of the coronary sinus <NUM>, thereby securing the distal end of the guidewire delivery catheter <NUM> in place. The wire <NUM> can extend along a length of the catheter to a proximal portion of the catheter <NUM> to allow a user to advance the wire <NUM> from outside an operative site. The material of the securing mechanism <NUM> can be a compliant, wire material such as a nickel titanium alloy (e.g., Nitinol). In some examples, the material can be shape set so that it coils upon exiting the wire port <NUM> to form the coil portion <NUM> of the wire <NUM>. The wire <NUM> can be pulled or withdrawn to retract the wire <NUM> into the catheter <NUM> to resume the delivery configuration.

The wire port <NUM> is illustrated as being positioned distally to the needle port <NUM>. However, it is to be understood that the wire port <NUM> can be positioned proximally to the needle port <NUM> or approximately even with the needle port <NUM>. In addition, although a single wire <NUM> is illustrated, it is to be understood that a plurality of coiling wires can be used, with configurations similar to the securing mechanism <NUM> described with reference to <FIG>. As in the securing mechanism <NUM>, the wire <NUM> (or at least the coiled portion <NUM> of the wire <NUM>) can be coated with a material to reduce the risk of harming the vessel wall that it contacts.

<FIG> illustrate a third example securing mechanism <NUM>. The securing mechanism <NUM> can be a wire <NUM> that advances out of wire port <NUM> in a distal portion of the guidewire delivery catheter <NUM>, as shown in <FIG>. The securing mechanism <NUM> includes a curved endcap <NUM> at a distal end of the wire <NUM>. The curved endcap <NUM> acts to cover the wire port <NUM> in a delivery configuration, as shown in <FIG>. As such, the curved endcap <NUM> can be shaped to approximately follow a curvature of the catheter <NUM> at the wire port <NUM>. As the wire <NUM> is advanced to change from the delivery configuration to the deployment configuration, a distal portion <NUM> of the wire <NUM> extends at an angle to the catheter <NUM>, as shown in <FIG>. The securing mechanism <NUM> can be guided into place as part of the catheter <NUM> to where the needle <NUM> is to puncture the wall of the coronary sinus <NUM>. Once in place, the wire <NUM> is pushed or advanced (e.g., from a proximal end of the catheter <NUM>) so that a distal portion <NUM> of the wire <NUM> extends out of the wire port <NUM> to extend the curved endcap <NUM> towards the wall of the coronary sinus <NUM>. Continued advancement of the wire <NUM> causes the curved endcap <NUM> to contact the wall of the coronary sinus <NUM>, thereby securing the distal end of the guidewire delivery catheter in place, as shown in <FIG>. The curved endcap <NUM> can be configured to approximately follow the curvature of the wall of the coronary sinus <NUM>. The wire <NUM> can be pulled or withdrawn to retract the wire <NUM> into the catheter <NUM> to resume the delivery configuration. When retracted, the curved endcap <NUM> can return to cover the wire port <NUM> to resume the delivery configuration.

The securing mechanism material can include a compliant, wire material such as a nickel titanium alloy (e.g., Nitinol). The wire <NUM> can be shape set so that it extends at a targeted angle from the catheter <NUM> as the wire is advanced out of the wire port <NUM>. The angle, θ, the distal end of the wire <NUM> makes relative to the longitudinal axis of the catheter <NUM> can be less than or equal to about <NUM> degrees, and can be at least about <NUM> degrees and/or less than or equal to about <NUM> degrees, or at least about <NUM> degrees and/or less than or equal to about <NUM> degrees.

In some examples, the curved endcap <NUM> can include padding made of a material similar to the material of the outer portion of the catheter <NUM>, such as a polyether block amide (e.g., PEBAX®). The curved endcap <NUM> can be sized to provide a surface area for a larger area of wall apposition.

The wire port <NUM> is illustrated as being positioned distally to the needle port <NUM>. However, it is to be understood that the wire port <NUM> can be positioned proximally to the needle port <NUM> or approximately even with the needle port <NUM>. In addition, although a single wire <NUM> is illustrated, it is to be understood that a plurality of wires with curved endcaps can be used, with configurations similar to the securing mechanism <NUM> described with reference to <FIG>.

Each of the securing mechanisms <NUM>, <NUM>, and <NUM> can include marker bands that are radio opaque to indicate a position of the securing mechanism, as visualized using fluoroscopy. In such examples, the marker bands can be opposite the needle <NUM> or needle port <NUM> to ensure that the needle <NUM> is located in a desirable position prior to extending the needle to puncture the wall <NUM>.

Conditional language used herein, such as, among others, "can," "could," "might," "may," "e.g.," and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is intended in its ordinary sense and is generally intended to convey that certain examples include, while other examples do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more examples or that one or more examples necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular example. The terms "comprising," "including," "having," and the like are synonymous, are used in their ordinary sense, and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Conjunctive language such as the phrase "at least one of X, Y and Z," unless specifically stated otherwise, is understood with the context as used in general to convey that an item, term, element, etc. may be either X, Y or Z. Thus, such conjunctive language is not generally intended to imply that certain examples require at least one of X, at least one of Y and at least one of Z to each be present.

It should be appreciated that in the above description of examples, various features are sometimes grouped together in a single example, Figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than are expressly recited in that claim. Moreover, any components, features, or steps illustrated and/or described in a particular example herein can be applied to or used with any other example(s). Further, no component, feature, step, or group of components, features, or steps are necessary or indispensable for each example. Thus, it is intended that the scope of the inventions herein disclosed and claimed below should not be limited by the particular examples described above but should be determined only by a fair reading of the claims that follow.

It should be understood that certain ordinal terms (e.g., "first" or "second") may be provided for ease of reference and do not necessarily imply physical characteristics or ordering. Therefore, as used herein, an ordinal term (e.g., "first," "second," "third," etc.) used to modify an element, such as a structure, a component, an operation, etc., does not necessarily indicate priority or order of the element with respect to any other element, but rather may generally distinguish the element from another element having a similar or identical name (but for use of the ordinal term). In addition, as used herein, indefinite articles ("a" and "an") may indicate "one or more" rather than "one. " Further, an operation performed "based on" a condition or event may also be performed based on one or more other conditions or events not explicitly recited.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example examples belong. It be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Although certain preferred examples and examples are disclosed below, inventive subject matter extends beyond the specifically disclosed examples to other alternative examples and/or uses and to modifications and equivalents thereof. Thus, the scope of the claims that may arise herefrom is not limited by any of the particular examples described herein. The structures, systems, and/or devices described herein may be embodied as integrated components or as separate components. For purposes of comparing various examples, certain aspects and advantages of these examples are described. Not necessarily all such aspects or advantages are achieved by any particular example. Thus, for example, various examples may be carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other aspects or advantages as may also be taught or suggested herein.

The spatially relative terms "outer," "inner," "upper," "lower," "below," "above," "vertical," "horizontal," and similar terms, may be used herein for ease of description to describe the relations between one element or component and another element or component as illustrated in the drawings. It be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, in the case where a device shown in the drawing is turned over, the device positioned "below" or "beneath" another device may be placed "above" another device. Accordingly, the illustrative term "below" may include both the lower and upper positions. The device may also be oriented in the other direction, and thus the spatially relative terms may be interpreted differently depending on the orientations.

Unless otherwise expressly stated, comparative and/or quantitative terms, such as "less," "more," "greater," and the like, are intended to encompass the concepts of equality. For example, "less" can mean not only "less" in the strictest mathematical sense, but also, "less than or equal to.

Reference herein to "catheters," "tubes," "sheaths," "steerable sheaths," and/or "steerable catheters" can refer or apply generally to any type of elongate tubular delivery device comprising an inner lumen configured to slidably receive instrumentation, such as for positioning within an atrium or coronary sinus, including for example delivery catheters and/or cannulas.

Claim 1:
A guidewire delivery catheter (<NUM>) used to implant a shunt between the coronary sinus and the left atrium, the catheter (<NUM>) comprising:
a needle (<NUM>) housed within the catheter in a delivery configuration, the needle (<NUM>) configured to extend out of the catheter (<NUM>) to puncture a vessel wall (<NUM>) in a deployment configuration;
a needle port (<NUM>) through which the needle (<NUM>) extends out of the catheter (<NUM>) to transition from the delivery configuration to the deployment configuration; characterised by
a securing mechanism (<NUM>) housed within the catheter (<NUM>) in a delivery configuration, the securing mechanism (<NUM>) comprising a compliant wire (<NUM>) configured to be advanced out of the catheter (<NUM>) in a deployment configuration; and
a wire port (<NUM>) through which the compliant wire (<NUM>) of the securing mechanism (<NUM>) extends out of the catheter (<NUM>) to transition from the delivery configuration to the deployment configuration,
wherein the compliant wire (<NUM>) includes a curved endcap (<NUM>) at a distal end of the compliant wire (<NUM>) so that the curved endcap of the compliant wire comes into contact with the vessel wall to provide wall apposition for the needle to puncture the vessel wall.