Catheter assembly including radiofrequency emitter

Abstract

Certain embodiments of the present application relate to a catheter assembly for augmenting separation between the parietal and visceral pericardium of a patient's heart. The catheter assembly generally includes an outer catheter, an inner catheter, and a balloon. The outer catheter includes a first lumen and a second lumen, and an aperture in a wall of the outer catheter is in fluid communication with the second lumen. The inner catheter is operable to be received and translated within the first lumen of the outer catheter, and the inner catheter comprises a radiofrequency emitter tip adapted to emit radiofrequency energy. The balloon is sealed to an external surface of the outer catheter, and an interior of the balloon is in fluid communication with the second lumen via the aperture such that the balloon is operable to be inflated via the second lumen.

Description

CATHETER ASSEMBLY INCLUDING RADIOFREQUENCY EMITTERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to US Provisional Patent Application No. 63 / 559,463, filed February 29, 2024, the contents of which are hereby incorporated by reference in their entirety.TECHNICAL FIELD

[0002] The present disclosure generally relates to catheters for performing cardiovascular procedures, and more particularly but not exclusively relates to catheter assemblies for performing cannulation and / or perforation procedures.BACKGROUND

[0003] Cannulation and perforation of cardiac or vascular tissue can be required to obtain intravascular, intracardiac or epicardial access for a variety of cardiac procedures. For example, surgeries for treating atrial or ventricular arrhythmias can require access to the epicardium. Catheters for cardiac ablation procedures or other epicardial electrophysiologic procedures are ubiquitous in treatment processes. Although percutaneous pericardial access for ablation procedures is often desired, such procedures are limited by a high rate of periprocedural complications related to bleeding and / or inadvertent cardiac perforation. Moreover, percutaneous procedures to recanalize occluded vessels (arteries or veins) may require the creation of small channels through the obstruction to allow for percutaneous recanalization with balloon angioplasty and / or stenting.

[0004] With reference to Figs. 1 and 2, one current treatment option for epicardial mapping and ablation of cardiac arrhythmias involves percutaneous pericardial access via an incision made just below the xiphoid process 82, which projects from the sternum 81. In this approach, a needle or catheter 70 is inserted through the subxiphoid incision to access the pericardial space 93 while avoiding contacting and / or damaging the liver 83. This approach is minimally invasive and provides direct access to the pericardial space 93 and epicardium. Such direct access via the subxiphoid access route 84 typically results in a cost-effective procedure and a fast recovery for the patient. However, this approach has relatively high complication rates due to a lack of- 1 -CCF06-GN009 / TSH 170230087acceptable visibility (e.g., under X-ray) and a lack of dedicated technology. More specifically, obtaining pericardial access often involves a blind puncture due to the dimensions of the pericardial space 93 (i.e., the distance between the parietal pericardium 92 and visceral pericardium 94). This can result in inadvertent cardiac perforations, pericardial bleeding, cardiac tamponade, and / or injury to surrounding tissues (e.g., liver, lungs, etc.), vessels, and nerves. To prevent this, the procedure generally requires an excessive amount of time to obtain acceptable visibility via fluoroscopy, thereby lengthening the overall time of the procedure. For these reasons and others, there remains a need for further developments in this field.SUMMARY

[0005] Certain embodiments of the present application relate to a catheter assembly for augmenting separation between the parietal and visceral pericardium of a patient’s heart. The catheter assembly generally includes an outer catheter, an inner catheter, and a balloon. The outer catheter includes a first lumen and a second lumen, and an aperture in a wall of the outer catheter is in fluid communication with the second lumen. The inner catheter is operable to be received and translated within the first lumen of the outer catheter, and the inner catheter comprises a radiofrequency emitter tip adapted to emit radiofrequency energy. The balloon is sealed to an external surface of the outer catheter, and an interior of the balloon is in fluid communication with the second lumen via the aperture such that the balloon is operable to be inflated via the second lumen. Further embodiments, forms, features, and aspects of the present application shall become apparent from the description and figures provided herewith.- 2 -CCF06-GN009 / TSH 170230087BRIEF DESCRIPTION OF THE FIGURES

[0006] Fig. 1 illustrates insertion of a catheter or needle for percutaneous pericardial access via a subxiphoid access route.

[0007] Fig. 2 is a sagittal image of a chest cavity that further illustrates the subxiphoid access route.

[0008] Fig. 3 is a perspective illustration of a catheter assembly according to certain embodiments.

[0009] Fig. 4 is a partially exploded view of the catheter assembly illustrated in Fig. 3.

[0010] Fig. 5 is a partially exploded view of an introducer according to certain embodiments.

[0011] Fig. 6 is a partially exploded view of an outer catheter assembly according to certain embodiments.

[0012] Fig. 7 is a cross-sectional view of an outer catheter, taken along the line VII- VII in Fig. 6.

[0013] Fig. 8A is a plan view of a distal end portion of an outer catheter according to certain embodiments.

[0014] Fig. 8B is a cutaway view of the distal end portion of the outer catheter.

[0015] Fig. 8C is a perspective view of the distal portion of the outer catheter.

[0016] Fig. 8D is a plan view of a distal portion of the catheter assembly.

[0017] Fig. 9 is a perspective illustration of an inner catheter assembly according to certain embodiments.

[0018] Fig. 10A is a cutaway view of a radiofrequency (RF) catheter tip according to certain embodiments.

[0019] Fig. 10B is a cross-sectional illustration of a wall of the RF catheter tip illustrated in Fig. 10A.

[0020] Fig. 11 A is a cutaway view of a radiofrequency (RF) catheter tip according to certain embodiments.

[0021] Fig. 1 IB is a cross-sectional illustration of a wall of the RF catheter tip illustrated in Fig.11 A.

[0022] Fig. 12 is a perspective illustration of a distal portion of an inner catheter having a guidewire extending therethrough.

[0023] Fig. 13 is a cross-sectional illustration of the catheter assembly in an assembled state.- 3 -CCF06-GN009 / TSH 170230087

[0024] Fig. 14 illustrates the inner catheter extending into the pericardial space between the parietal pericardium and the visceral pericardium.

[0025] Fig. 15 is a medical image illustrating separation of the pericardial layers following introduction of a fluid via the inner catheter.

[0026] Fig. 16 is a plan view of a catheter assembly according to certain embodiments.

[0027] Fig. 17 is a cross-sectional view of the catheter assembly illustrated in Fig. 16.

[0028] Fig. 18 is a longitudinal cross-sectional view of a distal end portion of the catheter assembly illustrated in Fig. 16.

[0029] Fig. 19 is a transverse cross-sectional view of the distal end portion of the catheter assembly illustrated in Fig. 16.

[0030] Fig. 20 is a plan view of a catheter assembly according to certain embodiments.

[0031] Fig. 21 illustrates a patient’s heart during introduction of the catheter assembly illustrated in Fig. 20.

[0032] Fig. 22 illustrates inflation of a balloon and perforation of a cardiac wall with the catheter assembly illustrated in Fig. 20.

[0033] Fig. 23 illustrates introduction of an inner catheter to the pericardial space and insufflation of the pericardial space.

[0034] Fig. 24 illustrates access to the pericardial space via the subxiphoid approach.- 4 -CCF06-GN009 / TSH 170230087DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0035] Although the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described herein in detail. It should be understood, however, that there is no intent to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives consistent with the present disclosure and the appended claims.

[0036] References in the specification to “one embodiment,” “an embodiment,” “an illustrative embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may or may not necessarily include that particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. It should further be appreciated that although reference to a “preferred” component or feature may indicate the desirability of a particular component or feature with respect to an embodiment, the disclosure is not so limiting with respect to other embodiments, which may omit such a component or feature. 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 to implement such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0037] Additionally, it should be appreciated that items included in a list in the form of “at least one of A, B, and C” can mean (A); (B); (C); (A and B); (B and C); (A and C); or (A, B, and C). Similarly, items listed in the form of “at least one of A, B, or C” can mean (A); (B); (C); (A and B); (B and C); (A and C); or (A, B, and C). Items listed in the form of “A, B, and / or C” can also mean (A); (B); (C); (A and B); (B and C); (A and C); or (A, B, and C). Further, with respect to the claims, the use of words and phrases such as “a,” “an,” “at least one,” and / or “at least one portion” should not be interpreted so as to be limiting to only one such element unless specifically stated to the contrary, and the use of phrases such as “at least a portion” and / or “a portion” should be interpreted as encompassing both embodiments including only a portion of such element and embodiments including the entirety of such element unless specifically stated to the contrary.

[0038] In the drawings, some structural or method features may be shown in certain specific arrangements and / or orderings. However, it should be appreciated that such specific- 5 -CCF06-GN009 / TSH 170230087arrangements and / or orderings may not necessarily be required. Rather, in some embodiments, such features may be arranged in a different manner and / or order than shown in the illustrative figures unless indicated to the contrary. Additionally, the inclusion of a structural or method feature in a particular figure is not meant to imply that such feature is required in all embodiments and, in some embodiments, may be omitted or may be combined with other features.

[0039] With reference to Figs. 3 and 4, illustrated therein is a catheter assembly 100 according to certain embodiments. As described herein, the catheter assembly 100 can be used to augment the separation between the parietal and visceral pericardium (via insufflation / inj ection) to greatly enhance visibility during the aforementioned xiphoid process approach. In the illustrated embodiment, the catheter assembly 100 is a nested assembly of catheters, including an inner assembly 102 selectively receivable in an outer assembly 104. The inner and outer assemblies 102, 104 have inner and outer catheters 106, 108, respectively, wherein the inner catheter 106 is insertable into an introducer 110 of the outer assembly 104 for translating within the outer catheter 108. Of note, the inner catheter 106 has a maximum outer diameter smaller than that of the outer catheter 108 to permit smooth translation of the inner catheter 106 within the outer catheter 108. For example, the inner catheter 106 may have an outer diameter of 1.8 French gauge (Fr), of 1.5 Fr, or of 1 Fr, while the outer catheter 108 may have an outer diameter of about 4 Fr.

[0040] In the illustrated form, each of the catheters 106, 108 is flexible and can have an outer surface with a low coefficient of friction and / or a hydrophilic coating. Additionally, the inner catheter 106 is longer than the outer catheter 108 such that a distal end portion 107 of the inner catheter 106 can project beyond a tip 148 of a distal end portion 109 of the outer catheter 108. For example, the outer catheter 108 may have a length between 130 cm and 180 cm, while the inner catheter 106 may have an overall length that is greater (e.g., by 10 cm to 20 cm) than that of the outer catheter 108. In the illustrated form, the outer catheter 108 has a preformed bend 181 at a distal portion thereof. For example, the bend 181 may be of about 45° degrees relative to a longitudinal axis of the outer catheter 108. Notably, this preconfigured bend 181 is likewise flexible, which may facilitate navigation of the outer catheter 108 in more tortuous vascular anatomy. Moreover, while the illustrated inner catheter 106 likewise includes a bend 182 at a distal portion thereof, this bend 182 is not necessarily preformed, and the inner catheter 106 is- 6 -CCF06-GN009 / TSH 170230087instead flexible so as to conform to the shape of the outer catheter 108. In certain forms, at least a portion of one or both of the catheters 106, 108 may be radiopaque. In certain forms, an entirety of the inner catheter 106 and / or an entirety of the outer catheter 108 may be radiopaque.

[0041] With additional reference to Fig. 5, the introducer 110 includes a branched manifold 112 having three branch inlets 120, which are respectively connectable to a catheter access port 114, a first fluid assembly 116, and a second fluid assembly 118. The access port 114 provides a guide for inserting the inner catheter 106 into the outer assembly 104 via the manifold 112. As described herein, the first and second fluid assemblies 116, 118 are connectable to fluid sources 117, 119 for injecting fluid into the outer catheter 108, also via the manifold 112.

[0042] Each of the access port 114 and the first and second fluid assemblies 116, 118 is connectable to a corresponding branch inlet 120 of the manifold 112 via conventional connectors (e.g., male-female connections, Luer fittings, etc.). In the illustrated form, each of the first and second fluid assemblies 116, 118 includes a tube 122 extending between a valve 124 and a fitting 126. Of note, the first fluid assembly 116 is directly connected to its corresponding branch inlet 120 of the manifold 112, whereas the second fluid assembly 118 is connected to its corresponding branch inlet 120 via an intermediate three-way (Y-) connector 128. The three- way connector 128 includes a convergent sensor inlet port 130 for receiving a sensor tip 141 (Fig. 13) of a pressure sensor 140 to be translated within the outer catheter 108, as will be further discussed below.

[0043] With additional reference to Fig. 6, an exit port 132 of the manifold 112 is connectable to and configured to be provided in fluid communication with a proximal end portion 182 of the outer catheter 108. As used herein, the term “proximal” refers to an end adjacent to or in the direction toward the operator, whereas the term “distal” refers to the opposite end, or in a direction away from the operator. Fluid communication between the exit port 132 and the outer catheter proximal end portion 182 may be established, for example, by a winged, female, Luer- type connector 134. A Luer-lock 136 may be provided to enhance the connection between the winged connector 134 and the manifold exit port 132. It should be appreciated, however, that other known connectors may be used to connect and fluidly couple the outer catheter 108 and the manifold 112. In the illustrated embodiment, an inflatable balloon 138 is provided to the distal end portion 109 of the outer catheter 108. The balloon 138 is inflatable via fluid supplied from the second fluid assembly 118, as will be discussed further below. When fully inflated (as- 7 -CCF06-GN009 / TSH 170230087shown in Fig. 6), an outer diameter of the balloon 138 may be at least 9 Fr, or in a range of 9 Fr to 15 Fr.

[0044] With additional reference to Fig. 7, the outer catheter 108 defines a first lumen 142 and a second lumen 144 that is fluidically isolated from the first lumen. As described herein, the first lumen 142 is provided for receiving the inner catheter 106 in order to deliver it to a targeted location within the heart 90. The first lumen 142 can be used as a conduit for delivering or evacuating fluids to / from the vicinity of the distal end portion 109 of the outer catheter 108. Separately, the second lumen 144 is provided to supply inflation fluid for inflating the balloon 138, and may further receive therein a pressure sensor 140 (Fig. 13). In the illustrated form, the first lumen 142 is circular in cross-section and is radially offset from a centerline of the outer catheter 108 such that the first lumen 142 is not coaxial with the outer catheter 108. The second lumen 144 of the illustrated embodiment is crescent-shaped in cross-section and is disposed radially adjacent to the first lumen 142. It is to be understood that the cross-sectional shapes of the first and second lumens 142, 144 are not limited to the aforementioned, and that other cross- sectional shapes are contemplated. The first lumen 142 extends the entire length of the outer catheter 108 (i.e., from its proximal end portion 182 to its distal tip 148). In contrast, the second lumen 144 does not extend the entire length of the outer catheter 108. Rather, as described in further detail below, the second lumen 144 extends from the proximal end portion 182 of the outer catheter 108 and terminates prior to reaching the distal tip 148 of the outer catheter 108.

[0045] With additional reference to Figs. 8A-8C, an aperture 146 is provided in the outer catheter 108 and is proximally offset from the distal tip 148 of the outer catheter 108. More specifically, the aperture 146 is formed in a sidewall 174 that defines an outer surface 175 of the outer catheter 108. The aperture 146 provides fluid communication with the second lumen 144 (as shown in FIG. 8B) through a wall of the outer catheter 108. The tip 148 of the outer catheter 108 is formed of a material that is radiopaque and includes an opening defining an open end 143 of the first lumen 142. In contrast, as mentioned above, no opening is provided at the tip 148 for accessing the second lumen 144. Rather, the second lumen 144 terminates at or optionally just distal of the aperture 146, which is proximally spaced from the tip 148.

[0046] With additional reference to Fig. 8D, the balloon 138 is shown in a fully inflated configuration. The balloon 138 includes distal and proximal mouths 150, 152 that are attached (e.g., sealed) to an outer surface 108' of the outer catheter 108 such that the inflated balloon 138- 8 -CCF06-GN009 / TSH 170230087is essentially in the form of a toroid. The distal mouth 150 is located distally from the aperture 146 along the length of the outer catheter 108, and the proximal mouth 152 is located proximally from the aperture 146. Accordingly, with the mouths 150, 152 being circumferentially sealed to the outer surface 108' of the outer catheter 108, the interior of the balloon 138 is provided in fluid communication with the second lumen 144 (via the aperture 146), and thus the balloon 138 is inflatable via injection of inflation fluid from the second fluid assembly 118. When the balloon 138 is fully inflated, a distal end 154 of the balloon 138 preferably extends to, but does not extend beyond, the tip 148 of the outer catheter 108. In certain forms, the outer catheter 108 may include one or more radiopaque markers 172, for example at or near one or both of the mouths 150, 152. The radiopaque marker(s) 172 may be viewed with conventional imaging techniques to indicate the position of the balloon 138. Additionally or alternatively, the outer catheter 108 may include radiopaque markers at other locations, for example to indicate the position of the tip of the outer catheter 108.

[0047] With additional reference to Fig. 9, the inner assembly 102 includes the inner catheter 106 and a handle 156 at the proximal end 183 of the inner catheter 106. The inner catheter 106 has a lumen 158 extending between its proximal and distal ends, and the lumen 158 is in fluid communication with an interior of the handle 156. The lumen 158 is configured to receive fluid (e.g., CO2, contrast agent, therapeutics, saline, etc.) from an external source 161, for example via the handle 156. The external source 161 can be selectively provided in fluid communication with the interior of the handle 156 (and thus with the lumen 158) via an entry port 160 of the handle 156. The lumen 158 is also configured to receive a coronary guidewire 162, which can be introduced via the entry port 160.

[0048] The inner catheter 106 can include a mechanical reinforcement to enhance its structural rigidity. For example, the inner catheter 106 can include at least one braid, coil, or other such mechanical insert provided at desired locations within the lumen 158 (e.g., at spaced intervals). If so, the inner catheter 106 can also have an inner liner (e.g., a hollow tube) provided within the lumen 158 to entrap said reinforcement between an inner circumferential surface that defines the lumen 158 and an external surface of the liner.

[0049] In the illustrated form, the inner catheter 106 has a radio frequency (RF) emitter tip 164 at its distal end. The RF emitter tip 164 is configured to emit radiofrequency energy, such as 5- 50W. It is also contemplated that the RF energy may be in a range of 10-25W, or in a range of- 9 -CCF06-GN009 / TSH 17023008725-40W. In certain embodiments, the RF emitter tip 164 may emit short bursts of RF energy, for example burst of less than one second at a power of 20W to 30W. In certain forms, the RF energy may be provided at a power and / or frequency selected to ensure that the size of the perforation corresponds to the diameter of the RF emitter tip 164. The RF emitter tip 164 is preferably radiopaque. The RF emitter tip 164 includes electrical connections that can be connected to an external RF generator via wiring extending out of a wiring sheath 166 of the handle 156.

[0050] With additional reference to Figs. 10A, 10B, 11 A, and 1 IB, illustrated therein is an embodiment of the RF emitter tip 164. The tip 164 has a hollow substantially cylindrical configuration, and the thickness of the wall defining the tip 164 tapers radially inward towards a distal surface 168, which in the illustrated form is circular and concentric with the cylindrical tip 164. It should be appreciated, however, that the taper may be omitted. In another alternative, the RF tip 164 may be closed at its distal end (e.g., provided with a dome or planar surface that defines the distal surface 168). In these forms and others, the lumen 158 of the inner catheter 106 may be omitted. The distal surface 168 is configured to directly contact tissue of the heart to perforate said tissue when radiofrequency energy is emitted. In certain forms (Figs. 10A and 10B), the distal surface 168 is planar. In other forms (Figs. 11A and 1 IB), the distal surface 168 is rounded. Additionally, the distal surface 168 may have another configuration, as desired.

[0051] Briefly returning to Fig. 9, a plurality of indicia or markings 170 may be provided on an external surface of the inner catheter 106, for example near the handle 156. The markings 170, when aligned with a reference point (e.g., the access port 114), provide a visual indication to an operator as to how far the distal end of the inner catheter 106 has translated through the first lumen 142 or beyond the tip 148 of the outer catheter 108. As discussed further below, at least one of the markings 170 may provide an indication when the RF emitter tip 164 of the inner catheter 106 extends a preselected distance (e.g., 3 mm) beyond the distal tip 148 of the outer catheter 108.

[0052]

[0053] The procedure may involve an operator making an incision to obtain peripheral vascular access, for example via the femoral vein. Next, a guidewire is introduced into the femoral vein (or other accessed peripheral vessel) and advanced therethrough to the vena cava (preferably the inferior vena cava) and from there into the right atrium. After a distal end of the guidewire- 10 -CCF06-GN009 / TSH 170230087reaches the atrium, a sheath (e.g., a sheath with a diameter greater than 5 Fr) is advanced over the guidewire until its distal end likewise reaches the atrium. With the distal end of the sheath positioned close to the target atrial wall, the guidewire may be removed.

[0054] The procedure also involves preparing the catheter assembly 100 for deployment. Such preparation may involve insertion of a sensor tip 141 of the pressure sensor 140 into the sensor inlet port 130 of the introducer 110, and the sensor tip 141 may be translated within the second lumen 144 of the outer catheter 108. Alternatively, the outer catheter 108 can be manufactured such that the sensor tip 141 is embedded therein (e.g., within its wall at a location corresponding to the illustrated second lumen 144) and such that the distal end of the sensor tip 141 is positioned at or adjacent the aperture 146. Thereafter, the distal end portion 109 of the outer catheter 108 is inserted into the proximal end of the sheath and advanced until its distal tip 148 reaches the target structure to perforate. At this stage, the balloon 138 is in a deflated state. Once the distal end portion 109 of the outer catheter 108 (including the balloon 138) emerges from the sheath, the balloon 138 can be inflated.

[0055] To inflate the balloon 138, the valve 124 of the second fluid assembly 118 may be connected to an inflation fluid source 119. Thereafter, the valve 124 may be opened to deliver inflation fluid into the manifold 112 via its corresponding branch inlet 120, and thereafter into the second lumen 144 of the outer catheter 108. The inflation fluid flows along the length of the outer catheter 108 towards the distal end portion 109 and enters the balloon 138 via the aperture 146, thereby inflating the balloon 138.

[0056] The pressure sensor 140 may provide real-time feedback of the fluid pressure within the second lumen 144 and / or the balloon 138. Additionally, the pressure sensor 140 may be connected to a controller 171 that regulates the delivery of inflation fluid from the inflation fluid source 119 (e.g., by controlling the inflation valve 124) and predicts the size of the balloon 138, thereby automating the inflation fluid delivery and providing a predictable size of the balloon 138. In certain forms, the pressure sensor 140 can help prevent accidental perforation. For example, the controller 171 can monitor the sensed pressure relative to a predetermined threshold pressure and emit an alarm in response to the sensed pressure exceeding the predetermined threshold pressure. With the balloon 138 inflated, the outer catheter 108 can be repositioned if necessary to ensure that the balloon 138 makes appropriate contact with the chamber of interest (e.g., the right atrial appendage).- 11 -CCF06-GN009 / TSH 170230087

[0057] In certain forms, acceptable positioning of the inflated balloon 138 within the chamber of interest may be confirmed in a conventional manner. For example, the operator can confirm the position of the balloon 138 via intracardiac echocardiogram, fluoroscopy, contrast injection or other conventional techniques. If a contrast agent is employed, the same may be injected via the first lumen 142 of the outer catheter 108. For example, the valve 124 of the first fluid assembly 116 can be connected to an external fluid source 117 containing a contrast agent. When the valve 124 of the first fluid assembly 116 is opened, contrast agent flows into the manifold 112, through the outer catheter 108 via the first lumen 142, and is eluted via the tip 148 into the chamber of interest (e.g., the right atrial appendage). The contrast agent increases the contrast of structures (e.g., the distal tip 148 of the outer catheter 108 and / or the balloon 138) within the chamber of interest under medical imaging (e.g., X-ray).

[0058] After confirmation of acceptable placement of the balloon 138, the distal end of the inner catheter 106 is inserted into the access port 114 of the introducer 110 and advanced through the first lumen 142 of the outer catheter 108. The inner catheter 106 is advanced until the RF emitter tip 164 emerges from the tip 148 of the outer catheter 108 and contacts a desired or targeted position on the cardiac wall or vascular structure. Next, radiofrequency energy is emitted from the RF emitter tip 164 in order to perforate the cardiac wall or vascular structure at the targeted position. As shown in Fig. 14, this perforation can permit access into the pericardial space 93 between the parietal pericardium 92 and the visceral pericardium 94. After perforation, the inner catheter 106 can be gently advanced.

[0059] While the aforementioned method of using the catheter assembly 100 is made with reference to accessing the pericardial space 93, it should be appreciated that the catheter assembly 100 may be used in other procedures. In one example, the catheter assembly 100 can be used to recanalize obstructed arteries or veins. For example, an operator may obtain arterial or venous access and advance a guidewire to a targeted obstructed vessel. Next, the inner catheter 106 may be introduced such that the RF emitter tip 164 contacts the vascular obstruction. Subsequently, radiofrequency energy (e.g., short pulses of radiofrequency) may be used to create a micro-channel within the obstructed vessel such that the inner catheter 106 can be passed therethrough and to the other side of the obstruction. Once the vascular occlusion has been crossed, additional interventions can be performed (e.g., balloon dilation and / or stenting).- 12 -CCF06-GN009 / TSH 170230087

[0060] In another example, the catheter assembly 100 may be used to facilitate trans-coronary sinus chemical ablation, for example with ethanol. By way of illustration, an operator may obtain femoral vein access and advance a guidewire to the right atrium. Next, a sheath is introduced within the coronary sinus, and the operator advances the outer catheter 108 within the sheath and inflates the balloon 138 to obtain a detailed coronary sinus venogram and select a target vessel for ethanol injection. This can be either an atrial venous branch (e.g., for atrial fibrillation ablation procedures) or a ventricular branch (e.g., for ventricular tachycardia or premature ventricular contraction ablation procedures). After the target vessel has been identified, the balloon 138 is deflated and the outer catheter 108 is advanced to the target vessel. Once positioned within the target vessel, the balloon 138 is inflated to occlude the vessel. Notably, the balloon 138 can increase its size progressively to facilitate occlusion of different vessel sizes. Thereafter, confirmation of effective vessel occlusion can be obtained with contrast injection from the outer catheter 108. Once the target vessel occlusion has been confirmed, a chemical ablative such as ethanol may be injected via the outer catheter 108 to achieve the desired chemical ablation.

[0061] Returning now to the aforementioned method in relation to the figures, advancement of the inner catheter 106 is assisted by the coronary guidewire 162 and the markings 170 provided on the external surface of the inner catheter 106. More specifically, the coronary guidewire 162 is inserted into the entry port 160 of the handle 156 and through the lumen 158 of the inner catheter 106 until a distal end of the coronary guidewire 162 reaches the target site (e.g., pericardial space, or other end of a venous or arterial obstruction). Next, the inner catheter 106 can be advanced over the coronary guidewire 162.

[0062] As mentioned above, at least one of the markings 170 may provide an indication when the distal end portion 107 of the inner catheter 106 extends a preselected distance, such as 3 mm, beyond the tip 148 of the outer catheter 108. For example, the operator can advance the inner catheter 106 until the corresponding marking 170 aligns with a reference point on the introducer 110 (e.g., the access port 114). With the marking 170 and the reference point aligned, the operator is assured that the distal end portion 107 of the inner catheter 106 extends the preselected distance (e.g., 3 mm) beyond the tip 148 of the outer catheter 108, equating to placement of the distal end portion 107 of the inner catheter 106 within the target cardiac wall, chamber or vessel. Notably, contrast agent and suitable intraoperative imaging can be employed- 13 -CCF06-GN009 / TSH 170230087to ensure proper placement. For example, an external source containing contrast agent can be connected to the entry port 160 of the handle 156 for injecting contrast agent via the inner catheter 106 (through the lumen 158 thereof) into the pericardial space 93. Proper placement of the distal end portion 107 of the inner catheter 106 can then be confirmed under medical imaging.

[0063] When properly positioned, the inner catheter 106 can be locked in the operative position so as to hinder / prevent unintended advancement / withdrawal of the inner catheter 106 and / or inadvertent perforation of other structures. For example, the outer assembly 104 (e.g., the outer catheter 108, the introducer 110, etc.) may include a locking mechanism 172 (e.g., a Tuohy-Borst adapter) to lock the position of the inner catheter 106 with respect to the outer catheter 108. With the placement of the distal end 107 of the inner catheter 106 in the target site confirmed and the inner catheter 106 optionally locked in place, introduction of fluid (e.g., contrast agent, CO2, or therapeutics) may begin. Such fluid can again be introduced via the lumen 158 of the inner catheter 106.

[0064] With additional reference to Fig. 15, insufflating the pericardial space 93 augments the separation between the parietal pericardium 92 and the visceral pericardium 94, which enhances the operator’s visibility of the pericardial anatomy under medical imaging. With this enhanced visibility, subxiphoid percutaneous epicardial access (e.g., via standard techniques) can now be performed more reliably while minimizing unintended punctures. Notably, the fluid inflating the pericardial space can be aspirated (if necessary) from the standard subxiphoid access point.

[0065] The disclosed nested catheter assembly 100 and its method of use may provide improvements to one or more areas of the standard subxiphoid percutaneous epicardial access approach for mapping and ablation procedures. For example, the catheter assembly 100 may reduce the risks of complications (e.g., bleeding and / or inadvertent cardiac perforation) by augmenting the separation between the parietal pericardium and the visceral pericardium to enhance the operator’s visibility while obtaining epicardial access via the subxiphoid approach. Additionally or alternatively, the enhanced visibility may reduce the amount of time that medical imaging (e.g., fluoroscopy) is required, thereby reducing the overall time of the procedure.

[0066] With additional reference to Figs. 16-19, illustrated therein is a catheter assembly 200 according to certain embodiments. The catheter assembly 200 is substantially similar to the catheter assembly 100, and similar reference characters are used to indicate similar elements and- 14 -CCF06-GN009 / TSH 170230087features. For example, the catheter assembly 200 generally includes an inner catheter 206, an outer catheter 208, an introducer 210, and a balloon 238, which respectively correspond to the inner catheter 106, outer catheter 108, introducer 110, and balloon 138 of the above-described catheter assembly 100. In the interest of conciseness, the following description of the catheter assembly 200 focuses primarily on features different from those described above with reference to the catheter assembly 100.

[0067] As with the above-described inner assembly 102, the inner assembly 202 of the illustrated embodiment includes the inner catheter 206, which has a handle 256 mounted at its proximal end. In the current embodiment, however, the inner assembly 202 includes a hypodermic tube or hypotube 292 and a liner 294 (e.g., a polyimide liner) nested within the inner catheter 206. The hypotube 292 electrically connects the RF emitter tip 264 to an external RF generator 296, and the liner 294 is provided as an insulator. In other words, the hypotube 292 serves as an electrical conductor that transmits radiofrequency energy from the external generator 296 to the RF emitter tip 264. In certain embodiments, the hypotube 292 can enhance the structural rigidity of the inner catheter 206.

[0068] In the illustrated embodiment, the hypotube 292 and the liner 294 are coaxial with the inner catheter 206 and are arranged such that the hypotube 292 is disposed between (i.e., radially interposing) the liner 294 and the wall of the inner catheter 206. Notably, the hypotube 292 and the liner 294 extend axially from the handle 256 at the proximal end of the inner catheter 206 to the RF emitter tip 264 at the distal end of the inner catheter 206. In this configuration, the liner 294 defines the lumen 258 configured to receive the guidewire 262 and / or fluid (e.g., CO2, contrast agent, therapeutics, saline, etc.) from an external source. In another example embodiment, the hypotube 292 can be integrally formed with the RF emitter tip 264 such that the hypotube 292 itself defines the RF emitter tip 264 at the distal end of the hypotube 292. In certain forms, the hypotube 292 may include a helical or spiral laser cut. The dimensions of the helical gaps, the pitch of the helical cuts, and / or the material may be selected to fine-tune the rigidity / flexibility of the catheter hypotube 292 as desired.

[0069] With additional reference to Fig. 20, illustrated therein is a catheter assembly 300 according to certain embodiments. The catheter assembly 300 is substantially similar to the catheter assembly 100, and similar reference characters are used to indicate similar elements and features. For example, the catheter assembly 300 generally includes an inner catheter 306, an- 15 -CCF06-GN009 / TSH 170230087outer catheter 308, an introducer 310, and a balloon 338, which respectively correspond to the inner catheter 106, outer catheter 108, introducer 110, and balloon 138 of the above-described catheter assembly 100.

[0070] In the catheter assembly 300, a contrast fluid source 317 is in fluid communication with the first lumen of the outer catheter 308 via a valve 324 that permits contrast fluid to flow through the introducer 310 to the outer catheter 308. Similarly, an inflation fluid source 319 is in fluid communication with the second lumen of the outer catheter 308 such that the balloon 338 can be inflated via the second lumen. An external source 361 is configured to provide fluid (e.g., CO2, contrast agent, therapeutics, saline, etc.) to the lumen of the inner catheter 306 via the handle 356. Additionally, an RF source 396 is in electrical communication with the RF emitter tip 364 of the inner catheter 306 such that the emitter tip 364 is operable to emit RF energy generated by the RF source 396.

[0071] With additional reference to Figs. 21-24, illustrated therein are portions of the catheter assembly 300 during an example surgical procedure. During the procedure, the outer catheter 308 is advanced to a selected location within the heart 90, as illustrated in Fig. 24. While other forms are contemplated, in the illustrated embodiment, the outer catheter 308 has been advanced to the right atrial appendage via the femoral artery. With the distal end portion 309 of the outer catheter 308 in the desired location, fluid is introduced from the inflation lumen source 319 to the balloon 338 via the second lumen of the outer catheter 308 to thereby inflate the balloon 338 as illustrated in Fig. 25.

[0072] With the balloon 338 inflated (Fig. 22), the distal end portion 309 of the outer catheter 308 is anchored at the selected location within the heart 90. The inner catheter 306 may be advanced within the first lumen of the outer catheter 308 until the RF emitter tip 364 projects beyond the distal tip 348 of the outer catheter 308 by a desired distance. For example, the inner catheter 306 may be advanced until one of the markings 370 aligns with a corresponding landmark to thereby indicate that the inner catheter 306 projects the desired distance from the distal tip 348. The RF source 396 may then be activated to cause the RF emitter tip 364 to emit RF energy that perforates the cardiac wall 95 to provide access to the pericardial space 93.

[0073] After perforating the cardiac wall 95, the inner catheter 306 may be advanced to extend through the perforation 96 and into the pericardial space 93 by a desired distance, as illustrated in Fig. 23. Fluid (e.g., CO2) may then be introduced to the pericardial space 93. For example, a- 16 -CCF06-GN009 / TSH 170230087user may activate the external fluid source 361 to insufflate the pericardial space 93 via the lumen of the inner catheter 306. With the pericardial space 93 insufflated, the procedure may continue with access to the pericardial space 93 via the traditional subxiphoid route, as illustrated in Fig. 24.

[0074] With continued reference to Figs. 21-24, an example use case for the catheter assembly 300 will now be described. In the example use case, the surgeon obtains femoral vein access and advances a guidewire to the right atrium of the heart 90. The surgeon then introduces a sheath to the right atrium. For example, the sheath may be a commercially available >5 Fr non-deflectable or deflectable sheath. The surgeon then positions the sheath at the ostium of the right atrial appendage (RAA). With the sheath in place, the surgeon advances the catheter (e.g., a 4 Fr catheter) within the sheath and inflates the distal balloon 338 at the ostium of the right atrial appendage. The catheter 308 (with the balloon 338 inflated) can be advanced safely within the right atrial appendage to achieve good contact with its wall.

[0075] Once good contact with the wall of the right atrial appendage is confirmed (e.g., with intracardiac echo, fluoroscopy and / or contrast injection from the outer sheath), a microcatheter 306, e.g., a microcatheter with a diameter of 1 Fr to 1.5 Fr, is introduced within the sheath and locked in place once 3 mm of its distal end is exposed. With the microcatheter 306 locked in place, RF energy is delivered from the RF emitter tip 364 to achieve perforation of the wall of the right atrial appendage. When locked at the proximal end of the 4 Fr outer sheath, the microcatheter will only advance for 3 mm, thereby preventing inadvertent puncture of the parietal pericardium 92.

[0076] Confirmation of position within the pericardial cavity can be achieved with contrast injection from the microcatheter. A coronary guidewire can be introduced within the microcatheter and positioned more distally within the pericardial cavity. The microcatheter can be advanced over the guidewire within the pericardial cavity. Contrast and / or CO2 can be injected / insufflated within the pericardial space 93 to augment the separation between the parietal pericardium 92 and the visceral pericardium 93 and facilitate subxiphoid percutaneous epicardial access with a standard technique. Once subxiphoid epicardial access is obtained, the microcatheter 306 is removed from the pericardial cavity and the mapping / ablation procedure is continued with the standard approach. The contrast and / or CO2 insufflated within the pericardial space can be aspirated (if needed) from the standard subxiphoid access.- 17 -CCF06-GN009 / TSH 170230087

[0077] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected.

[0078] It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and / or “a portion” is used the item can include a portion and / or the entire item unless specifically stated to the contrary.- 18 -CCF06-GN009 / TSH 170230087

Claims

WHAT IS CLAIMED IS:

1. A catheter assembly for augmenting separation between the parietal and visceral pericardium of a patient’s heart, the catheter assembly comprising: an outer catheter comprising a first lumen and a second lumen, wherein an aperture in a wall of the outer catheter is in fluid communication with the second lumen; an inner catheter operable to be received and translated within the first lumen of the outer catheter, and wherein the inner catheter comprises a radiofrequency emitter tip adapted to emit radiofrequency energy; and a balloon mounted to the outer catheter, wherein an interior of the balloon is in fluid communication with the second lumen via the aperture such that the balloon is operable to be inflated via the second lumen.

2. The catheter assembly of claim 1, wherein the radiofrequency tip is radiopaque.

3. The catheter assembly of claim 1, wherein the inner catheter comprises one or more markings, each configured to indicate when the radiofrequency tip extends a corresponding preselected distance beyond a distal end of the outer catheter.

4. The catheter assembly of claim 3, further comprising a locking mechanism for selectively locking a longitudinal position of the inner catheter with respect to the outer catheter when the radiofrequency tip extends beyond the distal end of the outer catheter by the preselected distance corresponding to one of the markings.

5. The catheter assembly of claim 1, further comprising a pressure sensor, wherein a sensing tip of the pressure sensor is received in the second lumen of the outer catheter.

6. The catheter assembly of claim 1, wherein the second lumen extends from a proximal end of the outer catheter and terminates prior to a distal end of the outer catheter.

7. The catheter assembly of claim 1, wherein the inner catheter further comprises a third lumen.- 19 -CCF06-GN009 / TSH 1702300878. The catheter assembly of claim 7, further comprising a handle provided at a proximal end of the inner catheter, wherein the handle comprises a port for fluidly coupling the third lumen with an external fluid source.

9. The catheter assembly of claim 1, further comprising a hypotube and a liner disposed within the inner catheter, the hypotube configured to transmit radiofrequency energy from an external generator to the radiofrequency emitter tip.

10. A method, compri sing : advancing a distal end portion of an outer catheter into a cardiovascular region; inflating a balloon provided to the distal end portion of the outer catheter to engage the balloon with a target structure of the cardiovascular region; advancing an inner catheter through a first lumen of the outer catheter such that a radiofrequency (RF) emitter tip of the inner catheter emerges from the distal end portion of the outer catheter and contacts the target structure; emitting radiofrequency energy from the RF emitter tip to perforate the target structure; further advancing the inner catheter such that the RF emitter tip enters a targeted space of the cardiovascular region; and injecting fluid to the targeted space via a lumen of the inner catheter.

11. The method of claim 10, wherein the targeted space is a pericardial space.

12. The method of claim 11, wherein injecting fluid to the targeted space comprises insufflating the pericardial space with carbon dioxide.

13. The method of claim 10, further comprising consulting a marking to determine that the inner catheter has reached a predetermined extension distance from the distal end portion of the outer catheter.

14. A catheter assembly, comprising: an outer catheter defining a distal tip, a first lumen, and a second lumen fluidically isolated from the first lumen, wherein the distal tip comprises an opening in communication with the first lumen;- 20 -CCF06-GN009 / TSH 170230087an inner catheter slidingly received in the first lumen, the inner catheter comprising a radiofrequency (RF) emitter tip and an inner catheter lumen extending through the RF emitter tip such that fluid is operable to flow from a fluid source connected with the inner catheter lumen and out of the RF emitter tip; and a balloon having an interior in fluid communication with the second lumen such that the balloon is operable to be inflated by fluid flowing through the second lumen.

15. The catheter assembly of claim 14, further comprising a fluid introduction valve operable to selectively connect the inner catheter lumen with a fluid source to thereby facilitate flow of fluid from the fluid source to a targeted space in which the RF emitter tip is received.

16. The catheter assembly of claim 14, further comprising a fluid valve operable to selectively connect the first lumen with a source of contrast fluid.

17. The catheter assembly of claim 14, further comprising an inflation valve operable to selectively connect the second lumen with an inflation fluid source to thereby facilitate inflation of the balloon.

18. The catheter assembly of claim 14, further comprising a pressure sensor operable to detect pressure in the balloon, the pressure sensor including a sensor tip that extends through at least a portion of the second lumen.

19. The catheter assembly of claim 18, further comprising a controller configured to regulate delivery of inflation fluid from an inflation fluid source to the balloon based on information generated by the pressure sensor.

20. The catheter assembly of claim 18, further comprising a controller configured to generate an alarm in response to a detected pressure in the balloon exceeding a threshold pressure.- 21 -CCF06-GN009 / TSH 170230087

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