Systems, devices and methods for forming anastomosis

Abstract

To provide systems, devices and methods for treating heart failure.SOLUTION: In some variations, a catheter for forming an anastomosis in a heart may comprise a first catheter comprising an electrode. A second catheter may be slidably disposed within the first catheter. The second catheter may comprise a barb and a dilator comprising a mating surface configured to engage the electrode.SELECTED DRAWING: Figure 36A

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 971,357, filed February 7, 2020, and U.S. Provisional Patent Application No. 62 / 900,034, filed September 13, 2019, the contents of each of which are incorporated herein by reference in their entirety.

[0002] Technical Field FIELD OF THE INVENTION

[0002] The devices, systems, and methods herein relate to forming anastomoses, including, but not limited to, anastomoses within a patient's heart. [Background technology]

[0003] background Congestive heart failure (CHF) is characterized by a decline in myocardial function, either due to a weakening of its pumping capacity or due to stiffening of the myocardium, reducing its ability to adequately distribute blood before ejection. Insufficient blood flow from the heart to vital organs activates the renin-angiotensin-aldosterone system (RAAS), which signals the body to retain fluid, thereby increasing pressure within the heart chambers. In particular, elevated left atrial pressure (LAP) can cause fluid to backflow into the pulmonary circulation, which can lead to pulmonary edema and severe shortness of breath. Therefore, additional devices, systems, and methods for treating heart failure are desirable. Summary of the Invention [Means for solving the problem]

[0004]

[0004] Described herein are devices, systems, and methods for treating heart failure. These devices and systems can form an anastomosis in a body structure. In some variations, a catheter for forming an anastomosis in the heart can include a first catheter including an electrode. A second catheter can be slidably disposed within the first catheter. The second catheter can include a barb and a dilator including a mating surface configured to engage the electrode.

[0005] In some variations, the barbs can be disposed within the lumen of the electrode when the mating surface engages the electrode. In some variations, the outer diameter of the dilator can be smaller than the outer diameter of the electrode. In some variations, the barbs can be configured to engage tissue.

[0006]

[0006] In some variations, the second catheter may define a longitudinal axis. The barbs may include at least one protrusion including a first portion and a second portion. The first portion may be angled relative to the second portion. The length of the first portion to the length of the second portion may be in a ratio of about 2:3 to about 1:5. In some variations, the second portion may include a length of about 0.1 mm to about 2 cm. The first portion may be angled at about 60 degrees to about 120 degrees relative to the longitudinal axis. In some variations, the first portion may be substantially perpendicular to the longitudinal axis. In some variations, the second portion may be angled at up to about 30 degrees relative to the longitudinal axis. In some variations, the second portion may be substantially parallel to the longitudinal axis. In some variations, the barbs may include about three protrusions to about seven protrusions. In some variations, the at least one protrusion may include one of an "L" shape, a "J" shape, and a "C" shape. In some variations, the at least one protrusion may include multiple protrusions arranged in a series of concentric rings. In some variations, the at least one protrusion may be configured to penetrate tissue.

[0007]

[0007] In some variations, the barb may include one or more protrusions angled at about 5 degrees to about 60 degrees relative to the longitudinal axis. In some of these variations, the one or more protrusions may be configured in a row along the length of the barb. In some variations, the protrusions may be configured to penetrate tissue and reduce tissue shear. In some variations, the length of the barb may be about 0.1 mm to about 5 cm. In some variations, the electrode and mating surface may be configured to compress tissue therebetween. In some variations, the second catheter may define a longitudinal axis, and the mating surface may be non-perpendicular and non-parallel to the longitudinal axis.

[0008] In some variations, the first catheter may include an insulator disposed over a portion of the electrode. In some variations, the insulator may include a fluoropolymer material. In some variations, a distal surface of the electrode and at least a portion of an inner diameter of the electrode may be uninsulated. In some variations, the electrode may be proximal to the dilator. In some variations, the first catheter may define an evacuation lumen. In some variations, the signal generator is configured to generate a biphasic waveform, and the signal generator may be coupled to the electrode.

[0009] In some variations, the barbs may define a longitudinal axis, and the barbs may be configured to rotate about the longitudinal axis. In some variations, the barbs may be configured to rotate up to about 360 degrees about the longitudinal axis.

[0010] In some variations, the dilator can define a recess configured to retain the barb. In some variations, the barb can be disposed inside the recess in the first configuration, and at least a portion of the barb can be disposed outside the recess in the second configuration. In some variations, the length of the recess can be at least equal to the length of the barb. In some variations, the barb can be configured to translate relative to the dilator to transition between the first configuration and the second configuration.

[0011]

[0011] In some variations, the dilator may include a fluid port configured to eject contrast agent. In some variations, a proximal portion of the dilator may include a fluid port. In some variations, the fluid port may be configured to receive contrast agent from a lumen of the electrode. In some variations, the first catheter may include a lumen for contrast agent. In some variations, the first catheter may be configured to eject contrast agent. In some variations, the contrast agent may be ejected into a lumen of the electrode. In some variations, the electrode may include a fluid port configured to eject contrast agent. In some variations, a distal end of the electrode may include a fluid port.

[0012]

[0012] In some variations, the dilator may include an echogenic region. In some variations, the echogenic region may include one or more concave or convex portions. In some variations, the one or more concave or convex portions may include a diameter of about 5 μm to about 100 μm. In some variations, the echogenic region may include an asperity density of about 5% to about 50%. In some variations, the dilator may include one or more microspheres. In some variations, the one or more microspheres may include a gas core. In some variations, the one or more microspheres may include glass. In some variations, the echogenic region may be on the surface of the dilator. In some variations, the echogenic region may be below the surface of the dilator.

[0013] In some variations, the first catheter actuator may be configured to deflect a distal portion of the first catheter, and the first catheter actuator may be electrically coupled to the electrode. In some variations, a proximal end of the first catheter actuator may be configured to couple to an actuation mechanism. In some variations, the first catheter actuator may include a pull wire extending along the length of the first catheter. In some variations, the distal portion of the first catheter may include a predetermined bend. In some variations, the predetermined bend may include an angle of about 30 degrees to about 70 degrees.

[0014]

[0014] In some variations, the mating surface may define a recess configured to receive the distal end of the electrode. In some variations, the electrode may be configured to be electrically shorted when the electrode engages the recess in the mating surface. In some variations, the mating surface may include a deformable material. In some variations, the mating surface may include a non-conductive portion. In some variations, the non-conductive portion may include one or more of a polymer, a ceramic, and aluminum oxide. In some variations, the mating surface may include a conductive portion.

[0015] In some variations, the proximal end of the dilator can be disposed within the lumen of the electrode when the mating surface engages the electrode. In some variations, about 0.5 mm to about 2 mm of the proximal portion of the dilator can be disposed within the lumen of the electrode when the mating surface engages the electrode.

[0016]

[0016] In some variations, the signal generator may be configured to generate a first waveform followed by a second waveform. The signal generator may be coupled to the electrodes. The first waveform may include a first voltage, and the second waveform may include a second voltage. The first voltage may be higher than the second voltage.

[0017]

[0017] Methods are also described herein. In some variations, a method of forming an anastomosis in the heart may include advancing first and second catheters into the right atrium. The first catheter may include a tubular electrode defining a lumen, and the second catheter may include a dilator and a barb. The second catheter may be advanced through the atrial septum into the left atrium such that the first catheter is in the right atrium. The second catheter may be retracted relative to the first catheter to engage a first portion of the septum with the barbs, retract the first portion into the lumen, and compress a second portion of the septum between the electrode and the dilator. An ablation waveform may be delivered to the electrode to ablate the second portion such that the first portion is retained in the lumen.

[0018] In some variations, retracting the second catheter toward the first catheter can include retracting the barbs into the lumen. In some of these variations, the size of the first portion that is cut off from the second portion can correspond to the distance the barbs are retracted into the lumen. In some variations, retracting the second catheter toward the first catheter can stretch the first portion. In some variations, the first portion can form a substantially conical or cylindrical shape when engaged by the barbs.

[0019]

[0019] In some variations, the first portion of the septum may form a substantially cylindrical shape when retracted into the lumen. In some variations, the first portion of the septum engaged by the barbs may be intact when retracted into the lumen. In some variations, the barbs may puncture the first portion when retracting the second catheter into the first catheter. In some variations, an anastomosis having a diameter of about 1 mm to about 1.5 cm may be formed in response to delivering an ablation waveform. In some variations, the first portion may form a substantially conical shape when engaged by the barbs. In some variations, the first portion may be engaged by the barbs at least during delivery of the ablation waveform. In some variations, the first portion may be engaged by the barbs after delivering the ablation waveform to the electrode.

[0020]

[0020] In some variations, the second portion can be compressed with a force of at least 20 grams. In some variations, at least a portion of the barbs can penetrate the septum during engagement. In some variations, the electrodes can be electrically shorted when they contact the dilator during delivery of the ablation waveform. In some variations, the ablation waveform can include a biphasic waveform. In some variations, one or more radiopaque portions of the first and second catheters can be imaged with a fluoroscope during one or more steps.

[0021] In some variations, engaging the first portion of the septum with the barb can include rotating the barb about a longitudinal axis of the barb. In some variations, the size of the first portion that is resected from the second portion can correspond to an angle of rotation of the barb. In some variations, rotating the barb can include an angle of rotation of up to about 360 degrees.

[0022]

[0022] In some variations, retracting the second catheter toward the first catheter may include translating the barb relative to the dilator to engage the first portion of the septum.

[0023]

[0023] In some variations, retracting the second catheter toward the first catheter may include retracting the barb away from the dilator.

[0024]

[0024] In some variations, retracting the second catheter toward the first catheter may include transitioning from a first configuration in which the barbs are positioned inside the recess of the expander to a second configuration in which the barbs are positioned outside the recess.

[0025] In some variations, a contrast agent may be introduced into the heart through a fluid port in the dilator. In some variations, a contrast agent may be introduced into the lumen of the electrode. In some variations, ultrasound may be received from the distal end of the ablation device. In some variations, the distal end of the ablation device may include one or more microspheres having a diameter of about 5 μm to about 100 μm.

[0026] In some variations, retracting the second catheter toward the first catheter can deform a proximal portion of the dilator. In some variations, retracting the second catheter toward the first catheter can include engaging an electrode with a mating surface of the second catheter. In some variations, compressing the second portion of the septum can include a distal end of the electrode and a mating surface of the dilator. In some variations, the second portion can be compressed with a force of up to about 25 N.

[0027] In some variations, the ablation waveform can include a first waveform followed by a second waveform. The first waveform can include a first voltage, and the second waveform can include a second voltage. The first voltage can be higher than the second voltage.

[0028]

[0028] In some variations, the proximal portion of the expander may include a first stepped portion having a first diameter and a second stepped portion having a second diameter larger than the first diameter. The first stepped portion may be proximal to the second stepped portion. In some variations, the second step may include a mating surface configured to engage with the distal end of the electrode. In some variations, the mating surface may be substantially perpendicular to the longitudinal axis of the expander. In some variations, the first step may be configured to engage with a sidewall of the electrode when the expander engages with the electrode. In some variations, the expander may be configured to attach to the first catheter when the expander engages with the electrode.

[0029] In some variations, a system for forming an anastomosis within the heart can include a first catheter including an electrode and a second catheter slidably disposed within the first catheter. The second catheter can include a barb and a dilator. A proximal portion of the dilator can include a first stepped portion having a first diameter and a second stepped portion having a second diameter larger than the first diameter. The first stepped portion can be proximal to the second stepped portion.

[0030] In some variations, a system for forming an anastomosis within the heart can include a first catheter including an electrode and a second catheter slidably disposed within the first catheter. The second catheter can include a barb and a dilator. The barb can be housed within the lumen of the electrode when the dilator engages the electrode.

[0031] In some variations, a system for forming an anastomosis in the heart can include a first catheter including an electrode and a second catheter slidably disposed within the first catheter. The second catheter can include a barb and a dilator. The system can be configured to compress tissue between the electrode and the dilator with a first predetermined force.

[0032] In some variations, the dilator can be configured to shear the tissue with a second predetermined force that is greater than the first predetermined force. In some variations, the first predetermined force can be up to about 25 N. In some variations, the second predetermined force can be greater than about 25 N. [Brief explanation of the drawings]

[0033] [Figure 1]

[0033] A cross-sectional view of the heart showing various anatomical structures is provided. [Figure 2A]

[0034] 1 is a schematic perspective view of an exemplary variation of a method for forming an anastomosis using an ablation system. [Figure 2B]

[0034] FIG. 1 is a schematic perspective view of an exemplary variation of a method for forming an anastomosis using an ablation system. [Figure 2C]

[0034] FIG. 1 is a schematic perspective view of an exemplary variation of a method for forming an anastomosis using an ablation system. [Figure 2D]

[0034] FIG. 1 is a schematic perspective view of an exemplary variation of a method for forming an anastomosis using an ablation system. [Figure 2E]

[0034] FIG. 1 is a schematic perspective view of an exemplary variation of a method for forming an anastomosis using an ablation system. [Figure 2F]

[0034] FIG. 1 is a schematic perspective view of an exemplary variation of a method for forming an anastomosis using an ablation system. [Figure 3]

[0035] FIG. 1 is a schematic block diagram of an exemplary variation of an ablation system. [Figure 4]

[0036] 1 is a perspective view of an exemplary variation of an ablation device. [Figure 5A]

[0037] 1 is a schematic cross-sectional side view of an exemplary variation of an ablation device in an open configuration. [Figure 5B]

[0037] FIG. 1 is a schematic cross-sectional side view of an exemplary variation of an ablation device in a closed configuration. [Figure 6A]

[0038] 1A-1C are schematic side views of exemplary variations of ablation devices in a closed configuration. [Figure 6B] FIG. 6B is a schematic cross-sectional side view of the ablation device shown in FIG. 6A. [Figure 6C] FIG. 6C is a detailed cross-sectional side view of the ablation device shown in FIG. 6B. [Figure 7A]

[0039] 1 is a schematic side view of an exemplary variation of an ablation device in an open configuration. [Figure 7B] FIG. 7B is a schematic cross-sectional side view of the ablation device shown in FIG. 7A. [Figure 7C] FIG. 7C is a detailed cross-sectional side view of the ablation device shown in FIG. 7B. [Figure 8]

[0040] 1 is a schematic perspective view of an exemplary variation of an ablation device. [Figure 9A]

[0041] 1A-1C are schematic side views of exemplary variations of ablation devices in a closed configuration. [Figure 9B]

[0041] FIG. 1 is a schematic cross-sectional side view of an exemplary variation of an ablation device in a closed configuration. [Figure 10A]

[0042] 1 is a schematic side view of an exemplary variation of an ablation device in an open configuration. [Figure 10B]

[0042] A schematic cross-sectional side view of an exemplary variation of an ablation device in an open configuration. [Figure 11A]

[0043] 1A-1C are schematic cross-sectional side views of exemplary variations of electrodes of an ablation device. [Figure 11B] FIG. 11B is a detailed cross-sectional side view of the distal end of the electrode shown in FIG. 11A. [Figure 12A]

[0044] 1 is a schematic perspective view of an exemplary variation of a connector for an ablation device. [Figure 12B]

[0044] FIG. 10 is a schematic front view of an exemplary variation of a connector for an ablation device. [Figure 12C]

[0044] A schematic side cross-sectional view of an exemplary variation of a connector for an ablation device. [Figure 13A]

[0045] 1A-1C are schematic perspective views of exemplary variations of barbs of an ablation device. [Figure 13B]

[0045] FIG. 1 is a schematic side view of an exemplary variation of the barbs of an ablation device. [Figure 13C]

[0045] FIG. 1 is a schematic front view of an exemplary variation of the barbs of an ablation device. [Figure 14]

[0046] 1A-1C are schematic side views of exemplary variations of barbs of an ablation device. [Figure 15A]

[0047] 1A-1C are schematic perspective views of exemplary variations of barbs of an ablation device. [Figure 15B]

[0047] FIG. 1 is a schematic front view of an exemplary variation of the barbs of an ablation device. [Figure 16]

[0048] 1A-1C are schematic side views of exemplary variations of barbs of an ablation device. [Figure 17A]

[0049] 1A-1C are schematic side views of exemplary variations of barbs of an ablation device. [Figure 17B]

[0049] FIG. 1 is a schematic perspective view of an exemplary variation of the barbs of an ablation device. [Figure 18]

[0050] 10 is a flowchart of an exemplary variation of a method for forming an anastomosis. [Figure 19A]

[0051] 1 is a schematic perspective view of an exemplary variation of an ablation device within the pericardial space. [Figure 19B]

[0051] A schematic perspective view of an exemplary variation of an ablation device within the pericardial cavity. [Figure 19C]

[0051] A schematic side cross-sectional view of an exemplary variation of an ablation device within the pericardial cavity. [Figure 19D]

[0051] A schematic side cross-sectional view of an exemplary variation of an ablation device within the pericardial cavity. [Figure 19E]

[0051] A schematic side cross-sectional view of an exemplary variation of an ablation device within the pericardial cavity. [Figure 19F]

[0051] A schematic side cross-sectional view of an exemplary variation of an ablation device within the pericardial cavity. [Figure 20]

[0052] 1 is a perspective view of an exemplary variation of an ablation device. [Figure 21]

[0053] 1 is a perspective view of an exemplary variation of an ablation device. [Figure 22]

[0054] 1A-1C are perspective views of an exemplary variation of an ablation device engaged to ablate tissue. [Figure 23]

[0055] 1A-1C are fluoroscopic visualization images of exemplary variations of ablation devices in open and closed configurations. [Figure 24]

[0056] 1 is an image of an anastomosis formed in cadaveric tissue. [Figure 25A]

[0057] 1 is an image of an anastomosis formed in porcine tissue. [Figure 25B]

[0057] Images of anastomoses formed in porcine tissue. [Figure 26A]

[0058] 1A-1C are schematic side views of exemplary variations of barbs of an ablation device. [Figure 26B]

[0058] FIG. 1 is a schematic perspective view of an exemplary variation of the barbs of an ablation device. [Figure 26C]

[0058] FIG. 1 is a schematic front view of an exemplary variation of the barbs of an ablation device. [Figure 27A]

[0059] 1A-1C are perspective views of an exemplary variation of an ablation device engaged to ablate tissue. [Figure 27B]

[0059] FIG. 1 is a perspective view of an exemplary variation of an ablation device engaged to ablate tissue. [Figure 27C]

[0059] An image of an anastomosis formed in tissue. [Figure 28A]

[0060] 1A-1C are perspective views of an exemplary variation of an ablation device engaged to ablate tissue. [Figure 28B]

[0060] A perspective view of an exemplary variation of an ablation device engaged to ablate tissue. [Figure 29A]

[0061] FIG. 10 is a side view of the barbs of the ablation device within the pericardial space. [Figure 29B]

[0061] A side view of the barb of the ablation device within the pericardial cavity. [Figure 29C]

[0061] A side view of the barb of the ablation device within the pericardial cavity. [Figure 30A]

[0062] 1 is a side cross-sectional view of the barbs and catheter of an ablation device. [Figure 30B]

[0062] A side cross-sectional view of the barbs and catheter of the ablation device. [Figure 31A]

[0063] FIG. 1 is a side view of an exemplary variation of an ablation device. [Figure 31B]

[0063] A cross-sectional view of an exemplary variation of an ablation device. [Figure 31C] FIG. 31C is a detailed cross-sectional side view of the ablation device shown in FIG. 31B. [Figure 31D]

[0063] A perspective view of an exemplary variation of the distal portion of the ablation device. [Figure 31E]

[0063] A perspective view of an exemplary variation of the distal portion of the ablation device. [Figure 31F]

[0063] A perspective view of an exemplary variation of the distal portion of the ablation device. [Figure 32]

[0064] 10A-10C are side views of an exemplary variation of an ablation device within the pericardial space. [Figure 33A]

[0065] 1 is a side view of an exemplary variation of the catheter of the ablation device. [Figure 33B]

[0065] A side cross-sectional view of an exemplary variation of a catheter for an ablation device. [Figure 34A]

[0066] FIG. 2 is a cross-sectional plan view of the distal end of the catheter of the ablation device. [Figure 34B]

[0066] A cross-sectional plan view of the distal end of the catheter of the ablation device. [Figure 34C]

[0066] A side cross-sectional view of the catheter of the ablation device. [Figure 34D]

[0066] A side cross-sectional view of the catheter of the ablation device. [Figure 35A]

[0067] 10A-10C are side cross-sectional views of exemplary variations of the distal portion of an ablation device. [Figure 35B]

[0067] A detailed side cross-sectional view of another variation of the distal portion of the ablation device. [Figure 36A]

[0068] 10A-10C are side views of an exemplary variation of an ablation device within the pericardial space. [Figure 36B]

[0068] A side view of an exemplary variation of an ablation device within the pericardial cavity. [Figure 37]

[0069] 10 is an exemplary variation of a voltage waveform for an ablation procedure. [Figure 38A]

[0070] 1 is a side cross-sectional view of an exemplary variation of an ablation device in an open configuration. [Figure 38B]

[0070] A side cross-sectional view of an exemplary variation of an ablation device in a closed configuration. [Figure 39A]

[0071] 1A-1C are perspective views of exemplary variations of the handle of an ablation device. [Figure 39B] FIG. 39B is a plan view of the handle shown in FIG. 39A. [Figure 40A]

[0072] 1A-1C are side views of exemplary variations of barbs of an ablation device. [Figure 40B]

[0072] FIG. 1 is a perspective view of an exemplary variation of the barbs of an ablation device. [Figure 41A]

[0073] 1A-1C are schematic side views of exemplary variations of barbs of an ablation device. [Figure 41B]

[0073] FIG. 1 is a schematic perspective view of an exemplary variation of the barbs of an ablation device. [Figure 42A]

[0074] 1A-1C are schematic side views of exemplary variations of electrodes of an ablation device. [Figure 42B]

[0074] A schematic perspective view of an exemplary variation of an electrode of an ablation device. DETAILED DESCRIPTION OF THE INVENTION

[0034] Detailed Description

[0075] Described herein are devices, systems, and methods for treating heart failure (e.g., congestive heart failure) by lowering blood pressure in a patient's left atrium. For example, an energy-based tissue ablation system may be used to create an anastomosis between the right and left atria to relieve elevated left atrial pressure. In general, the systems described herein may, for example, place a portion of the device on either side of the interatrial septum. A portion of the septum may engage with the device using barbs. In some variations, a portion of the barbs may penetrate the septum, thereby securely holding an intact portion of the septal tissue. The engaged tissue may be stretched, secured, and drawn into the lumen of the device. In some variations, the size (e.g., diameter) of the ablated tissue may be controlled by varying the distance the engaged tissue is drawn into the lumen. Another portion of the septum may be compressed between the electrode and the proximal end of the dilator to secure another portion of the septum to the tissue. The electrode may use radio frequency (RF) energy to ablate tissue to create an anastomosis in the interatrial septum. After ablation, the electrode may contact the dilator, engaging the barbs and thereby retaining and / or securing the tissue portion, which remains contained within the lumen of the device and is removed from the patient. One or more steps of the treatment may be visualized using one or more visualization techniques and mechanisms incorporated within the ablation device. Thus, the first and second catheters described herein may improve the efficiency and safety of anastomosis formation procedures and reduce catheter size.

[0035]

[0076] While the heart is the organ of interest, it may be helpful to briefly identify and describe the relevant cardiac anatomy. Figure 1 is a cross-sectional view of a heart (100). Shown therein are the left atrium (110), the right atrium (120), and the interatrial septum (130). Figure 1 also shows an opening (132) (e.g., a hole) formed between the left atrium (110) and the right atrium (120). For example, the opening (132) may be created during an anastomosis formation procedure using the systems, devices, and methods described herein. The opening (132) may have predetermined characteristics configured to treat heart failure.

[0036]

[0077] Methods are also described herein. In some variations, a method of forming an anastomosis in the atrial septum may include the steps shown in FIG. 2A , which include advancing an ablation device (200) into the patient's right atrium (230). The distal end of the device (200) may include a dilator of a second catheter (250), which is configured to puncture the patient's atrial septum (210) and advance into the left atrium (220). In some variations, a guidewire (not shown) of the device (200) may be advanced across the atrial septum (210) and into the left atrium (220). As shown in FIG. 2B , the dilator may puncture the septum (210), thereby positioning a portion of the second catheter (250) in the left atrium (220) and the first catheter (240) in the right atrium (230).

[0037]

[0078] 2C shows that the second catheter 250 has been advanced relative to the first catheter 240, such that the barbs 260 of the second catheter 250 have been advanced across the septum 210 and into the left atrium 220. The barbs 260 may be configured to engage a portion of the septum for ablation. For example, the engaged portion of the septum may be held and / or secured between the prongs of the barbs 260. By positioning the device 200 across either side of the atrial septum 210, a predetermined force may be applied from each catheter 240, 250 to engage and ablate a predetermined portion of septal tissue.

[0038]

[0079] As shown in FIG. 2D , the second catheter 250 can be retracted relative to the first catheter 240, causing a portion 212 of the septum 210 to engage and stretch the barbs 260. The electrode 242 ( FIG. 2A ) and barbs 260 can each be positioned to engage a respective side of the septal tissue 212. For example, retracting the barbs 260 into the lumen of the electrode 242 can engage and stretch the tissue 212, forming a tent-like shape that can assist in anastomosis formation. The tissue 212 in FIG. 2D is shown tented toward the right atrium 230. In this manner, the tissue 212 to be resected is secured within the device 200 prior to resection, reducing the risk of uncontrolled tissue loss within the heart chambers and vasculature.

[0039]

[0080] In some of these variations, the electrode (250) may include a tubular shape configured to ablate tissue using RF energy and facilitate tissue capture. In some variations, the mating surface of the dilator (250) may be configured to engage, retain, and secure the tissue to be ablated against the cutting surface of the electrode (242). An ablation waveform may be delivered to the electrode (242) to ablate the portion (212) of the atrial septum (210) stretched by the device (200). For example, as described in more detail herein, the ablation waveform may include RF energy. The second catheter (250) may be positioned relative to the first catheter (240) such that the barbs (260) are retained within the lumen of the electrode (242) when the electrode (242) is energized.

[0040]

[0081] Once the septum 210 is ablated, a hole 214 may be formed in the septum 210, as shown in FIG. 2E. The second catheter 250 may be retracted from the left atrium 220, and the device 210 may be removed from the patient, as shown in FIG. 2F. The ablation device 200 may thus form an inter-atrial anastomosis. The ablation devices described herein may improve the efficiency and safety of anastomosis formation procedures and allow for device miniaturization. For example, after passing through the atrial septum 210, the operator may capture and secure tissue by advancing and retracting the second catheter 250 relative to the first catheter 240, without the need for any other actuation mechanism. This and other advantages of the device and method are described in more detail later in this specification.

[0041] I. System overview

[0082] The systems described herein may include one or more of the components used to ablate tissue using the devices described herein. Figure 3 is a block diagram of one variation of an ablation system (300) including an ablation device (310), a handle (320), and a signal generator (330). In some variations, the ablation device (310) may be designed to be disposed of after each use, while in other variations, one or more portions of the ablation device (310), such as the handle (320) and the signal generator (330), may be designed to be reusable (e.g., used multiple times on one or more patients).

[0042]

[0083] In some variations, the ablation device (310) may include first and second catheters sized and shaped to be placed within a body cavity, such as a cardiac chamber of a patient. In some variations, the ablation device (310) may include one or more of a guidewire (312), a dilator (314), barbs (316), and an electrode (318). The distal end of the ablation device (310) may include the dilator (314), and the guidewire (312) may extend from a lumen of the dilator (314). In some variations, the electrode (318) may be positioned proximal to the barbs (316), while in other variations, the electrode (318) may be positioned distal to the barbs (318). Additionally or alternatively, the ablation system (300) may include a delivery catheter configured to be advanced over the ablation device (310). Additionally, the ablation device (310) may include one or more sensors configured to measure one or more predetermined characteristics, such as temperature, pressure, impedance, and the like.

[0043]

[0084] In some variations, the proximal end of the ablation device (310) may be coupled to a handle (320). The handle (320) may include an actuator (322) configured to control one or more of the movement, positioning, configuration, orientation, operation, and energy delivery of the ablation device (310). For example, the actuator (322) may be operated to guide and / or translate one or more portions of the ablation device (310). In some variations, a signal generator (330) may be coupled to one or more of the ablation device (310) and the handle (320). In some variations, the signal generator (330) may be configured to generate one or more ablation waveforms that are delivered to the electrodes (318) of the ablation device (310). The signal generator (330) may include a controller (332) configured to control the signal generator (330) and deliver appropriate energy waveforms for tissue ablation and to ensure patient safety.

[0044]

[0085] FIG. 4 is a perspective view of one variation of an ablation device (400). In some variations, the ablation device (400) may include a first catheter (410) and a second catheter (430). The first catheter (410) may include a tubular electrode (420). The electrode (420) may define a lumen (422) configured to hold one or more portions of the second catheter (430). The electrode (420) shown in FIG. 4 has a cylindrical shape. However, the electrode (420) may have any desired cross-sectional shape (e.g., oval, square, rectangular, triangular). The electrode (420) shown in FIG. 4 may include a distal cutting edge. However, the electrode (420) may also include a beveled or non-flat edge (e.g., wavy, jagged, sawtooth, sinusoidal, periodic, etc.).

[0045]

[0086] In some variations, the ablation device (400) may include a second catheter (430) slidably disposed within the first catheter (410). The second catheter (430) may include barbs (440) and a dilator (450) configured to engage the electrode (420). In some variations, the barbs (440) may be coupled to a proximal portion of the dilator (450). The tissue-engaging portions (e.g., prongs, tips) of the barbs (440) may generally face the electrode (420). The barbs (440) may include multiple prongs. In some variations, one or more of the prongs may be bent to form a curved shape. In some variations, the proximal portion of the dilator (450) may be configured to contact the electrode (420) when the second catheter (430) is retracted relative to the first catheter (410). The dilator 450 may have, for example, a generally conical shape tapering toward the distal end of the second catheter 430. However, the dilator 450 may comprise any predetermined size, pattern, and shape. For example, at least a portion of the dilator 450 may be configured to retract within the lumen 422 of the electrode 420 to secure the dilator 450 to the catheter 410 during delivery and removal of the catheter, further securing the excised tissue during removal from the patient.

[0046]

[0087] As described in more detail herein, the second catheter (430) may be configured to translate relative to the first catheter (410). For example, the second catheter (430) may translate along the longitudinal axis of the first catheter (410). In some variations, one or more of the second catheter (430), barbs (440), and dilator (450) may translate within the lumen (422) of the electrode (420). As described in more detail herein, the electrode (420) may be configured to ablate tissue compressed between the distal end (e.g., distal cutting edge, chamfer) of the electrode (420) and the dilator (450).

[0047]

[0088] 5A is a schematic cross-sectional side view of one variation of an ablation device (500) in an open configuration. In some variations, the ablation device (500) may include a first catheter (510) and a second catheter (530). The first catheter (510) may include a tubular electrode (520) and a connector (526) coupled to the electrode (520). The electrode (520) may define a lumen (522) configured to retain one or more portions of the second catheter (530). The first catheter (510) may further include a lead (524) coupled to the electrode (520) and a signal generator (not shown). In some variations, the first catheter (510) may include an insulator (560) configured to cover a portion of the electrode (520). For example, the insulator (560) may be configured to cover the outer surface of the electrode (520), with the distal end and inner surface of the electrode (520) remaining uninsulated.

[0048]

[0089] In some variations, the ablation device (500) may include a second catheter (530) slidably disposed within the first catheter (510). The second catheter (530) may include barbs (540) and a dilator (550) configured to engage the electrode (520). In some variations, the barbs (540) may include a plurality of protrusions arranged side by side and generally angled toward the electrode (520). For example, the protrusions may be arranged side by side along the length of the dilator (550). Additionally or alternatively, one or more of the protrusions may be bent to form a curved shape. The dilator (550) may be tapered and define a lumen (552). The electrode (520) may be proximal to the dilator (550). In some variations, the dilator (550) may include a mating surface (554) configured to engage the electrode (520). For example, the electrode 520 and mating surface 554 may be configured to compress tissue (not shown) therebetween. In some variations, the mating surface 554 may be non-perpendicular and non-parallel to the longitudinal axis of the second catheter 530 (e.g., chamfered or beveled). As shown in Figures 5A and 5B, the distal end of the electrode 520 and mating surface 554 may be radial.

[0049]

[0090] 5B is a schematic cross-sectional side view of a variation of the ablation device 500 in a closed configuration. In the closed configuration, the barbs 540 may be surrounded by the electrode 520, the connector 526, and the dilator 550. That is, the barbs 540 may be disposed within the lumen 522 of the electrode 520 when the mating surfaces 554 engage the electrode 520. Thus, any tissue engaged by the barbs 540 may be surrounded and secured within the ablation device 500 in the closed configuration by one or more of the barbs 540 and the electrode 520. In some variations, the outer diameter of the dilator 550 may be smaller than the outer diameter of the distal end of the first catheter 510. For example, the outer diameter of the dilator 550 may be smaller than the outer diameter of the electrode 520. This may control the shape of the tent-like tissue engaged by the ablation device 500. As described in more detail herein, the length and shape of the barbs (540) can further control the size and shape of the tent-like tissue.

[0050]

[0091] FIG. 6A is a schematic side view of one variation of an ablation device (600) in a closed configuration. FIG. 6A shows the ablation device (600) including a first catheter (610), an electrode (620), a dilator (650), and an insulator (660). FIG. 6B is a schematic side cross-sectional view of the ablation device (600). In some variations, the ablation device (600) may include a first catheter (610) and a second catheter (630). The first catheter (610) may include a tubular electrode (620) and a connector (626) coupled to the electrode (620). The electrode (620) may define a lumen (622) configured to hold one or more portions of the second catheter (630). The first catheter (610) may further include a lead (624) coupled to the electrode (620) and a signal generator (not shown). In some variations, the first catheter 610 may include an insulator 660 configured to cover a portion of the electrode 620. For example, the insulator 660 may be configured to cover the outer surface of the electrode 620, leaving the distal end and inner surface of the electrode 620 uninsulated.

[0051]

[0092] In some variations, the ablation device (600) may include a second catheter (630) slidably disposed within the first catheter (610). The second catheter (630) may include barbs (640) and a dilator (650) configured to engage the electrode (620). In some variations, the barbs (640) may include a plurality of protrusions arranged side by side and generally angled toward the electrode (620). For example, the protrusions may be arranged side by side along the length of the dilator (650). Additionally or alternatively, one or more of the protrusions may be bent to form a curved shape. The dilator (650) may be tapered and define a lumen (652). The electrode (620) may be proximal to the dilator (650). Additionally or alternatively, one or more of the protrusions may be bent to form a curved shape.

[0052]

[0093] In the closed configuration, the barbs 640 may be surrounded by the electrode 620, the connector 626, and the dilator 650. That is, the barbs 640 may be disposed within the lumen 622 of the electrode 620 when the mating surfaces 654 engage the electrode 620. Thus, any tissue that the barbs 640 engage may be surrounded, held, and / or secured within the ablation device 600 in the closed configuration.

[0053]

[0094] Figure 6C is a detailed side cross-sectional view of the ablation device (600) shown in Figure 6B. Specifically, the dilator (650) can include a mating surface (654) configured to engage the electrode (620). For example, the electrode (620) and the mating surface (654) can be configured to compress tissue (not shown) therebetween. In some variations, the mating surface (654) can be non-perpendicular and non-parallel to the longitudinal axis of the second catheter (630) (e.g., chamfered or beveled). The distal end of the electrode (620) and the mating surface (654) can be radial. As shown in Figures 6B and 6C, the outer diameter of the dilator (650) can be smaller than the outer diameter of the electrode (620).

[0054]

[0095] Figure 7A is a schematic side view of one variation of an ablation device (700) in an open configuration. Figure 7A shows the ablation device (700) including a first catheter (710), an electrode (720), a second catheter (730), barbs (740), a dilator (750), and an insulator (760). Figure 7B is a schematic side cross-sectional view of the ablation device (700) shown in Figure 7A. In some variations, the ablation device (700) may include a first catheter (710) and a second catheter (730). The first catheter (710) may include a tubular electrode (720) and a connector (726) coupled to the electrode (720). The electrode (720) may define a lumen (722) configured to retain one or more portions of the second catheter (730). The first catheter 710 may further include an electrode 720 and a lead 724 coupled to a signal generator (not shown). In some variations, the first catheter 710 may include an insulator 760 configured to cover a portion of the electrode 620. For example, the insulator 760 may be configured to cover the outer surface of the electrode 620, leaving the distal end and inner surface of the electrode 720 uninsulated.

[0055]

[0096] In some variations, the ablation device (700) may include a second catheter (730) slidably disposed within the first catheter (710). The second catheter (730) may include barbs (740) and a dilator (750) configured to engage the electrode (720). In some variations, the barbs (740) may include multiple protrusions arranged side by side and generally angled toward the electrode (720). For example, the protrusions may be arranged side by side along the length of the dilator (750). Additionally or alternatively, one or more of the protrusions may be bent to form a curved shape. The dilator (750) may be tapered and define a lumen (752). The electrode (720) may be proximal to the dilator (750).

[0056]

[0097] Figure 7C is a detailed side cross-sectional view of the ablation device (700) shown in Figure 7B. Specifically, the dilator (750) can include a mating surface (754) configured to engage the electrode (720). For example, the electrode (720) and the mating surface (754) can be configured to compress tissue (not shown) therebetween. In some variations, the mating surface (754) can be non-perpendicular and non-parallel to the longitudinal axis of the second catheter (730) (e.g., chamfered or beveled). The distal end of the electrode (720) and the mating surface (754) can be radial.

[0057]

[0098] 8-10B show additional variations of ablation devices. FIG. 8 is a perspective view of one variation of an ablation device (800). In some variations, the ablation device (800) may include a first catheter (810) and a second catheter (830). The first catheter (810) may include a tubular electrode (820). The electrode (820) may define a lumen (822) configured to retain one or more portions of the second catheter (830). The electrode (820) shown in FIG. 8 has a cylindrical shape. However, the electrode (820) may include any desired cross-sectional shape (e.g., elliptical, square, rectangular, triangular).

[0058]

[0099] In some variations, the ablation device (800) may include a second catheter (830) slidably disposed within the first catheter (810). The second catheter (830) may include barbs (840) and a dilator (850) configured to engage the electrode (820). In some variations, the barbs (840) may be coupled to a proximal portion of the dilator (850). The barbs (840) may include a tapered portion and multiple protrusions arranged radially around the barbs (840) and in a staggered arrangement along the length of the second catheter (830). Tissue engaged by one or more of the protrusions may form a generally conical shape that generally follows the tapered shape of the barbs (840). The multiple protrusions may have the same or different lengths, diameters, and tapers. Each row may have the same or different numbers of protrusions. The prongs may have the same or different angles relative to the second catheter (830).

[0059]

[0100] In some variations, the protrusions (e.g., tissue-engaging portions) of the barbs (840) may be generally parallel to the longitudinal axis of the second catheter (830). In some variations, the proximal portion of the dilator (850) may be configured to contact the electrode (820) when the second catheter (830) is retracted relative to the first catheter (810). The dilator (850) may have, for example, a generally conical shape tapering toward the distal end of the second catheter (830). However, the dilator (850) may have any predetermined size, pattern, and shape.

[0060]

[0101] As described in more detail herein, the second catheter (830) may be configured to translate relative to the first catheter (810). For example, the second catheter (830) may translate along the longitudinal axis of the first catheter (810). In some variations, the second catheter (830), barbs (840), and dilator (850) may translate within the lumen (822) of the electrode (820). As described in more detail herein, the electrode (820) may be configured to ablate tissue compressed between the distal end of the electrode (820) and the dilator (850).

[0061]

[0102] FIG. 9A is a schematic side view of one variation of an ablation device (900) in a closed configuration. FIG. 9A shows the ablation device (900) including a first catheter (910), an electrode (920), and a dilator (950). FIG. 9B is a schematic side cross-sectional view of the ablation device (900). In some variations, the ablation device (900) may include a first catheter (910) and a second catheter (930). The first catheter (910) may include a tubular electrode (920) and a connector (926) coupled to the electrode (920). The electrode (920) may define a lumen (922) configured to retain one or more portions of the second catheter (930), such as the barbs (940). The first catheter (910) may further include a lead (not shown) coupled to the electrode (920) and a signal generator (not shown). In some variations, the first catheter 910 may include an insulator 960 configured to cover a portion of the electrode 920. For example, the insulator 960 may be configured to cover the outer surface of the electrode 920, leaving the distal end and inner surface of the electrode 920 uninsulated.

[0062]

[0103] In some variations, the ablation device (900) may include a second catheter (930) slidably disposed within the first catheter (910). The second catheter (930) may include barbs (940) and a dilator (950) configured to engage with the electrode (920). In some variations, the barbs (940) may include multiple protrusions arranged side by side generally parallel to the longitudinal axis of the second catheter (930). For example, the protrusions may be arranged side by side along the length of the second catheter (930). Additionally or alternatively, one or more of the protrusions may be curved to form a curved shape. The dilator (950) may be tapered and define a lumen (952). In some variations, the dilator (950) may include a mating surface (954) configured to engage with the electrode (920). For example, the electrode (920) and mating surface (954) can be configured to compress tissue (not shown) therebetween. In Figure 9B, the mating surface (954) is generally perpendicular to the longitudinal axis of the second catheter (930). The electrode (920) can be proximal to the dilator (950). The distal end of the electrode (920) and the mating surface (954) can be radial.

[0063]

[0104] In the closed configuration, the barbs 940 may be surrounded by the electrode 920, the connector 926, and the dilator 950. That is, the barbs 940 may be disposed within the lumen 922 of the electrode 920 when the mating surface 954 of the dilator 950 engages the electrode 920. Thus, tissue engaged with the barbs 940 may also be surrounded, held, and / or secured within the ablation device 900 in the closed configuration.

[0064]

[0105] FIG. 10A is a schematic side view of one variation of an ablation device (1000) in an open configuration. FIG. 10A shows the ablation device (1000) including a first catheter (1010), an electrode (1020), a second catheter (1030), barbs (1040), and a dilator (1050). FIG. 10B is a schematic side cross-sectional view of the ablation device (1000) shown in FIG. 10A. In some variations, the ablation device (1000) may include a first catheter (1010) and a second catheter (1030). The first catheter (1010) may include a tubular electrode (1020) and a connector (1026) coupled to the electrode (1020). The electrode (1020) may define a lumen (1022) configured to retain one or more portions of the second catheter (1030). The first catheter 1010 may further include a lead (not shown) coupled to the electrode 1020 and a signal generator (not shown). In some variations, the first catheter 1010 may include an insulator 1060 configured to cover a portion of the electrode 1020. For example, the insulator 1060 may be configured to cover the outer surface of the electrode 1020, leaving the distal end and inner surface of the electrode 1020 uninsulated.

[0065]

[0106] In some variations, the ablation device (1000) may include a second catheter (1030) slidably disposed within the first catheter (1010). In some variations, the barbs (1040) may include multiple protrusions arranged side by side generally parallel to the longitudinal axis of the second catheter (1030). For example, the protrusions may be arranged side by side along the length of the second catheter (1030). Additionally or alternatively, one or more of the protrusions may be curved to form a curved shape. The dilator (1050) may be tapered and define a lumen (1052). In some variations, the dilator (1050) may include a mating surface (1054) configured to engage the electrode (1020). For example, the electrode (1020) and the mating surface (1054) may be configured to compress tissue (not shown) therebetween. In Figure 10B, the mating surface (1054) is generally perpendicular to the longitudinal axis of the second catheter (1030). The electrode (1020) can be proximal to the dilator (1050). The distal end of the electrode (1020) and the mating surface (1054) can be radial.

[0066]

[0107] FIG. 38A is a schematic cross-sectional side view of one variation of an ablation device 3800 in a closed configuration. In some variations, the ablation device 3800 may include a first catheter 3810 and a second catheter 3830. The first catheter 3810 may include an electrode 3820, such as a tubular electrode. The electrode 3820 may define a lumen configured to retain one or more portions of the second catheter 3830. The first catheter 3810 may further include a first catheter actuator 3822 (e.g., a lead, an electrical pull wire) coupled to the electrode 3820 and a signal generator (not shown). As described in more detail herein, the first catheter actuator 3822 may be configured to deliver electrical energy to the electrode 3820 and deflect a distal portion of the ablation device 3800 in the manner of a pull wire. In some variations, the first catheter 3810 can include an insulator 3824 configured to cover a portion of the electrode 3820. For example, the insulator 3824 can be configured to cover an outer surface of the electrode 3820, leaving a distal end and inner surface of the electrode 3820 uninsulated. In some variations, the first catheter 3810 can include a contrast lumen 3812, as described in more detail herein.

[0067]

[0108] In some variations, the ablation device (3800) may include a second catheter (3830) slidably disposed within the first catheter (3810). The second catheter (3830) may include barbs (3840) and a dilator (3850) configured to engage the electrode (3820). In some variations, the barbs (3840) may include a plurality of radially arranged protrusions (3842, 3844) extending generally toward the electrode (3820). For example, the protrusions (3842, 3844) may include a distal portion (3842) configured to pierce tissue and a proximal portion (3844) configured as a backstop against the tissue.

[0068]

[0109] In some variations, the dilator (3850) may be tapered and define a lumen (3852). In some variations, a guidewire (not shown) may be slidably disposed within the lumen (3852). In some variations, the dilator (3850) may include a proximal portion (3854) and an echogenic region (not shown). For example, the echogenic region may include a predetermined surface texture configured for visualization using ultrasound imaging. The proximal portion (3854) of the dilator (3850) may be configured to engage with the electrode (3820) in a closed configuration. That is, the proximal portion (3854) may be configured to reside within the lumen of the electrode (3820) in the closed configuration of the ablation device (3800). In some variations, the dilator (3850) may include a mating surface (3856) configured to engage with the electrode (3820). For example, the electrode 3820 and mating surface 3856 can be configured to compress tissue (not shown) therebetween, as described in more detail with respect to Figure 36A. The mating surface 3856 of the dilator 3850 can extend radially and / or longitudinally.

[0069]

[0110] In the closed configuration, the barbs 3840 can be surrounded by the first catheter 3810, the electrode 3820, and the dilator 3850. That is, the barbs 3840 can be disposed within the lumen of the electrode 3820 when the proximal portion 3854 (e.g., mating surface 3856) engages with (e.g., seats within) the electrode 3820. Thus, tissue engaged with the barbs 3840 can also be surrounded and secured within the ablation device 3800 in the closed configuration by the barbs 3840 and the electrode 3820. The proximal portion 3854 disposed within the lumen of the electrode 3820 can be securely and coaxially attached to the electrode 3820 and the dilator 3850. For example, the dilator 3850 can be secured to the first catheter 3810 to resist movement due to lateral loading, such as when the ablation device 3800 is advanced over a curved guidewire. Additionally, the electrode 3820 securely engaged with the dilator 3850 can be configured to prevent the ablation device 3800 from snagging (e.g., catching) on ​​vessels, tissue (e.g., septal intersections), introducers, sheaths, and the like while being advanced and retracted within a body cavity. In some variations, when the mating surfaces are engaged with the electrode 3820, about 0.5 mm to about 2 mm of the proximal portion 3854 of the dilator 3850 can be disposed within the lumen of the electrode 3820.

[0070]

[0111] Figure 38B is a schematic side view of one variation of ablation device (3800) in an open configuration. The second catheter (3830) may be configured for translational movement relative to the first catheter (3810) via an actuation mechanism in the handle as described herein with respect to Figures 39A and 39B. Figure 36A shows ablation device (3600) in an ablating configuration between an open configuration and a closed configuration. The ablation device (3600) may correspond to ablation device (3800).

[0071]

[0112] In some variations, the proximal portion (3854) of the dilator (3850) may include a first stepped portion having a first diameter and a second stepped portion having a second diameter larger than the first diameter. The first stepped portion may be proximal to the second stepped portion. In some variations, the second step may include a mating surface (3856) configured to engage with the distal end of the electrode (3820). In some variations, the mating surface (3856) may be substantially perpendicular to the longitudinal axis of the dilator (3850). In some variations, the first step may be configured to engage with a sidewall of the electrode (3820) when the dilator (3850) engages with the electrode (3820). In some variations, the dilator (3850) may be configured to attach to the first catheter (3810) when the dilator (3850) engages with the electrode (3820).

[0072] electrode

[0113] In general, the electrodes described herein can be configured to ablate tissue, such as a portion of a patient's interatrial septum, to reduce blood pressure in the patient's left atrium. In some variations, the electrode can engage the septum and be energized to ablate a portion of the septal tissue to form a predetermined opening between the left and right atria. For example, tissue can be heated using radio frequency (RF) energy during electrosurgery. RF energy tissue ablation can be used to quickly and precisely ablate tissue without causing significant damage to surrounding tissue. In some variations, RF energy can be delivered to tissue by the electrode to quickly and precisely ablate the tissue to form an anastomosis of a predetermined shape and size.

[0073]

[0114] In some variations, tissue ablation characteristics can be controlled by the size, shape, and / or placement of the electrode's conductive region. For example, the electrode can include a thin, radial edge that can be configured to apply high-density energy to a small contact surface area of ​​the tissue to be ablated. This can ablate tissue more quickly with less energy than an electrode with a larger contact surface area. In some variations, the distal end of the electrode can be angled (e.g., chamfered or beveled) relative to the electrode's longitudinal axis to further reduce the electrode's contact surface area with the tissue. In some variations, the width of the chamfer can be about 0.025 mm to about 0.040 mm, including all ranges and subvalues ​​therebetween. For example, the width of the chamfer can be about 0.05 mm to about 0.08 mm.

[0074]

[0115] Additionally, the small contact surface area of ​​the electrodes can aid in compressing the tissue prior to ablation. For example, as shown in FIGS. 6A-6C and 9A-9B, the distal ends of the electrodes (620, 920) can be configured to abut against corresponding mating surfaces (654, ​​954). A smaller electrode contact surface area can increase the compressive force exerted on the tissue contacting the mating surface. Compressing the tissue between the electrodes and the mating surface can provide various benefits. For example, the compression can reduce the thickness of the tissue being ablated, allowing the septum to be ablated more quickly and with less energy. Furthermore, tissue compression can hold (e.g., secure, lock) the tissue in place relative to the ablation device, thereby ensuring that only a predetermined portion of the tissue is ablated. In some variations, compressing the tissue during actuation can fuse layers of tissue (e.g., the left and right atrial septal layers) during ablation, thereby reducing the surface area of ​​exposed tissue along the periphery of the anastomosis after tissue ablation. In some variations, tissue compression may be used to reduce the volume of the tissue, thereby allowing a larger volume of tissue to be accommodated within the lumen of the electrode after ablation, thereby forming a relatively large anastomosis.

[0075]

[0116] In some variations, the shape of the atrial septal opening may be based on the shape of the electrode. For example, the electrodes (420, 820) of FIGS. 4 and 8, respectively, may have a tubular shape, which may be used to create a generally circular opening. In some variations, at least a portion of the distal end of the electrode may be angled from about 5 degrees to about 75 degrees relative to the longitudinal axis of the electrode to form a chamfer and / or bevel. For example, at least a portion of the distal end of the electrode may be angled from about 30 degrees to about 60 degrees relative to the longitudinal axis of the electrode. For example, the distal ends (628, 728) of the electrodes (620, 720) of FIGS. 6C and 7C, respectively, may be angled radially at an angle of about 45 degrees relative to the longitudinal axis of the electrode (620, 720).

[0076]

[0117] As described herein, a beveled electrode may reduce the electrode's contact surface area, allowing for greater compressive forces to be applied by tissue. In some variations, the corresponding mating surface of the dilator may be similarly beveled to facilitate alignment and coupling of the dilator with the electrode as the dilator is retracted relative to the electrode. In some variations, at least a portion of the mating surface of the dilator may be angled from about 5 degrees to about 75 degrees relative to the longitudinal axis of the dilator. For example, at least a portion of the mating surface of the dilator may be angled from about 30 degrees to about 60 degrees relative to the longitudinal axis of the dilator. In this manner, a beveled electrode may provide tolerance for misalignment between the electrode and the dilator, e.g., due to tissue sandwiched therebetween, allowing the dilator to seat within the electrode.

[0077]

[0118] In some variations, one or more portions of the electrode may be coated with an insulator (e.g., PTFE, ePTFE, PET, polyolefin, parylene, FEP, silicone, nylon, PEEK, polyimide) to reduce the electrode's contact surface area. A relatively small surface area may reduce bubble and char formation and electrode activation time. In some variations, the inner surface of the electrode may remain uninsulated and serve as a conductive path for current to flow through the contained tissue during and after tissue ablation. In some variations, conduction through the tissue may reduce the volume of the ablated tissue due to protein desiccation and / or denaturation, thereby allowing a larger volume of tissue to be accommodated.

[0078]

[0119] 11A and 11B are schematic cross-sectional side views of an electrode 1110 of an ablation device 1100. Specifically, the distal end of a first catheter may include an electrode 1110 having a distal tip 1120, an insulator 1130, a lead 1140, and a connector 1150. The electrode 1110 may include the distal tip 1120 and have a tubular shape defining a lumen 1112. In some variations, the lumen 1112 may be configured to surround one or more of the barbs, tissue engaged with the barbs, and a proximal portion of a dilator. FIG. 5A is a cross-sectional perspective view of the lumen 522, and FIG. 5B shows a portion of the barbs 540 and dilator 550 disposed within the lumen 522. Further, as shown in FIG. 22, the lumen (2222) can have a volume sufficient to encompass a predetermined volume of tissue (2260). Similarly, FIGS. 27A and 27B are images including a predetermined volume of tissue (2760) that fits within the lumen of the electrode (2720). As another example, the tissue (2860) shown in FIGS. 28A and 28B can be configured to fit within the lumen of an electrode (not shown). In some variations, the lumen can have a length of at least 1 mm. For example, the lumen can have a length of about 5 mm to about 4 cm.

[0079]

[0120] In some variations, a connector 1150 may be coupled to each of the electrode 1110 and the lead 1140. The insulator 1130 may be configured to cover one or more outer surfaces of the electrode 1110 and the connector 1150. In some variations, the inner surface of the electrode 1110 may be uninsulated. In some variations, up to about 2 mm of the outer surface of the electrode may be uninsulated. For example, up to about 0.15 mm of the outer surface of the electrode may be uninsulated.

[0080]

[0121] As shown in the detailed cross-sectional side view of FIG. 11B, the distal end 1120 of the electrode 1110 can be angled (e.g., chamfered or beveled) relative to the longitudinal axis of the electrode 1110. In some variations, the chamfer can extend radially along the distal end 1120. The distal end 1120 can have a single angle or multiple angles. For example, the surface of the distal end 1120 can have a sinusoidal shape, in which case the corresponding mating surface of the dilator can have a corresponding sinusoidal shape. This allows the mating surfaces of the electrode and dilator to contact and compress against each other in a predetermined orientation.

[0081]

[0122] In some variations, the electrodes may include one or more biocompatible metals, such as titanium, stainless steel, nitinol, palladium, silver, platinum, combinations thereof, and others. In some variations, the electrodes may include atraumatic (e.g., blunt, rounded) distal edges so as not to perforate tissue when the electrodes are pressed against an opposing surface, such as a mating surface of a dilator. For example, the electrodes may engage and compress tissue along their chamfered circumferential edges.

[0082]

[0123] In some variations, the diameter of the excised tissue may be from about 1 mm to about 1.5 cm, including all ranges and subvalues ​​therebetween. For example, the diameter of the excised tissue may be from about 0.5 mm to about 12 mm. For example, the diameter of the excised tissue may be from about 6 mm to about 9 mm.

[0083]

[0124] In some variations, heating the tissue can shrink the tissue before ablation. In some variations, heating the tissue can shrink the tissue after ablation. In some variations, the tissue can be heated to a predetermined temperature range. In some variations, the tissue to be ablated can be heated to at least about 60°C, about 70°C, about 80°C, about 90°C, and about 100°C for a predetermined length of time. In some variations, the tissue to be ablated can be heated to about 50°C to about 100°C for a predetermined length of time. In some variations, only the tissue to be ablated can be heated, and in other variations, only a portion of the tissue to be ablated can be heated. In some variations, the electrodes can be configured to rotate, vibrate, and / or oscillate during and after energy delivery to prevent, reduce, and / or impede char formation.

[0084]

[0125] In some variations, the electrodes may be connected to the signal generator by leads (e.g., conductive wires). The leads may extend from a proximal portion of the first catheter to the electrodes in a distal portion of the first catheter. One or more portions of the leads may be insulated. The leads may be configured to maintain a predetermined voltage potential without causing breakdown of the corresponding insulation.

[0085]

[0126] 12A and 12B are perspective and front views, respectively, of a connector 1200 of an ablation device. FIG. 12C is a side cross-sectional view of the connector 1200. In some variations, the connector 1200 can be configured to couple an electrode and a lead to the shaft of a first catheter (not shown for clarity). The connector 1200 can include a lumen 1210 configured for slidably disposing a second catheter and a channel 1220 configured for the distal end of a lead. In some variations, at least a portion of the inner surface of the connector 1200 can be slippery to facilitate translational movement of the second catheter relative to the connector 1200. For example, the inner surface of the connector 1200 can include a layer of PTFE to facilitate smooth translation and / or rotation of a second catheter slidably disposed within the lumen 1210. In some variations, the connector (1200) may include a vent lumen (not shown) configured to vent fluid (e.g., air, heat, liquid) from the lumen of the electrode to the lumen of the first catheter.

[0086]

[0127] In some variations, the connector (1200) may have a length of at least about 0.1 mm. For example, the connector (1200) may have a length of about 1 mm to about 2 cm and about 2 mm to about 7 mm. In some variations, the lumen (1210) may have a length of at least 0.1 mm. For example, the lumen (1210) may have a length of about 1 mm to about 1 cm. In some variations, the channel (1220) may have a length of at least 0.1 mm. For example, the channel (1220) may have a length of about 1 mm to about 5 mm.

[0087]

[0128] In some variations, the systems disclosed herein may include a return electrode (e.g., an RF energy sink) for drawing RF energy from the patient. In some variations, the second catheter may include the return electrode. In some variations, the return electrode may be external to and in contact with the return electrode (e.g., a skin patch electrode, a grounding pad). For example, a pair of return electrodes may be placed on the patient's back to allow current to pass from the electrodes through the patient's body and then to the return electrodes. For example, one or more return electrodes may be placed on the patient's skin. A conductive gel may be applied between the return electrodes and the skin to improve contact.

[0088] insulator

[0129] In general, the insulators described herein can be configured to electrically insulate one or more portions of an electrode and / or catheter of an ablation device. In some variations, the insulator can include one or more of poly(p-xylylene) polymers (e.g., Parylene C, Parylene N), polyurethane (PU), polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), polyimide (PI), polyester, polyethylene terephthalate (PET), PEEK, polyolefin, silicone, copolymers, ceramic, combinations thereof, and others.

[0089] return

[0130] In general, the barbs described herein can be configured to engage tissue, such as the patient's atrial septum, to control the size and shape of the septal tissue to be ablated. In some variations, a portion of the septal tissue can engage one or more prongs of the barb and be stretched over the one or more prongs to hold the tissue in place before or after tissue ablation. In some variations, the prongs can be configured to penetrate or pierce the tissue a predetermined distance. For example, the prongs can be configured to penetrate multiple layers of the atrial septum (e.g., one or more left atrial and right atrial layers) to secure the septal tissue to the barb while maintaining the structural integrity of the entire septum. In some of these variations, the prongs penetrate the tissue, thereby holding the tissue to the barb and reducing shear strain on the tissue as it is pulled into the electrode, improving the consistency and shape (e.g., cylindricity) of the ablation. That is, the barbs can be configured to capture but not tear the tissue, such that the tissue can be held in engagement with the barb during electrosurgery.

[0090]

[0131] For example, the barbs can be configured to prevent tearing by distributing pressure as tissue is engaged and pulled. For example, the engaged tissue can form a generally conical, tent-like shape around the barbs, applying tension to the septum. In some variations, the barbs can be configured to provide a counter-tensioning force to the atrial septum during electrode energization to minimize unintended tissue deformation, rotation, or displacement due to unbalanced forces (e.g., tissue movement due to heartbeat). The engaged tissue and barbs can be retracted into the lumen of the ablation device to hold and secure the tissue during tissue ablation. In some variations, the size of the anastomosis can depend on the distance the barbs are retracted into the electrode, and the size of the anastomosis can be independent of the diameter of the ablation device. This allows an ablation device to have an electrode of a fixed diameter and form an anastomosis with a diameter larger than that of the electrode. The size (e.g., diameter, length) and shape of the barb should be such that it can fit within the lumen of the electrode while engaging tissue. In some variations, the diameter of the tissue opening can be calculated using equation (1).

number

[0091]

[0132] 13A-13C show various views of a barb (1300) of an ablation device. The barb (1300) may include one or more projections (1320) (e.g., prongs) having a base (1310) and a proximal end including a tissue-engaging portion (1322) (e.g., a tip). The base (1310) may be generally cylindrical and configured to couple to a proximal portion of a dilator and shaft of a second catheter (not shown). For example, the base (1310) may be proximal to the dilator of the second catheter.

[0092]

[0133] One or more of the protrusions 1320 may be coupled to the proximal end of the base 1310. In some variations, the protrusions 1320 may comprise elongate elements. For example, the barbs 1300 may include at least one protrusion 1320. In some variations, the protrusions 1320 may be substantially equally spaced around the circumference of the base 1310. In some variations, each of the protrusions 1320 may have the same or different lengths. In some variations, the length of the barbs 1300 may be from about 0.1 mm to about 5 cm. In some variations, one or more of the protrusions 1320 may be linear, curved, curvilinear, rounded, arcuate, and the like.

[0093]

[0134] In some variations, the protrusions (1320) may include one or more tissue-engaging portions (1322). The tissue-engaging portions (1322) and / or the protrusions (1320) may be configured to engage tissue while not tearing the tissue, preventing loss of tissue integrity. In some variations, the tissue-engaging portions (1322) may be configured to puncture or penetrate tissue. In some variations, the shape and size of each tissue-engaging portion (1322) may be the same or different. For example, the tissue-engaging portions (1322) may include a pointed tip or a blunt, atraumatic end. In some variations, the tissue-engaging portions (1322) may include one or more secondary structures (e.g., serrations) to prevent tissue from slipping off the protrusions (1320). In some variations, tissue engaging portion 1322 may include an angle of about 10 degrees to about 90 degrees relative to the longitudinal axis of protrusion 1320. In some variations, protrusion 1320 and / or tissue engaging portion 1322 may have a length of about 0.1 mm to about 2 cm.

[0094]

[0135] In some variations, the protrusions (1320) are generally linear but may be angled relative to the longitudinal axis of the base portion (1310). For example, the protrusions (1320) may be configured to flare outward to capture and engage tissue. In some variations, the protrusions may include one or more curved or angled portions. In some variations, tissue may be configured to engage with one or more portions of the protrusions (1320). In some variations, the barbed protrusions may be angled from about 5 degrees to about 60 degrees relative to the longitudinal axis of the base portion (1310), including all values ​​and subranges therebetween. For example, the protrusions (1320) may include an angle from about 30 degrees to about 45 degrees. Each protrusion (1320) may have the same or different angles relative to the longitudinal axis.

[0095]

[0136] In some variations, protrusions (1320) can be configured to engage a predetermined length and / or volume of tissue. For example, protrusions (1320) can include a proximal portion that can be configured as a barrier (e.g., a backstop, a wall) to engaging (e.g., advancing, penetrating) tissue beyond, thereby reducing tissue tearing.

[0096]

[0137] Figure 14 is a schematic side view of a barb (1400) of an ablation device. The barb (1400) may include one or more prongs (1420) having a base (1410) and a proximal end including a tissue-engaging portion (1422). The prongs (1420) of the barb (1400) may be angled in a manner similar to the barb (1300) of Figures 13A-13C. In some variations, the barbs may include from about 2 prongs to about 12 prongs, including all values ​​and subranges therebetween. For example, the barbs may include from about 5 prongs to about 7 prongs.

[0097]

[0138] FIG. 15A is a schematic side view of a barb (1500) of an ablation device. FIG. 15B is a front view of the barb (1500). The barb (1500) may include one or more prongs (1520, 1530) having a base (1510) and a respective proximal end, each of which includes a respective tissue-engaging portion (1522, 1532). In some variations, the one or more prongs (1520, 1530) may be configured side by side along the length of the barb (1500). For example, the barb (1500) may include one or more side-by-side prongs (1520, 1530). In some variations, the rows of prongs (1520, 1530) may be staggered, as shown in FIGS. 15A and 15B. Tissue engaging the barb (1500) may form a generally conical, tent-like shape.

[0098]

[0139] Figure 16 is a schematic side view of a barb (1600) of an ablation device. The barb (1600) may include one or more prongs (1620) having a proximal end including a base (1610) and a tissue-engaging portion (1622). The prongs (1620) may be parallel to the longitudinal axis of the base (1610). Figures 17A and 17B are schematic side and perspective views, respectively, of a barb (1700) of an ablation device. The barb (1700) may include one or more prongs (1720) having a proximal end including a base (1710) and a tissue-engaging portion (1722). The tissue-engaging portion (1722) may extend along a majority of the length of the prong (1720). In some variations, the base (1610) may have a diameter smaller than the diameter of the electrode. In some variations, the prongs (1620, 1720) and tissue engaging portions (1622, 1722) can include lengths configured to penetrate the atrial septum. One or more tissue engaging portions (1722) can include lengths that are more tapered, as shown in Figures 17A and 17B, which can assist in puncturing and / or penetrating tissue with less force.

[0099]

[0140] Figures 41A and 41B are schematic side and perspective views, respectively, of a barb (4100) of an ablation device. The barb (4100) may include one or more prongs (4120) having a proximal end including a base (4110) and a tissue-engaging portion (4122). In some variations, the prongs (4120) and the tissue-engaging portion (4122) may include a length configured to penetrate the atrial septum. The one or more tissue-engaging portions (4122) may include a length that may assist in puncturing and / or penetrating tissue, as shown in Figures 41A and 41B.

[0100]

[0141] 26A-26C show various views of an ablation device barb 2600. The barb 2600 may include a base 2610 and one or more projections 2620 (e.g., prongs, tines). The protrusion (2620) may include a first portion (2624) and a distal portion (e.g., a tissue engaging portion (2622) (e.g., a tip). In some variations, the first portion (2624) may be angled relative to the second portion (2622). For example, the protrusion (2620) may include a bend, where the first portion (2624) is substantially perpendicular to the second portion (2622). The base portion (2610) may be generally cylindrical and configured to be coupled to a proximal portion of a dilator and shaft of a second catheter (not shown). For example, the base portion (2610) may be proximal to the dilator of the second catheter.

[0101]

[0142] One or more of the protrusions 2620 may be coupled to an end of the base portion 2610. In some variations, the protrusions 2620 may comprise elongate elements. For example, the barbs 2600 may comprise at least one protrusion 2620. In some variations, the protrusions 2620 may be substantially equally spaced around the circumference of the base portion 2610 and extend from the longitudinal axis of the base portion 2610. In some variations, each of the protrusions 2620 may have the same or different lengths. In some variations, the length of the barbs 2600 may be from about 0.1 mm to about 5 cm. In some variations, the ratio of the length of the proximal portion to the length of the distal portion may be from about 2:3 to about 1:5. In some variations, one or more of the protrusions (2620) can be linear, curved, curvilinear, rounded, arcuate, etc. For example, the protrusions (2610) can be "L" shaped, "J" shaped, or "C" shaped, and the protrusions (2610) collectively define a diameter that is greater than the diameter of the base (2610).

[0102]

[0143] In some variations, the distal portion (2620) of the prongs (2620) may include one or more tissue-engaging portions (2622). The tissue-engaging portions (2622) and / or the prongs (2620) may be configured to engage tissue without tearing the tissue and preventing loss of tissue integrity. In some variations, the tissue-engaging portions (2622) may be configured to puncture or penetrate tissue. In some variations, the shape and size of each tissue-engaging portion (2622) may be the same or different. For example, the tissue-engaging portions (2622) may include a pointed tip or a blunt, atraumatic end. In some variations, the tissue-engaging portions (2622) may include one or more secondary structures (e.g., serrations) to prevent tissue from slipping off the prongs (2620). In some variations, the tissue engaging portion 2622 can be substantially parallel to the longitudinal axis of the base portion 2620. In some variations, the length of the protrusions 2620 can be from about 0.1 mm to about 2 cm. For example, the protrusions 2620 can include lengths of from about 1.25 mm to about 1.75 mm and about 1.5 mm. In some variations, the length of the tissue engaging portion 2622 can be from about 1.0 mm to about 1.5 mm, including all ranges and subvalues ​​therebetween.

[0103]

[0144] In some variations, the protrusions (2620) may be generally linear but may include one or more bends. For example, the first portion (2624) of the protrusions (2620) may be configured to extend substantially perpendicular to the longitudinal axis of the base portion (2620). In some variations, the protrusions (2620) may include one or more curves or corners between the first portion (2624) and the second portion (2622). In some variations, tissue may be configured to engage one or more portions of the protrusions (2620).

[0104]

[0145] In some variations, the first portions 2624 of the projections 2622 may be angled from about 60 degrees to about 120 degrees relative to the longitudinal axis of the base 2610, including all values ​​and subranges therebetween. For example, the projections 2620 may be angled from about 80 degrees to about 100 degrees relative to the longitudinal axis of the base 2610. As shown in FIG. 26A , the first portions 2624 may be substantially perpendicular to the longitudinal axis of the base 2610. The first portions 2624 of the projections 2620 may each have the same or different angles relative to the longitudinal axis. In some variations, the second portions 2622 of the projections 2620 may be angled at up to about 30 degrees relative to the longitudinal axis of the base 2610. For example, as shown in FIG. 26A, second portion (2622) can be substantially parallel to the longitudinal axis of base portion (2610).

[0105]

[0146] In some variations, the prongs 2620 can be configured to engage a predetermined length and / or volume of tissue. For example, the second portion 2622 can engage and pierce tissue, and the first portion 2624 can engage and secure tissue to the barb 2600. The second portion 2622 can be configured to pierce tissue so that layers of the atrial septum (e.g., the left and right atrial layers) are held together, reducing tissue separation and / or tissue shearing. For example, the prongs 2620 can be configured to dig into and fasten together various layers of the septum, reducing relative shearing of the septal tissue layers during translation and resulting in reduced chamfering of the anastomosis formed. The first portion 2624 can further be configured as a barrier (e.g., backstop, wall) against engaging (e.g., advancing, penetrating) tissue beyond it, thereby reducing tissue tearing. A volume of tissue can be captured by the prongs (2620) as the barbs are drawn into the lumen of the electrode.

[0106]

[0147] In some variations, the barbs may include between about 3 prongs and about 12 prongs, including all values ​​and subranges therebetween. For example, the barbs may include between about 3 prongs and about 7 prongs. In some variations, multiple tissue-engaging portions (2622) may extend from the same first portion (2624), which may collectively comprise, for example, a series of concentric rings. In some variations, the series of prongs may be staggered. Tissue engaging the barbs (2600) may form a generally conical or cylindrical tent-like shape. In some variations, the tissue-engaging portions (2622) may extend along a majority of the length of the prongs (2620). In some variations, the base portion (2610) may have a diameter smaller than the diameter of the electrode.

[0107]

[0148] In some variations, the barbs can be configured to transition from a compressed configuration to an expanded configuration. For example, the barbs can be in a compressed configuration when disposed within the lumen of the electrode. The barbs can transition to an expanded configuration when the second catheter is advanced relative to the first catheter, advancing the barbs out of the lumen of the electrode and thereby allowing the barbs to engage a larger volume of tissue.

[0108]

[0149] In some variations, the barbs (2920) can be configured to engage tissue for ablation by rotating the barbs (2920) through a predetermined angle. Figures 29A, 29B, and 29C are side views of barbs (2920) of an ablation device (2900) within the pericardial space. The ablation device (2900) can include a catheter (2910) (e.g., a distal tip, a dilator) and barbs (2920). The barbs (2920) can include one or more prongs (e.g., prongs, tines) including a base portion (2926), a second portion (e.g., tissue engaging portion) (2922) (e.g., a tip, a distal end), and a first portion (2924).

[0109]

[0150] In some variations, the second portion 2922 (e.g., tissue engaging portion) can be configured to engage the tissue 2930 while not tearing the tissue to prevent loss of tissue integrity. In some variations, the second portion 2922 can be configured to puncture or penetrate the tissue. FIG. 29A depicts the second portion 2922 initially penetrating the tissue 2930. As the barb 2920 is advanced toward the tissue 2930, FIG. 29B shows the second portion 2922 penetrating the entire thickness of the tissue 2930 (e.g., the atrial septum).

[0110]

[0151] In some variations, the size (e.g., diameter) of the tissue (2930) to be excised can be controlled by rotating (e.g., twisting) the barbs (2920) about the longitudinal axis (2921) of their bases (2926). For example, rotating the barbs (2920) after engaging the tissue (2930) (FIG. 29B) can increase the amount of tissue (2930) engaged with the barbs (2920) for excision. As the barbs are rotated, the tissue (2930) is drawn (e.g., compressed) (2932) toward the longitudinal axis (2921) in the direction of the arrow (2932), as shown in FIG. 29C. This can allow the diameter (2934) of the tissue (2930) to be excised to be larger than the diameter of the barbs (2920). In some variations, twisting the barb may increase the diameter of the tissue by up to about 5 mm, up to about 3 mm, and up to about 1 mm, including all ranges and subvalues ​​therebetween.

[0111]

[0152] In some variations, the barbs (2920) may be configured to rotate up to about 30 degrees, up to about 45 degrees, up to about 60 degrees, up to about 90 degrees, up to about 180 degrees, up to about 270 degrees, up to about 360 degrees, up to about 720 degrees, up to about 1,080 degrees, between about 90 degrees and about 720 degrees, between about 180 degrees and about 360 degrees, including all ranges and subvalues ​​therebetween.

[0112]

[0153] In some variations, the handle of the device may be configured to control the rotation of the barbs 2920 and / or catheter 2910, thus allowing control of the amount of tissue ablated 2930. In some variations, the proximal portion of the ablation device (e.g., the first catheter) may be fixed relative to the rotating distal portion of the ablation device (e.g., the barbs 2920 and catheter 2910).

[0113]

[0154] In some variations, the first portion (2924) can be angled relative to the second portion (2922) in a manner similar to that described in detail herein with respect to FIGS. 26A-26C. In some variations, the protrusion can include a bend, and the first portion (2924) is at an acute angle relative to the second portion (2922). For example, as shown in FIGS. 29A-29C, the first portion (1924) is at an acute angle relative to the longitudinal axis (2921) of the base portion (2926). The base portion (2926) can be generally cylindrical and configured to be coupled to a proximal portion of the catheter (2910) (e.g., a second catheter, a distal catheter). For example, the base portion (2926) can be proximal to a dilator (not shown in FIGS. 29A-29C).

[0114]

[0155] In some variations, the barbs may be configured to translate relative to the dilator 3030 to transition between a first configuration (e.g., a retracted configuration) and a second configuration (e.g., an extended configuration). Figures 30A and 30B are side cross-sectional views of a distal portion of an ablation device 3000 including a catheter 3010 (e.g., a second catheter), barbs 3020, and a distal tip 3030 (e.g., a dilator). In some variations, the catheter 3010 and / or the dilator 3030 may include one or more lumens 3012. For example, a guidewire (not shown) may be configured to be slidably disposed within the lumen 3012 and / or another catheter 3010. In some variations, the dilator 3030 may define a recess 3040 configured to retain (e.g., surround, enclose) the barb 3020. That is, the barbs 3020 can be configured to seat within the recesses 3040. For example, the length of the recesses 3040 can be at least equal to the length of the barbs 3020, such that the barbs 3020 can fit entirely within the recesses 3040. In some variations, the recesses 3040 can be defined in the proximal end of the dilator 3030.

[0115]

[0156] Figure 30A shows the ablation device 3000 in a first configuration, where the barbs 3020 are positioned inside the recesses 3040 of the dilator 3030. In the first configuration, the barbs 3020 can be protected from tissue, which can be beneficial as the catheter 3010 and dilator 3030 are advanced within the patient. Figure 30B shows the ablation device 3000 in a second configuration, where the barbs 3020 are positioned outside the recesses 3040 of the dilator 3030. In the second configuration, the barbs 3020 can be configured to engage tissue, as described in detail herein.

[0116]

[0157] In some variations, the handle of the device can be configured to control the translation of the barbs 3020 and / or catheter 3010 relative to the dilator 3030, thereby allowing control of the size of the tissue ablated. For example, the barbs 3020 extending from the dilator 3030 can tent the tissue they engage, increasing the diameter of the tissue ablated by the ablation device 3000. In some variations, the position of the proximal portion of the ablation device (e.g., a catheter including electrodes) and the dilator 3030 can be fixed relative to the translatable barbs 3020. For example, the barbs 3020 can be transitioned from a first configuration to a second configuration after the dilator 3030 has been advanced through the atrial septum.

[0117]

[0158] In some variations, the barbs may be formed to have sufficient strength to hold tissue without breaking it. The barbs may include one or more of stainless steel, nitinol, platinum, polyvinyl chloride (PVC), polyethylene (PE), cross-linked polyethylene, polyolefin, polyolefin copolymer (POC), polyethylene terephthalate (PET), polyester, nylon, polymer blends, polyester, polyimide, polyamide, polyurethane, silicone, polydimethylsiloxane (PDMS), PEBAX, combinations thereof, and others.

[0118]

[0159] Additionally or alternatively, the barbs may have one or more of a spiral, helix, corkscrew, and coil shape. FIG. 40A is a side view, and FIG. 40B is a perspective view, of a barb (4000) having a double helix shape. The barb (4000) may include a base (4010), a first prong (4020), and a second prong (4022). The prongs (4020, 4022) may each include a distal tip configured to pierce (e.g., bite into) tissue. For example, the barb (4000) may be configured to rotate and penetrate (e.g., thread) into tissue. The prongs (4020, 4022) may have the same or different shapes and dimensions. In some variations, the catheter may be configured to rotate about a longitudinal axis to twist the barbs (4000) and engage tissue. As described in detail herein with respect to Figures 29A-29C, rotation of the barb can allow for control of the diameter of tissue being ablated.

[0119]

[0160] In some variations, the barbs may include a series of concentric rings along the length of the second catheter. For example, the barbs may include a series of rings, each with a thin radial edge configured to engage tissue. The tented tissue engaged by the barbs may be configured to generally form a conical or cylindrical shape. In some variations, at least a portion of the barbs may include an uneven or roughened surface configured to assist in engaging tissue. In other variations, the barbs may include a stepped structure. In some variations, the protrusions may include a mesh made up of one or more struts. For example, the mesh may be radially arranged around the second catheter and flared outward.

[0120] visualization mechanism

[0161] In some variations, the ablation devices and systems described herein may include one or more visualization mechanisms for indirectly visualizing the ablation device. For example, the visualization mechanisms and techniques may facilitate one or more of imaging, positioning, alignment, and operation of the ablation device within a body cavity. For example, indirect visualization techniques include, but are not limited to, ultrasound, fluoroscopy, and x-ray. Fluoroscopic visualization elements allow for alignment of catheters with respect to tissue and with each other, as described in detail herein.

[0121]

[0162] In some variations, the visualization mechanism may be visualized using techniques such as ultrasound and fluoroscopy during operation of the ablation system. For example, a contrast agent may be used to visualize one or more components of the ablation device and their position and / or orientation relative to tissue, such as the atrial septum. In some variations, the contrast agent (e.g., contrast medium) may include one or more of agitated saline and microbubbles (e.g., CO2). In particular, microbubbles may be used in conjunction with tomographic (e.g., ultrasound) examinations, such as echocardiography. For example, microbubbles may receive ultrasound energy and oscillate or vibrate upon reflecting ultrasound. Microbubbles introduced into a body cavity may enhance image contrast at interfaces between tissue, blood, and the ablation device.

[0122]

[0163] In some variations, the microbubbles may comprise a shell and a gas core. For example, the shell of the microbubbles may comprise one or more of albumin, galactose, proteins, lipids, polymers, combinations thereof, and the like. The gas core of the microbubbles may comprise one or more of air, nitrogen, perfluorocarbons, combinations thereof, and the like.

[0123]

[0164] Generally, the diameter of the microbubbles can be from about 1 μm to about 1 mm, from about 1 μm to about 5 μm, from about 1 μm to about 10 μm, from about 10 μm to about 50 μm, from about 50 μm to about 0.1 mm, from about 0.1 mm to about 0.5 mm, from about 0.5 mm to about 1 mm, including all ranges and subvalues ​​therebetween.

[0124]

[0165] In some variations, the ablation devices described herein can be configured to eject microbubbles for indirect visualization. FIG. 31A is a side view of an ablation device 3100 including a first catheter 3110, an electrode 3120, and a dilator 3150. In some variations, the dilator 3150 can include one or more fluid ports 3160 configured to eject microbubbles. That is, as described in detail herein, microbubbles can be introduced (e.g., injected) into a body cavity when the ablation device 3100 is in a closed configuration. FIG. 31A shows multiple fluid ports 3160 arranged radially around the proximal circumference of the dilator 3150. In some variations, microbubbles can be delivered within the lumen of the electrode 3120 and configured to exit the ablation device 3100 through one or more of the fluid ports 3160.

[0125]

[0166] Additionally or alternatively, the electrode 3120 may include one or more fluid ports, as described in more detail with respect to Figures 42A and 42B. For example, the distal end of the electrode may include one or more holes (e.g., apertures, slits, channels, recesses, protrusions) configured to eject microbubbles. In some variations, any portion of the electrode 3120 may include a fluid port 3160.

[0126]

[0167] FIG. 31B is a side cross-sectional view of an ablation device 3100 including a first catheter 3110, an electrode 3120, a second catheter 3130, barbs 3140, and a dilator 3150. The ablation device 3100 in a closed configuration shown in FIG. 31B shows the barbs 3140, microbubbles 3170, and the proximal end of the dilator 3150 enclosed within the lumen of the electrode 3120. One or more of the first catheter 3110 and the second catheter 3130 can be configured to eject contrast agent 3170 (e.g., microbubbles) from their respective contrast lumens (not shown in FIG. 31B). For example, the contrast agent 3170 can be ejected into the lumen of the electrode 3120 and then ejected out of the ablation device 3100 via a fluid port 3160.

[0127]

[0168] In some variations, contrast agent (e.g., microbubbles) can be introduced (e.g., injected) into the lumen of the electrode 3120 and then into the body cavity when the ablation device 3100 is in the closed configuration. FIG. 31C is a detailed side cross-sectional view of the ablation device 3100. In some variations, the dilator 3152 can include a mating surface 3152 configured to engage the distal end of the electrode 3120 in the closed configuration, for example, similar to that described with respect to FIGS. 6A-6C and 9A-9B. As shown in FIG. 31C, contrast agent 3170 can be configured to pass between the inner diameter of the electrode 3120 and the outer diameter of the proximal end of the dilator 3150 and flow out the fluid port 3160. Thus, the contrast agent 3170 can be expelled from the ablation device 3100 through the fluid port 3160. When the mating surface is not pressed against the electrode 3120 (e.g., when the operator is retracting the handle that applies the preload force), the ablation device 3100 can be configured to expel microbubbles from the fluid port 3160. Accordingly, one or more fluid ports 3160 of the expander 3150 can be configured to expel the contrast agent 3170 received from the lumen of the electrode 3120.

[0128]

[0169] 31D, 31E, and 31F are perspective views of the distal end of an ablation device 3100 including a first catheter 3110, an electrode 3120, a second catheter 3130, a barb 3140, and a dilator 3150. The ablation device 3100 is arranged in an open configuration to help illustrate the various fluid port configurations 3160, 3162, 3164 of the dilator 3150. The fluid ports 3160, 3162, 3164 can be configured to allow contrast agent (e.g., microbubbles) to flow from the lumen of the electrode 3120 to the exterior of the ablation device 3100. Without the fluid ports 3160, 3162, 3164, contrast media would be sealed within the lumen of the electrode 3120 when the ablation device 3100 is in the closed configuration, necessitating the separation of the electrode 3120 from the dilator 3150. In contrast, the fluid port 3160 allows contrast media to flow into the body cavity from the closed configuration.

[0129]

[0170] In some variations, the fluid port 3160 may include shapes including, but not limited to, holes, apertures, slits, channels, recesses, protrusions, holes, recesses, combinations thereof, and others. Figure 31D shows a fluid port 3160 configuration including multiple longitudinal channels disposed along a proximal portion of the dilator 3150 proximal to the mating surface 3152 of the dilator 3150. Figure 31E shows a fluid port 3162 configuration including multiple recesses disposed within the mating surface 3152 of the dilator 3150. Figure 31F shows a fluid port 3164 configuration including a combination of the longitudinal channels of Figure 31D and the recesses of Figure 31E. In some variations, the ablation device 3100 may include one or more fluid ports 3160. For example, the ablation device (3100) may include up to about 3 fluid ports, up to about 5 fluid ports, up to about 7 fluid ports, up to about 10 fluid ports, up to about 20 fluid ports, up to about 50 fluid ports, up to about 75 fluid ports, up to about 100 fluid ports, including all values ​​and subranges therebetween.

[0130]

[0171] As shown in FIGS. 42A and 42B , the electrode 4200 may include one or more fluid ports 4220. For example, the distal end 4210 of the electrode 4200 may include one or more fluid ports 4220 (e.g., holes, openings, slits, channels, recesses, protrusions, outlets) configured to eject fluids (e.g., contrast agents, contrast media, microbubbles). For example, the diameter of the fluid ports 4220 may be at least the same as the diameter of the microbubbles, allowing the microbubbles to pass through them. In some variations, the fluid ports of the electrode 4200 may be aligned or offset with the fluid ports of the dilator. In some variations, the fluid ports described herein may be formed by laser cutting. In some variations, any portion of the electrode 4200 may include a fluid port 4220.

[0131]

[0172] Figure 33A is a side view and Figure 33B is a cross-sectional side view of a distal portion 3310 (e.g., dilator, distal tip) of an ablation device 3300. In some variations, the dilator 3310 can include a lumen 3312, a proximal end 3314, a mating surface 3316, and one or more visualization features 3320, 3222. In some variations, the visualization features 3320, 3222 can correspond to echogenic regions.

[0132]

[0173] In some variations, the echogenic region may include one or more microspheres, depressions, protrusions, channels, grooves, scratches, edges, indentations, blind holes, peaks and valleys, undercuts, combinations thereof, and the like. For example, the diameter of the one or more microspheres, depressions, or protrusions may be from about 5 μm to about 100 μm. In some variations, the microspheres may include a gas core. The microspheres may include glass.

[0133]

[0174] In some variations, the echogenic region may include one or more portions of the dilator. For example, Figures 33A and 33B show the proximal portion (3314) without visualization features (3320, 3222). In some variations, the echogenic region may include multiple texture patterns. For example, a first texture pattern may be disposed along the distal end of the dilator (3310) and a second texture pattern may be disposed along the proximal end of the dilator (3310). This may assist in distinguishing different portions of the dilator (3310). In some variations, the texture pattern may include shapes including, but not limited to, circumferential, radial, hatched, random, linear, curved, spiral, oval, ellipsoidal, sinusoidal, polygonal, nonlinear, combinations thereof, and others.

[0134]

[0175] In some variations, the echogenic region may contain visualization features (e.g., depressions, protrusions, etc.) at a density of about 5% to about 50%, about 10% to about 40%, about 20% to about 30%, about 5% to about 10%, about 10% to about 20%, about 30% to about 40%, about 40% to about 50%, including all values ​​and subranges therebetween.

[0135]

[0176] In some variations, the echogenic region may be on and / or below the surface of the expander 3310. For example, FIG. 33A shows a schematic (e.g., not to scale) representation of a plurality of microspheres formed on the surface of the expander 3310. In some variations, the echogenic region may include one or more surface textures or patterns on the surface of the expander 3310. In some variations, the surface texture of the echogenic region may be created using one or more of injection molding, laser engraving, polishing, grooving, etching, vapor deposition, combinations thereof, and the like.

[0136]

[0177] FIG. 33B shows a schematic representation of multiple microspheres formed under the surface of the expander 3310. In some variations, a heat treatment (e.g., vesicle formation) can be applied to the expander 3310 to generate one or more microspheres under the surface of the expander 3310. For example, heating the expander 3310 to a temperature above the melting point of the expander's material (e.g., plastic) can induce microbubble formation that contains voids under the expander's surface through vaporization of volatile compounds. In some variations, the expander can be formed using microspheres, such as glass beads, disposed under the expander's surface. In some variations, a high-temperature heat source (e.g., flame, laser) can treat the surface of the expander 3310 in short bursts (e.g., less than one second), thereby melting the surface but not the entire thickness of the expander 3310. Additionally or alternatively, glass microspheres can be incorporated into a resin matrix that is injection molded to form the expander (3310).

[0137]

[0178] Additionally or alternatively, fluoroscopy is a technique for real-time X-ray imaging that can be used to guide catheters inserted into and navigated through blood vessels. Generally, in fluoroscopy, an X-ray beam is projected from a fluoroscope through a region of interest within the body. The object being visualized (e.g., an ablation device) can be imaged using an image intensifier. Thus, a user viewing the real-time image displayed by the image intensifier can determine the orientation and alignment of the catheters.

[0138]

[0179] In some variations, one or more of the first and second catheters may include metallic radiopaque markers including one or more of rings, bands, and inks (e.g., platinum, platinum-iridium, gold, nitinol, palladium) configured to allow visualization under a fluoroscope.

[0139]

[0180] The ablation devices described herein may comprise any radiopaque metal, such as tungsten, platinum iridium, stainless steel, titanium and tungsten-filled polymers, zirconia ceramic, or any suitable radiopaque material. The visualization mechanism may be located on or within the catheter at any suitable location (e.g., on one or more exterior surfaces of the device, the interior of the catheter, or otherwise). In some variations, one or more portions of the ablation device may be fabricated from a radiopaque material, or the visualization mechanism may be attached to the device by any suitable method, such as mechanical attachment (e.g., embedded in a portion of the catheter, circumferentially surrounding it, or otherwise), adhesive bonding, welding, soldering, a combination thereof, or otherwise.

[0140] Sensor

[0181] In some variations, the ablation devices and systems described herein may include one or more sensors. Generally, the sensors described herein may be configured to transmit and / or receive signals corresponding to one or more parameters. In some variations, the sensor may include one or more of a pressure sensor, a temperature sensor, an electrical sensor (e.g., impedance sensor, voltage sensor for detecting signals such as electromyogram, electrocardiogram, etc., and others), a magnetic sensor (e.g., RF coil), an electromagnetic sensor (e.g., infrared photodiode, optical photodiode, RF antenna), a force sensor (e.g., strain gauge), a flow rate or velocity sensor (e.g., hot wire anemometer, vortex flowmeter), an acceleration sensor (e.g., accelerometer), a chemical sensor (e.g., pH sensor, protein sensor, glucose sensor), an oxygen sensor (e.g., pulse oximetry sensor, myocardial oxygen consumption sensor), an audio sensor (e.g., microphone for heart murmur detection, auscultation), a sensor for detecting other physiological parameters (e.g., sensors for detecting the heart wall, heart rate, respiratory rate, arrhythmias), a stimulator (e.g., for stimulation and / or pacing functions), combinations thereof, and others. In some variations, the impedance sensor may be configured to monitor impedance between the electrode and the return electrode to confirm completion of tissue ablation.

[0141] Guidewire

[0182] In some variations, a guidewire may be slidably disposed within the ablation device and configured to be passed through the atrial septum (e.g., using a standard transseptal puncture technique). In some variations, the first and second catheters of the ablation device may translate along the guidewire relative to each other and / or the atrial septum. For example, the guidewire may include one or more of stainless steel, nitinol, platinum, and other suitable biocompatible materials.

[0142] catheter

[0183] In general, the catheters described herein can be configured to deliver electrodes and barbs to one or more heart chambers to ablate tissue, such as the atrial septum. In some variations, the catheters can include a shaft constructed of a flexible polymeric material, such as Teflon, nylon, Pebax, combinations thereof, and others. In some variations, the ablation device can include one or more steerable or deflectable catheters (e.g., one-way, two-way, four-way, multi-way). In some variations, the first catheter can include one or more pull wires configured to steer or deflect a portion of the first catheter. In some variations, the bend radius of the first catheter can be from about 45 degrees to about 270 degrees. In some variations, the second catheter described herein defines a lumen through which a guidewire can pass.

[0143]

[0184] In some variations, the catheters may be woven and / or braided and made of materials (e.g., nylon, stainless steel, polymers) configured for pushability and flexibility of the catheter. In some variations, the first catheter may have a predetermined curved shape configured to guide the second catheter toward the septum at a predetermined orientation and angle.

[0144]

[0185] 34A and 34B are side cross-sectional views of the distal end of a first catheter 3410 of an ablation device 3400. In some variations, the distal portion of the first catheter 3410 may include a predetermined bend (e.g., a pre-curved tip), as shown in FIG. 34A. For example, the predetermined bend may allow the distal end of the first catheter 3410 to be oriented at a predetermined angle relative to tissue, such as the atrial septum. In some variations, the angle of the predetermined bend may be between about 30 degrees and about 70 degrees.

[0145]

[0186] In some variations, the distal portion of the first catheter 3410 can be positioned at a predetermined position and / or orientation (e.g., substantially perpendicular to the tissue wall) by deflecting the first catheter 3410 (e.g., controlling its bend). In some variations, the first catheter actuator 3430 can be configured to deflect the distal end of the first catheter 3410 and simultaneously electrically couple the electrode 3430 to a signal generator (not shown). In this manner, the first catheter actuator 3430 can simultaneously act as a pull wire configured to manipulate the first catheter 3410 and deliver energy to the electrode 3420.

[0146]

[0187] In some variations, the ablation device 3400 may include a first catheter 3410, an electrode 3420 coupled to the distal end of the first catheter 3410, and a first catheter actuator 3430 coupled to the electrode 3420. For example, the first catheter actuator 3430 may be electrically coupled to the electrode 3420. In some variations, the first catheter actuator 3430 may be coupled (e.g., fixed, welded, laser welded) to an inner surface of the electrode 3420. Thus, pulling the first catheter actuator 3430 may apply a predetermined amount of tension to the distal portion of the first catheter 3410. The first catheter actuator 3430 may have a longitudinal axis that is offset and parallel to a central longitudinal axis (not shown) of the first catheter 3410. Pulling the first catheter actuator (3430) can create a bending moment between the central longitudinal axis of the first catheter (3410) and the radius at which the first catheter actuator (3430) is connected to the electrode (3420).

[0147]

[0188] The electrode 3420 may be configured to ablate tissue using current supplied from a signal generator through electrical conductors (e.g., lead wires) of the first catheter actuator 3430. In some variations, the first catheter actuator 3430 may include a pull wire extending along the length of the first catheter 3410. The proximal end of the first catheter actuator 3430 may be configured to be coupled to an actuation mechanism. For example, a handle may include an actuation mechanism configured to manipulate the first catheter 3410 via the first catheter actuator 3430. That is, as shown in FIG. 34B, tension and compression may be applied to the first catheter actuator 3430 to deflect (e.g., change angle) the distal portion of the first catheter 3410. Therefore, separate pull wires and lead wires are not required, which may reduce the size and manufacturing costs of the ablation device 3400.

[0148]

[0189] Figures 34C and 34D are side cross-sectional views of variations of an ablation device 3400. Figure 34C shows an ablation device 3400 including one first catheter actuator 3430, and Figure 34D shows an ablation device 3400 including a pair of first catheter actuators 3430, 3432. The first catheter actuators 3430, 3432 can each be configured to be electrically coupled to an electrode for redundancy.

[0149]

[0190] FIG. 34C shows an ablation device 3400 including a first catheter 3410 defining a first catheter lumen 3412 and a first catheter actuator lumen 3434. In some variations, the first catheter actuator 3430 may include a lead wire 3431, which includes insulation surrounding the electrode wire. In some variations, the insulation may be configured as a slidable channel. The insulation may include, for example, PTFE, PEEK, polyimide, combinations thereof, and others. In some variations, the first catheter actuators 3430, 3432 may be coupled to an inner wall of the first catheter 3410 along the length of the first catheter 3410.

[0150]

[0191] In some variations, multiple first catheter actuators may further aid in maneuverability and improve control of the ablation device. For example, the first catheter actuators may be actuated together to provide a push-pull action (e.g., one actuator configured to pull and the other configured to push). Figure 34D shows an ablation device (3400) including a first catheter (3410) defining first catheter actuator lumens (3434, 3436) having respective first catheter actuators (3430, 3432). In some variations, the first catheter actuators (3430, 3432) may be disposed on each side of the first catheter (3410). In some variations, the first catheter actuator lumens (3434, 3436) may have a "D" shape.

[0151]

[0192] In some variations, the first catheter actuator may be fabricated from stainless steel. In some variations, the first catheter (3410) may include a core (3411) (e.g., PTFE) configured to maintain the alignment and radial position of the first catheter actuators (3430, 3432).

[0152] expander

[0193] Generally, the dilators described herein can be configured to pierce tissue, such as the atrial septum, to advance one or more portions of the ablation device into a body cavity, such as the left atrium of the heart. In some variations, the dilators can generally be configured to spread tissue, such as the atrial septum. The dilators can be atraumatic in shape to minimize any accidental or unintended damage. The dilators can include a tapered section of about 1 degree to about 45 degrees to facilitate advancement of the device through the septum and into the left atrium. In some variations, the dilators can include thermoplastic polymers, nylon, polyurethane, ABS, acetal, polycarbonate, PET, PEBA, PEEK, PTFE, silicone, PS, PEI, latex, sulfates, barium sulfate, copolymers, combinations thereof, and others. As described in more detail herein, the dilators can include one or more visualization features, such as fluid ports and echogenic regions.

[0153]

[0194] In some variations, the expander of the ablation device can be configured to compress the tissue and / or assist in the ablation process. As described herein, the distal end of the electrode can be configured to abut a corresponding mating surface of the expander. For example, the second catheter can be retracted relative to the first catheter, causing the mating surface to apply a preload force to the electrode. When the tissue between the electrode and the mating surface is compressed (due to the preload force), the thickness of the tissue to be ablated can be reduced, thereby allowing the septum to be ablated more quickly and with less energy. Furthermore, tissue compression can hold (e.g., fixate, lock) the tissue in place relative to the ablation device, ensuring only a predetermined portion of the tissue is ablated. In some variations, tissue compression while electrical energy is applied can cause layers of tissue (e.g., the left and right atrial septum layers) to fuse together during ablation, thereby reducing the surface area of ​​exposed tissue along the periphery of the anastomosis after tissue ablation. Tissue compression can also reduce the volume of the tissue.

[0154]

[0195] In some variations, the dilator can be configured to contact and electrically short the electrode when tissue is completely ablated, thereby halting the formation of a cutting plasma and reducing excessive energy delivery, heat, bubble formation, nerve stimulation, and the like. For example, when the uninsulated distal end of the electrode is energized, a cutting plasma can be generated and ablate tissue compressed between the electrode and the mating surface of the dilator. However, once the tissue is ablated and separated from the electrode, the electrode becomes insulated from the internal electrical conduction pathway provided by the tissue, thereby extinguishing the cutting plasma. Thus, complete tissue ablation can be performed mechanically without sensors and / or feedback control, thereby simplifying the ablation procedure.

[0155]

[0196] FIG. 35A is a side cross-sectional view of the distal end of an ablation device 3500 including a dilator 3510, an insulator 3520, and an electrode 3530. The dilator 3510 may include a lumen 3512, a proximal end 3514, and a mating surface 3516 defining a recess 3518 configured to receive the distal end of the electrode 3530. As shown in FIG. 35A, the distal end of the electrode 3530 is not insulated. In some variations, the mating surface 3518 may include one or more non-conductive and / or heat-resistant portions. In some variations, the mating surface 3518 may be configured to withstand high temperatures generated during an ablation procedure. For example, the non-conductive portions may include one or more of a polymer (e.g., PEEK, polyimide), a ceramic (e.g., zirconia), and aluminum oxide. Thus, the electrode (3530) can be configured to electrically short when the electrode (3530) ablates tissue and engages the recess (3518) of the mating surface (3516).

[0156]

[0197] Additionally or alternatively, the mating surface may comprise a deformable material. Figure 35B is a detailed side cross-sectional view of an ablation device 3550 including a dilator 3560, an insulator 3570, and an electrode 3580. The dilator 3560 may include a proximal end 3564 and a mating surface 3566. In some variations, the mating surface 3516 may be configured to be deformable (e.g., compressible). When the dilator 3560 is retracted toward the electrode 3580, tissue disposed between the electrode 3580 and the mating surface 3566 may be compressed along with the mating surface itself.

[0157]

[0198] Additionally or alternatively, the mating surface may include a conductive portion configured to focus RF energy (e.g., focused monopolar) to function as a dissipative element and / or strengthen the power line and thus control stray ablation of tissue during ablation. For example, the conductive portion of the dilator may increase the surface area electrically coupled to the electrode, thereby reducing the current density of the electrode below a threshold level sufficient for tissue ablation. Thus, the electrode may be configured to contact the conductive mating surface after tissue ablation. In some variations, the surface area of ​​the conductive portion of the mating surface may be about 4 to about 10 times the surface area of ​​the exposed portion of the electrode (e.g., the distal edge of the electrode).

[0158]

[0199] In some variations, the dilator can have a length of about 2 mm to about 2 cm. For example, the dilator can have a length of about 5 mm to about 1 cm. In some variations, the dilator can have a taper of about 5 degrees to about 20 degrees relative to the longitudinal axis of the dilator. In some variations, the distal end of the dilator can be atraumatic (e.g., rounded, blunted). As described herein, barbs can be coupled to the proximal end of the dilator.

[0159] handle

[0200] In general, the handles described herein may be configured to allow an operator to grasp and control one or more of the position, orientation, and operation of the ablation device. In some variations, the handle may include an actuator that allows translation and / or rotation of the first and second catheters, in addition to manipulation by an optional delivery catheter. Deployment of the barbs may be performed by a deployment mechanism (e.g., a screw / rotation mechanism, a translation mechanism, a slider) in some variations. In some variations, the handle may be configured to limit the force a user may apply to advancement and retraction of the catheter shafts relative to one another. For example, the handle may be configured to apply energy to electrodes to ablate tissue and / or control one or more sensors. In some variations, the handle may be coupled between a signal generator and the ablation device.

[0160]

[0201] Figure 39A is a perspective view and Figure 39B is a plan view of the handle (3900) of the ablation device. In some variations, the handle (3900) can include one or more actuation mechanisms (3910), a fluid port (3920), and a removable electrical connector (3930). The handle (3900) can be coupled to the proximal end of a first catheter (3950). In some variations, the handle (3900) can be configured to allow an operator to hold (e.g., grasp) and control one or more of catheter deflection (e.g., maneuverability), tissue ablation (e.g., energy delivery to electrodes), catheter translation (e.g., transition between open and closed configurations, tissue compression), and visualization (e.g., contrast fluid delivery).

[0161]

[0202] For example, the actuation mechanism (3910) can be configured to control a preload force, described in detail herein, of the dilator of the second catheter applied to the electrode of the first catheter. In some variations, the actuation mechanism (3910) can include a screw mechanism that includes a plurality of predetermined stops, thereby allowing the operator to select the amount of preload at the distal end of the ablation device. For example, the operator can use the actuation mechanism (3910) to select a predetermined preload force when the ablation device is in the ablation configuration and tissue is compressed between the electrode and the dilator. In some variations, the actuation mechanism (3910) can be coupled to the shaft of the second catheter, such that the actuation mechanism (3910) can be configured to pull the distal portion of the second catheter toward the handle (3900) using the screw mechanism.

[0162]

[0203] In some variations, the actuation mechanism 3910 can be configured to actuate one or more first catheter actuators as described herein. For example, the first catheter actuators can be configured to manipulate and / or deflect the distal end of the first catheter. That is, the actuation mechanism 3910 can be configured to push and / or pull the first catheter.

[0163] signal generator

[0204] In general, the signal generators described herein can be configured to provide energy (e.g., energy waveforms) to an ablation device to ablate a predetermined portion of tissue, such as the atrial septum. In some variations, the ablation systems described herein can include an energy source and a signal generator having a processor configured to deliver waveforms to deliver energy to tissue (e.g., the atrial septum). The waveforms described herein can assist in creating an anastomosis. In some variations, the signal generator can be configured to control waveform generation and delivery in response to received sensor data. For example, energy delivery can be inhibited unless pressure sensor measurements confirm engagement and compression of tissue between the electrodes and corresponding mating surfaces.

[0164]

[0205] The signal generator may generate and deliver several types of signals, including, but not limited to, radio frequency (RF), direct current (DC) impulses, stimulation range impulses, and / or hybrid electrical impulses. For example, the signal generator may generate monophasic (DC) pulses and biphasic (DC and AC) pulses. The signal generator may include a processor, memory, an energy source, and a user interface. The processor may incorporate data received from one or more of the memory, the energy source, the user interface, and the ablation device. The memory may further store instructions that cause the processor to execute modules, processes, and / or functions associated with the system, such as waveform generation and delivery. For example, the memory may be configured to store patient data, clinical data, treatment data, and so forth.

[0165]

[0206] In some variations, the signal generator may be configured to generate alternating current, voltage, and / or power within the radio frequency spectrum from about 9 kHz to about 300 MHz at a power level of about 5 W to about 500 W. In some variations, the RF generator may operate by outputting a constant voltage, constant power, and / or constant current. In some variations, the RF generator outputs a constant sine wave for the duration of tissue ablation. For example, the RF generator may be configured to output a sine wave of about 400 kHz to about 600 kHz, about 450 kHz to about 550 kHz, about 475 kHz to about 525 kHz, including all values ​​and subranges therebetween. In some variations, the RF signal output is interrupted or attenuated to ensure that RF energy is applied for a certain percentage of the operating time.

[0166]

[0207] In some variations, the signal generator may be configured to synchronize energy delivery with a predetermined phase of the patient's cardiac cycle. For example, the sensor may be configured to measure an ECG signal, and the signal generator may be configured to deliver a signal waveform based on (e.g., synchronously with) the ECG signal. Additionally or alternatively, a pacing signal for cardiac stimulation may be generated and used to deliver a signal waveform by the signal generator synchronously with the pacing signal.

[0167]

[0208] 37 illustrates an exemplary variation of a voltage waveform (3700) for an ablation procedure, including a first waveform (e.g., an overshoot spike) (3710) and a second waveform (e.g., a substantially steady-state voltage) (3720). In some variations, a signal generator may be configured to generate the first waveform (3710) followed by a second waveform (3720), the first waveform having a higher voltage than the second voltage of the second waveform. The first waveform (3710) may be configured to rapidly ablate tissue upon energy delivery. The lower voltage second waveform (3720) may reduce one or more of heat propagation, bubbling, nerve stimulation, and the like. The second waveform may be configured to desiccate the ablated tissue retained within the ablation device, thereby assisting in tissue containment and compartmentalization.

[0168]

[0209] Alternatively, the first waveform can be configured to desiccate tissue. For example, the first waveform can include a voltage below the ionization threshold of vapor (e.g., less than about 130 volts) for a duration of about 100 milliseconds to about 60 seconds. Impedance can be monitored to prevent plasma formation.

[0169]

[0210] Generally, a processor (e.g., a CPU) described herein may process data and / or other signals to control one or more components of a system. The processor may be configured to receive, process, edit, calculate, store, access, read, write, and / or transmit data and / or other signals. In some variations, the processor may be configured to access or receive data and / or other signals from one or more of a sensor (e.g., a pressure sensor) and a storage medium (e.g., a memory, a flash drive, a memory card). In some variations, the processor may be any suitable processing device configured to run and / or execute a sequence of instructions or code, and may include one or more data processors, image processors, graphics processing units (GPUs), physical processing units, digital signal processors (DSPs), analog signal processors, mixed-signal processors, machine learning processors, deep learning processors, finite state machines (FSMs), compression processors (e.g., data compression to reduce data rates and / or memory demands), encryption processors (e.g., for securing wireless data and / or power transmissions), and / or central processing units (CPUs). The processor may be, for example, a general-purpose processor, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a processor board, and / or the like. The processor may be configured to run and / or execute application processes and / or other modules, processes and / or functions associated with the system. The underlying device technology may be provided in various types of components (e.g., metal oxide semiconductor field effect transistors (MOSFETs) such as complementary metal oxide semiconductor (CMOS), bipolar technologies such as emitter coupled logic (ECL), polymer technologies (e.g., silicon-conjugated polymers and metal-conjugated polymer-metal structures), mixed analog-digital, and the like.

[0170]

[0211] The systems, devices, and / or methods described herein may be implemented by software (executed on hardware), hardware, or a combination thereof. Hardware modules may include, for example, general-purpose processors (or microprocessors or microcontrollers), field-programmable gate arrays (FPGAs), and / or application-specific integrated circuits (ASICs). Software modules (executed on hardware) may be expressed in various software languages ​​(e.g., computer code), including C, C++, Java, Python, Ruby, Visual Basic, and other object-oriented, procedural, or other programming languages ​​and development tools. Examples of computer code include, but are not limited to, microcode or microinstructions, machine instructions such as those produced by a compiler, code used to create web services, and files containing higher-level instructions executed by a computer using an interpreter. Other examples of computer code include, but are not limited to, control signals, encryption code, and compression code.

[0171]

[0212] In general, the ablation devices described herein may include memory configured to store data and / or information. In some variations, the memory may include one or more of random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), memory buffer, erasable programmable read-only memory (EPROM), electrically erasable read-only memory (EEPROM), read-only memory (ROM), flash memory, volatile memory, nonvolatile memory, combinations thereof, and others. In some variations, the memory may store instructions that cause a processor to perform modules, processes, and / or functions related to the ablation device, such as generating signal waveforms, controlling the ablation device, transmitting data and / or signals, receiving data and / or signals, and / or communicating. Some variations described herein may relate to computer storage products having a non-transitory computer-readable medium (which may also be referred to as a non-transitory processor-readable medium) having instructions and computer code thereon for performing various computer-implemented operations. The computer-readable medium (or processor-readable medium) is non-transitory in that it does not itself include a transitory propagating signal (e.g., a propagating electromagnetic wave that carries information over a transmission medium such as air or cable). The medium and computer code (which may also be called code or algorithms) may be designed and constructed for one or more specific uses.

[0172]

[0213] In some variations, the ablation device may further include a communications device configured to allow an operator to control one or more of the devices of the ablation system. The communications device may include a network interface configured to connect the ablation device to other systems (e.g., the Internet, a remote server, a database) via a wired or wireless connection. In some variations, the ablation device may communicate with other devices (e.g., cell phones, tablets, computers, smart watches, and the like) via one or more wired and wireless networks. In some variations, the network interface may include one or more of a wireless receiver / transmitter, an optical (e.g., infrared) receiver / transmitter, and the like configured to communicate with one or more devices and / or networks. The network interface may communicate with one or more of the ablation device, a network, a database, and a server via a wired and / or wireless connection.

[0173]

[0214] The network interface may include RF circuitry configured to receive and / or transmit RF signals. The RF circuitry may convert between electrical and electromagnetic signals and communicate with communication networks and other communication devices via electromagnetic signals. The RF circuitry may include well-known circuitry for performing these functions, including, but not limited to, an antenna system, an RF transceiver, one or more amplifiers, a tuner, one or more oscillators, a mixer, a digital signal processor CODEC chipset, a subscriber identity (SIM) card, memory, etc.

[0174]

[0215] Wireless communications through any of the devices may use any of a number of communications standards, protocols, and technologies, including Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), High-Speed ​​Downlink Packet Access (HSDPA), High-Speed ​​Uplink Packet Access (HSUPA), Evolution, Data-Only (EV-DO), HSPA, HSPA+, Dual-Cell HSPA (DC-HSPA), Long-Term Evolution (LTE), Near Field Communication (NFC), Wideband Code Division Multiple Access (W-CDMA), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Bluetooth, Wireless Fidelity (WiFi) (e.g., IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, and others), and voice over Internet. Protocol (VoIP), Wi-Max, protocols for email (e.g., Internet Message Access Protocol (IMAP) and / or Post Office Protocol (POP)), instant messaging (e.g., Extensible Messaging and Presence Protocol (XMPP), Session Initiation Protocol for Instant Messaging and Presence Leveraging Extensions (SIMPLE), Instant Messaging and Presence Service (IMPS)) and / or Short Message Service (SMS), or any other suitable communication protocol. In some variations, devices herein may communicate directly with each other without transmitting data over a network (e.g., via NFC, Bluetooth, WiFi, RFID, and the like).

[0175]

[0216] In some variations, the user interface may include an input device (e.g., a touchscreen) and an output device (e.g., a display device) and may be configured to receive input data from one or more of the ablation device, a network, a database, and a server. For example, operator manipulation of the input device (e.g., a keyboard, a button, a touchscreen) may be received by the user interface, which may then be processed by the processor and memory, and the user interface may output a control signal to the ablation device. Some variations of the input device may include at least one switch configured to generate a control signal. For example, the input device may include a touch surface for an operator to provide input corresponding to the control signal (e.g., touching the touch surface with a finger). Input devices including a touch surface may be configured to detect contact and movement on the touch surface using any of a number of touch sensitivity technologies, including capacitive, resistive, infrared, optical imaging, dispersive signal, audio pulse recognition, and surface acoustic wave technologies. In variations of input devices that include at least one switch, the switch may include, for example, at least one of a button (e.g., hard key, soft key), a touch surface, a keyboard, an analog stick (e.g., a joystick), a directional pad, a mouse, a trackball, a jog dial, a step switch, a rocker switch, a pointer device (e.g., a stylus), a motion sensor, an image sensor, and a microphone. The motion sensor may receive operator movement data from an optical sensor and classify the operator's gestures into control signals. The microphone may receive audio data and recognize the operator's voice as a control signal.

[0176]

[0217] A haptic device may be incorporated into one or more of the input and output devices to provide additional sensory output (e.g., force feedback) to the operator. For example, the haptic device may generate a haptic response (e.g., vibration) to confirm an operator's input to the input device (e.g., touch surface). As another example, the haptic feedback may notify the operator that their input has been overridden by the ablation device.

[0177]

[0218] II. Method Also described herein are methods for forming an anastomosis in a patient's atrial septum using the systems and devices described herein. Specifically, the systems, devices, and methods described herein can be used to capture, resect, and remove a predetermined portion of tissue to create an anastomosis for treating heart failure. In some variations, the method for forming an anastomosis can include advancing a device into the patient's right atrium. A guidewire can be advanced through the atrial septum of the heart to the left atrium. The device can include a dilator configured to pierce the septum so that a first catheter is positioned in the right atrium and a second catheter is positioned in the left atrium. The second catheter can include barbs configured to engage and secure tissue when retracted relative to the first catheter. As the barbs are further retracted (e.g., toward the right atrium), the engaged tissue can be stretched and / or pressed against the barbs, forming a "tent" shape due to the elasticity of the tissue. The barbs and the engaged tented tissue can be retracted into the lumen of an electrode (e.g., a tubular electrode). By positioning ablation devices on either side of the atrial septum, a predetermined force can be applied to engage and / or compress a predetermined portion of the septal tissue to be ablated. For example, an electrode on a first catheter can press the septal tissue against the proximal end (e.g., mating surface) of a dilator. An electrode positioned within the right atrium can be energized and cut (e.g., ablate) the tissue with RF energy using an ablation waveform, as described in more detail herein. The ablated tissue can be surrounded by the ablation device to prevent tissue loss. For example, the ablated tissue can be held by barbs, and the electrode can surround the ablated tissue and barbs. Thus, the ablation devices described herein can be configured to safely and efficiently form interatrial anastomoses.

[0178]

[0219] FIG. 18 is a flowchart generally illustrating one variation of a method 1800 for forming an anastomosis. The method 1800 may include advancing 1802 an ablation device including a first catheter and a second catheter into the patient's right atrium. For example, the ablation device may be advanced over a guidewire and inserted through the femoral vein, e.g., via a transseptal puncture technique. In some variations, the ablation device within the right atrium may be oriented approximately perpendicular to the atrial septum. For example, a first catheter actuator described herein may be configured to deflect a distal portion of the ablation device to change the position of the ablation device relative to the atrial septum. The first catheter may abut the second catheter as it is advanced within the heart. For example, a delivery catheter may be configured to retain each of the first and second catheters until they are deployed within the heart.

[0179]

[0220] The ablation device catheter may be indirectly visualized as needed throughout the ablation procedure. Indirect visualization, such as echocardiography and / or fluoroscopy, may assist the operator in positioning and / or aligning the ablation device relative to tissue. For example, under ultrasound imaging, contrast agents such as microbubbles may be introduced into the pericardial cavity with the ablation device, thereby positioning the electrodes and / or dilators relative to the atrial septum, with the electrodes and / or dilators disposed therebetween. Thus, the user may bring the catheter very close to compress and ablate the tissue. In some variations, the ablation device may be configured to eject microbubbles in a closed configuration for ultrasound visualization of the ablation device and the atrial septum.

[0180]

[0221] In some variations, contrast media can be introduced into the heart through a fluid port in the dilator. In some of these variations, contrast media can be introduced into the lumen of the electrode. Additionally or alternatively, the distal end of the ablation device can include an echogenic region, which can receive ultrasound waves. For example, the distal end of the ablation device can include one or more microspheres having a diameter of about 5 μm to about 100 μm.

[0181]

[0222] Figure 32 is a side view of an ablation device 3200 within the pericardial space. In some variations, the ablation device 3200 may include a first catheter 3210, an electrode 3220, a second catheter 3230, barbs 3240, and a dilator 3250. The ablation device 3200 is shown in an open configuration with tissue (e.g., the atrial septum) 3280 disposed between the electrode 3220 and the dilator 3250, spaced from the barbs 3240. In some variations, the first catheter 3120 may be configured to eject contrast agents (e.g., microbubbles) 3270 into the lumen of the electrode 3220 and into the pericardial space. For example, the contrast lumen 3212 of the first catheter 3210 can be configured to eject contrast agent 3270 into the lumen of the electrode 3220. Contact between the contrast agent 3270 and the electrode 3220 and tissue 3280 can enable indirect visualization (e.g., echocardiography) during one or more steps of the ablation procedure. Visualization of the ablation device 3200 and tissue 3280 can aid in positioning the electrode relative to the tissue 3280. For example, the contrast agent 3270 can be introduced into the right atrium before engaging the tissue 3280 with the barbs. Contrast agent 3270 flowing through the lumen of the electrode 3220 and the pericardial space can allow visualization of the electrode 3220 and the right atrial side of the atrial septum.

[0182]

[0223] A second catheter may be advanced through the atrial septum into the left atrium (1804). For example, the dilator of the second catheter may be advanced through the atrial septum (e.g., over a guidewire) so that the guidewire and dilator are in the left atrium. The second catheter may translate relative to the first catheter. The barbs of the second catheter may be advanced into the left atrium so that the electrodes of the first device are in the right atrium. Septal tissue may slide over the barbs as it is advanced into the left atrium. As shown in FIGS. 19A and 19B, the ablation device (1900) may be positioned in the right atrium (1990) and advanced into the left atrium (1980) using the dilator of the second catheter (1950). The second catheter (1950) may translate relative to the first catheter in the right atrium (1990) and the atrial septum (1970). The barbs 1940 of the second catheter 1950 can be advanced through the septum 1970 and into the left atrium 1980. As shown in the side cross-sectional view of Figure 19C, the first catheter 1910 can include a tubular electrode 1920, a lumen 1922, a lead 1924, a connector 1926, and an insulator 1960. The second catheter 1950 can include the barbs 1940, a mating surface 1954, a dilator, and a dilator lumen 1952.

[0183]

[0224] In some variations, the ablation device may introduce contrast agents (e.g., microbubbles) to visualize the interface between the dilator, tissue, and electrode. In some variations, the electrode may be repositioned about 2 mm to about 5 mm away from the atrial septum based on visualization.

[0184]

[0225] The second catheter may be retracted 1806 relative to the first catheter. For example, the second catheter may be translated toward the first catheter to bring the electrode and dilator closer together. In some variations, the second catheter may be retracted while the first catheter is held in a substantially fixed position within the right atrium. In some variations, contrast agents (e.g., microbubbles) may be introduced to confirm the location of the tissue and the electrode.

[0185]

[0226] In some variations, retracting the second catheter toward the first catheter can include translating the barbs relative to the dilator to engage a first portion of the septum. For example, the barbs can be retracted from the dilator as shown in Figures 30A and 30B. Specifically, the first catheter (3030) can transition from a first configuration in which the barbs (3020) are disposed inside the recesses (3040) of the dilator (3030) to a second configuration in which the barbs (3020) are disposed outside the recesses (3040).

[0186]

[0227] As the second catheter is retracted, the barbs of the second catheter may engage a predetermined portion of the septum (1808). In some variations, this may include rotating the barbs about their longitudinal axes, as shown in Figures 29A-29C. The size of the first tissue portion excised from the second tissue portion may correspond to the angle of rotation of the barbs. The barbs may be rotated through a rotational angle of up to about 360 degrees.

[0187]

[0228] As shown in FIG. 19D , as the second catheter 1950 is retracted relative to the first catheter 1910, the barbs 1940 may engage the septal tissue 1970. For example, the barbs may puncture the first portion as the second catheter is retracted toward the first catheter. The barbs may puncture the first portion, thereby holding layers of the atrial septum (e.g., the left and right atrial layers) together and reducing tissue separation and / or tissue shearing. Thus, the barbs 1940 may capture (e.g., secure, hold) the tissue 1970 while maintaining the structural integrity of the septum. In some variations, the retracted barbs may apply a force to the septum to hold and stretch that portion of the septum (e.g., the first portion) on the barbs. The force may increase as the second catheter is further retracted toward the first catheter. In some variations, retraction of the second catheter may apply a force of at least 20 grams to the atrial septum. For example, the ablation device may apply a force of about 20 grams to about 30 grams to the atrial septum. In some variations, the first portion of the septum may form a substantially cylindrical shape as it is retracted into the lumen.

[0188]

[0229] The barbs described herein have a configuration designed to engage a first portion of the septum without shearing the tissue (e.g., without breaking or tearing one or more layers of the atrial septum), such that the first portion remains intact when engaged by the barbs and retracted into the lumen of the electrode. That is, the force applied by the barbs described herein maintains the structural integrity of the first portion even as the barbs puncture the septum. This can ensure that the first portion of the septum to be ablated remains held and secured by the barbs throughout the procedure, thereby improving the consistency and safety of the methods described herein.

[0189]

[0230] The septum may be retracted into the lumen of the electrode (1810). In some variations, a portion of the atrial septum may form a tent on the barbs as the septum is retracted into the lumen of the electrode. In this manner, the tissue to be ablated may be secured within the ablation device prior to ablation, reducing the risk of uncontrolled tissue loss within the heart chamber and vasculature. As shown in FIG. 19E, a portion of the septum (1970) may form a tent-like shape on the barbs (1940). In some variations, the tissue-engaged barbs (1970) may rotate as they are retracted into the lumen of the electrode, applying a rotational force to the stretched (e.g., tented) septal tissue. In some variations, the size (e.g., diameter) of the tissue to be ablated (1970) may be controlled by varying the distance the engaged tissue (1970) is retracted into the lumen (1922). Thus, the size of the anastomosis may be independent of the diameter of the electrode. By retracting the second catheter toward the first catheter, the ablation device (1900) engages the tissue, stretching, compressing, locking, tenting it, and controlling the size of the ablated opening. In some variations, the size of the anastomosis may depend on the distance the barbs are retracted into the electrode, such that the size of the anastomosis may be independent of the diameter of the ablation device.

[0190]

[0231] In some variations, contrast agents (eg, microbubbles) may be introduced to confirm the location of the tissue and the electrode (eg, to confirm that the electrode is within the right atrium).

[0191]

[0232] The septum may be compressed (1812) between the electrode and dilator. As shown in FIG. 19E, a portion of the atrial septum (1970) may be held between the electrode (1920) and the dilator (1950). For example, the electrode and dilator may be brought close together to abut (e.g., press against) each side of the atrial septum (1970) to "lock" the tissue (1970) in place relative to the ablation device (1900). In some variations, the force applied to the atrial septum by the barbs (1940) through compression may be applied before and during delivery of the ablation waveform. Compression of the tissue may reduce the applied RF energy required to ablate the tissue. In some variations, one or more of the barbs and dilator may be rotated about the longitudinal axis of the second catheter to further engage and / or compress the tissue.

[0192]

[0233] In some variations, as shown in FIG. 35B, the compressible proximal portion of the dilator can be deformed by retracting the second catheter toward the first catheter.

[0193]

[0234] FIG. 36A is a side view of an ablation device (3600) within the pericardial space, illustrating the compression step of the ablation procedure. In some variations, the ablation device (3600) may include a first catheter (3610), an electrode (3620), a second catheter (3630), barbs (3640), and a dilator (3650). In some variations, the first catheter (3610) may include a contrast lumen (3612), which is described in more detail herein. In some variations, the electrode (3620) may include a lumen configured to retain one or more of the barbs (3640), a first portion of tissue (3672), and a proximal portion (3652) of the dilator (3650). In some variations, a guidewire (3630) may be slidably disposed within the second catheter (3630).

[0194]

[0235] As shown in FIG. 36A , the barbs 3640 can be configured to engage a first portion 3672 of the atrial septum 3670 in an ablation configuration in which tissue 3674 is compressed between the distal edge of the electrode 3630 and the proximal portion 3652 of the dilator 3650. For example, the distal end of the electrode 3620 can be configured to abut a corresponding mating surface 3652 of the dilator 3650. For example, the second catheter 3630 can be retracted relative to the first catheter 3610, causing the mating surface 3652 to apply a preload force to the tissue 3674 and the electrode 3620. In some variations, the application of the preload force can be controlled by the operator via an actuator on the handle. Compression of the tissue between the electrode and the mating surface (via the preload force) can also reduce the thickness of the tissue being ablated, allowing the septum to be ablated more quickly and with less energy. Additionally, compressed tissue can hold (e.g., secure, lock) the tissue in place relative to the ablation device, ensuring only a predetermined portion of the tissue is ablated. Compressing the tissue can also reduce the volume of the tissue. In some variations, the preload force can be about 0.4 N to about 25 N, about 1 N to about 10 N, about 5 N to about 10 N, about 5 N to about 15 N, or about 10 N to about 20 N, including all ranges and subvalues ​​therebetween.

[0195]

[0236] In some variations, the compressed tissue 3674 and dilator 3650 may rest in a static equilibrium state in which the proximal portion 3652 of the dilator 3650 presses the tissue 3674 against the electrode 3620 with a shear force that includes a radial component. In some variations, extension of the dilator 3650 prior to ablation is advantageous for operator visualization using a fluoroscope. In some variations, the ablation device 3600 in the ablation configuration (FIG. 36A) may correspond to the dilator 3650 extending approximately 1 mm from the end of the electrode 3620.

[0196]

[0237] An ablation waveform can be delivered to the electrodes 1814 to ablate the septum. For example, the signal generator can generate a biphasic radiofrequency waveform configured to ablate a portion of the atrial septum retained by the device. In some variations, the electrodes can be configured to deliver a current of 50 mA to 4 A at about 0.1 kV to about 4.0 kV at a rate of up to about 500 kHz.

[0197]

[0238] In some variations, the delivery of the ablation waveform can be controlled based on the distance between the electrode and the dilator. For example, the electrode can be configured to electrically short when it contacts the mating surface of the dilator during delivery of the ablation waveform.

[0198]

[0239] In some variations, the ablation waveform may include a first waveform followed by a second waveform, the first waveform may include a first voltage, and the second waveform may include a second voltage, the first voltage may be higher than the second voltage.

[0199]

[0240] Figure 19F shows an ablation device 1900 in which the atrial septum 1970, which defines a predetermined opening, and the ablated tissue is held within the lumen 1922 of the electrode 1920 by the barbs 1940. As shown in Figure 19F, the septum 1970 may snap back once the tissue engaged with the barbs 1940 has been ablated. The tissue within the lumen 1922 may be sealed within the ablation device 1900 once ablation is complete and the electrode contacts the dilator 1950. In this manner, the ablated tissue may be prevented from being lost within the body.

[0200]

[0241] Figure 36B shows the ablation device 3600 in a closed (e.g., seated) configuration, with the ablated tissue (e.g., first portion) 3672 engaged with the barbs 3640 and held within the lumen of the electrode 3620. The proximal portion 3652 of the dilator 3650 can, for example, be seated within the lumen of the electrode 3620. Figure 36B shows a hole 3676 formed in the atrial septum 3670.

[0201]

[0242] In some variations, visualization may confirm completion of the energy delivery process. For example, the difference between the ablation device 3600 in an ablation configuration (FIG. 36A) and a closed configuration (e.g., FIG. 36B) may be confirmed through indirect visualization. For example, fluoroscopic visualization may confirm that tissue is sandwiched between the electrode 3620 and the dilator 3650 and that the tissue is ablated after energy delivery based on the imaged position of the dilator 3650 relative to the electrode 3620.

[0202]

[0243] In some variations, a preload force (e.g., a first predetermined force) may be applied to the electrode 3620 by the dilator 3650 during and / or after energy delivery to ensure that the second catheter 3630 is retracted toward the first catheter 3610. In some variations, the operator may activate a switch in the handle to initiate energy delivery to ablate tissue. As the proximal portion 3652 is retracted toward and pressed against the electrode 3620 during energy delivery, the proximal portion 3652 may shear (e.g., cut, separate) tissue from the septum 3670 with a second predetermined force greater than the first predetermined force. That is, the proximal portion 3652 may act as a cutting board, ensuring that even small fibers (e.g., a second portion) of the tissue 3574 are resected from the septum 3670. Alternatively, the preload force can be prevented from being applied to the tissue 3674 and the electrode 3620 when the ablation waveform is delivered to the electrode 3620. During energy delivery, the dilator 3650 can naturally retract into the lumen of the electrode 3620 as the tissue 3674 is cut (e.g., ablated).

[0203]

[0244] In some variations, as shown in FIG. 36B, the proximal portion (3652) of the dilator (3650) can be positioned within the lumen of the electrode (3620) when the mating surface (e.g., the proximal portion (3652) engages the electrode. The proximal portion (3652) positioned within the lumen of the electrode (3620) can securely and coaxially attach the electrode to the dilator. For example, the dilator can be secured to the first catheter (3610) to resist dislodging due to lateral loading, such as when the ablation device is advanced over a curved guidewire. Additionally, the dilator (3650) and The securely engaged electrode 3620 can be configured to prevent the ablation device 3600 from getting caught on (e.g., catching on) blood vessels, tissue (e.g., septal intersections), introducers, sheaths, and the like while being advanced and retracted within the body cavity. In some variations, when the mating surfaces engage the electrode 3620, about 0.5 mm to about 2 mm of the proximal portion 3652 of the dilator 3650 can be disposed within the lumen of the electrode 3620. In some variations, the ablation device 3600 shown in FIG. 36B can be removed from the patient.

[0204]

[0245] The first and second catheters may be removed from the patient 1816. This may include retracting the excised tissue held within the first catheter as the first and second catheters are retracted together. In some variations, the procedure may be imaged by ultrasound and / or fluoroscopy during one or more steps. [Example]

[0205]

[0246] 20 and 21 are perspective views of variations of the ablation device (2000, 2100). In some variations, the ablation device (2000, 2100) may include a first catheter (2010, 2110) and a second catheter (2030, 2130). The first catheter (2010, 2110) may include a tubular electrode (2020, 2120). The electrode (2020, 2120) may define a lumen (2022, 2122) configured to hold the barbs (2040, 2140) of the second catheter (2030, 2130). The tubular electrode (2020, 2120) may include a cylindrical shape. In some variations, the ablation device (2000, 2100) may include a second catheter (2030, 2130) slidably disposed within the first catheter (2010, 2110). The second catheter (2030, 2130) may include barbs (2040, 2140) and dilators (2050, 2150) configured to engage the electrodes (2020, 2120). In some variations, the barbs (2040, 2140) may include multiple protrusions generally angled toward the electrodes (2020, 2120). The dilators (2050, 2150) may have a tapered conical shape. Figure 22 is a perspective view of the ablation device (2200) engaging ablated tissue (2260). In some variations, the ablation device 2200 may include a first catheter 2210 and a second catheter 2230. The ablated tissue 2260 fits into the lumen 2222 of the electrode 2220 and is removed from the patient.

[0206]

[0247] 23 is a fluoroscopic visualization image 2300 of an ablation device 2310, 2320 in open and closed configurations, respectively. One or more portions of the ablation device 2310, 2320 may include radiopaque portions.

[0207]

[0248] Figure 24 is an image (2400) of an anastomosis (2420) formed in cadaveric tissue (2410) using the ablation systems and methods described herein. Figures 25A and 25B are images (2500) of an anastomosis (2520) formed in porcine tissue (2510) using the ablation systems and methods described herein.

[0208]

[0249] 27A and 27B are perspective views of variations of an ablation device (2700) engaged with tissue (2760). In some variations, the ablation device (2700) may include a first catheter (2710) and a second catheter (2730). The first catheter (2710) may include a tubular electrode (2720). The electrode (2720) may define a lumen (2722) configured to hold the barbs (2740) of the second catheter (2730). The tubular electrode (2720) may have a cylindrical shape. In some variations, the ablation device (2700) may include a second catheter (2730) slidably disposed within the first catheter (2710). The second catheter 2730 can include barbs 2740 similar to the variations shown in Figures 26A and 26B and a dilator 2750 configured to engage the electrode 2720. In some variations, the barbs 2740 can include multiple protrusions including tissue-engaging portions substantially parallel to the longitudinal axis of the second catheter 2730. The dilator 2750 can have a tapered conical shape.

[0209]

[0250] The tissue 2760 may be configured to engage the barbs 2740, as described in more detail herein. In Figures 27A and 27B, the second catheter 2730 is advanced relative to the first catheter 2710 to show the barbs 2740 and the ablated tissue 2760, while the ablated tissue 2260 is embedded in the lumen 2722 of the electrode 2720, facilitating removal of the tissue from the patient's body. In some variations, the lumen 2722 may have a length of at least 1 mm. For example, the lumen 2722 may have a length of about 5 mm to about 4 cm. Figure 27C is an image 2770 of an anastomosis 2790 formed in tissue 2780 using the ablation systems and methods described herein.

[0210]

[0251] 28A and 28B are perspective views of variations of an ablation device 2800 engaged with tissue 2860. In some variations, the ablation device 2800 may include a first catheter (not shown) and a second catheter 2830. In some variations, the ablation device 2800 may include a second catheter 2830 slidably disposed within the first catheter. The second catheter 2830 may include barbs 2840 similar to the variations shown in FIGS. 26A and 26B and a dilator 2850. In some variations, the barbs 2840 may include multiple protrusions including tissue-engaging portions substantially parallel to the longitudinal axis of the second catheter 2830. The tissue 2860 may be configured to engage the barbs 2840, as described in more detail herein.

[0211]

[0252] As used herein, the terms "about" and / or "approximately" when used in conjunction with a numerical value and / or range generally refer to a numerical value and / or range that is close to the specified numerical value and / or range. In certain instances, the terms "about" and "approximately" may mean within ±10% of the specified value. For example, in some instances, "about 100 units" may mean within ±10% of 100 (e.g., 90 to 110). The terms "about" and "approximately" may be used interchangeably.

[0212]

[0253] The specific examples and descriptions herein are exemplary in nature and variations may be devised by those skilled in the art based on the teachings herein without departing from the scope of the invention, which is limited only by the appended claims.

[0213]

[0254] While the foregoing embodiments have been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be apparent that certain modifications and improvements may be made and still fall within the scope of the appended claims. Furthermore, it should be understood that the components and features of the elements described herein may be used in any combination, and that the methods described herein may include all or a portion of the elements described herein. The description of a particular element or feature with respect to a particular figure is not to be construed as limiting or to suggest that they cannot be used in combination with any of the other described elements.

[0214]

[0255] In addition, any combination of two or more such features, structures, systems, articles, materials, kits, steps, and / or methods disclosed herein is within the inventive scope of the present disclosure, provided such features, structures, systems, articles, materials, kits, steps, and / or methods are not mutually inconsistent. Further, some variations disclosed herein may be distinguishable from the prior art by the specific absence of one or more features, elements, and functions found in a reference or combination of references (i.e., patent claims directed to such variations may include a negative limitation).

[0215]

[0256] All references to publications or other documents, including, but not limited to, patents, patent applications, articles, web pages, books, etc., presented anywhere in this application are incorporated herein by reference in their entirety. Furthermore, all definitions defined and used herein should be understood to supersede any dictionary definitions, definitions within documents incorporated by reference, and / or ordinary meanings of the defined terms.

Claims

1. 1. A system for forming an anastomosis in a heart, comprising: a first catheter including an electrode; a second catheter slidably disposed within the first catheter, the second catheter including barbs and a dilator configured to engage the electrode and house the barbs within a lumen of the electrode; and A system including:

2. The system of claim 1 , wherein the outer diameter of the dilator is smaller than the outer diameter of the electrode.

3. The system of claim 1 , wherein the barbs are configured to distribute pressure across engaged tissue to prevent tearing as the tissue is engaged.

4. The system of claim 1 , wherein the barbs have a length of about 0.1 mm to about 5 cm.

5. The system of claim 1 , wherein the barb includes a cylindrical base proximal to the dilator, and at least one protrusion is coupled to the cylindrical base.

6. The system of claim 5 , further comprising a plurality of protrusions, including said at least one protrusion, spaced substantially equally around the circumference of said cylindrical base.

7. The system of claim 5 , wherein the at least one protrusion includes an atraumatic tip.

8. 10. The system of claim 1, wherein the second catheter defines a longitudinal axis, and the barb includes at least one protrusion including a first portion and a second portion, the first portion being angled relative to the second portion.

9. The system of claim 8 , wherein the first portion is substantially perpendicular to the longitudinal axis.

10. The system of claim 8 , wherein the first portion is configured as a backstop for tissue engagement.

11. The system of claim 8 , wherein the at least one protrusion includes an atraumatic tip.

12. The system of claim 8 , wherein the at least one protrusion is radially disposed about the periphery of the barb.

13. The system of claim 1 , wherein the system is configured to compress tissue between the electrode and the expander with a first predetermined force.

14. The system of claim 13 , wherein the dilator is configured to shear the tissue with a second predetermined force greater than the first predetermined force.

15. The system of claim 1 , wherein the electrode includes a fluid port configured to eject a contrast agent.

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