Multiple electrode heart valve slitting device

Abstract

A puncture and slitting device (e.g., for slitting the tissue of heart valve leaflets) includes a flexible elongate member configured to be positioned within a body lumen of a patient, and a cutting assembly positioned at a distal portion of the flexible elongate member. The cutting assembly includes a first conductor, a crossing electrode configured to be energized by the first conductor, a second conductor electrically isolated from the first conductor, and a cutting electrode configured to be energized by the second conductor.

Description

MULTIPLE ELECTRODE HEART VALVE SLITTING DEVICETECHNICAL FIELD

[0001] The subject matter described herein relates to cardiac valve replacement and, in particular, to the reducing or eliminating blood flow obstruction to the human heart during and after cardiac valve replacement. For example, a catheter-deployed, intravascular leaflet slitting device may be utilized for aortic valve leaflet modification, to prevent obstruction of coronary arteries during or following an aortic valve replacement procedure.BACKGROUND

[0002] One common type of valve disease is aortic valve stenosis, in which the valve between the aorta and the heart’s left ventricle is narrowed and doesn't fully open. This reduces blood flow from the heart to the aorta and thus to the rest of the body. With the advent of minimally invasive procedures, valve replacement may currently be the most common therapy for aortic valve stenosis. More particularly, transvenous / transcatheter aortic valve replacement (TAVR) is becoming a more common valve replacement procedure, as technology and doctor skillsets improve. This minimally invasive approach to valve replacement is an alternative to open heart surgical aortic valve replacement (SAVR). In a TAVR procedure, the damaged valve, whether the valve is a natural aortic valve or a previous SAVR or TAVR valve, is left in place. These valves may have anatomical abnormalities, calcification, or infection. TAVR has been approved for low-risk patients, who in general are of younger age and live longer. Recent studies have shown that the life of a TAVR valve will only be on average 8 years, so there will be an increase in replacement TAVR procedures. Old TAVR leaflets may be fibrosed, calcified, or thickened during the life of the TAVR valve, creating a barrier to the replacement TAVR valve. The old leaflets may also pose a more serious risk of coronary obstruction than native valves.

[0003] Thus, certain structural heart procedures such as trans-catheter valve replacement can cause the leaflets of the native valve, or those of a previously implanted valve, to be forced outward radially from the valve, thereby closing off either vessels that originate in the vicinity of the valve, or the blood path downstream from the valve (outflow tract).

[0004] Accordingly, many structural heart procedures, including TAVR and other valve replacement procedures, benefit from modification of the leaflets of native and / or implanted valves. For example, aortic valve replacement can cause the coronary vessels to becomeoccluded when the leaflets of the native valve (or in the case of a valve-in- valve implant, the implanted valve leaflet), are pressed up against the side wall of the aortic valve annular region. Similarly, in a mitral valve replacement, the left ventricular out flow tract (LVOT) can become narrowed by the leaflets of the native valve or previously implanted valve. Another issue can be access to the coronary arteries after implantation of a prosthetic aortic valve. The leaflet of the native or implanted valve can prevent easy access for a guidewire to cross from the coronary sinus area into the ostia of the coronary arteries. Thus, a need exists for improved intracoronary methods to address the foregoing and other concerns.

[0005] The information included in this Introduction section of the specification, including any references cited herein and any description or discussion thereof, is included for context and / or technical reference purposes only and is not to be regarded as subject matter by which the scope of the disclosure is to be bound or otherwise limited in any manner.SUMMARY

[0006] Disclosed herein is a leaflet puncture and slitting device, with associated systems and methods. The device includes a first electrode capable of puncturing the tissue of the leaflet and a second, hook-shaped electrode capable of extending the puncture to slit the leaflet. The electrodes are energized with electrical energy. This leaflet puncture and slitting device enables a clinician to puncture the leaflet in a precise location and then slit it in a controlled manner, in a direction away from the wall of the heart or aorta, thus preventing unintended damage to nearby anatomical structures. The leaflet puncture and slitting device has particular but not exclusive utility for modifying heart valve leaflets during intracardiac valve replacements.

[0007] A system of one or more computers can be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions. One general aspect includes an apparatus that includes a puncture and slitting device, which may include: a flexible elongate member configured to be positioned within a body lumen of a patient, and a cutting assembly positioned at a distal portion of the flexible elongate member. The cutting assembly may include: a first conductor, a crossing electrode configured to be energized by the first conductor, a second conductor electrically isolated from the first conductor, and a cutting electrode configured to be energized by the second conductor. Other examples of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0008] Implementations may include one or more of the following features. In some aspects, the crossing electrode is cylindrical- shaped, conical- shaped, or wedge-shaped. In some aspects, the body lumen may include an aorta or a heart chamber of the patient, and the crossing electrode is configured to form a puncture in a heart valve leaflet when placed against the heart valve leaflet and energized by the first conductor. In some aspects, the cutting electrode may include a hook shape. In some aspects, the hook shape facilitates slitting of the heart valve leaflet when the cutting electrode is: placed within the puncture; energized by the second conductor; and pulled along a length of the heart valve leaflet. In some aspects, the second conductor may include a conductive tube, braid, or spring, where afirst portion of the conductive tube, braid, or spring is surrounded by an outer insulation layer, where a second portion of the conductive tube, braid, or spring is not surrounded by the outer insulation layer, and where the second portion may include the cutting electrode. In some aspects, the first conductor may include a core wire, where the conductive tube, braid, or spring is positioned around the core wire and separated from the core wire by an inner insulation layer. In some aspects, at least one of the first conductor or the second conductor may include a shape memory material. In some aspects, the apparatus may include a power source configured to energize: the crossing electrode via the first conductor; and the cutting electrode via the second conductor. In some aspects, the first conductor may include a pullwire, where the cutting electrode is configured to transition from a straight configuration to a hook-shaped configuration when the pullwire is pulled. In some aspects, the second conductor may include a conductive hypotube, which may include a lumen, where the first conductor is positioned within the lumen and electrically isolated from the first conductor by an inner insulation layer surrounding the first conductor. In some aspects, the cutting electrode may include a cut portion of the conductive hypotube. In some aspects, the cut portion of the conductive hypotube may include gaps configured to provide flexibility for the cutting electrode to transition between a straight configuration and a hook- shaped configuration. In some aspects, the lumen of the hypotube is configured to receive a fluid, where the gaps in the cut portion are configured to allow the fluid to flow out of the puncture and slitting device and into the body lumen, thereby suppressing electrical conduction by blood proximate to the cutting electrode. In some aspects, the cutting electrode is covered by an insulator that may include a plurality of openings. In some aspects, a thickness of the insulator and a width of the plurality of openings are selected such that electrical energy emitted by the cutting electrode is configured to cut the tissue without direct contact between the cutting electrode and the tissue. In some aspects, the plurality of openings is rectangular, circular, or slotted. In some aspects, the plurality of openings is arranged in a regular pattern. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.

[0009] One general aspect includes an apparatus including a flexible, elongate intracardiac device that may include: a crossing electrode defining a distal end of the intracardiac device and configured to cut a hole in a heart valve leaflet; and a cutting electrode proximal of the crossing electrode and configured to cut a slit starting from the hole in the heart valve leaflet, where the cutting electrode may include a portion of a hypotube with gaps, where the gaps are configured to provide flexibility for the cutting electrode totransition between a straight configuration and a hooked shape configuration, where the crossing electrode is configured to cut the hole while the cutting electrode is in the straight configuration, and where the cutting electrode is configured to cut the slit while the cutting electrode is in the hook-shaped configuration. Other examples of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0010] Implementations may include one or more of the following features. In some aspects, the intracardiac device further may include a pullwire conductor electrically coupled to the crossing electrode and electrically isolated from the cutting electrode, where the pullwire conductor is configured to carry electrical energy to power the crossing electrode to cut the hole, where the cutting electrode is configured transition from the straight configuration to the hook- shaped configuration when tension is applied to the pull wire conductor. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.

[0011] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. A more extensive presentation of features, details, utilities, and advantages of aspects of the present disclosure, e.g., as defined in the claims, is provided in the following written description of various examples and / or aspects of the disclosure and illustrated in the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Illustrative aspects of the present disclosure will be described with reference to the accompanying drawings, of which:

[0013] Figure 1A is a side view of a human heart according to aspects of the present disclosure.

[0014] Figure IB is a cross-sectional side view of a human heart according to aspects of the present disclosure.

[0015] Figure 2 is a cross-sectional side view of an aortic valve replacement in a human heart 100 according to aspects of the present disclosure.

[0016] Figure 3A is a diagrammatic, cross-sectional top view of an aortic valve replacement of a degenerated natural aortic valve utilizing a TAVR valve, according to aspects of the present disclosure.

[0017] Figure 3B is a diagrammatic cross-sectional top view of a valve-in- valve replacement of a degenerated TAVR valve utilizing a new TAVR valve, according to aspects of the present disclosure.

[0018] Figure 3C is a diagrammatic cross-sectional top view of a valve-in-valve replacement of a degenerated surgical aortic valve replacement (SAVR) valve utilizing a new TAVR valve, according to aspects of the present disclosure.

[0019] Figure 4A is a diagrammatic top view of an aortic valve, according to aspects of the present disclosure.

[0020] Figure 4B is a diagrammatic cross-sectional side view of a TAVR implant in an aortic valve according to aspects of the present disclosure.

[0021] Figure 5 is schematic, diagrammatic view of a system according to aspects of the present disclosure.

[0022] Figure 6A is a diagrammatic cross-sectional side view of an aortic valve according to aspects of the present disclosure.

[0023] Figure 6B is a diagrammatic cross-sectional side views of an aortic valve according to aspects of the present disclosure.

[0024] Figure 7A is a diagrammatic cross-sectional side view of an aortic valve according to aspects of the present disclosure.

[0025] Figure 7B is a diagrammatic cross-sectional side view of an aortic valve according to aspects of the present disclosure.

[0026] Figure 8 is a schematic, diagrammatic side view of an example resection wire of an example resection wire of a leaflet puncture and slitting device, according to aspects of the present disclosure.

[0027] Figure 9 is a schematic, diagrammatic side view of an example resection wire of a leaflet puncture and slitting device, according to aspects of the present disclosure.

[0028] Figure 10 is a schematic, diagrammatic, side cross-sectional view of at least a portion of an example leaflet puncture and slitting device, according to aspects of the present disclosure.

[0029] Figure 11 is a schematic, diagrammatic, side cross-sectional view of a resection wire 545 of an example leaflet puncture and slitting device, according to aspects of the present disclosure.

[0030] Figure 12 is a schematic, diagrammatic, side cross-sectional view of an example resection wire, according to aspects of the present disclosure.

[0031] Figure 13 is a schematic, diagrammatic, axial cross-sectional view of an example resection wire, taken along cut line 13-13 of Figure 11 according to aspects of the present disclosure.

[0032] Figure 14 is a schematic, diagrammatic, side cross-sectional view of an example resection wire, according to aspects of the present disclosure.

[0033] Figure 15 is a schematic, diagrammatic, side cross-sectional view of an example resection wire, according to aspects of the present disclosure.

[0034] Figure 16 is a schematic, diagrammatic, side cross-sectional view of an example resection wire, according to aspects of the present disclosure.

[0035] Figure 17 is a schematic, diagrammatic, side cross-sectional view of an example resection wire, according to aspects of the present disclosure.

[0036] Figure 18 is a schematic, diagrammatic, side cross-sectional view of an example resection wire, according to aspects of the present disclosure.

[0037] Figure 19 is a schematic, diagrammatic, side cross-sectional view of an example resection wire, according to aspects of the present disclosure.

[0038] Figure 20 is a schematic, diagrammatic, side cross-sectional view of a distal portion of an example resection wire, according to aspects of the present disclosure.

[0039] Figure 21 is a schematic, diagrammatic, side cross-sectional view of a distal portion of an example resection wire 545, according to aspects of the present disclosure.

[0040] Figure 22A is a schematic, diagrammatic, side cross-sectional view of a leaflet puncture and slitting device approaching a heart valve leaflet, according to aspects of the present disclosure.

[0041] Figure 22B is a schematic, diagrammatic, side cross-sectional view of a leaflet puncture and slitting device puncturing a heart valve leaflet, according to aspects of the present disclosure.

[0042] Figure 22C is a schematic, diagrammatic, side cross-sectional view of a leaflet puncture and slitting device puncturing a heart valve leaflet, according to aspects of the present disclosure.

[0043] Figure 22D is a schematic, diagrammatic, side cross-sectional view of a leaflet puncture and slitting device preparing to resect a heart valve leaflet, according to aspects of the present disclosure.

[0044] Figure 22E is a schematic, diagrammatic, side cross-sectional view of a leaflet puncture and slitting device resecting a heart valve leaflet, according to aspects of the present disclosure.

[0045] Figure 23A is a diagrammatic top view of an aortic valve, according to aspects of the present disclosure.

[0046] Figure 23B is a diagrammatic top view of an aortic valve, according to aspects of the present disclosure.

[0047] Figure 24 is a schematic diagram of a processor circuit, according to aspects of the present disclosure.

[0048] Figure 25 is a schematic, diagrammatic, side cross-sectional view of an example resection wire, according to aspects of the present disclosure.

[0049] Figure 26 is a side view of an example resection device in a straight configuration, according to aspects of the present disclosure.

[0050] Figure 27 is a side cross-sectional view of the resection device of Figure 26, according to aspects of the present disclosure.

[0051] Figure 28A is a side view of the resection device of Figure 26 in the hooked configuration, according to aspects of the present disclosure.

[0052] Figure 28B is a side cross-sectional view of the resection device of Figure 26 in the hooked configuration, according to aspects of the present disclosure.

[0053] Figure 29 is a close-up view of the laser-cut portion of the hypotube of the resection device of Figure 27B in its hooked shape, according to aspects of the present disclosure.

[0054] Figure 30 is a schematic, diagrammatic, side cross-sectional view of an example resection wire, according to aspects of the present disclosure.

[0055] Figure 31 is an end cross sectional view of an example pull wire surrounded by the inner insulator, according to aspects of the present disclosure.

[0056] Figure 32 is an end cross sectional view of an example pull wire surrounded by the inner insulator, according to aspects of the present disclosure.

[0057] Figure 33 is a side cross-sectional view of electrically contiguous conductive portions of the cutting electrode of a laser-cut portion of a hypotube, according to aspects of the present disclosure.

[0058] Figure 34A is a top view of the cutting electrode insulator covering the cutting electrode of the example resection wire of Figure 29 in its straight configuration, according to aspects of the present disclosure.

[0059] Figure 34B is a top view of the cutting electrode insulator covering the cutting electrode of the example resection wire of Figure 29 in its hooked configuration, according to aspects of the present disclosure.

[0060] Figure 35 is a top view of the outer insulator covering the cutting electrode of the example resection wire of Figure 30 in its hooked configuration, according to aspects of the present disclosure.

[0061] Figure 36 is a top view of the outer insulator covering the cutting electrode of the example resection wire of Figure 30 in its hooked configuration, according to aspects of the present disclosure.

[0062] Figure 37 is a top view of the outer insulator covering the cutting electrode of the example resection wire of Figure 30 in its hooked configuration, according to aspects of the present disclosure.

[0063] Figure 38A is a side view of the cut portion of an example hypotube in its straight configuration, according to aspects of the present disclosure.

[0064] Figure 38B is a bottom view of the cut portion of the example hypotube of Figure 38A, according to aspects of the present disclosure.DETAILED DESCRIPTION

[0066] Disclosed herein is a leaflet puncture and slitting device, with associated systems and methods. During a heart valve replacement or other intracardiac procedure, slitting a heart valve leaflet from the center of the valve annulus towards the root of the leaflet (or vice versa) can allow for blood flow and / or passage of a guidewire. Procedures incorporating such a slitting process may be known as BASILICA or LAMPOON procedures, depending upon which heart valve is being repaired or replaced. This procedure uses a guidewire to pierce the leaflet near the root, and then the guide wire tip is snared, and externalized. Once both ends of the wire are under direct physician control (outside of the patient body), radio frequency energy is applied to the wire, which allows it to “cut” through the leaflet as tension is applied to the ends of the wire. This creates a slit in the leaflet from the root towards the center of the annular space.

[0067] These procedures may employ a normal guide wire, with a short section of the coating on the wire, near the middle of the wire, being scraped off and heated with RF energy for use as a cutting wire. When the uncoated area of the wire is in contact with the leaflet, the wire is connected to a radio frequency (RF) generator. When energy is applied, the wire can cut through valve leaflet. An advantage of this method is that wire will self-navigate around calcific tissue that can occur in a leaflet. Another advantage of this method is that it is relatively inexpensive, requiring only a standard wire and standard RF generator.

[0068] However, the BASILICA and LAMPOON procedures can be very technically challenging, requiring very advanced wire technique to both pierce the leaflet, especially in the area intended, and also to snare the tip of the wire to externalize the distal end. It may also be difficult to know when the uncoated section of wire is in the correct position to slit the valve leaflet. Furthermore, if the uncoated section is made too large, it could damage tissue that is not intended to be resected.

[0069] To address these and other problems, disclosed herein is a leaflet puncture and slitting device, with associated systems and methods. The device includes a first heated electrode capable of puncturing the tissue of the leaflet and a second, hook-shaped heated electrode capable of extending the puncture into a slit, from the base of the leaflet to its tip. This leaflet puncture and slitting device enables a clinician to puncture the leaflet in a precise location and then slit it in a controlled manner, in a direction away from the wall of the heart or aorta, while reducing the risk of damage to nearby structures.

[0070] The leaflet puncture and slitting device facilitates the piercing of the leaflet by using RF energy to easily allow the wire to puncture the leaflet tissue, and prevents the need to snare the wire and externalize it by using a wire that is pre-shaped into a “hook” configuration.

[0071] The leaflet puncture and slitting device includes a resection wire with a pre-set hook shape made from a shape memory material with at least two separate electrodes. The resection wire may be coated on the surface with an insulative coating, except on the electrodes themselves. The leaflet puncture and slitting device also includes a means to easily connect the resection wire to an RF generator, such as an industry standard connector.

[0072] The device can be constructed in a number of ways. First, it can be made from a hollow conductive tube which would form the body of the wire, the hook, and one or more of at least two electrodes - a cutting electrode. The hollow tube can also form one of the two necessary electrical connections to a radio frequency (RF) generator. Inside the hollow tube, there may be an insulation layer around a wire which forms a second electrode at the tip of the device - the crossing electrode. This resection wire can also become the connection point for the second electrode to the RF generator.

[0073] Another method for manufacture would be to have a short section of tubing or a sheet of conductive material that is wrapped around an insulator tube to form the first electrode. The wire to connect the electrode and the electrode itself could be reflowed into the insulator tube wall. The lumen of the insulator tube would contain a wire that forms the electrical connection and electrode at the tip of the device.

[0074] Another method for manufacture would involve the first electrode being constructed of a wire braid or spring. The spring could be formed from laser cut tubing, or wire stock wrapped around a mandrel or formed using a spring forming machine. The wire stock could be flat, or could have a circular profile or any other shape. The resulting spring or braid could extend for the entire length of the device, as in the first method described, or just the electrode portion, as described in the second method.

[0075] Another method for manufacture would involve a hollow tube, wire braid, or spring as described above, where a section of the tube, braid, or spring, that becomes the electrode, is electrically isolated from the rest of the tube, braid, or spring by cutting a gap in the material either mechanically, or using a laser. The rest of the device would be manufactured as described above.

[0076] In an example, the resection wire is a first flexible elongate member that fits within a second flexible elongate member (e.g., a guide catheter). In use, the catheter isintroduced into the vasculature of the patient and directed to the valve leaflet of interest. Once there, the user extends the resection wire distally from the catheter until a crossing electrode is in contact with the leaflet. Radio frequency (RF) energy (e.g., from a standard electrocautery source) is applied to the crossing electrode in order to puncture the leaflet. Then the RF energy is switched off, and the resection wire is advanced through the puncture until a cutting electrode is within the puncture. Then, RF energy is applied to the cutting electrode, and the resection wire is pulled backward into the catheter, which causes the heated cutting electrode to slit the leaflet.

[0077] The present disclosure aids substantially in intracardiac procedures such as heart valve replacement, by improving a clinician’s ability to cut (e.g., bisect) a valve leaflet with precision, and with minimal risk of damage to neighboring tissues. Implemented on a guidewire-like assembly deployed from an intracardiac catheter in association with an intracardiac catheter system, the leaflet puncture and slitting device disclosed herein provides practical, precise surgical capabilities in an intracardiac environment. This improved leaflet modification technique transforms a complex, potentially imprecise procedure requiring high levels of skill and training into a repeatably precise leaflet slitting technique, without the normally routine need to achieve this precision through open -heart surgical interventions. This unconventional approach improves the functioning of the intracardiac catheter system, by allowing a greater range of procedures to be reliably performed using intracardiac techniques.

[0078] Control of the leaflet puncture and slitting device may be implemented at least partially through ultrasound or X-ray imaging under the control of a processor and viewable on a display, and operated by a control process executing on a processor that accepts user inputs from a keyboard, mouse, or touchscreen interface. In that regard, the control process performs certain specific operations in response to different inputs or selections made at different times. Certain structures, functions, and operations of the processor, display, sensors, and user input systems are known in the art, while others are recited herein to enable novel features or aspects of the present disclosure with particularity.

[0079] For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the examples illustrated in the drawings, and specific language will be used to describe the same. It is nevertheless understood that no limitation to the scope of the disclosure is intended. Any alterations and further modifications to the described devices, systems, and methods, and any further application of the principles of the present disclosure are fully contemplated and included within the presentdisclosure as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and / or steps described with respect to one example and / or aspect may be combined with the features, components, and / or steps described with respect to other examples and / or aspects of the present disclosure. Additionally, while the description below may refer to blood vessels, it will be understood that the present disclosure is not limited to such applications. For example, the devices, systems, and methods described herein may be used in any body chamber or body lumen, including an esophagus, veins, arteries, intestines, ventricles, atria, or any other body lumen and / or chamber. For the sake of brevity, however, the numerous iterations of these combinations will not be described separately.

[0080] Figure 1A is a side view of a human heart 100 according to aspects of the present disclosure. Visible are an aorta 102 from which stems a right coronary artery 104 and a left main coronary artery 106. The left main coronary artery 106 branches into a left circumflex coronary artery 108 and a left anterior descending coronary artery 110. The right coronary artery 104, the left main coronary artery 106, the left circumflex coronary artery 108, and a left anterior descending coronary artery 110 are the arteries that provide oxygen-rich blood to muscles of the human heart 100.

[0081] Figure IB is a cross-sectional side view of a human heart 100 according to aspects of the present disclosure. Visible are a right atrium 112 and a right ventricle 114. In that regard, oxygen-poor blood enters the human heart 100 in the right atrium 112 and travels to the right ventricle 114 through the tricuspid valve 116. The oxygen -poor blood leaves the right ventricle 114 and travels to the lungs. Also visible are a left atrium 118 and a left ventricle 120. In that regard, oxygen-rich blood is received from the lungs in the left atrium 118 and travels to the left ventricle 120 through the mitral valve 122. The oxygen-rich blood leaves the left ventricle 120 and goes out to the body through the aorta 102 via an aortic valve 124.

[0082] Figure 2 is a cross-sectional side view of an aortic valve 124 replacement in a human heart 100 according to aspects of the present disclosure. In some aspects, e.g., when aortic valve stenosis has occurred to the aortic valve 124 that keeps blood flowing in the correct direction from the left ventricle 120 to the aorta 102, a transvenous / transcatheter aortic valve repair (TAVR) procedure may be performed to replace the natural aortic valve 124 with a replacement aortic valve 202. In some instances, portions of one or more leaflets 204 of the natural aortic valve 124 may be resected so that openings 206 and 208 to the right coronary artery 104 and the left main coronary artery 106, respectively, so that, when the oneor more leaflets 204 are pressed against the natural heart wall 210, the openings 206 and 208 remain unobstructed so that oxygen-rich blood may flow to the muscles of the human heart. The natural heart wall 210 may be a natural aorta wall, a natural heart chamber wall, or a natural aortic valve wall.

[0083] The TAVR procedure is shown here for exemplary purposes only; it is understood that other heart valves and heart valve replacement procedure types may benefit from leaflet modification and thus fall within the scope of the present disclosure.

[0084] Figure 3 A is a diagrammatic, cross-sectional top view of an aortic valve replacement of a degenerated natural aortic valve utilizing a TAVR valve, according to aspects of the present disclosure. Visible are the natural heart wall 210, the natural aortic valve leaflets 304, the TAVR valve wall 306, the TAVR valve leaflets 308, and the TAVR commissural tabs 310. The TAVR valve leaflets 308 may for example be constructed from bovine animal tissue coupled to the wire frame of the TAVR valve wall 306 via the commissural tabs 310. When inserted, the TAVR valve pushes the remaining unresected portions of the natural aortic valve leaflets 304 against the natural heart wall 210 such that the natural aortic valve leaflets 304 are pinned and / or secured between an outside of the TAVR valve wall 306 and the natural heart wall 210.

[0085] Figure 3B is a diagrammatic cross-sectional top view of a valve-in- valve replacement of a degenerated TAVR valve utilizing a new TAVR valve, according to aspects of the present disclosure. Visible are the natural heart 210, the natural aortic valve leaflets 304, the degenerated TAVR valve wall 306, the degenerated TAVR valve leaflets 308, the degenerated TAVR commissural tabs 310, the new TAVR valve wall 312, the new TAVR valve leaflets 314, and the new TAVR commissural tabs 316. The new TAVR valve leaflets 314 are constructed from bovine animal tissue are coupled to the wire frame of the new TAVR valve wall 312 via the commissural tabs 316. When inserted, the TAVR valve pushes the remaining unresected portions of the degenerated TAVR valve leaflets 308 against an inside of the degenerated TAVR valve wall 306 such that the degenerated TAVR valve leaflets 308 are pinned and / or secured between an outside of the new TAVR valve wall 312 and the inside wall of the degenerated TAVR valve wall 306.

[0086] Figure 3C is a diagrammatic cross-sectional top view of a valve-in-valve replacement of a degenerated surgical aortic valve replacement (SAVR) valve utilizing a new TAVR valve, according to aspects of the present disclosure. Visible are the natural heart wall 210, a degenerated SAVR valve wall 318, the degenerated SAVR valve leaflets 320, the degenerated SAVR commissural tabs 322, the new TAVR valve wall 312, the new TAVRvalve leaflets 314, and the new TAVR commissural tabs 316. The new TAVR valve leaflets 314 are constructed from bovine animal tissue are coupled to the wire frame of the new TAVR valve wall 312 via the commissural tabs 316. When inserted, the TAVR valve pushes the remaining unresected portions of the degenerated SAVR valve leaflets 320 against an inside of the degenerated SAVR valve wall 318 such that the degenerated TAVR valve leaflets 320 are pinned and / or secured between an outside of the new TAVR valve wall 312 and the inside wall of the degenerated SAVR valve wall 318.

[0087] The natural valve, TAVR valve, and / or SAVR valve can be degenerated (e.g., not fully or correctly functioning) as a result of various causes. For example, the natural valve, TAVR valve, and / or SAVR valve can be degenerated because it is stenosed, because it is regurgitant, etc.

[0088] Figure 4A is a diagrammatic top view of an aortic valve 400, according to aspects of the present disclosure. Visible are the natural heart wall 210, the aortic valve leaflets 304, the right coronary artery 104, and the left main coronary artery 106. During and after valve replacement procedures, the leaflets 304 can obstruct the arteries 104, 106, as described below in Figure 4A. This can be alleviated by resecting one or more leaflets 304, as shown below in Figures 7 and 15-18B.

[0089] Figure 4B is a diagrammatic cross-sectional side view of a TAVR implant in an aortic valve 400 according to aspects of the present disclosure. Visible are the natural heart wall 210, the aortic valve leaflets 304, the right coronary artery 104, and the left main coronary artery 106. In some aspects, when a replacement aortic valve 202 is implanted and the aortic valve leaflets 304 are not resected or insufficiently resected, the aortic valve leaflets 304, when pinned and / or secured between an outside of the TAVR valve wall 306 and the natural heart wall 210, obstruct the openings 206 and 208 to the right coronary artery 104 and the left main coronary artery 106, respectively, as indicated by areas 402.

[0090] Figure 5 is schematic, diagrammatic view of a system 500 according to aspects of the present disclosure. The system 500 may be configured to evaluate (e.g., assess), display, and / or control (e.g., modify) one or more aspects of a cardiac valve replacement. For instance, the system 500 may be utilized to monitor and / or control one or more portions of a cardiac valve replacement process while reducing and / or eliminating aortic regurgitation, as described in greater detail below. In this regard, the system 500 may be used to assess coronary vessels and / or heart tissue (e.g., the myocardium). As illustrated, the system 500 may include a processing system 510 in communication with a display device 520 (e.g., an electronic display or monitor), an input device 530 (e.g., a user input device, such as akeyboard, mouse, joystick, microphone, and / or other controller or input device), a cutting assembly or cutting subsystem 540 and / or an imaging device 560. As illustrated, the system 500 may further include a TAVR delivery catheter 580 and a TAVR valve 590, which may be completely mechanical or may be connected to processing system 510 in order to provide intraluminal data to processing system 510. It is understood that other types of valves and valve delivery systems may be used instead of or in addition to TAVR.

[0091] The cutting subsystem 540 includes a guide catheter 544, along with a power source 542 coupled to a resection wire 545, coupled to a puncturing element or crossing electrode 548 and cutting element or cutting electrode 546. The resection wire 545 can also be referred to as a resection catheter, resection device, etc., and / or combinations thereof. The power source 542 may for example be a generator of radio-frequency (RF) alternating current. The resection wire 545, including the crossing electrode 548 and cutting electrode 546, is delivered by the guide catheter 544 to the site of the leaflet of interest. Once properly located, the resection wire 545 may be extended from a distal end of the catheter 544, such that the crossing electrode 548 can puncture the leaflet and the cutting electrode 546 can resect the leaflet, as described below. In some cases, the cutting subsystem 540 may require a return electrode 550 in contact with the outside of the patient’s body. In other instances, the resection wire 545 may be a loop that includes both a source and return.

[0092] The processing system 510 is generally representative of any device suitable for performing the processing and analysis techniques disclosed herein. In some aspects, the processing system 510 includes a processor circuit, such as the processor circuit 2400 of Figure 24. In some aspects, the processing system 510 is programmed to execute steps associated with the data acquisition, analysis, and / or instrument (e.g., device) control described herein. Accordingly, it is understood that any steps related to data acquisition, data processing, instrument control, and / or other processing or control aspects of the present disclosure may be implemented by the processing system 510 (e.g., computing device) using corresponding instructions stored on or in a non-transitory computer readable medium accessible by the computing device. In some instances, the processing system 510 is a console device. Further, it is understood that in some instances the processing system 510 includes one or a plurality of computing devices, such as computers, with one or a plurality of processor circuits. In this regard, it is particularly understood that the different processing and / or control aspects of the present disclosure may be implemented separately or within predefined groupings using a plurality of computing devices. Any divisions and / orcombinations of the processing and / or control aspects described below across multiple computing devices are within the scope of the present disclosure.

[0093] The system 500 is configured such that when the resection wire 545 is positioned within the heart, images captured by the imaging system 560 can show the location and orientation of the resection wire 545, and also potentially anatomical features such as heart valve leaflets.

[0094] It is noted that block diagrams are provided herein for exemplary purposes; a person of ordinary skill in the art will recognize myriad variations that nonetheless fall within the scope of the present disclosure. For example, block diagrams may show a particular arrangement of components, subcomponents, modules, units, etc. It is understood that some embodiments of the systems disclosed herein may include additional components, that some components shown may be absent from some embodiments, and that the arrangement of components may be different than shown, while still performing the methods described herein.

[0095] Figure 6A is a diagrammatic cross-sectional side view of an aortic valve 124 according to aspects of the present disclosure. Visible are the natural heart wall 210, the aortic valve leaflets 304, the right coronary artery 104, and the left main coronary artery 106. In the aspects of Figure 6A, during systole (indicated by directional arrows 604), the aortic valve leaflets 304 open and allow blood to flow from the left ventricle 120 to the aorta 102 indicated by directional arrows 604.

[0096] Figure 6B is a diagrammatic cross-sectional side views of an aortic valve 124 according to aspects of the present disclosure. Visible are the natural heart wall 210, the aortic valve leaflets 304, the right coronary artery 104, and the left main coronary artery 106. In the aspects of Figure 6B, during diastole (indicated by directional arrows 606), the aortic valve leaflets 304 may be pushed by the flow of blood from the aorta 102 toward the left ventricle 120 such that the aortic valve leaflets 304 close to prevent mitral regurgitation.

[0097] Figure 7A is a diagrammatic cross-sectional side view of an aortic valve 124 according to aspects of the present disclosure. In the example shown in Figure 7A, a leaflet puncture and slitting device 700 is being positioned onto one of the leaflets 304, in order to puncture and slit the leaflet as described below. The leaflet puncture and slitting device 700 advantageously enables the replacement of an aortic valve 124 in a non-obstructive way, by resecting old valve leaflets 304 and preparing the implant site for a cleaner valve deployment and operation. For example, resecting portions of the leaflets 304 of the degenerated aortic valve can allow the replacement valve to be expanded without the current leaflets 304covering the openings to the coronary arteries 104, 106, thereby allowing oxygenated blood to flow to the muscles of the heart. The leaflet puncture and slitting device 700 includes a guide catheter 544 which has deployed a hook-shaped resection wire 545 that has punctured the leaflet 304.

[0098] Figure 7B is a diagrammatic cross-sectional side view of an aortic valve 124 according to aspects of the present disclosure. In the example shown in Figure 7B, the leaflet puncture and slitting device 700 is being positioned onto one of the leaflets 304, in order to puncture and slit the leaflet as described below. However, the orientation of the leaflet puncture and slitting device 700 is flipped relative to what is what is shown in Figure 7A. More specifically, the resection wire 545 is puncturing the leaflet in a radially inward direction with respect to the aorta 102, rather than a radially outward direction. In either case, once the leaflet has been punctured, the leaflet can then be resected (e.g., slit) by pulling the resection wire into the guide catheter 544 (shown as an upward direction in Figures 7A and 7B), as described below.

[0099] Although Figures 7 A and 7B illustrate the leaflet puncture and slitting device 700 being used on the aortic valve 124, it is also noted that that the device can be used to resect a leaflet of any heart valve (e.g., an aortic valve, mitral valve, pulmonary valve, or tricuspid valve). Furthermore, the leaflet puncture and slitting device 700 could be in the heart (e.g., a heart chamber) or a great vessel (e.g., the aorta) while it is gripping and slitting the leaflet.

[0100] Figure 8 is a schematic, diagrammatic side view of an example resection wire 545 of a leaflet puncture and slitting device 700, according to aspects of the present disclosure. The resection wire 545 includes a connector 820 to connect the resection wire 545 to a power source such as an RF generator (e.g., power source 542 of Figure 5). The connector 820 includes a conductive portion 830 for carrying electrical signals and / or electrical energy to the crossing electrode 548 (see Figure 5), and a conductive portion 840 for carrying electrical signals and / or electrical energy to the cutting electrode 546.

[0101] A distal portion 800 of the resection wire 545 includes a hook shape 810 to facilitate puncturing and / or slitting of the heart valve leaflet, as described below. The resection wire 545 may be a flexible elongate member sized, shaped, structured, and / or otherwise configured to be extend through blood vessels and into / proximate to major vessels of the heart and / or chambers of the heart. For example, the resection wire 545 can be sufficiently flexible to travel through blood vessels. However, the resection wire 545 may also have a sufficient degree of rigidity so that it can be pushed through blood vessels without kinking, and such that the hook shape 810 can remain hooked while resecting the leaflet.

[0102] Figure 9 is a schematic, diagrammatic side view of an example resection wire 545 of a leaflet puncture and slitting device 700, according to aspects of the present disclosure. Portions of the resection wire 545 are surrounded by an outer insulation layer 940 (e.g., heat shrink tubing). The crossing electrode 548 extends from the distal end of the resection wire 545, and may for example be a portion of a core wire extending beyond the distal end 945 of the outer insulation layer 940. When energized with RF electrical energy, the crossing electrode is capable of puncturing tissue such as a heart valve leaflet. The core wire may extend distally to the connector 820 (see Figure 8).

[0103] In the example shown in Figure 9, the hook-shaped portion 810 of the resection wire 545 includes the cutting electrode 546, which may for example be a metallic tube (e.g., a hypotube) surrounding the core wire, from which the outer insulation layer 940 has been partially stripped. When energized with RF electrical energy, the cutting electrode is capable of cutting tissue such as the heart valve leaflet. In an example, the metal tube may extend proximally all the way to the connector 820 (see Figure 8), but may extend distally only to a location 915, between the cutting electrode 546 and the distal end 945 of the outer insulation layer 940.

[0104] Because the crossing electrode 548 and the cutting electrode 546 can be activated separately, the leaflet puncture and slitting device 700 provides the user (e.g., a clinician such as a heart surgeon) with precise control over where and how the RF energy is applied to the tissue, as described below.

[0105] Figure 10 is a schematic, diagrammatic, side cross-sectional view of at least a portion of an example leaflet puncture and slitting device 700, according to aspects of the present disclosure. The leaflet puncture and slitting device 700 can also include the resection wire 545 and the guide catheter 544 in some aspects. Prior to deployment, the resection wire 545 is positioned within the guide catheter 544 such that the cutting electrode 546 and the crossing electrode 548 are not exposed, and thus pose little risk of accidental tissue damage.

[0106] Figure 11 is a schematic, diagrammatic, side cross-sectional view of a resection wire 545 of an example leaflet puncture and slitting device 700, according to aspects of the present disclosure. The resection wire 545 includes a proximal portion 1170 terminating in a proximal end 1175 and a distal portion 1180 terminating in a distal end 1185. Visible are the connector 820, core wire 1110, hypotube 1130, outer insulation layer 940, as well as an inner insulation layer 1120 (e.g., heat shrink tubing or a coated polymer) that sits between the conductive core wire 1110 and hypotube 1130. Also visible are the crossing electrode 548, which is the portion of the core wire 1110 that extends past the distal end of the outerinsulation layer 940, and the cutting electrode 546, which is formed by a gap 1160 in the outer insulation layer 940 that exposes a portion of the hypotube 1130. For convenience and safety while transiting vascular tissues, an atraumatic chamfer or edge transition 1150 has been placed between the distal end of the outer insulation layer 940 and the crossing electrode 548.

[0107] Also visible is a cut line 13-13 that shows where the axial cross-sectional view of Figure 13 is taken. It is noted that, although the cutting electrode 546 occurs at the hooked portion 810 of the resection wire 545, the resection wire 545 is shown here as being straight for convenience. For example, Fig. 11-21 could illustrate the straight configuration that the leaflet puncture and slitting device takes when it is positioned inside the guide catheter (such as in Figure 10). In another example, Figs. 11-21 could be the straight configuration in an earlier stage of manufacturing before the material of the core wire 1110 (e.g., a shape memory material) is set into the hook shape 810.

[0108] It is noted that both the core wire 1110 and the hypotube 1130 may extend proximally to the connector. The core wire extends distally all the way to the distal end 1185 of the device, whereas the hypotube 1130 extends distally only to a point between the gap 1160 and the distal end of the outer insulation layer 940. In some aspects, the hypotube 1130 can be non-shape memory material (e.g., electrically conductive metal or metal alloy, such as copper, gold, platinum, stainless steel, alloys of platinum and iridium, silver and silver alloys, and the core wire 1110 can be a shape memory material (e.g., electrically conductive material, such as nitinol, gold / cadmium, silver / cadmium, copper / aluminum / nickel, / copper / tin, indium / titanium, nickel / aluminum, or manganese / copper. In other aspects, the core wire 1110 can be a non-shape memory material and the hypotube 1130 can be a shape memory material. In some aspects, within the connector, the conductive portion 830 for the crossing electrode 548 (see Figure 8) may be the central / core wire itself; conductive portion 840 for the cutting electrode 546 may be the hypotube 1130 itself.

[0109] In an example, an outer diameter of the resection wire 545 may be between 0.014 and 0.038 inches (e.g., 0.014 inches, 0.018 inches, 0.035 inches, etc.), and the length of the resection wire 545 may be between 50 cm and 260 cm.

[0110] The outer insulation layer 940 and the inner insulation layer 1120 may be made of the same or different materials. Example insulation materials include but are not limited to polytertoflouroethylene (PTFE), Pebax, nylon, polyethylene, polyethylene terephthalate (PET), polypropylene, urethane, or polyimide.

[0111] The resection wire 545 could be built in a number of ways. First, it could be made from a hollow tube 1130 which would form the body of the wire, the hook, and one or more of at least two electrodes. The hollow tube 1130 would also form one of the two necessary electrical connections to a radio frequency (RF) generator. Inside the hollow tube would be an insulation layer 1120 around a wire 1110 which forms the tip of the device, and a second electrode. This wire 1110 would also become the connection point for the second electrode to the RF generator.

[0112] Figure 12 is a schematic, diagrammatic, side cross-sectional view of an example resection wire 545, according to aspects of the present disclosure. Visible are the connector 820, core wire 1110, hypotube 1130, outer insulation layer 940, inner insulation layer 1120, crossing electrode 548, hooked portion 810, cutting electrode 546, and chamfer or edge transition 1150. The resection wire 545 of Figure 12 is similar to that of Figure 11A, except that the cutting electrode 546 is formed by a gap 1160 in the outer insulation layer 940 that occurs only on the inside curve 1270 of the hooked portion 810.

[0113] Figure 13 is a schematic, diagrammatic, axial cross-sectional view of an example resection wire 545, taken along cut line 13-13 of Figure 11 according to aspects of the present disclosure. Visible are the core wire 1110, inner insulation layer 1120, hypotube 1130, and outer insulation layer. The outer insulation layer 940 prevents the hypotube 1130 from making physical or electrical contact with the patient’s tissues at any location other than the exposed cutting electrode 546 (see Figure 11). The inner insulation layer 1120 prevents the core wire 1110 from making electrical contact with the hypotube 1130.

[0114] Figure 14 is a schematic, diagrammatic, side cross-sectional view of an example resection wire 545, according to aspects of the present disclosure. Visible are the connector 820, core wire 1110, hypotube 1130, outer insulation layer 940, inner insulation layer 1120, crossing electrode 548, hooked portion 810, cutting electrode 546, and chamfer or edge transition 1150. However, in the example shown in Figure 14, the hypotube 1130 does not extend proximally all the way to the connector 820, but is electrically connected to the connector 820 by means of a cutting electrode power wire 1410.

[0115] Figure 15 is a schematic, diagrammatic, side cross-sectional view of an example resection wire 545, according to aspects of the present disclosure. Visible are the connector 820, core wire 1110, outer insulation layer 940, inner insulation layer 1120, crossing electrode 548, hooked portion 810, cutting electrode 546, and chamfer or edge transition 1150. However, in the example shown in Figure 15, the solid hypotube 1130 has been replaced with a braided or laser-cut tube or spring 1530 that includes electrically contiguousconductive portions 1540 and openings 1550. The braided or laser-cut tube or spring 1530 may in some instances provide greater flexibility than a solid hypotube, while providing the same or similar functionality as both a conductor and as an electrode.

[0116] Figure 16 is a schematic, diagrammatic, side cross-sectional view of an example resection wire 545, according to aspects of the present disclosure. Visible are the connector 820, core wire 1110, hypotube 1130, outer insulation layer 940, inner insulation layer 1120, crossing electrode 548, hooked portion 810, cutting electrode 546, and chamfer or edge transition 1150. However, in the example shown in Figure 16, the solid hypotube 1130 has been replaced with a braided or laser-cut tube 1530 which does not extend proximally all the way to the connector 820, but rather is electrically connected to the connector 820 by means of the cutting electrode power wire 1410.

[0117] Figure 17 is a schematic, diagrammatic, side cross-sectional view of an example resection device 545, according to aspects of the present disclosure. Visible are the connector 820, core wire 1110, hypotube 1130, crossing electrode 548, hooked portion 810, and cutting electrode 546. However, in the example shown in Figure 17, the hypotube 1130 is a conductive layer embedded within a polymer sheath 1740. This may be achieved for example by placing an inner insulation layer around the core wire, placing the hypotube 1130 around the inner insulation layer, placing an outer insulation layer outside the hypotube, and then reflowing (e.g., heating and partially melting) the inner and outer insulation layers together. Alternatively, the polymer sheath 1740 and hypotube 1130 may be portions of a braid-reinforced catheter whose outer layer is stripped at the location of the cutting electrode 546. In some aspects, the polymer sheath 1740 includes its own chamfer or edge transition 1750.

[0118] Figure 18 is a schematic, diagrammatic, side cross-sectional view of an example resection device 545, according to aspects of the present disclosure. Visible are the connector 820, core wire 1110, braided tube 1530, polymer sheath 1740, crossing electrode 548, hooked portion 810, cutting electrode 546, and chamfer or edge transition 1750. The configuration shown in Figure 18 is similar to that of Figure 17, except that the hypotube 1130 has been replaced with a braided or laser-cut tube or spring 1530. This structure may be assembled for example by placing an inner insulation layer around the core wire, placing the braided tube 1530 around the inner insulation layer, placing an outer insulation layer outside the braided tube 1530, and then reflowing (e.g., heating and partially melting) the inner and outer insulation layers together. Alternatively, the polymer sheath 1740 and braided tube may beportions of a reinforced catheter whose outer layer is stripped at the location of the cutting electrode 546.

[0119] Figure 19 is a schematic, diagrammatic, side cross-sectional view of an example resection wire 545, according to aspects of the present disclosure. Visible are the core wire 1110, hypotube 1130, polymer sheath 1740, crossing electrode 548, hooked portion 810, cutting electrode 546, and chamfer or edge transition 1750. The configuration shown in Figure 19 is similar to that of Figure 17, except that there is a circumferential gap 1930 between the inner edge of the polymer sheath 1740 and the outer surface of the core wire 1110, such that the core wire 1110 can slide longitudinally in a distal or proximal direction relative to the polymer sheath 1740 and hypotube 1130. The connector 820 has also been replaced with a crossing electrode connector 1546 that is electrically connected to the core wire and a cutting electrode connector 1548 that is electrically connected to the hypotube 1130.

[0120] Figure 20 is a schematic, diagrammatic, side cross-sectional view of a distal portion 1180 of an example resection wire 545, according to aspects of the present disclosure. Visible are the core wire 1110, hypotube 1130, outer insulation layer 940, inner insulation layer 1120, crossing electrode 548, hooked portion 810, cutting electrode 546, and chamfer or edge transition 1150. The configuration shown in Figure 20 is similar to that of Figure 11, except that the cylindrical crossing electrode 548 of Figure 11 has been replaced with a conical, sharp-tipped crossing electrode 2020. This sharp, conical tip may, in some instances, facilitate the puncturing of a heart valve leaflet (e.g., at lower power or with no RF power applied).

[0121] Figure 21 is a schematic, diagrammatic, side cross-sectional view of a distal portion 1180 of an example resection wire 545, according to aspects of the present disclosure. Visible are the core wire 1110, hypotube 1130, outer insulation layer 940, inner insulation layer 1120, crossing electrode 548, hooked portion 810, cutting electrode 546, and chamfer or edge transition 1150. The configuration shown in Figure 21 is similar to that of Figure 11, except that the cylindrical crossing electrode 548 of Figure 11 has been replaced with a diagonally sliced, sharp-tipped crossing electrode 2120. This sharp, wedge-shaped tip may, in some instances, facilitate the puncturing of a heart valve leaflet (e.g., at lower power or with no RF power applied).

[0122] Figure 22A is a schematic, diagrammatic, side cross-sectional view of a leaflet puncture and slitting device 700 approaching a heart valve leaflet 304, according to aspects of the present disclosure. Visible are the guide catheter 544, resection wire 545, crossingelectrode 548, and cutting electrode 546. In an example, the resection wire 545 is advanced within the guide catheter until the crossing electrode 548 projects just beyond the distal end of the guide catheter 544. The guide catheter 544 is then placed against the heart valve leaflet 304 such that the crossing electrode 548 is in contact with the heart valve leaflet 304. RF energy can then be applied to the crossing electrode 548 in order to puncture the heart valve leaflet.

[0123] Figure 22B is a schematic, diagrammatic, side cross-sectional view of a leaflet puncture and slitting device 700 puncturing a heart valve leaflet 304, according to aspects of the present disclosure. Visible are the guide catheter 544, resection wire 545, crossing electrode 548, and cutting electrode 546. In an example, the resection wire 545 is advanced through the guide catheter 544 such that the crossing electrode 548, with RF energy applied to it, passes all the way through the heart valve leaflet 304.

[0124] Figure 22C is a schematic, diagrammatic, side cross-sectional view of a leaflet puncture and slitting device 700 puncturing a heart valve leaflet 304, according to aspects of the present disclosure. Visible are the guide catheter 544, resection wire 545, crossing electrode 548, and cutting electrode 546. In an example, the crossing electrode 548, with RF energy applied to it, has passed all the way through the heart valve leaflet 304, leaving behind a puncture lumen 2210. The clinician then continues to advance the resection wire 545 such that the cutting electrode 546 approaches the puncture lumen 2210.

[0125] Figure 22D is a schematic, diagrammatic, side cross-sectional view of a leaflet puncture and slitting device 700 preparing to resect a heart valve leaflet 304, according to aspects of the present disclosure. Visible are the guide catheter 544, resection wire 545, crossing electrode 548, and cutting electrode 546. In an example, the resection wire 545 has been advanced through the puncture lumen 2210 until the cutting electrode 546 is within the puncture lumen 2210. At this point the clinician turns off RF power to the crossing electrode 548, and then withdraws the guide catheter 544 by pulling it axially or longitudinally in a proximal direction, while leaving the resection wire 545 in its current position.

[0126] Figure 22E is a schematic, diagrammatic, side cross-sectional view of a leaflet puncture and slitting device 700 resecting a heart valve leaflet 304, according to aspects of the present disclosure. Visible are the guide catheter 544, resection wire 545, crossing electrode 548, and cutting electrode 546. In an example, the resection wire 545 is pulled back through the guide catheter 544 in a proximal, longitudinal direction such that the cutting electrode 546, with RF energy applied to it, is drawn through the heart valve leaflet 304, expanding the puncture lumen 2210 toward the tip of the heart valve leaflet 304. Because theheart valve leaflet 304 is flexible and the cutting electrode 546 is hook-shaped, the cutting electrode 546 may tend to slit the heart valve leaflet 304 from the puncture lumen 2210 all the way to the tip 2220, while remaining outside the guide catheter. The clinician then switches off RF energy to the cutting electrode, pulls the resection wire 545 back into the guide catheter 544, and then withdraws the guide catheter (with the resection wire inside it) from the patient. In some cases, before removing the device, the clinician may choose to make additional resection slits to the same leaflet, or may choose to slit additional leaflets in the same valve or other valves.

[0127] Figure 23A is a diagrammatic top view of an aortic valve 400, according to aspects of the present disclosure. Visible are the heart wall 210, the aortic valve leaflets 304, the right coronary artery 104, and the left main coronary artery 106. During and after valve replacement procedures, the leaflets 304 can obstruct the arteries 104, 106, as described above. This and other issues can, in certain circumstances, be alleviated by resecting one or more leaflets 304. Thus, in the example shown in Figure 23A, one leaflet has been given a puncture lumen 2210 (e.g., by a leaflet puncture and slitting device whose crossing electrode has been energized and passed through the leaflet 304).

[0128] Figure 23B is a diagrammatic top view of an aortic valve 400, according to aspects of the present disclosure. Visible are the heart wall 210, the aortic valve leaflets 304, the right coronary artery 104, and the left main coronary artery 106. In the example shown in Figure 23B, one leaflet has been given a total resection cut 2310 (e.g., by a leaflet puncture and slitting device 700 whose hook-shaped cutting electrode is pulled along the length of the leaflet 304 from the puncture lumen 2210 to the leaflet tip).

[0129] Figure 24 is a schematic diagram of a processor circuit 2450, according to aspects of the present disclosure. The processor circuit 2450 may be implemented in the processing system 510, the system 500, or other devices or workstations (e.g., third-party workstations, network routers, etc.), or on a cloud processor or other remote processing unit, as necessary to implement the method. As shown, the processor circuit 2450 may include a processor 2460, a memory 2464, and a communication module 2468. These elements may be in direct or indirect communication with each other, for example via one or more buses.

[0130] The processor 2460 may include a central processing unit (CPU), a digital signal processor (DSP), an ASIC, a controller, or any combination of general-purpose computing devices, reduced instruction set computing (RISC) devices, application- specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other related logic devices, including mechanical and quantum computers. The processor 2460 may also compriseanother hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 2460 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0131] The memory 2464 may include a cache memory (e.g., a cache memory of the processor 2460), random access memory (RAM), magnetoresistive RAM (MRAM), readonly memory (ROM), programmable read-only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In an embodiment, the memory 2464 includes a non-transitory computer-readable medium. The memory 2464 may store instructions 2466. The instructions 2466 may include instructions that, when executed by the processor 2460, cause the processor 2460 to perform the operations described herein. Instructions 2466 may also be referred to as code. The terms “instructions” and “code” should be interpreted broadly to include any type of computer- readable statement(s). For example, the terms “instructions” and “code” may refer to one or more programs, routines, sub-routines, functions, procedures, etc. “Instructions” and “code” may include a single computer-readable statement or many computer-readable statements.

[0132] The communication module 2468 can include any electronic circuitry and / or logic circuitry to facilitate direct or indirect communication of data between the processor circuit 2450, and other processors or devices. In that regard, the communication module 2468 can be an input / output (I / O) device. In some instances, the communication module 2468 facilitates direct or indirect communication between various elements of the processor circuit 2450 and / or the system 500. The communication module 2468 may communicate within the processor circuit 2450 through numerous methods or protocols. Serial communication protocols may include but are not limited to United States Serial Protocol Interface (US SPI), Inter-Integrated Circuit (I2C), Recommended Standard 232 (RS-232), RS-485, Controller Area Network (CAN), Ethernet, Aeronautical Radio, Incorporated 429 (ARINC 429), MODBUS, Military Standard 1553 (MIL-STD-1553), or any other suitable method or protocol. Parallel protocols include but are not limited to Industry Standard Architecture (ISA), Advanced Technology Attachment (ATA), Small Computer System Interface (SCSI), Peripheral Component Interconnect (PCI), Institute of Electrical and Electronics Engineers 488 (IEEE-488), IEEE- 1284, and other suitable protocols. Where appropriate, serial andparallel communications may be bridged by a Universal Asynchronous Receiver Transmitter (UART), Universal Synchronous Receiver Transmitter (USART), or other appropriate subsystem.

[0133] External communication (including but not limited to software updates, firmware updates, preset sharing between the processor and central server, or readings from the leaflet puncture and slitting device) may be accomplished using any suitable wireless or wired communication technology, such as a cable interface such as a universal serial bus (USB), micro USB, Lightning, or FireWire interface, Bluetooth, Wi-Fi, ZigBee, Li-Fi, or cellular data connections such as 2G / GSM (global system for mobiles) , 3G / UMTS (universal mobile telecommunications system), 4G, long term evolution (LTE), WiMax, or 5G. For example, a Bluetooth Low Energy (BLE) radio can be used to establish connectivity with a cloud service, for transmission of data, and for receipt of software patches. The controller may be configured to communicate with a remote server, or a local device such as a laptop, tablet, or handheld device, or may include a display capable of showing status variables and other information. Information may also be transferred on physical media such as a USB flash drive or memory stick.

[0134] As will be readily appreciated by those having ordinary skill in the art after becoming familiar with the teachings herein, the leaflet puncture and slitting device advantageously permits a clinician (e.g., a heart surgeon) to puncture and slit a heart valve leaflet with a repeatably straight incision that cuts away from the heart wall and thus presents minimal risk of damage to the heart wall or other adjacent tissues. Although the electrical energy powering the crossing and cutting electrodes is described herein as being radio frequency (RF) energy, it is understood that other types of electrical energy may be used instead or in addition, including but not limited to terahertz, gigahertz, microwave, 120 Hz, 60 Hz, 0 Hz (e.g., direct current or DC), etc.

[0135] Figure 25 is a schematic, diagrammatic, side cross-sectional view of an example resection device 545, according to aspects of the present disclosure. In the example shown in Figure 25, the resection device 545 can be constructed using a reinforced catheter over a wire, where the catheter has a lumen for a pullwire which, when tensioned, will form the hook shape in the portion 810. Visible are the core wire 1110, hypotube 1130, polymer sheath 1740 (which may for example be a catheter, reinforced catheter, etc.), crossing electrode 548, hooked portion 810, connector 820, cutting electrode 546, and chamfer or edge transition 1750.

[0136] Thus, the resection device 545 can be a catheter 1740 with a crossing electrode lumen 2530 for the crossing electrode 548 and a pullwire lumen 2540 for the pullwire 2550 (which may for example be made of a conductive material, such as a metal or metal alloy). A portion 2560 of the catheter wall forming the pullwire lumen 2540 is removed, which exposes a portion of the pullwire 2550 at the distal portion of the device. The exposed portion of the pullwire 2550 can be the cutting electrode 546. The pullwire 2550 is electrically isolated from the crossing electrode 548 by the insulating polymer 1740 forming the catheter (e.g., the walls defining pullwire lumen and / or the lumen for the crossing electrode).

[0137] The walls of the pullwire lumen 2540 can be spaced from the pullwire 2550 (as shown in Fig. 25) or in contact with the pullwire 2550. The walls of the crossing electrode lumen 2530 can be spaced from the crossing electrode 548 (as shown in Fig. 25) or in contact with the crossing electrode 548. The crossing electrode 548 may be movable relative to the catheter 1740 or fixedly coupled to the catheter 1740 such that the crossing electrode 548 is stationary relative to the catheter 1740 (e.g., when walls of the crossing electrode lumen 2530 are in contact with the crossing electrode 548).

[0138] Electrical connections for the cutting electrode 546 and crossing electrode 548 can be provided by one connector (e.g., connector 820) or multiple connectors (e.g., as shown in Figure 19, with separate connectors for cutting electrode or crossing electrode).

[0139] A user can provide actuation for the pullwire 2550, which tensions the pullwire 2550. For example, the user can pull the proximal portion (e.g., proximal end of pullwire 2550) proximally to provide the actuation. The distal end of the pullwire can be fixedly coupled to the distal portion of the catheter 1740 (e.g., embedded inside the polymer forming the catheter, adhesive, etc.). The pullwire is also laterally / radially offset to one side of the device 545. As a result, the tensioning of the pullwire 2550 can deflect the distal portion of the resection device 545, causing the resection device 545 (e.g., the pullwire 2550, the catheter 1740, and the crossing electrode 548) to have the hook shape portion 810 (as shown for example in Figure 9).

[0140] In some aspects, the user can directly contact / pull the proximal portion of the pullwire 2550, which can have insulation at the proximal portion (e.g., proximal end) to prevent electrical energy from flowing to the user. In some instances, the user can contact / pull a connector coupled (e.g., fixedly coupled) to the proximal portion / end of the pullwire 2550. The connector that the user contacts / pulls can be the same connector providing electrical energy to the pullwire / cutting electrode or a separate connector. In someinstances, the proximal portion of the pullwire 2550 is coupled (e.g., fixedly coupled) to an actuator of a handle. The user can provide actuation for the pullwire 2550 by, e.g., turning a knob or other user input, which in turn causes the actuator to pull or tension the pullwire 2550.

[0141] In some aspects, the pullwire 2550 is not the cutting electrode or the crossing electrode. Rather, the cutting electrode, the crossing electrode, and the pullwire 2550 are distinct from one another. Thus, the resection device 545 can include the pullwire 2550 and pullwire lumen 2540 (for deflection of the distal portion into the hook shape at the portion 810). The exposed section of the pullwire can be omitted. In such instances, the resection device 545 may also include the cutting electrode and the crossing electrode, similar to the structure shown in any of Figures 9-12, or 14-22E. In aspects where the pullwire is not connected to the power source 542, the pullwire may be made of non-conducting materials (e.g., polymers, ceramics, etc.)

[0142] Figure 26 is a side view of a distal portion of an example resection wire or device 545 in a straight configuration, according to aspects of the present disclosure. The resection wire or device 545 can also be referred to as a flexible elongate intracardiac device that extends through blood vessel to reach the heart or surrounding anatomy (e.g., heart valves, heart chambers, aorta, etc.). Visible are the cutting electrode 546 and the crossing electrode 548. The crossing electrode 548 can also be referred to as a piercing electrode. The intended anatomical targets for the cutting electrode and the crossing electrode 548 include structural heart anatomy, such as aortic valve leaflets 304.

[0143] The crossing electrode 548 is positioned at, coupled to, forms, and / or otherwise defines the distal tip of the resection device 545. The crossing electrode 548 is made of a conductive metal or metal alloy. The distal portion of the crossing electrode 548 is uncovered and exposed to the patient’s anatomy. In the straight configuration shown in Figure 26, the crossing electrode 548 can be energized and contacted with the leaflet 304 to pierce the leaflet 304 (e.g., at a base or other locations of the leaflet), as similarly shown and described with respect to, e.g., Figures 22A, 22B, and / or 23A. Accordingly, the straight configuration of Figure 26 can also be referred to a piercing configuration or a crossing configuration.

[0144] The resection device 545 includes the hypotube 1130. The hypotube 1130 can also be referred to as a conductive hypotube 1130 because, as described herein, the hypotube 1130 can carry electrical energy. In some examples, the hypotube 1130 extends for a majority of the length of the resection device 545, such as between the proximal portion andthe distal portion of the resection device 545. The hypotube 1130 can include a cut portion 2610. In some aspects, the entire length of the hypotube 1130 is the cut portion 2610. In other example, the hypotube 1130 includes both one or multiple cut portions 2610 and one or multiple uncut portions.

[0145] The cutting electrode 546 is formed by, includes, and / or is otherwise defined by the cut portion 2610 of the hypotube 1130. The cut portion 2610 includes cuts 2612 between segments of the hypotube 1130. The cuts 2612 can also be referred to as spaces or gaps. The cut portion 2610 can be cut by laser cutting other suitable types of cutting, such as wire electrical discharge machining (wire EDM). While the portion 2610 is referred to as a cut portion 2610, in other aspects, other types of manufacturing (e.g., 3D printing), are used to form the portion 2610 with the spaces 2612. As described in more detail herein (such as Figure 33), the cuts 2612 can be different sizes (e.g., widths) at the top and bottom of the hypotube 1130. For example, at the top in Figure 26, the gaps 2612 are relatively smaller, and at the bottom in Figure 26, the gaps 2612 are relatively larger.

[0146] The cutting electrode 546 is made of a conductive metal or metal alloy. The cutting electrode 546 is uncovered and exposed to the patient’s anatomy. However, when piercing or crossing the leaflet 304 in the straight configuration of Figure 26, electrical energy is not delivered to the hypotube 1130 (and thus the cutting electrode 546), such that the cutting electrode 546 is not energized to cut the leaflet 304. As described in more detail herein, the cutting electrode 546 is energized when the resection device 545 is in the hooked configuration for cutting the leaflet 304.

[0147] The resection device 545 includes different sections of outer insulation layer 940. The outer insulation layer 940 can be one or multiple polymers that provide electrical isolation for the crossing electrode 548 and / or the cutting electrode 546. One section of the outer insulation layer 940 is located proximal of the crossing electrode 548 and the distal of the cutting electrode 546 (e.g., between the crossing electrode 548 and the cutting electrode 546). This section of the outer insulation layer 940 can surround a proximal end of the crossing electrode 548 and the electrical / mechanical connections between a pull wire conductor 2710 and the crossing electrode 548 (shown and described with respect to Figure 27). Another section of the outer insulation layer 940 is located proximal of the cutting electrode 546. This portion of the outer insulation layer 940 surrounds the portion of the hypotube 1130 that is proximal of the cut portion 2610 such that cutting is only performed by the cutting electrode 546 when the hypotube 1130 is energized.

[0148] Figure 27 is a side cross-sectional view of the resection device 545 of Figure 26, according to aspects of the present disclosure. Visible are the outer insulation layer 940, cutting electrode 546, crossing electrode 548, hypotube 1130, laser-cut section 2610, and uncut sections 2620.

[0149] Also visible is a conductive pull wire or pull wire conductor 2710 surrounded by an inner layer of insulation 2720. In the example shown in Figure 27, the distal end of the conductive pull wire 2710 (a portion not surrounded by the inner layer of insulation 2720) is electrically coupled and mechanically coupled (e.g., welded, soldered, adhered with a conductive adhesive, etc.) directly to the proximal end of crossing electrode 548 at a location or length 2722. The crossing electrode 548 is electrically isolated from the hypotube 1130 by an insulator 2730, but is electrically connected to the pull wire 2710, which acts as an electrical conductor to energize the crossing electrode 548, for piercing of the valve leaflet 304.

[0150] The cross-sectional view of the cut portion 2610 of the hypotube 1130 includes multiple segments 2614 that are separated by gaps 2612. As shown and described with respect to Figures 28A and 28B, the gaps 2612 allow the segments 2614 of the cut portion 2610 to be angled relative to another (in response to tension applied to the pull wire conductor 2710 when pulled) so that the cutting electrode 546 transitions from the straight configuration (e.g., Figures 26 and 27) to the hook-shaped configuration (e.g., Figures 28A and 28B). The cut portion 2610 also has connectors 2616, which are uncut segments of the hypotube 1130. The connectors 2616 physically connect the segments 2614 to one another. The physical continuity provided by the connectors 2616 to the cut portion 2610 allow for all of the cutting electrode 546 to be energized, such as when the hypotube 1130 as a whole is energized. In the example shown in Figure 27, all of the connectors 2616 are located on one side of the resection device 545 (bottom in drawing). As shown and described with respect to Figures 28A and 28B, the connectors 2616 are positioned on the outer portion when the cutting electrode 546 is in the hook-shaped configuration.

[0151] In other examples, the resection device 545 can include a catheter shaft with a dedicated lumen for the pullwire 2710. The crossing electrode 548 can be bonded to such a catheter shaft.

[0152] Figure 28A is a side view of the resection device 545 of Figure 26 in the hooked configuration, according to aspects of the present disclosure. Visible are the outer insulation layer 940, cutting electrode 546, crossing electrode 548, hypotube 1130, cut section 2610, and pullwire 2710 (visible through gaps 2612). After the crossing electrode 548 has piercedthe valve leaflet 304, proximal tension on the pullwire (when the pullwire is pulled in the proximal direction) 2710 has pulled the cut section 2610 into a hook shape 810. The cutting electrode 546 can be pulled through the valve leaflet 304 in order to slit or resect it, as shown and described above. In particular, the portion of the valve leaflet 304 that is proximate to the inside of the hook shape 810 is slit when the resection device 545 is pulled in the proximal direction (causing the energized cutting electrode 546 to move in the proximal direction through this portion of the valve leaflet 304).

[0153] In the example shown in Figure 28 A, the portion of the hypotube 1130 that includes the cutting electrode 546 is laser cut or otherwise cut, forming a cut section 2610 that is flexible in such a way that when actuated by the pull wire 2710, cut section 2610 reversibly folds into a hook shape 810 that is rigid as long as tension is maintained on the pull wire 2710. The crossing electrode 546 forms the top of the hook shape via the cut section 2610 and is proximal-facing in the hook-shaped configuration (compared to distal facing in the straight configuration of Figures 26 and 27). With the cutting electrode 546 in the hookshaped configuration, the cutting electrode 546 can be energized and the resection device 545 can be pulled proximally in order to resect the leaflet 304 as described above. Once the resection is complete, tension on the pullwire conductor 2710 is released. The cutting electrode 546 and / or the resection device 545 transitions from the hook-shaped configuration to the straight configuration, and the device 545 is extracted from the patient body, e.g., via the delivery sheath or guide catheter 544 (see Figure 7A).

[0154] The laser cut hypotube 1130 is advantageously flexible yet maintains other desirable properties of a hypotube (e.g., a rigid profile and good torque transmission). In some existing devices, structures at the distal end of a catheter are often created using nitinol super-elastic metal. The disadvantage of such structures is a need to carefully balance forces, between structures being too rigid to fit in a delivery sheath on the one hand, and on the other hand not being rigid enough to perform the desired function. An advantage of the laser-cut hypotube in that when it is activated by a pullwire, it curls into a hook shape of a desired radius. As long as sufficient tension is maintained on the pull wire, the resulting hook shape is rigid enough for tissue cutting application and other applications where a rigid hook shape may be desirable. The process is reversible, e.g. by releasing tension on the pullwire, at which time the cut hypotube can be easily straightened again for extraction.

[0155] Deflection into the hooked-shaped configuration of the cutting electrode 546 and / or the resection device 545 can cause the segments 2614 of the cut portion 2610 to be closer to one another on the inside of the hook shape 810 and farther away from one anotheron the outside of the hook shape 810. In some aspects, the edges of the segments 2614 on the inside of the hook shape 810 can be in contact with another in the hook-shaped configuration. In other aspects, the edges of the segments 2614 on the inside of the hook shape 810 are still spaced from one another in the hook-shaped configuration, but the spacing is less than in the straight configuration (Figures 26 and 27). The spacing between the segments 2614 in the hooked shaped configuration can depend on the amount of tension on the pullwire conductor 2710 (more tension results in less spacing, less tension results in more spacing). The connectors 2616 between segments 2614 are the outside of the hook shape 810.

[0156] Figure 28B is a side cross-sectional view of the resection device 545 of Figure 26 in the hooked configuration, according to aspects of the present disclosure. Visible are the outer insulation layer 940, cutting electrode 546, crossing electrode 548, hypotube 1130, cut section 2610, and pullwire conductor 2710. The insulator 2730 electrically isolates the cutting electrode 546 and the crossing electrode 548 from one another. The pullwire conductor 2710 is attached to the crossing electrode 548 such that it can be used as a conductor to energize the crossing electrode 548, and such that when tension is applied to the pull wire conductor 2710, the cut section 2610 of the hypotube 1130 forms the hook shape 810, with the cutting electrode 546 on the inside of the hook shape.

[0157] In the example shown in Figure 28B, once the crossing electrode 548 has pierced the valve leaflet 304, tension on the pull wire conductor 2710 has pulled the laser-cut section 2610 into a hook shape 810, such that the cutting electrode 546 can be pulled through the valve leaflet 304 in order to slit or resect it, as shown and described above.

[0158] In the example of Figs. 28A and 28B, the resection device 545 includes one pull wire conductor 2710. The one pull wire conductor 2710 can allow for one type of deflection for the distal portion of the resection device 545. In particular, the cutting electrode 546 and / or the resection device 545 deflects in one direction when tension is applied to the pullwire conductor 2710. As shown in Figure 27, 28A, and 28B, for example, a longitudinal axis of the pull wire conductor 2710 and / or the coupling location 2722 between the pullwire conductor 2710 and the crossing electrode 584 can be positioned so that it is radially offset from the central longitudinal axis of the resection device 545 and / or the hypotube 1130 (e.g., radially positioned towards the inside of the hook shape). The pullwire conductor 2710 and / or coupling location 2722 being radially offset allows for the deflect when tension is applied to the pullwire conductor 2710. As such, the cut section 2610 of the hypotube 1130 flexes readily to form the hook shape 810, but does not easily flex in the in the direction opposite the hook, or out of the plane of the hook, such that when tension isapplied to the pullwire 270, the cut section 2610 flexes to form the hook shape 810 with the cutting electrode 546 on the inside of the hook shape, rather than an outside of the hook shape. The one direction of deflection results in, for example, the side of the cut potion 2610 with less spacing in the straight configuration (top side in Figs. 26 and 27) becomes the inside of the hook shape 810, the side of the cut potion 2610 with more spacing in the straight configuration (bottom side in Figs. 26 and 27) becomes the outside of the hook shape 810 side, and the connectors 2616 between segments 2614 are on the outside of the hook shape 810. The cross-sectional view plane in Figure 28 extends through the connectors 2616, which shows the physical continuity that that connectors 2616 provide to the cut portion 2610.

[0159] The arrangement of components at the distal portion of resection device 545 has some differences between Figure 28B and Figure 27. In Figure 28B, the proximal end of crossing electrode 548 has an opening that receives the distal end of the pullwire conductor 2710. The pullwire conductor 2710 can be mechanically and electrically coupled to the crossing electrode 548 inside of the opening at the location 2722. In Figure 27, the proximal end of crossing electrode 548 is shaped as an extension. Thus, the distal end of the pullwire conductor 2710 extends alongside the proximal end of crossing electrode 548 at the location 2722 where the pullwire conductor 2710 and the crossing electrode 548 are coupled in Figure 27. An end hypotube 2860 is crimped, friction-fit, or soldered to the pullwire conductor 2710 and welded or soldered to the crossing electrode 548, to form both the electrical and mechanical connections between the pullwire conductor 2710 and the crossing electrode 548.

[0160] Figure 29 is a close-up view of the cut portion 2610 of the hypotube of the resection device 545 of Figure 27B in its hooked shape 810, according to aspects of the present disclosure. The cuts, gaps, or openings 2612 separate segments 2614 of the cut portion 2610 of the hypotube. Figure 29 additionally illustrates that a layer of insulation 2820 is provided on the segments 2614 of the cut portion 2610. The insulation 2820 can be located on the outside, inside, and / or sides of the segments 2614. The insulation 2820 may for example be a polymer material, dielectric material, or other material.

[0161] As described above, radio frequency (RF) energy can be used to cut tissue and / or coagulate blood. When used as a cutting technique, the power, frequency, voltage, and waveform can all be adjusted to optimize cutting by either vaporization of tissue or by creating an arcing of electric current between the electrode and the tissue. There are situations where one type of cutting is preferable over the other, and there are situationswhere one type of cutting is dominant due to the conditions under which the cutting takes place.

[0162] For the resection of a heart valve leaflet, the cutting action is driven by vaporization, because there is fluid (e.g., blood) surrounding the tissue 304 to be cut. Cutting by vaporization occurs when the high frequency voltage waveform at the cutting electrode 546 causes the ions in the cells of the tissue 304 in the vicinity of the cutting electrode 546 to try to vibrate at that same frequency, which generates heat. This heat is high enough to vaporize individual cells, which at a macro level, causes the tissue 304 to be cut. In order to facilitate this type of cutting, it may be desirable to keep the tissue 304 from physically contacting the cutting electrode 546, but at the same time, not allow there to be too much distance between the cutting electrode 546 and the tissue 304.

[0163] The configuration shown in Figure 29 facilitates the vaporization cutting of tissue 304 by adjusting the thickness of the layer of insulation 2820 protecting the majority of the cutting electrode 546 from contacting the tissue 546 and causing an electrical short. In an example, the insulation 2820 may be adjusted to a thickness that also keeps the tissue 304 at a favorable distance away from the electrode 546 itself. In addition, small holes, pores, or openings 2830 are created in the insulation layer 2820, that are large enough to allow the passage of current between the cutting electrode 546 and the valve leaflet tissue 304, but small enough to prevent physical contact between the cutting electrode 546 and the tissue 304, and consequently an electrical short, between the tissue 304 and the electrode 546. The openings 2830 can be located on only the inside of the hook shape 810 (proximate to the portion of the leaflet 304 that will be slit), where the spacing between segments 2614 is relatively smaller in the straight configuration (Figures 26 and 27) and even smaller in the hooked configuration. The openings 2830 are located opposite the connectors 2616. The openings 2830 expose portions of the cutting electrode 546. The remaining portions of the cutting electrode (e.g., everywhere other than the inside of the hook shape 810, including the outside of the hook shape 810 and the sides of the hook shape 810) are not exposed because of being covered by the insulation 2820.

[0164] As described above, this configuration overcomes issues encountered when trying to cut tissue using RF energy vaporization and a non-insulated electrode surface. Aspects of the configuration include the thickness of the electrical insulation layer 2820 used to protect an electrical short between the RF energy electrode 546 and the tissue 304 which it is being used to cut, and the size and distribution of openings, holes, or pores 2830.

[0165] In some aspects, the insulation 2820 can be deposited (e.g., physical vapor deposition or PVD, chemical vapor deposition or CVD) or provided on the segments 2614 using any other suitable process. The electrical insulation 2820 could be applied in a number of fashions. It could be reflowed onto the surface, it could consist of heat shrink tubing applied to the surface, it could be deposited onto the surface using a technique such as vapor deposition (as with parylene), dip coating using a solvent based polymer solution, sprayed on in an aerosol fashion, or in any fashion that allows for an electrically insulative material to be applied to a surface in a manner which can also control the thickness of the layer applied. The insulation 2820 may be applied before or after the hypotube is laser cut to form openings, holes, or pores 2830.

[0166] Once the insulation layer 2820 has been applied, the desired area of the electrode 5465 that will be used for cutting can be selectively ablated (e.g., with a laser), creating a series of small holes or pores 2830. The pattern and size of the holes 2830 can be adjusted to the specific application. It is also possible to create these holes 2830 by mechanical techniques such as punching, or in the case of heat shrink tubing as the insulation layer, by creating the holes in the tubing prior to application on the device.

[0167] Figure 30 is a schematic, diagrammatic, side cross-sectional view of an example resection wire 545, according to aspects of the present disclosure. Visible are the connector 820 at the proximal portion of the device 545, outer insulation layer 940 (proximal and distal of the cutting electrode 546), crossing electrode 548, hooked portion 810, cutting electrode 546, and chamfer or edge transition 1150 (e.g., in the outer insulation layer 910 distal of the cutting electrode 546). In the example shown in Figure 30, the hypotube 1130 includes a cut portion 2610 with electrically contiguous conductive portions 1540 (because of the connectors 2616 in Figures 27, 28A, 28B) and openings 1550, 2910. The electrically continuous conductive portions 1540 can be an alternative way of referring to the segments 2614 of the cut portion 2610. The openings 1550, 2910 are similar the openings 2612 in Figures 26, 27, 28A, and 28B. Openings 1550 can be the smaller openings (e.g., smaller width) between segments 2614 of the cut portion 2610 that are located on the inside of the hook shape and openings 2910 can the larger openings (e.g., larger width) between segments 2614 of the cut portion 2610 that are located on the outside of the hook shape. The cut section 2610 may in some instances provide greater flexibility than uncut sections of the hypotube 1130 (e.g., proximal of and distal of the cutting electrode 546), while providing the same or similar functionality as both a conductor and as an electrode. The hypotube 1130 can be a conductor that receives and carries electrical energy from a power source (e.g.,power source 542 of Figure 5) via the connector 820. The hypotube 1130 can receive the electrical energy directly or indirectly (e.g., via a wire in the connector 820 or elsewhere). The hypotube 1130 can be referred to as a first conductor that energizes the cutting electrode 546.

[0168] Also visible is the pullwire conductor 2710, which is surrounded by the inner insulator 2720, and which is electrically bonded to and serves as the power source for the crossing electrode 548. The pullwire conductor 2710 can be referred to as a second conductor that energizes the crossing electrode 548. When tension is applied in the proximal direction (as a result of being pulled in the proximal direction), the pullwire conductor 2710 pulls the resection wire 545 into the hooked shape 810 described above. The configuration shown in Figure 30 does not include a core wire.

[0169] On the outside of the hook portion 810, the electrically contiguous conductive portions 1540 are coated by solid sections 2840 of the insulator 2820. On the inner side or cutting electrode 546 of the hook portion 810, the electrically contiguous conductive portions 1540 are coated by porous sections 2850 of the cutting electrode insulator 2820. The sections 2850 can be referred to as porous because of the openings 2830 to allow RF energy from the cutting electrode 546 to reach the tissue. As shown, the openings 2830 are not provided in the solid sections 2840 on the outer side of the hook portion 810.

[0170] In some aspects, a solution 3010 of dextrose, water, and / or saline, may be introduced through a lumen 3020 of the resection device 545 and / or hypotube 1130, which extends from the proximal portion of the resection device 545 to the gaps 1550, 2910, and may then be released into the patient body (e.g., proximate to valve leaflet that is being cut, such as into heart chamber or aorta) through the gaps 1550, 2910, to suppress boiling / vaporization of, and electrical conduction by, the blood surrounding the cutting electrode 546.

[0171] Figure 31 is an end cross sectional view of an example pullwire conductor 2710 surrounded by the inner insulator 2720, according to aspects of the present disclosure. The pullwire 2710 is electrically conductive, and can be used to energize the crossing electrode. In the example of Figure 31, the pull wire conductor 2710 is solid. The pullwire 2710 may for example be made of metal, metal alloy, or other conductive material. The inner insulator 2720 keeps the pullwire 2710 electrically isolated from the hypotube 1130, including the laser-cut portion 2610 that forms the cutting electrode 546 (see Figure 30, above). As shown in Figure 27, for example, the inner insulator 2720 can extend proximal of the distal end ofthe pullwire conductor 2710, to allow mechanical and electrical coupling to the crossing electrode.

[0172] Figure 32 is an end cross sectional view of an example pullwire 2710 surrounded by the inner insulator 2720, according to aspects of the present disclosure. The pullwire 2710 is electrically conductive, and can be used to energize the crossing electrode. In the example shown in Figure 32, the pull wire conductor 2710 is made up of smaller individual wires 3210 (e.g., in a braided or twisted configuration). The inner insulator 2720 keeps the individual wires 3210 electrically isolated from the hypotube 1130, including the laser-cut portion 2610 that forms the cutting electrode 546 (see Figure 30, above). The cross sections of the individual wires 3210 may be circular, elliptical, flat, rectangular, rectangular with rounded corners, or otherwise. The individual wires 3210 may for example be made of metal, metal alloy, or other conductive material. The individual wires 3210 may be spaced from one another or may contact one another.

[0173] Figure 33 is a side cross-sectional view of electrically contiguous conductive portions 1540 of the cutting electrode 546 of a cut portion 2610 of a hypotube 1130, according to aspects of the present disclosure. The electrically contiguous conductive portions 1540 are also referred to as segments of the cut portion 2610. As described herein, connectors 2616 (Figs. 27, 28 A, 29 A) are un-cut parts of the cut portion 2610 that physically extend between the separate portions 1540. The physical continuity provided by the connectors 2616 also allows for electrically energy to be transmitted between portions 1540, making them electrically contiguous. Visible are the solid sections 2840 and porous sections 2850 of the cutting electrode insulator 2820, and the holes, pores, or openings 2830 that allow RF energy from the cutting electrode 546 to reach the tissue. Also visible are the gaps 2910 between the electrically contiguous conductive portions 1540 of the cutting electrode 546 on the inside portion of the hook shape, as well as the gaps 1550 between electrically contiguous conductive portions 1540 on the outside of the hook shape. The resection device can include lumen 3010 (e.g., defined by the hypotube 1130), which receives a fluid 3020 (e.g., dextrose, water, saline, etc., and / or combinations thereof) that is delivered, via the openings 1550 and 2910 into the anatomy during operation of the cutting electrode 546 and / or the crossing electrode 548.

[0174] When the cutting electrode 546 is in its straight configuration, the gaps 2910 on the outside of the hook shape have a width W3. When the cutting electrode 546 is in its straight configuration, the gaps 2910 on the inner portion of the hook have a width Wl, which is less than W3, and may for example be in the range of 0.003” and 0.010”. W3 canact as a stress relief, to facilitate bending of the cut portion of the hypotube into the hook shape, e.g. when the hypotube is made of stainless steel.

[0175] The porous sections 2850 of the cutting electrode insulator 2820 have a thickness T. The holes, pores, or openings 2830 each have a width W2. The thickness T can also be referred to as a depth of the openings 2830. The thickness T can be between 0.5 and 3.0 thousandths of an inch. The ratio between W2 and T may be referred to as an aspect ratio. The aspect ratio (ratio between W2 and T) can be selected in order to allow RF energy from the cutting electrode 546 to reach the tissue, while not allowing the tissue to directly contact the cutting electrode 546.

[0176] In an example, W1 is larger than W2, W3 is larger than W 1 and W2, W2 is the smallest of Wl, W2, and W3. In other examples, W3 is not provided (e.g., there may be no openings on the outside surface of the hook shape 810). In other examples, the values of Wl can vary along the length of the cut portion 2610 (e.g., as shown in Figs. 38A and 38B), e.g., W 1 may be relatively larger more distally and relatively smaller more proximally. In other examples, Wl and W3 are equal or approximately equal (e.g., within + / - 5% of one another). In an example, W2 and T are equal or approximately equal (e.g., within + / - 5% of one another). In other aspects, W2 is larger than T or W2 is smaller than T. In some aspects, the layer of insulation 2820 is omitted on the inside curve of the hook shape 810 and / or on the outside curve of the hook shape 810. In some aspects, the layer of insulation 2820 does not include multiple openings along the length (e.g., along the longitudinal axis) of a given segment of the cut portion 2610. As shown in Figs. 34A and 34B, the layer of insulation 2820 can include one opening along its entire length for a given segment of the cut portion. In some aspects, there is direct contact between the tissue and the cutting electrode (whether or not there is a layer of insulation 2820 on the inside of the hook shape 810).

[0177] The shape of the pattern of holes 2830, the shape, size, and aspect ratio of the holes 2830 themselves, and the location of the holes 2830 on the electrode 546 are all variables that can be used to facilitate the cutting of tissue by vaporization for a given application. For example, in some situations it might be advantageous to have a single row of rectangular holes 2830 arranged in a linear fashion to facilitate cutting (as shown for example in Figure 29). For other situations, circular holes 2830, or a two-dimensional array of holes 2830 may be desirable. For still other applications, a slot instead of a round hole may be desirable.

[0178] Figure 34A is a top view of the cutting electrode insulator 2820 covering the cutting electrode 546 of the example resection wire of Figure 29 in its straight configuration,according to aspects of the present disclosure. Visible are the gaps 2910 between the electrically contiguous conductive portions 1540 of the cutting electrode 546 of a cut portion of a hypotube 1130, as well as the openings 2830 in the insulator 2820. In the example shown in Figure 34A, the openings 2830 are rectangular, and arranged / aligned in a single straight line, as shown for example in Figure 29. Being arranged / aligned in the single straight line can be a regular (e.g., not random) pattern for the openings 2830. The openings 2830 can extend completely across the portions 1540 in the longitudinal direction (from proximal edge to distal edge of the portions 1540).

[0179] Figure 34B is a top view of the cutting electrode insulator 2820 covering the cutting electrode 546 of the example resection wire of Figure 29 in its hooked configuration, according to aspects of the present disclosure. In the example shown in Figure 34B, in the hooked configuration, the gaps 2910 are largely but not entirely closed due to the bending of the cut portion of the hypotube. The proximal / distal edges of the portions 1540 and the openings 2830 are spaced from one another by the gaps 2910. In other aspects, the gaps 2910 may be entirely closed such that the proximal and distal edges of the portions 1540 contact one another and the openings 2830 align to form a continuous opening.

[0180] Figure 35 is a top view of the outer insulator 2820 covering the cutting electrode 546 of the example resection wire of Figure 30 in its hooked configuration, according to aspects of the present disclosure. Visible are the gaps 2910, which are largely but not entirely closed. In the example shown in Figure 35, the holes or pores 2830 are circular, which may be advantageous for delivering RF energy to a smaller area of tissue, without allowing the tissue to bulge into the pores 2830 and thus contact the cutting electrode 546. The openings 2830 in Figure 35 are arranged / aligned in a single straight line. Being arranged / aligned in the single straight line can be a regular (e.g., not random) pattern for the openings 2830.

[0181] Figure 36 is a top view of the outer insulator 2820 covering the cutting electrode 546 of the example resection wire of Figure 30 in its hooked configuration, according to aspects of the present disclosure. Visible are the gaps 2910, which are largely but not entirely closed. In the example shown in Figure 31, the holes or pores 2830 are smaller and more numerous, which may be advantageous for delivering RF energy to a larger area of tissue, without allowing the tissue to bulge into the pores 2830 and thus contact the cutting electrode 546. The holes or pores 2830 can be arranged / aligned in a regular (e.g., not random) pattern. For example, the holes or pores 2830 are arranged in multiple lines (extending longitudinally). Different lines (above and below one another) are offset longitudinally suchthat hole or pore 2830 from one line is aligned in the space between two holes or pores 2830 from another line.

[0182] Figure 37 is a top view of the outer insulator 2820 covering the cutting electrode 546 of the example resection wire of Figure 30 in its hooked configuration, according to aspects of the present disclosure. Visible are the gaps 2910, which are largely but not entirely closed. In the example shown in Figure 37, the holes or pores 2830 are narrow, non-circular slots, which may be advantageous for delivering RF energy to a larger area of tissue, without allowing the tissue to bulge into the pores 2830 and thus contact the cutting electrode 546. The openings 2830 in Figure 35 are arranged / aligned in a single straight line. Being arranged / aligned in the single straight line can be a regular (e.g., not random) pattern for the openings 2830.

[0183] Figure 38A is a side view of the cut portion 2610 of an example hypotube 1130 in its straight configuration, according to aspects of the present disclosure. In the example shown in Figure 38A, the cuts 2910 exist only on the inside portion of the hook shape, while the connectors or connector / connection region 2616 (uncut segment(s) of the hypotube) occur on the outside portion of the hook shape. The cuts 2910 separate the segments 2614 of the cut portion of the hypotube 1130. Spacing between the centers (or other corresponding locations) of adjacent cuts 2910 or segments 2614 can be referred to as the pitch P of the segments 2614, whereas spacing between the left and right edges of a cut 2910 or adjacent / successive segments 2614 can be referred to as the width W of the cut. The depth of each cut 2910 and / or segment 2614 can be referred to as D.

[0184] The hypotube 1130 can be made of a shape memory material such as nitinol. To facilitate bending into a desired hook shape, the cut portion 2610 includes a first portion 3810 with a first pitch Pl a, first cut width Wla, and a depth DI a, a second portion 3815 with a larger second pitch Plb, a larger second cut width W lb, and a second larger depth Dlb, and a third portion 3820 with a still larger third pitch Pic, cut width W 1c, and depth Die. To facilitate widening and narrowing of the cuts 2910 when the cut portion 2610 is pulled into and out of the hook shape, each cut 2910 includes a wide mouth 3830, a narrow neck 3840, and a bending lobe 3850, each of whose size is proportional to the pitch, width, and depth of the section 3810, 3815, or 3820 where it is located. To facilitate flexibility of the cut portion 2610, the cuts 2910 extend across a majority of the diameter of the hypotube 1130.

[0185] Figure 38B is a bottom view of the cut portion 2610 of the example hypotube 1130 of Figure 38A, according to aspects of the present disclosure. Visible are the first portion 3810, second portion 3815, third portion 3820, cuts 2910 defining segments 2614,and bending lobes 3850. Also visible are the connectors or connector / connection region 2616 (uncut segment(s) of the hypotube) that occur on the outside portion of the hook shape Depending on the implementation, to facilitate desirable bending modes, cuts 2910 may exist only on the inside of the hook shape, only on the outside of the hook shape, or on both the inside and outside of the hook shape.

[0186] Although intended for specific treatment of heart valve related diseases, the technology disclosed herein could be expanded to anywhere tissue needs to be remotely punctured and then slit, such as endoscopic, laparoscopic, intravascular, intraluminal, and / or robotic surgical procedures. The leaflet puncture and slitting device can replace the more complex BASILICA and LAMPOON procedures with a standalone device that requires less training and experience to operate. This device is intended for any medical procedure where a thin section of tissue needs to be punctured and then slit, either partially or completely, along a line and there is access to the area of the tissue via a catheter conduit.

[0187] The logical operations making up the aspects of the technology described herein are referred to variously as operations, steps, objects, elements, components, or modules. Furthermore, it should be understood that these may be arranged or performed in any order, unless explicitly claimed otherwise or a specific order is inherently necessitated by the claim language. It should further be understood that the described technology may be employed in single -use and multi-use devices for medical or nonmedical use.

[0188] All directional references e.g., upper, lower, inner, outer, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, proximal, and distal are only used for identification purposes to aid the reader’s understanding of the claimed subject matter, and do not create limitations, particularly as to the position, orientation, or use of aspects of the present disclosure.Connection references, e.g., attached, coupled, connected, and joined are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily imply that two elements are directly connected and in fixed relation to each other. The term “or” shall be interpreted to mean “and / or” rather than “exclusive or.” The word "comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. Unless otherwise noted in the claims, stated values shall be interpreted as illustrative only and shall not be taken to be limiting.

[0189] The above specification, examples and data provide a complete description of the structure and use of exemplary aspects of the present disclosure, e.g., as defined in the claims.Although various aspects of the claimed subject matter have been described above with a certain degree of particularity, or with reference to one or more individual aspects, those skilled in the art could make numerous alterations to the disclosed aspects without departing from the spirit or scope of the claimed subject matter.

[0190] Still other aspects are contemplated. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative only of particular aspects and not limiting. Changes in detail or structure may be made without departing from the basic elements of the subject matter as defined in the following claims.

Claims

CLAIMSWhat is claimed is:

1. An apparatus, comprising: a puncture and slitting device comprising: a flexible elongate member configured to be positioned within a body lumen of a patient; a cutting assembly positioned at a distal portion of the flexible elongate member and comprising: a first conductor; a crossing electrode configured to be energized by the first conductor; a second conductor electrically isolated from the first conductor; and a cutting electrode configured to be energized by the second conductor.

2. The apparatus of claim 1, wherein the crossing electrode is cylindrical-shaped, conical- shaped, or wedge-shaped.

3. The apparatus of claim 1, wherein the body lumen comprises an aorta or a heart chamber of the patient, and wherein the crossing electrode is configured to form a puncture in a heart valve leaflet when placed against the heart valve leaflet and energized by the first conductor.

4. The apparatus of claim 3, wherein the cutting electrode comprises a hook shape.

5. The apparatus of claim 4, wherein the hook shape facilitates slitting of the heart valve leaflet when the cutting electrode is: placed within the puncture; energized by the second conductor; and pulled along a length of the heart valve leaflet.

6. The apparatus of claim 1, wherein the second conductor comprises a conductive tube, braid, or spring, wherein a first portion of the conductive tube, braid, or spring is surrounded by an outer insulation layer,wherein a second portion of the conductive tube, braid, or spring is not surrounded by the outer insulation layer, and wherein the second portion comprises the cutting electrode.

7. The apparatus of claim 6, wherein the first conductor comprises a core wire, wherein the conductive tube, braid, or spring is positioned around the core wire and separated from the core wire by an inner insulation layer.

8. The apparatus of claim 1, wherein at least one of the first conductor or the second conductor comprises a shape memory material.

9. The apparatus of claim 1, further comprising a power source configured to energize: the crossing electrode via the first conductor; and the cutting electrode via the second conductor.

10. The apparatus of claim 1, wherein the first conductor comprises a pullwire, wherein the cutting electrode is configured to transition from a straight configuration to a hook- shaped configuration when the pull wire is pulled.

11. The apparatus of claim 1 , wherein the second conductor comprises a conductive hypotube comprising a lumen, wherein the first conductor is positioned within the lumen and electrically isolated from the first conductor by an inner insulation layer surrounding the first conductor.

12. The apparatus of claim 11, wherein the cutting electrode comprises a cut portion of the conductive hypotube.

13. The apparatus of claim 12, wherein the cut portion of the conductive hypotube comprises gaps configured to provide flexibility for the cutting electrode to transition between a straight configuration and a hook- shaped configuration.

14. The apparatus of claim 13,wherein the lumen of the hypotube is configured to receive a fluid, wherein the gaps in the cut portion are configured to allow the fluid to flow out of the puncture and slitting device and into the body lumen, thereby suppressing electrical conduction by blood proximate to the cutting electrode.

15. The apparatus of claim 1, wherein the cutting electrode is covered by an insulator comprising a plurality of openings.

16. The apparatus of claim 15, wherein a thickness of the insulator and a width of the plurality of openings are selected such that electrical energy emitted by the cutting electrode is configured to cut tissue without direct contact between the cutting electrode and the tissue.

17. The apparatus of claim 15, wherein the plurality of openings is rectangular, circular, or slotted.

18. The apparatus of claim 15, wherein the plurality of openings is arranged in a regular pattern.

19. An apparatus, comprising: a flexible, elongate intracardiac device comprising: a crossing electrode defining a distal end of the intracardiac device and configured to cut a hole in a heart valve leaflet; and a cutting electrode proximal of the crossing electrode and configured to cut a slit starting from the hole in the heart valve leaflet, wherein the cutting electrode comprises a portion of a hypotube with gaps, wherein the gaps are configured to provide flexibility for the cutting electrode to transition between a straight configuration and a hook- shaped configuration, wherein the crossing electrode is configured to cut the hole while the cutting electrode is in the straight configuration, and wherein the cutting electrode is configured to cut the slit while the cutting electrode is in the hook- shaped configuration.

20. The apparatus of claim 19,wherein the intracardiac device further comprises a pullwire conductor electrically coupled to the crossing electrode and electrically isolated from the cutting electrode, wherein the pullwire conductor is configured to carry electrical energy to power the crossing electrode to cut the hole, wherein the cutting electrode is configured transition from the straight configuration to the hook- shaped configuration when tension is applied to the pull wire conductor.

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