Access to the interventricular septum using a puncture catheter device

Abstract

A method for creating a transvenous access pathway into the ventricular septum of a patient's heart. The access pathway may be used for cardiac procedures such as cardiac pacing, radio frequency (RF) ablation, or mitral valve circulatio surgery. The method uses a catheter device that is steerable at its distal end. A puncture tool is advanced through the catheter device after passing through the coronary sinus and into a coronary vein (e.g., the great cardiac vein) and punctures through the vein wall. To facilitate this puncture, the distal end of the catheter device may be bent at an angle toward the vein wall. The puncture tool is pushed to puncture the myocardium toward the ventricular septum. This puncture creates an entry passage from the coronary vein through the myocardium and into the ventricular septum. This entry passage may be used for insertion of an electrode lead or a mitral valve loop circulatio wire.

Description

[Technical field]

[0001] The present invention relates to a catheter system for performing transvascular cardiac procedures. [Background technology]

[0002] Recent developments in interventional cardiology have created a need for creating a transvenous access pathway within the ventricular septum of a patient's heart. For example, this pathway may be used for novel catheter-based treatments for mitral regurgitation by mitral loop circulatio, physiologic pacing, or septal reduction by intraseptal radiofrequency (RF) ablation for hypertrophic cardiomyopathy. This procedure is relatively easier if the patient has a septal perforator vein within the ventricular septum. However, this procedure becomes more difficult if the patient does not have a suitable septal perforator vein within the ventricular septum. Thus, there is a need for a more general technique for creating a transvenous access pathway that can be used in patients with or without a suitable septal perforator vein. Summary of the Invention

[0003] The present invention is for creating a transvenous access pathway within the ventricular septum of a patient's heart. There are a variety of different types of cardiac procedures in which such an access pathway may be beneficial, such as cardiac pacing, RF (radio frequency) ablation, or mitral valve circulatio surgery. These procedures are described in more detail below. The method uses a catheter device that is steerable at its distal end. One example of a catheter device that may be used includes those described in published patent application WO 2021 / 119636 (Tau Cardio, Inc.), entitled "Septal Cross System," which is incorporated herein by reference. Other examples of catheter devices that may be used are further described herein.

[0004] The catheter device comprises a main tube having a distal end segment, a distal tip, and a lumen. As used herein, "distal end segment" refers to the portion of the main tube encompassed from the distal tip of the main tube to a distance of 5 cm inward (proximal) from the distal tip. The length of the main tube may be within a length range of 60-180 cm. The catheter device further comprises a puncture tool passing through the lumen. The puncture tool may be inserted into the lumen of the catheter device at any suitable stage of cardiac surgery.

[0005] The main tube is inserted into an entry vein (such as the femoral, subclavian, or jugular vein). The main tube is further advanced into a large vein (superior or inferior vena cava). The main tube is advanced into the right atrium of the heart. From the right atrium, the main tube is inserted into the coronary sinus and advanced through the coronary veins. Examples of coronary veins that may be traversed include tributaries that drain into the coronary sinus, such as the great cardiac vein, left ventricular vein, middle cardiac vein, left marginal vein, and septal perforator vein.

[0006] The distal tip is positioned at a target site within the coronary vein near the interventricular septum (e.g., within 4.0 cm distance). A puncture is introduced into the catheter device such that the puncture passes through the main vein via its lumen. The puncture may be any type of wire-like instrument capable of penetrating through the vein wall into the myocardium. For example, the puncture may be a wire, a drill tip, a sharp needle tip, etc.

[0007] The puncture tool is advanced distally through the lumen of the main vessel along the course of the main vessel (i.e., through the vena cava, right atrium, coronary sinus, and coronary vein). The puncture tool is advanced out the distal tip opening of the main vessel and pushed to puncture through the venous wall. The puncture tool is advanced further into the myocardium towards the interventricular septum, thereby creating an entrance passage from the coronary vein through the myocardium and into the interventricular septum.

[0008] Any suitable amount of force may be used to puncture through the vein wall. In situations where the patient has a septal perforating vein and the distal tip of the main vessel is located within the septal perforating vein, a relatively small force may be required. For example, the amount of pushing force applied to puncture through the vein wall may be less than 0.20 Newtons. In other situations (e.g., where the patient does not have a septal perforating vein), a relatively large pushing force may be required. For example, the amount of pushing force applied to puncture through the vein wall may be in the range of 0.20 to 1.25 Newtons. In situations where the distal tip of the main vessel is within the great cardiac vein and wall puncture is desired through the great cardiac vein, this amount of force may be suitable. To apply the pushing force, the use of the opposing wall of the coronary vein as a support wall support at the distal end segment of the main vessel may be utilized.

[0009] In some embodiments, at the target site for venous wall puncture, the distal end segment of the main vessel is bent at an angle relative to the longitudinal axis of the main vessel, such that the distal tip opening is oriented at an angle toward the venous wall. For example, the angle may be at least 45° relative to the longitudinal axis of the main vessel. With the main vessel so bent, the puncture tool is advanced at an angle toward the venous wall and punctured through the venous wall.

[0010] In some embodiments, the main tube comprises a bendable segment at its distal end segment. The bendable segment may be made to bend under operator control (e.g., as a steerable tip). In some cases, the bendable segment is more flexible than other segments of the main tube proximal to the bendable segment (e.g., the bendable segment is more flexible than other portions of the main tube). In some cases, the main tube comprises a coil element at its bendable segment. By having the coil element, the bendable segment has spring-like compliance that enhances the steering ability of the catheter device. In some cases, the length of the bendable segment is within the range of 10-40 mm in length.

[0011] In some embodiments, the main vessel comprises a preformed C-curve segment extending from a proximal point A to a distal point B. Point A is located within a 6.0-15 cm interval from the distal tip of the main vessel. Point B is located within a 0.4-4.0 cm interval from the distal tip of the main vessel. Point B is located distal to point A. The length of the C-curve segment (distance from point A to point B) may be within a length range of 5-20 cm. In some cases, a manipulating wire is located in the inner bend of the C-curve. In use, the main vessel is inserted into the coronary sinus such that the C-curve of the main vessel follows the curvature of the coronary sinus. This preformed C-curve can assist in favorably angling the main vessel toward the coronary sinus and providing torque capability through the coronary vein.

[0012] In some embodiments, the catheter device further comprises a steering wire operable to induce bending of the main vessel. The steering wire is fixed to the main vessel at a distal end segment of the main vessel. The bending is effected by pushing or pulling the steering wire. Depending on the detailed configuration of the catheter device, straightening or bending may be effected by pushing or pulling. The distal end of the steering wire is attached to the main vessel near the distal tip of the main vessel. In some cases, the distal end of the steering wire is attached to the main vessel at a location within 1.5 cm of the distal tip of the main vessel. The length of the steering wire may be within a length range of 80-200 cm. The length of the steering wire may be less than the length of the piercer.

[0013] In some embodiments, the catheter device further comprises a handle assembly comprising a steering actuator. The steering wire is coupled to the steering actuator which acts to push or pull the steering wire. The steering actuator may have any suitable component, such as a knob, dial, slider, lever, etc., to effect this actuation.

[0014] In some embodiments, the main tube further comprises a second lumen separate from the (first) lumen. The control wire passes through the separate second lumen of the main tube. In some cases, the main tube comprises an exit hole from the second lumen. The control wire exits the second lumen through the exit hole. This exit hole may be located within 4-40 mm of the distal tip of the main tube.

[0015] In some embodiments, the distal end segment of the main tube includes two or more radiopaque markers. The distance between the markers may be in the range of 2-8 mm. In some cases, the main tube includes at least three radiopaque markers. The radiopaque markers may be beneficial in allowing the operator to assess the amount of bending by imaging under fluoroscopy. The amount of deviation from a linear arrangement of the radiopaque markers will indicate the degree of bending.

[0016] In some embodiments, the catheter device is used to perform cardiac venography. With the distal tip of the main vessel within the coronary sinus or further into the coronary vein, contrast is injected through the catheter device into the coronary vein. In some cases, pressure venography is performed by placing an obstruction at or near (within 1.5 cm) the coronary sinus ostium. This allows pressure venography to be performed to allow better visualization of the smaller distal side branch veins of the coronary sinus.

[0017] In some embodiments, the method is used to insert an electrode lead into a patient's heart. Examples of electrode leads include those used for cardiac pacing or RF (radio frequency) ablation. The method includes introducing the electrode lead into the catheter device such that the electrode lead follows a same path along the main vessel and then passes through an entry passage in the myocardium and into the ventricular septum. An electrode of the electrode lead is positioned within the ventricular septum. In situations where the same lumen is used to advance the electrode lead, the piercer is withdrawn out of the catheter device and the electrode lead is advanced through this same lumen of the main vessel.

[0018] Cardiac pacing in the ventricular septum can be beneficial for treating rhythm disorders. For example, the treatment can be para-Hisian pacing of the right ventricle adjacent to the His bundle or the proximal right bundle branch (RBB). This para-Hisian pacing can be beneficial for patients with atrioventricular (AV) block as the cause of the rhythm disorder. RF (radio frequency) ablation in the ventricular septum can be beneficial for treating various cardiac disease conditions such as hypertrophic cardiomyopathy.

[0019] In some embodiments, the method is used for mitral valve cerclage surgery. Examples of such surgery are described in Kim et al., "Mitral cerclage annuloplasty, a novel transcatheter treatment for secondary mitral valve regurgitation: Initial results in swine" (2009) J Am Coll Cardiol.54(7):638-651, and Park et al., "Mitral Loop Cerclage Annuloplasty for Secondary MitralRegurgitation: First Human Results" (2017) JACCCardiovasc Interv.10(6):597-610, both of which are incorporated herein by reference.

[0020] The method includes introducing the mitral loop circlage wire into the catheter device such that the mitral loop circlage wire follows the same path along the main vessel, then passes through an entry passage in the myocardium and into the ventricular septum. The mitral loop circlage wire may then exit the ventricular septum to form the desired loop. In situations where the same lumen is used to advance the circlage wire, the piercer is withdrawn out of the catheter device and the circlage wire is advanced through this same lumen of the main vessel. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is an overall view of a catheter device. [Diagram 2] FIG. 2 is a detailed side view of the distal portion of the catheter device. [Diagram 3] FIG. 2 is a detailed cross-sectional view of the distal portion of the catheter device. [Figure 4] 5 shows the slider moving backwards, and FIG 6 shows the bending motion of the catheter device. [Diagram 5] 6 shows the bending motion of the catheter device, and FIG 7 shows the distal tip of the main tube being deflected at an angle. [Figure 6] 7 is a detailed view of a bendable segment, and FIG 7 shows a bendable segment bent to an angle of 90°. [Figure 7] 8 is a detailed view of the bendable segment, and FIG 9 shows the bendable segment further deflected to bend at an angle of 135°. [Figure 8] Figure 9 shows an example of how the steering mechanism may work. Figure 9 shows the main vessel inside the coronary vein. [Figure 9] Figure 10 shows an example of how the steering mechanism can work.Figure 10 shows a piercer inside a main tube in a bent configuration. [Figure 10] Figure 11 shows an example of how the steering mechanism can work. Figure 11 shows further bending of the main tube to point at a steeper angle towards the myocardium. [Figure 11] FIG. 1 shows a cross-section of the heart, highlighting an example of the overall insertion procedure of the catheter device. [Figure 12] FIG. 13 illustrates how an external ultrasound probe can be used by the operator to help guide the puncture procedure. [Figure 13] FIG 14 shows how the bendable segments of the main tube are made to bend by pulling back on the steering wire.FIG 14 shows the main tube in a relaxed position (no tension applied). [Figure 14]FIG. 15 is a diagram showing bending of the main pipe caused by pulling back the manipulation wire. [Figure 15] FIG. 16 is a diagram showing further bending of the main tube as the manipulation wire is further pulled back. [Figure 16] FIG. 1 shows an example of a conventional cardiac pacemaker device that may be implanted using a catheter device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS To aid in an understanding of the present invention, reference is made to the accompanying drawings, which show, by way of illustration, specific embodiments in which the invention may be practiced. The drawings herein are not necessarily made to scale or to actual proportion. For example, the length and width of components may be adjusted to correspond to page dimensions.

[0023] FIG. 1 illustrates an example of a catheter device 10 for creating a transvenous access pathway within the ventricular septum of a patient's heart. The orientation of a proximal end 13 and a distal end 11 for the catheter device 10 are shown. Toward the distal end 11, the catheter device 10 comprises a flexible main tube 20 having multiple (two or more) lumens therein. This configuration defines a longitudinal axis 21 (linear and vertical in this drawing) of the main tube 20. The main tube 20 comprises a bendable segment 34. The catheter device 10 also comprises a steering wire 40 for steering the bendable segment 34 of the main tube 20.

[0024] Towards the proximal end 13, the catheter device 10 comprises a handle assembly 50 with a conical hood 88 to which the main tube 20 is attached. The handle assembly 50 further comprises a handle grip 86. At the rear of the handle assembly 50 is a hub 56 with a primary port 84 and a secondary port 82. A guidewire and piercer (not shown here) are inserted into the primary port 84, which is the opening for the first lumen 26 (not shown here) of the main tube 20. The handle assembly 50 comprises a twist knob 52 and a slider 54. Inside the twist knob 52 is a helical rail 80. The twist knob 52 engages with the slider 54 at the helical rail 80. With this arrangement, turning the twist knob 52 (clockwise or counterclockwise) moves the slider 54 forward or backward, driven by the helical rail 80. As will be explained in more detail below, this movement causes bending at the bendable segment 34 of the main pipe 20 .

[0025] 2A and 2B show detailed views of the distal portion of the catheter device 10. As shown therein, the main tube 20 has a distal tip 20a with an opening 25. The opening 25 is part of a first lumen 26 through which a piercer 44 (not shown here) passes. An electrode lead or a circulatory wire may be inserted (after the piercer 44 is withdrawn) into this same first lumen 26 used by the piercer 44. In addition to the first lumen 26 for the piercer 44 (not shown), the main tube 20 has a second lumen 28 for the operating wire 40. Located in the second lumen 28 is a proximal side hole 24 that serves as an exit hole from the second lumen 28.

[0026] The control wire 40 exits the second lumen 28 from the proximal side hole 24 and passes alongside and outside the main body of the main tube 20. The control wire 40 re-enters the main body 20 through the distal side hole 22. The distal end of the control wire 40 is embedded within the main tube 20. This allows the distal end of the control wire 40 to be attached near the distal tip 20a of the main tube 20. The distal hole 22 is not necessary for attaching the control wire 40 to the main tube 20. For example, in other embodiments, the distal end of the control wire 40 may be attached to the outer surface of the main tube 20 at or near the distal tip 20a.

[0027] 2 and 3 also show some relevant dimensions of the catheter device 10. The overall length L2 of the main tube 20 is about 120 cm long. The length L3 of the bendable segment 34 is about 18 mm long. The length L1 of the control wire 40 is longer than the length L2 of the main tube 20. Here, the length L1 of the control wire 40 is about 150 cm long. The portion of the control wire 40 that passes outside the body of the main tube 20 (between the side holes 22 and 24) is about 12 mm long (when the main tube 20 is in a straight configuration). The distance from the proximal side hole 24 to the distal tip 20a of the main tube 20 is about 15 mm. The length of the second lumen 28 (for the control wire 40) is shorter than the length of the first lumen 26 for the piercer 44. These figures also show the metal coil 30 within the bendable segment 34 of the main tube 20. The metal coil 30 provides elastic flexibility to the bendable segment 34, i.e., allows the bendable segment 34 to be elastically deformable. These figures also show three radiopaque markers 32 .

[0028] The main vessel 20 also has a preformed C-shaped curved segment 88. That is, at this curved segment 88, the main vessel 20 tends to form a C-shape. This curved segment 88 encompasses a portion of the main vessel 20 from the proximal end of the bendable segment 34 to a point more proximal to it. In this example, the C-shaped curved segment 88 has a length L4 of about 10 cm. This C-shaped curve fits the natural curved passage of the coronary sinus. Having this C-shaped curve can be beneficial in ensuring that when the venipuncture is performed, the bend at the bendable segment 34 orients the main vessel 20 so that the distal tip points precisely inward toward the ventricular septum.

[0029] The main vessel 20 has three 1.0 mm wide radiopaque marker bands 32 for imaging under fluoroscopy. The radiopaque marker bands 32 allow the operator to assess the location of the distal end of the main vessel 20. Here, the marker bands 32 are spaced apart at a distance of about 5 mm. Having multiple spaced marker bands 32 also allows the operator to assess the shape of the distal end of the main vessel 20, i.e., the amount of bending. For example, a linear arrangement of three marker bands 32 would indicate that the distal end of the main vessel 20 is not bent. However, three marker bands 32 that deviate from the linear arrangement would give the operator an estimate of the amount of bending.

[0030] 4-6 show the bending operation of the catheter device 10. The main tube 20 and the first lumen 26 contained therein are shown here. Also shown is the control wire 40 passing through a separate second lumen 28 of the main tube. The control wire 40 passes through the proximal hole 24, exits the second lumen 28, and is fixed to the main tube 20 at the distal hole 22. The twist knob 52 holds a slider 54 that engages with a helical rail 80 inside the twist knob 52. By rotating the twist knob 52, the slider 54 moves back and forth. The proximal end of the control wire 40 is attached to the slider 54. Due to this actuation mechanism, the control wire 40 is pushed or pulled by turning the twist knob 52. This is the operation control mechanism for the catheter device 10.

[0031] In FIG. 4, the twist knob 52 is in a standby position with no tension applied to the manipulation wire 40. The main tube 20 is in a relaxed state with no forced bending at the distal end. In FIG. 5, the twist knob 52 is twisted by the operator, causing the slider 54 to slide backward along the rail 80. Due to this sliding, the slider 54 pulls the manipulation wire 40 backward. Due to the pulling tension applied to the manipulation wire 40, the distal end of the manipulation wire 40 pulls back the distal tip 20a of the main tube 20. Due to this bending, the bendable segment 34 of the main tube 20 forms a C-shaped bend, directing the distal tip 20a in a direction away from the longitudinal axis of the main tube 20.

[0032] 6, with the distal tip 20a deflected at an angle, the piercer 44 is advanced out of the opening at the distal tip 20a of the main vessel 20. The C-shaped bend at the bendable segment 34 of the main vessel 20 causes the piercer 44 to be oriented at an angle relative to the longitudinal axis of the main vessel 20. As can be seen, the length of the control wire 40 is less than the length of the piercer 44.

[0033] 7 and 8 are detailed views of the bendable segment 34. The main tube 20 includes a coil element 30 in the bendable segment 34. The coil element 30 acts as a spring-like reaction to facilitate manipulation. The coil element 30 may be embedded within the wall of the main tube 20 or may be sheathed around the first lumen 26 (not shown here). The coil element 30 wraps around the first lumen 26 in a helical manner and is coaxial (common axis) with the first lumen 26, which may function to reinforce the first lumen 26. The manipulation wire 40 exits the main tube 20 at the side hole 24 and runs outside the body of the main tube 20. The manipulation wire 40 is then attached to the main tube 20 at a more distal point.

[0034] In FIG. 7, the bendable segment 34 is bent at an angle of 90° relative to its initial 0° origin when the main vessel 20 is in a straight configuration (i.e., relative to the longitudinal axis). In FIG. 8, the bendable segment 34 is further deflected and bent at an angle of 135° from its initial 0° origin. As seen herein, the piercer 44 is oriented at a different angle due to the bending of the bendable segment 34. Also shown here is the most distal of the three radiopaque markers 32. As seen herein, the coil element 30 is located distal to the side hole 24 where the steering wire 40 exits the main vessel 20. The piercer 44 assembled in combination with the catheter device 10 may be considered a septal puncture assembly as another embodiment of the present invention.

[0035] 9-11 show how the steering mechanism can orient the puncture tool 44 at an angle. FIG. 9 shows the main vessel 20 inside a coronary vein 72 surrounded by a vein wall 70. The main vessel 20 is positioned so that its distal tip is located near the point where the vein wall 70 is to be punctured. Also shown is the guidewire 42 that is used to bring the main vessel 20 to this target location within the coronary vein 72. The steering wire 40 is in a relaxed state and the distal end of the main vessel 20 has a straight configuration.

[0036] In FIG. 10, the guide wire 42 (not shown) has been withdrawn from the first lumen 26 (not shown) and replaced by the insertion of the puncture tool 44 into the main vessel 20 via the same first lumen 26. To perform the puncture procedure, the control wire 40 is pulled back (proximally) in tension. Since the distal tip of the control wire 40 is attached to the main vessel 20 at the side hole 22, pulling the control wire 40 back in this manner causes the main vessel 20 to bend at the bendable segment 34. Due to this bending, the distal tip of the main vessel 20 is angled more toward the vein wall 70. With this bending of the main vessel 20, the puncture tool 44 is advanced with the force required to puncture through the vein wall 70 and into the myocardium 74. It should be noted that due to this advancement, the bendable segment 34 presses against the opposing wall 70, causing the opposing wall 70 of the coronary vein 72 to bulge.

[0037] 11, the steering wire 40 is pulled back further to apply more tension. This pullback causes the bendable section 34 to bend further such that the main tube 20 and the puncture tool 44 are oriented at a steeper angle toward the myocardium 74. The puncture tool 44 is advanced into the myocardium 74, creating an entry passage in the myocardium 74 toward the interventricular septum. This entry passage will be used by the electrode lead to be inserted later.

[0038] FIG. 12 shows the situation of FIG. 11 in a cross-section of the heart, demonstrating the overall insertion procedure of the catheter device 10. In this view, the right ventricle 62 and the left ventricle 60 are visible in cross-section. To establish an insertion path, a guidewire (not shown here) is inserted into the coronary sinus 68 located in the right atrium of the heart. From the coronary sinus 68, the guidewire is advanced through the great cardiac vein. The catheter device 10 is prepared to follow along this path by inserting the proximal end of the guidewire into the first lumen of the main vessel 20. The catheter device 10 is then advanced along the guidewire such that the main vessel 20 resides within the great cardiac vein 66. Thus, the catheter device 10 is inserted into the coronary sinus 68 and through the great cardiac vein 66. The catheter device 10 is advanced such that the distal tip of the main vessel 20 is located adjacent to the interventricular septum (IVS) 64.

[0039] In this approach to the ventricular septum 64, the main vessel 20 may be threaded through other coronary veins, such as the septal perforating vein. However, not all people have a septal perforating vein, and the present invention does not require the presence of such a septal perforating vein. With the catheter device 10 positioned at the target site, the guidewire is then exchanged for the puncture tool 44. The bendable section 34 of the main vessel 20 is made to bend. The puncture tool 44 is advanced at an angle to puncture the cardiac vein 66 and penetrate into the myocardium toward the ventricular septum 64.

[0040] The puncture tool 44 creates an entry passage in the myocardium to the ventricular septum 64. With this entry passage established, the puncture tool 44 is exchanged for an electrode lead or circulatory wire (not shown here). In the case of an electrode lead, the electrode lead is advanced so that its electrode is positioned within the ventricular septum 64. The electrode lead may then be implanted in the ventricular septum 64 and activated (e.g., for cardiac pacing or ablation therapy).

[0041] 13 shows how an external ultrasound probe 90 may be used by the operator to help guide the puncture procedure. The ultrasound probe 90 emits sound waves 92 that provide imaging of the distal end of the main vessel 20. The puncture tool 44 may also be visible in the ultrasound image. A C-shaped curved segment 88 of the main vessel 20 is also shown here. This curved segment 88 conforms to the natural curved path of the coronary sinus 68. This ensures that the main vessel 20 is correctly oriented such that the bend segment 34 curves outward to direct the deflection angle toward the ventricular septum 64.

[0042] 14-16 show how the bendable segment 34 of the main tube 20 is made to bend by pulling back the manipulation wire 40. In FIG. 14, the manipulation wire 40 has exited the main tube 20 through the proximal side hole 24 and is in a relaxed position (no tension applied). In FIG. 15, the manipulation wire 40 has been pulled back (proximally) in the direction of arrow 96. Since the distal tip of the manipulation wire 40 is attached to the main tube 20 at the distal side hole 22, pulling the manipulation wire 40 back in this manner causes the main tube 20 to bend at the bendable section 34. In FIG. 16, the manipulation wire 40 is pulled back further, increasing the tension. This pullback causes the bendable section 34 to bend further, directing the main tube 20 and the puncture tool 44 at a steeper angle.

[0043] 17 shows an example of a cardiac pacemaker device 100 that may be implanted using the catheter device 10. The pacemaker device 100 includes an electrical pulse generator 104 and an electrode lead. The electrode lead includes a lead wire 102 and an electrode 110 at its distal end. Also at the distal end is a ring cap 106 and prongs 108 for fixation within the myocardium.

[0044] Figures 18A and 18B show another example of a catheter device 120 of the present invention. Figure 18A shows the catheter device 120 with a handle assembly 130, a cone-shaped hood 132, and a port 134 on the back side for inserting a piercer. Also shown is a flexible main tube 122 with a preformed C-shaped curved segment 124 and a bendable segment 126. Figure 18B shows a detailed view of the distal portion of the main tube 122. The preformed C-shaped curved segment 124 is shown, defined by points A and B as described above. The dashed line 138 represents the length of the C-shaped curved segment 124 (i.e., the distance from point A to point B when overlapping with the C-shaped curved segment 124). The distal tip 128 of the main tube 122 has an exit hole 136 through which the piercer (not shown) can exit.

[0045] 19 shows another example of how the distal portion of a flexible main tube 140 may be shaped. Here, instead of a C-shaped bend, the main tube 140 has a V-shaped bend 142. The V-shaped bend has an apex 144. The V-shaped bend 142 may be defined by the same dimensional measurements as described above for the C-shaped bend. Also shown is the distal tip 148 of the main tube 140, and an exit hole 146 through which a piercer (not shown) may exit.

[0046] [experiment] A prototype of the experimental catheter device was tested in 10 porcine animals. A sheath was inserted into an entry vein (jugular, subclavian, or femoral) and the procedure was performed. A first guidewire was inserted through the sheath and moved into the coronary sinus. A balloon-tipped guiding catheter was introduced along the guidewire path into the heart and into the coronary sinus. The balloon was engaged with the coronary sinus to form a seal and a radiopaque contrast agent was injected under pressure to obtain a fluoroscopic image (i.e., a pressure venogram). The pressure venogram confirmed the presence or absence of septal perforator veins in the test animals.

[0047] The first guidewire was replaced with a second, thinner guidewire for introducing the experimental catheter device. This thinner guidewire was advanced into the great cardiac vein. The catheter device was introduced along this guidewire into the great cardiac vein and positioned at a suitable location and vector orientation to engage the septal myocardium. The distal tip of the catheter device was then angled toward the septal myocardium.

[0048] The second guidewire was replaced with a stiffer third guidewire to act as the puncture wire. The puncture wire was pushed forward to directly puncture the wall of the great cardiac vein and into the myocardium towards the septum. The amount of force required to push the puncture wire through the vein wall and into the myocardium was measured using a push-pull gauge. A force of 0.45 N (Newtons) was required to penetrate the vein wall. Once inside the myocardium, a smaller force of 0.04 N was required to push through the myocardial tissue.

[0049] Using fluoroscopic guidance, the puncture wire was further advanced to the target site within the interventricular septum. Ultrasound echocardiography and fluoroscopy confirmed that the puncture wire was in the desired location. This puncture procedure was successfully performed in all 10 porcine animals.

[0050] After the treatment experiment was completed, the hearts were removed for gross pathology and histopathology. On gross examination, there was no significant tissue damage to the blood vessels and myocardial wall. There was a hematoma around the puncture site, but there was no spread of the hematoma or serious damage to other areas. There was no bleeding in the epicardium where the guidewire entered the myocardium. On microscopic histopathology, no myocardial damage was observed. There were some hemorrhagic foci in the myocardium and epicardium. However, there was no ischemic damage or necrosis.

[0051] The descriptions and examples set forth herein are intended to merely illustrate the present invention and are not intended to be limiting. Each of the disclosed aspects and embodiments of the present invention may be considered individually or in combination with other aspects, embodiments, and variations of the present invention. In addition, unless otherwise specified, the steps of the method of the present invention are not limited to any particular order of execution. Modifications of the disclosed embodiments that incorporate the spirit and essence of the present invention may occur to those skilled in the art, and such modifications are within the scope of the present invention.

[0052] Any use of the word "or" herein is intended to be inclusive and is equivalent to the term "and / or" unless the context clearly dictates otherwise. Thus, for example, the term "A or B" means A, or B, or both A and B. Similarly, for example, the term "A, B, or C" means A, or B, or C, or any combination thereof.

Claims

1. a main tube having a distal end segment, a distal tip, a lumen, and an exit hole from said lumen, said main tube comprising a preformed C-shaped curved segment extending from a proximal point A to a distal point B of said main tube, point A being located within a distance of 6.0-15 cm from said distal tip of said main tube, point B being located within a distance of 0.4-4.0 cm from said distal tip of said main tube, point B being located distal to point A, and a length of the distance of said C-shaped curved segment from point A to point B being within a length range of 5-20 cm; a control wire passing through the lumen and secured to the distal end segment of the main tube at a point within 1.0 cm of the distal tip of the main tube, the control wire exiting the lumen through the exit hole of the main tube; A catheter device comprising: a handle body including a steering actuator, the steering wire being coupled to the steering actuator that acts to push or pull the steering wire.

2. The catheter device of claim 1 , wherein the steering actuator comprises a slider, the steering wire being fixed to the slider.

3. A septal puncture assembly comprising the catheter device of claim 1 or 2, wherein the lumen is a first lumen, the main tube further comprises a second lumen, and the septal puncture assembly further comprises a puncture tool passing through the second lumen.

4. The catheter device of claim 1 or 2, wherein the distal end segment is bent by pushing or pulling the steering wire with the steering actuator.

5. The catheter device of claim 1 or 2, wherein the distal end segment comprises three or more radiopaque markers.

6. The catheter device of claim 1 or 2, wherein the C-shaped curved segment is curved to follow the curved path of the coronary sinus.

7. The catheter apparatus of claim 4 , wherein the distal end segment comprises a coil element, and the bending occurs in the coil element.

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