Endovascular delivery system and method

Abstract

A delivery catheter and method for implanting a pacemaker lead. The delivery catheter includes a catheter body with a lumen, first and second electrodes connected with respective first and second conductor wires connecting the first and second electrodes to an energy source. The method includes inserting a delivery catheter into the patient, the catheter having a distal electrode, breaching cardiac tissue with the electrode, and inserting a pacemaker lead though the delivery catheter and electrode into the patient.

Description

[0001] ENDOVASCULAR DELIVERY SYSTEM AND METHOD

[0002] Field of the Invention

[0003] The present disclosure relates to improvements in devices and methods in the field of cardiac electrophysiology. More particularly, the disclosure relates to the field of cardiac pacemaker implantation, specifically to a system designed to facilitate the placement of pacemaker leads in the heart by modifying the mechanical properties of various cardiac tissues.

[0004] Background of the Invention

[0005] Conduction system pacing (CSP) has rapidly become established as a fundamental paradigm shift in pacemaker lead implantation for the mitigation and avoidance of heart failure in the past decade. In comparison to conventional lead placement techniques in the right ventricular septum or apex, CSP may potentially introduce new challenges in the optimisation of lead deployment. Specifically, in contrast to traditional pacing lead placement approaches, CSP introduces new complexities in relation the achievement of safe and reliable tunnelling of leads to the desired depth and position in the septum.

[0006] The interplay of biomechanical properties and electrophysiological characteristics within the cardiac conduction system, coupled with their dynamic interaction with a pacing lead is important in the performance of CSP. The emerging data showing benefit of LBBAP compared to His Bundle pacing highlights the importance of this complex interaction and the effects they have on success of CSP.

[0007] One of the primary interactions that contribute to failure of lead deployment is endocardial entanglement, which occurs often during CSP lead deployments. Endocardial entanglement is likely a result of the complex dynamics between the pacemaker lead and the endomyocardial tissues, which can hinder the lead from properly anchoring into the desired position within the heart. In addition to the above, conventional thought is that a surgeon does not want to use a cutting tool within the heart due to the danger of creating a catastrophic laceration, resulting in patient death. The present inventors of the system and method described below have discovered that creating a pre-lead insertion breach in a cardiac wall, followed by pacemaker lead insertion and placement, results in surprisingly better patient outcomes, with a much improved conductor placement within cardiac tissue.

[0008] The effective placement of pacemaker leads is critical for the long-term success of cardiac pacing therapies. Traditional methods of lead placement can be challenging, especially in patients with diseased or elderly hearts where fibrous tissue accumulation or highly elastic endocardial tissue can impede successful implantation. This is particularly problematic in procedures such as Left Bundle Area Pacing and His Bundle Pacing, where leads must be burrowed deeper into the heart wall to achieve optimal positioning.

[0009] The present disclosure provides a solution through a delivery catheter system designed to modify the properties of various cardiac tissues at the targeted implantation site. The catheter is equipped with two electrically isolated half-ring electrodes located at its distal tip. These electrodes are connected to an external energy source capable of delivering controlled RF energy. When activated, the RF energy is focused on a specific region of the heart, such as the endocardium or fibrotic tissue, altering its mechanical properties in a manner that facilitates pacemaker lead placement.

[0010] Effect of Heat on Cardiac Tissues

[0011] The heart is composed of different types of tissues, including the endocardium, myocardium, and fibrous tissues that can accumulate due to aging or disease. These tissues, particularly the endocardium and fibrotic structures, can present significant challenges during pacemaker lead implantation due to their elasticity or stiffness. When exposed to RF energy, these cardiac tissues undergo thermal-induced changes that significantly alter their mechanical properties:

[0012] 1 . Thermal Denaturation of Proteins: the application of RF energy causes the denaturation of collagen and elastin fibers within the endocardium and fibrous tissues. This process reduces tissue elasticity and increases stiffness, making these tissues more amenable to penetration by a pacemaker lead.

[0013] 2. Modification of Fibrous Tissue: in diseased or elderly hearts, fibrous tissue accumulation can lead to increased stiffness and resistance to lead penetration. The RF energy delivered by the catheter can alter the mechanical properties of this fibrous tissue, reducing its rigidity and making it easier to penetrate safely with the lead.

[0014] 3. Increased Tissue Stiffness: The localized heating effect induces crosslinking among the collagen fibers, further increasing tissue stiffness. This alteration helps create a more rigid, less elastic substrate for the pacemaker lead, reducing the risk of entanglement during insertion, particularly in the context of Left Bundle Area Pacing and His Bundle Pacing.

[0015] 4. Enhanced Lead Penetration in Tough Tissues: the modified tissue, with its increased stiffness and reduced elasticity, offers a more stable and penetrable surface for the pacemaker lead, ensuring secure and effective placement even in areas where tough or highly elastic tissues might otherwise impede the lead’s progress.

[0016] 5. Focused Tissue Modification: by concentrating the RF energy between the two half-ring electrodes, the system ensures that only the targeted area of the cardiac tissue is modified. This focused modification minimizes the risk of collateral damage to surrounding tissues and preserves the overall structural integrity of the heart. It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

[0017] Summary

[0018] The present disclosure in one preferred aspect provides for a method for pacemaker lead implantation into a heart of a patient. The method includes inserting a delivery catheter into the patient, the delivery catheter including an electrode at a distal end thereof; breaching cardiac tissue with the electrode of the delivery catheter; and inserting the pacemaker lead through the delivery catheter and electrode into the patient.

[0019] In another preferred aspect, there is provided a delivery catheter for delivering a pacemaker lead. The catheter includes a catheter body including: a distal end for insertion first into cardiac tissue; a proximal end opposite said distal end along a central longitudinal axis; and a central lumen from said proximal end to said distal end. The catheter also includes a first electrode at said distal end with a first conductor wire connecting said first electrode to an energy source; and a second electrode at said distal end with a second conductor wire connecting said second electrode to the energy source.

[0020] The system includes a delivery catheter with two half-ring electrodes capable of delivering focused radiofrequency (RF) energy to specific areas of the heart, including the endocardium and fibrous tissues, enhancing lead penetration and reducing the risk of entanglement or difficulty during implantation, particularly in challenging cases such as Left Bundle Area Pacing and His Bundle Pacing.

[0021] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. In the present specification and claims, the word “comprising” and its derivatives including “comprises” and “comprise” include each of the stated integers, but does not exclude the inclusion of one or more further integers. It will be appreciated that reference herein to “preferred” or “preferably” is intended as exemplary only.

[0022] The claims as filed and attached with this specification are hereby incorporated by reference into the text of the present description. The entire disclosure of U.S. Provisional Patent Application No. 63 / 627,035 is incorporated by reference herein. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.

[0023] Brief Description of the Figures

[0024] Fig. 1 is a partial perspective view of a heart.

[0025] Fig. 1 A is a partial cross sectional view of the heat shown in Fig. 1 , showing different anatomical structures and regions of the heart.

[0026] Fig. 2 is a partial cross sectional view of the heart of Fig. 1 A with a pacemaker lead engaged therein in accordance with a preferred embodiment of the present disclosure.

[0027] Fig. 2A is an expanded view along section A of Fig. 2 showing a distal end of the pace maker lead of Fig. 2 engaged with a septum of the heart of Fig. 1 A.

[0028] Fig. 3 is a partial cross sectional leading end view of a catheter tip configured for bipolar ablation in accordance with further preferred embodiment of the present description.

[0029] Fig. 4 is a cross sectional side view of a catheter with the catheter tip of Fig. 3 engaged with cardiac tissue, and a pacemaker lead being inserted through the catheter. Fig. 5 is a cross sectional side view of the catheter and tip of Fig. 4, with the pacemaker lead shown inserted into the cardiac tissue.

[0030] Detailed Description of the Drawings

[0031] Reference will now be made in detail to the present preferred embodiments of the disclosure, examples of which are illustrated in the accompanying drawings.

[0032] Figs. 1 to 2A show the anatomical structure of a typical human heart muscle relevant to illustrate application of endovascular delivery system 100 in a cardiac environment. Although described in relation to a human, it will be appreciated that principles described herein may be applied to other animals as appropriate (e.g., agricultural animals and / or pets). As would be appreciated by those of ordinary skill in the field, the heart contains the right atrium, left atrium, right ventricle, and left ventricle as shown in Figs. 1 A and 2. The endocardium is the innermost layer of tissue lining the heart chambers. The septum separates the right and left sides of the heart.

[0033] Referring now to Figs. 3 to 5, a delivery catheter system 100 is shown and described. As shown in Figs. 3 and 4, system 100 includes a delivery catheter 102, a pacemaker lead insertion tool / inner lumen 104, and a power source 106. At the center of the catheter, inner lumen 104 is preferably designed to accommodate the pacemaker lead. This central lumen helps ensure that the lead can be advanced smoothly through the catheter and accurately positioned at the target site within the heart.

[0034] Catheter 102 has a catheter body 108 with an inner surface 110 defining a lumen 112, and a distal end 114 with a projecting electrically conductive tip preferably configured as two electrically isolated half-ring electrodes 116 and 118. Half-ring electrodes 116, 118 are oriented to define a central through aperture 120, for passage of a pacemaker lead therethrough. These electrodes are positioned at the distal end of the catheter and are configured to operate in a bipolar fashion. During the procedure, energy is passed between these two electrodes, concentrating the energy within the specific region of tissue located directly between them. This bipolar configuration allows for precise energy delivery, minimizing the area of tissue modification and reducing the risk of unnecessary damage to surrounding tissues. The focused nature of this energy delivery makes it particularly effective for achieving controlled ablation and tissue modification, which is crucial for creating an optimal site for pacemaker lead implantation.

[0035] Electrodes 116, 118 are positioned for multiple purposes, including energy delivery, electrical mapping, and pacing. The electrodes are made from a conductive material and is designed to deliver focused energy, such as radiofrequency (RF) pulses, to modify the tissue properties at the implantation site. This modification enhances lead penetration and reduces the risk of entanglement during the implantation process.

[0036] In addition to energy delivery, electrodes 116, 118 are capable of sensing electrical signals from the heart tissue, transmitting these signals back through the conductor that runs the length of catheter body 108. This functionality allows electrodes 116, 118 to perform electrical mapping, providing real-time feedback on the electrical activity of the heart at the target site. The signals are transmitted to an external mapping system via the conductor, enabling the implanter to interpret the data and determine the suitability of the target site for pacemaker lead deployment.

[0037] Furthermore, electrodes 116, 118 can deliver pacing stimuli to the heart tissue, helping to diagnose the optimal location for lead placement by assessing the heart's response to the pacing pulses. Each half-ring electrode is connected with respective conductor wires 122, 124 to connect the respective half-ring electrode to power source 106. These wires are preferably embedded within the catheter body and extend from the proximal end of the catheter to the distal tip electrodes. Each conductor wire is responsible for carrying electrical signals and energy to its respective electrode, ensuring efficient and controlled energy delivery during the procedure. As shown in Fig. 3, catheter body 108 preferably includes an adhesive fillet 126 to secure the half-ring electrodes to the distal end of the catheter body, helping to ensure that they remain in place during the procedure. This structural feature enhances the reliability of the catheter by preventing any movement of the electrodes that could affect the accuracy of energy delivery or the effectiveness of the ablation process.

[0038] As shown in Figs. 4 and 5, pacemaker lead insertion tool 104 includes a shaft 128 having a distal end 130 with a helical tip 132 configured to engage at least one of the conductor wires.

[0039] Power source 106 is preferably a Radio Frequency (RF) power source.

[0040] Having described the preferred components of system 100, a preferred method of use will now be described with reference to Figs. 4 and 5. Catheter 102 is inserted into a patient. The distal end of delivery catheter 102 is moved forward and placed against the endocardium 10 of cardiac tissue 12 so that electrodes are proximate, preferably contacting cardiac tissue 12. Thermal energy preferably in the form of RF energy is delivered via wires 122, 124 to respective half-ring electrodes 116, 118 to cause a modification or breach 14 of the cardiac tissue. Thereafter, as shown in Fig. 5, pacing lead (pacemaker lead) 132 is inserted through the catheter and into cardiac tissue 12 through the ablation created in the tissue to an appropriate depth determined by the surgeon. If desired, catheter 102 may include a depth stop to limit travel of the pacing lead into the cardiac tissue to prevent overpenetration. Thereafter, when appropriately configured with one or more electrical sensors, electrical signals may be detected from electrically active cardiac tissue using the electrode of the delivery catheter. An electronic mapping of the cardiac tissue may be prepared using the electrode of the delivery catheter. Once the pacemaker lead is inserted into the cardiac tissue, breaching either endocardium tissue outside of the septum, or at the septum, the pacemaker lead is anchored within the wall through the lead insertion opening created by the breach.

[0041] It will be appreciated that the steps described above may be performed in a different order, varied, or some steps omitted entirely without departing from the scope of the present disclosure. For example only, catheter 102 may be connected to power source 106 at any point after it is at least partially inserted into the patient. Electronic sensing and mapping may be omitted if desired. The foregoing description is by way of example only, and may be varied considerably without departing from the scope of the present disclosure. For example only, various breaching means may be used to separate cardiac tissue, such as a mechanical mechanism (e.g., blade), thermal mechanism, ultrasound, and / or laser. Where the system includes electrodes, the electrodes may be detachabley attached by means other than a fillet. For example only, the electrodes may be attached to the catheter body by threaded engagement, snap-fit engagement, and / or magnetic engagement (where the magnetic field emitted is within an acceptable range given sensitive equipment being used).

[0042] The features described with respect to one embodiment may be applied to other embodiments, or combined with or interchanged with the features of other embodiments, as appropriate, without departing from the scope of the present disclosure.

[0043] The present disclosure in a preferred form provides the advantages of facilitating pacemaker lead placement to enhance a successful outcome, e.g., penetrating fully to a desired depth, for example, 9 to 10 mm to provide optimal pacemaker lead anchoring. Other advantages in the context of pacemaker lead implantation, particularly in challenging cases such as Left Bundle Area Pacing and His Bundle Pacing include: • Safer Lead Penetration in Diseased or Elderly Hearts: By modifying the mechanical properties of tough or fibrous tissues, the catheter system allows for safer and more effective lead penetration in areas where conventional methods may struggle.

[0044] • Reduced Risk of Entanglement: the system's ability to alter the mechanical properties of elastic and fibrotic tissues prevents the lead from becoming entangled, reducing the likelihood of complications during and after implantation.

[0045] • Precision and Control: the use of focused RF energy allows for precise control over the extent and location of tissue modification, ensuring that only the desired area is affected and minimizing the risk of unnecessary tissue damage.

[0046] The aforementioned approach to pacemaker lead implantation addresses the limitations of existing methods, providing a safer, more effective solution for patients requiring cardiac pacing, particularly in complex cases involving tough or fibrotic tissues.

[0047] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of forms of the embodiments disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

What is claimed is:1 . A delivery catheter for delivering a pacemaker lead, comprising: a catheter body including: a distal end for insertion first into cardiac tissue; a proximal end opposite said distal end along a central longitudinal axis; and a central lumen from said proximal end to said distal end; a first electrode at said distal end with a first conductor wire connecting said first electrode to an energy source; and a second electrode at said distal end with a second conductor wire connecting said second electrode to the energy source.

2. The catheter of claim 1 , wherein said first and second electrodes extend beyond the distal end of said catheter body.

3. The catheter of either claim 1 or 2, wherein said catheter body has a varying stiffness along the central longitudinal axis.

4. The catheter of any one of the above claims, wherein said electrode is configured to detect bioelectronic signals associated with the cardiac tissue.

5. A method for implanting a pacemaker lead into a patient, comprising: inserting a delivery catheter into the patient, the delivery catheter including an electrode at a distal end thereof; breaching cardiac tissue with the electrode of the delivery catheter; and inserting the pacemaker lead through the delivery catheter and electrode into the patient.

6. The method of claim 5, further comprising detecting electrical signals from electrically active cardiac tissue using the electrode of the delivery catheter.

7. The method of either claim 5 or 6, further comprising obtaining an electronic mapping of the cardiac tissue using the electrode of the delivery catheter.

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