The present invention relates generally to heart valve prosthetics. In particular, not by way of limitation, the present disclosure relates to systems and methods to modify heart valve prosthetic leaflet tissue to improve blood flow.
Heart valve replacement procedures are an established treatment for patients with heart diseases affecting the valves including, for example, Aortic Stenosis (AS). It is known and recognized that, with AS, calcium build-up over time narrows the aortic valve opening of the heart, thereby restricting blood flow therethrough. While AS patients generally experience mild symptoms in the early stages, more progressed AS can cause congestive heart failure, sudden loss of consciousness, and even sudden death.
As such, several procedures have been developed for the treatment of AS, with the most prevalent and successful approach being the Transcatheter Aortic Valve Replacement (TAVR). Commonly referred to as the gold standard for treating AS, TAVR involves replacing a diseased aortic valve with a man-made artificial heart valve or heart valve prosthetic.
To date, there are two common designs for these heart valve prosthetics, namely the intra-annular design and the supra-annular design. Placement of either design of prosthetic may be achieved by guiding a catheter through the femoral artery of a patient and up to the patient's aortic valve. Alternatively, the prosthetic may be implanted by creating a small incision in the chest wall of the patient and guiding the prosthetic through the apex of the heart and into the patient's aortic valve. While initially effective, it is known that the heart valve prosthetics used in TAVR procedures may fail over time and require replacement. One of the most common solutions is to perform a valve-in-valve implantation procedure, also referred to as a redo-TAVR, which simply places a second prosthetic within the primary, failing heart valve prosthetic. For some patients, however, the second heart valve prosthetic may cause unanticipated sinus sequestration, which can result in a coronary obstruction.
Sinus sequestration in patients who have undergone a valve-in-valve implantation procedure typically occurs due to the pinning of leaflet tissue from the primary heart valve prosthetic against the stent structure of the prosthetic when the second heart valve prosthetic is implanted within the first. To resolve this issue, a procedure called bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction (BASILICA) has been developed. During the BASILICA procedure, intervention cardiologists use one or more electrified wires to incise, or slice, the old leaflets of the primary heart valve prosthetic to improve blood flow to the coronary arteries.
However, while the BASILICA procedure may be an option for many valve-in-valve implantation procedure patients, there are known complications pertaining to the commissural alignment between the native and prosthetic valves. This alignment is critical in determining the efficacy of a BASILICA procedure because a misalignment renders the implantation procedure ineffective. For example, in cases where there is an overlap between the first valve prosthetic commissural posts and the coronary ostia, the BASILICA procedure is unlikely to improve blood flow into the coronary sinus.
Thus, there is a need for improved systems and methods of treatment for valve-in-valve prosthetic implantation recipients suffering from pinned leaflet tissue resulting in decreased blood flow, sinus sequestration, or coronary obstruction.
The following presents a simplified summary relating to one or more aspects and/or embodiments disclosed herein. As such, the following summary should not be considered an extensive overview relating to all contemplated aspects and/or embodiments, nor should the following summary be regarded to identify key or critical elements relating to all contemplated aspects and/or embodiments or to delineate the scope associated with any particular aspect and/or embodiment. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects and/or embodiments relating to the mechanisms disclosed herein in a simplified form to precede the detailed description presented below.
Some aspects disclosed herein address the above stated needs with systems, methods, and apparatuses for utilizing laser ablation to enhance blood flow through transcatheter valve prosthetics. In an embodiment, a method includes identifying a patient who has undergone a second prosthetic valve replacement procedure is presenting with, or is at risk of presenting with, coronary obstruction or decreased blood flow as a result of the placement of the second valve prosthetic. The method further comprises accessing the circulatory system of the patient, guiding a laser fiber through the patient's circulatory system to the primary and second prosthetic valves, applying laser ablation to remove portions of the primary prosthetic valve leaflet tissues between the stent structure of the primary prosthetic valve, and removing the laser fiber from the patient's circulatory system.
Aspects also include identifying a patient who has undergone a second prosthetic valve replacement procedure and is presenting with, or is at risk of presenting with, coronary artery obstruction or decreased blood flow as a result of the placement of the second valve prosthetic. The method further includes accessing the circulatory system of the patient, guiding a laser fiber through the patient's circulatory system to the primary and second prosthetic valves, identifying regions of overlap between the commissural posts of the primary prosthetic valve and an ostium, applying laser ablation to remove portions of the primary prosthetic valve leaflet tissues between the stent structure of the primary prosthetic valve, and removing the laser fiber from the patient's circulatory system.
According to another aspect, a method includes identifying a patient who has undergone a redo-TAVR procedure. The method further includes accessing the circulatory system of the patient, guiding a laser fiber through the patient's circulatory to the transcatheter aortic valve (TAV) replacement within an existing TAV (i.e., TAV-in-TAV) or TAV replacement within an existing surgical aortic valve (SAV) (i.e., TAV-in-SAV) prosthetics. The method also includes identifying regions of overlap between the commissural posts of the primary TAV prosthetic and the coronary ostia of the patient, applying laser ablation to remove portions of the TAV-in-TAV or TAV-in-SAV prosthetic leaflet tissues between the stent structures of the prosthetic valves, and removing the laser fiber from the patient's circulatory system.
In other aspects, the methods may be applied to other transcatheter heart valves (THVs), such as mitral, pulmonary, and tricuspid positions.
In an embodiment, a method for improving blood flow in a patient who has undergone a first heart valve replacement procedure followed by a second heart valve replacement procedure is disclosed. The method may include positioning a second prosthetic replacement valve to replace a primary prosthetic replacement valve within the patient, providing a laser fenestration system including a laser fiber, guiding the laser fiber through the patient's circulatory system to the second prosthetic replacement valve, performing a laser ablation process using the laser fiber to remove portions of a leaflet tissue between any stent structure of the primary prosthetic replacement valve, removing the laser fiber from the patient's circulatory system, and finalizing the second prosthetic valve replacement procedure.
In another embodiment, a method for improving blood flow after in a patient who has undergone a heart valve replacement procedure includes positioning a prosthetic replacement valve to replace a native valve within the patient, providing a laser fenestration system including a laser fiber, guiding the laser fiber through the patient's circulatory system to the prosthetic replacement valve, performing a laser ablation process using the laser fiber to remove portions of a leaflet tissue of the native valve, removing the laser fiber from the patient's circulatory system, and finalizing the prosthetic valve replacement procedure.
In still another embodiment, a system for improving blood flow in a patient who has undergone a heart valve replacement procedure is disclosed. The system includes a prosthetic replacement valve configured to replace a primary valve and to be positioned within the patient, and a laser fenestration system including a laser fiber. The laser fiber is adapted to be guided through the patient's circulatory system to the prosthetic replacement valve positioned within the patient. The laser fenestration system is adapted to perform a laser ablation process using the laser fiber to remove portions of a leaflet tissue between any stent structure of the prosthetic replacement valve, and the laser fiber is further adapted to be removable from the patient's circulatory system following the laser ablation procedure.
In an embodiment, a fenestration system for user by a user in performing a laser ablation process on a patient in association with a heart valve replacement procedure is disclosed. The fenestration system may include a catheter, a laser source for producing laser energy, an optical fiber for delivering the laser energy to the patient through the catheter, a controller for controlling the laser source, and a user interface for receiving input from the user in operating the fenestration system. The catheter may be configured for guiding the optical fiber through the patient's circulatory system to a heart valve of the patient.
In embodiments, the fenestration system may further include a monitoring system for monitoring at least one of operating conditions of the laser source, a power output of the laser source, and blood flow conditions associated with the heart valve replacement procedure, wherein the monitoring system includes at least one of a temperature sensor, a current meter, a voltmeter, a power meter, a pressure sensor, a flow sensor, and a spectrometer.
In further embodiments, the fenestration system further includes a flush mechanism for providing a liquid flush through the catheter at the fenestration site, wherein the flush mechanism includes a liquid reservoir, a pump, and tubing. In certain embodiments, the flush mechanism is a saline flush mechanism.
In other embodiments, the fenestration system further includes a steering cable connected with the user interface to enable the user to actively control a distal curvature of the catheter.
In yet another embodiment, a method for manufacturing a fenestration system for performing a laser ablation process on a patient in association with a heart valve replacement procedure is disclosed. The method includes providing a laser source for producing laser energy, the laser source being configured for delivering the laser energy through the optical fiber, providing a catheter configured for supporting the optical fiber therein, providing a controller for controlling the laser source, and providing a user interface for receiving input from a user and transmitting the input to the controller in operating the fenestration system. The controller includes a memory for storing machine readable instructions and a processor for executing the machine-readable instructions. In embodiments, the controller is further configured for enabling delivery of the laser energy at a user-specified location within the patient in association with the heart valve replacement procedure.
In certain aspects, the method further includes providing a monitoring system for monitoring at least one of operating conditions of the laser source, a power output of the laser source, and blood flow conditions associated with the heart valve replacement procedure. The monitoring system may include at least one of a temperature sensor, a current meter, a voltmeter, a power meter, a pressure sensor, a flow sensor, and a spectrometer.
In other aspects, the method further includes providing a flush mechanism for providing a liquid flush through the catheter, wherein the flush mechanism includes a liquid reservoir, a pump, and tubing.
In a further aspect, the method further includes providing a steering cable connected with the user interface and the optical fiber, and further configuring the catheter for supporting the steering cable therein. The steering cable and the user interface may be configured to cooperate to enable the user to actively control a distal curvature of the optical fiber in delivering the laser energy at the user-specified location.
These and other features, and characteristics of the present technology, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. As used in the specification and in the claims, the singular form of ‘a’, ‘an’, and ‘the’ include plural referents unless the context clearly dictates otherwise.
For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the embodiments detailed herein. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of the described embodiments. The flowcharts and block diagrams in the figures illustrate the operation of possible implementations of systems and methods according to various embodiments of the present disclosure. In this regard, in some alternative implementations, the steps noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. The same reference numerals in different figures denote the same elements.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. In the following detailed description, references are made to the accompanying drawings that form a part hereof, and in which are shown by way of illustrations or specific examples. These aspects may be combined, other aspects may be utilized, and structural changes may be made without departing from the present disclosure. Example aspects may be practiced as methods, systems, or apparatuses. The following detailed description is therefore not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims and their equivalents. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present specification and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The present disclosure relates generally to heart valve prosthetics. In particular, but not by way of limitation, the present disclosure relates to systems and methods for utilizing laser ablation to modify heart valve prosthetic leaflet tissue to improve blood flow through the heart valve prosthetic.
While the BASILICA approach described above has been shown to be effective, a new leaflet modification approach based on laser ablation would be desirable to prevent coronary obstruction and maintain coronary access in all at-risk patients. The new approach may include guiding a laser fiber catheter to the primary (initial) TAV and applying the laser to remove portions of leaflet tissue of the failed TAV or even native valve leaflets as needed. Such a process may be referred to as fenestration.
Beyond improving blood flow, the embodiments described herein enable the addressing of conditions such as:
From a biomechanical point of view, residual stress in native leaflets contributes significantly to the leaflet splay in BASILICA (i.e., the native valve leaflets spring open immediately due of residual stress in living tissue). However, there is no residual stress in pericardium sheets used to fabricate TAV leaflets. Consequently, BASILICA and similar methods are less effective in bioprosthetic heart valves (both surgical and TAVs) than native valves. Besides, newer-generation TAVs are designed with a redundant leaflet for better coaptation, which further limits the splay of these leaflets after the BASILICA and similar methods. Therefore, the laser ablation technique described herein may be significantly superior to the existing methods in preventing coronary obstruction and maintaining coronary access. Considering the history of laser atherectomy in percutaneous coronary intervention, the proposed leaflet modification technique using laser ablation should be safe. In addition, the reported risk for coronary obstruction is probably underestimated because of underdiagnosis when the presentation is atypical and because some high-risk patients were excluded from TAVR because of this potential complication. The new procedure can be expanded to other transcatheter heart valve interventions such as in (i) native aortic valves, (ii) failed surgical aortic bioprostheses, and (iii) other interventions in mitral, tricuspid, and pulmonic positions. This project is anticipated to be a prelude to future animal and clinical studies.
In real-world clinical practice, establishing perpendicular laser contact with the TAVs may not always be feasible. Therefore, the ablation laser may be held at angles, such as 30° to 90° with respect to the tissue to be ablated. For example, a neodymium-yttrium-argon-garnet (Nd:YAG) laser (operating at a wavelength of 1060 nm) may be used to create the fenestration because (i) it is more effective than an excimer laser in laser fenestration, (ii) thermal damage to the surrounding tissue (i.e., the index valve) is not a concern, and (iii) calcium remains an area of challenge for excimer lasers. Other laser systems may be used to provide the laser ablation, and the continuously growing selection and increasing power output of diode lasers may offer a relatively low-cost opportunity to develop laser-assisted therapeutic devices.
It is recognized herein that computational simulations may be used for modeling of blood flow dynamics with quantitative analysis of flow parameters, such as velocity and blood stasis, in the proximity of the TAV leaflets. Recognizing the variety of parameters influencing blood flow, a fluid-structure interaction (FSI) modeling approach may be used to simulate unsteady flow fields of bioprosthetic heart valves to be integrated into the implementation of the laser ablation-based methods described herein. Additionally, the three-dimensional unsteady flow fields of the valves may also be compared with in vitro tests using FSI simulations to further investigate flow patterns and determine the contours of blood residence time, quantity shear stress, shear stress gradient, and oscillatory shear index in neo-sinus and on the surface of the leaflets, thus further refining the laser operations in accordance with certain embodiments.
The laser ablation processes described herein may result in an increased velocity in the sinus and neo-sinus due to the ablated openings improving blood flow in the sinus and neo-sinus, thus potentially reducing the risk of subclinical leaflet thrombosis.
It is noted that the use of laser ablation to remove the unwanted tissue provides a variety of advantages over existing methods (e.g., leaflet tear using electrified wires) such as, not limited to, more precise control over the specific tissue removed in the procedure, accurate delivery of ablation energy, reduced likelihood of damage to the tissues of the heart and surroundings, and reduced patient trauma and recovery time due to the small incision required for arterial delivery of the laser fiber to the prosthetic area. While endovenous laser ablation has been used in the treatment of conditions such as varicose veins, the use of laser energy delivery via, for example, a laser catheter for heart surgery has thus far been limited to more diffuse delivery of laser energy such as for treatment of persistent atrial fibrillation (see, for example, Weber, et al. “Laser catheter ablation of long-lasting persistent atrial fibrillation: Longterm results,” J. Atr. Fibrillation, Vo. 10, No. 2, 2017, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5673290/accessed 2023-06-08). In the present disclosure, the laser fiber enables pinpoint accuracy in the delivery of laser energy for the precise removal of specific portions of the aortic leaflets after the replacement valve prosthetic has been positioned in the desired location to improve blood flow into the coronary artery. That is, in the embodiments disclosed herein, the goal is to create one or more openings at strategic locations in the tissue related to heart valves, thus is distinct the atrial fibrillation ablation of Weber, which instead creates scars in the heart to block the faulty electrical signals. Further, laser ablation may be used with both stented and stentless prosthetic valves without damaging the stent, if used.
In some embodiments the identified patient may have undergone a surgical aortic valve replacement (SAVR) procedure and may have received any heart valve prosthetic, such as a stented prosthetic valve, a stented, supra-annular position prosthetic valve, a stented, externally mounted leaflet prosthetic valve, or a stentless prosthetic valve, to name a few nonlimiting examples.
In some embodiments, the identified patient may have undergone a mitral valve replacement (MRV) procedure and may have any received any heart valve prosthetic, such as a stented prosthetic valve, a stented, supra-annular position prosthetic valve, a stented, externally mounted leaflet prosthetic valve, or a stentless prosthetic valve, to name a few nonlimiting examples.
In some embodiments, the identified patient may have undergone a transcatheter pulmonary valve replacement (TPRV) procedure and may have any received any valve prosthetic.
In some embodiments, the identified patient may have undergone a tricuspid valve replacement procedure and may have received any valve prosthetic.
In some embodiments the laser fiber is guided through a patient's circulatory system by means of a guide wire and/or a catheter.
In some embodiments the method may be executed by means of open-heart surgery or through other means of accessing a patient's heart valves.
In some embodiments the patient may be asymptomatic, or not present with or be at risk of presenting with coronary obstruction or decreased blood flow as a result of the placement of a second heart valve prosthetic.
In some embodiments laser ablation may be utilized to remove portions of heart valve leaflet tissue from either the primary or second heart valve prosthetic.
In some embodiments the method may be applied to other transcatheter heart valves (THVs), such as a mitral, pulmonary, and tricuspid positions.
In some embodiments the method can also be used in transcatheter heart valves to improve blood flow in the vicinity of the leaflets to reduce blood stasis and thereby minimize the risk of leaflet thrombosis.
It is noted that, while each one of the embodiments illustrated in
In contrast,
As shown in
Fenestration tool 800 may further include a flush mechanism 840, which may include a variety of components for implementing a liquid flush via tubing 842 to catheter 814 such as, and not limited to, a liquid reservoir, a connector to an external liquid source, a pump, and delivery tubing. For example, flush mechanism 840 may be a saline flush mechanism for providing targeted saline flush at or near the fenestration site. Additionally, a steering cable 850 may be connected with the user interface and the catheter and/or optical fiber to enable the user of fenestration tool 800 to control a distal curvature of the optical fiber, thus allowing the user to direct the laser energy to a desired location within the patient.
Method 900 proceeds to a step 904 to provide a laser fenestration system, such as laser ablation system 800 shown in
The implementation of the laser ablation fenestration process is described as applied to certain examples of intra- and sura-annular valve devices. For example,
Method 1700 proceeds to a step 1704 to provide a laser fenestration system, such as fenestration system 800 shown in
In an embodiment, catheter body 1810 includes a window 1820, through which the laser energy from a laser source (e.g., laser source 810 of
An end opening 1830 may also be formed into catheter body 1810 to enable dispersion of flush fluid from tubing 842 therethrough. Alternatively, end opening 1830 may also accommodate the delivery of laser energy from optical fiber 812 therethrough.
While catheter body 1810 is shown in
An inset 1950 shows a close-up view of an example configuration of laser delivery portion 1940. As seen in inset 1950, laser delivery portion 1940 includes a laser tubing 1960 capped with a laser ferrule 1962. Laser ferrule 1962, for example, may be configured for transmitting therethrough the laser energy from one or more optical fibers bundled within laser tubing 1960. Laser ferrule 1962 may be integrated with a flush nozzle 1964 such that laser energy may be transmitted through a surface 1966 around flush nozzle 1964. Other combinations of flush mechanism and laser energy delivery systems may be contemplated and are considered a part of the present disclosure.
It is noted that the fenestration process described above may be performed immediately following a TAVR procedure, if a coronary blockage is observed during the procedure. Alternatively, the fenestration process may be performed separately from the TAVR procedure, if there is a later diagnosed need for coronary access, for example, for coronary stent implantation.
The foregoing is considered as illustrative only on the principles of the disclosure. Further, since numerous modifications and changes will occur to those skilled in the art, it is not desired to limit the disclosure to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the disclosure. It is noted that certain aspects of the present disclosure may be performed by robots, such as in robot-implemented surgery methods. Further, certain aspects of the present disclosure may be performed by systems implementing artificial intelligence as trained by machine learning methods.
As used herein, the recitation of “at least one of A, B and C” is intended to mean “either A, B, C or any combination of A, B and C.” The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
The terms and expressions employed herein are used as terms and expressions of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof. Each of the various elements disclosed herein may be achieved in a variety of manners. This disclosure should be understood to encompass each such variation, be it a variation of an embodiment of any apparatus embodiment, a method or process embodiment, or even merely a variation of any element of these. Particularly, it should be understood that the words for each element may be expressed by equivalent apparatus terms or method terms—even if only the function or result is the same. Such equivalent, broader, or even more generic terms should be considered to be encompassed in the description of each element or action. Such terms can be substituted where desired to make explicit the implicitly broad coverage to which this invention is entitled.
As but one example, it should be understood that all action may be expressed as a means for taking that action or as an element which causes that action. Similarly, each physical element disclosed should be understood to encompass a disclosure of the action which that physical element facilitates. Regarding this last aspect, by way of example only, the disclosure of a “protrusion” should be understood to encompass disclosure of the act of “protruding”— whether explicitly discussed or not—and, conversely, were there only disclosure of the act of “protruding”, such a disclosure should be understood to encompass disclosure of a “protrusion”. Such changes and alternative terms are to be understood to be explicitly included in the description.
The present application claims the benefit of U.S. Provisional patent application Ser. No. 63/351,687, filed 2022 Jun. 13 and titled “Systems and Methods for Utilizing Laser Ablation to Modify Heart Valve Prosthetic Leaflet Tissue to Improve Blood Flow.” The above referenced application is incorporated hereby in its entirety by reference.
Number | Date | Country | |
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63351687 | Jun 2022 | US |