Optimizing the transseptal access point for the left atrial appendage (LAA)

Abstract

The disclosed method includes using a processor to identify the septum and left atrial appendage (LAA) of a patient's heart in an anatomical map of at least a portion of the heart. An inlet surface is defined on the anatomical map where a medical device to be delivered through a sheath that penetrates the septum will engage with the LAA. A normal to the inlet surface is calculated. A plurality of curves are calculated, each curve (i) having one end tangent to the normal, (ii) having a second end that contacts the septum, and (iii) conforming to specified mechanical properties of the sheath. A plurality of candidate locations on the septum for transseptal puncture with the sheath are derived from the curves. The candidate locations are presented to a user.

Description

[Technical Field]

[0001] The present invention relates generally to treatment planning for medical probes, and more particularly to planning closure of the left atrium appendage (LAA) using transseptal access for invasive medical devices. [Background technology]

[0002] Various methods for planning left atrial appendage (LAA) treatment using a catheter have been proposed in the patent literature. For example, U.S. Patent Application Publication No. 2019 / 0090951 describes an ultrasound imaging device provided for guiding LAA closure. The use of ultrasound imaging allows for anatomical modeling over time (e.g., throughout the cardiac cycle). The anatomical model of the LAA over time is used to create a biomechanical model personalized for the patient. The personalized model and models of one or more closure devices are used to select a closure device for the patient that is appropriate for the entire cardiac cycle and to guide the placement of the selected closure device during implantation. Summary of the Invention [Means for solving the problem]

[0003] One embodiment of the present invention, described below, provides a method that includes using a processor to identify the septum and left atrial appendage (LAA) of a patient's heart in an anatomical map of at least a portion of the heart. A medical device to be delivered through a sheath that penetrates the septum defines an ostium surface on the anatomical map that will engage the LAA. A normal to the ostium surface is calculated. A plurality of curves are calculated, each curve (i) having one end tangent to the normal, (ii) having a second end that contacts the septum, and (iii) conforming to specified mechanical properties of the sheath. A plurality of candidate locations on the septum for transseptal puncture with the sheath are derived from the curves. The candidate locations are presented to a user.

[0004] In some embodiments, the specified mechanical properties of the sheath include the smallest radius of curvature of the sheath that can be obtained within the heart by external manipulation of the sheath.

[0005] In some embodiments, defining the inlet surface includes (a) outlining the ostium of the LAA on an anatomical map and (b) best fitting a plane to the outlined ostium.

[0006] In one embodiment, calculating the curve depends on whether the sheath access location to the right atrium (RA) of the heart is from the inferior vena cava or the superior vena cava.

[0007] In one embodiment, the medical device is an LAA closure device, hi another embodiment, the medical device is one of a balloon catheter and a basket catheter.

[0008] In some embodiments, uploading the anatomical map includes obtaining the anatomical map using an invasive ultrasound probe.

[0009] In some embodiments, presenting the plurality of candidate locations includes presenting candidate locations on the sheath, the entrance surface, the normal, and the septum using a 3D mapping system.

[0010] According to another embodiment of the present invention, there is further provided a system including a memory and a processor. The memory is configured to store an anatomical map of at least a portion of a patient's heart. The processor is configured to (a) identify, within the anatomical map, a septum and a left atrial appendage (LAA) of the heart, (b) define on the anatomical map an inlet surface at which a medical device delivered above and through a sheath that penetrates the septum will engage the LAA, (c) calculate a normal to the inlet surface, (d) calculate a plurality of curves, each of which (i) has one end tangent to the normal, (ii) has a second end that contacts the septum, and (iii) conforms to specified mechanical properties of the sheath, (e) derive from the curve a plurality of candidate locations on the septum for transseptal puncture with the sheath, and (f) present the plurality of candidate locations to a user.

[0011] The present invention will be more fully understood from the following detailed description taken in conjunction with the drawings, in which: [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic, pictorial illustration of a catheterization system including a catheter delivering a left atrial appendage (LAA) closure device, according to one embodiment of the present invention. [Figure 2] 2 is a schematic, pictorial illustration of a method for finding one or more candidate locations for the sheath of the catheter of FIG. 1 to penetrate the septum, in accordance with one embodiment of the present invention. [Figure 3] 2 is a flow chart that schematically illustrates a method for finding one or more candidate locations for the sheath of the catheter of FIG. 1 to penetrate the septum, in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Overview Catheterization is an established therapy for controlling atrial fibrillation (AF) in the left atrium (LA). To access the LA with a catheter, a physician typically first introduces the catheter through the body vasculature into the right atrium (RA) and punctures the septum separating the left and right atria with the catheter's sheath. The physician then passes the sheath through the puncture into the LA and delivers a medical device (e.g., a catheter) through the sheath to engage the LA tissue.

[0014] Proper selection of the transseptal puncture location is important because it substantially affects obtaining stable contact with the septal tissue, advancing the sheath into a specific LA target location, and maintaining the catheter position at the target LA location during the interventional procedure.

[0015] To complicate matters, physicians must further carefully consider the transseptal puncture location, as it can limit the way in which an invasive device (e.g., a catheter) can be introduced into the RA. Specifically, a catheter can be introduced into the RA via either the inferior vena cava or the superior vena cava, but the choice between these two options may depend on the selected puncture location. Furthermore, the ability to subsequently control the catheter within the LA depends on which remote vein is selected for sheath entry into the body, through which the sheath is guided into either the inferior vena cava or the superior vena cava of the RA. Thus, the combination of the above considerations, along with a given patient's medical profile, can limit a physician's options for successfully performing a catheterization procedure in the LA.

[0016] An invasive procedure requiring particularly careful consideration of the transseptal puncture location is left atrial appendage (LAA) closure. This procedure is used to reduce the likelihood of blood clot formation in the atrial appendage, which is common in certain patients with AF. The LAA is closed using a catheter that deploys an LAA closure device. To achieve a successful procedural outcome, the closure procedure requires careful alignment of the catheter's angular position relative to the LAA ostium. However, due to limitations in the flexibility and maneuverability of the sheath and catheter, successfully navigating the catheter to the LAA from a suboptimal septal puncture location is challenging.

[0017] The embodiments of the present invention described below provide techniques for identifying multiple potential septal locations and directions for septal penetration by an invasive device, such as a catheter delivering an LAA closure device, to precisely engage a given LA target, such as the LAA. Using the disclosed techniques, a physician has the ability to consider multiple potential locations for septal penetration, leading to increased choices for both clinically effective RA access approaches and suitable invasive medical devices (e.g., LAA devices) available to the physician. Such greater choice is important, for example, when considering a given patient's medical condition (e.g., RA enlargement) that may initially limit a physician's catheterization options.

[0018] In some embodiments, the processor performs the following steps: ■ generating a 3D anatomical model (e.g., an anatomical map) of the region of interest (e.g., the region including the septum and LAA); ■ defining a landing site for the LAA device, i.e., the opening of the LAA where the catheter will be inserted into the LAA, taking into account the type of closure device and the LAA shape (such a landing site may be defined, for example, by outlining the ostium of the LAA in the form of a closed curve on a 3D anatomical model); ■ fitting a substantially parallel entrance surface (e.g., a plane) to the delineated LAA ostium at the landing site and calculating the normal to this plane; ■ Using predefined mechanical properties of a sheath used to deliver the device, calculating a plurality of curves, each of which (i) has one end tangent to the normal, (ii) has a second end contacting the septum, and (iii) matches the specified mechanical properties of the sheath; ■ deriving from the curve a plurality of candidate locations on the septum for transseptal puncture with a sheath, thereby creating one or more potential access points for transseptal puncture at each of one or more intersections of the curve with the septum; ■Performing the disclosed technique to find one or more candidate septal puncture locations for accessing the LAA by performing the step of presenting multiple candidate locations to the user.

[0019] Examples of mechanical properties include the minimum radius of curvature and maximum angle of deflection achievable with the sheath, and the location on the sheath to which the distal end of the sheath can be bent (to access the LAA).

[0020] In one embodiment, the processor overlays the identified septal location on an anatomical map so that the physician performing the LAA closure procedure can, for example, select the most suitable RA approach (e.g., inferior vena cava or superior vena cava) to the LAA with a given LAA closure device. The sheath, landing site (e.g., ostium surface), normal, and transseptal puncture point (also called "access") are all visualized in a 3D mapping system (e.g., CARTO®).

[0021] Typically, the processor is programmed with software that contains specific algorithms that enable the processor to perform each of the processor-related steps and functions outlined above.

[0022] By identifying one or more candidate septal locations that may be optimal for puncturing to reach the LAA, the disclosed techniques may increase the chances of successfully completing invasive LAA procedures for a variety of cardiac patients.

[0023] System Description 1 is a schematic, pictorial illustration of a catheterization system 20 including a catheter 21 carrying a left atrial appendage (LAA) closure device 40, according to one embodiment of the present invention. The distal end of the catheter's shaft 22 is inserted by a physician 30 through a sheath 23 into the left atrial appendage 45 of a heart 26 of a patient 28 lying on a table 29, seen in inset 25. During insertion of the shaft 22, the LAA closure device 40 is maintained in a collapsed configuration by the sheath 23. By housing the LAA closure device 40 in a collapsed configuration, the sheath 23 also helps minimize vascular trauma en route to the target location.

[0024] To reach the left atrial appendage (LAA) 55 in the left atrium (LA) 45, seen in inset 65, physician 30 first navigates sheath 23 into the inferior vena cava access approach in the right atrium 47. The physician then uses sheath 23 to drill a hole 52 in the septum 50 dividing the atria, for example, by manipulating manipulator 32 near the proximal end of the catheter and / or by manipulating deflection from sheath 23. Once the distal end of shaft 22 is within the LAA 55, the physician advances the distal end through sheath 23 to deploy LAA closure device 40, coupled to the distal edge of the shaft, within the LAA 55.

[0025] Physician 30 then manipulates sheath 23 of catheter 21 within LA 45 using catheter handle 31 to access and contact LAA 55. As further seen in inset 65, to successfully access LAA 55, the physician aligns sheath 23 in a particular direction 66 that points toward ostium 57 of LAA 55.

[0026] The proximal end of catheter 21 is connected to control console 24. In the embodiments described herein, catheter 21 may be used for any suitable therapeutic and / or diagnostic purpose, such as electrical sensing within heart 26 or the aforementioned LAA closure procedure, among other possible medical uses of such a catheter.

[0027] Control console 24 includes a processor 41, typically a general-purpose computer, with suitable front-end and interface circuitry 38 for receiving signals from catheter 21 and for administering treatment via catheter 21 within heart 26 and for controlling other components of system 20. Typically, processor 41 comprises a general-purpose computer programmed with software that performs the functions described herein. This software may be downloaded in electronic form into computer memory 35, for example, over a network, or alternatively, or may additionally be provided and / or stored on a non-transitory tangible medium, such as magnetic, optical, or electronic memory. In particular, processor 41 executes the dedicated algorithms disclosed herein, included in FIG. 3, that enable processor 41 to perform the steps of the present disclosure, as further described below.

[0028] The exemplary configuration shown in FIG. 1 is chosen solely for conceptual clarity. The techniques of the present disclosure can be similarly applied using other system components and settings. For example, other devices, such as a balloon catheter or a basket catheter, can be used. The anatomical map can be generated by system 20 using an invasive ultrasound (US) probe, such as a CARTOSOUND® module with a SOUNDSTAR® catheter. As another example, system 20 may include other components, such as components for temperature sensing of cardiac tissue, etc.

[0029] Optimizing the left atrial appendage (LAA) transseptal access point 2 is a schematic, pictorial illustration of a method for finding one or more candidate locations for penetration of the septum 50 by the sheath 23 of the catheter 21 of FIG. 1 , in accordance with one embodiment of the present invention. The right side of the illustration is a lateral cross-sectional view of the heart, and the left side is a frontal view of the septum. The goal of the technique is to enable best access of the LAA 55 (as shown in the anatomical map 80) by the catheter 21 carrying the LAA closure device 40. A suitable way to accomplish this is to advance the distal end of the shaft 22 of the catheter 21 in a direction 66 (as shown in FIG. 1 ) that is approximately perpendicular to the ostium 57 at a defined surface of the ostium.

[0030] To this end, processor 41 uploads map 80 and defines a landing site for the LAA closure device as a plane 70 that fits to the LAA ostium 57. As can be seen, plane 70 is substantially parallel to the LAA ostium at the landing site. Processor 41 then calculates a normal 72 to plane 70.

[0031] Using predefined mechanical properties (e.g., properties exemplified above) of the sheath 23 used to deliver the LAA closure device 40, the processor 41 calculates multiple curves 74 between the normal 72, the plane 70, and the septum 50. As described above, each curve 74 (i) has one end tangent to the normal, (ii) has a second end that contacts the septum, and (iii) conforms to the specified mechanical properties of the sheath. In this manner, the processor creates one or more potential access points for transseptal puncture at one or more respective intersections of the curve 74 with, for example, a plane 76 that the processor fits to the septum 50. The locations on the septum 50 of the multiple potential access points are represented as semicircular curves 56, with a particular selection being the locations 52 on the semicircle 56 in FIG. 1 .

[0032] As can be seen, processor 41 overlays potential access points on an anatomical map 80 that is presented to the physician performing the LAA closure procedure to assist in selecting the most suitable approach to the LAA, for example, using a catheter. In that sense, if no septal location seems good enough, the physician may try modeling a different sheath or a superior vena cava approach.

[0033] The exemplary technique shown in Figure 2 is chosen solely for conceptual clarity. In particular, curve 56 has been simplified for clarity of presentation. Furthermore, different access approaches to RA 47 will generate a number of entirely different potential access points (e.g., different from curve 56).

[0034] 3 is a flow chart that generally illustrates a method for finding one or more candidate locations 52 for a catheter sheath to penetrate the septum, according to an embodiment of the present invention. The algorithm according to the presented embodiment executes a process that begins with processor 41 generating (e.g., uploading from memory 35) an anatomical map 80 that includes septum 50 and LAA 55, in an anatomical map generation step 90.

[0035] Next, the processor 41 defines a landing site for the LAA closure device 40 by identifying the ostium 57 of the LAA 55 in a landing site definition step 92 .

[0036] Next, in a geometric construction step 94, the processor fits a plane 70 to the ostium 57 and then calculates the normal 72 to the plane 70.

[0037] In the candidate curve derivation step 96, the processor 41 calculates one or more candidate curves 74 between the normal 72 to the plane 70 and the septum 50 using predefined mechanical properties of the sheath 23 used to deliver the LAA closure device 40.

[0038] In a transseptal puncture location calculation step 98, the processor calculates multiple potential access points 56 on the septum 50 using the curve 74 as described above.

[0039] The exemplary flowchart shown in Figure 3 has been chosen purely for purposes of conceptual clarity, and additional steps, such as considering another access to RA47 and subsequently repeating steps 94-98, have been intentionally omitted from the highly simplified flowchart.

[0040] Although the embodiments described herein primarily address the left atrial appendage, the techniques described herein can also be used for other cardiac catheter applications of the LA, such as electrophysiological mapping of the LA and pulmonary vein isolation. In particular, the disclosed techniques can be applied to planning landing sites at the ostium of the pulmonary veins (PV) for catheters used for electrophysiological sensing and / or ablation, such as balloon catheters, basket catheters, lasso catheters, multi-arm catheters, or tip catheters.

[0041] Additionally, the disclosed techniques may be applied in conjunction with other LA treatment sites (eg, mitral valve) and for other catheter delivery devices (eg, prosthetic valves).

[0042] It will therefore be understood that the above-described embodiments are cited by way of example, and that the present invention is not limited to what has been particularly shown and described above. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described in the foregoing specification, as well as variations and modifications thereof not disclosed in the prior art that would occur to one skilled in the art upon reading the foregoing description. Documents incorporated by reference into this patent application are deemed to be part of this application, except that if any term is defined in such incorporated document in a way that contradicts the definition given herein, either expressly or impliedly, then only the definition given herein shall be considered.

[0043] [Embodiment] (1) A method comprising: using a processor to identify a septum and a left atrial appendage (LAA) of a patient's heart in an anatomical map of at least a portion of the heart; defining an entrance surface on the anatomical map at which a medical device to be delivered through the transseptal sheath will engage the LAA; calculating a normal to the entrance surface; calculating a plurality of curves, each of which (i) has one end tangent to the normal, (ii) has a second end contacting the septum, and (iii) conforms to specified mechanical properties of the sheath; deriving from the curve a plurality of candidate locations on the septum for transseptal puncture with the sheath; presenting the plurality of candidate locations to a user; A method comprising: (2) The method of embodiment 1, wherein the specified mechanical properties of the sheath include a minimum radius of curvature of the sheath that can be obtained within the heart by external manipulation of the sheath. (3) defining the inlet surface comprises: delineating the ostium of the LAA on the anatomical map; best fitting a flat surface to the contoured stoma; 2. The method of embodiment 1, comprising: (4) The method of embodiment 1, wherein calculating the curve depends on whether the access location of the sheath to the right atrium (RA) of the heart is from the inferior vena cava or the superior vena cava. (5) The method of embodiment 1, wherein the medical device is an LAA closure device.

[0044] (6) The method of embodiment 1, wherein the medical device is one of a balloon catheter and a basket catheter. (7) The method of embodiment 1, wherein uploading the anatomical map includes acquiring the anatomical map using an invasive ultrasound probe. (8) The method of embodiment 1, wherein presenting the plurality of candidate locations includes presenting the candidate locations on the sheath, the entrance surface, the normal, and the septum using a 3D mapping system. (9) A system comprising: a memory configured to store an anatomical map of at least a portion of the patient's heart; 1. A processor, comprising: identifying the septum and left atrial appendage (LAA) of the heart in the anatomical map; defining an entrance surface on the anatomical map at which a medical device to be delivered through the transseptal sheath will engage the LAA; calculating a normal to the entrance surface; calculating a plurality of curves, each of which (i) has one end tangent to the normal, (ii) has a second end contacting the septum, and (iii) conforms to specified mechanical properties of the sheath; deriving from the curve a plurality of candidate locations on the septum for transseptal puncture with the sheath; and a processor configured to present the plurality of candidate locations to a user. (10) The system of embodiment 9, wherein the specified mechanical properties of the sheath include a minimum radius of curvature of the sheath that can be obtained within the heart by external manipulation of the sheath.

[0045] (11) The processor: delineating the ostium of the LAA on the anatomical map; best fitting a flat surface to the contoured stoma; 10. The system of claim 9, wherein the inlet surface is defined by: (12) The system of embodiment 9, wherein the processor is configured to calculate the curve depending on whether the access position of the sheath to the right atrium (RA) of the heart is from the inferior vena cava or the superior vena cava. (13) The system of embodiment 9, wherein the medical device is an LAA closure device. (14) The system of embodiment 9, wherein the medical device is one of a balloon catheter and a basket catheter. (15) The system of embodiment 9, wherein the processor is configured to acquire the anatomical map using an invasive ultrasound probe.

[0046] (16) The system of embodiment 9, wherein the processor is configured to present the plurality of candidate locations by presenting the candidate locations on the sheath, the entrance surface, the normal, and the septum using a 3D mapping system.

Claims

1. 1. A system comprising: a memory configured to store an anatomical map of the patient's heart, the anatomical map including the septum and left atrial appendage; 1. A processor, comprising: identifying the septum and left atrial appendage (LAA) of the heart in the anatomical map; defining an entrance surface on the anatomical map at which a medical device to be delivered through the transseptal sheath will engage the LAA; calculating a normal to the entrance surface; calculating a plurality of curves, each of which (i) has one end tangent to the normal, (ii) has a second end contacting the septum, and (iii) conforms to specified mechanical properties of the sheath; deriving, for each of the plurality of curves, a candidate location on the septum for transseptal puncture with the sheath; presenting a plurality of the candidate locations to a user; and The system wherein the specified mechanical property of the sheath is a minimum radius of curvature of the sheath.

2. the processor: delineating the ostium of the LAA on the anatomical map; fitting a flat surface into the contoured stoma; The system of claim 1 , wherein the inlet surface is defined by:

3. The system of claim 1 , wherein the medical device is an LAA closure device.

4. The system of claim 1 , wherein the medical device is one of a balloon catheter and a basket catheter.

5. The system of claim 1 , wherein the processor is configured to acquire the anatomical map using an invasive ultrasound probe.

6. The system of claim 1, wherein presenting the plurality of candidate locations includes the processor using a 3D mapping system to present the candidate locations on the sheath, the entrance surface, the normal, and the septum.

Images