Left atrial appendage closure system

Abstract

The present invention relates to a catheter system (1) for closing the left atrial appendage (2), comprising: a first catheter (10) comprising a balloon (12) for temporarily sealing the left atrial appendage (2), and a second catheter (20) having a distal section (22a) that accommodates an adhesive (30), wherein the second catheter (20) is configured to be inserted into a lumen (14) of the first catheter (10) and to slide therein to apply the filling material to the collapsed left atrial appendage (2).

Description

[0001] Left atrial appendage closure system

[0002] The present invention relates to a catheter system for closing the left atrial appendage (LAA) of a human or animal patient.

[0003] About 20% of all strokes have atrial fibrillation as their cause. In this case, thrombi can form in the heart’s left atrial appendage (LAA), which are triggering the strokes. Therefore, one of the strategies to reduce the risk of stroke due to atrial fibrillation is to close the LAA.

[0004] To date, different closure systems for closing the left atrial appendage are known. Some of these systems are based on the targeted release of an implant in the left atrial appendage to close the cavity by means of a self-expandable wire mesh covered with a polymeric fabric.

[0005] Furthermore, minimally invasive procedures are known which separate the left atrial appendage from the heart by ligation.

[0006] Moreover, systems have been described that temporarily close the ostium of the LAA to evacuate the volume of the LAA distally behind it, as e.g. described in EP 3 772 339 Al.

[0007] Alternative treatment options are often surgical procedures. However, the inherent severity of an open-heart surgery and its associated risks and mortality rates are discouraging factors to conduct such surgeries for the sole reason to close off the LAA, presenting no valuable treatment option for a broad patient population.

[0008] The usage of closure systems based on self-expanding implants may lead to unsuccessful sealing of the LAA due to the large variation of the LAA cavity (i.e. geometry and number of cavities) in the human population. Disadvantages of this kind of solutions result from the difficulty to adapt such implants to various anatomies of the LAA. Further, leaving permanent implants behind in the LAA bears the risk of device-induced thrombosis, peri-device leakage, as well as stretching of the LAA. Furthermore, often, anticoagulation is necessary, because the surface of the implant or leakage may create thrombi. Furthermore, such implants have usually to be provided in several different device sizes due to variations in the anatomy of the LAA (see above). Moreover, the device may dislocate during release and / or after some time and residual peri-device leakages and device thrombogenicity remain a source for late event complications.

[0009] Furthermore, possible disadvantages of the epicardial approach may result from the epicardial closure of the LAA being a more complex procedure compared to less invasive methods. It may require open-heart surgery, which carries inherent risks associated with major surgical interventions, such as infection, bleeding, and longer recovery times. Particularly, epicardial procedures are invasive and typically involve a larger incision, which can lead to a longer hospital stay and a more extended recovery period compared to minimally invasive approaches. Furthermore, surgical procedures, especially those involving open-heart surgery, can be more expensive than less invasive treatments. As with any surgical procedure, there is a risk of complications, such as damage to surrounding structures, blood clots, irregular heart rhythms (arrhythmias), and the need for additional interventions. Additionally, not all patients may be suitable candidates for epicardial LAA closure. Individual factors, such as overall health, anatomy, and the presence of other medical conditions, can impact the appropriateness of this approach. Furthermore, there is a possibility that the LAA closure may not be completely successful in all cases, potentially leaving the patient at risk of stroke or other complications.

[0010] General disadvantages of other known implant-less approaches are the lack of a sealing membrane on the proximal end, and non-stable vacuum. Furthermore, the filling of the LAA with large amounts of foreign material, exposure of material to blood flow, and risk of loosening of material and embolization is often problematic in such approaches.

[0011] Thus, based on the above, the problem to be solved by the present invention is to provide a catheter system for the closure of the left atrial appendage (LAA), particularly to avoid strokes in case of atrial arrhythmia, that is minimally invasive, does not leave a metallic implant behind, and does not require permanent anticoagulation. Furthermore, particularly, the catheter system to be provided shall not be constrained by human anatomy variation.

[0012] This problem is solved by a catheter system having the features of claim 1. Preferred embodiments are stated in the corresponding dependent claims and are described below.

[0013] A catheter system for closing the left atrial appendage is disclosed according to claim 1. The catheter system for closing the left atrial appendage comprises a first (e.g. balloon) catheter comprising a first catheter shaft, a first lumen and a second lumen; and a second (e.g. filling material) catheter comprising a second shaft comprising at least one lumen that is configured to accommodate a filling material, wherein the second catheter is (e.g. slidably) arranged within the second lumen of the first catheter shaft or the second catheter is configured to be inserted into the second lumen of the first catheter shaft (and to slide therein towards the opening). The catheter system further comprises a balloon arranged on a distal section of the first catheter shaft. The balloon is connected to the first lumen of the first catheter shaft to inflate and deflate the balloon. The balloon is preferably configured to seal the left atrial appendage in an inflated state of the balloon.

[0014] Especially, in an embodiment, the catheter system for closing the left atrial appendage comprises or consists of:

[0015] - a first (e.g. balloon) catheter comprising a first catheter shaft and a balloon arranged on a distal section of the first catheter shaft, the balloon being connected to a first lumen of the first catheter shaft to inflate and deflate the balloon, (wherein the balloon is configured to seal the left atrial appendage in an inflated state of the balloon particularly by contacting a circumferential boundary region of the LAA to seal the LAA), and wherein the first catheter shaft comprises at least one second lumen comprising an opening at a distal end of the first catheter shaft, and

[0016] - a second (e.g. filling material) catheter comprising a second catheter shaft comprising at least one lumen that can accommodate a filling material, wherein a sealing mechanism is arranged at a distal end of the at least one lumen of the second shaft configured to prevent discharge of the filling material in a closed state of the sealing mechanism and to allow discharge of the filling material in an open state of the sealing mechanism, wherein the second catheter is (e.g. slidably) arranged within the second lumen of the first catheter shaft or the second catheter is configured to be inserted into the second lumen of the first catheter shaft (and particularly configured to slide therein towards the opening).

[0017] However, surprisingly, it has been found out that the sealing mechanism at the distal end of the second catheter is not mandatory and the filling material can be properly held in a distal portion of the at least one lumen of the second catheter shaft without said sealing mechanism. Thus, according to a preferred embodiment, the second catheter comprises at least one opening at the distal end of the second catheter shaft, which at least one opening is configured to be open permanently. Particularly, the at least one opening of the second catheter shaft is in permanent flow connection with the at least one lumen of the second catheter shaft. In case the second catheter shaft comprises a plurality of lumens, the second catheter shaft can comprise a corresponding plurality of openings at the distal end, each opening configured to be permanently open, and particularly, to be in permanent flow connection with an associated lumen of said plurality of lumens of the second catheter shaft.

[0018] Furthermore, the filling material may be one of: an adhesive, a glue, a multi-component adhesive, a multi-component glue. According to a preferred embodiment, the filling material comprises UV or Ultrasound-induced curing components. The filling material (e.g. adhesive or glue) may be accommodated in a distal portion of the at least one lumen of the second catheter. Preferably, the filling material (e.g. adhesive or glue) is biocompatible. According to yet another preferred embodiment, the filling material is a foam, preferably a polymeric foam or a bioadhesive (such as collagen and / or fibrin).

[0019] In other words, the catheter system according to the present invention particularly uses a balloon catheter system with multiple lumina to temporarily block and seal off the LAA at the ostium by means of an inflatable (e.g. compliant) balloon and subsequent collapse of the LAA by application of a vacuum and finally fixation of the LAA in the collapsed stated using the filling material. Both, the vacuum and the filling material, being applied and delivered via the first (balloon) catheter, particularly using a second catheter for the filling material. Access to the LAA can be accomplished by transseptal puncture from the right atrium to the left atrium.

[0020] Furthermore, the proposed invention particularly alleviates the above-mentioned drawbacks by using particularly a non-metallic filling material to permanently seal-off the LAA cavity while not leaving thrombogenic material and metallic implants behind as foreign body material. In addition, the associated risks with surgical approaches do not exist since the application is carried out intravascularly and minimal invasive.

[0021] Particularly, due to the use of an e.g. compliant balloon to temporarily seal off the LAA during the procedure, the solution according to the present invention will be atraumatic.

[0022] Particularly, employing a pre-loaded second (e.g. filling material) catheter, like a cartridge system, the complete catheter system is modular and exchangeable, maximizing flexibility of the procedure. Additionally, particularly, the physician does not need to handle the filling material itself and can focus solely on the procedure. Further, the sealing mechanism of the second catheter (e.g. a membrane) prevents the filling material from exiting the second catheter unintentionally and also prevents premature curing of the filling material. However, at least one lumen of the second catheter shaft can also be loaded with the filling material via a suitable device, such as a syringe, that can be brought in flow connection with said at least one lumen. This also allows to use the second catheter to inject a contrast agent fluid through said at least one lumen of the second catheter shaft into the LAA for verifying a sealing achieved with the balloon and particularly for measuring a volume of the LAA. The latter information can be used to determine the amount of filling material that is to be injected into the LAA eventually. Thus, the catheter system according to the present invention can comprise the filling material in a container (e.g. a container formed by a syringe) so that the filling material can be injected into the second catheter when needed or in a pre-loaded condition as described above.

[0023] According to an embodiment the second lumen of the first catheter is reinforced on the whole length or especially in the distal part, below the balloon to ensure the lumen remains open for the second catheter while the balloon is inflated. Reinforcing the second lumen can be achieved by choice of an appropriate material and / or reducing the lumen of the inner shaft of the first catheter with a nozzle, making the wall thickness higher while keeping the outer diameter constant.

[0024] According to an embodiment, the first catheter comprises an inner shaft which is arranged within the second lumen so that the first lumen is annularly arranged around the inner shaft, wherein the inner shaft comprises a fourth lumen, the first catheter shaft and the inner shaft are relatively movable to each other along a longitudinal axis, and a first end of the balloon is attached to the first catheter shaft and a second end of the balloon is attached to the inner shaft, wherein the fourth lumen comprises an opening at the distal end of the inner shaft.

[0025] According to this embodiment, the fourth lumen of the inner shaft serves the technical purposes of the second lumen of the first catheter shaft. That is, the second catheter is arranged within the second lumen of the first catheter shaft or the second catheter is configured to be inserted into the second lumen of the first catheter shaft.

[0026] By the attachment of the first end, the balloon is sealed to the first catheter shaft along the circumference of the balloon at the first end. By the attachment of the second end, the balloon is sealed to the inner shaft along the circumference of the balloon at the second end. Thus, the lumen of the balloon is arranged between the first catheter shaft and the inner shaft.

[0027] As the first catheter shaft and the inner shaft are relatively movable to each other along a longitudinal axis, the shape and size of the inflated balloon can be adjusted, in particular, a disc, plate or torus shaped ballon may be formed. The radial dimension of the inflated balloon may be larger than its length along the longitudinal axis. Said balloon is highly suitable for a reliable sealing of a vessel. According to an embodiment of the catheter system, the first catheter is configured to apply a negative pressure (with respect to atmospheric pressure) via the second lumen to the left atrial appendage for sealing the balloon in the inflated state at the left atrial appendage and / or for bringing the left atrial appendage to a collapsed state.

[0028] Furthermore, according to an alternative embodiment, the first catheter comprises a third lumen, wherein the first catheter is configured to apply a negative pressure via the third lumen to the left atrial appendage for sealing the balloon in the inflated state at the left atrial appendage and / or for bringing the left atrial appendage to a collapsed state. Thus, in this embodiment, the second lumen is solely for receiving the second catheter and the third lumen is solely for applying the negative pressure (e.g. vacuum) to the left atrial appendage.

[0029] Furthermore, according to yet another preferred embodiment, the balloon is a compliant low-pressure balloon. Furthermore, according to an embodiment, the balloon is welded on the distal section of the first catheter shaft. Particularly, in an embodiment, the balloon can comprise or consist of a thermoplastic polyurethane (TPU), preferably a (medical grade) polyether-based aromatic thermoplastic polyurethanes or (medical grade) aromatic polyester-based thermoplastic polyurethane such as, e.g., a Pellethane. Further, in an embodiment, the first catheter shaft can comprise one or more radiopaque markers in the area of the balloon to enhance visibility and facilitate the correct placement at the LAA ostium.

[0030] Furthermore, in an embodiment of the catheter system according to the present invention, a connector, particularly a Luer hub, is arranged on a proximal section of the first catheter, the connector being configured to providing a flow connection to the first lumen of the first catheter shaft of the first catheter for inflation and deflation of the balloon. Particularly, the catheter system can comprise an inflation / deflation pump to inflate and deflate the balloon, e.g., as used in percutaneous transluminal angioplasty (PTA).

[0031] According to yet a further embodiment of the catheter system, a Y-connector is provided on a proximal section of the first catheter shaft of the first catheter that provides a first and a separate second access to the second lumen and is configured to allow pulling a vacuum (e.g. via a syringe) in the second lumen via the first access while allowing to insert the second catheter shaft of the second catheter (and / or a guide wire) into the second lumen via the second access. Particularly, with this safety feature, introduction of air during device insertion / exchange can be minimized.

[0032] Further, in an embodiment, the balloon comprises a front side for contacting and particularly sealing a circumferential boundary region of the left atrial appendage in an inflated state of the balloon, wherein in the inflated state the front side comprises one of: a flat shape, a conical shape, an oval shape, a spherical shape.

[0033] Furthermore, according to an embodiment, the balloon is bonded to the first catheter shaft at the front side of the balloon by a rim portion (i.e. neck) turned over into an interior space defined by the balloon, particularly so as to support forming of a flat front side of the balloon in an inflated state of the balloon.

[0034] According to an embodiment of the catheter system, the balloon comprises an outer surface portion having one of: a friction-enhancing surface structure on a contact surface with the left atrial appendage ostium (e.g. a rippled and / or imprinted surface), a friction-reducing smooth surface portion on the front side of the balloon to prevent the filling material from sticking to the balloon.

[0035] According to yet a further embodiment of the catheter system, the first catheter shaft of the first catheter comprises a distal catheter tip that comprises said opening, wherein the catheter tip comprises a predetermined breaking point to allow release of the catheter tip from the remaining first shaft in case the catheter tip is bonded to the collapsed left atrial appendage by the filling material. With this, the first catheter of the catheter system can be withdrawn by leaving the catheter tip in the left atrial appendage. In this embodiment the catheter tip may be resorbable.

[0036] Furthermore, according to an embodiment, the balloon and / or the distal catheter tip of the first catheter shaft of the first catheter comprises a coating, particularly a silicone coating, to prevent the filling material sticking to the balloon and / or the catheter tip.

[0037] Further, according to an embodiment, the balloon and / or the distal tip of the first catheter shaft of the first catheter comprises a pericardium cover layer to prevent the filling material sticking to the balloon and / or the catheter tip.

[0038] Furthermore, according to yet another embodiment of the present invention, the balloon comprises a drug coating to enable an improved endothelization of a closed front surface of the collapsed left atrial appendage.

[0039] Furthermore, according to an embodiment, the balloon comprises a drug coating to locally reduce thrombosis formation. Particularly, the distal portion of the first catheter shaft of the first catheter is protruding only very little into the LAA, and the balloon is particularly mounted very close to the distal tip of the first catheter shaft of the first catheter. Thus, the protruding part (i.e., distal portion) is atraumatic to not puncture or perforate the LAA. According to an embodiment of the catheter system, a distal portion of the first catheter shaft of the first catheter that extends from the front side of the balloon in the inflated state to the distal tip of the first catheter shaft of the first catheter is smaller than 10 mm, preferably smaller than 5 mm, more preferably smaller than 2 mm.

[0040] According to a further embodiment of the catheter system, the first catheter can be coated with a hydrophobic coating to reduce friction and improve device lubricity.

[0041] According to a further embodiment, a coating of the inner surface of the second lumen of the first catheter shaft and / or the outer surface of the second catheter shaft is provided to reduce friction between both catheters.

[0042] Furthermore, in an embodiment of the catheter system, the first catheter shaft of the first catheter comprises a hole or valve on a proximal side of the balloon, configured to connect the second lumen of the first catheter shaft with surrounding blood in the atrium, so that through this hole or valve blood can be sucked through the second lumen, particularly for removing air bubbles in the first catheter, which could cause embolization.

[0043] Furthermore, in an embodiment of the catheter system, the first catheter shaft of the first catheter comprises a penetrable membrane at an intracardial opening of the second lumen with surrounding blood in the atrium, so that through this membrane blood can be sucked through the second lumen when the membrane is open, however once the second catheter passes through the opening of the membrane the opening of the membrane is sealed, which will prevent an aspiration of administered filling material into the first catheter shaft of the first catheter.

[0044] In a further embodiment the sealing effect is provided by form fitting of the second catheter with the distal part of the second lumen of the first catheter. The form fitting can be achieved with a stabilizing nozzle at the distal end of the second lumen of the first catheter.

[0045] Further, in another embodiment of the catheter system, the filling material is curable by mixing it with a curing agent accommodated in a distal section of a second lumen of the second catheter shaft of the second catheter, wherein a mixing device, particularly a static mixer, is arranged at a distal end of the first and the second lumen and configured to mix the filling material and the curing agent passed through the mixing device.

[0046] In a further embodiment of the catheter system the first and / or second catheter have steerable distal ends, which can be maneuvered from the proximal end.

[0047] In a further embodiment, the distal end of the first and / or second catheter has a predefined curvature (so-called “pigtail”, e.g.) or can be preformed by the user before the procedure.

[0048] In an embodiment of the catheter system, the filling material is a light-curing adhesive or glue or UV-curing adhesive or glue, wherein the second catheter shaft of the second catheter is configured to direct light onto the (e.g. dispensed) adhesive or glue to cure it. Particularly, the second catheter shaft can comprise a light emitting diode and / or a light guiding fiber for directing light or UV- radiation onto the filling material (e.g. adhesive or glue). In the framework of the present invention “curing” refers to all processes that cause the adhesive to bond LAA portions to one another. Particularly, the notion “curing” comprises “cross-linking”.

[0049] In an embodiment of the catheter system, the filling material is an ultrasound-curing adhesive or glue, wherein ultrasound is either applied from outside the body in direction LAA or the second catheter shaft of the second catheter is configured with an ultrasound electrode to direct ultrasound waves in the direction (e.g. dispensed) adhesive or glue to cure it.

[0050] Furthermore, according to an embodiment of the catheter system, the sealing mechanism is configured to be brought into an open state and let filling material pass, in case a pressure exerted onto the filling material exceeds a pre-defined threshold pressure.

[0051] Particularly, in case of using a curing agent, the sealing mechanism can be configured to also let the curing agent pass once the pre-defined threshold pressure is exceeded, wherein particularly the mixing device (e.g. static mixer) can be arranged downstream the sealing mechanism, particularly downstream the membrane.

[0052] Particularly, in an embodiment, the second catheter can be configured to be connected to a syringe that is configured to apply said pressure exceeding the threshold pressure.

[0053] Particularly, in an embodiment, the sealing mechanism comprises a membrane configured to let filling material pass in case the pressure exerted onto filling material (e.g. by means of said syringe) exceeds the pre-defined threshold pressure. Particularly, in case of using a curing agent, the membrane can be configured to also let the curing agent pass once the pre-defined threshold pressure is exceeded, wherein particularly the mixing device (e.g. static mixer) can be arranged downstream the sealing mechanism, particularly downstream the membrane. Particularly, the mixing device is configured to mix the adhesive or glue or filling material and the curing agent and to discharge the resulting mixture out of the second catheter (e.g. into the collapsed LAA).

[0054] Furthermore, according to another embodiment of the catheter system, the second catheter comprises a drainage, which allows mass flow from a distal portion to a proximal portion and vice versa of the second lumen of the first catheter for stable vacuum conditions and pressure equilibrium during movement of the second catheter shaft of the second catheter in the first catheter shaft of the first catheter, particularly during movement of the second catheter shaft in the second lumen of the first catheter shaft of the first catheter.

[0055] According to another embodiment of the catheter system, wherein the second catheter comprises an outer diameter and the first catheter comprises an inner diameter, wherein the outer diameter is smaller than the inner diameter to allow mass flow from a distal portion to a proximal portion and vice versa of the second lumen of the first catheter for stable vacuum conditions and pressure equilibrium during movement of the second catheter shaft of the second catheter in the first catheter shaft of the first catheter, particularly during movement of the second catheter shaft in the second lumen of the first catheter shaft of the first catheter. Particularly, the outer diameter and the inner diameter are configured to form a ring gap between the second catheter and the first catheter to allow mass flow from a distal portion to a proximal portion and vice versa of the second lumen of the first catheter for stable vacuum conditions and pressure equilibrium during movement of the second catheter shaft of the second catheter in the first catheter shaft of the first catheter, particularly during movement of the second catheter shaft in the second lumen of the first catheter shaft of the first catheter. Accordingly, said ring gap is formed around a circumference of the second catheter and within the second lumen of the first catheter. Alternatively and / or additionally to the drainage, said ring gap may form said passageway.

[0056] According to an embodiment, the second catheter comprises a first supply lumen that is configured to accommodate a first adhesive and to allow discharge of the first adhesive, a second supply lumen that is configured to accommodate a second adhesive and to allow discharge of the second adhesive, and a suction lumen that is configured for applying a negative pressure (e.g. vacuum) to the left atrial appendage. For example, the first adhesive may be a first component of a two-component adhesive and the second adhesive may be the second component of a two-component adhesive. The suction lumen may be configured to receive adhesive, which has been filled into the LAA, while a vacuum is applied through the suction lumen to the LAA.

[0057] By filling the LAA with a two-component adhesive, each component for example through an individual supply lumen, and a subsequent evacuation of the LAA, the LAA is collapsed and sealed in a way which leads to less thrombosis formation. The evacuation step leads to a removal of most of the adhesive from the LAA but leaves the inner sidewalls of the LAA wetted by the adhesive. Thus, not only a more favorable sealing with respect to thrombosis formation is achieved but also less exogenous material is left in the human body after the LAA sealing.

[0058] According to yet another aspect of the present invention, a method for closing a left atrial appendage is disclosed, wherein the method particularly uses a catheter system according to the present invention.

[0059] According thereto, the method comprises advancing a first catheter towards the LAA and inflating a balloon of the first catheter to temporarily block and seal off the LAA at the ostium by means of the balloon and subsequent collapse of the LAA by application of vacuum through the first catheter and finally fixation of the LAA in the collapsed state using a filling material (e.g. adhesive or glue) applied via a second catheter into the collapsed LAA, wherein the second catheter is inserted into a lumen of the first catheter.

[0060] In a further embodiment, the method comprises applying a vacuum to the LAA after applying the filling material (e.g. adhesive or glue) to the LAA. This evacuation step leads to a removal of most of the filling material from the LAA but leaves the inner sidewalls of the LAA wetted by the filling material so that the collapsed LAA is efficiently sealed.

[0061] In a preferred embodiment, applying the filling material comprises applying a first adhesive to the LAA, and applying a second adhesive to the LAA. The first adhesive may be a first component of a two-component adhesive and the second adhesive may be a second adhesive of the two-component adhesive. The first component of the two-component adhesive may be applied to the LAA before the second component of the two-component adhesive is applied to the LAA or the first component of the two-component adhesive and the second component of the two-component adhesive are applied simultaneously to the LAA (but through individual supply lumen). In a further preferred embodiment, the method further comprises applying a vacuum to the LAA after applying the first adhesive to the LAA and before applying the second adhesive to the LAA. This evacuation step leads to a removal of most of the first adhesive, respectively, the first component of the two-component adhesive from the LAA but leaves the inner sidewalls of the LAA wetted by the first adhesive so that a better mixing of the first adhesive and the second adhesive, respectively, the second component of the two-component adhesive can be achieved on the inner sidewalls of the LAA after applying the second adhesive to the LAA. This improves the sealing of the LAA after collapsing the LAA.

[0062] In an embodiment of the method, both, the vacuum and the filling material are applied through the same (e.g second) lumen of the first catheter. In this case, particularly, the second catheter being inserted into this lumen of the first catheter forms a passageway with the first catheter allowing to evacuate the LAA through this lumen of the first catheter. Particularly, as described herein, the second catheter can comprise a drainage (e.g. a groove formed on an outside of the second catheter) to form said passageway. Alternatively and / or additionally to the drainage, an outer diameter of the second catheter and an inner diameter of the first catheter may be configured to form a ring gap as described herein above. Said ring gap may form said passageway. In an alternative embodiment, vacuum and filling material are applied through different lumen of the first catheter.

[0063] Furthermore, according to a preferred embodiment of the method, the method further comprises the steps of (particularly after application of the vacuum and prior to applying said filling material):

[0064] - verifying a sealing of the evacuated LAA by discharging a contrast agent fluid into the evacuated LAA via a lumen of the second catheter that is inserted into the (e.g. second) lumen of the first catheter, and particularly measuring the volume of the contrast agent fluid that can be filled into the LAA before a sealing of the LAA by the balloon fails (wherein particularly the contrast agent fluid comprises a contrast agent and a sodium chloride solution), and

[0065] - removing the contrast agent fluid from the LAA through the lumen of the first catheter.

[0066] Alternatively or additionally, the method may comprise verifying a sealing of the evacuated LAA by determining a pressure inside the LAA and / or the lumen of the first catheter. In case that the sealing of the LAA does not work and the LAA is not evacuated, the method may comprise retracting the first catheter and inserting a new catheter comprising a balloon with a different shape compared to a shape of the balloon of the first catheter.

[0067] Furthermore, according to a preferred embodiment of the method, the above-described application of the filling material via the second catheter into the collapsed LAA comprises in particular: - establishing a flow connection between a container (e.g. syringe) containing the filling material (e.g. an adhesive or a glue or another substance as described herein) and the lumen of the second catheter,

[0068] - discharging a first volume of the filling material into the lumen of the second catheter so that a second volume of the contrast agent fluid remains in a distal portion of the lumen of the second catheter and such that a third volume of the contrast agent fluid is pushed from the lumen of the second catheter into the LAA,

[0069] - evacuating the LAA via the lumen of the first catheter to remove the third volume of the contrast agent fluid from the LAA, and

[0070] - injecting a fourth volume of the filling material together with the second volume of the contrast agent fluid remaining in the distal portion of the lumen of the second catheter into the LAA via the lumen of the second catheter.

[0071] For example, said container may be a syringe or an external reservoir containing the filling material to which the lumen of the second catheter fluidly connects. Alternatively, the container containing the filling material may be a pre-loaded reservoir containing the filling material, wherein the pre- loaded reservoir is part of the second catheter, e.g., like a cartridge system. The latter has the advantage of an easy, convenient and less error-prone method which makes the establishing of a flow connection between an external container and the lumen of the second catheter redundant.

[0072] In a further preferred embodiment, the method may comprise:

[0073] - removing the second catheter from the lumen of the first catheter,

[0074] - inserting a third catheter into the lumen of the first catheter, wherein the third catheter forms a passageway with the first catheter allowing to evacuate the LAA through this lumen of the first catheter,

[0075] - establishing a flow connection between a second container (e.g., a syringe or a pre-loaded reservoir) containing the filling material (e.g. an adhesive or a glue or another substance as described herein) and the lumen of the third catheter,

[0076] - applying a vacuum through the second lumen of the first catheter, and

[0077] - injecting a fifth volume of the filling material into the LAA via the lumen of the third catheter.

[0078] Accordingly, the method allows the application of the filling material from two different containers, e.g. from an external container like a syringe and from an internal pre-loaded container of the third catheter like a cartridge system. This leads to a more versatile method for application of the filling material to the LAA. Comparable to the above-described method comprising the discharging of the filling material from only one container, said method may comprise that an additional volume of the contrast agent fluid may be pushed from the lumen of the third catheter into the LAA prior to discharging the fifth volume of the filling material into the LAA via the lumen of the third catheter.

[0079] Furthermore, according to a preferred embodiment, subsequently, the balloon is deflated via the first catheter and the first and the second catheter are removed.

[0080] In a further preferred embodiment, the method comprises the steps:

[0081] - moving the second catheter towards its proximal end, and

[0082] - injecting a sixth volume of the filling material into the LAA via the lumen of the second catheter.

[0083] In a further preferred embodiment, the method comprises the steps:

[0084] - moving the third catheter towards its proximal end, and

[0085] - injecting a seventh volume of the filling material into the LAA via the lumen of the third catheter.

[0086] According to said methods, the LAA is sequentially filled with the filling material. The method may comprise several combined steps of moving the second catheter respectively the third catheter towards its proximal end and injecting an additional volume of the filling material into the LAA.

[0087] Particularly, in a preferred embodiment of the method, the first volume is about 0.4 ml [milliliters]. Furthermore, in a preferred embodiment of the method, the second volume is about 0.1 ml. Furthermore, in a preferred embodiment of the method, the third volume is equal to the first volume. Furthermore, in a preferred embodiment of the method, the fourth volume is about 1.3 ml.

[0088] In the following, embodiments of the invention as well as further features and advantages of the present invention shall be described with reference to the Figures, wherein

[0089] Fig. 1A-C schematically show a first catheter of a first embodiment of a catheter system according to the present invention, the first catheter comprising a balloon for sealing the LAA at the ostium,

[0090] Fig. 2A shows an embodiment of the balloon of the first catheter shown in Fig. 1,

[0091] Fig. 2B shows a further embodiment of the balloon of the first catheter shown in Fig. 1,

[0092] Fig. 2C shows a detail of an embodiment of the balloon of the first catheter, Fig. 3 shows an embodiment of second catheter of a catheter system of the present invention, the second catheter being configured to slide in a lumen of the first catheter (as e.g. shown in Fig. 1) and to apply a filling material to the LAA,

[0093] Fig. 4 shows a further embodiment of the second catheter configured to mix the filling material with a curing agent,

[0094] Fig. 5 shows a further embodiment of the second catheter configured to cure the filling material by means of light (e.g. UV light),

[0095] Fig. 6 shows a second catheter being inserted in the first catheter of an embodiment of the catheter system according to the present invention,

[0096] Fig. 7 shows a further embodiment of the second catheter configured to deliver a first component of a two-component adhesive, a second component of the two-component adhesive and to evacuate the LAA,

[0097] Fig. 8 A shows a first catheter of a second embodiment of a catheter system according to the present invention, the first catheter comprising a balloon, which is illustrated in a deflated mode, for sealing the LAA at the ostium,

[0098] Fig. 8B shows a first catheter of the second embodiment of a catheter system according to the present invention, the inner shaft is moved proximally in comparison to the first catheter shown in Fig. 8 A,

[0099] Fig. 8C shows a first catheter of the second embodiment of a catheter system according to the present invention, the balloon is illustrated in an inflated mode,

[0100] Fig. 8D shows a first catheter of a third embodiment of a catheter system according to the present invention,

[0101] Fig. 9 A shows a first catheter of a fourth embodiment of a catheter system according to the present invention, the first catheter comprising a balloon, which is illustrated in a deflated mode, for sealing the LAA at the ostium, Fig. 9B shows a first catheter of the fourth embodiment of a catheter system according to the present invention, the inner shaft is moved proximally in comparison to the first catheter shown in Fig. 9 A, and

[0102] Fig. 9C shows a first catheter of the fourth embodiment of a catheter system according to the present invention, the balloon is illustrated in an inflated mode.

[0103] Fig. 1A shows in conjunction with Figs. 3 and 6 an embodiment of a catheter system 1 for closing the left atrial appendage 2, the system 1 comprises a first catheter 10 comprising a first catheter shaft 11 and a balloon 12 arranged on a distal section 1 la of the first catheter shaft 11. The balloon 12 is in flow connection with a first lumen 13 of the first catheter shaft 11 to inflate and deflate the balloon 12, wherein the balloon 12 is configured to seal the left atrial appendage 2 in an inflated state of the balloon 12 by contacting a circumferential boundary region, e.g., ostium 2a. Furthermore, the first catheter shaft 11 comprises a second lumen 14 comprising an opening 142 at a distal end 1 lb of the first catheter shaft 11. The system 1 further comprises a second catheter 20 comprising a second catheter shaft 21 comprising a first lumen 22 having a distal section 22a that can accommodate a filling material 30 (e.g. as specified above). An optional sealing mechanism 23 can be arranged at a distal end 22b of the first lumen 22 of the second catheter shaft 21 configured to prevent discharge of the filling material 30 in a closed state of the sealing mechanism 23 and to allow discharge of the filling material 30 in an open state of the sealing mechanism 23 (cf. Fig. 3), wherein the second catheter shaft 21 is configured to be inserted into the second lumen 14 of the first catheter shaft 11 and to slide therein towards the opening 142. However, instead of the sealing mechanism 23 a permanent opening can be provided at the distal end 22b of the second catheter shaft 21.

[0104] Particularly, in an embodiment, the first lumen 13 for the balloon inflation and deflation comprises a smaller cross-sectional area (cf. Fig. IB) than the second lumen 14 that serves for applying a vacuum to the LAA 2 and also to deliver the adhesive 30 via the second catheter 20. Alternatively, as also indicated in Fig. 1C, a third lumen 15 of the first catheter shaft 11 can be provided, wherein the second lumen 14 is solely used for delivering the second catheter 20 and the third lumen 15 is solely used for applying a vacuum to the LAA. In both cases, the vacuum serves for collapsing the LAA 2 and holding the inflated balloon 2 with its front side 2a against the ostium 2a of the LAA 2 thus sealing the LAA 2. Furthermore, a vacuum can be used to draw off a contrast agent fluid filled into the LAA for the purpose of checking a seal of the LAA 2 by the balloon 12 or for measuring a volume of the LAA 2. Herein, the notion “proximal” refers to a location on the respective catheter 10, 20 that is closer to a user operating the catheters 10, 20 (as seen along a longitudinal axis of the catheters 10, 20) than a “distal” location on the respective catheter 10, 20.

[0105] Particularly, the balloon 12 provided on the distal section 1 la of the first catheter 10 is a compliant, low-pressure balloon (e.g. made of thermoplastic polyurethane, such as Pellethane etc.) and is particularly welded onto the first catheter shaft 11 of the first catheter 10. One or more radiopaque markers can be provided at the balloon area of the first catheter 10 to enhance visibility and facilitate the correct placement at the LAA ostium 2a.

[0106] At a proximal portion of the first catheter shaft 11 of the first catheter 10, a connector 130 such as a standard Luer hub can be connected to the first lumen 13 for inflation and deflation of the balloon 12 (e.g. with a standard PTA inflation / deflation pump).

[0107] Additionally, at the proximal portion, a Y-connector 140, 141 comprising a membrane can be incorporated at the second lumen 14, like an introducer sheath. With this it is possible to pull a vacuum via a syringe via a first access / port 140 of the Y-connector while still being able to insert the second catheter 20 or a guide wire into the second lumen 14 via a second access / port 141 of the Y-connector, which second access / port 141 can be sealed by said membrane. With this safety feature, possible introduction of air during device insertion / exchange can be minimized.

[0108] Further, as indicated in Figs. 2A, 2B, the e.g. compliant balloon 12 may feature different geometries for improved sealing and stability purposes. Particularly, according to Fig. 2A, the balloon 12 can comprise a conical shape, having a flat or conical front side 12a adapted for sealing the LAA 2 at a circumferential boundary region of the LAA such as its ostium 2a. Alternatively, as shown in Fig. 2B, the balloon 12 can have essentially a cylindrical shape with a flat or conical front side 12a.

[0109] Furthermore, for achieving a flat or conical front side (or a comparable shape), the balloon 12 can comprise an inversed distal welding of the balloon neck 12b, ideally resulting in a flat front side 12a of the balloon 12. Particularly, this means that the rim portion, i.e., neck 12b, via which the balloon 12 is bonded / welded to the first catheter shaft 11 at the front side 12a is turned over into an interior space 12c of the balloon as indicated in Fig. 2C.

[0110] Furthermore, as shown in Fig. 1, a distal catheter tip 11c can comprise a predetermined breaking point 100 in case the tip 11c is bonded to the collapsed LAA 2. With this, the system can be withdrawn by leaving the tip 11c in the LAA 2. Preferably, as described herein, a distal portion of the first catheter shaft 11 of the first catheter 10 that extends from the front side 12a to the distal end 1 lb of the first catheter shaft is protruding only very little into the LAA 2 when the LAA is sealed by the front side 12a of the inflated balloon 12. This can be achieved welding the balloon 12 to the first catheter shaft 11 very close to its distal end 1 lb. The protruding part is atraumatic to not puncture or perforate the LAA 2.

[0111] As further indicated in Fig. 4 / 5, the second catheter 20 can contain one or multiple lumens, in which the filling material (e.g. adhesive(s) or glue(s)) can be pre-loaded, similar to a ready-to-use cartridge system, or in which the filling material can be injected by means of an additional device such as a syringe. On the distal side 22b the optional sealing mechanism (e.g. membrane) 23 can prevent the filling material to exit the second catheter 20 unintentionally and can also prevent premature curing of the filling material. Also here, instead of a sealing mechanism 23 multiple permanent openings may be used.

[0112] In a further embodiment one of the multiple lumens of the second catheter is used for a guidewire to manoeuvre the second catheter more distally into the LAA. This allows a more accurate and controllable movement of the second catheter into the LAA.

[0113] As alternative to the second catheter 20 shown in Fig. 3, the embodiments shown in Figs. 4 and 5 can also be used with the catheter system 1.

[0114] Particularly, in case of a filling material being a multi-component adhesive or glue, e.g. when the filling material 30 has to be mixed with a curing agent 31, a mixing device 24 such as a static mixer 24 can be provided at the distal ends 22a, 27a of the corresponding lumina 22, 27 for accommodating the respective component e.g. filling material 30 and curing agent 31 (cf. Fig. 4).

[0115] According to Fig. 5, the filling material 30 can be cured by impinging light onto it, particularly UV light. Here, the second catheter 20 can comprise a light source and / or a light guiding fiber 26 to direct light onto the filling material 30 discharged into the LAA 2.

[0116] Regarding Figs. 3 to 5, on the proximal side, the second catheter 20 can comprise a connector 200 such as a standard Luer hub for connection of a syringe. By applying pressure on this syringe, the adhesive(s) or glue(s) (and particularly curing agent 31) overcome the distal sealing mechanism 23 (e.g. membrane) and can be injected in a controlled manner into the LAA 2. Further, as indicated in Figs. 3 to 5, the second catheter 20 can comprise a drainage 25 (e.g. comprising a groove extending along the second catheter shaft 21 of the second catheter 20), which allows mass flow from the distal to the proximal part of the second lumen 14 (and vice versa) of the first catheter 10 for evacuation of the LAA 2, stable vacuum conditions and / or pressure equilibrium during movement of the second catheter 20 in the first catheter 10.

[0117] Fig. 7 shows a further embodiment of the second catheter 20 which is configured to deliver a first component 33 of a two-component adhesive via a first supply lumen 51, deliver a second component 34 of a two-component adhesive via a second supply lumen 52 and to evacuate the LAA 2 via a suction lumen 50. The suction lumen 50 is further configured to receive (part of) the two-component adhesive which is sucked inside the lumen 50 by evacuating the LAA 2 through the suction lumen 50 after filling the LAA 2 with the two-component adhesive, i.e., the first component 33 and the second component 34.

[0118] Figs. 8A - 8C show an alternative embodiment of a first catheter 10. The catheter 10 comprises an inner shaft 16 which is arranged within the second lumen 14 of the catheter shaft 11 so that the first lumen 13 for inflating and deflating the balloon 12 is annularly arranged around the inner shaft 16. The inner shaft 16 comprises a fourth lumen 160 which comprises an opening 162 at the distal end of the inner shaft 16. The second catheter 20 is arranged within or can be inserted into the fourth lumen 160 of the inner shaft 16.

[0119] A first end 19 of the balloon 12 is attached to the first catheter shaft 11 and a second end 18 of the balloon 12 is attached to the inner shaft 16. The first end 19 of the balloon 12 is attached to the first catheter shaft 11 so that the ballon 12 extends distally from the first catheter shaft 11. The second end 18 of the balloon 12 is attached to the inner shaft 16 so that the balloon 12 extends distally from the inner shaft 16. This leads to durable attachments of the balloon 12 to the inner shaft 16 which withstand multiple inflation / deflation cycles of the balloon 12.

[0120] The first catheter shaft 11 and the inner shaft 16 are relatively movable to each other along a longitudinal axis. Figs. 8A and 8B show two different positions of the inner shaft 16 with respect to the first catheter shaft 11 of a first catheter 10 with a ballon 12 in a deflated mode: In Fig. 8B, the inner shaft 16 is moved proximally compared to the inner shaft 16 illustrated in Fig. 8 A.

[0121] Fig. 8C shows the first catheter 10 of Figs. 8A and 8B with the balloon 12 in an inflated mode. By moving the inner shaft 16 in respect to the first catheter shaft 10, the shape and size of the balloon 12 in the inflated mode can be adjusted to a disc-, plate- or torus-like shape. The inflated balloon 12 may comprise a diameter D which is larger than the length L of the balloon 12 along the longitudinal axis. Such balloons 12 are highly suitable for sealing a vessel, respectively, the LAA 2.

[0122] Fig. 8D shows a further embodiment of a first catheter 10. The first catheter 10 of Fig. 8D corresponds to the first catheter 10 of Figs. 8A - 8C but further comprises a spacer 17. The spacer 17 is arranged within the fourth lumen 160. The spacer 17 comprises a fifth lumen 170 which comprises an opening 172 at the distal end of the spacer 17. The spacer 17 may be movable with respect to the inner shaft 16 along the longitudinal axis.

[0123] The fifth lumen 170 of the spacer 17 serves the technical purposes of the second lumen 14 of the first catheter shaft 10. That is, the second catheter 20 is arranged within the second lumen 14 of the first catheter shaft 11 or the second catheter 20 is configured to be inserted into the second lumen 14 of the first catheter shaft 10. The spacer 17 enables a better accessibility to the sealed vessel, i.e., the LAA 2, e.g., for the second catheter 20, the filling material or any other medical device or material which needs to be delivered behind the balloon 12 and into the sealed vessel or the sealed LAA 2.

[0124] Figs. 9A - 9C show an alternative embodiment of a first catheter 10. The first catheter 10 of Figs. 9A - 9C corresponds to the first catheter 10 of Figs. 8A - 8D except that the second end 18 of the balloon 12 is attached to the inner shaft 16 so that the balloon 12 extends proximally from the inner shaft 16. This leads to a better accessibility of the sealed vessel via the fourth lumen 16O.Particularly, the embodiments of the catheter system 1 described herein can be used as follows in a corresponding method for closing an LAA 2:

[0125] To avoid air embolism, all device exchanges may be performed under water in a small water bath.

[0126] The procedure can be prepared by placing a standard femoral access to the vena cava inferior and placing a standard transseptal access sheath to the left atrium. This preparation can be identical as for an implanted LAA occlusion device.

[0127] Further, the first catheter 10 can be rinsed with saline solution to avoid embolization of air and is then delivered to the LAA 2 using the transseptal access sheath.

[0128] Furthermore, transesophageal echocardiography (TEE) and x-ray angiography can be used to monitor proper positioning and placement of the first catheter 10. According to a first sealing option, the e.g. compliant balloon 12 is inflated to the desired diameter by applying low pressure (e.g. 0 bar to 5 bar). Then, the complete first catheter 10 is advanced to the LAA ostium 2a. Upon contact with the ostium 2a, a vacuum will be applied through the second lumen 14 (using e.g. a standard one-way syringe of sufficient volume), resulting in balloon sealing at the LAA ostium 2a. By further applying vacuum, the LAA 2 is brought to the collapsed state.

[0129] According to an alternative second sealing option, the first catheter 10 is advanced to the LAA ostium 2a, wherein its position can be confirmed by the radiopaque markers, angiography and TEE. When the proper landing zone at the LAA ostium 2a is confirmed, the e.g. compliant balloon 12 is inflated to the desired diameter by applying low pressure (e.g. 0 bar to 5 bar), thus sealing off the LAA 2. By applying vacuum through the vacuum port 140 (using e.g. a standard one-way syringe of sufficient volume), the LAA 2 is brought to the collapsed state. To confirm proper sealing and rinsing of the LAA 2, contrast agent fluid (particularly containing a contrast agent, a solvent not reacting with the filling material and potentially also thrombus-dissolving and / or inhibiting substances) can be injected through the second lumen 14 by using a standard one-way syringe. X-ray angiography can be used to confirm that no contrast agent is exiting the LAA 2. Vacuum will then be applied again to remove the contrast agent fluid from the LAA 2. By further applying vacuum, the LAA 2 is brought again to the collapsed state.

[0130] According to a first option, the second catheter 20 can be advanced over the second lumen 14 into the LAA 2. Alternatively, according to a second option, the second catheter 20 can already be inserted into the first catheter 10 outside the patient and the complete system 1 is introduced together into the patient.

[0131] Furthermore, using TEE and X-ray angiography, the sealing of the compliant balloon 12 and the collapsed condition of the LAA 2 can be confirmed once again. If necessary, vacuum is further applied and confirmed.

[0132] Then, the filling material 30 is injected in a controlled manner using e.g. a standard syringe at the injection port (first lumen 22) of the second catheter 20.

[0133] Particularly, filling material 30 is injected into first lumen 22 of the second catheter 20 such that a portion of the contrast agent fluid remains in a distal portion of the first lumen 22 and another portion of the contrast agent fluid is thereby pushed into the LAA 2. Thereafter, the LAA 2 is again evacuated (e.g. via the first catheter) to remove said another portion of the contrast agent fluid from the LAA 2. - 1 -

[0134] Then a specified portion of the filling material is injected from the first lumen 22 of the second catheter into the LAA 2 together with said portion of the contrast agent fluid still remaining in the distal portion of the first lumen 22 of the second catheter to seal off the LAA 2.

[0135] Upon successful filling material delivery and optional curing (dependent on the curing mechanism), which can be confirmed by TEE and X-ray angiography, the second catheter 20 is retracted, the vacuum is released and finally the blocking balloon 12 deflated.

[0136] Again, the successful closing of the collapsed LAA 2 can be confirmed by TEE and angiography.

[0137] Finally, the entire system is withdrawn.

[0138] Furthermore, particularly, the following filling materials 30, particularly adhesives or glues, can be used in the framework of the present invention. According to an embodiment of the invention, the filling material 30 preferably is a biocompatible and non-resorbable filling material 30, particularly adhesive or glue, particularly one of:

[0139] - a superglue based on n-alkyl-cyanoacrylate(s) which reacts with the residual moisture within the LAA 2.

[0140] - two- or more component adhesive (e.g. adhesive and curing agent), reacting in the LAA 2 upon mixing within the second catheter and / or LAA 2,

[0141] - a light absorbing adhesive being cured using light (e.g. UV) to cure the adhesive in the LAA 2.

[0142] According to an embodiment, the filling material (e.g. adhesive or glue) is radiopaque and / or visible in MRI (Magnetic Resonance Imaging), or a corresponding agent is added to the filling material to improve visibility under x-ray angiography and / or MRI. Particularly, the filling material is stable in form and non-resorbable to avoid re-opening of the LAA 2 and to avoid excessive inflammation due to the absorption processes.

[0143] In case of using a two-component adhesive for sealing the LAA, an alternative method may be applied which leaves less material within the human body and leads to less thrombus formation. This method corresponds to the above-described method, but instead of injecting the specified portion of the filling material from the first lumen 22 of the second catheter into the LAA 2, a portion of a first component and a portion of a second component of the two-component adhesive is injected into the LAA 2, wherein the sum of the portion of the first component and the portion of the second component of the two-component adhesive corresponds to the specified portion of the filling material in the above-described method.

[0144] The first component is injected into the LAA from a first supply lumen 51 of the second catheter 20. The second component is injected into the LAA from a second supply lumen 52 of the second catheter 20.

[0145] In a further step, the LAA 2 is evacuated through a suction lumen 50 of the second catheter 20. Thus, most of the first component and the second component of the two-component adhesive which has been injected into the LAA 2 is sucked into the suction lumen 51 while the LAA 2 collapses. The inner sidewalls of the LAA 2 remain wetted by the first component and the second component so that the LAA 2 becomes sealed by the collapsing event of the evacuation step.

[0146] Due to the present invention, the anatomy and morphology of the LAA is not a limiting factor anymore. Advantageously, no metallic implant is left behind. Particularly, the risk of any device thrombosis and peri-device leakage is avoided. Furthermore, the LAA is not stretched. Furthermore, less anticoagulation is necessary and the device does not need to be provided in different sizes. Particularly, a vacuum can be ensured during the complete procedure by the proximal sealing valve and the modular approach utilizing the two catheters.

Claims

Claims1. A catheter system (1) for closing the left atrial appendage (2), comprising:- a first catheter (10) comprising a first catheter shaft (11) and a balloon (12) arranged on a distal section (I la) of the first catheter shaft (11), the balloon (12) being connected to a first lumen (13) ofthe first catheter shaft (11) to inflate and deflate the balloon (12), wherein the balloon (12) is configured to seal the left atrial appendage (2) in an inflated state of the balloon (12), and wherein the first catheter shaft (11) comprises a second lumen (14) comprising an opening (142) at a distal end (1 lb) of the first catheter shaft (11), and- a second catheter (20) comprising a second catheter shaft (21) comprising at least one lumen (22) that is configured to accommodate a filling material (30), and to allow discharge of the filling material (30), wherein the second catheter (20) is arranged within the second lumen (14) of the first catheter shaft (11) or the second catheter (20) is configured to be inserted into the second lumen (14) of the first catheter shaft (11).

2. The catheter system according to claim 1, wherein the first catheter (10) is configured to apply a vacuum via the second lumen (14) to the left atrial appendage (2) for sealing the balloon (12) in the inflated state at the left atrial appendage (2) and / or for bringing the left atrial appendage (2) to a collapsed state.

3. The catheter system according to claim 1, wherein the first catheter (10) comprises a third lumen (15), wherein the first catheter (10) is configured to apply a vacuum via the third lumen (15) to the left atrial appendage (2) for sealing the balloon (12) in the inflated state at the left atrial appendage (2) and / or for bringing the left atrial appendage (2) to a collapsed state.

4. The catheter system according to one of the preceding claims, wherein a connector (130), particularly a Luer hub, is arranged on a proximal section of the first catheter (10), the connector (130) being configured to provide a flow connection to the first lumen (13) of the first catheter shaft (11) of the first catheter (10) for inflation and deflation of the balloon (12).

5. The catheter system according to claim 2 or according to claim 4 insofar referring to claim 2, wherein a Y-connector (140, 141) is provided on a proximal section of the first catheter shaft (11) of the first catheter (10), wherein the Y-connector provides a first and a separate second access (140, 141) to the second lumen (14) and is configured to allow applying a vacuum in the second lumen (14) via the first access (140) while allowing to insert the second cathetershaft (21) of the second catheter (20) into the second lumen (14) of the first catheter (10) via the second access (141).

6. The catheter system according to one of the preceding claims, wherein the balloon (12) comprises a front side (12a) for contacting a circumferential boundary region (2a) of the left atrial appendage (2) in an inflated state of the balloon (12), wherein in the inflated state the front side (12a) comprises one of: a flat shape, a conical shape, an oval shape, a spherical shape.

7. The catheter system according to one of the preceding claims, wherein the balloon (12) is bonded to the first catheter shaft (11) at the front side (12a) by a rim portion (12b) turned over into an interior space (12c) defined by the balloon (12).

8. The catheter system according to one of the preceding claims, wherein the balloon (12) comprises an outer surface portion having one of: a friction-enhancing surface structure on a contact surface with the left atrial appendage ostium (2a), a friction-reducing smooth surface portion on the front side of the balloon to prevent the filling material (30) from sticking to the balloon (12).

9. The catheter system according to one of the preceding claims, wherein the first catheter shaft (11) of the first catheter (10) comprises a distal catheter tip (11c), wherein the catheter tip (11c) comprises predetermined breaking point (100) to allow release of the catheter tip (11c) from the remaining first catheter shaft (11) in case the catheter tip (11c) is bonded to the collapsed left atrial appendage (2) by the filling material (30).

10. The catheter system according to one of the preceding claims, wherein a distal portion of the first catheter shaft (11) of the first catheter (10), which distal portion extends from the front side (12a) of the balloon (12) in the inflated state to the distal end (1 lb) of the first catheter shaft (11) of the first catheter (10) is smaller than 10 mm, preferably smaller than 5 mm, more preferably smaller than 2 mm.

11. The catheter system according to one of the preceding claims, wherein the first catheter shaft (11) of the first catheter (10) comprises on a proximal side of the balloon (12) a hole or valve, configured to connect the second lumen (14) of the first catheter shaft (11) with surrounding blood in the atrium, so that through this hole or valve blood can be sucked through the second lumen (14).

12. The catheter system according to one of the preceding claims, wherein the filling material (30) is accommodated in a distal portion of the at least one lumen of the second catheter shaft, or is injectable by a syringe storing the filling material into the at least one lumen of the second catheter shaft.

13. The catheter system according to one of the preceding claims, wherein the filling material (30) is curable by light or UV-radiation, and wherein the second catheter (20) is configured to direct light or UV-radiation onto the filling material (30).

14. The catheter system according to one of the preceding claims, wherein a sealing mechanism (23) is arranged at a distal end of the at least one lumen of the second catheter shaft configured to prevent discharge of the filling material (30) in a closed state of the sealing mechanism (23) and to allow discharge of the filling material (30) in an open state of the sealing mechanism (23), wherein particularly the sealing mechanism (23) is configured to be brought into an open state and let filling material (30) pass when a pressure exerted onto the filling material (30) exceeds a pre-defined threshold pressure.

15. The catheter system according to one of the preceding claims, wherein the second catheter (20) comprises a drainage (25), which allows mass flow from a distal portion (14a) to a proximal portion (14b) and vice versa of the second lumen (14) of the first catheter (10), particularly for evacuation of the LAA (2), stable vacuum conditions, and / or pressure equilibrium during movement of the second catheter shaft (21) of the second catheter (20) in the first catheter shaft (11) of the first catheter (10).

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