Catheter for implantation of an implant

Abstract

The disclosure refers to a catheter (1, 24) for implantation of an implant (3) having a body (14) and at least one wire loop (4,5) extending from the body, wherein the catheter compnses: • an elongated catheter shaft (7) having a first lumen and at least one second lumen extending in longitudinal direction of the catheter shaft; • a guide wire (9) extending within the first lumen; • a retaining element (6, 26, 70) being arranged at a distal end of the catheter shaft (7) having ° at least one groove (18, 19, 50) configured to guide and / or to clamp the at least one wire loop (4, 5) with regard to radial direction when the body (14) of the implant (3) is located at the retaining element (6, 26, 70); and at least one fixing wire (10, 11, 27), wherein each fixing wire is configured to extend within one second lumen, wherein in the proximity of the retaining element (6, 26, 70), the catheter shaft comprises a first opening (21, 29, 36, 37) and at least one second opening (21, 29, 36, 37), wherein each one of the first opening and the at least one second opening extends from the inside of the corresponding second lumen to the outer surface of the catheter shaft or of the retaining element and is adapted to guide the respective fixing wire (10, 11, 27) from the corresponding second lumen to the outside or back inside to allow the fixing wire to loop around the at least one wire loop (4, 5) of the implant thereby fixing the at least one wire loop at the catheter.

Description

[0001] Applicant: BIOTRONIK SE & Co. KG

[0002] Date: 25.09.2025

[0003] Our Reference: 23.124P-WO

[0004] CATHETER FOR IMPLANTATION OF AN IMPLANT

[0005] The disclosure relates to a catheter for implantation of an implant having a body and at least one wire loop extending from the body as well as a system comprising the catheter and the implant and an assembly method.

[0006] Implants, e.g. sensors for temporarily or permanently implanting into the cardiovascular system, e.g. for measuring local pressure, temperature, O2, flow measurement, etc., if applicable, with their own power supply and telemetry, have been of interest for some time for home monitoring of critically ill patients.

[0007] Such implants are usually introduced into a patient’s body using an implantation catheter. Such implantation catheters are well known. Different implantation catheters are available for different implants to be delivered. For example, document WO 2021 / 198111 Al discloses an implantation catheter comprising a first inner catheter shaft and a holding element being arranged at the distal end of the first catheter shaft and being configured for holding and releasing the implant. Further, the implantation catheter comprises at a distal end of a second catheter shaft a protective sleeve, wherein the protective sleeve is configured for receiving the implant. The implant is housed inside the protective sleeve and secured to the distal end of the inner catheter shaft by means of the holding element while being navigated through the patient’s body to the desired implantation site. The holding element of the implantation catheter comprises a shape memory element, particularly a pseudoelastic element. The releasing of the implant is carried out by changing the shape of the shape of memory and / or pseudoelastic element. This shape memory and / or pseudoelastic functionality is provided for a particularly precise actuation of the holding element. However, the known implantation catheter with the protective sleeve has quite large dimensions and is therefore not suitable for implants having larger battery packs. Within the frame of the application distal is to be understood as away from the health care practitioner (HCP) handling the catheter. Consequently, the proximal end of the end of the catheter would be close to the HCP.

[0008] Furthermore, in case of an implant having at least one wire loop such wire must be arranged in the way that there is no risk of injury to the patient’s vessel wall when pushed forward into the target vessel. In addition, certain elements of the implant such as pressure measurement membranes should be protected during implantation movements.

[0009] Accordingly, it is an object of the present invention to provide a catheter for implantation of an implant which has low dimensions, reduces the risk of injury to the vessel wall and provides protection to important features of the implant.

[0010] The above object is solved by catheter for implantation of an implant having the features of claim 1, by a system comprising the catheter and an implantable implant having the features of claim 12, and an assembly method for this system having the features of claim 15.

[0011] In particular, the object is solved by a catheter for implantation of an implant having a body and at least one wire loop extending from the body, wherein the catheter comprises:

[0012] • an elongated catheter shaft having a first lumen and at least one second lumen extending in longitudinal direction of the catheter shaft;

[0013] • a guide wire extending within the first lumen;

[0014] • a retaining element being arranged at a distal end of the catheter shaft having o at least one groove configured to guide and / or to clamp the at least one wire loop with regard to radial direction when the body of the implant is located within the compartment; and

[0015] • at least one fixing wire, wherein each fixing wire is configured to extend within one second lumen, wherein in the proximity of the retaining element, the catheter shaft comprises a first opening and at least one second opening, wherein each one of the first opening and the at least one second opening extends from the inside of the corresponding second lumen to the outer surface of the catheter shaft or of the

[0016] 23.124P-WO | 25.09.2025 retaining element and is adapted to guide the respective fixing wire from the corresponding second lumen to the outside or back inside to allow the fixing wire to loop around the at least one wire loop of the implant thereby fixing the at least one wire loop at the catheter.

[0017] As indicated above, the catheter has an elongated catheter shaft having a first lumen and at least one second lumen. For example, the elongated catheter shaft has two lumens or three lumens. The elongated catheter shaft extends in a longitudinal direction. Each one of the at least two lumens extends within the catheter shaft, for example generally parallel to the longitudinal direction. For example, the length of each lumen may correspond to the major part of the catheter shaft length.

[0018] The catheter further comprises a guide wire which is used to guide the catheter shaft to the target implantation site according to the well-known over-the-wire method. The guide wire extends within the first lumen from the proximal to the distal end of the catheter shaft. Accordingly, the inner diameter of the first lumen is slightly greater than the diameter of the guide wire so that the guide wire can easily be guided within the first lumen.

[0019] The retaining element is provided for accommodation and release of the implant. The body of the implant is arranged at the and partly into the retaining element. The retaining element may be configured to have a semi-open volume which capable of receiving the implant, and preferably which has the same or a bigger volume that the body of the implant. In another embodiment the retaining element has have a semi-open volume which capable of receiving the implant, and the volume is smaller than the volume of the implant body. The retaining element may be configured to increase the contact surface between the implant and the elongated catheter shaft. Without a retaining element the contact surface would be limited to a line of contact points at the round outer surface of the catheter. Consequently, to increase the contact surface, a retaining element would have a (tangential) dimension along the tangent at the contact point at the outer surface of the elongated catheter shaft. The axial dimension of the retaining element may be less, equal or preferably larger the longitudinal dimension of the corresponding implant. The tangential dimension (parallel to the diameter of the catheter) may be less, equals or preferably lager than the outer diameter of elongated

[0020] 23.124P-WO | 25.09.2025 catheter shaft. In an embodiment the retaining element may have a height (dimension along the radial direction of the elongated catheter shaft) of 0.7 to 1 mm, a width (dimension along the tangential direction of the elongated catheter shaft) of 3,5 to 4 mm, in particular 3,7 mm, and a length (dimension along the axial direction of the elongated catheter shaft) of 25 to 30mm, in particular 29 mm. The retaining element may be made of polyetheretherketone (PEEK) or thermoplastic polyurethane (TPU).

[0021] With advantage the retaining element also provides protection for the sensible sensor technology, in particular the blood pressure measurement sensor technology, during implantation and the delivery to the implantation site. Also, since the retaining element preferably is configured to receive and accommodate the implant unnecessary turbulations of blood during delivery are prevented and the thereby the risk for thrombosis. The retaining element in its preferable dimensions moreover helps to straighten the blood vessel at the delivery site and thereby prepares the blood vessel for an uncomplicated delivery.

[0022] In a most basic embodiment the retaining element may be a flat cuboid, preferably forming have a semi-open volume which capable of receiving the implant. The flat cuboid may comprise a rectangular surface facing away from the elongated catheter shaft. The flat cuboid may have a width (tangential dimension) corresponding to at least the width of the implant. The flat cuboid may have a length (longitudinal or axial dimension) of at least the length of the implant.

[0023] In one embodiment, the retaining element may include at least one window in a side wall. The window may provide direct access of the sensor technology to the blood stream during implant delivery. Such measurement option during delivery has the advantage that a calibration can be performed before delivery as well as measurement to evaluate the quality of the implantation spot. Moreover, it can be tested whether the device is functioning well before the implantation. Thereby, it can be excluded that a malfunctioning device is implanted.

[0024] The retaining element further provides at least one groove adapted to guide and / or clamp the at least one wire loop of the implant with regard to a radial direction during a first state,

[0025] 23.124P-WO | 25.09.2025 wherein the first state is the state prior to and during implantation of the implant into the patient’s body. In one embodiment, the at least one groove has such a dimension (i.e. the inner diameter) that two sections, of the wire loop may be accommodated within this groove. For example, the first end section and the second end section (the second end section is opposite the first end section of the wire loop) located close to the implant body may be located within this groove such that the whole loop is guided (and may be additionally or alternatively bent and / or clamped), for example, along the upper side (the side of the opening of the “U”) into the direction of the front side or back side of the retaining element and / or of the catheter shaft. This reduces the outer diameter of the whole system comprising the catheter and the implant and avoids injury to the vessel wall as the at least one wire loop of the implant is thereby tightly fixed / guided at the surface of the catheter shaft or retainer. The at least one groove may extend parallel to the longitudinal direction of the catheter shaft to guide the at least one wire loop to the proximal or distal end of the retaining element.

[0026] In one embodiment the retaining element may have a compartment to accommodate the body of the implant. In a basic embodiment the compartment may be a recess corresponding to the width and length of the body of the implant. The recess may have a depth (dimension along the radial direction of the elongated catheter shaft) of 0.1 to 2.8 mm, in particular 0.2 mm.

[0027] In one embodiment the retaining element may be U-shaped. The retaining element may have a compartment such that compartment walls are formed by the two opposite legs of the U of the retaining element and / or a ground surface may provide protection to the implant body, in particular to sensitive features of the body, such as a membrane. The inner surface of the U-shape of the retaining element may form the two sidewalls of the compartment located opposite to one another and the one ground surface of the compartment connecting the sidewalls, wherein the sidewalls and the ground surface extend into longitudinal direction so that the U develops perpendicular to the longitudinal direction. The U-shape of the retaining element may form an opening at one side (i.e. between the two legs of the U) so that the body of the implant may easily be accommodated with in the compartment and released from it. Basically U-shaped means that the shape of the retaining element in a cross section is generally similar / comparable to a U over at least 80 % of its length (in longitudinal

[0028] 23.124P-WO | 25.09.2025 direction), e.g. over at least 95 % of its length, but its outer surface shape and the shape of the compartment may be different from a simple U and may be adapted to the usage of the catheter. The inner shape of the compartment may be adapted to the outer shape of the implant body. In one embodiment, the outer surface of the retaining element may be formed substantially cylindrical or cuboid and may be fixed to the outer surface of the catheter shaft at its side opposite the U-shape, for example, by gluing, welding and / or form-fitting. Alternatively, the distal end of the catheter shaft and the retaining element projecting therefrom may be formed as a single piece.

[0029] In one embodiment, the retaining element comprises a first groove located at the distal end of the retaining element and a second groove located at the proximal end of the retaining element. This is advantageous if the implant comprises a first wire loop and a second wire loop at opposite ends of the implant body, i.e at the distal end and the proximal end, to ease fixing of the respective wire loop. In one embodiment, the cross section (i.e. the cross section perpendicular to the longitudinal direction) of the first groove and / or the second groove runs inclined to a sidewall of the compartment thereby providing a clamping of the respective wire loop.

[0030] The catheter further comprises at least one fixing wire which is configured to extend within one second lumen separately from the first lumen and the guide wire. Accordingly, the at least one fixing wire can be controlled separately from the guide wire. The fixing wire is configured to loop around the at least one wire loop of the implant thereby fixing the at least one wire loop at the catheter, i.e. at the catheter shaft or the retaining element. For that, the fixing wire is provided such that it extends within a first opening from the second lumen to the outside of the catheter and then through the second opening back into the second lumen. In particular, the first opening, the second opening and the second lumen are located such that looping the fixing wire around the at least one wire loop tensions / tightens it in the way that it fits tightly against the outer surface of the catheter shaft or retaining element over its entire length or a major part of its length. At the same time, due to the tension provided by the fixing wire, the implant body is securely fixed within the U-shaped compartment prior and during implantation. Accordingly, the at least one fixing wire functions as a fastener not only for the wire loop of the implant but also for its body. In one embodiment, the fixing

[0031] 23.124P-WO | 25.09.2025 wire may be at least partially removed from the catheter, for example at the implantation’s target site, so that it does not loop anymore around the at least one wire loop but releases it. This is possible since the at least one fixing wire is connected to a handle (e.g. a cap) located at the proximal end of the catheter that may be manipulated by the user (e.g. the health care practitioner - HCP). This means that, in one embodiment, the at least one fixing wire is configured to be pulled out from its corresponding second lumen thereby undoing the fixing of the at least one wire loop of the implant. In this state, the at least one wire loop extents within the patient’s vessel thereby fixing the implant within the vessel and automatically drives the body of the implant out of the U-shaped compartment. The inner diameter of each second lumen is adapted to the diameter of the fixing wire guided therein such that it is slightly greater than the diameter of the respective fixing wire.

[0032] In one embodiment the catheter further comprises at least one retaining wire which is configured to extend within one third lumen separately from the second lumen, the first lumen and the guide wire. Accordingly, the retaining wire can be controlled separately from the guide wire. The retaining wire may be configured to loop around at least a part of the retaining element thereby fixing the implant at the catheter, i.e. the retaining element. For that, the retaining wire is provided such that it extends within a third opening from the third lumen to the outside of the catheter and then through the fourth opening back into the third lumen. In particular, the third opening, the fourth opening and the third lumen are located such that looping the retaining wire around at least a part of the implant tensions / tightens it in the way that it fits tightly against the outer surface of the catheter shaft or retaining element over a part of its length. At the same time, due to the tension provided by the retaining wire, the implant body is securely fixed within the U-shaped compartment prior and during implantation and after pulling the at least one fixing wire. Accordingly, the retaining wire functions as a fastener for the implant body.

[0033] In one embodiment, the retaining wire may be at least partially removed from the catheter, for example at the implantation’s target site, so that it does not loop anymore around the implant but releases it. This is possible since the at least one retaining wire is connected to a handle (e.g. a cap) located at the proximal end of the catheter that may be manipulated by the user (e.g. the health care practitioner - HCP). This means that, in one embodiment, the

[0034] 23.124P-WO | 25.09.2025 at least one retaining wire is configured to be pulled out from its corresponding third lumen thereby undoing the fixing of the implant. In this state, the at least one wire loop extents within the patient’s vessel thereby fixing the implant within the vessel and the body of the implant is released out of the U-shaped compartmentThe inner diameter of each third lumen is adapted to the diameter of the retaining wire guided therein such that it is slightly greater than the diameter of the respective retaining wire.

[0035] In one embodiment, the compartment comprises a first stop surface at its proximal end and / or a second stop surface at its distal end of the compartment. The first stop surface and the second stop surface delimit the movement of the body of the implant within the compartment in longitudinal direction. The first stop surface and the second stop surface may be realized as walls of the compartment.

[0036] In one embodiment, the compartment extends parallel to the longitudinal direction of the catheter shaft, wherein the U-shape of the retaining element develops perpendicular to the longitudinal direction so that the volume of the system comprising the catheter and the implant is small, and / or the at least one fixing wire, the first opening and the at least one second opening are configured such that the at least one wire loop can be tightly fixed at the catheter shaft. The location of the first opening and the second opening are adapted to the dimensions of the wire loop to be fixed such that the wire loop lies tightly and completely closely within or at the surface of the catheter shaft or the retaining element.

[0037] In one embodiment, the U-shaped retaining element comprises a recess configured for accommodation of the catheter shaft, wherein the recess is either on the side of the retaining element that is opposite the compartment or formed directly below the compartment. In the first case, in which the recess for the catheter shaft is one the opposite side relative to the compartment, the ground surface of the compartment may be formed by the retaining element. In the second case, in which the recess for the catheter shaft is formed directly below the compartment, the ground surface of the compartment may be formed at least partially by the outer surface of the catheter shaft if it is accommodated within the corresponding recess of the retaining element. The catheter shaft and the retaining element may realize a form-fit connection using the recess.

[0038] 23.124P-WO | 25.09.2025 In one embodiment the retaining element may comprise a distal and / or proximal radiopaque marker.

[0039] In one embodiment, the catheter comprises an atraumatic tip at its furthest distal end. The atraumatic tip may have, for example, a rounded cone-shape.

[0040] In one embodiment, the retaining element comprises or consists of a biocompatible polymer , in particular PEEK (polyetheretherketone), TPU (thermoplastic polyurethane), and / or comprises atraumatic edges. The fixing wire may comprise or consist of stainless steel or NiTi-alloy, in particular Nitinol.

[0041] The catheter comprises the retaining element, which ensures that the at least one wire loop of the implant can be folded and held by the fixing wires in such a way that it does not protrude during advancement, posing a risk of injury to the inner vessel wall. Furthermore, the catheter according to the invention has very small dimensions required, for example, for insertion into the femoral vasculature through the smallest possible introducer sheath (e.g., 16 F sheath). The shaft of the catheter may have a diameter in the range of 1.3 mm to 2 mm (4 F to 6 F), allowing it to pass easily over the guidewire with a diameter in the range of 0.47 mm. In addition, the retaining element protects by sidewalls or embedding into the compartment sensitive implant features, for example a pressure sensing membrane of an implantable pressure sensor during insertion within and positioning in the patient’s vessel. Furthermore, the retaining element ensures that the implant detached from the catheter is correctly positioned within the target vessel, e.g. an implantable pressure sensor in such a way that two opposing membranes used for the blood pressure measurement lie freely in the blood flow and do not make contact with the wall.

[0042] The above object is further solved by a system comprising the above described catheter and an implant having a body and at least one wire loop extending from the body, wherein the body of the implant is accommodated within the compartment and wherein each of the at least one wire loop is guided by and / or clamped within one groove and fixed by at least one

[0043] 23.124P-WO | 25.09.2025 fixing wire. This system is assembled prior implantation of the implant into the patient’s body. The system has the above explained embodiments (for the implant) and advantages. It is referred to above explanation. The implant may be an implantable (miniature) pressure sensor, an implantable sensors configured for determining respiration, activity, posture, sleep apnoea and / or the concentration of an analyte at the implantation site, in particular the concentration of glucose, potassium and / or calcium, or the implant may be a cardiac monitor. The implant housing may comprise electrical circuitry, a processor, a data memory, a power supply and elements for transmitting and / or receiving data. The processor, data memory as well as elements for transmitting and / or receiving data may be electrically connected to the electrical circuitry.

[0044] In one embodiment, the system may further comprise a protection sleeve arranged around the implant. The protection sleeve may be cylindrical having an inner lumen dimensioned to enclose the compartment with the implant arranged in the compartment. The protection sleeve may protect the implant during transport, storage or during the preparation of the implantation. If the implant comprises sensible part where slight mechanical damages could influence the performance, e.g. a pressure sensitive membrane of an implantable pressure sensor, the protection sleeve would protect these sensible parts prior implantation.

[0045] Furthermore, the protection sleeve may be designed to ease the introduction of the system (the catheter with the implant arranged in the compartment) into an introducer sheath or guide catheter and therefor may protect sensible parts of the implant against mechanical pressure loads of the introducer’s valve. Typically, such implantation catheters are inserted into a blood vessel of the patient, e.g. the femoral vasculature, and advanced through the blood vessel until the implantation site is reached. Introducers or guide catheters are used to either allow an easy access to the blood vessel or guide the catheter through the blood vessel to the implantation site. The protection sleeve may comprise a tapered distal end and / or a smooth outer surface. Introducing the system comprising the protection sleeve enclosing the implant into an introducer or guide catheter is much easier due to the tapered distal end and / or the regular smooth surface as compared to the system without the protection sleeve

[0046] 23.124P-WO | 25.09.2025 where catheter with the irregular surface of the implant and the corresponding at least one wire loop needs to be inserted into the introducer or guide catheter. The protection sleeve may be made of thermoplastic polyurethane (TPU), perfluorethylene-propylene (FEP) or polytetrafluorethylene (PTFE). The protection sleeve may be one piece or at least two connected pieces, e.g. two connected half cylinders.

[0047] In one embodiment the protection sleeve may comprise a proximal stop. The proximal stop may be configured as cylinder having a lager diameter the the distal part of the protection sleeve. The diameter may be larger than the inner diameter of a potential introducer or guide catheter, e.g. above 5.33 mm - 6 mm (16-18 F).

[0048] In one embodiment of the system, the implant comprises a first wire loop and a second wire loop, wherein in the fixed state at the catheter the first wire loop is accommodated above the second wire loop in radial direction or the first wire loop and the second wire loop are accommodated one after the other in longitudinal direction. This embodiment describes the two possibilities of accommodation of the two fixed wire loops in the fixed state at the catheter, namely, they may overlappingly or separately accommodated. Additionally, the first wire loop end and the second wire loop end, wherein both ends are located at one end of the respective loop without any help that may be folded around the retaining element or project from the retaining element.

[0049] The above object is further solved by an assembly method for the above system comprising the following steps:

[0050] • Providing the catheter with the retaining element and providing the implant, e.g. the implantable pressure sensor,

[0051] • Threading the catheter shaft through the at least one wire loop,

[0052] • Inserting the body of the implant into the compartment and each one of the at least one wire loop into the corresponding groove and

[0053] • Fixing the at least one wire loop using the at least one fixing wire at the catheter shaft.

[0054] 23.124P-WO | 25.09.2025 The above assembly method is a simple and cost-saving assembly method. During fixing the at least one wire loop using the at least one fixing wire the fixing wire is advanced into distal direction within the catheter. Further, for fixing the at least one wire loop, the fixing wire is advanced along the respective second lumen, through the first opening and at the outer surface of the catheter shaft or the retaining element, over the first wire loop and / or the second wire loop (i.e. looping around the wire of the respective wire loop) and returned back to the respective second lumen through the second opening. In one embodiment, the advancing of the fixing wire is similarly repeated at least once through another pair of first and second openings to fix another wire loop.

[0055] If the system comprises a protection sleeve made of one piece, the protection sleeve may be arranged over the catheter prior the insertion of the body of the implant into the compartment. If the system comprises a protection sleeve made of at least two connected pieces, e.g. two connected half cylinders, the protection sleeve may be arranged around the implant after fixing the at least one wire loop using the at least one fixing wire at the catheter shaft.

[0056] For implantation, first, the guide wire is introduced into the target vessel of the patient. Then, the assembled system is (over-the-wire) introduced into the patient’s vessel using the guide wire so that the implant is located in the area of the target position. Afterwards, the at least one fixing wire is retracted at least partly such that the at least one wire loop is released. Thereby, the at least one wire loop unfolds and slides out of the respective groove of the retaining element. Immediately, the body of the implant is automatically slid out of the compartment driven by the unfolding of the at least one wire loop and thereby released from the catheter. Then, the catheter may be retracted over the guide wire and afterwards the guide wire may be removed from the patient’s vessel.

[0057] The present invention will now be described in further detail with reference to the accompanying schematic drawing, wherein

[0058] Fig. 1 shows a first embodiment of a catheter with an embodiment of an implantable implant in a perspective side view,

[0059] 23.124P-WO | 25.09.2025 Fig. 2 depicts the distal end of the catheter of Fig. 1 with the implant in a bottom view,

[0060] Fig. 3 illustrates the implant of Fig. 1 in perspective side view,

[0061] Fig. 4 shows the implant of Fig. 3 in a side view,

[0062] Fig. 5 depicts the implant of Fig. 3 in a front view,

[0063] Fig. 6 shows a distal end of the catheter of Fig. 1 and the implant of Fig. 3, each in a perspective side view during assembly of the system,

[0064] Fig. 7 shows the system of Fig. 6 after assembly in a top view,

[0065] Fig. 8 depicts the system of Fig. 6 after assembly in a bottom view,

[0066] Fig. 9 shows the system of Fig. 6 after assembly in a side view and a partial longitudinal section,

[0067] Fig. 10 illustrates a cross-section of the system of Fig. 6 within the patient’s vessel during implantation,

[0068] Fig. 11 shows the system of Fig. 6 in a cross-section similar to Fig. 10 within the patient’s vessel during release of the implant at a target site,

[0069] Fig. 12 depicts a cross-section of the implant at its target site after release from the system of Fig. 6 and a cross-section of the guide wire,

[0070] Fig. 13 shows a second embodiment of a catheter with the implant of Fig. 3 in a perspective side view,

[0071] 23.124P-WO | 25.09.2025 Fig. 14 depicts the distal end of the catheter of Fig. 13 with the implant in a perspective bottom view,

[0072] Fig. 15 depicts the retaining element of the catheter of Fig. 13 in a perspective bottom view,

[0073] Fig. 16 shows the assembly of a system comprising the catheter of Fig. 13 and the implant of Fig. 3 in a perspective side view,

[0074] Fig. 17 illustrates a longitudinal section of the system of the catheter of Fig. 13 and the implant of Fig. 3 after assembly, and

[0075] Fig. 18 depicts a front view and partial cross-section of the assembled system of Fig. 17 at the position A-A within a patient’s vessel.

[0076] Fig. 19 depicts a third embodiment of the catheter with the implant of Fig. 3 in a top view

[0077] Fig. 20 depicts a fourth embodiment of the catheter with the implant of Fig. 3 in top view

[0078] Fig. 21 depicts an embodiment of a protection sleeve

[0079] A first embodiment of a catheter 1 is explained in the following with reference to Fig. 1, 2 and 6 to 12. It is used to implant an implant 3 that is exemplarily represented by an implantable pressure sensor depicted in more detail in Fig. 3 to 5. However, the catheter may be used for implantation of other implants having a body and at least one wire loop, as well. The first embodiment realizes an embodiment where two overlapping wire loops are fixed at the retaining element, whereas the second embodiment, explained with respect to Fig. 13 to 18, illustrates the variant where the fixed wire loops do not overlap but are accommodated longitudinally one after the other.

[0080] 23.124P-WO | 25.09.2025 The catheter 1 of the first embodiment comprises an elongated catheter shaft 7 with a U- shaped retaining element 6 at its distal end. The outer surface of the retaining element 6 is generally cylindrical or elliptical. At the proximal end of the catheter shaft 7 a Y-connector 13 is provided. The catheter 1 may be advanced to the target position in the patient’s vessel 22 (see Fig. 12) using a guide wire 9 that has already been inserted into the target vessel 22. The catheter 1 is a 3-lumen shaft 7 and has a soft atraumatic tip 8 at its furthest distal end. The guide wire 9 extends within a first lumen of the catheter shaft 7. The retaining element 6 is firmly connected to the shaft 7 (see, e.g., Fig. 11).

[0081] Fig. 3 to 5 show the exemplary implant 3 in the form of a pressure sensor which may be implanted using the catheters 1, 24 explained herein. The implant 3 comprises a housing 14 and wire loops 4, 5 projecting from the distal end and proximal end of the housing 14, respectively. The implant housing 14 has the shape of an elongated cuboid. The housing 14 contains, for example, the electronic circuit including a processor for pressure measurement, for transmitting and receiving signals, and the batteries for power supply. The pressure measurement is carried out by means of at least one pressure sensitive membrane, in particular by means of two sensitive membrane 15, each of which is located at one larger lateral surface of the housing 14. The membranes 15 are provided at opposite lateral surfaces of the housing 14. The distal and proximal wire loops 4 and 5 are attached to the opposite end faces of the housing 14, respectively. Each wire loop 4, 5 which is shaped as closed three-dimensional curve in the unfolded state provides fixation of the implant 3 within the patient’s vessel and, at the same time, functions as an antenna. The fixation function is illustrated in Fig. 4 where, in a side view, the two unfolded wire loops 4 and 5 appear as an opposing pair of hooks to fix the implant axially in the vessel. Fig. 5 depicts the radial fixation of the implant 3 based on the property of the wire loops 4, 5 to form congruent circles pressing the implant body 14 radially with its underside against the vessel wall. The two membranes 15 at the lateral surfaces are thus in direct blood contact.

[0082] In the assembled state shown in Fig. 1, 2, and 7 to 9, the implant 3 with its wire loops 4,5 is inserted into a cuboid compartment 17 of the retaining element 6. As best seen in Fig. 6, the compartment 17 comprises and is formed by side walls 17a, a ground surface 17b and stop

[0083] 23.124P-WO | 25.09.2025 walls 17c. For fixation, the end sections of the wire loops 4, 5 are guided within grooves 18, 19, respectively, and bent around the retaining element 6 to the opposite side of the catheter shaft (see Fig. 7, 8 and 9). For fixation of the wire loops the catheter 1 further provides a first fixing wire 10 and a second fixing wire 11 guided by a second lumen, wherein first fixing wire 10 loops around the wire loop 5 and the second fixing wire 11 loops around the wire loop 4. As a result, the implant 3 is accommodated and held within the retaining element 6 and firmly attached to the catheter shaft 7. The fixing wires 10 and 11 may be guided in one common second lumen or in two separate second lumens of the catheter shaft 7. For fixation of the wire loops 4, 5 the fixing wires 10, 11 exit the catheter shaft 7 through a corresponding openings 21 and return back into the respective second catheter lumen through a corresponding openings 21 (see Fig. 8). Both fixing wires 10, 11 are firmly connected to the tension cap 12 at the proximal end. The tension cap 12 is screwed to the laterally protruding Luerlock connection of the Y-connector 13. The tension cap 12 is used to control the fixing wires 10, 11, i.e. pulling them at least partially out of the catheter 1 at their distal ends to release the implant 3 as explained in more detail below.

[0084] During assembly of the implant 3 and the catheter 1, first, both units are provided and turned such that they are aligned as shown in Fig. 6. Then, the tip 8 of the catheter 1 is threaded along the dashed line 20 through the two wire loops 4, 5. Afterwards, the implant housing 14 is inserted into the compartment 17 such that one lateral surface with membrane 15 is opposite the ground surface 17b of the compartment 17 and the other lateral surface with membrane 15 is located at the free upper surface of the device housing 17 (see Fig. 17). The longitudinal movement of the implant body 14 within the compartment 17 is limited by the stop surfaces 17c located at the distal and proximal ends.

[0085] Fig. 7 to 9 show the end position of the implant housing 14 within the compartment 17 of the retaining element 6. The distal end portions of the proximal wire loop 5 are guided through and clamped by a proximal groove 18 and the proximal end portions of the distal wire loop 4 are guided through and clamped by the distal groove 19 thereby fixing the implant body 14 as well as covering the wire loops 4, 5 laterally and guiding them in longitudinal direction. The clamping of the wire loops 4, 5 within the grooves 18, 19 is realized due to the tilted and slightly offset arrangement of the grooves 18, 19 with regard to

[0086] 23.124P-WO | 25.09.2025 the longitudinal axis of the retaining element 6 and the side walls 17a of the compartment 17 as depicted in Fig. 10. The proximal wire loop 5 is wrapped around the retaining element 6 and held in place by the second fixing wire 10. Similarly, the distal wire loop 4 is placed above wire loop 5 and looped by the first fixing wire 11 and thus held in place. The fixing wires 10, 11 exit and reenter through openings 21 within the catheter shaft 7 (see Fig. 8, 9).

[0087] Fig. 10 to 12 depicts the release of the implant 3 within the patient’s target vessel 22. During implantation, the implant housing 14 rests with a lateral side comprising the membrane 15 opposite the ground surface 17b centrally within the compartment 17, stabilized by the retaining element 6. The distal wire loop 4 visible in Fig. 10 is tightly bound to the shaft 7 by the fixing wire 11. The same applies to the proximal wire loop 5, which is not visible in Fig. 10, with the fixing wire 10. Both membranes 15 are thereby protected from compression by the wire loops 4, 5 and fixing wires 11, 10 as well as from the concave inner wall of the introducer sheath. Via the guide wire 9, the retaining element 6 with coupled implant 3 is introduced and exactly positioned axially and rotationally within the target vessel 22. Fig. 11 shows an intermediate state in which the fixing wires 10, 11 are pulled proximally from the retaining element 6 using the pull cap 12 thereby releasing wire loops 4, 5. Immediately, the wire loops 4, 5 of the implant 3 separate from the catheter shaft 7, pop out of the distal groove 19 and the proximal groove 18, respectively, and unfold. Thereby, the implant housing 14 is driven out of the compartment so that it separates from the retaining element 6 and rotates (see arrows 23) by 90° until it seats against the vessel wall 22, as shown in Fig. 12. The membranes 15 remain protected from mechanical contact and damage and are now in direct blood contact. After full unfolding of the wire loops, the catheter 1 may be removed over the guide wire 9. This state is shown in Fig. 12. Finally, the guide wire 9 (still present in Fig. 12) is removed.

[0088] Fig. 13 to 18 show a second embodiment of a catheter 24 which differs from the first embodiment in the design and operation of its retaining element 26. The elements of the catheter 24 which are referred to with identical reference numbers compared to the first embodiment (catheter 1), are identical or similar in construction and function. It is referred to above explanation with regard to these reference numbers.

[0089] 23.124P-WO | 25.09.2025 The retaining element 26 is best seen in Fig. 15 and 16, wherein Fig. 16 shows the retaining element when it is fixed to the distal end of the catheter shaft 7 of catheter 24 and Fig. 15 depicts the retaining element 26 without catheter 24.

[0090] Fig. 15 shows a perspective view of the retaining element 26 from below having a base section 28 and two side legs 34 encompassing a recess 30 for the catheter shaft 7 and an adjacent compartment 50 for the implant. The compartment 50 is formed by sidewalls 33 and a base surface comprising a support surface section 38 of protrusions and an outer surface of the catheter shaft 7 (see Fig. 18). At the apex of the recess 30 the retaining element

[0091] 26 comprises a distal groove 31 and a proximal groove 32 for guiding a single fixing wire

[0092] 27 as indicated in Fig. 17. The base section 28 of the retaining element 26 comprises a cutout 29 for the exit and entry of the fixing wire 27 (see Fig. 17) to loop around and fixing of the wire loops 4 and 5. The wire loops 4 and 5 are guided via the compartment 50 forming a groove at its distal / proximal ends and along sidewalls 33 to the cutout 29.

[0093] During assembly, the implant 3 is inserted into the retaining element 26, wherein the catheter is threaded into the wire loops 4, 5 of the implant 3. The fixing wire 27 is looped around both wire loops 4 and 5, securing the implant 3 in the retaining element 26 and thus to the shaft 7. The fixing wire 27 may be guided in a second lumen of the shaft 7 separate from the first lumen for the guide wire 9. It exits and re-enters the shaft 7 at respective openings 36, 37 and is guided to the cutout 29 along grooves 31, 32 (see Fig. 17). The fixing wire 27 is firmly connected to the tension cap 12. The tension cap 12 is screwed to the Luerlock connection of the Y-connector 13. Similar to the first embodiment, the tension cap 12 is used to remove the fixing wire 27.

[0094] As one can derive from Fig. 16, the implant housing 14 is inserted into the compartment 50 of the retaining element 26 of catheter 24 such that its side legs 34 protect the large lateral surfaces of the housing 14 with the membranes 15 until the implant 3 is released. The compartment 50 of the retaining element 26 may comprise at least one window 53 which is preferably located where implant three has the membranes 15. With the window 53 and membranes 15 brought in line measurements and calibrations can be performed during the delivery procedure. Further, the wire loops 4, 5 are guided by the side legs 34 of the retaining

[0095] 23.124P-WO | 25.09.2025 element 26 to the proximal and distal end of the retaining element 26, respectively, so that they are firmly fixed to the retaining element 26 and the catheter shaft 7 after fixing with the fixing wire 27. Accordingly, the end sections of the compartment 50 forms a groove for the wire loops 4, 5

[0096] Fig. 18 shows the half-section view A-A of the retaining element 26 with the implant 3 attached from Fig. 17. The implant housing 14 is pressed against the support surface section

[0097] 38 of the retaining element 26 and the outer surface of catheter shaft 7 via the wire loops 4, 5, positioning it directly on the shaft 7. The side legs 34 protect the membranes 15 (not visible here) of the implant 3 and ensure the correct orientation of the implant 3 after the fixing wire 27 is pulled out, in which case the wire loops 4 and 5 spring upwards (see arrow

[0098] 39 in Fig. 18) until they reach the vessel wall 22. Almost simultaneously, the implant housing 14 is pushed downward away from the retaining element 26 (see arrow 40 in Fig. 18) until the implant housing 14 reaches the opposite vessel wall 22. The membrane 15 remains protected from mechanical contact and damage and gets into direct blood contact after release. After that, the catheter 24 is pulled out over the guide wire 9 and then the guide wire 9 is removed.

[0099] In the following, the materials of the system components are explained. The thin-walled implant housing 14 of the implant 3 may have, for example, dimensions of 2.8 mm x 3.5mm x 25 mm and be consist of titanium alloy. Membranes 15 consisting of a titanium diaphragm may be located on the two large surfaces (e.g., 3.5 mm x 25 mm in this case) of the housing 14 to allow transmission of blood pressure to the processor inside the implant housing 14. Distal and proximal wire loops 4 and 5 of NiTi alloy, 0.2 mm to 0.3 mm in diameter, serve to secure and align the implant 3 and thus its membrane 15 at the patient’ s vessel as explained above. These can be prepared using the shape memory effect into a variety of three- dimensional curve shapes, which are adapted to the target vessel diameter. For pulmonary artery branches, for example, these measure 7 mm to 11 mm. The catheter shaft 7 may be two- to three-lumen catheter, may comprise a diameter of 1.3 -2mm (4 F to 6 F), and a length of 1000 mm to 1200 mm. The guide wire 9 should be a 0.47mm ( 0.018 inch) stiff wire. With these dimensions, the use of a 16 F introducer is possible. The flat, top-mounted membrane 15 does not come into contact with the inner wall of the airlock and so that

[0100] 23.124P-WO | 25.09.2025 damaging is avoided. In the second embodiment (catheter 24), both membranes 15 are directly covered by the retaining element 26. However, at the cost of a larger insertion sheath (6 mm - 6.66 mm or (18 F - 20 F), since the implant housing 14 is rotated 90° with the narrow side on the shaft 7. With regard to the catheters 1 and 24, the guide wire 9 completely controls the bending of the catheter shaft 7, but at the same time the catheter shaft 7 is easily controllable in the direction of rotation and feed and has little elasticity. Thus, by means of the guide wire 9, the respective retaining element 6, 26 and implant 3 can be easily moved and correctly positioned axially and rotationally. The retaining element 6, 26 may consist of a biocompatible polymer (PEEK (polyetheretherketone), TPU (thermoplastic polyurethane) that can be well bonded or welded to the material of the shaft 7. The system comprising the retaining element 6, 26 and the implant 3 is atraumatic due to the rounded edges and closed fixation and fixing wire interlacing. Fixing wires 10, 11, 27 may be made of NiTi alloy and be 0.2 mm to 0.3 mm in diameter. They are adapted to be slidable in the respective second lumen of catheter shaft 7 in such a way that compression of the catheter shaft 7 and thus displacement of the set-down position of the implant 3 cannot occur during pulling on the pull cap 12.

[0101] Fig. 19 shows a third embodiment of the catheter as shown based on the first embodiment as explained in the previous sections with reference to Fig. 1, 2 and 6 to 12. Same parts are labelled with the same reference numbers. In addition to the embodiment shown in Fig. 1, 2 and 6 to 12, the embodiment according to Fig. 19 comprises two retaining wires 50 and 51. The retaining wires are independent from the fixing wires 10 and 11 (not shown in Fig. 19). Pulling the fixing wires 10 and 11 releases the wire loops 4 and 5 into the unfolded configuration. Due to the retaining wires 50 and 51 the implant is still connected to the retaining element 6 although the wire loops 4 and 5 are unfolded against the vessel wall 22. This would give the HCP the opportunity to check the position of the implant in the configuration where the wire loops are unfolded again. Due to the maintained connection between the implant 3 and the retaining element 6 the catheter could be (at least slightly) repositioned to ensure an ideal positioning of the wire loops and therefore, to minimize risk of migration of the implant.

[0102] 23.124P-WO | 25.09.2025 Fig. 20 shows a fourth embodiment of the catheter as shown based on the first embodiment as explained in the previous sections with reference to Fig. 1, 2 and 6 to 12. According to the fourth embodiment the implant 3 is still maintained within the retaining element 6 due to the retaining wire 52 which is fastened along the catheter axis over the implant 3 and the retaining element 6. The wire loops are fixed to the retaining element 6 and the catheter shaft 7 as explained in the first embodiment. Pulling the fixing wires 10 and 11 (not shownin Fig. 20) releases the wire loops 4 and 5 into the unfolded configuration. Due to the retaining wire 52 the implant is still connected to the retaining element 6 although the wire loops 4 and 5 are unfolded against the vessel wall 22. This would give the HCP the opportunity to check the position of the implant in the configuration where the wire loops are unfolded again. Due to the maintained connection between the implant 3 and the retaining element 6 the catheter could be (at least slightly) repositioned to ensure an ideal positioning of the wire loops and therefore, to minimize risk of migration of the implant.

[0103] Fig. 21 shows a schematic drawing of the catheter 1 with the elongated catheter shaft 7 and another embodiment of the retaining element 70. In this embodiment the retaining element 70 is a flat cuboid with a depression to hold the implant. Furthermore an embodiment of the protection sleeve 60 is shown having a proximal stop 62. The protection sleeve 60 has a basical cylindrical shape and is made of one piece. The proximal stop 62 has a larger diameter than the distal part 61 of the protection sleeve to fulfil the stop function when the catheter 1 with the implant (not shown) within the protection sleeve 60 is introduced into an introducer or a guide catheter (not shown).

[0104] An example of a method for implanting implant 3 (implantable pressure sensor) into the pulmonary artery is provided having the following steps in the indicated order: a. Access through the femoral vein using the Seidinger technique is created. b. Guide wire is inserted into the right atrium. c. Puncture is dilated and large introducer sheath with hemostasis valve is inserted. d. Guide wire is removed. e. A float balloon catheter through tricuspid valve, right ventricle, pulmonary valve is floated into one of the pulmonary artery branches.

[0105] 23.124P-WO | 25.09.2025 f. Guide wire 9 is placed over precoat balloon catheter. g. Contrast agent is applied to visualize the target vessel. h. The precoat balloon catheter is exchanged for pulmonary wedge pressure (PWP) balloon catheter and first calibration measurements are performed. i. PWP balloon catheter is pulled out. k. One of the catheters 1, 24 comprising the implant 3 within its retaining element 6, 26 is inserted into introducer sheath and over the guide wire 9 to the target vessel, always rotating the catheter 1, 24 so that the folded fixing wires 4, 5 can slide over the convex inner arcs of the vessel walls. l. The implant 3 is released as explained above at the target site within the vessel 22, the fixing wire(s) 10, 11, 27 are retracted by approximately 5 cm therefor. m. The catheter 1, 24 is then slowly withdrawn over the guide wire 9 through the unfolded fixing wires 4, 5 of the implant 3. n. "Pulmonary Wedge Pressure, PWP" balloon catheter is replaced and performs further calibration measurements for the implant 2. o. After final check, the guide wire 9 is removed.

[0106] The following advantages of the invention can be summarized:

[0107] A. The retaining element may easily be adapted to the implant design.

[0108] B. Sensitive functional element of the implant is protected.

[0109] C. The retaining element provides atraumatic enclosure of the implant during implantation.

[0110] D. Usage of the catheter is easy and safe (regarding positioning and release).

[0111] E. Due to stiffer guidewire may be used, a safer targeting is possible.

[0112] F. It is possible to use a 16 F sheath.

[0113] G. Catheter design is inexpensive and allows easier manufacturing.

[0114] H. The implantation methods may be adapted to the ones already practiced by the user.

[0115] 23.124P-WO | 25.09.2025

Claims

- 23 -Claims1. A catheter (1, 24) for implantation of an implant (3) having a body (14) and at least one wire loop (4,5) extending from the body, wherein the catheter comprises:• an elongated catheter shaft (7) having a first lumen and at least one second lumen extending in longitudinal direction of the catheter shaft;• a guide wire (9) extending within the first lumen;• a retaining element (6, 26, 70) being arranged at a distal end of the catheter shaft (7) having o at least one groove (18, 19, 50) configured to guide and / or to clamp the at least one wire loop (4, 5) with regard to radial direction when the body (14) of the implant (3) is located at the retaining element (6, 26, 70); and• at least one fixing wire (10, 11, 27), wherein each fixing wire is configured to extend within one second lumen, wherein in the proximity of the retaining element (6, 26, 70), the catheter shaft comprises a first opening (21, 29, 36, 37) and at least one second opening (21, 29, 36, 37), wherein each one of the first opening and the at least one second opening extends from the inside of the corresponding second lumen to the outer surface of the catheter shaft or of the retaining element and is adapted to guide the respective fixing wire (10, 11, 27) from the corresponding second lumen to the outside or back inside to allow the fixing wire to loop around the at least one wire loop (4, 5) of the implant thereby fixing the at least one wire loop at the catheter.

2. The catheter of claim 1, wherein the retaining element (6, 26, 70) is having a compartment (17, 50) configured to hold the body (14) of the implant during implantation and to release it at its target position.

3. The catheter of claim 1 or 2, where the retaining element (6, 26, 70) is U-shaped or flat cuboid.

4. The catheter of any one of the previous claims, wherein the retaining element comprises a first groove (19, 50) located at the distal end of the retaining element (6,23.124P-WO | 25.09.202526) and a second groove (18, 50) located at the proximal end of the retaining element (6, 26), wherein, for example, the cross section of the first groove (19) and / or the second groove (18) runs inclined to a sidewall (17a) of the compartment (17).

5. The catheter of any of claims 2 to 4, wherein the compartment (17) comprises a first stop surface (17c) at its proximal end and / or a second stop surface (17c) at its distal end.

6. The catheter of any one of claims 2 to 5, wherein the compartment (17, 50) extends parallel to the longitudinal direction of the catheter shaft (7) and / or wherein the at least one fixing wire (10, 11, 27), the first opening (21, 29, 36, 37) and the at least one second opening (21, 29, 36, 37) are configured such that the at least one wire loop (4, 5) can be tightly fixed at the catheter shaft (7).

7. The catheter of any one of the previous claims, wherein the at least one fixing wire (10, 11, 27) is configured to be pulled out from its corresponding second lumen thereby undoing the fixing of the at least one wire loop (4, 5) of the implant.

8. The catheter of one of the previous claims 5, wherein the catheter comprises at least one retaining wire (50, 51, 52) which is configured to extend within one third lumen separately from the second lumen, the first lumen and the guide wire.

9. The catheter of claim 8, wherein the retaining wire (50, 51, 52) is configured to loop around at least a part of the retaining element thereby fixing the implant body at the catheter, in particular at the retaining element.

10. The catheter of any one of claims 3 to 9, wherein the U-shaped retaining element (26) comprises a recess (30) configured for accommodation of the catheter shaft (7), wherein the recess is either on the side of the retaining element that is opposite the compartment or formed directly below the compartment (50).23.124P-WO | 25.09.202511. The catheter of any one of the previous claims, wherein the retaining element (6, 26) comprises or consists of a biocompatible polymer and / or comprises atraumatic edges.

12. A system comprising the catheter of any one of the previous claims and an implantable implant (3) having a body (14) and at least one wire loop (4, 5) extending from the body (14), wherein the body of the implant is accommodated within the compartment (17, 50) and wherein each of the at least one wire loop (4, 5) is guided by and / or clamped within one groove and fixed by at least one fixing wire (10, 11, 27).

13. The system of claim 12, wherein the implant (3) comprises a first wire loop (4) and a second wire loop (5), wherein in the fixed state the first wire loop (4) is accommodated above the second wire loop (5) in radial direction or the first wire loop (4) and the second wire loop (5) are accommodated one after the other in longitudinal direction.

14. The system of claim 12 or 13, wherein a protection sleeve (60) is arranged around the implant (3).

15. An assembly method for the system of claim 12 or 13 comprising the following steps:• Providing the catheter (1, 24) with the retaining element (6, 26) and providing the implantable implant (3),• Threading the catheter shaft (7) through the at least one wire loop (4, 5),• Inserting the body (14) of the implant (3) into the compartment (17, 50) and each one of the at least one wire loop (4, 5) into the corresponding groove (18, 19, 50) and• Fixing the at least one wire loop (4, 5) using the at least one fixing wire at the catheter shaft (7).23.124P-WO | 25.09.2025

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