Patent Application
20240000569
The present invention is directed towards minimally invasive fixation devices for fixating a feltable textile, sets comprising a fixation device and methods for fixating a feltable textile at a target site in a patient.
Although there has been significant progress in the treatment of cardiovascular diseases, globally they constitute the leading cause of deaths, according to the World Health Organization (WHO). 50% of the population in first world countries die of cardiovascular diseases, but alongside economic growth, the prevalence in developing countries is rising, too. Consequently, an increasing number of people are in need of an invasive cardiovascular intervention every year.
Neonates with a ventricular septal defect (VSD) are born with a hole in the wall of the heart (septum) that separates the two lower chambers (ventricles). VSD is the most common heart defect and occurs when an infant's septum does not fully develop during pregnancy. The exact cause is unknown. A recent study by the Centers for Disease Control and Prevention in Atlanta estimated that 42 of every 10,000 infants are born with a VSD.
In a healthy human heart, the right side of the heart pumps blood to the lungs where the blood picks up oxygen and the left side of the heart then pumps the oxygen-rich blood to the rest of the body. In babies with VSD, blood that should be on the left side of the heart leaks into the right side. Hence, all of that extra blood gets pumped back into the lungs. This forces the heart and lungs to work harder, which can increase the infant's risk for other medical problems. Typically, VSD is treated by closing the hole with an implant. In some techniques, VSD is treated using open-heart surgery.
In general, open-heart surgery usually requires an incision along the sternum (median sternotomy), followed by cardiopulmonary bypass and the temporary arrest of the heart of the patient (cardioplegia), so that the operation can be done in a still environment without blood flowing. Such highly invasive techniques are not suitable for patients considered high risk due to their age, fragility or medical condition, as they involve a long recovery period and risks of trauma and infection. Therefore, in the past decade, many less invasive procedures for a variety of cardiovascular indications were developed, where the heart is accessed via a catheter through blood vessels (catheter-based cardiac surgery) or through very small incisions in the chest (minimally invasive cardiac surgery, MICS). These techniques are recently being expanded to also treat intermediate and low risk patients.
Many interventions depend on some kind of implant, e.g. heart valve replacements, annuloplasty rings, vascular grafts or septum defect repairs. Often, they are sutured to the human tissue to fix them into place, which must be done in a very careful manner by a well-trained surgeon in order to get the desired outcome. Placing the sutures adequately makes up a significant proportion of the operation time and the execution can sometimes be challenging or even impossible. Additionally, sutures can cut through, open up or loosen, or knot slippage may occur. Further, sutures have the disadvantage of a high application of stress concentrated where they are placed.
One example of an attachment mechanism is disclosed in EP 3 132 811 A1. EP 3 132 811 A1 discloses a staple cartridge for stapling tissue. However, stapling has the disadvantage that relatively high forces are applied and tissues are damaged. Further, a distribution of the attachment force is concentrated around the staple leading to undesirable force transmission.
WO 95/32756 discloses a catheter for retrograde perfusion of the heart through the coronary sinus. The catheter includes an inflatable balloon with retention means. The inflatable balloon includes spikes, a felt or a coating on the surface of the balloon as retention means that keep the balloon firmly in space. Though this document discloses a balloon as retention means, the retention is lost as soon as the balloon is deflated.
WO 2016/044762 A1 describes apparatus and methods for fabricating tubular structures from a combination of fibrous materials for use in tissue engineering scaffold applications. The fiber scaffolds may include a nonwoven felt that is attached to a further nonwoven felt with an attachment device including a plurality of needles. Thereby, the fibers of the felts are entangled with each other.
A problem addressed by embodiments of the present invention is providing devices and methods for attaching implants to a target site within the body in a minimally invasive fashion. In particular, disclosed embodiments of the invention help to attach implants (e.g. cardiovascular implants) to the tissue in a strong and durable fashion, while also simplifying the surgical procedure and therefore saving critical time, which would allow for a safer and more efficient intervention. Optionally, embodiments of the present invention address attaching the implant in a uniform manner allowing a uniform stress distribution of forces that are transmitted from and to the implant at the target site.
According to disclosed embodiments of the invention benefits are achieved with minimally invasive fixation devices for fixating a feltable textile, sets comprising a fixation device and a method for fixating a feltable textile at a target site in a human or animal according to the independent claims. Optional embodiments are described in the dependent claims.
In one aspect, it is suggested to provide a minimally invasive fixation device for fixating a feltable textile at a target site. The feltable material is fixated at a target site in a human or in an animal. Preferable the target site comprises soft tissue. The fixation device comprises an elongate tubular member, a needle and a drive assembly. The elongate tubular member has a proximal end and a distal end and an interior lumen extending between the proximal end and the distal end. The elongate tubular member may be at least partially flexible. Preferably, the elongate tubular member is flexible over its entire length.
A textile as mentioned herein may be understood as a material made of fibers, filaments, or yarn. Flexible as mentioned herein may be understood in that the elongate tubular member may be bent, in particular while navigating a twisting path of a hollow organ (e.g. a blood vessel) and/or is capable of being brought into a bent shape. Elongate as mentioned herein might be understood to mean that the tubular member has a longer length than width (e.g. diameter). Preferably the elongate tubular member is flexible over its entire length. Alternatively, the elongate tubular member may have one or more flexible section(s). In some embodiments “elongate” may be understood as the tubular member having a length which is at least 5 times the width. The interior lumen may include a distal opening and a proximal opening.
The needle assembly comprises at least one felting needle, which is arranged or arrangeable at the distal end of the elongate tubular member. The at least one felting needle is movable relatively to the elongate tubular member, wherein the at least one felting needle is movable with a reciprocal motion. Reciprocal as mentioned herein may be understood as a back and forth motion, in particular a linear or circular back and forth motion. The needle assembly may comprise 2, 3, 4, 5, 6, 7, 8, 10 or more needles.
The more felting needles the needle assembly comprises, the less reciprocal motions need to be made for a sufficiently strong attachment between the feltable textile and the target site.
The needle assembly can felt the feltable textile with fibers of the body by interweaving animal or human soft tissue fibers with fibers of the textile by pushing fibers from one into the other. If this is done repeatedly, a strong mechanical connection is achieved. The needle, its shape and the mechanism are explained in detail in the application PCT/CH2019/000015 by the applicant ZuriMED Technologies AG.
The drive assembly is arranged in the interior lumen of the tubular member and operably connected to the needle assembly for moving the at least one felting needle with the reciprocal motion when the at least one needle is located at the distal end such that the feltable textile can be fixated at the target site. The drive assembly may be fixedly attached to the elongate tubular member or movable relatively to the elongate tubular member. For example, the drive assembly may comprise a wire that extends through the lumen of the elongate tubular member. In some embodiments the drive assembly is arranged fully within the interior lumen while in other embodiments only parts of the drive assembly are arranged in the inner lumen.
Additionally, the fixation device may comprise an actuator or motor for actuating the drive assembly. The actuator may be an electrical, mechanical, hydraulic and/or pneumatic motor. The at least one felting needle may be driven by a pneumatic or hydraulic or electromagnetic actuator or motor. The actuators maybe arranged within or outside of the elongate tubular member. The actuators may be arranged or are arrangeable at a distal end or operable connected to a distal end of the drive assembly. The actuator may by be arranged in a proximal or distal part of the fixation device, in some embodiments the actuator may be arranged in a distal portion of the fixation device, such that the reciprocal motion does not need to be transferred from the proximal end of the elongate tubular member to the at least one felting needle.
The fixation device provides a minimal invasive device and allows a deployment, positioning and fixing a feltable textile onto human or animal tissue. This device provides a reliable fixation while at the same time minimizing navigation and multi degrees of freedom problems which can occur when suturing in locations which are difficult to reach.
The elongate tubular member may have a diameter in the range of 2 Fr to 30 Fr, more specifically 4 Fr to 26 Fr, more specifically 12 to 22 Fr. These ranges correspond to suitable sizes for an atrial or venous access towards the heart.
As used herein the terms proximal and distal are defined from the perspective of a user of the percutaneous fixation device, in particular from the perspective of a medical professional such as a surgeon using the device.
The feltable textile may comprise or consist of absorbable fibers, particularly polyglycolic acid, polylactic acid, polydioxanone, or caprolactone. As mentioned herein, the term absorbable may relate to materials which are degraded after implantation in a human or animal body.
In some embodiments, the feltable textile comprises or consists of non-absorbable fibers, particularly silk, polypropylene, polyester or polyamide. As mentioned herein, the term non-absorbable relates to materials which are not degraded after implantation in a human or animal body.
In some embodiments, the feltable textile comprises or consists of a combination of absorbable fibers, particularly polyglycolic acid, polylactic acid, polydioxanone, or caprolactone and non-absorbable fibers, particularly silk, polypropylene, polyester or polyamide.
In certain embodiments, the fibers of the feltable textile comprise or consist of a biocompatible polymer, particularly polyethylene (PE, CAS No. 9002-88-4) polytetrafluorethylene (PTFE, CAS No. 9002-84-0), polyethylene terephthalate (PET, CAS No. 25038-59-9), poly(glycolide) (PGA, CAS No. 26124-68-5), poly(lactic-co-glycolic acid) (PLGA, CAS No. 26780-50-7), poly (L-lactic acid) (PLLA, CAS No. 33135-50-1), polycaprolactone (PCL, CAS No. 24980-41-4), 1,2-propanediol (PDO, CAS 57-55-6) or 1,3-propanediol (PDO, CAS No. 504-63-2).
In certain embodiments, the feltable textile could also be made of decellularized collagen tissue from human or animal origin.
In a preferred embodiment, the drive assembly is adapted to drive the reciprocal motion at a predetermined frequency. The frequency is preferably in a range from 1 Hz 1 kHz. The range is further preferred from 5 Hz to 500 Hz, from 10 Hz to 250 Hz and 50 Hz or 200 Hz and most preferably from 20 to 120 Hz. At these frequencies the felting needle can be moved without tearing single filaments of the material while at the same time providing a sufficient amplitude. At the same time, the feltable material can be attached quickly to the target site.
In a preferred embodiment the drive assembly is adapted to drive the reciprocal motion with an amplitude of 2 to 25 mm, particularly preferred 5 to 20 mm, further preferred from 6 to 16 mm most preferred from 8 to 12 mm. These amplitudes cover a sufficient thickness of feltable textile while penetrating the target soft tissue at the same time and result in a sufficiently strong attachment between the feltable material and the target site.
In a preferred embodiment, the fixation device additionally comprises the feltable textile. The feltable textile is arranged or arrangeable such that the at least one needle penetrates the feltable textile with the reciprocal motion. Further preferred, the at least one needle is arranged to penetrate through the feltable textile and into the target site. Thereby, the fixation device and the feltable textile are provided as a unit and are ready to be used together at the target site. As a result, only a single minimally invasive device or at least fewer minimally invasive device need to be inserted into the body of a human or animal.
In a preferred embodiment the at least one felting needle points in a distal direction of the elongate tubular member. This arrangement allows access to target sites that are arranged proximally to a distal tip of the elongate tubular member. In addition, this may allow pressing the feltable textile to the target site, which improves the felting. Further, the needle may be compact in the radial direction and a simple actuation mechanism can be provided.
In a preferred embodiment, the reciprocal motion of the at least one felting needle is linear, particularly preferred along a direction of the elongate tubular member. In an alternative embodiment, the reciprocal motion is rotational, preferably around an axis of the elongate tubular member. The type of reciprocal motion may be chosen depending on the feltable textile and the location of the target site. In case the feltable textile is expelled at the distal end of the elongate tubular member and fixated at the target site distally or proximally thereof, a linear motion is preferable. If the feltable textile is fixated to e.g. a vessel arranged at a radial direction of the elongate tubular member, a rotational motion may be preferable. For example, a feltable textile for an endograft for treating an aneurysm may be preferably fixated with the rotational motion. An annuloplasty ring or a heart valve may be preferably attached with a linear motion.
In a preferred embodiment, the drive assembly comprises an elongate driving wire or tube that extends from a proximal side of the elongate tubular member to the needle assembly. The elongate driving wire or tube is operably connected to the needle assembly such that the driving elongate wire or tube causes the reciprocal motion of the at least one felting needle. Thereby push and/or pull forces may be transmitted from a proximal end of the elongate tubular member to the distal end of the elongate tubular member.
The elongate tubular member as mentioned herein may be described herein as a catheter or sheath (i.e. an outer or inner catheter or sheath).
In a preferred embodiment the drive assembly comprises a resilient element that is arranged such that the resilient element forces the at least one felting needle to a preset position when the at least one felting needle is actuated by the driving elongate wire or tube. Thereby, the reciprocal motion is transmitted onto the at least one felting needle. Alternatively, the driving elongate wire or tube transmits both push and pull forces. In this case, the driving elongate wire or tube may be sufficiently stiff such that compressive forces are transmitted.
In a preferred embodiment the elongate driving wire or tube is configured to transfer tensile and optionally compressive force along the elongate direction of the elongate driving wire or tube to the needle assembly such that the wire or to actuates the reciprocal motion of the at least one felting needle. In a preferred embodiment the wire or tube is made of steel and may form a steel cable.
The driving elongate wire or tube may include a low friction coating on an outer surface. For example, the coating may be of polytetrafluoroethylene (PTFE). Thereby, forces along the longitudinal direction (i.e. compressive or tensile forces) are transmitted efficiently.
In a preferred embodiment, the elongate tubular member comprises at least one guiding element for the drive assembly in the interior lumen. The at least one guiding element preferably centers the elongate driving wire or tube in the elongate tubular member along the radial direction of the elongate tubular member. Thereby, a buckling of the elongate driving wire or tube is reduced, thus improving the efficiency of transmission of forces along the longitudinal direction. Further, vibration in the elongate tubular member may be reduced during operation of the felting needle(s). The guiding elements may also comprise a low friction coating for reducing friction between the driving elongate wire or tube and the guiding elements. This improves the guidance and force transmission of the driving wires or tubes.
In a preferred embodiment the feltable textile has the shape of a strip or patch. Further preferred, the textile may have an annular shape and/or forms an annuloplasty ring or forms part of an annuloplasty ring. Felting an annuloplasty ring is particularly advantageous, since reshaping the annulus of a heart requires a particularly strong and durable attachment due to the compression and expansion of the annuluses of the heart valves.
In a preferred embodiment, the fixation device additionally comprises a holding assembly for the feltable textile, wherein the holding assembly comprises at least one holder for securing the textile to the fixation device. The textile may be held in a folded position. Thereby, the textile and/or an implant comprising the textile has a compact shape and can be advanced to the target site. Further, only one minimally invasive device needs to be inserted that includes the felting needle(s) and a holding assembly with the feltable textile.
In a preferred embodiment, the fixation device additionally comprises a tube with an outer sheath with a distal end. The holding assembly is movable relatively to the outer sheath and upon being expelled from the distal end of the outer sheath, the holding assembly may assume an expanded position such that the textile is unfolded. The holding assembly may be made of a shaper memory alloy such as nitinol.
A further aspect relates to a set comprising a fixation device as described above and an implant comprising the feltable textile.
A further aspect relates to a set comprising a fixation device as described above and a guidewire. The feltable textile may be attached or attachable to the guidewire.
A further aspect relates to a set comprising a fixation device as described above and a pusher, preferably a pusher rod. The pusher may be adapted to push the feltable textile to a target site. The pusher may include a distal end face and may be arranged arrangeable within the elongate tubular member. The feltable textile may be arranged a distal end face of the pusher.
A further aspect relates to a method for fixating a feltable textile at the target site in a patient with a minimally invasive fixation device. The fixation device is preferably a fixation device as described above. The method includes the step of guiding a flexible elongate tubular member in the body of the human or animal to a target site. The flexible elongate tubular member has a proximal end, a distal end and an interior lumen. The interior lumen extends between the proximal end and the distal end. A needle assembly is actuated. The needle assembly comprises at least one felting needle arranged at the distal end of the elongate tubular member. The needle assembly is actuated by moving the at least one felting needle relatively to the elongate tubular member with a drive assembly arranged in the interior lumen of the tubular member. The drive assembly is operably connected to the needle assembly and moves the at least one felting needle with a reciprocal motion such that the feltable textile can be fixated at the target site.
The fixation devices, sets and methods as provided herein may be used in the repair and fixation of anatomical structures of the circulatory system (heart and blood vessels), fixation of an implant to these structures, the creation of artificial moderator bands (trabecula septomarginalis) to avoid or treat heart failure with dilated ventricles or cleft closures. In particular, heart defects (e.g. patent foramen ovale, atrial septal defect, ventricular septal defect, patent ductus arteriosus, paravalvular leak closure), heart valve repair and replacements (e.g. aortic valve replacement, mitral valve repair or replacement, tricuspid valve repair or replacement, annuloplasty, chordoplasty), edge-to-edge repair in heart valves and portions such as commissures, repair of blood vessels (e.g. aortic dissections, aneurysms, atherosclerosis), ischemic heart disease (cardio vascular diseases closure, reinforcement of ischemic ventricles and other degenerative cardio vascular diseases may be treated.
In a further aspect, it is suggested to provide a minimally invasive fixation device for fixating a feltable textile at a target site as described above. An end of the at least one felting needle may be directable or directed in a generally distal direction. A generally distal direction may be understood as having a component in the distal direction. Preferably an angle between the distal direction and the end of the felting needle is less than 600, less than 45° or less than 300 or the end of the felting needle points directly in the distal direction. Hereby the user can control the pressure on the tissue and the textile by pulling the fixation device instead of pushing the fixation device. This is particularly of interest where the target site (e.g. area in which surgical felting is performed) is behind anatomical structures such as e.g. valves. In particular, the needle may be curved or angled such that the at least one felting needle points in the generally distal direction.
The fixation device may additionally comprise a feltable textile and the at least one felting needle may be adapted to penetrate the feltable textile from a distal direction. The fixation device may comprise a holding assembly for an implant for the target site and the holding assembly may be adapted to apply a force on the implant in a distal direction. In a distal direction, higher forces can be applied, in particular when the elongate tubular member is bent.
The fixation device may additionally comprise an implant, in particular an annuloplasty ring or a heart valve, wherein the feltable textile is arranged on the implant.
The at least one felting needle may include a deformable joint, in particular a shape memory alloy, such that the at least one felting needle is directed in a generally distal direction when expelled from the interior lumen of the elongate tubular member.
In a further aspect, it is suggested to provide a minimally invasive fixation device for fixating a feltable textile at a target site as described above. The drive assembly may be adapted to move the at least one felting needle in a direction substantially orthogonal to the elongate tubular member with the reciprocal motion.
The at least one felting needle is preferably arranged to rotate around an axis during the reciprocal motion. The axis may be an axis, preferably a central or eccentrically axis, of the elongate tubular member. Thereby, an efficient transmission of the reciprocal motion to the at least one felting needle is provided.
In a preferred embodiment, the driving assembly comprises a driving rod operably connected to the at least one felting needle. The driving rod may be configured to transfer torque onto the needle assembly for rotating the at least one felting needle with the reciprocal motion.
In a preferred embodiment, the driving rod and/or the at least one felting needle is positioned as an eccentric position in the inner lumen of the elongate tubular member. Thereby, the at least one felting needle can be advanced to the inner lumen of the elongate tubular member.
In a preferred embodiment the at least one felting needle is directed or correctable in a direction substantially orthogonal to the elongate tubular member. In this way tissue laying in a radio position relatively to the catheter can be reached. For example, the feltable textile can be attached to walls of blood vessels through which the elongate tubular member may be advanced.
In a preferred embodiment, the at least one felting needle is curved or angled such that a distal tip of the needle is directed in the direction substantially orthogonal to the elongate tubular member. The at least one felting needle may have a curvature of a circle.
In a further aspect, it is suggested to provide a minimally invasive fixation device for fixating a feltable textile at a target site as described above. The fixation device may comprise a tubular outer sheath with a distal end, wherein the elongate tubular member is arranged in the outer sheath and wherein the elongate tubular member can be bent, in particular when the elongate tubular member is expelled from the distal end of the outer sheath such that the distal end of the elongate tubular member is steerable by rotating the elongate tubular member. Thereby, the needle assembly can be navigated to the feltable textile. In particular, the needle assembly can be rotated such that the feltable textile can be fixated along a circular track.
The elongate tubular member may comprise low friction outer coating such as PTFE or be made of a low friction material. Alternatively or additionally, the outer sheath may comprise a low friction outer coating (e.g. PTFE) or be made of a low friction material. As used herein any coating that reduces friction as compared to the base material may be considered to be a low friction coating. Material combinations which result in a dynamic coefficient of friction below 0.1 may be considered as “low friction”. (e.g. Teflon (PTFE) on teflon, or teflon on steel is around 0.04).
In a preferred embodiment, the elongate tubular member comprises a joint between its distal and proximal ends, wherein the elongate tubular member can be bent at the joint. Particularly preferred, the joint comprises a shape memory alloy. The joint may assume a bent position upon being expelled from the outer sheath.
Additionally, the elongate tubular member may comprise wires or cables or a pneumatic or hydraulic mechanism for rotating the elongate tubular member around its axis.
In a further aspect, it is suggested to provide a minimally invasive fixation device for fixating a feltable textile at a target site as described above. The elongate tubular member may comprise a distal tip portion that is arranged at least partially distal of the at least one felting needle, wherein the distal tip portion comprises a proximal counter surface opposed to the at least one felting needle for holding the feltable textile in place during fixation. Thereby, the tissue of the human or animal body may be held, e.g. clamped, in place during the felting. In alternative embodiments, the distal tip portion may also be arranged proximally of the at least one felting needle.
In a preferred embodiment, the distal tip portion includes a slot for receiving the feltable textile. The slot may be partially formed by the distal counter surface.
In a preferred embodiment, the distal tip portion may be formed by one, two, three or more tongues that are formed to provide a distal counter surface for the felting.
In a further aspect, it is suggested to provide a minimally invasive fixation device for fixating a feltable textile at a target site as described above. The fixation device may further comprise a textile holder and a feltable textile. At least a part of the feltable textile is held at the distal end of the elongate tubular member with the textile holder such that the feltable textile covers the needle assembly at least partially. The at least one felting textile is configured to penetrate the feltable textile.
In a preferred embodiment, the feltable textile has an elongate shape, a first end, an intermediate portion and a second end along the elongate extension. The elongate tubular member includes at least one, preferably two, guidance openings, preferably slots, for holding the feltable textile such that the feltable textile covers the new assembly at least partially. Thereby, the feltable textile may be hold in place during delivery and during fixation.
In a preferred embodiment the textile holder comprises a clamp for a frictional engagement between the feltable textile and the textile holder. Further preferred, the catheter assembly comprises a textile holder release mechanism for releasing the textile from the fixation device, wherein the textile holder release mechanism preferably comprises a textile with cables. Thereby, the feltable textile may be released from the fixation device. In a further preferred embodiment, the catheter assembly comprises a cutting-edge, preferably a knife for cutting the feltable textile. The cutting edge maybe rotatable, which allows an easy actuation of the textile cutting mechanism.
Nonlimiting embodiments of the invention are described, by way of example only, with respect to accompanying drawings. The drawings and its description provide examples of the invention, individual features of which may be used alone or in combination with each other.
While the above-identified figures set forth one or more embodiments of the present invention, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the invention. The figures may not be drawn to scale, and applications and embodiments of the present invention may include features, steps, and/or components not specifically shown in the drawings.
The situation, where the catheter 102 has reached the target site is shown in
In the next step, a pusher 106 is advanced through the catheter 102 over the guidewire 101 or over the second catheter 103. On its distal end, the pusher 106 includes a flat surface. On the flat surface, a folded patch 108 made of a feltable textile is arranged and pushed through an inner lumen of the catheter 102. When the folded patch is expelled from a distal end of the catheter 102 as shown in
The needle can be moved over the surface of patch 108 by rotating the catheter 102 around the second catheter 103. To cover a greater area this can be repeated by navigating to a new target site on the patch with catheter 102.
The catheter 202 comprises a linear bearing 203 at its distal end. Further, the catheter 202 includes a spring coil 204 and a felting needle 209 at its distal end. The driving wire 210 is rigidly connected to the felting needle 209 or forms the felting needle 209 and is connected to a distal end of the spring coil 204 with a washer 205. On the other hand, the spring coil contacts the linear bearing 203. When the wire 210 is pulled, the needle 209 is retracted and the spring 204 is compressed between the linear bearing 203 and the washer 205. Upon releasing the wire 210, the spring coil presses the felting needle forward. The amplitude (penetration depth) and frequency of the motion of the felting needle can be modulated and the suitable springs with resonance frequencies in the desired range may be chosen as is known in the art.
If a sufficiently stiff driving wire is used (e.g. steel cable) which is able to transport compressive and tensile forces from one end to the other end of the catheter, the spring 204 can be avoided. Alternatively to the above described driving assembly comprising an elastic element (spring 204) and a driving wire, the needling mechanism can be driven by a pneumatic or hydraulic force or by an electro-magnetic actuator.
Once, the guidewire 301 is at the target site, an outer sheath 302 is advanced over the guidewire into the body of the human or animal. The outer sheath 302 comprises an inner lumen, through which a further outer catheter 303 is advanced. The outer catheter 303 includes an inner catheter 305. The inner catheter 305 may be a catheter such as catheter 200 as described with reference to
In addition, the inner catheter 305 comprises a joint 304. The joint may comprise an elastic element such as a coil or an elastic material and a bearing, e.g. a pivot bearing. The elastic element is prestressed and forces the inner catheter to bend at the joint 304 around the bearing. For example, the elastic material maybe compressed which would bend the inner catheter to an opposing side or the elastic material may be stretched, which would bend the inner catheter to the side of the elastic material. The angle of the joint may in one example be controlled by a user with a wire pulling the elastic element.
Additionally or alternatively, the joint 304 is made of a shape memory alloy. Further, upon being expelled from the outer catheter 303, the joint bends the inner catheter 305 at a predetermined angle. The angle may be controlled by the axial position of the inner catheter 305 relative to the outer catheter. This allows the needle to cover a bigger felting area on the patch.
The predetermined angle may be less than 90°, preferably less than 60°, preferably less than 45° and particularly preferred about 30°. Due to the bending at the joint, a rotation of the inner catheter 305 around its own axis steers the distal tip of the inner catheter 305 similarly to a guidewire with a J-shaped end. Thereby, the end portion of the inner catheter with the felting needle can be guided to a desired position. As shown in particular in
A particular application of the above technique is shown with respect to
A further embodiment 500 of a fixation device is shown in
In addition, the device comprises two holders 510, 511 for the strip 508. A first holder 510 clamps an end of the strip 508. The second holder 511 also clamps the strip 508. On the side of the second holder, the strip 508 extends further along the length of the catheter 502 in the proximal direction. In some embodiments the strip may go along half or the entire catheter from the catheter tip. The catheter 502 also provides an inner lumen for a guidewire and a steering wire for positioning.
Strip 508 enters the catheter on one side and is stretched by the felt holders 510, 511 to the opposite side, where it is attached. In another embodiment a felt holder only holds the textile over the tissue wall and a fixation device as previously described with reference to
In the previous embodiments, the felting needle was moved linearly along the elongate direction of the respective catheters. However, the needle may also rotate or move in a direction orthogonal to the catheter. An example of such a needle is shown with respect to
Additionally, the eccentric position of the rod 601 may be changed by moving the rod 601 relatively to the catheter to another eccentric position. For example, as shown to the right in
A further embodiment of a fixation device 800 is shown with reference to
The embodiment shown in
One application of the above described fixation devices and feltable textile is a mitral valve repair, optionally with replacement/enhancement of the chordae tendineae. During diastole, the opening of the mitral valve lets blood flow from the left atrium to the left ventricle. During systole, the mitral valve closes, so that blood gets pumped through the aorta to the body. Patients suffering from mitral regurgitation have a mitral valve that does not close Lightly, which allows blood to flow from the left ventricle back to the left atrium. Depending on cause and severity of the case, one approach is to replace or enhance the chordae tendineae; the cords that transmit the contraction and relaxation of the papillary muscles to the mitral valve. Access to the mitral valve may be gained percutaneously through the femoral vein and puncture of the septum. The catheter enters the mitral valve and fixates the first end of a textile patch to the papillary muscle. A second end is fixated at the leaflet and gets released by the catheter. Thereby, the chordae tendineae are supported by the feltable textile that are fixated strongly and durably. In particular, the device shown with respect to
Another application of the above described fixation devices and feltable textiles is an Atrial Septal Defect (ASD). ASD is a congenital heart defect that occurs, when the septum between the two atria is not developed properly and a hole remains. Depending on the size and location of the defect, the hole needs to be closed. The majority of cases can be treated by a transcatheter approach shown above. Access to the defect of the septum is gained percutaneously through the femoral vein into the right atrium. The elongate tubular member in the form of a catheter contains a central rod with a folded disk at the tip, which is guided through the hole into the left atrium. There, the feltable textile can be unfolded and expanded. A holder as described above may fixate the feltable textile. The pusher may also push the folded textile that will occlude the hole. It gets pushed through the catheter, unfolds once it exits the catheter and is pressed onto the septum. Two hollow tubes, each equipped with a barbed needle next to the central rod are guided to the patch. They fixate the edge of the patch by rotating (in this case 90°) in both directions (clockwise and counterclockwise) and thereby occluding the hole as shown in
In a further example of a surgical procedure, the feltable textile is advanced through the septal defect, such that the main section is positioned in the septal defect, the first connecting section is arranged in the left atrium and the second connecting section is arranged in the right atrium, or vice versa. An upper portion of the first connecting section may then be connected to the upper part of the atrial septum adjacent the atrial septal defect, and an upper portion of the second connecting section may be connected to the upper part of the atrial septum by advancing a surgical felting needle repeatedly through the respective portion of the respective connecting section and into the atrial septum. In this manner, the fibers of the respective connecting section are inserted into the atrial septum to tightly connect the medical implant to the heart tissue. Subsequently, a mechanical force (e.g. an upward force on the lower part of the heart and hence the lower part of the atrial septum or a downward force on the upper part of the heart and hence the upper part of the atrial septum) may be applied to transiently close the septal defect, and the lower portion of the first connecting section and the lower portion of the second connecting section may then be connected to the heart tissue of the lower part of the atrial septum by advancing a surgical felting needle repeatedly through the respective portion of the respective connecting section and into the tissue of the lower part of the atrial septum. The described procedure is preferably performed using minimal invasive surgery, i.e. by advancing one or several catheters into the left atrium and or the right atrium of the heart via the vascular system of the patient.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
This Application is a Section 371 National Stage Entry Application of International Application No. PCT/EP2020/081881, filed Nov. 12, 2020 and published as WO 2022/100832 on May 19, 2022, in English.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/081881 | 11/12/2020 | WO |
