DEVICE FOR HEART REPAIR

Abstract

An anchor for implantation in body tissue has a number of hooks for engagement with the body tissue. The anchor is made of an elastic material such that it can be elastically deformed into a folded position by application of a constraining force, and will return to an unfolded position when no constraining force is applied. A plugging device is combined with one or more parts of the anchor to provide enhanced contact with the body tissue. The plugging device encircles at least one of the hooks. The anchor may be combined with a line which is a part of the plugging device. The line is optionally joined to the anchor by a knotting configuration having a plurality of loops around the anchor. At least one loop of the plurality of loops encircles at least two of the hooks.

Claims

1. An anchor configuration for implantation in body tissue, the anchor configuration comprising: an anchor comprising a number of hooks for engagement with the body tissue and having a folded and unfolded position, wherein the anchor is made of an elastic material such that it can be elastically deformed into the folded position by application of a constraining force, and will return to the unfolded position when no constraining force is applied; and a plugging device for enhancing contact with the body tissue; wherein the plugging device is for combining with one or more parts of the anchor to provide the enhanced contact; and wherein at least one of the hooks is encircled by the plugging device.

2. An anchor configuration as claimed in claim 1, wherein the plugging device is configured to seal an entry site between the hooks and the body tissue when the anchor is implanted in the body tissue.

3. An anchor configuration as claimed in claim 1 or 2, wherein the anchor comprises an anchor body, wherein the hooks extend from a base of the anchor body.

4. An anchor configuration as claimed in claim 3, wherein the anchor body is configured to compress the plugging device against the body tissue when the hooks are in the unfolded position and the anchor is implanted in the body tissue.

5. An anchor configuration as claimed in any preceding claim, wherein a portion of the plugging device encircling the at least one hook is configured to provide a first sealing surface around a respective entry site of the at least one hook, and wherein the plugging device is configured to provide a second sealing surface capturing all of the entry sites of all of the hooks.

6. An anchor configuration as claimed in any preceding claim, wherein the plugging device is formed of a biocompatible material, preferably wherein the material is ePTFE.

7. An anchor configuration as claimed in any preceding claim, wherein the plugging device comprises an overmolded structure formed around a base of the hooks.

8. An anchor configuration as claimed in any of claims 1 to 6, wherein the plugging device is a line, the line in combination with the anchor; wherein the line is joined to the anchor by a knotting configuration comprising a plurality of loops around the anchor; and wherein the at least one hook is encircled by at least one loop of the plurality of loops.

9. An anchor as claimed in claim 8, wherein the knotting configuration comprises at least two knots.

10. An anchor as claimed in claim 8 or 9 when dependent on claim 3, wherein the anchor body is a tubular body, and wherein at least part of the knotting configuration is located within the tubular body.

11. An anchor as claimed in claim 8, 9 or 10 when dependent on claim 3, wherein the anchor body comprises at least two threading holes, wherein the threading holes accommodate at least part of the knotting configuration.

12. A catheter device comprising an anchor deployment mechanism and an anchor configuration as claimed in any of claims 8 to 11.

13. A catheter device as claimed in claim 12 wherein the anchor is a leaflet anchor for implantation into a leaflet of the heart, and wherein the anchor deployment mechanism is hence a leaflet anchor deployment mechanism.

14. A catheter device as claimed in claim 12 or 13, wherein the line is an artificial chordae line and wherein the catheter device is for implanting the anchor during a procedure for implanting the artificial chordae line into the heart, the catheter device comprising: the anchor, the anchor deployment mechanism for deploying the anchor, and an ejector unit for releasably grasping the anchor.

15. A catheter device as claimed in claim 14, wherein the anchor deployment mechanism allows for retraction and repositioning of the anchor after deployment of the anchor into the body tissue via the ejector unit, wherein the ejector unit has a grasping device with a first configuration arranged to permit deployment of the anchor into the body tissue without disengagement of the anchor from the ejector unit, and a second configuration in which the anchor is reversibly released from the ejector unit; wherein in the first configuration the grasping device of the ejector unit grasps the centre of the anchor, whilst the pins of the anchor are unimpeded by the grasping device to enable it to be implanted in the body tissue; and wherein in the second configuration the grasping device of the ejector unit is disengaged from the anchor.

16. A catheter device as claimed in claim 15, wherein the anchor comprises tabs or recesses either side of the width of the anchor at its centre in order to allow for the grasping device of the ejector unit to engage with the anchor.

17. A catheter device as claimed in claim 15 or 16, wherein prior to deployment the ejector unit is placed within the anchor deployment mechanism inboard of the anchor and when the ejector unit and anchor are within the anchor deployment mechanism the ejector unit holds the anchor with the grasping device in the first configuration.

18. A catheter device as claimed in claim 15, 16 or 17, when dependent on claim 13, wherein the leaflet anchor and the ejector unit are housed inside an anchor tube of the leaflet anchor deployment mechanism prior to deployment, with the ejector unit further inside the anchor tube than the anchor.

19. A catheter device as claimed in claim 18, wherein the grasping device comprises two or more grappling hooks arranged to engage with the anchor at their ends when in the first configuration, and wherein the grasping device is arranged to engage and disengage from the anchor via a radial movement of the grappling hooks relative to the anchor tube.

20. A catheter device as claimed in any of claims 14 to 19, comprising a rod for deployment of the anchor, wherein the rod is a U-rod in order to allow for a pushing force directed toward the proximal end of the catheter device.

21. A method of manufacture of the anchor configuration as claimed in any of claims 1 to 7, the method comprising: forming the anchor from an elastic material; and forming the plugging device around the anchor via overmolding.

22. A method of manufacture of the anchor configuration as claimed any of claims 8 to 11, the method comprising: forming the anchor from an elastic material; and joining the line to the anchor.

23. A method of use of the anchor configuration as claimed in any of claims 8 to 11 for affixing the line to the heart, the method comprising using an anchor deployment device to implant the anchor in combination with the line into the tissue of the heart.

Description

[0246] Certain example embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings in which:

[0247] FIG. 1 illustrates the procedure for insertion of a catheter device through a mitral valve;

[0248] FIGS. 2 to 6 show the action of a mechanical gripping mechanism using two gripper arms;

[0249] FIG. 7 illustrates gripping of a leaflet of the mitral valve with one gripper arm;

[0250] FIGS. 8 to 12 show deployment of a leaflet anchor in a device using an ejector device;

[0251] FIG. 13 shows a close up view of the valve during placement of a leaflet anchor, which is coupled to an artificial chordae line;

[0252] FIG. 14 shows movement of the distal end of the catheter device to the papillary muscle for placement of a papillary anchor;

[0253] FIG. 15 illustrates withdrawal of a treatment catheter part of the device and adjustment of the chord length with an optional adjustment catheter;

[0254] FIGS. 16 and 17 show an example of a hook for an anchor which is threaded with a suture;

[0255] FIGS. 18 and 19 show the folded and unfolded configuration of an example of a papillary anchor;

[0256] FIG. 20 is a cross-section through a lower (distal) part of the main body of the catheter device showing how the main parts fit inside a papillary anchor deployment mechanism;

[0257] FIG. 21 shows an example arrangement for the routing of the artificial chordae line and other lines within the papillary anchor deployment mechanism of FIG. 20;

[0258] FIG. 22 is a cross-section of an example with the papillary anchor deployment mechanism of FIG. 20 and a gripping mechanism as in FIGS. 2 to 6, including one possible routing of the artificial chordae line between the papillary anchor and the first gripper arm;

[0259] FIG. 23 shows an anchor in combination with a line;

[0260] FIG. 24 shows an anchor in combination with a line implanted in body tissue;

[0261] FIG. 25 shows an anchor in combination with a line;

[0262] FIG. 26A shows an anchor in combination with a plugging device in a cross-sectional view; and

[0263] FIG. 26B shows an anchor in combination with a plugging device in a plan view.

[0264] The catheter devices presented here are proposed for non-surgical (endovascular) insertion of mitral chords to address mitral regurgitation caused by prolapse of a leaflet 12 of the valve. The Figures show different forms of catheter device 2 for this purpose, but it will be understood that the general principles are the same for each device in terms of implantation of a leaflet anchor 10 and a papillary anchor 9 in order to insert one or more artificial chordae lines 14 into the heart. The artificial chordae line(s) 14 are fixed to the prolapsing leaflet 12 and to the papillary muscle 26, thereby recreating a normal anatomy. A single catheter device 2 is used to place both a leaflet anchor 10 and a papillary anchor 9. The length of the chord 14 can be adjusted, again using the same catheter device 2, to eliminate the mitral regurgitation. Thus, the new device enables a single minimally invasive endovascular procedure to be used to repair the mitral valve, providing significant advantages compared to earlier systems requiring more invasive procedures and/or multiple operations.

[0265] It should be noted that although an endovascular approach is preferred and the device is hence capable of using this approach, the device could of course be used in different procedures, including more invasive procedures. Many of the advantages will remain, and it could be beneficial to use this device in situations where a more invasive procedure is merited. In addition, it is contemplated that, as discussed above, aspects of the design of the papillary anchor 9 could be used for an anchor for other purposes and this disclosure is not intended to be limited in this regard.

[0266] The catheter device 2 described in the following can be used to insert mitral chords through the venous system, starting in the femoral vein in the groin. A catheter is advanced to the right atrium. Approach to the left atrium is then gained by a so-called transseptal puncture whereafter a larger guidance catheter is advanced into the left atrium. The catheter device 2 for the heart repair is then introduced through the guiding catheter and into the left atrium.

[0267] X-ray and ultrasound guidance is used to position the device and, as explained in more detail below, the mitral leaflet 12 is grabbed and a new artificial chordae line 14 is attached using a self-expandable leaflet anchor 10. The artificial chordae line 14 is then attached to the papillary muscle 26, using a, papillary anchor 9. Advantageously, the catheter device shown in FIGS. 2 to 6, 14 and 20 to 22 can be used to place the papillary anchor 9 whilst the leaflet 12 is still being grasped by the device. The chord length can now be adjusted to eliminate any mitral regurgitation. Excess chord is then cut and all catheters are withdrawn. Echo and Doppler imaging is used to perform the procedure and monitor the result. The successful use of this endovascular technique will drastically reduce the invasiveness, complications and cost of mitral valve repair.

[0268] More detail on the structure and function of the device is set out below with reference to the Figures. The procedure of using one form of the device can be summarised as follows:

[0269] 1) The femoral vein is entered using standard Seldinger technique and the guiding catheter introduced.

[0270] 2) The guiding catheter is advanced to the right atrium under x-ray guidance.

[0271] 3) The left atrium is entered after penetration of the atrial septum, guided by x-ray and transesophageal echo.

[0272] 4) Correct position of the entrance site in the left atrium is verified to assure proper alignment for insertion of the guiding and treatment catheters. The entrance hole in the atrial septum is dilated and the guiding catheter is advanced into the left atrium.

[0273] 5) A treatment catheter device 2 is advanced through the guiding catheter and positioned in the left atrium above the mitral valve.

[0274] 6) The prolapsing segment of the mitral leaflet 12 is located with ultrasound and the treatment catheter device 2 is advanced into the left ventricle placing a gripper 6 of the treatment catheter device 2 in position to grip the prolapsing segment. Advantageously, this may use a gripper 6 with two gripping arms 30, 32 as discussed in more detail below with reference to FIGS. 2 to 6.

[0275] 7) The prolapsing segment is gripped and after assuring correct position the leaflet anchor 10 is pushed through the leaflet 12 allowing it to open and fix the leaflet 12.

[0276] 8) The connection of the leaflet anchor 10 may be tested whilst it remains attached to the catheter device 2 via an ejector unit 36 as discussed further below with reference to FIGS. 8 to 12, and if the connection is sufficient then the distal end of catheter is advanced further into the left ventricle, advantageously using a flexible and extendable joint 34 as shown in FIGS. 2 to 6 and 14, or using a flexible joint as shown in FIGS. 31 and 32 to angle the joint without extension, until the distal end makes contact with the papillary muscle 26 or surrounding tissue.

[0277] 9) The papillary anchor 9 is pushed into the papillary muscle 26 area and out of its housing 8 thereby letting the papillary anchor 9 open inside the papillary muscle 26.

[0278] 10) If the gripper 6 is still grasping the leaflet 12 then it is released, such as by releasing the leaflet anchor 12 from the ejector unit 36 as discussed below with reference to FIGS. 8 to 12.

[0279] 11) The length of the artificial chordae line 14 is adjusted until mitral regurgitation is eliminated.

[0280] 12) The catheter device 2 is pulled back from the papillary anchor 9, and elimination of mitral regurgitation is again confirmed by echocardiography.

[0281] 13) The position of the artificial chordae line 14 is locked at the papillary anchor 9.

[0282] 14) The excess chordae line 14 is cut.

[0283] 15) Additional artificial chordae lines may be placed if necessary.

[0284] 16) The catheter device is fully withdrawn and removed from the vascular system.

[0285] FIG. 1 shows guide catheter 22 that has been used to steer a catheter device 2 to a required position within the heart adjacent extending through the mitral valve and hence being between two leaflets 12. The catheter device 2 is composed of four different main parts; a steerable catheter, a gripper housing 4, a gripper device 6 and a papillary anchor housing 8, which holds a papillary anchor 9. Advantageously the gripper housing 4 and the papillary anchor housing 8 may form a proximal part 4 and a distal part 8 of a two part housing section with a central flexible and extendable joint 34 as shown in FIGS. 2 to 6, 14 and 20 to 22. Thus, it should be understood that the procedure shown in FIG. 1 (and likewise in FIGS. 7, 13 and 15) may use this arrangement for the gripper housing (proximal part) 4 and papillary anchor housing (distal part) 8. The steerable catheter could be replaced with an alternative arrangement using a steerable sheath about a steerable catheter and flexible tubing within the steerable catheter.

[0286] FIG. 1 shows a front view of one example catheter device with the gripper device 6 closed. The gripper device 6 of some arrangements uses a single gripper arm 30 that grips the leaflet 12 against the gripper housing part 4 as shown in FIG. 7. In other arrangements the gripper device 6 uses two gripper arms 30, 32 as shown in FIGS. 2 to 6 in order to allow the leaflet 12 to be grasped between the two gripper arms 30, 32 at a point spaced apart from the main body of the catheter device. The gripper device 6 is a part of a leaflet anchor deployment mechanism for deploying the leaflet anchor 10 to attach it to the leaflet 12 of the heart. The gripper device 6 includes a leaflet anchor tube 38 for housing the leaflet anchor 10 in a folded configuration prior to deployment. In the example embodiments the leaflet anchor tube 38 is in the (first) gripper arm 30, as seen in FIGS. 2 and 4, for example. When the gripper device 6 grasps the leaflet 12, the leaflet anchor 10 can be pushed out of the leaflet anchor tube 38 to pierce the leaflet 12 and form the leaflet anchor 10 into an unfolded configuration so that hooked formations 40 of the leaflet anchor 10 secure it in the leaflet 12.

[0287] The leaflet anchor 10 is connected to an artificial chordae line 14, which can sit inside a narrow channel that goes along the surface of the first gripper arm 30 (as shown in FIGS. 8 to 12, for example) and via the papillary anchor housing 8 to the papillary anchor 9 (as shown in FIGS. 20 to 22, for example). The channel can be slightly smaller than the diameter of the new artificial chordae line 14 and/or have a thin shielding structure (not shown). This makes the artificial chordae line 14 sit in place due to a friction fit. The new artificial chordae line 14 goes into the papillary anchor housing 8 and through a papillary anchor locking section, through a locking and cutting piece 18, and through Z shaped fork 20. These parts are described in further detail below with reference to FIGS. 20 to 22. The new artificial chordae line 14 can be attached to a wire which passes back along the catheter all the way to the outside (to make the adjustment smoother). The wire allows for a shortening of the chord during the procedure, by pulling, or a lengthening of the chord, since the wire can be pushed through the catheter.

[0288] The two-part housing section, with the gripper housing (proximal part) 4 and papillary anchor housing (distal part) 8 might be approximately 6-7 mm in diameter, and approximately 30 mm in length.

[0289] FIGS. 2 to 6 show steps in movement of the gripper mechanism 6 in an example with two gripper arms 30, 32 as discussed above. This gripper mechanism 6 is a part of a housing section that also includes a flexible and extendable joint allowing the papillary anchor housing 8 (distal part) to be moved toward the papillary muscle 26 after the leaflet 12 has been grabbed by the gripper mechanism 6. In this example, in order to grasp the leaflet 12, the first gripper arm 30 is rotated to move its end 42 away from the main body of the catheter device, with this rotation being enabled via a weakened area 44 of the tubular form of the main body. It can be seen that the leaflet anchor tube 38 sits inside the first gripper arm 30, with the end of the leaflet anchor tube 38 having an opening at the end 42 of the first gripper arm 30. With the first gripper arm 30 open, the second gripper arm 32 is free to rotate to move its end 46 outward of the main body. In this example the second gripper arm 32 rotates around a hinge formed by pins 48 placed in holes in the proximal part 4 of the two-part housing section, but it will be appreciated that a similar final placement of its end 46 may be achieved via a sliding movement. With the second gripper arm 32 folded outward the first gripper arm 30 can close so that the two ends 42, 46 come into contact at a point spaced apart from the main body of the device. This allows the leaflet 12 to be grasped. With the leaflet 12 in place the leaflet anchor 10 can be moved out of the leaflet anchor tube 38 to implant it, such as via a mechanism with an ejector unit 36 as described below in relation to FIGS. 8 to 12, with the final positioning of the leaflet anchor 10 being similar to that shown in FIG. 13.

[0290] FIG. 7 shows an alternative form of gripper mechanism 6 that grasps the leaflet 12 with a single gripper arm that holds it against the gripper housing 4. This could also use the ejector unit 36 mechanism of FIGS. 8 to 12.

[0291] A ridged surface on the gripper arm(s) 30, 32 may be provided to help it grip the leaflet 12. 3D ultrasound and/or other available sources can be used to confirm that the gripper mechanism 6 has grasped the correct part of the leaflet 12.

[0292] The gripper mechanism 6 can be opened and closed as many times as needed to grasp the right part of the leaflet 12. The opening and closing may be facilitated by a system allowing for one wire to pull the gripper mechanism 6 open, and one to pull it closed. Different arrangements of wires and/or rods may be used to control the example with two gripper arms 30, 32, as discussed above. Once the position of the gripper mechanism 6 is confirmed then the leaflet anchor 10 can be pushed out of the end of the leaflet anchor tube 38, such as by pulling a wire in the other end of the catheter. FIG. 13 shows a close up view of the leaflet anchor 10 placed in the leaflet 12 with the hooked formations 40 engaging with the leaflet 12.

[0293] As noted above, an ejector unit 36 may be used as shown in FIGS. 8 to 12. With the use of the ejector unit 36 the leaflet anchor deployment mechanism allows for retraction and repositioning of the leaflet anchor 10 after deployment of the anchor 10 into the leaflet 12. This is achieved via the ejector unit 36, which includes a grasping device 50 with a first configuration, as shown in FIG. 8 and FIG. 9 and a second configuration as shown in FIG. 10 and FIG. 11.

[0294] In the first configuration the grasping device arranged to permit deployment of the leaflet anchor 10 into the leaflet 12 without disengagement of the leaflet anchor 10 from the ejector unit 36. Thus, the grasping device 50, which in this example comprises two grappling hooks 50 as shown, grips the leaflet anchor 10 and can advance along the leaflet anchor tube 38 from the fully stowed position as in FIG. 8, to a position in which the anchor 10 is deployed as shown in FIG. 9, without releasing the anchor 10. The grappling hooks 50 are held to the leaflet anchor 10 as they are constrained within the leaflet anchor tube 38. The ejector unit 36 is hence arranged so that it remains in the first configuration whilst the leaflet anchor 10 is being implanted. With the leaflet anchor 10 implanted the grasping device 50 and ejector unit 36 can be used to test the connection of the leaflet anchor 10 to the leaflet 12, for example by a force being applied to the leaflet anchor from the ejector unit whilst the grasping device 50 is in the first configuration.

[0295] The grasping device 50 moves into the second configuration when the constraint from the leaflet anchor tube 38 is no longer present, for example when the grappling hooks 50 move beyond the end of the tube as shown in FIG. 10. Thus, if the connection has been tested and the physician decides to release the leaflet anchor 10 then they can further advance the ejector unit 36, which will move it into the second configuration. In this second configuration the grasping device 50 of the ejector unit 36 is disengaged from the leaflet anchor 10.

[0296] If the physician is not satisfied by the connection during the testing (for example, if there is too much movement of the anchor 10 and/or not enough resistance to force on the line) then the leaflet anchor 10 can be retracted and placed in another location. If the grasping device 50 did not change from the first configuration during this test then the latter procedure may be carried out by reversing the deployment of the ejector unit 36 and leaflet anchor 10, for example by drawing those parts back into the leaflet anchor deployment mechanism. If the second configuration was used before it was determined that the connection of the anchor was not adequate then to retract the anchor 10 the ejector unit 36 should be first moved back to the first configuration so that the grasping device 50 reengages with the leaflet anchor 10, and then after that the deployment of the ejector unit 36 and leaflet anchor 12 is reversed, for example by drawing those parts back into the leaflet anchor tube 38.

[0297] A groove 52 is provided in a wall of the leaflet anchor tube 38 for guiding the ejector unit 36. The groove 52 ensures that the ejector unit 36 remains a single orientation relative to the tube 38 while it is moved along the tube. The groove 52 can set maximum limits on the range of movement of the ejector unit 36 and thus may prevent it from going too far in either direction, out of or into the leaflet anchor tube 38. The ejector unit 36 has a guide pin 56 for engagement with the groove 52. A narrowing 54 in the groove 52 is provided to act as an indicator to let the operator know when the ejector unit 36 has reached a certain position. The size of the guide pin 56 and the width of the narrowing 54 are set so that engagement of the pin 56 with the narrowing 54 in the groove 52 will require an increased force before further movement can be made, thus providing tactile feedback to the operating physician.

[0298] The leaflet anchor deployment mechanism of FIGS. 8 to 12 also includes a line pusher 58 for directing the artificial chordae line 14 out of and away from the leaflet anchor tube 38 during deployment of the anchor 10. The line pusher 58 directs the artificial chordae line away from the leaflet anchor tube 38 so that it can be more readily accessed for later manipulation, such as for tightening the line 14 or for pulling on the implanted leaflet anchor 10 for testing of the connection. The line pusher 58 is actuated during the action of deployment of the leaflet anchor 10, with this actuation being triggered when the leaflet anchor 10 is released from the ejector unit 36. Thus, the line pusher 50 is released when the ejector unit 36 withdraws away from the implanted leaflet anchor 10.

[0299] In the example shown, the line pusher 58 transitions from a constrained state to a non-constrained state and moves radially outward to push the line 14 out, with this radially outward movement being permitted and the line pusher released once a constraint from the leaflet anchor 10 is removed. The line pusher 58 is an arm that extends axially forward from the ejector unit toward the leaflet anchor 10 and radially outward of the leaflet anchor tube 38 when the arm is at rest with no forces applied. Prior to deployment of the leaflet anchor 10 the arm of the line pusher 58 is bent elastically to place its distal end within the leaflet anchor 10, as shown in FIGS. 8 and 9, so that it is constrained and cannot move to its radially outward position until the leaflet anchor 10 and the ejector unit 36 move apart, as is best shown in FIG. 11. As the ejector unit 36 continues to withdraw into the leaflet anchor tube 38 the line pusher 58 remains in its unconstrained state with the line pusher 58 as well as the line 14 being pushed out of a slit in the leaflet anchor tube 38, as shown in FIG. 12.

[0300] With the leaflet anchor 10 implanted in the leaflet 12 the papillary anchor housing 8 at the end of the treatment catheter is then placed onto the papillary muscle 26. With the use of a flexible and extendable joint 34 this may be done as shown in FIG. 14. In this example, the flexible and extendable joint 34 is formed by flexible meandering sections cut into a tubular form of the main body. Advantageously the flexible and extendable joint 36 is formed integrally with a tubular distal part 8, which provides the papillary anchor housing 8 and with a tubular proximal part 4, which provides the gripper housing 4. Further advantageously the tubular form of the gripper housing 4 may include an integrally formed gripper arm 30, with a weakened section 44 of the tube providing a hinge. The flexible and extendable joint 34 can be extended by means of wires and/or rods 60 (or via an adjustment catheter 21, that also may push out the papillary anchor 9), which may apply a force to stretch elastic elements of the joint 34. This extension is used to move the papillary anchor 9, within its housing part 8, to place it against the papillary muscle 26, or close to it, since the wires/rods along with the papillary anchor 8 within the distal housing part 8 move with the housing 8 as the joint 34 extends. This can be due to friction between the papillary anchor 9 (or a papillary anchor push tube) and the internal surface of the distal part 8 of the housing section. The position can be confirmed by 3D ultrasound and/or other available sources.

[0301] When the distal end of the distal part 8 meets the body tissue, and as further force is applied the counterforce from the body tissue eventually surpasses the forces holding the papillary anchor 9 in place, at this point tissue is pushed flat below the base of the distal part 8 giving a maximal chance of placing all pins 62 of the papillary anchor 9 correctly in tissue, and force can be applied to the papillary anchor 9 so that the ends of the pins 62 then move beyond the distal end of the distal part 8 to meet the body tissue. This may be done via additional force on the papillary anchor 9 from rods or wires 60 or extending the adjustment catheter 21, or advantageously it may be done through a pre-tension on the papillary anchor 9 (or friction between the adjustment catheter 21 and the distal part 8) that is held by friction with the distal part until the forces from the body tissue on the distal part 8 changes the balance of forces with the friction sufficiently so that the papillary anchor 9 ejects in a way similar to a paper stapler. As the papillary anchor 9 is ejected the pins 62 fold out and form into the hook shape of the unconstrained papillary anchor 9 to thereby engage with the body tissue 26. At this point the connection can be pull tested by operator, and/or visually confirmed on x-ray and/or ultrasound. If the connection is not satisfactory, the papillary anchor 9 can be pulled back into the distal part 8 and re-placed to attempt an improved coupling of the anchor 9 with the body tissue 26.

[0302] FIG. 15 shows the possible next steps. The main part 4, 8 of the device is retracted to minimize influence on the moving leaflets 12. An adjustment catheter 21, which may comprise a Z-shaped fork 20 at its distal end as shown in FIGS. 20 to 22, can remain at the papillary anchor 9. The length of the artificial chordae line 14 can be adjusted with a wire from the outside. The length is continuously adjusted and the functioning of the leaflet 12 is monitored. The length of the artificial chordae line 14 can be reduced by pulling the chord wire back through the catheter. The length can also be increased by pushing the chord wire, which will slacken the artificial chordae line 14 and allow the movement of the leaflet 12 to pull it out of the adjustment catheter 21. The small size of the adjustment catheter 21 means that the effect of the device on the functioning of the leaflet 12 is minimised. The right length for the artificial chordae line 14 is confirmed with 3D ultrasound and/or other available sources.

[0303] When the correct length is confirmed then the device is disengaged from the papillary anchor 9. This process also locks the artificial chordae line 14 in place and cuts off any excess, which is retained in the catheter and withdrawn from the body when the catheter is removed. FIGS. 20 to 22 include more detail of the Z-shaped fork 20 and the cutting piece 18, as discussed below. The Z-shaped fork is used to hold open a locking segment 28 of the papillary anchor 9. The locking segment 28 is a band of the papillary anchor 9 that can be flexed to open a gap for the artificial chordae line 14 to pass through. In the natural shape of the papillary anchor 9, when no forced is applied, this locking segment 28 fits closely with the remainder of the anchor 9 and so it will hold the artificial chordae line 14 in place. The Z-shaped fork 20 is used to hold the locking segment 28 open until the artificial chordae line 14 is the correct length. The cutting piece 18 cuts the artificial chordae line 14, which is pulled against the blade when the adjustment process is completed.

[0304] FIGS. 16 to 19 include more details of the papillary anchor 9, including its hooks 62 which are formed by curving pins 62. FIGS. 16 and 17 show one possible form for the hooks 62, with a central slit 64 and a series of holes 66 threaded with a suture 68. As discussed above, this suture 68 and the holes 66 can allow the hooks 62 to better engage with body tissue during healing, as well as keeping the material of the hooks 62 connected to the main body of the papillary anchor 9 in the event of a breakage. FIG. 16 shows the folded/constrained shape of the hook 62, which is also the shape of a tine formed in a tubular section during manufacture of the anchor 9, prior to heat setting to form the curve. FIG. 17 shows the curved form of the hook 62, i.e. the unfolded/unconstrained form.

[0305] FIGS. 18 and 19 show an example of an entire papillary anchor 9, again illustrating the folded (FIG. 18) and unfolded (FIG. 19) configurations. This papillary anchor 9 includes hooks 62 with an opening in the form of a slit 64, which gives various advantages as discussed above, including better engagement with the body during healing as well as increased surface area without loss of flexibility.

[0306] The device can include a safety wire 72 that acts to prevent the papillary anchor 9 from escaping into the body in the event that it is not correctly placed. Once the locking and cutting have been done, and the papillary anchor 9 is seen to be secured to the papillary muscle 26 and to the leaflet anchor 10 then the safety wire 72 is cut.

[0307] In order to deploy the leaflet anchor then a U-rod can be used. This U-rod 30 would be housed within the gripper arm 30 and partly within the main part of the catheter, with a free end of the U-shape being used to push the leaflet anchor 10 (and ejector unit 36, where present) along the leaflet anchor tube 38. The U-rod has a bendable section so the gripper can open and close, while the U-rod is inside. Advantageously, this bendable section can act as a sort of a spring, applying a restoring force to return the gripper arm 30 to the closed position. The U-rod is made of a material with the ability to deform elastically to a high degree in order to allow for the bending of the bendable section. Suitable materials include shape memory materials, for example shape memory metals such as nitinol. A shape memory metal also has the advantage that the U-rod can be made stiff, which makes the transfer of force with the U-rod more efficient. The U-rod may consist of a thin nitinol wire and tubes on the outside of the wire, to make the U section stiffer. Alternatively, the U-rod could be made of several types of materials to achieve the required properties.

[0308] As noted above, imaging techniques such as 3-D ultrasound or fluoroscopy can be used when guiding the device and to confirm the correct location of the leaflet 12 within the gripper device 6. To assist in this, the echogenic properties of the device may be improved by abrasive blasting, mechanical texture or a special coating, for example an echogenic polymer coating. The gripper device 6 can also be provided with a detection system to confirm the location of the leaflet 12 within the gripper 6. In a modified gripper (not shown) a fluid based sensor system is provided. This uses holes on the gripping surface of the gripper housing 4. The holes are connected through tubes to a fluid supply, such as contrast fluid from a syringe. When the gripper pinches the leaflet (or other tissue), the holes will be blocked by tissue preventing the flow of fluid. This can be used to determine if the leaflet is in the correct position to deploy the leaflet anchor. The device could be built with various numbers of holes, for example three or four, with the combination of open and closed holes being used to determine the position of the leaflet/tissue within the gripper 4. If four valves are placed in a square pattern, two closed and two open valves could represent the correct position of the leaflet. In one example, the sensor system consists of one-four fluid channels that can be located in the instrument wall, opposite of the gripper arm, alternatively in the gripper arm tip. The channels are connected to ports on the instruments handle where they can be injected with a contrast fluid, which can be visible on either echocardiography or fluoroscopy. An absence (or reduction) of visible fluid and/or the increased resistance to inject fluid in both channels tells the operator that the leaflet is correctly placed prior to leaflet anchor deployment.

[0309] In another example a pump with a monitoring circuit constantly pumps a small amount of water through the tubes of the sensor. The detection circuit can detect pressure rise or change in the volume going through each tube, the rise in pressure can indicate which tubes that are obstructed and to some degree says something about how thick the tissue in the leaflet actually is (thinner tissue tend to cause less pressure rise, relative to thicker tissue). The monitor device can for example be equipped with simple LEDs that go green if leaflet is properly gripped. This will give physicians further confirmation (in addition to Ultrasound) that they have captured the leaflet correctly, which ultimately results in higher procedure success rates. In a slightly different embodiment the pump can be programmed to slowly pump fluid in and out of the tubes, which does not require additional fluid if the procedure takes long time.

[0310] The device may include a suture/line management system, to prevent tangling. Sutures may be held inside slits or tubes, until everything is ready for them to be released, this will reduce the chance of entanglement. The suture slit in the papillary housing 8 may be equipped with a one way “suture valve” cut from the nitinol tube itself, it will prevent native chordaes from entering the chordae channel.

[0311] The artificial chordae line 14 can be attached to the anchor(s) in several ways. For example, wire through holes with knots, welds or glue. The artificial chordae line 14 can be made of Gore-Tex® suture material, or a thin nitinol wire. This preferred embodiment uses Gore-Tex® since it is easier to cut once the length has been adjusted. The artificial chordae line 14 has a diameter of approximately 0.1-0.6 mm. The leaflet anchor 10 is approximately 1-2 mm in diameter, and approximately 4-6 mm in length (when straight).

[0312] The leaflet anchor pins can be cut with several different profiles to achieve different strength, and/or faster healing. Since the leaflet anchor 10 is cut from tubing using laser cutting then different shapes are easy to produce. The pins of the anchor may for example have a straight edge (minimum friction) or a profile for increased friction, such as a smooth or sharp saw tooth, or a barbed profile. The anchor shape can vary based on the requirements of the procedure. Different anchor designs could be available for a surgeon to select based on their assessment of the patient.

[0313] As with the leaflet anchor pins, the papillary anchor pins can be cut with several different shapes to achieve different pull out strength and/or faster healing. The pins of the anchor may for example have a straight edge (minimum friction) or a profile for increased friction, such as a smooth or sharp saw tooth, or a barbed profile. The anchor shape can vary based on the requirements of the procedure. Different anchor designs could be available for a surgeon to select based on their assessment of the patient.

[0314] FIGS. 20 to 22 illustrate interaction of the papillary anchor 9 with the chord and a cutting piece 18 of the catheter device. The cutting piece 18, is made of a suitable biocompatible material, preferably cut with laser and sharpened by grinding away some material. The material may for example be stainless steel, titanium or titanium alloy. Nitinol could also be used. The Z-shaped fork 20 is used to hold the locking segment 28 open to make room for the chord between the locking rings and locking segment 28 in the papillary anchor 9.

[0315] Once the papillary anchor 9 is placed and the delivery device is retracted, as discussed above, then a chordae-wire 14 is used to adjust the chordae length. An optional wire lock (not shown) can be pulled to gently pinch the artificial chordae line 14 in the temporary adjusted state during analysing of the length, the wire-chordae will in addition be held from the outside. Once the correct length is achieved, a locking wire 70 is pulled, which bends/retracts the Nitinol Z shape 20 and locks the chordae in place by releasing the locking segment 28. Then the cutting piece 18 is pulled and its nitinol knife engages with the artificial chordae line 14 as well as one strand of a papillary anchor holder suture 72. The papillary anchor 9 is now free from the adjustment and cutting device 18, 20.

[0316] The use of the Z shaped nitinol fork 20 to hold the locking segment 28 open allows the suture/chordae pathway to get a very gentle curve. It also allows the suture to come out of the device in line with the gripper opening. This is important to get as good as possible load conditions on the papillary anchor (Chorda comes out of the anchor in the correct place for optimal holding strength).

[0317] In one embodiment the cutter 18 is made from a thin sheet nitinol, which allows the blade to be pulled around a curved surface, to allow a minimal footprint of a relative long sliding action component (it can be pulled for example perpendicular to the cutting surface, taking up much less space). The Z-fork 20 can be produced from a laser cut heat set Nitinol sheet part, where certain sections can be grinded thinner, to obtain different thickness and flex along the part. It is possible to add in a simple temporary wire lock, when pulled it will gently squeeze the chordae 14 in order to maintain its temporary adjusted length, in addition to hold the wire that is connected to the chordae 14 on the outside (not in illustrations). Note that the supports inside the adjustment device 21 are not shown. The chamfer on the top part of adjustment “box” will allow the device to find the anchor 9 if it needs to be retrieved.

[0318] In one embodiment a push out tube connected to the papillary anchor 9 contains several markers that can be used as a rough reference point on the distance between the papillary anchor and the leaflet anchor, this could allow the physician to roughly adjust the chordae prior to do the final adjustments as they normally have a hunch about how long the final chordae length should be.

[0319] To prevent the cutter 18 from exceeding its desired range of motion, the cutter 18 may be equipped with two stopping features disposed at an upper and lower end of the cutter 18. To prevent the cutter 18 from moving further than its upper position in the housing, a cutter wire may be threaded through the housing and/or the cutter to stop the cutter 18 in an upper position. Even if the cutter wire were to break, the cutter 18 and a wire attached to the cutter operating it cannot escape from an upwards end of the housing as both are contained within the housing. To prevent the cutter 18 from moving further than its lower position in the housing, a cam may be used.

[0320] The shaft of the part of the catheter device 2 which houses the cutter 18 and the adjustment device 21 (not shown) can be constructed with two lumens: one chordae lumen and one cutter lumen. The construction can be reinforced with braiding around the chordae lumen (the shaft may also include any lumens required to house pullwires used for operating the device, which may also be reinforced with braiding). In addition to the braiding, a wire made out of Kevlar or another similar material may be implemented in the construction running along the length of the shaft, to increase the tensile strength of the device 2. Additionally or alternatively, a composite tube may be positioned around the lumens. The components and tubing of the shaft can also be embedded in a soft polymer, such as Pebax (e.g. by Pebax reflow), to allow for sufficient flex. The composite tubing may also be anchored in the distal end to prevent the tubing from being torn out of the soft polymer during actuation of the cutter wire. The composite tubing may be anchored in the distal end with, for example, a flat ribbon coil, a stainless steel hypotube ring, or a stainless steel collar.

[0321] The braid around the chordae lumen may comprise a laser cut hypotube, which increases the tensile and compression strength of the of the shaft construction. The laser cut hypotube can be ‘flex tailored’ such that different sections have different flex patterns to accommodate a desired movement of the shaft. The laser cut hypotube can also be welded directly onto the head of the cutter 18. The strong bond between the cutter head and the laser cut hypotube allows for more reliable retrieval of the papillary anchor if readjustment is desired. A braided composite tubing may be disposed outside the laser cut hypotube to form the wire lumens.

[0322] In some cases the natural chordae could be a problem for the device. There is a risk of fouling if one of the existing chordae is caught in the hole provided for the exit of the new artificial chordae line 14. One way to eliminate this is to have a one-way chord exit so that the artificial chordae line 14 can only go out of the device, and not in, although this feature is not essential.

[0323] Inside the papillary housing 8 there may be small notches in the walls to hold the pins of the papillary anchor 9 and prevent the papillary anchor 9 from rotating so that the pins could fold out in the opening for the new chord 14.

[0324] FIG. 23 shows a leaflet anchor 10 in combination with a line 14. The leaflet anchor 10 comprises a number of hooks 62 extending from an anchor body 80 of the leaflet anchor 10. The hooks 62 are in the unfolded position. The hooks 62 extend from a base of the anchor body 80. The anchor body 80 comprises a number of threading holes 82 accommodating at least part of the knotting configuration 90. Whilst a single threading hole 82 is visible in the Figures, it will be appreciated that multiple threading holes can be located around a circumference of the anchor body 80. The line 14 is seen passing through two threading holes 82, for example, in the plane of the page of FIG. 23.

[0325] The line 14 is joined to the leaflet anchor 10 is joined to the line 14 by a knotting configuration 90. The knotting configuration 90 comprises a plurality of loops and a plurality of knots. A first knot 92 is located at a proximal end of the anchor body 80, located within the anchor body 80. The line 14 is then looped twice around the first hook 62a by a first loop 94a and a second loop 94b, and is then looped twice around the second hook 62b by a third loop 96a and a fourth loop 96b. Whilst the line 14 shown is looped twice around each hook 62a, 62b in FIGS. 23 to 25, the line 14 may only be looped once around each hook 62a, 62b. Equally, the line 14 may be looped more than twice around each hook 62a, 62b. Shown in FIG. 25, a second knot 98 is located at a distal end of the anchor 14. The second knot 98 is adjacent to the second loop 94b and the fourth loop 96b. The second knot 98 comprises the fourth loop 96b.

[0326] Whilst not shown in any of FIGS. 23 to 25, the end of the line 14 distal to the leaflet anchor 10 can be attached to the papillary anchor 9. The line 14 can be joined to the papillary anchor 9 by the locking segment 28. The leaflet anchor 10 in combination with the line 14 is suitable for use as the leaflet anchor 10 in any of the devices and/or methods discussed above.

[0327] FIG. 24 shows the leaflet anchor 10 in combination with the line 14 implanted in body tissue 12, which in this case the mitral leaflet 12. The hooks 62 engage the mitral leaflet 12 as described above. As the hooks 62 pierce the mitral leaflet 12, entry sites 84 form around each hook 62. These entry sites 84 each or collectively may be regarded as an entry site 84 of the anchor 10 when implanted in the mitral leaflet 12. The entry sites 84 may generally comprise narrow channels and/or passageways around the length of the hooks 62 through the mitral leaflet 12.

[0328] The leaflet anchor 10 is implanted in the mitral leaflet 12 from the ventricular side, and thus the side of the mitral leaflet 12 that the anchor body 80 of the leaflet anchor 10 is located may be regarded as a high pressure side of the leaflet 12. During the cardiac cycle, blood may be forced through the entry sites 84 due to the fluid pressure generated by contraction of the heart. The blood forced through the entry sites 84 may produce a high-velocity jet into the atrial side of the leaflet 12, i.e. a low pressure side. Flow of blood through the leaflet via the entry sites 84 will inhibit tissue regrowth where the hooks pass through the tissue of the leaflet. To reach the entry sites 84 the blood may flow at high pressure and/or velocity between the anchor body 80 of the leaflet anchor 10 and the mitral leaflet 12, which exerts a force on the anchor 10 at the site of implantation in the mitral leaflet 12. This force may act to drive the anchor body 80 of the leaflet anchor 10 away from the mitral leaflet 12. The exerted force can therefore weaken the tensile strength of the anchor 14 when implanted in the mitral leaflet 12. For example, the presence of high pressure flow between the anchor body 80 and the mitral leaflet 12 may discourage the ingrowth of tissue around the base of the anchor 10 which could otherwise strengthen the implantation of the anchor 10.

[0329] The provision of the knotting configuration 90 provides a sealing effect against the entry site 84, which prevents and/or impedes the flow of blood through them. This helps to prevent the flow of high-velocity jets through the entry site 84 which could otherwise prevent the ingrowth of tissue around the anchor 10. The loops 94b, 96b each respectively provide a first sealing surface 86a, 86b which seal the entry site of the hook 62a, 62b the loop 94b, 96b is wrapped around. The first sealing surfaces 86a, 86b provide a localised sealing effect around each entry site 84a, 84b created by the respective hook 62a, 62b it is wrapped around.

[0330] The knotting configuration 90 also provides a second sealing surface 88. In contrast to the first sealing surfaces 86a, 86b, the second sealing surface 88 provides an overall sealing effect which captures all the entry sites 84 created by all the hooks 62. The second sealing surface 88 is generally formed by the second knot 98, the second loop 94b and the fourth loop 96b. As the second knot 98, the second loop 94b and the fourth loop 96b are adjacent one another, they form a ‘psuedo-loop’ due to their contact with one another, which thus in turn provides the overall sealing effect.

[0331] In combination, the first sealing surfaces 86a, 86b and the second sealing surface 88 provide a plugging effect which prevents and/or impedes the flow of high-velocity jets through the entry sites 84 of the anchor 10 when implanted in the mitral leaflet 12. This may encourage the ingrowth of body tissue around the base of the anchor 10, which overall improves the tensile strength of the anchor.

[0332] The plugging effect may be realised due to the pressure differential of the high-pressure side and the low-pressure side across the entry sites 84. The sealing surfaces 86, 88 may be suctioned to the mitral leaflet 12 around the entry sites 84. Additionally, the anchor body 80 can act to compress the loops 94, 96 to the mitral leaflet 12 to further strengthen the sealing surfaces 86, 88. The anchor body 80 can compress the sealing surfaces 86, 88 due to a fluid pressure acting on the anchor body 80 to compress the anchor body 80, and hence the sealing surfaces 86, 88 against the mitral leaflet 12; and due to a springback effect owing to the elastic properties of the hooks 62, which act to ‘pull’ the leaflet anchor 10 into the mitral leaflet 12 during implantation.

[0333] The knotting configuration 90 also provides an increased surface area for body tissue to grow around the base of the anchor 10. To encourage the growth of body tissue around the knotting configuration 90 and thus the base of the anchor 10, the line 14, or at least an outer coating of the line 14, may be formed of a biocompatible material, such as ePTFE.

[0334] The knotting configuration 90 can be regarded as a plugging device as, in accordance with the above description, the knotting configuration 90 and particularly the sealing surfaces 86, 88 of the knotting device plug the entry sites 84 of the anchor 10 in body tissue such as the mitral valve.

[0335] FIG. 26A shows a cross-sectional view of an anchor 10 comprising an alternative plugging device 89 to the knotting configuration 90. The plugging device 89 is formed of a biocompatible material and is formed at a base of the hooks 62 (shown in the folded position) of the anchor 10, such that the plugging device 89 does not interfere with the unfolding/folding action of the hooks 62 during implantation of the anchor 10 within body tissue. FIG. 26B shows a plan view of the plugging device 89 in combination with the anchor 10, as viewed from the tips of the hooks 62.

[0336] The plugging device 89 combines with the anchor 10 to provide enhanced contact with the body tissue 12. The plugging device 89 sits adjacent to and partially around the base of the anchor body 80. The plugging device additionally encircles the two hooks 62a, 62b of the anchor 10. The plugging device 89 leaves a number of threading holes 82 unimpeded, such that the anchor 10 can be used e.g. in combination with a line such as an artificial chordae line, or for holding a component in place within the body such as a stent, valve or the like. In various embodiments the anchor 10 can be used as a standalone implant, and can be formed of a radiopaque material such that it can be used as a marker, or could be used to staple regions of body tissue together.

[0337] Similarly to the knotting configuration 90 shown in FIGS. 23 to 25, the plugging device provides a sealing effect against entry sites (not shown) into which hooks 62a, 62b of the anchor 10 enter the body tissue. The sealing effect prevents and/or impedes the flow of blood through the entry sites such that tissue ingrowth around the base of the anchor 10 and the plugging device 89 is better facilitated. The portions of the plugging device 89 which encircle the hooks 62a, 62b respectively provide a first sealing surface 85a, 85b which seal the entry sites of the hooks 62a, 62b. The first sealing surfaces 85a, 85b provide a localised sealing effect around each entry site created by the respective hook 62a, 62b portions of the plugging device 89 encircle.

[0338] Similarly to the knotting configuration 90, the plugging device 89 also provides a second sealing surface 87. In contrast to the first sealing surfaces 85a, 85b of the plugging device 89, the second sealing surface 87 provides an overall sealing effect which captures all the entry sites created by all the hooks 62. The second sealing surface 87 is generally formed by all the surfaces of the plugging device 89 which surround the circumferential extent of the anchor 10 and are configured to be in contact with body tissue when the anchor 10 is implanted in body tissue (i.e. the surfaces 85a, 85b, 87 of the plugging device 89 located towards the tips or ends of the hooks 62).

[0339] As with the knotting configuration 90, the anchor body 80 can act to compress the plugging device 89 and hence each of the sealing surfaces 85a, 85b, 87 of the plugging device 89, against the area of body tissue in which the anchor 10 is implanted to further strengthen the plugging/sealing effect achieved by the plugging device 89. Again, due to the springback effect owing to the elastic properties of the hooks 62, the leaflet anchor 10 is effectively ‘pulled’ through the body tissue until the plugging device 89 contacts the body tissue and is compressed against the body tissue by the action of the hooks 62 unfolding.

[0340] As shown herein, the plugging device 89 is of a single-piece construction, and is preferably formed by an overmolding process such that the anchor 10 and the plugging device 89 form a tight interference fit with one another. Thus the plugging device 89 is generally an overmolded structure itself. This can help ensure that a seal is formed around the entry sites 84 of hooks 62a, 62b in body tissue.

[0341] Whilst not shown in FIGS. 26A and 26B, in various embodiments one or more portions of the plugging device 89 can be formed through one or more of the threading holes 82 such that the plugging device 89 is fixed to the anchor 10. However the plugging device 89 is generally not bonded or adhered to the anchor 10, such that the plugging device 89 can freely move during compression against body tissue when the anchor 10 is implanted in body tissue, such that the desired sealing/plugging effect is reliably achieved.