JP7332587B2 - Tissue remodeling device and method - Google Patents

Description

The present invention relates to RF instruments used to remodel tissue. The instruments and methods disclosed herein have broad utility for contracting collagenous tissue, and in particular, such instruments and methods remodel cardiac tissue (e.g., heart valve annulus and chordae tendineae). Suitable for reducing regurgitation through the valve to increase valve capacity.

Mitral annulus enlargement is a common feature of mitral valve disease, especially in functional or secondary mitral valve disease. As the annulus dilates, the cusps are pulled apart until the edges no longer coapt or adhere to each other during systole, resulting in regurgitation. Reducing the overall circumference of the annulus is one of the most common components of successful surgical mitral valve repair. This can be done surgically by suturing the mitral annulus to an annuloplasty ring having a smaller diameter than the mitral annulus. This permanently reduces the circumference of the mitral annulus, but requires an open or minimally invasive surgical procedure with considerable trauma, morbidity, and recovery time.

A number of different catheter-assisted mitral valvuloplasty concepts have been explored. For example, an instrument was placed in the coronary sinus lying parallel to the mitral valve annulus, or a number of anchors were placed in the valve annulus and then pulled together.

Several techniques have been attempted for performing mitral valvuloplasty using radio frequency (RF) energy. For example, a ring of electrodes is applied to the atrial surface of the valve annulus, then RF energy is delivered between the paired electrodes to heat and contract the tissue. In another technique, a pair of spaced-apart electrodes are driven into the annulus and RF energy is delivered between the electrodes to contract the annulus.

Other techniques deliver RF energy through catheters to reshape tissue and thereby other valve remodeling techniques, such as reducing the length of the chordae tendineae to reduce the heart valve leaflet tissue itself. to implement. However, these techniques have drawbacks, eg, with respect to controlling the degree of shrinkage. For example, the mitral valve has delicate and carefully shaped tissue features that may only need to be reduced in certain specific directions.

Chemically induced ablation was also applied to the mitral valve. One such attempt is Tomasz A. Timek et al., "Ablation of Mitral Annular and Leaflet Muscles: Effects on Annular and Leaflet Dynamics." mitral annular and leaflet muscle: effects on annular and leaflet dynamics”, American Journal of Physiology, October 1, 2003, available at https:// See article PubMed 12969884 at doi.org/10.1152/ajpheart.00179.2003.

Tomasz A. Timek et al., "Ablation of mitral annular and leaflet muscle: effects on annular and leaflet dynamics." : effects on annular and leaflet dynamics”, American Journal of Physiology, October 1, 2003, https://doi.org/10.1152/ajpheart.00179.2003, article PubMed 12969884.

Given the difficulties associated with current procedures, there continues to be a need for simple, effective, and less invasive instruments and methods for treating dysfunctional heart valves.

A minimally invasive method for reducing the size of an annulus in a beating heart comprising:
a. advancing an energy delivery catheter system into the heart proximate a heart valve, the energy delivery catheter system including at least two electrodes;
b. advancing the electrodes such that the two electrodes penetrate into the heart valve annulus at a distance from each other;
c. applying a proximity force to at least one of the two electrodes thereby reducing the distance between the two electrodes;
d. A method, comprising: applying energy between at least two electrodes, thereby heating and contracting a valve annulus in the direction of the proximal force.

The method further includes extending the electrodes from the energy delivery catheter by widening the spacing between the electrodes from the compact spacing to the stretched spacing, wherein the spacing between the electrodes in the stretched spacing is: Wider than the spacing between the electrodes in compact spacing.

In any of the above methods, the at least two electrodes are configured to self-extend away from each other when unconstrained, and increasing the spacing between the two electrodes includes causing the at least two electrodes to self-extend. including the step of allowing them to move away from each other.

In any of the above methods, increasing the spacing between the two electrodes includes inflating a bladder interposed between the two electrodes.

In any of the above methods, increasing the spacing between the electrodes includes actuating a mechanism for actively increasing the spacing between the two electrodes.

In any of the above methods, the two electrodes comprise a first electrode and a second electrode, the method comprising:
a. withdrawing the first electrode from the valve annulus while the second electrode remains embedded in the valve annulus;
b. rotating the energy delivery catheter about the second electrode;
c. advancing a first electrode into the heart valve annulus;
d. applying a proximity force that urges at least one of the first or second electrodes toward the other;
e. applying energy between the first electrode and the second electrode, thereby heating and contracting the valve annulus in the direction of the proximal force.

In any of the above methods, the method comprises:
a. ceasing the delivery of energy to allow the annulus to cool;
b. withdrawing the two electrodes from the valve annulus.

In any of the above methods, applying a proximal force includes advancing a Sheath Catheter toward the at least two electrodes.

In any of the above methods, applying a proximity force includes deflating a bladder between the electrodes.

In any of the above methods, applying the proximity force comprises actuating a mechanism that actively reduces the spacing between the two electrodes.

Also, a minimally invasive method for selectively reducing the geometry of cardiac tissue in a beating heart comprising:
a. advancing a catheter system into the heart proximate a heart valve, the catheter system including at least two engagement members and an energy delivery mechanism;
b. advancing the engagement members such that the engagement members engage heart tissue at a distance from each other;
c. applying a proximity force to the engagement member;
d. A method, comprising applying energy between engaging members using an energy delivery member, thereby contracting heart tissue in the direction of the proximal force.

The above method for selectively reducing the size of heart tissue further includes extending the engagement members from the catheter system by increasing the distance between the engagement members from a compact spacing to an elongated spacing. A contained and stretched interval is wider than a compact interval.

In any of the above methods for selectively reducing the dimensions of heart tissue, the engagement members are configured to self-extend away from each other when unrestrained to increase the distance between the engagement members. The steps include allowing the engagement members to self-extend away from each other.

In any of the above methods for selectively reducing the size and shape of heart tissue, the step of increasing the distance between the engaging members includes inserting a bladder interposed between the engaging members. Including the step of flitting.

In any of the above methods for selectively reducing the size and shape of heart tissue, the step of increasing the distance between the engaging members includes a mechanism for actively increasing the spacing between the engaging members. Including the step of actuating the body.

In any of the above methods for selectively reducing the size and shape of heart tissue, the engaging member comprises a first engaging member and a second engaging member, the method comprising:
a. withdrawing the first engaging member from the heart tissue while the second engaging member remains engaged to the heart tissue;
b. rotating the energy delivery catheter about the second engagement member;
c. advancing the first engagement member to engage the heart tissue;
d. moving at least one of the engagement members along the proximal path toward the other engagement member;
e. applying at least one of energy and/or chemical between the engaging members, thereby contracting the heart tissue in the direction of the proximal force.

In any of the above methods for selectively reducing the size and shape of heart tissue, the step of moving at least one of the engaging members along the proximal path toward the other engaging member includes: toward the engagement member.

In any of the above methods for selectively reducing the size of heart tissue, the step of moving at least one of the engagement members along the proximal path toward the other engagement member includes: , including the step of deflating the

In any of the above methods for selectively reducing the size of heart tissue, the step of moving at least one of the engagement members along the proximal path toward the other engagement member comprises: actuating the body thereby narrowing the spacing between the engagement members.

In any of the above methods, applying energy comprises applying an energy modality selected from the group (bipolar, monopolar, resistive heating, ultrasound, laser, and microwave).

In any of the above methods for selectively reducing the size and shape of heart tissue, the chemical is selected from the group (phenol and glutaraldehyde).

Also, a minimally invasive device for reducing the size and shape of a heart valve annulus in a beating heart, comprising:
a. having an elongated delivery catheter;
b. Having at least two engagement members supported by the delivery catheter, the engagement members having a retracted position in which the engagement members are housed within the delivery catheter and an extension in which the engagement members extend beyond the distal end of the delivery catheter. can move between positions and
c. a tissue contraction component configured to deliver at least one of energy and/or chemicals between the engagement members;
d. A minimally invasive instrument comprising a approximation mechanism configured to apply a force to the engagement member, the force being selected from the group of approximation force and/or separation force.

In the above instruments, the tissue contraction component includes an energy delivery mechanism configured to deliver an energy modality selected from the group (bipolar, resistive heating, ultrasound, laser, and microwave).

In any of the above devices, the tissue contraction component comprises a chemical selected from the group (phenol and glutaraldehyde).

In any of the above instruments, the tissue contraction component is operably connected to the engagement member.

In any of the above instruments, the approximation mechanism includes a linkage that couples the engagement members together.

In any of the above instruments, the linkage may include a hinge.

In any of the above instruments, the approximation means includes a pull wire coupled to the linkage such that pulling on the pull wire applies a biasing force to the engagement member.

In any of the above instruments, the approximation mechanism includes a sleeve surrounding at least a portion of the engagement members such that advancement of the sleeve urges the engagement members together.

FIG. 12 shows an energy delivery device; FIG. 12 shows an energy delivery device; FIG. 12 shows an energy delivery device; 1A-1D illustrate energy delivery devices and methods for contracting heart tissue in selective directions. 1A-1D illustrate energy delivery devices and methods for contracting heart tissue in selective directions. 1A-1D illustrate energy delivery devices and methods for contracting heart tissue in selective directions. 1A-1D illustrate energy delivery devices and methods for contracting heart tissue in selective directions. FIG. 10 illustrates a method for contracting heart tissue in selective directions. FIG. 10 illustrates a method for contracting heart tissue in selective directions. FIG. 10 illustrates a method for contracting heart tissue in selective directions. FIG. 10 illustrates a method for contracting heart tissue in selective directions. FIG. 12 shows an energy delivery device; FIG. 4 illustrates an optional feature of the energy delivery device of FIGS. 1-3; FIG. 4 illustrates an optional feature of the energy delivery device of FIGS. 1-3; FIG. 4 illustrates an optional feature of the energy delivery device of FIGS. 1-3; FIG. 12 shows an energy delivery device;

The present invention is useful for contracting collagenous tissue in general, and the present invention allows heart tissue, such as the annulus and/or chordae of a heart valve, to contract in a controlled and predictable manner to pass through the valve. It is particularly useful for reducing reflux.

Annuloplasty Several existing mitral annuloplasty techniques contract collagen fibers by heating them to a transition temperature. It is known that the application of energy to heat collagenous tissue in a relaxed state causes the collagenous tissue to contract, and this contraction typically occurs in all directions. In general, shrinkage is greater in the direction of fiber orientation. However, heating the collagen tissue while it is under a certain degree of tension often results in contraction of the collagen in a dimension different from the direction of tension. This presents a particular challenge for mitral valve procedures as the action of ventricular pressure on the mitral annulus induces substantial tension in the mitral annulus. The general stiffness of the mitral annulus and the nature of surrounding tissue, including muscular ventricular tissue, also tend to retain collagen in its original shape even after application of energy. In addition, the collagenous tissue within the annulus is surrounded by other tissue, such as muscle, that probably does not contract when heated. As a result, existing mitral annuloplasty techniques fail to contract the collagen fibers in the desired manner.

The present invention is expected to address the shortcomings of existing mitral annuloplasty techniques by grasping heart tissue and approximating it in a desired direction of contraction. Energy is applied to the tissue either during or after tissue approximation. The desired contraction may be circumferential (eg, around the heart valve annulus) or may be in another direction. For example, tissue approximation reduces the tension experienced by heart tissue, thereby preferentially contracting collagen tissue in a desired direction. The tissue approximating force can be maintained briefly after energy delivery has ceased. The tissue will contract more in the desired direction than without pre-approximation, and the tissue retains much of the contraction in the desired direction even after the energy is applied and the device is removed. will do.

FIG. 1 shows an energy delivery device 100 having a delivery catheter 120 and an optional guiding catheter 122. FIG. The instrument 100 has a plurality of pin-shaped electrodes 102 (individually shown as first electrode 102a and second electrode 102b) at the distal end. The electrodes 102 may be advanced and/or retracted independently, thereby inserting the electrodes into the annulus and/or withdrawing the electrodes from the annulus. For example, a pushing action may be used to advance the electrodes (e.g., a push rod or push wire) and/or the electrodes 102 may have a threaded surface that engages and advances them into the annulus by rotation. 104. Electrode 102 may have a conductive, non-stick coating 106 so that the electrode can be easily retracted from the tissue after heating the tissue. Electrodes 102 may be relatively stiff so that they resist bending when a proximal force is applied to pull the two electrodes together.

The first and second electrodes 102a, 102b can be housed within respective guide tubes 108a, 108b, respectively, and the catheter 100 includes a approximation mechanism 110 that can pull the guide tubes 108a, 108b together. Better to have more. For example, the approximation mechanism can pull the guide tubes 108a, 108b together with sufficient force to overcome the tension naturally occurring in tissue. In some embodiments, the proximity mechanism 110 includes a pull wire 111W extending through the catheter and a hinge 112 located proximal to the distal tip as shown in FIG. These embodiments produce an arcuate proximity motion (indicated by arrows A _A ) between the first electrode 102a and the second electrode 102b. In some embodiments, as shown in FIG. 2, the proximity mechanism 110 provides linear proximity motion (indicated by arrows A _L ) between the first electrode 102a and the second electrode 102b. are connected by a linkage 114 configured to maintain a constant orientation between the first electrode 102a and the second electrode 102b when the electrodes are brought into close proximity. For example, the proximity mechanism 110 of FIG. 2 can maintain a parallel relationship between the first electrode 102a and the second electrode 102b throughout the motion portion of the proximity motion. For example, in some embodiments shown in FIG. 2, proximity mechanism 110 is a threaded mechanism 111S including a worm gear (not shown) or the like. However, the embodiment shown in FIG. 2 allows the threaded mechanism 111S to replace the pull wire 111W for actuating the linkage 114. As shown in FIG.

FIG. 3 shows a constriction member 116 in which the proximity mechanism 110 is positioned around the first and second electrodes 102a, 102b and an extension member interposed between the first electrode 102a and the second electrode 102b. Instrument 100 including 118 is shown. A contracting member 116 pulls the two electrodes 102a, 102b together (bringing them closer together), while an expanding member 116 separates the electrodes 102a, 102b from each other. In some embodiments, expansion member 116 is an elastic sleeve and expansion member 118 is a balloon 118 or the like. Expansion member 118 is configured to overcome the biasing force of contraction member 116 to separate electrodes 102a, 102b from each other. For example, if expansion member 118 is a balloon, the balloon may be inflated with a fluid, such as saline, to overcome the proximal force of contraction member 116, thereby further separating electrodes 102a, 102b from one another. . By deflating the balloon by withdrawing some of the fluid from the balloon, the approximation force from the deflation member 116 can overcome the expansion force of the balloon, thereby approximating the electrodes 102 . Constriction member 116 may include one or more biasing members, e.g., springs, elastomeric members, worm gears, etc., that interconnect electrodes 102a, 102b and/or tubes 108a, 108b instead of elastic sleeves. . Many other mechanisms can be used to adjust the spacing between the electrodes 102, as will be appreciated by those skilled in the art.

The catheter 100 shown in FIGS. 1-3 includes a first sensor 130a located at the first electrode 102a and a second sensor 130b located at the second electrode 102b (collectively, "sensor 130 ). Sensor 130 may be an impedance sensor or thermistor embedded in one or both of electrodes 102 . Sensor 130 may monitor tissue temperature or impedance to determine tissue condition before, during, and/or after energy is applied to tissue via electrodes 102a, 102b. The sensor 130 can send signals to the controller to ensure electrode operation, ensure electrode contact, control the degree of contraction, avoid overtreatment, and the like. For example, signals from sensor 130 can be used to determine the total energy delivered to tissue or estimate the distance between electrodes based on the relative spacing of the electrodes.

Electrodes 102a, 102b may be solid members (eg, solid wires) or may have longitudinal lumens (eg, hollow wires, not shown) and distal holes (not shown). It may be a tube. For example, the lumens can extend the entire longitudinal length of the electrodes 102a, 102b, and the side holes can be in fluid communication with the lumens such that fluid introduced into the lumens exits through the holes. Physiological or hypertonic saline can be injected through the lumen and orifices while applying energy via electrodes 102a, 102b to increase the effective heating area and control the degree of tissue desiccation at electrodes 102a, 102b. good. Alternatively, the electrodes 102a, 102b may be cooled by circulation of fluid through them to prevent overheating of the electrodes while the intervening tissue is being heated.

4A-4D illustrate an example of the principle of operation of the instrument 100 shown in FIG. 1. FIG. As will be appreciated by those skilled in the art, the instrument 100 shown in Figures 2 and 3 operates in a similar manner. In use, the distal end of energy delivery catheter 120 is first positioned near or against heart tissue, eg, the mitral valve annulus. (See FIG. 4A.) The energy delivery catheter 120 may be introduced to the left atrial surface of the annulus in a transseptal or transatrial manner, or it may be delivered to the ventricular surface of the annulus in a transaortic or transapical manner. You can guess. The energy catheter 120 or guiding catheter 122 can be manipulated to position the tip 120a of the catheter 120 near or in contact with the appropriate annulus tissue. A first electrode 102a is then advanced into the annulus as shown in FIG. 4A. The first or second electrodes 102a, 102b may be advanced independently of each other into the annulus tissue or they may be advanced together into the tissue. The electrodes 102 are exposed by withdrawing the energy delivery catheter 120 from the guiding catheter 122 or by extending the energy delivery catheter 120 from the guiding catheter 122 and then withdrawing the energy delivery catheter 120 relative to the tubes 108a, 108b. . Withdrawing the energy delivery catheter 120 may self-bias the electrodes 102a, 102b to move further apart. A second electrode 102b can then be advanced into the tissue. (See FIG. 4B.) A proximal force is applied to pull the two electrodes 102a, 102b together, thereby tightening the annular tissue between the electrodes 102a, 102b, thereby reducing the overall diameter of the valve annulus. (See FIG. 4C.) For example, the electrodes 102a, 102b may be inserted 10 mm apart into the annulus tissue and then pulled together to a separation distance of 2 mm to 8 mm, or 3 mm to 7 mm, or about 5 mm. . The instrument 100 shown in FIGS. 4A-4C pulls the electrodes 102a, 102b together using the pull wire 111W described above with reference to FIG. Worm gears, linkages, etc. as described above with reference to FIGS. 2 and 3 may be used.

After the electrodes 102a, 102b are spaced apart from each other by the desired distance, energy is then applied between the electrodes 102a, 102b to heat the tissue for a desired period of time (eg, 15 seconds) until the collagen is released. Deform appropriately so that the annulus retains its new, smaller circumference. The energy can be bipolar RF energy, monopolar RF energy, laser energy, ultrasonic energy, resistive heating of electrodes, micro It may be wave energy, or it may be another energy modality. Energy is applied based on power and time to produce the desired amount of contraction without causing undesirable destruction of tissue. For example, the energy is 10W to 100W, 15W to 85W, 20W to 70W, 25W to 55W, 10W, 15W, 20W, 25W, 30W, 40W, 45W, 50W, 55W, 60W, 65W, 70W, 75W, 80W, 85W, It can be applied at 90W, 95W or 100W or any suitable wattage therebetween. In addition, energy from 5 seconds to 300 seconds, 10 seconds to 240 seconds, 10 seconds to 60 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds, 30 seconds, 35 seconds, 40 seconds, 45 seconds, 50 seconds , 55 seconds, or 60 seconds. A chemical (eg, phenol, glutaraldehyde, or other fixative chemical) may be applied between the two electrodes in addition to or instead of delivering electromagnetic or mechanical energy through the first and second electrodes 102a, 102b. good to add to heart tissue.

Bipolar RF energy has the advantage of being naturally directed between two electrodes to heat tissue and cause it to contract in desired areas, although other energy modalities may also be utilized. can be done. For example, any of the catheters 100 described above may include monopolar RF energy, laser energy, ultrasound energy, resistive heating of electrodes, microwave energy, or other energy modalities in addition to or in place of RF energy. can be used for Additionally, chemical methods, such as injection of small amounts of phenol, glutaraldehyde, or other fixative chemicals, can also be used to shape the tissue into the desired shape.

The process described above with reference to FIGS. 4A-4C is repeatedly performed on different regions of the annulus to further reduce the perimeter of the annulus in selected regions, thereby selectively regenerating the annulus. It may be formed to promote bonding or adhesion. For example, referring to FIG. 4D, after tissue approximation, heating, contraction, and sufficient cooling at the first region of the annulus, at least one of the electrodes 102a, 102b is withdrawn from the tissue to form the annular tissue. It is better to move it to another section of If it is desired to treat adjacent tissue located on one side or the other of the first region of the annulus, the first electrode 102a is removed from the tissue while the second electrode 102b remains in the tissue. It can be withdrawn, and then the energy delivery catheter 120 can be rotated (pivoted) about the second electrode 102b by 180° so that the first electrode 102a is connected to the second electrode 102b. located on the other side of the The first electrode 102a can then be advanced into the tissue at a new location so that the first and second electrodes 102a, 102b are positioned adjacent to the first region of the valve annulus. 2 areas are straddled. Treatment can then continue by applying energy to the second region of the valve annulus via the first and second electrodes 102a, 102b. Thus, the catheter can be "walked" from one area of annulus tissue to the next while the catheter remains attached to the annulus at all times. This is expected to make repositioning of the electrodes 102a, 102b extremely quick and easy.

In any of the above embodiments, a guiding catheter 122 may be used to position the energy delivery catheter 120 on or near the mitral valve annulus. For example, guiding catheter 120 may be inserted into the femoral vein and advanced across the atrial septum of the heart until tip 122a of guiding catheter 122 is positioned within the left atrium. The energy delivery catheter 120 can be inside the guiding catheter 122 at this point. Guiding catheter 122 can then be deflected until tip 122a opens toward a location above the mitral valve. The energy delivery catheter 120 can then be advanced distally through the guiding catheter 122 until the electrode 102 is positioned at or near the mitral valve. One or both of the electrodes 102a, 102b can be advanced into the annulus as described above with reference to Figure 4A. For example, once the first electrode 102a is fixed in place, the guide catheter 122 can be withdrawn to allow the two electrodes to move laterally away from each other. The energy delivery catheter 120 can be rotated until the second electrode 102b is positioned over the mitral valve and the second electrode 102b is advanced into the valve annulus as described above with reference to FIG. It is better to let The two electrodes 102a, 102b may be drawn toward each other until they are spaced apart a distance that places the tissue in the desired state of tension. Energy can then be delivered to the tissue via the first and second electrodes 102a, 102b. After a sufficient amount of energy has been delivered to the tissue between the first electrode 102a and the second electrode 102b, the first electrode 102a is withdrawn and the adjacent segments of the valve annulus are separated for subsequent treatment. It is better to reposition to FIG. 4D shows an example of the resulting annular contraction of the valve annulus.

Some of the above embodiments may be modified to require two electrodes and instead use a single electrode and/or chemical delivery device. For example, instead of having two active electrodes 102a, 102b, the catheter 100 described above with reference to FIGS. It can have monopolar electrodes and/or chemical injection needles configured to extend between each other. In operation, the proximity mechanism 110 may draw the guide tubes 108a, 108b together to move the electrically inoperative arms closer together as described above, and then (a) use monopolar electrodes to Electrical energy can be applied to the tissue located between the arms and/or (b) a chemical contraction agent can be applied to the tissue located between the arms via a chemical injection needle.

Although this concept has been described for performing mitral annuloplasty, the concept can be applied to the tricuspid annulus as well. The elasticity of the tricuspid annulus is even more pronounced than that of the mitral annulus, so each segment may be further compressed prior to energy delivery. For example, each segment may be compressed to ⅓ of its pretreatment length prior to energy delivery.

Chordotomy Mitral valve prolapse or regurgitation can result from excessively long chordae. The chordae tendineae are taut and straight during systole and become limp and tortuous during diastole. It has previously been proposed to shorten the chordae by applying energy to heat and contract the chordae tendineae. In the prior art, electrodes are placed against the chordae tendineae and energy is applied until the chordae tendineae contract appropriately. This is an uncontrolled method, and this uncontrolled method can easily result in excessive contraction of the chordae tendineae, which ultimately results in "tethering" the cusps. )” and prevent the valve from closing. In addition, it can be difficult to control the chordae tendineae and visualize how large contractions are occurring.

5A-5D illustrate selecting a chordae tendineae using an instrument 500 having an energy delivery mechanism 501 (individually shown as first energy delivery mechanism 501a and second energy delivery mechanism 501b). 1 shows a technique for thermally and controllably heating and contracting. The first and second energy delivery mechanisms 501a, 501b are configured to grip one or more chordae tendineae at two locations at a particular distance. The energy delivery mechanisms 501a, 501b may then be brought closer together by the desired contraction length, and energy may then be delivered between the energy delivery mechanisms 501a, 501b to cause the energy delivery mechanisms 501a, 501b to Retract the portion of the chordae that are located. For example, the first energy delivery mechanism 501a can be energized with one polarity and the second energy delivery mechanism 501b can be energized with the opposite polarity, resulting in a current is allowed to flow through the region of the chordae tendineae located between the first energy delivery mechanism 501a and the second energy delivery mechanism 501b.

Grasping the chordae or chordae in the beating heart can be a challenge. For example, it may be difficult to manipulate existing catheter-based systems to grasp such chordae tendineae so that the electrodes are spaced apart from each other by the desired distance. One solution to this challenge is shown in Figures 5A-5D. Referring to FIG. 5A, the first and second energy delivery mechanisms 501a, 501b are initially brought close together, possibly at an oblique angle to the axis of the catheter, thereby allowing delivery through the guiding catheter 530 to Minimize these cross-sectional profiles to allow for The energy delivery elements 501a, 501b may have jaws 502a, 502b, respectively, which are (a) open to receive the cord and (b) slidable along the cord. and (c) fully closed to grip the cord to prevent it from sliding relative to the jaws 502a, 502b. 5A and 5B together, the first and second energy delivery mechanisms 501a, 501b can be placed close to each other at a first region of the ligament (FIG. 5A) and then the second region. One energy delivery mechanism 501a can be moved away from the second energy delivery mechanism 501b, thereby separating the first and second energy delivery mechanisms 501a, 501b from each other along the line (FIG. 5B). Let The first and second jaws 502a, 502b are then tightly clamped against the cord and then brought closer together (closer), resulting in a certain amount of slack S shown in FIG. 5C. Allow it to be induced during the search. Energy is then applied between the first and second energy delivery mechanisms 501a, 501b to preferentially and controllably contract the cord longitudinally as shown in FIG. 5D. good. After the cord has achieved the desired length, the jaws 502a, 502b can be released (eg, opened) to release the cord. The performance of the valve can then be reassessed and, if necessary, energy can be reapplied to further contract the chord or other chords can be contracted.

A transatrial, transaortic, transapical, or transseptal approach can be used to place device 500 at the chordae. In this setting, ultrasound imaging, especially three-dimensional transesophageal imaging, would be very helpful in managing the procedure. The instrument can also be used in a surgical setting with a visual confirmation of the cord's grasp and length to be shortened.

The energy may be bipolar RF energy applied between the first jaw 502a and the second jaw 502b, may be monopolar RF energy, may be laser energy, may be ultrasonic energy. , resistive heating of the electrodes, microwave energy, or other energy modalities. Bipolar energy can have the advantage of directing energy to the tissue between the two jaws. A chemical (eg, phenol, glutaraldehyde, or other fixative chemical) may be applied to the heart tissue between the two jaws 502a, 502b in addition to or instead of energy delivery.

FIG. 6 shows several embodiments of the energy delivery mechanism 501 of the instrument 500 described above with reference to FIGS. 5A-5D. In some embodiments, the energy delivery mechanism 501 has a jaw 502 with a first jaw portion 503a and a second jaw portion 503b, the first and second jaw portions 503a, 503b respectively , first and second electrical contacts 504a, 504b (collectively referred to as "contacts 504"). Each of the first and second jaw portions 503a, 503b can have a shaft 506a, 506b, respectively, and a gripping portion 508a, 508b, respectively. Shafts 506a, 506b extend longitudinally along the length of the instrument and are configured to be manipulated to move gripping portions 508a, 508b toward or away from each other. Shafts 506a, 506b and gripping portions 508a, 508b may be electrically conductive and coated with a dielectric except in the areas of contacts 504a, 504b. Alternatively, the shafts 506a, 506b and gripping portions 508a, 508b may be made of a dielectric material, with separate conductive contacts 504a, 504b and wires located in or on the shafts 506a, 506b. do. The energy delivery mechanism 501 can further include a coiled sleeve 522 through which the shafts 506a, 506b and gripping portions 508a, 508b can pass. In operation, the gripping portions 508a, 508b may be closed (eg, clamped together) by slidingly advancing the coiled sleeve 522 distally toward the gripping portions 508a, 508b; Alternatively, it may be opened (eg, separated) by sliding the coiled sleeve proximally (retracted) away from gripping portions 508a, 508b. Accordingly, gripping portions 508a, 508b may extend from shafts 506a, 506b along smooth bends 509a, 509b, respectively, to facilitate opening and closing of gripping portions 508a, 508b by movement of coiled sleeve 522. . The energy delivery mechanism may have only one of the electrical contacts 504a, 504b in some embodiments.

In operation, a common polarity may be applied to both contacts 504a, 504b within a single jaw 502 of one energy delivery mechanism 501. Accordingly, two energy delivery mechanisms 501 can be used as described above with reference to FIGS. 5A-5D to apply bipolar RF energy into the ligament. Alternatively, a common electrode may be used in place of one of the energy delivery mechanisms 501a, 501b. Additionally, the contacts 504a, 504b of the single energy delivery mechanism 501 may be energized with opposite polarities to focus the energy on the region of the ligament between the contacts 504a, 504b.

Recusp remodeling mitral regurgitation often occurs because there is excessive loose tissue in the posterior leaflet. Dr. Dwight McGoon of the Mayo Clinic developed a technique to excise a V-shaped segment of the P2 segment of the free edge of the posterior leaflet and stitch the severed edges together. More recently, surgeons have simply woven excess tissue into the ventricle and sewed the edges of the segment together without cutting the apex, a technique known as "foldoplasty" or " It is sometimes called "dunkoplasty". Several attempts have been made to contract the cusps using RF energy, but existing techniques do not provide adequate control over the direction of contraction. For most patients with mitral valve prolapse due to excess posterior leaflet tissue, move the leaflets along the lateral-medial direction of the free edge rather than from the free edge to the annulus (anterior-posterior direction). It is desirable to shrink The present invention provides a mechanism that inhibits contraction in the anterior-posterior direction while promoting contraction in the lateral-medial direction. Additionally, the RF energy can moderate the elastic modulus of the cusps (eg, can stiffen the cusps) in ways that can reduce the amount of deflection.

Figures 7A-7C illustrate an instrument 600 for controlled contraction of the cusps by application of energy and/or application of chemicals. As shown in FIG. 7A, device 600 includes a catheter 620 introduceable into the left atrium and energy delivery elements 602 (individually shown as first energy delivery element 602a and second energy delivery element 602b). ) with two energy delivery arms 601 (individually shown as first arm 601a and second arm 601b). The energy delivery elements 602a, 602b may be configured to bear against the native leaflet of a heart valve, e.g., the posterior leaflet of the mitral valve, each of the energy delivery elements 602a, 602b including an electrode 604 and a hole 606. good to have The energy delivery elements 602 a , 602 b can be individually secured against the cusps with suction directed through holes 606 . The energy delivery elements 602 a , 602 b may optionally have extensions 608 configured to wrap around the free edges of the cusps and press the cusps against the energy delivery elements 602 . The electrodes 604 can be flexible, eg, a conductive mesh, so that they can be held firmly against the cusps. (See FIG. 7B.) Alternatively, electrode 604 may be a more rigid conductive element. Energy delivery element 602 has surface features that engage tissue and prevent this tissue from contracting along the length of electrode 604 during energy delivery as shown in FIG. 7B. 609a, for example, may also have a face 609 with roughness, serrations, small spikes, and the like. The instrument 600 includes a pull wire system 611 designed to pull the two arms 601 together before applying energy or to allow the arms 601 to freely move closer together when the tissue is contracting. It can also have a proximity mechanism 610 that includes a. The proximity mechanism may alternatively be any of the proximity mechanisms 110 described above with reference to FIGS. The energy can be bipolar RF energy, monopolar RF energy, laser energy, ultrasonic energy, resistive heating of electrodes, micro It may be wave energy or other energy modalities. A chemical (eg, phenol, glutaraldehyde, or other fixative chemical) may be applied to cardiac tissue located between the two energy delivery elements 602 in addition to or instead of energy delivery. (See Figure 7C.)

Surgical Applications of These Concepts The apical plasty, chord shortening, and apex reshaping techniques described above in accordance with the present invention are also applicable to open and minimally invasive surgical techniques. For example, FIG. 8 has an instrument 700 having a pair of surgical forceps with pointed electrodes 702 at the tips, which the surgeon can insert into the annulus. can. Electrodes 702 are used to approximate tissue and deliver energy. Electrodes 702 are electrically isolated from forceps body 704 so that energy can be delivered between electrodes 702 . Alternatively, the electrodes 702 and arms 706 may be attached to a catheter, single shaft instrument, or the like (not shown), perhaps by a covering sleeve. This allows insertion through a thoracoscopic port for "Port-Access" surgery and/or for purse string sutures in the wall of the left atrium for beating heart surgery. Insertion through lime layers is possible. The catheter or instrument shaft may be designed to be flushed to prevent introduction of air into the bloodstream and to prevent backflow of blood from the instrument. In some embodiments, the catheter can have an overall shaft diameter of 3-10 mm, and the shaft can be made flexible to accommodate various surgical angles. The catheter may be a disposable device or a reusable device. Similarly, other concepts described above may be modified for use in a surgical environment. The energy can be bipolar RF energy, monopolar RF energy, laser energy, ultrasonic energy, resistive heating of electrodes, micro It may be wave energy, or it may be another energy modality. Chemicals (eg, phenol, glutaraldehyde, or other fixative chemicals) may be applied to the heart tissue between the two electrodes in addition to or instead of energy delivery.

Combining These Concepts with Other Techniques It should be noted that when performing mitral valve repair, it is often desirable to perform several different repair techniques in the same procedure. For example, the cardiac tissue contraction techniques described in this disclosure can be combined with chordal contraction procedures, incisal repair with MitraClip® devices (Abbott Vascular) or other devices, or procedures.

Claims (14)

1. A minimally invasive device for reducing the size and shape of a heart valve annulus in a beating heart, comprising:
having an elongated delivery catheter;
Having at least two engagement members supported by the delivery catheter, the engagement members are positioned in a retracted position in which the engagement members are retracted within the delivery catheter and in a retracted position in which the engagement members are distal of the delivery catheter. movable between an extended position extending beyond an end, wherein the engagement member is configured to engage tissue of the heart valve annulus in the extended position;
a tissue contraction component configured to deliver at least one of energy and/or chemicals between the engagement members;
a approximation mechanism configured to apply a directional force to the engagement member, the force being selected from the group of approximation and/or separation forces, the force causing the tissue contraction component to The energy and/or chemical is applied to the tissue either during or after the approximation to change the tension in the tissue between the engaging members to force the tissue in the direction of the force. A minimally invasive device configured to induce contraction of a 2. The minimally invasive instrument of Claim 1, wherein the tissue contraction component comprises an energy delivery mechanism configured to deliver an energy modality selected from the group of bipolar, resistive heating, ultrasound, laser, and microwave. 3. The tissue contraction component of claim 1 or 2, wherein the tissue contraction component comprises a chemical delivery mechanism configured to deliver a chemical between the engaging members, the chemical being selected from the group of phenol and glutaraldehyde. A minimally invasive device as described. 4. The minimally invasive instrument of any one of claims 1-3, wherein the approximation mechanism is operably connected to the engagement member. 5. The minimally invasive instrument of any one of claims 1-4, wherein the approximation mechanism includes a linkage coupling the engagement members together. 6. The minimally invasive instrument of Claim 5, wherein the linkage includes a hinge. 6. The minimally invasive instrument of claim 5, wherein the approximation mechanism includes a pull wire coupled to a linkage such that pulling on the pull wire applies a biasing force to the engagement member. 8. The approximation mechanism according to any one of claims 1 to 7, wherein the approximation mechanism includes a sleeve surrounding at least a portion of the engagement members, and advancement of the sleeve urges the engagement members together. A minimally invasive device as described. 3. The tissue contraction component comprises an electrode on each of the engagement members, the electrodes configured to penetrate into the heart valve annulus at a distance from each other. 9. Minimally invasive device according to any one of 4-8. 10. The minimally invasive instrument of Claim 9, wherein the electrode is configured to be inserted into the annulus using a pushing action. 10. The minimally invasive instrument of Claim 9, wherein at least one electrode has a threaded surface configured to be advanced into annulus tissue by rotation. 9. The minimally invasive instrument of any one of claims 1, 2, 4-8, wherein the tissue contraction component includes an energy delivery mechanism configured to apply energy to the chordae tendineae in the direction of the force. The tissue contraction component includes an energy delivery mechanism having jaws with a first jaw portion and a second jaw portion, the first jaw portion including a first electrical contact, and the second jaw portion. includes a second electrical contact. Claims 1-13, wherein the tissue contraction component comprises an energy delivery mechanism having two electrodes and a chemical delivery mechanism configured to deliver chemicals to cardiac tissue between the two electrodes. The minimally invasive device according to any one of

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