US 20080234702 A1
Methods and devices provide constriction of a heart valve annulus to treat cardiac valve regurgitation and other conditions. Embodiments typically include a device for attaching a cinching or tightening apparatus to a heart valve annulus to reduce the circumference of the annulus, thus reducing valve regurgitation. Tightening devices may include multiple tethered clips, multiple untethered crimping clips, stabilizing devices, visualization devices, and the like. In one embodiment, a plurality of tethered clips is secured circumferentially to a valve annulus, and the tether coupling the clips is cinched to reduce the circumference of at least a portion of the annulus. Methods and devices may be used in open heart surgical procedures, minimally invasive procedures, catheter-based procedures, and/or procedures on beating hearts or stopped hearts.
79. A method of tightening mitral valve annular tissue, comprising:
attaching first, second and third annular tissue fasteners to mitral valve annular tissue, wherein the first, second and third annular tissue fasteners are pre-coupled to a plurality of slidably coupled tether segments;
applying a tensile force to the plurality of tether segments;
shortening a distance between the first and second annular tissue fasteners and a distance between the second and third annular tissue fasteners; and
locking the plurality of tether segments in a tensioned state.
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The application claims the benefit of Provisional Application Nos. 60/388,935 (Attorney Docket No. 016886-000300US), filed on Jun. 13, 2002; 60/429,288 (Attorney Docket No. 016886-000700US), filed on Nov. 25, 2002; 60/445,890 (Attorney Docket No. 016886-000800US), filed on Feb. 6, 2003, and 60/462,502 (Attorney Docket No. 016886-001100US), filed on Apr. 10, 2003, the full disclosures of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates generally to medical methods and devices. More particularly, the invention relates to methods and devices for circulatory valve repair, especially for the repair of heart valves, such as repair of the mitral or tricuspid valve for treating mitral or tricuspid regurgitation.
Four valves in the heart direct blood flow through the heart in a forward direction. On the left side of the heart, the mitral and aortic valves direct oxygenated blood from the lungs to the aorta for distribution to the body. On the right side of the heart, the tricuspid and pulmonary valves direct de-oxygenated blood from the body to the pulmonary arteries for distribution to the lungs.
The four heart valves consist of moveable leaflets that open and close in response to differential pressures on either side of the valve. The mitral valve, for example, has two leaflets while the tricuspid valve has three. The components of the mitral valve assembly include a mitral valve annulus, an anterior leaflet, a posterior leaflet, two papillary muscles which are attached at their bases to the interior surface of the left ventricular wall, and multiple chordae tendineae, which are cord-like structures that couple the mitral valve leaflets to the papillary muscles. The other heart valves have similar supporting structures, though each is somewhat unique.
If a functional problem occurs in one or more heart valves, cardiac function is often adversely affected. Such valve problems may be classified as either stenosis, in which a valve does not open properly, or insufficiency (also known as regurgitation), in which a valve does not close properly. Mitral regurgitation, for example, is typically caused by dysfunction of the mitral annulus, subvalvular apparatus, or direct injury to the valve leaflets. Severe mitral regurgitation is a serious problem which, if left untreated, can adversely affect cardiac function and compromise a patient's quality of life and longevity. In cases where an atrioventricular valve becomes regurgitant due to damage to the valve supporting structures, papillary muscles, leaflets or annular geometry, the fraction of blood in the ventricle that is actually moved forward with each beat is reduced. To compensate, the ventricular cavity enlarges in an attempt to maintain forward output. By enlarging, the heart attempts to maintain the same absolute volume of forward flow by ejecting a reduced percentage of a larger volume. This enlargement of the ventricle is accompanied by an enlargement of the supporting structures and annulus of the valve, resulting in separation of the valve leaflets at their point of co-aptation during ventricular systole and further leaking of blood retrograde across the valve. This continues the cycle of ventricular enlargement, annular dilatation and regurgitation and subsequent loss of forward output and progressive heart failure. Other heart valve problems often cause similarly grave sequelae.
Treatment of heart valve stenosis or regurgitation, such as mitral or tricuspid regurgitation, often involves an open-heart surgical procedure to replace or repair the valve. Repair of a regurgitant valve such as the mitral valve is often performed in preference to replacement. Such procedures generally require a large incision into the thorax of the patient (a thoracotomy), sometimes requiring a median sternotomy (cutting through the middle of the sternum). Such procedures routinely include a corrective procedure called an annuloplasty, designed to restore the valve annulus shape, strengthen the annulus, and allow better leaflet co-aptation as a part of the repair. Such open heart procedures also usually involve placing the patient on a cardiopulmonary bypass machine for sustained periods so that the patient's heart and lungs can be artificially stopped during the procedure. Finally, valve repair and replacement procedures are typically technically challenging and require that a relatively large incision be made through the wall of the heart to access the valve. Due to the highly invasive nature of open heart valve repair or replacement, many patients, such as elderly patients, patients having recently undergone other surgical procedures, patients with comorbid medical conditions, children, late-stage heart failure patients and the like, are often considered too high-risk to undergo heart valve surgery and are committed to progressive deterioration and cardiac enlargement. Often, such patients have no feasible alternative treatments for their heart valve conditions.
Therefore, it would be advantageous to have methods and devices for repairing a mitral valve to treat mitral regurgitation in a less invasive manner than is available through current techniques. In some instances, it may be advantageous to provide for repair of a mitral valve, as well as other heart valves, through minimally invasive incisions or intravascularly. In other cases, it may be beneficial to use improved devices and methods in an open heart surgical procedure, on either a beating heart or a stopped heart. In beating heart procedures, including both minimally invasive and intravascular access procedures, it would be useful to provide for stabilization of the valve annulus while any procedure is being performed. In such beating heart procedures, it would be further useful to provide systems for the direct observation of the valve annulus from within a heart chamber to facilitate performing desired interventions. Moreover, it would be still further desirable if the apparatus and systems of the present invention were useful for treating not only the annulus of heart valves, but also other natural and created holes in tissue which require strengthening or closing. Improved devices and methods would ideally be relatively simple and easy to use and would enable durable, long-lasting mitral valve repair, either in a minimally invasive or open heart procedure, for many patients who are not candidates for more conventional procedures. At least some of these objectives will be met by the present invention.
2. Description of the Background Art
Published U.S. Application 2002/0163784A12 describes a port for providing access to a beating heart to perform diagnostic and therapeutic procedures, including a stapled annuloplasty procedure. Published U.S. Application 2002/0042621 describes a heart valve annuloplasty system with constrictable plication bands which are optionally attached to a linkage strip. Published U.S. Application 2002/0087169 describes a remote controlled catheter system which can be used to deliver anchors and a tether for performing an annuloplasty procedure. Other patent publications of interest include WO01/26586; US2001/0005787; US2001/0014800; US2002/0013621; US2002/0029080; US2002/0035361; US2002/0042621; US2002/0095167; and US2003/0074012. U.S. patents of interest include U.S. Pat. Nos. 4,014,492; 4,042,979; 4,043,504; 4,055,861; 4,700,250; 5,366,479; 5,450,860; 5,571,215; 5,674,279; 5,709,695; 5,752,518; 5,848,969;5,860,992; 5,904,651; 5,961,539; 5,972,004; 6,165,183; 6,197,017; 6,250,308; 6,260,552; 6,283,993; 6;269,819; 6,312,447; 6,332,893; and 6,524,338. Publications of interest include De Simone et al. (1993) Am. J. Cardiol. 73:721-722 and Downing et al. (2001) Heart Surgery Forum, Abstract 7025.
Methods and devices provide heart valve repair for mitral valve regurgitation and other heart valve conditions. Embodiments typically include a device for attaching a cinching or tightening apparatus to a heart valve annulus to reduce the circumference of the annulus, thus reducing valve regurgitation. Tightening devices include multiple tethered clips, multiple tethered or untethered crimping (deformable) clips, apparatus for delivering such clips, apparatus for selectively deforming clips onto the tether, systems for stabilizing the valve annulus during interventions, systems for viewing the valve annulus during an intervention, and the like.
As used hereinafter, the term “clips” is intended to refer to a wide variety of tissue anchors or fasteners which are able to (1) penetrate and fix to tissue, particularly into the fibrous tissue of a heart valve annulus and (2) provide for a secure attachment to a tether. Usually, the clips will initially be slidably received over the tether, e.g., through eyelets as described in greater detail hereinafter. Particular ones of the clips, however, may be fixedly secured to the tether even at the outset of the procedure. For example, often at least a first clip will be fixed to a lead end of the tether, where the first clip will be initially deployed into the annulus and will serve as an anchor at one end of the tether which is deployed about the annulus. Usually the remaining clips, including a series of intermediate clips and at least one terminal clip, will remain slidably secured over the tether until one of more of those clips is crimped or otherwise fixed to the tether during the interventions, as described in more detail below.
While the methods of the present invention are directed particularly at constricting a valve annulus, particularly for the treatment of valve regurgitation, the apparatus of the present invention may find broader applications. In particular, the clip deploying apparatus of the present invention may be used whenever it is desired to deliver a plurality of sequential clips, either in a straight line or in a curved line, in order to tighten tissue or optional to tether portions of tissue which are separate or which have been traumatically severed. Thus, the apparatus claimed herein are not meant to be limited in any way by the exemplary methods in which they are being used.
Generally, in accordance with the principles of the present invention, a plurality of tethered clips is secured circumferentially to a valve annulus, and the tether coupling the clips is cinched to reduce the circumference of at least a portion of the annulus. Optionally, at least a terminal clip may be deformed, such as by crimping, to secure the clip(s) to the tether, and the tether may pass through one, two or more eyelets on each clip. Methods and devices may be used in open heart surgical procedures, minimally invasive procedures and/or procedures on beating hearts or stopped hearts. Furthermore, a heart valve may be accessed by any suitable route, such as any veinous access route, through any incision(s) in the heart wall and/or atrial septum, through any heart chamber and/or through the aorta.
In one aspect of the invention, a method for constricting a valve annulus comprises introducing a plurality of clips to a heart valve annulus, the clips being coupled with a tether, securing individual clips at circumferentially spaced-apart locations about at least a portion of the annulus, and cinching the tether to circumferentially tighten the annulus. At least a first clip at a lead end of the tether is usually fixed to the tether, and the remaining clips are usually slidably coupled to the tether to facilitate cinching. Often, all of a series of intermediate clips and at least a single terminal clip will be introduced to the annulus prior to cinching by applying tension to the free end of the tether. After the proper amount of tension is applied, the terminal clip(s) will then be crimped onto or otherwise fixed to the tether to maintain the desired degree of annular constriction. Of course, it may be desirable to crimp or otherwise fix two or more clips at the lead end of the tether and/or two or more clips at the terminal end of the tether to help assure that the tether will not loosen. In some instances, it may even be desirable to deform or otherwise fix each and every clip to the tether after the desired level of cinching has been achieved. In general, however, the methods of the present invention will not rely on cinching a clip immediately after that clip is placed in order to placate tissue between adjacent clips. Deforming the portion of the at least one clip may involve applying force to at least one eyelet on the clip to reduce the inner diameter of the eyelet and secure the tether within the eyelet. Some embodiments may involve deforming two eyelets on a clip to secure the tether within each of the two eyelets.
In some embodiments, introducing the plurality of clips comprises advancing a tethered clip applicator through an incision in a wall of the heart to a desired location for treating the heart valve annulus. For example, the applicator will be introduced through an incision in the left atrial wall of the heart in some embodiments, to a location at or near the posterior or anterior commisure of the mitral valve annulus. Some embodiments further include placing an instrument introduction device through the incision in the wall of the heart, and the clip applicator is advanced through the instrument introduction device. Optionally, such embodiments may also include securing the introduction device to the heart wall before the advancing step. In some embodiments, the instrument introduction device comprises a valve, a diaphragm and/or a hemostatic barrier for allowing passage of the clip applicator and any other devices while preventing outflow of blood from the heart. In one embodiment, for example the clip applicator is generally an elongate hand-held applicator, insertable through the introduction device.
In some embodiments, securing the individual clips comprises securing a first tethered clip to the heart valve annulus and securing a plurality of subsequent tethered clips at circumferentially spaced-apart locations about at least a portion of the annulus. In some cases, the first clip is pre-secured the tether. In other cases, securing the first tethered clip to the valve annulus includes deforming a portion of the first tethered clip to secure it to the tether. Alternatively, a portion of the first tethered clip may be deformed after securing the clip to the annulus to secure the first clip to the tether. In still other embodiments, a portion of the first tethered clip may be deformed before securing the clip to the annulus to secure the first clip to the tether. In some embodiments, the plurality of subsequent tethered clips are slidably coupled with the tether. Optionally, such embodiments may further include deforming a portion of at least a second clip to secure the second clip to the tether.
In some embodiments, cinching generally involves applying tensile force to the tether. A method may further include deforming a portion of at least one of the plurality of subsequent tethered clips after the cinching step to secure the at least one partially-deformed clip to the tether. For example, deforming a portion of the at least one clip may involve deforming a last clip of the subsequent tethered clips. Optionally, such embodiments may further include deforming at least a penultimate clip of the subsequent tethered clips.
Some embodiments also include securing a tether anchor, coupled to the tether, to the valve annulus adjacent a last clip of the individual clips. For example, securing the tether anchor may involve securing a rivet to the valve annulus. Such embodiments may also include deforming a portion of the last clip around the rivet to secure the tether to the rivet and secure the last clip to the annulus. Optionally, a portion of a penultimate clip may also be deformed around the rivet to secure the tether to the rivet and secure the penultimate clip to the annulus.
Some embodiments of the method further involve visualizing the heart valve using at least one visualization device. For example any one of (or combination of ) an ultrasound device, an angioscopic device, a transesophageal echocardiogram device and a fluoroscopic device may be used for visualization. In some embodiments, an ultrasound device comprising a gel-containing cone for enhancing ultrasound visualization may be used. Some embodiments may involve using a real-time Doppler ultrasound device to visualize a regurgitant flow across the heart valve during at least the cinching step. Optionally, such methods may also include visualizing a reduction in the regurgitant flow during the cinching step and selecting an amount of cinching based on the reduction in the regurgitant flow in real time. Particularly useful visualization may be accomplished using optical viewing elements disposed directly in the heart chamber, typically adjacent to the valve annulus or other target tissue being treated. Particularly in beating heart procedures, such optical visualization will be accomplished using a transparent element to exclude blood, such as a lens, a solid optically transparent block, or most preferably a transparent inflatable balloon which may be inflated with a transparent inflation medium. By engaging such balloon against the surface to be visualized, direct and highly accurate visualization of the annulus may be accomplished. In some embodiments, the optical or other visualization device is coupled with a device for introducing and securing the clips, such as the clip applicator.
As mentioned above, the introducing, securing and cinching steps may be performed as part of any suitable procedure, from any suitable access route, and the like. For example, the may be performed as part of an open heart surgical procedure, with or without stopping the heart, through one or more minimally invasive incisions and/or intravascularly. Furthermore, any suitable cardiovascular valve may be treated, such as the mitral valve, tricuspid valve or the like.
In another aspect, a method for inhibiting heart valve regurgitation comprises: introducing a plurality of crimping clips to a heart valve annulus; securing individual crimping clips at circumferentially spaced-apart locations about at least a portion of the annulus; and crimping at least one of the clips to circumferentially tighten the annulus. Crimping clips may generally be tethered or untethered, but in one embodiment the crimping clips are slidably coupled with a tether, and the method further includes cinching the tether to circumferentially tighten the annulus. Cinching typically involves applying tensile force to the tether. In some embodiments, crimping a tethered clip secures the crimped clip to the annulus and to the tether. In some embodiments, for example, crimping a clip comprises compressing at least one eyelet in the clip, the tether running through the eyelet. In some embodiments, the clips each have two eyelets and the tether runs through the two eyelets on each clip.
In some embodiments, crimping comprises crimping a first clip before the cinching step to secure the first clip to the annulus and the tether and crimping at least a last clip after the cinching step to secure the last clip to the annulus and the tether. Various embodiments may further include crimping at least a penultimate clip to secure the penultimate clip to the annulus and the tether. Crimping may further involve crimping at least the last clip around a tether anchor to secure the last clip to the tether anchor and secure the tether anchor to the annulus.
In many embodiments, at least the introducing and securing steps are performed using an elongate, hand-held, surgical device. The surgical device may include an actuator at or near its proximal end for performing at least the securing step. In some embodiments, for example, the actuator may include, but is not limited to a trigger, a handle, a plunger, a squeeze-activated device and a syringe-grip device.
In yet another aspect, a method for inhibiting heart valve regurgitation comprises securing a flexible cord about at least a portion of the annulus of the valve and cinching the flexible cord to reduce the annular circumference. As with the above procedures, such a method may be performed as part of an open heart surgical procedure, with or without stopping the heart, through one or more minimally invasive incisions, intravascularly, or via any other suitable approach.
In some embodiments, securing and cinching are performed through a small incision in a wall of the heart. Such embodiments may further include placing an instrument introduction device in the heart wall through the incision before performing the securing and cinching steps. This method may further include securing the instrument introduction device to the wall. The instrument introduction device may include, for example, a valve for allowing passage of one or more surgical instruments while preventing outflow of blood from the heart through the valve. The method may optionally further include introducing at least one surgical instrument into a chamber of the heart through the instrument introduction device. For example, at least one elongate, hand-held instrument may be introduced for performing the securing and cinching steps.
As described above, in any of the above methods, one or more visualization devices may be used, such as ultrasound and/or transesophageal echocardiogram devices. Also as mentioned above, the methods may be used to operate on any suitable cardiovascular valves, such as a mitral, tricuspid, aortic or pulmonary valve.
In still further embodiments of the methods of the present invention, a heart valve annulus of a beating heart is constricted by first stabilizing the heart valve annulus. After the annulus is stabilized, individual clips are secured at circumferentially spaced-apart locations about at least a portion of the annulus. A tether passed through the clips may be cinched in order to circumferentially tighten the annulus. Stabilization of the beating heart is very beneficial in both minimally invasive and intravascular (closed-chest) procedures.
The valve annulus may be stabilized in a variety of ways. Usually, stabilization will involve engaging the annulus with at least a first stabilizing ring which is typically in the case of a mitral valve disposed beneath the valve leaflets to engage an intersection between the leaflets and the interior ventricular wall. Usually, the stabilization ring will be introduced from the left atrium, together with the other interventional tool(s), to a location at the valve commisure. A curved or C-shaped component of the stabilizer will then be deployed beneath the valve annulus. Preferably, a second stabilization ring will be introduced to a location above the valve annulus, where the first and second stabilizing rings will typically have similar or congruent geometries permitting clamping of the valve annulus therebetween. Optionally, either or both of the stabilizing rings may be further provided with a vacuum source, microhooks, adhesives, or the like to assist in engaging and capturing the tissue of and surrounding the valve annulus. Still further optionally, the stabilization ring disposed above the valve annulus may be adapted to deliver clips directly to the tissue, thus in some cases eliminating the need for a separate clip applier as described elsewhere in this application. Alternatively, of course, the clips may be successively applied from an applicator, as described elsewhere herein, which is advanced around at least a portion of the valve annulus while the valve annulus remains stabilized. When using a separate clip applicator, the stabilizing ring or other stabilization apparatus may provide a template to guide the applicator around the annulus as clips are applied. In most cases, the stabilization device will also shape the annulus to a geometry compatible with the applicator. After the clips are delivered, the rings or other stabilizing device will be removed, and the tether cinched to constrict the annulus as described elsewhere herein.
In yet another aspect of the method of the present invention, valve annulus may be constricted in a beating heart while directly viewing at least a portion of the valve annulus from within the atrium (left atrium in the case of the mitral valve). Individual clips are secured at circumferentially spaced-apart locations about at least a portion of the valve annulus while annulus remains under direct viewing. After the clips are properly placed, as confirmed by direct viewing, the tether may be cinched through the clips to circumferentially tighten the annulus, as generally described elsewhere in the application. Such direct viewing may be accomplished using an ultrasonic imaging element, for example one placed on a clip applier. More preferably, however, direct viewing may be accomplished by engaging a transparent element against the valve annulus and optically viewing the annulus through said element. Usually, the transparent element comprises an inflatable balloon which is inflated with a transparent inflation medium. Optical viewing may then be performed from within the inflated balloon using a fiberoptic scope, a CCD (charged coupled device), other type of camera, or the like.
In yet another aspect, a device for applying tethered clips to a heart valve annulus comprises a shaft having a proximal end and a distal end and a plurality of clips slidably coupled to a tether. The tethered clips are carried by the shaft; and the device further includes a clip applier at or near the distal end of the shaft for securing the clips to the annulus and at least one actuator at or near the proximal end of the shaft for causing the device to advance the clips and for activating the clip applier to secure the clips to the annulus. Optionally, the means for selectively advancing and securing the clips may further comprise a pusher coupled with the actuator for advancing the clips and at least one slot in an inner surface of the shaft for guiding the clips.
In some embodiments, the clip applier comprises a clip crimping member. Also in some embodiments, the at least one actuator includes means for tensioning and cinching the tethered clips to reduce the circumference of the valve annulus. The actuator itself may comprise any suitable device(s), such as but not limited to a trigger, a handle, a plunger, a squeeze-activated device, a syringe-grip device and/or any suitable foot-operated device.
In some embodiments, each of the plurality of clips includes at least one eyelet, and the tether passes through the eyelet of each clip. Optionally, in some embodiments, each clip includes two eyelets, and the tether passes through both eyelets of each clip. In such embodiments, the device may further include means for crimping the at least one eyelet of any of the plurality of clips such that a clip with a crimped eyelet is secured to the tether.
In some embodiments, the shaft comprises an elongate, hand-held shaft. Optionally, the shaft may be introducible into a patient through a minimally invasive incision. In these or other embodiments, a tether anchor may be coupled to the tether and carried by the shaft. For example, the tether anchor may comprise a rivet. The tether anchor may be coupled with at least a last clip of the tethered clips such that crimping the last clip secures the last clip to the tether anchor and the tether anchor to the tether. In some embodiments, the tether anchor is further coupled with a penultimate clip, such that crimping the penultimate clip secures the penultimate clip to the tether anchor and the tether anchor to the tether.
The tether itself may comprise any material or configuration. In some embodiments, for example, the tether comprises at least one of a suture material, a Teflon strip, a band, a filament, a wire and a strap. Embodiments including tethers may optionally also include means for cinching the tethered clips to reduce the circumference of the valve annulus.
In another aspect, a device for applying tethered clips to a heart valve annulus comprises: a shaft having a proximal end and a distal end, a plurality of clips slidably coupled to a tether, the tethered clips carried by the shaft; a clip applier at the distal end of the shaft for securing the clips to the valve annulus; and tensioning means for providing tension to the tether to cinch the tether, thus reducing a diameter of the valve annulus. In some embodiments, the clip applier comprises means for partially deforming at least one of the clips to secure the deformed clip(s) to the tether. In some embodiments, the tensioning means allows for tensioning of the tether while the clips are being secured to the valve annulus. Optionally, the device may further include cutting means at the distal end of the shaft for cutting an end of the tether after the clips have been secured and cinched.
In still another aspect or the invention, a device for treating heart valve regurgitation includes: a shaft having a proximal end and a distal end; a rotatory cord applicator at a location near the distal end, for securing a cord to the annulus of the valve; and means for cinching the cord to reduce the circumference of the valve. The shaft, for example, may comprise an elongate, handheld shaft. In some embodiments, the means for selectively advancing and securing the clips comprises a cable member coupled with the shaft. The cord may comprise any of a number of suitable materials or combinations of materials, including but not limited to a length of suture material, a length of Teflon strip, a wire, a band, and/or the like.
In another aspect, a device for applying crimping clips to a heart valve annulus comprises: an elongate, handheld shaft having a proximal end and a distal end; a plurality of crimping clips carried by the shaft; and means for selectively advancing individual clips, securing the individual clips to the annulus, and crimping each individual clip to tighten at least a portion of the valve annulus. In some embodiments, the means for selectively advancing and securing the clips comprises a cable member coupled with the shaft. As mentioned above, these crimping clips may be either tethered or untethered. Thus, some embodiments further include a tether for connecting the plurality of clips for circumferentially tightening at least a portion of the valve annulus.
In embodiments including a tether, the at least one actuator may include means for cinching the tethered clips to reduce the circumference of the valve annulus. In some embodiments, each of the plurality of crimping clips includes at least one eyelet, and the tether passes through the at least one eyelet of each clip. In some embodiments, each clip includes two eyelets, and the tether passes through both eyelets of each clip. In some embodiments, crimping the at least one eyelet of any of the plurality of clips such that a clip with a crimped eyelet is secured to the tether. More generally, any of the various features described above may be suitably used with tethered or untethered crimping clips in various embodiments.
The present invention still further provides devices for applying tethered clips to an annulus, where the device includes a shaft, a tether, a plurality of clips, and a clip applier at or near a distal end of the shaft. In particular, the tether will have at least two parallel segments, where the segments may be separate or may be simply two ends of a tether which has been folded over itself. The clips slidably receive both segments of the tether, where the clips are arranged successively on the tether. The clip applier is adapted to secure the clips individually and usually successively to the annulus while the clips remain on the tether. The use of the tether having at least one additional segment is beneficial since it provides a redundancy, i.e., if either of the segments is severed or compromised, the other remains. Moreover, in the specific embodiments, each of the clips includes at least one eyelet for receiving the tethers, preferably including two eyelets so that each segment is received in a separate eyelet. The portion of the clips surrounding the eyelets will preferably be deformable to provide for crimping of both eyelets around both tether segments, again providing for redundancy.
Apparatus according to the present invention still further includes an annular fastener. The annular fastener comprises a tether and a plurality of clips on the tether. The tether includes at least a pair of parallel segments, generally as described above, and the clips include a pair of spaced-apart eyelets, where one tether segment is received in each of the eyelets on each clip. Usually, a terminal clip will be provided on the fastener, where the terminal clip is fixed to a leading end of the tether, and may or may not include two eyelets. Usually, there will be at least two clips on the tether, more usually at least ten clips, often at least 15 clips, and sometimes as many as 30 or more. Additionally, at least a portion of the clips will be deformable in the region to permit crimping.
The present invention also provides systems comprising any of the clip delivery devices described herein. In a first instance, the system comprises a clip applier device in combination with a stabilization device which is adapted to capture and immobilize the target valve or other annulus. Typically, the stabilization device comprises a pair of rings which are adapted to clamp opposed faces of the annulus. More typically, the clamps will be adapted to clamp over and under a heart valve annulus.
Alternatively, systems according to the present invention may comprise any of the clip delivery devices in combination with a visualization device adapted to directly view a valve annulus in a heart chamber. The visualization device may comprise an ultrasonic imaging transducer, but will more typically comprise an optical viewing element disposed in a transparent element. Usually, the optical viewing element is a fiberoptic scope or a CCD, and the transparent viewing element comprises a transparent balloon inflatable with a transparent inflation medium.
Generally, the present invention provides methods and devices for repairing a heart valve, such as the mitral valve, to treat heart valve regurgitation or insufficiency. Although the following description focuses on the treatment of mitral valves, various embodiments may be used to treat other cardiovascular valves, such as tricuspid, aortic and/or pulmonary valves. Furthermore, various embodiments of devices and methods of the invention may be used in open heart surgical procedures, minimally invasive surgical procedures, or both. Although minimally invasive valve repair may be advantageous in some circumstances, in other cases it may be advantageous to perform an open procedure. If the heart is to be stopped, for example, it may be advantageous to perform an open procedure to reduce the amount of time the patient is placed on cardiopulmonary bypass. The devices and methods of the invention themselves may also reduce the overall duration of a valve repair procedure, thus reducing the time the patient is on cardiopulmonary bypass.
Generally, devices and methods of the invention involve coupling one or more devices with a valve annulus and using the devices to reduce the circumference of the annulus to reduce valve regurgitation. In some embodiments, methods involve securing a flexible cord about at least a portion of the annulus of the valve and cinching the flexible cord to reduce the annular circumference. Some embodiments, for example, involve placing multiple tethered anchoring devices into the mitral valve annulus. The tether is then tightened, applying force to the anchoring devices, to reduce the circumference of the mitral valve annulus. In some embodiments, clips may be crimped to reduce the annular circumference. Such crimping clips may be used with or without a tether in various embodiments. In other embodiments, a tethering device such as a rotatory cord may be applied to a valve annulus to tighten the annulus. Other embodiments may involve one or more other suitable techniques. Therefore, the following description is provided for descriptive purposes only and should not be interpreted to limit the scope of the invention as set forth in the claims.
Referring now to
At any suitable time before or during a mitral valve repair procedure, an imaging device may be placed in or on the patient to monitor the progress of the procedure. For example, in some embodiments a 3-dimensional, transesophageal echocardiogram device and/or a fluoroscopic C-arm may be used for visualization. After a skin incision is made, one or more various devices may then be used to navigate a path between the skin incision and the patient's heart. For example, an imaging devices such as an angioscope, as well as cutting and/or suturing devices may be used. Cutting and/or suturing devices may then be used to make a small incision in the left atrium, for example at the left atrial appendage. In one embodiment, an incision and a purse string suture will be used to gain access to the left atrium. Any suitable access methods or devices may be used, however, to gain surgical access to the mitral valve (or other valve to be repaired). As noted briefly above, methods of the present invention may typically be performed on a beating heart, thus eliminating the need for cardiopulmonary bypass. It is contemplated, however, that many embodiments will also be suitable for use in open-heart surgery techniques and/or in conjunction with use of cardiopulmonary bypass.
In some embodiments, repair device 16 will then be advanced into the left atrium through the incision, purse string suture, or other access site. In other embodiments, as described further below, an instrument introduction device may be inserted into the incision in the heart wall and may be secured to the wall, such as with suture material. At or near the distal end of repair device 16, one or more repair actuators (not shown in
In many embodiments, the repair actuators will be generally configured to attach one or more fasteners to the mitral valve annulus and to tighten the fasteners to cinch, or tighten, the mitral valve annulus, thus decreasing the overall circumference of the mitral valve and reducing mitral regurgitation. In other embodiments, however, a fastener or other device may be placed across the valve, a device may be placed to bolster or increase the bulk of the valve annulus, or the like. Therefore, the invention is in no way limited to including fasteners, sutures, or the like.
Referring now to
Repair device 16 suitably includes an elongate shaft 32, a proximal actuator 27, and several distal repair actuators. In one embodiment, as shown more clearly in
As shown in
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In some embodiments, clips 34 will be configured as double-clips or crimping clips. Such crimping clips, for example may be configured similarly to two V-shaped clips, connected together at the bottom of the V. Each crimping clip may be attached to valve annulus tissue at two locations, adjacent to one another, and the clip may be crimped, to squeeze, pinch, or pleat annular tissue within the clip. Thus, multiple crimping clips may be applied circumferentially to an annulus to crimp, or tighten, tissue along the annulus, thereby tightening the annulus and reducing regurgitation. In some embodiments, such crimping clips will be used without a tether, while in other embodiments they will be coupled with a tether to provide for further annulus tightening. As with clips 34 described above, such crimping clips may have any suitable size, shape and configuration and are not limited to V-shaped double clips.
Tether 36 generally runs between a first clip 34, or a device coupled with first clip 34, through each of a plurality of subsequent clips 34, to rivet 35. Tether 36 may be coupled with each clip by any suitable means. For example, in
Tether 36, which couples clips 34 and rivet 35 together may be any suitable substance for coupling and/or tightening multiple fastening devices. For example, in some embodiments tether 36 will be conventional, durable suture material, having a diameter between about 1 mm and about 3 mm, and preferably about 2 mm. In other embodiments, a pre-shaped Teflon strip having a diameter between about 1 mm and about 6 mm, and preferably between about 2 mm and about 5 mm, may be used. Those skilled in the art will recognize that any suitable suturing, coupling, tensioning or similar devices may be used to tether and/or add tension between clips 34.
With continued reference to
Generally, tether 36 may be coupled with each clip 34 or other attachment device, and with rivet 35, and one end of tether 36 then runs proximally back towards proximal actuator 27. In one embodiment, an end of tether 36 runs through shaft 32 of repair device 16 to a location at or near handle, so that a surgeon or other physician using the device may use the tether 36 to apply force or tension to clips 34, rivet 35 and the like. In other embodiments, other suitable tethering and/or tightening devices may be used.
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When the methods of the present invention are performed on beating hearts, either in minimally invasive procedures through ports or otherwise as described herein, or via an intravascular (closed chest) approach, it will be desirable to be able to stabilize and/or locate the valve annulus. It is important that the clips be applied to the fibrous tissue of the annulus and in particular that they not be delivered into the leaflet tissue or the tissue of the atrial wall, neither of which will provide the desired purchase for holding the clip. An exemplary method for achieving such stabilization utilizes a clamping device, such as device 200 illustrated in
The device 200 will be introduced to the left atrium of a beating heart, either transeptally or through an incision in the heart wall, as described hereinafter in connection with the clip appliers of the present invention. Once in the atrium, the lower or ventricular ring will be introduced through the mitral valve opening, with a corner 206 of the ring typically being engaged against a commisure. The ventricular ring 204 may be adjusted so that it lies at a junction between the valve leaflet L and the ventricular wall VW, as illustrated in
Although not illustrated, in some instances it may be desirable to provide a third stabilization element on the exterior of the heart, optionally between the coronary sinus CS and circumflex artery CF or within the coronary sinus.
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Once staples 156 are secured to the tissue, tether 146 is pulled from the proximal end of device 140 to cinch staples 156 and thereby reduce the annular diameter. Tension may be adjusted on tether 146 while using ultrasound Doppler flow guidance or direct visualization in real time to allow the annulus to expand for precise adjustment of the annular correction. After an optimal size of the annulus is achieved, one or more final staples are dispensed and crimped (using crimp bar 184 described with reference to
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Once the distal staple 156 is moved into nose piece 148, anvil 144 moves forward (or distally) to move staple 156 distally until it bumps against staple mandrel 152 on the distal end of nose piece 148 (
In one embodiment, as shown in
In another embodiment, as shown in
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The various features of distal end assembly 140 described above may be made from any suitable materials and combinations of materials. For example, nose piece 148 and housing 142, in one embodiment, may be made from materials such as but not limited to stiff polymers such as polycarbonate, nylon, acrylonitrile butadiene styrene (ABS), polypropylene, PEEK, PVDF or urethane. In another embodiment, nose piece 148 may be made from one or more stainless steel materials such as 17-4, 304, or 316 steel. Staple mandrel 152, anvil 144, crimp bar 184, and cutter 190 in one embodiment are made from a hard stainless steel such as hardened 17-4 steel and/or 440 steel. Alternatively, these features may be made from tungsten carbide or any other suitable material, such as softer stainless steels coated with titanium nitride to increase surface hardness. Leaf springs 154 and compression springs 166 in one embodiment may be made from a polymer like PEEK, nickel titanium, or stainless steel, but other materials may alternatively be used. Staple retainer belt 158 may be made out of flexible polymers such as high flex PVDF, PTFE, nylons, polyethylene, polyurethane, polyester, isoprene, silicones and/or the like. Generally, any of these materials, combinations of these materials, or any other suitable materials or combinations not mentioned here may be used to manufacture one or more of the elements of a surgical device for repairing cardiovascular valves according to the invention.
An exemplary stapling device 141 is illustrated in
Although the foregoing is a complete and accurate description of the present invention, it should be emphasized that the description provided above is for exemplary purposes only that variations may be made to the embodiments described without departing from the scope of the invention. For example, various embodiments of the invention may be used to repair a valve other than the mitral valve, such as the tricuspid valve. In other embodiments, clips may be eliminated and a rotatory cord such as a suture alone may be used. Other embodiments may include only a single, larger clip or fastener. Thus, the above description should not be construed to limit the scope of the invention as described in the appended claims.