Patent Description:
As illustrated in <FIG>, the human heart <NUM> has four chambers, which include two upper chambers denoted as atria <NUM>, <NUM> and two lower chambers denoted as ventricles <NUM>, <NUM>. A septum <NUM> divides the heart <NUM> and separates the left atrium <NUM> and left ventricle <NUM> from the right atrium <NUM> and right ventricle <NUM>. The heart further contains four valves <NUM>, <NUM>, <NUM>, and <NUM>. The valves function to maintain the pressure and unidirectional flow of blood through the body and to prevent blood from leaking back into a chamber from which it has been pumped.

Two valves separate the atria <NUM>, <NUM> from the ventricles <NUM>, <NUM>, denoted as atrioventricular valves. The left atrioventricular valve, the mitral valve <NUM>, controls the passage of oxygenated blood from the left atrium <NUM> to the left ventricle <NUM>. A second valve, the aortic valve <NUM>, separates the left ventricle <NUM> from the aortic artery (aorta) <NUM>, which delivers oxygenated blood via the circulation to the entire body. The aortic valve <NUM> and mitral valve <NUM> are part of the "left" heart, which controls the flow of oxygen-rich blood from the lungs to the body. The right atrioventricular valve, the tricuspid valve <NUM>, controls passage of deoxygenated blood into the right ventricle <NUM>. A fourth valve, the pulmonary valve <NUM>, separates the right ventricle <NUM> from the pulmonary artery <NUM>. The right ventricle <NUM> pumps deoxygenated blood through the pulmonary artery <NUM> to the lungs wherein the blood is oxygenated and then delivered to the left atrium <NUM> via the pulmonary vein. Accordingly, the tricuspid valve <NUM> and pulmonic valve <NUM> are part of the "right" heart, which control the flow of oxygen-depleted blood from the body to the lungs.

Both the left and right ventricles <NUM>, <NUM> constitute "pumping" chambers. The aortic valve <NUM> and pulmonic valve <NUM> lie between a pumping chamber (ventricle) and a major artery and control the flow of blood out of the ventricles and into the circulation. The aortic valve <NUM> and pulmonic valve <NUM> have three cusps, or leaflets, that open and close and thereby function to prevent blood from leaking back into the ventricles after being ejected into the lungs or aorta <NUM> for circulation.

Both the left and right atria <NUM>, <NUM> are "receiving" chambers. The mitral valve <NUM> and tricuspid valve <NUM>, therefore, lie between a receiving chamber (atrium) and a ventricle so as to control the flow of blood from the atria to the ventricles and prevent blood from leaking back into the atrium during ejection into the ventricle. Both the mitral valve <NUM> and tricuspid valve <NUM> include two or more cusps, or leaflets (shown in <FIG>), that are encircled by a variably dense fibrous ring of tissues known as the annulus. The valves are anchored to the walls of the ventricles by chordae tendineae (chordae) <NUM>. The chordae tendineae <NUM> are cord-like tendons that connect the papillary muscles <NUM> to the leaflets (not shown) of the mitral valve <NUM> and tricuspid valve <NUM> of the heart <NUM>. The papillary muscles <NUM> are located at the base of the chordae <NUM> and are within the walls of the ventricles. They serve to limit the movements of the mitral valve <NUM> and tricuspid valve <NUM> and prevent them from being reverted. The papillary muscles <NUM> do not open or close the valves of the heart, which close passively in response to pressure gradients; rather, the papillary muscles <NUM> brace the valves against the high pressure needed to circulate the blood throughout the body. Together, the papillary muscles <NUM> and the chordae tendineae <NUM> are known as the subvalvular apparatus. The function of the subvalvular apparatus is to keep the valves from prolapsing into the atria when they close.

As illustrated with reference to <FIG>, the mitral valve <NUM> includes two leaflets, the anterior leaflet <NUM> and the posterior leaflet <NUM>, and a diaphanous incomplete ring around the valve, called the annulus <NUM>. The mitral valve <NUM> has two papillary muscles <NUM>, the anteromedial and the posterolateral papillary muscles, which attach the leaflets <NUM>, <NUM> to the walls of the left ventricle <NUM> via the chordae tendineae <NUM>. The tricuspid valve <NUM> typically is made up of three leaflets with three papillary muscles. However, the number of leaflets can range between two and four. The three leaflets of the tricuspid valve <NUM> are referred to as the anterior, posterior, and septal leaflets. Although both the aortic and pulmonary valves each have three leaflets (or cusps), they do not have chordae tendineae.

Various disease processes can impair the proper functioning of one or more of the valves of the heart. These disease processes include degenerative processes (e.g., Barlow's Disease, fibroelastic deficiency), inflammatory processes (e.g., Rheumatic Heart Disease), and infectious processes (e.g., endocarditis). Additionally, damage to the ventricle from prior heart attacks (i.e., myocardial infarction secondary to coronary artery disease) or other heart diseases (e.g., cardiomyopathy) can distort the valve's geometry causing it to dysfunction. However, the vast majority of patients undergoing valve surgery, such as mitral valve surgery, suffer from a degenerative disease that causes a malfunction in a leaflet of the valve, which results in prolapse and regurgitation.

Generally, a heart valve may malfunction two different ways. One possible malfunction, valve stenosis, occurs when a valve does not open completely and thereby causes an obstruction of blood flow. Typically, stenosis results from buildup of calcified material on the leaflets of the valves causing them to thicken and thereby impairing their ability to fully open and permit adequate forward blood flow.

Another possible malfunction, valve regurgitation, occurs when the leaflets of the valve do not close completely thereby causing blood to leak back into the prior chamber. There are three mechanisms by which a valve becomes regurgitant or incompetent; they include Carpentier's type I, type II and type III malfunctions. A Carpentier type I malfunction involves the dilation of the annulus such that normally functioning leaflets are distracted from each other and fail to form a tight seal (i.e., do not coapt properly). Included in a type I mechanism malfunction are perforations of the valve leaflets, as in endocarditis. A Carpentier's type II malfunction involves prolapse of one or both leaflets above the plane of coaptation. This is the most common cause of mitral regurgitation, and is often caused by the stretching or rupturing of chordae tendineae normally connected to the leaflet. A Carpentier's type III malfunction involves restriction of the motion of one or more leaflets such that the leaflets are abnormally constrained below the level of the plane of the annulus. Leaflet restriction can be caused by rheumatic disease (IIIa) or dilation of the ventricle (IIIb).

<FIG> illustrates a prolapsed mitral valve <NUM>. As can be seen with reference to <FIG>, prolapse occurs when a leaflet <NUM>, <NUM> of the mitral valve <NUM> is displaced into the left atrium <NUM> during systole. Because one or more of the leaflets <NUM>, <NUM> malfunction, the mitral valve <NUM> does not close properly, and, therefore, the leaflets fail to coapt. This failure to coapt causes a gap <NUM> between the leaflets <NUM>, <NUM> that allows blood to flow back into the left atrium <NUM>, during systole, while it is being ejected into the left ventricle <NUM>. As set forth above, there are several different ways a leaflet may malfunction, which can thereby lead to regurgitation.

Although stenosis or regurgitation can affect any valve, stenosis is predominantly found to affect either the aortic valve <NUM> or the pulmonic valve <NUM>, whereas regurgitation predominately affects either the mitral valve <NUM> or the tricuspid valve <NUM>. Both valve stenosis and valve regurgitation increase the workload on the heart <NUM> and may lead to very serious conditions if left un-treated; such as endocarditis, congestive heart failure, permanent heart damage, cardiac arrest, and ultimately death. Since the left heart is primarily responsible for circulating the flow of blood throughout the body, malfunction of the mitral valve <NUM> or tricuspid valve <NUM> is particularly problematic and often life threatening. Accordingly, because of the substantially higher pressures on the left side of the heart, left-sided valve dysfunction is much more problematic.

Malfunctioning valves may either be repaired or replaced. Repair typically involves the preservation and correction of the patient's own valve. Replacement typically involves replacing the patient's malfunctioning valve with a biological or mechanical substitute. Typically, the aortic valve <NUM> and pulmonic valve <NUM> are more prone to stenosis. Because stenotic damage sustained by the leaflets is irreversible, the most conventional treatment for stenotic aortic and pulmonic valves is removal and replacement of the diseased valve. The mitral valve <NUM> and tricuspid valve <NUM>, on the other hand, are more prone to deformation. Deformation of the leaflets, as described above, prevents the valves from closing properly and allows for regurgitation or back flow from the ventricle into the atrium, which results in valvular insufficiency. Deformations in the structure or shape of the mitral valve <NUM> or tricuspid valve <NUM> are often repairable.

Valve repair is preferable to valve replacement. Bioprosthetic valves have limited durability. Moreover, prosthetic valves rarely function as well as the patient's own valves. Additionally, there is an increased rate of survival and a decreased mortality rate and incidence of endocarditis for repair procedures. Further, because of the risk of thromboembolism, mechanical valves often require further maintenance, such as the lifelong treatment with blood thinners and anticoagulants. Therefore, an improperly functioning mitral valve <NUM> or tricuspid valve <NUM> is ideally repaired, rather than replaced. However, because of the complex and technical demands of the repair procedures, the overall repair rate in the United States is only around <NUM>%.

Conventional techniques for repairing a cardiac valve are labor-intensive, technically challenging, and require a great deal of hand-to-eye coordination. They are, therefore, very challenging to perform, and require a great deal of experience and extremely good judgment. For instance, the procedures for repairing regurgitating leaflets may require resection of the prolapsed segment and insertion of an annuplasty ring so as to reform the annulus of the valve. Additionally, leaflet sparing procedures for correcting regurgitation are just as labor-intensive and technically challenging, if not requiring an even greater level of hand-to-eye coordination. These procedures involve the implantation of sutures (e.g., ePTFE or GORE-TEX™ sutures) so as to form artificial chordae in the valve. In these procedures, rather than performing a resection of the leaflets and/or implanting an annuplasty ring into the patient's valve, the prolapsed segment of the leaflet is re-suspended using artificial chord sutures. Oftentimes, leaflet resection, annuplasty, and neochord implantation procedures are performed in conjunction with one another.

Regardless of whether a replacement or repair procedure is being performed, conventional approaches for replacing or repairing cardiac valves are typically invasive open-heart surgical procedures, such as sternotomy or thoracotomy, that require opening up of the thoracic cavity so as to gain access to the heart. Once the chest has been opened, the heart is bypassed and stopped. Cardiopulmonary bypass is typically established by inserting cannulae into the superior and inferior vena cavae (for venous drainage) and the ascending aorta (for arterial perfusion), and connecting the cannulae to a heart-lung machine, which functions to oxygenate the venous blood and pump it into the arterial circulation, thereby bypassing the heart. Once cardiopulmonary bypass has been achieved, cardiac standstill is established by clamping the aorta and delivering a "cardioplegia" solution into the aortic root and then into the coronary circulation, which stops the heart from beating. Once cardiac standstill has been achieved, the surgical procedure may be performed. These procedures, however, adversely affect almost all of the organ systems of the body and may lead to complications, such as strokes, myocardial "stunning" or damage, respiratory failure, kidney failure, bleeding, generalized inflammation, and death. The risk of these complications is directly related to the amount of time the heart is stopped ("cross-clamp time") and the amount of time the subject is on the heart-lung machine ("pump time").

Furthermore, the conventional methods currently being practiced for the implantation of the artificial chordae are particularly problematic. Because the conventional approach requires the heart to be stopped (e.g., via atriotomy) it is difficult to accurately determine, assess, and secure the appropriate chordal length. Since the valve will not function properly if the length of the artificial chordae is too long or too short, the very problem sought to be eradicated by the chordal replacement procedure may, in fact, be exacerbated. Using conventional techniques, it is very difficult to ensure that the chordae are of the correct length and are appropriately spaced inside the ventricle to produce a competent valve.

There is a significant need to perform mitral valve repairs using less invasive procedures while the heart is still beating. Accordingly, there is a continuing need for new procedures and devices for performing cardiac valve repairs, such as mitral and tricuspid valve repairs, which are less invasive, do not require cardiac arrest, and are less labor-intensive and technically challenging. Chordal replacement procedures and artificial chordae that ensure the appropriate chordal length and spacing so as to produce a competent valve are of particular interest. The methods and repair devices presented herein meet these needs.

<CIT> relates to a soft tissue defect repair system for approximating defects, such as defects in the annulus fibrosus of an intervertebral disc, includes a cannulated rod through which is disposed a suture retrieval device. A strand of suture includes a locking or ratcheting knot pre-tied around the outside of the cannulated rod and a free end that is guided in and out of the soft tissue. A knot pusher fits around the cannulated rod, which is used to push the knot off of the cannulated rod after the stitching of the tissue is accomplished. The defect is approximated by tensioning the free end. Various suturing methods or patterns are disclosed for defect approximation.

<CIT> relates to a filament-guiding device that directs a filament to spool over a rotating device within tissue. The filament-guiding device has both closed and open positions. In the closed position, the filament-guiding device is resiliently straightened for delivering into tissue. Within tissue, the filament-guiding device resumes a curved configuration in the open position to orient the filament perpendicular to the rotating device for spooling. The spooled filament is deployed by withdrawing the rotating device and filament-guiding device to bulk and repair the tissue.

<CIT> relates to a method and system to achieve leaflet coaptation in a cardiac valve percutaneously by creation of neochordae to prolapsing valve segments. This technique is especially useful in cases of ruptured chordae, but may be utilized in any segment of prolapsing leaflet. The described technique is adjustable in the beating heart which allows tailoring of leaflet coaptation height under various loading conditions using image-guidance, such as echocardiography, and also allows for placement of multiple artificial chordae, as dictated by the patient's pathophysiology.

<CIT> provides methods and devices for grasping, and optional repositioning and fixation of the valve leaflets to treat cardiac valve regurgitation, particularly mitral valve regurgitation. Such grasping will typically be atraumatic providing a number of benefits. For example, atraumatic grasping may allow repositioning of the devices relative to the leaflets and repositioning of the leaflets themselves without damage to the leaflets. However, in some cases it may be necessary or desired to include grasping which pierces or otherwise permanently affects the leaflets. In some of these cases, the grasping step includes fixation.

It is an object of the disclosure to provide a method and device to enable minimally invasive, beating-heart, mitral valve repair.

It is another object of the disclosure to provide an expansile element that can be inserted through a mitral valve leaflet, and which can be deployed above the valve leaflet in order to secure it in place.

It is another object of the disclosure to enable chordal replacement with ePTFE. A related object of the present disclosure is to provide a chordal replacement that facilitates mitral valve repair.

Another object of the disclosure is to provide a method and device for transapical mitral valve repair that uses a small incision. A related object of the disclosure is to provide a method that does not require a Sternotomy. Another related object of the disclosure is to provide a method that does not require cardiopulmonary bypass or aortic manipulation.

Another object of the disclosure is to provide a method and device for transapical mitral valve repair that uses real-time, echo-guided, chordal length adjustment.

A basic concept of the method of the disclosure herein is to insert a tool via the apex of the heart, grasp or pierce the defective heart valve leaflet, deploy a PTFE neochord, and adjust the length of the chord under echo guidance to resolve the mitral valve regurgitation.

These and other objects of the present disclosure are accomplished by providing a device for minimally invasive repair of a defective heart valve while the heart is beating. The heart can be accessed through the apex or a point lateral/near to the apex with a small-diameter shafted instrument. The instrument might be a needle or a catheter. Using ultrasound guidance (real-time transesophagael echocardiography), the shafted instrument is inserted through an access port at the apex (or near the apex) and the instrument is guided to make contact with the mitral valve leaflet at the location where the operator has decided that a neochord should be inserted. Typically, this would be the body of the anterior or posterior leaflet in a location where the valve has prolapsed as a result of a broken or elongated chord. The instrument punctures the apex of the heart and travels through the ventricle. The tip of the instrument rests on the defective valve and punctures the valve leaflet. The instrument then inserts either a suture or a suture/guide wire combination, securing the top of the leaflet to the apex of the heart with an artificial chordae. A resilient element or shock absorber mechanism adjacent to the outside of the apex of the heart minimizes the linear travel of the instrument in response to the beating of the heart or opening/closing of the valve.

In a first comparative example, the instrument punctures the defective leaflet twice. A first needle deploys a loop wire with the loop encircling the area immediately above a second needle. The second needle deploys a suture through the loop deployed by the first needle. After the loop ensnares the suture, the loop and suture are retracted into the first needle. The instrument is pulled out of the heart while the suture remains through the leaflet. The length of the suture is adjusted and the ends of the suture are then affixed to the outer surface of the heart near the apex of the heart. Typically, the suture would be secured to a pledget.

According to another comparative example, once the instrument is in contact with the mitral valve leaflet in the targeted location, a "PTFE-wrapped needle" is advanced rapidly across the leaflet and subsequently rapidly withdrawn. After the PTFE-wrapped needle is advanced across the leaflet, the core is withdrawn and a pusher needle/sheath remains across the needle. Withdrawal pressure is applied to the two ends of the PTFE suture at the base of the needle (outside of the heart). This withdrawal pressure results in the development of a preformed knot that attains a significant size in the atrium, above the leaflet. The pusher needle is then withdrawn with the delivery instrument, and the length of the PTFE sutures are adjusted so that the amount of mitral regurgitation is minimized. Once this length is determined, the PTFE is secured to the outer surface of the heart using a pledget.

In another comparative example, a single needle punctures the defective leaflet and deploys a coated, coiled guide wire having a suture woven through it. The suture is then pulled, causing the guide wire to configure into a predetermined shape above the leaflet. The instrument is then retracted out of the heart and the length of the guide wire/suture is adjusted. Once this length is determined, the guide wire/suture is affixed near the apex of the heart.

The above and other features, aspects, and advantages of the present disclosure are considered in more detail, in relation to the following description of comparative examples and embodiments thereof shown in the accompanying drawings, in which:.

In accordance with the methods disclosed herein, the heart may be accessed through one or more openings made by a small incision(s) in a portion of the body proximal to the thoracic cavity, for instance, in between one or more of the ribs of the rib cage, proximate to the xyphoid appendage, or via the abdomen and diaphragm. Access to the thoracic cavity may be sought so as to allow the insertion and use of one or more thorascopic instruments, while access to the abdomen may be sought so as to allow the insertion and use of one or more laparoscopic instruments. Insertion of one or more visualizing instruments may then be followed by transdiaphragmatic access to the heart. Additionally, access to the heart may be gained by direct puncture (i.e., via an appropriately sized needle, for instance an <NUM> gauge needle) of the heart from the xyphoid region. Access may also be achieved using percutaneous means. Accordingly, the one or more incisions should be made in such a manner as to provide an appropriate surgical field and access site to the heart. See for instance,<NPL> and <NPL>.

After prepping and placing the subject under anesthesia a transesophageal echocardiogram (TEE) (2D or 3D), a transthoracic echocardiogram (TTE), intracardiac echo (ICE), or cardio-optic direct visualization (e.g., via infrared vision from the tip of a <NUM> F catheter) may be performed to assess the heart and its valves. A careful assessment of the location and type of dysfunction on the TEE, TTE, or other such instrument, facilitates the planning of the appropriate surgical procedure to be performed. The use of TEE, TTE, ICE, or the like, can assist in determining if there is a need for adjunctive procedures to be performed on the leaflets and subvalvular apparatus and can indicate whether a minimally invasive approach is advisable.

Once a minimally invasive approach is determined to be advisable, one or more incisions are made proximate to the thoracic cavity so as to provide a surgical field of access. The total number and length of the incisions to be made depend on the number and types of the instruments to be used as well as the procedure(s) to be performed. The incision(s) should be made in such a manner so as to be minimally invasive. By "minimally invasive" is meant in a manner by which an interior organ or tissue may be accessed with as little as possible damage being done to the anatomical structure through which entry is sought. Typically, a minimally invasive procedure is one that involves accessing a body cavity by a small incision made in the skin of the body. By "small incision" is meant that the length of the incision generally should be about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> in length. The incision may be vertical, horizontal, or slightly curved. If the incision is placed along one or more ribs, it should follow the outline of the rib. The opening should extend deep enough to allow access to the thoracic cavity between the ribs or under the sternum and is preferably set close to the rib cage and/or diaphragm, dependent on the entry point chosen.

One or more other incisions may be made proximate to the thoracic cavity to accommodate insertion of a surgical scope. Such an incision is typically about <NUM> to about <NUM>, or about <NUM> to <NUM>, or about <NUM> in length and should be placed near the pericardium so as to allow ready access to and visualization of the heart. The surgical scope may be any type of endoscope, but is typically a thorascope or laparoscope, dependent upon the type of access and scope to be used. The scope generally has a flexible housing and at least a <NUM>-times magnification. Insertion of the scope through an incision allows a practitioner to analyze and "inventory" the thoracic cavity and the heart so as to determine further the clinical status of the subject and plan the procedure. For example, a visual inspection of the thoracic cavity may reveal important functional and physical characteristics of the heart, and will indicate the access space (and volume) required at the surgical site and in the surgical field in order to perform the reparative cardiac valve procedure. At this point, the practitioner can confirm that access of one or more cardiac valves through the apex of the heart is appropriate for the particular procedure to be performed.

With reference to <FIG>, once a suitable entry point has been established, a suitable device such as one described herein, may be advanced into the body in a manner so as to make contact with the heart <NUM>. The advancement of the device may be performed in conjunction with sonography or direct visualization (e.g., direct transblood visualization). For instance, the device may be advanced in conjunction with TEE guidance or ICE so as to facilitate and direct the movement and proper positioning of the device for contacting the appropriate apical region of the heart. Typical procedures for use of echo guidance are set forth in<NPL>.

One or more chambers <NUM>, <NUM>, <NUM>, <NUM> in the heart <NUM> may be accessed in accordance with the methods disclosed herein. Access into a chamber in the heart may be made at any suitable site of entry but is preferably made in the apex region of the heart (e.g., at or adjacent to the apex <NUM>). Typically, access into the left ventricle <NUM>, for instance, to perform a mitral valve repair, is gained through making a small incision into the apical region, close to (or slightly skewed toward the left of) the median axis <NUM> of the heart <NUM>. Typically, access into the right ventricle <NUM>, for instance, to perform a tricuspid valve repair, is gained through making a small incision into the apical region, close to or slightly skewed toward the right of the median axis <NUM> of the heart <NUM>. Generally, an apex region of the heart is a bottom region of the heart that is within the left or right ventricular region but is distal to the mitral valve <NUM> and tricuspid valve <NUM> and toward the tip or apex <NUM> of the heart <NUM>. More specifically, an "apex region" of the heart is within a few centimeters to the right or to the left of the septum <NUM> of the heart <NUM>. Accordingly, the ventricle can be accessed directly via the apex <NUM>, or via an off apex location that is in the apical region, but slightly removed from the apex <NUM>, such as via a lateral ventricular wall, a region between the apex and the base of a papillary muscle, or even directly at the base of a papillary muscle. Typically, the incision made to access the appropriate ventricle of the heart is no longer than about <NUM> to about <NUM>, from <NUM> to about <NUM>, from about <NUM> to about <NUM> in length.

As explained above, both the mitral valve <NUM> and tricuspid valve <NUM> can be divided into three parts - an annulus, leaflets, and a sub-valvular apparatus. If the valve is functioning properly, when closed, the free margins of the leaflets come together and form a tight junction the arc of which, in the mitral valve, is known as the line of coaptation. The normal mitral and tricuspid valves open when the ventricles relax allowing blood from the left atrium to fill the decompressed ventricle. When the ventricle contracts, the increase in pressure within the ventricle causes the valve to close, thereby preventing blood from leaking into the atrium and assuring that all of the blood leaving the ventricle is ejected through the aortic valve <NUM> and pulmonic valve <NUM> into the arteries of the body. Accordingly, proper function of the valves depends on a complex interplay between the annulus, leaflets, and subvalvular apparatus. Lesions in any of these components can cause the valve to dysfunction and thereby lead to valve regurgitation. As set forth above, regurgitation occurs when the leaflets do not coapt at peak contraction pressures. As a result, an undesired back flow of blood from the ventricle into the atrium occurs.

Once the malfunctioning cardiac valve has been assessed and the source of the malfunction verified, a corrective procedure can be performed. Various procedures can be performed in accordance with the methods of the disclosure herein in order to effectuate a cardiac valve repair, which will depend on the specific abnormality and the tissues involved.

A method of the present disclosure includes the implantation of one or more artificial chordae tendineae into one or more leaflets of a malfunctioning mitral valve <NUM> and/or tricuspid valve <NUM>. It is to be noted that, although the following procedures are described with reference to repairing a cardiac mitral or tricuspid valve by the implantation of one or more artificial chordae, the methods herein presented are readily adaptable for various types of leaflet repair procedures well-known and practiced in the art, for instance, an Alfieri procedure. In general, the methods herein will be described with reference to a mitral valve <NUM>.

As illustrated in <FIG>, in accordance with the methods of the present disclosure, once an appropriate incision has been made in the apex region of the heart, for instance, in the apex <NUM>, a suitable instrument <NUM> is then introduced into the ventricle <NUM> of the heart and advanced in such a manner so as to contact one or more cardiac tissues (for instance, a leaflet, an annulus, a cord, a papillary muscle, or the like) that are in need of repair. Sonic guidance, for instance, TEE guidance or ICE, may be used to assist in the advancement of the device into the ventricle and the grasping of the cardiac tissue with the device. Direct trans-blood visualization may also be used.

A suitable instrument <NUM>, such as the one presented in <FIG>, <FIG>, and <FIG>, will typically include an elongate member <NUM> with a functional distal portion <NUM> having a tip <NUM> configured for repairing a cardiac valve tissue, for instance, a mitral valve leaflet <NUM>, <NUM>. The functional distal portion <NUM> of the device is configured for performing one or more selected functions, such as grasping, suctioning, irrigating, cutting, suturing, or otherwise engaging a cardiac tissue. Using a manipulatable handle portion <NUM>, the instrument <NUM> is then manipulated in such a manner so that a selected cardiac tissue (for instance, a papillary muscle, one or more leaflet tissues, chordae tendineae, or the like) is contacted with the functional distal portion <NUM> of the instrument <NUM> and a repair effectuated, for instance, a mitral or tricuspid valve repair.

The instrument <NUM> can be designed to extend and contract with the beat of the heart. During systolic contraction, the median axis <NUM> of the heart <NUM> shortens. The distance from the apex <NUM> of the heart (where the device is inserted) to the mitral leaflet <NUM>, <NUM> varies by <NUM> - <NUM> with each heartbeat. Accordingly, the instrument <NUM> is designed such that the tip <NUM> of the device (i.e. the part that contacts the mitral leaflet <NUM>, <NUM>) is "floating" wherein each systole is associated with approximately <NUM> - <NUM> of outward extension of the device. Referring to <FIG>, the instrument <NUM> includes an inner tube <NUM> and an outer tube <NUM>. The inner tube <NUM> is configured to slide within the outer tube <NUM>. A handle <NUM> is attached to the outer tube <NUM>. A resilient element <NUM>, such as a spring is present so that, as the outer tube <NUM> is advanced and the tip <NUM> makes contact with the leaflet <NUM>, <NUM>, the elongate portion <NUM>, being connected to the inner tube <NUM>, pushes against the resilient element <NUM>. With forward pressure predetermined by the resilient element <NUM>, once the tip <NUM> comes in contact with the leaflet <NUM>, <NUM>, even though the user continues to advance the instrument <NUM>, the amount of pressure applied by the tip to the leaflet <NUM>, <NUM> will remain constant as a result of the presence of the resilient element <NUM>. The resilient element <NUM> allows a defined, constant forward force on the leaflet <NUM>, <NUM>. A user may feel contact, but will also be able to confirm visually that the resilient element <NUM> is extending and contracting.

While a smaller seating surface enables the tip <NUM> to be more easily localized, it may be more likely to perforate the leaflet. A larger seating surface is more likely to remain in the selected location, but is harder to land on the leaflet <NUM>, <NUM>. Accordingly, the delivery system may have a blunt end, to avoid pushing the entire device through the leaflet; to that end, a device with an expandable balloon <NUM> at the distal end, such as shown in <FIG>, may be provided.

The inflatable balloon <NUM> is provided at the tip <NUM>. The balloon <NUM> can distribute pressure more widely on the underside of the leaflet <NUM>, <NUM>, and minimize the likelihood that the leaflet will be perforated unintentionally by the device. Such a balloon <NUM> can be configured to surround the tip <NUM>, thereby providing a broader seating surface against the leaflet. Once the instrument <NUM> is inserted, the balloon <NUM> can be inflated using methods known in the art. For example, the instrument <NUM> may include an inner lumen <NUM> comprising annealed stainless steel surrounded by an outer tube <NUM> made of urethane or other flexible material. A clearance space <NUM> between the inner lumen <NUM> and the outer tube <NUM> provides an inflation lumen. The outer tube should be bonded at one end around the tip <NUM> and at the other end to a valve <NUM>, such as a Touhy valve. The valve <NUM> is tightened to the inner lumen <NUM>. An inflation port <NUM> is provided to enable inflation of the balloon <NUM>. The balloon <NUM> may provide an expanded seating surface of approximately <NUM>-<NUM>.

Preferably, characteristics of the end surface of the tip <NUM> include ease of location on the leaflet, tendency to remain in one location, does not harm the leaflet by penetration, and can serve as a platform to deploy one or more needles, as described below.

<FIG> show exemplary stages of the tip portion <NUM> of an instrument <NUM> according to a comparative example of the present disclosure. In the example illustrated in <FIG>, the tip <NUM> has two channels; each channel contains a needle. Preferably, one channel contains a larger needle, such as a <NUM>-gauge and the other channel contains a smaller needle. It is not necessary that the needles be different sizes, nor is the needle gauge particular to the practice of this disclosure; other sizes may be used. The snare described below could be a smaller gauge than the suture, allowing the needles to be the same size. Preferably, the two needles are as far apart as possible in the tip <NUM>, so as to make the resulting suture that is installed less likely to tear the leaflet. In <FIG>, the needles are retracted. In <FIG>, both needles puncture the mitral valve leaflet (not shown); first the snare needle <NUM>, then the suture needle <NUM>. As shown in <FIG>, a metal (steel, nitinol, or other material) snare <NUM> is advanced through the larger needle. The snare <NUM> is adapted so that the loop can be selectively retracted or extended within the larger needle. The snare <NUM> is further adapted so that once it emerges (on the atrial side of the leaflet), it will deform in a predetermined manner, such as approximately a <NUM>-degree bend, and is in position to capture a PTFE suture. While these steps may occur in rapid sequence, the snare <NUM> should not emerge until both needles have punctured the mitral valve leaflet. Preferably, the snare <NUM> includes a directional handle so that it is always deployed toward the center of the tip <NUM>. <FIG> shows a PTFE suture <NUM> that is injected through the smaller needle (<NUM> or <NUM> gauge) and passes through the deployed snare <NUM>. Preferably, heparinized saline is used to inject the PTFE suture <NUM>. As shown in <FIG>, the snare <NUM> is withdrawn into the <NUM>-gauge needle, capturing the PTFE suture <NUM>. In <FIG>, the device is removed, leaving a PTFE suture in the leaflet. An alternate approach would be to advance a metal guide wire through the smaller needle, grasp it, and pull it back. The PTFE suture could then be tied to the guide wire and pulled through.

<FIG> illustrates another comparative example using a "between the leaflets" approach for grasping and attaching a suture to a mitral valve leaflet <NUM>, <NUM>. In this example, a shafted instrument <NUM> is inserted between two mitral valve leaflets <NUM>, <NUM>, as shown in <FIG> shows a snare <NUM> and a stiff "upper stabilizer" <NUM> deployed at the end of the instrument <NUM>. Preferably, the snare <NUM> extends at approximately a <NUM>-degree angle from the shaft <NUM>. Typically, the upper stabilizer <NUM> will have an angle of approximately <NUM> - <NUM>° from the shaft. A user then pulls the instrument <NUM> back until the upper stabilizer <NUM> lands on the mitral leaflet <NUM>. Essentially, the leaflet <NUM> is stabilized by the shaft <NUM> (on the leading edge of the leaflet) and the snare stabilizer <NUM>. Next, as shown in <FIG>, a second stabilizer (a narrow snare or prong) <NUM> is deployed below the leaflet <NUM>. Typically, the second stabilizer <NUM> will have an angle of approximately <NUM> - <NUM>° from the shaft. The second stabilizer <NUM> is progressively advanced toward the upper stabilizer <NUM>. The leaflet <NUM> is "grabbed" by the two stabilizers <NUM>, <NUM>. Once the leaflet <NUM> is grasped, as shown in <FIG>, a needle <NUM> is ejected at an angle from the shaft <NUM>. The needle <NUM> penetrates the leaflet <NUM>, and passes through the upper stabilizer <NUM> and the snare <NUM>. A PTFE suture is then injected through the needle <NUM> and captured by the snare <NUM>. The needle <NUM> can then be retracted while the snare <NUM> holds the suture. Next, the snare <NUM> is withdrawn with the suture penetrating through the leaflet <NUM>. The lower stabilizer <NUM> is withdrawn, followed by the upper stabilizer <NUM>.

An embodiment of the present invention is shown in <FIG>. A slotted needle <NUM> is wrapped with a PTFE suture. The needle <NUM> can be as small as <NUM> gauge. In some embodiments, the needle <NUM> may be electropolished to make it smooth. Referring to <FIG>, a suture <NUM> is prepared on the needle <NUM>. Preferably, the suture is made of PTFE material. One end of the suture <NUM> emerges from a distal end <NUM> of the needle <NUM>, and another end emerges from a slot <NUM>. The suture <NUM> may have a simple knot <NUM> (see <FIG>) where it emerges from the distal end <NUM> of the needle <NUM> and another knot at the end of the wrapping near the slot <NUM>. In some embodiments, small, temporary silicone rings (not shown) may be used to hold the suture <NUM> at the distal and proximal ends. As shown in <FIG>, a first coil <NUM> is wound from the outside toward the inside (top to bottom). The suture <NUM> should wrapped tightly around the needle <NUM> for approximately <NUM>-<NUM> turns. Other numbers of turns may be used. As shown in <FIG>, a second coil <NUM> is wound from the outside toward the inside (bottom to top). Again, the suture <NUM> should be wrapped tightly around the needle <NUM> for approximately <NUM>-<NUM> turns. Other numbers of turns may be used. A short section may be left in the center for threading and completing the rest of the knot. The ends of the suture <NUM> may be crossed and looped from the end of the distal coil in the distal direction or in the direction of the proximal coil. The knot can be tightened by sliding the two coils <NUM>, <NUM> to the center and twisting the coils to take up the slack in the needle slot, as shown in <FIG>. In some embodiments, a medical grade silicone may be used on the needle <NUM> and the wrapped suture <NUM> to allow smooth withdrawal of the needle <NUM> during subsequent procedure. <FIG> shows a finished version of a needle <NUM> with a suture <NUM> wrapped thereon.

Referring to <FIG>, and particularly the portion labeled (a), the needle <NUM> has a suture <NUM> tightly wrapped around one end thereof. A pusher <NUM> or hollow guide wire may be provided on the needle <NUM>. As shown in <FIG>, the wrapped needle <NUM> is inserted into the heart toward the mitral valve leaflet <NUM>. The wrapped needle <NUM> can be advanced across the mitral valve leaflet <NUM> until the end of the wrapping, indicated by <NUM>, is in the atrium above the leaflet <NUM>, as shown in <FIG>, leaving a small hole. In <FIG>, the needle <NUM> is withdrawn, but the pusher <NUM> and suture <NUM> remain. In <FIG>, a withdrawal force applied to the ends of the suture <NUM> resulting in the transformation of the tightly wrapped coil of the suture <NUM> into a bulky knot <NUM> as shown in <FIG>. Lastly, as shown in <FIG>, the pusher <NUM> is withdrawn, leaving the permanent bulky knot <NUM>, which anchors the suture <NUM> to the leaflet <NUM>. In this embodiment, the resulting implant is made solely of a PTFE suture, which is a time-tested means of fixing the mitral valve.

There are many possible configurations of PTFE material and needle to form the bulky knot <NUM>. For example, the suture <NUM> may form two or more loops, such as a <FIG>. In some embodiments, the suture <NUM> may be double wrapped on the needle <NUM>. Alternatively, the needle <NUM> may be non-hollow; that is, a solid needle. <FIG> illustrates how the simple bulky knot <NUM>, described above, is formed. In <FIG>, the suture <NUM> is deployed. In <FIG>, the withdrawal force applied to the ends of the suture <NUM> pulls the knot <NUM> toward the end of the wrapping <NUM>. Once the two ends meet, the bulky knot <NUM> remains, as shown in <FIG>.

In other words, according to the "bulky knot" concept: a PTFE suture <NUM> (or any kind of suture, or perhaps even a "filament") is wrapped tightly around a small-gauge needle <NUM>, near the tip. The needle <NUM> is then advanced through the valve leaflet <NUM>. A "pusher" <NUM> surrounds the needle <NUM> and extends to the level of the "wrap" of suture/filament. Once the sharp point end of the needle and the wrap/coil of suture/filament <NUM> has passed through the leaflet <NUM>, the needle <NUM> is withdrawn. This leaves the coil (s) <NUM>, <NUM> unsupported. Tension on the ends of the filament/suture <NUM> at the base of the needle then cause a bulky knot <NUM> to form. Finally, the pusher <NUM> is pulled back, leaving a bulky knot <NUM> on the "far" side of the leaflet <NUM>.

<FIG> illustrates an alternate embodiment of the bulky knot described above. An additional bulky knot <NUM> is created below the leaflet <NUM>. The additional bulky knot <NUM> will sandwich the leaflet <NUM> between two knots. The distance between the knots should be no more than the thickness of the leaflet <NUM>. As shown in <FIG>, a spacer <NUM> may be provided between the bulky knots <NUM>, <NUM>.

Referring to <FIG>, once one or more bulky knots <NUM> have been implanted to one or more cardiac tissues, lengthening or shortening of the artificial chordae can be performed by knotting, tying, cutting, anchoring, and otherwise manipulating the cords in a manner so as to achieve the desired (e.g., optimal) length. Once the optimal length of the neochord is determined, the suture <NUM> can be tied off and/or anchored, outside of the apex <NUM>, by any means well known in the art, for instance, by tying one or more knots into the suture <NUM>. One or more pledgets <NUM> may also be used.

According to embodiments herein, the bulky knot concept can be used for an Alfieri stitch; that is, an Alfieri stitch can be created by sequentially deploying a double helix knot on first one leaflet of the mitral valve (i.e., the anterior leaflet <NUM>), followed by the posterior leaflet <NUM>, then tying the two together, using a knot pusher deployed from the apex <NUM>.

Furthermore, while the embodiments disclosed herein are described with reference to a heart valve leaflet, the concepts are equally applicable to penetrating and applying similar knots to the annulus <NUM> of the valves. For example, several bulky knots <NUM> may be installed in the annulus <NUM> and tied together.

<FIG> shows another comparative example in which an expansile element <NUM> has been created. One approach for the expansile element <NUM> is a standard guide wire <NUM> made of an elongated spring formed of steel, nitinol, or other material. The guide wire <NUM> may be coated with PTFE or other appropriate coating. Alternatively, the guide wire <NUM> may remain uncoated. The guide wire <NUM> should be appropriately sized, such as <NUM>. Other sizes may be used. The expansile element <NUM> includes a suture <NUM> in the core. Preferably, the suture <NUM> is made of PTFE. The suture <NUM> is woven through the guide wire <NUM> as illustrated in <FIG> so that pulling on the suture <NUM> causes deformation of the tip of the expansile element <NUM> into a figure of <NUM> (or similar) configuration. <FIG> shows the progression of the expansile element <NUM> from an inactivated form as shown in <FIG> to a partially activated form in <FIG>, then to a fully activated form in <FIG>. The fully activated form may be in a spiral or helical shape or have one, two, three, or more loops, as desired.

Using an expansile element <NUM>, a single-needle puncture procedure can be performed. As shown in <FIG>, a neochord implant <NUM> that contains an expansile element <NUM> on the tip can be deployed once it has passed through the leaflet <NUM>. The neochord implant <NUM> is inside an appropriately sized needle <NUM>. The needle <NUM> may be <NUM>-gauge, <NUM>-gauge, <NUM>-gauge, or other appropriate size. The needle <NUM> is used to penetrate the leaflet <NUM> and is then withdrawn, leaving the neochord implant <NUM> in place. The expansile element <NUM> is activated by pulling on the suture <NUM> causing deformation of the expansile element <NUM> at the tip into a predetermined configuration such as shown at <NUM>, which keeps the implant <NUM> in place.

The expansile element <NUM> may be self-forming; that is, the expansile element <NUM> can be made of a pre-shaped "memory" metal that is inserted into the needle <NUM>. Withdrawal of the needle <NUM> allows the expansile element <NUM> to form its required shape.

Alternatively, as shown in <FIG>, an appropriately sized needle <NUM> or fine wire may be located inside the neochord implant <NUM>. As above, the needle <NUM> is used to penetrate the leaflet <NUM> and is then withdrawn, leaving the neochord implant <NUM> in place. An advantage of having the needle <NUM> inside the implant <NUM> is that it enables tighter tolerance between the implant <NUM> and the leaflet <NUM>. Additionally, if a fine wire is used, it could also be used to activate the expansile element <NUM> instead of the suture <NUM>.

<FIG> shows an alternate configuration for the expansile element <NUM>. An additional loop <NUM> is created below the leaflet <NUM>. The additional loop <NUM> will sandwich the leaflet <NUM> between two loops of the implant <NUM>. The distance between the loops should be no more than the thickest a leaflet <NUM> could be. As the additional loop <NUM> is formed, it will conform to the thickness of the leaflet <NUM>.

Referring to <FIG>, once one or more implants <NUM> have been implanted to one or more cardiac tissues, the implantation device is removed through the access (e.g., via the access port), and the tail ends of the suture(s) <NUM> are trailed therethrough. Artificial chordae lengthening or shortening can be performed by knotting, tying, cutting, anchoring, and otherwise manipulating the cords in a manner so as to achieve the desired (e.g., optimal) length. Once the optimal length of the neochord is determined, the suture <NUM> can be tied off and/or anchored, outside of the apex <NUM>, by any means well known in the art, for instance, by tying one or more knots into the suture <NUM>. One or more pledgets <NUM> may also be used.

In another approach, the neochord implant <NUM> of the present disclosure herein can be used in an edge-to-edge (Alfieri) repair, as shown in <FIG>. A first implant <NUM> is deployed on one leaflet <NUM>. A second implant <NUM> is deployed on the second leaflet <NUM>. The two implants are then banded together to create adjoining edges.

The sutures that are to be implanted (for instance, so as to function as artificial chordae tenidinae or neochords) may be fabricated from any suitable material, such as but not limited to: polytetrafluoroethylene (PTFE), nylon, Gore-Tex, Silicone, Dacron, or the like. With respect to the implantation of artificial chordae, the particular function of the replacement cord is dependent upon the configuration, physical characteristics and relative positioning of the structure(s). The structures may act to restrain the abnormal motion of at least a portion of one or more of the valve leaflets. Alternatively, the prosthetic chordae provide a remodeling as well as a leaflet restraint function where the latter may address latent or residual billowing of the leaflet body and/or latent or residual prolapsing of the leaflet edge, either of which may result from the remodeling itself or from a physiological defect.

It is to be noted that a fundamental challenge in successfully replacing one or more chordae tendineae and restoring proper functioning of a cardiac valve, is determining the appropriate artificial cord length and securing the artificial cord at a location so as to ensure the optimal replacement chordae length. The valve will not function properly if the length of the artificial cord is too long or too short. Because the heart is stopped using conventional techniques, it is virtually impossible to ensure that the cords are of the correct length and are appropriately spaced inside the ventricle to produce a competent valve. Accordingly, methods of the disclosure herein include the measuring and determining of the optimal arrangement, length, placement, and configuration of an implanted suture, for instance, a replacement cord length, while the heart is still beating and, typically, before the access site of the heart is closed. An optimal arrangement of a suture, for instance, an optimal cord length, is that arrangement that effects said repair, for instance, by minimizing reperfusion as determined by means well known in the art, for instance, by direct echo guidance.

Therefore, in accordance with the methods of the disclosure herein, once one or more artificial chordae have been implanted to one or more cardiac tissues, the implantation device is removed through the access (e.g., via the access port), and as stated above, the tail ends of the suture(s) are trailed therethrough. The optimal length of the implanted suture(s) (i.e., neochord) can then be determined by manipulating the ends of the suture(s) in a graded and calibrated fashion that is akin to manipulating a marionette. The manipulation of the artificial chordae may be done in conjunction with audio or visual assistance means, for instance, direct echo (e.g., echocardiographic) guidance, by which the degree and extent of regurgitation can be measured while the chordal length is being manipulated, so as to determine a chordal length that minimizes any observed regurgitation. Since it is preferred that the heart is still beating, the degree of cardiac regurgitation can be evaluated real time and the optimal neochord(s) length determined. Accordingly, an optimal cord length is a cord length that is determined, for instance, by direct echo guidance, to minimize or at least reduce cardiac valve regurgitation. Artificial chordae lengthening or shortening can be performed, as described above, by knotting, tying, cutting, anchoring, and otherwise manipulating the cords in a manner so as to achieve the desired (e.g., optimal) length. Once the optimal length of the neochord is determined, the sutures can be tied off and/or anchored, outside of the apex, by any means well known in the art, for instance, by tying one or more knots into the suture. One or more pledgets may also be used.

Once the corrective procedures are completed, the repaired valve may be further assessed, and if the repair is deemed satisfactory, the one or more devices (e.g., cannulae, sheath, manifold, access port, etc.) are removed, the access closed, as described above, and the percutaneous incisions are closed in a fashion consistent with other cardiac surgical procedures. For instance, one or more purse-string sutures may be implanted at the access site of the heart and/or other access sites, so as to close the openings.

Claim 1:
A device (<NUM>) for minimally invasive repair of a defective valve in a human heart, the device (<NUM>) comprising:
a slotted needle (<NUM>) suitable to be advanced through a valve leaflet (<NUM>);
a tubular pusher (<NUM>) surrounding the needle (<NUM>); and
suture material (<NUM>) wrapped around a distal end of the slotted needle (<NUM>) so as to form a wrapping (<NUM>, <NUM>),
characterised in that: the slotted needle (<NUM>) further comprises an inner lumen (<NUM>), the slotted needle (<NUM>) having a slot (<NUM>) that communicates with the inner lumen (<NUM>), with a portion of the suture material (<NUM>) emerging from a distal end (<NUM>) of the needle (<NUM>) and another portion of the suture material emerging from the slot (<NUM>),
the suture material (<NUM>) is wrapped around the slotted needle (<NUM>) such that the wrapping (<NUM>, <NUM>) is configured to be formed into a loop by:
(<NUM>) advancing the slotted needle (<NUM>) together with at least a distal portion of the wrapping (<NUM>, <NUM>) through a valve leaflet (<NUM>);
(<NUM>) withdrawing the slotted needle (<NUM>) through the wrapping (<NUM>, <NUM>) and the pusher (<NUM>) to separate the wrapping (<NUM>, <NUM>) from the slotted needle (<NUM>); and
(<NUM>) applying a withdrawal force to the ends of the suture material (<NUM>) to draw the ends of the wrapping (<NUM>, <NUM>) towards each other such that the wrapping (<NUM>, <NUM>) transforms into a bulky knot (<NUM>) suitable to anchor the suture material (<NUM>) to the valve leaflet (<NUM>).