Method and apparatus for repairing a mitral valve

A method for beneficially displacing a papillary muscle, the method comprising: anchoring one end of an implant suture to a trigone or central fibrous body of the mitral valve; passing another end of the implant suture through a papillary muscle so that the implant suture extends between a trigone or central fibrous body of the mitral valve and the papillary muscle; tensioning the implant suture while displacing the papillary muscle toward the trigone or central fibrous body of the mitral valve; and securing the tensioned implant suture to the displaced papillary muscle so as to maintain the displaced papillary muscle in position relative to the trigone or central fibrous body of the mitral valve; wherein the foregoing steps of anchoring, passing, tensioning and securing are all effected while the heart is beating.

The six (6) above-identified patent applications are hereby incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to methods and apparatus for performing cardiac structural repairs in general, and more particularly to methods and apparatus for performing mitral valve repairs and beneficial left ventricular structural repairs.

BACKGROUND OF THE INVENTION

The mitral valve is located in the heart between the left atrium and the left ventricle. SeeFIG. 1. A properly functioning mitral valve permits blood to flow from the left atrium to the left ventricle when the left ventricle expands (i.e., during diastole), and prevents the regurgitation of blood from the left ventricle back into the left atrium when the left ventricle contracts (i.e., during systole).FIG. 2shows a properly functioning mitral valve during diastole, andFIG. 3shows a properly functioning mitral valve during systole.

In some circumstances the mitral valve may fail to function properly, such that regurgitation may occur. By way of example but not limitation, mitral regurgitation is a common occurrence in patients with heart failure. Mitral regurgitation in patients with heart failure is caused by changes in the geometric configurations of the left ventricle, papillary muscles, chordae tendinae and mitral annulus. These geometric alterations result in incomplete coaptation of the mitral leaflets at systole. In this situation, mitral regurgitation is generally corrected by plicating the mitral valve annulus so as to reduce the circumference of the distended annulus and restore the original geometry of the mitral valve annulus.

More particularly, current surgical practice for mitral valve repair generally requires that the mitral valve annulus be reduced in radius by surgically opening the left atrium and then fixing sutures, or more commonly sutures in combination with a support ring, to the internal surface of the annulus; this structure is used to draw the annulus, in a purse-string-like fashion, to a smaller radius, thereby improving leaflet coaptation and reducing mitral regurgitation.

This method of mitral valve repair, generally referred to as “annuloplasty”, effectively reduces mitral regurgitation in heart failure patients. This, in turn, reduces symptoms of heart failure, improves quality of life and increases longevity. Unfortunately, however, the invasive nature of such mitral valve surgery (i.e., general anesthesia, chest wall incision, cardiopulmonary bypass, cardiac and pulmonary arrest, incision on the heart itself so as to gain access to the mitral valve, etc.), and the risks associated therewith, render most heart failure patients poor surgical candidates for an annuloplasty. Thus, a less invasive means to increase leaflet coaptation and thereby reduce mitral regurgitation in heart failure patients would make mitral valve repair available to a much greater percentage of patients.

Mitral regurgitation also occurs in approximately 20% of patients suffering acute myocardial infarction. In addition, mitral regurgitation is the primary cause of cardiogenic shock in approximately 10% of patients who develop severe hemodynamic instability in the setting of acute myocardial infarction. Patients with mitral regurgitation and cardiogenic shock have about a 50% hospital mortality. Elimination of mitral regurgitation in these patients would be of significant benefit. Unfortunately, however, patients with acute mitral regurgitation complicating acute myocardial infarction are particularly high-risk surgical candidates, and are therefore not good candidates for a traditional annuloplasty procedure. Thus, a minimally invasive means to effect a temporary reduction or elimination of mitral regurgitation in these critically ill patients would afford them the time to recover from the myocardial infarction or other acute life-threatening events and make them better candidates for other medical, interventional or surgical therapy.

SUMMARY OF THE INVENTION

As a result, one object of the present invention is to provide an improved method for reducing mitral regurgitation.

Another object of the present invention is to provide improved apparatus for reducing mitral regurgitation.

Another object of the present invention is to provide a method and apparatus for cardiac valve repair, and particularly mitral valve repair, that avoid certain disadvantages of the prior art.

Another object of the present invention is to enable mitral valve repair in a minimally invasive manner without the need for cardiopulmonary bypass or significant surgical intervention.

Another object of the present invention is to provide a means for placing one or more spanning sutures across the mitral valve, and anchoring those spanning sutures to the mitral annulus and nearby cardiac structures, in such a manner as to effect a beneficial reduction in the dilation and distortion of the mitral annulus which causes mitral regurgitation.

A further object of the present invention is to provide a method and apparatus for favorably remodeling the left ventricle.

Another object of the present invention is to provide a method and apparatus for mitral valve repair, either via transapical access with a small exposure incision to the skin in the vicinity of the apex of the left ventricle, complete percutaneous access to the left ventricle, or a combination of transapical and percutaneous access including trans-septal puncture or retrograde access through the aorta and aortic valve. In any case, it is an object of the present invention to provide procedure access through the left ventricular wall to the interior of the left ventricle via a small diameter apical access sheath or access/closure device.

A related object of the present invention is to provide a method and apparatus that do not require a sternotomy when providing procedure access to the mitral valve.

Another related object of the present invention is to provide a method and apparatus that do not require cardiopulmonary bypass or aortic manipulation when reducing mitral regurgitation.

Another object of the present invention is to provide a method and apparatus for mitral valve repair that provides for a controllable anterior/posterior dimension change of the mitral valve while a functional improvement in valve competence is continuously evaluated by real-time cardiac ultrasound or other diagnostic means.

One preferred embodiment of the present invention comprises the provision and use of novel, low-profile devices that are sequentially inserted into the left ventricle of the heart, deploy a spanning suture across the mitral valve on the atrial side, anchor the spanning suture to one side of the annulus with a first anchor, adjust the length of the spanning suture crossing the left atrium while performing real-time ultrasound evaluation of mitral regurgitation, and permanently terminate the spanning suture to a second anchor on the other side of the annulus. The present invention provides novel tools that allow this novel process to be performed quickly, easily and safely, by one of several possible approaches, optionally multiple times on a given valve, until satisfactory correction of the mitral regurgitation has been achieved.

A well-known limitation of prior art devices is that they are not broadly effective because of the high degree of variation in patient anatomies. Significantly, the present invention provides a method and apparatus that provides a high degree of effectiveness across a wide range of patient anatomies, particularly in allowing a clinician to adjust their technique based upon observation of the effectiveness of the initial adjustment of the spanning suture and to increase or decrease the magnitude of the adjustment made on the valve until an acceptable correction has been achieved.

In one preferred embodiment of the present invention, the procedure is generally as follows. External access is established to the left ventricular apex using conventional trans-apical techniques (e.g., such as those used in the positioning of aortic valves). The left ventricular apex is exposed, either surgically through incision or via direct needle access using the Seldinger technique. An apical access sheath having an internal working diameter of approximately 3-5 mm is passed through the myocardium and directed towards the center of the mitral valve. SeeFIG. 4.

A first positioning sheath is passed into the left ventricle via the apical access sheath and the distal tip of the first positioning sheath is positioned against the annulus of the valve at a structurally advantageous point. SeeFIG. 5. Once proper positioning is verified (e.g., by imaging, either via echocardiography or fluoroscopy), a first curved tube is advanced out of the first positioning sheath and through the annulus. SeeFIG. 6. A first guidewire is passed through the first curved tube (and hence through the annulus) and into the left atrium. SeeFIG. 7. The first guidewire preferably has an atraumatic tip to avoid damaging the atrial wall and/or surrounding tissues and is visible via ultrasonic or fluoroscopic imaging.

Separately, a center sheath is advanced through the apical access sheath and through the leaflets of the mitral valve so that the distal end of the center sheath is positioned in the left atrium. SeeFIG. 8. This center sheath may be placed before or after the aforementioned puncture crossing of the mitral annulus via the first positioning sheath, first curved tube and first guidewire. A snare is then advanced through the center sheath. SeeFIG. 9. Under ultrasonic and/or fluoroscopic guidance, the first guidewire and snare are manipulated so that the first guidewire is captured by the snare, and then the snare is used to bring the first guidewire out to the operative sterile field through the center sheath. SeeFIG. 10. This leaves the first guidewire extending from the apex, across the left ventricle, through one side of the annulus, into the left atrium, into the center sheath, between the mitral leaflets and then back across the left ventricle. SeeFIG. 11.

The annulus puncture process is then repeated on the opposite side of the annulus, e.g., using a second positioning sheath and an associated annulus-crossing second curved tube. SeeFIGS. 12 and 13. Once the second curved tube has been placed across the annulus, a second guidewire is passed through the annulus-crossing second curved tube and advanced into the left atrium. SeeFIG. 14. Then a snare is advanced through the center sheath and captures the distal end of the second guidewire. SeeFIG. 15. At this point the snare is retracted so as to bring the second guidewire out to the operative sterile field through the center sheath. SeeFIG. 16. Once the distal ends of the first and second guidewires have been brought out to the operative sterile field, they are terminated (i.e., connected together) at the operative sterile field. SeeFIG. 17. Then the termination is sent back up through the center sheath so that the termination resides in the left atrium. SeeFIG. 18.

Once the first and second guidewires have been passed through opposing sides of the annulus, terminated (i.e., joined) to one another, and their termination advanced back to the left atrium, the termination between the two guidewires is pulled through the second positioning sheath and its annulus-crossing second curved tube, thereby establishing a continuous loop of guidewire extending from the apex, across the left ventricle, through one side of the annulus, across the left atrium, through the other side of the annulus, across the left ventricle, and back down to the apex. SeeFIG. 19.

At this point, the first positioning sheath (and its annulus crossing first curved tube), the second positioning sheath (and its annulus crossing second curved tube), and the center sheath may all be removed from the operative site, if they have not already been removed.

The aforementioned continuous section of guidewire is sometimes hereinafter referred to as “the crossing guidewire”.

And the aforementioned approach for placing the crossing guidewire is sometimes hereinafter referred to as the “cross and snare” approach.

It should be appreciated that the term “crossing guidewire” is intended to be a broad term of art, since in fact the construction of the crossing “guidewire” may be effected with wire, suture, filaments, coils, and/or other materials known in the art capable of establishing a spanning structure able to provide the desired device handling in vivo.

It should be further appreciated that, if desired, a single, dedicated tool could be employed, sequentially, to provide both a positioning sheath and a curved tube, and this single, dedicated tool could be used, sequentially, for both sides of the mitral annulus. Thus, with such a construction, the single, dedicated tool (providing the positioning sheath and the curved tube) would be used first on one side of the mitral annulus to route a guidewire through the annulus; and then the single, dedicated tool (providing the positioning sheath and curved tube) would be removed from the first side of the mitral annulus and then re-positioned on the opposite side of the annulus and used in a similar fashion to pass a second guidewire through the opposite side of the annulus.

In an alternative embodiment of the present invention, the crossing guidewire can be established using a somewhat different approach, which will sometimes hereinafter be referred to as the “cross and catch” approach. More particularly, with the “cross and catch” approach, the first positioning sheath is passed into the left ventricle via the apical access sheath and its distal end is positioned against the annulus at a first location. SeeFIG. 5. Then the first curved tube is advanced out of the first positioning sheath and through the annulus at that first location. SeeFIG. 6. Next, the second positioning sheath is passed into the left ventricle via the apical access sheath and its distal end is positioned against the annulus at a second location. SeeFIG. 20. Then the second curved tube is advanced out of the second positioning sheath and through the annulus at that second location. SeeFIG. 21.

Next, a funnel-shaped snare is advanced through the second curved tube of the second positioning sheath so that the funnel-shaped snare faces the first curved tube exiting the first positioning sheath. SeeFIG. 22. Then a guidewire is advanced through the first curved tube of the first positioning sheath, across the left atrium and into the funnel-shaped snare exiting the second curved tube of the second positioning sheath. SeeFIG. 23. The funnel-shaped snare captures the distal end of the guidewire, and then the funnel-shaped snare is retracted through the second curved tube of the second positioning sheath until the distal end of the guidewire emerges at the operative sterile field. SeeFIG. 24. Then the distal end of the guidewire is detached from the funnel-shaped snare. SeeFIG. 25. The first positioning sheath and its associated annulus-crossing first curved tube are withdrawn, and the second positioning sheath and its associated annulus-crossing second curved tube are withdrawn, leaving the guidewire extending from the apex, across the left ventricle, through one side of the annulus, into the left atrium, through the other side of the annulus, across the left ventricle and back down to the apex. SeeFIG. 26.

In another alternative embodiment of the present invention, the crossing guidewire can be placed using still another approach, which will sometimes hereinafter be referred to as the “cross and receive” approach. More particularly, with the “cross and receive” approach, a first positioning sheath is passed into the left ventricle via the apical access sheath and its distal end is positioned against the annulus at a first location. SeeFIG. 5. Then a first curved tube is advanced out of the first positioning sheath and through the annulus at that first location. SeeFIG. 6. Next, a second positioning sheath is passed into the left ventricle via the apical access sheath and its distal end is positioned against the annulus at a second location. SeeFIG. 20. Then a second curved tube is advanced out of the second positioning sheath and through the annulus at that second location. SeeFIG. 21.

Next, an inflatable funnel is advanced, in a deflated state, through the second curved tube of the second positioning sheath so that the inflatable funnel faces the first curved tube exiting the first positioning sheath. Then the inflatable funnel is inflated so that the mouth of the inflatable funnel faces the first curved tube exiting the first positioning sheath. SeeFIG. 27. Next, a guidewire is advanced through the first curved tube of the first positioning sheath, across the left atrium and into the inflatable funnel exiting the second curved tube of the second positioning sheath. SeeFIGS. 28 and 29. The guidewire is advanced down the second curved tube of the second positioning sheath until the distal end of the guidewire emerges at the operative sterile field. SeeFIG. 30. The inflatable funnel is deflated and withdrawn from the second curved tube of the second positioning sheath. SeeFIG. 31. Then the first positioning sheath and its associated annulus-crossing first curved tube are withdrawn, and the second positioning sheath and its associated annulus-crossing second curved tube are withdrawn, leaving the guidewire extending from the apex, across the left ventricle, through one side of the annulus, into the left atrium, through the other side of the annulus, across the left ventricle and back down to the apex. SeeFIG. 32.

By any of the foregoing approaches, a continuous path of guidewire (or suture or other filamentary element) is established, travelling from the apical access sheath, through the mitral annulus on one side, across the left atrium, back through the mitral annulus and back out through the apical access sheath. It should be noted that by the methods and tools described herein, such a crossing path can be established at a wide range of anatomically-preferred locations and with the establishment of only “small caliber” holes through the annulus, that is, holes approximately the diameter of the intended implant suture.

Once the crossing guidewire has been established, preferably using one of the aforementioned three approaches (i.e., the “cross and snare” approach, the “cross and catch” approach, or the “cross and receive” approach), a spanning implant can be deployed across the annulus of the mitral valve so as to reconfigure the geometry of the mitral valve.

More particularly, the spanning implant comprises a spanning suture having a first end, a second end and a first anchor connected to the first end of the spanning suture. The spanning implant also comprises a second anchor which is fit over the second end of the spanning suture, slid along the spanning suture to an appropriate position and then secured in place, as will hereinafter be discussed. SeeFIG. 33.

Note that the spanning suture may comprise conventional surgical suture (e.g., braided suture, monofilament suture, etc.), filament, wire, cable and/or substantially any other flexible elongated body consistent with the requirements of the present invention. For the purposes of the present invention, all such constructions are intended to be encompassed by the term “spanning suture”.

The spanning implant is preferably deployed in the following manner. First, one end of the crossing guidewire is secured to the second end of the spanning suture. SeeFIG. 34. Then the crossing guidewire is used to draw the spanning suture from the apex, across the left ventricle, through one side of the annulus, across the left atrium, through the other side of the annulus, across the left ventricle, and back down to the apex. The crossing guidewire is pulled until the first anchor at the first end of the spanning suture is seated against the annulus, generally disposed in the space between the leaflet insertion and the ventricular wall. SeeFIG. 35. The second anchor is then slid onto the second end of the spanning suture and advanced along the spanning suture toward the annulus. SeeFIG. 36. The second anchor is advanced until the second anchor seats against the opposite side of the annulus, on the ventricular side of the annulus. SeeFIG. 37. Thus, as a result of the foregoing, the first anchor is disposed against the ventricular side of the annulus at a first location, the spanning suture extends through the annulus at that first location, across the left atrium, and through the annulus at a second location, and the second anchor seats against the ventricular side of the annulus at the second location.

Finally, an implant tensioning tool, integrally fitted with a coaxial suture lock, is advanced over the second end of the spanning suture so as to engage the second anchor. The implant tensioning tool is then used to progressively tension the spanning suture, which causes the two sides of the annulus to be drawn together along the line of the spanning suture, until the desired anterior/posterior dimension is achieved for the annulus, whereby to provide the desired reduction in mitral regurgitation. Preferably this tensioning of the spanning suture is done under real-time ultrasound observation. Once the desired mitral reconfiguration has been achieved, the implant tensioning tool is used to lock the second anchor in position on the spanning suture with the coaxial suture lock. SeeFIG. 38. This maintains the mitral valve in its reconfigured state. The implant tensioning tool is then removed, and the excess spanning suture remaining proximal to the coaxial suture lock may then be removed (e.g., with a cutoff tool) or terminated to the left ventricular wall. SeeFIG. 39.

In a separate preferred embodiment, the implant tensioning tool additionally houses and delivers the second anchor.

This foregoing process may then be repeated as needed with other spanning implants so as to effect a complete, effective and structurally durable reconfiguration of the mitral valve. SeeFIG. 40. It is anticipated that, in a typical case, two spanning implants will be used to reconfigure the annulus, each anchored in either the anterior or posterior trigone and spanning from the trigone to the posterior annulus, with the anterior trigone connected to the posterior annulus generally in the vicinity of the P1/P2 leaflet intersection, and the posterior trigone connected to a point in the vicinity of the P2/P3 leaflet intersection. It is anticipated that, depending upon the degree of dilation of the mitral annulus, and the specialized anatomical issues of a particular patient, as many as four or five spanning implants may be used to reconfigure the annulus, anchored through the anterior and posterior trigones, or from a more central point along the central fibrous body of the heart, and across and through the posterior annulus.

For the purposes of the present invention, the first anchor may be considered “fixed” (i.e., “the first, fixed anchor”), in the sense that the spanning suture may be tensioned relative to the first anchor when the first anchor is positioned against the mitral annulus. However, the term “first, fixed anchor” is not intended to be construed as requiring that the first anchor be fixedly secured to the spanning suture, since the first anchor may be connected to the spanning suture in a manner which allows the spanning suture to be to tensioned relative to the first anchor when the first anchor is positioned against the mitral annulus, yet which also allows the spanning suture to move relative to the first anchor when the spanning suture is moved in an opposite direction. By way of example but not limitation, the “first, fixed anchor” may comprise a central through-hole, and the spanning suture may comprise an end having an enlargement larger than the central through-hole of the anchor; in this case, the spanning suture may extend through the central through-hole of the anchor and be tensioned by pulling the spanning suture so that the enlargement engages the first, fixed anchor, however, the spanning suture may also be moved relative to the first, fixed anchor by pushing the spanning suture so that the enlargement moves away from the first, fixed anchor.

Furthermore, for purposes of the present invention, the second anchor may be considered “sliding” (i.e., “the second, sliding anchor”), in the sense that the second anchor may be slid along the spanning suture prior to fixation relative to the spanning suture. However, the term “second, sliding anchor” is not intended to be construed as requiring that the second anchor be slidable relative to the spanning suture at all times, since the second, sliding anchor is intended to be fixedly secured to the spanning suture after the spanning suture has been tensioned so as to reconfigure the mitral annulus.

In one preferred form of the invention, the spanning implant may be deployed from anterior to posterior, i.e., the first, fixed anchor is deployed against the anterior annulus and the second, sliding anchor is deployed against the posterior annulus. However, it is also anticipated that the direction of the spanning implant might be reversed, with the first, fixed anchor deployed against the posterior annulus and the second, sliding anchor deployed against the anterior annulus.

It should be appreciated that each anchor (i.e., the aforementioned first, fixed anchor and the aforementioned second, sliding anchor) may be optimized for the anatomical location for which it is deployed, with preferably smaller shapes in the higher-flow, highly fibrous trigone locations and larger shapes in the slower-flow, less fibrous posterior wall locations.

It should be appreciated that the procedure described above has distinct advantages over many alternative approaches. The approach of the present invention can, as described, effect substantial, effectively unlimited reduction of the anterior/posterior dimension of the mitral annulus. Furthermore, the method affords all of the advantages of a minimally invasive procedure.

In one preferred form of the invention, there is provided a method for repairing a mitral valve, the method comprising:

positioning a crossing guidewire across the mitral valve, the crossing guidewire passing through the annulus of the mitral valve at a first location and passing through the annulus of the mitral valve at a second location;

using the crossing guidewire to position a spanning implant across the mitral valve, with the spanning implant extending from the first location to the second location;

anchoring the spanning implant at the first location;

tensioning the spanning implant so as to draw the first location and the second location together; and

anchoring the spanning implant at the second location.

In another preferred form of the invention, there is provided apparatus for repairing a mitral valve, the apparatus comprising:

a suture having a first end and a second end, a first anchor secured to the first end of the suture, a second anchor slidably mounted to the second end of the suture, and a coaxial suture lock for locking the second anchor to the suture.

In another preferred form of the invention, there is provided apparatus for repairing a mitral valve, the apparatus comprising:

a crossing guidewire extending from the left ventricle, through the annulus at a first location, into the left atrium, through the annulus at a second location, and into the left ventricle.

In another preferred form of the invention, there is provided apparatus for repairing a mitral valve, the apparatus comprising:

a positioning sheath having a distal end, a proximal end, and a lumen extending therebetween, the positioning sheath being configured to extend across the left ventricle and contact the annulus of the mitral valve at a first location, with the distal end of the positioning sheath set so that the lumen of the positioning sheath is aimed into the left atrium; and

a curved tube having a distal end, a proximal end, and a lumen extending therebetween, the curved tube being configured to telescopically extend through the positioning sheath, across the annulus at the first location and present its distal end substantially parallel to the plane of the mitral valve annulus.

In another preferred form of the invention, there is provided apparatus, said apparatus comprising:

an anchor, said anchor comprising:an elongated body having a distal end and a proximal end, and a first side and a second side;a through-hole formed in said body intermediate said distal end and said proximal end and extending through said body from said first side to said second side, said through-hole being sized to receive a spanning suture;a proximal slot formed in said first side of said body and communicating with said through-hole, said proximal slot being sized to receive a spanning suture; anda distal slot formed in said second side of said body and communicating with said through-hole, said distal slot being sized to receive a spanning suture;at least a portion of said proximal slot being axially aligned with at least a portion of said distal slot so that said proximal slot, said through-hole and said distal slot together form an axial passageway extending from said distal end of said elongated body to said proximal end of said elongated body, with said axial passageway being sized to receive a spanning suture.

In another preferred form of the invention, there is provided apparatus comprising:

a form-fitting, stretchable sheath; and

a medical component disposed within said form-fitting, stretchable sheath.

In another preferred form of the invention, there is provided a pledget assembly comprising:

a central ring having a distal end and a proximal end and an opening extending from said distal end to said proximal end;

a surgical pledget mounted to said central ring and extending radially outboard thereof; and

a helical coil having a distal end and a proximal end, said helical coil being mounted to said central ring and extending distally thereof, said helical coil being configured for turning into tissue for fixation thereto.

In another preferred form of the invention, there is provided a method for reconfiguring a mitral valve, said method comprising:

positioning a spanning suture across the mitral valve, said spanning suture extending from the left ventricle of the heart, through the annulus of the mitral valve at a first location, across the left atrium of the heart, through the annulus of the mitral valve at a second location, and back to the left ventricle of the heart;

positioning a first anchor connected to said spanning suture against the ventricular side of the mitral valve at the first location and positioning a second anchor connected to said spanning suture against the ventricular side of the mitral valve at the second location and tensioning said spanning suture so as to draw the first location and the second location together, whereby to reconfigure the mitral valve; and

fixedly securing said second anchor to the spanning suture so as to maintain the mitral valve in its reconfigured state;

wherein at least one of said first anchor and said second anchor comprises:an elongated body having a distal end and a proximal end, and a first side and a second side;a through-hole formed in said body intermediate said distal end and said proximal end and extending through said body from said first side to said second side, said through-hole being sized to receive said spanning suture;a proximal slot formed in said first side of said body and communicating with said through-hole, said proximal slot being sized to receive said spanning suture; anda distal slot formed in said second side of said body and communicating with said through-hole, said distal slot being sized to receive said spanning suture;at least a portion of said proximal slot being axially aligned with at least a portion of said distal slot so that said proximal slot, said through-hole and said distal slot together form an axial passageway extending from said distal end of said elongated body to said proximal end of said elongated body, with said axial passageway being sized to receive said spanning suture.

In another preferred form of the invention, there is provided a method for reconfiguring a mitral valve, said method comprising:

positioning a spanning suture across the mitral valve, said spanning suture extending from the left ventricle of the heart, through the annulus of the mitral valve at a first location, across the left atrium of the heart, through the annulus of the mitral valve at a second location, and back to the left ventricle of the heart;

positioning a first anchor connected to said spanning suture against the ventricular side of the mitral valve at the first location and positioning a second anchor connected to said spanning suture against the ventricular side of the mitral valve at the second location and tensioning said spanning suture so as to draw the first location and the second location together, whereby to reconfigure the mitral valve; and

fixedly securing said second anchor to the spanning suture so as to maintain the mitral valve in its reconfigured state;

wherein at least one of said first anchor and said second anchor is delivered through a form-fitting, stretchable sheath making an engaging fit with said at least one of said first anchor and said second anchor.

In another preferred form of the invention, there is provided a method for beneficially displacing a papillary muscle, the method comprising:

anchoring one end of an implant suture to a trigone or central fibrous body of the mitral valve;

passing another end of the implant suture through a papillary muscle so that the implant suture extends between a trigone or central fibrous body of the mitral valve and the papillary muscle;

tensioning the implant suture while displacing the papillary muscle toward the trigone or central fibrous body of the mitral valve; and

securing the tensioned implant suture to the displaced papillary muscle so as to maintain the displaced papillary muscle in position relative to the trigone or central fibrous body of the mitral valve;

wherein the foregoing steps of anchoring, passing, tensioning and securing are all effected while the heart is beating.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention summarized above may be better understood by reference to the following exemplary description of the preferred embodiments, which should be read in conjunction with the accompanying drawings wherein like reference numbers are used for like parts. The following description of the preferred embodiments, set out below to facilitate the construction and use of an implementation of the present invention, is not intended to limit the present invention, but instead to serve as a particular example thereof so as to facilitate its construction and use. Those skilled in the art should appreciate that they may readily use the conception and specific embodiments disclosed herein as a basis for modifying the method and apparatus disclosed, or designing additional methods and apparatus, for carrying out the same purposes of the present invention. It should be appreciated that such methods and apparatus do not depart from the spirit and scope of the present invention in its broadest form.

In accordance with the present invention, the heart may be accessed through one or more openings made by one or more small incisions in a portion of the body proximal to the thoracic cavity, for example, between one or more of the ribs of the rib cage, proximate to the xyphoid appendage, or via the abdomen and diaphragm. This location can be appreciated by viewing the anatomy shown inFIG. 1. Access to the thoracic cavity may be sought so as to allow the insertion and use of one or more thorascopic instruments. Additionally, access to the heart may be gained by direct puncture of the heart from the xyphoid region (i.e., via an appropriately sized needle, e.g., an 18 gauge needle). 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.

Suitable surgical candidates are identified by reviewing available cardiac imaging which may include, but is not limited to, transesophageal echocardiogram (TEE), transthoracic echocardiogram (TTE), magnetic resonance imaging (MRI), computer tomagraphy (CT), fluoroscopy, chest x-rays, etc. Rendered 3D models of the patient's anatomy may be constructed and reviewed, in addition to reviewing previous imaging of the anatomy, in order to plan device access and the mitral valve repair.

The patient is prepped and placed under anesthesia, and appropriate ultrasound imaging (TEE or TTE) is set up so as to provide real-time assessment of the geometry and function of the mitral valve. The procedure is conducted in a standard cardiac operating room or, optionally, in a hybrid operating room which additionally provides for fluoroscopic imaging. A minimally invasive approach is used to access the thoracic cavity. This minimally invasive approach involves a small incision in the skin between the ribs to expose a surgical field suitable for device access and to provide a purse-string suture for the access site if necessary. Such an incision is typically about 1 cm to about 10 cm in length, or about 3 cm to about 7 cm in length, or about 5 cm in length, and should be placed near the pericardium so as to allow ready access to, and visualization of, the heart.

The planned access point and device orientation are generally determined by pre-procedure imaging and anatomical models, and are confirmed by anatomical landmarks and procedural imaging such as ultrasound and fluoroscopy. Access to the left ventricle of the heart may be made at any suitable site of entry, but is preferably made through a point near to, but not at, the apex of the heart, in a region of diffuse vasculature, so as to avoid coronary arteries, papillary muscles and chordae tendineae. The papillary muscles and chordae tendineae of the mitral valve are shown inFIGS. 2 and 3. Apparatus orientation is optimized so as to provide access to the applicable target locations of the mitral valve annulus and to minimize the need to manipulate the access site during device use. The apparatus is advanced into the heart through a small incision stabilized by a purse-string suture, a direct puncture of the heart with the apparatus (with or without a purse-string suture), or by a series of devices of increasing diameter (dilators) until the apparatus with the largest diameter is positioned (with or without a purse-string suture) through the wall of the left ventricle. It is thus expected that the generally preferred axis of alignment of the apparatus will be along a central axis defined by the point of access to the left ventricular apex and the centroid of the mitral valve plane.

Transesophageal echocardiography (TEE) (2D or 3D), transthoracic echocardiography (TTE), intracardiac echo (ICE), or cardio-optic direct visualization (e.g., via infrared vision from the tip of a 7.5 French catheter) may be performed to assess the condition of the heart and its valves. A careful assessment is made of the location and type of cardiac dysfunction via conventional echocardiographic means, e.g., TEE or TTE, so as to facilitate planning of the appropriate structural correction to be performed on the mitral valve annulus, whereby to improve mitral valve function and reduce mitral valve regurgitation. The use of TEE, TTE, ICE or the like can also assist in determining if there is a need for adjunctive procedures to be performed on the leaflets and subvalvular structures, and can indicate whether an adjunctive or alternative minimally invasive approach, or direct surgery, is advisable.

All of the steps and apparatus described below can be best appreciated by reference to the attached figures. The operative method and preferred apparatus characteristics will now be described, including multiple preferred embodiments of the method and apparatus of the present invention.

1. Left Ventricular Access

Access will generally be effected along the left lateral chest wall between the ribs, either with an initial small surgical exposure cut-down, or via direct percutaneous needle puncture. The choice of the specific access method will generally be guided by imaging and considerations such as possible interference with the lobes of the lung.

Apical access is directed by pre-procedural modeling and imaging, and inter-procedural imaging, as previously described. It is expected that the preferred access location and direction will be along an axis directed centrally through the chosen rib space, left ventricle and mitral valve.

Direct percutaneous left ventricular puncture, with or without supplemental dilation, is effected using standard Seldinger techniques well understood in the surgical arts including, in this specific case, the use of an appropriate left ventricular closure device.

Following the establishment of left ventricular access, an apical access sheath5(FIG. 4), preferably between about 3 cm and about 10 cm long, and between about 2.5 mm and about 4 mm internal diameter, typically fitted with an integral, adjustable internal diameter hemostasis valve10, and with minimal rigid length, is placed into the left ventricle.FIG. 4shows apical access sheath5and hemostasis valve10positioned through the chest wall and through the myocardium.

Alternatively,FIG. 41shows another preferred embodiment of apical access sheath5. As seen inFIG. 41, in addition to the access sheath features described above, a second branch or “Y” leg, constituting a side port access sheath15, is provided to allow for a second independent access path from the operative sterile field into apical access sheath5. Side port access sheath15is preferably also fitted with an integral, adjustable internal diameter hemostasis valve20, and joins apical access sheath5distal to hemostasis valve10. The provision of side port access sheath15allows for more independent manipulation of multiple clinical tools during the procedure, as will be discussed further below. One preferred design for the joining side port access sheath15to apical access sheath5is for the “Y” junction of the branches to be formed of a flexible material such as urethane, silicone, etc., to allow for manipulation of the legs and to allow for the insertion of curved tools into apical access sheath5.

2. Establishing the Crossing Guidewire by the “Cross and Snare” Approach

One preferred approach for beneficially modifying the mitral annulus employs a novel technique, sometimes herein referred to as the “cross and snare” approach, for safely and accurately establishing a desired suture path across the mitral annulus.

The first tool employed in the “cross and snare” procedure is sometimes referred to herein as the “target and cross tool”, or “TCT”. The TCT can be prepared in various specific variants depending upon the particular preferred embodiment being implemented. More particularly, the TCT may have a multitude of sizes and shapes, e.g., longer or shorter lengths, more or less curves, more or less curvature, etc., depending on the specific patient (e.g., large patient, small patient, etc.) and anatomy to be targeted (e.g., anterior annulus, posterior annulus, a specific trigone, etc.). Thus, the TCT has a preferred shape to allow the clinician to direct the TCT to a desired location on the underside of the posterior mitral annulus in a precise and controlled fashion. Preferably the TCT has a shape which allows the TCT to be directed into a desired position on the ventricular side of the mitral annulus by a direct approach and without requiring significant lateral movement, since such lateral movement can be problematic given the presence of the chordae tendineae on the ventricular side of the mitral valve. Furthermore, the TCT preferably has a shape which allows it to advance to, and directly engage, the ventricular side of the mitral annulus without requiring the deformation or displacement of any intervening cardiac anatomy (e.g., the papillary muscles, chordae tendineae, etc.) when the TCT is advancing to, and engaging, the annulus “crossing” site. Significantly, by providing a method and means which allows the annulus “crossing” site to be accessed without requiring the deformation or displacement of any intervening cardiac anatomy, subsequent steps in the annulus reconfiguration may also be performed without requiring any intervening cardiac anatomy to be deformed or displaced By the methods described herein, once a crossing location has been reached, the TCT tool does not need to be moved laterally within the ventricle, risking entanglement or interference with chordae or other structures. And subsequent steps in the procedure follow the suture path back to the same crossing location, again without requiring lateral motion and the risk of entanglement by either the delivery tools or the deployed implant. This combination of devices and method are a significant advance in the art. The preferred tool characteristics can also be appreciated by reference to the included figures.

FIG. 5shows a TCT comprising a first positioning sheath25and its steering handle30. First positioning sheath25is advanced through apical access sheath5, through the left ventricle, and into contact with a desired location on the ventricular side of the mitral annulus (e.g., beneath the posterior ventricular side of the mitral annulus). First positioning sheath25is generally of low profile, typically 7 French or less. First positioning sheath25may include the option for either (i) passive re-shaping by the clinician by careful bending (e.g., in the manner often applied to interventional tools), or (ii) by active tip control (e.g., by providing a “steerable” positioning sheath).

Looking now atFIG. 6, a first curved tube35is slidably disposed within first positioning sheath25. First curved tube35includes a handle40. First curved tube35is preferably between about 19 gauge and 23 gauge, and is also pre-shaped in a curvilinear fashion so as to allow it to pass through the annulus and arc towards the central open area of the left atrium. First curved tube35may either be sharp, and thus passed through the annular tissue under direct pressure, or it may be smooth-tipped and serve to guide an internally-positioned RF puncture wire (either custom-made or commercially available). If first curved tube35is fitted with an internally-positioned RF puncture wire, such wire may be activated with RF energy and advanced through the annulus. First curved tube35can then be advanced so as to track along the internally-positioned RF puncture wire in a standard manner while dilating the tissue to achieve passage. Such a configuration has the advantage of stretching the tissue around the internally-positioned RF puncture wire as the first curved tube35advances, and thus can be expected to leave a smaller hole upon removal. The advancement of first curved tube35and the internally-positioned RF puncture wire may be done simultaneously or, alternatively, the internally-positioned RF puncture wire can be advanced independently of first curved tube35.

As can be appreciated from the figures, curving first curved tube35in the range of a radius of curvature of about 6-20 mm will provide for a crossing path that curves through the fibrous annulus from the left ventricle side into the left atrium while minimizing the possibility of first curved tube35puncturing the left atrium. SeeFIG. 6. The curvature can be readily observed and oriented using fluoroscopy, echocardiography, and pre-planning CT images. First curved tube may be made of Nitinol or other superelastic material, a coiled or braided construction, or a solid hypotube of stainless steel or other similar material with a pattern of openings for flexibility such as holes, slits, or other patterns, to facilitate the retention of a desired, pre-curved shape as first curved tube35is advanced out of first positioning sheath25. Similarly, a curved internally-positioned RF puncture wire fitted to first curved tube35may also be fabricated from Nitinol or other superelastic material.

First curved tube35includes a guidewire lumen within the tube, which may first carry the aforementioned internally-positioned RF puncture wire, and later carries a first guidewire45(seeFIG. 7), which may be either a conventional guidewire or a custom-curved guidewire. The lumen in first curved tube35is preferably sized to allow passage of conventional coronary guidewires, such as guidewires having diameters of 0.014 inch, 0.025 inch or 0.035 inch.

In accordance with the present invention, first positioning sheath25is positioned so as to contact the annulus in the desired location on the left ventricle side of the posterior annulus, and oriented so as to point into the left atrium. The targeting and shaping of first positioning sheath25can be readily appreciated with reference toFIG. 5. The orientation of first positioning sheath25is facilitated by the orientation of steering handle30and also referenced to real-time echocardiography and fluoroscopy, as well as referenced to previously-recorded computed tomography data. The shape of first positioning sheath25, and the single, low-profile nature of its construction, allows the clinician to safely and controllably direct first positioning sheath25to any point beneath the mitral annulus and orient first positioning sheath25such that the crossing by first curved tube35will occur across the annulus approximately along the intended final line of travel of the spanning implant.

There are various possible approaches to effecting the controlled and safe crossing of first curved tube35into the left atrium, the principles of which are generally adapted from well-understood clinical techniques. The simplest approach is to use a sharpened or beveled edge on first curved tube35, and pressure on the proximal end of handle40of first curved tube35, to cross the annulus and enter the left atrium. In this particular setting, this approach has the disadvantage of causing the release of potential embolic debris, and being less controlled, inasmuch as more pressure might be required to penetrate the annulus and also raises the possibility of damaging surrounding anatomy if first curved tube35should plunge forward as it exits the far side of the annulus. Alternatively, first curved tube35may be provided with the aforementioned internally-positioned RF puncture wire so as to facilitate passage of first curved tube35through the mitral annulus.

In one preferred form of the invention, a crossing wire with preset shape is first advanced out of first positioning sheath25, across the annulus, and into the left atrium with or without RF energy, and then first curved tube35is advanced over the crossing guidewire so as to position first curved tube35in the left atrium. Thus, in this form of the invention, the crossing wire essentially acts as a tracking wire for making a preliminary opening in the annulus and then providing a track to be followed by first curved tube35as first curved tube35is advanced through the annulus. The curved shape of the crossing wire is set so that the crossing wire preferentially emerges back into the left atrium with minimal risk of injury to adjacent structures, and also upon exit into the left atrium is directed generally towards the opposite side of the annulus in the direction of the planned spanning suture. Advancing a crossing wire through the annulus in advance of first curved tube35has the advantage that the crossing wire provides a preliminary opening in the annulus which is further dilated by passage of the following first curved tube35. This sequential opening of the annulus can be less traumatic to the tissue. In addition, using a crossing wire to prepare a track for first curved tube35also has the benefit of crossing the annulus with a very small profile element, e.g., one that may be only 0.016″ or 0.018″. As a result, if the location of the annular cross is not as intended, the crossing wire may be withdrawn with minimal injury to the annulus, and the annular crossing may thereafter be redone, before passing the larger first curved tube35through the annulus. Where a crossing wire is used, the handle on the TCT is designed to limit the maximum advance of the crossing wire so as to minimize the possibility of injuring unintended anatomical structures, and also is preferentially fitted with a feature to indicate the rotational or “azimuth” orientation of the crossing wire curvature, conceptually similar to how a periscope is directed.

First curved tube35is advanced (either alone, or carrying an internally-positioned RF puncture wire, or over the aforementioned crossing wire) into the left atrium with operator-controlled pressure and forward motion. SeeFIG. 6. Handle30on first positioning sheath25, and handle40on first curved tube35, are presented and labeled so as to give the operator good indication of the orientation and degree of advancement of first curved tube35vis-à-vis first positioning sheath25. Note that if first curved tube35is advanced carrying an internally-positioned RF puncture wire, or over the aforementioned crossing wire, the internally-positioned RF puncture wire or the crossing wire is removed from first curved tube35after first curved tube35has been advanced through the annulus, thus leaving a hollow conduit extending from the operative field to the left atrium.

After first curved tube35has been advanced through the mitral annulus, first guidewire45(controlled by a guidewire handle50) is then advanced through first curved tube35and into the left atrium, to be positioned visibly and stably in the left atrium. SeeFIG. 7. If desired, first guidewire45may be a conventional guidewire or, alternatively, first guidewire45may be an RF guidewire, in which case the functions of the aforementioned internally-positioned RF puncture wire and first guidewire45may be combined. In other words, where first guidewire45is an RF guidewire, first guidewire45may first be used as the internally-positioned RF puncture wire to facilitate passing first curved tube35through the mitral annulus, and thereafter used for establishing the crossing guidewire, as will hereinafter be discussed. A preferred embodiment for a custom “guidewire” is to use a construction based on suture such as braided polyester suture or other braided, porous, or solid material. An atraumatic tapered tip can be formed from the suture or other material by preferential removal of material. The length of the suture can then be modified in stiffness (i.e., to give it adequate column strength for longitudinal advancement) and visual markers may be added, e.g., with layers such as heat-shrink polymers. Such a construction can have the beneficial property of being visible on echocardiography.

In one preferred form of the invention, and looking now atFIG. 8, a center sheath55is advanced through apical access sheath5, between the mitral valve leaflets and into the left atrium. Then a snare60(e.g., a conventional, low-profile interventional snare) is advanced through center sheath55and into the left atrium so that it sits in alignment with first guidewire45. SeeFIG. 9. Such coronary snares are well-known in the art of interventional cardiology. Where apical access sheath5includes a side port access sheath15, snare60may be introduced into apical access sheath5by advancing the snare through side port access sheath of apical access sheath5.

In one preferred form of the invention, snare60comprises a conventional, low-profile interventional snare tool of the sort well known in the art of interventional cardiology. In another preferred form of the invention, novel snare60may comprise a tool with unique features suitable for the described procedure, and can be constructed in various forms from suture material or other braided/coiled material. By way of example but not limitation, and looking now atFIG. 42, in one preferred embodiment, snare60comprises a loop65of suture or other material with a flexible distal section70and a more rigid proximal section75. When the loop65of suture is advanced from a hypotube or sheath80, the flexible distal section70of loop65bends away from the axis of the hypotube or sheath80while the more rigid proximal section section75of loop65tends to remain aligned with the axis of the hypotube or sheath80. This causes the loop65to form a preferential “D” shape that has the benefit of possessing this shape at small and large formed loops and forming a loop that is at least partially eccentric about the axis of the snare tool that may be steered to better align the loop with snaring targets located off of the axis of the loop. The “D” loop can be enlarged in a continuous fashion across a practical size range to best fit the target anatomy and, when rotated, reach to the edges of the atrial anatomy and thus more readily effect cross-suture capture. The suture loop65could also be generally circular or oval in shape, or comprise multiple loops in a “tulip” configuration (seeFIG. 9), again to better effect suture capture. It should be further noted that constructing the snare loop from a base material of braided suture results in a device with beneficial features of being atraumatic to the adjacent atrial structures, readily visible when viewed via echocardiographic means, and resistant to kinking and damage due to the braided construction of the suture.

Snare60is advanced through center sheath55and used to capture first guidewire45. SeeFIG. 9. Snare60is then fully retracted back through center sheath55and apical access sheath5until the distal end of first guidewire45is drawn through apical access sheath5and out into the operative sterile field. SeeFIG. 10. This leaves the first guidewire extending from the apex, across the left ventricle, through one side of the annulus, into the left atrium, into the center sheath, between the mitral leaflets and then back across the left ventricle. SeeFIG. 11.

Next, and looking now atFIGS. 12-14, a second TCT, comprising a second positioning sheath25A, is used to place a second curved tube35A and a second guidewire45A through the opposite (i.e., anterior) side of the annulus, using a technique identical to that used to pass first guidewire45A through the posterior side of the annulus.

Once second curved tube35A and second guidewire45A are positioned through the second (i.e., anterior) side of the mitral annulus, snare60is advanced back down apical access sheath5and center sheath55while first guidewire45remains in the lumen of center sheath55. SeeFIG. 15. Snare60is then used to capture second guidewire45A and snare60, carrying the captured second guidewire45A with it, is fully retracted down center sheath55and apical access sheath5, causing the distal end of second guidewire45A to be drawn through apical access sheath5and out into the operative sterile field. SeeFIG. 16.

The distal tips of the two guidewires45,45A are then joined, or “docked”, in the operative sterile field, e.g., at a connection83. SeeFIG. 17.

Thereafter, the joined distal ends of guidewires45,45A are drawn back through apical access sheath5and center sheath55, crossing the left ventricle, so that the joined distal ends of guidewires45,45A are located in the left atrium. SeeFIG. 18.

At this point, first positioning sheath25(and its annulus crossing first curved tube35), second positioning sheath25A (and its annulus crossing second curved tube35A), and center sheath55may all be removed from the operative site, if they have not already been removed. SeeFIG. 19.

As a result of the foregoing, a continuous guidewire path (i.e., a “crossing guidewire”) is established, traveling from the left ventricle, through the posterior annulus, across the left atrium, back through the anterior annulus, and then out through the left ventricle, with the continuous guidewire path extending out to the operative sterile field through apical access sheath5.

3. Establishing the Crossing Guidewire by the “Cross and Catch” Approach

An alternative approach for establishing the crossing guidewire across the mitral annulus (and hence establishing a desired suture path across the mitral annulus) is sometimes hereinafter referred to as the “cross and catch” approach. With this alternative approach, the same operative objective (i.e., the establishment of the crossing guidewire) is achieved using a different combination of steps and apparatus, in particular using a first “target and cross tool”, sometimes hereinafter referred to as TCT1, and a second “target and cross tool”, sometimes hereinafter referred to as TCT2, as described below.

Preferably TCT1 and TCT2 have a shape which allows them to be directed into a desired position on the ventricular side of the mitral annulus by a direct approach and without requiring significant lateral movement, since such lateral movement can be problematic given the presence of the chordae tendineae on the ventricular side of the mitral valve. Furthermore, the TCT1 and TCT2 preferably have a shape which allows them to advance to, and directly engage, the ventricular side of the mitral annulus without requiring the deformation or displacement of any intervening cardiac anatomy (e.g., the papillary muscles, chordae tendineae, etc.) as the TCTs are advancing to, and engaging, the annulus “crossing” site. Significantly, by providing a method and means which allows the annulus “crossing” site to be accessed without requiring the deformation or displacement of any intervening cardiac anatomy, subsequent steps in the annulus reconfiguration may also be performed without requiring any intervening cardiac anatomy to be deformed or displaced. By the methods described herein, once a crossing location has been reached, the TCT tools do not need to be moved laterally within the ventricle, risking entanglement or interference with chordae or other structures. And subsequent steps in the procedure follow the suture path back to the same crossing location, again without requiring lateral motion and the risk of entanglement by either the delivery tools or the deployed implant. This combination of devices and method is a significant advance in the art.

TCT1 is reinforced for pushability and proximally shapeable, and preferably comprises at least the following two elements, as follows:(i) TCT 1 comprises a low-profile, approximately 6 French first positioning sheath25(seeFIG. 5) having a through lumen and a steering handle30. First positioning sheath25is sufficiently stiff to allow stable placement of the distal tip of first positioning sheath25against target locations on the mitral annulus. First positioning sheath25may be shaped in various ways to best match the target anatomy, either as supplied or as modified in the field by the clinician.(ii) TCT1 also comprises a first curved tube35(seeFIG. 6), approximately 19-23 gauge in diameter, with handle40, which is fitted in the lumen of first positioning sheath25. First curved tube35is typically fitted with either a sharpened piercing tip or a smooth tip intended to be used in conjunction with an RF puncture wire of the type discussed above.

In one preferred form of the invention, TCT1 may also comprise a steering tube (not shown) which may be disposed within first curved tube35and receive first guidewire45. This steering tube may be provided to allow the clinician to further control the direction of first guidewire45as it passes into the left atrium. The steering tube may be fabricated from Nitinol or another highly elastic material. The steering tube is preferably curved at least as tightly as the distal aspect of first curved tube35, and is independently rotatable relative to first curved tube35, so as to provide for more precise manipulation of guidewire45(seeFIG. 7) into a funnel-shaped snare of TCT2, as will be described below.

TCT2 is reinforced for pushability and proximally shapeable and steerable. TCT2 preferably comprises three main elements, as follows:(i) TCT2 comprises a low-profile, approximately 6 French or approximately 7 French second positioning sheath25A (seeFIG. 20) having a through lumen and a steering handle similar to the aforementioned steering handle of first positioning sheath25. Second positioning sheath25A of TCT2 is shaped as shown inFIGS. 20-25so that it can be readily directed within the left ventricle to positions on the ventricular side of the mitral annulus.(ii) TCT2 also comprises a second curved tube35A (seeFIGS. 21-25) of approximately 19 gauge or approximately 20 gauge, with a steering handle similar to the aforementioned steering handle40of first curved tube35. Second curved tube35A is slidably disposed in the lumen of second positioning sheath25A and can be controllably advanced through the annular tissue under the control of its steering handle40.(iii) TCT2 also comprises a funnel-shaped snare85(FIGS. 22-24) of approximately 0.035 inch outer diameter in a collapsed, undeployed state and fitted within the lumen of second curved tube35A. Funnel-shaped snare85passively collapses when travelling through the 0.035 inch lumen of second curved tube35A and then, when advanced into the left atrium, passively expands into an outwardly directed funnel as shown inFIGS. 22 and 23. In one preferred embodiment, the funnel-shaped snare is fabricated from elastic stiffening ribs90such as might be fabricated from Nitinol or another highly elastic material, and an elastomer web95which fills out the spaces between stiffening ribs90of funnel-shaped snare85.

To effect the “cross and catch” approach, TCT1 is positioned so as to contact one side of the annulus in a desired location and oriented so as to point into, and across, the left atrium as described previously and shown in the figures. More particularly, as seen inFIGS. 5 and 6, first positioning sheath25is advanced against the ventricular side of the posterior annulus, and then first curved tube35is advanced (with RF assistance if necessary, or with the aforementioned crossing wire) into the left atrium so that the outlet of first curved tube35is oriented generally parallel to the mitral annulus plane and oriented by rotation so as to point at the opposite planned anchor point (see below).

A guidewire45(seeFIG. 7) is advanced through first curved tube35and into the left atrium. If desired, a steering tube may also, optionally, be positioned between first curved tube35and guidewire45so as to further guide the advance of guidewire45into the desired position in the left atrium.

TCT2 is then used to position second curved tube35A and funnel-shaped snare85through the opposite side of the annulus and into the left atrium, oriented to point generally in the direction of the opposite anchor point established by TCT1. More particularly, second positioning sheath25A is advanced against the ventricular side of the anterior annulus (seeFIG. 20), and then second curved tube35A of TCT2 is advanced (with RF assistance if necessary, or with the aforementioned crossing wire) into the left atrium so that the outlet of second curved tube35A is generally parallel to the mitral annulus plane and oriented by rotation so as to point at the opposite anchor point established by TCT1. SeeFIG. 21. Then funnel-shaped snare85is advanced through second curved tube35A so that the mouth of funnel-shaped snare85enters the left atrium and is directed toward guidewire45. SeeFIG. 22.

Guidewire45is then advanced into funnel-shaped snare85. SeeFIG. 23. Then funnel-shaped snare85is retracted into second curved tube35A so that funnel-shaped snare85collapses inwardly on guidewire45, thereby establishing a positive grip on guidewire45(i.e., as the funnel-shaped snare is compressed upon recapture within second curved tube35A).

It will be appreciated that the orientations of TCT1 and TCT2, the first and second curved tubes35and35A, guidewire45, and funnel-shaped snare85can be manipulated by advancing or rotating, using techniques familiar to those skilled in the art of interventional cardiology, so as to ensure proper docking of guidewire45with funnel-shaped snare85.

Using funnel-shaped snare85, the distal end of captured guidewire45is retracted by pulling funnel-shaped snare85proximally along second curved tube35A until the assembly has been withdrawn out of the anatomy into the operative sterile field (seeFIG. 24). At this point, guidewire45is detached from funnel-shaped snare85(seeFIG. 25), whereby to complete deployment of the crossing guidewire via the “cross and catch” approach. At this point, first positioning sheath25(and its annulus crossing first curved tube35) and second positioning sheath25A (and its annulus crossing second curved tube35A) may be removed from the operative site, if they have not already been removed. SeeFIG. 26.

4. Establishing the Crossing Guidewire by the “Cross and Receive” Approach

Another alternative approach for establishing a crossing guidewire across the mitral annulus is sometimes hereinafter referred to as the “cross and receive” approach. This alternative approach is effected using a first “target and cross tool”, sometimes referred to herein as TCT3, and a second “target and cross tool”, sometimes referred to herein as TCT4, as described below.

Preferably TCT3 and TCT4 have a shape which allows them to be directed into a desired position on the ventricular side of the mitral annulus by a direct approach and without requiring significant lateral movement, since such lateral movement can be problematic given the presence of the chordae tendineae on the ventricular side of the mitral valve. Furthermore, the TCT3 and TCT4 preferably have a shape which allows them to advance to, and directly engage, the ventricular side of the mitral annulus without requiring the deformation or displacement of any intervening cardiac anatomy (e.g., the papillary muscles, chordae tendineae, etc.) as the TCTs are advancing to, and engaging, the annulus “crossing” site. Significantly, by providing a method and means which allows the annulus “crossing” site to be accessed without requiring the deformation or displacement of any intervening cardiac anatomy, subsequent steps in the annulus reconfiguration may also be performed without requiring any intervening cardiac anatomy to be deformed or displaced. By the methods described herein, once a crossing location has been reached, the TCT tools do not need to be moved laterally within the ventricle, risking entanglement or interference with chordae or other structures. And subsequent steps in the procedure follow the suture path back to the same crossing location, again without requiring lateral motion and the risk of entanglement by either the delivery tools or the deployed implant. This combination of devices and method is a significant advance in the art.

The key features of TCT3 and TCT4 will first be described, and then their sequence of use will be addressed.

TCT3 preferably comprises at least the two following elements, as follows:(i) TCT3 comprises a 6 French reinforced first positioning sheath (seeFIG. 5) with a lumen extending therethrough, curved distal and middle sections, and a steering handle30. First positioning sheath25is shaped so as to reach from the entry point of apical access sheath5near the apex of the left ventricle to locations on the mitral annulus; the distal section of first positioning sheath25is curved so that the line of action of the exit of the sheath is oriented into the left atrium over a wide range of apical access locations and left ventricular anatomies.(ii) TCT3 also includes an advanceable first curved tube35(seeFIG. 6) made of Nitinol and having a curved distal section, generally about 19 gauge to 20 gauge in diameter, with a 0.035 inch lumen, and a proximal handle40. First curved tube35is slidably disposed within first positioning sheath25. The distal section of first curved tube35is curved so that, as it is advanced out of first positioning sheath25, its exit may be controllably oriented towards the opposite side of the annulus. Nitinol tubing is generally preferred for this application because the curvature of the distal tip may not otherwise be maintained as it is manipulated through the shaped sections of first positioning sheath25. First curved tube35is intended to provide a crossing lumen through the mitral annulus, as will hereinafter be discussed.

In one preferred form of the invention, TCT3 may also comprise an innermost steering tube (not shown) which may be disposed within first curved tube35and receive first guidewire45. This steering tube is also preferably made of Nitinol, with a curved distal section, a <0.035 inch outside diameter, an internal 0.014 inch lumen, and a proximal handle. The distal section of this steering tube is curved (differentially from the first curved tube35) so that as the steering tube is advanced out of first curved tube35, its exit may be oriented toward the opposite side of the annulus. Nitinol tubing is generally preferred for this application due to its superelastic properties, which will help ensure that the curvature of the distal tip will be maintained as it is manipulated through the shaped sections of first curved tube35. Alternatively, other potentially desirable constructions for forming the steering tube include coils, braids, or a solid tube with slots or hole patterns to provide flexibility to the steering tube.

TCT4 comprises three major elements as follows:(i) TCT4 comprises an approximately 6 French second positioning sheath25A (seeFIG. 27) having an interior lumen extending therethrough, curved distal and middle sections, and a handle similar to the aforementioned steering handle30. Second positioning sheath25A is shaped so as to extend through apical access sheath5(placed in the apex of the left ventricle) and from there to reach locations on the mitral annulus. In the preferred embodiment, the distal section of second positioning sheath25A is curved so that the exit of the second positioning sheath is oriented into the left atrium over a wide range of apical access locations and left ventricular anatomies. Second positioning sheath25A may be re-shapeable by various means including bending, and/or several alternative shapes may be provided so as to account for varying patient size and anatomy.(ii) TCT4 also comprises a second curved tube35A (seeFIG. 27) which is disposed within second positioning sheath25A. Second curved tube35A is preferably made of Nitinol and, in a preferred embodiment, fitted with a progressively curved distal section, of 19 gauge or 20 gauge diameter, with an inner lumen of approximately 0.035 inch, and a handle similar to the aforementioned handle40. The distal section of the second curved tube35A is curved so that, as it is advanced out of second positioning sheath25A, its exit may be oriented toward the opposite side of the mitral annulus, and also afford control of the elevation angle of the most distally-advanced aspect of second curved tube35A. Nitinol is generally preferred for this application inasmuch as the range of preferred curvatures of the distal tip may not be maintained as it is manipulated and advanced through the curved sections of second positioning sheath25A. The distal aspect of second curved tube35A may be finished to a conventional needle-sharp condition, thus facilitating controlled advance of second curved tube35A through annular tissue by pushing. Alternatively, the distal aspect of second curved tube35A may be finished square and smooth, and employed in combination with a conventional, flexible RF-assisted puncture wire or a custom RF-assisted puncture wire of matched-curve construction. In the case of a RF assisted puncture wire, the RF puncture wire may be independently advanced through the annulus and then second curved tube35A advanced over the RF puncture wire, thus allowing second curved tube35A to be guided (or “track”) over the RF puncture wire along the preferred path. Alternatively, second curved tube35A may be employed in combination with a crossing wire of the type described above.(iii) TCT4 also comprises an inflatable funnel100(seeFIGS. 27-30). Inflatable funnel100is configured with novel features beneficial to the performance of the “cross and receive” approach. Inflatable funnel100could, alternatively, be replaced by a non-inflatable, but still self-expanding, Nitinol (or other superelastic material) funnel-shaped element, i.e., a funnel-shaped element with a self-expanding mesh structure, either with/without a polymer covering, depending upon the fineness of the Nitinol mesh and the desired mating guidewire. The key features of inflatable funnel100are as follows:(a) In the anticipated preferred embodiment, inflatable funnel100can be advanced and retracted through an approximately 0.035 inch lumen, with inflatable funnel100deflated during advancement and removal. Inflatable funnel100is equipped with a 0.014 inch lumen.(b) The main shaft of inflatable funnel100is preferably reinforced with either steel or Nitinol tubing, or a braided composite tube, so as to provide for positive torsional and advance/retraction control during positioning.(c) In a preferred embodiment, inflatable funnel100comprises a unique elastomeric distal balloon with several important properties. The inflated shape of the distal balloon is such that when inflated, it projects distally beyond the end of second curved tube35A with an overall diameter of approximately 10 mm. Viewed on end, the distal face of the balloon forms a funnel-like mouth105(seeFIG. 28) with diameter of approximately 6 mm of maximum acceptance diameter, to thereby create a fluoroscopically-visible target for a conventional 0.014 inch guidewire. The interior of the funnel transitions continuously and smoothly into the through lumen110of inflatable funnel100.

The funnel-like mouth105of inflatable funnel100, and through-passing 0.014 inch inner lumen110of the inflatable funnel, are designed so that there is a smooth transition between the two, whereby to readily guide an advancing guidewire into the lumen of inflatable funnel100and then out to the sterile operative field (via second curved tube35A).

A crossing guidewire45(FIGS. 27-31) is also utilized in the “cross and receive” approach. Crossing guidewire45can preferably exhibit properties of a conventional coronary guidewire with several desirable characteristics, in particular, a 0.014 inch maximum diameter throughout, excellent distal radio-opacity to facilitate fluoroscopic visualization and/or distal ultrasonic visibility to facilitate echocardiographic visualization, and a flexible, atraumatic tip with adequate “crossability” to allow crossing guidewire45to be readily guided and tracked into mouth105of inflatable funnel100. The proximal end of guidewire may have features such as a reduced diameter (e.g., to allow it to readily dock with the spanning suture of the spanning implant in a manner which maintains a maximum crossing profile of 0.014 inch after docking).

The key steps of the “cross and receive” approach, using the apparatus just described, will now be presented.

First, the first positioning sheath25of TCT3 is advanced through apical access sheath5and its distal end positioned adjacent to the posterior annulus (FIG. 5). Then first curved tube35is advanced through the annulus and into the left atrium (seeFIG. 6). As noted above, first curved tube35may be advanced through the annulus either alone, or carrying an internally-positioned RF puncture wire, or over an aforementioned crossing wire. Once first curved tube35is advanced through the annulus and into left atrium, guidewire45is projected out the distal end of first curved tube35and into the left atrium. SeeFIG. 7. In one preferred form of the invention, guidewire45is an RF puncture guidewire, and first curved tube35and guidewire45are inserted into first positioning sheath25and positioned and affixed so that the tip of guidewire45emerges from the tip of first curved tube35by approximately 1 mm or 2 mm, i.e., a distance sufficient to allow the RF action to “lead” the advancement of first curved tube35through the annulus on the posterior side of the mitral valve. The RF guidewire45is connected to the RF generator and RF guidewire45and first curved tube35are passed through the posterior annulus.

Next, second positioning sheath25A of TCT4 is inserted through apical access sheath5and positioned against the anterior annulus in the desired anchor location, with the line of action of the distal curved section being oriented so as to point into the left atrium and towards the opposite planned annular anchor point. SeeFIG. 20. This is done under ultrasound and/or fluoroscopic guidance. The target anatomical locations will, in normal practice, be selected in advance based upon echocardiogram, computer tomography and fluoroscopic data.

Then, second curved tube35A is advanced through the annulus and into the left atrium (seeFIG. 21). As noted above, second curved tube35A may be advanced through the annulus either alone, or carrying an internally-positioned RF puncture wire, or over an aforementioned crossing wire. In one preferred form of the invention, an RF puncture wire is inserted into second positioning sheath25A and positioned and affixed so that the tip of the RF puncture wire emerges from the tip of second curved tube35A by approximately 1 mm or 2 mm, i.e., a distance sufficient to allow the RF action to “lead” the advancement of second curved tube35A through the annulus on the anterior side of the mitral valve. The RF generator is turned on, and second curved tube35A and the RF puncture wire are simultaneously advanced, as an assembly, along a curved path through the anterior annulus as defined by the pre-curve of the devices. Advancement continues until second curved tube35A and the RF puncture wire emerge into the left atrium sufficiently far that second curved tube35A is generally parallel with respect to the mitral annulus plane, and oriented by rotation so as to point at the opposite planned anchor point.

After second curved tube35A has been passed through the mitral annulus (and any RF puncture wire or crossing wire has been withdrawn from the lumen of second curved tube35A), inflatable funnel100is advanced through second curved tube35A and into the left atrium. If desired, a 0.014 inch guidewire may first be tracked through second curved tube35A and into the left atrium so as to assist advancement of inflatable funnel100and so as to maintain proper positioning of inflatable funnel100in the left atrium.

With inflatable funnel100positioned in the left atrium, the proximal end of inflatable funnel100is locked to second curved tube35A for stability. Then the inflatable funnel100is inflated, preferably with contrast agent.

First curved tube35of TCT3 is then adjusted under both echocariodogram and multi-view fluoroscopic guidance so that first curved tube35(and hence crossing guidewire45) are pointed towards the center of inflatable funnel100. SeeFIGS. 27 and 28. Note that a steering tube of the sort discussed above may be employed within first curved tube35so as to facilitate steering first curved tube (and hence crossing guidewire45) are pointed towards the center of inflatable funnel100.

Crossing guidewire45is then advanced into the lumen of inflatable funnel100and then into the lumen of second curved tube35A. SeeFIG. 29. Crossing guidewire45is advanced until it exits from the proximal end of apical access sheath5in the operative sterile field. SeeFIG. 30. Then inflatable funnel100is deflated and removed from second curved tube35A. SeeFIG. 31. At this point, first positioning sheath25(and its annulus crossing first curved tube35) and second positioning sheath25A (and its annulus crossing second curved tube35A) may be removed from the operative site, if they have not already been removed. SeeFIG. 32.

This completes positioning of the crossing guidewire via the “cross and receive” approach.

The three approaches discussed above (i.e., the “cross and snare” approach, the “cross and catch” approach and the “cross and receive” approach), provide highly accurate and controllable means for routing a crossing guidewire (and, subsequently, a spanning implant) along a structurally preferred path from the ventricular side of the mitral annulus, through the mitral annulus to the left atrium, across the mouth of the valve along a desired path, and then back through the annulus on the opposite side of the valve so as to extend into the left ventricle.

In this novel fashion, the method of the present invention allows for targeting a wide range of structural landmarks while avoiding the possibility of entanglement or interference with ventricular structures such as the chordae tendinae and papillary muscles. SeeFIGS. 2 and 3. Furthermore, the procedure can be performed through a single, low-profile apical access sheath, using a limited set of operative procedures well within the skill of the average interventional clinician. Additionally, and as will hereinafter be discussed, successive, additional spanning passes can be made to effect progressive change to the valve shape in response to observed shape and functional regurgitation on real-time continuous echocardiography.

Other features may be added to the aforementioned apparatus to effect more preferred embodiments. One such feature may be the addition of a compliant balloon on the outer distal tip of the positioning sheath (e.g., first positioning sheath25, second positioning sheath25A, etc.). This compliant balloon may be inflated once the distal end of a positioning sheath is nearly in place against the target location on the ventricular side of the annulus. This compliant balloon would serve at least two purposes. First, when filled with a contrast agent, the compliant balloon would provide both an echocardiogram- and fluoroscopically-visible target on the tip of the positioning sheath so as to improve clinical confidence when navigating the positioning sheath against the mitral annulus. Second, the compliant balloon tip would provide a more stable and atraumatic contact of the positioning sheath against the ventricular side of the annulus. An additional possible refinement of a positioning sheath is the addition, by various means, of either echo-attenuating or echo-genic structures and surfaces to the tip of a positioning sheath. A positioning sheath might, in an unmodified state, be fabricated from a material such as stainless steel or Nitinol tubing that would, in the as-manufactured state, create strong, directional echo reflections. The addition of diffusing and attenuating coatings on the distal end of a positioning sheath could render the positioning sheath more readily visible by echocardiographic means. In addition, by attenuating highly directional reflections along the shaft of a positioning sheath, the additional option exists to add echogenic features (such as grooves) or discrete echogenic structures (such as air-entrapping coils), such that specific points on the positioning sheath, preferably the distal tip, are rendered more echogenic.

5. Positioning of the Spanning Implant Across the Mitral Annulus

Once the crossing guidewire is in place, preferably using one of the procedures discussed above (e.g., the “cross and snare” approach, the “cross and catch” approach and the “cross and receive” approach), it is a relatively straightforward matter to effect the implantation and controlled adjustment of the spanning implant. These devices and steps will be described below and can be further appreciated by reference to the figures.

Significantly, inasmuch as the present invention provides a method and means for positioning the crossing guidewire across the mitral valve without requiring the deformation or displacement of any intervening left ventricle anatomy (e.g., the papillary muscles, chordae tendineae, etc.), the spanning implant may also be positioned across the mitral valve without requiring the deformation or displacement of any intervening left ventricle anatomy.

Implantation of the spanning implant can be conducted proceeding from either the anterior side or the posterior side of the crossing guidewire. The crossing guidewire may be constructed of conventional metallic guidewire elements, including combinations of coil, tube and solid elements, to vary the properties of the crossing guidewire from distal end to proximal end. Furthermore, a preferred embodiment of the crossing guidewire includes a pre-prepared continuous transition to the spanning suture of the spanning implant so that, when the spanning implant is to be positioned across the mitral valve, there is already a continuous length of spanning suture routed through the annulus, extending from the operative sterile field, through one side of the annulus from left ventricle to left atrium, across the left atrium, back down through the annulus from left atrium to left ventricle, and then back out into the operative sterile field.

The spanning implant preferably comprises conventional cardiovascular suture, in combination with pre-mounted and procedure-mounted anchoring and covering elements, as discussed below. More particularly, and looking now atFIG. 33, in one form of the present invention, a spanning implant115comprises a spanning suture120having a first end125, a second end130and a first anchor135connected to first end125of spanning suture120. The spanning implant also comprises a second anchor140which is fit over second end130of spanning suture120, slid along spanning suture120to an appropriate position and then secured in place, preferably using a coaxial suture lock145, as will hereinafter be discussed.

The spanning suture of the spanning implant is, in one preferred embodiment, a section of suitable permanent, non-bioabsorbable, hemocompatible suture, preferably either PTFE- or ePTFE-covered braided polyester suture. The size of the spanning suture is preferably in the range of 2-0 or larger, given the tensile load expected in this particular application, while presenting a PTFE surface to the blood so as to provide for hemocompatible surface properties. Preferably the spanning suture has a starting length of 25-40 cm to facilitate handling, routing and tensioning. However, only a much smaller portion of this length will ultimately become part of the spanning implant, as discussed below.

In one preferred form of the invention, one end of spanning suture120(i.e., first end125) is pre-fitted with a T-bar anchor (i.e., the aforementioned first, fixed anchor135), preferably made out of 316 stainless steel, titanium, PTFE or other material well known for durable permanent implantation, and also preferable fitted with one or several radiopaque markers, typically tantalum, and optionally coated and buffered with pledgets or a polyester cover. Spanning suture120is terminated at first, fixed anchor135by a knot, thermal deformation, thermal bonding, adhesive bonding, or a combination of the foregoing. In one preferred form of the invention, first, fixed anchor135comprises a concave seat for receiving the termination of spanning suture120. One preferred configuration of first, fixed anchor135is shown inFIG. 43.

In one preferred embodiment, the first, fixed anchor135is provided with a through-hole150to allow a control line155to be passed through the anchor on one end, or possibly on both ends of the anchor. As will be described further below, such a control line155will, in conjunction with spanning suture120, allow the first, fixed anchor135to be re-positioned once the first, fixed anchor is in place, particularly if a stiffening sleeve is fitted over control line155to provide for both tension and lateral steering of first, fixed anchor135. Also, control line155can be used to positively retain the first, fixed anchor135in the delivery tool (see below) during routing into position. Furthermore, control line155can allow for elective retrieval of first, fixed anchor135subsequent to deployment.

In one preferred embodiment, the opposing end of spanning suture120(i.e., second end130, as seen inFIG. 33) is further fitted with a “docking” feature so that the spanning suture can be attached to the crossing guidewire in a conventional, coaxial manner, e.g., at connection157(seeFIG. 34). Such docking feature may be effected by various constructions. By way of example but not limitation, a simple approach is to tie a knot of suitable configuration between the spanning suture, factory-terminated, onto the back of the crossing guidewire as previously described. Alternatively, the docking feature may be provided with a coaxial screw lock feature as is conventionally found on docking guidewires employed to facilitate “over the wire” catheter exchanges. In another approach, the free end of spanning suture120may be temporarily fused, using thermal or adhesive means, so as to form an attachment with the crossing guidewire. Or the free end of spanning suture120may be connected with a tubular mechanical crimped, fused or bonded lock, whereby to secure the spanning suture to the crossing guidewire.

An implant-advancing sheath160(seeFIG. 44) is preferably provided to allow for ready advancement of first, fixed anchor135into position under the annulus. Implant-advancing sheath160preferably comprises an approximately 6 French to approximately 9 French tubular construction with a central through-lumen suitable to accommodate first, fixed anchor135. In a preferred embodiment, the distal end of implant advancing sheath160may be shaped to accommodate first, fixed anchor135, with control line155exiting the proximal end of implant-advancing sheath160and with spanning suture120exiting the distal end of implant-advancing sheath160.

Positioning of spanning implant115across the mitral annulus will now be described. For purposes of example but not limitation, the implantation sequence will be described beginning from the anterior (trigone) side of the annulus, although it could also be conducted beginning from the posterior side of the annulus.

With crossing guidewire45in place, the proximal end (i.e., the anterior side) of crossing guidewire45is then, as described above, terminated (by one of several means) to the free end (i.e., second end130) of spanning suture120, with spanning implant115loaded into the implant-advancing sheath160. SeeFIG. 34. In a preferred embodiment, spanning implant115and implant-advancing sheath160are provided, already-assembled, for use in the clinical setting. Then implant-advancing sheath160is advanced through apical access sheath5and across the left ventricle until it sits near the ventricular side of the anterior annulus. SeeFIG. 34A.

Crossing guidewire45is then used to draw spanning suture120through the annulus so that the spanning suture extends through the anterior annulus, across the left atrium, through the posterior annulus and extends into the left ventricle, with first, fixed anchor135seated against the ventricular side of the anterior annulus. More particularly, with free end130of spanning suture120attached to crossing guidewire45, the crossing guidewire45(and hence spanning suture120) is withdrawn (anterior to posterior) until first, fixed anchor135exits implant-advancing sheath160and engages the ventricular side of the anterior annulus. As this occurs, first, fixed anchor135turns, from a position parallel to the longitudinal axis of implant-advancing sheath160to a position perpendicular to the axis of implant-advancing sheath160—and hence parallel to the ventricular side of the anterior annulus. Crossing guidewire45is pulled until first, fixed anchor135seats against the ventricular side of the anterior annulus. SeeFIG. 35. Control line155can be used to help adjust the orientation of first, fixed anchor135if necessary or desirable.

Implant-advancing sheath160is then removed from the left ventricle.

At this point, the spanning implant115has its first, fixed anchor135positioned against the ventricular side of the anterior annulus and the spanning suture120extending through the anterior annulus, across the left atrium, through the posterior annulus and back out the left ventricle.

At any chosen point in the procedure, control line155can be readily removed from first, fixed anchor135by sliding control line155out of the body of first, fixed anchor135. In the preferred embodiment shown inFIGS. 43 and 44, control line155can be quickly and easily removed by simply pulling on either free end of the control line.

6. Implant Sizing and Termination

The final step in the procedure is sizing and termination of spanning implant115, preferably utilizing the tools and steps described below.

A second, sliding anchor140(seeFIG. 33) and coaxial suture lock145(seeFIG. 33) are provided. Second, sliding anchor140preferably comprises a T-bar anchor, preferably 316 stainless steel, titanium, PTFE or other material or combination of materials known for durable permanent implantation, and also preferably fitted with one or several radiopaque markers, typically tantalum, and finally coated and buffered with pledgets or a polyester cover. This second, sliding anchor140can be advanced coaxially over the free end130of spanning suture120so as to be brought up against the ventricular side of the posterior annulus and fixed in place, as will hereinafter be discussed.

In one preferred form of the invention, second, sliding anchor140and coaxial suture lock145are loaded within, and applied to, spanning suture120by the aforementioned implant tensioning tool, such as a “Span-Tension-Terminate Tool” (STTT)165(seeFIG. 45). More particularly, and looking now atFIG. 45, spanning suture120is routed coaxially through STTT165and coaxial suture lock145. Coaxial suture lock145is fitted to the distal end of STTT165and maintained in position by lightly pulling on coaxial suture lock145so as to hold the coaxial suture lock in position in the distal end of STTT165.

STTT165allows the clinician to controllably tension and then, while maintaining suture tension and without altering the optimum treatment location, terminally and permanently lock the spanning suture120, with the spanning suture being held under tension between the first, fixed anchor135set on the anterior side of the annulus and the second, sliding anchor140set on the posterior side of the annulus (seeFIG. 39), with the second, sliding anchor140being held in position by coaxial suture lock145. There are various other means of achieving the same suture locking action well known in the mechanical arts, including the use of a collet-and-sleeve action or a tapered wedge action or a wedging pin forced into a constraining sleeve, etc.

STTT165is contained within an overall 7-9 French reinforced sheath to facilitate control and delivery of the spanning implant.

In the operative field, the free end (i.e., second end130) of spanning suture120is routed through the second, sliding anchor140, through coaxial suture lock145and through STTT165(with coaxial suture lock145preferably being held in STTT165).

STTT165is advanced over spanning suture120, pushing second, sliding anchor140ahead of it, until second, sliding anchor140reaches the ventricular side of the posterior annulus, with coaxial suture lock145engaging second, sliding anchor140. SeeFIGS. 36 and 37.

Spanning suture120is then tensioned through STTT165to progressively decrease the anterior/posterior dimension of the mitral valve, and hence progressively reduce the mitral regurgitation of the valve. This adjustment is done in increments with observation periods in between while under real-time echo, fluoro, and EKG monitoring. If desired, STTT165can be provided with means for continuously measuring and displaying the tension applied to the spanning suture as the therapeutic input is applied. STTT165may also be provided with means for continuously measuring the length of spanning suture120withdrawn into STTT165. And STTT165may be provided with means for withdrawing spanning suture120in pre-defined increments such as 1 mm, e.g., by the provision of a ratchet and pawl mechanism. Or STTT165may be provided with a one-way clutch to maintain tension on spanning suture120through the STTT, e.g., by a one-way needle-bearing clutch of the sort well-known in the medical arts. Also, STTT165may include a motorized withdrawal of spanning suture120, e.g. with a small gear motor and the provision of calibrated retraction steps, again, such as 1 mm per increment.

When the desired anterior/posterior (“A/P”) dimension of the mitral valve has been achieved, and hence the desired reduction of mitral regurgitation has been effected, coaxial suture lock145is deployed by STTT165by rotating a handle on the proximal end of the STTT which causes the STTT to permanently deform the coaxial suture lock145, thus affixing a permanent diametrical lock onto spanning suture120in such a manner that the final treatment tension of the spanning suture is precisely secured, avoiding any alteration of the applied treatment effect. SeeFIG. 38. Alternatively, other means may be used to lock coaxial suture lock145to spanning suture120(e.g., by creating an interference fit between spanning suture120and coaxial suture lock145).

STTT165is then removed from the left ventricle coaxially over the suture. Alternatively, STTT165could be provided in a so-called “rapid exchange” configuration, i.e., spanning suture120is exited from the shaft of the STTT at a point relatively distal on the STTT, which thus allows more independent handling of the spanning suture or guidewire in the operative sterile field. STTT165would otherwise function as when provided in a conventional coaxial or “over-the-wire” form.

The free end of spanning suture120(i.e., the end proximal to coaxial suture lock145) may then be cut proximal to the now-fixed sliding, second anchor140. Alternatively, it may be terminated to a pledget outside the left ventricle wall, to leave a tether to the implant assembly, thereby guaranteeing that even if the spanning implant becomes loose, it will not embolize and travel in the bloodstream through the body, potentially causing injury.

Significantly, the spanning implant may be sized and terminated (i.e., spanning suture120tensioned and second, sliding anchor140set) without requiring the deformation or displacement of any intervening left ventricle anatomy (e.g., the papillary muscles, chordae tendineae, etc.).

FIG. 38shows a spanning implant115positioned across a mitral valve. As seen inFIG. 38, first, fixed anchor135is positioned against the ventricular side of the anterior annulus, spanning suture120extends through the anterior annulus, across the left atrium, and through the posterior annulus, where second, sliding anchor140, secured by coaxial suture lock145, bears against the ventricular side of the posterior annulus, whereby to hold the reconfigured mitral annulus under tension.

7. Additional Spanning Implants

Additional spanning implants may then be electively deployed across the mitral annulus as needed so as to provide correction in one or more other locations, to increase the A/P reduction as needed, and to distribute the A/P reduction forces among a greater number of spanning implants. SeeFIG. 40.

It should be appreciated that the sequence described above could, alternatively, be applied simultaneously to multiple spanning implants, in particular through the use of a “temporary” STTT on one spanning implant while a conventional, permanent-anchoring STTT is employed on a second spanning implant. Such an approach would provide the clinical advantage of allowing for more complete consideration of various geometric and structural changes to the valve. In a particular preferred embodiment of a multiple-spanning implant approach, one spanning implant would be placed from the posterior trigone to a position on the posterior annulus approximately at the intersection of the P2 and P3 cusps of the posterior leaflet. Similarly, a second spanning implant would be effected between the anterior trigone and a position on the posterior annulus approximately at the intersection of the P1 and P2 cusps. These two spanning implants would effect balanced control of the valve with respect to the central aortic-mitral structural axis.

To complete the procedure, the apical access sheath is removed and the apical and chest wall access closed and the patient recovered.

It will be appreciated that spanning suture120of spanning implant115passes through opposing sides of the annulus, e.g., from the ventricular side of the anterior annulus into the left atrium, and from the left atrium across the posterior annulus into the left ventricle. If desired, “grommets”, that is, various constructions of tissue-mediating devices, can be disposed in the annulus at the crossing points prior to passing spanning suture120through the annulus, with the grommets acting as protective liners to mitigate tissue erosion and trauma, and prevent suture migration or “pull through” across the annulus.

In this form of the invention, after the crossing guidewire45has been positioned in the anatomy, and prior to routing spanning suture120across the anterior annulus, a tubular “tissue grommet” or dedicated pledget170(seeFIG. 46) may be deployed across the annulus. Tissue grommet170may be advanced into position by loading the tissue grommet on crossing guidewire45and advancing the tissue grommet (e.g., with an advancing sheath) along crossing guidewire45so that tissue grommet170passes into, and spans, the anterior annulus. A corresponding tubular “tissue grommet” or dedicated pledget175may be deployed across the posterior annulus. Preferably the posterior tissue grommet is deployed after spanning suture120has been deployed, e.g., posterior grommet175is advanced (e.g., with an advancing sheath) over second end130of spanning suture120until the posterior tissue grommet is seated in, and spans, the posterior annulus.

The tissue grommets170,175may consist of a PTFE sleeve, with an approximately 0.042 inch outer diameter, an approximately 0.014 inch inner diameter, and a flange at the ventricular end (to act as a stop during insertion of the tissue grommet into the annulus). Alternatively, the tissue grommet may have an additional cover of, or be completely formed out of, Dacron or ePTFE. In the preferred embodiment, similar tissue grommets are placed in the anterior annulus and the posterior annulus. In one preferred form of the invention, the tissue grommets170,175are constructed so as to enable tissue in-growth into the surface of the grommets, thus enhancing the durability of spanning implant115. It will also be appreciated that, after spanning implant115has been put in place, first, fixed anchor135will bear against the flange of anterior tissue grommet170, second, sliding anchor140will bear against the flange of posterior tissue grommet175, thereby ensuring that, even in the absence of tissue ingrowth, tissue grommets170,175stay in place.

9. Alternative STTT with Alternative Sliding Second Anchor and Alternative Coaxial Suture Lock

In one preferred embodiment, the implant tensioning and locking procedure is effected with a novel tool configuration referred to as the “Span-Tension-Terminate Tool” or the “STTT”. The STTT allows the clinician to controllably track into the left ventricle and place the second, sliding anchor against the ventricular side of the posterior annulus, controllably tension spanning suture120, and then terminally lock the coaxial suture lock, thus anchoring the spanning suture in position across the mitral valve. In one preferred embodiment, there is provided an STTT180which generally comprises a sheath185, a hemostasis element190, one or more removable spacers192, a drive tube195, a handle200carrying a suture tensioning mechanism205, and a pusher210. SeeFIG. 47. In one preferred embodiment, STTT180carries a second, sliding anchor215and a coaxial suture lock220. SeeFIGS. 48-50. Spanning suture120is routed through STTT180, passing through second, sliding anchor215and coaxial suture lock220. SeeFIGS. 50A and 50B, which show second, sliding anchor215and coaxial suture lock220disposed within sheath185, with spanning suture120routed through STTT180and passing through second, sliding anchor215and coaxial suture lock220. See alsoFIGS. 50C and 50D, which are similar toFIGS. 50A and 50B, but with sheath185removed.

Sheath185preferably comprises an overall 7-11 Fr reinforced sheath to facilitate control and delivery of second, sliding anchor215and coaxial suture lock220. The length of sheath185, in conjunction with removable spacers192, aligns the distal end of second, sliding anchor215with the distal end of sheath185so as to form a smooth end for advancing the assembly through cardiac anatomy. Sheath185is preferably sized so that there is slight interference fit with second, sliding anchor215so that second, sliding anchor215is retained within sheath185until it is deployed by the clinician.

In one preferred form of the present invention, sheath185comprises a form-fitting, stretchable (preferably elastomeric) sheath, preferably formed out of a polymer, making a stretch fit about second, sliding anchor215, coaxial suture lock220and other elements of STTT180(e.g., seat250, disposed at the end of drive tube195, for releasably receiving coaxial suture lock220, as hereinafter discussed). In this way, sheath185has the smallest possible diameter, thus facilitating atraumatic advance of STTT180through the left ventricle. Furthermore, by virtue of its form-fitting, stretchable construction, sheath185can releasably grip various elements disposed therein (e.g., second, sliding anchor215, coaxial suture lock220, etc.), whereby to assist in the control of such elements. With reference toFIG. 50D, position “A-A” is the fully distal position of sheath185(see below). The distal margin of sheath185stretches so as to intimately fit to the outer diameter of second, sliding anchor215, thus, the two elements, in combination, presenting a smooth distal transition comprising the rounded end of second, sliding anchor215merging directly to the stretched sheath185. Thus, the distal tip of second, sliding anchor215effectively forms an atraumatic “obturator tip” for sheath185. Position “B-B” is the partially-retracted position of sheath185(see below), which is employed to release second, sliding anchor215and establish a smooth distal aspect for the system comprising the spherical distal end340(see below) of coaxial suture lock220merging with the stretched sheath185. Thus, with second, sliding anchor215released from sheath185, spherical distal end340of coaxial suture lock220effectively forms an atraumatic “obturator tip” for sheath185. Note that in both of the aforementioned positions “A-A” and “B-B”, the stretched sheath185is, at the same time, also serving to securely hold the D-shaped annular ring345of coaxial suture lock220(see below) in seat250(see below), awaiting final drive of locking pin275of coaxial suture lock220(see below). Position “C-C” is the fully retracted position of sheath185when coaxial suture lock220is released from seat250(see below) following the locking pin275being driven into position in coaxial suture lock220(see below).

STTT180is preferably fitted with a hemostasis element190(seeFIGS. 51 and 51A) to functionally supplement the integral hemostasis in the sheath185. Hemostasis element190preferably comprises a tubular section225having a lumen230formed therein and handle235formed thereon. Lumen230contains sheath185and is sized about 0.004″ or 0.007″ larger than the sheath it receives. The small clearance provides hemostasis when STTT180is in place without the friction associated with standard access sheath hemostasis valves. Handle235allows hemostasis element190to be readily engaged or removed by the clinician.

Spanning suture120is routed coaxially through STTT180and through a suture passage240formed in tubular section225of hemostasis element190and emerges in the area of handle235.

Drive tube195comprises a distal end245carrying a seat250for releasably receiving coaxial suture lock220. SeeFIGS. 48, 49, 52 and 53. More particularly, seat250comprises a fork255including a pair of raised tines260for receiving the body of coaxial suture lock220as will hereinafter be discussed, a transverse slot265for receiving the proximal end of coaxial suture lock220as will hereinafter be discussed and a camming surface270for selectively releasing coaxial suture lock220from seat250as will hereinafter be discussed. In one preferred embodiment, drive tube195is constructed out of stainless steel or Nitinol tubing of approximately 0.038″ OD and 0.032″ ID.

Drive tube195preferably comprises a handle200at its proximal end for manipulating drive tube195.

The suture tensioning mechanism205is mounted to handle200. The suture tensioning mechanism205receives the free end of spanning suture120so that tension may be selectively applied to the free end of spanning suture120. More particularly, it is clinically desirable to provide for the controlled addition of tension to spanning suture120by the controlled withdrawal of spanning suture120out through STTT180. It is desirable that the level of precision of suture withdrawal allow the clinician to increment suture withdrawal in steps of approximately one millimeter, or preferably less, by withdrawing the suture, and also to be able to pause, or controllably reverse, the suture withdrawal process at any time during the procedure and with the expectation that STTT180will stably maintain the position of spanning suture120. In one preferred embodiment of the present invention, suture tensioning mechanism205is provided, and suture tensioning mechanism205comprises a one-way drive mechanism to allow spanning suture120to be controllably withdrawn by spooling the spanning suture about a shaft so as to alter the anterior-posterior dimension of the mitral valve. A preferred embodiment comprises one-way clutches mounted within handle200. Such one-way clutches are commercially available and provide bearing and clutch functions. One or more clutches may be used. Optionally, the clutches may be mounted to handle200such that they may be forcibly rotated so as to provide a back-drive function to remove tension from spanning suture120. This may be done by mounting the clutches to handle200with compressed O-rings or other material that provides for a limited slip function. The O-ring retention force may be set to be much greater than necessary for mitral valve dimensional correction or inadvertent handling, but less than intentional clinician manipulation to remove suture tension.

The suture tensioning mechanism205preferably comprises a suture tie-down which provides features to retain the free end of the spanning suture120during the tensioning and terminating processes. One preferred form of suture tie-down comprises a flexible element that has one or multiple slits that retain the free end of the spanning suture when the spanning suture has been slid into the slits. The flexible element may be formed from silicone, urethane, thermoplastic elastomer or other similar rubber-like materials. Each slit has a lead-in feature so that the spanning suture may be easily inserted into the slit. The spanning suture may be wound around the suture tie-down so that multiple slits are used. The flexible element may be held between two rigid disks, and they are all mounted on a single drive shaft. Alternatively, other forms of suture tie-downs may be provided, e.g., a suture cleat.

Pusher210is disposed within drive tube195and serves to selectively advance a locking pin275of coaxial suture lock220as will hereinafter be discussed. Pusher210is preferably constructed out of stainless steel, Nitinol, or titanium wire of, in a practical embodiment, 0.031″ diameter. As will hereinafter be discussed in further detail, pusher210is disposed within drive tube195, proximal to locking pin275of coaxial suture lock220, and is used to selectively advance locking pin275into coaxial suture lock220so as to create a binding interference fit between coaxial suture lock220and spanning suture120, whereby to fix the position of spanning suture120relative to second, sliding anchor215and thus permanently fix the length of spanning suture120extending across the mitral valve. In one preferred form of the invention, pusher210can be advanced by simple manual pushing. In another preferred form of the present invention, pusher210can be advanced via an advancer mechanism280which controllably advances pusher210for deployment of locking pin275into coaxial suture lock220. One preferred construction for advancer mechanism280comprises a threaded knob285which is secured to pusher210. The distal end of threaded knob285is received in a threaded bore in handle200. When threaded knob285is rotated, the threads of threaded knob285engage with the threaded bore in handle200so as to drive threaded knob285, and hence pusher210, distally or proximally. When threaded knob285is fully advanced to its most distal position, additional distal advancement of pusher210is prohibited.

In one preferred form of the invention, second, sliding anchor215comprises a body290having a smooth and rounded profile in all three dimensions whereby to best effect both delivery and atraumatic permanent implantation. SeeFIGS. 48-50 and 54-59. Second, sliding anchor215comprises a first side295, a second side300and a generally central through-hole305from where spanning suture120will ultimately emerge. In one preferred form of the invention, in order to maintain as small a crossing profile as possible during delivery through sheath185, first side295comprises a proximal slot310extending from central through-hole305to the proximal end of second, sliding anchor215, and second side300comprises a distal slot315extending from central through-hole305to the distal end of second, sliding anchor215. The slots310,315are deep enough, and aligned with one another, so that they “overlap” and thereby provide a continuous axial passage sufficiently large to transit spanning suture120through second, sliding anchor215without interference. SeeFIGS. 58 and 59. This allows second end130of spanning suture120to reside parallel and coaxial to second, sliding anchor215and within the anchor's profile when second, sliding anchor215is contained within sheath185. Furthermore, on account of this construction, and as will hereinafter be discussed in further detail, after second, sliding anchor215is deployed from sheath185, second, sliding anchor215may rotate away from the spanning suture so that the second, sliding anchor215is substantially perpendicular to the adjacent spanning suture120. Central through-hole305preferably comprises chamfers on either side of the central through-hole. These chamfers may be of equivalent size or, more preferably, one chamfer may be larger and one chamfer may be smaller. By way of example but not limitation, a smaller chamfer320on second side300provides a smooth exit profile for spanning suture120to exit from second, sliding anchor215. A larger chamfer325on first side295provides a seating surface for the distal end of coaxial suture lock220. In one preferred embodiment, second, sliding anchor215may be provided with one or more additional through-holes330to allow the elective fitting of a control suture (not shown) through second, sliding anchor215on one or the other end (or both ends) of the anchor.

Looking next atFIGS. 48-50 and 60-63, there is shown coaxial suture lock220. In one preferred embodiment, coaxial suture lock220comprises a tubular element335having a spherical distal end340and a D-shaped annular ring345at its proximal end. Coaxial suture lock220also comprises the aforementioned associated locking pin275. Coaxial suture lock220and/or its associated locking pin275may be formed out of stainless steel, titanium, Nitinol, or similar materials suitable for permanent implantation. The spherical distal end340of coaxial suture lock220engages the proximal end of second, sliding anchor215when second sliding anchor215and coaxial suture lock220are disposed in sheath185, and spherical distal end340seats in larger chamfer325of through-hole305of second, sliding anchor215when second, sliding anchor215is fixed on spanning suture120. It should be appreciated that, given the complex topology of the mitral annular groove on the ventricular side of the annulus, second, sliding anchor215and the through-running spanning suture120may be disposed at a wide range of angles. The spherical distal end340of coaxial suture lock220allows a wide range of angular orientations between coaxial suture lock220and the larger chamfer325of second, sliding anchor215when the second, sliding anchor215is engaged with the tissue, without inducing undesirable chafing of the spanning suture against the exit chamfer of the second, sliding anchor. Tubular element335of coaxial suture lock220is received in fork255of seat250, and D-shaped annular ring345at the proximal end of coaxial suture lock220is received in transverse slot265, whereby to preferentially retain coaxial suture lock220in seat250prior to the release of second, sliding anchor215from sheath185. Tubular element335of coaxial suture lock220has a cylindrical bore355which is sized to slidably receive the spanning suture when second sliding anchor215and coaxial suture lock220are disposed in sheath185, and to fixedly receive the spanning suture and locking pin275when second, sliding anchor215is fixed on spanning suture120. More particularly, when locking pin275is advanced into cylindrical bore355of coaxial suture lock220, the locking pin compresses spanning suture120radially within the cylindrical bore355of tubular element335of the coaxial suture lock220and thereby forms an interference fit between spanning suture120and coaxial suture lock220, whereby to fix the disposition of spanning suture120relative to second, sliding anchor215. It will be appreciated that locking pin275may be a solid cylinder or tubular in construction. Locking pin275preferably has a tapered feature on its distal end to help lead-in the locking pin within coaxial suture lock220.

In use, after spanning suture120has been passed through the anterior annulus and the posterior annulus, with first, fixed anchor135seated against the ventricular side of the anterior annulus, the free end (i.e., second end130) of spanning suture120is routed through second, sliding anchor215and coaxial suture lock220. Preferably this is done while second, sliding anchor215and coaxial suture lock220are loaded in STTT180. This may be facilitated by first positioning a loading loop (not shown) through coaxial suture lock220and second, sliding anchor215so that a loading loop is disposed on the distal end of second, sliding anchor215, with the loading loop emerging from the distal end of STTT180. Free end130of spanning suture120is threaded through the loading loop, and the loading loop is then pulled from the proximal end until free end130of spanning suture120emerges from STTT180.

Spanning suture120is then routed through hemostasis element190. Note that the suture hemostasis provided by hemostasis element190has the significant advantage over a conventional hemostasis valve in that there is no friction on the proximal leg of the spanning suture so that tension of the spanning suture reflects the forces applied to the mitral valve.

STTT180is then advanced through apical access sheath5to proximate the ventricular side of the posterior annulus. Spanning suture120is then fixed to STTT180by looping the free end of the spanning suture through one or multiple slits of the suture tie-down. Spanning suture120is then tensioned by suture tensioning mechanism205of STTT180. This progressive tensioning of spanning suture120progressively decreases the anterior-posterior dimension of the mitral valve, and hence progressively decreases mitral regurgitation. Distance increment markers (not shown) integrated into handle200of STTT180provide feedback to the clinician.

Once spanning suture120has been tensioned to the point where the mitral valve has been appropriately reconfigured, the one or more removable spacers192are removed and sheath185is retracted so as to free second, sliding anchor215from the constraint of sheath185. With tension maintained on the free end of spanning suture120, drive tube195is moved distally. As drive tube195is moved distally, seat250is moved distally, whereby to move coaxial suture lock220distally (note that inasmuch as the D-shaped annular ring345of coaxial suture lock220and seat250are held within sheath185, coaxial suture lock220is bound to seat250). This causes second, sliding anchor215to “tip over” into place against the ventricular side of the posterior mitral annulus, and spherical distal end340of coaxial suture lock220nestles into larger chamfer325of second, sliding anchor215. SeeFIG. 64. Threaded knob285is then turned to move pusher210distally, which advances locking pin275into cylindrical bore355, whereby to create an interference fit between locking pin275, spanning suture120and coaxial suture lock220. SeeFIG. 65. Coaxial suture lock220is then released from STTT180by removing one or more additional removable spacers192and further retracting sheath185. This uncovers coaxial suture lock220and the coaxial suture lock easily swings free of fork255and transverse slot265of seat250. If desired, pusher210can be moved distally slightly, causing D-shaped annular ring345of coaxial suture lock220to engage camming surface270, whereby to assist dismounting coaxial suture lock220from seat250. Note that spherical distal end340of coaxial suture lock220is able to set into larger chamfer325of second, sliding anchor215at a variety of angles so as to accommodate a wide range of patient anatomies. SeeFIG. 66.

Thus it will be seen that the process of freeing second, sliding anchor215and coaxial suture lock220from STTT180consists of several primary functional steps. First, after STTT180has been tracked into position proximate to the ventricular side of the posterior annulus, sheath185is retracted a sufficient distance to free second, sliding anchor215from sheath185. The length of sheath retraction can be controlled by various means, e.g., with the preferred construction of the present invention, by means of one or more removable spacers192of correct length, such that when the spacers are removed, sheath185can be retracted the intended distance. Second, after coaxial suture lock220has been secured in place against second, sliding anchor215, sheath185is retracted a further sufficient distance to free coaxial suture lock220from seat250, e.g., with the preferred construction of the present invention, by means of one or more additional removable spacers192that allow for the desired magnitude of controlled removal of sheath185to release coaxial suture lock220from seat250.

Additional spanning implants may then be deployed across the mitral valve as required to further adjust the configuration of the mitral annulus and hence reduce mitral regurgitation.

A suture trimming tool is then preferably used to cut spanning suture120proximal to coaxial suture lock220. In one preferred form of the invention, and looking now atFIG. 67, a suture trimming tool360generally comprises an outer sheath365extending distally from a handle370, and an inner cutting blade375extending distally from an actuator380. Outer sheath365has an internal lumen385and is preferably approximately 6-9 Fr in size of flexible construction such as from a polymer, rubber, thermoplastic elastomer, or a combination of such materials, and may comprise a braid, coil, or other stiffening element. Outer sheath365comprises a side opening390at the distal tip though which spanning suture120is inserted. Side opening390may be a slot, diametrically-opposed holes, etc. Inner cutting blade375resides in the internal lumen385of outer sheath365and has its distal blade oriented perpendicular or diagonal to the axis of outer sheath365. A long, flexible pusher section395connects inner cutting blade375to actuator380.

If desired, outer sheath365of suture trimming tool360may be fitted with a dedicated pre-fitted accessory hemostasis device to temporarily supplement the permanently-fitted hemostasis valve in the proximal end of apical access sheath5.

In use, spanning suture120is inserted through side opening390of suture trimming tool360while in the operative field. Suture trimming tool360is then advanced into apical access sheath5, and the suture trimming tool is advanced down to coaxial suture lock220. While slight tension is applied to the free end of spanning suture120, inner cutting blade375is advanced and the free end of the spanning suture is cut away. The excess suture and suture trimming tool are then removed from the surgical site.

In one preferred embodiment, locking features may be provided to prevent inadvertent advance of the inner blade until the suture is ready to be cut. This may be accomplished by sliding or rotational elements or by other means.

And in one preferred embodiment, suture trimming tool360may include a suture retracting wire400movably disposed within outer sheath365for applying tension to spanning suture120during cutting.

In one preferred embodiment of the present invention, the first, fixed anchor may have a configuration generally similar to that of second, sliding anchor215. More particularly, and looking now atFIGS. 68A-68F, in one form of the invention, there is shown a first, fixed anchor500that comprises a body505having a smooth and rounded profile in all three dimensions whereby to best effect both delivery and atraumatic permanent implantation. First, fixed anchor500comprises a first side510, a second side515and a generally central through-hole520through which spanning suture120will ultimately emerge. In one preferred form of the invention, in order to maintain as small a crossing profile as possible during delivery through a sheath, first side510comprises a proximal slot525extending from central through-hole520to the proximal end of first, fixed anchor500, and second side515comprises a distal slot530extending from central through-hole520to the distal end of first, fixed anchor500. The slots525,530are deep enough, and aligned with one another, so that they “overlap” and thereby provide a continuous axial passage sufficiently large to transit spanning suture120through first, fixed anchor500without interference. SeeFIGS. 68A and 68E. This allows first end125of spanning suture120to reside parallel and coaxial to first, fixed anchor500and within the anchor's profile when first, fixed anchor500is contained within a delivery sheath. Furthermore, on account of this construction, after first, fixed anchor500is deployed from its delivery sheath, first, fixed anchor500may rotate away from the spanning suture so that the first, fixed anchor500is substantially perpendicular to the adjacent spanning suture120(seeFIG. 68F). Central through-hole520preferably comprises chamfers on either side of the central through-hole. These chamfers may be of equivalent size or, more preferably, one chamfer may be larger and one chamfer may be smaller. By way of example but not limitation, a smaller chamfer535on second side515provides a smooth exit profile for spanning suture120to exit from first, fixed anchor500(i.e., to extend towards the ventricular side of the annulus). A larger chamfer540on first side510provides a seating surface for a cap545set on first end125of spanning suture120. The smaller chamfer535minimizes the chance of the suture rubbing against the anchor, which could cause fraying and breaking of the suture. The larger chamfer540allows controlled contact for cap545at varying angular orientations, maximum contact between cap545and the anchor, and minimizes the distance that cap545protrudes into the blood stream. In one preferred embodiment, first, fixed anchor500may be provided with one or more additional through-holes550to allow the elective fitting of a control suture (not shown) through first, fixed anchor500on one or the other end (or both ends) of the anchor.

Depending on where first, fixed anchor500is set in the anatomy, it may vary in size from second, sliding anchor215. By way of example but not limitation, first, fixed anchor500may be shorter or longer than second, sliding anchor215.

If desired, a surgical felt pledget may be disposed between the ventricular side of the mitral annulus and one or both of first, fixed anchor135and second, sliding anchor140. By way of example but not limitation, where a surgical felt pledget is to be disposed between the ventricular side of the anterior mitral annulus and first, fixed anchor135, the surgical felt pledget may be loaded onto spanning suture120“ahead of” first, fixed anchor135so that the surgical felt pledget is towed into position against the anterior mitral annulus when first, fixed anchor135is deployed against the anterior mitral annulus. By way of further example but not limitation, where a surgical felt pledget is to be disposed between the ventricular side of the posterior mitral annulus and second, sliding anchor140, the surgical felt pledget may be loaded onto spanning suture120“ahead of” second, sliding anchor140so that the surgical felt pledget is pushed up into position against the anterior mitral annulus when second, sliding anchor140is pressed up against the posterior mitral annulus.

If desired, and looking now atFIGS. 69, 70, 70A and 71, the surgical felt pledget may comprise a novel felt pledget405. Novel felt pledget405generally comprises a molding ring407having a felt body410secured thereto. A helical coil415is secured to molding ring407and projects distally therefrom. In this form of the invention, helical coil415can be “turned into” the mitral valve annulus, whereby to secure felt body410against the mitral valve annulus. By way of example but not limitation, where novel felt pledget405is to be disposed between the ventricular side of the anterior mitral annulus and first, fixed anchor135, surgical felt pledget405may be loaded onto crossing guidewire45and advanced into the anterior mitral annulus. After surgical felt pledget405has been secured to the anterior mitral annulus, then spanning suture120may be used to tow first, fixed anchor135up against surgical felt pledget405. By way of further example but not limitation, where a surgical felt pledget405is to be disposed between the ventricular side of the posterior mitral annulus and second, sliding anchor140, surgical felt pledget405may be loaded onto spanning suture120before second, sliding anchor140is loaded onto spanning suture120—in this form of the invention, surgical felt pledget405is pushed up spanning suture120and is turned into the ventricular side of the posterior mitral annulus, then, with surgical felt pledget405in position, second, sliding anchor140is loaded onto spanning suture120and advanced into position against the surgical felt pledget405before being locked onto spanning suture120.

As seen inFIG. 71, where surgical felt pledget405is to be disposed between the ventricular side of the posterior mitral annulus and second, sliding anchor140, surgical felt pledget405may be loaded into STTT180distal to second, sliding anchor215, with STTT180including a torque driver420for turning helical coil415into the posterior mitral annulus.

In the foregoing disclosure, the preferred constructions of the aforementioned first, fixed anchor and the aforementioned second, sliding anchor comprise so-called T-bar anchors. However, as an alternative to T-bar anchors, a screw-in anchor, providing for central routing of the spanning suture, could be employed as a general substitute for one or both of the aforementioned first, fixed anchor and the aforementioned second, sliding anchors.

By way of example but not limitation, in one preferred form of the invention, a suture-locking anchor (preferably formed out of stainless steel or titanium) comprises a proximal component and a distal component, with the proximal component and the distal component being threaded together so as to effect locking onto the spanning suture. In this form of the invention, the proximal component and the distal component both possess a central hole for passing the spanning suture, and one or both of the proximal component and the distal component may have tines or other features to permanently lock onto the spanning suture when the aforementioned threads are fully engaged.

13. Permanently Beneficially Displacing One or Both of the Papillary Muscles

In accordance with the present invention, there is also provided a method and apparatus for permanently beneficially displacing one or both of the papillary muscles.

More particularly, in this form of the invention, a spanning procedure is performed that attaches the tip of one (or both) of the papillary muscles to either the fibrous trigones or the central fibrous body of the mitral valve so as to beneficially displace one or both of the papillary muscles. This spanning suture may be anchored to a trigone (or the central fibrous body) in a manner similar to how the annular spans are anchored to one another (see above), but in the case of anchoring the papillary muscles, the distal anchor of the spanning suture is placed on the atrial side of the mitral valve and the spanning suture is routed into the left ventricle and then on to the papillary tip. In this way, the spanning suture is anchored on the atrial side of the mitral valve, extends through the fibrous trigone or central fibrous body, extends across the left ventricle and extends through the papillary muscle. Then the same “span-tension” procedure discussed above with respect to the annular spanning procedure may be employed to precisely and sequentially reduce the length of the span between the trigone (or the central fibrous body) and the papillary tip, so as to beneficially displace the papillary tip towards the fibrous base of the heart. In this respect it will be appreciated that as the “span-tension” procedure reduces the length of the span between the trigone (or the central fibrous body) and the papillary tip, the papillary tip is displaced toward the fibrous base of the heart since the fibrous base of the heart is effectively immobile during the “span-tension” procedure. The goal of the papillary displacement procedure is to reduce excessive leaflet “tethering” due to the adverse displacement of the papillary muscles and thus the mitral leaflet which is connected to the papillary muscle via chordae. Reduction or elimination of leaflet tethering allows the leaflets to return to their normal physiologic location with increased coaptation and reduced regurgitation.

Surgeons have, for at least four decades, experimented with performing papillary displacement and tethering reduction by surgically attaching sutures to the papillary tips and routing those sutures to the fibrous base of the heart with the thought that this would increase the durability of a mitral valve repair to reduce regurgitation, especially in cases of subsequent ventricular dilation after surgery. But these prior art papillary displacement and tethering procedures require open-heart, on-bypass surgery, and the effect of the tethering reduction cannot be directly observed on a beating heart, since the conventional papillary displacement and tethering reduction procedure is performed as an “on-bypass” surgery (i.e., with the heart stopped).

Therefore, in accordance with the present invention, there is now provided a method and apparatus for effecting the papillary displacement and tethering reduction using, generally, the aforementioned spanning/tensioning tools of the present invention, and leaflet tethering is relieved prior to undertaking the annular repair in the manner discussed above. There are critical advantages to performing the papillary displacement and tethering reduction using the apparatus and method of the present invention, most particularly that the subsequent annular repair is both more effective and more durable, and less “aggressive”, inasmuch as the reduction in tethering will, a priori, improve leaflet coaptation. It is well documented that overly-aggressive mitral repairs result in mitral orifice area restriction that adversely affects exercise capacity. At the same time, it is also well known that the presence of uncorrected leaflet tethering is the primary cause of recurrent mitral regurgitation following mitral repair. Thus, in accordance with the present invention, beneficial papillary displacement and tethering reduction is effected using the apparatus and method of the present invention, preferably before undertaking annular repair in the manner discussed above, whereby to provide improved leaflet coaptation. Significantly, inasmuch as the present invention allows the papillary displacement and tethering reduction to be effected on a beating heart, the tethering reduction can be directly observed as tensioning of the suture span occurs, whereby to permit the tethering reduction to be dynamically tailored while the heart is beating. It should also be appreciated that the papillary displacement and tethering reduction can be utilized independently of annulus reconfiguration, i.e., papillary displacement and tethering reduction can be effected where no annulus reconfiguration is undertaken.

One approach to the papillary displacement and tethering reduction procedure of the present invention is shown in the attachedFIGS. 72-84.

FIG. 72shows the target anatomy, i.e., the left atrium, the left ventricle, the mitral valve, the chordae tendinae (“the chordae”) and the papillary muscles.

FIG. 73shows a 2-port access sheath600(e.g., of the sort well known in the art) placed in the left ventricle so as to provide direct access to the anatomy. Also shown is a “target and cross tool” (also known as a “Target-Cross Tool”) (TCT)605(e.g., of the sort disclosed above) crossing the anterior annulus of the mitral valve in a desired location, and a snare610(e.g., of the sort disclosed above) placed through the mitral valve leaflets and into the left atrium so as to capture a suture615advanced out of TCT605and into the left atrium. Snare610is used to retrieve suture615from TCT605and draw suture615out of the left atrium, through the mitral valve leaflets, through the left ventricle and out access sheath600.

FIG. 74shows a “clean run” of suture615extending into a port620of access sheath600, across the left ventricle, through the anterior annulus, across the left atrium, between the valve leaflets, across the left ventricle and out a port625of access sheath600.

FIG. 75shows a fixed anchor630(e.g., of the sort disclosed above) on the end of implant suture635drawn into position on the atrial side of the mitral annulus using the “tie on and draw in” technique discussed above in connection with establishing an annular span. By way of example but not limitation, implant suture635carrying fixed anchor630is secured to the portion of suture615emerging from port625of access sheath600, and the portion of suture615emerging from port620of access sheath600is pulled proximally so as to “tow” implant suture635and fixed anchor630along the path followed by suture615until fixed anchor630is drawn up against the atrial side of the mitral annulus. A pledget (not shown) may be advanced over implant suture635ahead of anchor630so as to reinforce anchor seating against the atrial side of the mitral annulus.

FIG. 76shows TCT605and snare610being used to pass a routing suture640through the papillary muscle near the robust tip of the papillary muscle. By way of example but not limitation, TCT605is placed into port625of the 2-port access sheath600, and snare610is placed into port620of 2-port access sheath600, to facilitate final routing of implant suture635(see below).

FIG. 77shows how routing suture640is passed through the tip of the papillary muscle using TCT605and snare610. Note that the two ends of routing suture640emerge from ports620and625of 2-port access sheath600. Note also that the end of routing suture640emerging from port620of the 2-port access sheath is tied to the free end of implant suture635at a knot645, and then the suture leg coming out of port625is pulled out so that knot645is drawn into the left ventricle so as to establish the final routing of implant suture635.

FIG. 78shows the suture routing for a papillary displacement span of implant suture635in an untensioned configuration. Note that the papillary displacement span extends from atrial anchor630, through the annulus, across the left ventricle, through the tip of the papillary muscle, further across the left atrium, and out port625of 2-port access sheath600.

FIG. 79shows the “Span-Tension-Terminate-Tool” (also known as the “Span-Tension-Tool”) (STTT)650(e.g., of the sort disclosed above) routed over implant suture635. One or more pledgets (not shown) are preferably pushed on the implant suture ahead of the sliding anchor660(e.g., of the sort disclosed above) to buttress the sliding anchor when the sliding anchor is placed against the papillary muscle. The tensioning capabilities of STTT650are used to reduce the length of the span between the trigone and the tip of the papillary muscle by tensioning implant suture635so as to displace the papillary muscle superiorly and septally towards the fibrous base of the heart, whereby to beneficially reduce the tension on the chordae tendinae and the mitral leaflets, and hence improve leaflet coaptation and valve closing function. When the desired degree of papillary correction is observed (e.g., by echocardiogram, effected while the heart is beating), the suture lock665(e.g., of the sort disclosed above) is set and deployed (e.g., in the manner discussed above with respect to annular spanning) so as to set sliding anchor660in position against the papillary muscle. The suture tail is trimmed in the manner discussed above using a trim tool (not shown).

FIG. 80shows the completed, tensioned span displacing the papillary muscle toward the fibrous base of the heart, whereby to effect beneficial papillary displacement and tethering reduction.

FIG. 81is a cross-sectional view showing the relevant anatomy on the left side of the heart.

FIGS. 82-84show possible preferred orientations for the papillary spans (i.e., the implant suture635extending between the mitral annulus and the papillary muscles). The papillary spans are shown inFIGS. 82-84as pairs of spans (i.e., one span to each papillary muscle); however, a single papillary span to either papillary muscle may be all that is required for a particular patient for effective treatment of their leaflet tethering and associated mitral regurgitation with increased repair durability.

FIG. 82shows papillary spans originating from the Anterior Lateral Papillary Muscle (ALPM) and Posterior Medial Papillary Muscle (PMPM) and engaging the Central Fibrous Body (CFB).

FIG. 83shows papillary spans originating from the Anterior Lateral Papillary Muscle (ALPM) and Posterior Medial Papillary Muscle (PMPM) and each engages the diagonally-opposed trigone, for example, the Posterior Medial Papillary Muscle to the Anterior Lateral Trigone (ALT) and the Anterior Lateral Papillary Muscle to the Posterior Medial Trigone (PMT).

FIG. 84shows papillary spans originating from the Anterior Lateral Papillary Muscle (ALPM) and Posterior Medial Papillary Muscle (PMPM) and each engages the nearby trigone, for example, the Anterior Lateral Papillary Muscle to the Anterior Lateral Trigone (ALT) and the Posterior Medial Papillary Muscle to the Posterior Medial Trigone (PMT).

It will be appreciated that in the novel method shown inFIGS. 72-84, the 2-port access sheath600is advanced through the apex of the heart; TCT605is advanced across the left ventricle and used to pass suture615through the anterior annulus of the mitral valve and into the left atrium; snare610is advanced through the left ventricle, between the leaflets of the mitral valve, into the left atrium, and used to draw suture615out of the left atrium, between the leaflets of the mitral valve, and into the left ventricle, etc. Furthermore, suture615is then used to draw implant suture635and fixed anchor630across the left ventricle, between the leaflets of the mitral valve, and into the left atrium so that implant suture635can pass through the anterior annulus and into the left ventricle and fixed anchor630can be seated against the atrial side of the mitral annulus.

It will be appreciated by those skilled in the art that, as snare610is advanced from the left ventricle, between the leaflets of the mitral valve and into the left atrium, and as snare610is retracted from the left atrium, between the leaflets of the mitral valve and into the left atrium, there arises the possibility that snare610may inadvertently engage the chordae. Such inadvertent engagement can damage the chordae and/or impede function of the chordae. Furthermore, it will be appreciated that as suture615is used to draw implant suture635and fixed anchor630across the left ventricle, between the leaflets of the mitral valve, and into the left atrium so that implant suture635can pass through the anterior annulus and into the left ventricle and fixed anchor630can be seated against the atrial side of the mitral annulus, there arises the possibility that implant suture635and/or fixed anchor630may inadvertently engage the chordae. Again, such inadvertent engagement can damage the chordae or impede function of the chordae.

To this end, and looking now atFIGS. 85-93, there is provided another novel approach for permanently beneficially displacing one or both of the papillary muscles wherein actions do not need to take place in the vicinity of the chordae.

More particularly,FIG. 85shows the target anatomy, i.e., the left atrium, the left ventricle, the mitral valve, the chordae tendinae (“the chordae”) and the papillary muscles.FIG. 85also shows a 2-port access sheath600(e.g., of the sort well known in the art) placed in the left ventricle so as to provide direct access to the anatomy (if desired, in this form of the invention, 2-port access sheath600may be replaced by a 1-port access sheath, a 3-port access sheath, etc.).

FIG. 86shows a trigone anchor delivery tool670crossing the left ventricle and deploying a trigone screw anchor675into the fibrous trigones or the central fibrous body of the mitral valve. Trigone screw anchor675may be a conventional screw anchor of the sort well known in the art, e.g., it may comprise a corkscrew anchor of the sort used to anchor a pacing lead. If desired, the corkscrew anchor may be configured to provide radio frequency (RF) energy to the tissue so as to facilitate deployment of the corkscrew anchor into the fibrous trigones or the central fibrous body of the mitral valve. Trigone anchor delivery tool670may be a conventional anchor delivery tool of the sort well known in the art, e.g., it may comprise a cannulated sheath for turning screw anchor675into tissue (with the suture, see below, emanating from screw anchor675passing through the hollow lumen of the cannulated sheath). Note that as trigone anchor delivery tool670deploys trigone screw anchor675into the fibrous trigones or the central fibrous body of the mitral valve, trigone anchor delivery tool670passes directly across the left ventricle, well clear of the chordae.

FIG. 87shows a “clean run” of an implant suture680extending from trigone screw anchor675, across the left ventricle, through 2-part access sheath600, and out one port of the access sheath trigone. Again, note that implant suture680passes directly across the left ventricle, well clear of the chordae.

FIG. 88show TCT605(e.g., of the sort disclosed above) and snare610(e.g., of the sort disclosed above) being prepared to pass a papillary suture685through the papillary muscle near the robust tip of the papillary muscle. By way of example but not limitation, TCT605is placed into a port of the 2-port access sheath600and advanced through the papillary muscle, and snare610is placed into a port of 2-port access sheath600and advanced into the left atrium, in preparation for routing of papillary suture685(see below). If desired, TCT605and snare610can be combined into a single device for the convenience of the surgeon.

FIG. 89shows how papillary suture685is passed through the tip of the papillary muscle using TCT605and then snared by snare610.

Snare610is then used to draw the distal end of papillary suture685back through 2-port access sheath600, whereupon the snared end of papillary suture685emerging from the 2-port access sheath is tied to implant suture680at a knot690. SeeFIG. 90. Then the free leg of papillary suture685is pulled out so that knot690is drawn into the left ventricle so as to establish the final routing of implant suture680.

FIG. 91shows the suture routing for a papillary displacement span of implant suture680in an untensioned configuration. Note that the papillary displacement span extends from trigone screw anchor675, across the left ventricle, through the tip of the papillary muscle, further across the left atrium, and out a port of 2-port access sheath600.

FIG. 92shows the “Span-Tension-Terminate-Tool” (also known as the “Span-Tension-Tool”) (STTT)650(e.g., of the sort disclosed above) routed over implant suture680. One or more pledgets655are preferably pushed on the implant suture ahead of the sliding anchor660(e.g., of the sort disclosed above) to buttress the sliding anchor when the sliding anchor is placed against the papillary muscle. The tensioning capabilities of STTT650are used to reduce the length of the span between the trigone and the tip of the papillary muscle, by tensioning implant suture680, so as to displace the papillary muscle superiorly and septally towards the fibrous base of the heart, whereby to relocate the chordae tendinae and the mitral leaflets, and hence improve leaflet coaptation and valve closing function.

When the desired degree of papillary correction is observed (e.g., by echocardiogram, effected while the heart is beating), the suture lock665(e.g., of the sort disclosed above) is set and deployed (e.g., in the manner discussed above with respect to annular spanning) so as to set sliding anchor660in position against the papillary muscle. The suture tail is trimmed in the manner discussed above using a trim tool (not shown).

FIG. 93shows the completed, tensioned span displacing the papillary muscle toward the fibrous base of the heart, whereby to effect papillary displacement and tethering reduction.

MODIFICATIONS

The foregoing is considered to be only illustrative of the principles of the present invention. Since numerous modifications and changes will readily occur to those skilled in the art, the present invention is not limited to the exact constructions and operation shown and described above. While the preferred embodiment has been described, the details may be changed without departing from the spirit and scope of the present invention.