Patent Description:
The present invention relates to apparatus for use in replacing heart valves. In particular, the present invention relates to apparatus for use in replacing mitral valves.

The mitral valve is the most complex of the human heart's valves and is commonly associated with disease. Conditions affecting the normal functioning of the mitral valve include, for example, mitral valve regurgitation, mitral valve prolapse, and mitral valve stenosis. Mitral valve regurgitation refers to the condition whereby the leaflets of the mitral valve fail to coapt into apposition during ventricular contraction, resulting in abnormal leaking of blood from the left ventricle into the left atrium. Mitral valve prolapse refers to the condition where the mitral valve leaflets bulge abnormally up into the left atrium causing irregular behaviour of the mitral valve. Mitral valve stenosis refers to the narrowing of the heart's mitral valve obstructing blood flow. A number of factors may affect the normal functioning of the mitral valve leaflets.

Although intermediate grades of impaired functioning of the mitral valve may not require treatment, severely impaired mitral valve function may result in symptoms (for example, breathlessness, fatigue, exercise intolerance), and may represent a threat to life expectancy. Often, invasive surgery must be performed to repair or replace an abnormal mitral valve.

Traditionally, repairing or replacing a mitral valve involves an open heart procedure. Open heart procedures present subjects with morbidity and mortality risks and require a post-op period of convalescence that is typically several months in duration. Open heart surgery may pose prohibitive risks, or may otherwise not be ideal for some subjects, including some elderly subjects and subjects with other health issues. Repairing or replacing the mitral valve without invasive open heart procedures may be attractive therapy for such subjects.

Transcatheter mitral valve replacement (TMVR) apparatus and methods for treating mitral regurgitation in subjects at high or prohibitive surgical risks are known. Traditional TMVR technologies use anchoring features to securely attach a prosthetic mitral valve to the native mitral valve. The replacement valves often cause left ventricular outflow tract (LVOT) obstruction. LVOT obstruction occurs when the replacement valve pushes the anterior leaflet of the mitral valve underneath the aortic (i.e. outflow) valve, and against the ventricular septum. Further, successful implantation of such devices is complicated by the distinct structure and functioning of the mitral valve. A heart <NUM> showing LVOT obstruction is shown in <FIG>. A conventional TMVR apparatus <NUM> pushes anterior mitral valve leaflet <NUM> under aortic valve <NUM> obstructing outflow.

While there has been some success in developing replacement heart valve prosthetics for percutaneous catheter-based delivery, such methods have not been particularly successfully applied to mitral valve replacement. Mitral valve replacement is complicated by the anatomy of the mitral valve, and particularly that of the mitral valve annulus in which the mitral valve leaflets are located. The mitral valve annulus is typically of unpredictable and nonuniform configuration, as compared to the relatively uniform aortic valve annulus. The unpredictable anatomy of the mitral valve annulus complicates safe, stable, and meticulous deployment of mitral valve prostheses. Transcatheter aortic valves for treating mitral regurgitation are known, and can be implanted when a suitable docking device (e.g. a surgically placed mitral annular ring) is present on the mitral valve. However, transcatheter aortic valves can suffer from similar complications as a TMVR apparatus, including LVOT obstruction when the replacement valve pushes the anterior mitral valve leaflet underneath the aortic valve.

Some mitral valve replacement techniques involve the division or incision of the native valve prior to positioning and implanting the mitral valve prosthesis. This is a challenging technique associated with potentially fatal complications if the mitral valve prosthesis is not precisely positioned and/or the mitral valve prosthesis is not implanted at least closely or immediately following the division or incision of the native valve.

<CIT> discloses a scoring catheter comprising an elongated catheter body and at least one scoring element positioned at the distal end of the catheter body, wherein said scoring element is expandable from a contracted state when positioned near said catheter body to an expanded state with a larger diameter so that diseased heart valves can be scored and reopened.

The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.

The apparatus according to the invention is defined in claim <NUM>. The methods of operation disclosed are not recited by the wording of the claims. They are considered useful for understanding the invention.

The following embodiments of the present disclosure, and aspects thereof, are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.

Some aspects of the present disclosure provide an apparatus for use in mitral valve replacement comprising a controller, a cutting section movable between a collapsed position for delivering the apparatus to a mitral valve and an expanded position for incising a mitral valve leaflet, and a guidewire. The apparatus is sized and dimensioned to enter a subject through a first access site, traverse through at least part of a subject's circulatory system, and exit the subject through a second access site so that a distal end of the guidewire and the controller are external to the subject's circulatory system when the apparatus is situated intravascularly.

In some embodiments a proximal end of the guidewire extends longitudinally from a distal end of the cutting section.

In some embodiments a proximal end of the cutting section extends longitudinally from a distal end of the controller.

In some embodiments the cutting section defines a lumen extending longitudinally through the cutting section and the guidewire extends through and is slideable within the cutting section.

In some embodiments the cutting section comprises at least one blade configured to radially extend away from a longitudinal axis defined by the apparatus in the expanded position and radially collapse toward the longitudinal axis in the collapsed position.

In some embodiments each blade is formed from a memory material.

ln some embodiments the memory material comprises a memory metal alloy from the group consisting of one or more of stainless steel, nickel, titanium, and nitinol.

In some embodiments the blade retains a pre-deformed shape in the expanded position and is deformable into a deformed shape in the collapsed position.

In some embodiments each blade comprises a cutting blade pivotally coupled at a proximal end to a distal end of a lever arm, each cutting blade pivotally coupled at a distal end to the proximal end of the guidewire and each lever arm pivotally coupled at a proximal end to the controller.

In some embodiments the distance between the distal end of the cutting blade and the proximal end of the lever arm is greater in the collapsed position than in the expanded position.

In some embodiments the cutting section comprises a rod and a runner longitudinally slidable about the rod.

In some embodiments each blade comprises a distal end pivotally coupled to a distal section of the rod and a proximal end pivotally coupled to the runner.

In some embodiments the distance between the proximal and distal ends of each blade is greater in the collapsed position than in the expanded position.

In some embodiments the runner is rotatable about the rod to rotate each blade about the longitudinal axis.

In some embodiments a radial cross-sectional area of the cutting section is reduced by rotating each blade about the longitudinal axis in a first direction.

In some embodiments the radial cross-sectional area of the cutting section is increased by rotating each blade about the longitudinal axis in a second direction opposed to the first direction.

In some embodiments the cutting section comprises a rotator housed within a case defining one or more slots configured to receive the at least one blade.

In some embodiments each blade extends radially from the rotator and wraps concentrically about an inside surface of the case in the collapsed position.

In some embodiments each blade is expandable and retractable within the slot.

In some embodiments each blade extends radially from the rotator through the slot in the expanded position.

In some embodiments the cutting section is configured to incise the mitral valve leaflet with a predetermined pattern.

In some embodiments the predetermined pattern is selected from the group consisting of: a T-shaped incision, a linear incision, and an X-shaped incision.

In some embodiments the at least one blade extends radially away from a longitudinal axis defined by the apparatus and in a configuration that corresponds to the predetermined pattern.

In some embodiments the controller is configured to move the cutting section from the collapsed position to the expanded position and vice versa.

Another aspect of the present disclosure, not forming part of the claimed invention, provides a method for replacing a mitral valve. The method comprises inserting an apparatus percutaneously through a first access site of a subject, advancing the apparatus intravascularly through the subject's circulatory system, and advancing the apparatus through a second access site of the subject. The apparatus comprises a controller, a cutting section, and a guidewire and the apparatus is sized and dimensioned to traverse the subject's circulatory system from the first access site to the second access site such that a distal end of the guidewire and the controller are external to the subject's body when the apparatus is situated intravascularly. The method further comprises incising a mitral valve leaflet using the cutting section and delivering a prosthetic valve intravascularly to the incised mitral valve leaflet from the second access site using the guidewire.

In some embodiments incising the mitral valve leaflet comprises expanding the cutting section from a collapsed position into an expanded position and advancing the cutting section in the expanded position through the mitral valve leaflet.

In some embodiments the method further comprises positioning the prosthetic valve into the incised mitral valve leaflet following incision.

In some embodiments the method further comprises positioning the prosthetic valve into the incised mitral valve leaflet immediately following incision.

In some embodiments the method comprises positioning the prosthetic valve into the incised mitral valve leaflet within less than about <NUM> seconds following incision.

In some embodiments the method comprises positioning the prosthetic valve into the incised mitral valve leaflet within less than about <NUM> second following incision.

In some embodiments the method comprises incising the mitral valve leaflet and implanting the prosthetic valve at a predetermined location determined using Transesophageal Echocardiography (TEE) and/or fluoroscopy techniques.

In some embodiments the predetermined location is selected to minimize or eliminate anterior displacement of the anterior leaflet.

In some embodiments the predetermined location is along a central axis of the anterior leaflet at a position away from the anterior annulus so that an adequate amount of anterior leaflet tissue is available for hemostatic implantation of the prosthesis within a docking device.

In some embodiment the predetermined location is selected to minimize or eliminate left ventricular outflow tract (LVOT) obstruction.

In some embodiments inserting the apparatus through the first access site and advancing the apparatus through the subject's circulatory system comprises using a retrograde transcatheter approach.

In some embodiments inserting the apparatus through the first access site and advancing the apparatus through the subject's circulatory system comprises using an antegrade transcatheter approach.

In some embodiments advancing the apparatus through the second access site comprises inserting and advancing a snaring guidewire percutaneously through the second access site, snaring the distal end of the apparatus intravascularly, and withdrawing the distal end of the apparatus through the second access site.

Another aspect of the present disclosure provides an apparatus for performing a method for replacing a mitral valve. The apparatus comprises a controller, a cutting section movable between a collapsed position for delivering the apparatus to a mitral valve and an expanded position for incising a mitral valve leaflet, and a guidewire. The apparatus is sized and dimensioned to enter a subject through a first access site, traverse through at least part of a subject's circulatory system, and exit the subject through a second access site so that a distal end of the guidewire and the controller are external to the subject's circulatory system when the apparatus is situated intravascularly.

In some embodiments the memory material comprises a memory metal alloy from the group consisting of one or more of stainless steel, nickel, titanium, and nitinol.

Another aspect of the present disclosure provides a system for use in a mitral valve replacement. The system comprises a subaortic introducer and an apparatus comprising a controller, a cutting section movable between a collapsed position for delivering the apparatus to a mitral valve and an expanded position for incising a mitral valve leaflet, and a guidewire. The apparatus is sized and dimensioned to enter a subject through a first access site, traverse through at least part of a subject's circulatory system, and exit the subject through a second access site so that a distal end of the guidewire and the controller are external to the subject's circulatory system when the apparatus is situated intravascularly.

In some embodiments the subaortic introducer comprises a destructible tip that maintains the guidewire in a linear position as the apparatus is advanced through a subject's circulatory system and permits the guidewire to deform in a J-shaped position as the apparatus destructs and is advanced through the tip.

In some embodiments the cutting section comprises at least one blade configured to radially extend away from a longitudinal axis defined the apparatus in the expanded position and radially collapse toward the longitudinal axis in the collapsed position.

In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.

Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.

Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

Unless context dictates otherwise, the term "anterior" (as used herein in relation to a subject's body and parts thereof) refers to a position that is more near the front surface of the subject's body or part thereof than the rear surface of the subject's body or part thereof.

Unless context dictates otherwise, the term "posterior" (as used herein in relation to a subject's body and parts thereof) refers to a position that is more near the rear surface of the subject's body or part thereof than the front surface of the subject's body or part thereof.

Unless context dictates otherwise, the term "proximal" (as used herein in relation to an apparatus according to an example embodiment of the present invention and parts thereof) refers to a position that is more near a controller of the apparatus or part thereof.

Unless context dictates otherwise, the term "distal" (as used herein in relation to an apparatus according to an example embodiment of the present invention and parts thereof) refers to a position that is situated further away from a controller of the apparatus or part thereof.

Unless context dictates otherwise, the terms "percutaneous", "percutaneously", and the like (as used herein) refer to a method of accessing a subject's circulatory system and/or heart through the skin, such as by needle access.

Unless context dictates otherwise, the term "antegrade" (as used herein) refers to a percutaneous approach to a mitral valve via a subject's femoral vein, right atrium, atrial septal puncture, and left atrium.

Unless context dictates otherwise, the term "retrograde" (as used herein) refers to a percutaneous approach to a mitral valve via a subject's femoral artery, wherein the left ventricle is accessed via the aortic valve.

Unless context dictates otherwise, the term "intravascular" (as used herein) means situated or occurring within a subject's blood vessel or circulatory system.

Unless context dictates otherwise, the term "external" (as used herein in relation to a subject's body and parts thereof) means situated outside of a subject's circulatory system or body.

Unless context dictates otherwise, the term "transcatheter" (as used herein) refers to a method performed intravascularly through the lumen of a catheter.

Unless context dictates otherwise, the term "collapsed position" (as used herein) refers to a radially compressed state. Although the terms "radial", "radially", and the like are most commonly used in connection with circular objects or features, it should be understood for the purpose of this description and accompanying aspects that the terms "radial", "radially", and the like are used in a broader context and are not limited to describing strictly circular objects or features or objects or features with strictly circular cross-section.

Unless context dictates otherwise, the term "expanded position" (as used herein) refers to a radially enlarged, extended, or otherwise broadened state.

Unless context dictates otherwise, the term "circulatory system" (as used herein) refers to a system that circulates blood and/or lymph through a subject's body, consisting of one or more of a heart, blood vessels, blood, lymph, lymphatic vessels, and lymphatic glands.

Unless context dictates otherwise, the term "transcatheter heart valve prosthesis" (as used herein) refers to a prosthesis used to repair or replace a heart valve (e.g. mitral valve, aortic valve, etc.) percutaneously using a transcatheter heart valve delivery system, including (but not limited to) a transcatheter mitral valve prosthesis.

Unless the context dictates otherwise, "subject" (as used herein) refers to a human and/or an animal (i.e. a bird and/or a mammal) and includes any subject that will benefit or that is likely to benefit from the present invention (for example, a subject with a condition affecting the normal functioning of a heart valve, including (but not limited to) the mitral valve, for example, mitral valve regurgitation, mitral valve prolapse, and mitral valve stenosis.

Unless the context dictates otherwise, "nitinol" (as used herein) refers to a nickel-titanium alloy with shape memory and/or superelastic characteristics. Nitinol is capable of deforming into a deformed shape and recovering its original, undeformed shape without applying heat.

Although the methods and apparatus disclosed may be used for the percutaneous repair of any of the cardiac valves, the following description will focus on the replacement of mitral valves. Further, while the methods and apparatus disclosed will preferably be percutaneous and intravascular, such methods and apparatus may be used for performing open heart surgery where the heart is accessed through the myocardial tissue and/or in minimally invasive procedures where access to the heart is achieved thorascopically. Further still, while the methods and apparatus disclosed will preferably be used with conventional transcatheter heart valve prostheses, such methods and apparatus may be used with prostheses implanted through the myocardial tissue of the heart and/or prostheses implanted using minimally invasive procedures where access to the heart is achieved thorascopically.

The human heart <NUM>, shown in <FIG> and <FIG>, is a muscle pump which relies on heart valves to achieve forward blood flow. In normal physiology, oxygenated blood returning from the lungs is collected in a left atrium <NUM>, and then passes through a mitral (inlet) valve <NUM> to enter a left ventricle <NUM> (i.e. the pumping chamber). With contraction of left ventricle <NUM>, the elevation of left ventricular pressure causes mitral valve <NUM> to close, preventing reversal of blood flow back into atrium <NUM>. As ventricular pressure exceeds aortic pressure, aortic (outlet) valve <NUM> opens, and blood is pumped forward into aorta <NUM>. When left ventricle <NUM> relaxes, the ventricular pressure drops, mitral valve <NUM> reopens to permit flow of blood from left atrium <NUM> to left ventricle <NUM>, and the process repeats.

Mitral valve <NUM> separates left atrium <NUM> from left ventricle <NUM>, and is comprised of a mitral annulus <NUM>, leaflets (anterior <NUM> and posterior <NUM>), chordae tendinae <NUM>, and papillary muscles <NUM>. During ventricular contraction (systole), the ventricular pressure rises, which forces displacement of mitral valve leaflets <NUM>, <NUM> towards atrium <NUM> (i.e. commonly known as atrial or leaflet displacement). The length and integrity of chordae tendinae <NUM> determines the degree of leaflet displacement. In normal physiology, equal displacement of anterior mitral valve leaflet <NUM> and posterior mitral valve leaflet <NUM> results in contact (coaptation) between the leaflets, and consequent competence of mitral valve <NUM>.

In circumstances where mitral valve leaflet <NUM> and/or <NUM> is supported by chordae tendinae <NUM> which are elongated or ruptured, ventricular contraction may result in excessive atrial displacement of the leaflet(s), and this may prevent coaptation between the leaflets (<FIG>). This is referred to as mitral valve leaflet prolapse. In this circumstance, the competency of mitral valve <NUM> may be compromised and leakage may occur. Leakage through the mitral valve is referred to as mitral regurgitation, and when it is due to mitral valve leaflet prolapse it is referred to as degenerative mitral regurgitation. In other circumstances, the ventricular muscle itself can be diseased and its function impaired causing limited ventricular contraction and progressive ventricular dilation. Since mitral valve leaflets <NUM>, <NUM> are attached by chordae tendinae <NUM> to the ventricular muscle, ventricular dilation can limit leaflet movement toward atrium <NUM> during contraction, resulting in poor leaflet coaptation and causing mitral regurgitation. This is referred to as functional mitral regurgitations.

The methods and apparatus of example embodiments use existing transcatheter heart valve prostheses to percutaneously replace a mitral valve. The methods and apparatus of example embodiments are used to percutaneously incise an anterior mitral valve leaflet and to permit precise implantation of a transcatheter heart valve prosthesis in that incision. In this way, incision and implantation are both controlled, deliberate, and precise and LVOT obstruction may be avoided or minimized. In some embodiments the size and design of the incision may be controlled to optimize implantation. Some embodiments use percutaneous incision of the anterior mitral valve leaflet to allow a transcatheter heart valve prosthesis to be implanted after the mitral valve leaflet is incised to reduce or eliminate the risk of hemodynamic instability.

An apparatus 10D for use in replacing a heart valve, such as a mitral valve, is shown in <FIG>. Alternate embodiments, apparatus <NUM>, apparatus <NUM>, and apparatus <NUM>, are shown in <FIG>, <FIG>, and <FIG>. Many features and components of apparatus <NUM>, <NUM>, <NUM> are similar to features and components of apparatus <NUM>, with the same reference numerals being used to indicate features and components that are similar between the embodiments. In some embodiments apparatus <NUM>, <NUM>, <NUM>, <NUM> is used to percutaneously incise an anterior mitral valve leaflet and to permit precise implantation of a transcatheter heart valve prosthesis in the incision. Apparatus <NUM>, <NUM>, <NUM>, <NUM> is sized and dimensioned to traverse a subject's circulatory system percutaneously from a first access site to a second access site. In some embodiments the first access site enters the subject's femoral artery or femoral vein. In some embodiments the second access site enters the subject's femoral artery or femoral vein. When the first access site enters the subject's femoral artery, the second access site enters the subject's femoral vein and vice versa. The example embodiment of apparatus 10D shown in <FIG> and 11A-11J traverses a subject's circulatory system <NUM> from a first access site <NUM> (FIGS. 11A-11J) to a second access site <NUM> (FIGS. 11A-11J) such that proximal end <NUM> and distal end <NUM> of apparatus <NUM> are external to the subject's body when apparatus <NUM> is situated intravascularly and traverses a subject's circulatory system. Apparatus <NUM>, <NUM>, <NUM> are similarly situated in a subject's circulatory system. In the embodiment illustrated in <FIG>, proximal end <NUM> is external the femoral artery and distal end <NUM> is external the femoral vein when apparatus <NUM> is situated intravascularly and traverses the subject's circulatory system. However, this is not necessary and the proximal end <NUM> may be external the femoral artery and the distal end <NUM> may be external the femoral vein when apparatus <NUM> is situated intravascularly and traverses the subject's circulatory system.

The apparatus includes a controller, a cutting section, and a guidewire. The apparatus is configured to be operated external to a subject's body. For example, the controller may be operated external to the subject's body to advance the apparatus intravascularly through the subject's circulatory system from a first access site (e.g. access site <NUM> (FIGS. 11A-11J)) to a second access site (e.g. access site <NUM> (FIGS. In some embodiments the controller is configured to operate the cutting section and/or the guidewire intravascularly from outside the subject's body, as described elsewhere herein.

The controller (e.g. controller <NUM>) is operable to move the apparatus between a collapsed position and an expanded position. In the collapsed position, the apparatus is in a radially compressed state to intravascularly traverse a subject's circulatory system. In the expanded position, the apparatus is in a radially enlarged, extended, or otherwise broadened state whereby the radial cross-sectional area of the apparatus is greater in the expanded position than in the collapsed position. In the expanded position, the apparatus is operable for incising a mitral valve leaflet. In some embodiments the cutting section (e.g. cutting section <NUM>, <NUM>, <NUM>, <NUM>) is operable to move the apparatus between a collapsed position (<FIG>, <FIG>, <FIG>, <FIG> and <FIG>) and an expanded position (<FIG>, <FIG>, <FIG>, <FIG>, and <FIG>). In the collapsed position, the cutting section is in a radially compressed state to reduce the cross-sectional area of the cutting section. In the expanded position, the cutting section is in a radially enlarged, extended, or otherwise broadened state whereby the radial cross-sectional area of the cutting section is greater in the expanded position than in the collapsed position.

A guidewire (e.g. guidewire <NUM>, <NUM>, <NUM>, <NUM>) longitudinally extends from the cutting section for guiding and positioning the cutting section to incise a mitral valve leaflet and for positioning a transcatheter heart valve prosthesis (e.g. a mitral valve prosthesis) into the incised leaflet as described elsewhere herein. In this way, the transcatheter heart valve prosthesis may be precisely positioned within the incision following incision to reduce or eliminate the risk of hemodynamic instability. In some embodiments the transcatheter heart valve prosthesis is positioned within the incision within less than about <NUM> seconds following incision. In some embodiments the transcatheter heart valve prosthesis is positioned within the incision within less than about <NUM> seconds following incision. In some embodiments the transcatheter heart valve prosthesis is positioned within the incision within less than about <NUM> second following incision. In some embodiments the transcatheter heart valve prosthesis is closely or immediately positioned within the incision following incision. Precise positioning of the transcatheter heart valve prosthesis may avoid or minimize LVOT obstruction. Immediate positioning of the transcatheter heart valve prosthesis following incision may minimize the risk of hemodynamic instability.

In the embodiment illustrated in <FIG>, apparatus <NUM> includes a cutting section <NUM>, a guidewire <NUM> extending away from a distal end of cutting section <NUM>, and a controller <NUM> extending away from a proximal end of cutting section <NUM> opposed to the distal end. In the embodiment illustrated in <FIG>, controller <NUM> includes a handle <NUM> and a knob <NUM>. Handle <NUM> has a lumen (not shown) extending longitudinally therethrough. A rod <NUM> coupled to knob <NUM> extends through the lumen and slides within the lumen to move rod <NUM> and knob <NUM> concentrically and/or longitudinally relative to handle <NUM>. By longitudinally sliding and/or rotating knob <NUM> relative to handle <NUM>, apparatus <NUM> may be operated. In some embodiments cutting section <NUM> is rotatable relative to controller <NUM>. In some other embodiments, controller <NUM> and cutting section <NUM> are rotatably fixed such that rotation of controller <NUM> rotates cutting section <NUM>.

Guidewire <NUM> comprises a proximal end <NUM> (<FIG>) coupled to cutting section <NUM> and a distal end <NUM> opposed to the proximal end. In some embodiments guidewire <NUM> is rotatable relative to controller <NUM> and/or cutting section <NUM>. In some other embodiments, cutting section <NUM> and guidewire <NUM> are rotatably fixed such that rotation of cutting section <NUM> rotates guidewire <NUM> and vice versa. In the illustrated embodiment, distal end <NUM> of guidewire <NUM> includes a hook <NUM> for engaging a snaring guidewire as described elsewhere herein. Other means for engaging a snaring guidewire are considered to be within the knowledge of persons skilled in the art of interventional cardiology.

Cutting section <NUM> includes one or more radially expandable blades <NUM> for incising a mitral valve leaflet. Each blade <NUM> may be expanded or contracted using controller <NUM>. In the embodiment illustrated in <FIG>, cutting section <NUM> includes three radially expandable blades <NUM> configured to incise the mitral valve leaflet with a "T-shaped" incision. The number and configuration of the blades of apparatus <NUM> may be selected to achieve other desired incision patterns. For example, the number and configuration of blades <NUM> may be selected to incise a mitral valve leaflet with a "T-shaped" incision, a linear incision, or an "X-shaped" incision (<FIG>). Other incision patterns are considered to be within the knowledge of persons skilled in the art of heart surgery. In some embodiments, each blade <NUM> is expandable and retractable within a corresponding blade window (not shown) defined by the cutting section.

In the embodiment illustrated in <FIG>, each blade <NUM> comprises a cutting blade 126a pivotally coupled to a lever arm 126b by a hinge 126c. Hinge 126c may comprise a pin, a screw, or another mechanical fastener conventionally known. To expand and collapse blades <NUM>, cutting section <NUM> includes a rod <NUM> coupled to rod <NUM> at a proximal end 129a and coupled to lever arm 126b at a distal end 129b (<FIG>). In some embodiments rods <NUM>, <NUM> are coupled together. In some other embodiments, rods <NUM>, <NUM> are formed together as a unitary rod (not shown). In some embodiments lever arm 126b is pivotally coupled to distal end 129b by a hinge (not shown), such as a pin, a screw, or another mechanical fastener conventionally known. Cutting blade 126a is coupled to a proximal end <NUM> of guidewire <NUM>. In some embodiments cutting blade 126a is pivotally coupled to guidewire <NUM> by a hinge (not shown), such as a pin, a screw, or another mechanical fastener conventionally known.

In a collapsed position (<FIG>), cutting blade 126a and lever arm 126b are folded together about hinge 126c in a radially compressed state to reduce the cross-sectional area of cutting section <NUM> so that apparatus <NUM> may be inserted percutaneously and traversed intravascularly. To expand cutting section <NUM> (<FIG>), knob <NUM> coupled to rod <NUM> is pulled away from handle <NUM> along an axis A defined by apparatus <NUM> (<FIG>). In this way, rod <NUM> coupled to rod <NUM> longitudinally slides within the lumen (not shown) defined by handle <NUM>, thereby pulling distal end 129b of rod <NUM> away from proximal end <NUM> of guidewire <NUM>. As distal end 129b is pulled away from guidewire <NUM> along axis A, cutting blade 126a and lever arm 126b unfold about hinge 126c and radially extend away from axis A. In this way, cutting blade 126a is oriented to incise a mitral valve leaflet as described elsewhere herein. To collapse cutting section <NUM>, knob <NUM> is pushed toward handle <NUM> along axis A, drawing distal end 129b of rod <NUM> toward proximal end <NUM> of guidewire <NUM> and folding cutting blade 126a and lever arm 126b about hinge 126c. Cutting blade 126a and lever arm 126b radially compress towards axis A. In the collapsed position, apparatus <NUM> may be inserted into a catheter (e.g. catheter <NUM>).

In the illustrated embodiment, apparatus <NUM> includes a blade tube <NUM> (although this is not necessary). Blade tube <NUM> defines a lumen (not shown) extending longitudinally therethrough and one or more slots 121c, each slot 1221c configured to permit blade <NUM> to pass therethrough. Distal end 129b of rod <NUM> and proximal end <NUM> of guidewire <NUM> extend through the lumen. In this way blade tube <NUM> spans a gap between distal end 129b of rod <NUM> and proximal end <NUM> of guidewire <NUM> when apparatus <NUM> is in an expanded position. Accordingly, blade tube <NUM> couples cutting section <NUM> and guidewire <NUM> together along axis A. Blade tube <NUM> prevents material from becoming lodged between cutting section <NUM> and guidewire <NUM> when apparatus <NUM> is in an expanded position. Blade tube <NUM> may enhance the precision of apparatus <NUM> in incising a mitral valve leaflet and implanting a transcatheter heart valve prosthesis as described elsewhere herein.

In the illustrated embodiment, apparatus <NUM> includes a connecting tube <NUM> (although this is not necessary). Connecting tube <NUM> defines a lumen (not shown) extending longitudinally therethrough. A distal end 121b of blade tube <NUM> and proximal end <NUM> of guidewire <NUM> extend through the lumen. In this way connecting tube <NUM> rigidly couples cutting section <NUM> and guidewire <NUM> together along axis A. Connecting tube <NUM> may enhance the precision of apparatus <NUM> in incising a mitral valve leaflet and implanting a transcatheter heart valve prosthesis as described elsewhere herein.

In the illustrated embodiment, apparatus <NUM> includes a rod tube <NUM> (although this is not necessary). Rod tube <NUM> defines a lumen (not shown) extending longitudinally therethrough. A proximal end 121a of blade tube <NUM> and rod <NUM> extend through the lumen and longitudinally slides within the lumen. Rod tube <NUM> may enhance the rigidity of apparatus <NUM>. For example, rod tube <NUM> may rigidly couple controller <NUM> and cutting section <NUM> together along axis A. Rod <NUM> and/or rod <NUM> are slidable within the lumen of rod tube <NUM> along axis A.

In the illustrated embodiment, apparatus <NUM> includes a tube <NUM> (although this is not necessary). Tube <NUM> defines a lumen (not shown) extending longitudinally therethrough. A proximal end 121a of blade tube <NUM> and rod tube <NUM> (and/or rod <NUM>) extend through the lumen and longitudinally slides within the lumen. Tube <NUM> may enhance the rigidity of apparatus <NUM>.

In some embodiments apparatus <NUM> and/or the parts thereof comprise a sterilized or sterilisable material. In some embodiments, apparatus <NUM> and/or the parts thereof comprise one or more of medical grade plastic, thermal plastic, stainless steel, metal, a metal alloy (e.g. nitinol or another nickel/titanium alloy), and titanium. Persons skilled in the art will recognize that apparatus <NUM> and/or the parts thereof may be made of any sterilized or sterilisable material conventionally used to manufacture tools used in heart surgery.

In some embodiments, each blade <NUM> is formed from a sterilized or sterilisable memory material, such as a memory metal alloy including (but not limited to) stainless steel and/or nickel and/or titanium and/or nitinol. For example, blades 126d shown in <FIG> are constructed in one-piece from a sterilized or sterilisable memory material, such as a memory metal alloy including (but not limited to) stainless steel and/or nickel and/or titanium and/or nitinol. Blade 126d retains a pre-deformed shape in the expanded position shown in <FIG>. Each blade 126d is deformable into the collapsed position (not shown).

To expand and collapse blade 126d, a proximal end 126e of blade 126d is coupled to distal end 129b (<FIG>) of rod <NUM>. In some embodiments proximal end 126e is pivotally coupled to rod <NUM> by a hinge (not shown), such as a pin, a screw, or another mechanical fastener conventionally known. A distal end 126f of blade 126d is coupled to a proximal end <NUM> of guidewire <NUM>. In some embodiments distal end 126f is pivotally coupled to guidewire <NUM> by a hinge (not shown), such as a pin, a screw, or another mechanical fastener conventionally known.

In a collapsed position (not shown), blade 126d is deformed in a radially compressed state to reduce the cross-sectional area of cutting section <NUM> so that apparatus <NUM> may be inserted percutaneously and traversed intravascularly. To expand cutting section <NUM>, knob <NUM> coupled to rod <NUM> is advanced toward handle <NUM> along an axis B defined by apparatus <NUM> (<FIG>). In this way, rod <NUM> coupled to rod <NUM> longitudinally slides within the lumen (not shown) defined by handle <NUM>, thereby pushing distal end 129b of rod <NUM> toward proximal end <NUM> of guidewire <NUM>. As distal end 129b is advanced toward guidewire <NUM> along axis B, the distance between ends 126e, 126f of blade 126d decreases and blade 126d radially expands away from axis B into its pre-deformed state. In this way, blade 126d is oriented to incise a mitral valve leaflet as described elsewhere herein. To collapse cutting section <NUM>, knob <NUM> is pulled away from handle <NUM> along axis B, drawing distal end 129b of rod <NUM> away from proximal end <NUM> of guidewire <NUM>. As distal end 129b is pulled away from guidewire <NUM> along axis B, the distance between ends 126e, 126f of blade 126d increases, which radially collapses blade 126d towards axis B into its deformed state. In the collapsed position, apparatus <NUM> may be inserted into a catheter (e.g. catheter <NUM>).

In the embodiment illustrated in <FIG>, apparatus <NUM> includes a cutting section <NUM>, a guidewire <NUM> extending away from a distal end of cutting section <NUM>, and a controller (not shown) extending away from a proximal end of cutting section <NUM> opposed to the distal end. Many features and components of the controller are similar to features and components of controller <NUM> described elsewhere herein. In some embodiments the controller includes a handle (not shown) and a knob (not shown). The handle has a lumen (not shown) extending longitudinally therethrough. A rod (not shown) coupled to the knob extends through the lumen and longitudinally slides within the lumen to move the rod and the knob concentrically and/or longitudinally relative to the handle. By longitudinally sliding and/or rotating the knob relative to the handle, apparatus <NUM> may be operated.

Cutting section <NUM> includes one or more radially expandable blades <NUM> for incising a mitral valve leaflet. Each blade <NUM> may be expanded or contracted using the controller. In the embodiment illustrated in <FIG>, cutting section <NUM> includes three radially expandable blades <NUM> configured to incise the mitral valve leaflet with a "T-shaped" incision. The number and configuration of the blades of apparatus <NUM> may be selected to achieve other desired incision patterns as described elsewhere herein. Each blade <NUM> is constructed in one-piece from a sterilized or sterilisable memory material, such as a memory metal alloy including (but not limited to) stainless steel and/or nickel and/or titanium and/or nitinol. Each bade <NUM> retains a pre-deformed shape in the expanded position shown in <FIG> and <FIG>. Each blade <NUM> is deformable into the collapsed position shown in <FIG> and <FIG>. In some other embodiments (not shown) each blade <NUM> may comprise a cutting blade pivotally coupled to a lever arm by a hinge. Such blades are structurally and functionally similar to blades <NUM> of apparatus <NUM>.

To expand and collapse blades <NUM>, cutting section <NUM> includes a runner <NUM>. A proximal end 526a of each blade <NUM> is coupled to runner <NUM>. A distal end 526b of each blade <NUM> is coupled to guidewire <NUM>. Runner <NUM> defines a lumen (not shown) extending longitudinally therethrough. Runner <NUM> is slideably mounted about a rod <NUM>. Rod <NUM> extends from the controller through the lumen of runner <NUM> to permit the runner to slide longitudinally across rod <NUM>. Runner <NUM> is coupled to a distal end 529a of a tube <NUM> for operating cutting section <NUM>. Tube <NUM> is coupled to handle <NUM> of the controller for sliding runner <NUM> along rod <NUM> by pulling or pushing knob <NUM>. Tube <NUM> defines a lumen (not shown) extending longitudinally therethrough. Rod <NUM> extends through the lumen of tube <NUM>.

In some embodiments, apparatus <NUM> includes a joint <NUM> fixedly coupled to a proximal end <NUM> of guidewire <NUM> and a distal end 526b of each cutting blade <NUM> is coupled to joint <NUM>. Runner <NUM> longitudinally slides across rod <NUM> relative to joint <NUM>. Each blade <NUM> is movable from a collapsed position (<FIG> and <FIG>) into a radially expanded position (<FIG> and <FIG>) by pushing tube <NUM> toward joint <NUM> along an axis C defined by apparatus <NUM> (<FIG>). In this way, runner <NUM> slides along rod <NUM> towards joint <NUM>. As runner <NUM> is pushed towards joint <NUM> along axis C, the distance between ends 526a, 526b of blade <NUM> decreases and each blade <NUM> radially expands away from axis C. In this way, blade <NUM> is oriented to incise a mitral valve leaflet as described elsewhere herein. To collapse blade <NUM>, tube <NUM> is pulled away from joint <NUM> along axis C, drawing runner <NUM> away from joint <NUM>. As runner <NUM> is pulled away from joint <NUM> along axis C, the distance between ends 526a, 526b of blade <NUM> increases and each blade <NUM> radially collapses towards axis C. In the collapsed position, apparatus <NUM> may be inserted into a catheter (e.g. catheter <NUM>).

In some embodiments, the cutting section includes one or more blades that are rotatably deformable. For example, apparatus <NUM> shown in <FIG> comprises three rotatably deformable blades <NUM>. In the embodiment illustrated in <FIG>, apparatus <NUM> includes a cutting section <NUM>, a guidewire <NUM> extending away from a distal end of cutting section <NUM>, and a controller (not shown) extending away from a proximal end of cutting section <NUM> opposed to the distal end. Many features and components of the controller are similar to features and components of controller <NUM> described elsewhere herein. In some embodiments the controller includes a handle (not shown) and a knob (not shown). The handle has a lumen (not shown) extending longitudinally therethrough. A rod (not shown) coupled to the knob extends through the lumen and longitudinally slides within the lumen to move the rod and the knob concentrically and/or longitudinally relative to the handle. By longitudinally sliding and/or rotating the knob relative to the handle, apparatus <NUM> may be operated.

Cutting section <NUM> includes one or more radially expandable blades <NUM> for incising a mitral valve leaflet. Each blade <NUM> may be expanded or contracted using the controller. In the embodiment illustrated in <FIG>, cutting section <NUM> includes three radially expandable blades <NUM> configured to incise the mitral valve leaflet with a "T-shaped" incision. The number and configuration of the blades of apparatus <NUM> may be selected to achieve other desired incision patterns as described elsewhere herein. Each blade <NUM> is constructed in one-piece from a sterilized or sterilisable memory material, such as a memory metal alloy including (but not limited to) stainless steel and/or nickel and/or titanium and/or nitinol. Each bade <NUM> retains a pre-deformed shape in the expanded position shown in <FIG>. Each blade <NUM> is deformable into the collapsed position shown in <FIG>.

To expand and collapse blades <NUM>, cutting section <NUM> includes a runner <NUM>. A proximal end 626a of each blade <NUM> is coupled to runner <NUM>. A distal end 626b of each blade <NUM> is coupled to guidewire <NUM>. Runner <NUM> defines a lumen (not shown) extending longitudinally therethrough. Runner <NUM> is rotatably mounted about a rod <NUM>. In some embodiments runner <NUM> is rotatably and slideably mounted to rod <NUM>. Rod <NUM> extends from the controller through the lumen of runner <NUM> to permit the runner to rotate concentrically about rod <NUM> and/or slide longitudinally across rod <NUM>. Runner <NUM> is coupled to a distal end 629a of a tube <NUM> for operating cutting section <NUM>. Tube <NUM> is coupled to handle <NUM> of the controller for sliding runner <NUM> along rod <NUM> by pulling or pushing knob <NUM>. Tube <NUM> defines a lumen (not shown) extending longitudinally therethrough. Rod <NUM> extends through the lumen of tube <NUM>.

In some embodiments, apparatus <NUM> includes a joint <NUM> fixedly coupled to a proximal end <NUM> of guidewire <NUM> and a distal end 626b of each cutting blade <NUM> is coupled to joint <NUM>. In some embodiments runner <NUM> longitudinally slides across rod <NUM> relative to joint <NUM>. Each blade <NUM> is movable from a collapsed position (<FIG>) into a radially expanded position (<FIG>) by rotating runner <NUM> relative to fixed joint <NUM> concentrically in a first direction about an axis D defined by apparatus <NUM> (<FIG>). As tube <NUM> is rotated in the first direction, each blade <NUM> is rotatably deformed about rod <NUM>, reducing the radial cross-sectional area of the cutting section. In the collapsed position, apparatus <NUM> may be inserted into a catheter (e.g. catheter <NUM>).

By rotating tube <NUM> relative to fixed joint <NUM> concentrically in a second direction opposite the first direction about axis D, each blade <NUM> is returned to a pre-deformed state in the expanded position whereby the radial cross-sectional area of the cutting section is greater in the expanded position than in the collapsed position. In this position, blade <NUM> is oriented to incise a mitral valve leaflet as described elsewhere herein. In some embodiments, by pulling tube <NUM> away from fixed joint <NUM> along axis D (with or without rotation in the first direction), the distance between ends 626a, 626b of blade <NUM> increases and each blade <NUM> radially contracts towards axis D. To radially expand blade <NUM>, tube <NUM> is pushed towards fixed joint <NUM> along axis D (with or without rotation in the second direction), drawing runner <NUM> towards joint <NUM>. As runner <NUM> is pushed towards joint <NUM> along axis D, the distance between ends 626a, 626b of blade <NUM> decreases and each blade <NUM> radially expands away from axis D.

Cutting section <NUM> includes one or more radially expandable blades <NUM> for incising a mitral valve leaflet. Each blade <NUM> may be expanded or contracted using the controller. To expand and collapse blades <NUM>, cutting section <NUM> includes a rotator <NUM> housed within a case <NUM>. Case <NUM> comprises at least one slot <NUM>, each slot <NUM> configured to receive a corresponding blade <NUM> therethrough. Each blade <NUM> is expandable and retractable within a corresponding slot <NUM> defined by case <NUM>. In some embodiments rotator <NUM> is coupled to rod <NUM> and rotator <NUM> is actuated by rotating rod <NUM>. In some other embodiments rotator <NUM> extends longitudinally through the controller for actuating cutting section <NUM> by rotating rotator <NUM>.

In the embodiment illustrated in <FIG>, cutting section <NUM> includes three radially expandable blades 726a, 726d, <NUM> configured to incise the mitral valve leaflet with a "T-shaped" incision (<FIG>). The number and configuration of the blades of apparatus <NUM> may be selected to achieve other desired incision patterns as described elsewhere herein. Each blade <NUM> is constructed in one-piece from a sterilized or sterilisable memory material, such as a memory metal alloy including (but not limited to) stainless steel and/or nickel and/or titanium and/or nitinol. Each bade <NUM> retains a pre-deformed shape in the expanded position shown in <FIG>. Each blade <NUM> is deformable into the collapsed position shown in <FIG> by operating rotator <NUM>. In some embodiments one or more blades <NUM> are solid in construction. In some other embodiments one or more blades <NUM> comprise one or more openings (not shown) to permit deformation within case <NUM>, while maintaining a desirable shape and mount of force to incise a heart valve leaflet.

To provide the "T-shaped" incision pattern, a first end 726b of blade 726a is attached to an arm <NUM> coupled to and extending radially away from rotator <NUM>. A first end 726e of blade 726d is attached to arm <NUM> so that ends 726b, 726e are coupled to opposed sides of arm <NUM>. A first end <NUM> of blade <NUM> is coupled to rotator <NUM>. In some embodiments, end <NUM> is coupled to rotator <NUM> at a position that is substantially opposed to arm <NUM> about the diameter of rotator <NUM>. Blades 726a, 726d extend from arm <NUM> and wrap concentrically about an inside surface <NUM> of case <NUM> in a first direction (i.e. in the counter-clockwise direction in <FIG>). Blade <NUM> extends from rotator <NUM> and wraps concentrically about inside surface <NUM> in the first direction. With blades 726a, 726d, <NUM> wrapped concentrically about inside surface <NUM>, cutting section <NUM> of apparatus <NUM> is in a collapsed position (<FIG>).

Cutting section <NUM> is movable from the collapsed position (<FIG>) into a radially expanded position (<FIG>) by rotating rotator <NUM> in the first direction. Ends 726c, 726f, 726i of blades 726a, 726d, <NUM> move concentrically about inside surface <NUM> of case <NUM> in the first direction and advance through slots <NUM>. In some embodiments to provide the "T-shaped" incision pattern, blade 726d comprises a wedge <NUM> coupled adjacent to end 726f. Wedge <NUM> contacts inside surface <NUM> as blade 726d moves concentrically inside case <NUM>. As rotator <NUM> is rotated in the first direction, wedge <NUM> prevents blade 726d from advancing through slot 782a. Wedge <NUM>, however, does not prevent blade 726d from advancing through slot 782d. In this way, blade 726a advances through slot 782a, blade 726d advances through slot 782d, and blade <NUM> advances through slot <NUM> (<FIG>). To retract blade(s) <NUM> back through slot(s) <NUM>, rotator <NUM> is rotated in a second direction (i.e. in the clockwise direction in <FIG>), wrapping each blade <NUM> concentrically about inside surface <NUM> of case <NUM> (<FIG>).

A method for replacing a mitral valve of a heart according to an example embodiment is shown in <FIG> and <FIG>. The features and parts of the heart are similar to features and parts of heart <NUM>, with the same reference numerals being used to indicate features and parts that are similar. The method shown in <FIG> demonstrates the use of apparatus <NUM>. Apparatus <NUM>, <NUM>, <NUM> are deployed similarly as described elsewhere herein.

To replace a mitral valve, apparatus <NUM>, <NUM>, <NUM>, <NUM> is inserted into first access site <NUM> of a subject and advanced using a transcatheter approach conventionally known. Apparatus <NUM>, <NUM>, <NUM>, <NUM> may be inserted using a subaortic introducer. As described elsewhere herein, guidewire <NUM>, <NUM>, <NUM>, <NUM> may define a hook <NUM> at a distal end <NUM> thereof. Distal end <NUM> may be "J-shaped" to avoid damaging heart tissue, while retaining a sharp tip to puncture a heart valve leaflet. The subaortic introducer must maintain guidewire <NUM>, <NUM>, <NUM>, <NUM> in a linear position as apparatus <NUM>, <NUM>, <NUM>, <NUM> is advanced through the subject's circulatory system, but must permit distal end <NUM> of guidewire <NUM>, <NUM>, <NUM>, <NUM> to deform into a J-shaped configuration defining hook <NUM> as guidewire <NUM>, <NUM>, <NUM>, <NUM> exits the subaortic introducer. To do so, the subaortic introducer may comprise a tip constructed from a material that may be stretched and/or torn by applying a force to distal end <NUM> of guidewire <NUM>, <NUM>, <NUM>, <NUM>. In some embodiments, the tip is constructed from a rigid material defining one or more points of weakness to advance guidewire <NUM>, <NUM>, <NUM>, <NUM> therefrom. In some embodiments apparatus <NUM>, <NUM>, <NUM>, <NUM> may be inserted using a conventional subaortic introducer (e.g. subaortic introducer <NUM>) (<FIG> and <FIG>) or other device considered to be within the knowledge of persons skilled in the art of interventional cardiology.

In some embodiments apparatus <NUM>, <NUM>, <NUM>, <NUM> is advanced through introducer <NUM> using an antegrade transcatheter approach. In some other embodiments, apparatus <NUM>, <NUM>, <NUM>, <NUM> is advanced through introducer <NUM> using a retrograde transcatheter approach. Where apparatus <NUM>, <NUM>, <NUM>, <NUM> is introduced into a subject's femoral artery, guidewire <NUM>, <NUM>, <NUM>, <NUM> is advanced through introducer <NUM> intravascularly through the artery and through an aortic valve to retroflex towards a ventricular surface of anterior leaflet <NUM> of mitral valve <NUM> (<FIG> and <FIG>). Guidewire <NUM>, <NUM>, <NUM>, <NUM> is punctured and advanced through the anterior leaflet (<FIG> and <FIG>) at a location determined using conventional Transesophageal Echocardiography (TEE) and/or fluoroscopy techniques. As described elsewhere herein, the location of the guidewire puncture through anterior leaflet <NUM> defines the location through which cutting section <NUM>, <NUM>, <NUM>, <NUM> will be advanced, and so guidewire <NUM>, <NUM>, <NUM>, <NUM> is used to define the location where a transcatheter heart valve prosthesis will ultimately be implanted. In some embodiments the location of the guidewire puncture is selected so that anterior displacement of the anterior leaflet is minimized when a transcatheter heart valve prosthesis is implanted. In this way, LVOT obstruction may be avoided or minimized. In some embodiments the location of the guidewire puncture is along a central axis of the anterior leaflet at a position away from the anterior annulus so that an adequate amount of anterior leaflet tissue is available for hemostatic implantation of a transcatheter heart valve prosthesis within a docking device (not shown) and LVOT obstruction may be avoided or minimized.

In the left atrium, guidewire <NUM>, <NUM>, <NUM>, <NUM> is snared by a snaring guidewire <NUM> as is conventionally known and traversed through the femoral vein to exit the subject's circulatory system at second access site <NUM> (<FIG> and <FIG>). Snaring guidewire <NUM> is introduced into the femoral vein via second access site <NUM> using an antegrade transcatheter approach conventionally known. For example, snaring guidewire <NUM> may be inserted using a conventional transseptal introducer (e.g. transseptal introducer <NUM>) or other device considered to be within the knowledge of persons skilled in the art of interventional cardiology. Snaring guidewire <NUM> is advanced through the femoral vein, through an atrial septum, to a left atrium of the subject's heart. Snaring guidewire <NUM> is positioned to face an atrial surface of anterior mitral valve leaflet <NUM>. Snaring guidewire <NUM> snares distal end <NUM> of guidewire <NUM>, <NUM>, <NUM>, <NUM> and withdraws guidewire <NUM>, <NUM>, <NUM>, <NUM> through the subject's atrial septum. Guidewire <NUM>, <NUM>, <NUM>, <NUM> and snaring guidewire <NUM> exit the subject's circulatory system through second access site <NUM> via the femoral vein. As guidewire <NUM>, <NUM>, <NUM>, <NUM> is withdrawn through second access site <NUM> via the femoral vein, cutting section <NUM>, <NUM>, <NUM>, <NUM> is advanced in a collapsed position through the subject's femoral artery and may be positioned adjacent the ventricular surface of anterior mitral valve leaflet <NUM> (<FIG> and <FIG>). For apparatus <NUM>, <NUM>, <NUM>, <NUM>, guidewire <NUM>, <NUM>, <NUM>, <NUM> is coupled to corresponding cutting section <NUM>, <NUM>, <NUM>, <NUM> and, accordingly, as guidewire <NUM>, <NUM>, <NUM>, <NUM> is withdrawn through second access site <NUM>, corresponding cutting section <NUM>, <NUM>, <NUM>, <NUM> is simultaneously advanced in the collapsed position through the subject's femoral artery and positioned adjacent the ventricular surface of anterior mitral valve leaflet <NUM>.

Before the anterior mitral valve leaflet is incised, a compressed transcatheter heart valve prosthesis <NUM> (conventionally known) and its delivery system <NUM> may be passed over guidewire <NUM>, <NUM>, <NUM>, <NUM> and introduced into the femoral vein via second access site <NUM> to be positioned in the subject's heart (<FIG>). In this way, prosthesis <NUM> is ready to be advanced into a precise implant location closely or immediately following incision of the anterior leaflet by cutting section <NUM>, <NUM>, <NUM>, <NUM> as described elsewhere herein.

As shown in <FIG>, with guidewire <NUM>, <NUM>, <NUM>, <NUM> extending through anterior mitral valve leaflet <NUM>, cutting section <NUM>, <NUM>, <NUM>, <NUM> is advanced in a collapsed position to the ventricular surface of the anterior mitral valve leaflet. With prosthesis <NUM> positioned over guidewire <NUM>, <NUM>, <NUM>, <NUM> inside the left atrium, prosthesis <NUM> is deliverable along guidewire <NUM>, <NUM>, <NUM>, <NUM> to the incision site closely following incision. To incise the anterior leaflet, cutting section <NUM>, <NUM>, <NUM>, <NUM> is deployed into an expanded position as described elsewhere herein and is advanced through the anterior leaflet incising the leaflet (<FIG>, and <FIG>).

After incising anterior mitral valve leaflet <NUM>, cutting section <NUM>, <NUM>, <NUM>, <NUM> is collapsed into the collapsed position and withdrawn through the incision into the left ventricle (<FIG>). Prosthesis <NUM> is then advanced over guidewire <NUM>, <NUM>, <NUM>, <NUM> and positioned within the incision (<FIG> and <FIG>). As shown in <FIG> and <FIG>, closely following incision and after cutting section <NUM>, <NUM>, <NUM>, <NUM> has been withdrawn into the left ventricle, prosthesis <NUM> may be delivered to the incision via guidewire <NUM>, <NUM>, <NUM>, <NUM> and implanted therein. Prosthesis <NUM> is implanted as is conventionally known according to the prosthesis type. With prosthesis <NUM> implanted, apparatus <NUM>, <NUM>, <NUM>, <NUM> may be withdrawn (with cutting section <NUM>, <NUM>, <NUM>, <NUM> in a collapsed position) from the subject through first access site <NUM> via the femoral artery. Prosthesis <NUM> replaces the function of the mitral valve.

The location of the guidewire puncture through the anterior leaflet defines both the incision site (i.e. the location through which cutting section <NUM>, <NUM>, <NUM>, <NUM> is advanced to incise the anterior leaflet) and the implant site (i.e. the location where the valve prosthesis is delivered and implanted in the anterior leaflet). In this way, anterior displacement of the anterior leaflet may be minimized when the valve prosthesis is implanted and LVOT obstruction may be avoided or minimized.

Persons skilled in the art will recognize that the method disclosed may be modified so that apparatus <NUM>, <NUM>, <NUM>, <NUM> is inserted through a first access site and advanced through a subject's femoral vein using an antegrade transcatheter approach conventionally known. Where apparatus <NUM>, <NUM>, <NUM>, <NUM> is introduced into a subject's femoral vein, guidewire <NUM>, <NUM>, <NUM>, <NUM> is advanced through the femoral vein into the left atrium of the subject's heart. Guidewire <NUM>, <NUM>, <NUM>, <NUM> then punctures and is advanced through the anterior leaflet at a precise location as described elsewhere herein. In the left ventricle, guidewire <NUM>, <NUM>, <NUM>, <NUM> is snared by snaring guidewire <NUM> as is conventionally known and is traversed through the femoral artery to exit the subject's circulatory system at the second access site.

Snaring guidewire <NUM> is introduced into the femoral artery via the second access site using a retrograde transcatheter approach conventionally known. Snaring guidewire <NUM> is advanced through the femoral artery, through the aortic valve, and is positioned to face a ventricular surface of the anterior mitral valve leaflet. Snaring guidewire <NUM> snares distal end <NUM> of guidewire <NUM>, <NUM>, <NUM>, <NUM> and withdraws guidewire <NUM>, <NUM>, <NUM>, <NUM> through the subject's aortic valve. Guidewire <NUM>, <NUM>, <NUM>, <NUM> and snaring guidewire <NUM> exit the subject's circulatory system through the second access site via the femoral artery.

Before the anterior mitral valve leaflet is incised, prosthesis <NUM> and its delivery system may be passed over guidewire <NUM>, <NUM>, <NUM>, <NUM> and introduced into the femoral artery via the second access site to be positioned in the subject's heart. Cutting section <NUM>, <NUM>, <NUM>, <NUM> is advanced in a collapsed position to the left atrium surface of the anterior mitral valve leaflet. With prosthesis <NUM> positioned over guidewire <NUM>, <NUM>, <NUM>, <NUM> inside the left ventricle, prosthesis <NUM> is deliverable along guidewire <NUM>, <NUM>, <NUM>, <NUM> to the incision site closely or immediately following incision as described elsewhere herein. To incise the anterior leaflet, cutting section <NUM>, <NUM>, <NUM>, <NUM> is deployed into an expanded position as described elsewhere herein and is advanced through the anterior leaflet incising the leaflet. As cutting section <NUM>, <NUM>, <NUM>, <NUM> is withdrawn, prosthesis <NUM> is advanced over guidewire <NUM>, <NUM>, <NUM>, <NUM> and positioned within the incision as described elsewhere herein. Apparatus <NUM>, <NUM>, <NUM>, <NUM> may then be withdrawn (with cutting section <NUM>, <NUM>, <NUM>, <NUM> in a collapsed position) from the subject through the first access site via the femoral vein.

Each of cutting sections <NUM>, <NUM>, <NUM>, <NUM> and guidewires <NUM>, <NUM>, <NUM>, <NUM> can have various lengths between corresponding proximal and distal ends. The length of apparatus <NUM>, <NUM>, <NUM>, <NUM> is selected to intravascularly traverse a subject's circulatory system from a first access site to a second access site. In some embodiments the length of apparatus <NUM>, <NUM>, <NUM>, <NUM> is selected to intravascularly traverse a subject's circulatory system from a first access site, through the femoral artery, through the aortic valve to the left ventricle, through the mitral valve to the left atrium, and through the femoral vein to a second access site such that the controller (e.g. controller1 <NUM>) and distal end <NUM> of guidewire <NUM>, <NUM>, <NUM>, <NUM> are external to the subject. The relative lengths of cutting section <NUM>, <NUM>, <NUM>, <NUM> and guidewire <NUM>, <NUM>, <NUM>, <NUM> may be selected depending on the identity of the first and second access sites. For example, where apparatus <NUM>, <NUM>, <NUM>, <NUM> is introduced into a subject's circulatory system via the femoral artery, the length of guidewire <NUM>, <NUM>, <NUM>, <NUM> is sufficient to traverse the subject's circulatory system from the anterior leaflet to a femoral vein puncture (i.e. the second access site) and to advance a conventional transcatheter heart valve prosthesis over distal end <NUM> external the subject's body using a conventional transcatheter valve delivery system. The length of cutting section <NUM>, <NUM>, <NUM>, <NUM> is sufficient to traverse the subject's circulatory system from a femoral artery puncture (i.e. the first access site) to the anterior leaflet. Where apparatus <NUM>, <NUM>, <NUM>, <NUM> is introduced into a subject's circulatory system via the femoral vein, the length of guidewire <NUM>, <NUM>, <NUM>, <NUM> is sufficient to traverse the subject's circulatory system from a femoral artery puncture (i.e. the second access site) to the anterior leaflet and to advance a conventional transcatheter heart valve prosthesis over distal end <NUM> external the subject's body using a conventional transcatheter valve delivery system. The length of cutting section <NUM>, <NUM>, <NUM>, <NUM> is sufficient to traverse the subject's circulatory system from the anterior leaflet to a femoral vein puncture (i.e. the second access site). In some embodiments the length of guidewire <NUM>, <NUM>, <NUM>, <NUM> is approximately at least twice the length of a conventional transcatheter valve delivery system. The femoral artery may be favored in some embodiments as the first access site for one or more of its size, ease of insertion, and least tortuous path to the heart.

In some embodiments the methods and apparatus disclosed may include one or more catheters (for example, catheter <NUM> and/or <NUM> (<FIG>)) for advancing apparatus <NUM>, <NUM>, <NUM>, <NUM> through a subject's circulatory system. The catheter may be sized and dimensioned to house apparatus <NUM>, <NUM>, <NUM>, <NUM> and/or parts thereof, and/or snaring guidewire <NUM>, and/or a compressed transcatheter heart valve prosthesis <NUM> and/or its delivery system intravascularly. In some embodiments the methods and apparatus disclosed may include one or more transcatheter valve delivery systems (for example, transcatheter valve delivery system <NUM> (<FIG>, <FIG>, and <FIG>) for advancing transcatheter heart valve prosthesis <NUM> through a subject's circulatory system. The transcatheter valve delivery system may be sized and dimensioned to house prosthesis <NUM> and/or parts thereof intravascularly.

Transcatheter mitral and aortic valve prostheses for use with the methods and apparatus disclosed are conventionally known and include, but are not limited to, apical tethers, annular winglets, native leaflet engagement devices, radial force devices, mitral annulus clamping devices, external anchor devices, and annular docking devices. Other transcatheter mitral and aortic valve prostheses for use with the methods and apparatus disclosed are considered to be within the knowledge of persons skilled in the art of interventional cardiology and cardiac surgery.

Unless the context clearly requires otherwise, throughout the description and the claims:.

Words that indicate directions such as "vertical", "transverse", "horizontal", "upward", "downward", "forward", "backward", "inward", "outward", "vertical", "transverse", "left", "right", "front", "back", "top", "bottom", "below", "above", "under", and the like, used in this description and any accompanying claims (where present), depend on the specific orientation of the apparatus described and illustrated. The subject matter described herein may assume various alternative orientations. Accordingly, these directional terms are not strictly defined and should not be interpreted narrowly.

Claim 1:
An apparatus (<NUM>) for use in mitral valve replacement comprising:
a controller (<NUM>) comprising a handle (<NUM>) having a knob;
a cutting section (<NUM>) comprising:
a tube (<NUM>) coupled to the handle of the controller, the tube defining a lumen extending longitudinally therethrough;
a rod (<NUM>) extending from a distal end of the controller through the lumen of the tube;
a runner (<NUM>) fixedly coupled to a distal end (629a) of the tube, and rotatably and slideably mounted to the rod, the runner defining a lumen extending longitudinally therethrough, wherein the rod extends through the lumen of the runner;
at least one cutting blade (<NUM>) radially expandable about a longitudinal axis of the apparatus between a radially collapsed position for delivering the apparatus to a mitral valve and a radially expanded position for incising a mitral valve leaflet, wherein a proximal end (626a) of each blade is coupled to the runner, and a distal end (626b) of each blade is coupled to a guidewire (<NUM>) extending away from a distal end of the cutting section (<NUM>);
a joint (<NUM>) fixedly coupled to a distal section of the rod and to a proximal end (<NUM>) of the guidewire and to the distal end of each blade,
wherein the tube and/or the runner are rotatable about a longitudinal axis (D) defined by the apparatus;
wherein a rotatable movement of the tube and/or the runner about the longitudinal axis defined by the apparatus and/or a slideable movement of the tube and/or the runner relative to the joint moves the at least one cutting blade between the radially collapsed position and the radially expanded position,
and wherein the distance between the proximal end and the distal end of the at least one cutting blade is greater in the radially collapsed position than in the radially expanded position.