Patent Description:
The use of surgically implanted mechanical heart valves has become widespread throughout the world and even routine in many countries. There are a variety of mechanical heart valves that have become well-accepted for use in the United States, Europe and Japan as well as in other countries throughout the world, one of which is sold as the On-X heart valve by Medical Carbon Research Institute, LLC, the assignee of this application. This mechanical heart valve prosthesis is shown in <CIT>, <CIT>, <CIT> and <CIT>, for example.

Special tools have been developed to assist in the implantation of mechanical heart valves of this general type. It is important that an effective tool should be capable of holding the valve and facilitating its manipulation at the implantation site in order to properly position it.

Shown in <FIG> is a prior art valve holder <NUM> of the type often used for implanting a mechanical heart valve in <NUM> and earlier. The valve holder <NUM> consists of two parts which are generally symmetrical to one another, a first or front part <NUM> and a second or back part <NUM>. The prior art valve holder <NUM> is illustrated in <FIG> in an open condition. The two main body parts of the holder are hinged in some fashion, as example, by a pin <NUM> or by a living hinge. Two legs <NUM> and <NUM> are configured to press outward against an inside wall of an annular valve body when front and rear upper shaft sections <NUM>, <NUM>, respectively, are held together, which is often accomplished by a knotting a flexible tie. The front upper section <NUM> also has a longitudinal slot <NUM> which aids in cutting the tie, and it may have a transverse bore through which the tie is threaded and knotted so it remains associated with the inserter and is removed with it following implantation. The distal end of a handle (not shown) is usually received in a cavity or receptacle <NUM> formed in a cap portion <NUM> that surmounts the front part <NUM> of the holder, and the handle is secured in a conventional manner.

Reference is also made to the above-described inserter in <CIT> entitled "Heart Valve Holder-Rotator". This patent illustrates and describes a similar inserter where the main body of the holder is formed with a pair of opposed hinged side sections which have depending legs that move toward and away from each other in a manner similar to the two hinged parts described above, but both legs pivot with respect to a central portion of the body. Another heart valve holder of this general type is shown in <CIT>.

Whereas these heart valve holders do securely engage a heart valve prosthesis so as to allow it to be positioned and rotated, oftentimes it is difficult to facilitate the passage of the leading end of the heart valve prosthesis through the annulus in the heart of the patient where the damaged natural valve leaflets were excised. It has been found that this may be a particular problem during the aortic valve replacement when the surgeon must work through the immediately upstream portion of the aorta. Accordingly, improvements in these tools for handling and implanting heart valves have been sought.

<CIT> discloses devices and methods for the treatment of cardiac valves, but fails to disclose the guide members sloping from their tips outward to about a diameter of the valve leading portion.

<CIT> and <CIT> were also cited by the EPO during prosecution.

According to the present invention, there is provided a device for inserting a prosthetic heart valve into an annulus of the heart of a patient, which device comprises a main body proportioned for releasable engagement with a prosthetic valve, said main body having means for connection to a handle for moving and positioning the main and the valve engaged therewith and said main body also having two sloping guide members extending longitudinally from said main body in a direction generally opposite that in which said handle extends, which guide members have tips which are diametrically spaced apart a distance less than a corresponding dimension of a leading portion of a heart valve that would be releasably carried thereon, with outward-facing surfaces of said guide members sloping from said tips outward to about a diameter of the valve leading portion, whereby passage of the leading portion of the valve prosthesis into an annulus, from which the patient's defective valve leaflets have been excised, is facilitated. This design allows the heart valve carried by the holder to be smoothly inserted into the annulus and spread the tissue orifice to facilitate passage therethrough of the leading portion of the heart valve by engaging the tissue over a substantial area and slowly forcing it outward. The holder- inserter is found to be particularly advantageous in inserting an aortic valve, and even more advantageous in inserting an aortic valve having the construction shown in the aforementioned '<NUM> patent where the entrance into the valve body flares outward, thus presenting a rim having an exterior concave, toroidal surface which is designed to seat against the inward facing surface of the heart tissue annulus.

To enable a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:.

The invention provides a device <NUM> which serves as a holder- inserter for implanting a mechanical heart valve prosthesis in an annulus in the human heart. The principles embodied in the device <NUM> are effective in creating a useful holder- inserter suited for implanting a wide variety of mechanical heart valves, particularly bileaflet heart valves; however, the preferred embodiment of the device that is shown in the drawings is proportioned and shaped to facilitate the implantation of the On-X heart valve <NUM>, a cross-sectional view of which is illustrated in <FIG>. This valve <NUM> employs a pair of leaflets <NUM> that are pivotally mounted on a valve body or orifice ring <NUM>, as described in detail in the earlier mentioned US patents, which valve body <NUM> has an outwardly flaring entrance end <NUM>. The illustrated valve <NUM> is designed to be inserted as an aortic valve replacement where it will be positioned so that the concave, generally toroidal exterior surface of the curved entrance end <NUM> lies in contact with the tissue annulus from which leaflets of the defective natural valve were excised. The implanted prosthesis is secured in place by suturing through a sewing ring <NUM> which is affixed to a
central exterior region of the valve body <NUM>, with sutures being secured by pledgets which are positioned on the heart side of the annulus, i.e. facing the left ventricle of the heart.

The holder-inserter device <NUM> has a main body <NUM> which comprises two hinged parts that are movable relative to each other. These are arbitrarily referred to as a front part <NUM> and a rear part <NUM>. The body can be made of any acceptable material as well known in this art, but will usually be molded from polymeric material capable of being sterilized, such as nylon, Teflon, Delrin or polysulfone. The two parts <NUM>, <NUM> may be molded separately and suitably joined at a pivot or hinge point therebetween. Alternatively they may be molded as a single integral piece being interconnected by a living hinge. The front or left hand part <NUM> (as oriented in <FIG>) is formed with an upper section <NUM> and a depending leg <NUM>. The rear or right hand part <NUM> is formed with an upper section <NUM> and a depending leg <NUM>. The two legs <NUM> and <NUM> have the same construction, being mirror images of each other; the recessed upper portions of the legs constitute a groove proportioned to receive valve body <NUM> to be carried thereupon.

The main body <NUM> is molded as two separate pieces with a hinge point therebetween which is established in any suitable manner. For example, a separate hinge pin can be seated in bores provided in both parts <NUM>, <NUM>, or short stub pivots can be seated in receptacles molded in the mating part. The two parts will pivot between their engaging orientation (as illustrated in <FIG> and <FIG>) and a release orientation ( such as that shown in the <FIG>) wherein one leg <NUM> has swung closer to the other leg <NUM> so as to release a mechanical heart valve with which it was earlier engaged.

The heart valve holder-inserter <NUM> generally resembles the prior art device depicted in <FIG> except for the incorporation of a pair of sloping guide members <NUM>, <NUM> which are respectively located at the lower ends of the legs <NUM>, <NUM> and formed integrally therewith. Each guide member has a transverse surface or a flange <NUM> formed at its upper end against which the leading edge <NUM> of the mechanical heart valve seats; this engagement secures the valve in place on the holder-inserter <NUM> when the two body parts <NUM>, <NUM> are in the engaging orientation, as depicted in <FIG> and <FIG>, for example.

The guide member <NUM> is formed with a sloping exterior surface <NUM> that smoothly extends from the outer edge of the flange <NUM> down to a tip <NUM>. When the two legs <NUM>, <NUM> are in their engaging position, the outer edge of the transverse surface <NUM> lies close to the outer edge of the rim <NUM> of the heart valve, as best seen perhaps in <FIG> where the inserter <NUM> is illustrated with a heart valve <NUM> engaged thereon. The longitudinally sloping surface <NUM> extends smoothly over the entire distance from the edge of the ledge to the lower or bottom tip <NUM>, which is described as being a continuous curve, i.e. having no reentrant section. In <FIG>, the outer edges of the tips <NUM> are spaced apart at their greatest distance, a distance which is substantially less than the diameter of the rim <NUM> of the heart valve at its leading edge, preferably a distance between about <NUM>% and <NUM>% of the diameter of the rim and more preferably between about <NUM>% and <NUM>% of the diameter of the rim. Preferably these outer edges are arcs which lie on a circle which has its center on the longitudinal axis of the inserter <NUM>; however, such is not a requirement as explained hereinafter.

Basically the exterior surface of the guide members <NUM>, <NUM> may be any surface curved in a plane perpendicular to longitudinal axis. It is preferably curved both in the plane perpendicular to the longitudinal axis of the heart valve inserter and in the plane parallel to the longitudinal axis, as is depicted in <FIG> and <FIG>; however it may be curved only in the plane perpendicular to longitudinal axis, as shown in <FIG> where the surface <NUM> is a section of a cone. The exterior surfaces <NUM>, which are preferably double-curved as illustrated in <FIG>, are more preferably sections of a surface of revolution. They may be sections of a sphere or of an ovoid or any generally similar shape which might be referred to as spheroidal or ovoidal. By ovoidal is meant ellipsoidal, paraboloidal or the like, with ellipsoidal being most preferred. Although from the standpoint of symmetry it is preferable that both guide members <NUM> and <NUM> have surfaces <NUM> which are sections of the same surface of revolution, it should be understood that the guide members, when they are in the ultimate engaging orientation shown in <FIG>, may not lie precisely on the same surface of revolution because their orientation may be somewhat askew with regard to each other, e.g. because of tolerances or other such factors.

As best seen in <FIG>, at the upper ends of the guide members where the flanges <NUM> are located, their circular outer edges should subtend an arc of at least about <NUM>° and more preferably an arc between about <NUM>° and about <NUM>°. The upper size limitation on the arc is determined by the amount of clearance which exists in the heart valve to be implanted, because as apparent from <FIG>, the guide members need to pass between the leaflets <NUM> and the interior wall of the valve body <NUM>. An arc of at least about <NUM>° at the upper regions is felt to be sufficient to adequately spread the tissue orifice to facilitate the easy entry of the valve into position. Hollows <NUM> in the interior surfaces (<FIG>) also provide clearance for the leaflets.

Side edge surfaces <NUM> of the guide members <NUM>, <NUM>, as best seen in <FIG> and <FIG>, are not longitudinal but are canted; they are preferably canted at a slight angle of at least about <NUM>° and preferably at least about <NUM>°. Thus, as can be seen from <FIG>, although the respective side surfaces <NUM> of the guide members <NUM>, <NUM> are co-planar, they do not lie in a plane parallel to the longitudinal axis, but they are offset so that there is a taper towards the longitudinal axis as these side surfaces extend toward the tips of the guide members. The flanking side edge surfaces of the guide members (which are identified in <FIG> by the reference numeral <NUM>) more easily enter the annulus because of this about <NUM>°-<NUM>° offset; moreover, these surfaces <NUM> exert an outward camming action with regard to both the tissue and any pledglets being used to retain sutures on the heart side of the orifice when the holder-inserter carrying the heart valve is rotated after it has been inserted sufficiently into the excised orifice so that the guide members are in contact with the tissue.

The longitudinal length of the guide members is also considered to be important so that further insertion of the guide members, after contact with the tissue is made, exerts a relatively slow and smooth outward deflection of the tissue. In this respect, it is preferred that the longitudinal length of the guide members, i.e., the distance A in <FIG>, should be between about <NUM>% and about <NUM>% of the diameter of the leading portion of the valve body, more preferably between about <NUM>% and about <NUM>% of the diameter of the valve body circular rim. The longer the length of the guide member, the more gradual may be the radius of curvature of the exterior surfaces which in turn results in a smoother spreading of the annulus. When the valve is close to being in its fully inserted position, it is normal that the inserter be rotated, and it is during this rotation that the side edge surfaces <NUM> cam outward regions of the tissue annulus that were not initially in contact with a guide member exterior surface.

It can also be seen from <FIG> that the edge from one corner C (<FIG> and <FIG>) of a tip to the opposite corner C would be an arc of slightly less than the arc at the upper edge of the surface at the edge of the flange <NUM> as a result of the canting of the side surfaces <NUM>. Moreover, to avoid a sharp edge at the distal end, the tip ends of the guide members are flattened creating narrow flat surfaces <NUM>. The interior surfaces of the guide members, which are recessed to provide the hollows <NUM> facing each other, further avoid interference with the leaflets of the bileaflet valve.

When the holder-inserter <NUM> is in engagement orientation with a bileaflet heart valve <NUM>, as depicted in <FIG>, the upper sections <NUM> and <NUM> of the two main body parts have been pivoted into abutting engagement with each other. The upper sections include an annular groove <NUM> about the periphery wherein a flexible tensile member <NUM> is routed and tied to lock them in this abutting position. The tensile member <NUM>, usually a short length of suture cord, is preferably threaded through a transverse bore <NUM> in the upper section <NUM> and knotted. <FIG> shows a longitudinally extending slot <NUM> which facilitates the surgeon cutting the tensile member <NUM> to release the engagement and permit the removal of the holder-inserter after the heart valve <NUM> has been implanted and at least preliminarily sutured into the desired orientation in the wall of the heart.

The front portion <NUM> of the main body also includes a cap section <NUM> wherein a top cavity <NUM> is formed that may extend completely through the body (as indicated in <FIG>). The upper end of the cavity <NUM> is shaped so as to interengage with a cooperating member formed at the distal end of a handle (not shown) as well known in this art. The holder-inserter <NUM> is designed such that it would be commonly packaged together with the heart valve and sterilized prior to shipment to a hospital or other facility. When ready for use, the package would be opened in the operating room, and a sterilized handle would be mated with the assembly via the cavity <NUM> at the upper end of the holder-inserter once the operation is ready to begin, or later when the surgeon has selected the precise size of heart valve to be implanted. During shipment, the assembly is stably supported in packaging by a C-shaped clip that is received in the pair of side slots <NUM> provided in the main body, as best seen in perhaps <FIG> and as generally known in this art.

After the leaflets of the defective natural valve have been excised by operating through the aorta, sutures are placed about the annulus, sometimes with supporting pledglets disposed on the left ventricle side of the annulus, and spaced around the circumference thereof. The surgeon would then insert the holder-inserter <NUM> with the engaged valve <NUM> so that the guide members <NUM>, <NUM> extend through the annulus. This insertion movement causes the sloping surfaces <NUM> to engage the edge of the tissue annulus, causing it to be smoothly and slowly expanded outward and guiding entry of the leading edge of the valve body into the orifice. The surgeon then rotates the device to smoothly spread the remaining circumference of the tissue annulus outward in arcuate locations where it was not initially in contact, to align the bileaflet valve as desired with respect to the left ventricle. The rotation causes the side edges surfaces <NUM> not only to cam the tissue outward, but also to engage edges of any pledglets that might be located there to displace them so they will not possibly lie between the valve body exterior surface and the raw edge of the tissue. An appropriate corner blend (not shown) between the surfaces <NUM> and <NUM> is preferably included to facilitate this displacement. As a result, the engaged heart valve <NUM> is moved smoothly into its desired orientation with the raw edge of the tissue annulus lying in abutment against the concave, generally toroidal exterior surface of the leading edge <NUM> of the heart valve <NUM>. At this time, the surgeon sutures the valve at least partially in place using curved suture needles which are passed through the sewing ring <NUM> and then tied off, as well known in this art. The surgeon can then cut the tensile member <NUM> where it passes over the cutting slot <NUM> so as to release the engagement at the upper end of the main body; this allows the leg <NUM> at the bottom of the rear part <NUM> to pivot freely and disengage from its contact with the interior surface of the valve body. Slight movement of the inserter to the right in <FIG> disengages the leg <NUM> from its contact; this allows the holder-inserter to be withdrawn straight away, carrying with it the cut flexible member <NUM> which is retained in the transverse bore <NUM> in the cap section.

Depicted in <FIG> is an alternative embodiment of a holder-inserter wherein, instead of using guide members that have the double curved exterior surfaces, smooth sloping surfaces are provided by forming each of the guide members <NUM> with surface <NUM> which is a section of a cone. Except for this change, the guide members <NUM> resemble the guide members <NUM>, <NUM> previously described. They have similar flat bottom tips <NUM> which have outer edges that are similarly spaced apart and oriented as described above.

Illustrated in <FIG> is an alternative embodiment of a holder-inserter <NUM> which is designed to support a different mechanical heart valve; it is shown as carrying a mechanical heart valve of the general type as has been sold for several decades by St. Jude Medical, Inc. The components of the holder-inserter <NUM> are given reference numerals the same as the holder-inserter <NUM> plus <NUM>. Accordingly, it should be understood that statements made earlier with respect to such a corresponding part are equally applicable to the part bearing the corresponding reference numeral in <FIG>.

This alternative embodiment of the device <NUM> that is shown is proportioned and shaped to facilitate the implantation of a mechanical heart valve <NUM>, similar to that which is marketed by St. Jude Medical, Inc. and shown in <CIT>. This valve <NUM> likewise employs a pair of leaflets <NUM> that are pivotally mounted on a valve body or orifice ring <NUM>. The illustrated valve <NUM> is designed to be inserted as an aortic valve replacement where it will be positioned so that a pair of semicircular extensions <NUM> at its entrance end protrude toward the left ventricle in the annulus from which leaflets of the defective natural valve were excised. The implanted prosthesis is secured in place by suturing through a sewing ring <NUM> which is affixed to a central exterior region of the valve body <NUM>, with sutures being secured by pledgets which are positioned on the heart side of the annulus, i.e. facing the left ventricle of the heart.

The holder-inserter device <NUM> has a main body <NUM> which comprises two hinged, relatively movable parts, a front part <NUM> and a rear part <NUM>. The front or left hand part <NUM> (as oriented in <FIG>) is formed with an upper section <NUM> and a depending leg <NUM>. The rear or right hand part <NUM> is formed with an upper section <NUM> and a depending leg <NUM>. The two legs <NUM> and <NUM> have the same construction, being mirror images of each other, with a pair of integral, sloping guide members <NUM>, <NUM> being located at their lower ends. Each guide member has a transverse surface or a flange <NUM> formed at its upper end against which the entrance end <NUM> of the valve seats, in the groove provided in the legs <NUM>, <NUM>; this end is the leading edge of the heart valve during implantation from the aorta. Engagement in the groove secures the valve in place on the holder-inserter <NUM> when the two body parts <NUM>, <NUM> are in the engaging orientation, as depicted in the drawings.

A sloping exterior surface <NUM> of the guide member <NUM> smoothly extends from the outer edge of the flange <NUM> down to a tip <NUM>. When the two legs <NUM>, <NUM> are in their engaging position, the outer edge of the transverse surface <NUM> lies close to the outer edge of the rim of the heart valve entrance end <NUM>. The longitudinally sloping surface <NUM> extends smoothly as a continuous curve over the entire distance from the edge of the ledge to the lower or bottom tip <NUM>. As best seen in <FIG>, the outer edges of the tips <NUM> are again spaced apart at a distance which is substantially less than the outer diameter of the rim <NUM> of the heart valve.

The upper ends of the guide members where the flanges <NUM> are located have circular outer edges that again each subtend an arc of about <NUM>° and about <NUM>°. Hollows <NUM> in the interior surfaces also provide clearance for the leaflets.

Side edge surfaces <NUM> of the guide members <NUM>, <NUM> are again preferably canted at a slight angle of at least about <NUM>° and preferably at least about <NUM>°. Again, the preferred longitudinal length of the guide members, i.e., the distance B in <FIG>, should be between about <NUM>% and about <NUM>% of the diameter of the leading edge of the valve body <NUM>, more preferably between about <NUM>% and about <NUM>% of the diameter of the outer circular rim surface of the valve body <NUM>.

The remainder of the construction of the holder-inserter <NUM>, primarily the upper portion thereof, is the same as that hereinbefore described for the holder-inserter <NUM>. The bileaflet heart valve <NUM> would be installed and released in the manner described hereinbefore. Similarly, the surgeon would insert the holder-inserter <NUM> with the valve <NUM> carried thereon so that the sloping guide members <NUM>, <NUM> extend through the annulus from which the defective leaflets of the natural valve have been excised. Again, the sloping surfaces <NUM> would cause the edges of the tissue annulus to be smoothly and slowly expanded outward, guiding the entry of the leading edge of the valve body <NUM> into the orifice. Then, the surgeon would rotate the device to smoothly spread the remaining circumference of the tissue annulus outward, and to align the bileaflet valve as desired with respect to the left ventricle. Once the desired, correct orientation has been attained, the surgeon would suture the valve at least partially in place and then, as earlier described, cut a tensile member to release the engagement at the upper end of the main body of the two portions of the holder- inserter, allowing the leg <NUM> at the bottom of the rear part <NUM> to pivot freely and disengage so that the holder- inserter <NUM> can be withdrawn straightaway.

Claim 1:
A device (<NUM>, <NUM>) for inserting a mechanical, surgically implantable prosthetic heart valve into an annulus of a heart of a patient, which device comprises:
a main body (<NUM>, <NUM>) proportioned for releasable engagement with the valve,
said main body having means (<NUM>) for connection to a handle for moving and positioning the main body and the valve engaged therewith; and
said main body also having two sloping guide members (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) extending longitudinally from said main body in a distal direction generally opposite that in which said handle extends, which guide members have tips (<NUM>, <NUM>) which are diametrically spaced apart a distance less than a diameter of an outer edge of a distal rim of the valve that would be releasably carried thereon, with outward-facing surfaces (<NUM>, <NUM>, <NUM>) of said guide members sloping from said tips outward to about the diameter of the outer edge of the distal rim, whereby passage of the outer edge of distal rim into an annulus, from which the patient's defective valve leaflets have been excised, is facilitated,
wherein said main body has a longitudinal axis that substantially coincides with a longitudinal axis of the valve and wherein said outward-facing surfaces (<NUM>, <NUM>, <NUM>) are smoothly curved in a plane perpendicular to said longitudinal axis, and
wherein said guide member outward-facing surfaces (<NUM>, <NUM>) are also curved in a plane parallel to said longitudinal axis, and are sections of a surface of revolution, such as a sphere, an ovoid, or an ellipsoid.