Releasable hanger for heart valve prosthesis low profile holder

A device for engaging a heart valve prosthesis during implantation includes a hanger and a holder. The holder includes a distal engaging surface adapted for engaging the heart valve prosthesis. The hanger is used to suspend the prosthesis in packaging and may be used to manipulate the prosthesis during implantation.

FIELD OF THE INVENTION
 The present invention relates to devices for implanting heart valve
 prostheses. More specifically, the invention relates to a releasable
 hanger for a low profile holder which holds a heart valve prosthesis
 during implantation.
 BACKGROUND OF THE INVENTION
 Holders for holding and supporting heart valve prostheses during shipping
 and implantation are known. They are used for positioning, holding,
 supporting and presenting the valve during surgery. U.S. Pat. No.
 3,828,787, issued Aug. 13, 1974, to Anderson et al., entitled COLLET FOR
 HOLDING HEART VALVE, shows a heart valve holder carried on a distal end of
 an elongated handle. U.S. Pat. No. 4,932,965, issued Jun. 12, 1990, to
 Phillips, entitled ARTIFICIAL VALVE, AND NEEDLE AND SUTURE HOLDER AND
 METHOD OF USING SAME, shows another heart valve holder in which the valve
 is held against distal ends of a pair of elongated legs during
 implantation.
 Traditionally, heart valve replacement surgery is an involved procedure in
 which a sternotomy or thoracotomy is performed and the chest cavity of the
 patient must be widely opened to provide access to the patient's heart.
 This provides a surgeon with direct, unobstructed access to the heart.
 However, this procedure requires a prolonged period to recover from the
 trauma suffered to the upper torso.
 A minimally invasive procedure has been developed wherein open heart
 surgery is performed through small incisions which eliminate the need for
 a lateral sternotomy. This is described in International Publication No.
 WO 94/18881, entitled METHOD FOR PERFORMING THORASCOPIC CARDIAC BYPASS
 PROCEDURES and WO 95/15715, entitled DEVICES AND METHODS FOR INTRACARDIAC
 PROCEDURES. In this procedure, elongated tools are used to operate on the
 heart through the trocars. As discussed in Publication Nos. 94/18881 and
 95/15715, this procedure can be used during heart valve replacement.
 The trocar requires minimal rib spreading and does not involve the
 significant chest trauma associated with traditional open heart surgery.
 One advantage of this procedure is that the recovery period can be reduced
 significantly.
 Heart valve prostheses are typically carried in packaging which are not
 designed for a low profile holder such as those which may be used to
 perform such minimally invasive surgery. For example, the packaging may
 include a collar which is adapted to receive a traditional (non-low
 profile) holder such that the holder and prosthesis are suspended from the
 collar in the packaging. Such a traditional holder may also be used during
 implantation and couples to an elongated handle. Unfortunately, low
 profile holder designs may not be compatible with the packaging used with
 traditional holders. Further, a low profile holder is not adapted for
 prosthesis implantation using traditional techniques.
 SUMMARY OF THE INVENTION
 An apparatus for engaging a heart valve prosthesis during implantation
 includes a hanger and a low profile holder. The low profile holder
 includes a coupling area and a distal engaging surface adapted for
 coupling to the prosthesis. The hanger is adapted for releasably coupling
 to the low profile holder. In one embodiment, the hanger is slidably
 coupled to the holder at a groove defined in the holder. Further, in one
 embodiment the hanger is adapted for suspension in packaging used to
 transport and store the heart valve prosthesis prior to implantation. In
 another embodiment, the hanger may be used in conjunction with the low
 profile holder to perform a traditional (i.e., non-minimally invasive)
 implantation while the low profile holder alone may be employed to perform
 minimally invasive heart valve replacement surgery.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
 The invention relates to a device which is used to position a heart valve
 prosthesis during implantation. The implantation may be through minimally
 invasive surgery, performed through an incision smaller than that which is
 required for a sternotomy or thoracotomy, or using a more traditional
 implantation technique in which the axis of the valve is generally
 parallel with the axis of the handle to which it is attached. For purposes
 of this description of the invention, the device will be described
 generally with regard to its use with a bi-leaflet mechanical heart valve
 which has an annulus with a substantially annular aperture. Such a heart
 valve prosthesis is available from St. Jude Medical, Inc. of St. Paul,
 Minn. However, it will be understood that the invention is applicable to
 other types of heart valves as well.
 The invention provides a hanger and holder for use with a heart valve
 prosthesis. The holder is preferably a low profile holder suitable for
 minimally invasive implantation. The hanger is adapted for suspension from
 packaging such as that used for shipment and storage of the prosthesis.
 The packaging may be of a standard configuration such that the assembly is
 retrofit to function with existing packaging. Further, the hanger may be
 used in conjunction with the holder to perform a traditional
 (non-minimally invasive) implantation in which the prosthesis is moved
 into position in the patient in a direction along the axis of the
 prosthesis. FIG. 1 is a perspective view and FIG. 2 is an exploded
 perspective view, respectively, of an assembly 10 which includes mitral
 heart valve prosthesis 12, heart valve holder 14 and hanger 16 in
 accordance with one embodiment. Valve 12 includes valve orifice 18 having
 leaflet pivot guards 20 and 22 which carry leaflets 24 and 26. A suture
 cuff 28 surrounds the outer radius of orifice 18.
 Holder 14 includes distal surface 30 which provides leaflet conforming
 surfaces 32 and 34 adapted for receiving a proximal side of valve 12. A
 radial lip 36 extends around the outer circumference of distal surface 30
 and conforms to valve orifice 18. Holder 14 includes pivot guard receiving
 portion 40 adapted for receiving pivot guards 20 and 22. Holder proximal
 surface 42 is a planar surface which is substantially parallel with the
 annulus of valve 12 and perpendicular to the axis of the hanger body 88.
 Surface 42 is positioned adjacent pivot guards 20 and 22 to provide an
 overall low profile to holder 14 as viewed from the side. Surface 42
 overlies slot 44 and includes cantilever arm 46 which carries a tab (not
 shown). Surface 42 includes suture holes 50,52 and the outer radius of
 holder 14 includes suture holes 54.
 Hanger 16 includes holder stems 60 and 62 and collar 64 which couples stems
 60 and 62 when hanger 16 is assembled onto holder 14. Tab 66 extends from
 stem 60 throughout the length of hanger body 88 adjacent pivot 68. Stem 62
 includes slot 70 for receiving tab 66 and pivot receptacle 72 for
 receiving pivot 68. Leg 74 of stem 62 fits in slot 45 of holder 14 and
 legs 76 of stem 60 fit in downward extensions 78 of slot 44. Hanger 16 is
 adapted for suspending holder 14 and valve 12 at notch 80 in packaging
 (not shown) during transportation and prior to implantation. Holder 14 is
 removed from hanger 16 by removing collar 64 as shown by arrows 65 from
 stems 60 and 62 such that stems 60 and 62 rotate about pivot 68 as shown
 by the arrows 63 in FIG. 1. Holder 14 is secured to valve 12 by sutures 82
 which extend through holes 50 and 54 of holder 14 and through cuff 28 of
 valve 12.
 During minimally invasive implantation, the surgeon removes assembly 10
 from the packaging (not shown). Hanger 16 is removed from holder 14 by
 removing collar 64 in the direction shown by arrows 65 and squeezing the
 proximal end of hanger 16 together. This causes legs 74, 76 to pivot about
 pivot 68, thereby separating hanger 16 from holder 14. A handle is
 inserted into slot 44 and locked into place by a tab on cantilever 46.
 Leaflets 24 and 26 are protected within orifice 18 during insertion. The
 valve 12 is passed through the chest wall and is secured to the heart
 tissue annulus. After valve 12 is secured to the tissue annulus of the
 heart, holder 14 is then removed by cutting sutures 82 and removing holder
 14 from the patient. Further, assembly 10 may be used for traditional
 implantation through a sternotomy or thoracotomy by using an elongated
 handle (not shown in FIGS. 1 and 2) which couples to hanger 16 at
 receptacle or bore 67 and extends in an axial direction with respect to
 the valve prosthesis.
 FIGS. 3 and 4 show a perspective view and an exploded perspective view,
 respectively, of assembly 100 in accordance with another embodiment.
 Assembly 100 includes holder 102 which couples to valve 12 and is
 supported by hanger 104 in a package (not shown). A distal engaging
 surface 105 of holder 102 is similar to surface 30 shown for holder 14 in
 FIGS. 1 and 2. Holder 102 includes pivot guard receiving portions 106 and
 proximal surface 108. A slot 110 and suture openings 112 extend through
 holder 102 perpendicular to the axis of valve 12.
 Hanger 104 includes suture shoulders 114 and legs 116 having suture
 openings 118. Sutures 120 extend through holes 118 of hanger 104 and
 through holes 112 of holder 102 thereby securing hanger 104 to holder 102.
 Sutures 122 extend through holes 112 of holder 102 and through cuff 28 of
 valve 12 thereby securing holder 102 to valve 12. Hanger 104 includes
 threaded receptacle 124 and notch 126. Notch 126 is used to suspend hanger
 104 from packaging (not shown) during transportation prior to implantation
 of valve 12. Threaded receptacle 124 is optionally used to receive a
 threaded handle 125 to facilitate removal of assembly 100 prior to
 implantation. Handle 125 may also be used in conjunction with assembly 100
 to perform a traditional (non-minimally invasive) implantation.
 Assembly 100 is used in a minimally invasive manner similar to that
 described for assembly 10. The surgeon removes the assembly from the
 packaging (not shown). A handle is inserted into slot 110 of holder 102.
 Alternatively, the handle 125 may be inserted into assembly 100 before
 removing assembly 100 from the package. Sutures 120 are cut such that
 holder 102 may be removed from hanger 104. The minimally invasive
 implantation procedure proceeds as described above. After valve 12 has
 been sutured to the patient's heart, sutures 122 are cut and holder 102 is
 removed.
 FIG. 5 is a perspective partially exploded view of assembly 200 in
 accordance with another embodiment. Assembly 200 is adapted for use with
 aortic heart valve prosthesis 202 and includes holder 204 and hanger 206.
 Aortic valve 202 includes valve orifice 208, cuff 210, leaflets 212 and
 214 protected by leaflet pivot guard 216.
 Hanger 206 includes hanger legs 220 having suture holes 222 to receive
 sutures 224. Hanger 206 includes notch 226 adapted for being held in
 packaging (not shown). A threaded receptacle 227 extends axially into stem
 229 of hanger 206 and is adapted for receiving a handle used to facilitate
 removal of the valve assembly from the package and/or present the valve
 for a traditional valve replacement surgical procedure.
 Holder 204 includes hanger leg receptacles 230 adapted for receiving hanger
 legs 220 of hanger 206. Hanger 206 is attached to holder 204 with sutures
 224 which extend through holes 222 and around holder 204. Holder 204
 attaches to valve 202 with sutures 225, shown in more detail in FIG. 5.
 Holder 204 includes handle receptacle 240 which includes recessed area 242
 and cantilever 244 which carries tab 246. Holder 204 is attached to valve
 202 by passing a suture 225 through cuff 210. One portion of suture 225
 lies within groove 250 and the other portion of suture 225 lies on holder
 proximal surface 205. The ends of suture 225 are then wrapped around
 protrusion (not shown) within groove 250 and knotted. The recessed suture
 opening reduces the likelihood that both ends of suture 225 projecting
 from cuff 210 are unintentionally severed by the surgeon, thus reducing
 the possibility of a portion of suture 225 being inadvertently left within
 the patient's body.
 FIG. 6 is a plan view of hanger 366 adapted for carrying holder 300, or one
 or more of the holder embodiments shown herein. For illustrative purposes,
 valve 202 is shown in cross section. Hanger 366 includes notches 368
 adapted for attachment to packaging (not shown), release points 370, pivot
 372 and legs 374. Each leg 374 includes tab 376 at its distal end which is
 adapted to be received in openings 378 of holder 300. Application of
 pressure to points 370 in the direction shown by the arrows causes legs
 374 to spread apart outwardly thereby releasing tabs 376 from openings 378
 in holder 300. In one embodiment, a locking member, such as a bar
 extending between points 370, prevents holder 300 from inadvertently being
 released from hanger 366 by application of pressure to points 370. Such a
 locking member can be removed or cut at the appropriate time to allow
 release of holder 300.
 FIGS. 7A through 7E show an assembly 400 for supporting a mitral heart
 valve prosthesis (not shown in FIGS. 7A-7E) in accordance with another
 embodiment. FIG. 7A is an exploded top perspective view of hanger 402 and
 holder 404 of assembly 400. FIG. 7B is a top perspective view of hanger
 402 coupled to holder 404. FIG. 7C is a bottom perspective view of
 assembly 400 showing hanger 402 partially attached to holder 404. FIG. 7D
 is a top perspective exploded view of assembly 400. FIG. 7E is a
 cross-sectional view of assembly 400 taken along line 7E--7E shown in FIG.
 7B.
 Referring to FIGS. 7A-7E, hanger 402 includes elongated stem 406 which
 extends in an axial direction relative to the valve prosthesis and
 includes head portion 408 having finger grip surfaces 410 formed therein,
 and is used for coupling hanger 402 to packaging. A handle receiving bore
 414 is formed in stem 406 and includes slot 416 formed therethrough.
 Hanger 402 includes legs 420 which carry leg extensions 422. Leg
 extensions 422 extend inward from legs 420 in a direction generally
 perpendicular to the axis of stem 406. As shown in the cross-sectional
 view of FIG. 7E, a cantilever 424 includes tab 426 and couples to stem 406
 at attachment point 428.
 Holder 404 includes distal engaging surface 450 adapted for engaging a
 heart valve prosthesis as shown and described above for the other
 embodiments. It will be understood by those skilled in the art that
 engaging surface 450 may be modified for us an aortic heart valve
 prosthesis. Holder 404 includes suture guide grooves 452, suture guide
 grooves 454 and suture holes 456 for receiving a suture, such as sutures
 458 (shown in FIG. 7B) to thereby couple holder 404 to a heart valve
 prosthesis. Suture cutting grooves 460 are formed in a proximal surface of
 holder 404 and expose suture 458, thereby allowing suture 458 to be cut
 with a scalpel, for example, to release the prosthesis from holder 404.
 Side surfaces of holder 404 include grooves 462 formed therein which are
 adapted to slidably receive leg extensions 422. The proximal surface of
 holder 404 also includes tab stops 464 which receive and abut tab 426 as
 shown in FIG. 7E to thereby lock hanger 402 to holder 404. A handle
 receiving slot 466 is formed in holder 404 under tab stops 464. Suture
 holes 456 are also adapted to receive sutures 470 shown in FIG. 7C which
 extend through suture slots 472 formed in the distal surface 450 of holder
 404. Sutures 470 are used to maintain the leaflets of the valve in a
 substantially closed position during implantation, and may be used to
 couple holder 404 to the valve prosthesis. Alternative suture 458 and
 sutures 472 may be the same suture.
 As illustrated in FIGS. 7A-7E, hanger 402 is releasably coupled to holder
 404. Specifically, leg extensions 422 are slidably received in grooves
 462. When leg extensions 422 are slid completely into grooves 462, tab 426
 is urged downward by cantilever 424 and into abutting contact with tab
 stop 464 as cantilever 424 bends or deflects on joint 428. In this
 position, hanger 402 is secured to holder 404.
 Hanger 402 is adapted for traditional (i.e. non-minimally invasive)
 implantation using, for example, an elongated handle 480 having a shaft
 482 and radially extending keys 484 as shown in FIG. 7A. Shaft 482 is
 adapted for insertion into bore 414 and keys 484 are received in slot 416.
 A surgeon may use handle 480 to manipulate the heart valve prosthesis
 during implantation as the prosthesis is moved in a direction generally
 along the axis of the prosthesis and into the patient. Further, torque may
 be transmitted from handle 480 to hanger 402 using keys 484 and groove 416
 such that the prosthesis may be rotated during the implantation procedure.
 Additionally, finger grip surfaces 410 may be used by the surgeon to
 rotate the prosthesis. In the event of a minimally invasive procedure, the
 handle attached through slot 466 may be used to manipulate and rotate the
 prosthesis.
 Holder 404 may be removed from hanger 402 by disengaging tab 426 from tab
 stop 464 and slidably removing leg extensions 422 from grooves 462. Slot
 466 in holder 404 may receive an elongated handle which extends generally
 parallel to a plane of the prosthesis such that holder 404 may be used for
 a minimally invasive implantation procedure.
 FIG. 8 is a perspective view of a distal end 500 of one such handle. Distal
 end 500 includes body portion 502 adapted for being received in slot 466
 of holder 404. Distal end 500 includes spring loaded member 504 which is
 pivotally coupled to axis 506 by spring 508. Spring loaded member 504
 provides an engagement mechanism to couple distal end 500 to holder 404 at
 slot 466. As distal end 500 is inserted into slot 466, edge 501 contacts
 tab 426 along inclined surface 427 forcing cantilever 424 upward and
 causing tab 426 to disengage tab stops 464, thereby releasing hanger 402
 from holder 404. Thus, it will be apparent that assembly 400 may be used
 in either a traditional implantation procedure or a minimally invasive
 procedure.
 FIGS. 9A and 9B are perspective views of an assembly 400A in accordance
 with another embodiment. Assembly 400A is similar to assembly 400 as shown
 in FIGS. 7A-7E except that hanger 402A is removed from holder 404A by
 rotating hanger 402A relative to holder 404A. Holder 404A includes
 chamfered walls 490A which define grooves 462A. Grooves 462A are ramped
 and have a detent such that leg extensions 422A follow the ramp and snap
 into the detent. FIG. 9A shows hanger 402A attached to holder 404A. FIG.
 9B is an exploded view showing hanger 402A spaced apart from holder 404A.
 Arrows 492A in FIG. 9B show the direction hanger 402A is rotated relative
 to holder 404A to attach hanger 402A to holder 404A. Similar to the other
 embodiments described above, assembly 400A can be used for either a
 traditional implantation through a sternotomy or thoracotomy or a
 minimally invasive implantation.
 The above embodiments set forth in FIGS. 7 and 9 have described packaging
 from which the hanger may be suspended. FIG. 10 is a top plan view of a
 container top 520 which includes collar 522 formed therein which provides
 post opening 524. Collar 522 includes hanger receiving opening 526. Head
 portion 408 is secured in opening 524. Container top 520 is held in a
 sealed container (not shown). Thus, the hanger/holder/prosthesis assembly
 may be suspended from container top 520. Additionally, if minimally
 invasive implantation is to be performed, the holder and prosthesis can be
 removed from container top 520 while the hanger 402 remains suspended in
 collar 522.
 In general, the materials used herein are materials suited for the
 biomedical industry. For example, the holder can be made of a polymer such
 as polyphenylsulfone, known under the trade name of Radel.RTM., or other
 similar biocompatible durable material, and is suitable for forming by
 injection molding or other manufacturing methods. Typical materials for
 the handle include stainless steel, or other biocompatible metals or
 polymers. Additionally, all designs tend to allow easy attachment of the
 handle to the holder during surgery while maintaining the sterile
 condition of the pieces. Injection molding techniques are well suited for
 fabricating the low profile holder set forth herein. A suitable distance
 between a leaflet and a leaflet engaging surface is maintained so as to
 not apply pressure to the leaflets during transportation or use of the
 valve while attached to the low profile holder. This stabilizes the
 leaflet without substantial contact to the leaflet which could damage the
 leaflet. Additional soft padding material may be carried on the leaflet
 engaging surface. Furthermore, the holder set forth herein provides a
 pivot guard to prevent the handle from contacting the valve during use.
 The hanger and holder of the invention allow the low profile holder to
 couple to existing packaging. Further, the hanger may remain coupled to
 the holder such that the assembly may be used in a traditional
 (non-minimally invasive) implantation procedure. Further, "coupling area"
 is hereby defined as any area of the holder which is used to couple the
 holder to the hanger. The various holders and hangers may be used with
 either aortic or mitral valves. All hangers shown herein may be used with
 the packaging of FIG. 10, or with other appropriate packaging with minor
 modifications.
 The invention as set forth herein securely attaches the holder to the valve
 and the holder to the handle or hanger as one integral piece. The low
 profile design allows easy and safe manipulation of the valve in a
 surgical environment and during implantation. Easy engagement (and
 disengagement) of the holder and handle assembly is provided which has
 advantages including speed, ease of use, safety and effectiveness in a
 surgical environment. The integral packaging allows the entire assembly to
 be sterilized as a unit. The various elements are provided for easy
 manufacture using injection molding techniques. Protection of the leaflets
 within the valve orifice is maintained and the low profile allows
 minimally invasive surgical techniques. Further, those skilled in the art
 will recognize that the invention may be used with a type of handle or
 handles with simple modifications. The invention is in no way limited to
 the particular handles or configurations set forth herein.
 Although the present invention has been described with reference to
 preferred embodiments, workers skilled in the art will recognize that
 changes may be made in form and detail without departing from the spirit
 and scope of the invention, including use of the hanger with holders for
 bioprosthetic valves and annuloplasty rings.