US20030199974A1 - Annuloplasty apparatus and methods - Google Patents

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Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/24—Heart valves ; Vascular valves, e.g. venous valves; Heart implants, e.g. passive devices for improving the function of the native valve or the heart muscle; Transmyocardial revascularisation [TMR] devices; Valves implantable in the body
  • A61F2/2442—Annuloplasty rings or inserts for correcting the valve shape; Implants for improving the function of a native heart valve
  • A61F2/2451—Inserts in the coronary sinus for correcting the valve shape
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/24—Heart valves ; Vascular valves, e.g. venous valves; Heart implants, e.g. passive devices for improving the function of the native valve or the heart muscle; Transmyocardial revascularisation [TMR] devices; Valves implantable in the body
  • A61F2/2442—Annuloplasty rings or inserts for correcting the valve shape; Implants for improving the function of a native heart valve

Definitions

• the invention relates to heart valve repair and particularly to annuloplasty apparatus and methods.
• the invention is especially useful in mitral valve annuloplasty procedures, which generally involve mitral insufficiency (e.g., regurgitation when the mitral valve does not properly close).
• Heart valves which allow blood to pass through the four chambers of the heart in one direction.
• the valves have either two or three cusps, flaps, or leaflets, which comprise fibrous tissue that attaches to the walls of the heart.
• the cusps open when the blood flow is flowing correctly and then close to form a tight seal to prevent backflow.
• the four chambers are known as the right and left atria (upper chambers) and right and left ventricles (lower chambers).
• the four valves that control blood flow are known as the tricuspid, mitral, pulmonary, and aortic valves.
• the tricuspid valve allows one-way flow of deoxygenated blood from the right upper chamber (right atrium) to the right lower chamber (right ventricle).
• the pulmonary valve allows one-way blood flow from the right ventricle to the pulmonary artery, which carries the deoxygenated blood to the lungs.
• the mitral valve also a one-way valve, allows oxygenated blood, which has returned to the left upper chamber (left atrium), to flow to the left lower chamber (left ventricle). When the left ventricle contracts, the oxygenated blood is pumped through the aortic valve to the aorta.
• mitral valve insufficiency also known as mitral regurgitation
• mitral regurgitation is a common cardiac abnormality where the mitral valve leaflets do not completely close when the left ventricle contracts. This allows blood to flow back into the left atrium, which then requires the heart to work harder as it must pump both the regular volume of blood and the blood that has regurgitated back into the left atrium. Obviously, if this insufficiency is not corrected, the added workload can eventually result in heart failure.
• valve replacement One option to correct valve defects is complete valve replacement. This intervention, however, is quite invasive and traumatic. There are more conservative surgical interventions that are less traumatic than implanting valvular prostheses. These approaches include valve leaflet repair, chordae tendinae shortening or replacement, and or valve annulus repair also known as annuloplasty. One example where annuloplasty procedures have been developed is in the field of mitral valve insufficiency correction.
• Mitral valve insufficiency typically results from a change in the size and shape of the mitral valve annulus.
• Mitral valve annuloplasty involves reestablishing the normal shape and size of the mitral valve annulus so that it can effect full closure of the valve leaflets.
• C-shaped bands or partial annuloplasty rings also have been developed. These devices can be attached solely to the posterior portion of the valve annulus which eliminates the need to attach material to the anterior portion of the annulus.
• the annulus is fibrous and generally does not require plication and/or reinforcement.
• the partial rings can preserve the normal function of the anterior portion of the annulus.
• Full and partial ring devices are disclosed, for example, in U.S. Pat. No. 3,656,185, which issued to Carpentier.
• the O'Connor patent discloses a plication approach, particularly suitable for use with an annuloplasty operation on heart valves (e.g., mitral or tricuspid valves).
• the approach involves a ligament, which can comprise a wide, flexible strip of expanded polytetrafluorethylene or similar material, and sutures to retain the ligament in place.
• the ligament has at least an end of constricted diameter and a needle attached thereto, or it can have two constricted ends and a needle attached to each of the ends. This construction permits the ligament to be drawn through an area of tissue to be plicated.
• a first end of the ligament is anchored, preferably with sewing of conventional sutures through the ligament, and the tissue is cinched along the length of the ligament to provide the desired amount of plication.
• the second end of the ligament is then likewise anchored in place, again preferably through the use of a suture sewn through the ligament.
• the Howanec patent describes a system that includes an elongate flexible band with a needle attached to one end of the band and a fit adjuster attached to the other end of the band.
• the needle is used to introduce the band into the atrioventricular groove (hereafter “AV groove”) and then pull a portion of the band out of the tissue.
• AV groove atrioventricular groove
• a fit adjuster is used to couple the exposed ends of the band and size and position the band in the annulus.
• the band is pulled to cinch the tissue in the AV groove until the valve annulus is reconfigured to an optimal shape, the band can be secured to the valve annulus with sutures and the exposed portions of the annuloplasty system removed.
• the Cox patent describes a system that comprises a combined annuloplasty ring implant, which has a rigid section and a flexible section.
• a needle is coupled to one end of the implant. The needle facilitates introducing the implant into the fatty pad of the AV groove, which surrounds the valve annulus, at one end of the posterior portion of the annulus and pulling one end portion of the implant out of the AV groove in the vicinity of the other end of the posterior portion of the annulus.
• the flexible section of the ring extends adjacent to the flexible posterior portion of the annulus, while the rigid section of the ring spans the substantially rigid inter-trigone section of the annulus.
• the flexible material is also elastic to accommodate the expansion and contraction of the annulus, in addition to flexing.
• the system further includes means for joining the ends of the ring, which are positioned along the inter-trigone section, after the needle is removed. Sutures can be added to secure the annuloplasty ring to the annulus, for example, along the inter-trigone section.
• annuloplasty ring and band recipients are required to undergo anticoagulation therapy for a minimum of several months post-operatively due to the high risk of prosthesis-induced thrombosis.
• anticoagulation therapy increases the risk of bleeding complications due to the inhibition of blood clot formation.
• the present invention involves annuloplasty systems that avoid problems and disadvantages of the prior art.
• the present invention involves an annuloplasty system for repairing a valve in a patient's heart.
• the system comprises a surgical implant, which includes a member having first and second end portions.
• the implant member further is configured and/or adapted to form a partial ring along a portion of one of the valve annulae of a patient's heart such as the mitral or tricuspid valve annulus.
• the implant member is axially elastic such that it can axially expand and contract and includes first and second anchors extending from the end portions of the implant member to anchor the implant in tissue such as the mitral or tricuspid valve annulus.
• the system can facilitate tissue plication (e.g., of the posterior annulus of the mitral valve or the anterior annulus of the tricuspid valve) and reinforcement of a valve annulus.
• the partial ring configuration may reduce or minimize the risk of stenosis as compared to more bulky systems using full rings. This configuration also can reduce the amount of prosthetic material that is exposed to blood flow, thus, minimizing or eliminating the requirement for post-operative anticoagulation. Further, since the ends are not joined, the surgeon need not place anything on the anterior portion of the annulus (in the case of mitral valve repair), which otherwise could obstruct flow intake.
• clips can be used in lieu of sutures to anchor or fasten the implant in the desired position. This eliminates cumbersome suturing approaches, simplifies implantation as compared to conventional methods, and facilitates minimally invasive (e.g., endoscopic) approaches to valve annuloplasty (e.g., mitral or tricuspid valve annuloplasty).
• minimally invasive e.g., endoscopic
• valve annuloplasty e.g., mitral or tricuspid valve annuloplasty
• the implant member has a small cross-sectional dimension, but it is curved to form an implant of much greater overall transverse dimension or diameter.
• the implant member can comprise a wire formed to have, for example, an undulating configuration adapted for implantation within the valve annulus.
• the implant wire with a wire diameter for example, can range from about 0.002 to 0.062 inches, yet have an overall transverse dimension (measured from peak to trough) of about 0.010 to 0.375 inches.
• the overall transverse dimension which also may be described as the width or amplitude of the undulating member, taken along a portion of the implant is about 5 to 10 times greater than the implant wire diameter.
• the curved wire construction of the present invention also can be configured to provide desirable flexibility so that the implant can comply with annulus flexure during normal cardiac function.
• the implant also can be configured to be axially elastic or compliant. With such axial elasticity, the implant can expand and contract to accommodate annulus expansion and contraction during relaxation (i.e., expansion) and contraction of the left ventricle.
• the implant member can comprise a wire formed to have a plurality of loops formed therein.
• Anchors or sutures can be attached to the loops and tissue to secure the implant member to the tissue.
• the wire diameter typically is about 0.002 to 0.062 inches and the diameter of the loops preferably range from about 0.010 to 0.050 inches.
• a needle can be releasably coupled to one end of the implant.
• the needle simplifies implant delivery and avoids the need for time-consuming suture procedures.
• FIG. 1A is a perspective view of an annuloplasty system constructed in accordance with the present invention.
• FIG. 1B is a longitudinal sectional view of the annuloplasty system depicted in FIG. 1.
• FIG. 1C is a variation of the annuloplasty system of FIG. 1.
• FIGS. 2A, 2B, 2 C, and 2 D diagrammatically show release of the implant illustrated in FIG. 1.
• FIG. 3A is a perspective view of the pivotally mounted retainer illustrated in longitudinal and transverse positions in FIGS. 2 A- 2 D.
• FIG. 3B is an end view taken along line 3 B- 3 B in FIG. 3A.
• FIG. 3C is a sectional view taken along line 3 C- 3 C in FIG. 3A.
• FIG. 4A and 4B depicts a straight and curved embodiment of the implant shown in FIG. 1A.
• FIGS. 5A, 5B, 5 C, 5 D, and 5 E diagrammatically illustrate a method using of the annuloplasty system of FIG. 1.
• FIGS. 6A, 6B, 6 C, 6 D, and 6 E diagrammatically illustrate another method of using the annuloplasty system of FIG. 1A.
• FIGS. 7A, 7B, 7 C, and 7 D diagrammatically illustrate a further method of using the annuloplasty system of FIG. 1A.
• FIG. 8A shows another annuloplasty system in accordance with principles of the present invention.
• FIG. 8B is a sectional view of the release mechanism of FIG. 8A taken along line 8 B- 8 B.
• FIG. 8C is a sectional view of taken along line 8 C- 8 C in FIG. 8B.
• FIG. 9 diagrammatically illustrates one juncture configuration between one of the surgical clips and the implant member of FIG. 8A.
• FIGS. 10A, 10B, 10 C, 10 D, and 10 E show a method of using the annuloplasty system of FIG. 8A.
• FIG. 11 is a perspective view of the delivery and release apparatus of FIG. 1 coupled to a self-closing clip such as the self-closing clip of FIG. 11.
• FIGS. 12A, 12B, 12 C, and 12 D diagrammatically illustrate the operation of one release apparatus for use with the system of FIGS. 1 or 11 .
• FIGS. 13A, 13B, 13 C, and 13 D diagrammatically illustrate the operation of another release apparatus for use with the system of FIG. 1 or 11 .
• FIGS. 14A, 14B, 14 C, and 14 D diagrammatically illustrate the operation of yet another release apparatus for use with the system of FIG. 1 or 11 .
• FIG. 1 illustrates an annuloplasty system 100 constructed in accordance with the principles of the invention.
• Annuloplasty system 100 generally comprises an implant member 102 , a flexible member 104 , and a needle 106 .
• system 100 also includes anchors or stoppers 112 (FIG. 1A) and 114 (FIG. 1B) and a release mechanism 108 to releasably couple the implant to the flexible member.
• the distal end of the implant member may have an enlarged portion 110 as shown in the drawings.
• a stopper or anchor 112 preferably in the form of a disc and preferably welded to the distal end of the implant member, may be provided adjacent to the enlarged portion 110 .
• another stopper or anchor 114 may be provided adjacent to the implant's proximal enlarged portion 116 as shown in FIG. 1B. Stopper or anchors 112 and 114 also may referred to as retainers. Stopper 114 will be described in further detail in the discussion of FIGS. 2 A- 2 D and 3 A- 3 C. Pledgets 118 and 120 (see e.g. FIG.
• TEFLON® polytetrafluoroethylene material or DACRON® synthetic polyester textile fiber
• DACRON® synthetic polyester textile fiber also may coupled to the implant adjacent to the stoppers to minimize or eliminate the risk of having the implant tear the tissue in which is it embedded.
• release mechanism 108 generally includes a plurality of arms or cables 122 , which releasably engage enlarged portion 116 of implant 102 , and a sleeve 124 that retains the arms 122 in a closed configuration such that enlarged portion 116 is locked or secured therein.
• Arms 122 have notches 126 and 128 (FIG. 2D) formed therein to form inner annular grooves 130 and 132 , respectively.
• Annular groove 130 holds or retains enlarged portion 116 and annular groove 132 holds or retains enlarged portion 134 , which is formed on the end of cable or wire 136 , which, in turn, is secured to needle 106 .
• a band 138 is fit into an outer annular channel 140 (FIG. 2C), which is formed by forming notches 142 in the outer surface of cables or arms 122 .
• Band 138 retains the portion of the bundle of cables or arms 122 adjacent thereto tightly together so that enlarged portion 134 remains secured therein.
• a flexible tubular member 104 is provided between needle 106 and release mechanism sleeve 124 .
• one end of tubular member receives one end of release mechanism sleeve 124 .
• Release mechanism sleeve 124 is sufficiently flexible so that it can slide within tubular member 104 as it is retracted or removed from the bundle of cables or arms 122 to release enlarged portion 116 and, thus, implant member 102 as will be described in more detail below.
• the other end of tubular member 104 together with the end of wire 136 is inserted in a recess 146 (FIG. 1B) formed in the needle and secured therein such as by swaging.
• FIG. 1C a variant of the system illustrated in FIG. 1B is shown where tubular member 104 is eliminated and the tubular sleeve 124 of the release mechanism 108 is directly coupled to the needle.
• a needle 106 ′ is formed with a deep recess 146 ′ so that release mechanism sleeve 124 can sufficiently slide into the recess and be sufficiently removed from the cable bundle to release enlarged portion 116 and, thus, implant 102 .
• FIGS. 2 A- 2 D sequentially depict release of implant member 102 , which in the illustrated embodiments includes straight portion 102 ( a ) and undulating portion 102 ( b ) the length of which is indicated in FIG. 2D with reference characters “a” and “b,” respectively.
• the surgeon or assistant can slide pledget 120 over needle 106 , tube 104 , and release mechanism 108 (FIG. 2A) so that it can be positioned adjacent to undulating portion 102 ( b ) of the implant prior to actuating release of the implant member (FIG. 2B).
• Sleeve 124 is retracted and drawn into tubular member 104 first releasing pivotally mounted stopper or anchor 114 , which also may be referred to as a retainer, so that it may pivot to a transverse position relative to the wire of which the illustrated implant comprises. As sleeve 124 is further retracted, it releases arms 122 of release mechanism 108 , which in turn release enlarged portion 116 of implant member 102 (FIG. 2D). Since sleeve 124 biases arms 122 , which normally assume the radially outward expanded configuration shown in FIG. 2D, to the closed configuration shown in FIGS. 2 A-C, the arms open as shown in FIG. 2D when sleeve 124 is retracted.
• proximal stopper or anchor 114 which also may be referred to as a retainer, is shown in further detail.
• Stopper 114 can be formed from a tube by removing two half tubular sections as shown in the drawings. One can remove one have tubular section along one section of the tube and another half tubular section along another section of the tube on the other side thereof as illustrated in FIGS. 3 A-C. As shown, surfaces 112 ( a ) and 112 ( b ) can be angled to simplify the material removal process in forming stopper 112 .
• undulating portion 102 ( b ) of implant 102 can comprise a wire, which is formed so that it is generally two-dimensional (flat or planar) and straight as previously shown prior to implantation.
• a curved, arc-shaped, or crescent shaped undulating wire member that is generally two-dimensional (flat or planar) can be used for implantation as shown in FIG. 4B.
• These configurations afford orientation stability when embedded in a mitral valve annulus, for example and as will be further described below, while minimizing the size or bulk of the implant. It is believed that the reduced valve implant bulk can reduce the risk of thrombosis.
• the undulating portion also may be formed so that it has two and three dimensional portions or so that is entirely three dimensional, the two dimensional variation is believed to offer optimal stability.
• the wire diameter can vary from application to application. For example, when applied to normal human mitral valves, it can range from about 0.002 to 0.062 inches, more preferably in the range of about 0.005 to 0.015 inches, and typically will be about 0.089 inches.
• the wire diameter range is the same when applied to tricuspid valves.
• the transverse dimension or width “W” (FIG. 2C) of the undulating member can range from about 0.010 to 0.375 inches and thus can be 5 to 10 times greater than the wire diameter.
• the implant length also can vary depending on the application. When used for mitral annuloplasty it is embedded in the annulus from one trigone to the other trigone. Therefore, its length ranges from about 25 to 85 mm when applied to normal adult human mitral valves. When applied to human tricuspid valves it is implanted along the posterior annulus and extends in a circumferential direction from trigone to trigone, and its length can be in the same ranges.
• the implant or implant wire preferably comprises a shape memory alloy or elastic material.
• shape memory material has thermal or stress relieved properties that enable it to return to a memory shape. When stress is applied to shape memory alloy material causing at least a portion of the material to be in its martensitic form, it will retain its new shape until the stress is relieved. Then it returns to its original, memory shape. On the other hand, when shape memory material is cooled to where it is in its martensitic form and then deformed, it retains the deformed shape until its temperature is increased so that the material becomes austenitic. Then it returns to its original, memory shape.
• One preferred shape memory material for the implant member is nitinol.
• the shape memory wire (e.g., nitinol) can be shape set into the undulating configuration by weaving the wire through a fixture having a row of rods and affixing the two ends of the nitinol wire under tension.
• the nitinol wire can be shape set by press molding using a mold with a crimped pattern.
• the heat treatment to permanently set the shape of the nitinol wire can be achieved by heat-treating in either a convection oven or bath at a temperature range of 100 to 600° C. for a duration of 2 to 20 minutes.
• the distal stopper can be welded to one end of the shape set imbedded wire.
• the retractable stopper is loaded onto the proximal end of the imbedded wire.
• a ball is formed onto the proximal end of the imbedded wire by welding.
• the release mechanism is assembled with a flexible member and a taper component to transition from the flexible member to the release mechanism.
• the release mechanism is attached to the ball of the imbedded wire at the proximal end and the retractable stopper is placed into its retracted position within the release mechanism component. Then, a needle is swaged onto the flexible member.
• annuloplasty system 100 for mitral valve annuloplasty is shown in accordance with the present invention.
• MV competent mitral valve
• the left ventricle then pumps the oxygenated blood to the rest of the body.
• the mitral valve comprises a pair of leaflets, the anterior leaflet (AL) and the posterior leaflet (PL) of which the latter is larger.
• the base of each leaflet is attached to the mitral valve annulus (MVA).
• the mitral valve annulus includes a posterior portion (PP) and an anterior portion (AP) also known as the inter-trigone section, which is a generally straight substantially rigid section.
• the posterior portion of the annulus is a flexible, curved section that encompasses a larger portion of the annulus circumference than the anterior portion.
• the right and left fibrous trigones (generally indicated with reference characters RT and LT) mark the end of the generally straight section (inter-trigone section) and define the intersection points between the posterior and anterior portions (PP, AP).
• the leaflets open and close in response to pressure differences on either side of thereof. However, when the leaflets do not fully close, regurgitation and valve insufficiency can result.
• One method to treat the insufficiency using the annuloplasty system of FIG. 1 will be described with reference to FIGS. 5 B- 5 E.
• needle 106 of annuloplasty system 100 is passed though the endocardium and the left atrial myocardial wall and into the right fibrous trigone (RT).
• the needle is then moved in a clockwise direction through the fibrous structure of mitral valve annulus toward the left fibrous trigone (LT).
• the needle is passed back through the left atrial myocardial wall from the epicardium and back through the endocardium at the left fibrous trigone (FIG. 5C).
• the needle is further drawn from the annulus until the release mechanism is fully withdrawn from the annulus and above the tissue surface. This preloads the implant wire and plicates the annulus.
• Pledget 120 is drawn over the needle and slid over the flexible member and release mechanism and then positioned between the undulating implant member and the release mechanism as described above.
• the surgeon withdraws sleeve 124 , thereby releasing implant member 102 from the release mechanism 108 , flexible member 104 , and needle 106 , and deploying proximal retainer or anchor 112 so that is opens to its active position as previously shown in FIGS. 2C and 2D and here in FIG. 5E where both retainers or anchors are firmly set at the fibrous trigones.
• the needle can be introduced through the left fibrous trigone and withdrawn from the right fibrous trigone.
• the undulating wire is fully embedded within the valve annulus with the anterior and posterior leaflets restored in a sealed configuration.
• the only non-embedded, blood contacting components are the anchors or retainers 112 and 114 , which are positioned at the two fibrous trigones (RT, LT). Due to the implant wire's undulating configuration, the wire can be elongated in the axial direction. In the elongated condition (partially in FIG. 5C and fully in FIG. 5D), the wire, which has shape memory to regain its original unloaded length, applies a recoil force to draw the two ends of the implant together in the axial direction.
• the shape memory force draws the annulus together resulting in tissue plication and a reduction in annulus size (FIG. 5C).
• the procedure generally provides annuloplasty plication and reinforcement, while maintaining annular compliance.
• FIGS. 6 A- 6 E a variation on the procedure described above is illustrated. This procedure is the same as that shown in FIGS. 5 A- 5 E with the exception that needle 106 is not drawn through the entire posterior annulus in a single pass. In this case, the surgeon makes multiple bites (see FIGS. 6B and 6C) with the needle to cover the distance of the posterior annulus. The procedure is completed in the same way as that described above (FIGS. 6D & E are the same as FIGS. 5D & E)
• FIGS. 7 A- 7 D a further variation on the procedures described above is illustrated.
• multiple undulated implants are used to span the length of the posterior annulus.
• two implants are used to span the annulus.
• the initial needle penetration occurs at either fibrous trigone.
• a needle bite length segment of wire is terminated with each needle bite resulting in the plication of discrete sections of the annulus.
• Subsequent wire segments are penetrated at and are linked to the terminating distal retainer 112 . In this manner, separate, but joined wire segments span the posterior annulus to the opposite fibrous trigone resulting in the plication of the entire posterior annulus and reduction in annular size.
• the implant member returns to its memory shape upon stress release (i.e., actuation of release mechanism 108 ).
• stress release i.e., actuation of release mechanism 108
• the tissue and pulling forces placed on the device to pull it into position cause it to axially expand.
• the release mechanism is actuated, thereby removing the pulling force and allowing the implant to axially contract toward its memory shape.
• the device can be designed to have thermal properties to return to its memory shape at a predetermined temperature. It can be deformed at a first temperature to generally remove or reduce the amplitude(s) or period(s) of the undulations and then inserted into the tissue. After insertion, its temperature rises to the predetermined temperature and it assumes its original, undulating memory configuration. As it returns to its memory shape, it axially contracts and decreases the circumferential dimension of the valve annulus.
• the wire can be flat.
• the undulations can have varying or changing amplitude or frequency.
• the radius of the crests and troughs also can vary from implant to implant or within a single implant.
• the implant wire can be a single length of wire as shown in the drawings or it can be made up of multiple lengths of wire joined together.
• the undulating implant can provide high strength and elasticity to material volume (or diameter) ratio.
• the implant configuration and construction can provide desirable elasticity that allows for physiological motion in the linear direction (annular dilatation) and planar surface. Since the undulating member can be self-terminating at the trigones, it does not require knot tying, connectors, or cutting.
• the implant can be less traumatic to the annular tissue as compared to other devices. For example, it does not require multiple suture passes.
• the implant configuration and placement also can minimize the amount of implant surface that comes into contact with blood flow.
• Annuloplasty system 200 generally comprises an implant member 202 , anchors comprising or in the form of surgical clips 204 coupled to ends of implant member 202 , flexible members or wires 206 , release mechanisms 208 , which releasably couple the flexible members to implant member 202 , and tissue piercing members or needles 210 , which are secured to the flexible members or wires 206 .
• Implant member 202 can be straight (not shown), or crescent or arc-shaped so as to form a partial ring as shown in FIG. 8A.
• Implant member 202 has a plurality of attachment loops 212 formed therein such as by folding the wire of which the implant comprises according to this embodiment.
• loops 212 may be separately formed and secured to implant member 202 by welding, soldering or other suitable process.
• the loops are equidistantly spaced from one another.
• each anchor-clip, release mechanism, flexible member and needle combination forms a tissue connector assembly 214 similar to tissue connector assemblies described in U.S. patent application Ser. Nos. 09/089,884 and 09/090,305 both filed Jun. 3, 1998 and Ser. Nos. 09/259,705 and 09/260,623 both filed Mar. 1, 2000 and International Application Nos. PCT/US99/12563 and PCT/US99/12566 both filed Jun. 3, 1999 and published under International Publication Nos. WO 99/62409 and WO 99/62406, all of which are hereby incorporated by reference herein. Although one tissue connector assembly configuration is shown herein, any other suitable assemblies described in the applications cited in the preceding sentence can be used.
• tissue connector assemblies having self-closing clips which can be characterized as having two end points, which tend to come closer together either by elasticity or so-called pseudoelasticity.
• a clip may be made by heat-treating a NiTi wire to a certain temperature and time to have a desired undeformed shape.
• the surgical clip generally comprises a wire, preferably, comprise shape memory alloy.
• each clips preferably has two end points, an unbiased closed configuration, the ability to be moved or biased to an open configuration, the tendency to return to the naturally closed memory configuration, which reduces the separation between the two end points as compared to the spaced end point orientation when the clip is in an open configuration.
• the clips disclosed in aforementioned U.S. and PCT patent applications describe a clip comprising a deformable wire made of a shape memory alloy, which clip can assume a U-shape when in the open configuration and one example of a suitable clip for this embodiment of the present invention.
• Such a clip may be deployed, for example, in the form of a single-arm clip assembly as shown in FIG. 8A and designated with reference numeral 214 and as generally described in the aforementioned U.S. patent application Ser. Nos. 09/089,884 and 09/090,305, and the section of International Application No. PCT/US99/12566 from page 10, line 10 through page 11, line 21, which section and accompanying FIG. 1 is hereby specifically incorporated by reference herein.
• the ends of the clip coil 204 ( b ) are constrained with the coil in compression to urge or bias clip wire 204 ( a ) into a generally U-shaped open configuration.
• a release mechanism 208 such as disclosed in aforementioned U.S. patent application Ser. No. 09/260,623 (or International Application No. PCT/US99/12566, which published on Dec. 9, 1999 under International Publication No. WO 99/62406 is provided so that clip wire 204 ( a ) can readily be released by squeezing the release mechanism with a surgical instrument.
• One suitable release mechanism is specifically described in International Application No. PCT/US99/12566 from page 25, line 12 through page 27, line 30 ending with the text “mechanism 23c” (but without the text “such as needle 17 as shown in FIG. 1” on line 27 of page 27) and the referenced figures are hereby incorporated by reference herein.
• a summary of such a release mechanism is provided below with reference to FIGS. 8B and 8C.
• release mechanism 208 generally comprises a plurality of substantially rigid strands, cables or wires 216 (which are the same as cables or strands 122 in FIG. 1B). Cables 208 can be metal and are arranged substantially parallel to one another and circularly about a longitudinal axis. The hidden end portions of the strands are coupled to tapered section “T,” which is coupled to piercing member a needle 210 . The strands can be coupled to rod 218 , which is fixed to the tapered section.
• End portions of the strands include notches, which form a chamber 220 for releasably receiving and/or holding enlarged portion “E 1 ” of the clip and/or fastener wire 204 ( a ) which also has and enlarged portion “E 2 ” at its other end to facilitate compression of coil 204 ( b ).
• the notches preferably are placed about 0.015 inches from the free ends of the strands, but this distance can vary depending upon the desired compression on the coil or spring 204 ( b ).
• a shrink wrap layer 222 preferably in the form of tubing, is provided around at lest the free end portions of the strands and the shrink wrap heated to compress against the strands and hold them in place against enlarged wire portion “E 1 ” to effectively hold the enlarged portion captive until the shrink wrap is squeezed, the strands displaced and the enlarged portion released.
• implant member 202 and the surgical clip can be formed from a single element or wire.
• a single wire forms the surgical clip and implant member 202 .
• clip wire 204 ( a ) is long enough to form implant member 202 . It can also form a similar clip wire at the other end of the implant as well.
• the wire can be passed through a washer 224 (FIG. 9) or similar device having a hole formed therethrough and the washer secured to the wire by swaging, for example.
• the washer is placed at a location along the wire to provide the desired compression of coil 204 ( b ).
• a clip having an enlarged portion E 2 can be used and the enlarged portion E 2 secured to the implant member 202 by any suitable means such as welding.
• the loops and the general curve shape of member 202 are made from the same piece of wire.
• the loops are formed by wrapping the wire around mandrels.
• the mandrels are arranged in the general curve shape, thus giving the appearance of loops superposed onto a general curve shape.
• Wire cross section diameters can range from about 0.002 to 0.062 inches.
• Loop diameters can range from about 0.010 to 0.050 inches.
• the radius of curvature of the overall implant member 202 , having loops formed therein, can range from about 0.25 to 1.25 inches, but can be made to any radius.
• the straight-line distance between the ends of the implant member 202 (between washers 224 ) ranges from about 0.5 to 2.5 inches.
• the length of the implant member (measured from washer 224 to washer 224 ) can range from about 0.75 to 3.0 inches.
• the profile is essentially the thickness of prosthetic material attached to the annulus. The smaller the diameter, the lower the profile. Lower profile may prevent nonphysiological blood flow, which can lead to undesirable hemodynamic effects, e.g., thrombosis, disruption of red blood cells, or slower tissue healing.
• the last loop is the one that abuts washer 224 , which is passed onto the multiloop member and crimped to act as a stopper for the coil 204 ( b ), which surrounds a portion of the wire that forms the implant member and surgical clip.
• the release mechanism 208 compresses the coil against washer or constraint 224 , which maintains the surgical clip in a U-shaped configuration.
• implant member 202 is implanted onto the mitral valve annulus of the target mitral valve such that the implant member or wire is attached to the surface of the annular tissue.
• the implant member or wire is secured along the posterior annulus with the ends of the implant member secured to the annulus at the two fibrous trigones.
• the surgeon first secures tissue connector assemblies 214 at the right and left fibrous trigones. This is accomplished by threading needles 210 into the fibrous structure of the annulus and then drawing the needles out from the annulus sufficiently so that anchors 204 extend out from the annulus at incisions “I.”
• a 5-0 needle can be used in this example.
• Release mechanisms 208 are squeezed to release the anchors 204 from the release mechanisms 208 , flexible members 206 , and needles 210 and allow anchors to close as shown in FIG. 10B.
• discrete or individual tissue connector assemblies 214 are passed through loops 212 (FIG. 10C) and released so that the clips or anchors 204 of the individual tissue connector assemblies close and secure the loops to the tissue as shown in FIG. 10D, which shows inserting clips 204 radially.
• the anchors or clips 204 can be inserted circumferentially as shown in FIG. 10E.
• the attachment loops provide elasticity and act as torsion springs.
• the spring properties generally provide elasticity.
• the implant having shape memory to regain its original unloaded length, applies a recoil force to draw the two ends together along the length of the implant.
• the shape memory force draws the annulus together resulting in tissue plication and a reduction in annulus size.
• the preloaded condition of the implant wire continues to provide a reinforcement force to prevent further dilation of the valve annulus.
• the elastic nature of the loops allow for the natural compliance and physiological motion of the annulus.
• the low profile characteristic of the implant as compared to conventional annuloplasty rings or bands reduces the amount or volume of prosthetic material that is exposed to blood flow. This can substantially reduce the need for post-operative anticoagulation therapy.
• annuloplasty system 200 has been described with self-closing clip type anchors, other surgical clips can be used as anchors such as that disclosed in U.S. Pat. No. 5,972,024, which issued to Northrop, III et al. Further, sutures can be used to form the anchors as will be discussed in more detail below.
• FIGS. 8 A-C Although a particular system embodiment having two clip anchors, release mechanisms, and delivery needles has been described and illustrated in FIGS. 8 A-C, variations of this system can be made within the scope of the invention.
• only one clip anchor, release mechanism, and delivery member may be used.
• the clip anchor with its release mechanism and delivery needle can be coupled to one end of the implant member as shown in FIG. 8A.
• the other end of the implant member can be constructed to end with one of the loops illustrated in FIG. 8A. That loop is then sutured to the tissue with conventional suture techniques.
• it can be secured to the tissue using a surgical clip such as any one of the clips described above.
• both clip anchors and their release mechanisms and delivery needles can be eliminated and both ends of the implant member constructed to end in a loop as described above. Both loops can then be fastened to the tissue using a suture or clip as described with respect to the previous example.
• the implant member can be a full ring and the loops secured to tissue thereunder.
• the tissue connector assembly 400 generally comprises a needle 106 , tubular flexible member 104 , clip or anchor 204 (all of which have been described above) and a remote release mechanism “R.”
• a remote release mechanism is especially advantageous where the operative space or field is limited such as in the case of valve annuloplasty.
• FIGS. 12 A- 12 D, 13 A- 13 D, and 14 A- 14 D Various remote release mechanisms in accordance with the invention are illustrated in FIGS. 12 A- 12 D, 13 A- 13 D, and 14 A- 14 D.
• the remote release mechanism “R” comprises a holding mechanism, such as the plurality of arms or wires 122 illustrated in FIGS. 2 A-D, and a sheath or tubular member for holding the holding mechanism closed, such as tubular member 124 illustrated in FIGS. 2 A-D and, therefore can be the same as release mechanism 108 .
• the holding mechanism or member(s) when constructed for holding a clip or anchor, can comprise multiple strands, cables or wires 122 having a radially outward bias as shown in FIGS. 12 A- 12 D, two halves 122 ′ of hypodermic tubing as shown in FIGS. 13 A- 13 D (with recesses 126 ′ for receiving the surgical clip and having an inner diameter less than the diameter of enlarged portion E 2 ), or one piece of hypodermic tubing 122 ′′ as shown in FIGS. 14 A- 14 D. That is the holding mechanism has recesses 126 , 126 ′, or 126 ′′ formed therein to receive and/or hold the enlarged end E 2 of the clip or anchor 204 .
• the strands 122 have notches 128 , as shown in FIGS. 2 A-D, to hold enlarged portion 134 .
• Sleeve 124 is retracted to release the holding mechanism and the clip or anchor 204 as shown in FIGS. 12D, 13D, and 14 D. The longer the sleeve, the more remotely one can actuate release of the clip.
• the hypodermic halves shown in FIGS. 13 A-D also have cut out portions that form arms 240 and collars 242 .
• Collars 242 surround wire 136 and have inner diameters less than the diameter of enlarged portion or ball 134 to secure halves 122 ′ to wire 136 . In this manner, the delivery apparatus can be readily removed, while leaving the clip or anchor at the desired site.
• the one-piece hypodermic tubing embodiment of FIGS. 14 A-D has a cut out to form a longitudinal opening for releasing a clip or anchor 204 from holding member 122 ′′.
• the tubing also has cut outs to form arm 240 ′ and collar 242 ′ having an inner diameter less than the diameter of enlarged portion or ball 134 to secure the tubing to wire 136 and facilitate removal of the delivery apparatus, while leaving the clip or anchor at the desired site.

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• Health & Medical Sciences (AREA)
• Cardiology (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Transplantation (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Vascular Medicine (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Prostheses (AREA)

Abstract

Description

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• 2002
  • 2002-04-18 US US10/125,811 patent/US20030199974A1/en not_active Abandoned
• 2003
  • 2003-04-18 AU AU2003228586A patent/AU2003228586A1/en not_active Abandoned
  • 2003-04-18 WO PCT/US2003/012073 patent/WO2003088875A1/en not_active Application Discontinuation
• 2004
  • 2004-11-10 US US10/985,768 patent/US20050065601A1/en not_active Abandoned
• 2010
  • 2010-09-13 US US12/880,823 patent/US8167933B2/en not_active Expired - Fee Related

Patent Citations (31)