US 3263239 A
Description (OCR text may contain errors)
Aug; 2, 1966 M. L- WA ETAL 3,263,239
AORTA VALVE WITH EXPANSIBLE SUTURING RING Filed April 1, 1963 INVENTORS. wuss LOWELL EDWARDS ALBERT STARR AHorney United States Patent G 3,263,239 AORTA VALVE WITH EXPANSIBLE SU'l'URlNG RING Miles Lowell Edwards, Santa Ana, Calif., and Albert Starr,
Portland, ()reg., nssignors to Edwards Laboratories, 1116.,
Santa Ana, Calif., a corporation of Cnlifomla Filed Apr. 1, 1963, Ser. No. 269,299 13 Claims. (Cl. 3-1) This application is a continuation-in-part of co-pending application Serial No. 49,044 filed August 11, 1960, now Patent No. 3,099,016.
This invention relates to an artificial valve as a prothesis in a heart to take the place of a defective natural valve.
The valve illustrated in said prior patent is a mitral valve, although the general features of construction therein disclosed are applicable to both mitral and aorta valves. The present application is directed to certain modifications of structure in order to adapt the general principles of the prior invention for utilization in an aorta valve. The present invention is not limited to aorta valves, however.
An aorta valve requires special consideration in its design and construction because the valve body must project into the aorta itself. There is less space for such mechanism in the aorta than in the chamber of the left ventricle which contains the body of the mitral valve. Thus, although the aorta valve must handle the same quantity of blood as the mitral valve, it must be smaller in its outside dimensions whereby special provision must be made to avoid throttling the flow of blood.
The objects of the invention are, therefore, .to provide an improved artificial valve, to provide an improved aorta valve, to provide a valve for implantation directly in the entrance to the aorta below the coronary arteries and to provide a sewing ring for an aorta valve of conical skirt shape and made of expansile material which can change in diameter as variations in the blood pressure expand and contract the diameter of the aorta.
The present valve is generally similar to the mitral valve mentioned above but incorporates certain special features to increase the size of the port opening relative to the size of the valve body and to facilitate attachment of the sewing ring to the heart tissue directly at the entrance to the aorta. Other features and advantages will become apparent from the following detailed description of the preferred embodiment illustrated on the accompanying drawing. All variations and modifications within the scope of the appended claims are included in the invention.
In the drawing:
FIGURE 1 is a longitudinal sectional view of a valve embodying the principles of the invention;
FIGURE 2 is a top plan view of the valve in reduced scale with parts broken away;
FIGURE 3 is a bottom plan view of the valve; and
FIGURE 4 is a section of a human heart, showing the present valve installed therein.
The valve comprises an integral body member made of a suitable material which is compatible with the human body. Various types of non-toxic plastic may be used, such as Dupont Lucite acrylic resin, Rohrn & Haas Plexiglas acrylic plastic, and the like. Metal is preferable to plastic, however, the preferred material being an alloy known as Stellite which is non-corrodible and inert to blood and living tissue. Stainless steel may also be used.
The entire body 10 comprising a base or port ring portion 11 and a cage portion 12 is preferably made in one piece either as a molding or a casting. The base ring defines a valve port having an internal spherical seat 13 corresponding to the curvature of silicone rubberball 15. In order to provide as large a port as possible, the maximum inclination of seat 113 from the vertical is 15 as right atrium 48.
3,263,239 Patented August 2, 1966 indicated by the angle at 16. In order to prevent any possibility of the ball escaping through the port, special retention means may be provided. These comprise three inwardly and downwardly directed stop fingers .17. Preferably, these stops are disposed between the three legs of cage 12. The stops may be omitted when the dimensions and angular relationships are such as to prevent the ball from escaping through the port in use. The resilient ball is inserted in the cage by squeezing it between two of the cage legs.
The outside of base ring 11 forms an annular channel having a nearly horizontal bottom wall 21 having a slight downward inclination and an upwardly inclined top wall 22. In the illustrated embodiment the inclination of wall 22 is approximately 45. A flexible sewing ring 25 is mounted and secured in channel 20.
Sewing ring 25 preferably comprises a piece of knitted Teflon cloth having a mid-portion clamped in the channel 20 by a one-piece split spreader ring '26 of suitable material such as Teflon plastic. The spreader ring 26 is itself channel-shapcd in cross section with an external shape corresponding generally to the shape of channel 20 and having an outwardly facing channel 27. The spreader ring is clamped against at least one thickness of the cloth by a winding 28 of Teflon thread which is wound under tension in chancl 27. When the body member 10 is made of metal, all the other parts should be non-metallic to prevent electrolysis.
The lower end portion 30 of the cloth is folded back on upper portion 32 and stitched with Teflon thread 31 to a folded back upper end portion 33 of the cloth as shown. This produces a bight portion at 35 which encloses a resilient silicone rubber ring 36. The cloth is formed into a smoth frusto-conieal shape -by a pressing operation. This results in a sleeve of inverted flaring skirt shape which makes an angle of about 22' with the vertical as indicated by the angle 40. Rubber ring 36 serves as an extens-i-le element to stiffen the free upper end of the skirt and hold it extended in circular configuration in plan view. The folded end portions at 30 and 33 abut each other to form a pad having a thickness of at least three layers of cloth. This provides secure anchorage for the sutures. Rubber ring 36 is not necessary in small sizes of the valve as then the cloth will hold itself in conical shape without a separate extensi-le element.
FIGURE 4 shows the manner of installing the valve in a human heart 45. The heart has a left atrium 46. a left ventricle 47, a right atrium 48 and a right ventricle 49. A mitral valve 50 prevents reverse flow of blood from left ventricle 47 back into left atrium 46 and a mitral valve 51 prevents reverse flow from right ventricle 49 back into Blood flows from left ventricle 47 through an aorta valve into aorta 56 from whence it is distributed into main arteries 57 and others leading to different parts of the body. The aorta normally makes a sharp bend between the heart and the arteries 57, as shown.
The present valve is usually installed by making an incision 52 through the outside of this bend which provides access for surgical treatment of the natural aorta valve. The natural aorta valve parts are removed and the present valve is installed in the same location. The sewing ring 25 is secured to living tissue at the entrance to the aorta by threads or sutures 53 with the cage 12 extending up into the aorta. The suturing is facilitated by the act-ion of extensile rubber ring 36 which holds the upper free end of the skirt portion of the sewing ring expanded into contact with the inside of .the aorta wall, as shown. Normally, the aorta increases in size at this point whereby the flare of the skirt of the sewing ring conforms generally. with the taper of the aorta.
The combination of upwardly inclined wall 22, the top surface of which conforms to the flow pattern of the blood, and tlte spacing of stop fingers l7 staggered between cage legs 12 provide maximum flow around the legs 12. This minimizes tlte tendency toward a shadow in the flow pattern between the legs and the sewing ring where clots could form. Usually abouLtwo-thirds of tlte sutures may be tied against the inner sttrface of the conical sewing ring adjacent to the legs of the cage. These suture knots are inclined to excite the clot formation. The staggered arrangement of stop fingers and cage legs is to avoid a concentration of impediments in the flow through the valve. This provide maximum washing of blood around the cage legs to the area directly between the leg and the inside of the sewing skirt to minimize tlte possibility of clot formation at that area.
It is to be noted that the valve is installed below the coronary arteries 55 so that it functions in the circulatory system the same as the natural aorta valve.
A most important feature of the valve is the expansile sewing ring brought about by the nature of the cloth used and the rubber ring placed in the upper extremity of the skirt. It aids the surgeon in selection of a valve. Although measuring devices are used, they are not precise and a certain amount of flexibility here is important.
Another point is that the valve is installed when the aorta is at zero pressure. When in use, the pressure extends the aorta diameter and the sewing ring must expand accordingly.
There is also the important point that the rttbber rittg being placed at the upper extremity of the skirt causes the pressure difference across the valve, when the valve is in a closed position, to be sealed at the location of the rubber ring forcing the entire area of the skirt outward against the aorta wall, preventing wrinkles. This action is very ntuch like the seal in the leather cup of a bicycle tire pump.
Having now described our invention and in what manner the same may be used, what we claim as new and desire to protect by Letters Patent is:
1. A heart valve comprising a port ring, a movable valve member cooperating with the port in said ring, an outwardly facing annular channel in said port ring, said channel having a bottom side wall inclined slightly downward from the plane of said ring and a top side wall inclined upward at a much greater angle front said plane, an annular sewing ring comprising an upwardly flaring skirt of flexible material capable of being pierced by a needle and suture, and means clamping the lower end of said skirt in said channel.
2. A heart valve comprising a port ring, a movable valve member cooperating with the port in said ring, and an annular sewing ring secured to said port ring, said sewing ring comprising an upwardly flaring skirt of flexible material capable of being pierced by a needle and suture, said skirt comprising multiple layers of cloth formed to frusto-eonical shape.
3. A heart valve comprising a port ring, a ball cage on the upper side of said port ring, a ball in said cage coopcrating with the port in said ring, a plurality of stop fingers projecting inwardly from said ring to retain said ball in said cage, and an annular sewing ring secured to said port ring, said sew-ing ring comprising an upwardly flaring skirt of flexible material capable of being pierced by a needle and suture.
4. A heart valve as defined in claim 6, said cage com prising a plurality of spaced legs extending from said port ring and said stop fingers being staggered between said legs.
5. A heart valve comprising a port ring, a ball cage cxtcndittg upwardly from the upper side of said ring, a ball in said cage, stop fingers projccting'inwardly front said ring to retain said ball in said cage, an outwardly facing annular channel in said ring, a piece of cloth having its ntid-portion secured in said channel, upper and lower ends of said clotlt projecting front said channel being stitched together and formed into a frusto-conical skirt flaring upwardly and outwardly from said channel, and a rubber rittg enclosed itt a fold in the free upper ettd of said skirt.
6. A heart valve comprising a port ring, a ball cage extending upwardly front the upper side of said ring. a ball in said cage, a flexible skirt made of material capable of being pierced by a needle and suture, said skirt having its lower end secured about said ring and having a free upper end extending above said ring, and an extensilc flexible ring secured in said upper end of said skirt.
7. A heart valve comprising a port ring, a ball cage on one side of said ring, a ball in said cage, and a flexible skirt made of ntatcrial capable of being pierced by a needle and suture, said skirt having a small lower end secured to said ring and flaring outwardly and upwardly to a free upper end surrounding said cage above said ring.
8. A heart valve comprising a circular valve body having a valve member, a clotlt having a portion disposed against said body, means sccttring said portion of said clotlt around said body and a ring of soft, resilient material enfolded in other portions of said cloth in outstanding position from said body.
9. A heart valve comprising a circular valve body having a valve ntentbcr, an outwardly facing channel around said body, a cloth having a portion disposed in said channel, means securing said portion of said cloth itt said channel, and a soft rubber ring enfolded in other portions of said cloth in otttstanding position front said body.
10. A heart valve prosthesis comprising a substantially rigid circular valve body having a valve member and a cloth sleeve having a lower end surrounding and secured to said body, said sleeve extending axially of the valve body and having a substantially circular free upper end surrounding said valve member, spaced radially therefront and at a substantial distance above said secured end.
11. A heart valve as set forth in claim 10 including circumferentially spaced stop fingers projecting inwardly from the side of said valve body opposite said valve member.
12. A lteart valve as defined in claim 10, said valve body having an annular channel therearound, and means secur ing said lower end of said cloth sleeve in said channel.
13. A heart valve as defined in claim 10 ine-lding a soft rubber ring enfolded in said upper end of said sleeve.
References Cited by the Examiner UNITED STATES PATENTS 1,890,594 12/1932 Turner 273-653 2,682,057 6/1954 Lord 3-1 2,688,979 9/1954 Kendrick 137-5251 X 3,099,016 7/1963 Edwards 3-1 3,143,742 8/1964 Cromie 3-1 RICHARD A. GAUDET, Primary Examiner.
R. L. FRINKS, Assistant Examiner.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,263,239 August 2, 1960 Miles Lowell Edwards et a1.
It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.
Column 3, line 13, for "provide" read provides line 67, for the claim reference numeral "6" read 3 Signed and sealed this 1st day of August 1967.
EDWARD M. FLETCHER, JR. EDWARD J. BRENNER Ilvfiting Officer Cmnmiseinnvr of Pzuvnis