1. Technical Field
The invention relates to apparatus and methods for prosthesis implantation and is especially useful in aortic valve repair procedures.
2. Background Art
Essential to normal heart function are four 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. In a normally functioning heart, the tricuspid valve allows one-way flow of deoxygenated blood from the right upper chamber (right atrium) to the right lower chamber (right ventricle). When the right ventricle contracts, 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.
Certain heart abnormalities result from heart valve defects, such as valvular insufficiency. Valve insufficiency is a common cardiac abnormality where the valve leaflets do not completely close. This allows regurgitation (i.e., backward leakage of blood at a heart valve). Such regurgitation requires the heart to work harder as it must pump both the regular volume of blood and the blood that has regurgitated. Obviously, if this insufficiency is not corrected, the added workload can eventually result in heart failure.
Another valve defect or disease, which typically occurs in the aortic valve is stenosis or calcification. This involves calcium buildup in the valve which impedes proper valve leaflet movement.
In the case of aortic valve insufficiency or stenosis, treatment typically involves removal of the leaflets and replacement with valve prosthesis. However, known procedures have involved generally complicated approaches that can result in the patent being on cardio-pulmonary bypass for an extended period of time.
Applicants believe that there remains a need for improved valvular repair apparatus and methods that use minimally invasive techniques and/or reduce time in surgery.
The present invention involves valve repair apparatus and methods that overcome problems and disadvantages of the prior art. The present invention may facilitate the delivery and attachment of various prosthetic device into the body. The present invention may also reduce the amount time used to perform a delivery and attachment procedure.
In one aspect of the present invention, a method for attaching a valve prosthesis to a target tissue is provided. The method includes attaching a plurality of anchors each having a guide wire to the target tissue. A delivery device having a fastener housing may be slidably advanced along the guide wires, wherein the fastener housing has grooves or slots for receiving the guide wires. The method may include positioning the delivery device so that fasteners inside the fastener housing will engage the target tissue when the fasteners are deployed. The guide wires may be clipped so that the anchors can remain embedded in tissue when the guide wires are removed.
The method may also include sliding the fastener so that a sewing ring on the valve prosthesis is advanced over barbed portion of the anchor. A second set of fasteners may be deployed with each of the fasteners housed in the anchors. The fasteners may be delivered along a curved path near the distal en of the barbed portion of the anchor. The fasteners may assume a first linear configuration and a second curled configuration once delivered at the target tissue. A proximal end of each of the fasteners may extend outward from an opening on the anchor to secure the fastener to the anchor. The method may include removing the delivery device and leaving the plurality of fasteners with the valve prosthetic attached to the target tissue. A hollow sharpened shaft may be extended from the fastener housing to pierce through a sewing ring on the valve prosthesis. The method may include advancing a push rod through the sharpened shaft to extend a fastener outward from the hollow shaft. The target tissue may be an aortic valve annulus with valve leaflets removed. The valve prosthesis may be a mechanical valve.
In another aspect of the present invention, a device for use with a valve prosthesis is provided. The device to deliver a valve prosthesis to a target tissue may include at least one anchor and at least one guide wire coupled to the anchor. The device may have a fastener housing. The device may also include a first set of fasteners in said fastener housing, wherein the fasteners are movable from a first position to a second, tissue engagement position. The device may also include a second set of fasteners housed in the anchor to attach the anchor to the tissue, wherein the fasteners are movable from a first position to a second, tissue engagement position. The guide wire may be slidably received in the fastener housing and has a length sufficient to extend from the fastener housing to the target tissue site, wherein the guide wire is used to direct the fastener housing into place.
The device may also include an anchor having a sharpened barb portion for attaching the anchor to a sewing ring on the valve prosthesis. The fasteners may have a curved distal portion, a sharpened distal tip, or a blunt distal tip. The fasteners may be made of a shape memory material such as but not limited to nitinol or the like.
The above is a brief description of some deficiencies in the prior art and advantages of the present invention. Other features, advantages, and embodiments of the invention will be apparent to those skilled in the art from the following description and accompanying drawings, wherein, for purposes of illustration only, specific forms of the invention are set forth in detail. A further understanding of the nature and advantages of the invention will become apparent by reference to the remaining portions of the specification and drawings.
A further understanding of the nature and advantages of the invention will become apparent by reference to the remaining portions of the specification and drawings.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. It may be noted that, as used in the specification and the appended claims, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a material” may include mixtures of materials, reference to “a chamber” may include multiple chambers, and the like. References cited herein are hereby incorporated by reference in their entirety, except to the extent that they conflict with teachings explicitly set forth in this specification.
In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings:
“Optional” or “optionally” means that the subsequently described circumstance may or may not occur, so that the description includes instances where the circumstance occurs and instances where it does not. For example, if a device optionally contains a feature for analyzing a blood sample, this means that the analysis feature may or may not be present, and, thus, the description includes structures wherein a device possesses the analysis feature and structures wherein the analysis feature is not present.
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the anchor 20 may include a barbed portion 30 and a curved, sharpened portion 32. As will be discussed later, the barbed portion 30 have barbs or teeth oriented to allow the sewing ring 24 to slide down into position but prevent the sewing ring from pulling off the barbed portion 30 when retracted. The curved portion 32 with the sharpened tip will act as anchors in tissue in the annulus. Fasteners may be housed inside the portion 32 and pushed out by pushers (hidden in this view) inside the guide wire 14.
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While the invention has been described and illustrated with reference to certain particular embodiments thereof, those skilled in the art will appreciate that various adaptations, changes, modifications, substitutions, deletions, or additions of procedures and protocols may be made without departing from the spirit and scope of the invention. For example, with any of the above embodiments, a prosthetic valve or a graft may be premounted on to the apparatus. With any of the above embodiments, the apparatus may be configured to be delivered percutaneously or through open surgery. Some of the embodiments above may not use a barbed portion 32. The number of fasteners used may also be varied. By way of example and not limitation, some embodiments may only have 3-5 fasteners. Others may have more than 10, 15, 20, 25, 30, 25, 40, 45, 50, or more fasteners per sewing ring. It should be understood that the present invention may also be used with non-mechanical valves that have a sewing ring or penetratable outer ring that the fasteners may pierce to secure the valve to target tissue.
The publications discussed or cited herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed. All publications mentioned herein are incorporated herein by reference to disclose and describe the structures and/or methods in connection with which the publications are cited.
Expected variations or differences in the results are contemplated in accordance with the objects and practices of the present invention. It is intended, therefore, that the invention be defined by the scope of the claims which follow and that such claims be interpreted as broadly as is reasonable.
This application claims the benefit of priority from U.S. Provisional Application Ser. No. 60/629,983 (Attorney Docket Number 40450-0010US) filed on Nov. 22, 2004, fully incorporated herein by reference for all purposes.
Number | Date | Country | |
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60629983 | Nov 2004 | US |