The present invention relates generally to an extra-anatomic aortic valve placement, which can be employed to replace the function of a patient's aortic valve.
A heart valve can become defective or damaged, such as resulting from congenital malformation, disease, or aging. When the valve becomes defective or damaged, the leaflets may not function properly. One common problem associated with a degenerating heart valve is an enlargement of the valve annulus (e.g., dilation). Other problems that may result in valve dysfunction include chordal elongation, lesions developing on one or more of the leaflets and calcification of the valve.
It is well known to utilize mechanical heart valves, such as the ball check valve, and natural tissue cardiac valves to replace defective aortic and mitral valves in human patients. One type of natural tissue heart valve typically employs a porcine valve for implantation in a human, as they are very similar to human valves of appropriate size and generally are easy to procure. Typically, the porcine valve is fixed by chemically treating it, such as with an appropriate glutaraldehyde solution. The treated porcine valve further may be mounted into a stent to support the valve at a fixed position.
A stent typically is formed of a resilient material, such as a plastic (e.g., DELRIN). Examples of various stent structures are disclosed in U.S. Pat. No. 3,983,581, U.S. Pat. No. 4,035,849. The stent usually is covered with a fabric material, such as DACRON or a suitable textile material. The fabric material provides structure for securing the valve relative to the stent. The stented heart valve prosthesis may be implanted into a patient for a heart valve replacement.
In order to surgically implant a heart valve into a patient, the patient typically is placed on cardiopulmonary bypass during a complicated, but common, open-chest and open-heart procedure. In certain situations, an individual requiring a heart valve replacement may be sufficiently ill, such that placing the individual on cardiopulmonary bypass may pose too great of risk. As one example, such individuals may correspond to a class of patients who may have severe aortic valve insufficiency. Patients with aortic valve defects often may also exhibit calcification of the aortic valve and the aorta, including one or both of the aortic arch and the descending aorta. When the aorta is calcified, there are increased risks associated with performing cardio pulmonary bypass, as is typically performed for aortic valve replacement procedures. Additionally, patients having a diseased or defective aortic valve may be too ill to survive conventional open-heart surgery, which may include cardio pulmonary bypass.
Patients exhibiting these and other conditions in the aortic valve would benefit from a low invasive approach for replacing the function of the aortic valve.
The present invention relates generally to an extra-anatomic aortic valve placement, which can be employed to replace the function of a patient's aortic valve.
One aspect of the present invention provides an extra-anatomic aortic valve placement method. The method includes creating an aperture through the patient's heart that extends from a location outside of the patient's heart and into a left ventricle of the heart. A valve is mounted at least partially within the aperture and a continuous path is provided for fluid communication from the mounted valve and into the patient's aorta. The method can be implemented in the absence of cardio pulmonary bypass.
Another aspect of the present invention provides a method for extra-anatomic aortic valve placement. The method includes creating an aperture through the patient's heart that extends from a location outside of the patient's heart and into a left ventricle of the heart (e.g., through the apex of the patient's heart). The aperture is obstructed to inhibit blood loss through the aperture. A valve is mounted at least partially within the aperture while the aperture is obstructed. A length of a flexible conduit is attached between an outflow end of the valve and the patient's aorta to provide for substantially unidirectional flow of blood from the left ventricle, through the conduit and into the patient's aorta, the method being performed in the absence of cardio pulmonary bypass.
Still another aspect of the present invention provides a system for extra-anatomic aortic valve placement. The system includes means for creating an aperture through the patient's heart that extends from a location outside of the patient's heart and into a left ventricle of the heart. The system also includes means for obstructing the aperture to inhibit blood loss through the aperture and valve means for, when mounted at least partially within the aperture, providing substantially unidirectional flow of blood from the left ventricle and through the means for providing. The system also includes means for, when connected between the valve means and the patient's aorta, providing for fluid communication along a continuous path from the left ventricle into the patient's aorta.
In the example of
The valve member 14 can be mounted within the support between an inflow end 20 and an outflow end 22 of the prosthesis 12. In
The valve member 14 includes at least one moveable member 28 that is configured as means for providing substantially unidirectional flow of blood through the valve prosthesis 12. In the example of
The support 16 includes axially spaced apart ends 30 and 32 interconnected by generally axially extending support features 34. In the example of
The support 16 further includes one or more projections or spikes 40 that extend axially and radially outwardly from at least some of the respective end junctures 36 and/or 38 of the support. While a pair of such spikes 40 are illustrated as associated with each end juncture 36, 38, other number of spikes can be implemented, such as single spike or more than two spikes at some or all of the junctures. In the example illustrated in
The support 16 can be formed a shape memory material, such as NITINOL. For example, the support can be formed from a small cylindrical tube of the shape memory material, such as via a laser cutting (ablation) process in which the desired sinusoidal sidewall is cut from the tube. In this way, the support features 34, the interconnecting end junctures 36 and 38, and associated spikes 40 can be formed as an integrated (e.g., monolithic) structure having a desired shape and size. Additionally, ends of the spikes 40 can have tapered or sharpened tips to facilitate gripping surrounding tissue when implanted. For example, the spikes 40 can be formed by laser cutting from the same tube or, alternatively, they could be welded onto the support 16 at desired positions. The resulting structure can then be heated to its transformation temperature and forced to a desired cross-sectional dimension and configuration (its austentic form), such as shown in
The prosthesis 12 can also include an outer sheath 42 of a substantially biocompatible material. The outer sheath 42 covers at least a substantial amount of exposed portions of the support 16, such as including the ends 20 and 22, to mitigate contact between the blood and the support when the prosthesis 12 is implanted. The valve member 14 further can be attached relative to the sheath 42, such as by sutures along the inflow and outflow ends of the prosthesis. Such sutures (not shown) further can connect the valve member 14 and the sheath 42 relative to the support 16. The outer sheath 42 can cover the entire support, such that all non-biological material is completely covered, for example. The outer sheath 42 can be formed of one or more natural tissue sheets (e.g., animal pericardium, dura matter, fascia lata), although other natural or synthetic biocompatible materials also could be used to provide an outer sheath in accordance with an aspect of the present invention.
The natural tissue material utilized to provide the outer sheath 42 can include a NO-REACT® tissue product, which is commercially available from Shelhigh, Inc., of Union, N.J. The NO-REACT® tissue products help improve the biocompatibility of the apparatus 50, thereby mitigating the likelihood of a patient rejecting an implanted prosthesis that includes the apparatus. The NO-REACT® tissue products also has been shown to resist calcification when implanted in vivo. The NO-REACT® tissue products further have been shown to facilitate growth of endothelium after being implanted.
The prosthesis 12 can also include an outflow flange 44 that extends radially outwardly from the sidewall of the prosthesis adjacent the outflow end 22. The flange 44 facilitates attachment to the heart, such as described herein. The flange 44 can be any substantially biocompatible material, such as a natural tissue material (e.g., pericardium, dura matter, fascia lata), a synthetic material (e.g., DACRON) or a combination of natural and synthetic materials (e.g., a collagen impregnated fabric). One example of a natural tissue is a sheet of animal pericardium that has been fixed and substantially detoxified, such as formed from NO-REACT tissue product mentioned herein. The flange 44 can be attached to the exterior of the prosthesis 12 (e.g., by sutures). For example, the flange 44 can be spaced apart from the outflow end 22 a small distance, such as from about 2 mm to about 7 mm, which distance may vary depending on the size of the valve prosthesis 12 and/or the size of the patient's heart. The flange 44 can extend radially outwardly from the sidewall of the prosthesis 12 a predetermined distance (e.g., from about 3 mm to about 10 mm).
While the example valve 12 in
The system 10 also includes an elongated flexible conduit 50. The conduit 50 includes a side wall portion 52 that extends longitudinally between spaced apart ends 54 and 56. The conduit can be curved to facilitate attachment between the heart and a patient's aorta, such as described herein. At least one of the ends 54, 56 is dimensioned and configured for attachment to the outflow end of the valve prosthesis 12. For example, the end 54 can be attached (e.g., by sutures) in a circumscribing relationship with the outflow end portion 22 of the valve prosthesis 12 such that the combined valve and conduit 50 provides for substantially unidirectional flow of fluid therethrough.
As an example, the conduit 50 is formed of a tube of a substantially biocompatible material and is configured to provide for fluid communication between the spaced apart ends 54 and 56. For instance, the conduit 50 can be formed of a biological material (e.g., animal pericardium, dura matter, collagen) or synthetic material (e.g., DACRON, another polymer or the like) or as well as a combination of materials which can be natural and/or synthetic. By way of further example, the conduit 50 can be formed from an elongated sheet of animal pericardium that can be folded along a longitudinal axis and its corresponding side edges attached together and in which the tubular portion is fixed over a substantially corrugated mandrel to provide circumferential corrugations 58 along its length. Those skilled in the art will understand and appreciate that the corrugations 58 can be provided in other ways for the conduit 50.
The system 10 can also include a sheet of a biocompatible flexible material that can be applied to the heart to facilitate attachment of the valve 12 and the conduit 50 to the patient's heart. The sheet 70 can be substantially rectangular sheet as shown in
The system 10 also includes a balloon catheter 80 includes an elongated tube 82 of a substantially flexible material that extends between a proximal end 84 and a distal end 86. A balloon circumscribes a portion of the tubular member 82 near the distal end 86. The balloon 88 is in fluid communication with a lumen that extends longitudinally through the tubular member 82, which can be utilized to inflate the balloon 88 to an expanded condition, indicated by dashed lines at 88′. As an example, the lumen within the tubular member 82 is connected to an inflation member 90 that is coupled to the tubular member 82 near the proximal end 84. The inflation member 90 provides access to the lumen for inflation and deflation of the balloon 88. As an example, an inflation fluid such as air, saline, plasma, blood or other biocompatible inflation fluid can be introduced into the lumen of the tubular member 82 via the inflation member 90. The balloon 88 thus responds to introduction of inflation fluid by inflating toward its expanded condition 88 commensurate with the amount of fluid introduced into the catheter 80. As an example, the inflation fluid can be introduced by a syringe or other inflation mechanisms known or yet to be developed in the art.
The system 10, or at least a portion thereof, can be employed to perform an extra-anatomic aortic valve placement procedure according to aspect of the present invention.
As shown in
By further example, the implanter 120 can be employed to facilitate sutureless implantation of the valve 12 into the aperture 100, such as under direct vision of the surgeon into the aperture 100. The implanter 120 includes an elongated cylindrical barrel 122 that extends from a body portion 124 and terminates in a distal open end 126. The barrel 122 has an inner diameter that is less than the outer diameter of the valve prosthesis 12 in its expanded condition. Thus, in order to insert the prosthesis 12 into the barrel 122, the prosthesis is deformed to a reduced cross-sectional dimension, that is less that its fully expanded condition.
For example, the inner diameter of the barrel 122 can range from about 5 mm to about 20 mm, whereas the outer diameter of the valve prosthesis 12 (in its expanded condition) typically ranges from about 15 mm to about 35 mm. Thus, the barrel 122 can accommodate a prosthesis 12, which has been deformed to reduced cross-sectional dimension, without compromising the durability and operation of the valve. The exterior of the barrel 122 further can include indicia (e.g., ruler markings) 710 that can help indicate the distance the barrel is inserted into a patient's heart 102, such as for positioning the inflow end 20 of the prosthesis 12 a predetermined distance into the heart.
By way of further example, prior to reducing the cross-sectional size of the valve and before inserting the prosthesis 12 into the barrel, the elongated tubular member 82 of the catheter 80 can be inserted axially through the valve member 28 of the prosthesis 12. The prosthesis 12 can then be slid along the tubular member 82 toward the aperture 100 so that the remaining length of the tubular member 82 and the proximal end extend therefrom. The tubular member 82 can then be inserted through a central lumen 128 of the implanter 120 and out a proximal end 130 of the implanter. The lumen 128 also provides a passage through which one or more other elongated objects (e.g., sutures or other instruments) can be inserted. The prosthesis 12 can then be inserted into the barrel 122 of the implanter. In this way, the prosthesis 12 can be implanted without removing the balloon 88 so that cardiopulmonary bypass is not required. Alternatively, the catheter 80 can be inserted through the implanter 120 prior to its insertion and inflation of the balloon within the patient's heart 102.
The implanter 120 also includes a handle 132 that extends outwardly from a proximal end 134 of the body portion 124. A plunger 136 has a distal end 138 that can be urged into engagement with the outflow end 22 of the prosthesis 12 to push the prosthesis discharge it from the open end 126 of the barrel 122. The plunger 136 includes an elongated portion that extends from its distal end 138 and terminates in a proximal end portion 140. The plunger 136 includes the lumen 128 that is sized to enable feeding the tubular member 82 through the implanter 120. The proximal end portion 140 of the plunger 136 operates as a trigger that can be grasped in conjunction with the handle 132 by a surgeon to move the plunger axially through the barrel 122. Other means to discharge the heart valve prosthesis 12 could also be utilized in accordance with an aspect of the present invention. Fluid, such as saline, can also be introduced into the barrel 122, such as through the lumen 128, to facilitate the discharge of the prosthesis 12 from the barrel.
The implanter apparatus 120 can also include a spring (or other means) 144 for resisting movement of the plunger 136 relative to the body 124. The spring 144 engages a distal end 146 within the interior of the body portion 124 and an adjacent shoulder surface 148 of the plunger 136. The spring 144 is thus biased to urge the plunger surface 148 axially apart away from the end 146 of the body portion 124. The amount of tension provided by the spring 144 can be tuned to provide an ergonomic feel for the user.
As mentioned above, the prosthesis 12 includes a self-expanding support 16. Thus, the heart valve prosthesis 12 can expands toward its fully expanded condition as it is discharged from the barrel 122. Alternatively, other means can be employed to expand the valve prosthesis 12. For the example valve 12 shown and described herein, the projections or spikes 40 can insert into surrounding tissue to maintain the valve at a desired axial and angular, thereby anchoring the prosthesis 12 relative to the aperture 100. As the prosthesis 12 is being discharged, the implanter barrel 122 can be concurrently withdrawn from the heart, as is being shown in
While the implantation can be performed completely sutureless, those skilled in the art will understand and appreciate that one or more sutures can be utilized to further help secure the prosthesis 12 relative to the surrounding tissue 110 along the aperture 100. As depicted in
In
In the example of
In view of the foregoing, those skilled in the art will understand and appreciate that the extra-anatomic aortic valve placement provides a low-invasive alternative to aortic valve replacement, such as for patients that might be considered high risk. Additionally, the approach described herein further enables the procedure to be implemented in the absence of cardio pulmonary bypass. It is to be further understood that the patient's aortic valve 116 can be closed, such as by sutures, at some point during the procedure. Alternatively, the aortic valve 116 can remain unmodified, as the procedure may be performed when the aortic valve is substantially non-functioning or dysfunctional. The valve 12 and conduit 50 thus can provide an alternative blood flow path with significantly improved functionality relative to the patient's existing aortic valve 116. The patient's existing valve 116 can be the patient's own native valve or a prior replacement valve, which has failed or no longer functions adequately for the patient.
What have been described above are examples of the present invention. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present invention, but one of ordinary skill in the art will recognize that many further combinations and permutations of the present invention are possible. Accordingly, the present invention is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims.
This application is a continuation-in-part of application Ser. No. 10/266,380, which was filed on Oct. 8, 2002, and entitled HEART VALVE PROSTHESIS AND SUTURELESS IMPLANTATION OF A HEART VALVE, which is a continuation-in-part of U.S. patent application Ser. No. 09/973,609, which was filed on Oct. 9, 2001, and entitled HEART VALVE PROSTHESIS AND SUTURELESS IMPLANTATION OF A HEART VALVE PROSTHESIS, which is a continuation-in-part of U.S. patent application Ser. No. 09/659,882, which was filed on Sep. 12, 2000 and entitled VALVULAR PROSTHESIS AND METHOD OF USING SAME, all of which applications are incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
Parent | 10266380 | Oct 2002 | US |
Child | 11355732 | Feb 2006 | US |
Parent | 09973609 | Oct 2001 | US |
Child | 10266380 | Oct 2002 | US |
Parent | 09659882 | Sep 2000 | US |
Child | 09973609 | Oct 2001 | US |