RECONFIGURING HEART FEATURES
Among other things, a heart tissue support has gripping elements, each element having a free end that is sharp enough to penetrate heart tissue when pushed against the tissue, and a feature to resist withdrawal from the tissue after the sharp free end has penetrated the tissue. Among other things, the shape of a heart valve annulus is corrected in a catheter laboratory by orienting a tip of a catheter holding a heart tissue support that has gripping elements at the valve annulus, applying a radial force from the catheter against the annulus by opening a structure at the tip of the catheter, and while the structure is opened, forcing the support onto the annulus. Among other things, the shape of a heart valve annulus is corrected during a surgical procedure by pushing a heart tissue support that has gripping elements onto the annulus.
This is a continuation-in-part of U.S. patent application Ser. No. 11/620,955, filed on Jan. 8, 2007, which is incorporated herein in its entirety by reference.
BACKGROUNDThis description relates to reconfiguring heart features.
The annulus of a heart valve (a fibrous ring attached to the wall of the heart), for example, maintains the shape of the valve opening and supports the valve leaflets. In a healthy heart, the annulus is typically round and has a diameter that enables the leaflets to close the valve tightly, ensuring no blood regurgitation during contraction of the heart. Because the annulus of the tricuspid valve, for example, is supported more stably by the heart tissue on one side of the annulus than on the other side, and for other reasons, the size and shape of the annulus may become distorted over time. The distortion may prevent the valve from closing properly, allowing blood to regurgitate backwards through the valve. The distortion can be corrected, for example, during open heart surgery, by attaching a ring or other support around the annulus to restore its shape and size.
SUMMARYIn general, in an aspect, a heart tissue support has gripping elements, each gripping element having a free end that is sharp enough to penetrate heart tissue when pushed against the tissue, and a feature to resist withdrawal of the gripping element from the tissue after the sharp free end has penetrated the tissue.
Implementations may include one or more of the following features. The free ends of the gripping elements may project away from a surface of the support. The feature that resists withdrawal of the gripping element from the tissue may comprise a finger projecting laterally from the gripping element. The heart tissue support may comprise an annular surface bearing the gripping elements. The support may be expandable and contractible. The support may have a native size that is configurable. A wire may configure the native size. The support may comprise at least one of stainless steel, gold, Nitinol, or a biologically compatible elastomer. The support may comprise a torus. The support may comprise a helically wound portion. Some portions of the support may bear no gripping elements. The gripping elements may be organized in a pattern. The pattern may comprise rows. The pattern may comprise a group in which the gripping elements are more densely placed and a group in which the gripping elements are less densely placed. The pattern may comprise arcs. The pattern may comprise clusters. The pattern may comprise random placement. At least some of the gripping elements may comprise at least one of platinum, gold, palladium, rhenium, tantalum, tungsten, molybdenum, nickel, cobalt, stainless steel, Nitinol, and alloys of any combination of them. The gripping elements may have the same size. Some of the gripping elements may be of different sizes. At least some of the gripping elements may have more than one of the feature that resists withdrawal. At least some of the gripping elements may project from the surface orthogonally. At least some of the gripping elements may be curved. The heart tissue support may also include a sleeve through which tissue can grow. The sleeve may comprise polyethylene terephthalate. There may be between about 15 and a million gripping elements on the support. There may be between about 100 and about 100,000 gripping elements. The gripping elements may comprise burr hooks. The gripping elements may comprise arrows. The gripping elements may comprise hooks.
In general, in an aspect, the shape of a heart valve annulus is corrected in a catheter laboratory by orienting a tip of a catheter holding a heart tissue support that has gripping elements at the valve annulus, applying a radial force from the catheter against the annulus by opening a structure at the tip of the catheter, and while the structure is opened, forcing the support onto the valve annulus.
In general, in an aspect, the shape of a heart valve annulus is corrected during a surgical procedure by pushing a heart tissue support that has gripping elements onto the valve annulus.
In general, in an aspect, a method comprises attaching, to different sized heart valve annuli in different patients, supports that can be expanded in preparation for attachment and allowed to contract to a common relaxed, non-expanded native size when they are in place on the annuli, and reducing the sizes of at least some of the in-place supports to be smaller than the common relaxed non-expanded native size, to accommodate the different sized heart valve annuli of different patients.
In general, in an aspect, a heart tissue support comprises a large number of small grippers, each having a tissue penetration feature and a retention feature, and the configuration of the grippers relative to a configuration of a given area of heart tissue to which the support is to be attached by force being such that the penetration features of a failed set of the grippers will fail to penetrate the tissue, the penetration features of a second set of the grippers will successfully penetrate the tissue, the retention features of a subset of the second set of grippers will fail to retain the grippers in the tissue, and the retention features of the remaining grippers of the second set will successfully retain the grippers in the tissue and hold the support in an intended configuration on the tissue.
In general, in an aspect, a method comprises pushing a support onto a region of heart tissue to cause only a portion of a number of small grippers on the support to embed themselves and be retained in the tissue, the portion being sufficient to attach the support securely to the heart tissue.
In general, in an aspect, an annular heart valve support is expandable and contractible and bears gripping elements configured to penetrate heart tissue and to retain the elements in the tissue after penetration.
In general, in an aspect, a tool to attach a support to a heart valve annulus comprises mechanisms to hold the support in an expanded configuration prior to attachment, to expand the heart valve annulus prior to attachment, to enable the attachment of the support in its expanded configuration to the expanded valve annulus, and to release the expanded support to a contracted configuration after the attachment.
Implementations may include one or more of the following features. The tool may be attached to an end of a catheter. The tool may also comprise an inflatable balloon. The balloon may play a role in positioning the tool. The mechanisms may also be to remove the tool from the heart after attachment.
In general, in an aspect, tool to attach a support to a heart valve annulus comprises a structure to expand the annulus of the heart to a predetermined shape under control of an operator.
Implementations may include one or more of the following features. The structure of the tool may have a conical outer surface at least a portion of which conforms to the predetermined shape. The structure of the tool may have an outer surface that can be expanded to the predetermined shape.
Among advantages of these and other aspects and features are one or more of the following. The operator need not work as slowly in order to correctly attach the heart tissue support to the annulus, nor does placement require as much precision. Not all of the burr hooks or grippers need be attached to the annulus to keep the support in place. Some of the burr hooks or grippers might fail to grab onto tissue, or be pulled away from tissue by force. Nonetheless, as long as a minimum threshold percentage of the burr hooks or grippers remain in place, so will the tissue support. Further, because of its ease and simplicity, this procedure can be done in a catheterization laboratory, as well as in surgery.
These and other aspects and features, and combinations of them, may be expressed as apparatus, methods, systems, and in other ways.
Other features and advantages will be apparent from the description and the claims.
As shown in the examples of
A. Push 201 (
B. Continue to push 201 the delivery tool to drive an expanded heart valve support 100 (which has the desired configuration and the larger size and is temporarily held in its expanded configuration on the basket of the tool) towards the annulus to seat multiple (for example, eight, as shown, or a larger or smaller number of) recurved hooks 120 located along the periphery of the support simultaneously into the valve tissue at multiple locations along the periphery 121 of the annulus (
C. After the hooks are seated, pull 204 (
D. After the hooks are further embedded, continue to pull 204 (
The entire procedure can be performed in less than a minute in many cases. By temporarily forcing the annulus of the valve to expand to the desired circular shape, it is possible to attach the support quickly, easily, and somewhat automatically by forcing multiple gripping elements into the tissue at one time. Hooks are used in this example, although other types of gripping elements may be used as well. The physician avoids the time consuming steps of having to attach individual sutures or clips one at a time along the periphery of a distorted annulus and then cinch them together to reform the supported annulus to a desired shape and size. Thus, the physician does not even need to be able to see the annulus clearly (or at all). Once attached, when the tool is removed, the support automatically springs back to its final shape and size.
As shown in
In some examples, the body 110 has the same (e.g., circular) shape but different diameters in the delivery configuration and the long-term configuration. The body is constructed of a material or in a manner that biases the body to contract to the long-term configuration. For example, all or portions of the body 110 may be formed as a helical spring 110a such as a continuous helical spring connected at opposite ends to form a circular body or one or more interconnected helical spring segments (
The hooks 120 may number as few as three or as many as ten or twenty or more and may be arranged at equal intervals along the body or at unequal intervals as needed to make the body easy and quick to deliver, permanent in its placement, and effective in correcting distortion of the valve annulus. The hooks are configured and together mounted along the circular outer periphery so that they can be inserted simultaneously into the tissue along the periphery of the annulus and then firmly embedded when the tool is pulled away and the basket is everted.
In some examples, a portion or portions of the support body may not have hooks attached if, for example, a segment of the valve annulus shares a boundary with sensitive or delicate tissue, such as the atrioventricular (AV) node of the heart. This tissue should not be pierced by the hooks. A support body configured to avoid interfering with the AV node could have a section having no hooks attached or otherwise covered or protected to prevent penetration by hooks into the AV node. The support body should be positioned so that this special section of the support body is adjacent the sensitive or delicate tissue as the support body is put into place. The support body may have more than one special section lacking hooks, so that the operator has more than one option when placing the support body near the sensitive tissue. In some examples, the support body could have a section removed entirely, and would be shaped somewhat like the letter “C” instead of a complete ring. In any of these examples, the procedure described above could have an additional step preceding step A, in which the operator rotates the delivery head to position the section having no hooks or to position the gap in the support body to be adjacent to the sensitive tissue at the moment when the hooks are to be embedded in the other tissue. The support body may have radiopaque marks to help the operator view the positioning.
For this reason, as shown in
Each hook 120 can be formed of biologically compatible materials such as platinum, gold, palladium, rhenium, tantalum, tungsten, molybdenum, nickel, cobalt, stainless steel, Nitinol, and alloys, polymers, or other materials. During delivery the barbs of the hooks are together (and more or less simultaneously) forced into the tissue at a series of locations around the outer periphery of the temporarily expanded annulus. In a later step, the sharp free ends are forced to rotate somewhat away from the leaflets for secure (e.g., permanent) attachment.
To cause the hooks to rotate during delivery, the hooks 120 are attached permanently to the support body 110 and the support body can be rolled 123 (
In some examples, applying an axial force (arrows 113) to the inner peripheral edge of the ring (we sometimes refer to the support broadly as a ring) will cause the ring to tend to roll and the hooks to embed themselves in the annulus as intended. By appropriately mounting the inner periphery of the ring on the outer periphery of the delivery tool, the axial force 113 can be applied by pulling the tool away from the leaflets of the valve, as explained earlier.
For delivery to the valve annulus, the valve support 100 is first expanded to its delivery configuration and temporarily mounted on a delivery head 220 of the tool 200 (
The heart valve support 100 is held in place on the delivery head 220 using one or more releasable connections 246. The connections 246 are arranged to translate forces from the tool 200 to the support 100 in each of two opposite directions 248 and 250, toward or away from the leaflets of the valve. When the support has been embedded in the annulus and the tool is pulled in the direction 250 to release it from the support, the force on the connections 246 exceeds a predetermined threshold, and the connections break, releasing the tool from the support at the end of the delivery process. The connections 246 may be, in some examples, breakable sutures 252 (
In some examples, the connections 246 include retainers that can take, e.g., the configurations shown as 254a or 254b (
In the example shown in
As shown in
The example of the basket shown in
In some implementations, the shaft 210 defines a lumen 236 extending between the heart valve end 218 of the shaft 210 and the handle 212. A wire 238 is arranged to move freely back and forth within the lumen 236. The wire 238 has one end 240 that extends from the handle 212 and an opposite end 242 that is connected to the inside of tip 228. The wire 238 can be pulled (arrow 244) to cause the delivery head 220 to collapse (hidden lines) and evert radially inwardly starting at the tip 228 as mentioned earlier.
Returning to a more detailed discussion of
As the operator continues to push on the tool, the ring of barbs of the hooks touch and then enter (pierce) the heart tissue along a ring of insertion locations defined by the outer periphery of the annulus, and the sharp free ends of the hooks enter and seat themselves within the tissue, much like fish hooks. Depending on how the operator guides the tool, the basket can be oriented during insertion so that essentially all of the hooks enter the tissue at the same time. Or the tool could be tilted during insertion so that hooks on one side of the support enter the tissue first and then the tool delivery angle could be shifted to force other hooks into the tissue in sequence.
Generally, when the number of hooks is relatively small (say between 6 and 20, comparable to the number of sutures that the physician would use in conventional stitching of a ring onto an annulus), it is desirable to assure that all of the hooks penetrate the tissue and are seated properly.
Once the hooks are embedded in the tissue, the operator pulls on the near end 240 of wire 238 to cause the basket 220 to collapse, evert, and be drawn out of the valve 16. Eventually, the everted portion of the basket reaches the valve support 100. By further tugging, the operator causes the body 110 of the support 100 to roll about its central axis (as in the o-ring example mentioned earlier) which causes the hooks 120 to embed more firmly in the tissue of the annulus 18 of the valve 16.
Using a final tug, the operator breaks the connections between the tool 200 and the valve support 100 and removes the tool 200, leaving the valve support 100 in place. As the everting basket 220 passes the points of connection 246, the retaining forces exerted by the embedded hooks 120 of the support body 110, acting in direction 248, exceed the forces exerted by the withdrawing basket 220 on the support body 110 (through the connections 246), acting in direction 250, thereby causing the connections 246 to break or release, in turn releasing the support 100.
The tool 200 is then withdrawn, allowing the valve support 100, along with the annulus 18, to contract to the long-run configuration.
In implementations useful for delivery of the support percutaneously, as shown in
The projections 216a are resiliently mounted to the catheter shaft 210a and are biased towards the expanded, tapered orientation shown, for example, by spring biased projections 216b shown in
A wire 238a slides within a lumen 236a of the shaft 210a in a manner similar to the one described earlier.
The tool 200a also includes a sheath 280 in which the catheter shaft 210a can slide during placement of the support. The sheath 280, the catheter shaft 210a, and the wire 238a are all flexible along their lengths to allow the tool 200a to be deflected and articulated along a blood vessel to reach the heart and to permit manipulation of the delivery head once inside the heart.
To deliver the support percutaneously, as shown in
The sheath 280 is then moved along the catheter shaft 210a towards the delivery head 220, causing the projections 216a and the delivery head 220a to contract radially inwardly to fit within the sheath 280, as shown in
To deliver the support to the valve annulus, the end 230 of the tool 200a is fed percutaneously through blood vessels and into the right atrium 24 (
In steps that are somewhat similar to the open heart placement of the support, the catheter shaft 210a is then advanced, e.g., under image guidance, in the direction 248a along an axis 30 of the annulus 18. The operator forces the distal end 230a of the self-centering delivery head 220a into the valve 16 (
Once the tip is in the valve 16, the operator pushes on the end 214a of the catheter shaft 210a to force the tool further into the valve 16. This causes the tapered body 222a of the delivery head 220a to restore the shape of the annulus 18 to a circle or other desired shape (such as the distinctive “D” shape of a healthy mitral valve). The tool 200a tends to be self-centering because of its shape. The net-like construction of the delivery head 220a (and the head used in open heart surgery, also) allows blood to flow through the valve even while the delivery head 220a is inserted.
As tool 200a reaches the position at which the support hooks touch the annulus, by giving an additional push, the operator drives the hooks 120 of the valve support 100 together into all of the annular locations at which it is to be attached, as shown in
Once the valve support 100 has been attached to the valve 16, the operator pulls on the proximal end 240a causing the delivery head 220a to evert (hidden dashed lines) and be drawn out of the valve 16 (shown in
Using a final tug, the operator breaks the connections 246 between the tool 200a and the valve support 100 and retracts the catheter shaft 210, leaving the support 100 in place. The catheter shaft 210 is retracted to a position beyond the valve annulus 18 and the wire is advanced in the first direction allowing the delivery head 220a to assume its original tapered shape (
In some examples, as shown in
With the tool 200a withdrawn, the valve support 100 contracts, reshaping the annulus 18 such that the valve leaflets 14 coapt to prevent a backflow of blood during systole.
Other implementations are within the scope of the claims.
For example, distortion of either the tricuspid valve or mitral valve can be corrected. For tricuspid valve repair, the hooks can be arranged around only about three-quarters of the support and therefore the annulus. During the placement procedure, the operator will rotate the support to position the portion of the support having hooks. For mitral valve repair, the hooks can cover the entire periphery of the annulus. In this scenario, the hooks are arranged around the full circumference of the support. Alternatively, the hooks can cover only the posterior section of the annulus of the mitral valve. In this scenario, the hooks can be arranged around two-thirds of the support. Similarly to the tricuspid valve example, the operator will position the portion of the support having hooks against the posterior section of the mitral valve annulus. Further, for mitral valve repair, a back-up valve can be provided as part of the delivery tool to maintain heart function during the delivery procedure. Materials other than shape memory materials may be used as the material for the support body, and other ways can be used to force the support back to a desired size following expansion, including, for example, cross-bars that span the opening of the support.
In addition, the left atrial appendage of the heart can be closed by a similar technique. For example, the tool can be pushed into an opening of an atrial appendage causing the opening to assume a predetermined shape. The tool can continue to be pushed in order to embed the hooks of the expanded support into the periphery of the opening of the appendage. The tool can then be withdrawn, releasing the support, and allowing the support to contract. The support can have a relatively small contracted diameter such that, when the tool is withdrawn, releasing the support, the support can contract to a relatively small size, effectively closing off the appendage.
In addition to the open heart and percutaneous deployment procedures, the valve support can also be deployed through the chest.
The head-end of the tool need not be a basket, but can take any form, mechanical arrangement, and strength that enables the valve annulus to be forced open to a shape that corresponds to the shape of the support. The basket can be made of a wide variety of materials. The basket can be held and pushed using a wide variety of structural mechanisms that permit both pushing and pulling on the support both to seat and embed the support in the annulus tissue and disconnect the support from the tool.
The tool need not be conical.
The support could take a wide variety of configurations, sizes, and shapes, and be made of a wide variety of materials.
The hooks could be replaced by other devices to seat and embed the support using the pushing force of the tool.
The hooks of the support need not be embedded directly in the annulus but might be embedded in adjacent tissue, for example.
The support could take other forms and be attached in other ways.
In
A close-up view of a fragment of this support body,
The burr hooks, which are small relative to the body, are each configured to partially or fully pierce annular tissue when the part of the body to which the burr hook is attached is pushed against the tissue.
As shown in
Each burr hook 120a can be structured and attached so that the free end 122a points in a direction 122b perpendicular (or some other selected effective direction, or deliberately in random directions) to the body surface 111. In some cases, the burr hook can be curved. A barbed end 128a could be located on a concave edge 113 (
The burr hooks bear a resemblance to burr hooks on natural plant burrs. A different kind of attachment device could be used by analogy to metal tipped hunting arrows in which a sharp point has two broad and sharp shoulders that cut the tissue as the point enters. The tips of the two shoulders serve a similar function to the barbs, keeping the arrow embedded once it enters the tissue.
In some implementations, the burr hooks on a support body have two or more (in some cases, many) different shapes, sizes, orientations, materials, and configurations. By varying these features, for example, the orientations of the burr hooks, it may be more likely that at least some of the burr hooks will become embedded in the tissue, no matter how the support body is oriented at the moment that it comes into contact with the annulus. Varying the number, orientation, and curvature of the hooks may make it more likely that the support body will remain in place. For example, in such a support, a force applied to the support body in a particular direction may unseat or partially unseat some of the burr hooks by disengaging the barbed ends from the tissue, but the same force may not affect other burr hooks that have barbed ends oriented in a different direction or in a different configuration than the unseated burr hooks. The force applied to seat the support may cause some burr hooks to embed more securely than other burr hooks.
In use, typically not all of (in some cases not even a large portion of) the burr hooks will embed themselves in the tissue when the support body is pushed against the tissue, or remain embedded after placement. As shown in
When the burr hooks come into contact with the annular tissue during delivery, some 131, 133, but not necessarily all, of the burr hooks pierce the tissue and (when a retracting force is applied to the delivery tool) their barbs grip the tissue. Of the remaining burr hooks, some 135, 137 may (because of the contours of the tissue, for example) not even come into contact with the tissue, and others 139, 141 may not come into contact with the tissue with sufficient force or in the right orientation to pierce the tissue and have their barbs seat securely in the tissue. Some of the burr hooks 143, 145 may penetrate the tissue but fail to grip the tissue. Some of the burr hooks 147, 149 may only penetrate the tissue at the barbed end 128a, and not with respect to the free end 122a, providing a physical bond that may be weaker than one in which the free end has been embedded in the tissue. For some or many or most of the burr hooks that enter the tissue, however, the barbed ends 128a seat properly and resist forces in the direction 151 that would otherwise unseat the burr hook. Even though a wrenching force applied to a particular burr hook in direction 151 could still be large enough to unseat the barbed end, overall the combination of many burr hooks embedded in tissue tends to keep the support body set in place and in the proper configuration. Over time, some of the burr hooks that were not embedded when the support was placed may become embedded, and some of the burr hooks that were embedded when the support was placed may become unseated.
The resistance provided by each of the barb or barbs to removal of a given burr hook from the tissue may be relatively small. However, the aggregate resistance of the burr hooks that successfully embed themselves will be higher and therefore can reliably keep the support body in place and the annulus of the valve in a desirable shape. In addition, because there are a number (potentially a very large number) of small burr hooks spread over a relatively large area, the stress on any part of the tissue of the annulus is quite small, which helps to keep the support body properly seated and the valve shape properly maintained along its entire periphery, all without damaging the tissue. The fact that a large number of burr hooks at close spacings may become embedded along the length of the support means that the support may become attached to the annulus more evenly and continuously than might be the case with the relatively smaller number of hooks described earlier, and therefore perform better.
With respect to the implementations described beginning with
Each burr hook can be formed of a biologically compatible material such as platinum, gold, palladium, rhenium, tantalum, tungsten, molybdenum, nickel, cobalt, stainless steel, Nitinol, and alloys, polymers, or another material. As for the hooks shown beginning with
The length 901 of each burr hook could be between about 1 and 12 millimeters, as measured from the attached end 124a to the free end 122a along the principal axis. Each barbed end could extend a distance 902 from the burr hook lesser or greater than a principal width or diameter 903 of the burr hook as measured at the attached end. The cross-section of the body of the burr hook could be flat or cylindrical or ovoid or any other of a wide variety of shapes.
Different burr hooks may be placed on the support body surface in different sizes and configurations. For example, different burr hooks may have different lengths and different numbers and placement of barbed ends. As shown in
A single support body can include a wide variety of patterns of burr hooks on its surface, because the physical characteristics of a particular heart valve may mean that the valve tissue is either more receptive or less receptive to a particular pattern of burr hook distribution. Some patterns may be more effective on some types of tissue, and other patterns may be more effective on other types of tissue.
In addition, as shown in
As shown in
As shown in
The sleeve is formed as a half-torus in this example, but could have a wide variety of other configurations. Such a sleeve may be used with any kind of support, including the one shown beginning in
Using burr hooks may make attaching the support faster, simpler, more reliable, and easier than for the larger hooks described earlier. The delivery tool operator may not need to apply as much force as might be necessary to embed larger hooks in the annular tissue. In some cases, the barbs would not need to be rotated as described for the larger hooks in order to embed them securely. The operator need not be concerned whether all of the burr hooks have become embedded. Once the operator has determined that the support body has made contact with the tissue and by inference that many of the burr hooks have become attached, the operator can tug on the support to confirm that it has been seated and then release the support body from the delivery tool using one of the mechanisms described earlier. Because of the ease of positioning, the procedure could be performed easily in a non-surgical context, such as in a catheterization laboratory.
As shown in
In some of the examples described earlier, the annulus of the heart valve is expanded to the desired shape by pushing a conical surface, such as the basket, along the axis of and into the heart valve. Whether the delivery is done in the context of open heart surgery or in a catheterization lab, or elsewhere, the pushing of the conical surface into the annulus can be supplemented by or replaced by a technique in which the expansion of the annulus is done after the delivery tool is inserted into the valve.
During delivery, shown in
If the support body is made of a material or alloy that is appropriately plastic, the support body may not fully contract to its original native diameter. However, if the support body is made of a shape memory alloy such as Nitinol, the memory effect of the alloy will tend to cause the support body to contract to a diameter nearly identical or identical to its original diameter.
As shown in
As shown in
As shown in
Two non-binding sections are shown, but the support body can also have three or more of these sections. The non-binding sections 974, 978 span angles 975, 979 between about 40 and 60 degrees of the total circumference. In the example of two non-binding sections, there will also be two binding sections 980, 982 spanning angles 981, 983 of the remaining two lengths of circumference.
As shown in
As shown in
For example, the implementation of the sheath 280a shown in side section in
As shown in
Referring to
When the delivery head 220 expands, the sheath 280a is also released from the crossbar. A cross-section of the delivery head 220 including the crossbar 1010 is shown in
During the expansion process, as shown in
As shown in
When the support body 110a is firmly seated at the heart valve annulus 18 (for example, in the scenario shown in
The adjusted circumference becomes permanent as the burr hooks of the support embed themselves in the annular tissue. Although some burr hooks will already have been embedded, the tightening procedure will pull out some of those burr hooks and embed other burr hooks in the tissue. This “bunches” annular tissue closer together.
Referring to
As shown in
As shown in
The placement of the support from the basket onto the annulus can be done either as part of the operation of opening the basket or following the opening of the basket. In the former case, illustrated in
In the other approach, akin to the process shown in
In either approach, once the support is placed, the basket would be at least partially closed, releasing the basket from the support, and the tool would be withdrawn from the valve.
Further, in some implementations, a combination of the approaches could be used. For example, the basket could be partially opened, inserted into the annulus, and then fully opened.
The approach of
A. Position 1301 (
B. Press a button 1302 on the operator end 214b to inflate a balloon 228b (
C. Slide 1208 or twist the control 1150 to expand 1306 the basket bringing the support body 110a into contact with the distorted annulus 18. The support bears burr hooks that embed themselves in valve tissue at the periphery 121 of the annulus 18 upon contact, thus attaching the support to the tissue (
D. When the basket 220b has reached a desired diameter 1303, the expanded heart valve support 110a forces the annulus 18 to conform to a desired configuration (e.g., a circle) and to a size that is larger (e.g., in diameter) than a desired final diameter of the annulus. Optionally, pull 1104 the wire loop 1102 to tighten the coils of the support body 110a to achieve a smaller final diameter.
E. When the heart valve support is in its final position, to break the tool away from the support attachments 246b, pull 1304 (
Claims
1. An apparatus comprising:
- a heart tissue support having gripping elements,
- each gripping element having a free end that is sharp enough to penetrate heart tissue when pushed against the tissue, and a feature to resist withdrawal of the gripping element from the tissue after the sharp free end has penetrated the tissue.
2. The apparatus of claim 1 in which the free ends of the gripping elements project away from a surface of the support.
3. The apparatus of claim 1 in which the feature that resists withdrawal of the gripping element from the tissue comprises a finger projecting laterally from the gripping element.
4. The apparatus of claim 1 in which the heart tissue support comprises an annular surface bearing the gripping elements.
5. The apparatus of claim 1 in which the support is expandable and contractible.
6. The apparatus of claim 5 in which the support has a native size that is configurable.
7. The apparatus of claim 6 in which a wire configures the native size.
8. The apparatus of claim 1 in which the support comprises at least one of stainless steel, gold, Nitinol, or a biologically compatible elastomer.
9. The apparatus of claim 1 in which the support comprises a torus.
10. The apparatus of claim 1 in which the support comprises a helically wound portion.
11. The apparatus of claim 1 in which some portions of the support bear no gripping elements.
12. The apparatus of claim 1 in which the gripping elements are organized in a pattern.
13. The apparatus of claim 12 in which the pattern comprises rows.
14. The apparatus of claim 12 in which the pattern comprises a group in which the gripping elements are more densely placed and a group in which the gripping elements are less densely placed.
15. The apparatus of claim 12 in which the pattern comprises arcs.
16. The apparatus of claim 12 in which the pattern comprises clusters.
17. The apparatus of claim 12 in which the pattern comprises random placement.
18. The apparatus of claim 1 in which at least some of the gripping elements comprise at least one of platinum, gold, palladium, rhenium, tantalum, tungsten, molybdenum, nickel, cobalt, stainless steel, Nitinol, and alloys of any combination of them.
19. The apparatus of claim 1 in which the gripping elements have the same size.
20. The apparatus of claim 1 in which some of the gripping elements are of different sizes.
21. The apparatus of claim 1 in which at least some of the gripping elements have more than one of the feature that resists withdrawal.
22. The apparatus of claim 2 in which at least some of the gripping elements project from the surface orthogonally.
23. The apparatus of claim 1 in which at least some of the gripping elements are curved.
24. The apparatus of claim 1 also including a sleeve through which tissue can grow.
25. The apparatus of claim 24 in which the sleeve comprises polyethylene terephthalate.
26. The apparatus of claim 1 in which there are between about 15 and a million gripping elements on the support.
27. The apparatus of claim 1 in which there are between about 100 and about 100,000 gripping elements.
28. The apparatus of claim 1 in which the gripping elements comprise burr hooks.
29. The apparatus of claim 1 in which the gripping elements comprise arrows.
30. The apparatus of claim 1 in which the gripping elements comprise hooks.
31. A method comprising:
- correcting the shape of a heart valve annulus in a catheter laboratory by orienting a tip of a catheter holding a heart tissue support that has gripping elements at the valve annulus, applying a radial force from the catheter against the annulus by opening a structure at the tip of the catheter, and while the structure is opened, forcing the support onto the valve annulus.
32. A method comprising:
- correcting the shape of a heart valve annulus during a surgical procedure by pushing a heart tissue support that has gripping elements onto the valve annulus.
33. A method comprising
- attaching, to different sized heart valve annuli in different patients, supports that can be expanded in preparation for attachment and allowed to contract to a common relaxed, non-expanded native size when they are in place on the annuli, and
- reducing the sizes of at least some of the in-place supports to be smaller than the common relaxed non-expanded native size, to accommodate the different sized heart valve annuli of different patients.
34. A heart tissue support comprising:
- a large number of small grippers, each having a tissue penetration feature and a retention feature, and
- the configuration of the grippers relative to a configuration of a given area of heart tissue to which the support is to be attached by force being such that
- (1) the penetration features of a failed set of the grippers will fail to penetrate the tissue,
- (2) the penetration features of a second set of the grippers will successfully penetrate the tissue,
- (3) the retention features of a subset of the second set of grippers will fail to retain the grippers in the tissue, and
- (4) the retention features of the remaining grippers of the second set will successfully retain the grippers in the tissue and hold the support in an intended configuration on the tissue.
35. A method comprising:
- pushing a support onto a region of heart tissue to cause only a portion of a number of small grippers on the support to embed themselves and be retained in the tissue, the portion being sufficient to attach the support securely to the heart tissue.
36. An apparatus comprising:
- an annular heart valve support that is expandable and contractible and bears gripping elements configured to penetrate heart tissue and to retain the elements in the tissue after penetration.
37. A tool to attach a support to a heart valve annulus, the tool comprising mechanisms to hold the support in an expanded configuration prior to attachment, to expand the heart valve annulus prior to attachment, to enable the attachment of the support in its expanded configuration to the expanded valve annulus, and to release the expanded support to a contracted configuration after the attachment.
38. The tool of claim 37 attached to an end of a catheter.
39. The tool of claim 37 also comprising an inflatable balloon.
40. The tool of claim 39 in which the balloon plays a role in positioning the tool.
41. The tool of claim 37 also in which the mechanisms are also to remove the tool from the heart after attachment.
42. A tool to attach a support to a heart valve annulus, the tool comprising a structure to expand the annulus of the heart to a predetermined shape under control of an operator.
43. The tool of claim 42 in which the structure has a conical outer surface at least a portion of which conforms to the predetermined shape.
44. The tool of claim 42 in which the structure has an outer surface that can be expanded to the predetermined shape.
Type: Application
Filed: Mar 19, 2009
Publication Date: Jul 16, 2009
Applicant: Millipede LLC (Ann Arbor, MI)
Inventor: Steven F. Bolling (Ann Arbor, MI)
Application Number: 12/407,656
International Classification: A61F 2/24 (20060101);