Methods and devices for altering blood flow through the left ventricle
An element is expanded in the left ventricle to isolate part of the left ventricle. The element has a generally convex outer surface and an apex which together define a desired geometry of the left ventricle. The isolated part of the wall of the left ventricle may be left so that the wall naturally forms around the element or the isolated portion of the ventricle may be evacuated and/or filled. The element may also be used to isolate part of the left ventricle containing a ventricular septal defect or other perforation or opening in the ventricular wall.
This application is a continuation in part of application Ser. No. 10/622,129 filed on Jul. 16, 2003 which is hereby incorporated by reference.
BACKGROUNDThe present invention is directed to methods and devices for altering the function of the left ventricle. The methods and devices may be used to alter the function of the left ventricle for any reason. For example, the methods and devices of the present invention may be useful in treating congestive heart failure (CHF), ventricular aneurysms or dilation of the heart for other reasons such as coronary artery disease, hypertension, infection, or malfunctioning heart valve. The present invention may also find uses in treating ventricular septal defects or perforations of the left ventricular wall.
Various devices for altering the function of the left ventricle have been suggested. The present invention is directed to alternative devices for altering the function of the left ventricle.
SUMMARYThe present invention provides devices and methods for altering blood flow in the left ventricle and reducing pressure on an isolated or non-blood flow side. An element is provided which is movable between collapsed and expanded conditions. The element is collapsed within a delivery device and advanced into the left ventricle in the collapsed condition. The element is then expanded in the left ventricle and secured to the wall of the left ventricle to form a circumferential attachment to the wall of the left ventricle. The element separates the left ventricle into a blood flow side and a non-blood flow side with the element forming a hemostatic seal at the circumferential attachment so that pressure in the blood flow side is not communicated to the non-blood flow side. In this manner, the cyclical pressure in the left ventricle is not fully communicated, if at all, to the non-blood flow side.
The present invention is also directed to devices and methods for reducing the volume of the non-blood flow side. A reduction in volume may provide remodeling benefits when treating a dilated heart since the dilated heart often has an inefficient geometry for pumping. The volume may be reduced and maintained in a reduced volume with the element forming a hemostatic seal. The volume may be reduced by simply evacuating blood from the non-blood flow side. The volume may also be reduced by manipulating the wall of the left ventricle from within the left ventricle or using a tool which engages the outside of the heart. The volume may be reduced until a part of the wall of the left ventricle moves into contact with the element.
The element may be secured below the papillary muscles or another suitable location. For example, the element may be secured above the papillary muscles when treating a ventricular septal defect. The element may be advanced through a peripheral vessel or directly through a wall of the left ventricle. The element may be generally shaped to provide a desired geometry of the left ventricle wall. For example, the element may have an outer surface which is generally convex and has an apex.
The present invention also provides devices and methods for displacing the heart and maintaining the displaced condition with the element. The heart may be displaced by pulling, compressing or twisting the heart in a desired manner.
These and other aspects of the invention are described in the following description of the preferred embodiment, drawings and claims.
DESCRIPTION OF DRAWINGS
Referring to
The element 6 is movable between the collapsed and expanded shapes of
The element 6 has a generally convex outer surface 16 with an apex 18. The shape of the outer surface 16 is selected so that the heart will assume a more desirable shape as will be described further below. The element 6 also forms a recess 20 formed by a concave inner surface 22. The element 6 may be used to help remodel the left ventricle wall to restore the wall to a more natural shape. To this end, the element 6 may have a generally conical shape or a generally elliptical shape similar to the area around the apex of the heart (see
The element 6 has a cover 24 with a number of support members 26 secured to the cover 24. The support members 26 extend generally toward the apex 18. The support members 26 may be coupled to one another at or near the apex 18 or to a central member 29 near the apex 18. The support members 26 are attached to a circumferential band 28, which may be elastic, extending around the proximal end. The support members 26 may, for example, exert a radial force equal in sum to the left ventricular end diastolic filling pressure to secure element 6 to the left ventricular wall circumferentially and hemostatically. The support members 26 may be oriented in a manner which permits distortion particularly in a manner favoring contraction of the left ventricle. For example, the support members 26 may be somewhat flexible to permit the heart to contract. The support members 26 may be formed of any suitable material such as a stainless steel, a plastic polymer, or a superelastic material such as nitinol. The cover 24 may be any suitable biologic or biocompatible material such as mammalian (bovine or porcine) fixed pericardium, Gortex or Dacron. In particular, it may be desirable to quickly induce tissue ingrowth along the edges of the element to help seal and separate the left ventricle at the circumferential band 28. Of course, the element 6 may be formed in any other suitable manner.
Referring to
Referring to
Referring again to
Use of the system 2 is now described with reference to element 6, however, it is understood that the description concerning the use of any of the elements is equally applicable to the other elements described herein or another suitable element. Before introducing the element 6 into the left ventricle, it may be necessary to determine the appropriate size and geometry of the element 6. This can be performed before introduction of the device using various known visualization techniques. The size and geometry of the element 6 may be selected to achieve a desirable shape for the heart. For example, the element 6 may help restore a dilated heart toward a more normal geometry. Of course, the present invention may be accomplished with a number of different sizes and geometries or the element 6 itself may be flexible enough to accommodate a range of size requirements. The present invention may also be practiced with the element 6 being specifically designed with the particular geometry of the patient's heart in mind including not only the overall geometry of the heart and left ventricle but also the size and extent of non-functioning areas and the location of transition zones between functioning and non-functioning areas.
In some applications, the element 6 is secured to the wall of the left ventricle at or near the transition zone between functioning and non-functioning parts of the wall of the left ventricle. In this manner, the amount of functioning wall of the left ventricle remaining in the blood flow path is maximized. For other applications, it may be desirable to secure the element 6 just within functioning parts of the wall of the left ventricle. For example, the element 6 may be somewhat compliant or resilient so that the heart is not overly restrained during contraction. Of course, the element 6 may also simply be positioned at a more fixed location such as below the papillary muscles. For example, the element may be positioned less than one cm below the papillary muscles. This position may be within the functioning part of the wall of the left ventricle thereby excluding some portion of the wall of the left ventricle upon deployment of the element 6.
As mentioned above, the delivery device 4 may be used to deliver the element 6 endovascularly when introduced through a peripheral vessel such as the femoral artery as shown in
Once the element 6 is secured to the wall of the left ventricle, the element 6 has essentially separated the left ventricle into a blood flow side and a non-blood flow side. The blood flow side continues to form part of the blood flow path through the heart while the non-blood flow side, or isolated side, does not. The blood on the non-blood flow side may be partially or completely evacuated through the delivery device 4, a separate catheter 50 which is subsequently removed (
The blood may be evacuated until at least part of the wall of the left ventricle on the non-blood flow side moves into contact with the element 6 or until a low pressure threshold is reached (
The isolated side may also be injected with a material 52 after removing some or all of the blood as shown in
Referring to
Referring to
Referring to
It may also be desirable to twist the heart, such as in the direction favoring contraction of the left ventricle, so that the element 6 and/or left ventricle is naturally biased toward the contracted state. Referring to
The wall of the left ventricle may also be attached to the element 6 apart from the circumferential connection to the element 6. In this manner, the desired changes in the shape of the heart, which may be thought of as partial or complete remodeling of the heart, is maintained. Referring again to
Referring now to
The support member 102 is configured to contract from the expanded configuration of
The element 100 may be delivered and used in any manner described herein and those methods are expressly incorporated here. For example, the element 100 may be delivered through a blood vessel or directly through a penetration in the heart.
The present invention also provides the ability to treat a septal defect SD or other opening or tear in the septum or a perforation P in the left ventricle free wall by isolating the defect or opening by isolating that portion with the element as shown in
The element 6 may also be delivered directly through a penetration in the left ventricle. Referring to
Depending upon the particular cardiac condition being treated, the element 6 may also help reduce future dilation of an already dilated heart. First, the isolated area is often a non-functioning and/or dilated region. Eliminating or reducing blood flow pressure in the isolated area may reduce or prevent further dilation due to the blood pressure. The element 6 also provides a mechanical advantage to the dilated left ventricle by isolating the non-contracting and dilated segments. The element 6 may also reduce the radius of curvature of the non-isolated and/or functioning portion of the left ventricular wall. The reduction in radius of curvature may reduce wall stress and work of the non-isolated area. Finally, the element 6 may also provide physical support for the heart to reduce or prevent further dilation and also provide physical remodeling of the heart and a mechanical advantage which can further reduce dilation.
It can be appreciated that the present invention may be practiced in a number of different ways with varying devices without departing from the scope of the invention. For example, the element may be attached closer to the apex or the element may be formed from two or more parts delivered independently.
Claims
1-64. (canceled)
65. A system for altering blood flow through the left ventricle, the system comprising:
- a delivery device;
- a sealing element for sealing against an inner wall of a left ventricle, the sealing element a body having a generally convex outer surface, a circumferential sealing portion which is attached to the body, the circumferential sealing portion configured to seal against an internal wall of the left ventricle.
66. The system of claim 65, wherein:
- the convex outer surface of the body has an apex, the convex outer surface and the apex generally conforming to a desired shape of a heart into which the device is implanted.
67. The system of claim 65, further comprising:
- an attachment tool, the attachment tool being positioned outside the heart and being configured to engage the outside surface of the heart to attach at least part of the element to the wall of the left ventricle.
68. The system of claim 65, wherein:
- the attachment tool has an anchor, the anchor being driven through the heart wall and into engagement with the element.
69-96. (canceled)
97. A system for altering blood flow through the left ventricle, the system comprising:
- a delivery device;
- a sealing element for sealing against an inner wall of a left ventricle, the sealing element a body having a generally convex outer surface, a circumferential sealing portion which is attached to the body, the circumferential sealing portion configured to seal against an internal wall of the left ventricle, the sealing element separating the left ventricle into a blood flow side and a non-blood flow side, the sealing element preventing blood to pass from the blood flow side to the non-blood flow side thereby reducing pressure forces on the wall of the non-blood flow side.
98. The system of claim 97, further comprising:
- an attachment device for attaching part of the convex outer surface to the wall of the left ventricle.
99. The system of claim 97, wherein:
- the sealing element is configured to hold the heart in a biased shape when secured within the left ventricle.
100. The system of claim 97, wherein:
- the attachment device mechanically attaches the sealing element to the heart.
101. The system of claim 97, wherein:
- the attachment device delivers energy to secure the sealing element to the heart.
102. The method of claims 1, 33 or 69, wherein:
- the securing step is carried out with the element isolating at least one of a ventricular septal defect and a perforation in the ventricular wall.
103. The method of claims 1, 33 or 69, wherein:
- the providing step is carried out with the element having a support member having flexible sections, the flexible sections bending to permit the support member to collapse.
104. The system of claims 65 or 97, wherein:
- the element has a support member having flexible sections, the flexible sections bending to permit the support member to collapse.
105. A method of altering blood flow through the left ventricle, comprising the steps of:
- providing an element which is movable between collapsed and expanded conditions, the outer surface of the element being generally shaped to provide a desired geometry of the left ventricle wall;
- collapsing the element in a delivery device;
- advancing the element into the left ventricle in the collapsed condition with the delivery device;
- expanding the element in the left ventricle; and
- securing the element to the wall of the left ventricle.
106. The method of claim 105, wherein:
- the providing step is carried out with the outer surface of the element being generally convex and having an apex when in the expanded position, the shape of the element in the expanded position being the desired geometry of the left ventricle wall;
- the securing step being carried out so that the element is attached to the left ventricle wall so that the left ventricle has desired geometry.
107. The method of claim 105, further comprising the step of:
- evacuating blood from a space between the element and the wall of the left ventricle.
108. The method of claim 105, wherein:
- the evacuating step is carried out until at least part of the left ventricle wall moves into contact with the element.
109. The method of claim 105, wherein:
- the securing step is carried out by driving an anchor through the wall of the left ventricle and into engagement with the element.
110. The method of claim 105, wherein:
- the providing step is carried out with a material positioned between the element and the left ventricle wall, the material being an adhesive which causes the element to become attached to the left ventricle wall.
111. The method of claim 105, wherein:
- the providing step is carried out with the element having a plurality of support members extending toward the apex.
112. The method of claim 105, wherein:
- the securing step is carried out with the element isolating at least one of a ventricular septal defect and a perforation in the ventricular wall.
113. The method of claim 105, wherein:
- the providing step is carried out with the element having a support member having flexible sections, the flexible sections bending to permit the support member to collapse.
Type: Application
Filed: Jul 16, 2004
Publication Date: Apr 12, 2007
Inventor: Samuel Lichtenstein (Vancouver)
Application Number: 10/571,165
International Classification: A61N 1/362 (20060101);