Abstract:
A cardiac support device formed from a plurality of compliant sections individually delivered and deployed at positions around the heart and interconnected to one another.

Description:
FIELD OF THE INVENTION 
   The present invention is a cardiac support device and associated delivery tool and deployment method. 
   BACKGROUND OF THE INVENTION 
   Cardiac support devices for treating congestive heart failure are known. One such cardiac support device includes a compliant and sometimes elastic jacket for reducing tension in the heart wall by constraining or resisting expansion of the heart. Tools and methods for delivering cardiac support devices using minimally invasive surgical procedures are also known. Cardiac support devices of these types and associated delivery tools and methods are described, for example, in the following U.S. patents and published applications, all of which are incorporated herein by reference in their entirety: U.S. Pat. Nos. 5,702,343, 6,155,972, 6,193,648, 6,293,906, 6,482,146, 6,682,476, 6,902,524, 6,425,856, 6,908,426, 6,572,533, 6,951,534, 6,702,732, 6,723,041, 2006/0009831, 2005/0288715, 2005/0256368, 2005/0171589, 2005/0090707, 2005/0059854 and 2005/0059855. 
   There remains, however, a continuing need for improved cardiac support devices and related delivery tools and methods. In particular, there is a need for devices, tools and methods of these types that can be used in connection with minimally invasive surgical procedures. 
   SUMMARY OF THE INVENTION 
   The present invention is an improved cardiac support device and a delivery tool that can be used to mount the support device on the patient during a minimally invasive surgical procedure. One embodiment of the invention includes placing a plurality of compliant cardiac support device sections around at least a portion of a lower portion of a heart and interconnecting the compliant sections to form the cardiac support device. The compliant sections can be balloon-rupturable members that are adhesively interconnected to one another. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an illustration of a delivery device in accordance with one embodiment of the present invention positioned adjacent to the apex of the heart. 
       FIG. 2  is an illustration of the delivery device and heart shown in  FIG. 1 , with the cardiac support device inserted but undeployed or partially deployed from the delivery device. 
       FIG. 3  is an illustration of the delivery device and heart shown in  FIG. 1 , with a section of the cardiac support device deployed and placed on the surface of the heart. 
       FIG. 4  is an illustration of the heart shown in  FIG. 2  with several sections of the cardiac support device placed on the heart. 
       FIG. 5  is a cross section of an inferior, near apical portion of a heart with a cardiac support device in accordance with the invention positioned on the heart. 
       FIG. 6  is a cross sectional view take at line  6 - 6  in  FIG. 2 , showing the cardiac support device partially deployed from the delivery device. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  is an illustration of the distal portion of a delivery tool or device  8  including a balloon section  12   a  of a cardiac support device in accordance with the present invention positioned adjacent to the apex A of a heart H. As shown, the heart H also has a right atrium RA, left atrium LA, right ventricle RV and left ventricle LV. The ventricles RV and LV are generally separated by the atrioventricular (AV) groove AV. In the illustrated embodiment the delivery device  8  includes a tubular sheath  10  that surrounds at least a portion of the cardiac support device balloon section  12   a . The cardiac support device section  12   a  is an inverted balloon, and is shown in an undeployed, collapsed form in  FIG. 1 . 
   Access of the delivery device  8  to the epicardial space and heart H can be obtained through a sub-xiphoid or similar approach. Using conventional techniques, for example, a needle (e.g., 16-gauge or 18-gauge) (not shown) would enter the intrapericardial space using an alligator clamp for ECG monitoring. Once in the pericardial space the needle can be used for the insufflation of a gas such as carbon dioxide. Insufflation of gas permits definition of the anatomy with stark contrast both by fluoroscopy and echocardiographic imaging approaches. For example, this approach will provide a true space separating the visceral pericardium from the parietal pericardium. Clear identification of the left ventricle and surrounding structures such as the apex A of heart H can be achieved. Other advantages include efficacious and safe access to the intrapericardial space and potentially reduced ventricular ectopy and coronary artery trauma. Furthermore, this action facilitates the efficient insertion of the sheath  10  and deployment of the balloon section  12   a.    
   The distal end of the sheath  10  is then advanced toward the heart H, and is preferably located adjacent to the apex A as shown in  FIG. 1 . If needed or otherwise appropriate, structures and methods can be used to secure the delivery device  8  to the apex A of the heart H. Suction-tike devices and screw-like devices can, for example, be used for this purpose. Securing the apex A of the heart H in this manner may be particularly advantageous in connection with the coaxial deployment of delivery device  8 . 
   After the sheath  10  is properly positioned, the uninflated balloon section  12   a  of the cardiac support device is deployed by advancing or otherwise removing that section from the sheath and locating the section adjacent to the side of the heart H. In the illustrated embodiment the balloon section  12   a  is advanced from the distal end of the sheath  10 . However, in other embodiments (not shown) other structures and methods are used to position the balloon section  12   a  adjacent to the heart H. 
   As shown in  FIG. 2 , balloon section  12   a  has a score line  14  extending in a generally longitudinal direction with respect to the heart H. Score line  14  is a structure that facilitates the controlled breakage or rupture of the balloon section  12   a  into sheaves (e.g., segments that can be flattened). Other structures or approaches (not shown) are used for this purpose in other embodiments. 
   Balloon section  12   a  is inflated by a source of pressurized gas after it is positioned relative to the heart H to continue the deployment process.  FIG. 6  is a cross sectional illustration of balloon section  12   a  during inflation. With continued inflation the balloon section  12   a  will rupture at a predetermined inflation pressure along the score line  14 . This action causes the balloon section  12   a  to take on a generally flat, panel-shaped configuration overlaying a portion of the heart H as shown in  FIG. 3 . In the deployed position shown in  FIG. 3  the balloon section  12   a  will overlie a portion of the heart H between the AV groove AV and the apex A. Radiopaque elements or portions (not shown) on the balloon sections  12   a  can be used in connection with fluoroscopic or other imaging approaches to locate and orient the balloon sections on the heart and relative to other structures. 
   The balloon section  12   a  can be a formed from materials that take the panel-shaped configuration upon deployment (e.g., composites). Alternatively, additional elements such as shape memory elements or resilient members (not shown) can be can be incorporated on the balloon sections  12   a  to bias the balloon sections to the desired configuration upon deployment. These additional elements can be permanently mounted to the balloon sections  12   a , or temporarily mounted thereto and removed following deployment. 
   Additional balloon sections such as  12   b  and  12   c  shown in  FIG. 4  are then deployed around all or portions of the heart H in a manner similar to that described above. Additional balloon sections (e.g.,  12   b  and  12   c ) can be advanced out of the sheath  10  that was used to deploy balloon section  12   a . Alternatively, sheath  10  can be withdrawn and additional sheaths containing the additional balloon sections (not shown) can be used for this purpose. As shown in  FIG. 4 , balloon sections  12   a - 12   c  overlap one another. The balloon segments  12 - 12   c  can include structure for causing the overlapping portions of the segments to join together. In the embodiment illustrated in  FIG. 6 , for example, the segments  12   a - 12   c  include a layer of adhesive  20  on the side of the segments facing the heart H. The overlapping portions of the segments  12   a - 12   c  are then secured together by the adhesive. Other structures and approaches can also be used to join the balloon sections  12   a - 12   c , and the adjacent edges of the sections need not overlap. For example, the adhesive  20  could be located on the opposite side of the balloon sections  12   a - 12   c  and/or only on the edges.  FIG. 5  is a cross sectional illustration of heart H with a completed cardiac support device in accordance with the invention formed from joined segments  12   a - 12   j  that surround the lower portion of the heart. 
   Resilient elements or other structures and methods can be used to cause the balloon sections  12   a - 12   j  to flatten and lie adjacent to the side of the heart H following deployment. In the embodiment shown in  FIG. 6 , for example, the balloon segment  12   a  includes a nitinol spring element  22  that will bias to the balloon segment to a flattened state after deployment. 
   Balloon segments such as  12   a - 12   j  are formed from materials that cause the cardiac support device to have characteristics (e.g., compliance and elasticity) that can vary and provide the therapeutic benefits of the cardiac support devices described in the background section of this document. As a non-limiting example, materials of the types used for commercially-available balloon-deployable stents can be used for this device. Although not shown, additional structures such as nitinol mesh that have compliances or other characteristics that contribute to the therapeutic functionality of the cardiac support device can be incorporated onto the balloon segments  12   a - 12   j.    
   The invention offers a number of important advantages. In addition to providing the therapeutic effects of a cardiac support device, it can be efficiently and effectively implanted on a patient&#39;s heart using noninvasive surgical procedures. 
   Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention. For example, cardiac support devices in accordance with the present invention that are assembled from segments can take other forms and be deployed by other approaches.