Patent Abstract:
Methods for cardiac ventricular restoration include delivering an implantable expandable device into the ventricle via a catheter. The expandable device is anchored either to the wall of the left ventricle or to the inter-ventricular septum and then expanded. When expanded, the device assumes a size and shape which fills the lower portion of the ventricular cavity restoring the normal volume and ellipsoid shape of the remaining portion of the cavity and favorably altering myocardial oxygen demand and wall stress.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of U.S. Ser. No. 11/070,789, filed Mar. 2, 2005, which is hereby incorporated by reference herein in its entirety. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     This invention relates broadly to methods and apparatus for performing a heart reshaping intervention. More particularly, this invention relates to methods and apparatus for minimally invasive restoration of the left ventricle in patients suffering from congestive heart failure.  
         [0004]     2. State of the Art  
         [0005]     In the U.S., approximately 5 million patients are currently diagnosed with congestive heart failure (CHF). CHF generally relates to a dysfunction of the left ventricle. About one third of the patients suffering from CHF have a form of CHF which results from a myocardial infarction (MI). The Ml progressively increases the residual volume of blood in the left ventricle, due to stagnation from decreasing contractility of the heart muscle.  
         [0006]     The increase in blood volume also results in an increase in left ventricular pressure which increases stress on the wall of the left ventricle. The stress requires the myocardium to work harder which increases oxygen demand. Since oxygen delivery to the heart has already been reduced because of coronary artery disease, the Ml and the resulting reduced ventricular output, heart muscle tissue dies and the ventricle expands. This causes the myocardium to stretch, thin out and distend, further decreasing heart performance, decreasing the thickness of the ventricle wall and increasing wall stress.  
         [0007]      FIG. 1  shows a normal heart  10  having right ventricle  12 , left ventricle  14 , right atrium  16  and left atrium  18 . Though not illustrated, those skilled in the art will appreciate that there are a pair of valves between each ventricle and its associated atrium. The ventricles are separated by an inter-ventricular septum  20 . The left ventricle  14  has what is called a generally elliptical (ellipsoidal) shape.  
         [0008]      FIG. 2  shows a heart  10 ′ suffering from CHF. The left ventricle  14 ′ is enlarged and assumes a circular (spherical) shape. The stress on the ventricle wall is determined by the Laplace Law as illustrated in Equation 1, below.  
               wall   ⁢             ⁢             ⁢   stress     =         (     pressure   ⁢           ⁢   in   ⁢           ⁢   cavity     )     ·     (     radius   ⁢             ⁢             ⁢   of   ⁢           ⁢   cavity     )         2   ·     (     wall   ⁢           ⁢   thickness     )                 (   1   )               
         [0009]     Thus, as wall thickness is decreased, wall stress increases. This increased wall stress and oxygen demand cause a relative chronic myocardial ischemic state which results in decreased pump function.  
         [0010]     It has also been discovered that the change in the shape of the left ventricle adversely affects the way the heart muscle fibers work. The normal ellipsoidal shape most efficiently assists in blood flow through the left ventricle.  
         [0011]     State of the art methods for treating CHF involve extremely invasive open heart surgery. For example, use of a “ventricular restoration patch” installed via “purse string” sutures is disclosed in U.S. Pat. No. 6,544,167. The patch seals off a portion of the ventricle thereby reducing the volume and restoring the shape of the cavity. However, installation of the patch requires incision into the left ventricle which severs muscle fibers and the subsequent healing scar increases the risk of arrhythmia.  
         [0012]     Another method described in U.S. Pat. No. 6,126,590 involves wrapping the heart in a mesh and suturing the mesh to the heart. The mesh constricts both right and left ventricles, thus not allowing them to fill completely in diastole. It also may cause a constrictive effect on the ventricles known as the tamponade effect.  
         [0013]     Yet another method for treating CHF is described in U.S. Pat No. 6,537,198 and involves the use of trans-ventricular wires anchored by external fixation buttons on either side of the left ventricle. This method puts a compressive force on the ventricle but also results in a mid-level constriction without favorably altering volume, pressure, or wall stress.  
         [0014]     Because of the highly invasive nature of these treatments, many CHF patients are not suitable candidates for the surgery.  
       SUMMARY OF THE INVENTION  
       [0015]     It is therefore an object of the invention to provide methods and apparatus for treating CHF.  
         [0016]     It is another object of the invention to provide methods and apparatus for reducing the volume of the left ventricle.  
         [0017]     It is a further object of the invention to provide methods and apparatus for restoring the left ventricular cavity to an ellipsoidal shape  
         [0018]     It is also an object of the invention to provide minimally invasive methods and apparatus for achieving the above objects without the side effects of the prior art methods and apparatus.  
         [0019]     In accord with these objects, which will be discussed in detail below, the methods of the present invention include delivering an implantable expandable device into the left ventricle via a catheter. The expandable device is anchored either to/through the wall of the left ventricle or to/through the inter-ventricular septum and then expanded. When expanded, the device assumes a size and shape which fills the lower portion of the ventricular cavity thus restoring the volume and ellipsoidal shape of the remaining portion of the cavity. According to one embodiment, the device is a balloon which is expanded by filling it with fluid such as saline. It is anchored with an anchor which extends into or through either the wall of the left ventricle or the inter-ventricular septum. There are two versions of the first embodiment, one having a central stem that extends all the way through the balloon to its opposite end. The other has a very short stem which just extends into the balloon. In both cases the stem includes a valve and an inflation tube coupling. The coupling allows the inflation tube to be coupled to and uncoupled from the balloon and the valve prevents saline from leaking out of the balloon after the tube is uncoupled from it. A second embodiment includes a pair of umbrella-like structures, at least one of which is covered with a biocompatible membrane and is provided with peripheral barbs which engage the wall of the left ventricle and the inter-ventricular septum. A third embodiment utilizes a single umbrella covered with a biocompatible membrane and provided with peripheral barbs which engage the wall of the left ventricle and the inter-ventricular septum. In both of the umbrella embodiments an aspiration tube coupling and valve are provided. The aspiration tube coupling allows an aspiration tube to aspirate the blood which has been segregated from the remaining portion of the ventricle and the valve prevents blood from reentering when the aspiration tube is uncoupled.  
         [0020]     The catheter sheath with which the device is delivered to the left ventricle includes conduit channels, ports and other means for deploying the device, stabilizing it, anchoring it, expanding it, and disengaging from it. A suitable catheter for practicing the invention is one of the type used to install heart pacing electrodes, e.g. the catheter disclosed in U.S. Pat. No. 5,571,161 which is hereby incorporated by reference herein in its entirety.  
         [0021]     The invention thus provides a percutaneous, intra-cardiac implantation device that directly reduces the amount of volume load on the left ventricle. As less volume is received in the left ventricle, the intra-cavity pressure is decreased, thereby reducing wall stress on the myocardium, decreasing oxygen demand and improving pump function. It is the shape, volume and size of the cavity of the ventricle that determines wall stress and not the external shape of the heart. In several embodiments of the invention, the dimensions of the cavity of the ventricle are changed but not the external shape of the ventricle. In other embodiments, the dimensions of the cavity are initially changed and thereafter as ventricular remodeling occurs the external shape of the ventricle is also favorably altered.  
         [0022]     Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]      FIG. 1  is a schematic sectional view of a normal human heart;  
         [0024]      FIG. 2  is a schematic sectional view of a human heart afflicted with CHF;  
         [0025]      FIG. 3  is a schematic longitudinal sectional view of a first embodiment of an implantable expandable device in a catheter;  
         [0026]      FIG. 3A  is a schematic longitudinal sectional view of the first embodiment of an implantable expandable device in a catheter illustrating a preferred locking mechanism between the inflation tube and the central stem;  
         [0027]      FIG. 4  is a schematic longitudinal sectional view of the first embodiment being anchored to the wall of the ventricle;  
         [0028]      FIG. 5  is a schematic longitudinal sectional view of the first embodiment with the catheter partially withdrawn;  
         [0029]      FIG. 6  is a schematic sectional view of the first embodiment anchored and inflated with the catheter partially withdrawn;  
         [0030]      FIG. 7  illustrates an alternate embodiment with a hinged anchor for anchoring to the inter-ventricular septum;  
         [0031]      FIG. 8  illustrates an alternate embodiment with a threaded connector rather than a snap connector;  
         [0032]      FIG. 8A  is a illustrates another embodiment similar to  FIG. 8 ;  
         [0033]      FIGS. 9 and 10  illustrate an alternate embodiment having a claw anchor;  
         [0034]      FIG. 11  illustrates an alternate embodiment having a cork screw anchor;  
         [0035]      FIG. 12  illustrates an alternate embodiment having a short stem;  
         [0036]      FIG. 13  is a schematic perspective view of a second embodiment of an implantable expandable device;  
         [0037]      FIG. 14  is a schematic side elevation view of the second embodiment implanted in a ventricle;  
         [0038]      FIG. 15  is a schematic perspective view of the cog-wheel arrangement of the second embodiment of the invention;  
         [0039]      FIG. 16  is a schematic perspective view of a third embodiment of an implantable expandable device;  
         [0040]      FIG. 17  is a schematic side elevation view of the third embodiment implanted in a ventricle;  
         [0041]      FIG. 18  is a schematic side elevation view of a fourth embodiment implanted in a ventricle;  
         [0042]      FIG. 19  is a schematic side elevation view of the fourth embodiment implanted in a ventricle and evacuated;  
         [0043]      FIG. 20  is a schematic side elevation view of a fifth embodiment implanted in a ventricle;  
         [0044]      FIGS. 21 through 23  are schematic side elevation views of a sixth embodiment being implanted in a ventricle;  
         [0045]      FIGS. 24 through 26  are schematic side elevation views of a seventh embodiment being implanted in a ventricle;  
         [0046]      FIGS. 27 and 28  are schematic side elevation views of an eighth embodiment being implanted in a ventricle; and  
         [0047]      FIGS. 29 and 30  are schematic side elevation views of a ninth embodiment being implanted in a ventricle. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0048]     Turning now to  FIG. 3 , an implantable expandable device  100  is shown inside a catheter sheath  102  and coupled to an inflation tube  104 . The device  100  includes a central shaft  106  having a distal anchor  108 , an inflatable balloon  110  surrounding the shaft  106 , and a proximal coupling  112  with a self-closing valve  114 . The valve  114  is in fluid communication with inflation ports  116 . In this embodiment, the coupling  112  is a snap fit to which the inflation tube  104  is removably coupled. Referring to  FIG. 3A , the snap fit coupling  112  includes a male-female type connection. The distal end of the inflation tube  104  has a cable operating or similar control mechanism, whereby, in a resting state, two spring loaded, lateral expansions  117  of the distal end of  104  itself, are opened to engage within the proximal end of the lumen of the central shaft  106 . To disengage, the control mechanism (a button, lever etc) at the proximal control end (operator end) of the inflation tube  104  is activated to pull on control wires  115 , whereby, the two lateral expansions are pulled radially inward and the snap fit into the central shaft is released, thus separating the inflation tube  104  from the central shaft  106 . Reengagement is accomplished by, similarly, compressing the lateral expansions first, aligning the inflation tube and the central shaft (via fluoroscopic/ultrasound guidance) and then allowing the lateral expansions  117  to deploy, thereby securing a fit between the two.  
         [0049]     The methods of the invention include delivering the catheter sheath  102  with the device  100  and inflation tube catheter  104  therein to the interior of the left ventricle in a trans-atrial septal fashion via the femoral vein or jugular vein. Alternatively, the device may be delivered via the femoral or brachial artery in a retrograde fashion through the aorta. The inflation tube  104  is then advanced relative to the catheter sheath  102  until the anchor  108  extends beyond the end of the catheter sheath  102 . When entering through the jugular vein, the approach is to the right atrium, then across the inter-atrial septum to the left atrium and through the mitral valve into the left ventricle. The anchor  108  is then deployed into or through the apex of the left ventricle or into the septum or through the septum into the right ventricle.  FIG. 4  illustrates the anchor  108  piercing the apex of the left ventricle  14 ′. It will be appreciated that the anchor is important to prevent balloon migration during cardiac contractions which could otherwise result in blockage of the mitral and/or aortic valves.  
         [0050]     In the closed (un-deployed) position, the anchor  108  resembles a dart, and is advanced into the wall of the apex or beyond the apex of the ventricle or into the other ventricular cavity across the inter-ventricular septum. Once the desired position of the anchor is confirmed (on x-ray fluoroscopy), the anchor is deployed thereby preventing removal. This anchor deployment mechanism is activated via a wire passing along the catheter to the anchor either through the central stem of the balloon or on the outside of the balloon (when the balloon is in a collapsed position). Upon twisting the central wire, a torquing motion at its tip activates the anchor device. If the need arises to retrieve the balloon at a later date, the anchor can be reconfigured into a narrow dart to permit removal by twisting/untwisting (e.g., clockwise-anti-clockwise) a mechanism at the junction of the anchor  108  and the central shaft  106  of the balloon.  
         [0051]     With the anchor  108  in place, the catheter sheath  102  is withdrawn exposing the inflatable balloon  110  as illustrated in  FIG. 5 . The balloon  110  is then inflated by injecting saline (or another biocompatible fluid preferably having a specific gravity equal to or less than that of blood) through the inflation tube  104  as shown in  FIG. 6 . It is important to note the preferred shape of the balloon  110 . The shape is designed to reduce the size and also to restore the ellipsoidal shape of a healthy left ventricular cavity, and define a new ventricular apex  22 ′. The shape of the balloon can be described as “rotationally asymmetric about an axis”. In the illustrated embodiment of  FIG. 6  the axis can be considered the axis of the central shaft  106 . More particularly, the shape is a paraboloid which is truncated at an angle relative to its directorix thereby producing the inclined upper surface shown in  FIG. 6 . The balloon is oriented so that the inclined upper surface preferably slopes down from the inter-ventricular septum as shown. With the high end of the upper surface positioned against the septum, there is no impedance to contraction by the middle and upper portions of the lateral wall of the left ventricle. In addition, pressure in the balloon should be sufficient to distend the balloon appropriately and yet keep the balloon compliant enough to avoid impeding the contraction of the myocardium.  
         [0052]     As discussed above, the catheter  102  may be provided with a distal stabilizing configuration  103  which grips the inflation tube  104  to prevent lateral or other movement while engaging/disengaging from the balloon  110 .  
         [0053]     When the balloon  110  is expanded to the correct volume, the inflation tube  104  is decoupled from the coupling  112  ( FIG. 3 ), as discussed above, and the self-closing valve  114  retains the saline inside the balloon. The inflation tube  104  and the catheter sheath  102  are then removed from the patient&#39;s body.  
         [0054]     It will be appreciated that different size balloons  110  may be provided so that different size hearts may be treated. The expansion of the balloon can be monitored by fluoroscopy. Alternatively, each different size balloon can be indicated to contain a certain volume of saline when fully inflated. Inflation can then be monitored by metering the amount of saline which is injected into the balloon. It is presently preferred that pre-shaped balloons be provided in volumetric increments of 10 or 20 ml and that balloons range in size from 40 ml to 350 ml.  
         [0055]     According to the preferred embodiments, the balloon  110  and anchor  108  are removable via the catheter  102  and inflation tube  104 . The inflation tube is preferably re-attachable to the coupling  112  should the balloon ever need to be removed. When the inflation tube  104  is coupled to the coupling  112 , the self-closing valve  114  opens and allows the saline to be suctioned, thus deflating the balloon.  
         [0056]     The balloon is preferably soft, light weight, and compliant/compressible in order to prevent any interference with cardiac muscle contractions. It is also non-thrombogenic, inert (e.g. made from PTFE or suitable polyester) and impervious. It is capable of sustaining long-term implantation. It is preferably of unitary construction and capable of delivery via established catheter delivery systems. Radiopaque markers may be placed at strategic locations on the balloon and anchoring mechanisms to enable detection of the location and expansion of the balloon within the cavity during its insertion and future surveillance. Marker locations may be, for example, at the anchor, rim of the balloon, the self-closing valve, attachment/detachment location of balloon to catheter, central injection stem, etc.  
         [0057]     Turning now to  FIG. 7 , an alternate embodiment  100 ′ of the invention is similar to the embodiment  100  described above with similar reference numerals referring to similar parts. In this embodiment the central shaft has a distal hinge  107 ′ which allows the anchor  108 ′ to be rotated up to 90° so that it can be anchored to or through the septum  20 ′ or other suitable areas of the apex of the ventricle. The hinge  107 ′ is activated and controlled and fixed in position by control cables/channels or similar devices running the length of the inflation tube  104  and controlled by lever mechanisms at the operator end of the device. Anchoring is achieved by the central wire control system as described in the other embodiments. Sufficient lateral force is achieved by torquing of the inflation tube and if necessary by stabilizing the inflation tube within the catheter sheath  102  and thereby translating torquing force on  102  to the hinge  107 . This is an established and standard industry method in widespread use, such as with steerable catheters and the trans-atrial septum catheters, when such lateral torquing motion is applied to pass through the inter atrial septum at right angles to the axis of catheter passage into the heart.  
         [0058]      FIG. 8  shows yet another alternate embodiment  100 ″ which is similar to the embodiment  100  described above with similar reference numerals referring to similar parts. The difference here is that the coupling  112 ″ between the inflation tube  104 ″ and the central shaft  106 ″ is a rotational locking mechanism, such as a threaded coupling or a luer lock, with the inflation tube catheter  104  and central shaft  106  deployed in precoupled state. When adequate anchor to the apex and inflation of the balloon  110 ″ is confirmed, the inflation tube and the central shaft are disengaged by a counter-clockwise torque motion of the inflation tube  104 ″.  
         [0059]     In order to facilitate torquing motion of the inflation tube  104 ″, the distal end of the catheter sheath  102 ″ may be also provided with a constricting mechanism which couples the catheter sheath and inflation tube catheter together for application of torquing motion to the inflation tube by the catheter sheath. For example, control wires  118 ″ may be coupled to compressible elements such as leaves or pincers  121 ″ at the distal end of the catheter sheath  102 ″ producing a grasping/gripping effect, or a Teflon/ PTFE cuff can be inflated at or purse-string coupled to the distal end of the catheter sheath. These mechanisms serve to stabilize the central shaft  106 ″ or the distal end of the inflation tube catheter  104 ″ for disengagement or reengagement as needed, and while the torquing motion is applied.  
         [0060]      FIG. 8A  shows a similar embodiment to  FIG. 8 , wherein the central shaft  106   a ″ at its proximal alignment end to the inflation tube  104   a ″ is preferably slightly longer than its balloon  110   a ″ component so that enough purchase is afforded to the catheter sheath  102   a ″ stabilizing mechanism to act upon.  FIGS. 9 and 10  illustrate another alternate embodiment  100 ′″ which is similar to the embodiment  100  described above with similar reference numerals referring to similar parts. The difference here is that the anchor  108 ′″ is a group of claws. After the apparatus  100 ′″ is delivered to the ventricle, the claws are opened as shown in  FIG. 9 . The claws are brought into engagement with the inside wall of the ventricle at the apex or the septum. After an adequate amount of myocardial tissue is grasped between the claws, they are closed as shown in  FIG. 10 .  
         [0061]     More particularly, the anchor claws  108 ′″ are aligned around the periphery of a cog wheel arrangement, the center of which has an opening for passage and insertion of the aligning end of the central wire passed through the inflation tube. The central wire is inserted into the lumen of the cog wheel arrangement and a torquing clockwise motion opens the cog wheel and the claws, and a counterclockwise motion closes it. After the desired effect, the central wire maybe withdrawn. Claws deployable into cardiac tissue and mechanisms for their deployment and release are well known to individuals skilled in the art of cardiac active pacing leads.  
         [0062]      FIG. 11  illustrates another alternate embodiment  100 ″″ which is similar to the embodiment  100  described above with similar reference numerals referring to similar parts. The difference here is that the anchor  108 ″″ is a “cork screw” which is controlled by a wire passing through the central shaft  106 ″″. Alternatively, the cork screw may be threaded into the wall by a twisting motion of the whole catheter and central shaft without need for a central wire. Alternatively, the corkscrew may be threaded into the anchor site by stabilizing, fixing and immobilizing the distal end of the catheter sheath on the inflation tube and central shaft, thus making all three of these components into one single rigid torque tube.  
         [0063]      FIG. 12  illustrates another alternate embodiment  100 ′″″ which is similar to the embodiment  100  described above with similar reference numerals referring to similar parts. The difference here is that the central shaft  106 ′″″ is relatively shorter and does not extend through to the anchor  108 ′″ 41  after the balloon  110 ′″″ is inflated.  
         [0064]     Turning now to  FIGS. 13 and 14 , a second embodiment  200  of the device of the invention includes a catheter sheath  202  and a deployment/suction tube  204 . In lieu of an inflatable balloon, this embodiment has two spaced apart biocompatible umbrellas  206 ,  208  which are each covered with a biocompatible membrane  210 ,  212 . The periphery of each umbrella is provided with barbs  214 ,  216  which are located on the ends of radial spokes  215 ,  217 , and the umbrellas are coupled to each other by a semi-rigid stem  218  which is provided with aspiration ports  220 . The top of the stem  218  has a coupling  222  for removably coupling to the end of the tube  204 . The coupling  222  includes a valve which automatically seals the passage into the stem  218  when the tube  204  is decoupled from it. Clock-wise or anti-clockwise rotation of the tube  204  (when coupled to the stem  218 ) produces an expanding or retracting motion on the radial spokes of the umbrellas. The articulating part of the catheter and the umbrella spoke attachments have a cog wheel configuration linkage that allows torque motion which opens or closes the umbrellas.  
         [0065]     More particularly, referring to  FIGS. 13-15 , the distal tip of the stem  218  (anchor end) and the distal tip of the tube  204  have circular cog wheel arrangements  226 , which fit into complimenting recesses  228  in hubs  230  of the radial spokes of the distal and proximal umbrellas  206 ,  208 . The device is pre-assembled in this fashion. Upon deployment of the anchor mechanism, the catheter sheath  202 , tube  204 , and the central shaft  218  are fixed by the stabilizing mechanism of the catheter sheath into a rigid component that torques the distal cog wheel  226  and the proximal cog wheel (not shown) such that it rotates clockwise the hub  228  of the radiating spokes, which expands the umbrellas  206 ,  208  and causes engagement of the barbs  214 ,  216  upon expansion to anchor the umbrellas. Now, the proximal end of the central shaft is disengaged from the inflation tube, and the stabilizing mechanism of the catheter sheath is deactivated, thus leaving the deployed umbrellas with their connecting central shaft in place inside the heart cavity. It will be appreciated from the figures that one umbrella is upside down and the other is right side up. The upside down umbrella  208  engages the apex of the ventricle and expands less and/or is smaller that the other umbrella  206 .  
         [0066]     The catheter, tube and umbrellas are delivered to the left ventricle with the umbrellas closed and inside the catheter. The umbrellas are pushed out of the catheter either by pulling back on the catheter while holding the tube or pushing forward on the tube while holding the catheter. The umbrellas are then opened until their barbs engage the ventricular wall and septum as shown in  FIG. 4 . Blood trapped between the umbrellas is aspirated via the ports and the tube. The vacuum used to aspirate also causes the umbrellas to further engage the ventricle wall and septum.  
         [0067]      FIGS. 16 and 17  illustrate a third embodiment  300  which is similar to the second embodiment just described. It includes a catheter  302 , a deployment/aspiration tube  304 , and an umbrella  306 . The umbrella is covered with a biocompatible membrane  310 . The periphery of the umbrella is provided with barbs  314  and the center of the umbrella is provided with a valved coupling  322 . The valved coupling  322  allows the tube  304  to couple and uncouple from the umbrella. When the tube  322  is coupled to the umbrella, rotation of the tube causes the umbrella to open or close, as discussed above. After the umbrella is deployed, blood trapped between the apex of the ventricle and the umbrella is aspirated through the tube  304  and the tube is then uncoupled from the umbrella. At uncoupling, the valve  322  closes and prevents blood from reentering the space between the apex of the ventricle and the umbrella. Another alternate (non-illustrated) embodiment is similar to the embodiment  300  but includes a central stem extending from the center of the umbrella to the apex of the ventricle with an anchor at its tip.  
         [0068]     Turning now to  FIG. 18 , another embodiment of device for percutaneous ventricular restoration is shown. The device  400  includes a balloon  410  with a central perforate stem  406 . The balloon  410  is coupled at the apex of the left ventricular substantially as described above, with an anchor  408 . The sides of the balloon  410  include an abrasive and/or porous surface  416  preferably provided with an irritant coating  418 , such as tetracycline or bleomycin or other such sclerosing agent. Such surface  416  and coating  418  enhances adhesion of the balloon  410  to the ventricular wall and promotes ingrowth of fibrous tissue from the ventricular wall onto the balloon. Inflation fluid  420  is delivered through a delivery tube (not shown) and valve  414  to expand the balloon within the apex of the ventricle so that the porous surface is in contact with the heart wall tissue. The expanded balloon, as shown in  FIG. 18 , is left in place for a period of time, e.g., eight to twelve weeks, to allow such ingrowth and tissue-to-balloon adhesion. Then, after the period of time required for tissue ingrowth, the patient undergoes a subsequent procedure during which the inflation fluid is percutaneously removed from the balloon by re-coupling a tube at the valve  414  and applying suction. Referring to  FIG. 19 , as the balloon  410  is evacuated and collapsed its volume is reduced, the diameter of the balloon decreases, thereby reshaping the ventricular cavity by causing movement of the left ventricular wall and the septum toward each other. Thus, not only the shape and size of the cavity of the ventricle is restored, but the external shape of the ventricle is also favorably altered. In an alternate embodiment, the top surface of the balloon may be thicker and non-compliant relative to the sides of the balloon, e.g., provided with stiffening ribs. Then, upon evacuation of the balloon, reshaping is limited to the sides of the balloon (rather than its top surface), maximizing movement of the lateral ventricular wall toward the septum.  
         [0069]     Referring to  FIG. 20 , the wall  516  of the balloon  510  may be provided with a porous trabeculae or lattice  518  that forms a thin wall chamber  520  that is communicable with a suction source tube  522  applied at valve  514 . By rotating suction source tube  522  relative to the valve  514  suction may be selectively applied to the interior of the balloon  524  or the chamber  520 . Upon application of suction to the balloon wall chamber  520 , the perforate outer surface of the balloon wall  516  adheres to the ventricular wall by way of negative pressure. The negative pressure can be maintained on the wall even after the active application of negative pressure is discontinued, creating adhesion similar to that created by a suction cup. In use, the balloon is inflated at the apex as described in prior embodiments to provide good balloon wall/tissue contact. Then, suction adhesion is created between the balloon wall and the ventricular wall. After suction adhesion is effected, the balloon may be evacuated of fluid by application of suction to the interior of the balloon. Such will reduce weight in the left ventricle in addition to reducing volume.  
         [0070]     Turning now to FIGS.  21  to  23 , another embodiment of a percutaneous device for modifying the volume of the left ventricle of the heart is shown. Referring to  FIG. 21 , the device is initially inserted as a balloon  610  anchored to the apex and about its upper surface, substantially as previously shown and described. The balloon is preferably, but not necessarily, inflated. Referring to  FIG. 22 , then through valve  614 , a delivery device  624  provided with a collapsed basket  626  at its distal end is inserted into the interior of the balloon  610 . The basket  626  is preferably spring-loaded to self expand to the interior periphery of the balloon upon retraction of a covering sheath (not shown). After basket insertion, the delivery device is then operated to retract the covering sheath to allow the basket to expand and decouple the basket into the interior of the balloon. Alternatively, the basket may be made from a shape memory alloy that can be activated to assume an expanded configuration upon application of heat or other energy, and the delivery device is then configured and operated to activate the basket to reconfigure from a collapse state into an expanded state once inserted into the balloon. Referring to  FIG. 23 , after expansion of the basket  626 , if fluid is initially used to inflate the balloon  610 , the fluid may be evacuated coupling a tube  622  to valve  614  and applying appropriate suction to the interior of the balloon.  
         [0071]     Turning now to FIGS.  24  to  26 , another embodiment of a percutaneous device for modifying the volume of the left ventricle is shown. The device  700 , provided at the distal end of a delivery instrument  724 , is initially in the form of a radially collapsed wire basket  726  within a balloon  710 . An outer sheath  728  confines the device  700  to the collapsed state ( FIG. 24 ). The device  700  is delivered to the apex of the left ventricle and coupled thereat. Referring to  FIG. 25 , then the outer sheath  728  is retracted causing the device  700  to expand within the apex of the left ventricle. Finally, referring to  FIG. 26 , the delivery instrument  724  is decoupled from the device  700  and removed from the heart.  
         [0072]     Turning now to  FIGS. 27 and 28 , the volume of the left ventricle may also be reduced in a non-percutaneous, but relatively minimally invasive approach via a sub-xiphoid incision or through a thoracoscope  832  via a left anterior thoracotomy incision. A delivery device  830  including an introducer  822 , a balloon  810  preferably substantially similar to one of the embodiments described above at the distal end thereof, and a retractable sheath  828  over the balloon is advanced to the apex of the heart through the selected approach. The distal end of the delivery device  830  is inserted trans-apically into the left ventricle. The apical side of the balloon  810  includes an anchor  808  with an inflation valve  814 . The balloon  810  is inflated through the inflation valve  814  and the anchor  808  is then pulled back through the apex of the heart wall. The anchor  808  is preferably locked to the wall with a button  809  or other suitable fastener. The anchor and button may be reliably coupled permitting removal of the balloon if necessary. A preferred attachment includes a releasable ratchet mechanism. The button  809  may be introduced over the introducer  822  and seated prior to releasing the introducer from the balloon  810 , or the introducer may be released from the balloon and the button attached thereafter.  
         [0073]     Referring to  FIGS. 29 and 30 , another minimally invasive embodiment is shown and now described. A balloon  910  is delivered trans-apically into the left ventricle. The balloon  910  has a valve  914  at its apical side. A collapsed basket  916  is introduced on a delivery device  922  into the balloon  910  and then expanded. The basket  916  may be self-expanding or comprised of a shape memory alloy expandable via application of appropriate energy. If energy is required, the delivery device  922  also includes an energy applicator to deliver the required energy for basket expansion. The apical end of at least one of the balloon and the basket includes an anchor  908 , optionally for receiving a button  909 , to couple the balloon/basket within the left ventricle. Such anchor  909  additionally comprises the site for energy reception to expand the basket, if necessary. Alternatively, the balloon  910  and basket  916  can be introduced together, as discussed above, into the left ventricle trans-apically.  
         [0074]     There have been described and illustrated herein several embodiments of apparatus and a methods for ventricular restoration. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular anchors have been disclosed, it will be appreciated that other anchors could be used as well. For example, a simple bayonet anchor could be used. In addition, while the presently preferred embodiment of the balloon has been described as a truncated paraboloid with the truncation plane at an angle to the directorix plane, other shapes could be used provided they yield equivalent results. For example, and not by way of limitation, the top surface of the balloon could be concave, convex, flat or angled. Other types of couplings between the inflation tube and the balloon could also be used, e.g. a bayonet coupling. Also, while the term balloon has been used, it is not necessary that the balloon be made of an elastic element, but such balloon should be made of a material relatively impermeable to the fluid (saline, blood) that must be kept in and/or out of the interior of the balloon for the given embodiment. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its scope as claimed.

Technology Classification (CPC): 0