Abstract:
A partitioning device for separating a patient&#39;s heart chamber into a productive portion and a non-productive portion which is suitable for treating patients with heart disease, particularly congestive heart failure. The partitioning device has a reinforced membrane with outwardly biased members to help seal the periphery of the membrane against the wall of the patient&#39;s heart chamber. In one embodiment, the outwardly biased member is an expansive strand that extends between adjacent ribs of an expandable frame which reinforces the membrane. In another embodiment, the outwardly biased member is a hydrophilic body such as foam which swells upon contact with body fluid such as blood in the heart chamber. The reinforced membrane has a central hub with a distally extending support stem with a plurality of feet which extend radially from a centerline axis and preferably have ends that are aligned in a common plane. The ends of the pods which extend radially away from the centerline axis may be interconnected by flexible struts and/or webs.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a of U.S. patent application Ser. No. 11/151,164, filed on Jun. 10, 2005 entitled “PERIPHERAL SEAL FOR A VENTRICULAR PARTITIONING DEVICE”. 
       INCORPORATION BY REFERENCE 
       [0002]    All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. 
       FIELD OF THE INVENTION 
       [0003]    The present invention relates generally to the field of treating heart disease, particularly congestive heart failure, and more specifically, to a device and method for partitioning a patient&#39;s heart chamber and a system for delivering the treatment device. 
       BACKGROUND OF THE INVENTION 
       [0004]    Congestive heart failure (CHF) is characterized by a progressive enlargement of the heart, particularly the left ventricle and is a major cause of death and disability in the United States. Approximately 550,000 new cases occur annually in the U.S. alone. As the patient&#39;s heart enlarges, it cannot efficiently pump blood forward with each heart beat. In time, the heart becomes so enlarged the heart becomes ineffective as a pump and cannot adequately supply blood to the body. Even in healthy hearts only a certain percentage of the blood in a patient&#39;s left ventricle is pumped out or ejected from the chamber during each stroke of the heart. The pumped percentage, commonly referred to as the “ejection fraction”, is typically about sixty percent for a healthy heart. A patient with congestive heart failure can have an ejection fraction of less than 40% and sometimes much lower. As a result of the low ejection fraction, a patient with congestive heart failure is fatigued, unable to perform even simple tasks requiring exertion and experiences pain and discomfort. Further, as the heart enlarges, the internal heart valves such as the mitral valve cannot adequately close. An incompetent mitral valve allows regurgitation of blood from the left ventricle back into the left atrium, further reducing the heart&#39;s ability to pump blood forwardly. 
         [0005]    Congestive heart failure can result from a variety of conditions, including viral infections, incompetent heart valves (e.g. mitral valve), ischemic conditions in the heart wall or a combination of these conditions. Prolonged ischemia and occlusion of coronary arteries can result in myocardial tissue in the ventricular wall dying and becoming scar tissue. Once the myocardial tissue dies, it is less contractile (sometimes non-contractile) and no longer contributes to the pumping action of the heart. It is referred to as hypokinetic or akinetic. As the disease progresses, a local area of compromised myocardium may bulge out during the heart contractions, further decreasing the heart&#39;s ability to pump blood and further reducing the ejection fraction. In this instance, the heart wall is referred to as dyskinetic. The dyskinetic region of the heart wall may stretch and eventually form an aneurysmic bulge. 
         [0006]    Patients suffering from congestive heart failure are commonly grouped into four classes, Classes I, II, III and IV. In the early stages, Classes I and II, drug therapy is presently the most common treatment. Drug therapy typically treats the symptoms of the disease and may slow the progression of the disease, but it can not cure the disease. Presently, the only permanent treatment for congestive heart disease is heart transplantation, but heart transplant procedures are very risky, extremely invasive and expensive and are performed on a small percentage of patients. Many patient&#39;s do not qualify for heart transplant for failure to meet any one of a number of qualifying criteria, and, furthermore, there are not enough hearts available for transplant to meet the needs of CHF patients who do qualify. 
         [0007]    Substantial effort has been made to find alternative treatments for congestive heart disease. For example, surgical procedures have been developed to dissect and remove weakened portions of the ventricular wall in order to reduce heart volume. This procedure is highly invasive, risky and expensive and is commonly only done in conjunction with other procedures (such as heart valve replacement or coronary artery by-pass graft). Additionally, the surgical treatment is usually only offered to Class III and IV patients and, accordingly, is not an option for most patients facing ineffective drug treatment. Finally, if the procedure fails, emergency heart transplant is the only presently available option. 
         [0008]    Mechanical assist devices have been developed as intermediate procedures for treating congestive heart disease. Such devices include left ventricular assist devices and total artificial hearts. A left ventricular assist device includes a mechanical pump for increasing blood flow from the left ventricle into the aorta. Total artificial heart devices, such as the Jarvik heart, are usually used only as temporary measures while a patient awaits a donor heart for transplant. 
         [0009]    Recently, improvements have been made in treating patient&#39;s with CHF by implanting pacing leads in both sides of the heart in order to coordinate the contraction of both ventricles of the heart. This technique has been shown to improve hemodynamic performance and can result in increased ejection fraction from the right ventricle to the patient&#39;s lungs and the ejection fraction from the left ventricle to the patient&#39;s aorta. While this procedure has been found to be successful in providing some relief from CHF symptoms and slowed the progression of the disease, it has not been able to stop the disease and is only indicated in patients with ventricular dissynchrony. 
         [0010]    Other efforts to treat CHF include the use of an elastic support, such as an artificial elastic sock, placed around the heart to prevent further deleterious remodeling. 
       SUMMARY OF THE INVENTION 
       [0011]    The present invention is directed to a ventricular partitioning device and method of employing the device in the treatment of a patient with heart disease and particularly congestive heart failure (CHF). Specifically, the device partitions a chamber of the patient&#39;s heart into a main productive portion and a secondary non-productive portion. This partitioning reduces the total volume of the heart chamber, reduces the stress applied to weakened tissue of the patient&#39;s heart wall and, as a result, improves the ejection fraction thereof. Moreover, the expansive nature of the device improves the diastolic function of the patient&#39;s heart. 
         [0012]    A partitioning device embodying features of the invention has a reinforced partitioning component with a concave, pressure receiving surface which defines in part the main productive portion of the partitioned heart chamber when secured within the patient&#39;s heart chamber. The reinforced partitioning component has a flexible membrane that forms the pressure receiving surface. The partitioning component is preferably reinforced by a radially expandable frame component formed of a plurality of ribs. The ribs of the expandable frame have secured distal ends, which are preferably secured to a central hub, and free proximal ends. The distal ends of the ribs are preferably secured to the central hub to facilitate radial self expansion of the free proximal ends of the ribs away from a centerline axis. The distal ends of the ribs may be pivotally mounted to the hub and biased outwardly or fixed to the hub. The ribs are preferably formed of material such as superelastic NiTi alloy which allows for compressing the free proximal ends of the ribs toward a centerline axis into a contracted configuration for delivery and self expansion when released for deployment to an expanded configuration when released within the patient&#39;s heart chamber. 
         [0013]    The free proximal ends of the ribs are configured to engage and preferably penetrate the tissue lining the heart chamber to be partitioned so as to secure the peripheral edge of the partitioning component to the heart wall and fix the partitioning component within the chamber so as to partition the chamber in a desired manner. The tissue penetrating proximal tips are configured to penetrate the tissue lining at an angle approximately perpendicular to a center line axis of the partitioning device. The tissue penetrating proximal tips of the ribs may be provided with barbs, hooks and the like which prevent withdrawal from the tips from the heart wall. 
         [0014]    An expansive member such as one or more strands or swellable pads extend between at least one pair of adjacent ribs at or close to the outer edge or periphery of the membrane to exert enough pressure to the flexible membrane periphery when the partitioning device is in an expanded configuration to ensure an adequate seal between the membrane periphery and the lining of the heart wall. In one embodiment, a single strand or strands extend around essentially the entire periphery of the membrane so that the flexible periphery of the membrane between each pair of ribs is effectively sealed against the heart wall. The expansive strand or strands are formed of material which is stiffer than the flexible, unsupported material of the membrane to provide an outward expansive force or thrust to prevent formation of inwardly directed folds or wrinkles when the ribs of the partitioning device are in at least a partially contracted configuration. Suitable strand or strands are formed of material such as polypropylene suture or superelastic NiTi alloy wires. Such strands are typically about 0.005 to about 0.03 inch (0.13-0.76 mm) in diameter to provide the requisite outward expansive force when placed in a circular position such as around the periphery of the membrane in less than completely expanded configuration. 
         [0015]    In another embodiment expandable pads are provided between each adjacent pair of ribs which are configured to swell upon contact with body fluids to provide an outward expansive force or thrust, as above, to prevent formation of inwardly directed folds or wrinkles when the ribs of the partitioning device are in at least a partially contracted configuration. Preferably the pads are formed of expansive hydrophilic foam. Suitable swellable materials includable collagen, gelatin, polylactic acid, polyglycolic acid, copolymers of polylactic acid and polyglycolic acid, polycaprolactone, mixtures and copolymers thereof. Other suitable swellable bioresorbable polymeric materials may be employed. The expandable pads may be formed so as to delivery a variety of therapeutic or diagnostic agents. 
         [0016]    The ribs in their expanded configuration angle outwardly from the hub and the free proximal ends curve outwardly so that the membrane secured to the ribs of the expanded frame forms a trumpet-shaped, pressure receiving surface. 
         [0017]    The partitioning membrane in the expanded configuration has radial dimensions from about 10 to about 160 mm, preferably about 25 to about 50 mm, as measured from the center line axis. The membrane is preferably formed of flexible material or fabric such as expanded polytetrafluoroethylene (ePTFE). 
         [0018]    The partitioning device is designed to be oversized with respect to the chamber in which it is to be deployed so that the ribs of the device apply an outward force against the chamber wall. When the partitioning device is collapsed for delivery, the outwardly biased strand or strands ensures that there are no inwardly directed folds or wrinkles and that none are formed when the partitioning device is expanded for deployment within the heart chamber. 
         [0019]    In one partitioning device design embodying features of the invention, the free ends of the expansive strand or strands may be secured together or to the partitioning device. Alternatively, in another device design, the expansive strand or strands may be long enough so that one or both free ends thereof extend out of the patient to facilitate collapse and retrieval of the partitioning device. Pulling on the free ends of the strand extending out of the patient closes the expanded portion i.e. the ribs and membrane, of the partitioning device to collapse of the device and such pulling can pull the collapsed partitioning device into the inner lumen of a guide catheter or other collecting device 
         [0020]    The reinforced partitioning component preferably includes a supporting component or stem which has a length configured to extend distally to the heart wall surface to support the partitioning device within the heart chamber. The supporting component has a plurality of pods or feet, preferably at least three, which distribute the force of the partitioning device about a region of the ventricular wall surface to avoid immediate or long term damage to the tissue of the heart wall, particularly compromised or necrotic tissue such as tissue of a myocardial infarct (MI) and the like. Pods of the support component extend radially and preferably are interconnected by struts or planes which help distribute the force over an expanded area of the ventricular surface. 
         [0021]    The partitioning device may be delivered percutaneously or intraoperatively. One particularly suitable delivery catheter has an elongated shaft, a releasable securing device on the distal end of the shaft for holding the partitioning device on the distal end and an expandable member such as an inflatable balloon on a distal portion of the shaft proximal to the distal end to press the interior of the recess formed by the pressure receiving surface to ensure that the tissue penetrating tips or elements on the periphery of the partitioning device penetrate sufficiently into the heart wall to hold the partitioning device in a desired position to effectively partition the heart chamber. A suitable delivery device is described in co-pending application Ser. No. 10/913,608, filed on Aug. 5, 2004, and assigned to the present assignee. 
         [0022]    The partitioning device embodying features of the invention is relatively easy to install and is a substantially improved treatment of a diseased heart. A more normal diastolic and systolic movement of a patient&#39;s diseased heart is achieved. Concomitantly, an increase in the ejection fraction of the patient&#39;s heart chamber is usually obtained. These and other advantages of the invention will become more apparent from the following detailed description of the invention and the accompanying exemplary drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is an elevational view of a partitioning device embodying features of the invention in an expanded configuration. 
           [0024]      FIG. 2  is a plan view of the partitioning device shown in  FIG. 1  illustrating the upper surface of the device. 
           [0025]      FIG. 3  is bottom view of the partitioning device shown in  FIG. 1 . 
           [0026]      FIG. 4  is a perspective view of the non-traumatic tip of the distally extending stem of the device shown in  FIG. 1 . 
           [0027]      FIG. 5  is a partial cross-sectional view of the hub of the partitioning device shown in  FIG. 2  taken along the lines  5 - 5 . 
           [0028]      FIG. 6  is a transverse cross sectional view of the hub shown in  FIG. 5  taken along the lines  6 - 6 . 
           [0029]      FIG. 7  is a longitudinal view, partially in section of a reinforcing rib and membrane at the periphery of the partitioning device shown in  FIG. 1 . 
           [0030]      FIG. 8  is a schematic elevational view, partially in section, of a delivery system with the partitioning device shown in  FIGS. 1 and 2  mounted thereon. 
           [0031]      FIG. 9  is a transverse cross-sectional view of the delivery system shown in  FIG. 8  taken along the lines  9 - 9 . 
           [0032]      FIG. 10  is an elevational view, partially in section, of the hub shown in  FIG. 5  being secured to the helical coil of the delivery system shown in  FIG. 8 . 
           [0033]      FIGS. 11A-11E  are schematic views of a patient&#39;s left ventricular chamber illustrating the deployment of the partitioning device shown in  FIGS. 1 and 2  with the delivery system shown in  FIG. 8  to partition a patient&#39;s heart chamber (left ventricle) into a primary productive portion and a secondary, non-productive portion. 
           [0034]      FIG. 12  is a schematic plan view of the deployed device shown in  FIG. 11E  within a patient&#39;s heart chamber. 
           [0035]      FIG. 13  is a schematic plan view of the partitioning device shown in  FIG. 1  without the expansive strand after deployment within a patient&#39;s heart chamber. 
           [0036]      FIG. 14  is a partial schematic view of the partitioning device shown in  FIGS. 1 and 2  in a contracted configuration resulting from pulling the free ends of the expansive strand at the periphery of the reinforced membrane. 
           [0037]      FIG. 15  is a schematic view of the contracted device shown in  FIG. 14  being pulled into an expanded distal end of a receiving catheter to facilitate withdrawal of the partitioning device into a receiving catheter. 
           [0038]      FIG. 16  is a schematic view of the contracted device shown in  FIG. 14  pulled further into the inner lumen of the receiving catheter. 
           [0039]      FIG. 17  is a plan view of the top of an alternative partitioning device which has swellable pads disposed between adjacent ribs to press the membrane between the ribs against the heart wall. 
           [0040]      FIG. 18  is a cross-sectional view of a swellable pad disposed between two membrane layers secured to the ribs of the partitioning device taken on line  18 - 18  of  FIG. 17 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0041]      FIGS. 1-4  illustrate a partitioning device  10  which embodies features of the invention and which includes a partitioning membrane  11 , a hub  12 , preferably centrally located on the partitioning device, and a radially expandable reinforcing frame  13  is secured to the proximal or pressure side of the frame  13  as shown in  FIG. 1 . The ribs  14  have distal ends  15  which are secured to the hub  12  and free proximal ends  16  which are configured to curve or flare away from a center line axis. Radial expansion of the free proximal ends  16  unfurls the membrane  11  secured to the frame  13  so that the membrane presents a pressure receiving surface  17  which defines in part the productive portion of the patient&#39;s partitioned heart chamber. The peripheral edge  18  of the membrane  11  may be serrated as shown. 
         [0042]    A continuous expansive strand  19  extends around the periphery of the membrane  11  on the pressure side thereof to apply pressure to the pressure side of the flexible material of the membrane to effectively seal the periphery of the membrane against the wall of the ventricular chamber. The ends  20  and  21  of the expansive strand  19  are shown extending away from the partitioning device in  FIGS. 2 and 3 . The ends  20  and  21  may be left unattached or may be secured together, e.g. by a suitable adhesive or the membrane  11  itself. While not shown in detail, the membrane  11  has a proximal layer secured to the proximal faces of the ribs  14  and a distal layer secured to the distal faces of the ribs in a manner described in co-pending application Ser. No. 10/913,608, filed on Aug. 5, 2004. 
         [0043]    The hub  12  shown in  FIGS. 4 and 5  preferably is connected to a non-traumatic support component  22 . The support component  22  has a stem  23  a plurality of pods or feet  24  extending radially away from the center line axis and the ends of the feet  24  are secured to struts  25  which extend between adjacent feet. A plane of material (not shown) may extend between adjacent feet  24  in a web-like fashion to provide further support in addition to or in lieu of the struts  25 . The inner diameter of the stem  23  is threaded to secure the partitioning device  10  to a delivery catheter as shown in  FIGS. 8-10 . 
         [0044]    As shown in  FIG. 5 , the distal ends  15  of the ribs  14  are secured within the hub  12  and, as shown in  FIG. 6 , a transversely disposed connector bar  26  is secured within the hub which is configured to secure the hub  12  to the nontraumatic support component  22 . 
         [0045]    As illustrated in  FIGS. 5 and 6 , the connector bar  26  of the hub  12  allows the partitioning device  10  to be secured to the non-traumatic support component  22  and to be released from the delivery system within the patient&#39;s heart chamber. The distal ends  15  of the reinforcing ribs  14  are secured within the hub  12  in a suitable manner or they may be secured to the surface defining the inner lumen or they may be disposed within channels or bores in the wall of the hub  12 . The distal end of the ribs  14  are preshaped so that when the ribs are not constrained, other than by the membrane  11  secured thereto (as shown in  FIGS. 1 and 2 ), the free proximal ends  16  thereof expand to a desired angular displacement away from the centerline axis which is about 20° to about 90°, preferably about 50° to about 80°. The unconstrained diameter of the partitioning device  10  should be greater than the diameter of the heart chamber at the deployed location of the partitioning device so that an outward force is applied to the wall of the heart chamber by the partially expanded ribs  14  during systole and diastole so that the resilient frame  13  augments the heart wall movement. 
         [0046]      FIG. 7  illustrates the curved free proximal ends  16  of ribs  14  which are provided with sharp tip elements  27  configured to engage and preferably penetrate into the wall of the heart chamber and hold the partitioning device  10  in a deployed position within the patient&#39;s heart chamber so as to partition the ventricular chamber into a productive portion and a non-productive portion. 
         [0047]      FIGS. 8-10  illustrate a suitable delivery system  30  delivering the partitioning device  10  shown in  FIGS. 1 and 2  into a patient&#39;s heart chamber and deploying the partitioning device to partition the heart chamber as shown in  FIGS. 11A-11E . The delivery system  30  includes a guide catheter  31  and a delivery catheter  32 . 
         [0048]    The guide catheter  31  has an inner lumen  33  extending between the proximal end  34  and distal end  35 . A hemostatic valve (not shown) may be provided at the proximal end  34  of the guide catheter  31  to seal about the outer shaft  37  of the delivery catheter  32 . A flush port  36  on the proximal end  34  of guide catheter  31  is in fluid communication with the inner lumen  33 . 
         [0049]    The delivery catheter  32  has an outer shaft  37  with an adapter  38  on the proximal end thereof having a proximal injection port  39  which is in fluid communication with the interior of the shaft  37 . As shown in more detail in  FIG. 9 , the outer shaft  37  has an inner shaft  41  which is disposed within the interior thereof and is secured to the inner surface of the outer shaft  37  by webs  43  which extend along a substantial length of the inner shaft. The injection port  39  is in fluid communication with the passageways  42  between the inner and outer shafts  41  and  37  respectively and defined in part by the webs  43 . A torque shaft  44 , which is preferably formed of hypotubing (e.g. formed of stainless steel or superelastic NiTi), is disposed within the inner lumen  45  of the inner shaft  41  and has a proximal end  46  secured within the adapter  38 . Balloon inflation port  47  is in fluid communication with the inner lumen  48  of the torque shaft  44 . Torque shaft  44  is rotatably disposed within the inner lumen  45  of the inner shaft  41  and is secured to rotating knob  49 . A helical coil screw  50  is secured to the distal end  51  of the torque shaft  44  and rotation of the torque knob  49  on the proximal end  46  of the torque shaft  44  rotates the screw  50  to facilitate deployment of a partitioning device  10 . The proximal end  52  of inflatable balloon  53  is sealingly secured by adhesive  54  about the torque shaft  44  proximal to the distal end  51  of the torque shaft. The balloon  53  has an interior  55  in fluid communication with the inner lumen  48  of the torque shaft  44 . Inflation fluid may be delivered to the balloon interior  55  through port  47  which is in fluid communication with the inner lumen  48  of the torque shaft  44 . The distal end  56  of the balloon  53  is sealingly secured by adhesive  57  to the helical screw  50 . The proximal and distal ends  52  and  56  of the balloon  53  are blocked by the adhesive masses  54  and  57  to prevent the loss of inflation fluid delivered to the interior  55  of the balloon  53 . Delivery of inflation fluid through a fluid discharge port  58  in the distal end  51  of the torque shaft  44  inflates the balloon  53  which in turn applies pressure to the proximal surface of the partitioning device  10  to facilitate securing the partitioning component  10  to the wall  59  of heart chamber  60  as shown in  FIGS. 11A-11E  discussed below. 
         [0050]    As shown in  FIG. 11A , the partitioning component  10  is delivered through a delivery system  30  which includes a guide catheter  31  and a delivery catheter  32 . The partitioning component  10  is collapsed in a first, delivery configuration which has small enough transverse dimensions to be slidably advanced through the inner lumen  33  of the guide catheter  31 . Preferably, the guide catheter  31  has been previously percutaneously introduced and advanced through the patient&#39;s vasculature, such as the femoral artery, in a conventional manner to the desired heart chamber  60 . The delivery catheter  32  with the partitioning component  10  attached is advanced through the inner lumen  33  of the guide catheter  31  until the partitioning component  10  is ready for deployment from the distal end of the guide catheter  31  into the patient&#39;s heart chamber  60  to be partitioned. 
         [0051]    As shown in  FIG. 11B , the partitioning component  10  mounted on the screw  50  is urged further out of the inner lumen  33  of the guide catheter  32  until the support component  22  engages the heart wall  59 . The guide catheter  31  is withdrawn while the delivery catheter  32  is held in place until the proximal ends  16  of the ribs  14  exit the distal end  35  of the guide catheter. As shown in  FIG. 11C , the free proximal ends  16  of ribs  14  expand outwardly to press the sharp proximal tips  27  of the ribs  14  against and preferably into the tissue lining the heart wall  59 . 
         [0052]    With the partitioning component  10  deployed within the heart chamber  60  and preferably partially secured therein, inflation fluid is introduced through the inflation port  58  in the distal end  51  torque shaft  44  where it is directed into the balloon interior  54  to inflate the balloon  53 . The inflated balloon  53  presses against the pressure receiving surface  17  of the membrane  11  of the partitioning component  10  to ensure that the sharp proximal tips  27  are pressed well into the tissue lining the heart wall  59  as shown in  FIG. 11D . 
         [0053]    With the partitioning device  10  properly positioned within the heart chamber  60 , the knob  49  on the torque shaft  44  (as shown in  FIG. 8 ) is rotated counter-clockwise to disengage the helical coil screw  50  of the delivery catheter  32  from the stem  23  secured within hub  12 . The counter-clockwise rotation of the torque shaft  44  rotates the helical coil screw  50  which rides on the connector bar  26  secured within the hub  12 . Once the helical coil screw  50  disengages the connector bar  26 , the delivery system  30 , including the guide catheter  31  and the delivery catheter  32 , may then be removed from the patient. 
         [0054]    The proximal end  34  of the guide catheter  31  is provided with a flush port  36  to inject fluids such as therapeutic, diagnostic or other fluids through the inner lumen  33  during the procedure. Similarly, the proximal injection port  39  of adapter  38  is in communication with passageways  42  if the delivery catheter  32  for essentially the same purpose. 
         [0055]    The deployment of the partitioning component  10  in the patient&#39;s heart chamber  60  as shown in  FIG. 11E  divides the chamber into a main productive or operational portion  61  and a secondary, essentially non-productive portion  62 . The operational portion  61  is smaller than the original heart chamber  60  and provides for an improved ejection fraction and an improvement in blood flow. Over time, the non-productive portion  62  fills first with thrombus and subsequently with cellular growth. Bio-resorbable fillers such as polylactic acid, polyglycolic acid, polycaprolactone and copolymers and blends may be employed to initially fill the non-productive portion  62 . Fillers may be suitably supplied in a suitable solvent such as dimethylsulfoxide (DMSO). Other materials which accelerate tissue growth or thrombus may be deployed in the non-productive portion  62  as well as non-reactive fillers. 
         [0056]      FIG. 12  is a top view of the deployed partitioning device shown in  FIG. 11E  schematically illustrating the sealed periphery of the membrane  11  against the ventricular wall. This is to be compared with the schematic presentation shown in  FIG. 13  which illustrates a partitioning device without a strand having folds along the periphery  18  which do not allow for an effective seal against the wall  59  of the heart chamber  60 . 
         [0057]    The partitioning device  10  may be conveniently formed by the method described in co-pending application Ser. No. 10/913,608, filed on Aug. 5, 2004, which is incorporated herein by reference. 
         [0058]    While porous ePTFE material is preferred, the membrane  11  may be formed of suitable biocompatible polymeric material which includes Nylon, PET (polyethylene terephthalate) and polyesters such as Hytrel. The membrane  11  may be foraminous in nature to facilitate tissue ingrowth after deployment within the patient&#39;s heart. The delivery catheter  32  and the guiding catheter  31  may be formed of suitable high strength polymeric material such as PEEK (polyetheretherketone), polycarbonate, PET, Nylon, and the like. Braided composite shafts may also be employed. 
         [0059]      FIGS. 14-16  illustrate the collapse and retrieval of a partitioning device  10  by pulling on the ends  20  and  21  of the expansive strand  19  which extends around the periphery of the membrane  11 . Typically, the partitioning device  10  would still be secured to the delivery catheter  32 , but the delivery catheter is not shown to simplify the drawings. In  FIG. 14  the partitioning device  10  is shown in a partially collapsed configuration. In  FIG. 15  the partially collapsed partitioning device  10  is shown being withdrawn into the flared distal end  63  of retrieval catheter  64 .  FIG. 16  illustrates the completely collapsed partitioning device  10  pulled further into the retrieval catheter  64 . The partitioning device  10  may be withdrawn by pulling the device through the inner lumen  65  of the retrieval catheter  64 . Optionally, the partitioning device  10  and retrieval catheter may be withdrawn from the patient together. 
         [0060]    To assist in properly locating the device during advancement and placement thereof into a patient&#39;s heart chamber, parts, e.g. the distal extremity, of one or more of the ribs  14  and/or the hub  12  may be provided with markers at desirable locations that provide enhanced visualization by eye, by ultrasound, by X-ray, or other imaging or visualization means. Radiopaque markers may be made with, for example, stainless steel, platinum, gold, iridium, tantalum, tungsten, silver, rhodium, nickel, bismuth, other radiopaque metals, alloys and oxides of these metals. 
         [0061]      FIGS. 17 and 18  illustrate an alternative design which embodies features of the invention in which the partitioning device  10  is provided with swellable bodies  70 , preferably hydrophilic foam, around the periphery of the membrane  11  between adjacent ribs  14 . When these bodies contact body fluid, such as blood, upon deployment, they swell, thereby sealing the peripheral portion of the membrane  11  against the patient&#39;s heart wall as previously described. The details of the partitioning device  10  are essentially the same as in the previous embodiment and elements in this alternative embodiment are given the same reference numbers as similar elements in the previous embodiments. 
         [0062]    To the extent not otherwise described herein, the various components of the partitioning device and delivery system may be formed of conventional materials and in a conventional manner as will be appreciated by those skilled in the art. 
         [0063]    While particular forms of the invention have been illustrated and described herein, it will be apparent that various modifications and improvements can be made to the invention. Moreover, individual features of embodiments of the invention may be shown in some drawings and not in others, but those skilled in the art will recognize that individual features of one embodiment of the invention can be combined with any or all the features of another embodiment. Accordingly, it is not intended that the invention be limited to the specific embodiments illustrated. It is intended that this invention to be defined by the scope of the appended claims as broadly as the prior art will permit. 
         [0064]    Terms such a “element”, “member”, “component”, “device”, “section”, “portion”, “step”, “means” and words of similar import, when used herein shall not be construed as invoking the provisions of 35 U.S.C. §112(6) unless the following claims expressly use the term “means” followed by a particular function without specific structure or the term “step” followed by a particular function without specific action. Accordingly, it is not intended that the invention be limited, except as by the appended claims. All patents and patent applications referred to herein are hereby incorporated by reference in their entirety.