Apparatus and methods for cardiac restraint

Abstract

Apparatus and methods for using the apparatus are disclosed for cardiac restraint. More specifically, the apparatus and methods are directed to accessing the pericardium, accessing the heart within the pericardium, and restraining the heart by at least partially enclosing the heart with the apparatus. An embodiment of a cardiac restraint apparatus according to the present invention comprises a jacket, the jacket having a rim which defines an opening for receiving a heart. The apparatus also comprises a knot pusher that has a hollow elongate body, as well as a strand that extends around the rim of the jacket and is tied into a slipknot. The strand is positioned such that at least one end portion of the strand extends through the knot pusher such that a distal end of the knot pusher can be moved into engagement with the slipknot, whereby pulling the end portion of the strand away from the heart while pushing the knot pusher against the slipknot and reducing the diameter of the opening defined by the rim. In addition, the apparatus comprises one or more guide elements that are attached to the jacket.

1 - 7 . (canceled)  
     
     
         8 . A method for positioning a cardiac restraint apparatus about the heart, the method comprising the steps of: 
 forming a surgical incision as an entry port for the cardiac restraint apparatus;    introducing a cutting tool through the incision for forming an opening in the pericardium to pass the cardiac restraint apparatus therethrough;    advancing the cardiac restraint apparatus through the incision and the opening into engagement with the heart; and    positioning the cardiac restraint apparatus about at least a portion of the heart.    
     
     
         9 . The method according to  claim 8  in which the cardiac restraint apparatus includes a flexible jacket disposed within a confined configuration, the method comprising advancing said cardiac restraint apparatus including the flexible jacket in confined configuration through the incision and the opening into engagement with the heart; and 
 positioning includes expanding the flexible jacket from the confined configuration to an expanded configuration with at least a portion of the heart disposed within the jacket.    
     
     
         10 . The method according to  claim 8 , wherein the surgical incision is a subxiphoid incision.  
     
     
         11 . The method according to  claim 8 , wherein the incision is a trans-xiphoid incision.  
     
     
         12 . The method according to  claim 8 , wherein the incision is a thorascopic incision.  
     
     
         13 . The method according to  claim 9  in which the flexible jacket includes a rim defining an opening through which to receive a heart, the method further comprising the steps of: 
 tacking the rim of the jacket in expanded configuration to posterior pericardium; and    manipulating the rim of the jacket over the anterior aspect of the heart to enclose at least the portion of the heart within the jacket.    
     
     
         14 . The method according to  claim 13  including the step of reducing the opening defined by the rim to enclose at least the portion the heart therein.  
     
     
         15 . The method according to  claim 13 , in which the rim includes elements of sufficient length to extent outwardly through an incision as an entry port for manipulating the rim remotely about the heart, the method comprising the steps of: 
 manipulating the elements from outside the entry port for positioning the rim of the jacket to enclose at least the portion of the heart within the jacket.    
     
     
         16 . The method according to  claim 13  in which the rim of the cardiac restraint apparatus includes at least one elastic band having a first end and a second end, the method further comprising the steps of: 
 advancing the cardiac restraint apparatus through the incision and the opening to position the elastic band about the heart; and    attaching the first and second ends of the elastic band to secure the elastic band around the heart.    
     
     
         17 . The method according to  claim 16  in which securing the elastic band around the heart comprises the steps of: 
 tacking the elastic band to posterior pericardium at a point between said first and second ends;    moving the first end to the anterior aspect of the heart, and tacking the first end to the pericardium overlying the anterior aspect of the heart; and    attaching the first and second ends together at a location over the anterior aspect of the heart.    
     
     
         18 . The method according to  claim 17  in which the first and second ends of the elastic band are attached using a grasping tool inserted through the incision and opening.  
     
     
         19 . Cardiac restraint apparatus for constraining installation about the heart of a patient, the apparatus comprising: 
 a flexible jacket having a rim, defining an opening for receiving a heart therein;    at least one element attached to the rim of sufficient length to extend outside the body of a patient to facilitate remote manipulation of the jacket into position about the heart of the patient from outside the patient's body; and    a sheath enclosing the jacket in confined configuration and including a confining wall having a path thereon of diminished shear strength to facilitate tearing of the confining wall along the path for selectively releasing the jacket from the confining configuration within the sheath.    
     
     
         20 . The apparatus according to  claim 19  in which the path includes a succession of perforations to promote tearing of the confining wall along the path.