Implant and agent delivery device

Abstract

The present invention provides a system ( 178 ) for delivering a therapeutic agent in combination with an implantable device ( 2 ) to maximize a therapeutic benefit offered by each. Preferably, the therapeutic agent is contained within a solid matrix form such as a pellet or gel to facilitate its handling and to regulate its rate of dissipation into the tissue after delivery. The implant device ( 2 ) is specially configured to receive and retain the matrix but permit blood to interact with the matrix so that the agent can be released to the blood in and around the device and the surrounding tissue. A delivery system ( 178 ) comprises an implant delivery device having an obturator ( 180 ) capable of piercing the tissue and an agent matrix delivery device ( 210 ) to place a matrix form, such as a pellet, into the interior of the implant ( 2 ) after it has been implanted. Preferably, the implant delivery device ( 180 ) and the matrix delivery device ( 210 ) are contained in one apparatus to facilitate delivery of the pellet into the embedded implant. The present invention is useful for treating tissue in any area of the body, especially ischemic tissue experiencing reduced blood flow. The present devices and methods are especially useful for treatment of ischemia of the myocardium. In treatment of the myocardium, the present implant device and matrix combination may be delivered surgically through the epicardium of the heart.

1 . A tissue implant comprising: 
 a porous body having an interior and proximal and distal ends;    wherein the proximal end of the implant is adapted to permit insertion of an agent carrying matrix into the interior of the implant after the implant has been placed in host tissue.    
   
   
       2 . An implant as defined in  claim 1  wherein the implant comprises a spring coil.  
   
   
       3 . An implant as defined in  claim 2  wherein the coil is substantially a constant diameter throughout its length.  
   
   
       4 . An implant as defined in  claim 2  wherein the coil is tapered, reducing in diameter from its proximal end to its distal end.  
   
   
       5 . An implant as defined in  claim 2  further comprising: a central region lying between the proximal and distal ends of the implant wherein coils that define the proximal and distal ends are of a smaller diameter than the coils of the central region.  
   
   
       6 . An implant as defined in  claim 5  wherein the coils that define the proximal region may be expanded temporarily to permit insertion of an agent carrying matrix into the interior of the implant, then released to return to a smaller diameter to retain the matrix within the interior of the implant.  
   
   
       7 . An implant as defined in  claim 5  wherein the proximal coils are compressed to a smaller diameter configuration after delivery of an agent substance carrying matrix into the interior of the implant through the proximal coils.  
   
   
       8 . An implant as defined in  claim 1  further comprising a therapeutic substance carrying matrix residing in the interior of the implant.  
   
   
       9 . An implant as defined in  claim 8  wherein the matrix is a solid form.  
   
   
       10 . An implant as defined in  claim 8  wherein the matrix is a pellet.  
   
   
       11 . An implant as defined in  claim 9  wherein the matrix is a gel.  
   
   
       12 . An implant as defined in  claim 10  wherein the pellet is substantially cylindrically shaped.  
   
   
       13 . An implant as defined in  claim 10  wherein the pellet is substantially cone shaped to facilitate entry into and frictional engagement with the interior of the implant.  
   
   
       14 - 18 . (Canceled)  
   
   
       19 . A method of treating tissue comprising: 
 delivering a tissue implant defining an interior into tissue;    inserting into the interior of the tissue implant a matrix carrying a therapeutic agent;    securing the matrix in the interior of the implant so that the therapeutic agent is permitted to be released to surrounding tissue.    
   
   
       20 . A method of delivering an implant and agent carrying matrix into tissue comprising: 
 providing a tissue implant device defining an interior, an agent carrying matrix and a combination implant and agent matrix delivery device having proximal and distal ends and an interior;    loading the delivery device with a tissue implant and agent matrix;    positioning the delivery device adjacent tissue to be treated;    delivering the tissue implant device into tissue while maintaining communication of the interior of the implant with the interior of the delivery device;    delivering the agent matrix into the interior of the implant from the interior of the delivery device;    withdrawing the delivery device and leaving the implant and matrix in the tissue.    
   
   
       21 . A method of delivering an implant and agent matrix as defined in  claim 20  wherein the implant is secured after delivery of the agent matrix to prevent the matrix from leaving the interior of the implant while permitting the agent to be released into surrounding tissue.  
   
   
       22 . A method of delivering an implant and agent matrix into tissue as defined in  claim 20  wherein the implant is carried external to the delivery device and the matrix is carried internal to the delivery device during delivery.