Medical assembly with transducer for local delivery of a therapeutic substance and method of using same

Abstract

A medical Assembly is used to delivery a therapeutic substance to a treatment area. The medical assembly comprises a catheter having a distal end and a proximal end, a transducer supported by at least a portion of the distal end of the catheter assembly, and a delivery lumen mounted on the catheter for delivery of a therapeutic substance. Support for the transducer is provided at a preselected number of anchoring points, wherein an inner surface of the transducer is positioned at a preselected distance from an outer surface of the catheter. The preselected distance defines a gap that is occupied by a low density material such as a gas which reflects acoustic pressure waves directed toward the gap by a transducer when a voltage is applied to the transducer. The reflected pressure wave increases the energy in the system, enhancing transport of therapeutic substances from the delivery lumen to the surrounding tissues and/or cells to be treated. The medical assembly may optionally be used in conjunction with both macroporous and microporous balloons. The medical assembly may optionally be modified so that a plurality of transducers are used, wherein the distal end of a transducer is positioned at a preselected distance from the proximal end of an adjacent transducer.

1 . A medical assembly for local delivery of a therapeutic substance to an internal body tissue target area comprising: 
 (a) a catheter having a distal end and a proximal end;    (b) a delivery lumen on said catheter, said lumen extending from the distal end of the catheter to the proximal end of the catheter for the delivery of a therapeutic substance therethrough; and    (c) a first transducer supported at the distal end of the catheter, said first transducer being supported by said catheter distal end at a preselected number of anchoring points, wherein an inner surface of the transducer is positioned at a controlled and preselected distance from an outer surface of the catheter, wherein said distance defines a gap between said outer surface of the catheter and said inner surface of the transducer, wherein perfusion holes are disposed at the proximal end of the catheter.    
   
   
       2 . The medical assembly of  claim 1 , wherein a balloon is incorporated at said distal end of the catheter, in fluid communication with said lumen, wherein said first transducer is disposed within said balloon.  
   
   
       3 . The medical assembly of  claim 2 , wherein the perfusion holes allow blood to flow past the balloon upon expansion of the balloon within an internal body tissue target area.  
   
   
       4 . A medical assembly for local delivery of a therapeutic substance to an internal body tissue target area comprising: 
 (a) a catheter having a distal end and a proximal end;    (b) a delivery lumen on said catheter, said lumen extending from the distal end of the catheter to the proximal end of the catheter for the delivery of a therapeutic substance therethrough;    (c) a first transducer supported at the distal end of the catheter, said first transducer being supported by said catheter distal end at a preselected number of anchoring points, wherein an inner surface of the transducer is positioned at a controlled and preselected distance from an outer surface of the catheter, wherein said distance defines a gap between said outer surface of the catheter and said inner surface of the transducer; and    (d) a balloon incorporated at said distal end of the catheter, the balloon in fluid communication with said lumen, said balloon being formed from a membrane having pores, wherein said transducer is disposed within said balloon.    
   
   
       5 . The medical assembly of  claim 4 , wherein the pores are sized from about 0.3 μm to about 2.5 μm.  
   
   
       6 . The medical assembly of  claim 4 , wherein the pores are sized from about 25 μm.  
   
   
       7 . The medical assembly of  claim 4 , wherein the membrane comprises a material selected from the group consisting of polyester, polyolefin, fluoropolymer, and polyamide.  
   
   
       8 . A medical assembly for local delivery of a therapeutic substance to an internal body tissue target area comprising: 
 (a) a catheter having a distal end and a proximal end;    (b) a first transducer supported by at least a portion of the distal end of the catheter assembly, said first transducer being supported by said catheter distal end at a preselected number of anchoring points, wherein an inner surface of said first transducer is positioned at a preselected distance from an outer surface of the catheter, and wherein said distance defines a gap between said outer surface of the catheter and said inner surface of said first transducer;    (c) a delivery lumen on said catheter, said lumen extending from the distal end of the catheter to the proximal end of the catheter for the delivery of a therapeutic substance therethrough; and    (d) a balloon incorporated at said distal end of the catheter, in fluid communication with said lumen, wherein said first transducer is disposed within said balloon.    
   
   
       9 . The medical assembly of  claim 8 , wherein perfusion holes are disposed at the proximal end of the catheter.  
   
   
       10 . The medical assembly of  claim 9 , wherein the perfusion holes allow blood to flow past the balloon upon expansion of the balloon within an internal body tissue target area.  
   
   
       11 . The medical assembly of  claim 8 , further comprising: 
 a second transducer supported by at least a portion of the distal end of the catheter assembly, the first and second transducer each having a proximal end and a distal end, wherein the distal end of the first transducer is positioned at a preselected distance from the proximal end of the second transducer.    
   
   
       12 . The medical assembly of  claim 11 , wherein the transducers are supported by the catheter assembly at a preselected number of anchoring points, and wherein an inner surface of each transducer is positioned at a preselected distance from an outer surface of the catheter, and wherein the distance defines a gap between the outer surface of the catheter and the inner surface of the transducer.  
   
   
       13 . The medical assembly of  claim 8 , wherein the gap is occupied by a low density material.  
   
   
       14 . The medical assembly of  claim 13 , wherein the low density material is selected from the group consisting of ambient air, oxygen, nitrogen, helium, open-cell polymer foam, closed-cell polymer foam and mixtures thereof.  
   
   
       15 . The medical assembly of  claim 8 , wherein the transducer comprises a hollow tubular shaped body, and wherein the catheter is extended through the hollow body.  
   
   
       16 . The medical assembly of  claim 8 , wherein the transducer is tubular.  
   
   
       17 . The medical assembly of  claim 8 , wherein the therapeutic substance is selected from a group consisting of antineoplastic, antiinflammatory, antiplatelet, anticoagulant, fibrinolytic, thrombin inhibitor, antimitotic, and antiproliferative substances and mixtures thereof.