Methods and systems for treating ischemic tissues

Abstract

Methods and systems for regenerating damaged tissue rely on direct injection of selected therapeutic cells into a tissue at or near the site of tissue damage. Direct injection is accomplished using an intravascular catheter having a deployable needle, and injection is usually targeted into the adventitial and peri-adventitial tissues surrounding the blood vessel from which the needle is deployed.

What is claimed is: 
     
         1 - 24 . (canceled) 
     
     
         25 . A system for treating ischemic tissue, said system comprising:
 an amount of therapeutic cells selected to revascularize the ischemic tissue; and   an intravascular catheter advancable into a lumen of a blood vessel, the intravascular catheter having a needle advancable beyond the external elastic lamina of the blood vessel to inject the therapeutic cells into a location in the perivascular space surrounding the blood vessel adjacent the ischemic tissue.   
     
     
         26 . The system of claim  1 , wherein the ischemic tissue comprises ischemic cardiac tissue, neurological tissue damaged by stroke, or other tissue damaged by inadequate blood circulation. 
     
     
         27 . The system of claim  2 , wherein the ischemic tissue comprises ischemic cardiac tissue, and the ischemic cardiac tissue is cardiac tissue which has been damaged by a myocardial infarction or by inadequate blood circulation. 
     
     
         28 . The system of claim  1 , wherein the therapeutic cells are selected from a group comprising stem cells, cardiomyocytes, fibroblasts, endothelial cells, skeletal myoblasts, mesenchymal stem cells, cells from unprocessed or minimally processed bone marrow, peripheral blood stem cells, and mobilized peripheral blood stem cells. 
     
     
         29 . The system of claim  1 , wherein the therapeutic cells are pluripotent stem cells. 
     
     
         30 . The system of claim  5 , wherein the pluripotent stem cells are mesenchymal adult progenitor cells. 
     
     
         31 . The system of claim  1 , wherein the blood vessel comprises a coronary blood vessel. 
     
     
         32 . The system of claim  1 , wherein the blood vessel is a vein. 
     
     
         33 . The system of claim  1 , wherein the blood vessel is an artery. 
     
     
         34 . The system of claim  1 , wherein the needle is advancable in a radial direction relative to a longitudinal axis of the intravascular catheter. 
     
     
         35 . The system of claim  10 , wherein the needle is advancable to a radial direction to a depth beyond a endothelium of the blood vessel equal to at least 10% of the mean luminal diameter of the blood vessel at a location of the needle. 
     
     
         36 . The system of claim  11 , wherein the depth is a distance in the range from 10% to 50% of the mean luminal diameter of the blood vessel at the location. 
     
     
         37 . The system of claim  1 , wherein the intravascular catheter comprises an expandable section, wherein the needle is disposed on the expandable section and the expandable section is expandable to advance the needle. 
     
     
         38 . The system of claim  13 , wherein the needle extends approximately perpendicularly from a surface of the expandable section. 
     
     
         39 . The system of claim  1 , wherein the intravascular catheter comprises a plurality of the needles. 
     
     
         40 . The system of claim  1 , wherein the needle is 30-gauge or smaller.