Variable length catheter for drug delivery

A catheter system comprising:

• an outer elongated element having an outer elongated element proximal end and an outer elongated element distal end, said outer elongated element having an outer elongated element lumen extending from said outer elongated element proximal end to said outer elongated element distal end and having an outlet port at said outer elongated element distal end, and a proximal occlusion element located at said outer elongated element distal end, said proximal occlusion element proximal to said outlet port;
• and
• an inner elongated element having an inner elongated element proximal end and an inner elongated element distal end, said inner elongated element having an inner elongated element lumen extending from said inner elongated element proximal end to said inner elongated element distal end, and a distal occlusion element located at said inner elongated element distal end, said inner elongated element positioned within said outer elongated element lumen wherein said outer elongated element is coaxially arranged with respect to said inner elongated element, and wherein said inner elongated element distal end is distal to and movable with respect to said outer elongated element distal end;
• a blood-release element at said inner elongated element distal end;
• and
• a supply elongated element coaxial to said outer elongated element, said supply elongated element having an inlet port at a distal end thereof, wherein said inlet port is proximal to said outer elongated element distal end.