Methods and devices for treating diseased blood vessels

A catheter for delivering a therapeutic agent to a blood vessel having a diseased region along a vessel wall thereof, comprising:

• an elongate body adapted to be inserted into a blood vessel lumen;
• at least one expandable balloon mounted on the elongate body, the expandable balloon having an outer wall and an inflation lumen in fluid communication with a source of therapeutic agent;
• and
• at least one microneedle extending from the outer wall of the at least one balloon, the at least one microneedle having at least one injection port extending from a base of the microneedle to a distal-most end for delivering the therapeutic agent to a select layer within the vessel wall;
• wherein when the balloon is fully expanded within the blood vessel lumen at the diseased region, the microneedle effectively punctures and extends into the select layer of the vessel wall to be treated.