Apparatus and methods are disclosed for endovascular ultrasound delivery to treat stenosis and inhibit restenosis, including delivery of therapeutic agents into the vessel wall. In some embodiments, delivery of therapeutic agent may be combined with angioplasty techniques and with blood flow protection devices. In other embodiments, treatment of endovascular stenosis or restenosis may be achieved without the use of ultrasound energy, and without performing an interventional procedure. In some other embodiments, a therapeutic agent may be removed from the body after exposure to the vessel wall to minimize a systemic effect of the therapeutic drug.
