The potential applications of high-intensity focused ultrasound (HIFU) in vascular neurosurgery.

This review assesses the feasibilty of high-intensity focused ultrasound (HIFU) in neurosurgical applications, specifically occlusion of intact blood vessels. Fourteen articles were examined. In summary, MRI was effective for HIFU guidance whereas MR angiography assessed vessel occlusion. Several studies noted immediate occlusion of blood vessels with HIFU. Long-term data, though scarce, indicated a trend of vessel recanalization and return to pre-treatment diameters. Effective parameters for extracranial vascular occlusion included intensity ranges of 1,690-8,800 W/cm(2), duration <15 seconds, and 0.68-3.3 MHz frequency. A threshold frequency-intensity product of 8,250 MHzW/cm(2) was needed for vascular occlusion with a sensitivity of 70% and a specificity of 86%. Complications include skin burns, hemorrhage, and damage to surrounding structures. With evidence that HIFU can successfully occlude extracranial blood vessels, refinement in applications and demonstrable intracranial occlusion are needed.