Progress in Sonothrombolysis for the Treatment of Stroke

Rapid restoration of vascular flow is the primary goal of acute stroke treatment. US offers new thrombolytic mechanisms when combined with microbubbles. Recent data suggesting that US and microbubbles can improve microvascular flow may provide new concepts for treatment of stroke. Therapy of the microcirculation will require new transducer designs for US delivery to this therapeutic target. Moreover, systems that estimate the intracranial acoustic pressure through direct detection of cavitation or through observations of microbubble behavior will allow more consistent application of US parameters to individual patients in clinical trials. US-sensitive thrombolytic drug delivery combined with specific targeting is highly attractive. Targeting of clotdissolving therapeutics could potentially decrease the frequency of complications at the same time as simultaneously increasing treatment effectiveness by concentrating the available drug at the desired site and permitting a lower systemic dose.65 Any new system must be simple and safe when widely used. If safety can be proven even in hemorrhagic strokes, it may well be possible to use some technique of microbubble-augmented US lysis or US-augmented thrombolysis in patients who have not yet been transported to the hospital for CT to determine the presence or absence of intracranial hemorrhage. Even if the improvement in outcomes is only moderate with this new technique, the addition of many more patients to therapy within the earliest part of the time window would be a service with tremendous impact. © 2012 American Heart Association, Inc.