Transcranial ultrasound in clinical sonothrombolysis (TUCSON) trial. Sonothrombolysis in acute ischemic stroke for patients ineligible for rt-PA. Sonothrombolysis with transcranial color-coded sonography and recombinant tissue-type plasminogen activator in acute middle cerebral artery main stem occlusion: results from a randomized study.
Microspheres (microS) reach intracranial occlusions and transmit energy momentum from an ultrasound wave to residual flow to promote recanalization. We report a randomized multicenter phase II trial of microS dose escalation with systemic thrombolysis.
                Stroke patients receiving 0.9mg/kg tissue plasminogen activator (tPA) with pretreatment proximal intracranial occlusions on transcranial Doppler (TCD) were randomized (2:1 ratio) to microS (MRX-801) infusion over 90 minutes (Cohort 1, 1.4ml; Cohort 2, 2.8ml) with continuous TCD insonation, whereas controls received tPA and brief TCD assessments. The primary endpoint was symptomatic intracerebral hemorrhage (sICH) within 36 hours after tPA.
                Among 35 patients (Cohort 1 = 12, Cohort 2 = 11, controls = 12) no sICH occurred in Cohort 1 and controls, whereas 3 (27%, 2 fatal) sICHs occurred in Cohort 2 (p = 0.028). Sustained complete recanalization/clinical recovery rates (end of TCD monitoring/3 month) were 67%/75% for Cohort 1, 46%/50% for Cohort 2, and 33%/36% for controls (p = 0.255/0.167). The median time to any recanalization tended to be shorter in Cohort 1 (30 min; interquartile range [IQR], 6) and Cohort 2 (30 min; IQR, 69) compared to controls (60 min; IQR, 5; p = 0.054). Although patients with sICH had similar screening and pretreatment systolic blood pressure (SBP) levels in comparison to the rest, higher SBP levels were documented in sICH+ patients at 30 minutes, 60 minutes, 90 minutes, and 24-36 hours following tPA bolus.
                Perflutren lipid microS can be safely combined with systemic tPA and ultrasound at a dose of 1.4ml. Safety concerns in the second dose tier may necessitate extended enrollment and further experiments to determine the mechanisms by which microspheres interact with tissues. In both dose tiers, sonothrombolysis with microS and tPA shows a trend toward higher early recanalization and clinical recovery rates compared to standard intravenous tPA therapy. Ann Neurol 2009;66:28-38. The authors studied the effect of transcranial ultrasound on patients with acute middle cerebral artery occlusion and contraindications for thrombolysis. Fifteen consecutive subjects were randomized for insonation over 1 hour or for inclusion in a control group. By day 4, recanalization and neurologic improvement occurred more frequently in the target group. Ultrasound-induced acceleration of clot dissolution may be an option for patients with contraindications for recombinant tissue plasminogen activator. Sonothrombolysis is a new treatment approach in acute ischemic stroke. The results of a monocenter, randomized clinical study are presented.
                Subjects with acute middle cerebral artery main stem occlusion were randomized into a target group receiving 1-hour transcranial continuous insonation using a 1.8-MHz Doppler ultrasound (US) probe or a control group. All underwent standard thrombolysis with intravenous recombinant tissue-type plasminogen activator.
                Thirty-seven subjects were included; 19 subjects were treated in the target (US) group and 18 in the control (no-US) group, all with no residual flow in the middle cerebral artery main stem occlusion (Thrombolysis in Brain Ischemia recanalization grade 0). Compared with the no-US group, the US group showed greater improvement in National Institutes of Health Stroke Scale values at days 1 and 4 and a higher median Thrombolysis in Brain Ischemia grade 1 hour after recombinant tissue-type plasminogen activator initiation. Recanalization (complete or partial) after 1 hour occurred in 57.9% of the US group and 22.2% of the no-US group (P=0.045). After 90 days, 4 subjects from the US group had a modified Rankin Score <or=1 (none from the no-US group) and 8 had a Barthel Index >or=95 (none from the no US group; P=0.106 and P=0.003, respectively). Three subjects from the US group (15.8%) developed a symptomatic intracranial hemorrhage as did one (5.6%) in the no-US group (P=0.60).
                This small randomized study indicates a beneficial impact of transcranial ultrasound on recanalization and short-term outcome in subjects with middle cerebral artery main stem occlusion and recombinant tissue-type plasminogen activator treatment.
Sonothrombolysis appears to reduce death or dependency at three months (although CIs are quite wide), and increases recanalisation without clear hazard. A larger clinical trial is warranted.