Sonothrombolysis for acute ischemic stroke: a systematic review of randomized controlled trials.
OBJECTIVE
Sonothrombolysis has recently been considered an emerging modality for the treatment of stroke. The purpose of the present paper was to review randomized clinical studies concerning the effects of sonothrombolysis associated with tissue plasminogen activator (tPA) on acute ischemic stroke.


METHODS
Systematic searches for literature published between January 1996 and July 2011 were performed for studies regarding sonothrombolysis combined with tPA for acute ischemic stroke. Only randomized controlled trials were included. Data extraction was based on ultrasound variables, patient characteristics, and outcome variables (rate of intracranial hemorrhages and arterial recanalization).


RESULTS
Four trials were included in this study; 2 trials evaluated the effect of transcranial Doppler (TCD) ultrasonography on sonothrombolysis, and 2 addressed transcranial color-coded duplex (TCCD) ultrasonography. The frequency of ultrasound waves varied from 1.8 to 2 MHz. The duration of thrombus exposure to ultrasound energy ranged from 60 to 120 minutes. Sample sizes were small, recanalization was evaluated at different time points (60 and 120 minutes), and inclusion criteria were heterogeneous. Sonothrombolysis combined with tPA did not lead to an increase in symptomatic intracranial hemorrhagic complications. Two studies demonstrated that patients treated with ultrasound combined with tPA had statistically significant higher rates of recanalization than patients treated with tPA alone.


CONCLUSIONS
Despite the heterogeneity and the limitations of the reviewed studies, there is evidence that sonothrombolysis associated with tPA is a safe procedure and results in an increased rate of recanalization in the setting of acute ischemic stroke when wave frequencies and energy intensities of diagnostic ultrasound systems are used.
Division of Neurological Surgery, Hospital das Clinicas, University of Sao Paulo School of Medicine, Sao Paulo, Brazil. edsonshu@hotmail.com
Edson
E
Bor-Seng-Shu
Ricardo De Carvalho
Rde C
Nogueira
Eberval G
EG
Figueiredo
Eli Faria
EF
Evaristo
Adriana Bastos
AB
Conforto
Manoel Jacobsen
MJ
Teixeira
D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000188:drug therapy; D006801:Humans; D020300:Intracranial Hemorrhages / Q000209:etiology; D016032:Randomized Controlled Trials as Topic; D020521:Stroke / Q000000981:diagnostic imaging / Q000188:drug therapy*; D015912:Thrombolytic Therapy / Q000379:methods*; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D016896:Treatment Outcome; D014463:Ultrasonography / Q000379:methods*; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods
D010959:Tissue Plasminogen Activator