https://www.ncbi.nlm.nih.gov/pubmed/20104930
Author information
- 1Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, Alabama, USA. mrubifu@hotmail.com
Abstract
Multiple
in vitro and animal models have demonstrated the efficacy of ultrasound
to enhance fibrinolysis. Mechanical pressure waves produced by
ultrasound energy improve the delivery and penetration of alteplase
(recombinant tissue plasminogen activator [tPA]) inside the clot. In
human stroke, the CLOTBUST phase II trial showed that the combination of
alteplase plus 2 hours of continuous transcranial Doppler (TCD)
increased recanalization rates, producing a trend toward better
functional outcomes compared with alteplase alone. Other small clinical
trials also showed an improvement in clot lysis when transcranial
color-coded sonography was combined with alteplase. In contrast,
low-frequency ultrasound increased the symptomatic intracranial
hemorrhage rate in a clinical trial. Administration of microbubbles
(MBs) may further enhance the effect of ultrasound on thrombolysis by
lowering the ultrasound-energy threshold needed to induce acoustic
cavitation. Initial clinical trials have been encouraging, and a
multicenter international study, TUCSON, determined a dose of newly
developed MBs that can be safely administered with alteplase and TCD.
Even in the absence of alteplase, the ultrasound energy, with or without
MBs, could increase intrinsic fibrinolysis. The intra-arterial
administration of ultrasound with the EKOS NeuroWave catheter is another
ultrasound application for acute stroke that is currently being studied
in the IMS III trial. Operator-independent devices, different
MB-related techniques, and other ultrasound parameters for improving and
spreading sonothrombolysis are being tested.
- PMID:
- 20104930
- DOI:
- 10.2165/11316850-000000000-00000
No comments:
Post a Comment