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Updated: May 31, 2026
Real-Time Monitoring and Modulation of Blood Pressure in a Rabbit Model of Ischemic Stroke
Published on: February 10, 2023
Successful microbubble sonothrombolysis without tissue-type plasminogen activator in a rabbit model of acute ischemic
William C Culp1, Rene Flores, Aliza T Brown
1Department of Radiology, University of Arkansas for Medical Sciences, Little Rock, AR 72205-7199, USA. culpwilliamc@uams.edu
Background And Purpose:
Microbubbles (MB) combined with ultrasound (US) have been shown to lyse clots without tissue-type plasminogen activator (tPA) both in vitro and in vivo. We evaluated sonothrombolysis with 3 types of MB using a rabbit embolic stroke model.
Methods:
New Zealand White rabbits (n=74) received internal carotid angiographic embolization of single 3-day-old cylindrical clots (0.6 × 4.0 mm). Groups included: (1) control (n=11) embolized without treatment; (2) tPA (n=20); (3) tPA+US (n=10); (4) perflutren lipid MB+US (n=16); (5) albumin 3 microm MB+US (n=8); and (6) tagged albumin 3 microm MB+US (n=9). Treatment began 1 hour postembolization. Ultrasound was pulsed-wave (1 MHz; 0.8 W/cm²) for 1 hour; rabbits with tPA received intravenous tPA (0.9 mg/kg) over 1 hour. Lipid MB dose was intravenous (0.16 mg/kg) over 30 minutes. Dosage of 3 microm MB was 5 × 10⁹ MB intravenously alone or tagged with eptifibatide and fibrin antibody over 30 minutes. Rabbits were euthanized at 24 hours. Infarct volume was determined using vital stains on brain sections. Hemorrhage was evaluated on hematoxylin and eosin sections.
Results:
Infarct volume percent was lower for rabbits treated with lipid MB+US (1.0%± 0.6%; P=0.013), 3 microm MB+US (0.7% ± 0.9%; P=0.018), and tagged 3 microm MB+US (0.8% ± 0.8%; P=0.019) compared with controls (3.5%± 0.8%). The 3 MB types collectively had lower infarct volumes (P=0.0043) than controls. Infarct volume averaged 2.2% ± 0.6% and 1.7%± 0.8% for rabbits treated with tPA alone and tPA+US, respectively (P=nonsignificant).
Conclusions:
Sonothrombolysis without tPA using these MB is effective in decreasing infarct volumes. Study of human application and further MB technique development are justified.
