TY - JOUR
T1 - Treatment of microvascular micro-embolization using microbubbles and long-tone-burst ultrasound
T2 - An invivo study
AU - Pacella, John J.
AU - Brands, Judith
AU - Schnatz, Frederick G.
AU - Black, John J.
AU - Chen, Xucai
AU - Villanueva, Flordeliza S.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - Despite epicardial coronary artery reperfusion by percutaneous coronary intervention, distal micro-embolization into the coronary microcirculation limits myocardial salvage during acute myocardial infarction. Thrombolysis using ultrasound and microbubbles (sonothrombolysis) is an approach that induces microbubble oscillations to cause clot disruption and restore perfusion. We sought to determine whether this technique could restore impaired tissue perfusion caused by thrombotic microvascular obstruction. In 16 rats, an imaging transducer was placed on the biceps femoris muscle, perpendicular to a single-element 1-MHz treatment transducer. Ultrasound contrast perfusion imaging was performed at baseline and after micro-embolization. Therapeutic ultrasound (5000 cycles, pulse repetition frequency=0.33Hz, 1.5MPa) was delivered to nine rats for two 10-min sessions during intra-arterial infusion of lipid-encapsulated microbubbles; seven control rats received no ultrasound-microbubble therapy. Ultrasound contrast perfusion imaging was repeated after each treatment or control period, and microvascular volume was measured as peak video intensity. There was a 90% decrease in video intensity after micro-embolization (from 8.6±4.8 to 0.7±0.8dB, p<0.01). The first and second ultrasound-microbubble sessions were respectively followed by video intensity increases of 5.8±5.1 and 8.7±5.7dB (p<0.01, compared with micro-embolization). The first and second control sessions, respectively, resulted in no significant increase in video intensity (2.4±2.3 and 3.6±4.9) compared with micro-embolization (0.6±0.7dB). We have developed an invivo model that simulates the distal thrombotic microvascular obstruction that occurs after primary percutaneous coronary intervention. Long-pulse-length ultrasound with microbubbles has a therapeutic effect on microvascular perfusion and may be a valuable adjunct to reperfusion therapy for acute myocardial infarction.
AB - Despite epicardial coronary artery reperfusion by percutaneous coronary intervention, distal micro-embolization into the coronary microcirculation limits myocardial salvage during acute myocardial infarction. Thrombolysis using ultrasound and microbubbles (sonothrombolysis) is an approach that induces microbubble oscillations to cause clot disruption and restore perfusion. We sought to determine whether this technique could restore impaired tissue perfusion caused by thrombotic microvascular obstruction. In 16 rats, an imaging transducer was placed on the biceps femoris muscle, perpendicular to a single-element 1-MHz treatment transducer. Ultrasound contrast perfusion imaging was performed at baseline and after micro-embolization. Therapeutic ultrasound (5000 cycles, pulse repetition frequency=0.33Hz, 1.5MPa) was delivered to nine rats for two 10-min sessions during intra-arterial infusion of lipid-encapsulated microbubbles; seven control rats received no ultrasound-microbubble therapy. Ultrasound contrast perfusion imaging was repeated after each treatment or control period, and microvascular volume was measured as peak video intensity. There was a 90% decrease in video intensity after micro-embolization (from 8.6±4.8 to 0.7±0.8dB, p<0.01). The first and second ultrasound-microbubble sessions were respectively followed by video intensity increases of 5.8±5.1 and 8.7±5.7dB (p<0.01, compared with micro-embolization). The first and second control sessions, respectively, resulted in no significant increase in video intensity (2.4±2.3 and 3.6±4.9) compared with micro-embolization (0.6±0.7dB). We have developed an invivo model that simulates the distal thrombotic microvascular obstruction that occurs after primary percutaneous coronary intervention. Long-pulse-length ultrasound with microbubbles has a therapeutic effect on microvascular perfusion and may be a valuable adjunct to reperfusion therapy for acute myocardial infarction.
KW - Micro-embolization
KW - Microbubble
KW - Microvascular obstruction
KW - Sonothrombolysis
KW - Ultrasound
UR - http://www.scopus.com/inward/record.url?scp=84922740294&partnerID=8YFLogxK
U2 - 10.1016/j.ultrasmedbio.2014.09.033
DO - 10.1016/j.ultrasmedbio.2014.09.033
M3 - Article
C2 - 25542487
AN - SCOPUS:84922740294
VL - 41
SP - 456
EP - 464
JO - Ultrasound in medicine and biology
JF - Ultrasound in medicine and biology
SN - 0301-5629
IS - 2
ER -