Sonoreperfusion therapy for microvascular obstruction: A step toward clinical translation

Filip Istvanic, Gary Z Yu, Francois T H Yu, Jeff Powers, Xucai Chen, John J Pacella, Filip Istvanic, Gary Z Yu, Francois T H Yu, Jeff Powers, Xucai Chen, John J Pacella

Abstract

Sonoreperfusion therapy is being developed as an intervention for the treatment of microvascular obstruction. We investigated the reperfusion efficacy of two clinical ultrasound systems (a modified Philips EPIQ and a Philips Sonos 7500) in a rat hindlimb microvascular obstruction model. Four ultrasound conditions were tested using 20 min treatments: Sonos single frame, Sonos multi-frame, EPIQ low pressure and EPIQ high pressure. Contrast-enhanced perfusion imaging of the microvasculature was conducted at baseline and after treatment to calculate microvascular blood volume (MBV). EPIQ high pressure treatment resulted in significant recovery of MBV from microvascular obstruction, returning to baseline levels after treatment. EPIQ low pressure and Sonos multi-frame treatment resulted in significantly improved MBV after treatment but below baseline levels. Sonos single-frame and control groups showed no improvement post-treatment. This study demonstrates that the most effective sonoreperfusion therapy occurs at high acoustic pressure coupled with high acoustic intensity. Moreover, a clinically available ultrasound system is readily capable of delivering these effective therapeutic pulses.

Keywords: Cardiac disease; Contrast agents; Microvascular obstruction; Ultrasound.

Conflict of interest statement

Conflict of interest disclosure The authors declare no competing interests.

Copyright © 2019 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1:. Rodent hindlimb model of microvascular…
Figure 1:. Rodent hindlimb model of microvascular obstruction.
Our rodent hindlimb model of microvascular obstruction was created by injecting microthrombi into the hindlimb muscle microvasculature via the contralateral femoral artery (arrow bottom left). Lipid encapsulated microbubbles were infused through the contralateral femoral artery during therapy (arrow bottom left). DEFINITY® microbubble contrast agent was infused through the jugular vein (arrow top right). Therapeutic US was delivered to the obstructed microvasculature using the therapy transducer superior to the hindlimb. Contrast-enhanced US perfusion imaging of the microvasculature was conducted using the imaging transducer lateral to the hindlimb.
Figure 2:. Experimental timeline of each run.
Figure 2:. Experimental timeline of each run.
The timeline is composed of four imaging timepoints, one 10 min microvascular obstruction time period, and two 10 min treatment sessions. The four imaging timepoints are indicated with labeled black boxes along the arrow and include: baseline (BL); MVO (microvascular obstruction, 10 min after microthrombi injection); Tx1 (immediately after first 10 min treatment session); and Tx2 (immediately after second 10 min treatment session). Microthrombi are injected just prior to the 10 min MVO time period.
Figure 3:. Size distribution of a representative…
Figure 3:. Size distribution of a representative suspension of microthrombi.
Particle size mean ± standard deviation of 46 μm ± 16 μm (range 32 μm to 155 μm).
Figure 4:. Contrast-enhanced US perfusion still-frame images…
Figure 4:. Contrast-enhanced US perfusion still-frame images at four timepoints for each experimental group.
Imaging at BL yielded homogenous distribution of microbubbles. Imaging 10 minutes after microthrombi injection yielded marked MVO. After Tx2, there was significantly more reperfusion in the (d) EPIQ high pressure group relative to all other groups.
Figure 5:. Microvascular blood volume in the…
Figure 5:. Microvascular blood volume in the treated hindlimb for all experimental groups.
Microvascular volumes (MBV) are shown for all EPIQ conditions (A) and all Sonos conditions (B). The EPIQ high pressure group showed significant improvement of MBV after Tx1, returning to baseline levels after Tx2, while the EPIQ low pressure group saw significant improvement only after Tx2 and to a lesser extent than that for the high pressure group. For the Sonos conditions, only the multi-frame group saw a significant improvement in MBV after Tx2. Double asterisks (**) indicates significant difference from MVO state. Dagger (†) indicates no statistical difference from baseline (BL). Single asterisk indicates significant difference for the indicated comparison. Error bars represent standard deviation.
Figure 6:. Representative hematoxylin and eosin-stained sections…
Figure 6:. Representative hematoxylin and eosin-stained sections of four treatment groups.
Images show no evidence of microvasculature trauma, hemorrhage, or architectural derangements directly under the therapy transducer. Scale bar = 500 μm.

References

    1. Bekkers SC, Yazdani SK, Virmani R, Waltenberger J. Microvascular obstruction: underlying pathophysiology and clinical diagnosis. Journal of the American College of Cardiology. 2010;55(16):1649–1660.
    1. Belcik JT, Mott BH, Xie A, Zhao Y, Kim S, Lindner NJ, Ammi A, Linden JM, Lindner JR. Augmentation of limb perfusion and reversal of tissue ischemia produced by ultrasound-mediated microbubble cavitation. Circulation: Cardiovascular Imaging. 2015;8(4)e002979.
    1. Black JJ, Yu FTH, Schnatz RG, Chen X, Pacella JJ. Effect of thrombus composition and viscosity on sonoreperfusion efficacy in a model of microvascular obstruction. Ultrasound Med Biol. 2016;42(9):2220–31.
    1. Chen WS, Brayman AA, Matula TJ, Crum LA, Miller MW. The pulse length-dependence of inertial cavitation dose and hemolysis. Ultrasound Med Biol. 2003;29:739–748.
    1. Chen X, Leeman JE, Wang J, Pacella JJ, Villanueva FS. New insights into mechanisms of sonothrombolysis using ultra high speed imaging. Ultrasound Med Biol. 2014;40:258–262.
    1. Goyal A, Yu FTH, Tenwalde MG, Chen X, Althouse A, Villanueva FS, Pacella JJ. Inertial cavitation ultrasound with microbubbles improves reperfusion efficacy when combined with tissue plasminogen activator in an in vitro model of microvascular obstruction. Ultrasound Med Biol. 2017;43(7):1391–1400.
    1. Ito H, Maruyama A, Iwakura K, Takiuchi S, Masuyama T, Masatsugu H, Higashino Y, Fujii K, Minamino T. Clinical implications of the ‘No Reflow’ phenomenon: a predictor of complications and left ventricular remodeling in reperfused anterior wall myocardial infarction. Circulation. 1996;93:223–228.
    1. Leeman JE, Kim JS, Yu FT, Chen X, Kim K, Wang J, Chen X, Villanueva FS, Pacella JJ. Effect of acoustic conditions on microbubble-mediated micro-vascular sonothrombolysis. Ultrasound Med Biol. 2012;38:1589–1598.
    1. Mathias W Jr, Tsutsui JM, Tavares BG, Xie F, Aguiar MO, Garcia DR, Oliveira MT Jr, Soeiro A, Nicolau JC, Neto Lemos PA, Rochitte CE, Ramires JA, Filho Kalil R, Porter TR. Diagnostic ultrasound impulses improve microvascular flow in patients with STEMI receiving intravenous microbubbles. J Am Coll Cardiol. 2016;67(21):2506–2515.
    1. Mathias W Jr, Tsutsui JM, Tavares BG, Fava AM, Aguiar MOD, Borges BC, Oliveira MT Jr, Soeiro A, Nicolau JC, Ribeiro HB, Pochiang H, Sbano JCN, Morad A, Goldsweig A, Rochitte CE, Lopes BBC, Ramirez JAF, Filho RK, Porter TR. Sonothrombolysis in ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention. J Am Coll Cardiol. 2019; pii: S0735–1097(19)33870–7.
    1. Menees DS, Peterson ED, Wang Y, Curtis JP, Messenger JC, Rumsfeld JS, Gurm HS. Door-to-balloon time and mortality among patients undergoing primary PCI. N Engl J Med. 2013;369(10):901–909.
    1. Nakano M, Otsuka F, Finn AV, Virmani R. Microvascular Obstruction Is Caused by Atherothrombosis in ACS Patients Undergoing PCI. Circulation Cardiovascular Imaging. 2011;4(6):597–600.
    1. Pacella JJ, Brands J, Schnatz FG, Black JJ, Chen X, Villanueva FS. Treatment of microvascular micro-embolization using microbubbles and long-tone-burst ultrasound: an in vivo study. Ultrasound Med Biol. 2015;41(2):456–464.
    1. Phillips PJ. Contrast pulse sequences (CPS): Imaging non-linear microbubbles. Proceedings, IEEE International Ultrasonics Symposium. 2001;2:1739–1745.
    1. Postema M, van Wamel A, Lancee CT, de Jong N. Ultrasound-induced encapsulated microbubble phenomena. Ultrasound Med Biol. 2004;30(6):827–840.
    1. Roos ST, Yu FTH, Kamp O, Chen X, Villanueva FS, Pacella JJ. Sonoreperfusion therapy kinetics in whole blood using ultrasound, microbubbles, and tissue plasminogen activator. Ultrasound Med Biol. 2016;42(12):3001–3009.15.
    1. Tu J, Matula TJ, Brayman AA, Crum LA. Inertial cavitation dose produced in ex vivo rabbit ear arteries with Optison by 1-MHz pulsed ultrasound. Ultrasound Med Biol. 2006;32:281–288.
    1. Villanueva FS, Gertz EW, Csikari M, Pulido G, Fisher D, Sklenar J. Detection of coronary artery stenosis with power Doppler imaging. Circulation. 2001;103:2624–2630.
    1. Wei K, Jayaweera AR, Firoozan S, Linka A, Skyba DM, Kaul S. Quantification of myocardial blood flow with ultrasound-induced destruction of microbubbles administered as a constant venous infusion. Circulation. 1998;97:473–483.
    1. Weller GE, Villanueva FS, Klibanov AL, Wagner WR. Modulating targeted adhesion of an ultrasound contrast agent to dysfunctional endothelium. Ann Biomed Eng. 2002;30:1012–1019.
    1. Xie F, Gao S, Wu J, Lof J, Radio S, Vignon F, William Shi, Powers J, Unger E, Everbach EC, Liu J, Porter TR. Diagnostic ultrasound induced inertial cavitation to non-invasively restore coronary and microvascular flow in acute myocardial infarction. PLoS One. 2013;8(7):e69780.
    1. Xie F, Lof J, Everbach C, He A, Bennett RM, Matsunaga T, Johanning J, Porter TR. Treatment of acute intravascular thrombi with diagnostic ultrasound and intravenous microbubbles. JACC: Cardiovascular imaging. 2009;2(4):511–518.
    1. Yu FTH, Chen X, Straub AC, Pacella JJ. The role of nitric oxide during sonoreperfusion of microvascular obstruction. Theranostics. 2017;7(14):3527–3538.

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