Copyright © 2006, The European Society of Cardiology
Coronary artery wall enhances with intracoronary injection of echocontrast media during in vivo intravascular ultrasound
a19 Mayis University, Cardiology Department, Samsun, Turkey
bThe Cleveland Clinic Foundation, Cardiovascular Medicine Department, 9500 Euclid Avenue, Cleveland, OH 44195, USA
Received 22 March 2006; received in revised form 14 July 2006; accepted after revision 26 July 2006.
* Corresponding author. Tel.: +1 216 4446735. kapadis{at}ccf.org
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Currently, vascularity of the coronary artery wall can be assessed only in vitro. We sought to determine if there is any contrast enhancement of the coronary artery wall after injection of echocontrast media during in vivo intravascular ultrasound imaging, which may represent blood flow within the wall supplied by the vasa vasorum.
Keywords: Intravascular ultrasound; Vasa vasorum
The vasa vasorum is a network of small arteries and veins in the adventitial layer of the vessel wall. It is present in the aorta and coronary, carotid, and femoral arteries.1 In normal blood vessels, outer components of the vessel wall are nourished by the vasa vasorum and the intima is supplied by diffusion from the lumen. When the thickness of the vessel wall impairs effective diffusion from the lumen, the vasa vasorum proliferates abnormally in the inner layers of the vessel wall.2 Adventitia-derived vasa vasorum neovascularization in coronary arteries is thought to play important roles in the development and progression of atherosclerosis, in the plaque vulnerability and in the vascular reaction to coronary interventions, hyperlipidemia and hypertension.3–6 We sought to determine if there is any contrast enhancement of the coronary artery wall after injection of echocontrast media during in vivo intravascular ultrasound (IVUS) imaging, which may represent blood flow within the wall supplied by the vasa vasorum. IVUS was performed in a juvenile, female farm pig. Proximal, mid and distal segments of left anterior descending (LAD) and circumflex coronary arteries were imaged with a 20MHz, 2.9F IVUS catheter. After baseline imaging, same sites were reevaluated during the injection of perflutren protein-type A microspheres as an echocontrast agent. At each site, 0.5ml of 1:20 diluted echocontrast agent was injected as bolus. Brightness of the arterial wall before injection was compared to the brightness after injection, immediately following the clearance of the lumen. National Institutes of Health Image Software was used for evaluating brightness. Mean brightness increased from 75±42units to 90±41units at proximal LAD coronary artery wall (Fig. 1). Increased brightness after injection was evident in both LAD and circumflex coronary arteries and in proximal, mid and distal segments. This enhancement may represent blood flow within the wall of the artery through the vasa vasorum. Since vascularity of the vessel wall can be assessed only in vitro currently (by magnetic resonance imaging, computed tomography, immunofluorescence or electron microscopy), contrast IVUS may be a helpful modality to evaluate the vasa vasorum in vivo. This hypothesis was also supported by other preliminary studies. It was found that microbubble contrast-enhanced IVUS could measure activity and inflammation within the atherosclerotic plaques by imaging the vasa vasorum density.7 Harmonic imaging technique was developed for the sensitive detection of microbubble contrast agents during IVUS examination and its feasibility was proven for the vasa vasorum imaging.8 As a summary, we can say that contrast IVUS is now emerging as a new technique for in vivo evaluation of the vessel wall vascularity.
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- Heistad D.D., Marcus M.L. Role of vasa vasorum in nourishment of the aorta. Blood Vessels (1979) 16(5):225–238.[Web of Science][Medline]
- Williams J.K., Heistad D.D. The vasa vasorum of the arteries. J Mal Vasc (1996) 21(Suppl. C):266–269.[Web of Science][Medline]
- Moreno P.R., Purushothaman K.R., Sirol M., Levy A.P., Fuster V. Neovascularization in human atherosclerosis. Circulation (2006) 113(18):2245–2252.
[Free Full Text] - Kwon H.M., Sangiorgi G., Ritman E.L., Lerman A., McKenna C., Virmani R., et al. Adventitial vasa vasorum in balloon-injured coronary arteries: visualization and quantitation by a microscopic three-dimensional computed tomography technique. J Am Coll Cardiol (1998) 32(7):2072–2079.
[Abstract/Free Full Text] - Kai H., Kuwahara F., Tokuda K., Shibata R., Kusaba K., Niiyama H., et al. Coexistence of hypercholesterolemia and hypertension impairs adventitial vascularization. Hypertension (2002) 39(2 Pt 2):455–459.
[Abstract/Free Full Text] - Lerman A., Ritman E.L. Evaluation of microvascular anatomy by micro-CT. Herz (1999) 24(7):531–533.[Web of Science][Medline]
- Carlier S., Kakadiaris I.A., Dib N., Vavuranakis M., O'Malley S.M., Gul K., et al. Vasa vasorum imaging: a new window to the clinical detection of vulnerable atherosclerotic plaques. Curr Atheroscler Rep (2005) 7(2):164–169.[Medline]
- Goertz D.E., Frijlink M.E., Tempel D., van Damme L.C., Krams R., Schaar J.A., et al. Contrast harmonic intravascular ultrasound: a feasibility study for vasa vasorum imaging. Invest Radiol (2006) 41(8):631–638.[CrossRef][Web of Science][Medline]
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