Objective: To study the role of intravascular ultrasound (IVUS) imaging in identifying the visceral artery in aortic dissection.
Methods: Twenty-two patients with aortic dissection were studied by IVUS via a femoral approach. The relationship between the visceral artery origin and the true and false lumens were differentiated by IVUS. The detection rate of visceral artery by IVUS was compared with those of CT and digital subtraction angiography (DSA). The cause of visceral ischemia was determined by the relationship between the intimal flap and the visceral artery origin in IVUS findings, and compared with routine examinations.
Results: The outer wall of the true lumen had a three layer structure while that of the false lumen had only one layer structure in IVUS imaging. There was an acute angle between the outer wall of the false lumen and the intimal flap at the true and false lumen junction. The thrombosis in the false lumen could be detected by IVUS. These features can assist in the differentiation of the true and false lumen. The relationship between the visceral artery origin and the true and false lumen could be determined in 81 out of 84 arteries, among which 54 were originated from the true lumen, and 27 from the false lumen. The detecting rate of visceral arteries by IVUS was 96.4%, higher than CT (70.2%) and DSA (84.5%), chi(2) = 20.74 and 6.91, P < 0.01. Static narrowing in 6 arteries and dynamic narrowing in 1 artery were visualized by IVUS, while only 2 static narrowings could be detected by CT.
Conclusions: IVUS has an advantage over routine examinations at detecting visceral artery origin and clarifying the mechanism of visceral ischemia.