USEFULNESS OF INTRAVASCULAR ULTRASOUND IMAGING FOR DETECTING EXPERIMENTALLY INDUCED AORTIC DISSECTION IN DOGS AND FOR DETERMINING THE EFFECTIVENESS OF ENDOLUMINAL STENTING

Acute thoracic aortic dissection is a life-threatening disorder, with frequency of approximately 2,000 new cases per year in the USA. Overall mortality remains high despite advances in both operative and nonoperative management.1 Critical variables in determining treatment options and outcome are the exact anatomic location of the lesion and the premorbid general condition of the patient. Diagnostic techniques include angiography, computerized tomography, magnetic resonance imaging, and transthoracic and transesophageal echocardiography. Each of these techniques has limitations related to the method of image production and resolution.2 Recent advances in catheter-based technology have provided devices suitable for both diagnosing aortic dissection and treating the lesion without recourse to major surgery. Intravascular ultrasound is a rapidly developing method for defining luminal and transmural anatomy of vascular structures.3 It is capable of producing high-resolution images of acute aortic dissection, and may have advantages over conventional imaging techniques in identifying the origin and distal end point and relation of the false lumen to major visceral aortic branches.4 Intravascular balloon-expandable stents have been used to successfully obliterate acute aortic dissections in dogs, but require total occlusion of the aorta during deployment as the balloon is expanded to force the stent against the aortic wall. Recently available self-expanding stents have the potential advantages of higher flexibility and a deployment mechanism that does not obstruct blood flow during insertion. © 1992.