Intravascular ultrasound imaging of an acute dissecting aortic aneurysm: A case report

Intravascular ultrasound

Vascular anatomy can be more accurately assessed from an endoluminal position applying the principles of conventional ultrasound. It may effectively batter select patients for endovascular procedures and complement the information gained from CT, MRA, transcutaneous ultrasound, and contrast angiography. Three-dimensional and longitudinal grey-scale reconstruction of tomographic IVUS images are made available through computer software programs. Information gained includes: plaque characterization and morphology, a cross-sectional evaluation of stenoses, assessment of the impact/effect of balloon angioplasty, evaluation of vessel dissections and the ability to selectively place intravascular stents.

Usefulness of a prototype intravascular ultrasound imaging in evaluation of aortic dissection and comparison with angiographic study, transesophageal echocardiography, computed tomography, and magnetic resonance imaging

The aim of this study was to evaluate the accuracy of information obtained with a prototype intravascular ultrasound (IVUS) system in chronic aortic dissection by comparing results with angiography, transesophageal echocardiography (TEE), computed tomography, or magnetic resonance imaging. We assigned 15 patients to IVUS imaging after they underwent angiography. The detection rate of the intimal flap was 100% in all segments of the aorta, and the detection rate of the intimal tear was 0%, 50%, 50%, and 77.8% in the ascending, arch, descending, and abdominal aorta, respectively. IVUS demonstrated 100% of the celiac and renal arteries, and 80% of the superior mesenteric arteries as well as their relation to dissection. It clarified the origin of 12 of 60 main abdominal branches (20%) which were not clear on the angiogram. It also determined the distal extent of the dissection in all cases. With regard to the size of the vessel, there was a good correlation between IVUS and computed tomographic values (r = 0.98, p < 0.01). No complications occurred in any patient. IVUS accurately demonstrated thrombus or spontaneous echo contrast in the false lumen that was confirmed with computed tomography or TEE, or both. It was especially useful in evaluating the abdominal aorta with regard to determining the size of the vessel, the extent of dissection, the relation of the branches to the false lumen, and the detection of intimal tears--important information for follow-up of patients and for planning surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Intravascular ultrasound imaging in acute aortic dissection

OBJECTIVES

This study was performed to determine the potential of intravascular ultrasound in the detection and delineation of aortic dissection.

BACKGROUND

Intravascular ultrasound is a new technique capable of displaying real-time cross-sectional images of arterial vasculature. Its clinical use has been explored mostly in coronary and peripheral arterial circulation.

METHODS

Intravascular ultrasound imaging of the aorta was performed using a 20-MHz ultrasound catheter in 28 patients with suspected aortic dissection. All patients underwent contrast angiography; 7 had computed tomography; and 22 had transesophageal echocardiography.

RESULTS

Imaging of the aorta from the root level to its bifurcation was performed in all patients in an average of 10 min. No complications occurred. Dissection was present in 23 patients and absent in 5. In the patients without dissection, intravascular ultrasound revealed normal aortic anatomy. In all 23 patients with dissection, intravascular ultrasound demonstrated the intimal flap and true and false lumena. The longitudinal and circumferential extent of aortic dissection, contents of the false lumen, involvement of branch vessels and the presence of intramural hematoma in the aortic wall could also be identified. In cases where aortography could not define the distal extent of the dissection, intravascular ultrasound did.

CONCLUSIONS

Our experience in this series of patients with aortic dissection indicates that intravascular ultrasound could be valuable in the identification and categorization of aortic dissection and in the description of associated pathologic changes that may be clinically important. It can be performed rapidly and safely and could serve as an alternative or adjunct diagnostic procedure in patients with aortic dissection.

Intravascular ultrasound imaging: the new standard for guidance and assessment of endovascular interventions?

Intravascular ultrasound has developed rapidly during the last few years, and provides a unique perspective from which to view vascular disease and the effects of intervention. This catheter-based imaging technique utilizes advances in echographic data processing and computerized image manipulation to produce accurate luminal and transmural images of blood vessels. Although these devices have only been available for a relatively short time, numerous diagnostic and therapeutic applications have been reported. By providing a detailed image of vessels before, during, and after intervention, intravascular ultrasound provides a method for both guidance of endoluminal devices and immediate assessment of the results of therapeutic techniques including balloon angioplasty, atherectomy, laser-assisted angioplasty, and intravascular stent deployment. Intravascular ultrasound also offers exciting possibilities in peripheral vascular research such as investigation of blood vessel compliance, dynamic changes in the vessel wall caused by disease or pharmacologic intervention, and elucidation of the morphologic changes associated with the natural history of atherosclerosis.

Intravascular ultrasonography

Intravascular ultrasonography is developing rapidly as a method for defining the transmural anatomy of vascular structures, with diagnostic and therapeutic applications. The ultrasound technology not only has unique diagnostic capabilities by defining the distribution and character of lesions, but also provides accurate control information regarding efficacy of angioplasty methods. An exciting recent development is the three-dimensional reconstruction of two-dimensional images which permits global examination of luminal and transmural vessel morphology. This technology may enable improved guidance of intraluminal devices to enhance lesion removal without damaging adjacent normal wall structure and appropriate device selection by differentiating specific plaque characteristics.