P329Visualizing the thoracic aorta with modified transoesophageal echocardiography - the A-View technique

Introduction. Recently, the Partner trial showed us that the improvement in prognosis after TAVI comes at the costs of a 30-day incidence of stroke or TIA of 6.7%. In cardiac surgery, the association of the degree of aortic atherosclerosis and post-operative cerebral complications is well known. Therefore, it is of paramount importance to obtain preprocedural information on aortic atherosclerosis; which is stressed in multiple guidelines. However, sensitivity of TOE in diagnosing atherosclerosis of the distal ascending aorta is only 21% (95% CI 13-32). [1] In regular TOE, the interposition of air in the trachea creates a “blind spot” preventing adequate visualization of the thoracic aorta.

New Technology. A modification of regular TOE overcomes this limitation. During general anesthesia, a balloon is positioned in the trachea and inflated with saline, creating an acoustic window to the distal ascending aorta (DAA), aortic arch and its branches; the so called A(ortic)-View. Multiple studies have proven safety and efficacy of the A-View technique.

Results: Compared with epiaortic ultrasound; sensitivity and specificity in detecting severe atherosclerosis of the DAA were 95% and 79% respectively (PPV 67%, NPV 97%), AUC 0.89. [2] Use of the A-View during cardiac surgery resulted in a trend towards a reduction of 30-day mortality (adjusted OR 0.61, 95% CI 0.36 - 1.03). [3] The kappa for inter and intraobserver variability ranged from 0.11 to 0.61; we hope to reduce variability with a course for future A-View users. Futhermore, the effect of A-View on cerebral ischemic lesion after cardiac surgery is being studied in a randomized trial.

Indications. The A-View technique is part of our TAVI-protocol, it has been used in the diagnosis of aortic dissection, and it is a standard diagnostic in cardiothoracic surgery. Imaging with 3D-TOE is feasible.

1. van Zaane B, Zuithoff NP, Reitsma JB, et al. Meta-analysis of the diagnostic accuracy of transesophageal echocardiography for assessment of atherosclerosis in the ascending aorta In patients undergoing cardiac surgery. Acta Anaesthesiol Scand 2008 Oct; 52(9): 1179-87.

2. van Zaane B, Nierich AP, Brando Bravo Bruinsma GJ, et al. Diagnostic accuracy of modified transoesophageal echocardiography for pre-incision assessment of aortic atherosclerosis in cardiac surgery patients. Br J Anaesth 2010 Aug; 105(2): 131-8.

3. Nierich AP, Jansen Klomp WW. Clinical outcome after pre-incision assessment of aortic atherosclerosis by A-View echocardiography in 5886 elective cardiac surgery patients. Data presented at the congress of European Association of Thoracic Anesthesiologists.