Resolving the blind spot of transoesophageal echocardiography: A new diagnostic device for visualizing the ascending aorta in cardiac surgery

Abstract

Background. Atherosclerosis of the ascending aorta (AA) and stroke after cardiac surgery are related. Knowledge of the location of AA-atherosclerosis pre-sternotomy allows changes in surgical strategy to avoid manipulation of the AA. The gold-standard for assessment of AA-atherosclerosis is intraoperative epiaortic ultrasound scanning (EUS). Transoesophageal echocardiography (TOE) is unable to detect atherosclerosis in the distal AA due to the 'blind spot'. A new method [A-View® (Aortic-view) method] using a fluid-filled catheter may enhance the assessment of distal AA-atherosclerosis. The aim of this study was to evaluate whether the A-View® method indeed visualizes the distal AA and to assess the safety of this technology. Methods. In a cross-sectional diagnostic study, 41 patients undergoing cardiac surgery including sternotomy underwent the same work-up including TOE, the A-View® method, EUS, and routine operative monitoring. Results. With the A-View® method, the distal AA was visible in all (100%) patients. There were no clinical important side-effects associated with the use of the A-View® catheter; however, in one patient the endotracheal tube was accidentally dislocated leading to a decrease in SaO2. Severity of atherosclerosis visualized with the A-View® method compared with EUS results showed good agreement between the two methods [Kappa of 0.69 (0.50-0.88)]. The Bland-Altman analysis showed poor agreement in plaque-size measurements (bias 0.05 cm2, limits of agreement -0.63 to 0.74 cm2). Conclusions. The A-View® method offers a minimally invasive and safe approach to preoperatively resolving the blind spot of TOE. Compared with EUS, the A-View® method yielded satisfactory results in the detection of AA-atherosclerosis. The A-View® method seems a promising tool for patients undergoing cardiac surgery to direct surgical management. © The Board of Management and Trustees of the British Journal of Anaesthesia 2007. All rights reserved.