Epiaortic ultrasound assessment of the aorta in cardiac surgery

The dislodgement of atheroma from the ascending aorta and proximal arch is a major cause of stroke and neurological injury following cardiac surgery. The accurate detection of atheroma prior to aortic manipulation is necessary to facilitate surgical strategies to reduce the risk of embolisation.

The traditional method for atheroma detection is manual palpation by the surgeon. This technique misses about half the number of the atheroma lesions, as the soft (non-calcified) lesions offer little resistance to the surgeon's fingers. Trans-oesophageal echocardiography (TOE) is commonly used in cardiac surgery, but the interposition of the bronchus between the aorta and the oesophagus causes an ultrasound ‘blind spot’ in the ascending aorta and proximal arch, such that it does not offer improved detection compared to manual palpation. Accurate detection of atheroma requires direct ultrasound assessment using epiaortic scanning, with a high-frequency, linear-array probe. This allows the surgeon to correctly assess and localise any atheroma. In this article, a suggested epiaortic examination sequence is described and strategies for surgeons to avoid atheroma are discussed.

Keywords: epiaortic, ultrasound, atheroma, cardiac surgery