Transoesophageal echocardiography (TOE) is often the initial investigation of choice for imaging acute and chronic aortic disease including dissection and ectasia. It is also used in the placement of endovascular stent grafts, to monitor deployment of the stent, and to assess results.¹ It is ideally suited because of the close proximity of the oesophageal imaging window to the arch and descending thoracic aorta. However, endovascular stent grafting is increasingly being performed under regional and local anaesthesia and it is impossible to tolerate a TOE probe for the length of the procedure. We therefore investigated the feasibility of imaging the thoracic aorta using a device originally developed for intracardiac echocardiography.

PATIENTS AND METHODS

The ultrasound-tipped catheter (AcuNav, Siemens, Mountain View California) is 90 mm long and 3.2 mm (10 F) in diameter compared with 9 mm (27 F) for a standard TOE probe. The imaging range is from 5.5–10 MHz and it has colour (5–7 MHz) and pulsed Doppler (4–5 MHz) capabilities. There is only one imaging plane, but transverse and intermediate views are possible because the …