Role of real time three-dimensional transesophageal echocardiography in guidance of interventional procedures in cardiology

Real-time three-dimensional transesophageal echocardiography (RT-3D TEE) employs a dedicated novel matrix-array technology and allows live three-dimensional (3D) presentation of cardiac structures, circumventing most of the time-consuming acquisition and offline data processing associated with reconstructive 3D methods. It is particularly useful in guiding non-coronary cardiac interventions, defining location, morphology and possible pathology of cardiac structure of interest, its anatomical relation to neighbouring landmarks while providing improved spatial resolution and, in addition, allowing online monitoring of the procedure. These advantages over two-dimensional (2D) transesophageal echocardiography (TEE), intracardiac echocardiography and fluoroscopy may enhance decision-making, reduce fluoroscopy time and increase procedural safety and efficacy in short and long-term follow-up. It is foreseeable that RT-3D TEE will have the most clinical utility in the following 5 years. This review summarises the current development and clinical applications of RT-3D TEE for the guidance of percutaneous cardiac interventions, as well as surgical planning and subsequent follow-up of valvular repair and replacement. 3D TEE was developed approximately 25 years ago with the aim of providing additional anatomical detail and improved spatial relationships, not previously seen with transthoracic two-dimensional echocardiography. Until the introduction of the matrix TEE probe 2 years ago, 3D TEE was performed with a multiplane probe using a rotational approach for sequential data acquisition, gated to ECG and respiration. From a transesophageal fixed acoustic window, 2D images were collected at small angular increments, post-processed offline and converted into a Cartesian coordinate system to obtain conical volume datasets. From these data, any desired cut-plane could be derived and structures of interest rendered. Unfortunately, this methodology was limited by the need for multiple image sampling resulting in lengthy data acquisition times and frequent radial artifacts. As a consequence, this methodology has not been routinely embraced in clinical practice and was predominantly used for research purposes. To overcome these limitations and introduce …