Intraoperative Echocardiography

Excerpt

Although transesophageal ultrasound was first reported in the 1970s, the advent of phased array transducers and flexible transesophageal probes in the early 1980s enabled improved visualization of cardiac structures. Transesophageal echocardiography (TEE) has become a commonly used imaging modality in a wide range of settings including the cardiac operating theatre, the intensive care unit, the interventional suit, as an outpatient procedure, and as a monitoring or rescue device in patients who have or are expected to have unexplained cardiovascular instability. TEE is able to provide excellent ultrasonic imaging compared to transthoracic echocardiography (TTE) because of the proximal location of the esophagus next to the heart and great vessels, and avoidance of the lungs and ribs as impediments to imaging. In addition, TEE is more practical than TTE during most surgeries and especially during cardiac surgical operations because of the need to avoid the sterile operating field. For these reasons, TEE is superior to TEE during cardiac surgery, for certain diagnosis, and for many catheter-based cardiovascular interventions. Recently, the development and widespread availability of real-time 3-dimensional echocardiography has expanded the role of TEE in the guidance of complicated cardiac surgical procedures and catheter-based cardiac interventions such as transcatheter aortic valve replacements (TAVR).

The Society of Cardiovascular Anesthesiologists (SCA) and the American Society of Echocardiography (ASE) published a first set of guidelines for the performance of a comprehensive intraoperative TEE exam in 1999. The aim of these guidelines was to define a standard examination for the purposes of training, consistency, storage, and quality. These guidelines contain a set of twenty TEE views that were primarily designed for intraoperative use although they have been widely adopted outside of the operating room. These guidelines were updated in 2013 to now include an expanded 28 standard views as well as 3-dimensional imaging. In addition, a set of basic perioperative TEE guidelines were also published in 2013 that included 11 standard views. The SCA and the ASE realized that the availability and use of TEE as a monitoring and diagnostic rescue tool outside of cardiac surgery had dramatically increased. Therefore, a basic set of guidelines that were intended for use in general operating rooms by non-cardiac anesthesiologists were developed.

Many practicing physicians that utilize TEE become certified in its use by the National Board of Echocardiography. This requires passing a test and the completion of several other requirements including a certain number of personally performed TEE exams.