Transesophageal Echocardiography for Minimally Invasive Cardiac Surgery

Cardiovascular surgery is, conventionally, performed through a median sternotomy enabling generous exposure to the operative field. This allows central cannulation for cardiopulmonary bypass (CPB) and performance of complex procedures under direct view. Concurrent advances in cardiopulmonary perfusion, intracardiac endoscopic visualization, instrumentation, and robotic telemanipulation have resulted in a dramatic shift toward efficient and safe cardiac procedures through minimal access. The term minimally invasive, or minimal access, cardiac surgery refers to the size of the incision, the avoidance of sternotomy, and possible avoidance of CPB. Minimally invasive cardiac surgery is a nonspecific term that groups together different surgical procedures (Fig. 20.1). Using this approach the surgeon must master levels of technical complexity starting with small incision, direct vision (level 1), then progressing toward more complex video-assisted procedures (level 2), video-directed and robot-assisted procedures (level 3), and, finally, to telemanipulation and robotic-assisted valve operations (level 4). To be successful, the anesthesiologist must have detailed knowledge of each surgical procedure and the appropriate anesthesia technique, as well as being skilled in the use of transesophageal echocardiography (TEE). As the surgeon’s visual field shrinks, the reliance on TEE to aid visualization increases. Transesophageal echocardiography is an indispensable tool in guiding venous and arterial catheter placement, monitoring cardiac function, and diagnosing complications and contraindications related to different procedures. The role of TEE in minimally invasive cardiac surgery is summarized in Table 20.1. In this chapter, the emphasis will be placed on the use of perioperative TEE for diverse, minimally invasive, cardiac surgical procedures. For practical reasons, only the echographic considerations are presented for the different classes of well-established procedures (Table 20.2) available for cardiac surgery. MITRAL VALVE PROCEDURE