Robot-Assisted Epicardial Ultrasound for Coronary Artery Localization and Anastomosis Quality Assessment in Totally Endoscopic Coronary Bypass Surgery

Coronary artery bypass grafting (CABG) is a routine procedure, traditionally performed via median sternotomy access on the arrested heart with use of cardiopulmonary bypass (onpump). It is the clinical gold standard for myocardial revascularization in patients with multivessel coronary heart disease but remains associated with significant morbidity and mortality (Borst & Gründeman, 1999). Over the last 2 decades, minimally invasive approaches to CABG in the form of smaller incisions (Diegeler et al., 2002) and elimination of the heart lung machine (off-pump) (Borst et al., 1996) have been introduced to reduce surgical trauma and adverse effects of cardiopulmonary bypass, respectively. The introduction of robotic systems with 3D vision, tremor elimination and instruments with 7 degrees of freedom (mimicking the human wrist) has provided an important part of the technology that enables the ultimate form of minimally invasive CABG, namely off-pump totally endoscopic CABG (TECAB) (Loulmet et al., 1999; Falk et al., 2000a; Argenziano et al., 2006). TECAB (both on-pump and off-pump) remains a technically highly demanding procedure that is performed by only a selected number of surgeons worldwide. Major obstacles in TECAB include: creation of adequate working space, identification of the target vessel, exposure and stabilization of the coronary segment, anastomosis suturing and the evaluation of anatomosis quality. High frequency (7.5 – 15 MHz) epicardial ultrasound (ECUS) is a non-invasive means to both locate and evaluate coronary arteries and assess the quality of the coronary anastomosis in open chest CABG (Suematsu et al., 2001; Haaverstad et al., 2002). In 2002, a 13 MHz epicardial ultrasound mini-transducer has become available that is small enough to pass a trocar and be handled by surgical robot systems (Budde et al., 2004a). In this chapter we will summarize our previously published results of the endoscopic application of this ECUS mini-transducer to locate and assess target coronary arteries for bypass grafting as well as its use for quality assessment of the coronary anastomosis in a porcine model of robot-assisted closed-chest off-pump CABG (Budde et al., 2004a; Budde et al., 2004b; Gründeman et al., 2003). O pe n A cc es s D at ab as e w w w .ite ch on lin e. co m