Augmented reality for intraoperative guidance in endoscopic coronary artery bypass grafting

Endoscopic bypass grafting can be complicated by limited intraoperative orientation. A method to overlay the preoperative model of the coronary tree on the live endoscopic images of the heart was therefore developed. The method is three-fold: (1) the three-dimensional (3D) model of the coronary tree is reconstructed from traditional angiograms; (2) preoperative images are registered with the intraoperative position of the patient in the operating room (OR); and (3) an iterative and interactive identification of clinically relevant landmarks within the operative field on the heart surface before their registration with the preoperative model of the coronaries. This algorithm allows one to compensate deformations (breathing, intraoperative heart shift) and leads to a precise overlay of the coronary network on the heart surface. For ergonomic reasons, the 3D model can be displayed directly within the visual field of any telesurgical master console. It thus provides an effective navigational aid to the surgeon similar to a global positioning system (GPS) in vehicles. Animal trials have been performed using the Da Vinci (Intuitive Surgical, Sunnyvale, CA, USA) teleoperated system to validate the method. Qualitative and quantitative analysis demonstrate the potential value during total endoscopic coronary artery bypass grafting.