Navigation in endoscopic soft tissue surgery: perspectives and limitations.

Despite rapid developments in the research areas of medical imaging, medical image processing, and robotics, the use of computer assistance in surgical routine is still limited to diagnostics, surgical planning, and interventions on mostly rigid structures. In order to establish a computer-aided workflow from diagnosis to surgical treatment and follow-up, several proposals for computer-assisted soft tissue interventions have been made in recent years. By means of different pre- and intraoperative information sources, such as surgical planning, intraoperative imaging, and tracking devices, surgical navigation systems aim to support surgeons in localizing anatomical targets, observing critical structures, and sparing healthy tissue. Current research in particular addresses the problem of organ shift and tissue deformation, and obstacles in communication between navigation system and surgeon. In this paper, we review computer-assisted navigation systems for soft tissue surgery. We concentrate on approaches that can be applied in endoscopic thoracic and abdominal surgery, because endoscopic surgery has special needs for image guidance due to limitations in perception. Furthermore, this paper informs the reader about new trends and technologies in the area of computer-assisted surgery. Finally, a balancing of the key challenges and possible benefits of endoscopic navigation refines the perspectives of this increasingly important discipline of computer-aided medical procedures.