title: A navigation system for open liver surgery: design, workflow and first clinical applications.
abstract: BACKGROUND
  The surgical treatment of liver tumours relies on precise localization of the lesions and detailed knowledge of the patient-specific vascular and biliary anatomy. Detailed three-dimensional (3D) anatomical information facilitates complete tumour removal while preserving a sufficient amount of functional liver tissue.
  
  
  METHODS
  We present an easy to use, clinically applicable navigation system for efficient visualization and tool guidance during liver surgery. Accurate instrument guidance within 3D planning models was achieved with a fast registration procedure, assuming a locally rigid and temporarily static scenario. After deformations occurring during the procedure, efficient means for registration updates are provided. Special focus was given to workflow integration and the minimization of overhead time. The navigation system was validated with nine clinical cases.
  
  
  RESULTS
  Navigated surgical interventions were performed with a median time overhead of 16.5 min. The navigation technology had a median accuracy of 6.3 mm, improving anatomical orientation and the detection of structures at risk.
  
  
  CONCLUSIONS
  Successful application of the navigation technology to open liver surgery was achieved by minimizing the procedural complexity and optimizing integration within the existing surgical environment. The assumption of locally rigid patient registration was validated, and clinical evaluation shows clear benefits for the surgeon.
authors.affiliation: ARTORG Center for Computer Aided Surgery and Institute for Surgical Technology and Biomechanics, University of Bern, Stauffacherstrasse 78, Bern, Switzerland. matthias.peterhans@istb.unibe.ch
authors.forename: M
authors.initials: M
authors.lastname: Peterhans
authors.forename: A
authors.initials: A
authors.lastname: vom Berg
authors.forename: B
authors.initials: B
authors.lastname: Dagon
authors.forename: D
authors.initials: D
authors.lastname: Inderbitzin
authors.forename: C
authors.initials: C
authors.lastname: Baur
authors.forename: D
authors.initials: D
authors.lastname: Candinas
authors.forename: S
authors.initials: S
authors.lastname: Weber
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006498:Hepatectomy / Q000295:instrumentation*; D006801:Humans; D010865:Pilot Projects; D015203:Reproducibility of Results; D012371:Robotics / Q000295:instrumentation*; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D014584:User-Computer Interface