title: Real-time image guidance in laparoscopic liver surgery: first clinical experience with a guidance system based on intraoperative CT imaging.
abstract: BACKGROUND
  Laparoscopic liver surgery is particularly challenging owing to restricted access, risk of bleeding, and lack of haptic feedback. Navigation systems have the potential to improve information on the exact position of intrahepatic tumors, and thus facilitate oncological resection. This study aims to evaluate the feasibility of a commercially available augmented reality (AR) guidance system employing intraoperative robotic C-arm cone-beam computed tomography (CBCT) for laparoscopic liver surgery.
  
  
  METHODS
  A human liver-like phantom with 16 target fiducials was used to evaluate the Syngo iPilot(®) AR system. Subsequently, the system was used for the laparoscopic resection of a hepatocellular carcinoma in segment 7 of a 50-year-old male patient.
  
  
  RESULTS
  In the phantom experiment, the AR system showed a mean target registration error of 0.96 ± 0.52 mm, with a maximum error of 2.49 mm. The patient successfully underwent the operation and showed no postoperative complications.
  
  
  CONCLUSIONS
  The use of intraoperative CBCT and AR for laparoscopic liver resection is feasible and could be considered an option for future liver surgery in complex cases.
authors.affiliation: Department of Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany, hannes.kenngott@med.uni-heidelberg.de.
authors.forename: Hannes G
authors.initials: HG
authors.lastname: Kenngott
authors.forename: Martin
authors.initials: M
authors.lastname: Wagner
authors.forename: Matthias
authors.initials: M
authors.lastname: Gondan
authors.forename: Felix
authors.initials: F
authors.lastname: Nickel
authors.forename: Marco
authors.initials: M
authors.lastname: Nolden
authors.forename: Andreas
authors.initials: A
authors.lastname: Fetzer
authors.forename: Jürgen
authors.initials: J
authors.lastname: Weitz
authors.forename: Lars
authors.initials: L
authors.lastname: Fischer
authors.forename: Stefanie
authors.initials: S
authors.lastname: Speidel
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Meinzer
authors.forename: Dittmar
authors.initials: D
authors.lastname: Böckler
authors.forename: Markus W
authors.initials: MW
authors.lastname: Büchler
authors.forename: Beat P
authors.initials: BP
authors.lastname: Müller-Stich
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000601:surgery*; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D004867:Equipment Design; D057918:Fiducial Markers; D006498:Hepatectomy / Q000379:methods*; D006801:Humans; D010535:Laparoscopy / Q000379:methods*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D013997:Time Factors