title: Augmented environments for the targeting of hepatic lesions during image-guided robotic liver surgery.
abstract: BACKGROUND
  Stereotactic navigation technology can enhance guidance during surgery and enable the precise reproduction of planned surgical strategies. Currently, specific systems (such as the CAS-One system) are available for instrument guidance in open liver surgery. This study aims to evaluate the implementation of such a system for the targeting of hepatic tumors during robotic liver surgery.
  
  
  METHODS
  Optical tracking references were attached to one of the robotic instruments and to the robotic endoscopic camera. After instrument and video calibration and patient-to-image registration, a virtual model of the tracked instrument and the available three-dimensional images of the liver were displayed directly within the robotic console, superimposed onto the endoscopic video image. An additional superimposed targeting viewer allowed for the visualization of the target tumor, relative to the tip of the instrument, for an assessment of the distance between the tumor and the tool for the realization of safe resection margins.
  
  
  RESULTS
  Two cirrhotic patients underwent robotic navigated atypical hepatic resections for hepatocellular carcinoma. The augmented endoscopic view allowed for the definition of an accurate resection margin around the tumor. The overlay of reconstructed three-dimensional models was also used during parenchymal transection for the identification of vascular and biliary structures. Operative times were 240 min in the first case and 300 min in the second. There were no intraoperative complications.
  
  
  CONCLUSIONS
  The da Vinci Surgical System provided an excellent platform for image-guided liver surgery with a stable optic and instrumentation. Robotic image guidance might improve the surgeon's orientation during the operation and increase accuracy in tumor resection. Further developments of this technological combination are needed to deal with organ deformation during surgery.
authors.affiliation: Clinic for Visceral and Transplantation Surgery, Department of Surgery, University Hospital of Geneva, Geneva, Switzerland. Electronic address: Nicolas.c.buchs@hcuge.ch.
authors.forename: Nicolas C
authors.initials: NC
authors.lastname: Buchs
authors.forename: Francesco
authors.initials: F
authors.lastname: Volonte
authors.forename: François
authors.initials: F
authors.lastname: Pugin
authors.forename: Christian
authors.initials: C
authors.lastname: Toso
authors.forename: Matteo
authors.initials: M
authors.lastname: Fusaglia
authors.forename: Kate
authors.initials: K
authors.lastname: Gavaghan
authors.forename: Pietro E
authors.initials: PE
authors.lastname: Majno
authors.forename: Matthias
authors.initials: M
authors.lastname: Peterhans
authors.forename: Stefan
authors.initials: S
authors.lastname: Weber
authors.forename: Philippe
authors.initials: P
authors.lastname: Morel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000209:etiology / Q000601:surgery*; D004724:Endoscopy; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008099:Liver / Q000601:surgery; D008103:Liver Cirrhosis / Q000150:complications; D008113:Liver Neoplasms / Q000209:etiology / Q000601:surgery*; D008297:Male; D019060:Minimally Invasive Surgical Procedures; D010865:Pilot Projects; D012371:Robotics; D013238:Stereotaxic Techniques; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome
keywords: Computer surgery; Hepatic mass; Liver resection; Robotic; Virtual reality