title: Augmented Reality Guidance for the Resection of Missing Colorectal Liver Metastases: An Initial Experience.
abstract: BACKGROUND
  Modern chemotherapy achieves the shrinking of colorectal cancer liver metastases (CRLM) to such extent that they may disappear from radiological imaging. Disappearing CRLM rarely represents a complete pathological remission and have an important risk of recurrence. Augmented reality (AR) consists in the fusion of real-time patient images with a computer-generated 3D virtual patient model created from pre-operative medical imaging. The aim of this prospective pilot study is to investigate the potential of AR navigation as a tool to help locate and surgically resect missing CRLM.
  
  
  METHODS
  A 3D virtual anatomical model was created from thoracoabdominal CT-scans using customary software (VR RENDER(®), IRCAD). The virtual model was superimposed to the operative field using an Exoscope (VITOM(®), Karl Storz, Tüttlingen, Germany). Virtual and real images were manually registered in real-time using a video mixer, based on external anatomical landmarks with an estimated accuracy of 5 mm. This modality was tested in three patients, with four missing CRLM that had sizes from 12 to 24 mm, undergoing laparotomy after receiving pre-operative oxaliplatin-based chemotherapy.
  
  
  RESULTS
  AR display and fine registration was performed within 6 min. AR helped detect all four missing CRLM, and guided their resection. In all cases the planned security margin of 1 cm was clear and resections were confirmed to be R0 by pathology. There was no postoperative major morbidity or mortality. No local recurrence occurred in the follow-up period of 6-22 months.
  
  
  CONCLUSIONS
  This initial experience suggests that AR may be a helpful navigation tool for the resection of missing CRLM.
authors: IRCAD-IHU, University of Strasbourg, 1 place de l'Hôpital, 67091, Strasbourg, France. dntourakis@hotmail.com.
authors: Dimitrios
authors: D
authors: Ntourakis
authors: IRCAD-IHU, University of Strasbourg, 1 place de l'Hôpital, 67091, Strasbourg, France.
authors: Ricardo
authors: R
authors: Memeo
authors: IRCAD-IHU, University of Strasbourg, 1 place de l'Hôpital, 67091, Strasbourg, France.
authors: Luc
authors: L
authors: Soler
authors: IRCAD-IHU, University of Strasbourg, 1 place de l'Hôpital, 67091, Strasbourg, France.
authors: Jacques
authors: J
authors: Marescaux
authors: IRCAD-IHU, University of Strasbourg, 1 place de l'Hôpital, 67091, Strasbourg, France.
authors: Didier
authors: D
authors: Mutter
authors: IRCAD-IHU, University of Strasbourg, 1 place de l'Hôpital, 67091, Strasbourg, France. patrick.pessaux@chru-strasbourg.fr.
authors: Patrick
authors: P
authors: Pessaux
mesh_terms: D000368:Aged; D059925:Anatomic Landmarks; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006498:Hepatectomy / Q000379:methods; D006801:Humans; D021621:Imaging, Three-Dimensional; D008113:Liver Neoplasms / Q000188:drug therapy / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000601:surgery; D018365:Neoplasm, Residual; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D010865:Pilot Projects; D011446:Prospective Studies; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed
chemical_list: D009944:Organoplatinum Compounds; D000077150:Oxaliplatin