title: Augmented reality-assisted bypass surgery: embracing minimal invasiveness.
abstract: OBJECTIVE
  The overlay of virtual images on the surgical field, defined as augmented reality, has been used for image guidance during various neurosurgical procedures. Although this technology could conceivably address certain inherent problems of extracranial-to-intracranial bypass procedures, this potential has not been explored to date. We evaluate the usefulness of an augmented reality-based setup, which could help in harvesting donor vessels through their precise localization in real-time, in performing tailored craniotomies, and in identifying preoperatively selected recipient vessels for the purpose of anastomosis.
  
  
  METHODS
  Our method was applied to 3 patients with Moya-Moya disease who underwent superficial temporal artery-to-middle cerebral artery anastomoses and 1 patient who underwent an occipital artery-to-posteroinferior cerebellar artery bypass because of a dissecting aneurysm of the vertebral artery. Patients' heads, skulls, and extracranial and intracranial vessels were segmented preoperatively from 3-dimensional image data sets (3-dimensional digital subtraction angiography, angio-magnetic resonance imaging, angio-computed tomography), and injected intraoperatively into the operating microscope's eyepiece for image guidance.
  
  
  RESULTS
  In each case, the described setup helped in precisely localizing donor and recipient vessels and in tailoring craniotomies to the injected images.
  
  
  CONCLUSIONS
  The presented system based on augmented reality can optimize the workflow of extracranial-to-intracranial bypass procedures by providing essential anatomical information, entirely integrated to the surgical field, and help to perform minimally invasive procedures.
authors.affiliation: Neurosurgery Division, Department of Clinical Neurosciences, Faculty of Medicine, Geneva University Medical Center, Geneva, Switzerland. Electronic address: ivan.cabrilo@hcuge.ch.
authors.forename: Ivan
authors.initials: I
authors.lastname: Cabrilo
authors.affiliation: Neurosurgery Division, Department of Clinical Neurosciences, Faculty of Medicine, Geneva University Medical Center, Geneva, Switzerland.
authors.forename: Karl
authors.initials: K
authors.lastname: Schaller
authors.affiliation: Neurosurgery Division, Department of Clinical Neurosciences, Faculty of Medicine, Geneva University Medical Center, Geneva, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Bijlenga
mesh_terms: D000328:Adult; D001808:Blood Vessels / Q000637:transplantation; D002526:Cerebellar Diseases / Q000601:surgery; D003399:Craniotomy; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D020768:Middle Cerebral Artery / Q000601:surgery; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D009072:Moyamoya Disease / Q000601:surgery; D019635:Neurosurgical Procedures / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013699:Temporal Arteries / Q000601:surgery; D016896:Treatment Outcome; D014584:User-Computer Interface
keywords: Augmented reality; Extracranial-to-intracranial bypass surgery; Image-guided surgery; Minimal invasiveness; Neuronavigation