Lead Sponsor: University of Zurich

Collaborators: Mayo Clinic, Emory University, University of California, San Francisco, University of California, Los Angeles, Stanford University, Brigham and Women's Hospital, Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA), University of Illinois at Chicago, Leiden University Medical Center, University of Wisconsin, Madison, Medical University Innsbruck, University of Bern, Macquarie University, Australia, University of Melbourne, Kepler University Hospital, General University Hospital, Prague, Universitätsklinikum Köln, Goethe University, University Medical Center Mainz, University of Göttingen, University Hospital Dresden, Charite University, Berlin, Germany, Heinrich-Heine University, Duesseldorf, University of Roma La Sapienza, University of Padova, University of Florence, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta, University of Messina, Universita di Verona, Uniuversity of Genua, Italy, UMC Utrecht, Burdenko Neurosurgery Institute, Sahlgrenska University Hospital, Barrow Neurological Institute, Endeavor Health, Fondazione Policlinico Universitario Agostino Gemelli IRCCS

Intervention / Treatment: PROCEDURE: Microsurgery