title: Conversion technique from neuroendoscopy to microsurgery in ventricular tumors: Technical note.
abstract: BACKGROUND
  Ventricular tumors represent a major neurosurgical challenge, making endoscopic approach an invaluable tool as it gained importance due to technological advances. Nevertheless, the method is not exempt of risk and limitations, sometimes requiring an open surgery. Thus, initial measurements must be adopted in order to simplify an eventual need for conversion to open craniotomy.
  
  
  METHODS
  Here, we describe a series of 6 patients with ventricular tumors approached by neuroendoscopy where the conversion to microsurgery turned out to be necessary. Patients' average age was 59.5 years (39-75 years). Average tumoral size was 17.8 mm (15-21 mm). There were 2 cases of lateral ventricle subependymoma and 4 cases of third ventricle colloid cysts. A standard surgical incision was performed in the coronal direction, allowing lateral expansion to 10 cm. Moreover, the endoscopic burr hole was enlarged to a 5 cm craniotomy. A small enlargement of the endoscopic cortical access was performed to gain a transcortical microsurgical corridor to the ventricular cavity. The need for conversion arose due to high consistency of the tumor (3 cases), technical problems (2 cases), and cortical collapse (1 case).
  
  
  RESULTS
  There was one case of cerebrospinal fluid fistula and infection and one case of transitory memory disturbance. In both the cases, we obtained a complete functional recovery. Clinical and radiological follow-up showed total tumor removal with no recurrences.
  
  
  CONCLUSIONS
  The technique herein described was easy to perform, promptly bypassed the endoscopic limitations, and gathered excellent surgical results. The possibility of adapting the method to other tumor locations may be considered.
authors.affiliation: Department of Surgical Specialties, Neurosurgery Teaching and Assistance Unit, Pedro Ernesto University Hospital, Rio de Janeiro State University, Rio de Janeiro, RJ, Brazil.
authors.forename: Pedro Henrique
authors.initials: PH
authors.lastname: da C F Pinto
authors.affiliation: Department of Surgical Specialties, Neurosurgery Teaching and Assistance Unit, Pedro Ernesto University Hospital, Rio de Janeiro State University, Rio de Janeiro, RJ, Brazil; Nervous System Electric Stimulation Laboratory (LabEEL) - Neurosurgery Teaching and Assistance Unit, Pedro Ernesto University Hospital, Rio de Janeiro State University, Rio de Janeiro, RJ, Brazil.
authors.forename: Flavio
authors.initials: F
authors.lastname: Nigri
authors.affiliation: Department of Surgical Specialties, Neurosurgery Teaching and Assistance Unit, Pedro Ernesto University Hospital, Rio de Janeiro State University, Rio de Janeiro, RJ, Brazil.
authors.forename: Gabriel N
authors.initials: GN
authors.lastname: Gobbi
authors.affiliation: Department of Physiological Sciences, Roberto Alcântara Gomes Biology Institute, Rio de Janeiro State University, Rio de Janeiro, RJ, Brazil; Nervous System Electric Stimulation Laboratory (LabEEL) - Neurosurgery Teaching and Assistance Unit, Pedro Ernesto University Hospital, Rio de Janeiro State University, Rio de Janeiro, RJ, Brazil.
authors.forename: Egas M
authors.initials: EM
authors.lastname: Caparelli-Daquer
keywords: Conversion technique; microsurgery; neuroendoscopy; open craniotomy; ventricular tumors