title: Bilateral telovelar approach: A safe route revisited for resections of various large fourth ventricle tumors.
abstract: BACKGROUND
  Tumors located in the posterior fossa and especially in the middle and upper fourth ventricle are comparatively rare and technically very challenging. For some lesions, the telovelar approach has been shown to be a suitable approach. The unilateral approach is sufficient in most cases of small lesions. However, large fourth ventricle tumors are more problematic since they distort the normal anatomy with both vermis and cerebellar peduncles thinned and stretched out. This puts the patient at increased risk for a neurological deficit, which is minimized with a bilateral telovelar approach. By illustrating the adequacy of this technique, we emphasize the suitability of a rather unusual bilateral approach, which will provide excellent panoramic visualization of entire fourth ventricle and thus avoids complications usually associated with resections of large fourth ventricle tumors.
  
  
  METHODS
  Here we present three cases of benign intraventricular tumors (meningioma, solitary fibrous tumor and ependymoma) in patients with site specific symptoms from local mass effect. Typical symptoms of posterior fossa lesions were present preoperatively and resolved after surgery. The bilateral telovelar approach was used to remove these tumors completely and the pertinent intraoperative steps are described for each case. All three patients had excellent postoperative outcome and could be discharged after short hospital stays.
  
  
  CONCLUSIONS
  The different pathological entities could be completely resected without added neurological deficit employing a bilateral approach. In cases of large or giant fourth ventricle tumors, the bilateral telovelar approach provides excellent intraoperative visibility allowing complete excision of extensive tumors with minimal morbidity.
authors.affiliation: Department of Neurosurgery, PLA Navy General Hospital, Beijing, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.affiliation: Department of Surgery, Division of Neurosurgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Ekkehard M
authors.initials: EM
authors.lastname: Kasper
keywords: Cerebellomedullary fissure; fourth ventricle; microsurgery; telovelar approach