2. Materials and Methods Pubmed literature searches were performed using search terms ��(endoscop*) AND ventric*��, ��(endoscop*) AND tumor��, ��((neuro-endoscop*) OR neuroendoscop*) AND tumor��, then and ��(tumor) AND ventric*��. Additional articles were located via cross-referencing of articles discovered initially through Pubmed searches. Articles included in the study were required to originate from peer-reviewed, English language journals describing the attempted resection (e.g., biopsies and cyst fenestrations without attempted resection were excluded) of an intraventricular tumor (e.g., suprasellar neoplasms without intraventricular extension were excluded) by purely endoscopic means (e.g., ��endoscope-assisted�� microsurgical resections were excluded) through a single endoscope (��dual-port�� resections were excluded).

Care was taken to exclude any redundant patient data from the analysis, and five articles required exclusion from the study due to an inability to definitively distinguish study patients in these five articles from patients in other study articles by the same author. In these five cases, the earlier of the two conflicting publications was omitted. Selected articles were also required to report on one or more of the following variables: (1) estimated completeness of resection achieved, (2) radiographic recurrence rates, and/or (3) complications related to the procedure. Cases involving the use of stereotactic radiosurgery, chemotherapy, or other nonsurgical treatment adjuncts were included. Two hundred and twenty articles were reviewed, and 40 were selected based on the above criteria.

Data collected from these 40 studies included tumor type, location within the ventricular system, tumor size, the presence of hydrocephalus preoperatively, operative technique, success of endoscopic resection, rates of intraoperative hemorrhage, and other procedure-related complications, rates of tumor recurrence, and length of clinical and/or radiographic follow-up. Estimates regarding the completeness of endoscopic resection were obtained most commonly by surgeon or observer recollection and self-report, but were also obtained through assessments of postoperative imaging studies and chart review in some cases. Complete endoscopic resection was defined as gross total resection of all visible tumor as confirmed by visual intraoperative assessment or by the absence of any visible tumor residual on postoperative contrast magnetic resonance imaging (MRI). Near-complete resection was defined as resection of all but a very small amount of tumor adherent to nearby tissues. Partial resection was defined by a considerable tumor remnant as assessed Batimastat either intraoperatively or on postoperative contrast MRI.