Endoscopic neurosurgery and endoscope-assisted microneurosurgery for the treatment of intracranial cysts

OBJECTIVE: Different endoscopic techniques have been introduced into neurosurgery, but accepted terminology and definitions are still missing. We propose a terminology based on whether the endoscope is used alone or in conjunction with an operating microscope and on whether the route of surgical manipulations is through or outside the endoscope. Accordingly, procedures are categorized into endoscopic neurosurgery (EN), endoscope-assisted microneurosurgery (EAM), and endoscope-controlled microneurosurgery (ECM). METHODS: We treated 36 patients with intracranial arachnoid cysts (ACs) and intraventricular cysts endoscopically. The patients ranged in age from 4 months to 69 years (mean age, 31 yr). The follow-up period ranged from 6 to 44 months (mean follow-up duration, 14 mo). The indications were hydrocephalus in 17 patients, focal neurological deficits in 4 patients, progressive nonlocalizing symptomatology in 13 patients, and space occupation in 2 asymptomatic patients. EN was used in 14 cases, EAM in 15 cases, and ECM in 7 cases. RESULTS: The overall success rate was 70%. Nine patients (25%) had unchanged symptomatology, and the condition of two patients (5%) deteriorated. The best success rates were achieved in patients with intraventricular cysts (89%) and posterior fossa ACs (78%). Symptomatic improvement was best achieved in patients with hydrocephalus or focal neurological deficits (81%). CONCLUSION: Different endoscopic techniques (i.e., EN, EAM, and ECM) provide sufficient treatment of selected intracranial cysts. Our data suggest that intraventricular cysts and suprasellar ACs should be approached using EN whereas posterior fossa and sylvian ACs may be more effectively treated using a combined technique (EAM or ECM).