Object: Arachnoid cysts account for 1% of all intracranial lesions. They usually occur in the subarachnoid space of the major cerebral fissures and arachnoid cisterns. They are very rarely located within the brain parenchyma devoid of communication with the subarachnoid space. The author of this study evaluated the role of endoscopy in the treatment of intraparenchymal arachnoid cysts (IPACs), which have a paraventricular location noncontiguous with the basal cisterns.
Methods: The records of all patients who had undergone surgery performed by one neurosurgeon between March 2004 and October 2011 were retrospectively reviewed to find cases of arachnoid cysts with a paraventricular location noncontiguous with the basal cisterns that were treated with a purely endoscopic cystoventriculostomy. Data were collected, summarized, and analyzed as regards improvement in symptomatology, decrease in cyst size, improvement in hydrocephalus, incidence of complications, surgical failure, and incidence of recurrence.
Results: Twelve pediatric patients with symptomatic IPACs were included in this study. The group included 7 boys and 5 girls with a mean age of 5.2 years. All of the patients had undergone endoscopic cystoventriculostomy. In addition, endoscopic third ventriculostomy had been performed during the same operative session in 3 patients who had associated hydrocephalus. Significant clinical improvement occurred in 10 patients (83.3%). Postoperative imaging showed a reduction in the cyst size in 9 patients (75%), whereas the cyst size was unchanged in the remaining 3 patients (25%). A reduction in ventricle size occurred in 2 (66.7%) of the 3 patients who had hydrocephalus. A postoperative subdural hygroma occurred in 2 patients (16.7%) and required the insertion of a subduroperitoneal shunt in 1 patient. During the follow-up period (mean 42.5 months), 1 patient had a recurrence and required a repeat endoscopic procedure.
Conclusions: Endoscopic cystoventriculostomy is recommended in the treatment of symptomatic IPACs. It maintains the basic strategy of cyst fenestration into the lateral ventricle without either the invasiveness of open craniotomy or the implantation of shunt systems. The procedure is simple, effective, and minimally invasive. It saves operative and recovery times and is associated with low morbidity and mortality rates.
Keywords: EEG = electroencephalography; ETV = endoscopic third ventriculostomy; IPAC = intraparenchymal arachnoid cyst; arachnoid cyst; congenital; cystoventriculostomy; endoscopy; intraparenchymal.