Neuroendoscopic treatment for hydrocephalus associated to midline arachnoid cysts in a series of nine pediatric patients.

Background: Arachnoid cysts are extra-axial cerebrospinal fluid (CSF) collections surrounded by a membrane. Occasionally, hydrocephalus is associated due to a change in CSF circulatory dynamics. Neuroendoscopic treatment has been recommended for patients who develop symptoms resulting from the cyst location.

Methods: We retrospectively evaluate the results in our series of 9 patients with hydrocephalus associated to midline arachnoid cysts treated endoscopically. Success was rated on a scale of five degrees of neuroendoscopical success.

Results: We performed endoscopic third ventriculostomy (ETV) in three cases; ETV was associated to ventriculocystostomy (VC) in three cases; ETV, VC and septostomy (SPT) were performed in one patient; neuroendoscopic Monro foraminoplasty (NEFPMO) plus SPT were associated in one case; last patient was performed ETV, VC and cystocysternostomy (CC). For first procedures, 6 patients completed permanent Success (grade I). In one case success was transitory (grade II) and required a second procedure (ETV). In one patient VC success and ETV failure implied partial success (grade III). One patient's early failure (grade V) required a second procedure (ETV + NEFPMO). Success in second procedures was grade I in both patients. Follow-up period was over 12 months and altogether success was grade I in 8/9 patients and grade III in 1/9 patients. Shunt independency went over 88%.

Conclusions: Endoscopy allows a solution avoiding the implantation of cerebrospinal fluid shunt devices. When possible, we likely approach both, hydrocephalus and arachnoid cyst, with different endoscopic maneuvers in a single procedure. It is important to expand the usage of success classifications for combined procedures.