Assessment of endoscopic treatment for quadrigeminal cistern arachnoid cysts: A 7-year experience with 28 cases

Quadrigeminal cistern arachnoid cysts (QACs) are difficult to treat because of their deep location and the presence of nervous and vascular structures of the pineal-quadrigeminal region. There are several surgical procedures available for QACs, including craniotomy and cyst excision or fenestration, ventriculoperitoneal or cystoperitoneal shunting, and endoscopic fenestration. There is a debate about which method is the best.

The aim of this study is to evaluate the effectiveness and safety of endoscopic ventriculocystostomy (VC) and third ventriculostomy (ETV) for treatment of arachnoid cysts of the quadrigeminal cistern.

Twenty-eight patients with QACs who had undergone endoscopic treatment in our department between August 2007 and June 2014 were studied retrospectively. Patient age at the time of endoscopic treatment ranged from 5 months to 42 years, including 25 children (14 males and 11 females) and 3 adults (one male and two females). All patients presented with hydrocephalus and did not undergo shunting prior to neuroendoscopic surgery. The first endoscopic procedures included lateral ventricle cystostomy (LVC) together with ETV in 18 cases, third ventricle cystostomy (3rd VC) together with ETV in 3 cases, and double VC (3rd VC and LVC) together with ETV in 7 cases. Data were obtained on clinical and neuroradiological presentation, indications to treat, surgical technique, complications, and the results of clinical and neuroradiological follow-up.

Complete success was achieved in 25 (89.3 %) of 28 cases. During the follow-up period, one case underwent endoscopic reoperation with success. Shunts were implanted in 2 patients due to progression of symptoms and increase in hydrocephalus after the first endoscopic operation. Shunt independency was achieved in 26 (92.9 %) of 28 cases. The cyst was reduced in size in 22 cases (78.6 %). Postoperative images showed a reduction in the size of the ventricles in 23 cases (82.1 %). There was no surgical mortality. Subdural collection developed in 4 cases (14.3 %) and required a transient subduroperitoneal shunt in 2 cases, whereas the other 2 patients were asymptomatic and did not require any surgical treatment.

VC together with ETV through precoronal approach is an effective treatment for symptomatic QACs and should be the initial surgical procedure. The surgical indications should include signs of elevated ICP (including increased head circumference), Parinaud syndrome, gait ataxia, and nystagmus. Also, surgery is indicated by progressive enlargement of the cyst and young children with large cysts even if the patients are asymptomatic. Contraindications to surgery include the absence of symptoms (older children and adult) and isolated developmental delay. The main criterion for successful surgery should be improvement of clinical symptoms instead of reduced cyst volume and/or ventricular size. Repeated endoscopic procedures may be considered only for the patients whose symptoms improved after first endoscopic operation.