Endoscopic Cystoventricular Stenting in Awake Patients with Electrical Stimulation Mapping for Convexity Cysts: Three...

Surgical interventions for arachnoid cysts and glioependymal cysts primarily focus on cyst decompression and establishing communication with cerebrospinal fluid spaces. However, a standardized surgical strategy for symptomatic convexity cysts lacking surrounding cerebrospinal fluid space is still lacking due to the limited number of cases. This systematic review aims to evaluate surgical interventions for symptomatic convexity cysts and proposes a safe and effective treatment approach we have developed. A systematic review of the literature was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Surgical techniques were categorized into cystoperitoneal shunt, cyst excision, cyst fenestration, cyst ventriculostomy, and several uniquely modified methods. Using a method different from these previous reports, we performed endoscopic cystoventricular stenting via burr hole in 3 cases of convexity cysts. While traditional methods have proven effective, cystoperitoneal shunt may lead to malfunction, infection, and subdural hematoma; wall excision is invasive and increases morbidity risks. Fenestration and cystoventriculostomy have also reported cases of recurrence. Other methods also pose issues, including off-label use of instruments and inadequate consideration for removal. The method we performed for placing the stent catheter with multiple side holes demonstrated long-term effectiveness. Furthermore, the surgery was conducted with the patient fully awake, and the use of electrical stimulation mapping enabled preservation of higher neurocognitive functions, including language, working memory, and spatial cognition, at the puncture site. This novel approach offers advantages such as minimally invasive procedure, preservation of safe brain function, and long-term patency. Further studies are warranted to validate these findings and improve surgical strategies for convexity cysts.