Performance of fixed-pressure valve with antisiphon device SPHERA® in hydrocephalus treatment and overdrainage prevention Desempenho da válvula de pressão fixa com antissifão SPHERA® no tratamento da hidrocefalia e na prevenção da ocorrência de hiperdrenagem

Surgical treatment of hydrocephalus in adults is attained through the implantation of ventricular shunt (VS) systems, neuroendoscopy or through the association of both procedures, offering the possibility of significant neurological improvement1. The United Kingdom Shunt Registry showed in 13,206 adults with hydrocephalus submitted to VS implant that 22% of patients required reoperation within five years2. Patients with hydrocephalus and risk factors for overdrainage may be submitted to VS implant with antisiphon device. This valve-integrated device allows the patient, while in the orthostatic position, to increase the resistance to drainage of cerebrospinal fluid (CSF), reducing the siphoning effect that always occurs, thus avoiding overdrainage2-6. The objective of this study was to prospectively evaluate for two years the clinical performance of fixed-pressure valve with SPHERA® antisiphon device in the treatment of 35 adult patients, with hydrocephalus and high clinical susceptibility to overdrainage.