Initial experience with the Codman Certas adjustable valve in the management of patients with hydrocephalus

Forty-two patients with hydrocephalus from different etiologies were treated with the CertasTM adjustable shunt system. Data regarding implantation procedures, the use of the TMS system, x-ray imaging, and MRI procedures were recorded prospectively. All patients had clinical follow-up at four weeks after implantation and every three months until a stable clinical condition was obtained.The mean time for follow-up was 8.6？months (1–16.6). Seventy-one adjustments were performed with the TMS, 12 were problematic. Twenty-nine MRI procedures were performed and did not cause accidental resetting. Five patients were treated with the "virtual off" function for a period.We found the CertasTM valve valuable in the treatment of hydrocephalus, usability of the TMS was high because it is small and portable, but in some cases we experienced adjustment problems with the first procedures performed by a surgeon, indicating that there is a learning curve. The "virtual off" function provided a possibility of treating over-drainage without the need for shunt ligation or other invasive procedures.Treating patients with hydrocephalus with an implanted shunt is not always just straightforward and simple: there are occurrences of under-drainage of cerebral spinal fluid (CSF) where a large ventricle and clinical symptoms of hydrocephalus continue or the shunt implantation may cause over-drainage with slit ventricles and development of subdural hygromas [1,2]. It has been shown that adjustable valves can be useful in handling these problems [3-6]. For nearly 25？years, different types of adjustable valves have been on the market with a number of settings from 3 to 20; these valves allow the neurosurgeon to adjust the opening pressure non-invasively and thus correct the volume of CSF shunted. A new adjustable valve, The Codman Certas？ programmable valve, was approved for clinical use in Europe and the USA in 2011. It can be set to 7 different settings for drainage of CSF where the opening pres