title: Initial experience with the Codman Certas adjustable valve in the management of patients with hydrocephalus.
abstract: BACKGROUND
  A new adjustable valve, the Codman CertasTM valve for treatment of hydrocephalus was introduced into clinical practice in January 2011. It has 8 different settings with an opening pressure varying from 36 to over 400 mm H2O at a flow rate of 20 mL/h. The 8th setting is designed to provide a "virtual off" function. The objective of this report is to describe the initial clinical experience with the CertasTM valve and evaluate clinical usage with the main focus on the portable adjustment device - Therapeutic Management System (TMS), the "virtual off" setting and compatibility with magnetic resonance imaging (MRI).
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: The Neuroscience Centre, Department of Neurosurgery, Section NK 2092, Blegdamsvej 9, Copenhagen, DK-2100, Denmark. bertil.romner@rh.regionh.dk.
authors.forename: Sara
authors.initials: S
authors.lastname: Watt
authors.forename: Niels
authors.initials: N
authors.lastname: Agerlin
authors.forename: Bertil
authors.initials: B
authors.lastname: Romner