First clinical experiences in patients with idiopathic normal-pressure hydrocephalus with the adjustable gravity valve manufactured by Aesculap (proGAVAesculap®)

Objective. Improved clinical outcomes after implantation of a low pressure valve in patients with idiopathic normal-pressure hydrocephalus is usually achieved at the expense of a higher overdrainage rate. Can an adjustable valve with a gravitational unit provide optimal results? Method. In a prospective clinical outcome study conducted in the Unfallkrankenhaus Berlin, 30 patients with idiopathic normal-pressure hydrocephalus were treated surgically between June 2004 and May 2005 with the valve combination described above, and re-examination 3 months or 6 months postoperatively. Results. Clinical outcome correlates with opening pressure level of the valve. Controlled adjustment of the valve from 100 mmH(2)O to 70 mmH(2)O, and then to 50 mmH(2)O after 3 months, permits optimum adaptation of the brain to the implanted valve without overdrainage complications. Conclusions. Advantages of this programmable gravity valve include: 1) the absence of unintentional readjustment through external magnets, and 2) the possibility of controlling the valve setting using an accessory instrument without the need for x-ray monitoring. A significant disadvantage is adjusting the valve after implantation, From the clinical point of view, this new "proGAV(Aesculap)(R)" valve is a necessary development in the right direction, but at the moment it is still beset with technical problems.