Article
Adjustment with gravitational valves – The end of overdrainage?
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Authors
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Christian Sprung
- Neurosurgical Department, Charité – Universitätsmedizin Berlin, Campus Rudolf Virchow, Berlin, Germany
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Florian B. Freimann
- Neurosurgical Department, Charité – Universitätsmedizin Berlin, Campus Rudolf Virchow, Berlin, Germany
| Published: | September 16, 2010 |
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Outline
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Objective: After the introduction of conventional differential pressure valves for shunting 60 years ago, the clinical course was often complicated by severe deteriorations due to overdrainage. The introduction of the first generation of adjustable valves improved the situation, but could not avoid all pitfalls. Whether the combination of adequate adjustment with hydrostatic gravitational-units is capable of treating overdrainage-related complications successfully, will be evaluated by a retrospective analysis of a proGAV-series.
Methods: Out of a series of 250 adult hydrocephalic patents shunted with the gravitation-assisted proGAV, 29 developed clinical and/or radiological signs of overdrainage- related problems during follow-up. In every case of complication, we evaluated the time-course, possible reasons and correlated clinical and radiological findings. Depending on the severity of overdrainage we elevated the opening pressure of the valve in several steps. Finally, clinical and radiological follow-up until resolution was documented.
Results: 2 patients suffered only hydrostatic headache, 3 had slit-like ventricles, 20 cases developed signs of a hygroma and 4 had clear subdural hematomas. The majority of patients with hygroma and even hematoma did not presesignificant clinical signs and symptoms. We learned that in case of distinct hygroma or hematoma it is advantageous to elevate the opening pressure in greater steps towards the upper limit of 20 cm H2O. After disappearance of the subdural effusion it is necessary to decrease the opening pressure in most cases. Whereas all 29 cases of overdrainage could be treated successfully only by adjustments without operation or ligation, our results with underdrainage-related problems were less convincing.
Conclusions: Our series proves that with the use of adequate valves, there is the possibility of successful treatment of all overdrainage-related problems without increasing the incidence of underdrainage. Because of the distinct nature of the latter complication, the treatment is more difficult.
