Objective: Overdrainage in children is a long-term problem for shunted patients which might lead to chronic anatomical changes. In order to prevent these problems, valve exchange is performed on a regular basis in patients without hydrostatic units towards a valve with both an adjustable and a gravitational unit. The clinical outcome of these patients is reported in a retrospective study.
Methods: Between 2009 and 2014, the in-house database was analyzed for patients who received a valve exchange towards an adjustable differential pressure valve with gravitational unit. The study protocol included the patients shunt history, image analysis for ventricular width, and necessity of revision surgery after valve exchange. A questionnaire was sent to the patients in order to ask for their subjective experience for symptom changes and treatment experience.
Results: Forty-six patients were identified (26 girls, mean age 11.8 ± 6.1 years) with a mean follow-up of 36.3 ± 15 months. The ventricular width did increase after valve exchange as measured in frontal and occipital horn ratio (0.364 ± 0.032 vs. 0.402 ± 0.09, p = 0.0017). Of the patients suffering from acute symptoms, 89% improved after treatment. The shunt and valve survival rates were 88 and 95%, respectively, after 12 months. Comparing the total amount of revisions before and after valve exchange, a significant reduction was seen in total but a no significant difference was analyzed in amount of revisions to time ratio.
Conclusion: Valve exchange might be cautiously decided if patients seem to perform clinically well. In our study, we were able to show that the strategy of valve exchange to prevent chronic overdrainage is well tolerated and seem to improve patient's clinical outcome in terms of ventricular width, symptom relieve, and revision rate.
Keywords: Garvitational valve; Hydrocephalus; Overdrainage; Shunt revision; Ventricle width; Ventriculoperitoneal shunt.