gms | German Medical Science

Objective: It is a controversial issue whether it is of greater importance to implant vp-shunts with adjustable valves or adjustable gravitational units. The intention of this trial is to compare two groups of iNPH-patients in regard to valve adjustments, complications and clinical outcome.

Methods: Patients with iNPH were randomized to receive a VP-Shunt either with an adjustable valve (pressure setting 05/20) or an adjustable gravitational unit (pressure setting 05/20). After surgery the patients underwent follow-up examinations after 3, 6, 9 and 12 months and the outcome was assessed through specific iNPH grading scales like Kiefer Score, NPH Recovery Rate and Black Grading Scale.

Results: From March 2014 to May 2017 40 patients were included in the study. In the adjustable gravitational unit cohort, 35 % of the patients were evaluated with excellent and 20 % with good results. Currently only one patient of the adjustable valve group attained excellent results (5 %) but 35 % achieved a good clinical outcome measured by the Black Grading Scale. The rate of revision operations because of catheter dysfunction or subdural hematoma was higher in the group with adjustable valves with 15 % in contrast to 5% in the adjustable gravitational unit group. Theincidence of overdrainage complications was also higher among the patients with adjustable valves with 10 % vs. 5 %. The necessity of valve adjustments due to underdrainage was fairly equal with 40 % in both groups.

Conclusion: The results of this study reveal the superiority of adjustable gravitational units over adjustable valves for patients with iNPH.