91379
document
The importance of the dual-switch valve for the treatment of adult normotensive or hypertensive hydrocephalus . Since the beginning of 1995 the new hydrostatic dual-switch valve ( DSV ) was implanted in 35 adult patients with hydrocephalus of different etiology . 26 patients suffered from normotensive hydrocephalus ( 10 idiopathic and 16 symptomatic ) , and 9 patients from hypertensive hydrocephalus of various origin . The first 21 cases of this cohort were compared in a randomized study with a comparable group of 21 hydrocephalic patients who received a conventional differential-pressure ( DP- ) valve . The clinical status and CT were assessed prior to shunting , 14 days and 3 and 6 months after the operation . The reduction of ventricular size was evaluated by the measurement of the Evans Index . The CT follow-up in the DSV group was characterized by an only minimal ( 14 ) or only slight ( 16 ) reduction of ventricular size in the vast majority of cases . A comparison of 21 patients with a DSV and the patients with DP valves , evaluated by measuring the reduction of the Evans Index , revealed a distinctly higher percentage of significant regressions in the DP valve collective , without doubt due to chronic overdrainage . The overall clinical result of our 35 patients with a DSV was excellent and good in 31 patients , but the outcome seems to be more dependent on the preshunt damage of the brain than on hydrocephalic aspects . A neglegible incidence of subdural effusions in the DSV group compared to 11 cases in the DP valve collective reflects the ability of the DSV to prevent overdrainage . The capability of the DSV to maintain the IVP within physiological limits after shunting , especially in the upright position , is documented by a comparison with possible unphysiological IVP variations in other valve constructions , which depend on the level of implantation , subcutaneous pressure or CSF flow through the valve .
91380
Intervention_Physical
dual-switch valve
91381
Intervention_Physical
hydrostatic dual-switch valve ( DSV )
91382
Intervention_Physical
conventional differential-pressure ( DP- ) valve
91383
Intervention_Physical
DSV
91384
Intervention_Physical
DSV
91385
Intervention_Physical
DP valves
91386
Intervention_Physical
DP valve
91387
Intervention_Physical
DSV
91388
Intervention_Physical
DSV
91389
Intervention_Physical
DP valve
91390
Intervention_Physical
DSV
91391
Intervention_Physical
DSV
91392
Outcome_Physical
ventricular size
91393
Outcome_Physical
Evans Index
91394
Outcome_Physical
preshunt damage of the brain
91395
Outcome_Physical
hydrocephalic aspects .
91396
Outcome_Physical
subdural effusions
91397
Outcome_Physical
overdrainage
91398
Outcome_Physical
IVP
91399
Outcome_Physical
possible unphysiological IVP variations
91400
Outcome_Physical
level of implantation , subcutaneous pressure or CSF flow through the valve .