An improved reservoir for the flushing test to diagnose shunt insufficiency.

OBJECTIVE Reservoirs integrated into hydrocephalus shunts are commonly used for the removal of CSF and for intra-ventricular pressure measurement. Pumping with the reservoir to diagnose shunt sufficiency is still a matter of controversy. The authors describe an improved flushing device and its characteristic features in vitro and in vivo.

The Frankfurt horizontal plane as a reference for the implantation of gravitational units: a series of 376 adult patients.

Background: The in-line combination of adjustable differential pressure valves with fixed gravitational units is increasingly recommended in the literature. The spatial positioning of the gravitational unit is thereby decisive for the valve opening pressure. We aimed at providing data on factors contributing to primary overdrainage and underdrainage of cerebrospinal fluid (CSF), with special attention paid to the implantation angle of the gravitational unit.

Large-scale referencing of the telemetric neurovent-P-tel intracranial pressure sensor in a porcine model.

The Neurovent-P-tel sensor is a promising device for telemetric intracranial pressure (ICP) measurements in cases of complex hydrocephalus. Data on its accuracy within a broad ICP range are missing. We applied a porcine model for large-scale manipulation of the ICP values.

Differential pressure in shunt therapy: investigation of position-dependent intraperitoneal pressure in a porcine model.

Object: The differential pressure between the intracranial and intraperitoneal cavities is essential for ventriculoperitoneal shunting. A determination of the pressure in both cavities is decisive for selecting the appropriate valve type and opening pressure. The intraperitoneal pressure (IPP)-in contrast to the intracranial pressure-still remains controversial with regard to its normal level and position dependency.

Flow-related noise in patients with ventriculoperitoneal shunt using gravitational adjustable valves.

Background: Noise disturbance arising from the valve is a rare event of ventriculoperitoneal shunts. We queried and investigated shunt patients for occurrence and evaluated the possible factors related to noise development.

Methods: Fifty ambulatory patients with implanted proGAV valve were investigated consecutively.

Patients benefit from low-pressure settings enabled by gravitational valves in normal pressure hydrocephalus.

Objective: The ability of siphon regulatory devices to improve overdrainage control despite low-pressure settings of the valve for the horizontal body position has been described previously. We aim to provide a systematic investigation on the ability of gravitational units as siphon regulatory devices to improve clinical outcome in shunt therapy.

Methods: We analyzed retrospectively postoperative complications, type and frequency of valve adjustments and the clinical outcome using Black's outcome scale at different time points of all iNPH patients operated in our center between January 2007 and December 2010.

Shunting with gravitational valves--can adjustments end the era of revisions for overdrainage-related events?: clinical article.

Object: Overdrainage of CSF remains an unsolved problem in shunt therapy. The aim of the present study was to evaluate treatment options on overdrainage-related events enabled by the new generation of adjustable gravity-assisted valves.

Methods: The authors retrospectively studied the clinical course of 250 consecutive adult patients with various etiologies of hydrocephalus after shunt insertion for different signs and symptoms of overdrainage.

Diffusion tensor imaging in hydrocephalus--findings before and after shunt surgery.

Background: To evaluate changes in diffusion tensor imaging (DTI)-derived parameters in patients with hydrocephalus (HC) before and several weeks after shunt surgery.

Methods: Thirteen HC patients were examined with DTI before and after shunt surgery. In a combined region of interest and whole brain voxel-based analysis, different DTI parameters were compared with an age-matched control group.

Reduction of shunt obstructions by using a peel-away sheath technique? A multicenter prospective randomized trial.

Objective: Shunt obstructions may partly be caused by brain debris, which intrude into the ventricular catheter during ventricle puncture. Avoiding contact between the catheter and brain tissue, by using a peel-away sheath, should reduce the number of shunt failures caused by obstruction. To test this hypothesis, we conducted a randomized, prospective multicenter study.

Alteration of brain viscoelasticity after shunt treatment in normal pressure hydrocephalus.

Introduction: Normal pressure hydrocephalus (NPH) represents a chronic neurological disorder with increasing incidence. The symptoms of NPH may be relieved by surgically implanting a ventriculoperitoneal shunt to drain excess cerebrospinal fluid. However, the pathogenesis of NPH is not yet fully elucidated, and the clinical response of shunt treatment is hard to predict.

In vivo viscoelastic properties of the brain in normal pressure hydrocephalus.

Nearly half a century after the first report of normal pressure hydrocephalus (NPH), the pathophysiological cause of the disease still remains unclear. Several theories about the cause and development of NPH emphasize disease-related alterations of the mechanical properties of the brain. MR elastography (MRE) uniquely allows the measurement of viscoelastic constants of the living brain without intervention.

Arachnoid cysts of the middle cranial fossa accompanied by subdural effusions--experience with 60 consecutive cases.

Background: Subdural effusions (SDEs) can complicate arachnoid cysts of the middle cranial fossa (ACMFs). While there is a consensus that at least in adults asymptomatic ACMFs should not be operated, those with concomitant subdural and/or intracystic effusions are clinically apparent in the majority of cases and should be surgically treated. But it remains unclear, which surgical procedure is best.

The adjustable proGAV shunt: a prospective safety and reliability multicenter study.

Objective: To evaluate the reliability of the gravitation-assisted adjustable proGAV shunt system with a prospective multicenter study conducted in 10 German hospitals.

Methods: Enrollment for this observational study began in April 2005 and concluded in February 2006. The protocol required re-examinations 3 and 6 months postoperatively and fixed the endpoint of follow-up at 12 months after implantation.

Perforation holes in ventricular catheters--is less more?

Objective: Obstruction is a common cause of cerebrospinal fluid (CSF) shunt failure. Risk factors for proximal obstructive malfunction are suboptimal ventricular catheter positioning and slit-like ventricles. A new ventricular catheter design to decrease risk of obstruction was evaluated.

Evaluation of the Miethke dual- switch valve in patients with normal pressure hydrocephalus.

Objective: Especially in patients with normal pressure hydrocephalus (NPH), conventional differential-pressure valves are known to create nonphysiological negative intraventricular pressure values (IVP) when the patient moves into the upright position, with the consequence of numerous, sometimes severe, complications. The recently presented gravitational devices promise improvement, primarily in respect to this disadvantage.

Methods: In a prospective multicenter study the new Miethke dual- switch valve (DSV) has been implanted in 128 patients with NPH.