scholarly journals Considerations in the Use of Gravitational Valves in the Management of Hydrocephalus. Some Lessons Learned with the Dual-Switch Valve

2021 ◽  
Vol 10 (2) ◽  
pp. 246
Author(s):  
Maria A. Poca ◽  
Dario F. Gándara ◽  
Katiuska Rosas ◽  
Aloma Alcina ◽  
Diego López-Bermeo ◽  
...  
Keyword(s):  
Drainage System ◽  
Vertical Axis ◽  
Normal Pressure ◽  
Lessons Learned ◽  
Opening Pressure ◽  
Clear Trend ◽  
Shunt System ◽  
Physiological Limits ◽  
Device Implantation ◽  
Hydrostatic Valves

In the past decade, there has been a clear trend towards better outcomes in patients with hydrocephalus, especially those with normal pressure hydrocephalus (NPH). This is partly due to the availability of more sophisticated hardware and a better understanding of implants. However, there is little evidence to show the superiority of a specific type of valve over another. The most commonly reported consequence of hydrodynamic mismatch is shunt over-drainage. Simple differential pressure valves, with a fixed opening pressure or even adjustable valves, lead to non-physiologic intraventricular pressure (IVP) as soon as the patient moves into an upright posture. These valves fail to maintain IVP within physiological limits due to the changes in hydrostatic pressure in the drainage system. To solve this problem more complex third-generation hydrostatic valves have been designed. These gravitational devices aim to reduce flow through a shunt system when the patient is upright but there are important technical differences between them. Here we review the main characteristics of the Miethke® Dual-Switch valve, which includes two valve chambers arranged in parallel: a low-opening pressure valve, designed for working in the supine position, and a second high-opening pressure valve, which starts working when the patient assumes the upright position. This paper specifies the main advantages and drawbacks of this device and provide a series of recommendations for its use. The discussion of this specific gravitational valve allows us to emphasize the importance of using gravitational control in implanted shunts and some the caveats neurosurgeons should take into consideration when using gravitational devices in patients with hydrocephalus. The correct function of any gravitational device depends on adequate device implantation along the vertical body axis. Misalignment from the vertical axis equal to or more than 45° might eliminate the beneficial effect of these devices.

Overdrainage shunt complications in idiopathic normal-pressure hydrocephalus and lumbar puncture opening pressure

2013 ◽  
Vol 119 (6) ◽  
pp. 1498-1502 ◽  
Author(s):  
Qurat ul Ain Khan ◽  
Robert E. Wharen ◽  
Sanjeet S. Grewal ◽  
Colleen S. Thomas ◽  
H. Gordon Deen ◽  
...  
Keyword(s):  
Lumbar Puncture ◽  
Normal Pressure Hydrocephalus ◽  
Subdural Hematoma ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Complication Rates ◽  
Shunt Surgery ◽  
Opening Pressure ◽  
Presenting Symptoms ◽  
Subdural Hematomas

Object Management of idiopathic normal-pressure hydrocephalus (iNPH) is hard because the diagnosis is difficult and shunt surgery has high complication rates. An important complication is overdrainage, which often can be treated with adjustable–shunt valve manipulations but also may result in the need for subdural hematoma evacuation. The authors evaluated shunt surgery overdrainage complications in iNPH and their relationship to lumbar puncture opening pressure (LPOP). Methods The authors reviewed the charts of 164 consecutive patients with iNPH who underwent shunt surgery at their institution from 2005 to 2011. They noted age, sex, presenting symptoms, symptom duration, hypertension, body mass index (BMI), imaging findings of atrophy, white matter changes, entrapped sulci, LPOP, valve opening pressure (VOP) setting, number of valve adjustments, serious overdrainage (subdural hematoma requiring surgery), radiological overdrainage (subdural hematomas or hygroma seen on postoperative imaging), clinical overdrainage (sustained or postural headache), other complications, and improvements in gait, urine control, and memory. Results Eight patients (5%) developed subdural hematomas requiring surgery. All had an LPOP of greater than 160 mm H2O and an LPOP-VOP of greater than 40 mm H2O. Radiological overdrainage was more common in those with an LPOP of greater than 160 mm H2O than in those with an LPOP of less than 160 mm H2O (38% vs 21%, respectively; p = 0.024). The BMI was also significantly higher in those with an LPOP of greater than 160 mm H2O (median 30.2 vs 27.0, respectively; p = 0.005). Conclusions Serious overdrainage that caused subdural hematomas and also required surgery after shunting was related to LPOP and LPOP-VOP, which in turn were related to BMI. If this can be replicated, individuals with a high LPOP should have their VOP set close to the LPOP, or even higher. In doing this, perhaps overdrainage complications can be reduced.

scholarly journals Validation of a noninvasive test routinely used in otology for the diagnosis of cerebrospinal fluid shunt malfunction in patients with normal pressure hydrocephalus

2016 ◽  
Vol 124 (2) ◽  
pp. 342-349 ◽  
Author(s):  
Laurent Sakka ◽  
Alexandre Chomicki ◽  
Jean Gabrillargues ◽  
Toufic Khalil ◽  
Jean Chazal ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Phase Shift ◽  
Normal Pressure Hydrocephalus ◽  
Otoacoustic Emissions ◽  
Normal Pressure ◽  
Shunt Malfunction ◽  
Cerebrospinal Fluid Shunt ◽  
Opening Pressure ◽  
Valve Opening ◽  
Group 2

OBJECT Ventriculoperitoneal shunting is the first-line treatment for normal pressure hydrocephalus. Noninvasive auditory tests based on recorded otoacoustic emissions were assessed, as currently used for universal neonatal hearing screenings, for the diagnosis of cerebrospinal fluid shunt malfunction. The test was designed based on previous works, which demonstrated that an intracranial pressure change induces a proportional, characteristic, otoacoustic-emission phase shift. METHODS Forty-four patients with normal pressure hydrocephalus (23 idiopathic and 21 secondary cases) were included in this prospective observational study. The male:female sex ratio was 1.44, the age range was 21–87 years (mean age 64.3 years), and the range of the follow-up period was 1–3 years (mean 20 months). Patients were implanted with a Sophy SU8 adjustable-pressure valve as the ventriculoperitoneal shunt. The phase shifts of otoacoustic emissions in response to body tilt were measured preoperatively, immediately postoperatively, and at 3–6 months, 7–15 months, 16–24 months, and more than 24 months postoperatively. Three groups were enrolled: Group 1, 19 patients who required no valve opening-pressure adjustment; Group 2, 18 patients who required valve opening-pressure adjustments; and Group 3, 7 patients who required valve replacement. RESULTS In Group 1, phase shift, which was positive before surgery, became steadily negative after surgery and during the follow-up. In Group 2, phase shift, which was positive before surgery, became negative immediately after surgery and increasingly negative after a decrease in the valve-opening pressure. In Group 3, phase shift was positive in 6 cases and slightly negative in 1 case before revision, but after revision phase shift became significantly negative in all cases. CONCLUSIONS Otoacoustic emissions noninvasively reflect cerebrospinal fluid shunt function and are impacted by valve-opening pressure adjustments. Otoacoustic emissions consistently diagnosed shunt malfunction and predicted the need for surgical revision. The authors’ diagnostic test, which can be repeated without risk or discomfort by an unskilled operator, may address the crucial need of detecting valve dysfunction in patients with poor clinical outcome after shunt surgery.

Telemetric Intracranial Pressure Recording via a Shunt System Integrated Sensor: A Safety and Feasibility Study

2017 ◽  
Vol 78 (06) ◽  
pp. 572-575 ◽  
Author(s):  
Elvis Hermann ◽  
Hans Heissler ◽  
Joachim Krauss ◽  
Philipp Ertl
Keyword(s):  
Intracranial Pressure ◽  
Normal Pressure Hydrocephalus ◽  
Sampling Rate ◽  
Normal Pressure ◽  
Shunt Surgery ◽  
Shunt System ◽  
Measuring Device ◽  
Handheld Device ◽  
Additional Surgery ◽  
Postural Changes

Background The dynamics of intracranial pressure (ICP) after shunt surgery in patients with normal pressure hydrocephalus (NPH) are poorly known. Temporarily implanted parenchymal pressure probes are reliable for accurate ICP monitoring; however, a disadvantage of this method is that the ICP probe has to be explanted after a period of time, requiring additional surgery. We present two patients with NPH with an integrated ICP measuring device in the shunt system that allows for long-term postoperative telemetric monitoring of ICP. Methods Two patients (one man, 66 years old, and one woman, 78 years old) with normal pressure hydrocephalus underwent shunt surgery using the Aesculap-Miethke Sensor Reservoir (Potsdam) as an ICP measuring device integrated in the shunt system. On the first postoperative day and during follow-up examination 3 months later, several measurements of ICP were performed using a handheld device to read the Sensor Reservoir data. Postural changes such as lying down, sitting, and standing with different head postures were assessed according to an experimental protocol in a randomized order during which the ICP was measured. Results There were clear ICP responses due to postural changes, in line with physiologically expected values. Because the highest sampling rate of the Aesculap-Miethke Sensor Reservoir is 1 Hz for continuous measurement of ICP, however, the collected data have to be considered an approximation for actual ICP dynamics. Conclusion The Aesculap-Miethke Sensor Reservoir is an easy-to-use tool to measure ICP changes reliably in patients with a shunt system. The sampling rate and handling of data acquisition may eventually be developed further.

scholarly journals Cerebrospinal fluid closing pressure-guided tap test for the diagnosis of idiopathic normal pressure hydrocephalus: A descriptive cross-sectional study

2020 ◽  
Vol 11 ◽  
pp. 315
Author(s):  
Diego Fernando Gómez-Amarillo ◽  
Luis Fernando Pulido ◽  
Isabella Mejía ◽  
Catalina García-Baena ◽  
María Fernanda Cárdenas ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Normal Pressure Hydrocephalus ◽  
Normal Pressure ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Opening Pressure ◽  
Cross Sectional ◽  
Tap Test ◽  
The Mean ◽  
Closing Pressure

Background: Tap test improves symptoms of idiopathic normal pressure hydrocephalus (iNPH); hence, it is widely used as a diagnostic procedure. However, it has a low sensitivity and there is no consensus on the parameters that should be used nor the volume to be extracted. We propose draining cerebrospinal fluid (CSF) during tap test until a closing pressure of 0 cm H2O is reached as a standard practice. We use this method with all our patients at our clinic. Methods: This is a descriptive cross-sectional study where all patients with presumptive diagnosis of iNPH from January 2014 to December 2019 were included in the study. We used a univariate descriptive analysis and stratified analysis to compare the opening pressure and the volume of CSF extracted during the lumbar puncture, between patients in whom a diagnosis of iNPH was confirmed and those in which it was discarded. Results: A total of 92 patients were included in the study. The mean age at the time of presentation was 79.4 years and 63 patients were male. The diagnosis of iNPH was confirmed in 73.9% patients. The mean opening pressure was 14.4 cm H2O mean volume of CSF extracted was 43.4 mL. Conclusion: CSF extraction guided by a closing pressure of 0 cm H2O instead of tap test with a fixed volume of CSF alone may be an effective method of optimizing iNPH symptomatic improvement and diagnosis.

Sign in / Sign up

Export Citation Format

Share Document