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Poca MA, Gándara DF, Rosas K, Alcina A, López-Bermeo D, Sahuquillo J. Considerations in the Use of Gravitational Valves in the Management of Hydrocephalus. Some Lessons Learned with the Dual-Switch Valve. J Clin Med 2021; 10:E246. [PMID: 33445418 PMCID: PMC7830811 DOI: 10.3390/jcm10020246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/02/2021] [Accepted: 01/07/2021] [Indexed: 11/17/2022] Open
Abstract
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.
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Affiliation(s)
- Maria A. Poca
- Department of Neurosurgery, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (D.F.G.); (K.R.); (A.A.); (D.L.-B.); (J.S.)
- Neurotrauma and Neurosurgery Research Unit, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
- Department of Surgery, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Dario F. Gándara
- Department of Neurosurgery, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (D.F.G.); (K.R.); (A.A.); (D.L.-B.); (J.S.)
- Neurotrauma and Neurosurgery Research Unit, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
| | - Katiuska Rosas
- Department of Neurosurgery, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (D.F.G.); (K.R.); (A.A.); (D.L.-B.); (J.S.)
- Neurotrauma and Neurosurgery Research Unit, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
| | - Aloma Alcina
- Department of Neurosurgery, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (D.F.G.); (K.R.); (A.A.); (D.L.-B.); (J.S.)
| | - Diego López-Bermeo
- Department of Neurosurgery, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (D.F.G.); (K.R.); (A.A.); (D.L.-B.); (J.S.)
| | - Juan Sahuquillo
- Department of Neurosurgery, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (D.F.G.); (K.R.); (A.A.); (D.L.-B.); (J.S.)
- Neurotrauma and Neurosurgery Research Unit, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
- Department of Surgery, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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Gutowski P, Gölz L, Rot S, Lemcke J, Thomale UW. Gravitational shunt valves in hydrocephalus to challenge the sequelae of over-drainage. Expert Rev Med Devices 2020; 17:1155-1168. [PMID: 33176494 DOI: 10.1080/17434440.2020.1837622] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION In hydrocephalus treatment, ventriculo-peritoneal shunts (VPS) have become the most relevant therapy for seven decades among other treatment options. Due to the hydrostatic pressure in vertical position, CSF diversion is somehow non-physiological. The integration of gravitational valves in VPS was established to counteract the hydrostatic draining force and to approach a physiological condition of the cerebrospinal diverting system. Numerous clinical studies have shown that gravitational valves are able to reduce secondary complications of VPS treatment. It remains a challenge for the treating neurosurgeon to select the correct valve resistance based on individual anatomies and different etiologies of hydrocephalus as well as varying levels of activity of the patient. AREAS COVERED This review covers the development of gravitational shunt valves from historical, theoretical and clinical aspects for pediatric and adult etiologies of hydrocephalus. We discuss the role of gravitational shunt valves in preventing over-drainage issues and present the state-of-the-art literature. Furthermore, ongoing prospective trials are presented. EXPERT OPINION Counteracting the hydrostatic force by selecting the correct valve in a VPS system to achieve physiological balance in CSF diversion during vertical and horizontal body changes has become the current standard for hydrocephalus management. Gravitational shunt valves reliably address this need to minimize over-drainage events in the vertical position without affecting the CSF flow in the horizontal position. The results of ongoing prospective studies on the safety and efficacy of adjustable gravitational valves are still pending. Due to the complexity of the CSF flow, lifelong follow-up care for patients with VPS is critical.
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Affiliation(s)
- Paweł Gutowski
- Department of Neurosurgery, Unfallkrankenhaus Berlin , Berlin, Germany.,Department of Neurosurgery, Bródno Mazovia Hospital , Warsaw, Poland
| | - Leonie Gölz
- Institute of Radiology and Neuroradiology, Unfallkrankenhaus , Berlin, Germany
| | - Sergej Rot
- Department of Neurosurgery, Unfallkrankenhaus Berlin , Berlin, Germany
| | - Johannes Lemcke
- Department of Neurosurgery, Unfallkrankenhaus Berlin , Berlin, Germany
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Scholz R, Lemcke J, Meier U, Stengel D. Efficacy and safety of programmable compared with fixed anti-siphon devices for treating idiopathic normal-pressure hydrocephalus (iNPH) in adults - SYGRAVA: study protocol for a randomized trial. Trials 2018; 19:566. [PMID: 30333067 PMCID: PMC6192316 DOI: 10.1186/s13063-018-2951-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 09/28/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Idiopathic normal-pressure hydrocephalus (iNPH) is a distinct form of dementia, characterized by gait ataxia, cognitive impairment and urinary incontinence. In contrast to all other causes of dementia (e.g., Alzheimer-type and others), ventriculoperitoneal (VP) shunt surgery may offer a curative treatment option to patients. While being a rather low-risk type of surgery, it may cause significant over- or underdrainage complications (e.g., headaches, dizziness, vomiting, intracerebral bleeding, etc.) during posture change. Anti-siphon devices (ASDs) are a group of technically different additional valves used in shunt surgery. They are designed to maintain intraventricular pressure within a normal physiological range regardless of patient position. Fixed ASDs proved to substantially lower the rate of overdrainage complications. No significant differences, however, were noted regarding underdrainage complications. Technical successors of fixed ASDs are programmable ASDs. The aim of this study is to evaluate whether programmable ASDs compared to fixed ASDs are able to avoid both over- and underdrainage complications. METHODS/DESIGN In this investigator-initiated, multicenter randomized trial, 306 patients are planned to be recruited. Male and female patients aged ≥18 years with iNPH who are eligible for VP shunt surgery and meet all other entry criteria can participate. Patients will be randomized in a balanced 1: 1 fashion to a VP shunt with a programmable valve either supplemented with a fixed ASD, or a programmable ASD. Patients will be followed-up 3, 6 and, on an optional basis, 12 months after surgery. The primary outcome measure is the cumulative incidence of over- or underdrainage 6 months post surgery, as defined by clinical and imaging parameters. DISCUSSION SYGRAVA is the first randomized trial to determine whether programmable ASDs reduce complications of drainage compared to fixed ASDs in patients with iNPH. The results of this study may contribute to health-technology assessment of different valve systems used for VP-shunt surgery, and determination of the future standard of care. TRIAL REGISTRATION International Standard Randomised Controlled Trial Number: ISRCTN13838310 . Registered on 10 November 2016.
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Affiliation(s)
- Romy Scholz
- Centre for Clinical Research, Unfallkrankenhaus Berlin, Warener Str. 7, 12683, Berlin, Germany
| | - Johannes Lemcke
- Department of Neurosurgery, Unfallkrankenhaus Berlin, Warener Str. 7, 12683, Berlin, Germany.
| | - Ullrich Meier
- Department of Neurosurgery, Unfallkrankenhaus Berlin, Warener Str. 7, 12683, Berlin, Germany
| | - Dirk Stengel
- Centre for Clinical Research, Unfallkrankenhaus Berlin, Warener Str. 7, 12683, Berlin, Germany.,Department of Trauma and Orthopaedic Surgery, Unfallkrankenhaus Berlin, Warener Str. 7, 12683, Berlin, Germany.,Julius Wolff Institute, Charité Medical University Centre, Augustenburger Platz 1, 13353, Berlin, Germany
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Gehlen M, Kurtcuoglu V, Daners MS. Patient Specific Hardware-in-the-Loop Testing of Cerebrospinal Fluid Shunt Systems. IEEE Trans Biomed Eng 2016. [DOI: 10.1109/tbme.2015.2457681] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Mirzayan MJ, Klinge PM, Samii M, Goetz F, Krauss JK. MRI safety of a programmable shunt assistant at 3 and 7 Tesla. Br J Neurosurg 2012; 26:397-400. [DOI: 10.3109/02688697.2011.625060] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Effect of transcranial magnetic stimulation on four types of pressure-programmable valves. Acta Neurochir (Wien) 2010; 152:689-97. [PMID: 19957091 DOI: 10.1007/s00701-009-0564-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Accepted: 11/03/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND Exposure to powerful magnetic fields may alter the settings of programmable ventriculoperitoneal shunt valves or even cause permanent damage to these devices. Transcranial magnetic stimulation (TMS) and magnetic resonance imaging both generate a high-intensity, focal magnetic field. To the best of our knowledge, there is no literature data on the compatibility of TMS with neurosurgical implants. The aim of the present in vitro study was to investigate the effects of TMS on four types of pressure-programmable valves (the Strata 2 from Medtronic, the Polaris from Sophysa, the ProGAV from Miethke, and a cylindrical valve from Codman-Hakim). METHODS We used a Magpro X100 stimulator (Medtronic) for monophasic or biphasic TMS via a circular or a figure-of-eight coil. Each valve setting was tested before and after exposure to TMS. Experiment 1: The effect of the coil-valve distance (10, 5, 2.5, and 1 cm) was assessed. Experiment 2: We mimicked in situ stimulation with a human mannequin by placing the valve in a retroauricular position, the TMS circular coil on the apex, and figure-of-eight coil centered over the primary motor area site. Temperature changes were monitored throughout the experiments. Experience 3: TMS-induced valve movements were assessed by using an in-house accelerometric setup. RESULTS Our results primarily demonstrated that the Strata 2 and Codman-Hakim valves' settings were perturbed by TMS. There was no heating effect for any of the valves. However, TMS induced movements of the Strata 2, Polaris, and ProGAV valves. Experiment 1: The unsetting frequencies observed for the Strata 2 and the Codman-Hakim valve showed an influence of the distance, the coil model, and the magnetic field characteristics, whereas the Polaris and ProGAV's settings remained unchanged. Experiment 2: Unsetting occurred for Strata 2 valve with the circular coil only, whereas the Polaris, ProGAV, and Codman-Hakim valves' settings remained stable. Experiment 3: The Strata 2, Polaris, and ProGAV valves showed high-amplitude oscillations during TMS under all stimulation conditions, whereas the Codman-Hakim valve did not move. CONCLUSIONS Our in vitro experiments showed that TMS can interfere with programmable shunt valves by inducing unsetting or movement. This finding suggests that great care must be taken if applying TMS in hydrocephalic, shunted patients.
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Abstract
OBJECTIVE Hydrocephalus is much more complex than a simple disorder of cerebrospinal fluid (CSF) circulation. Shunting primarily corrects disturbed fluid flow which may have an impact on cerebral blood flow and metabolism. We studied hydrocephalic patients before and after shunting to characterize changes in their CSF compensatory parameters. MATERIAL AND METHODS We selected 25 patients and studied them retrospectively. All patients had ventriculomegaly and clinical symptoms of normal pressure hydrocephalus. After shunting, they were still presenting with some adverse symptoms, mainly headaches, slow improvement or no improvement of ventriculomegaly. Therefore, they underwent further infusion studies to assess shunt function. In all cases, the shunts were confirmed to be draining CSF adequately. Parameters of CSF dynamics: baseline intracranial pressure (ICP), resistance to CSF outflow, cerebrospinal elasticity, content of vasogenic pressure waves (pulse, respiratory and B waves) and compensatory reserve assessed as moving correlation coefficient between mean CSF pressure and pulse amplitude (RAP), were compared before and after shunting. RESULTS Mean ICP and resistance to CSF outflow decreased (P < 0.003) after shunting. All vasogenic pressure waves decreased (P < 0.005). Compensatory reserve (RAP) significantly improved (P < 0.005). CONCLUSION A functioning shunt has an important impact on CSF circulation and pressure-volume compensation. Infusion studies can demonstrate the return of disturbed CSF dynamics to normal values even if clinical or radiological changes are not dramatic.
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Affiliation(s)
- G Petrella
- Academic Neurosurgical Unit, Addenbrookes Hospital, Cambridge, UK
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Lavinio A, Harding S, Van Der Boogaard F, Czosnyka M, Smielewski P, Richards HK, Pickard JD, Czosnyka ZH. Magnetic field interactions in adjustable hydrocephalus shunts. J Neurosurg Pediatr 2008; 2:222-8. [PMID: 18759607 DOI: 10.3171/ped/2008/2/9/222] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Exposing patients with ventricular shunts to magnetic fields and MR imaging procedures poses a significant risk of unintentional changes in shunt settings. Shunt valves can also generate considerable imaging artifacts. The purpose of this study was to determine the magnetic field safety and MR imaging compatibility of 5 adjustable models of hydrocephalus shunts. METHODS The Codman Hakim (regular and with SiphonGuard), Miethke ProGAV, Medtronic Strata, Sophysa Sophy and Polaris programmable valves were tested in a low-intensity magnetic field, and then translational attraction (TA), magnetic torque (MT), and volume of artifacts on T1-weighted spin echo (SE) and gradient echo (GE) pulse sequences in a 3-T MR imaging unit were measured. RESULTS The ProGAV and Polaris valves were immune to unintentional reprogramming by magnetic fields up to 3 T. Other valves randomly changed settings, starting from the intensity of field: Sophy valve 24 mT, Strata valve 30 mT, and both Codman Hakim programmable valves from 42 mT. Shunt performances in the 3-T MR imaging unit are reported in the order of compatibility: 1) Codman Hakim regular, TA = 0.005 N, MT = 0.000 Nm, GE = 30 cm(3), SE = 2 cm(3); 2) Miethke ProGAV, TA = 0.001 N, MT = 1.4 x 10(3) Nm, GE = 231 cm(3), SE = 13 cm(3); 3) Codman Hakim with SiphonGuard, TA = 0.005 N, MT = 2.3 x 10(3) Nm, GE = 233 cm(3), SE = 19 cm(3); 4) Medtronic Strata, TA = 0.27 N, MT = 18.0 x 10(3) Nm, GE = 484 cm(3), SE = 86 cm(3); 5) Sophysa Sophy, TA = 0.82 N, MT = 38.9 x 10(3) Nm, GE = 758 cm(3), SE = 72 cm(3); and 6) Sophysa Polaris, TA = 0.80 N, MT = 39.6 x 10(3) Nm, GE = 954 cm(3), SE = 100 cm(3). CONCLUSIONS All valves, with the exception of the Polaris and ProGAV models, are prone to unintentional reprogramming when exposed to heterogeneous magnetic fields stronger than 40 mT. All tested valves can be considered safe for 3-T MR imaging. All valves generated a distortion of the MR image, especially the GE sequences.
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Affiliation(s)
- Andrea Lavinio
- United Kingdom Shunt Evaluation Laboratory, University of Cambridge, Cambridge, United Kingdom
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Investigation of the hydrodynamic properties of a new MRI-resistant programmable hydrocephalus shunt. Cerebrospinal Fluid Res 2008; 5:8. [PMID: 18426562 PMCID: PMC2365935 DOI: 10.1186/1743-8454-5-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Accepted: 04/21/2008] [Indexed: 12/03/2022] Open
Abstract
Background The Polaris valve is a newly released hydrocephalus shunt that is designed to drain cerebrospinal fluid (CSF) from the brain ventricles or lumbar CSF space. The aim of this study was to bench test the properties of the Polaris shunt, independently of the manufacturer. Methods The Polaris Valve is a ball-on-spring valve, which can be adjusted magnetically in vivo. A special mechanism is incorporated to prevent accidental re-adjustment by an external magnetic field. The performance and hydrodynamic properties of the valve were evaluated in the UK Shunt Evaluation Laboratory, Cambridge, UK. Results The three shunts tested showed good mechanical durability over the 3-month period of testing, and a stable hydrodynamic performance over 45 days. The pressure-flow performance curves, operating, opening and closing pressures were stable. The drainage rate of the shunt increased when a negative outlet pressure (siphoning) was applied. The hydrodynamic parameters fell within the limits specified by the manufacturer and changed according to the five programmed performance levels. Hydrodynamic resistance was dependant on operating pressure, changing from low values of 1.6 mmHg/ml/min at the lowest level to 11.2 mmHg/ml/min at the highest performance level. External programming proved to be easy and reliable. Even very strong magnetic fields (3 Tesla) were not able to change the programming of the valve. However, distortion of magnetic resonance images was present. Conclusion The Polaris Valve is a reliable, adjustable valve. Unlike other adjustable valves (except the Miethke ProGAV valve), the Polaris cannot be accidentally re-adjusted by an external magnetic field.
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