Programmable Shunt Valves Research Articles

Smartphone Magnetometers for Assessing Programmable Shunt Valve Settings: A Proof-of-Concept Study.

Programmable shunt valves (PSVs) used to treat hydrocephalus require specialized valve-specific devices that determine their setting. However, these devices are typically only accessible in major medical centers. This study explores the feasibility of using smartphone magnetometers to assess PSV settings. We investigated 2 PSVs, the Codman Certas Plus and Medtronic Strata II, using 3 different smartphones. Free open-source software was used to measure magnetic flux densities of the shunts, and PSV-specific algorithms were developed to interpret these measurements. All measurements were performed ex vivo. We demonstrated that this method could accurately determine PSV settings with 100% accuracy in ex vivo blinded trials. The technique was effective even with a scalp analog simulating different skin thicknesses. This proof-of-concept study suggests that smartphones can be used for PSV assessment. However, further development and validation are needed to refine this method for clinical use. This technology could enhance PSV management accessibility, allowing for remote or at-home evaluations by trained individuals or caregivers, thus improving patient care in underserved areas.

Optimizing shunt integrity during acute subdural hematoma evacuation.

Even mild head trauma can cause severe intracranial hemorrhage in patients with cerebrospinal fluid (CSF) shunts for hydrocephalus. CSF shunts are considered a risk factor for subdural hematoma (SDH). The management of acute SDH (ASDH) in shunted patients with normal pressure hydrocephalus can be challenging. Addressing the hematoma and the draining function of the shunt is important. To preserve the shunt, we set the shunt valve pressure to the highest and perform hematoma evacuation for ASDH. In this study, we report the surgical cases of ASDH in patients with shunts. Between 2013 and 2019, five patients with ASDH and CSF shunts underwent hematoma evacuation at our hospital. We retrospectively analyzed data regarding their clinical and radiological presentation, hospitalization course, the use of antithrombotic medications, and response to different treatment regimens. The patients presented with scores of 5-14 in the Glasgow coma scale and severe neurological signs, consciousness disturbance, and hemiparesis. Most patients were elderly, taking antithrombotic medications (four of five cases), and had experienced falls (4 of 5 cases). All patients underwent hematoma evacuation following resetting their programmable shunt valves to their maximal pressure setting and shunt preservation. ASDH enlargement was observed in only one patient who underwent burr-hole drainage. Glasgow outcome scale scores at discharge were 1 and 3, respectively. In hematoma evacuation, increasing the valve pressure may reduce the bleeding recurrence. To preserve the shunt, setting the shunt valve pressure to the highest level and performing endoscopic hematoma evacuation with a small craniotomy could be useful.

Programmable Versus Differential Pressure Ventriculoperitoneal Shunts for Pediatric Hydrocephalus: A 20-Year Single-Center Experience From Saudi Arabia.

Background Shunt malfunction is the most common complication after ventriculoperitoneal shunt (VPS) insertion for pediatric hydrocephalus. The incidence of shunt malfunction and the need for VPS revision may be related to the type of valve used in the shunt. Therefore, we aimed to compare the outcome of VPS in the pediatric age group stratified by differential pressure valves (DPV) and programmable shunt valves (PSV). Materials and methods This ethics-approved retrospective study was conducted at a tertiary care hospital in Saudi Arabia. We included 175 children with congenital hydrocephalus who underwent a shunt insertion or revision between 2003 and 2018 and followed them up to December 2022. The VPS complication and revision rates were compared with the patient's demographics and shunt valve types. The Kaplan-Meier method, log-rank test, and univariate and multivariate Cox proportional hazards regression were used to analyze several variables and subsequent shunt revisions. Results Females represented 52% of the study participants, and the mean age of the patients was 21.7 ± 38.4 months. The main indication for VPS was congenital hydrocephalus due to aqueductal stenosis (40%). The differential shunt valve was used in 78.9% and the PSVin 21.1% of the patients. Surgical complications occurred in 33.7% of the patients. Shunt malfunction and infection occurred in 16% and 11.4% of the patients, respectively. The VPS revision rate was significantly lower when PSV was used (odds ratio = 0.39, P < 0.05). Conclusion Overall, one-third of the studied pediatric cohort required shunt revision at some point during the 15-year follow-up. However, children with PSV had fewer revision rate-related complications compared to children with DPV during the first five years of follow-up.

The Effects of Using Hearing Aids and Hearing Assistive Technologies on Programmable Ventriculoperitoneal Shunt.

To investigate interaction between behind-the-ear (BTE) hearing aids, hearing assistive technologies, and programmable shunt valve to understand how use of BTE hearing aids in patients who underwent ventriculoperitoneal shunt (VPS) surgery affects the settings of a programmable shunt valve. In this study, we investigated the magnetic field (MF) generation of 3 BTE hearing aids made by different companies, 1 frequency modulated system using telecoil technology, and 1 wireless microphone technology and their interactions with 2 programmable shunt valves. All measurements were made in a silent booth using 2 different models. The influence of MF strength in the distance modeling was investigated based on the distance from source auditory prostheses. The measurements were recorded using a Gauss meter. In the anatomical modeling, the change in the settings and interaction of the valve in a bust mannequin were investigated. No MF created by BTE hearing aids was detected in the distance modeling. The highest value measured was 32.67 μT (<90 dB noise) when BTE hearing aids and frequency modulated systems were used, and this value decreased as the distance increased. No MF generation was observed at measurements done for distances >10 mm. In the anatomical modeling, the settings of both programmable valves did not change under all acoustic conditions. This is the first study to our knowledge examining the MF created by hearing aids and hearing assistive technologies and its impact on programmable valves and variations in their settings. Our findings showed that it is safe to use BTE hearing aids, frequency modulated systems, and wireless microphone technologies in patients with a programmable VPS.

Cochlear Implants: What the Neurosurgeon Needs to Know.

Patients with cochlear implants (CIs) commonly undergo neurosurgical interventions for concurrent pathologies. The neurosurgeon must be aware of the limitations these devices place on treating these patients and all pertinent interactions CIs have with common neurosurgical instruments and procedures. A literature search was performed utilizing the terms "cochlear implant" and "neurosurgery" or "neurosurgical" and all associated iterations. We reviewed the abstracts of 146 generated reports and eight published papers discussing the interaction and limitations of CI use in different neurosurgical procedures. Five realms were identified in which a CI may potentially interfere with standard neurosurgical care: Magnetic resonance imaging (MRI), radiotherapy, deep brain stimulation (DBS),intraventricular shunt placement, andintraoperative neuromonitoring (IONM). First, MRI use with CIs is limited due to thermal injury risk, imaging disruption, and implant damage. Secondly, high-dose >50 Gysingle-fraction linear accelerator-based radiosurgery has been demonstrated to result in a loss of radio frequency link range in CIs, interfering with their function. Next, during surgery for DBS, the need for MRI and microelectrode recording requires CI magnet removal by neurotology and the surgeon must communicate with a non-hearing patient. Tunneling of shunts must accommodate CI position retroauricularly, if ipsilateral, and programmable valves must be placed >2 cm from the CI to prevent interference. Intraoperative neuromonitoring may produce voltages that interfere with CIs, and while monopolar cautery may pose the same risk, no study has proven this to date. Generally, bipolar cautery is safe and favored >1 cm from CIs. MRI use is limited in CI patients, although MRI-safer devices are in production. DBS electrodes may be successfully placed after CI magnet removal. Programmable shunt valves may be placed >2 cm away from CIs and radiosurgery <50 Gy has not demonstrated harm to these devices. IONM and monopolar cautery have not been demonstrated to directly affect CIs; however, more research is needed.

TU-178. Maladjustment of pressure settings of programmable shunt valves by weak magnetic fields

TU-178. Maladjustment of pressure settings of programmable shunt valves by weak magnetic fields

Maladjustment of pressure settings of a programmable shunt valve by electromagnetic door locks in Forensic Psychiatry – a case report

IntroductionMaladjustments and failures of programmable ventriculo-peritoneal shunts have been reported in patients encountering powerful electromagnetic fields, e. g. MRI.We describe the case of a 53-year old man treated for hydrocephalus with a programmable Codman-Hakim shunt valve. During his hospitalization in Forensic Psychiatry, the patient’s valve pressure setting changed randomly despite frequent reprogramming and surveillance.ObjectivesMaladjustments and failures of programmable ventriculo-peritoneal shunts have been reported in cases in which patients have encountered powerful electromagnetic fields, e.g., MRI. Through a case, this study shows easy maladjustment of a Codman-Hakim programmable valve also by small magnetic fields from everyday life.MethodsA 53-year old man presented with periventricular hydrocephalus due to aqueductal stenosis. The patient was treated with a left ventriculo-peritoneal Codman-Hakim programmable shunt valve. During his hospitalization in Forensic Psychiatry, the patient’s valve pressure setting changed randomly, presumably by walking through electromagnetically controlled doors of a hospital ward. With a test dummy, changes in pressure settings were tracked.ResultsBoth - pressure settings of the patient’s Codman-Hakim programmable valve as well as pressure settings of a new valve - were unwantedly modified simply by walking through standard doors in a hospital ward.ConclusionsThus already weak magnetic fields (&lt; 200 mT) might cause changes in the pressure settings of programmable shunt valves and therefore lead to maladjustment. Patients should be informed and pay attention to using everyday life’s devices, like rod magnets or mobile phones.DisclosureNo significant relationships.

P 68 Unintentional maladjustment of a shunt valve due to electromagnetic door locks – A case report

Normal-pressure hydrocephalus is caused by dilatation of the internal cerebrospinal fluid spaces at normal intracranial pressure. The resulting progressive accumulation of CSF in the brain space can cause permanent damage and, if left untreated, complete loss of brain tissue [2, 4]. The standard treatment for hydrocephalus in children and adults is the implantation of a ventriculo-peritoneal shunt (VP shunt). Most of the currently used shunt systems have a valve to control pressure and drain CSF if necessary [4]. In recent years, malfunction of programmable VP shunts has been reported in patients exposed to strong electromagnetic fields, such as those generated during magnetic resonance imaging (MRI) [1, 3]. However, little is known about the effects of weak magnetic fields on VP shunts. We present the case of a 53 -year-old forensic psychiatric patient in whom the pressure setting of an implanted Codman-Hakim programmable shunt valve changed during passage through various ward doors, leading to the onset of psychiatric symptoms. During the inpatient stay, the valve's pressure setting changed at least six times randomly despite frequent reprogramming and monitoring. References 1 Akbar M, Aschoff A, Georgi JC, Nennig E, Heiland S, Abel R, Stippich C (2010) Adjustable Cerebrospinal Fluid Shunt Valves in 3.0-Tesla MRI: a Phantom Study using Explanted Devices. Rofo 182(7):594-602 2 Kahle KT, Kulkarni AV, Limbrick DD, Warf BC (2016) Hydrocephalus in children. Lancet 387(10020):788–799 3 Mirzayan MJ, Klinge PM, Samii M, Goetz F, Krauss JK (2012) MRI safety of a programmable shunt assistant at 3 and 7 Tesla. Br J Neurosurg 26(3):397-400 4 Portillo Medina SA, Franco JVA, Ciapponi A, Garotte V, Vietto V (2017) Ventriculo-peritoneal shunting devices for hydrocephalus. Cochrane Database Syst Rev. 2017(7): CD012726 Figure 1. Scetch of a Codman-Hakim shunt valve. Figure 2. Image of a Codman-Hakim VP shunt before and after passing a door.

Maladjustment of Pressure Settings of Programmable Shunt Valves by Weak Magnetic Fields – A Case Report

Maladjustment of Pressure Settings of Programmable Shunt Valves by Weak Magnetic Fields – A Case Report

Programmable shunt valve affected by behind-the-ear hearing device: A case report and literature review

Background: It is known that interactions between programmable Ventriculoperitoneal Shunt (VPS) valves and electromagnetic and hearing devices may change the valve settings. We reported a patient using programmable VPS valves and hearing devices and reviewed the literature.&#x0D; Case Description: A 71-year-old man was implanted with a programmable VPS valve with the diagnosis of Normal Pressure Hydrocephalus. A hearing device (behind-the-ear) was proposed because of hearing difficulties, but it was suggested that it be discontinued because it did not help. However, the patient used it twice because of his current dementia, forgetting the doctor’s recommendations. The setting of the valve has changed in these two different times that this behind-the-ear hearing device is used. Long-term follow-ups showed no change in valve settings except those two situations.&#x0D; Conclusion: It is important to note that patients using hearing devices and programmable VPS valves are a unique group of patients. There are not enough studies showing the relationship between the behind-the-ear hearing devices and programmable VPS. It should be kept in mind that hearing devices with magnetic field strength may change the setting of the valves.

Programmable Shunt Valves for Pediatric Hydrocephalus: 22-Year Experience from a Singapore Children's Hospital.

(1) Background: pediatric hydrocephalus is a challenging condition. Programmable shunt valves (PSV) have been increasingly used. This study is undertaken to firstly, to objectively evaluate the efficacy of PSV as a treatment modality for pediatric hydrocephalus; and next, review its associated patient outcomes at our institution. Secondary objectives include the assessment of our indications for PSV, and corroboration of our results with published literature. (2) Methods: this is an ethics-approved, retrospective study. Variables of interest include age, gender, hydrocephalus etiology, shunt failure rates and incidence of adjustments made per PSV. Data including shunt failure, implant survival, and utility comparisons between PSV types are subjected to statistical analyses. (3) Results: in this case, 51 patients with PSV are identified for this study, with 32 index and 19 revision shunts. There are 3 cases of shunt failure (6%). The mean number of adjustments per PSV is 1.82 times and the mean number of adjustments made per PSV is significantly lower for MEDTRONIC™ Strata PSVs compared with others (p = 0.031). Next, PSV patients that are adjusted more frequently include cases of shunt revisions, PSVs inserted due to CSF over-drainage and tumor-related hydrocephalus. (4) Conclusion: we describe our institutional experience of PSV use in pediatric hydrocephalus and its advantages in a subset of patients whose opening pressures are uncertain and evolving.

Magnetic resonance imaging-related programmable ventriculoperitoneal shunt valve setting changes occur often.

Patients with programmable ventriculoperitoneal (VP) shunt valves undergo multiple skull radiographs to evaluate for setting changes resulting from MRI. Our purpose was to determine the rates of inadvertent, MRI-related, programmable VP shunt valve setting changes. In this retrospective cohort with a study period of January 2015-December 2018, we reviewed the pre- and post-MRI skull radiographs of patients with programmable VP shunts and collected the following data: Demographics, commercial type of the valve used, magnetic field strength of the MRI device used, and whether a setting change occurred. We used the chi-square test to identify variables associated with valve setting change. We identified 210 MRI exposure events in 156 patients, and an MRI-related valve setting change rate of 56.7%. The setting change rate was significantly higher with higher magnetic field strength (p = 0.03), and with Medtronic Strata™ valves compared to Codman Hakim™ valves (p < 0.0001). Inadvertent, MRI-related shunt valve setting changes are frequent with valves that lack a locking mechanism. Therefore, we suggest that when feasible, the clinicians could opt to manually reprogram the valves after the MRI to the preferred setting without the need for pre- and post-MRI radiographs. We believe that this protocol modification could help reduce ionizing radiation exposure and cost. Manufacturers may consider incorporating locking mechanisms into the design of such devices in order to reduce the unintended setting change rates.

Maladjustment of pressure settings of a Codman-Hakim programmable shunt valve by electromagnetic door locks – a case report

Maladjustment of pressure settings of a Codman-Hakim programmable shunt valve by electromagnetic door locks – a case report

607 A Close Loop Audit on Proper Documentation of Ventriculo-Peritoneal (VP) Shunt Valve Settings in Operation Note

Abstract Aim Re-audit the practice of proper documentation of shunt type and settings in VP shunt surgery in Queen's Medical Centre, Nottingham for the period of 1st November 2019 – 31st October 2020. It is very important as programmable shunt setting could get changed during MRI, causing shunt failure. Method It was a retrospective collection of data of patients admitted to Queens medical Centre, Nottingham who had undergone VP shunt procedure. Exceptions: 4 files were excluded from study as they did not undergo VP shunt procedure. Results Total number of patients: 98. 4 patients were excluded. Actual sample size 94. Total VP shunt procedure done: 107. In 96 out of 107 procedures the shunt valve type and settings were properly documented. In 11 out of 107 procedures the shunt valve type and settings were not documented. In 33 out of 107 procedures programmable shunt valves were used. All 33 procedures had proper documentations. Previous audit result Duration of data collection: 2 years (from March 2016 to February 2018). Sample size 200. Total VP shunts done 247. Proper documentation of shunt valve type and settings were done in 209 out of 247 procedures. In 38 out of 247 procedures shunt valve type and settings were not documented. In 55 out of 247 procedures programmable shunt valves were used. 3 out of these 55 procedures (programmable shunt valves) lacked proper documentation. Conclusions There is an overall improvement in the practice of documentation of VP shunt valve type and settings in operative notes after implementing the plan of actions decided on first audit.

Evaluation of smartphone-integrated magnetometers in detection of safe electromagnetic devices for use near programmable shunt valves: a proof-of-concept study.

External magnetic forces can have an impact on programmable valve mechanisms and potentially alter the opening pressure. As wearable technology has begun to permeate mainstream living, there is a clear need to provide information regarding safety of these devices for use near a programmable valve (PV). The aim of this study was to evaluate the magnetic fields of reference devices using smartphone-integrated magnetometers and compare the results with published shunt tolerances. Five smartphones from different manufacturers were used to evaluate the magnetic properties of various commonly used (n = 6) and newer-generation (n = 10) devices using measurements generated from the internal smartphone magnetometers. PV tolerance testing using calibrated magnets of varying field strengths was also performed by smartphone magnetometers. All tested smartphone-integrated magnetometers had a factory sensor saturation point at around 5000 µT or 50 Gauss (G). This is well below the threshold at which a magnet can potentially deprogram a shunt, based on manufacturer reports as well as the authors' experimental data with a threshold of more than 300 G. While many of the devices did saturate the smartphone sensors at the source, the magnetic flux density of the objects decreases significantly at 2 inches. The existence of an upper limit on the magnetometers of all the smartphones used, although well below the published deprogramming threshold for modern programmable valves, does not allow us to give precise recommendations on those devices that saturate the sensor. Based on the authors' experimental data using smartphone-integrated magnetometers, they concluded that devices that measure < 40 G can be used safely close to a PV.

Computed tomography based assessment of programmable shunt valve settings

IntroductionProgrammable shunt valve settings can sometimes be difficult to assess using classic read-out tools, warranting a skull X-ray. Research questionCan we use available head computed tomography (CT) scans to determine the valve settings, in order to obviate the need for additional skull X-rays? Material and methodsThe valve setting of two different programmable shunts (Codman Certas Plus® and Sophysa Polaris®) were assessed by two blinded observers in 24 patients using 65 head CT scans (slice thickness ≤2 ​mm). Using multi-planar reconstruction (MPR) tools, images were resliced according to the direction of the valve, allowing a direct readout of the valve settings. We validated our CT based method against 32 available skull X-rays. ResultsFor all CT scans it was possible to assess the valve setting. No interobserver variability was found and there was a 100 ​% concordance between the CT based method and skull X-rays. DiscussionCT based assessment of programmable shunt valve settings is feasible and reliable. It may obviate the need for additional skull x-rays when a head CT scan is available. ConclusionsThis technique can reduce radiation exposure and can be applied to historical CT imaging with unknown valve settings.

Interactions between programmable shunt valves and magnetically controlled growing rods for scoliosis.

Although the advent of magnetic growing rod technology for scoliosis has provided a means to bypass multiple hardware lengthening operations, it is important to be aware that many of these same patients have a codiagnosis of hydrocephalus with magnet-sensitive programmable ventricular shunts. As the magnetic distraction of scoliosis rods has not previously been described to affect the shunt valve setting, the authors conducted an investigation to characterize the interaction between the two devices. In this ex vivo study, the authors carried out 360 encounters between four different shunt valve types at varying distances from the magnetic external remote control (ERC) used to distract the growing rods. Valve settings were examined before and after every interaction with the remote control to determine if there was a change in the setting. The Medtronic Strata and Codman Hakim valves were found to have setting changes at distances of 3 and 6 inches but not at 12 inches. The Aesculap proGAV and Codman Certas valves, typically described as MRI-resistant, did not have any setting changes due to the magnetic ERC regardless of distance. Although it is not necessary to check a shunt valve after every magnetic distraction of scoliosis growing rods, if there is concern that the magnetic ERC may have been within 12 inches (30 cm) of a programmable ventricular shunt valve, the valve should be checked at the bedside with a programmer or with a skull radiograph along with postdistraction scoliosis radiographs.

An Update on Programmable CSF Shunt Valves: Identification, MR Imaging Safety and Potential Pitfalls

Programmable shunt valves are commonly used devices for the treatment of hydrocephalus. Unlike fixed shunt valves, programmable devices allow the operator to alter the amount of CSF drainage without the need for shunt revision or valve replacement. With their increased use, many different programmable shunt valves have been developed by various manufacturers; each programmable shunt valve has a distinct radiographic appearance and CSF drainage setting. Because of potential interactions with MR imaging scanners, which can alter programmable shunt valve function, understanding and accurately reporting these devices is essential.Learning Objectives: Identify commonly used programmable shunt valves and understand their CSF drainage settings to enable the detection of device alterations after MR imaging scanning.

Safety and Efficacy of Syringoperitoneal Shunting with a Programmable Shunt Valve for Syringomyelia Associated with Extensive Spinal Adhesive Arachnoiditis: Technical Note

Although syringomyelia associated with extensive spinal adhesive arachnoiditis (SAA) can be a progressive disease that has potentially devastating clinical consequences, its surgical resolution has remained poorly defined. The aim of the present study was to verify the safety and efficacy of syringoperitoneal shunting for syringomyelia associated with extensive SAA. The present retrospective study included 15 patients who had undergone syringoperitoneal shunting with a programmable shunt valve for the diagnosis of syringomyelia associated with extensive SAA from October 2012 to June 2018. The shunt pressure was appropriately adjusted according to the postoperative sequential clinical condition and change in syringomyelia evaluated using magnetic resonance imaging. The average postoperative follow-up duration was 32.7 months. No surgery-related complications such as shunt dysfunction or infection occurred during the follow-up period, except for 2 patients with minor issues with the shunt tube. The average shunt pressure at the last follow-up examination was 4.5 cm H2O. The findings from the clinical assessment suggested that the average grade on the sensory pain scale was 2.9 before surgery and had improved significantly to 2.5 at the most recent follow-up examination. Radiological analysis suggested that improvement of syringomyelia was noted in 14 of the 15 patients (93.3%), with no cases of radiological aggravation. No recurrence of syringomyelia developed during the follow-up period in the present study. Syringoperitoneal shunting with a programmable shunt valve was safe and effective for clinical control of syringomyelia associated with extensive SAA. Long-term follow-up is mandatory to monitor for shunt dysfunction and mechanical trouble.

Infantile Hydrocephalus: Health-Related Quality of Life Outcome following Ventriculoperitoneal Shunt

Aims: To investigate the impact of Ventriculo-Peritoneal Shunt (VPS) on the Health-Related Quality of Life (HRQOL) of children with the infantile hydrocephalus who underwent their first shunt insertion in the first year of life. To compare the outcome of health domains according to sex, follow-up period, etiology and shunt valve type (fixed versus programmable pressure). Methods: 102 children ≤1 years old at the time of new-onset hydrocephalus and shunt insertion. Age-appropriate PedsQL 4.0 versions were completed by the parents or caregivers with the assistance of single neurosurgery resident. Patients were divided into subgroups according to etiology; neural tube defect associated hydrocephalus (NTD-H), intra-ventricular hemorrhage associated with infantile hydrocephalus (IVH-H) and according to the shunt valve type; fixed versus programmable. Statistical analyses were performed using SPSS, IBM version 20. PedsQL 4.0 was presented using mean and standard deviations. Results: A decreasing social domain score at 1-3 years follow up (n=61) compared to 1 year follow up (n=41) was observed. The two groups did not differ significantly in sex distribution. The mean cognitive score was significantly lower in patients with IVH-H of prematurity compared to NTD-H. Better physical and cognitive domains in programmable shunts were compared to fixed pressure type. Conclusion: IVH-H associated with worse cognitive function possibly due to associated brain damage was reported. With long-term follow-up, social function decline probably due to the patients’ awareness of their disability was observed. Programmable shunt valve is recommended over fixed type due to the improvement in physical and cognitive functions. Sex of the patients did not affect the outcome.