CSF Shunt Research Articles

The CSF lipid profile in patients with probable idiopathic normal pressure hydrocephalus differs from control but does not differ between shunt responders and non-responders.

Idiopathic normal pressure hydrocephalus is a common form of hydrocephalus in the elderly, characterized by enlarged ventricles combined with clinical symptoms presenting as gait impairment, urinary incontinence, and dementia. Idiopathic normal pressure hydrocephalus may be difficult to differentiate clinically from other neurodegenerative disorders, and up to 80% of cases may remain unrecognized and thus untreated. Consequently, there is a pressing demand for biomarkers that can confirm the diagnosis of idiopathic normal pressure hydrocephalus. In this exploratory study, CSF was sampled from the lumbar compartment of 21 control individuals and 19 probable idiopathic normal pressure hydrocephalus patients and analyzed by an untargeted mass spectroscopy-based platform to reveal a complete CSF lipid profile in these samples. Two hundred forty-four lipids from 17 lipid classes were detected in CSF. Various lipid classes, and select individual lipids, were reduced in the CSF obtained from patients with probable idiopathic normal pressure hydrocephalus, whereas a range of lipids belonging to the class of triacylglycerols was elevated. We detected no difference in the CSF lipid profile between probable idiopathic normal pressure hydrocephalus patients with and without clinical improvement following CSF shunting. In conclusion, the lipidomic profile of the CSF in patients with probable idiopathic normal pressure hydrocephalus, therefore, may serve as a sought after biomarker of the pathology, which may be employed to complement the clinical diagnosis.

Pediatric CSF diversion procedures for treatment of hydrocephalus during the COVID-19 pandemic.

Because there is not a link between COVID-19 and pediatric hydrocephalus, the COVID-19 pandemic should not have altered the incidence of pediatric hydrocephalus or the rate of CSF diversion procedures or shunt failure. Therefore, hydrocephalus-related surgical volume should have remained constant. The goal of this study was to evaluate the rates of hydrocephalus surgeries in the COVID-19 era compared with the baseline pre-COVID-19 era. Ten institutions collected information about all hydrocephalus-related surgeries performed between March 2018 and February 2022. The period after March 1, 2020, was considered the COVID-19 era; the period prior to this date was considered the baseline pre-COVID era. Four COVID surge periods were defined using the New York Times COVID-19 database. Total case volumes were compared between the COVID era and baseline, both overall and for each surge period. Sex, race, ethnicity, insurance status, Area Deprivation Index (ADI), and rural-urban commuter area were collected for each surgery. Proportions of patients were then compared overall and for each surge based on these variables. Of 8056 procedures, 54% were in male patients (n = 4375), 65% in White patients (n = 5247), 18% in Hispanic patients (n = 1423), and 54% in patients with public insurance (n = 4371). There was no change in the number of surgeries per site per month in the COVID era compared with baseline (16.7 vs 17.9, p = 0.113). However, there was a significant decrease in the first surge period (April 2020; 11.5 vs 17.7, p = 0.034). Male sex (p < 0.0039) and Black race (p < 0.001) were found to be associated with a significantly higher proportion of hydrocephalus procedures during the COVID-19 era. Some surge periods showed different proportions of privately insured patient and ADI levels. However, these relationships were inconsistent between surges. Overall average monthly case numbers were not significantly different between the pre-COVID and COVID eras. There was a significant decrease in hydrocephalus surgery during the first COVID surge. More hydrocephalus surgeries were performed in children of male sex and Black race proportionally during the COVID period overall, but not during individual surges.

Association between social determinants of health and select neurosurgical procedures in the National Spina Bifida Patient Registry.

Myelomeningocele (MMC) is a lifelong condition requiring complex multidisciplinary management. Using the National Spina Bifida Patient Registry (NSBPR), the authors tested the association between sociodemographic variables and odds of undergoing neurosurgical procedures. The authors extracted sociodemographic, clinical, and neurosurgical procedure data on participants with MMC aged ≥ 1 year who visited an NSBPR clinic between 2009 and 2020. The zip code of the participant's residence at the time of the last spina bifida clinic visit was linked to the Distressed Communities Index (DCI) tier. Multivariate models were built to identify factors associated with undergoing CSF diversion, shunt revision, tethered cord release (TCR), and Chiari decompression. There were 7924 participants with a median visit age of 13 years (IQR 7-20 years); 49.1% were male, 30.2% were non-Hispanic Black or Hispanic, 54.5% had public/supplemental insurance, and 16.9% were from distressed communities. CSF diversion, shunt revision, TCR, and Chiari decompression were performed in 81.8%, 47.7%, 22.9%, and 8.7% of participants, respectively. In multivariate analyses controlling for age, sex, insurance, DCI tier, lesion level, and surgical closure timing, Hispanic individuals were less likely than their non-Hispanic White counterparts to undergo shunt revision (p = 0.013). Non-Hispanic Black and Hispanic individuals were less likely to undergo TCR (p < 0.001 each) or Chiari decompression (p < 0.001 each). Compared with privately insured individuals, publicly insured individuals were more likely to undergo CSF diversion (p = 0.031). Those in distressed communities had increased odds of undergoing CSF diversion (p = 0.004) than those in prosperous communities. Among individuals with MMC participating in the NSBPR, there were differences in receiving neurosurgical procedures by race/ethnicity, insurance type, and DCI tier. Additional prospective studies are necessary to elucidate the reasons for these variations and their impact on long-term outcomes for this patient population in order to created targeted interventions.

Incidence of infection rate for shunt implantation: the zero % rate is always a myth

IntroductionPaediatric CSF shunt infection rate remains a well-known complication that is not only responsible of potentially severe sequels for patients but also for economical expenses. In that study, we questioned if it is possible to attain the zero percent rate of infection that should be the goal of every paediatric neurosurgeon.MethodsWe report our series of patients treated with a CSF device from January the first 2016 to December 31 2018.ResultsIn all 147 patients treated for hydrocephalus, the follow-up was of at least of 2 years from the implantation. Antibiotic-coated tubes were always used with a differential pressure valve system. A total of 172 surgical procedures were performed for 147 patients. In the follow-up time period, 4 patients presented a post-operative infection (2.3%). Two infections appeared early after the surgical procedure one after 24 h and the other after 6 days; the other two infections were diagnosed after 53 days and the other after 66 days. The germs responsible of the infections were a Staphylococcus capitals, an Escherichia coli, a Klebsiella pneumonia, and a Staphylococcus aureus.ConclusionsShunts will always be implanted especially in new-borns and for particular aetiologies of hydrocephalus. To reduce the rate of infection, the best thing to do is to adopt adapted protocols. Our low incidence of infection rate for shunts represent a long history to research preventive factors that helped us to improve our results during the time.

18F-FDG brain PET: a metabolic predictive factor for gait improvement after cerebrospinal fluid shunting in normal pressure hydrocephalus?

The pathophysiology of normal pressure hydrocephalus (NPH) has not been fully elucidated. Treating NPH with cerebrospinal fluid shunts to improve gait disturbances may have some risks and inconsistent benefits. No clear predictive factor has been identified thus far. This preliminary study aimed to evaluate the predictive value of preoperative brain 18F-FDG positron emission tomography (PET) on overall gait response in patients with NPH. Sixteen patients with NPH who underwent 18F-FDG PET before shunt surgery between 2012 and 2022 were included retrospectively and separated into two groups based on their gait response one year after surgery: responders (R) or nonresponders (NR). Brain glucose metabolism was assessed using visual and semiquantitative analyses using SPM8 software (Welcome Department of Cognitive Neurology, University College, London, UK). Five regions of interest were selected: global cortex, cerebellum, thalamus, striatum, and midbrain. Visual interpretation showed more frequent hypometabolism of the striatum, thalamus and global cortex in NR. None of the patients showing hypometabolism of these regions were R. Based on these results, the visual interpretation allowed us to identify 3/8 NR and 8/8 R. Semiquantitative analysis confirmed significantly lower thalamic metabolism in the NR group (P=0.037) and a trend towards lower metabolism of the striatum (P=0.075) with an area under the curve of 0.77 for thalamic metabolism to discriminate between R and NR. This preliminary study using brain 18F-FDG PET suggests that reduced brain metabolism in the thalamus and striatum along with cortical hypometabolism may be associated with poorer gait response to CSF shunting in normal pressure hydrocephalus (NPH). Although these findings suggest that preoperative brain 18F-FDG PET could potentially aid in selecting appropriate candidates for shunt surgery, further research with larger sample sizes is needed to confirm these results.

Shunt, endoscopic, and microsurgical management of trapped temporal horn following resection of lateral ventricle trigonal or peritrigonal tumors: A retrospective multicenter study

ObjectiveTo investigate the surgical management and outcomes of trapped temporal horn (TTH) following resection of lateral ventricle trigonal or peritrigonal tumors. MethodsPatients who underwent surgical treatment for TTH in three different tertiary centers between 2012 and 2022 were retrospectively studied. The primary outcome was reoperation rate. ResultsThirty-one patients were included for analysis. The underlying pathology was meningioma in 17 patients, central neurocytoma in 7, glioma in 4, ependymoma in 2, and cavernous malformation in 1. The median KPS score was 50 (range 10–90) and the mean volume of TTH was 53.1 ± 29.9 cm³ (range 14.8–118.6). Six patients (19.3 %) required multiple operations. A total of 39 procedures were performed, including 28 CSF shunting, 2 endoscopic septostomy, 3 microsurgical fenestration or temporal tip lobectomy via craniotomy, 2 decompressive craniectomy (DC), and 4 shunt revisions. Reoperation rates according to procedure were as follows: 10.7 % (3/28) for CSF shunting, 50 % (1/2) for endoscopic septostomy, 100 % (2/2) for DC, and 0 (0/3) for microsurgical fenestration or temporal tip lobectomy. CSF shunting tended to have a lower reoperation rate compared to other surgical approaches (p = 0.079). The reoperation rate was significantly higher for DC than for other surgical techniques (p = 0.025). ConclusionCSF shunting was the most frequently used technique with a relatively low revision rate. Long-term patency can be achieved through endoscopic septostomy in selected patients. Microsurgical fenestration or temporal tip lobectomy should be reserved for refractory cases. DC has limited effectiveness and should not be recommended.

Widespread haemorrhages in infants post-shunting (WHIPS): clinical features, risk factors and neuroimaging characteristics of a rare and under-recognised phenomenon

PurposeInfants undergoing CSF shunting procedures face a rare complication which we propose to rename “Widespread Haemorrhages in Infants Post-Shunting” (WHIPS) to better capture this unique phenomenon specific to infants undergoing CSF diversion. Our objective is to analyse the risk factors for WHIPS development and provide a detailed neuroradiological description of these haemorrhages.Materials and methodsA radiology information system (RIS) was searched using the search terms “shunt” and/or “catheter” and/or “drain” and/or “ventriculoperitoneal” and/or “VP” between September 2008 to January 2021 for patients < 12 months of age. Clinical data was compiled for each patient meeting the inclusion criteria. Included cases were reviewed by three radiologists for the presence of WHIPS with calculation of the bifrontal ratio and documenting haemorrhage number, morphology, location and lobar distribution.Results51 patients met inclusion criteria, 8 WHIPS patients and 43 controls. There was a statistically significant correlation between a larger post-op head circumference and WHIPS (p = 0.04). WHIPS was associated with post-haemorrhagic hydrocephalus and post-infectious hydrocephalus (p = 0.009). WHIPS were identified in the cortico-subcortical regions, periventricular white matter, and deep white matter. Haemorrhages were either punctate, ovoid or confluent. Haemorrhages ranged from single to innumerable.ConclusionsWHIPS represent a rare and under-recognised complication of CSF shunting unique to the infantile population. We postulate deep and superficial medullary venous haemorrhage as an underlying mechanism related to disordered intracranial hydrodynamics which are exacerbated in the infantile population due to underdeveloped arachnoid granulations and a compliant skull.

Regional variations in morbidity and mortality among neonates with intraventricular hemorrhage: a national database analysis.

Intraventricular hemorrhage (IVH) often affects newborns of low gestational age and low birth weight, requires critical care for neonates, and is linked to long-term neurodevelopmental outcomes. Assessing regional differences in the U.S. in care for neonatal IVH and subsequent outcomes can shed light on ways to mitigate socioeconomic disparities. Using the 2016-2019 National Inpatient Sample (NIS), patients with a primary diagnosis of IVH were identified using ICD-10-CM codes. A retrospective cohort study was conducted with patients stratified by hospital region. Demographics, comorbidities, presentation, intraoperative variables, and inpatient outcomes were assessed. Multivariate logistic regression analyses were used to identify the impact of insurance status on extended LOS (defined as > 75th percentile of LOS), exorbitant cost (defined as > 75th percentile of cost), and mortality. Included in this study were 1630 newborns with IVH. A larger portion of patients in the South and Midwest were Black, compared to the Northeast and West (Northeast: 12.2% vs Midwest: 30.2% vs South: 22.8% vs West: 5.8%, p < 0.001), while a greater percentage of patients in the West and South were Hispanic (Northeast: 7.3% vs Midwest: 9.5% vs South: 22.8% vs West: 36.2%, p < 0.001). LOS was similar among all regions. Factors associated with prolonged LOS included hydrocephalus and CSF diversions. Median total cost of admission was highest in the West, while the South was associated with decreased odds of exorbitant cost. LOS was associated with exorbitant cost, and large bed-volume hospital, VLBW, and permanent CSF shunt were associated with mortality. Demographic variables, but not presenting or intraoperative variables, differed among regions, pointing to possible geographic health disparities. The West had the highest total cost of admission, while the South was associated with reduced odds of exorbitant admission costs.

Infection rates during eras of intrathecal antibiotic use followed by antibiotic-impregnated catheter use in prevention of cerebrospinal fluid shunt infection.

The Hydrocephalus Clinical Research Network (HCRN) implemented a perioperative infection prevention bundle for all CSF shunt surgeries in 2007 that included the relatively unproven technique of intrathecal instillation of the broad-spectrum antibiotics vancomycin and gentamicin into the shunt. In the meantime, the field debated the use of antibiotic-impregnated catheter (AIC) shunt tubing using clindamycin and rifampin, an increasingly widespread, but expensive and controversial, technique. It is unknown whether there were changes in infecting organisms associated with the use of these techniques during CSF shunt surgery at the hospital level. Key comparison periods include during the use of intrathecal antibiotics (period 1 from June 1, 2007, to December 31, 2011, at HCRN hospitals) and AIC (period 2 from January 1, 2012, to December 31, 2015, at HCRN as well as increasing over time at non-HCRN hospitals) and only standard use of routine prophylactic antibiotics (period 1 at non-HCRN hospitals). The aim of this study was to examine rates of CSF shunt surgery-related infections from 2007 to 2012 at the hospital level, including HCRN and non-HCRN hospitals, with a focus on infections with gram-negative organisms. The authors conducted a retrospective observational cohort study at 6 children's hospitals with enrollment from 2007 to 2012 and surveillance through 2015. Bimonthly rates of shunt surgery-related infections were summarized to produce an overall hospital-specific time series, as well as by HCRN/non-HCRN status. An interrupted time series analysis was performed to assess the impact of change in HCRN perioperative infection prevention bundle on overall bimonthly infection rates. Quarterly rates of gram-negative shunt surgery-related infections were summarized to produce an overall hospital-specific time series. The overall bimonthly CSF shunt infection rate over time did not change significantly from 2007 to 2012. There was no difference in the trajectory of infection rates between HCRN and non-HCRN hospitals during the entire study period. No change in distributions of gram-negative organism infections was observed in hospitals from 2007 to 2015. There were no differences observed in hospital-level infection rates for low-risk patients undergoing CSF shunt surgery. This included analyses based on participation in the HCRN network, given their regular use of intrathecal antibiotics in period 1 and a focus on gram-negative infections with increasing adoption of AICs in period 2.

1224 Signs &amp; Symptoms Predictive of CSF Shunt Dysfunction in Children &amp; Young People Presenting to ED

1224 Signs &amp; Symptoms Predictive of CSF Shunt Dysfunction in Children &amp; Young People Presenting to ED

Device and surgical procedure-related infections in Canadian acute care hospitals, 2018-2022.

Healthcare-associated infections (HAIs) are a significant healthcare burden in Canada. National surveillance of HAIs at sentinel acute care hospitals is conducted by the Canadian Nosocomial Infection Surveillance Program. This article describes device and surgical procedure-related HAI epidemiology in Canada from 2018 to 2022. Data were collected from over 60 Canadian sentinel acute care hospitals between January 1, 2018, and December 31, 2022, for central line-associated bloodstream infections (CLABSIs), hip and knee surgical site infections (SSIs), cerebrospinal fluid shunt (CSF) SSIs and paediatric cardiac SSIs. Case counts, rates, patient and hospital characteristics, pathogen distributions and antimicrobial resistance data are presented. Between 2018 and 2022, 2,258 device-related infections and 987 surgical procedure-related infections were reported. A significant rate increase was observed in adult mixed intensive care unit CLABSIs (1.07-1.93 infections per 1,000 line days, p=0.05) and a non-significant rate increase was observed in SSIs following knee arthroplasty (0.31-0.42 infections per 100 surgeries, p=0.45). A fluctuating rate trend was observed in CSF shunt SSIs over the time period and a significant rate decrease in paediatric cardiac SSIs was observed (68%, from 7.5-2.4 infections per 100 surgeries, p=0.01). The most commonly identified pathogens were coagulase-negative staphylococci (22.8%) among CLABSIs and Staphylococcus aureus (42%) among SSIs. Epidemiological and microbiological trends among selected device and surgical procedure-related HAIs are essential for benchmarking infection rates nationally and internationally, identifying any changes in infection rates or antimicrobial resistance patterns and helping inform hospital infection prevention and control and antimicrobial stewardship policies and programs.

Rare Complications of CSF Diversion: Paradoxical Neuroimaging Findings in a Double, Chiasmic Case Report.

Two patients with CSF shunting systems exhibited symptoms of altered intracranial pressure. Initial neuroimaging led to misinterpretation, but integrating clinical history and follow-up imaging revealed the true diagnosis. In the first case, reduced ventricular size was mistaken for CSF overdrainage, while the actual problem was increased intracranial pressure, as seen in slit ventricle syndrome. In the second case, symptoms attributed to intracranial hypertension were due to CSF overdrainage causing tonsillar displacement and hydrocephalus. Adjusting the spinoperitoneal shunt pressure resolved symptoms and imaging abnormalities. These cases highlight the necessity of correlating clinical presentation with a deep understanding of CSF dynamics in shunt assessments.

Antibiotic impregnated catheters and intrathecal antibiotics for CSF shunt infection prevention in children undergoing low-risk CSF shunt surgery

BackgroundCerebrospinal fluid (CSF) shunts allow children with hydrocephalus to survive and avoid brain injury (J Neurosurg 107:345-57, 2007; Childs Nerv Syst 12:192-9, 1996). The Hydrocephalus Clinical Research Network implemented non-randomized quality improvement protocols that were shown to decrease infection rates compared to pre-operative prophylactic intravenous antibiotics alone (standard care): initially with intrathecal (IT) antibiotics between 2007–2009 (J Neurosurg Pediatr 8:22-9, 2011), followed by antibiotic impregnated catheters (AIC) in 2012–2013 (J Neurosurg Pediatr 17:391-6, 2016). No large scale studies have compared infection prevention between the techniques in children. Our objectives were to compare the risk of infection following the use of IT antibiotics, AIC, and standard care during low-risk CSF shunt surgery (i.e., initial CSF shunt placement and revisions) in children.MethodsA retrospective observational cohort study at 6 tertiary care children’s hospitals was conducted using Pediatric Health Information System + (PHIS +) data augmented with manual chart review. The study population included children ≤ 18 years who underwent initial shunt placement between 01/2007 and 12/2012. Infection and subsequent CSF shunt surgery data were collected through 12/2015. Propensity score adjustment for regression analysis was developed based on site, procedure type, and year; surgeon was treated as a random effect.ResultsA total of 1723 children underwent initial shunt placement between 2007–2012, with 1371 subsequent shunt revisions and 138 shunt infections. Propensity adjusted regression demonstrated no statistically significant difference in odds of shunt infection between IT antibiotics (OR 1.22, 95% CI 0.82–1.81, p = 0.3) and AICs (OR 0.91, 95% CI 0.56–1.49, p = 0.7) compared to standard care.ConclusionIn a large, observational multicenter cohort, IT antibiotics and AICs do not confer a statistically significant risk reduction compared to standard care for pediatric patients undergoing low-risk (i.e., initial or revision) shunt surgeries.

Prospects of CSF shunt independence among chronically shunted patients.

CSF shunt placement for hydrocephalus and other etiologies has arguably been the most life-saving intervention in pediatric neurosurgery in the past 6 decades. Yet, chronic shunting remains a source of morbidity for patients of all ages. Neuroendoscopic surgery has made shunt independence possible for newly diagnosed hydrocephalic patients. In this study, we examine the prospects of shunt independence with or without endoscopic third ventriculostomy (ETV) in chronically shunted patients. After IRB approval, a retrospective analysis was completed on patients whose shunt was ligated or removed to achieve shunt independence, with or without ETV. Clinical and imaging data were collected. Eighty-eight patients with CSF shunts had their shunt either ligated or removed, 57 of whom had a concomitant ETV. Original reasons for shunting included: congenital hydrocephalus 20 (23%), post-hemorrhagic hydrocephalus (PHH) of prematurity 14 (16%), aqueductal stenosis 10 (11%), intracranial cyst 8 (9%), tumor 8 (9%), infantile subdural hematomas 8 (9%), myelomeningocele 7 (8%), post-traumatic hydrocephalus 7 (8%) and post-infectious hydrocephalus 6 (7%). The decision to perform a simultaneous ETV was made based on etiology. Forty-nine (56%) patients became shunt independent. The success rate was 46% in the ETV group and 73% in the no ETV group. Using multivariate analysis and Cox Proportional Hazards models, age > 4 months at shunt placement (p = 0.032), no shunt revisions (p = 0.01), select etiologies (p = 0.043), and ETVSS > 70 (in the ETV group) (p = 0.017), were protective factors for shunt independence. Considering the long-term complications of shunting, achieving shunt independence may provide hope for improved quality of life. While this study is underpowered, it provides pilot data identifying factors that predict shunt independence in chronically shunted patients, namely age, absence of prior shunt revision, etiology, and in the ETV group, the ETVSS.

Predictors of Satisfactory Surgical Outcome in Idiopathic Normal Pressure Hydrocephalus (Review).

Idiopathic normal pressure hydrocephalus is a widespread neurodegenerative disease of the elderly. If not treated surgically early, it results in a severe decrease in quality of life and disability. According to current clinical Russian and foreign guidelines the candidates for CSF shunting procedures are selected based on the results of invasive tests, though treatment outcomes are not always optimal. At the same time, in the last decade there have been published a number of studies on promising noninvasive diagnosis and prognosis of the surgical treatment of idiopathic normal pressure hydrocephalus based on neuroimaging findings. The aim of the present systematic review is to demonstrate the most promising imaging predictors of satisfactory outcomes of CSF shunting procedures in patients with idiopathic normal pressure hydrocephalus based on published literature data.

Assessment and analysis of motor dysfunction in idiopathic normal pressure hydrocephalus using computer-assisted stabilometry

The article presents the results of a study of the assessment and analysis of motor dysfunction in idiopathic normal pressure hydrocephalus using computer-assisted stabilometry. The purpose of this publication is to present the first experience of using computer stabilography in assessing motor function over time in the treatment of patients with idiopathic normal pressure hydrocephalus (iNPH). A non-randomized prospective observational study of the state of balance and gait in patients with iNPH is being conducted on the basis of the Department and Clinic of Neurosurgery of the Pavlov First St. Petersburg State Medical University and the Hospital for War Veterans using the ST-150 computer stabilography system. To date, the study has included 9 patients with a confirmed diagnosis of iNPH who underwent CS at the stages before / after the tap test and after CSF shunt surgery. In all 9 cases, we received a positive result from the operation in the form of improved locomotor function. Computer-assisted stabilometry makes it possible to objectively assess motor function disorders in patients with idiopathic normal pressure hydrocephalus in the preoperative period, optimize diagnostics when selecting patients for surgery and conducting invasive research methods, as well as significantly improve the assessment of the effectiveness of surgical treatment after surgery due to objective quantitative assessment of motor disorders over time.

Development of an in vitro ventricular shunt material testing model and utility of PEG as antifouling coating.

CSF shunts, most commonly the ventriculoperitoneal shunt, remain a first and last line of management for children and adults with hydrocephalus. However, the failure rates of these shunts are extremely high, leaving many patients with the need for revision surgical procedures. The objective of this study was to develop a model to assess the efficacy of a nonfouling ventricular catheter. A second objective was to test polyethylene glycol (PEG) as an antifouling coating. Microglial cells were grown on medical-grade catheter silicone with biofouling simulated by collagen incubation over a range of concentrations from 31 to 103 µg/ml and durations from 2 to 18 hours. After ideal fouling conditions were identified, catheter silicone was then coated with PEG as an antifouling surface, and cell growth on this surface was compared to that on uncoated standard catheter silicone. Collagen biofouling increased cell growth on silicone surfaces with an ideal concentration of 69 µg/ml and incubation of 6 hours. PEG coating of silicone catheter material yielded 70-fold lower cell growth (p < 0.0001), whereas collagen-fouled PEG-coated silicone yielded 157-fold lower cell growth (p < 0.0001). Catheter coating significantly reduced cell growth, particularly in the setting of biofouling. The application of antifouling surfaces to ventricular shunts shows considerable promise for improving efficacy.

Quantitative noninvasive measurement of cerebrospinal fluid flow in shunted hydrocephalus.

Standard MRI protocols lack a quantitative sequence that can be used to evaluate shunt-treated patients with a history of hydrocephalus. The objective of this study was to investigate the use of phase-contrast MRI (PC-MRI), a quantitative MR sequence, to measure CSF flow through the shunt and demonstrate PC-MRI as a useful adjunct in the clinical monitoring of shunt-treated patients. The rapid (96 seconds) PC-MRI sequence was calibrated using a flow phantom with known flow rates ranging from 0 to 24 mL/hr. Following phantom calibration, 21 patients were scanned with the PC-MRI sequence. Multiple, successive proximal and distal measurements were gathered in 5 patients to test for measurement error in different portions of the shunt system and to determine intrapatient CSF flow variability. The study also includes the first in vivo validations of PC-MRI for CSF shunt flow by comparing phase-contrast-measured flow rate with CSF accumulation in a collection burette obtained in patients with externalized distal shunts. The PC-MRI sequence successfully measured CSF flow rates ranging from 6 to 54 mL/hr in 21 consecutive pediatric patients. Comparison of PC-MRI flow measurement and CSF volume collected in a bedside burette showed good agreement in a patient with an externalized distal shunt. Notably, the distal portion of the shunt demonstrated lower measurement error when compared with PC-MRI measurements acquired in the proximal catheter. The PC-MRI sequence provided accurate and reliable clinical measurements of CSF flow in shunt-treated patients. This work provides the necessary framework to include PC-MRI as an immediate addition to the clinical setting in the noninvasive evaluation of shunt function and in future clinical investigations of CSF physiology.

157 Minimally Invasive Treatment of Idiopathic Normal Pressure Hydrocephalus Using the Endovascular eShunt Implant

INTRODUCTION: Idiopathic Normal Pressure Hydrocephalus (NPH) is a reversible form of dementia typically treated with ventriculo-peritoneal shunt surgery. Recently we have described the first percutaneous transfemoral transvenous deployment of an endovascular CSF shunt (eShunt® System; CereVasc, Inc., Auburndale, MA, USA) to treat communicating hydrocephalus. METHODS: Patients were included after demonstrating &gt;20% gait improvement in lumbar drainage trial. Gait was assessed using Timed Up &amp; Go (TUG) test, cognition using Montreal cognitive assessment (MoCA), and urinary incontinence using Neurogenic Bladder Symptom Score (NBSS). Results were normalized per-patient to pre-treatment scores. A composite outcome score (COS) incorporating TUG/MOCA/NBSS was computed. RESULTS: Eleven patients (4 female; mean age 74.8 ± 4.2 years) underwent successful eShunt placement. Follow-up data showed significant improvement in gait by 35.4% at 30-days (n = 6, P &lt; 0.003), 24.8% at 90-days (n = 6, p &lt; 0.03) and by 32.8% at 180-days (n = 4, p &lt; 0.01) compared to baseline. MOCA and NBSS showed significant improvements at 30-days and the COS was significantly improved at all time points (p &lt; 0.005 at 30-, 90- and 180-days). No procedural/delayed hemorrhage or unexpected readmissions were encountered during this early follow-up phase. CONCLUSIONS: In elderly patients affected by NPH and its insidious effect on mobility, cognition and urinary continence, these results show that the endovascular eShunt implant can be safely deployed with a favorable risk profile and with rapid and sustained improvements in functional outcome scores.

Measuring CSF shunt flow with MRI using flow enhancement of signal intensity (FENSI).

To develop and validate a noninvasive imaging technique for accurately assessing very slow CSF flow within shunt tubes in pediatric patients with hydrocephalus, aiming to identify obstructions that might impede CSF drainage. A simulation of shunt flow enhancement of signal intensity (shunt-FENSI) signal is used to establish the relationship between signal change and flow rate. The quantification of flow enhancement of signal intensity data involves normalization, curve fitting, and calibration to match simulated data. Additionally, a phase sweep method is introduced to accommodate the impact of magnetic field inhomogeneity on the flow measurement. The method is tested in flow phantoms, healthy adults, intensive care unit patients with external ventricular drains (EVD), and shunt patients. EVDs enable shunt-flow measurements to be acquired with a ground truth measure of CSF drainage. The flow-rate-to-signal simulation establishes signal-flow relationships and takes into account the T1 of draining fluid. The phase sweep method accurately accounts for phase accumulation due to frequency offsets at the shunt. Results in phantom and healthy human participants reveal reliable quantification of flow rates using controlled flows and agreement with the flow simulation. EVD patients display reliable measures of flow rates. Shunt patient results demonstrate feasibility of the method and consistent flow rates for functional shunts. The results demonstrate the technique's applicability, accuracy, and potential for diagnosing and noninvasively monitoring hydrocephalus. Limitations of the current approach include a high sensitivity to motion and strict requirement of imaging slice prescription.