Predicting shunt failure on the basis of clinical symptoms and signs in children

Optimizing Advanced Imaging of the Pediatric Patient in the Emergency Department: Technical Report

Advanced diagnostic imaging modalities, including ultrasonography, computed tomography, and magnetic resonance imaging, are key components in the evaluation and management of pediatric patients presenting to the emergency department. Advances in imaging technology have led to the availability of faster and more accurate tools to improve patient care. Notwithstanding these advances, it is important for physicians, physician assistants, and nurse practitioners to understand the risks and limitations associated with advanced imaging in children and to limit imaging studies that are considered low value, when possible. This technical report provides a summary of imaging strategies for specific conditions where advanced imaging is commonly considered in the emergency department. As an accompaniment to the policy statement, this document provides resources and strategies to optimize advanced imaging, including clinical decision support mechanisms, teleradiology, shared decision-making, and rationale for deferred imaging for patients who will be transferred for definitive care.

Odd presentation of shunt malfunction: a case series and review of literature

OBJECTIVE

Children with previous ventriculoperitoneal shunt (VPS) insertion due to hydrocephalus may refer to the hospital with various clinical complaints. Shunt malfunction is frequently diagnosed in these children necessitating shunt revision. Although increased head circumference, setting sun eye in younger children, and headache, nausea/vomiting, loss of consciousness, visual disturbance, and other signs of intracranial hypertension are common clinical manifestations of shunt malfunction, some patients may present with odd or unusual symptoms. Here, we present a series of patients with shunted hydrocephalus who presented with odd and unexpected clinical manifestations of shunt malfunction.

METHODS

Eight children with shunt malfunction were enrolled in this series. The age, sex, age of shunting, etiology of hydrocephalus and management, post-shunt insertion symptoms/sign, revision surgery, outcome, and follow-up were evaluated.

RESULTS

Patients were aged from 1 to 13 years (mean, 6.38 years). There were 5 males and 3 females. The odd presentation associated with shunt malfunction included facial palsy in three children, ptosis in 3 children, and torticollis and dystonia each in one child. All patients underwent shunt revision except for one patient in whom a new shunt was inserted. Follow-up showed improvement of the symptoms in all patients.

CONCLUSION

In this series, we reported eight patients with unusual signs and symptoms following shunt malfunction that were successfully diagnosed and managed.

Use of a Prophylactic Retrograde-Flushing Device in High-Risk Pediatric Patients with Ventriculoperitoneal Shunts: A Technical Note

INTRODUCTION

Ventriculoperitoneal shunt (VPS) malfunction rates are as high as 40% in the first year with posthemorrhagic hydrocephalus (PHH) patients having the highest proximal occlusion risk. Debris, protein, and cellular ingrowth most commonly obstruct the proximal ventricular catheter and/or valve. Historically, no preventative methods have demonstrated efficacy. We present a technical note and case series describing the use of a retrograde proximal flushing device and prophylactic flushing protocol to maintain ventricular catheter patency and reduce proximal shunt occlusions.

METHODS

We present our 2.8-4-year follow-up data on the first 9 pediatric cases of ReFlow (Anuncia Inc, Scottsdale, AZ) device implantation combined with routine prophylactic flushing. Rationale for device implantation, patient selection, surgical procedure details, postoperative follow-up, and prophylactic flushing protocol are discussed as well as pre- and postimplantation ventricular catheter obstruction rates. We include a technical note on the device setup and prophylactic flushing protocol.

RESULTS

Patient average age was 5.6 years and all patients had PHH. Minimal follow-up was 2.8 years (range 2.8-4 years). Prophylactic flushing was initiated between 2 and 14 days after ReFlow implantation and has continued as of the last follow-up. In 7 patients, ReFlow implantation occurred during the revision of an existing shunt and in two, implantation was coincident with initial VPS placement. In the 2 years preceding ReFlow and prophylactic flushing, 14 proximal shunt failures occurred in the 7 patients with existing VPS. This was reduced to only one proximal shunt failure in all 9 patients during the full follow-up period after ReFlow and prophylactic flushing.

CONCLUSION

Pediatric VPS placement carries high rates of proximal catheter occlusion, often leading to emergency surgery, morbidity, or even death. The ReFlow device along with routine prophylactic flushing may reduce proximal obstruction and need for revision surgery. Higher patient numbers and longer follow-up periods are necessary to further elucidate the safety and effect of such a device on longer term shunt failures and revision surgery.

Symptoms of Cerebrospinal Shunt Malfunction in Young Children: A National Caregiver Survey

Objective: This study aimed to describe shunt malfunction symptoms in children ≤5 years old. Results: In a national survey of 228 caregivers, vomiting (23.1%), irritability (20.8%), and sleepiness (17.2%) were the most frequent symptoms of malfunction. These symptoms also occurred in over 1/3 of "false alarms" experienced by 75% of respondents. Compared with malfunctions, irritability (OR = 1.39, 95% CI [1.05, 1.85], p = 0.022) and fever (OR = 2.22, 95% CI [1.44, 3.44], p < 0.001) were more likely false alarms. Caregivers counseled about "most" symptoms were more confident detecting malfunctions than those informed of "some" (p = 0.036). The majority of caregivers (85%) first contacted a neurosurgeon with concerns about malfunction, followed by neurologists (22%) and family/friends (19%). Most (85%) struggled to differentiate malfunction from regular development. Conclusions: Vomiting, irritability, and sleepiness were the most common symptoms of shunt malfunction and false alarms for children ≤5 years. Most caregivers reported challenges differentiating malfunctions from their child's development.

Prediction of shunt failure facilitated by rapid and accurate volumetric analysis: a single institution's preliminary experience

BACKGROUND

Shunt malfunction is a common complication and often presents with hydrocephalus. While the diagnosis is often supported by radiographic studies, subtle changes in CSF volume may not be detectable on routine evaluation. The purpose of this study was to develop a novel automated volumetric software for evaluation of shunt failure in pediatric patients, especially in patients who may not manifest a significant change in their ventricular size.

METHODS

A single-institution retrospective review of shunted patients was conducted. Ventricular volume measurements were performed using manual and automated methods by three independent analysts. Manual measurements were produced using OsiriX software, whereas automated measurements were produced using the proprietary software. A p value < 0.05 was considered statistically significant.

RESULTS

Twenty-two patients met the inclusion criteria (13 males, 9 females). Mean age of the cohort was 4.9 years (range 0.1-18 years). Average measured CSF volume was similar between the manual and automated methods (169.8 mL vs 172.5 mL, p = 0.56). However, the average time to generate results was significantly shorter with the automated algorithm compared to the manual method (2244 s vs 38.3 s, p < 0.01). In 3/5 symptomatic patients whose neuroimaging was interpreted as stable, the novel algorithm detected the otherwise radiographically undetectable CSF volume changes.

CONCLUSION

The automated software accurately measures the ventricular volumes in pediatric patients with hydrocephalus. The application of this technology is valuable in patients who present clinically without obvious radiographic changes. Future studies with larger cohorts are needed to validate our preliminary findings and further assess the utility of this technology.

Preoperative risk and postoperative outcome from subdural fluid collections in African infants with postinfectious hydrocephalus

OBJECTIVE

This study investigated the incidence of postoperative subdural collections in a cohort of African infants with postinfectious hydrocephalus. The authors sought to identify preoperative factors associated with increased risk of development of subdural collections and to characterize associations between subdural collections and postoperative outcomes.

METHODS

The study was a post hoc analysis of a randomized controlled trial at a single center in Mbale, Uganda, involving infants (age < 180 days) with postinfectious hydrocephalus randomized to receive either an endoscopic third ventriculostomy plus choroid plexus cauterization or a ventriculoperitoneal shunt. Patients underwent assessment with the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III; sometimes referred to as BSID-III) and CT scans preoperatively and then at 6, 12, and 24 months postoperatively. Volumes of brain, CSF, and subdural fluid were calculated, and z-scores from the median were determined from normative curves for CSF accumulation and brain growth. Linear and logistic regression models were used to characterize the association between preoperative CSF volume and the postoperative presence and size of subdural collection 6 and 12 months after surgery. Linear regression and smoothing spline ANOVA were used to describe the relationship between subdural fluid volume and cognitive scores. Causal mediation analysis distinguished between the direct and indirect effects of the presence of a subdural collection on cognitive scores.

RESULTS

Subdural collections were more common in shunt-treated patients and those with larger preoperative CSF volumes. Subdural fluid volumes were linearly related to preoperative CSF volumes. In terms of outcomes, the Bayley-III cognitive score was linearly related to subdural fluid volume. The distribution of cognitive scores was significantly different for patients with and those without subdural collections from 11 to 24 months of age. The presence of a subdural collection was associated with lower cognitive scores and smaller brain volume 12 months after surgery. Causal mediation analysis demonstrated evidence supporting both a direct (76%) and indirect (24%) effect (through brain volume) of subdural collections on cognitive scores.

CONCLUSIONS

Larger preoperative CSF volume and shunt surgery were found to be risk factors for postoperative subdural collection. The size and presence of a subdural collection were negatively associated with cognitive outcomes and brain volume 12 months after surgery. These results have suggested that preoperative CSF volumes could be used for risk stratification for treatment decision-making and that future clinical trials of alternative shunt technologies to reduce overdrainage should be considered.

Bradycardia Without Hypertension: Is It a Common Clinical Presentation of Ventriculoperitoneal Shunt Malfunction in Pediatric Patients?

BACKGROUND

Mechanical shunting of cerebrospinal fluid is an effective treatment for hydrocephalus. Some studies suggest that bradycardia without hypertension may also be observed in ventriculoperitoneal (VP) shunt malfunction; however, in our experience, this is not a common presenting sign.

OBJECTIVE

The aim of this study was to evaluate whether bradycardia without hypertension was a common sign in patients presenting to the pediatric emergency department (ED) with a VP shunt malfunction.

METHODS

A retrospective observational study, from May 2006 to April 2015, which included a random sample of children admitted to the ED with clinical features suggestive of possible VP shunt malfunction. Control patients were defined as those who arrived at our ED with suspected VP shunt malfunction that was later ruled out on further workup.

RESULTS

A total of 65 patients were included in this study. A significantly greater number of patients with a confirmed shunt pathology presented with vomiting (P = 0.01) and lethargy/apathy (P = 0.01). In the control group, a significantly greater number of patients presented with fever (P = 0.004) and seizures (P = 0.02). The number of patients presenting with bradycardia was not significantly different between the shunt pathology and control groups (P > 0.05).

CONCLUSIONS

Bradycardia is not a common presentation in patients with VP shunt malfunction. Bradycardia is often recognized as a significant sign; however, it is one of the last presenting signs. Educating patients about the early signs must be considered as part of the treatment for VP shunt malfunction.

Clinical Indicators of Pediatric Shunt Malfunction: A Population-Based Study From the Nationwide Emergency Department Sample

OBJECTIVES

The majority of the previous literature on clinical predictors of shunt malfunction is from the neurosurgical data, looking at the symptoms of patients who had surgery. Because common childhood illnesses are filtered from these samples, the prevalence of shunt malfunction is markedly higher than it would be for the pediatrician's office or emergency department (ED). Clinical predictive values obtained from a representative population can better inform clinical judgment in these environments.

METHODS

A retrospective analysis of the Nationwide Emergency Department Sample (2006-2015) was performed. International Classification of Diseases, Ninth Revision, Clinical Modification Diagnosis/Procedure Codes were used to identify pediatric (≤20 years of age) ED visits with the presence of a cerebrospinal fluid (CSF) shunt (V45.2). Shunt malfunction was defined as any condition resulting in surgical revision (02.41, 02.42, 02.43). Multivariable logistic regression was used to examine the associations between shunt malfunction, demographic factors, and clinical presentation.

RESULTS

There were 74,552 observations for ED visits by pediatric patients with a CSF shunt between 2006 and 2015, of which 12.8% (9,560) required shunt revision. Positive predictive values for clinical indicators were reported along with the results of multivariable logistic regression.

CONCLUSIONS

We identified peritonitis, papilledema, and oculomotor palsies as the strongest clinical indicators for shunt malfunction in pediatric ED visits with a CSF shunt. We found that patients presenting with headache, nausea/vomiting, convulsions, or fever were more likely to have an etiology other than shunt malfunction. Thus, after an appropriate shunt evaluation, other sources of symptoms should be investigated.

Replacing Computed Tomography with "Rapid" Magnetic Resonance Imaging for Ventricular Shunt Imaging

Supplemental Digital Content is available in the text.

Introduction:

Children with ventricular shunts undergo frequent neuroimaging, and therefore, radiation exposures, to evaluate shunt malfunctions. The objective of this study was to safely reduce radiation exposure in this population by reducing computed tomography (CT) and increasing “rapid” magnetic resonance imaging (rMRI-shunt) among patients warranting neuroimaging for possible shunt malfunction.

Methods:

This was a single-center quality improvement study in a tertiary care pediatric emergency department (ED). We implemented a multidisciplinary guideline for ED shunt evaluation, which promoted the use of rMRI-shunt over CT. We included patients younger than 18 years undergoing an ED shunt evaluation during 11 months of the preintervention and 25 months of the intervention study periods. The primary outcome was the CT rate, and we evaluated the relevant process and balancing measures.

Results:

There were 266 encounters preintervention and 488 during the intervention periods with similar neuroimaging rates (80.7% versus 81.5%, P = 0.8.) CT decreased from 90.1% to 34.8% (difference −55.3%, 95% confidence interval [CI]: −71.1, −25.8), and rMRI-shunt increased from 9.9% to 65.2% (difference 55.3%, 95% CI: 25.8, 71.1) during the preintervention and intervention periods, respectively. There were increases in the mean time to neuroimaging (53.1 min; [95% CI: 41.6, 64.6]) and ED length of stay (LOS) (52.3 min; [95% CI: 36.8, 67.6]), without changes in total neuroimaging, 72-hour revisits, or follow-up neuroimaging.

Conclusions:

Multidisciplinary implementation of a standardized guideline reduced CT and increased rMRI-shunt use in a pediatric ED setting. Clinicians should balance the reduction in radiation exposure with ED rMRI-shunt for patients with ventricular shunts against the increased time of obtaining imaging and LOS.

The Sensor Reservoir-does it change management?

BACKGROUND

The Miethke Sensor Reservoir sits within a ventriculoperitoneal shunt system to give a reading of the pressure within the shunt. This information can guide the management of hydrocephalus patients who present frequently with headaches.

METHODS

We reviewed a cohort of 12 patients who underwent implantation of a Sensor Reservoir to assess how the management of their symptoms changed over a 4-year period.

RESULTS

When comparing the group before the Sensor Reservoir and after the Sensor Reservoir insertion, there was a 75% reduction in number of CT head scans (P<0.05), 100% reduction in episodes of ICP monitoring (P<0.05), 55% reduction in number of X-ray shunt series, and a 50% reduction in acute presentation to hospital with shunt-related symptoms. The number of clinic attendances increased by 44%. In addition, cost analysis showed a saving of £6952 per patients over the 2-year period following Sensor Reservoir insertion as a result of reduced admissions and investigations. Complications were seen in 3 patients-two patients developed shunt-related infections, and 1 patient underwent shunt revision due to a proximal shunt obstruction. Seventy-five percent of patients showed an improvement in their symptoms at the end of the 4-year period.

CONCLUSION

Implantation of a Sensor Reservoir in shunt patients with chronic headaches can reduce the number of investigations and hospital admissions and guide management resulting in a clinical improvement.

Gillespie C, Hennigan D, Bagga V, Mallucci C, Pettorini B. Efficacy and safety of the Miethke programmable differential pressure valve (proGAV®2.0): a single-centre retrospective analysis

PURPOSE

Achieving decompression without CSF over-drainage remains a challenge in hydrocephalus. Differential pressure valves are a popular treatment modality, with evidence suggesting that incorporation of gravitational units helps minimise over-drainage. This study seeks to describe the utility of the proGAV®2.0 programmable valve in a paediatric population.

METHODS

Clinical records and imaging of all patients fitted with proGAV®2.0 valves and Miethke fixed-pressure valves between 2014 and 2019 at our tertiary centre were analysed. Patient demographics, indication for shunt and valve insertion/revision and time to shunt/valve revision were collected. Ventricular linear metrics (fronto-occipital horn ratio (FOHR) and fronto-occipital horn width ratio (FOHWR)) were collected pre- and post-valve insertion. Microsoft Excel and SPSS v24 were used for data collection and statistical analysis.

RESULTS

Eighty-eight proGAV®2.0 valves were inserted in a population of 77 patients (n = 45 males (58%), mean age 5.1 years (IQR: 0.4-11.0 years)). A total of 102 Miethke fixed-pressure valves were inserted over the same time period. Median follow-up was 17.5 months (1.0-47.3). One (1.1%) proGAV®2.0 was revised due to over-drainage, compared to 2 (1.9%) fixed-pressure valves (p > 0.05). ProGAV®2.0 insertion resulted in a significant decrease in the mean number of revisions per patient per year (1.77 vs 0.25; p = 0.01). Overall shunt system survival with the proGAV®2.0 was 80.4% at 12 months, and mean time to revision was 37.1 months, compared to 31.0 months (95%CI: 25.7-36.3) and 58.3% in fixed-pressure valves (p < 0.01). Significant decreases were seen following proGAV®2.0 insertion in both FOHR and FOHWR, by 0.014 (95%CI: 0.006-0.023, p = 0.002) and 0.037 (95%CI: 0.005-0.069, p = 0.024) respectively.

CONCLUSION

The proGAV®2.0 provides effective decompression of hydrocephalic patients, significantly reduces the number of valve revisions per patient and had a significantly greater mean time to revision than fixed-pressure valves.

Analysis of shunted hydrocephalus follow-up: What do routine clinic visits yield? What factors affect revision surgery presentation and outcomes?

Frequency and duration of outpatient clinic follow-up for patients with shunted hydrocephalus varies among clinicians and assessment of follow-up regimens is lacking. The aim of this study is to investigate whether routine clinic visits alter care and whether they identify patients requiring shunt revision surgery, as well as, to better understand how patients utilize the outpatient clinic and present for shunt revision evaluation. This is a single-centered retrospective study of 154 patients requiring shunt revision surgery from 2009 to 2018 who had at least one prior clinic evaluation. The median age for shunt placement and revision were 3 months and 11 years old, respectively. Routine clinic visits led to a change in care for 16 patients (10.4%); including additional imaging, follow-up, or a combination of the two. With regards to revision surgery, days from prior shunt surgery, Chiari II/myelomeningocele pathology, and shunt type (p < 0.01) did affect time to presentation. Four patients (2.6%) requiring revision surgery were identified at routine clinic follow-up, while 92 (59.7%) and 47 (30.5%) presented to the emergency department and clinic sick visit, respectively. Presentation to clinic resulted in a statistically significant decrease in shunt revision surgery length-of-stay compared to presentation to the emergency department or inpatient admission for another condition. Even with increased emergency room utilization, increased clinic connectivity, and improved patient education, routine clinic visits remain an important component in the follow-up of patients with shunted hydrocephalus by helping to guide clinical care and identify patients requiring shunt revision surgery.

United States emergency department visits for children with cerebrospinal fluid shunts

OBJECTIVE

CSF shunt placement is the primary therapy for hydrocephalus; however, shunt malfunctions remain common and lead to neurological deficits if missed. There is a lack of literature characterizing the epidemiology of children with possible shunt malfunctions presenting to United States emergency departments (EDs).

METHODS

A retrospective study was conducted of the 2006-2017 National Emergency Department Sample. The data were queried using an exhaustive list of Current Procedural Terminology and International Classification of Diseases, Ninth Revision and International Classification of Diseases, Tenth Revision codes representing children with hydrocephalus diagnoses, diagnostic imaging for shunt malfunctions, and shunt-related surgical revision procedures.

RESULTS

In 2017, there were an estimated 16,376 ED visits for suspected shunt malfunction. Children were more commonly male (57.9%), ages 0-4 years (42.2%), and publicly insured (55.8%). Many did not undergo diagnostic imaging (37.2%), and of those who did, most underwent head CT scans (43.7%). Between 2006 and 2017, pediatric ED visits for suspected shunt malfunction increased 18% (95% CI 12.1-23.8). The use of MRI increased substantially (178.0%, 95% CI 176.9-179.2). Visits resulting in discharge home from the ED increased by 76.3% (95% CI 73.1-79.4), and those involving no surgical intervention increased by 32.9% (95% CI 29.2-36.6).

CONCLUSIONS

Between 2006 and 2017, ED visits for children to rule out shunt malfunction increased, yet there was a decline in surgical intervention and an increase in discharges home from the ED. Possible contributing factors include improved clinical criteria for shunt evaluation, alternative CSF diversion techniques, changing indications for shunt placement, and increased use of advanced imaging in the ED.

ABBREVIATIONS

CPT = Current Procedural Terminology; ED = emergency department; ETV = endoscopic third ventriculostomy; ICD-9 = International Classification of Diseases, Ninth Revision; ICD-10 = International Classification of Diseases, Tenth Revision; NEDS = National Emergency Department Sample.

Diagnostic modalities to determine ventriculoperitoneal shunt malfunction: A systematic review and meta-analysis

BACKGROUND

Ventriculoperitoneal (VP) shunt malfunction is an emergency. Timely diagnosis can be challenging because shunt malfunction often presents with symptoms mimicking other common pediatric conditions.

METHODS

We performed a systematic review and meta-analysis to determine which commonly used imaging modalities; Magnetic resonance imaging (MRI), Computed Tomography (CT), X-ray Shunt series or Optic Nerve Sheath Diameter (ONSD) ultrasound, are superior in evaluating shunt malfunction.

INCLUSION CRITERIA

patients less than 21 years old with symptoms of shunt malfunction. We calculated the pooled sensitivity, specificity, Likelihood Ratios (LR+, LR-) using a random-effects model.

RESULTS

Eight studies were included encompassing 1906 patients with a prevalence of VP shunt malfunction of (29.3%). Shunt series: sensitivity (14%-53%), specificity (99%), LR+ (23.2), and LR- (0.47-0.87). CT scan: sensitivity (53%-100%), specificity (27%-98%), LR+ (1.34-22.87), LR- (0.37). MRI: sensitivity (57%), specificity (93%), LR+ (7.66), and LR- (0.49). ONSD: sensitivity (64%), specificity (22%-68%), LR+ (4.4-8.7), LR- (0.93). A positive shunt series, CT scan, MRI, or ONSD has a post-test probability of (23%-84%). A normal shunt series, CT scan, MRI, or ONSD results in a post-test probability of (7%-31%). A positive shunt series results in a post-test probability of 80%, which is equivalent to the post-test probability of CT scan (23-84%) and MRI (83%).

CONCLUSION

Despite the low sensitivity, a positive shunt series obviates the need for further imaging studies. Prompt referral for neurosurgical intervention is recommended. A negative shunt series or any result (positive or negative) from CT, MRI, or ONSD will still require an emergent neurosurgical referral.

Fatal ventriculoperitoneal shunt occlusions diagnosed at autopsy

The placement of a ventriculoperitoneal (VP) shunt is frequently used in the management of chronic hydrocephalus. Failure of the shunt may occur due to physical obstruction, which is a recognized complication. Autopsy examination of deceased individuals with chronic disability is often not performed, which contributes to the difficulty in determining the frequency of mortality from VP shunts. Examination, when it does occur, should focus on the patency and positioning of the shunt, and this evaluation is especially important when the cause of death is poorly defined. In this report, we describe two cases of death caused by obstruction of VP shunts documented at autopsy. The first death was determined to be secondary to cerebellar edema with uncal and tonsillar herniation after posterior left VP shunt occlusion. The second was due to VP shunt occlusion resulting in diffuse cerebral edema and ventricular enlargement with compression and hemorrhage of the cerebellar tonsils and medulla.

Reliability of the radiopharmaceutical shunt flow study for the detection of a CSF shunt malfunction in the presence of stable ventricular size

OBJECTIVE

The authors sought to determine the reliability of a radiopharmaceutical (RP) shunt flow study for the detection of a CSF-diverting shunt malfunction in the presence of stable ventricular size.

METHODS

After the authors obtained IRB approval, all CSF RP shunt flow studies done between January 1, 2014, and January 1, 2019, in pediatric patients at Children's Hospital Los Angeles were identified. Included in the study were only those patients in whom an MRI or CT scan was done during the hospital admission for shunt malfunction and showed no increase in ventricular size compared with the most recent prior MRI or CT scan when the patient was asymptomatic. Data recorded for analysis were patient age and sex, etiology of the hydrocephalus, shunt distal site, nonprogrammable versus programmable valve, operative findings if the shunt was revised, and follow-up findings for a minimum of 90 days after admission. The RP shunt flow study consisted of tapping the reservoir and injecting technetium-99m DTPA according to a set protocol.

RESULTS

The authors identified 146 RP flow studies performed in 119 patients meeting the above criteria. Four of the 146 RP studies (3%) were nondiagnostic secondary to technical failure and were excluded from statistical analysis. Of the 112 normal flow studies, operative intervention was not undertaken in 102 (91%). The 10 (9%) remaining normal studies were performed in patients who underwent operative intervention, in which 8 patients had a proximal obstruction, 1 had a distal obstruction, and 1 patient had no obstruction. Of the 30 patients with abnormal flow studies, symptoms of shunt malfunction subsided in 9 (30%) patients and these patients did not undergo operative intervention. Of the 21 (70%) operated patients, obstruction was proximal in 9 patients and distal in 5, and for 7 patients the shunt tubing was either fractured or disconnected. Regression analysis indicated a significant association between the flow study interpretation and the odds for shunt revision (OR 27, 95% CI 10-75, p < 0.0001). No other clinical variables were significant. The sensitivity of a shunt flow study alone for detection of shunt malfunction in cases with stable ventricular size was the same as a shunt flow study plus an MRI or CT (70% vs 70%), but performing a shunt flow in addition to MRI or CT did increase the specificity from 92% to 100% and the accuracy from 87% to 94%.

CONCLUSIONS

RP shunt flow studies were of definite value in deciding whether to operatively intervene in patients with symptoms of shunt malfunction in whom no change in ventricular size was detected on current MRI or CT scans compared to scans obtained when the patients were asymptomatic.

Noninvasive Thermal Evaluation of Ventriculoperitoneal Shunt Patency and Cerebrospinal Fluid Flow Using a Flow Enhancing Device

BACKGROUND

While a noninvasive flow determination would be desirable in the diagnosis of cerebrospinal fluid shunt malfunction, existing studies have not yet defined a role for thermal flow detection.

OBJECTIVE

To evaluate a revised test protocol using a micropumper designed to transiently enhance flow during thermal testing to determine whether thermal detection of flow is associated with progression to shunt revision surgery.

METHODS

Eighty-two unique tests were performed in 71 shunts. The primary outcome, need for revision within 7 d of testing, was compared with results of micropumper-augmented thermal flow detection. Statistical analysis was based on blind interpretation of test results and raw temperature data recorded during testing.

RESULTS

The test was sensitive (73%) and specific (68%) in predicting need for revision, with 5.6-fold higher probability of revision when flow was not detected. Negative predictive value in our sample was 94.2%. The probability of not requiring revision increased with increasing total temperature drop. Analysis of various possible thresholds showed that the optimal temperature cutoff may be lower than suggested by the manufacturer (0.125°C vs 0.2°C).

CONCLUSION

This is the first study to report a strong association between thermal flow evaluation and a clinical impression that a shunt is not malfunctioning. The current recommended threshold may increase the false positive rate unnecessarily, and as clinicians gain experience with the method, they may find value in examining the temperature curves themselves. Multicenter studies are suggested to further define a role for this diagnostic test.

Continuous, noninvasive wireless monitoring of flow of cerebrospinal fluid through shunts in patients with hydrocephalus

Hydrocephalus is a common disorder caused by the buildup of cerebrospinal fluid (CSF) in the brain. Treatment typically involves the surgical implantation of a pressure-regulated silicone tube assembly, known as a shunt. Unfortunately, shunts have extremely high failure rates and diagnosing shunt malfunction is challenging due to a combination of vague symptoms and a lack of a convenient means to monitor flow. Here, we introduce a wireless, wearable device that enables precise measurements of CSF flow, continuously or intermittently, in hospitals, laboratories or even in home settings. The technology exploits measurements of thermal transport through near-surface layers of skin to assess flow, with a soft, flexible, and skin-conformal device that can be constructed using commercially available components. Systematic benchtop studies and numerical simulations highlight all of the key considerations. Measurements on 7 patients establish high levels of functionality, with data that reveal time dependent changes in flow associated with positional and inertial effects on the body. Taken together, the results suggest a significant advance in monitoring capabilities for patients with shunted hydrocephalus, with potential for practical use across a range of settings and circumstances, and additional utility for research purposes in studies of CSF hydrodynamics.

Utility of Shunt Series in the Evaluation of Ventriculoperitoneal Shunt Dysfunction in Adults

BACKGROUND

When patients present to emergency departments (EDs) with symptoms suspicious for ventriculoperitoneal shunt malfunction, evaluation often includes imaging of the shunt with both computed tomography (CT) of the head without contrast and a plain radiograph "shunt series" (SS). Recent literature has called into question the diagnostic value of the SS for the detection of ventriculoperitoneal shunt complications, suggesting that the plain radiographs provide redundant information and unnecessary exposure to radiation.

OBJECTIVE

The aim of our study was to assess the frequency of abnormal SS plain radiography and head CT in the evaluation of shunt malfunction in all adult ED patients and to measure the association of abnormalities on CT and SS with surgical intervention.

METHODS

We performed a retrospective chart review of all emergency department encounters at an urban level I trauma center between August 1, 2013 and October 3, 2018 in which an SS and head CT examination were performed within 24 h of each other. We described the results of imaging studies qualitatively and descriptive statistics were performed.

RESULTS

Positive findings on CT were significantly associated with the decision to proceed to surgery. Positive findings on SS, however, were not significantly associated with the decision to proceed to surgery.

CONCLUSIONS

The potential information gained from SS and convenience of ordering simultaneously with head CT does not appear to outweigh the risk of increased radiation exposure to the patient, the additional costs of the study, and the potential delay in time to head CT. These findings support the initial use of head CT in evaluation of shunt malfunction.

Use of computed tomography and diffusion weighted imaging in children with ventricular shunt

PURPOSE

To evaluate the indications, number, and imaging results of brain computed tomography (CT) and diffusion weighted imaging (DWI) in children with ventriculoperitoneal shunt, to estimate the radiation dose, and to evaluate the effectiveness of DWI.

METHODS

This retrospectively study included 54 consecutive patients (boys/girls = 30/24, mean age, 3 ± 4.1 years) with shunt that were placed due to congenital abnormalities-hypoxic ischemic encephalopathy between January 2015 and March 2018. The presence of shunt-related complications (SRC) was assessed using clinical and neuroimaging findings, and the standard reference was accepted as the shunt revision. Size comparisons of ventricles were performed using Evans index and the frontal and occipital horn ratio, and each measurement made by the observers were compared using Bland-Altman analysis. A kappa coefficient and the intraclass correlation coefficient were calculated to assess the agreement between observers.

RESULTS

The mean number of hospital admission, number of CT scans, and DWI were 5.8, 4.8, and 1.1, respectively per patient. A significant linear correlation was observed between hospital admission and CT scans (r = 0.288, p = 0.035). The number of CT scans and the cumulative effective dose per patient were higher in patients with SRC than in those without (p < 0.001). The mortality rate due to radiation-induced neoplasia has increased by 0.33% in the study period. The inter-observer agreement was perfect or substantial for the catheter visualization, assessment of the ventricular system on DWI, and for the image quality of DWI between observers (κ = 0.704-1, p ≤ 0.001). No significant difference was found between CT and DWI in the measurements of Evans index and the frontal and occipital horn ratio (p > 0.05). Inter-observer agreements between observers were almost perfect for the Evans index and the frontal and occipital horn ratio (ICC = 0.94-0.99, p < 0.001).

CONCLUSIONS

An awareness of the use of CT in children is still inadequate and difficulties in the diagnosis of SRC probably cause the overuse of CT. DWI should be preferred in the diagnosis of SRC and the follow-up of patients. Otherwise, the increase in the prevalence of several diseases, particularly neoplasia, may be inevitable because of the over use of CT.

Validating a Clinical Prediction Rule for Ventricular Shunt Malfunction

OBJECTIVE

This study aims to validate a published ventricular shunt clinical prediction rule for the identification of children at low risk for ventricular shunt malfunction based on the absence of 3 high-risk clinical predictors (irritability, nausea or vomiting, and headache).

METHODS

We identified children aged 21 years and younger with a ventricular shunt who presented between 2010 and 2013 to a single pediatric emergency department (ED) for evaluation of potential shunt malfunction. We defined a ventricular shunt malfunction as obstruction to cerebrospinal fluid flow requiring operative neurosurgical intervention within 72 hours of initial ED evaluation. We applied this ventricular shunt clinical prediction rule to the study population and report the test characteristics.

RESULTS

We identified 755 ED visits for 294 children with potential ventricular shunt malfunction. Of these encounters, 146 (19%; 95% confidence interval [CI], 17%-22%) had a ventricular shunt malfunction. The ventricular shunt clinical prediction rule had a sensitivity of 99% (95% CI, 94%-100%), specificity of 7% (95% CI, 5%-9%), and negative predictive value of 95% (95% CI, 82%-99%). Two children with a ventricular shunt malfunction were misclassified as low risk by this clinical prediction rule.

CONCLUSIONS

Ventricular shunt malfunctions were common. Although children classified as low risk by the ventricular shunt clinical prediction rule were less likely to have a shunt malfunction, routine neuroimaging may still be required because exclusion of ventricular shunt malfunction may be difficult on clinical grounds alone.

Is Shunt Evaluation Useful in Children With Intraventricular Shunts With Seizures?

BACKGROUND

Seizures are a common presenting symptom to the emergency department (ED) in children with intraventricular shunts (IVS). The incidence of shunt malfunction and the yield of imaging studies in children with IVS presenting with seizures is unknown.

OBJECTIVES

We assessed the utility and diagnostic yield of evaluation for shunt malfunction in patients with IVS with seizure and identified clinical predictors for shunt malfunction in these children.

METHODS

We performed a retrospective review of children aged zero to 21 years of age with IVS who presented to the ED with seizure between 2011 and 2015. Demographic, clinical, laboratory and radiological data were collected. Shunt malfunction was diagnosed based on whether a shunt revision was performed during the hospitalization.

RESULTS

We evaluated 408 ED visits (median age: six years [IQR: 3, 11], males 61.5%) for IVS with seizures. Few visits were for first seizure (37; 9.1%) or for status epilepticus (46 visits; 11.3%). Computerized tomography head was performed in 318 patients (95.2%), of which 32 scans (10.6%) were suggestive of shunt malfunction. A shunt series was performed in 302 (90.4%) and was suggestive of shunt malfunction in eight (2.6%) patients. Shunt malfunction was diagnosed in 40 of 408 visits (9.8%). Only a history of multiple (≥3) shunt revisions was significantly associated with shunt malfunction. There was no association between number, type, or prior history of seizures and shunt malfunction.

CONCLUSION

Our study demonstrates a low yield of imaging studies for the evaluation of shunt malfunction in children with IVS with seizures, and shunt malfunction is an uncommon cause of seizures in these children.

Shunt Devices for Neurointensivists: Complications and Management

Cerebrospinal fluid diversion has become the mainstay treatment in hydrocephalus for over 50 years. As the number of patients with ventricular shunt systems increases, neurointensivists are becoming the first-line physicians for many of these patients. When symptoms of a shunt malfunction are suspected and access to a neurosurgeon is limited or delayed, workup and temporizing measures must be initiated. The article highlights the functional nuances, complications, and management of current programmable shunt valves and their MRI sensitivity.

Parent/guardian knowledge regarding implanted shunt type, setting, and symptoms of malfunction/infection

OBJECTIVE Patients with shunts often interact with providers distant from their primary hospital, making it important that the parent(s)/guardian(s) is well versed in the type of shunt implanted and symptoms of malfunction/infection. This is particularly important with magnetic-sensitive programmable valves, as the use of MRI becomes more prevalent. METHODS Over a 6-month period, primary caregivers of 148 consecutive patients who received shunts were prospectively administered questionnaires at clinic visits. Caregivers were asked to do the following: 1) identify shunt valve name, type, and setting if applicable; 2) list symptoms of shunt malfunction/infection; and 3) indicate whether they had access to references regarding shunt type/setting, booklets from the Hydrocephalus Association, and quick reference cards with symptoms of shunt malfunction/infection. One cohort of caregivers (n = 75) was asked to carry informational cards with shunt valve/setting information (group I); this cohort was compared with another subgroup of caregivers (n = 73) not carrying cards (group II). RESULTS The mean (± SD) age of patients at implantation/revision was 3.71 ± 4.91 years, and the age at follow-up was 6.12 ± 5.4 years. The average time from surgery to administration of the questionnaire was 2.38 ± 3.22 years. There were 86 new shunt insertions and 62 revisions. One hundred twenty-eight caregivers (87%) could identify the type of valve (programmable vs nonprogrammable). On the other hand, only 72 caregivers (49%) could identify the valve name. Fifty-four of 73 (74%) caregivers of patients who had shunts with programmable valves could correctly identify the valve setting. One hundred caregivers (68%) had a copy of the Hydrocephalus Association booklet, and 103 (70%) had quick reference cards. Eighty caregivers (54%) had references on shunt type/setting. Most caregivers (127 [86%]) could name ≥ 3 signs/symptoms of shunt malfunction, with vomiting (61%), headache (49%), and sleeps more/lethargic (35%) most frequently reported. Caregivers of patients in group I were more likely to have cards with symptoms of shunt infection or malfunction (p = 0.015); have information cards regarding shunt type/setting (p < 0.001); and correctly identify valve type (p = 0.001), name (p < 0.001), and setting if programmable (p = 0.0016). There were no differences in ability to list symptoms of shunt malfunction or infection (p = 0.8812) or in access to Hydrocephalus Association booklets (p = 0.1288). There were no significant demographic differences between the groups, except that group I patients had a shorter time from surgery to last follow-up (1.66 vs 3.17 years; p = 0.0001). CONCLUSIONS Education regarding the care of patients with shunts by providing written cards with shunt type/setting and access to reference materials seems to be effective. Developing plans for guided instruction with assessment in the clinic setting of a caregiver's knowledge is important for patient safety.

The Neuroimaging Studies in Children with Ventriculoperitoneal Shunt Complications: A 10 Years Descriptive Sudy in Tehran

Background

Any mismatch between the production and absorption of CSF results in hydrocephalus. In most cases, the selected choice of treatment is the ventriculoperitoneal shunt insertion. Although, the surgery could have complications such as infection, shunt malfunction, subdural hematoma, seizure and Shunt immigration; so, the early and proper detection of these complications could result in better prognosis. The aim of this study was to evaluate and compare the efficacy of CT scan, CSF analysis and X-ray radiography in detection of shunt complications and problems in shunt placement and further follow-up in hospitalized children.

Methods

The medical records of children in Rasul Akram hospital in Tehran were reviewed retrospectively in the last 10 years, from 2006 to 2016. All data were recorded in the prepared form including the age, sex, shunt complication, CT scan and CSF characteristics.

Results

The total number of 95 patients were interfered in this study including 56 males (58.9%) and 39 females (41.1%). The mean age at the onset of complications were 2.8±2.2 years-old. The shunt obstruction (60%) and infection (25.3%) were the most common complications. The CT scan was able to detect 36.5% of shunt complications. The CT scan had the sensitivity and specificity of 50 and 87%, respectively in detection of shunt obstruction. The all cases of brain hematoma and hemorrhage were revealed by CT scan. On the other hand, the CT scan had 20% of sensitivity and 60% of specificity in the detection of shunt infection. The CSF evaluation in shunt infection revealed 92% hypoglycemia, 87.5% pleocytosis, and 62.5% positive CSF culture. CSF had the sensitivity, specificity, positive predictive value and negative predictive value of 92, 82, 63 and 97%, respectively. The patient's symptoms and signs were helpful in obtaining higher test accuracy.

Conclusion

The CT scan was not a good sensitive and specific study in the detection of shunt obstruction and infection, but it was very accurate in detection of hemorrhage and hematoma. On the other hand, CSF evaluation was a reliable test in shunt infection disclosure.

Fifteen-minute consultation: assessment of a child with suspected shunt problems

Cerebrospinal fluid diversion procedures have saved more lives than any other neurosurgical procedure. However, they do have a unique set of complications which a paediatrician in a district general hospital may encounter. Timely recognition and appropriate referral to the neurosurgeon is vital in order to avoid serious consequences and to have a favourable outcome.

Imaging Strategies for Suspected Acute Cranial Shunt Failure: A Cost-Effectiveness Analysis

OBJECTIVES

We compared cost-effectiveness of cranial computed tomography (CT), fast sequence magnetic resonance imaging (fsMRI), and ultrasonography measurement of optic nerve sheath diameter (ONSD) for suspected acute shunt failure from the perspective of a health care organization.

METHODS

We modeled 4 diagnostic imaging strategies: (1) CT scan, (2) fsMRI, (3) screening ONSD by using point of care ultrasound (POCUS) first, combined with CT, and (4) screening ONSD by using POCUS first, combined with fsMRI. All patients received an initial plain radiographic shunt series (SS). Short- and long-term costs of radiation-induced cancer were assessed with a Markov model. Effectiveness was measured as quality-adjusted life-years. Utilities and inputs for clinical variables were obtained from published literature. Sensitivity analyses were performed to evaluate the effects of parameter uncertainty.

RESULTS

At a previous probability of shunt failure of 30%, a screening POCUS in patients with a normal SS was the most cost-effective. For children with abnormal SS or ONSD measurement, fsMRI was the preferred option over CT. Performing fsMRI on all patients would cost $269 770 to gain 1 additional quality-adjusted life-year compared with POCUS. An imaging pathway that involves CT alone was dominated by ONSD and fsMRI because it was more expensive and less effective.

CONCLUSIONS

In children with low pretest probability of cranial shunt failure, an ultrasonographic measurement of ONSD is the preferred initial screening test. fsMRI is the more cost-effective, definitive imaging test when compared with cranial CT.

Ultrasound characterization of interface oscillation as a proxy for ventriculoperitoneal shunt function

Hydrocephalus, where cerebrospinal fluid (CSF) production rate is greater than reabsorption rate, leads to impaired neurological function if left untreated. Ventriculoperitoneal shunts (VPS) are implanted in the brain ventricles to route CSF. VPS systems have a high failure rate, and failure symptoms resemble symptoms of common maladies. The current gold standard for shunt diagnosis, surgical intervention, poses high risk and requires an expensive procedure for patients. Current non-invasive methods lack proper insight to assist physicians. We propose a noninvasive method of characterizing the oscillation of the shunt's pressure-relief valve to assist physicians in shunt diagnosis. Brightness-mode and motion-mode ultrasound images can be used to determine fluid flow. Blockage in the system could be detected by observing the phase change of the ultrasound signal in different flow cases with or without perturbation. Future testing and implementation can allow for the use of this method in localizing and identifying the modality of failure.

The Burden of Ionizing Radiation Studies in Children with Ventricular Shunts

OBJECTIVES

To quantify the number of shunt-related imaging studies that patients with ventricular shunts undergo and to calculate the proportion of computed tomography (CT) scans associated with a surgical intervention.

STUDY DESIGN

Retrospective longitudinal cohort analysis of patients up to age 22 years with a shunt placed January 2002 through December 2003 at a pediatric hospital. Primary outcome was the number of head CT scans, shunt series radiograph, skull radiographs, nuclear medicine, and brain magnetic resonance imaging studies for 10 years following shunt placement. Secondary outcome was surgical interventions performed within 7 days of a head CT. Descriptive statistics were used for analysis.

RESULTS

Patients (n = 130) followed over 10 years comprised the study cohort. The most common reasons for shunt placement were congenital hydrocephalus (30%), obstructive hydrocephalus (19%), and atraumatic hemorrhage (18%), and 97% of shunts were ventriculoperitoneal. Patients underwent a median of 8.5 head CTs, 3.0 shunt series radiographs, 1.0 skull radiographs, 0 nuclear medicine studies, and 1.0 brain magnetic resonance imaging scans over the 10 years following shunt placement. The frequency of head CT scans was greatest in the first year after shunt placement (median 2.0 CTs). Of 1411 head CTs in the cohort, 237 resulted in surgical intervention within 7 days (17%, 95% CI 15%-19%).

CONCLUSIONS

Children with ventricular shunts have been exposed to large numbers of imaging studies that deliver radiation and most do not result in a surgical procedure. This suggests a need to improve the process of evaluating for ventricular shunt malfunction and minimize radiation exposure.

2017 Infectious Diseases Society of America's Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis

The Infectious Diseases Society of America (IDSA) Standards and Practice Guidelines Committee collaborated with partner organizations to convene a panel of 10 experts on healthcare-associated ventriculitis and meningitis. The panel represented pediatric and adult specialists in the field of infectious diseases and represented other organizations whose members care for patients with healthcare-associated ventriculitis and meningitis (American Academy of Neurology, American Association of Neurological Surgeons, and Neurocritical Care Society). The panel reviewed articles based on literature reviews, review articles and book chapters, evaluated the evidence and drafted recommendations. Questions were reviewed and approved by panel members. Subcategories were included for some questions based on specific populations of patients who may develop healthcare-associated ventriculitis and meningitis after the following procedures or situations: cerebrospinal fluid shunts, cerebrospinal fluid drains, implantation of intrathecal infusion pumps, implantation of deep brain stimulation hardware, and general neurosurgery and head trauma. Recommendations were followed by the strength of the recommendation and the quality of the evidence supporting the recommendation. Many recommendations, however, were based on expert opinion because rigorous clinical data are not available. These guidelines represent a practical and useful approach to assist practicing clinicians in the management of these challenging infections.

Diagnosis and Treatment of Central Nervous System Infections in the Emergency Department

Central nervous system (CNS) infections, including meningitis, encephalitis, and brain abscess, are rare but time-sensitive emergency department (ED) diagnoses. Patients with CNS infection can present to the ED with nonspecific signs and symptoms, including headache, fever, altered mental status, and behavioral changes. Neuroimaging and CSF fluid analysis can appear benign early in the course of disease. Delaying therapy negatively impacts outcomes, particularly with bacterial meningitis and herpes simplex virus encephalitis. Therefore, diagnosis of CNS infection requires vigilance and a high index of suspicion based on the history and physical examination, which must be confirmed with appropriate imaging and laboratory evaluation.

Soluble membrane attack complex is diagnostic for intraventricular shunt infection in children

BACKGROUND

Children treated with cerebrospinal fluid (CSF) shunts to manage hydrocephalus frequently develop shunt failure and/or infections, conditions that present with overlapping symptoms. The potential life-threatening nature of shunt infections requires rapid diagnosis; however, traditional microbiology is time consuming, expensive, and potentially unreliable. We set out to identify a biomarker that would identify shunt infection.

METHODS

CSF was assayed for the soluble membrane attack complex (sMAC) by ELISA in patients with suspected shunt failure or infection. CSF was obtained at the time of initial surgical intervention. Statistical analysis was performed to assess the diagnostic potential of sMAC in pyogenic-infected versus noninfected patients.

RESULTS

Children with pyogenic shunt infection had significantly increased sMAC levels compared with noninfected patients (3,211 ± 1,111 ng/ml vs. 26 ± 3.8 ng/ml, P = 0.0001). In infected patients undergoing serial CSF draws, sMAC levels were prognostic for both positive and negative clinical outcomes. Children with delayed, broth-only growth of commensal organisms (P. acnes, S. epidermidis, etc.) had the lowest sMAC levels (7.96 ± 1.7 ng/ml), suggesting contamination rather than shunt infection.

CONCLUSION

Elevated CSF sMAC levels are both sensitive and specific for diagnosing pyogenic shunt infection and may serve as a useful prognostic biomarker during recovery from infection.

FUNDING

This work was supported in part by the Impact Fund of Children's of Alabama.

Return to the emergency department after ventricular shunt evaluation

OBJECT Patients with CSF shunts are medically complex and frequently present to the emergency department (ED) with suspected shunt malfunction. After adequate evaluation in the ED and proper disposition, some patients return to the ED within a short period of time. In this study, the authors examined the reasons for ED revisits within 7 days of the index ED visit to discern possible preventable returns. METHODS There were 3080 index ED visits made by patients with shunted hydrocephalus between 2010 and 2013. Index ED visits preceded by another ED visit or neurosurgical procedure within 60 days were excluded. Index ED visits for reasons unrelated to shunt function and those that led directly to admissions and shunt revision surgeries were also excluded. The remaining 1509 ED visits were eligible for analysis in this study. Final dispositions from the index ED visit included home (1176 cases), admission to the neurosurgery service for observation (134 cases), and admission to other services (199 cases). Subsequent events within 7 days, including ED revisits, hospital admissions, and shunt-related surgery were recorded, and reasons for the ED revisits were categorized based on whether the visit was related to shunt function concerns. Clinical and socioeconomic factors were analyzed for their association with ED revisits by using statistical methods. RESULTS Of the 1176 patients discharged home from the ED after shunt function evaluation, 101 (8.6%) returned to the ED within 7 days. Of the 134 patients admitted to the neurosurgery service for observation only, 8 (6.0%) returned to the ED within 7 days of discharge. Of the 199 patients admitted to hospital services other than neurosurgery, 13 (6.5%) returned to the ED within 7 days of discharge. The reasons for ED revisits vary (total of 122 visits combining the 3 groups), but at least 60% of the revisits were clearly unrelated to shunt function. A younger age, daytime arrival to the ED, and living within the metropolitan area were identified as risk factors for ED revisits. CONCLUSIONS Children with CSF shunts are medically complex and use ED services often. After an index ED visit at which shunt function was deemed to be the chief concern, the purpose of the subsequent return to the ED within 7 days was often for complaints unrelated to shunt function. Caution is warranted when attempting to classify these complex patients as having potential preventable return-to-system events.

[Semiology of ventriculoperitoneal shunting dysfunction in children - a review]

INTRODUCTION

Ventriculoperitoneal shunting (VPS) is a treatment of the hydrocephalus that may dysfunction. The clinical presentation of shunt dysfunction is variable. We therefore decided to focus on the clinical presentation of VPS malfunction in children, as this condition requires immediate emergency treatment and because of the sometimes confusing signs of intracranial hypertension in a shunted child.

MATERIALS AND METHODS

We searched PubMed with the following groups of keywords: (dysfunction OR blockage) AND shunting AND hydrocephalus; shunt complications AND hydrocephalus; hydrocephalus AND shunt AND malfunction. Articles dealing with ventriculo-atrial shunt were excluded. A total of 79 articles were retained for analysis (English and French). Case reports were excluded.

RESULTS

The clinical presentation varies by age: vomiting and alterated level of consciousness are the most frequent signs in older children, whereas infants present more often with raised intracranial pressure symptoms such as nausea, vomiting, irritability and bulging fontanel. Drowsiness is a good predictor of VPS dysfunction. An asymptomatic presentation is rare but possible. Abdominal presentation is also possible, ranging from abdominal discomfort to peritonitis. Fever, occurring a short time after the last intervention, and irritability are good predictors of shunt infection. Pumping the chamber of the VPS has a weak positive predictive value (12%). Shunt dysfunction can lead to death, with an estimated mortality rate at 1% per year during the first years.

CONCLUSION

It is essential to be aware of the variability of the clinical presentation of VPS dysfunction, because of the potential severity of this condition. Also it is important to pay attention to the comments of the parents, especially if the child experienced a previous shunt malfunction.

Emergency Department Use of Computed Tomography for Children with Ventricular Shunts

OBJECTIVES

To quantify rates and variation in emergency department (ED) cranial computed tomography (CT) utilization in children with ventricular shunts, estimate radiation exposure, and evaluate the association between CT utilization and shunt revision.

STUDY DESIGN

Retrospective longitudinal cohort study of ED visits from 2003-2013 in children 0-18 years old with initial shunt placement in 2003. Data were examined from 31 hospitals in the Pediatric Health Information System. Main outcomes were cranial CT performed during an ED visit, estimated cumulative effective radiation dose, and shunt revision within 7 days. Multivariable regression modeled the relationship between patient- and hospital-level covariates and CT utilization.

RESULTS

The 1319 children with initial shunt placed in 2003 experienced 6636 ED visits during the subsequent decade. A cranial CT was obtained in 49.4% of all ED visits; 19.9% of ED visits with CT were associated with a shunt revision. Approximately 6% of patients received ≥10 CTs, accounting for 37.2% of all ED visits with a CT. The mean number of CTs per patient varied nearly 20-fold across hospitals; the individual hospital accounted for the most variation in CT utilization. The median (IQR) cumulative effective radiation dose was 7.2 millisieverts (3.6-14.0) overall, and 33.4 millisieverts (27.2-43.8) among patients receiving ≥10 CTs.

CONCLUSIONS

A CT scan was obtained in half of ED visits for children with a ventricular shunt, with wide variability in utilization by hospitals. Strategies are needed to identify children at risk of shunt malfunction to reduce variability in CT utilization and radiation exposure in the ED.

Are parents and professionals making shared decisions about a child's care on presentation of a suspected shunt malfunction: a mixed method study?

BACKGROUND

Shunts, the main treatment for hydrocephalus, are problematic as they frequently malfunction. Identifying shunt malfunction requires parents to recognize its symptoms and health professionals to integrate parents' information about the child's symptoms within the clinical assessment to reach a diagnosis.

AIM

To investigate parent-professional shared decision making during the diagnosis of suspected shunt malfunction in acute hospital admissions.

DESIGN AND METHODS

A mixed method study involving audio recordings of admission consultations, a shared decision making questionnaire and interviews 1-week post-consultation, was undertaken. Twenty-eight family members and fourteen health professionals participated. The interactions were analysed using conversational analysis, framework approach for the interview data and descriptive statistics for questionnaire responses.

FINDINGS

Both parents and professionals focussed on establishing a diagnosis and ruling out shunt malfunction when a child with hydrocephalus was ill. Participants' perceived effective collaboration as central to this task: parents wanted to contribute to the process of diagnosis by providing information about the likely cause of symptoms. Professionals were satisfied with the level of involvement by parents, although parent satisfaction was more variable. The challenge for professionals was to integrate parents' expertise of their child's presenting symptoms within clinical decision making processes.

CONCLUSION

In this context, both parents' and professionals' perceived their interactions to be about problem-solving, rather than making decisions about treatments. Although the shared decision-making model can help patients to make better decisions between treatment options, it is unclear how best to support collaboration between professionals and parents to ensure a good problem-solving process.

[Clinical scale for the diagnosis of ventriculoperitoneal shunt malfunction in children in Emergency Department]

INTRODUCTION

It is well known that some symptoms in children with ventriculoperitoneal shunt are associated with a higher risk of developing shunt malfunction. However none of those symptoms are sensitive or enough specific enough to diagnose the shunt malfunction.

OBJECTIVE

To develop a diagnostic scale to identify children with an increased risk of shunt malfunction in the Emergency Department.

MATERIAL AND METHODS

This is a prospective study including children aged one to eighteen years old admitted to the Emergency Department between April 2010 and March 2013 with symptoms of ventriculoperitoneal shunt malfunction. Logistic regression Analysis was used to determine whether or not the variables were considered independent risk factors for shunt malfunction. The results led to the development of a diagnostic scale.

RESULTS

A scale was developed using 9 variables (erythema, swelling or discharge from the catheter trajectory, drowsiness, stiff neck, headache, afebrile, age>4 years, vomiting, recent neurological deficit, and time since last surgery ≤ 2 years) with a maximum score of 20 points. It was found that Scale scores ≥ 7 points were associated with an increased risk of shunt malfunction (OR 34.0, 95% CI 15.4-74.9; sensitivity 88.3%, specificity 81.1%, PPV 53.4%, NPV 96.7%).

DISCUSSION

A diagnostic scale is designed for assessing the risk of shunt malfunction, selecting those patients with a higher risk. The use of this scale could help the management of these patients, reducing complementary tests, as well the usual radiation suffered by these children.

Radiographic evaluation of pediatric cerebrospinal fluid shunt malfunction in the emergency setting

Children with ventricular cerebrospinal fluid shunts for treatment of hydrocephalus require frequent evaluation for potential shunt malfunction. Current practice relies heavily on neuroimaging, particularly cranial computed tomography, which repeatedly exposes children to ionizing radiation. Rapid cranial magnetic resonance imaging is a new radiation-sparing alternative to CT for evaluation of potential shunt malfunction. We review the diagnostic test performance, radiation exposure, advantages, and limitations of the major neuroimaging modalities available to providers caring for children with possible shunt malfunction in the emergent setting.

Clinical Outcome of Children With Suspected Shunt Malfunction Evaluated in the Emergency Department

BACKGROUND:

Patients with cerebrospinal fluid shunts frequently present to the emergency department (ED) with suspected shunt malfunction. The outcome of those patients who were discharged from ED when shunt malfunction was deemed unlikely has not been previously documented.

OBJECTIVE:

To demonstrate there is no increase in severity or likelihood of harm for patients who are discharged directly from the ED after adequate evaluation, as compared to patients who were selected for inpatient hospitalization.

METHODS:

The report screens 3080 ED visits between 2010 and 2013 made by patients with shunted hydrocephalus. ED visits preceded by another ED visit or neurosurgical procedures within 60 days were excluded. ED visits for reasons unrelated to shunt function were excluded, and 1943 visits met the inclusion criteria. Final dispositions from the ED included home (n = 1176), admission to neurosurgery service (n = 550), and admission to other services (n = 217). Subsequent events within 30 days, including ED visits and elective and nonelective shunt-related surgery, were reviewed.

RESULTS:

The clinical characteristics of the 3 groups were similar. Of patients discharged home from the ED, 19.0% returned to ED, and 4.5% required shunt-related surgeries. Of the patients admitted for observation, 18.7% returned to ED and 14.2% required shunt-related surgery. Of the patients admitted to other hospital services, 19.6% patients returned to the ED, with 2.0% requiring surgical intervention. There were no shunt-related mortalities in any of the 3 groups.

CONCLUSION:

Children with cerebrospinal fluid shunts are often evaluated in the ED. Discharge from the ED, when suspicion for shunt malfunction is low, is an appropriate practice.

Utility of computed tomography or magnetic resonance imaging evaluation of ventricular morphology in suspected cerebrospinal fluid shunt malfunction

OBJECT

It is common to evaluate children with suspected CSF shunt malfunctions using CT of the head or, more recently, "quick brain" MRI. However, the reliability of using ventricular behavior, as assessed on cranial imaging during previous presentations with shunt obstructions, is not well defined. The authors conducted a study to determine if CT or MRI of ventricular morphology added useful clinical information in the evaluation of shunt malfunctions.

METHODS

A retrospective chart review of children operated on at Texas Children's Hospital from February 20, 2011, to June 18, 2013, for shunt obstruction was conducted. Inclusion criteria involved age 3 years or older in patients who had undergone two or more shunt revisions for intraoperatively confirmed obstructions. Patients with shunt infection but without shunt obstruction and patients with fourth ventricular shunt failure were excluded from the study. Preoperative CT or MRI results were dichotomized into two distinct categories, as determined by a radiologist's report: either dilation of the ventricular system in comparison with prior scans at points the shunt was deemed functional, or no dilation of the ventricular system in comparison such scans. Determination of the presence of shunt obstruction was assessed by findings documented by the surgeon in the operative report. Each case was then analyzed to see if the patient has a reliable pattern of ventricular dilation, or no dilation, at times of shunt obstruction.

RESULTS

Forty-two patients (25 males and 17 females) were included in the study. There were a total of 117 patient encounters analyzed and an average of 2.79 encounters per patient. The mean age at shunt failure presentation was 10.8 years (range 3-23 years). In 4 encounters, patients presented with a CSF leak or pseudomeningocele. Twenty-seven patients (64%) consistently demonstrated dilation of the ventricular system during episodes of shunt obstruction. Four patients (10%) consistently demonstrated no dilation during episodes of shunt obstruction. Eleven patients (26%) demonstrated inconsistent changes in ventricular size at times of shunt obstruction. In those first patient encounters with shunt obstruction presenting with ventricular dilation, 92% (49 of 53) of subsequent encounters demonstrated ventricular dilation with shunt obstruction presentations.

CONCLUSIONS

Historical CT or MRI data regarding ventricular morphology patterns seen during prior examinations of shunt obstructions may inform a clinician's judgment of shunt obstruction on subsequent presentations, but they are not conclusive. In the present series, the authors found that changes in the morphology of a given patient's ventricular system when shunt obstruction occurs were often consistent and predictable, but not always. It remains imperative, however, that cranial images obtained to rule out shunt malfunction be compared with prior studies.

Comparison of rapid cranial MRI to CT for ventricular shunt malfunction

OBJECTIVES

To compare the accuracy of rapid cranial magnetic resonance imaging (MRI) with that of computed tomography (CT) for diagnosing ventricular shunt malfunction.

METHODS

We performed a single-center, retrospective cohort study of children ≤21 years of age who underwent either rapid cranial MRI or cranial CT in the emergency department (ED) for evaluation of possible ventricular shunt malfunction. Each neuroimaging study was classified as "normal" (unchanged or decreased ventricle size) or "abnormal" (increased ventricle size). We classified a patient as having a ventricular shunt malfunction if operative revision for relief of mechanical causes of altered shunt flow was needed within 72 hours of initial ED evaluation. Our primary analysis tested noninferiority of the accuracy of rapid cranial MRI to CT for diagnosing shunt malfunction (noninferiority margin 10%).

RESULTS

We included 698 ED visits for 286 unique patients, with a median age at visit of 10.0 years (interquartile range 5.9-15.5 years). Patients underwent CT in 336 (48%) or rapid cranial MRI in 362 (52%) of ED visits for evaluation of possible shunt malfunction. Patients had operative revision for ventricular shunt malfunction in 140 ED visits (20%). The accuracy of rapid cranial MRI was not inferior to that of CT scan for diagnosing ventricular shunt malfunction (81.8% MRI vs 82.4% CT; risk difference 2.0%; 95% confidence interval, -4.2% to 8.2%).

CONCLUSIONS

Rapid cranial MRI was not inferior to CT for diagnosing ventricular shunt malfunction and offers the advantage of sparing a child ionizing radiation exposure.

Risk factors for first cerebrospinal fluid shunt infection: findings from a multi-center prospective cohort study

OBJECTIVE

To quantify the extent to which cerebrospinal fluid (CSF) shunt revisions are associated with increased risk of CSF shunt infection, after adjusting for patient factors that may contribute to infection risk.

STUDY DESIGN

We used the Hydrocephalus Clinical Research Network registry to assemble a large prospective 6-center cohort of 1036 children undergoing initial CSF shunt placement between April 2008 and January 2012. The primary outcome of interest was first CSF shunt infection. Data for initial CSF shunt placement and all subsequent CSF shunt revisions prior to first CSF shunt infection, where applicable, were obtained. The risk of first infection was estimated using a multivariable Cox proportional hazard model accounting for patient characteristics and CSF shunt revisions, and is reported using hazard ratios (HRs) with 95% CI.

RESULTS

Of the 102 children who developed first infection within 12 months of placement, 33 (32%) followed one or more CSF shunt revisions. Baseline factors independently associated with risk of first infection included: gastrostomy tube (HR 2.0, 95% CI, 1.1, 3.3), age 6-12 months (HR 0.3, 95% CI, 0.1, 0.8), and prior neurosurgery (HR 0.4, 95% CI, 0.2, 0.9). After controlling for baseline factors, infection risk was most significantly associated with the need for revision (1 revision vs none, HR 3.9, 95% CI, 2.2, 6.5; ≥2 revisions, HR 13.0, 95% CI, 6.5, 24.9).

CONCLUSIONS

This study quantifies the elevated risk of infection associated with shunt revisions observed in clinical practice. To reduce risk of infection risk, further work should optimize revision procedures.

Techniques that decrease or eliminate ionizing radiation for evaluation of ventricular shunts in children with hydrocephalus

Shunted hydrocephalus in children is a commonly seen diagnosis in hospitals throughout the world and is one of the most common chronic pediatric neurosurgical conditions. These children undergo numerous studies for routine surveillance as well as for evaluation of shunt malfunction, many of which are associated with significant radiation exposure over the child׳s lifetime. It is in the child׳s best interest to minimize the overall exposure to ionizing radiation so as to decrease the chance of the deleterious effects from occurring. The article outlines the epidemiology of ventricular shunt catheters, the typical indications and methods for shunt evaluation, and the preferred alternative imaging methods that eliminate or reduce radiation exposure.

Return to system within 30 days of discharge following pediatric shunt surgery

OBJECT

The rate of readmission after CSF shunt surgery is significant and has caught the attention of purchasers of health care. However, a detailed description of clinical scenarios that lead to readmissions and reoperations after index shunt surgery is lacking in the medical literature.

METHODS

This study included 1755 shunt revision and insertion surgeries that were performed at a single institution between May 1, 2009, and April 30, 2013. Demographic, socioeconomic, and clinical characteristics were prospectively collected in the administrative, business, and operating room databases. Clinical events within the 30 days following discharge were reviewed and analyzed. Two events of interest, Emergency Department (ED) utilization and reoperation, were further analyzed for risk factor associations by using multivariate logistic regression.

RESULTS

There were 290 readmissions within 30 days of discharge (16.5%). Admission sources included ED (n = 216), hospital transfers (n = 23), and others. Of the 290 readmissions, 184 were associated with an operation, but only 165 of these were performed by the neurosurgical service. These included surgeries for shunt occlusion and externalization (n = 150), wound revision (n = 7), and other neurosurgical procedures that were not shunt related (n = 8). The remaining readmissions (n = 106) were not associated with an operation, and only 59 patients were admitted for issues related to the index shunt surgery. When return to the ED was the dependent variable in a multivariate regression model, patients who returned to the ED were more likely to be from the Atlanta metropolitan area and to be either uninsured or insured with public assistance. When reoperation was the dependent variable, patients whose surgery started after 3 p.m. were more likely to undergo subsequent CSF shunt revision surgery on readmission.

CONCLUSIONS

Of the readmissions within 30 days of shunt surgery, 74.5% were related to the index shunt surgery. Whether and to what extent these readmissions are preventable continues to be controversial. Further study is needed to identify modifiable risk factors that may eventually improve patient care.

Imaging evaluation of CSF shunts

OBJECTIVE

The objective of this article is to describe an approach to imaging CSF shunts. Topics reviewed include the components and imaging appearances of the most common types of shunts and the utility of different imaging modalities for the evaluation of shunt failure. Complications discussed include mechanical failure, infection, ventricular loculation, overdrainage, and unique complications related to each shunt type.

CONCLUSION

This article reviews the imaging features of common CSF shunts and related complications with which radiologists should be familiar.

Return to system within 30 days of pediatric neurosurgery

OBJECT

Quality assessment measures have not been well developed for pediatric neurosurgical patients. This report documents the authors' experience in extracting information from an administrative database to establish the rate of return to system within 30 days of pediatric neurosurgical procedures.

METHODS

Demographic, socioeconomic, and clinical characteristics were prospectively collected in administrative, business, and operating room databases. The primary end point was an unexpected return to the hospital system within 30 days from the date of a pediatric neurosurgical procedure. Statistical methods were used to identify clinical and demographic factors associated with the primary end point.

RESULTS

There were 1358 pediatric neurosurgical procedures performed in the Children's Healthcare of Atlanta operating rooms in 2012, with 37.4% of these surgeries being preceded by admissions through the emergency department. Medicare or Medicaid was the payor for 54.9% of surgeries, and 37.6% of surgeries were shunt related. There were 148 unexpected returns to the system within 30 days after surgery, and in 109 of these cases, the patient had a presenting complaint that was attributable to the index surgery (related returns). The most common complaints were headache, nausea, vomiting, or seizure after shunt revision or cranial procedures (n = 62). The next most common reason for re-presentation was for wound concerns (n = 30). Thirty-seven of the 109 related returns resulted in a reoperation. The monthly rate of related returns was 8.1% ± 2.5% over the 12-month study period. When using related returns as the dependent variable, the authors found that patients who underwent a shunt-related surgery were both more likely to unexpectedly return to the system (OR 1.86, p = 0.008) and to require surgery upon readmission (OR 3.28, p = 0.004). Because an extended hospitalization shortened the window of time for readmission after surgery, extended length of stay was protective against return to system within 30 days of surgery. Importantly, if related and unrelated returns were analyzed together as the dependent variable (n = 148), no independent clinical and demographic risk factor could be identified.

CONCLUSIONS

Quality assessment measures need to be clearly and carefully defined, as the definition itself will impact the analytical results. Clinicians must play a leading role in the development of these measures to ensure their clinical meaningfulness.

Cranial computed tomography utilization for suspected ventriculoperitoneal shunt malfunction in a pediatric emergency department

BACKGROUND

Computed tomography (CT) scan, the largest medical source of ionizing radiation in the United States, is used to test for failure of ventricular peritoneal shunts.

STUDY OBJECTIVES

To quantify the exposure to cranial CT scans in pediatric patients presenting with symptoms of shunt malfunction, and to measure the association of signs and symptoms with clinical shunt malfunction and the need for neurosurgical intervention within 30 days of presentation.

METHOD

This was a quality improvement study evaluating a pathway used by providers in a tertiary care pediatric emergency department with 85,000 patient visits per year, by retrospective chart review of 223 patient visits for suspected shunt malfunction. We determined the median CT scan per patient per year and the association of signs and symptoms on the pathway with radiological signs of shunt failure and neurosurgical intervention within 30 days of scan.

RESULTS

The median exposure was 2.6 (interquartile range 1.44-4.63) scans per patient per year. Among 11 signs and symptoms, none was associated with radiologic shunt failure. Neurosurgical intervention within 30 days was positively associated with bulging fontanelle (adjusted odds ratio [AOR] 11.78; 95% confidence interval [CI] 1.67-83.0) and behavioral change (AOR 3.01; 95% CI 1.14-7.93), and negatively associated with seizure (AOR 0.13; 95% CI 0.02-0.79) and fever (AOR 0.15; 95% CI 0.04-0.55).

CONCLUSIONS

Patients with ventricular peritoneal shunts underwent many cranial CT scans each year. None of the signs or symptoms included on the clinical pathway was predictive of changes on CT scan.