Low surgical weight associated with ETV failure in pediatric hydrocephalus patients

The use of endoscopic third ventriculostomy (ETV) for treatment of pediatric hydrocephalus has higher failure rates in younger patients. Here we investigate the impact of select perioperative variables, specifically gestational age, chronological age, birth weight, and surgical weight, on ETV failure rates. A retrospective review was performed on patients treated with ETV - with or without choroid plexus cauterization (CPC) - from 2010 to 2021 at a large academic center. Analyses included Cox regression for independent predictors and Kaplan-Meier survival curves for time to-event outcomes. In total, 47 patients were treated with ETV; of these, 31 received adjunctive CPC. Overall, 66% of the cohort experienced ETV failure with a median failure of 36 days postoperatively. Patients aged < 6 months at time of surgery experienced 80% failure rate, and those > 6 months at time of surgery experienced a 41% failure rate. Univariate Cox regression analysis showed weight at the time of ETV surgery was significantly inversely associated with ETV failure with a hazard ratio of 0.92 (95% CI 0.82, 0.99). Multivariate analysis redemonstrated the inverse association of weight at time of surgery with ETV failure with hazard ratio of 0.76 (95% CI 0.60, 0.92), and sensitivity analysis showed < 4.9 kg as the optimal cutoff predicting ETV/CPC failure. Neither chronologic age nor gestational age were found to be significantly associated with ETV failure.In this study, younger patients experienced higher ETV failure rates, but multivariate regression found that weight was a more robust predictor of ETV failure than chronologic age or gestational age, with an optimal cutoff of 4.9 kg in our small cohort. Given the limited sample size, further study is needed to elucidate the independent role of weight as a peri-operative variable in determining ETV candidacy in young infants. Previous presentations: Poster Presentation, Congress of Neurological Surgeons.

Ventriculopleural shunt outcomes for pediatric hydrocephalus: a single-institution experience

PURPOSE

The aim of this study is to analyze rates of ventriculopleural (VPL) shunt failure and complications among patients with pediatric hydrocephalus, and to analyze which factors may predict early (< 1 year) or late (> 1 year) VPL shunt failure in this sample.

METHODS

A retrospective chart review was conducted of all consecutive VPL shunt placements from 2000 to 2019 at our institution. Data was collected on patient characteristics, shunt history, and shunt type. Primary endpoints include rates of VPL shunt survival and rates of symptomatic pleural effusion. The Kaplan-Meier method was used to calculate shunt survival, and Fisher's exact test and t-test were used to compare differences between categorical variables and means, respectively (p < 0.05).

RESULTS

Thirty-one patients with pediatric hydrocephalus underwent VPL shunt placement (mean age 14.2 years). Of the 27 patients with long-term follow-up (mean 46 months), VPL shunt revision was required in 19, seven of which were due to pleural effusion. Overall shunt survival rates at 1, 3, 5, and 7 years were 76%, 62%, 55%, and 46%, respectively. Mean duration of shunt survival was 26.74 months. Overall pleural effusion rate was 26%. No patient-specific factors, including shunt valve type, were significantly associated with shunt survival, risk of early revision, or risk of pleural effusion.

CONCLUSIONS

Our results are comparable to those reported in the literature and represent one of the largest case series on the topic. VPL shunts are a viable second-line option when ventriculoperitoneal (VP) shunt placement is not possible or desirable, though there are high rates of shunt revision and pleural effusion.

Image quality and related outcomes of the ShuntScope for catheter implantation in pediatric hydrocephalus-experience of 65 procedures

PURPOSE

Ventricular catheter implantation in pediatric hydrocephalus can become a highly challenging task due to abnormal anatomical configuration or the need for trans-aqueductal stent placement. Transluminal endoscopy with the ShuntScope has been invented to increase the rate of successful catheter placements. This study aims to evaluate ShuntScope's image qualities and related surgical outcomes in the pediatric population.

METHODS

A retrospective analysis of all pediatric patients undergoing ventricular catheter placement using the ShuntScope from 01/2012 to 01/2022 in the author's department was performed. Demographic, clinical, and radiological data were evaluated. The visualization quality of the intraoperative endoscopy was stratified into the categories of excellent, medium, and poor and compared to the postoperative catheter tip placement. Follow-up evaluation included the surgical revision rate due to proximal catheter occlusion.

RESULTS

A total of 65 ShuntScope-assisted surgeries have been performed on 51 children. The mean age was 5.1 years. The most common underlying pathology was a tumor- or cyst-related hydrocephalus in 51%. Achieved image quality was excellent in 41.5%, medium in 43%, and poor in 15.5%. Ideal catheter placement was achieved in 77%. There were no intraoperative complications and no technique-related morbidity associated with the ShuntScope. The revision rate due to proximal occlusion was 4.61% during a mean follow-up period of 39.7 years. No statistical correlation between image grade and accuracy of catheter position was observed (p-value was 0.290).

CONCLUSION

The ShuntScope can be considered a valuable addition to standard surgical tools in treating pediatric hydrocephalus. Even suboptimal visualization contributes to high rates of correct catheter placement and, thereby, to a favorable clinical outcome.

The effect of shunt removal on the quality of life in patients with congenital hydrocephalus

BACKGROUND

Although there have been reports investigating the quality of life of patients who underwent ventriculoperitoneal shunting or endoscopic third ventriculostomy (ETV) for congenital hydrocephalus, there have been no studies of the quality of life of patients after ventriculoperitoneal shunt (VPS) removal. In the present study, a survey of pediatric and congenital hydrocephalus patients was conducted to compare the quality of life of patients with a remaining VPS with that of patients who had the shunt removed.

METHODS

Between February 2020 and November 2021, an outpatient survey was administered to patients 8 years of age and older who had undergone VPS due to a diagnosis of congenital hydrocephalus. The Hydrocephalus Outcome Questionnaire (HOQ) was used to assess the quality of life for this study. The HOQ scores (overall health score, physical health score, cognitive health score, and social-emotional health score) were compared among three groups: a VPS-remaining group, VPS-removed with endoscopic third ventriculostomy (ETV) group, and VPS-removed without ETV group.

RESULTS

The total number of patients who underwent VPS for hydrocephalus was 71, with 47 in the VPS-remaining group, 14 in the shunt-removed with ETV group, and 10 in the shunt-removed without ETV group. The HOQ overall health score was 0.68 for the VPS-remaining group, 0.74 for the shunt-removed with ETV group, and 0.74 for the shunt-removed without ETV. There were no significant differences between the VPS-remaining group and the VPS-removed with or without ETV groups (p = 0.3255, 0.4178, respectively).

CONCLUSION

There was no significant difference in the quality of life between patients with a remaining VPS and those who had their VPS removed with or without ETV.

Pediatric ventriculoperitoneal shunt: a comparative study between anterior fontanel ultrasound-guided versus conventional cranial end insertion

PURPOSE

Ventriculoperitoneal (V-P) shunt is one of the most common neurosurgical procedures in pediatrics for the treatment of hydrocephalus. Shunt failure is one of the common mechanical complications which lead to major morbidities. This study aims to compare between cranial part insertions of the V-P shunts guided by trans-anterior fontanel ultrasound versus conventional insertion.

METHODS

A prospective comparative randomized study was conducted on 60 pediatric patients aged ≤ 2 years who suffered hydrocephalus and allocated into 2 groups. In the first group (n = 30), the cranial parts of the ventriculoperitoneal shunts were inserted guided by trans-anterior fontanel ultrasound, and in the second group (n = 30), the insertions were by the conventional method. The follow-up duration of the patients was 3 months.

RESULTS

Proximal part obstruction of the V-P shunt was found in 3 cases of the conventional group during follow-up with statistical insignificance (p = 0.237) while adequate proximal part location recorded statistical significance (p = 0.0005) in favor of ultrasound-guided group.

CONCLUSION

The use of the anterior fontanel ultrasound guide during ventriculoperitoneal shunt insertion is a feasible, safe, and effective technique for the placement of ventricular catheters in pediatric patients with a patent anterior fontanel.

Shunt technology for infants and a lifetime

The use of cerebrospinal fluid (CSF) shunts remains a fundamental therapeutic modality in the management of hydrocephalus. Nowadays, neurosurgeons have an arsenal of different shunt technologies on their hands, with several companies producing many different configurations of them. The greatest difficulty of treating a child with hydrocephalus is to deal with a brain that will enormously change its size and hydrodynamic conditions and a body that will multiply its height and weight in a short time. Detailed knowledge of the hydrodynamic properties of shunts is mandatory for any neurosurgeon and much more for those taking care of pediatric patients. It is necessary to know that these properties of the valve may influence the evolution of the patient after shunting and it is recognized that a patient physiology-specific valve selection may yield better outcomes and decrease complications. This article provides a summary of the most common available CSF valves and overdrainage control devices, their technology, and possible combinations. The objective is to offer a quick overview of the armamentarium to facilitate the recognition of the implanted device and improve the selection of the most suitable valve for each patient.

Transependymal Edema as a Predictor of Endoscopic Third Ventriculostomy Success in Pediatric Hydrocephalus

BACKGROUND

The Endoscopic Third Ventriculostomy Success Score (ETVSS) is based on the clinical features of hydrocephalus except for radiological findings. A previous study suggested that transependymal edema (TEE) as a radiological finding may be a reliable predictor of endoscopic third ventriculostomy (ETV) success in patients of all ages. We aimed to investigate whether TEE on preoperative magnetic resonance imaging can predict ETV success in pediatric patients.

METHODS

Medical and radiological records of all pediatric patients with an initial ETV in our hospital between 2013 and 2019 were retrospectively reviewed.

RESULTS

This study included 32 patients with hydrocephalus. The median age at surgery was 10.0 years (interquartile range: 5.6-12.9 years). There were 20 patients in the high ETVSS (90-80) group and 12 patients in the moderate ETVSS (70-50) group. The median follow-up period was 29.0 months (interquartile range: 12.9-46.2 months). The ETV success rate at the final follow-up was 81%. Preoperative brain magnetic resonance imaging revealed TEE in 20 patients and third ventricle floor ballooning in 25 patients, of whom 19 (95%) and 22 (88%), respectively, achieved successful ETV. Patients with TEE had a significantly better outcome than patients without TEE (95% vs. 58%, P = 0.018). Multivariate analysis demonstrated that the presence of TEE (odds ratio 13.6, 95% confidence interval 1.3-137.5, P = 0.027) is a significant predictor of ETV success.

CONCLUSIONS

In our cohort with a high or moderate ETVSS, the ETV success rate in patients with TEE was significantly higher than in patients without TEE, suggesting that TEE may be a useful predictor of ETV success in pediatric hydrocephalus.

MR Elastography demonstrates reduced white matter shear stiffness in early-onset hydrocephalus

INTRODUCTION

Hydrocephalus that develops early in life is often accompanied by developmental delays, headaches and other neurological deficits, which may be associated with changes in brain shear stiffness. However, noninvasive approaches to measuring stiffness are limited. Magnetic Resonance Elastography (MRE) of the brain is a relatively new noninvasive imaging method that provides quantitative measures of brain tissue stiffness. Herein, we aimed to use MRE to assess brain stiffness in hydrocephalus patients compared to healthy controls, and to assess its associations with ventricular size, as well as demographic, shunt-related and clinical outcome measures.

METHODS

MRE was collected at two imaging sites in 39 hydrocephalus patients and 33 healthy controls, along with demographic, shunt-related, and clinical outcome measures including headache and quality of life indices. Brain stiffness was quantified for whole brain, global white matter (WM), and lobar WM stiffness. Group differences in brain stiffness between patients and controls were compared using two-sample t-tests and multivariable linear regression to adjust for age, sex, and ventricular volume. Among patients, multivariable linear or logistic regression was used to assess which factors (age, sex, ventricular volume, age at first shunt, number of shunt revisions) were associated with brain stiffness and whether brain stiffness predicts clinical outcomes (quality of life, headache and depression).

RESULTS

Brain stiffness was significantly reduced in patients compared to controls, both unadjusted (p ≤ 0.002) and adjusted (p ≤ 0.03) for covariates. Among hydrocephalic patients, lower stiffness was associated with older age in temporal and parietal WM and whole brain (WB) (beta (SE): -7.6 (2.5), p = 0.004; -9.5 (2.2), p = 0.0002; -3.7 (1.8), p = 0.046), being female in global and frontal WM and WB (beta (SE): -75.6 (25.5), p = 0.01; -66.0 (32.4), p = 0.05; -73.2 (25.3), p = 0.01), larger ventricular volume in global, and occipital WM (beta (SE): -11.5 (3.4), p = 0.002; -18.9 (5.4), p = 0.0014). Lower brain stiffness also predicted worse quality of life and a higher likelihood of depression, controlling for all other factors.

CONCLUSIONS

Brain stiffness is reduced in hydrocephalus patients compared to healthy controls, and is associated with clinically-relevant functional outcome measures. MRE may emerge as a clinically-relevant biomarker to assess the neuropathological effects of hydrocephalus and shunting, and may be useful in evaluating the effects of therapeutic alternatives, or as a supplement, of shunting.

Semantic segmentation of cerebrospinal fluid and brain volume with a convolutional neural network in pediatric hydrocephalus-transfer learning from existing algorithms

Background

For the segmentation of medical imaging data, a multitude of precise but very specific algorithms exist. In previous studies, we investigated the possibility of segmenting MRI data to determine cerebrospinal fluid and brain volume using a classical machine learning algorithm. It demonstrated good clinical usability and a very accurate correlation of the volumes to the single area determination in a reproducible axial layer. This study aims to investigate whether these established segmentation algorithms can be transferred to new, more generalizable deep learning algorithms employing an extended transfer learning procedure and whether medically meaningful segmentation is possible.

Methods

Ninety-five routinely performed true FISP MRI sequences were retrospectively analyzed in 43 patients with pediatric hydrocephalus. Using a freely available and clinically established segmentation algorithm based on a hidden Markov random field model, four classes of segmentation (brain, cerebrospinal fluid (CSF), background, and tissue) were generated. Fifty-nine randomly selected data sets (10,432 slices) were used as a training data set. Images were augmented for contrast, brightness, and random left/right and X/Y translation. A convolutional neural network (CNN) for semantic image segmentation composed of an encoder and corresponding decoder subnetwork was set up. The network was pre-initialized with layers and weights from a pre-trained VGG 16 model. Following the network was trained with the labeled image data set. A validation data set of 18 scans (3289 slices) was used to monitor the performance as the deep CNN trained. The classification results were tested on 18 randomly allocated labeled data sets (3319 slices) and on a T2-weighted BrainWeb data set with known ground truth.

Results

The segmentation of clinical test data provided reliable results (global accuracy 0.90, Dice coefficient 0.86), while the CNN segmentation of data from the BrainWeb data set showed comparable results (global accuracy 0.89, Dice coefficient 0.84). The segmentation of the BrainWeb data set with the classical FAST algorithm produced consistent findings (global accuracy 0.90, Dice coefficient 0.87). Likewise, the area development of brain and CSF in the long-term clinical course of three patients was presented.

Conclusion

Using the presented methods, we showed that conventional segmentation algorithms can be transferred to new advances in deep learning with comparable accuracy, generating a large number of training data sets with relatively little effort. A clinically meaningful segmentation possibility was demonstrated.

Changes of third ventricle diameter (TVD) mirror changes of the entire ventricular system at acute shunt failure and after shunt revision in pediatric hydrocephalus

PURPOSE

In hydrocephalic children, regular investigations of the ventricles are important for initial diagnosis and after initial treatment. Our recent study showed that changes of the third ventricle diameter (TVD) reliably reflect changes of the entire ventricular system at diagnosis and following initial therapy. This study compares changes of TVD with changes of ventricle indices at acute shunt failure and after shunt revision in hydrocephalic children.

METHODS

A total of 117 children with hydrocephalus were included in this study. MRI/CT images of 30 children were evaluated at the time of acute shunt dysfunction and after subsequent shunt revision. Measurements included axial TVD and three standard measures of lateral ventricles (Evans index, frontal occipital horn ratio (FOHR), and cella media index (CMI)). In 97 children, correlation between axial and coronal/diagonal TVD was evaluated at the time of initial diagnosis of hydrocephalus.

RESULTS

At acute shunt dysfunction, the best linear correlation was found between TVD and CMI (r = 0.702, p < 0.01). Changes of TVD correlated very well to changes of FOHR (r = 0.74, p < 0.01) after shunt revision. The correlation between axial and coronal/diagonal TVD was outstanding (r = 0.995, p < 0.01).

CONCLUSION

TVD showed a significant correlation with all lateral ventricle indices at acute shunt dysfunction and after shunt revision. It is therefore not only an excellent mirror of ventricular changes at initial hydrocephalus diagnosis and therapy, but it can also reliably reflect changes of the ventricular system in relevant clinical situations associated with the lifelong treatment of pediatric hydrocephalus.

Planar single plane area determination is a viable substitute for total volumetry of CSF and brain in childhood hydrocephalus

BACKGROUND

In the treatment of childhood hydrocephalus, 3D volumetry seems to have many advantages over classical planar index measurements for dedicated monitoring of changes in cerebrospinal fluid and brain volume. Nevertheless, this method requires extensive technical effort and access to the complete three-dimensional data set. Against this background, we evaluated the possibility of planar area determination in a single plane and the correlation to volumetry.

METHODS

138 routinely performed true FISP MRI sequences (1 mm isovoxel) were analyzed retrospectively in 68 patients with pediatric hydrocephalus. After preprocessing, the 3D-data sets were skull stripped to estimate the inner skull volume. A 2-class segmentation into different tissue types (brain matter and CSF) was performed, and the volumes of CSF (VCSF) and brain matter (VBrain) were calculated. A plane at the level of the foramina of Monro was manually identified in the ac-pc oriented data. In this plane, the areas of brain (ABrain) and CSF (ACSF) in cm² were calculated and used for further correlation analysis.

RESULTS

Mean VCSF was 340 ± 145 cm³ and VBrain 1173 ± 254 cm³. In the selected plane, ACSF was 26 ± 14 cm², and ABrain was 107 ± 25 cm². There was a very strong positive correlation between both ACSF and VCSF (r = 0.895) and between ABrain and VBrain (r = 0.846). The prediction equations for VBrain and VCSF were highly significant.

CONCLUSION

Planar area determination of brain and CSF correlates excellently with both VCSF and VBrain. Thus, areas can serve as a surrogate marker for total brain and CSF volumes for a quantitated objective tracking of changes during treatment of childhood hydrocephalus.

Changes of third ventricle diameter (TVD) mirror changes of the entire ventricular system after initial therapy and during follow-up in pediatric hydrocephalus

PURPOSE

Regular measurement of ventricular size is important in children with hydrocephalus. After closure of the fontanelle this is currently addressed by repetitive cranial MRI or CT imaging, coming along with risks of anaesthesia or radiation. As the third ventricle is accessible via the temporal bone window using ultrasound, determination of its diameter might be an easy and radiation-free alternative to assess the ventricular system. An essential precondition is that changes of the third ventricle diameter (TVD) mirror changes of the whole ventricular system. This study compares changes of TVD with changes of ventricular indices before and after initial treatment of hydrocephalus and during the following evolution.

METHODS

MRT/CT images from 117 children with hydrocephalus were evaluated at time of diagnosis, after initial therapy and during follow-up with functional shunts. Measurements included axial TVD and three standard linear measures of the lateral ventricles (Evans Index - EI, fronto-occipital horn ratio - FOHR Index, and Cella Media Index - CMI). Furthermore, a correlation within subjects was calculated in 8 patients over the entire available follow-up.

RESULTS

Relative changes of TVD were significantly correlated to relative changes of all ventricular indices (r = 0.48, r = 0.68 and r = 0.701 for EI, FOHR and CMI, respectively, p < 0.01). The correlation within subjects was outstanding for EI (r = 0.988), FOHR (r = 0.99) and CMI (r = 0.99).

CONCLUSION

TVD showed a significant correlation with all three linear indices at the time of diagnosis and during follow-up changes independently of age, aetiology and ventricular width. TVD and its changes are therefore a reliable surrogate of changes in ventricular size in pediatric hydrocephalus undergoing treatment.

Neurogenic Bladder Dysfunction as Signal of Late Failure of Endoscopic Third Ventriculostomy in Child with Spina Bifida

BACKGROUND

Endoscopic third ventriculostomy (ETV) is an option for hydrocephalus treatment in patients with myelomeningocele, mostly after a previous shunt dysfunction. Late failure of ETV is a rare event, traditionally associated with dramatic symptoms of intracranial hypertension. In patients with myelodysplasia and neurogenic bladder dysfunction, urodynamic deterioration can be a signal of neurologic worsening as a consequence of tethered cord or shunt problems.

CASE DESCRIPTION

We describe here a rare case of a 12-year-old female patient with myelomeningocele and evidence of a failure 10 years after a previously successful ETV whose initial symptoms were worsening of urinary complaints. After 2 months, she was admitted to the emergency department with seizures and acute hydrocephalus and was shunted.

CONCLUSIONS

Pediatric neurosurgeons must follow myelomeningocele patients with successful ETV for a long time and take care of subtle alterations of organic functions that have a close relationship with central nervous system integrity. A multidisciplinary approach can facilitate this strategy and avoid a tragic outcome.

The value of CSF flow studies in the management of CSF disorders in children: a pictorial review

CSF flow disorders are frequently encountered in children. The advent of MR technology with the emergence of new pulse sequences allowed better understanding of CSF flow dynamics. In this pictorial review, we aim to conduct a comprehensive review of the MR protocol used to study CSF flow disorders and to discuss the utility of each pulse sequence in the adopted protocol. We will focus on the key anatomical structures that should be examined to differentiate hydrocephalus form ventricular dilatation ex-vacuo. The MR features of obstructive and communicating hydrocephalus will be discussed, in addition to the manifestations of CSF disorders associated with posterior fossa malformations (Dandy-Walker malformation, Chiari, and Blake’s pouch cyst). Moreover, the value of MRI in the assessment of patients following interventional procedures (ventriculoperitoneal shunt and third ventriculostomy) will be addressed.

Operative planning aid for optimal endoscopic third ventriculostomy entry points in pediatric cases

OBJECT

Endoscopic third ventriculostomy (ETV) uses anatomical spaces of the ventricular system to reach the third ventricle floor and create an alternative pathway for cerebrospinal fluid flow. Optimal ETV trajectories have been previously proposed in the literature, designed to grant access to the third ventricle floor without a displacement of eloquent periventricular structures. However, in hydrocephalus, there is a significant variability to the configuration of the ventricular system, implying that the optimal ETV trajectory and cranial entry point needs to be planned on a case-by-case basis. In the current study, we created a mathematical model, which tailors the optimal ETV entry point to the individual case by incorporating the ventricle dimensions.

METHODS

We retrospectively reviewed the imaging of 30 consecutive pediatric patients with varying degrees of ventriculomegaly. Three dimensional radioanatomical models were created using preoperative MRI scans to simulate the optimal ETV trajectory and entry point for each case. The surface location of cranial entry points for individual ETV trajectories was recorded as Cartesian coordinates centered at Bregma. The distance from the Bregma in the coronal plane represented as "x", and the distance from the coronal suture in the sagittal plane represented as "y". The correlation between the ventricle dimensions and the x, y coordinates were tested using linear regression models.

RESULTS

The distance of the optimal ETV entry point from the Bregma in the coronal plane ("x") and from the coronal suture in the sagittal plane ("y") correlated well with the frontal horn ratio (FHR). The coordinates for x and y were fitted along the following linear equations: x = 85.8 FHR-13.3 (r ² = 0.84, p < 0.001) and y = -69.6 FHR + 16.7 (r ² = 0.83, p < 0.001).

CONCLUSION

The surface location of the optimal cranial ETV entry point correlates well with the ventricle size. We provide the first model that can be used as a surgical planning aid for a case specific ETV entry site with the incorporation of the ventricle size.

Long-term mortality rates in pediatric hydrocephalus-a retrospective single-center study

PURPOSE

Very long-term follow-up and outcome are rare for pediatric patients with hydrocephalus and shunt operations. The aim of this study was to determine the long-term mortality rates in these patients.

METHODS

Pediatric patients with first shunt operation between 1982 and 1992 were included. For each patient, time and cause of death were determined. Further, patients with first operation from 1982 to 1987 were compared to those first operated from 1988 to 1992.

RESULTS

One-hundred thirty-seven patients were included. Etiologies of hydrocephalus were intraventricular hemorrhage (31.4 %), meningomyelocele (25.5 %), postinfectious (11.7 %), congenital (10.2 %), posterior fossa cyst (8.8 %), aqueductal stenosis (8 %), and others (4.4 %). Overall, 53 patients (38.7 %) died. The percentage of patients surviving 1, 2, 10, and 20 years after first operation were 82.6, 73.6, 69.4, and 65.3 %, respectively. In 23 patients, the cause of death was related to shunt treatment: shunt infection was diagnosed in 18 and acute shunt dysfunction in 5 patients. Mortality was considerably higher for patients with their first operation in time period 1982-1987 compared to time period 1988-1992 (51 versus 25 %). The reduction of mortality was mainly due to an increased survival after shunt infection. Eighty-seven patients survived more than 20 years after initial shunt operation. Of those long-term survivors, three (3.4 %) patients died 22-24 years after first operation.

CONCLUSION

Mortality in hydrocephalic pediatric patients is high especially in the first postoperative years but is even significant in adult patients with pediatric hydrocephalus. As deaths occur even after 20 years, routine follow-up of long-term survivors remains necessary.

Advanced Neuroimaging Techniques in Pediatric Hydrocephalus

From the early days of pneumoencephalography and ventriculography to the emerging technology of magnetic resonance diffusion tensor imaging (DTI) of the present day, neuroimaging has always been a critical tool in the diagnosis and treatment of pediatric hydrocephalus. There is accumulating evidence from both human and animal research suggesting that one of the major pathophysiological mechanisms underlying poor outcomes in these children is damage to vulnerable white matter (WM) structures in the brain as a result of ventricular enlargement and increased intracranial pressure. However, a clear understanding of these WM abnormalities and their implications on neurobehavioral outcomes in these patients is not well understood. To this end, DTI has recently been studied to allow noninvasive quantification of these abnormalities. Our review discusses the evolution of neuroimaging in pediatric hydrocephalus and focuses on the use of advanced imaging techniques, such as DTI, which is supported by a growing body of literature as a promising noninvasive imaging tool in the diagnosis and long-term management of this patient population. We conclude with a brief discussion on emerging techniques and experimental imaging.

Surgical outcome of the shunt: 15-year experience in a single institution

PURPOSE

Surgical outcome after shunt insertion in pediatric hydrocephalus can vary greatly. Although first shunt survival rates and complications have been studied by several teams, much less is known about survival and complications of subsequent systems. The goals of this study were to evaluate the surgical outcome in a series of pediatric patients followed for a long time and establish the differences between first and subsequent extracranial shunt survival and complications.

METHODS

We undertook a retrospective study in pediatric patients treated with ventriculoperitoneal shunts between 2000 and 2015 at our institution. Surgical outcome was assessed, and different shunt survival curves were studied with Kaplan-Meier. Complications related to each shunt failure were examined and compared.

RESULTS

A total of 166 patients underwent 425 procedures, with a mean follow-up period of 93 months. The median number of shunt revision surgeries was 2. Shunt survival rates were better with the first shunt compared to those with the subsequent shunts. The main complication necessitating system revision surgery was overdrainage, the frequency of proximal and distal dysfunctions was similar in all the shunt failures, and isolated ventricle and infection were more frequent in younger patients. Shunt-related infections accounted for 7 % of the procedures, and the shunt independence rate was 10 %.

CONCLUSIONS

The frequency of complications related to shunt failure in pediatric patients changes during follow-up. A strict protocol of overdrainage detection and active treatment could explain the need for repeat surgeries and the progressively shorter shunt survival time in our series.

Left hemisphere structural connectivity abnormality in pediatric hydrocephalus patients following surgery

Neuroimaging research in surgically treated pediatric hydrocephalus patients remains challenging due to the artifact caused by programmable shunt. Our previous study has demonstrated significant alterations in the whole brain white matter structural connectivity based on diffusion tensor imaging (DTI) and graph theoretical analysis in children with hydrocephalus prior to surgery or in surgically treated children without programmable shunts. This study seeks to investigate the impact of brain injury on the topological features in the left hemisphere, contratelateral to the shunt placement, which will avoid the influence of shunt artifacts and makes further group comparisons feasible for children with programmable shunt valves. Three groups of children (34 in the control group, 12 in the 3-month post-surgery group, and 24 in the 12-month post-surgery group, age between 1 and 18 years) were included in the study. The structural connectivity data processing and analysis were performed based on DTI and graph theoretical analysis. Specific procedures were revised to include only left brain imaging data in normalization, parcellation, and fiber counting from DTI tractography. Our results showed that, when compared to controls, children with hydrocephalus in both the 3-month and 12-month post-surgery groups had significantly lower normalized clustering coefficient, lower small-worldness, and higher global efficiency (all p < 0.05, corrected). At a regional level, both patient groups showed significant alteration in one or more regional connectivity measures in a series of brain regions in the left hemisphere (8 and 10 regions in the 3-month post-surgery and the 12-month post-surgery group, respectively, all p < 0.05, corrected). No significant correlation was found between any of the global or regional measures and the contemporaneous neuropsychological outcomes [the General Adaptive Composite (GAC) from the Adaptive Behavior Assessment System, Second Edition (ABAS-II)]. However, one global network measure (global efficiency) and two regional network measures in the insula (local efficiency and between centrality) tested at 3-month post-surgery were found to correlate with GAC score tested at 12-month post-surgery with statistical significance (all p < 0.05, corrected). Our data showed that the structural connectivity analysis based on DTI and graph theory was sensitive in detecting both global and regional network abnormality when the analysis was conducted in the left hemisphere only. This approach provides a new avenue enabling the application of advanced neuroimaging analysis methods in quantifying brain damage in children with hydrocephalus surgically treated with programmable shunts.

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We studied the structural connectivity of left hemisphere brain network in children with hydrocephalus post-surgery

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Children with hydrocephalus post-surgery had significantly abnormal structural connectivity in the left hemisphere based on graph analysis

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Significant correlation was found between graph measures at 3-months post-surgery and developmental outcome at 12-month post-surgery

MR assessment of pediatric hydrocephalus: a road map

PURPOSE

This study was conducted to design a rational approach to the MR diagnosis of hydrocephalus based on a pathophysiologic reevaluation of its possible mechanisms and to apply it to the different etiological contexts.

METHOD

A review of the literature reports describing new physiologic models of production and absorption and of the hydrodynamics of the CSF was made.

RESULTS

Besides the secretion of CSF by the choroid plexuses, and its passive, pressure-dependent transdural absorption (arachnoid villi, dural clefts, cranial, and spinal nerve sheaths), water transporters, aquaporins, allow water (if not ions and organic molecules) to exchange freely between the brain parenchyma and the CSF spaces across the ependymal and the pial interfaces (including the Virchow-Robin spaces). Consequently, the CSF bulk flow is not necessarily global, and situations of balanced absorption-secretion may occur separately in different CSF compartments such as the ventricular, intracranial, or intraspinal CSF spaces. This means that rather than from a hypothetical pressure gradient from the plexuses to the dural sinuses, the dynamics of the CSF depend on the force provided in those different compartments by the arterial systolic pulsation of the pericerebral (mostly), intracerebral, and intraventricular (choroid plexuses) vascular beds.

CONCLUSION

Using MR imaging, diverse varieties of hydrocephalus may tentatively be explained by applying those concepts to the correspondingly diverse causal diseases. Hopefully, this may have an impact on the choice of the treatment strategies also.

Abnormal structural connectivity in the brain networks of children with hydrocephalus

Increased intracranial pressure and ventriculomegaly in children with hydrocephalus are known to have adverse effects on white matter structure. This study seeks to investigate the impact of hydrocephalus on topological features of brain networks in children. The goal was to investigate structural network connectivity, at both global and regional levels, in the brains in children with hydrocephalus using graph theory analysis and diffusion tensor tractography. Three groups of children were included in the study (29 normally developing controls, 9 preoperative hydrocephalus patients, and 17 postoperative hydrocephalus patients). Graph theory analysis was applied to calculate the global network measures including small-worldness, normalized clustering coefficients, normalized characteristic path length, global efficiency, and modularity. Abnormalities in regional network parameters, including nodal degree, local efficiency, clustering coefficient, and betweenness centrality, were also compared between the two patients groups (separately) and the controls using two tailed t-test at significance level of p < 0.05 (corrected for multiple comparison). Children with hydrocephalus in both the preoperative and postoperative groups were found to have significantly lower small-worldness and lower normalized clustering coefficient than controls. Children with hydrocephalus in the postoperative group were also found to have significantly lower normalized characteristic path length and lower modularity. At regional level, significant group differences (or differences at trend level) in regional network measures were found between hydrocephalus patients and the controls in a series of brain regions including the medial occipital gyrus, medial frontal gyrus, thalamus, cingulate gyrus, lingual gyrus, rectal gyrus, caudate, cuneus, and insular. Our data showed that structural connectivity analysis using graph theory and diffusion tensor tractography is sensitive to detect abnormalities of brain network connectivity associated with hydrocephalus at both global and regional levels, thus providing a new avenue for potential diagnosis and prognosis tool for children with hydrocephalus.