Management of posterior fossa tumors and hydrocephalus in children: a review

Pediatric hemispheric cerebellar low-grade gliomas: clinical approach, diagnosis, and management challenges-experience at a tertiary care children's hospital

PURPOSE

This study aims to provide an exhaustive analysis of pediatric low-grade gliomas (pLGGs) in the cerebellar hemispheres, focusing on incidence, clinical characteristics, surgical outcomes, and prognosis. It seeks to enhance understanding and management of pLGGs in the pediatric population.

METHODS

We conducted an observational, descriptive, retrospective, and cross-sectional study at a pediatric hospital, reviewing medical records of 30 patients with cerebellar hemispheric pLGGs treated from December 2014 to January 2023. Data collection included demographics, clinical presentation, imaging findings, surgical approach, postoperative complications, histopathological diagnosis, hydrocephalus management, and follow-up. Molecular markers and adjuvant therapies were also analyzed.

RESULTS

The cohort predominantly presented with cerebellar symptoms, with 60% showing hydrocephalus at diagnosis. MRI with gadolinium was crucial for diagnosis. Surgical focus was on achieving gross total resection (GTR), accomplished in 70% of cases. Postsurgical hydrocephalus was less common, and cerebellar mutism was not reported. While a complete molecular analysis was not performed in all cases, available data suggest significant influence of molecular markers on prognosis and therapeutic options of pLGGs.

CONCLUSIONS

This study highlights the unique clinical and molecular characteristics of cerebellar hemispheric pLGGs in children. The lower incidence of postoperative hydrocephalus and absence of cerebellar mutism are notable findings. Emphasizing a multidisciplinary approach, our findings contribute to a deeper understanding of pediatric pLGGs, underscoring the need for personalized treatment strategies and vigilant follow-up.

Prevalence of dysphagia following posterior fossa tumor resection: a systematic review and meta‑analysis

OBJECTIVE

Dysphagia is common in individuals who have undergone posterior fossa tumor (PFT) resection and negatively impacts on the individual's quality of life, nutritional status, and overall health. We aimed to quantitatively synthesize data from studies of the prevalence of dysphagia following PFT resection.

METHODS

PubMed, Web of Science, the Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), Wanfang database, and VIP database were searched for case-control and cross-sectional studies that evaluated the prevalence of dysphagia after PFT surgery. Meta-analyses were performed to determine the prevalence of dysphagia. Subgroup and meta-regression analyses were performed to determine the sources of heterogeneity among the studies.

RESULTS

A total of 22 studies were included, involving 20,921 cases. A meta-analysis of the random-effects model showed that the pooled global prevalence of dysphagia following PFT resection was 21.7% (95% confidence interval: 16.9-26.6). The subgroup and meta-regression analyses demonstrated that participant age (P < 0.001), assessment methods (P = 0.004), and geographical region of the study participants (P = 0.001) were sources of heterogeneity among the studies.

CONCLUSIONS

Dysphagia has a high prevalence following PFT resection. Individuals with PFTs who are at a high risk for dysphagia should be identified early through screening. Multidisciplinary diagnosis and treatment of dysphagia are required to improve the outcomes in the early stages after PFT resection.

Characterizing the association between CSF biomarkers and risk for ventriculoperitoneal shunt following posterior fossa tumor resection in a case-control study

BACKGROUND

Recalcitrant hydrocephalus necessitating permanent cerebrospinal fluid (CSF) diversion is a known complication after resection of a posterior fossa tumor (PFT). Various CSF contents, such as protein and other markers, have been variably correlated with the need for permanent CSF diversion. This study aims to evaluate which CSF laboratory values are associated with permanent CSF diversion following PFT resection in adults.

METHODS

This study queried our multi-institutional database (Central Nervous System Tumor Outcome Registry at Emory; CTORE) consisting of 617 adult patients with PFT resections from 2006 to 2021. Retrospective data was collected from the 89 patients of this cohort that required EVD placement. Patients were stratified into two groups: those that required a shunt following EVD removal (n = 30) and those that did not (n = 40). CSF variables collected included glucose, protein, nucleated cell count, and presence of infection. An unadjusted logistic regression was performed to assess exposures associated with shunt requirement and unadjusted odds ratios (ORs) and their associated 95 % confidence intervals (CIs) were obtained.

RESULTS

Immediately following surgery, no CSF variables were significantly associated with shunt placement. Except for post-operative CSF being not-clear (OR: 4.15 (1.47-12.56), p = 0.009) and CSF glucose (OR: 0.97 (1.03-1.07), p = 0.031) all other variables were not significantly associated with shunt at time point 2.

CONCLUSION

In our retrospective analysis, most routinely collected CSF values were not associated with permanent CSF diversion via a ventriculoperitoneal shunt following PFT resection. Further research is needed to identify other potential predictive markers.

Analysis of Evolution of Hydrocephalus in Posterior Fossa Tumors and Validation Study of the Modified Canadian Preoperative Prediction Rule for Hydrocephalus in Children and Frankfurt Grading System for Prediction of Cerebrospinal Fluid Diversion in Adults with Posterior Fossa Tumors

OBJECTIVE

We sought to analyze the evolution of hydrocephalus and enumerate its predictive factors in posterior fossa tumors in children and adults. We also validated the modified Canadian Preoperative Prediction Rule for Hydrocephalus (mCPPRH) and Frankfurt grading systems as tools to predict cerebrospinal fluid (CSF) diversion in children and adults, respectively.

METHODS

A retrospective review of patients with posterior fossa tumors operated between 2012 and 2019 was performed. Clinical, radiologic, and operative data were obtained. Validation was performed for both scores via receiver operating characteristic (ROC) curves and evaluation of the area under the curve (AUC).

RESULTS

We included 116 children and 343 adults in the study. Of the adults, 141 patients had intraaxial tumors and 172 had extraaxial tumors. The insertion of external ventricular drain (EVD), its duration, papilledema was noted to have significant influence on the need for permanent CSF diversion (P < 0.05) in children. The ROC for mCPPRH score was 0.659 (0.501-0.816), Age- 0.496 (0.334-0.658) and Evans index- 0.788 (0.654-0.922). In adults- Intraaxial tumours Age, Frankfurt score, duration of EVD, Diagnosis, Extent of resection and periventricular capping significant predictors and ROC age AUC 0.300 (0.193-0.407), Evans index 0.939 (0.888-0.990), and Frankfurt score 0.908 (0.853-0.964) (P < 0.05), whereas in extraaxial tumors Frankfurt grading, sex, duration of EVD, presence of perilesional edema and extent of resection (P < 0.05) ROC age AUC 0.439 (0.344-0.534), Evans index 0.941 (0.906-0.977), and Frankfurt score 0.847 (0.782-0.912).

CONCLUSIONS

This is the first external validation study for the 2 predictive systems in use. mCPPRH demonstrated poor predictive accuracy, and Frankfurt grading system demonstrated good accuracy. EVD insertion and its duration was significantly predictive of the need for permanent CSF diversion.

Predictive factors for persistent postoperative hydrocephalus in children undergoing surgical resection of periventricular tumors

Objective

The aim of this study is to identify the factors predicting persistent hydrocephalus after periventricular tumor resection in children and assess the need and efficacy of perioperative cerebrospinal fluid (CSF) intervention.

Methods

We performed a retrospective analysis of pediatric patients who underwent resection surgery of a periventricular tumor between March 2012 and July 2021 at the Department of Neurosurgery in Zhujiang Hospital of South Medical University. Demographic, radiographic, perioperative, and dispositional data were analyzed using univariate and multivariate models.

Results

A total of 117 patients were enrolled in our study. Incidence of postoperative persistent hydrocephalus varied with tumor pathology (p = 0.041), tumor location (p = 0.046), surgical approach (p = 0.013), extension of resection (p = 0.043), tumor volume (p = 0.041), preoperative Evan's index (p = 0.002), and preoperative CSF diversion (p = 0.024). On logistic regression, posterior median approach (OR = 5.315), partial resection (OR = 20.984), volume > 90cm³ (OR = 5.768), and no preoperative CSF diversion (OR = 3.661) were independent predictors of postoperative persistent hydrocephalus. Preoperative Evan's index is significantly correlated with tumor volume (p = 0.019). Meanwhile, the need for preoperative CSF drainage in patients in this cohort was significantly correlated with tumor location (p = 0.019).

Conclusion

Tumor pathology, location, surgical approach, the extension of resection, tumor volume, preoperative Evan's index, and preoperative CSF diversion were considered to be predictive factors for postoperative persistent hydrocephalus. Notably, posterior median approach, partial resection, and tumor volume > 90cm³, without preoperative CSF diversion, were identified as independent risk factors for persistent postoperative hydrocephalus. Preoperative identification of children at risk of developing persistent postoperative hydrocephalus would avoid delays in planning the cerebrospinal fluid diversion. Active and effective preoperative hydrocephalus intervention in children with periventricular tumors is beneficial to reduce the incidence of persistent hydrocephalus and ventriculoperitoneal shunt surgery after resection.

Obstructive Hydrocephalus Due to Posterior Fossa Tumors in Adults: A Comparative Analysis of 3 Surgical Techniques

BACKGROUND

The main treatments for hydrocephalus due to posterior fossa tumors are tumor resection with or without an external ventricular drain, ventriculoperitoneal shunt (VPS), and endoscopic third ventriculostomy. Although preoperative cerebrospinal fluid diversion by any of these techniques improves clinical outcomes, evidence comparing the efficacy of these techniques is scarce. Therefore, we aimed to retrospectively evaluate each treatment modality.

METHODS

This single-center study analyzed 55 patients. Treatments were classified as successful (hydrocephalus resolution with a single surgical event) or failed and compared with a χ2 test. Kaplan-Meier curves and log-rank tests were employed. A Cox proportional hazard model was used to determine relevant covariates predicting outcomes.

RESULTS

Mean patient age was 36.3 years, 43.4% of patients were men, and 50.9% of patients presented with uncompensated intracranial hypertension. Mean tumor volume was 33.4 cm3, and extent of resection was 90.85%. Tumor resection with or without an external ventricular drain was successful in 58.82% of cases, VPS was successful in 100%, and endoscopic third ventriculostomy was successful in 76.19% (P = 0.014). Mean follow-up time was 15.12 months. Log-rank test found statistically significant differences between survival curves of treatments (P = 0.016) favoring the VPS group. Postoperative surgical site hematoma was a significant covariate in the Cox model (hazard ratio = 17; 95% confidence ratio, 2.301-81.872; P = 0.004).

CONCLUSIONS

This study favored VPS as the most reliable treatment of hydrocephalus due to posterior fossa tumors in adult patient; however, several factors influence clinical outcomes. We proposed an algorithm based on our findings and other authors' findings to facilitate the decision-making process.

Treatment of hydrocephalus following posterior fossa tumor resection: a multicenter collaboration from the Hydrocephalus Clinical Research Network

OBJECTIVE

Persistent hydrocephalus following posterior fossa brain tumor (PFBT) resection is a common cause of morbidity in pediatric brain tumor patients, for which the optimal treatment is debated. The purpose of this study was to compare treatment outcomes between VPS and ETV in patients with persistent hydrocephalus following surgical resection of a PFBT.

METHODS

A post-hoc analysis was performed of the Hydrocephalus Clinical Research Network (HCRN) prospective observational study evaluating VPS and ETV for pediatric patients. Children who experienced hydrocephalus secondary to PFBT from 2008 to 2021 were included. Primary outcomes were VPS/ETV treatment failure and time-to-failure (TTF).

RESULTS

Among 241 patients, the VPS (183) and ETV (58) groups were similar in age, extent of tumor resection, and preoperative ETV Success Score. There was no difference in overall treatment failure between VPS and ETV (33.9% vs 31.0%, p = 0.751). However, mean TTF was shorter for ETV than VPS (0.45 years vs 1.30 years, p = 0.001). While major complication profiles were similar, compared to VPS, ETV patients had relatively higher incidence of minor CSF leak (10.3% vs. 1.1%, p = 0.003) and pseudomeningocele (12.1% vs 3.3%, p = 0.02). No ETV failures were identified beyond 3 years, while shunt failures occurred beyond 5 years. Shunt infections occurred in 5.5% of the VPS cohort.

CONCLUSIONS

ETV and VPS offer similar overall success rates for PFBT-related postoperative hydrocephalus. ETV failure occurs earlier, while susceptibility to VPS failure persists beyond 5 years. Tumor histology and grade may be considered when selecting the optimal means of CSF diversion.

Sensitivity of Papilledema as a Sign of Increased Intracranial Pressure

Our study evaluates the sensitivity of papilledema as a sign of high intracranial pressure in children. Patients younger than 18 years old, diagnosed with increased ICP, and who had received dilated fundus examination between 2019 and 2021 were retrospectively reviewed. Factors including the patient's age, sex, aetiology, duration of signs or symptoms, intracranial pressure (ICP), and presence of papilledema were evaluated. We included 39 patients in this study, whose mean age was 6.7 years. The 31 patients without papilledema had a mean age of 5.7 years, and 8 patients (20%) with papilledema had a mean age of 10.4 (p < 0.037). The mean duration of signs or symptoms was nine weeks in patients without papilledema and seven weeks in those with papilledema (p = 0.410). The leading causes of increased ICP with papilledema were supratentorial tumor (12.5%), infratentorial tumor (33.3%), and hydrocephalus (20%) (p = 0.479). Papilledema was statistically significantly more common in older patients. We found no statistical significance between sex, diagnosis, and symptoms. The relatively low incidence of papilledema (20%) in our study shows that papilledema's absence does not ensure the absence of increased ICP, especially in younger patients.

Posterior Fossa Laser Interstitial Thermal Therapy in Children

Real-time, MRI-guided laser interstitial thermal therapy (MRgLITT) is emerging as a minimally invasive technique for epilepsy surgery and for deep-seated tumors in the pediatric population. However, MRgLITT for posterior fossa lesions poses a unique challenge that is especially evident in this age range and remains understudied. In this study, we report our experience and analyze the current literature on MRgLITT for the treatment of posterior fossa in children.

Placement of EVD in pediatric posterior fossa tumors: safe and efficient or old-fashioned? The Vienna experience

PURPOSE

The perioperative treatment of hydrocephalus in pediatric posterior fossa tumors with an external ventricular drain (EVD) is the treatment of choice in our center. We analyzed our experience in using EVD concerning safety and effectivity.

METHODS

This is a single-center retrospective cohort study of 100 consecutive pediatric patients who underwent resection for a newly diagnosed tumor in the posterior fossa between 2011 and 2022.

RESULTS

Of the 100 patients with posterior fossa tumors, 80 patients (80%) had radiological signs of hydrocephalus at presentation, 49 patients (49%) of whom underwent placement of an EVD. In 40 patients, the EVD was inserted at a mean of 2.25 days prior to the tumor resection; 9 had the EVD inserted during tumor resection (frontal trajectory in 7 patients, occipital trajectory in 2 patients). Histology revealed pilocytic astrocytoma in 48 patients, medulloblastoma in 32, ependymoma in 11, and other histologic entities in 9 patients. Gross total/near-total resection was achieved in 46 (95.83%) of the 48 pilocytic astrocytomas, 30 (93.75%) of the 32 medulloblastomas, and 11 (100%) of the 11 ependymomas. The mean number of total days with the EVD in place was 8.61 ± 3.82 (range 2-16 days). The mean number of days with an EVD after tumor resection was 6.35 ± 3.8 (range 0-16 days). EVD-associated complications were seen in 6 patients (12.24%) including one infection. None of these resulted in a worse clinical course or any long-term sequelae. Permanent CSF diversion at 6 months after surgery was necessary in 13 patients (13%), including two VP shunt, two SD-shunt, six endoscopic third ventriculostomy (ETV), and three combined VP shunt and ETV procedures. Patients with a medulloblastoma or ependymoma had a higher rate of permanent CSF diversion needed than the group of pilocytic astrocytoma patients (27.9% versus 2.13%, p < 0.001). In patients with metastatic disease, 7 of 17 patients (41.18%) needed a permanent CSF diversion, compared to 6 of 83 patients (7.23%) in the group without metastasis (p = 0.001).

CONCLUSION

The treatment of hydrocephalus in pediatric posterior fossa tumors with an EVD as a temporary measure is safe and effective, provided that a multi-professional understanding for its handling is given and there is no need for a long transport of the children.

Childhood cancer and hematological disorders negatively affect spermatogonial quantity at diagnosis: a retrospective study of a male fertility preservation cohort

STUDY QUESTION

What is the impact of cancer or hematological disorders on germ cells in pediatric male patients?

SUMMARY ANSWER

Spermatogonial quantity is reduced in testes of prepubertal boys diagnosed with cancer or severe hematological disorder compared to healthy controls and this reduction is disease and age dependent: patients with central nervous system cancer (CNS tumors) and hematological disorders, as well as boys <7 years are the most affected.

WHAT IS KNOWN ALREADY

Fertility preservation in pediatric male patients is considered based on the gonadotoxicity of selected treatments. Although treatment effects on germ cells have been extensively investigated, limited data are available on the effect of the disease on the prepubertal male gonad. Of the few studies investigating the effects of cancer or hematologic disorders on testicular function and germ cell quantity in prepuberty, the results are inconsistent. However, recent studies suggested impairments before the initiation of known gonadotoxic therapy. Understanding which diseases and at what age affect the germ cell pool in pediatric patients before treatment is critical to optimize strategies and counseling for fertility preservation.

STUDY DESIGN, SIZE, DURATION

This multicenter retrospective cohort study included 101 boys aged <14 years with extra-cerebral cancer (solid tumors), CNS tumors, leukemia/lymphoma (blood cancer), or non-malignant hematological disorders, who were admitted for a fertility preservation programme between 2002 and 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In addition to clinical data, we analyzed measurements of testicular volume and performed histological staining on testicular biopsies obtained before treatment, at cryopreservation, to evaluate number of spermatogonia per tubular cross-section, tubular fertility index, and the most advanced germ cell type prior to chemo-/radiotherapy. The controls were data simulations with summary statistics from original studies reporting healthy prepubertal boys' testes characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

Prepubertal patients with childhood cancer or hematological disorders were more likely to have significantly reduced spermatogonial quantity compared to healthy controls (48.5% versus 31.0% prevalence, respectively). The prevalence of patients with reduced spermatogonial quantity was highest in the CNS tumor (56.7%) and the hematological disorder (55.6%) groups, including patients with hydroxyurea pre-treated sickle cell disease (58.3%) and patients not exposed to hydroxyurea (50%). Disease also adversely impacted spermatogonial distribution and differentiation. Irrespective of disease, we observed the highest spermatogonial quantity reduction in patients <7 years of age.

LIMITATIONS, REASONS FOR CAUTION

For ethical reasons, we could not collect spermatogonial quantity data in healthy prepubertal boys as controls and thus deployed statistical simulation on data from literature. Also, our results should be interpreted considering low patient numbers per (sub)group.

WIDER IMPLICATIONS OF THE FINDINGS

Cancers, especially CNS tumors, and severe hematological disorders can affect spermatogonial quantity in prepubertal boys before treatment. Consequently, these patients may have a higher risk of depleted spermatogonia following therapies, resulting in persistent infertility. Therefore, patient counseling prior to disease treatment and timing of fertility preservation should not only be based on treatment regimes, but also on diagnoses and age.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Marie Curie Initial Training Network (ITN) (EU-FP7-PEOPLE-2013-ITN) funded by European Commision grant no. 603568; ZonMW Translational Adult stem cell research (TAS) grant no. 116003002. No competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Contribution of tumor characteristics and surgery-related factors to symptomatic hydrocephalus after posterior fossa tumor resection: a single-institution experience

OBJECTIVE

Pediatric patients are at risk of persistent hydrocephalus after posterior fossa tumor resection. The relationship between surgery-related factors and postoperative symptomatic hydrocephalus has not been elucidated. The objective of this study was to analyze features influencing postoperative hydrocephalus in Chinese children.

METHODS

The authors retrospectively evaluated 197 patients younger than 15 years of age who underwent posterior fossa tumor resection at their institution from January 2015 to June 2021. The outcome was whether children underwent CSF diversion within 6 months of resection. Preoperative characteristics, surgery-related factors, and postoperative features were included to identify independent prognosticators. A new logistic model containing independent prognosticators was developed and compared with the modified Canadian Preoperative Prediction Rule for Hydrocephalus (mCPPRH).

RESULTS

In this study, 30 patients (15.2%) underwent CSF diversion within 6 months after tumor resection. Tumor location and consistency, intracranial or spinal tumor metastasis determined by perioperative cerebral and spinal MRI, intraoperative blood loss, ventricular blood as determined on postoperative CT, and pathology were statistically significant variables in the univariate analysis. The only two independent predictors of postoperative symptomatic hydrocephalus were tumor metastasis (OR 3.463, 95% CI 1.137-10.549; p = 0.029) and postoperative ventricular blood (OR 4.212, 95% CI 1.595-11.122; p = 0.004). The final logistic model comprising tumor metastasis and postoperative ventricular blood was found to have better discrimination than the mCPPRH.

CONCLUSIONS

Tumor characteristics and surgery-related features were associated with postoperative symptomatic hydrocephalus. Tumor metastasis and postoperative ventricular blood were found to be important prognosticators of persistent hydrocephalus.

External ventricular drainage in the management of pediatric patients with posterior fossa tumors and hydrocephalus: a retrospective cohort study

PURPOSE

To determine whether intraoperative adjunctive EVD placement in patients with a posterior fossa tumor (PFT) led to improved surgical, radiographic, and clinical outcomes compared to those who did not receive an EVD.

METHODS

Patients were grouped as those who underwent routine intraoperative adjunctive EVD insertion and those who did not at time of PFT resection. Patients who pre-operatively required a clinically indicated EVD insertion were excluded. Comparative analyses between both groups were conducted to evaluate clinical, radiological, and pathological outcomes. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were computed for post-operative outcomes.

RESULTS

Fifty-five selected patients were included, 15 who had an EVD placed at the time of PFT resection surgery, and 40 who did not. Children without an EVD did not experience a higher rate of complications or poorer post-operative outcomes compared to those with an EVD placed during resection surgery. There was no significant difference in the degree of gross total resection (p = 0.129), post-operative CSF leak (p = 1.000), and post-operative hemorrhage (p = 0.554) between those with an EVD and those without. The frequency of new cranial nerve deficits post-operatively was higher in those with an EVD (40%) compared to those without (3%, p = 0.001). There was a trend towards more frequently observed post-operative hydrocephalus in the EVD group (p = 0.057).

CONCLUSION

The routine use of EVD as an intraoperative adjunct in clinically stable pediatric patients with posterior fossa tumors and hydrocephalus may not be associated with improved radiological or clinical outcomes.

A Predictive Nomogram for Postoperative Hydrocephalus After Intra- and Paraventricular Tumor Resection: A Retrospective Study of 196 Patients

BACKGROUND

Hydrocephalus is a common complication of intra- and paraventricular tumors both before and after tumor resection. We investigated the risk factors for postoperative hydrocephalus and established a predictive nomogram to improve surgical planning and adjust the frequency of postoperative clinical and radiographic monitoring.

METHODS

A retrospective study of 196 intra- and paraventricular tumor patients with follow-up data was conducted to investigate the risk factors for postoperative hydrocephalus via univariate and multivariate Cox regression analyses. We developed a nomogram incorporating these factors based on multivariate analysis and according to scores calculated by the predictive model; a hazard function curve was used to compared risk of hydrocephalus.

RESULTS

Among the 196 patients, 33 had postoperative hydrocephalus. Intraventricular tumor (P = 0.005), glioblastoma (P = 0.010), preoperative hydrocephalus (P = 0.007), and radiotherapy (P = 0.033) were independent risk factors for postoperative hydrocephalus. The nomogram including these independent risk factors had moderate predictive accuracy, with a concordance index of 0.716 (95% confidence interval [CI]: 0.605-0.828), while the area under the curve values at 6, 12, and 24 months were 0.708 (95% CI: 0.563-0.853), 0.763 (95% CI: 0.656-0.870) and 0.861 (95% CI: 0.779-0.943), respectively. The hazard function showed differences between the lower and higher nomogram score groups. The higher the nomogram score, the higher the risk of postoperative hydrocephalus (P < 0.001).

CONCLUSIONS

The established nomogram performs well for predicting postoperative hydrocephalus. Clinicians can use this nomogram to review their practice regarding hydrocephalus associated with intra- and paraventricular tumors, plan surgical treatment and adjust the frequency of postoperative clinical and radiographic monitoring.

Arterial Spin-Labeling Perfusion Metrics in Pediatric Posterior Fossa Tumor Surgery

BACKGROUND AND PURPOSE

Pediatric posterior fossa tumors often present with hydrocephalus; postoperatively, up to 25% of patients develop cerebellar mutism syndrome. Arterial spin-labeling is a noninvasive means of quantifying CBF and bolus arrival time. The aim of this study was to investigate how changes in perfusion metrics in children with posterior fossa tumors are modulated by cerebellar mutism syndrome and hydrocephalus requiring pre-resection CSF diversion.

MATERIALS AND METHODS

Forty-four patients were prospectively scanned at 3 time points (preoperatively, postoperatively, and at 3-month follow-up) with single- and multi-inflow time arterial spin-labeling sequences. Regional analyses of CBF and bolus arrival time were conducted using coregistered anatomic parcellations. ANOVA and multivariable, linear mixed-effects modeling analysis approaches were used. The study was registered at clinicaltrials.gov (NCT03471026).

RESULTS

CBF increased after tumor resection and at follow-up scanning (P = .045). Bolus arrival time decreased after tumor resection and at follow-up scanning (P = .018). Bolus arrival time was prolonged (P = .058) following the midline approach, compared with cerebellar hemispheric surgical approaches to posterior fossa tumors. Multivariable linear mixed-effects modeling showed that regional perfusion changes were more pronounced in the 6 children who presented with symptomatic obstructive hydrocephalus requiring pre-resection CSF diversion, with hydrocephalus lowering the baseline mean CBF by 20.5 (standard error, 6.27) mL/100g/min. Children diagnosed with cerebellar mutism syndrome (8/44, 18.2%) had significantly higher CBF at follow-up imaging than those who were not (P = .040), but no differences in pre- or postoperative perfusion parameters were seen.

CONCLUSIONS

Multi-inflow time arterial spin-labeling shows promise as a noninvasive tool to evaluate cerebral perfusion in the setting of pediatric obstructive hydrocephalus and demonstrates increased CBF following resolution of cerebellar mutism syndrome.

Peritoneal metastasis of a brainstem anaplastic ganglioglioma in a 2-year-old boy: case report and literature review

Anaplastic gangliogliomas (AGG) are rare tumors of the central nervous system (CNS) that commonly affect children and young adults, with an unusual infratentorial presentation, which is related to hydrocephalus and a worse prognosis. We report a case of a brainstem AGG in a 2-year-old boy who underwent a ventriculoperitoneal shunting (VPS) and later presented peritoneal metastasis. We also reviewed the related literature. Even though rare, disease dissemination through VPS should be sought in patients with CNS tumors and VPS who develop new abdominal symptoms. The early diagnosis and intervention may minimize morbidity and improve quality of life of such patients.

Posterior fossa ependymoma in neurodevelopmental syndrome caused by a de novo germline pathogenic POLR2A variant

Ependymoma is the third most common pediatric brain tumor. Predisposition to develop ependymomas has been reported in different hereditary diseases, but the pathogenic variants related to the familial syndromes have rarely been detected in sporadic ependymomas. De novo variants in POLR2A, the gene encoding the largest subunit of RNA polymerase II, cause a neurodevelopmental disorder with a wide range of clinical manifestations, characterized by severe infantile-onset hypotonia, developmental delay, feeding difficulties, palatal anomalies, and facial dysmorphisms. As somatic events, POLR2A mutations represent a recurrent somatic lesion in benign meningiomas. Here we describe a case of ependymoma in a 2-year-old male with a de novo pathogenic variant in POLR2A predicted to impair proper interaction of the subunit with transcription-elongation factor TFIIS, whose function is required for back-tracking of the enzyme due to elongation blocks or nucleotide misincorporation, and expected to result in an increased error and reduced elongation rates. To date, ependymoma has never been reported in patients harboring pathogenic POLR2A variants. Further information is required to explore the possibility of a differential clinical and functional impact of the pathogenic POLR2A variants and the eventual inclusion of the POLR2A neurodevelopmental disorder among the cancer predisposition syndromes with the possible development of ependymomas.

Management of Posterior Fossa Tumors in Adults Based on the Predictors of Postoperative Hydrocephalus

Objective

This study aims to identify the predictors of postoperative hydrocephalus in patients with posterior fossa tumors (PFTs) and guide the management of perioperative hydrocephalus.

Methods

We performed a single-institution, retrospective analysis of patients who underwent resection of PFTs in our department over a 10-year period (2011–2021). A total of 682 adult patients met the inclusion criteria and were divided into either a prophylactic external ventricular drainage (EVD) group or a nonprophylactic-EVD group. We analyzed data for the nonprophylactic-EVD group by univariate and multivariate analyses to identify predictors of postoperative acute hydrocephalus. We also analyzed all cases by univariate and multivariate analyses to determine the predictors of postoperative ventriculoperitoneal (VP) shunt placement.

Results

Tumor infiltrating the midbrain aqueduct [P = 0.001; odds ratio (OR) = 9.8], postoperative hemorrhage (P &lt; 0.001; OR = 66.7), and subtotal resection (P = 0.006; OR = 9.3) were independent risk factors for postoperative EVD. Tumor infiltrating the ventricular system (P &lt; 0.001; OR = 58.5) and postoperative hemorrhage (P &lt; 0.001; OR = 28.1) were independent risk factors for postoperative VP shunt placement.

Conclusions

These findings may help promote more aggressive monitoring and earlier interventions for postoperative hydrocephalus in patients with PFTs.

Posterior Fossa Tumours in the First Year of Life: A Two-Centre Retrospective Study

Posterior fossa tumours (PFTs) in infants are very rare, and information on these tumours is scarce in the literature. This retrospective study reports their pathological characteristics and describes surgical aspects and treatment outcomes. A two-centre cohort of infants with PFTs treated from 2007 to 2018 was retrospectively reviewed. Patient characteristics, clinical, and treatment data were reviewed. Survival curves for progression-free survival (PFS) and overall survival (OS) were generated. Thirty-three infants were retrieved. There were 11 low grade and 22 high-grade tumours. The most common presenting symptom was intracranial hypertension. Fifteen children out of thirty-three progressed. Five-year PFS was significantly lower in children with high-grade tumours (38.3%) than those with low-grade tumours (69.3%), p = 0.030. High-grade pathology was the only predictor of progression (HR 3.7, 95% CI 1.1–13.31), p = 0.045. Fourteen children with high-grade tumours died, with a 5-year OS of 55.25%. PFTs in children below one year of age still represent a unique challenge. Infants with high-grade tumours display the worst outcomes and the lowest survival, indicating that more effective strategies are needed.

Endoscopic third ventriculostomy for the management of hydrocephalus secondary to posterior fossa tumors: A retrospective study

Background:

Endoscopic third ventriculostomy (ETV) is an effective alternative to ventriculoperitoneal shunting as well as external ventricular drainage for the urgent management of acute hydrocephalus. We performed this study to investigate the efficacy and safety of ETV before tumor resection in managing hydrocephalus in patients with posterior fossa brain tumors (PFBT) in our neurosurgery department.

Methods:

We conducted this retrospective observational study between February 2018 and February 2020 on all cases diagnosed with PFBT associated with triventricular obstructive hydrocephalus. We retrospectively reviewed the demographic characteristics, operative procedures, and radiological investigations of all cases. During the follow-up period, clinical, as well as radiological success were evaluated.

Results:

Twenty-two ETV procedures were performed in 22 cases of PFBT (mean age = 22.1 years, SD = 11.4). Of the 22 cases, 8 cases (36.4%) had ependymoma, 7 cases (31.8%) had cerebellar astrocytoma, and 5 cases (22.7 %) had medulloblastoma, while 2 cases (9.1%) had diffuse pontine gliomas. The median follow-up duration was 9 months (range 3–13 months). The most commonly reported clinical presentation was the significant intracranial pressure increase. All operations were performed successfully in all cases. Only two ETV post-tumor resection failures were documented during the follow-up period.

Conclusion:

Preoperative ETV has shown to be an effective long-term cerebrospinal fluid diversion procedure to manage PFBT-associated hydrocephalus, with a relatively low rate of complications. Further prospective studies are required to assess the regular use of ETV before complete tumor resection.

Postoperative hydrocephalus management may cause delays in adjuvant treatment following paediatric posterior fossa tumour resection: a multicentre retrospective observational study

INTRODUCTION

Hydrocephalus persists in 10-40% of children with posterior fossa tumours (PFT). A delay in commencement of adjuvant therapy (AT) can negatively influence survival. The objective of this study was to determine whether postoperative cerebrospinal fluid (CSF) diversion procedures caused potentially preventable delays in AT.

METHODS

A retrospective study of children diagnosed with PFT requiring AT from 2004 to 2018 from two large centres was conducted. Data on histology, timing of ventriculo-peritoneal shunt (VPS) insertion, and AT was collected. The modified Canadian Preoperative Prediction Rule for Hydrocephalus (mCPPRH) score was calculated. The primary outcome was delay in AT beyond 40 days post-resection. Progression-free and overall survival were assessed.

RESULTS

Out of 196 primary PFT resections, 144 fitted the inclusion criteria. Mean age was 6.57 ± 4.62. Histology was medulloblastoma (104), ependymoma (27), and others (13). Forty patients had a VPS inserted; 17 of these experienced a delay in AT. A total of 104 patients were not shunted; 15 of these had delayed AT (p = 0.0007). Patients who had a VPS insertion had longer intervals from surgery to commencement of AT (34.5 vs 30.8, p = 0.05). There was no significant difference in mCPPRH score between those who had a VPS (4.03) and those who did not (3.61; p = 0.252). Multivariable linear regression modelling did not show a significant effect of VPS or mCPPRH on progression-free survival or OS.

CONCLUSION

CSF diversion procedures may cause a preventable delay in the initiation of adjuvant therapy. Early post-operative VP shunt insertion, rather than a 'wait and see policy' should be considered in order to reduce this delay.

Tumor-related hydrocephalus in infants: a narrative review

Primary brain tumors diagnosed during infancy present several challenges for the pediatric neurosurgeon including the management of tumor-related hydrocephalus. Infant tumor-related hydrocephalus (iTRH) is present in over 70% of new diagnoses overall and in over 90% of infants with infratentorial neoplasms. iTRH may be related to direct obstruction of cerebrospinal fluid (CSF) pathways, shedding of protein and/or cells leading to dysfunctional subarachnoid, tumor-related CSF production, or, most frequently, a combination of these mechanisms. Treatment plans must consider the acuity of presentation, the mechanism of iTRH, and the additional neoadjuvant or adjuvant therapies required to treat the neoplasm. This narrative review provides a broad reference on the epidemiology, pathophysiology, and treatment of iTRH.

Surgical outcome of children with medulloblastoma: a retrospective study of a 405-patient series from Children's Cancer Hospital Egypt (CCHE-57357)

PURPOSE

To analyze the impact of increasing the extent of resection (EOR) on the survival rates and on the surgical outcome of children with medulloblastoma.

METHODS

A series of consecutive 405 children operated for medulloblastoma between July 2007 and April 2018 was identified. The details of pre-operative data, surgical interventions, post-operative complications, and survival rates were analyzed.

RESULTS

The Kaplan-Meier (KM) analysis showed no advantage of gross total resection (GTR) over near and subtotal resection regarding over all (OS) (p=0.557) and progression free survival (PFS) (p=0.146). In the same time, increasing the EOR was not associated with higher morbidity. Tumor dissemination at onset correlated to worse OS (KM: p=0.003, OR 1.999, 95% CI: 1.242-3.127; p = 0.004) and PFS (KM: p<0.001, Cox: OR 2.171, 95% CI: 1.406-3.353; p<0.001). OS was significantly affected in patients < 3 years old (KM: p=0.011, OR 2.036, 95% CI: 1.229-3.374; p = 0.006), while PFS was worse among patients who had pre-op seizures (KM: p=0.036, Cox: OR 2.852, 95% CI: 1.046-7.773; p=0.041) or post-op pseudomeningocele (KM: p=0.021, Cox: OR 2.311, 95% CI: 1.123-4.754; p=0.023).

CONCLUSIONS

Although surgical excision of medulloblastoma is the standard of care, there was no significant benefit for GTR over near or subtotal resection on the OS or PFS rates that are mainly influenced by the patient's age and tumor dissemination. However, GTR should be targeted, as it is not associated with increased incidence of mutism or other surgery-related complications.

Anesthetic Management of Patients Undergoing Open Suboccipital Surgery

The posterior cranial fossa with its complex anatomy houses key pathways regulating consciousness, autonomic functions, motor and sensory pathways, and cerebellar centers regulating balance and gait. The most common posterior fossa pathologies for which neurosurgical intervention may be necessary include cerebellopontine angle tumors, aneurysms, and metastatic lesions. The posterior cranial fossa can be accessed from variations of the supine, lateral, park-bench, prone, and sitting positions. Notable complications from positioning include venous air embolism, paradoxic air embolism, tension pneumocephalus, nerve injuries, quadriplegia, and macroglossia. An interdisciplinary approach with careful planning, discussion, and clinical management contributes to improved outcomes and reduced complications.

Risk Factors of Persistent Hydrocephalus in Children with Brain Tumor: A Retrospective Analysis

OBJECT

Hydrocephalus is one of the main complications of brain tumors in children, being present in about 50% of cases at the time of the tumor diagnosis and persisting up to 10-40% of cases after surgical resection. This is a single-institution retrospective study on the variables that may predict the need for treatment of persistent hydrocephalus in pediatric patients presenting with a brain tumor.

METHODS

Retrospective case note review of 43 newly diagnosed brain tumors in children referred between April 2012 and January 2018 to our regional pediatric neuro-oncology service was carried out. Diagnosis of hydrocephalus was carried out using both preoperative and postoperative MRI to determine Evans' index (EI) and the fronto-occipital horn ratio (FOHR) from each scan. Simple logistic regression was used to analyze categorical variables as appropriate. A p value <0.05 was considered significant.

RESULTS

Forty-three children were analyzed, 26 males and 17 females with a median age at diagnosis 10.4 years (IQR: 5.2-13.5). Hydrocephalus was present in 22/43 children (51%) preoperatively; in 8/22 children (36%) with hydrocephalus undergoing tumor resection, hydrocephalus persisted also in the postoperative period. An EI >0.34 (p = 0.028) and an FOHR >0.46 (p = 0.05) before surgery were associated with a higher prevalence of persistent hydrocephalus and therefore to the need for a cerebrospinal fluid drain device in the postoperative phase.

CONCLUSION

Preoperative identification of children at risk for developing persistent hydrocephalus would avoid delays in planning the permanent cerebrospinal fluid drain devices. This study finds that an EI >0.34 and an FOHR >0.46 at diagnosis could impact on the therapeutic management of children with hydrocephalus associated with brain tumors. Prospective and larger-scale studies are needed to standardize this approach.

Cerebellar swelling after surgery for medulloblastoma with leptomeningeal dissemination in children. A case based-update

OBJECT

Despite the improvement in the overall management of medulloblastomas in recent years, certain phenomena and in particular postoperative cerebellar swelling remain an enigma. This rare complication, little described in the literature, is nonetheless life threatening for the patients.

CASE REPORTS

We report our experience about two children who developed severe cerebellar swelling with hydrocephalus and upward herniation soon after a gross total resection of a fourth ventricle medulloblastoma by a telo-velar approach. Despite rapid management of ventricular dilation and optimal medical intensive treatment of intracranial hypertension, both children died quickly after the surgery. Pathological examination analyses were in favour of anaplastic/large cell medulloblastoma.

DISCUSSION

Diffuse cerebellar swelling with upward herniation may occur postoperatively in young children with anaplastic/large cell medulloblastoma with leptomeningeal spread. In the literature, only 4 cases have been so far described with delayed onset of symptoms. Two children survived with an aggressive management (decompressive surgery and early radio-chemotherapy).

CONCLUSION

Cerebellar swelling is an unrecognised and sudden complication of posterior fossa surgery for metastatic anaplastic medulloblastoma with leptomeningeal dissemination in young children. An initial less invasive surgical approach could be considered in such cases, in order to prevent this complication with potentially tragic issue, and which cannot be managed with a CSF shunt alone.

Risk factors for hydrocephalus following fourth ventricle tumor surgery: A retrospective analysis of 121 patients

BACKGROUND AND AIM

Most patients who present with a fourth ventricle tumor have concurrent hydrocephalus, and some demonstrate persistent hydrocephalus after tumor resection. There is still no consensus on the management of hydrocephalus in patients with fourth ventricle tumor after surgery. The purpose of this study was to identify the factors that predispose to postoperative hydrocephalus and the need for a postoperative cerebrospinal fluid (CSF) diversion procedure.

MATERIALS AND METHODS

We performed a retrospective analysis of patients who underwent surgery of the fourth ventricle tumor between January 2013 and December 2018 at the Department of Neurosurgery in West China Hospital of Sichuan University. The characteristics of patients and the tumor location, tumor size, tumor histology, and preventive external ventricular drainage (EVD) that were potentially correlated with CSF circulation were evaluated in univariate and multivariate analysis.

RESULTS

A total of 121 patients were enrolled in our study; 16 (12.9%) patients underwent postoperative CSF drainage. Univariate analysis revealed that superior extension (p = 0.004), preoperative hydrocephalus (p<0.001), and subtotal resection (p<0.001) were significantly associated with postoperative hydrocephalus. Multivariate analysis revealed that superior extension (p = 0.013; OR = 44.761; 95% CI 2.235-896.310) and subtotal resection (p = 0.005; OR = 0.087; 95% CI 0.016-0.473) were independent risk factors for postoperative hydrocephalus after resection of fourth ventricle tumor.

CONCLUSION

Superior tumor extension (into the aqueduct) and failed total resection of tumor were identified as independent risk factors for postoperative hydrocephalus in patients with fourth ventricle tumor.

Pediatric posterior fossa tumors outcomes: Experience in a tertiary care center in the Middle East

BACKGROUND

Among all childhood cancers, brain tumors are second only to leukemia in incidence and are the most common solid pediatric tumors. More than 60 % of pediatric brain tumors are infra-tentorial. The first-line treatment for most infra-tentorial tumors in pediatric patients is surgical resection, with the goal of gross-total resection, relief of symptoms and hydrocephalus, and increased survival. The proximity to the fourth ventricle, and therefore, the cerebrospinal fluid (CSF) pathways, predisposes children with posterior fossa tumors to the development of obstructive hydrocephalus and multiple other co-morbidities pre and post-surgery.

OBJECTIVES

This study aims to present our series of pediatric posterior fossa tumor surgeries in the Neurosurgical Department at the American University of Beirut Medical Center(AUBMC) and perform internal quality control for our single-institution consecutive series as one of the largest referral and tertiary care centers in the region. The second purpose of this retrospective study is to weigh the risks of surgery against the presumed advantages and to have specific knowledge about the complication rates, especially those related to the CSF pathway, comparing our results to those in the literature.

METHODS

All pediatric patients (< 18 years of age), referred to our center from different regions in the middle east, and surgically treated for a posterior fossa tumor from June 2006 to June 2018 at the American University of Beirut Medical Center were included. A thorough review of all medical charts was performed to validate all the database records.

RESULTS

The patient sample consisted of 64 patients having a mean age of 6.19 ± 4.42 years and 59.37 % of whom were males. The most common tumor pathology was pilocytic astrocytoma (40.62 %) followed by medulloblastoma (35.93 %) and ependymoma. The most common type of tumor that was seen in patients that developed mutism postoperatively (n = 6, 9.37 %) was medulloblastoma (n = 4, 66.66 %). In this patient sample, 12.28 % (n = 7) of the patients developed hydrocephalus postoperatively.Midline tumors were more associated with the development of mutism(OR = 4.632, p = 0.306) and hydrocephalus (OR = 5.056, p = 0.135) postoperatively, albeit not statistically significantly.The presence of a preoperative shunt was shown to be protective against the development of CSF leak (OR = 0.636, p = 0.767), as none of the patients that came in with CSF diversion developed a CSF leak after their surgery.

CONCLUSION

This study from a single center experience accompanied by a thorough literature review sheds light on the complications frequently encountered after posterior fossa tumor surgery in children. These included transient cerebellar mutism, CSF leak, and hydrocephalus as seen in some of our patients. Our findings highlight the need for prospective studies with well-defined protocols directed at assessing novel ways and approaches to minimize the risk of these complications.

The role of external ventricular drainage for the management of posterior cranial fossa tumours: a systematic review

Posterior cranial fossa tumours frequently develop hydrocephalus as first presentation in up to 80% of paediatric patients and 21.4% of adults, although it resolves after tumour removal in 70-90% and 96%, respectively. New onset hydrocephalus is reported in about 2.1% of adult and 10-40% of paediatric patients after posterior fossa surgery. There is no consensus concerning prophylactic external ventricular drainage (EVD) placement that is frequently used before posterior fossa lesion removal, as well in those cases without clear evidence of hydrocephalus. The aim of the study was to define the most correct management for patients who undergo posterior fossa tumour surgery, thus identifying cohorts of patients who are at risk of persistent hydrocephalus prior to surgery. A systematic review of literature has been performed, following PRISMA guidelines. Most of the studies reported CSF shunt only in the presence of hydrocephalus, whereas only a few authors suggested its prophylactic use in the absence of signs of ventricular dilatation. Predictive factors for postoperative hydrocephalus has been identified, including young age (< 3 years), severe symptomatic hydrocephalus at presentation, EVD placement before surgery, FOHR index > 0.46 and Evans index > 0.4, pseudomeningocele, CSF leak and infection. The use of pre-resection CSF shunt in case of signs and symptoms of hydrocephalus is mandatory, although it resolves in the majority of cases. As reported by several studies included in the present review, we suggest CSF shunt also in case of asymptomatic hydrocephalus, whereas it is not indicated without evidence of ventricular dilatation.

Anaplastic ependymoma metastases though a ventriculoperitoneal shunt

Ependymomas are rare glial tumors that comprise 10% of intracranial pediatric malignancies. Primary central nervous system malignancies can rarely metastasize extracranially. When metastases occur, it usually does so in the setting of surgical manipulation of the central nervous system and can spread through the blood, lymph, or artificial means, for example, a ventriculoperitoneal shunt. We describe the presentation and progression of an 18-month-old boy diagnosed with an ependymoma. Initially managed with surgery, radiation, and ventriculoperitoneal shunt placement for symptomatic hydrocephalus, the tumor later recurred with drop metastasis to the thoracic spinal cord. The patient subsequently developed extensive metastases within the abdominal cavity, which were seeded through a ventriculoperitoneal shunt. We present a case of a rare complication of intra-abdominal tumor seeding and carcinomatosis from an intracranial ependymoma through a ventriculoperitoneal shunt. This is a rare presentation of a possible complication, which requires awareness of both surgeons and radiologists.

Does pre-resection endoscopic third ventriculostomy prevent the need for post-resection CSF diversion after pediatric posterior fossa tumor excision? A historical cohort study and review of the literature

OBJECTIVE

Children with posterior fossa tumors (PFTs) may present with hydrocephalus. Persistent (or new) hydrocephalus is common after PFT resection. Endoscopic third ventriculostomy (ETV) is sometimes performed prior to resection to 1) temporize hydrocephalus prior to resection and 2) prophylactically treat post-resection hydrocephalus. The objective of this study was to establish, in a historical cohort study of pediatric patients who underwent primary craniotomy for PFT resection, whether or not pre-resection ETV prevents the need for post-resection CSF diversion to manage hydrocephalus.

METHODS

The authors interrogated their prospectively maintained surgical neuro-oncology database to find all primary PFT resections from a single tertiary pediatric neurosurgery unit. These data were reviewed and supplemented with data from case notes and radiological review. The modified Canadian Preoperative Prediction Rule for Hydrocephalus (mCPPRH) score was retrospectively calculated for all patients. The primary outcome was the need for any form of postoperative CSF diversion within 6 months of PFT resection (including ventriculoperitoneal shunting, ETV, external ventricular drainage [EVD], and lumbar drainage [LD]). This was considered an ETV failure in the ETV group. The secondary outcomes were time to CSF diversion, shunt dependence at 6 months, and complications of ETV. Statistical analysis was done in RStudio, with significance defined as p < 0.05.

RESULTS

A total of 95 patients were included in the study. There were 28 patients in the ETV group and 67 in the non-ETV group. Patients in the ETV group were younger (median age 5 vs 7 years, p = 0.04) and had more severe preoperative hydrocephalus (mean frontal-occipital horn ratio 0.45 vs 0.41 in the non-ETV group, p = 0.003) and higher mCPPRH scores (mean 4.42 vs 2.66, p < 0.001). The groups were similar in terms of sex and tumor histology. The overall rate of post-resection CSF diversion of any kind (shunt, repeat ETV, LD, or EVD) in the entire cohort was 25.26%. Post-resection CSF diversion was needed in 32% of patients in the ETV group and in 22% of the patients in the non-ETV group (p > 0.05). Shunt dependence at 6 months was seen in 21% of the ETV group and 16% of the non-ETV group (p > 0.05). The median time to ETV failure was 9 days. ETV failure correlated with patients with ependymoma (p = 0.02). Children who had ETV failure had higher mCPPRH scores than the ETV success group (5.67 vs 3.84, p = 0.04).

CONCLUSIONS

Pre-resection ETV did not reliably prevent the need for post-resection CSF diversion. ETV was more likely to fail in children with ependymoma and those with higher mCPPRH scores. Based on the findings of this study, the authors will change the practice at their institution; pre-resection ETV will now be performed based on a newly defined protocol.

Thirty-day readmission risk after intracranial tumor resection surgeries in children

OBJECTIVE

The risk of readmission after brain tumor resection among pediatric patients has not been defined. The authors' objective was to evaluate the readmission rates and predictors of readmission after pediatric brain tumor resection.

METHODS

Nationwide Readmissions Database (NRD) data sets from 2010 to 2014 were searched for unplanned readmissions within 30 days of the discharge date after pediatric brain tumor resection. Patient demographic variables included sex, age, expected payment source (Medicaid or private insurance), and median annual household income. Readmission events for chemotherapy, radiation therapy, or further tumor resection were not included.

RESULTS

Of 282 patients (12.7%) readmitted within 30 days of the index event, the median time to readmission was 10 days (IQR 5-19 days). The most common reason for readmission was hydrocephalus, which accounted for 19% of readmission events. Other CNS-related complications (24%), surgical site infections or septicemia (14%), seizures (7%), and hematological disorders (7%) accounted for other major readmission events. The median charge for readmission events was $35,431, and the median length of readmission stay was 4 days. In multivariate regression, factors associated with a significant increase in readmission risk included Medicaid as the primary payor, discharge from the index event with home health services, and fluid and electrolyte disorders during the index event.

CONCLUSIONS

More than 10% of pediatric brain tumor patients have unplanned readmission events within 30 days of discharge after tumor resection. Medicaid patients and those with preoperative or early postoperative fluid and electrolyte disturbances may benefit from early or frequent outpatient visits after tumor resection.

Cytokine and inflammatory mediator effects on TRPV4 function in choroid plexus epithelial cells

The choroid plexus (CP), composed of capillaries surrounded by a barrier epithelium, is the main producer of cerebrospinal fluid (CSF). The CP epithelium regulates the transport of ions and water between the blood and the ventricles, contributing to CSF production and composition. Several studies suggest a connection between the cation channel transient receptor potential vanilloid-4 (TRPV4) and transepithelial ion movement. TRPV4 is a nonselective, calcium-permeable cation channel present in CP epithelia reported to be activated by cytokines and inflammatory mediators. Utilizing the PCP-R (porcine choroid plexus-Riems) cell line, we investigated the effects of various cytokines and inflammatory mediators on TRPV4-mediated activity. Select proinflammatory cytokines (TNF-α, IL-1β, TGF-β1) had inhibitory effects on TRPV4-stimulated transepithelial ion flux and permeability changes, whereas anti-inflammatory cytokines (IL-10, IL-4, and IL-6) had none. Quantitative mRNA analysis showed that these cytokines had no effect on TRPV4 transcription levels. Inhibition of the transcription factor NF-κB, involved in the production and regulation of several inflammatory cytokines, inhibited TRPV4-mediated activity, suggesting a link between TRPV4 and cytokine production. Contrary to published studies, the proinflammatory mediator arachidonic acid (AA) had inhibitory rather than stimulatory effects on TRPV4-mediated responses. However, inhibition of AA metabolism also caused inhibitory effects on TRPV4, suggesting a complex interaction of AA and its metabolites in the regulation of TRPV4 activity. Together these data imply that TRPV4 activity is involved in the inflammatory response; it is negatively affected by proinflammatory mediators. Furthermore, arachidonic acid metabolites, but not arachidonic acid itself, are positive regulators of TRPV4.

Management of hydrocephalus after resection of posterior fossa lesions in pediatric and adult patients-predictors for development of hydrocephalus

The surgical management of hydrocephalus in patients with posterior fossa lesions (PFL) is critical for optimal patient outcome(s). Accordingly, it is prudent to identify patients in need of aggressive surgical intervention (i.e., ventriculoperitoneal [VP] shunting). To analyze prevalence of, and risk factors associated with, the development of post-operative hydrocephalus in both pediatrics and adults. A retrospective institutional analysis and review of patient records in those who had undergone PFL surgery was performed. In so doing, the authors identified patients that went on to develop post-operative hydrocephalus. The study included pediatric and adult patients treated between 2009 and 2017. Fifteen of 40 pediatric (37.5%) and 18 of 262 adult (6.9%) patients developed hydrocephalus after PFL surgery. The most common tumor entity in pediatrics was medulloblastoma (34%), astrocytoma (24.4%), and pilocytic astrocytoma (22%), whereas in adults, metastasis (29.5%), meningioma (22%), and acoustic neuroma (17.8%) were most common. Young age ≤ 2 years, medulloblastoma (OR 13.9), and brain stem compression (OR 5.4) were confirmed as independent predictors for hydrocephalus in pediatrics and pilocytic astrocytoma (OR 15.4) and pre-operative hydrocephalus (OR 3.6) in adults, respectively. All patients received VP shunts for hydrocephalus management and the mean follow-up was 29.5 months in pediatrics vs 19.2 months in adults. Overall complication rates related to VP shunts were 33.3% in pediatrics and 16.7% in adults, respectively. Shunt dependency and associated complications in pediatrics were noted to be higher than in adults. Given the identification of predictors for hydrocephalus, it is authors' contention that certain patients with those predictors may ultimately benefit from an alternative treatment regimen (e.g., pre-operative interventions) prior to PFT surgery.

Postoperative intraventricular blood: a new modifiable risk factor for early postoperative symptomatic hydrocephalus in children with posterior fossa tumors

OBJECTIVE

To analyze factors associated with the development of early symptomatic hydrocephalus following posterior fossa tumor (PFT) surgery in children.

METHODS

In this retrospective study, data from 148 children (age < 18 years) who underwent primary resection of their PFTs without preoperative permanent CSF diversion procedures were collected. The incidence of symptomatic hydrocephalus within 30 days of tumor resection was studied and its association with various demographic, tumor-related, and surgery-related risk factors was analyzed.

RESULTS

At presentation, 131 (89%) of the 148 patients had symptomatic hydrocephalus. There were 99 males and 49 females (mean age 8.7 years; range 1 to 17 years). Postoperatively, 14 (9.4%) patients required shunt placement for symptomatic hydrocephalus. The indications for shunt surgery were persistent symptoms of raised intracranial pressure (n = 6, 43%), CSF leak from the wound (n = 7, 50%), and tense pseudomeningocele (n = 1, 7%). On multivariate analysis, age < 6 years (OR 5.9, 95% CI 1.6-22.6, p = 0.009) and the presence of intraventricular blood (IVB) on postoperative CT (OR 6.4, 95% CI 1.7-23.7, p = 0.006) were independent risk factors for developing symptomatic hydrocephalus.

CONCLUSIONS

The incidence of postoperative symptomatic hydrocephalus in our series (9.4%) is lower than that reported in most previous studies. Age < 6 years and the presence of postoperative IVB were independent risk factors for developing symptomatic hydrocephalus. Of these, postoperative IVB is probably the only modifiable risk factor.

[Implantation of VPS in the early postoperative period following removal of posterior cranial fossa tumors in children]

One of the main manifestations of posterior cranial fossa (PCF) tumors is the development of hydrocephalus (HC) symptoms that in most cases are the reason for examination and diagnosis [1, 2]. According to the literature, the rate of shunt surgery after removal of PCF tumors in the children's population is 18-40% [3-9]. Hydrocephalus remaining after removal of PCF tumor and requiring further treatment is called persistent hydrocephalus. The above figures are based on the treatment outcomes in children, which were obtained as early as in the 1990s. Given these facts, we conducted a modern study to assess the risk of persistence/development of persistent hydrocephalus in children after removal of posterior cranial fossa tumors and to explore factors affecting this risk.

MATERIAL AND METHODS

We performed a retrospective analysis of the treatment outcomes in 155 children operated on at the Burdenko Neurosurgical Institute between 2012 and 2014. All children were operated on by a single surgeon. Factors, such as the patient age, histological pattern of tumor, and primary/repeated surgery, were analyzed.

RESULTS

A total of 13 (8.4%) patients needed shunt surgery. An analysis demonstrated no need for shunt surgery in children with piloid astrocytomas. In children with medulloblastoma, the need for a permanent shunt occurred in 5 (9.1%) cases; all these children were older than 3 years. A group of anaplastic ependymoma included 23 children; of these, 13 children were older than 3 years, and 10 children were under the age of 3 years. Five (21.7%) patients required shunt surgery. Shunting was needed in 3 children from group 4. In one case, a child younger than 3 years of age who was operated on for a dermoid cyst of the PCF, and in 2 children older than 3 years of age who were operated on for ganglioastroscytoma and atypical teratoid-rhabdoid tumor (ATRT).

CONCLUSION

At present, the risk of persistent hydrocephalus in children after removal of PCF tumors is lower than that reported in the literature. In our study, it was 8.4%. The age of children under 3 years and repeated operations do not statistically significantly increase the risk of persistent hydrocephalus. Only tumor histology is statistically significant: the highest risk of the need for implantation of VPS was found in the group with anaplastic ependymomas, and the minimal risk was in the group of piloid astrocytomas.

Frequency and treatment of hydrocephalus prior to and after posterior fossa tumor surgery in adult patients

BACKGROUND

There is paucity of information about the frequency of hydrocephalus prior to and after posterior fossa tumor surgery in adult patients and about the best way it should be managed. The present study was conducted to determine the frequency of hydrocephalus prior to and after posterior fossa tumor surgery in adult patients as well as the value of an endoscopic third ventriculostomy (ETV) prior to posterior fossa tumor surgery with regard to the rate of perioperative complications and persistent hydrocephalus.

METHODS

A single-institution retrospective chart review of all posterior fossa tumor surgeries of our department in a 10-year period (2005 to 2014) has been done.

RESULTS

Fifty-two of 243 adult patients with posterior fossa tumors presented with hydrocephalus at the time of admission prior to tumor surgery. 39/52 received early tumor surgery, 11/52 an ETV prior to tumor surgery and in 2/52 an external ventricular drainage (EVD) was inserted prior to tumor surgery. 3/52 patients required a permanent cerebrospinal fluid (CSF) diverting procedure for persistent hydrocephalus after tumor removal. One hundred ninety-one patients did not demonstrate a hydrocephalus before surgical treatment and four of them developed a post-resection hydrocephalus.

CONCLUSION

The frequency of hydrocephalus prior to posterior fossa tumor surgery in adult patients is 21.4% and therefore much lower than in respective reports of pediatric patients. The risk of persistent hydrocephalus and newly developed hydrocephalus after tumor surgery was very low, too (5.7 and 2.1%, respectively). An ETV is not justified in every adult patient prior to posterior fossa tumor surgery.

Management of hydrocephalus in pediatric metastatic tumors of the posterior fossa at presentation

PURPOSE

Presence of metastases in newly diagnosed pediatric posterior fossa tumors (PFT) is not a rare situation, but optimal treatment of associated hydrocephalus in these children has remained undetermined.

METHODS

Twenty-nine children treated between January 2005 and December 2015 for a metastatic PFT associated with hydrocephalus constituted the study cohort. Patients were divided into three groups: ventriculoperitoneal shunt (VPS), endoscopic third ventriculostomy (ETV), and temporary ventricular drainage before or during tumor resection (PVD).

RESULTS

There were 4 VPS, 18 ETV, and 7 PVD. The global incidence of CSF diversion failure was 52%. No case of dysfunction or dissemination of metastatic cells occurred in the VPS group. Recurrence of hydrocephalus occurred in 55% of the ETV group. Presence of multiple macroscopic metastases and CSF metastatic cells after tumor surgery was associated with ETV failure. Fifty-seven percent of the children in the PVD group were reoperated after an average time of 53 days. Specific oncologic treatment was initiated earlier in the VPS group (11 days) compared to ETV (27 days) and PVD (23 days) groups.

CONCLUSIONS

ETV should be avoided in cases of multiple macroscopic metastases, and children who underwent ETV must be followed carefully when metastatic cells are present in CSF after tumor surgery. External ventricular drainage before or during surgical removal should not be considered as a final option to treat hydrocephalus. VPS remains a safe alternative in this situation and allows an early specific oncologic treatment.

Pediatric central nervous system hemangioblastomas: different from adult forms? A retrospective series of 25 cases

BACKGROUND

Pediatric hemangioblastomas are rare, and the clinical features, timing of surgical intervention, optimal treatment, and clinical outcomes are still unclear.

METHODS

We performed a retrospective study of all patients with CNS hemangioblastomas who were treated at West China Hospital from January 2003 to March 2015. Patients under the age of 16 years were included in the study. The medical records of these patients were reviewed and statistically analyzed.

RESULTS

Twenty-five children (15 females and ten males, [mean age 12.6 ± 4.7 years, range 1-16 years]) presented with hemangioblastomas. Tumors were detected in the cerebellum, brainstem, and spinal cord in 40, 28, and 32% of patients, respectively. Sixteen children (64%) had VHL syndrome. The most frequent symptoms were those related to increased intracranial pressure. The mean duration of symptoms was 1.5 ± 2.1 months. Preoperative hydrocephalus was noted in 11 children (44%). Gross total resection was achieved in all children. Clinical symptoms improved in 19 children (76%), unchanged in four children (16%), and aggravated in two children (8%), respectively. The mean follow-up was 44.5 ± 32.3 months. Five patients (20%) experienced disease progression. Using univariate analysis, both tumor-associated cysts (P = 0.027) and VHL disease (P = 0.032) were significantly related to postoperative outcomes.

CONCLUSIONS

Pediatric hemangioblastomas have many different clinical features compared with adult cases. A high degree of suspicion for VHL disease should be raised in pediatric hemangioblastomas. Despite many challenges involved, surgical outcomes for pediatric hemangioblastomas are favorable. Lifelong follow-up is mandatory to detect the disease progression.

Papilledema in children with hydrocephalus: incidence and associated factors

OBJECTIVE The aim of this study was to report the incidence of and the factors associated with papilledema in children with hydrocephalus. METHODS Patients younger than 15 years of age who had been diagnosed with hydrocephalus and treated by extra-ventricular drainage or ventriculoperitoneal shunt surgery between 2005 and 2015 were retrospectively reviewed. Factors including patient age and sex, etiology of hydrocephalus, duration of signs or symptoms, intracranial pressure (ICP), and presence of papilledema were evaluated. RESULTS Forty-six patients, whose mean age was 6.3 ± 4.7 years, were included in the study. The 19 patients without papilledema had a mean age of 2.7 ± 2.7 years, and the 27 patients with papilledema had a mean age of 8.8 ± 4.2 years (p < 0.001). The mean ICP was 19.9 ± 10.0 cm H₂O among those without papilledema and 33.3 ± 9.1 cm H₂O among those with papilledema (p < 0.001). The mean duration of signs or symptoms was 3.0 ± 4.6 months in the patients without papilledema and 3.4 ± 3.9 months in those with papilledema (p = 0.704). The patients with papilledema were older and presented with higher ICP than those without. The causes of hydrocephalus were tumor (59%), congenital anomaly (19%), hemorrhage (13%), and infection (9%). CONCLUSIONS Papilledema was more common in patients who were older, who had higher ICP, and whose hydrocephalus had been induced by brain tumor. However, since papilledema was absent in 41% of the children with hydrocephalus, papilledema's absence does not ensure the absence of hydrocephalus, especially in younger patients.

The durability of endoscopic third ventriculostomy and ventriculoperitoneal shunts in children with hydrocephalus following posterior fossa tumor resection: a systematic review and time-to-failure analysis

OBJECTIVE Up to one-third of patients with a posterior fossa brain tumor (PFBT) will experience persistent hydrocephalus mandating permanent CSF diversion. The optimal hydrocephalus treatment modality is unknown; the authors sought to compare the durability between endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt (VPS) therapy in the pediatric population. METHODS The authors conducted a systematic review of articles indexed in PubMed between 1986 and 2016 describing ETV and/or VPS treatment success/failure and time-to-failure rate in patients < 19 years of age with hydrocephalus related to a PFBT. Additionally, the authors conducted a retrospective review of their institutional series of PFBT patients requiring CSF diversion. Patient data from the systematic review and from the institutional series were aggregated and a time-to-failure analysis was performed comparing ETV and VPS using the Kaplan-Meier method. RESULTS A total of 408 patients were included from 12 studies and the authors' institutional series: 284 who underwent ETV and 124 who underwent VPS placement. The analysis included uncontrolled studies with variable method and timing of CSF diversion and were subject to surgeon bias. No significant differences between cohorts were observed with regard to age, sex, tumor grade or histology, metastatic status, or extent of resection. The cumulative failure rate of ETV was 21%, whereas that of VPS surgery was 29% (p = 0.105). The median time to failure was earlier for ETV than for VPS surgery (0.82 [IQR 0.2-1.8] vs 4.7 months [IQR 0.3-5.7], p = 0.03). Initially the ETV survival curve dropped sharply and then stabilized around 2 months. The VPS curve fell gradually but eventually crossed below the ETV curve at 5.7 months. Overall, a significant survival advantage was not demonstrated for one procedure over the other (p = 0.21, log-rank). However, postoperative complications were higher following VPS (31%) than ETV (17%) (p = 0.012). CONCLUSIONS ETV failure occurred sooner than VPS failure, but long-term treatment durability may be higher for ETV. Complications occurred more commonly with VPS than with ETV. Limited clinical conclusions are drawn using this methodology; the optimal treatment for PFBT-related hydrocephalus warrants investigation through prospective studies.