Validation and modification of a predictive model of postresection hydrocephalus in pediatric patients with posterior fossa tumors

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.

Role of endoscopic third ventriculostomy in patients undergoing resection of pulvinar area lesions: Preliminary clinical results

BACKGROUND

Patients with pulvinar area lesions may develop hydrocephalus at any stage. The role of endoscopic third ventriculostomy (ETV) in this setting remains unclear.

METHOD

We retrospectively enrolled 15 patients with a mean age of 43 years who underwent endoscopic resection of pulvinar area lesions using the supracerebellar infratentorial approach (SCITA). We compared the different modalities of hydrocephalus management and their outcomes.

RESULTS

Nine of 15 patients (60.0%) had preoperative obstructive hydrocephalus. Five patients underwent ETV before tumor resection, and none developed postoperative hydrocephalus. Four patients underwent one-stage surgery for tumor removal, and one patient with a polymorphous low-grade neuroepithelial tumor of the young required postoperative ETV. Another patient with diffuse astrocytoma and hydrocephalus underwent concurrent lamina terminalis fenestration and endoscopic resection via the SCITA, which resulted in the resolution of hydrocephalus. The preoperative ETV group had no major postoperative complications, while the non-ETV group had three (0/5 vs. 3/4, P = 0.048). The ETV group also had a shorter intensive care unit stay; however, the difference was not significant (1.2 vs. 2.8; P = 0.188). ETV was effective in alleviating symptoms of postoperative hydrocephalus in patients with midbrain-invading tumors.

CONCLUSION

Endoscopic surgery via the SCITA can address both tumor and hydrocephalus issues in some cases but has a higher surgical risk and postoperative hydrocephalus rate. Preoperative ETV can prevent these complications and improve postoperative outcomes.

A scoring system categorizing risk factors to evaluate the need for ventriculoperitoneal shunt in pediatric patients after brain tumor resection

Objectives

To develop a scoring system based on independent predictors of the need for ventriculoperitoneal (VP) shunt after brain tumor resection in pediatric patients.

Methods

A total of 416 pediatric patients (≤ 14 years old) with brain tumors who underwent surgery were randomly assigned to the training (n = 333) and validation cohorts (n = 83). Based on the implementation of VP shunt, the training cohort was divided into the VP shunt group (n = 35) and the non-VP shunt group (n = 298). Univariate and multivariate logistic analyses were performed. A scoring system was developed based on clinical characteristics and operative data, and scores and corresponding risks were calculated.

Results

Age < 3 (p = 0.010, odds ratio [OR] = 3.162), blood loss (BL) (p = 0.005, OR = 1.300), midline tumor location (p < 0.001, OR = 5.750), preoperative hydrocephalus (p = 0.001, OR = 7.044), and total resection (p = 0.025, OR = 0.284) were identified as independent predictors. The area under the curve (AUC) of the scoring system was higher than those of age < 3, BL, midline tumor location, preoperative hydrocephalus, and total resection (0.859 vs. 0.598, 0.717, 0.725, 0.705, and 0.555, respectively; p < 0.001). Furthermore, the scoring system showed good performance in the validation cohort (AUC = 0.971). The cutoff value for predictive scores was 5.5 points, which categorized patients into low risk (0-5 points) and high risk (6-14 points) groups.

Conclusions

Our scoring system, integrating age < 3, BL, midline tumor location, preoperative hydrocephalus, and total resection, provides a practical evaluation. Scores ranging from 6 to 14 points indicate high risk.

A nomogram for predicting post-operative hydrocephalus in children with medulloblastoma

Post-operative hydrocephalus is common among children with medulloblastoma after initial tumor resection. This study aimed to establish a novel model for predicting the development of post-operative hydrocephalus in children with medulloblastoma. Only pediatric patients who received initial medulloblastoma resection at Beijing Tiantan Hospital between January 2018 and May 2021 were included in this study. The potential risk factors associated with post-operative hydrocephalus were identified based on multivariate logistic regression and the nomogram. Receiver operating characteristic (ROC) curve were used to evaluate the performance of the nomogram model based on an independent cohort of medulloblastoma patients who underwent surgery from June 2021 to March 2022. A total of 105 patients were included in the primary cohort. Superior invasion (P = 0.007), caudal invasion (P = 0.025), and intraventricular blood ≥ 5 mm (P = 0.045) were significantly related to the development of post-operative hydrocephalus and thus were assembled into the nomogram model. The model accurately predicted post-operative hydrocephalus based on the calibration curve. The area under the ROC curves for the primary and validation cohorts was 0.849 and 0.855, respectively. In total, the nomogram we developed may aid clinicians in assessing the potential risk of pediatric patients with MB developing post-operative hydrocephalus, especially those who would otherwise not have received a diversionary procedure at presentation.

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.

Blood Loss in Operation Is Independently Predictive of Postoperative Ventriculoperitoneal Shunt in Pediatric Patients With Posterior Fossa Tumors

BACKGROUND

To identify the risk factors for postoperative hydrocephalus and the need for ventriculoperitoneal (VP) shunt after posterior fossa tumor (PFT) resection in pediatric patients and establish a predictive model.

METHODS

A total of 217 pediatric patients (≤14 years old) with PFTs who underwent tumor resection from November 2010 to December 2020 were divided into a VP shunt group (n = 29) and non-VP shunt group (n = 188). Univariate and multivariate logistic regression were performed. A predictive model was established based on the independent predictors. Receiver operating characteristic curves were generated to determine the cutoff values and areas under the curve (AUCs). The Delong test was performed to compare the AUCs.

RESULTS

Age less than three years (P = 0.015, odds ratio [OR] = 3.760), blood loss (BL) (P = 0.002, OR = 1.601), and locations at fourth ventricle (P < 0.001, OR = 7.697) were the independent predictors. The predictive model was as follows: total score = age (<3; yes = 2, no = 0) + BL + tumor locations (fourth ventricle; yes = 5, no = 0). The AUC of our model was higher than those of age less than three years, BL, locations at the fourth ventricle, and compound factors (age <3 + locations) (0.842 vs 0.609, 0.734, 0.732, and 0.788, respectively). The cutoff values of the model and BL were 7.5 points and 2.75 U, respectively.

CONCLUSIONS

BL, age less than three years, and tumors at the fourth ventricle were independent predictors. Model scores over 7.5 points predict a high risk.

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.

Molecular subgroup of medulloblastoma: evaluation of contribution to CSF diversion following tumour resection

INTRODUCTION

Medulloblastoma is the commonest malignant brain tumour in children. Pre-operative hydrocephalus is present in up to 90% of these patients at presentation. Following posterior fossa surgery, despite resolution of fourth ventricular obstruction, a proportion of these children will still require cerebrospinal fluid (CSF) diversion for management of persistent or new hydrocephalus. Various scoring systems have been developed to predict the risk for CSF diversion following posterior fossa surgery. However, no accurate tool exists regarding which pathological subset or group of medulloblastoma patients will require a shunt post-operatively. In this study we investigated the impact of molecular subgroup of medulloblastoma on shunt dependency post-operatively in paediatric patients.

METHODS

We undertook a retrospective multi-centre study of children with medulloblastoma who underwent tumour resection. Those with available molecular subgroup were identified. Demographic data and clinical parameters including age, sex, presence of pre-operative hydrocephalus, extent of surgical resection, evidence of metastasis/leptomeningeal disease and need for CSF diversion post-operatively were further analysed.

RESULTS

Sixty-nine children with medulloblastoma with available molecular data were identified during the study period with male to female ratio of 1.5:1 (42M:27F). Twelve patients (17.4%) belonged to SHH, 10 (14.5%) Wnt, 19 (27.5%) Group 3 and 15 (21.7%) Group 4; 13 (18.8%) were non-specified Group 3 or 4. A total of 18 (26%) patients had evidence of leptomeningeal disease at presentation (20% of Wnt, 42% of Group 3, 33% of group 4, 23% of group 3/4, and 0% of SHH). Fifteen patients (22%) underwent post-operative ventriculoperitoneal (VP) shunt insertion. No patient in the Wnt group required ventriculoperitoneal (VP) shunt post-operatively in this cohort. Need for shunt was associated with pre-operative hydrocephalus, leptomeningeal disease, with molecular group 3 or 4 demonstrating higher rate of leptomeningeal disease, and pre-operative hydrocephalus. Age, extent of resection and pre-operative EVD were not associated with need for shunt in this cohort. Regression analysis identified only pre-operative hydrocephalus and leptomeningeal disease as independent predictors of need for shunt post-resection in this cohort.

CONCLUSION

All patients requiring permanent post-operative VP shunt belonged to non-Wnt groups, particularly group 3 and 4. Although medulloblastoma subgroup does not independently predict need for post-operative shunt, presence of leptomeningeal disease and pre-operative hydrocephalus, and their higher prevalence in group 3 and 4, likely account for observed higher rate of shunting in these groups.

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.

Perioperative external ventricular drainage vs. no-EVD strategy in pediatric posterior fossa tumors-pilot study results

INTRODUCTION

Pediatric brain tumors of the posterior fossa often present with occlusive hydrocephalus. Endoscopic third ventriculostomy (ETV) or ventriculoperitoneal shunting (VPS) has been established for definite hydrocephalus treatment. The aim of the study was to analyze the impact and safety of perioperative temporary external ventricular CSF drainage (EVD) placement on postoperative hydrocephalus outcome compared to a no-EVD strategy.

PATIENTS AND METHODS

In a prospective database, 36 posterior fossa tumor patients of 2-18 years were included with a follow-up of 1 year. Fifty-eight percent presented with preoperative hydrocephalus. Patients were assigned to non-hydrocephalus group: group I (n = 15) and to preoperative hydrocephalus, group IIa with EVD placement (n = 9), and group IIb without EVD (n = 12).

RESULTS

Median age of patients was 8.1 years (range 3.17 to 16.58 years). One-third of 21 hydrocephalus patients required ETV or VPS (n = 7). Occurrence of de novo hydrocephalus in group I after surgery was not observed in our cohort. Age and histology were no confounding factor for EVD placement between group IIa and IIb (p = 0.34). The use of EVD did not result in better control of hydrocephalus compared to no-EVD patients considering pre- and postoperative MRI ventricular indices (p = 0.4). Perioperative placement of an EVD resulted in a threefold risk for subsequent VPS or ETV (group IIa 55.5% vs group IIb 16.6%): relative risk for EVD patients compared to no-EVD patients with hydrocephalus was 3.3 (CI = 1.06-13.43, p = 0.09).

CONCLUSION

Perioperative EVD placement appears to harbor a threefold relative risk of requiring subsequent permanent CSF diversion in children above 2 years. EVD was not more effective to control ventricular enlargement compared to tumor removal alone. The no-EVD strategy was safe and did not result in postoperative complications. Thus, to evaluate potential adverse effects on hydrocephalus outcome by EVD placement, a prospective study is warranted to falsify the results.

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.

Evolution of Making Clinical Predictions in Neurosurgery

Prediction of clinical outcomes is an essential task for every physician. Physicians may base their clinical prediction of an individual patient on their intuition and on scientific material such as studies presenting population risks and studies reporting on risk factors (prognostic factors). A relatively new and more informative approach for making clinical predictions relies on the use of statistical models that simultaneously consider multiple predictors that provide an estimate of the patient's absolute risk of an outcome. There is a growing body of literature in the neurosurgical field reporting on clinical prediction models. These tools have high potential in supporting (not replacing) neurosurgeons with their prediction of a patient's outcome. If used sensibly, these tools pave the way for more informed decision-making with or for individual patients. Patients and their significant others want to know their risk of the anticipated outcome, how it is derived, and the uncertainty associated with it. Learning from these prediction models and communicating the output to others has become an increasingly important skill neurosurgeons have to master. This article describes the evolution of making clinical predictions in neurosurgery, synopsizes key phases for the generation of a useful clinical prediction model, and addresses some considerations when deploying and communicating the results of a prediction model. The paper is illustrated with multiple examples from the neurosurgical literature, including predicting arachnoid cyst rupture, predicting rebleeding in patients suffering from aneurysmal subarachnoid hemorrhage, and predicting survival in glioblastoma patients.

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.

Telovelar versus transvermian approach to tumors of the fourth ventricle and their impact on postoperative neurological complications: A multicenter study

Background

Tumors of the fourth ventricle are exceedingly rare; however, such lesions are formidable due to the severe postoperative neurological complications (pNCs) which often occur. The adoption of the telovelar approach over the transvermian was created to supposedly mitigate the pNCs; however, there is a lack of sufficient data supporting this theory.

Methods

Records from six hospitals were reviewed for patients surgically treated for a single tumor within the 4^th ventricle from 2016 to 2022. The pNCs which had 10 or more occurrences among the patients were individually assessed as the dependent variable in a binary logistic regression model against covariates which included the surgical approach.

Results

This study of 67 patients confirms no significant differences in risk for pNCs between the transvermian and telovelar approach. Rather, multivariate analysis identified neurophysiological monitoring (IONM) as a protective factor for postoperative speech and swallowing defects (odds ratio [OR]: 0.076, 95% confidence interval [CI] 0.011-0.525). Furthermore, intraoperative external ventricular drainage (EVD) was a protective factor for postoperative gait and focal motor defects (OR: 0.075, 95% CI 0.009-0.648) and for postoperative hydrocephalus (OR: 0.020, 95% CI 0.002-0.233). A univariate meta-analysis pooling the present study's patients and an additional 304 patients from the three additional studies in the literature confirms no significant differences in risk between the transvermian and telovelar approach for pNCs.

Conclusion

Intraoperative adjuncts including IONM and EVD may play a significant role in the postoperative outcome. Despite the present study's sample size being a major limitation, the findings may provide great value to neurosurgeons given the scarcity of the current literature.

Etiology- and region-specific characteristics of transependymal cerebrospinal fluid flow

OBJECTIVE

Transependymal flow (TEF) of CSF, often delineated as T2-weighted hyperintensity adjacent to the lateral ventricles on MRI, is a known imaging finding, usually in the setting of CSF flow disturbances. Specific radiological features of TEF and their relationships with clinical markers of hydrocephalus and underlying disease pathology are not known. Here, the authors describe the radiological features and clinical associations of TEF with implications for CSF circulation in the setting of intracranial pathology.

METHODS

After obtaining IRB review and approval, the authors reviewed the radiological records of all patients who underwent intracranial imaging with CT or MRI at St. Louis Children's Hospital, St. Louis, Missouri, between 2008 and 2019 to identify individuals with TEF. Then, under direct review of imaging, TEF pattern, degree, and location and underlying pathology and other radiological and clinical features pertaining to CSF circulation and CSF disturbances were noted.

RESULTS

TEF of CSF was identified in 219 patients and was most prevalent in the setting of neoplasms (72%). In 69% of the overall cohort, TEF was seen adjacent to the anterior aspect of the frontal horns and the posterior aspect of the occipital horns of the lateral ventricles, and nearly half of these patients also had TEF dorsal to the third ventricle near the splenium of the corpus callosum. This pattern was independently associated with posterior fossa medulloblastoma when compared with pilocytic astrocytoma (OR 4.75, 95% CI 1.43-18.53, p = 0.0157). Patients with congenital or neonatal-onset hydrocephalus accounted for 13% of patients and were more likely to have TEF circumferentially around the ventricles without the fronto-occipital distribution. Patients who ultimately required permanent CSF diversion surgery were more likely to have the circumferential TEF pattern, a smaller degree of TEF, and a lack of papilledema at the time of CSF diversion surgery.

CONCLUSIONS

CSF transmigration across the ependyma is usually restricted to specific periventricular regions and is etiology specific. Certain radiological TEF characteristics are associated with tumor pathology and may reflect impaired or preserved ependymal fluid handling and global CSF circulation. These findings have implications for TEF as a disease-specific marker and in understanding CSF handling within the brain.

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.

Ventriculomegaly and postoperative lateral/third ventricular blood as predictors of cerebrospinal fluid diversion following posterior fossa tumor resection

OBJECTIVE

Postoperative hydrocephalus occurs in one-third of children after posterior fossa tumor resection. Although models to predict the need for CSF diversion after resection exist for preoperative variables, it is unknown which postoperative variables predict the need for CSF diversion. In this study, the authors sought to determine the clinical and radiographic predictors for CSF diversion in children following posterior fossa tumor resection.

METHODS

This was a retrospective cohort study involving patients ≤ 18 years of age who underwent resection of a primary posterior fossa tumor between 2000 and 2018. The primary outcome was the need for CSF diversion 6 months after surgery. Candidate predictors for CSF diversion including age, race, sex, frontal occipital horn ratio (FOHR), tumor type, tumor volume and location, transependymal edema, papilledema, presence of postoperative intraventricular blood, and residual tumor were evaluated using a best subset selection method with logistic regression.

RESULTS

Of the 63 included patients, 26 (41.3%) had CSF diversion at 6 months. Patients who required CSF diversion had a higher median FOHR (0.5 vs 0.4) and a higher percentage of postoperative intraventricular blood (30.8% vs 2.7%) compared with those who did not. A 0.1-unit increase in FOHR or intraventricular blood was associated with increased odds of CSF diversion (OR 2.9 [95% CI 1.3-7.8], p = 0.02 and OR 20.2 [95% CI 2.9-423.1], p = 0.01, respectively) with an overfitting-corrected concordance index of 0.68 (95% CI 0.56-0.80).

CONCLUSIONS

The preoperative FOHR and postoperative intraventricular blood were significant predictors of the need for permanent CSF diversion within 6 months after posterior fossa tumor resection in children.

Endoscopic third ventriculostomy before surgery of third ventricle and posterior fossa tumours decreases the risk of secondary hydrocephalus and early postoperative complications

Endoscopic third ventriculostomy (ETV) is an effective treatment for obstructive hydrocephalus (HCP) at the level of third or fourth ventricle. To date, there is no consensus regarding its role as intervention preceding the operation of tumour removal. The aim of this prospective open-label controlled study is to assess if ETV prevents secondary HCP after tumour removal and if ETV influences the early results of tumour surgery. The study was performed on 68 patients operated for tumours of the third ventricle and posterior fossa. In 30 patients, ETV was performed several days before tumour removal, while in 38 patients, the tumour was removed during a one-stage procedure without ETV. Patients who did not receive ETV before the tumour removal procedure had a higher probability of developing postoperative HCP (n = 12, p = 0.03). They also demonstrated a substantially higher rate of early postoperative complications (n = 20, p = 0.002) and a lower Karnofsky score (p = 0.004) than patients in whom ETV was performed before tumour removal. The performance of external ventricular drainage in the non-ETV group did not prevent secondary HCP (p = 0.68). Postoperative cerebellar swelling (p = 0.01), haematoma (p = 0.04), cerebrospinal fluid leak (p = 0.04) and neuroinfection (p = 0.04) were the main risk factors of persistent HCP. Performance of ETV before tumour removal is not only beneficial for control of acute HCP but also prevents the occurrence of secondary postoperative HCP and may also minimize early postoperative complications.

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.

Endoscopic third ventriculostomy for pediatric tumor-associated hydrocephalus

OBJECTIVE

Surgical options for managing hydrocephalus secondary to CNS tumors have traditionally included ventriculoperitoneal shunting (VPS) when tumor resection or medical management alone are ineffective. Endoscopic third ventriculostomy (ETV) has emerged as an attractive treatment strategy for tumor-associated hydrocephalus because it offers a lower risk of infection and hardware-related complications; however, relatively little has been written on the topic of ETV specifically for the treatment of tumor-associated hydrocephalus. Here, the authors reviewed the existing literature on the use of ETV in the treatment of tumor-associated hydrocephalus, focusing on the frequency of ETV use and the failure rates in patients with hydrocephalus secondary to CNS tumor.

METHODS

The authors queried PubMed for the following terms: "endoscopic third ventriculostomy," "tumor," and "pediatric." Papers with only adult populations, case reports, and papers published before the year 2000 were excluded. The authors analyzed the etiology of hydrocephalus and failure rates after ETV, and they compared failure rates of ETV with those of VPS where reported.

RESULTS

Thirty-two studies with data on pediatric patients undergoing ETV for tumor-related hydrocephalus were analyzed. Tumors, particularly in the posterior fossa, were reported as the etiology of hydrocephalus in 38.6% of all ETVs performed (984 of 2547 ETVs, range 29%-55%). The ETV failure rate in tumor-related hydrocephalus ranged from 6% to 38.6%, and in the largest studies analyzed (> 100 patients), the ETV failure rate ranged from 10% to 38.6%. The pooled ETV failure rate was 18.3% (199 failures after 1087 procedures). The mean or median follow-up for ETV failure assessment ranged from 6 months to 8 years in these studies. Only 5 studies directly compared ETV with VPS for tumor-associated hydrocephalus, and they reported mixed results in regard to failure rate and time to failure. Overall failure rates appear similar for ETV and VPS over time, and the risk of infection appears to be lower in those patients undergoing ETV. The literature is mixed regarding the need for routine ETV before resection for posterior fossa tumors with associated hydrocephalus.

CONCLUSIONS

Treatment of tumor-related hydrocephalus with ETV is common and is warranted in select pediatric patient populations. Failure rates are overall similar to those of VPS for tumor-associated hydrocephalus.

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.

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.

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.

Graft dural closure is associated with a reduction in CSF leak and hydrocephalus in pediatric patients undergoing posterior fossa brain tumor resection

OBJECTIVE

The authors aimed to evaluate clinical, radiological, and surgical factors associated with posterior fossa tumor resection (PFTR)-related outcomes, including postoperative complications related to dural augmentation (CSF leak and wound infection), persistent hydrocephalus ultimately requiring permanent CSF diversion after PFTR, and 90-day readmission rate.

METHODS

Pediatric patients (0-17 years old) undergoing PFTR between 2000 and 2016 at Monroe Carell Jr. Children's Hospital of Vanderbilt University were retrospectively reviewed. Descriptive statistics included the Wilcoxon signed-rank test to compare means that were nonnormally distributed and the chi-square test for categorical variables. Variables that were nominally associated (p < 0.05) with each outcome by univariate analysis were included as covariates in multivariate linear regression models. Statistical significance was set a priori at p < 0.05.

RESULTS

The cohort consisted of 186 patients with a median age at surgery of 6.62 years (range 3.37-11.78 years), 55% male, 83% Caucasian, and average length of follow-up of 3.87 ± 0.25 years. By multivariate logistic regression, the variables primary dural closure (PDC; odds ratio [OR] 8.33, 95% confidence interval [CI] 1.07-100, p = 0.04), pseudomeningocele (OR 7.43, 95% CI 2.23-23.76, p = 0.0007), and hydrocephalus ultimately requiring permanent CSF diversion within 90 days of PFTR (OR 9.25, 95% CI 2.74-31.2, p = 0.0003) were independently associated with CSF leak. PDC versus graft dural closure (GDC; 35% vs 7%, OR 5.88, 95% CI 2.94-50.0, p = 0.03) and hydrocephalus ultimately requiring permanent CSF diversion (OR 3.30, 95% CI 1.07-10.19, p = 0.0007) were associated with wound infection requiring surgical debridement. By multivariate logistic regression, GDC versus PDC (23% vs 37%, OR 0.13, 95% CI 0.02-0.87, p = 0.04) was associated with persistent hydrocephalus ultimately requiring permanent CSF diversion, whereas pre- or post-PFTR ventricular size, placement of peri- or intraoperative extraventricular drain (EVD), and radiation therapy were not. Furthermore, the addition of perioperative EVD placement and dural closure method to a previously validated predictive model of post-PFTR hydrocephalus improved its performance from area under the receiver operating characteristic curve of 0.69 to 0.74. Lastly, the authors found that autologous (vs synthetic) grafts may be protective against persistent hydrocephalus (p = 0.02), but not CSF leak, pseudomeningocele, or wound infection.

CONCLUSIONS

These results suggest that GDC, independent of potential confounding factors, may be protective against CSF leak, wound infection, and hydrocephalus in patients undergoing PFTR. Additional studies are warranted to further evaluate clinical and surgical factors impacting PFTR-associated complications.

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.

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.

Predictive factors associated with ventriculoperitoneal shunting after posterior fossa tumor surgery in children

PURPOSE

The aim of the study was to evaluate established risk factors and define new inflammation-associated factors associated with postoperative ventriculoperitoneal shunt placement.

METHODS

The electronic medical records of children who underwent surgery for a tumor in the posterior fossa between January 2009 and January 2018 were retrospectively analyzed. Factors evaluated include age, clinical symptoms, tumor type, extent of surgical tumor resection, treatment with EVD and/or ETV, radiological findings, postoperative serum CRP, and leucocyte levels. Tumor tissue was stained immunohistochemically with antibodies against CD3, and leucocyte counts were performed. Patients with pre- or postoperative signs of infection or confirmation of a concurrent infection were excluded from some analyses.

RESULTS

Seventy patients ages 0.4-20.8 years (median, 8.2) were included. Forty-five of 70 (65.3%) presented postoperative radiological signs of hydrocephalus. Fifteen of 70 (21.4%) patients required shunt placement postoperatively. Shunt placement was significantly associated with age < 3 years at diagnosis (p = 0.013), perioperative EVD placement (p < 0.001), signs of hydrocephalus in postoperative imaging (p = 0.047), a frontooccipital horn ratio (FOHR) > 0.46 within the first 72 h postoperatively (p < 0.001), and the presence of intraventricular blood postoperatively (p = 0.007). Six patients who underwent shunting had serum CRP levels > 40 mg/l (p = 0.030) within the first 48 h postoperatively. Tumor type or extent of resection did not correlate with shunt placement.

CONCLUSIONS

Several established and new factors associated with shunt placement after posterior fossa tumor surgery could be identified. Additional studies are needed to explore the aseptic inflammation pathways involved with increased CRP levels and shunt placement.

[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.

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.

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.

Two-stage surgical resection of an atypical teratoid rhabdoid tumor occupying the infratentorial and supratentorial compartment in children under two years: Report of two cases

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ATRTs are malignant neoplasms that occur in young children.

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These tumors can achieve large size prior to detection.

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A staged operative approach maximizes resection and minimizes morbidity.

Introduction

Atypical teratoid rhabdoid tumors are highly malignant neoplasms that present in young children and can grow to a large size. Maximal safe surgical resection is a mainstay of treatment.

Presentation of cases

Two cases of children under the age of two with large tumors involving the supratentorial and infratentorial compartments are presented. A two-staged operative approach combining a standard suboccipital approach to the fourth ventricle followed by an infratentorial, supracerebellar approach was utilized for resection.

Discussion

Maximal safe surgical resection of large tumors in young children is challenging. A staged approach is presented that affords maximal tumor resection while minimizing perioperative morbidity.

Conclusion

A staged operative approach appears safe and efficacious when resecting large tumors from both the infratentorial and supratentorial compartments in children less than two years of age.

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

OBJECT

Most pediatric patients that present with a posterior fossa tumor have concurrent hydrocephalus. There is significant debate over the best management strategy of hydrocephalus in this situation. The objectives of this paper were to review the pathophysiology model of posterior fossa tumor hydrocephalus, describe the individual risks factors of persistent hydrocephalus, and discuss the current management options. Specifically, the debate over preresection cerebrospinal fluid diversion is discussed.

RESULTS

Only 10-40 % demonstrate persistent hydrocephalus after posterior fossa tumor resection. It appears that young age, moderate to severe hydrocephalus, transependymal edema, the presence of cerebral metastases, and tumor pathology (medulloblastoma and ependymoma) on presentation predict postresection or persistent hydrocephalus. The Canadian Preoperative Prediction Rule for Hydrocephalus (CPPRH), a validated prediction model, can be used to stratify patients at point of first contact into high and low risk for persistent hydrocephalus.

CONCLUSIONS

A protocol is proposed for managing hydrocephalus that utilizes the CPPRH. Low-risk patients can be monitored conservatively with or without an intraoperative extraventricular drain, while high-risk patients require the use of an intraoperative extraventricular drain, higher postoperative hydrocephalus surveillance, and even consideration for a preoperative endoscopic third ventriculostomy.

Does size matter? Minimally invasive approach in pediatric neurosurgery--a review of 125 minimally invasive surgeries in children: clinical history and operative results

OBJECTIVE

Surgery is an integral component and typically the first line of therapy for children with central nervous system tumors. Conventional aims of neurosurgery including tumor removal, management of hydrocephalus, and diagnostic sampling have been radically modified with innovative technologies such as navigational guidance, functional mapping, endoscopic surgery, second-look surgery, and physiologic imaging. The aim of the study was to investigate our operative results using minimally invasive technique in children.

METHODS

Clinical features, surgical technique and results, length of hospital stay, and complications were reviewed retrospectively. Pre- and early postoperative MRI was evaluated for degree of surgical resection. Correlation of tumor localization, lengths of hospital stay as well as surgical techniques and clinical outcome with follow-up was investigated.

RESULTS

One hundred ten patients underwent 125 tumor resections using minimally invasive approaches (image- and functional guided tailored keyhole approaches for supratentorial, retrosigmoidal, and suboccipital keyhole approaches for infratentorial lesions). Most tumors were located supratentorial (62.4 %). In 29.6 % of the cases, the surgery was performed endoscope-assisted or endoscope-controlled; neuronavigation was used in 45.6 % and ultrasound in 24 % of the cases. Astrocytomas were diagnosed in 26.4 % of cases, ependymomas in 9.6 %, and medulloblastomas in 14.4 %. Gross total resection was achieved in 60.8 %. The most common complication was CSF fistula (n = 9), and the occurrence was significantly higher in younger children (p = 0.0001) and infratentorial located tumors (p = 0.02). Surgery for posterior fossa lesions was associated with a longer hospital stay (p = 0.02) compared to surgery of supratentorial lesions. Mean follow-up was 29.7 months (range 0.3-79.1 months), and most of the children recovered during the further course of the follow-up (symptoms better or idem in 74.4 %).

CONCLUSION

In conclusion, our study shows that it is possible to achieve surgical results in the pediatric population applying minimal invasive techniques comparable to those described in the literature.

Clinical implications of medulloblastoma subgroups: incidence of CSF diversion surgery

OBJECT

While medulloblastoma was initially thought to comprise a single homogeneous entity, it is now accepted that it in fact comprises 4 discrete subgroups, each with its own distinct demographics, clinical presentation, transcriptomics, genetics, and outcome. Hydrocephalus is a common complication of medulloblastoma and not infrequently requires CSF diversion. The authors report the incidence of CSF diversion surgery in each of the subgroups of medulloblastoma (Wnt, Shh, Group 3, and Group 4).

METHODS

The medical and imaging records for patients who underwent surgery for medulloblastoma at The Hospital for Sick Children were retrospectively reviewed. The primary outcome was the requirement for CSF diversion surgery either before or within 60 days of tumor resection. The modified Canadian Preoperative Prediction Rule for Hydrocephalus (mCPPRH) was compared among subgroups.

RESULTS

Of 143 medulloblastoma patients, treated from 1991 to 2013, sufficient data were available for 130 patients (15 with Wnt, 30 with Shh, 30 with Group 3, and 55 with Group 4 medulloblastomas). Of these, 28 patients (22%) ultimately underwent CSF diversion surgery: 0% with Wnt, 29% with Shh, 29% with Group 3, and 43% with Group 4 tumors. Patients in the Wnt subgroup had a lower incidence of CSF diversion than all other patients combined (p = 0.04). Wnt patients had a lower mCPPRH score (lower risk of CSF diversion, p = 0.045), were older, had smaller ventricles at diagnosis, and had no leptomeningeal metastases.

CONCLUSIONS

The overall rate of CSF diversion surgery for Shh, Group 3, and Group 4 medulloblastomas is around 30%, but no patients in the present series with a Wnt medulloblastoma required shunting. The low incidence of hydrocephalus in patients with Wnt medulloblastoma likely reflects both host factors (age) and disease factors (lack of metastases). The absence of hydrocephalus in patients with Wnt medulloblastomas likely contributes to their excellent rate of survival and may also contribute to a higher quality of life than for patients in other subgroups.