Permanent CSF Diversion Research Articles

Validating the modified Canadian Preoperative Prediction Rule for Hydrocephalus for accurate hydrocephalus prediction in a statewide pediatric brain tumor cohort.

The modified Canadian Preoperative Prediction Rule for Hydrocephalus (mCPPRH) was developed to predict the need for permanent CSF diversion in children with posterior fossa tumors (PFT). This study aimed to externally validate the mCPPRH in a cohort of 113 pediatric patients with PFTs. We conducted a retrospective analysis, calculating the mCPPRH score for each patient and performing receiver operating characteristic (ROC) curve analysis to assess the tool's discriminative ability. Sensitivity, specificity, predictive values, and likelihood ratios were calculated using a cutoff score of ≥ 5. Multivariable logistic regression with bidirectional stepwise selection was used to evaluate individual components of the score. ThemCPPRH components were modified and the performance of adjusted tools was compared to the original. Of the 113 patients, 35 (31.0%) required permanent CSF diversion. The mCPPRH demonstrated acceptable discriminative ability (AUC = 0.701, 95% CI 0.608-0.795, p < 0.0003). Sensitivity was 34.1%, specificity 89.7%, positive predictive value 60%, and negative predictive value 75.3%. Initial regression identified no significant predictors. In stepwise regression, moderate-severe hydrocephalus independently predicted permanent CSF diversion (OR 6.37, 95% CI 1.71-41.55, p = 0.02). Increasing the age cutoff to < 5years, removing tumor diagnosis, and modifying hydrocephalus weighting improved performance (AUC = 0.768, sensitivity 71.4%, specificity 75.6%). The mCPPRH demonstrates acceptable discriminative ability (AUC 0.701) in our cohort, with particular utility in identifying low-risk patients. However, its poor sensitivity (34.1%) and variable predictor performance suggest that additional clinical factors should be considered for treatment planning, particularly in higher-risk cases. Further modification of mCPPRH components is suggested to improve its utility.

Neurodevelopmental outcomes of permanent and temporary CSF diversion in posthemorrhagic hydrocephalus: a Hydrocephalus Clinical Research Network study.

This study investigated neurodevelopmental outcomes in preterm neonates with posthemorrhagic hydrocephalus (PHH), focusing on the comparative effectiveness of temporary and permanent CSF diversion strategies. This multicenter prospective observational cohort study (2012-2021) involved preterm infants diagnosed with PHH who underwent either initial permanent or temporary CSF diversion. Patients were assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III), at 15-30 months and, when possible, at 36-42 months of corrected age. Statistical analyses included univariable and multivariable regression models to examine the associations between BSID-III scores and various treatment and patient factors. Among 106 patients, 15 (14%) underwent initial permanent CSF diversion, while 91 (86%) received temporary diversion. Patients who underwent permanent diversion had lower cognitive scores (58.2 ± 5.7) compared to those temporized (69.0 ± 15.9) (p = 0.01). Temporized patients who later required conversion to permanent diversion demonstrated poorer composite (66.6 ± 18.0 vs 79.9 ± 18.8, p = 0.02), expressive (4.6 ± 3.2 vs 7.0 ± 3.7, p = 0.03), and receptive (4.2 ± 3.3 vs 6.1 ± 3.0, p = 0.04) language scores compared to those weaned from temporary CSF diversion. No significant difference in outcomes was observed between patients temporized with a ventriculosubgaleal shunt versus a ventricular reservoir. Ventricle size at the time of initial CSF diversion was not associated with BSID-III scores. However, univariable analysis showed that a larger ventricle size at the time of conversion to permanent diversion was associated with lower neurodevelopmental scores across all domains. Multivariate analysis, adjusting for intraventricular hemorrhage (IVH) grade, complex chronic conditions, and postmenstrual age, revealed that larger ventricle size at the time of conversion correlated negatively with composite motor (effect size -0.47, CI -0.82 to -0.11, p = 0.01) and fine motor (-0.08, CI -0.15 to -0.01, p = 0.03) scores. This study suggested that the choice between permanent and temporary CSF diversion as initial treatments may affect neurodevelopmental outcomes in preterm neonates with PHH, which are influenced by IVH severity and timing of intervention. The findings support early temporization and avoiding delays to optimize permanent shunting. Monitoring ventricular size closely during this phase is critical, as larger ventricular size at the time of conversion is associated with poorer outcomes. These results highlight the necessity for adapting treatment strategies on the basis of individual patient characteristics, responses, and progress in managing PHH.

Neuroendoscopic lavage for posthemorrhagic hydrocephalus of prematurity: preliminary results at a single institution in the United States.

The current neurosurgical treatment for intraventricular hemorrhage (IVH) of prematurity resulting in posthemorrhagic hydrocephalus (PHH) seeks to reduce intracranial pressure with temporary and then permanent CSF diversion. In contrast, neuroendoscopic lavage (NEL) directly addresses the intraventricular blood that is hypothesized to damage the ependyma and parenchyma, leading to ventricular dilation and hydrocephalus. The authors sought to determine the feasibility of NEL in PHH. The records of patients with a diagnosis of grade III or IV IVH were reviewed between September 2022 and February 2024. The Papile grade was determined on cranial ultrasonography. Demographic information collected included gestational age, birth weight, weight at the time of surgical intervention, infection confirmed with CSF, and rehemorrhage. Standard local guidelines for temporary (CSF reservoir) and permanent (shunt or endoscopic third ventriculostomy [ETV]) CSF diversion were implemented. Warmed lactated Ringer's was utilized for NEL. The primary outcome was the need for permanent CSF diversion (shunt or ETV). Twenty consecutive patients with grade III or IV IVH complicated by PHH were identified. Twelve patients underwent CSF reservoir placement and NEL, 4 underwent CSF reservoir placement only, 1 underwent shunt placement only, and 3 did not require neurosurgical intervention. Of the 12 patients who underwent reservoir placement and NEL, 8 (67%) ultimately met criteria for permanent CSF diversion compared with 2 of 4 (50%) who underwent CSF reservoir placement only. The mean gestational age at birth, birth weights, and age/weight at time of temporary CSF diversion were similar across groups. The average time interval between temporary and permanent CSF diversion was longer in patients who underwent NEL (2.5 months for shunt and 6.5 months for ETV) compared with CSF reservoir placement only (1.1 months). NEL is an innovative alternative for the treatment of PHH of prematurity. The authors established an endoscopic lavage program at their institution and herein report the first published account in the United States of the feasibility of NEL for PHH.

In utero progression of cephaloceles: prenatal to postnatal analysis.

The natural history of cephaloceles is not well understood. The goal of this study was to better understand the natural history of fetal cephaloceles from prenatal diagnosis to the postnatal period. Between January 2013 and April 2023, all patients evaluated with a cephalocele at the Center for Fetal Diagnosis and Treatment were identified. All patients underwent prenatal and postnatal MRI. Demographic and imaging covariates were obtained from the electronic medical record. Volumetric analyses were performed to determine the percentage of neural tissue within the cephalocele. Progressive herniation was defined as an increase in cephalocele absolute neural tissue volume ≥ 5% or new herniation of an additional intracranial structure into the cephalocele. A total of 25 patients met the inclusion criteria. Of these patients, 6 (24%) exhibited progressive cephalocele herniation from the prenatal to postnatal MRI. The median sac volume was 2.2 mL (mean 6.2 mL, range 0.3-40.5 mL). The median change in brain volume in the patients with cephalocele progression was a decrease of 1.5% (mean -7.3%, range -36.4% to 3.1%). Cephalocele sac volume at the time of fetal imaging was predictive of progressive herniation, which persisted on multivariate analysis when controlling for gestational age, sex, and percentage of herniated neural tissue. While 44% of the patients had ventriculomegaly, 56% ultimately required permanent CSF diversion. Progressive neural herniation from the fetal to postnatal period is not commonly seen in fetal cephaloceles. Sac volume is associated with an increased risk of progressive herniation into the cephalocele.

Can a single basal cistern urokinase bolus help to prevent subarachnoid hemorrhage consequences?

Study designRetrospective. BackgroundIn the 1980s, aneurysmal subarachnoid clot lysis with urokinase or alteplase (rtPA) was proven to effectively reduce vasospasm and neurological ischemic deficits, improving survival and clinical outcomes. This therapeutic option has been less commonly used since the introduction of endovascular treatment, but renewed interest has sparked in recent years. AimsTo investigate if single bolus cisternal urokinase subarachnoid clot lysis reduces vasospasm, neurological ischemic deficits, mortality, and permanent CSF diversion rates and improves outcomes. Additionally, we want to unveil which subgroup of patients benefit most. Material and methodsStudy period January 2007–December 2019. 415 patients with saccular aneurysms and >1-year follow-up analyzed. Six groups created according to the treatment applied: no treatment (42), only external ventricular drain (16), endovascular treatment (155), clipping (53), clipping + 100,000UI urokinase (116), and incidental brain aneurysm (33). ResultsThe rates and severity of vasospasm, permanent CSF diversion, and mortality in Fisher grades ≥3 subarachnoid hemorrhages were higher with endovascular treatment than with surgical clipping with simultaneous cisternal urokinase administration. The best GOSE results on discharge and 6- and 12-month follow-ups happened in this latter group. The differences were more significant the higher the Fisher grade. We neither saw intraventricular, subarachnoid, subdural, or epidural hemorrhages nor systemic fibrinolysis or infections that could be related to the urokinase administration. ConclusionsSingle bolus cisternal 100,000UI urokinase administration during emergency aneurysm clipping reduces vasospasm, mortality, and the need for permanent CSF diversion. It is not associated with a significant increase in intracranial hemorrhages or systemic fibrinolysis.

Association of germinal matrix hemorrhage volume with neurodevelopment and hydrocephalus.

The objective of this study was to evaluate whether volumetric measurements on early cranial ultrasound (CUS) in high-grade germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH) are associated with hydrocephalus and neurodevelopmental metrics. A retrospective case series analysis of infants with high-grade GMH-IVH admitted to the St. Louis Children's Hospital neonatal intensive care unit between 2007 and 2015 who underwent neurodevelopmental testing using the Bayley Scales of Infant and Toddler Development, 3rd Edition (Bayley-III) at 2 years of corrected age was performed. GMH volume, periventricular hemorrhagic infarction volume, and frontotemporal horn ratio were obtained from direct review of neonatal CUS studies. Univariate and multivariable regression models were used to evaluate the association between hemorrhage volumes and hydrocephalus requiring permanent CSF diversion with ventricular shunt or endoscopic third ventriculostomy with or without choroid plexus cauterization and composite Bayley-III cognitive, language, and motor scores. Forty-three infants (29 males, mean gestational age 25 weeks) met the inclusion criteria. The mean age at time of the CUS with the largest hemorrhage volume or first diagnosis of highest grade was 6.2 days. Nineteen patients underwent treatment for hydrocephalus with permanent CSF diversion. In multivariable analyses, larger GMH volume was associated with worse estimated Bayley-III cognitive (left-sided GMH volume: p = 0.048, total GMH volume: p = 0.023) and motor (left-sided GMH volume: p = 0.010; total GMH volume: p = 0.014) scores. Larger periventricular hemorrhagic infarction volume was associated with worse estimated Bayley-III motor scores (each side p < 0.04). Larger left-sided (OR 2.55, 95% CI 1.10-5.88; p = 0.028) and total (OR 1.35, 95% CI 1.01-1.79; p = 0.041) GMH volumes correlated with hydrocephalus. There was no relationship between early ventricular volume and hydrocephalus or neurodevelopmental outcomes. Location-specific hemorrhage volume on early CUS may be prognostic for neurodevelopmental and hydrocephalus outcomes in high-grade GMH-IVH.

Treatment of hydrocephalus following fetal repair of myelomeningocele: comparing endoscopic third ventriculostomy with choroid plexus cauterization to ventricular shunting.

The aim of this study was to compare clinical and craniometric outcomes of patients treated for hydrocephalus following fetal myelomeningocele repair (fMMR) via a ventriculoperitoneal shunt (VPS) or endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC). This was a retrospective cohort study of children who were treated for hydrocephalus following fMMR via VPS or ETV with or without CPC (ETV ± CPC) at Vanderbilt between 2012 and 2021. The primary outcomes were treatment failure and time to failure (TTF). Secondary outcomes included changes in hydrocephalus metrics (fronto-occipital horn ratio [FOHR] and head circumference measurements) and healthcare resource utilization (number of hospital admissions, clinic visits, and neuroimaging findings). Among 88 patients who underwent fMMR, 37 (42%) required permanent CSF diversion, of whom 19 received treatment at the authors' institution. Twelve patients underwent ETV ± CPC, and 7 underwent VPS placement at a median corrected age of 23 weeks versus 1 week (p = 0.002). The preoperative median head circumference percentiles and z-scores for patients in the ETV ± CPC cohort were similar to those of the VPS cohort (percentiles: 98.5 vs 94.0, p = 0.064; z-scores: 2.32 vs 1.60, p = 0.111). There was no difference in preoperative median FOHR measurements between the two cohorts (0.57 vs 0.59, p = 0.53). At 6 months postoperatively, the median head circumference percentile and z-score for the ETV ± CPC cohort remained similar between the two cohorts (percentiles: 98.0 vs 67.5, p = 0.315; z-scores: 2.12 vs 0.52, p = 0.307). There was no difference in the change in FOHR (-0.06 vs -0.09, p = 0.37) and change in head circumference percentile (-1.33 vs -28.6, p = 0.058) between the cohorts 6 months after the index CSF diversion procedure. One patient in the ETV ± CPC cohort experienced a seizure and a nonoperative subdural hemorrhage postoperatively; no other complications were observed. Six of the 7 patients in the VPS cohort required shunt revision with a median TTF of 9.8 months while 2 of the 12 ETV ± CPC patients required a repeat ETV at a median of 17.5 months (86% vs 17%, p = 0.013). The median number of hydrocephalus-related hospital readmissions was significantly lower in the ETV ± CPC cohort than in the VPS cohort (0 vs 1, p = 0.006). The ETV ± CPC cohort had fewer CT scans (0 vs 2, p = 0.004) and radiographs (0 vs 2, p < 0.001) than the VPS cohort. In a single-center cohort, hydrocephalic fMMR patients treated via ETV ± CPC remained shunt free, while a majority of patients receiving an upfront shunt required revision. This is the first study comparing ETV ± CPC with VPS in the fMMR hydrocephalus population. While larger, multicenter studies are needed, these results suggest that ETV/CPC may be a preferred means of CSF diversion following fMMR.

P.136 Implementation of BC Children’s Hospital’s intraventricular hemorrhage of prematurity management pathway: a quality improvement analysis

Background: Early placement of a ventricular access device (VAD) may decrease the need for permanent CSF diversion and improve cognitive outcomes in premature infants with intraventricular hemorrhage. In 2019, BC Children’s Hospital implemented a multidisciplinary early intervention pathway for these infants. This study evaluated process and compliance measures related to protocol implementation. Methods: A retrospective quality improvement chart review of enrolled infants was performed. Select measures included time to neurosurgery consult and intervention, compliance with VAD tapping and ultrasound protocols, overall ultrasound resource use, and complications. Results: Sixteen patients were included. Median time to VAD insertion was 6 days (IQR 4-9.5), greater than the 3-day target. Transfer time from peripheral NICUs and access to OR time were found to be important reasons for delay. Patients received a median 92.2% (IQR 85.1-100%) of the ultrasounds required by protocol, with a median of 36.5 (IQR 29-43.25) ultrasounds per patient. VAD tapping was 88.8% (IQR 75.6-94.8%) compliant; most protocol deviations were indicated taps not performed due to technical difficulties. Conclusions: Compliance with the new protocol was satisfactory. Areas for improvement include continued education at peripheral NICU sites to minimize transfer delays, improved access to the OR, and maintenance of technical skills amongst our NICU partners.

275 Absence of Hindbrain Herniation in Myelomeningocele Myeloschisis: A Closer Look at Patients Who Progress to Hindbrain Herniation in the Prenatal and Postnatal Period

INTRODUCTION: Prenatal repair is the gold standard for appropriate patients with fetal myelomeningocele/myeloschisis. Hindbrain herniation is a prerequisite for fetal repair; however, there is a subset of patients without herniation on initial imaging and then progress to herniation on subsequent prenatal/postnatal imaging. METHODS: From July 2016 to July 2022, patients seen at the Center of Fetal Diagnosis and Treatment for myelomeningocele/myeloschisis were evaluated for hindbrain herniation. The osseous lesion level was defined as the bony defect level on prenatal ultrasound. Prenatal sac volume was measured on MRI. Prenatal ventricular size was determined on US. The fronto-occipital horn ratio was measured on the first postnatal US. RESULTS: Of 422 patients identified with a prenatal diagnosis of myelomeningocele/myeloschisis, 73 were identified who initially had negative hindbrain herniation; of these, 9 and 11 patients progressed to herniation on subsequent prenatal and postnatal imaging, respectively; 32 remained without herniation throughout the prenatal/postnatal period. Sac volume was significant (p = 0.04) for those whose hindbrain herniation was detected on subsequent prenatal visits but not for those diagnosed in the postnatal period (p = 0.10). The majority of patients with hindbrain herniation progression had L1-2 lesions. A subset of patients ultimately underwent permanent CSF diversion (no herniation: 21.8%, prenatal herniation: 33.3%, postnatal herniation: 36.3%). CONCLUSIONS: Patients who initially exhibit no hindbrain herniation and then ultimately progress to herniation in subsequent prenatal or postnatal evaluation are more likely to have higher levels of osseous defect. Sac volume was determined as significant for delayed prenatal progression of hindbrain herniation. Further long-term outcomes are necessary to better characterize this unique cohort of patients.

Head growth in patients with myelomeningocele treated with prenatal and postnatal surgery.

The need for permanent CSF diversion is lower in patients who have undergone prenatal surgery for myelomeningocele (MMC) than in those who have undergone postnatal closure. Differences in brain development and head growth between treatment groups are not known, particularly for those who do not require surgical treatment for hydrocephalus. The objective of this study was to determine differences in head growth and to generate MMC-specific head circumference (HC) growth curves for patients who underwent either prenatal or postnatal surgery. The authors retrospectively identified patients from St. Louis Children's Hospital who were treated for MMC between 2016 and 2021. HC data were obtained from birth until the most recent follow-up or hydrocephalus treatment. Nonlinear least-squares regression analysis was performed to fit the data into four models: two-term power, Gompertz, West ontogenetic, and Weibull. Subsequently, the curves were assessed for their utility in predicting hydrocephalus treatment. Sixty-one patients (29 females [47.5%], 25 [41%] underwent prenatal surgery, mean gestational age at birth 36.6 weeks) were included in the study. The Weibull model best fit the HC data (prenatal adjusted R2 = 0.95, postnatal adjusted R2 = 0.95), while the Gompertz model had the worst fit (prenatal adjusted R2 = 0.56, postnatal adjusted R2 = 0.39) across both cohorts. Prenatal MMC repair patients had significantly larger HC measurements than their postnatal repair counterparts. The 50th percentile of the Weibull curve was determined as a useful threshold for hydrocephalus treatment: children with HC measurements that crossed and remained above this threshold were significantly more likely to have hydrocephalus treatment regardless of time of MMC repair (prenatal relative risk [RR] 10.0 [95% CI 1.424-70.220], sensitivity 85.7% [95% CI 0.499-0.984], and specificity 82.4% [95% CI 0.600-0.948]; postnatal RR 4.750 [95% CI 1.341-16.822], sensitivity 90.5% [95% CI 0.728-0.980], and specificity 75.0% [95% CI 0.471-0.924]). The HC growth curves of the MMC patients treated prenatally were significantly larger than the WHO HC curves (p < 0.001). The Weibull model was identified as the HC growth curve with the best fit for MMC patients and serves as a useful predictor of hydrocephalus treatment. For MMC patients with hydrocephalus, prenatal repair patients fit the model well but postnatal repair patients did not, potentially indicating different mechanisms of hydrocephalus development. Those treated prenatally had significantly larger HC measurements compared with both the general population and those treated postnatally. Further study is needed to understand the long-term cognitive outcomes and optimal management of clinically asymptomatic patients with large HC measurements who were treated prenatally for MMC.

A tailored approach to the management of post-haemorrhagic hydrocephalus

PurposeNeuro-endoscopic lavage (NEL) is an increasingly popular intervention for intraventricular haemorrhage (IVH) and post-haemorrhagic hydrocephalus (PHH), with considerable variation in technique dependent on clinician and clinical circumstances. Whilst efforts to standardise the technique are ongoing, this work describes a tertiary centre experience utilising NEL, highlighting potential caveats to standardisation.MethodsA retrospective review of electronic case notes for patients undergoing temporising surgical intervention for IVH between 2012 and 2021 at our centre was performed. Data collected included (i) gestational age, (ii) aetiology of hydrocephalus, (iii) age at time of intervention, (iv) intervention performed, (v) need for permanent CSF diversion, (vi) ‘surgical burden’, i.e. number of procedures following primary intervention, and (vii) wound failure and infection rate. Data was handled in Microsoft Excel and statistical analysis SPSS v27.0Results49 neonates (n = 25 males) were included. Overall mean gestational age was 27 weeks and at intervention 35 + 3 weeks. IVH was the predominant cause of hydrocephalus (93.8%) and primary surgical interventions included insertion of a ventriculosubgaleal shunt (VSGS) in n = 41 (83.6%) patients, NEL in n = 6 (12.2%) patients and insertion of an EVD in n = 2 (4.1%). N = 9 (18.4%) patients underwent NEL at some point during the time interval reviewed; n = 4 (8.2%) received NEL monotherapy and n = 5 (10.2%) also received a VSGS. Rate of conversion to definitive CSF diversion between NEL (n = 8, 88.9%) and VSGS cohorts (n = 37, 92.5%) was not significantly different (p = 0.57), nor between NEL alone (n = 3, 75%) and NEL + VSGS (n = 5, 100%) (p = 0.44). None of the patients that underwent NEL monotherapy had any wound issues or CNS infection as a result of the initial intervention, compared to n = 3 (60%) of those that underwent NEL and implantation of VSGS (p = 0.1).ConclusionBoth NEL and VSGS are effective in temporising hydrocephalus in neonates, occasionally offering a definitive solution in and of themselves. The benefit of dual therapy however remains to be seen, with the addition of VSGS potentially increasing the risk of wound failure in an already vulnerable cohort.

Neurosurgical outcomes of pediatric cerebral venous sinus thrombosis following acute mastoiditis: a systematic review and meta-analysis.

Neurosurgical outcomes are not well defined in the management of pediatric patients with cerebral venous sinus thrombosis (CVST) following acute mastoiditis. Specific notable sequelae are otogenic (otitic) hydrocephalus and CVST management. Correspondingly, the aim of this study was to integrate the currently published metadata to summarize these outcomes. Electronic searches were performed using the Ovid Embase, PubMed, Scopus, and Cochrane databases from inception to November 2022 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Cohort-level data were then abstracted for analysis for appropriate pediatric patients. Outcomes were pooled by random-effects meta-analyses of proportions where possible. Twenty-three study cohorts describing 312 pediatric patients with otogenic CVST were included. At a cohort level, the median patient age was 6 years among 181 boys (58%) and 131 girls (42%). Modeling indicated papilledema at presentation in 46% of cases (95% CI 30%-62%). Regarding management, antibiotics were applied universally in all cases, mastoidectomy or other otologic surgery was performed in 91% (95% CI 82%-98%), and prophylactic anticoagulation was administered in 86% (95% CI 75%-95%). There was only 1 case (0.3%) of postprocedural intracranial hemorrhage, and there were no deaths reported among all studies. Although diagnostic lumbar puncture was performed in 14% (95% CI 3%-28%) at presentation, clinical otogenic hydrocephalus was ultimately suspected in 31% (95% CI 14%-49%), and acetazolamide was given in 65% (95% CI 35%-91%) overall. There were 10 cases (3%) that proceeded to permanent CSF diversion in the form of ventricular shunting. At a median follow-up of 8 months among all studies, the venous sinus was completely recanalized in 67% (95% CI 53%-79%). Most CVSTs following acute mastoiditis will recanalize with the standard use of antibiotics, otologic surgery, and anticoagulation, with minimal symptomatic hemorrhage risk. However, an appreciable proportion of these patients will develop symptomatic otogenic hydrocephalus, and it is imperative that the appropriate surveillance and workup is performed to fully optimize patient outcomes long-term. The possible need for permanent CSF diversion should be recognized.

The natural history of postoperative hydrocephalus after pediatric hemispherectomy for medically refractory epilepsy: an institutional experience.

Hemispherectomy is a complex surgical intervention for medically refractory epilepsy, and its surgical sequelae continue to be defined. The incidence, timing, and predictors of postoperative hydrocephalus are not well understood. Correspondingly, the aim of this study was to define the natural history of the development of hydrocephalus after hemispherectomy based on the authors' institutional experience. The authors performed a retrospective review of their departmental database for all relevant cases between 1988 and 2018. Demographic and clinical results were abstracted and analyzed using regression analyses to identify predictors of postoperative hydrocephalus. Of the 114 patients who satisfied selection criteria, there were 53 females (46%) and 61 males (53%) with mean ages of 2.2 and 6.5 years at first seizure and at hemispherectomy, respectively. There were 16 patients (14%) with a history of previous seizure surgery. In terms of surgery, the mean estimated blood loss was 441 ml, with a mean operative time of 7 hours, and 81 patients (71%) required intraoperative transfusions. A planned postoperative external ventricular drain (EVD) was placed in 38 patients (33%). The most common procedural complications were infection and hematoma, occurring in 7 patients (6%) each. Overall, there were 13 patients (11%) with postoperative hydrocephalus requiring permanent CSF diversion, occurring at a median of 1 year (range 0.1-5 years) after surgery. On multivariable analysis, a postoperative EVD (OR 0.12, p < 0.01) was significantly associated with a decreased likelihood of postoperative hydrocephalus, whereas previous surgery history (OR 4.32, p = 0.03) and postoperative infection complication (OR 5.14, p = 0.04) were significantly associated with increased likelihood of postoperative hydrocephalus. Postoperative hydrocephalus mandating permanent CSF diversion following hemispherectomy can be expected in approximately 1 in 10 cases, presenting months after surgery on average. A postoperative EVD appears to reduce this likelihood, whereas postoperative infection and previous history of seizure surgery were shown to statistically increase this likelihood. These parameters should be carefully considered in the management of pediatric hemispherectomy for medically refractory epilepsy.

A Comparison of Clinical Outcomes for Subependymal Giant Cell Astrocytomas Treated with Laser Interstitial Thermal Therapy, Open Surgical Resection, and mTOR Inhibitors

Introduction: Subependymal giant cell astrocytoma (SEGA) is the most common CNS tumor in patients with tuberous sclerosis complex (TSC). Although these are benign, their proximity to the foramen of Monroe frequently causes obstructive hydrocephalus, a potentially fatal complication. Open surgical resection has been the mainstay of treatment; however, this can cause significant morbidity. The development of mTOR inhibitors has changed the treatment landscape, but there are limitations to their use. Laser interstitial thermal therapy (LITT) is an emerging treatment modality that has shown promise in treatment of a variety of intracranial lesions, including SEGAs. We present a single institution, retrospective study of patients treated for SEGAs with LITT, open resection, mTOR inhibitors, or a combination of these modalities. The primary study outcome was tumor volume at most recent follow-up compared with volume at treatment initiation. The secondary outcome was clinical complications associated with treatment modality. Methods: Retrospective chart review was performed to identify patients with SEGAs treated at our institution from 2010 to 2021. Demographics, treatment information, and complications were collected from the medical record. Tumor volumes were calculated from imaging obtained at initiation of treatment and at most recent follow-up. Kruskal-Wallis nonparametric testing was used to assess differences in tumor volume and follow-up duration between groups. Results: Four patients underwent LITT (3 with LITT only), three underwent open surgical resection, and four were treated with mTOR inhibitors only. Mean percent tumor volume reduction for each group was 48.6 ± 13.8, 90.7 ± 39.8, and 67.1 ± 17.2%, respectively. No statistically significant difference was identified comparing percent tumor volume reduction between the three groups (p = 0.0513). Additionally, there was no statistically significant difference in follow-up duration between groups (p = 0.223). Only 1 patient in our series required permanent CSF diversion and 4 discontinued or decreased the dose of mTOR inhibitor due to either cost or side effects. Conclusions: Our study suggests that LITT could be considered as a treatment option for SEGAs as it was effective in reducing tumor volume with very few complications. This modality is less invasive than open resection and may be an alternative for patients who are not candidates for mTOR inhibitors. We recommend an updated paradigm for SEGA treatment which includes LITT in select cases after consideration of patient-specific factors.

Successful weaning versus permanent cerebrospinal fluid diversion after aneurysmal subarachnoid hemorrhage: post hoc analysis of a Swiss multicenter study.

Acute hydrocephalus is a frequent complication after aneurysmal subarachnoid hemorrhage (aSAH). Among patients needing CSF diversion, some cannot be weaned. Little is known about the comparative neurological, neuropsychological, and health-related quality-of-life (HRQOL) outcomes in patients with successful and unsuccessful CSF weaning. The authors aimed to assess outcomes of patients by comparing those with successful and unsuccessful CSF weaning; the latter was defined as occurring in patients with permanent CSF diversion at 3 months post-aSAH. The authors included prospectively recruited alert (i.e., Glasgow Coma Scale score 13-15) patients with aSAH in this retrospective study from six Swiss neurovascular centers. Patients underwent serial neurological (National Institutes of Health Stroke Scale), neuropsychological (Montreal Cognitive Assessment), disability (modified Rankin Scale), and HRQOL (EuroQol-5D) examinations at < 72 hours, 14-28 days, and 3 months post-aSAH. Of 126 included patients, 54 (42.9%) developed acute hydrocephalus needing CSF diversion, of whom 37 (68.5%) could be successfully weaned and 17 (31.5%) required permanent CSF diversion. Patients with unsuccessful weaning were older (64.5 vs 50.8 years, p = 0.003) and had a higher rate of intraventricular hemorrhage (52.9% vs 24.3%, p = 0.04). Patients who succeed in restoration of physiological CSF dynamics improve on average by 2 points on the Montreal Cognitive Assessment between 48-72 hours and 14-28 days, whereas those in whom weaning fails worsen by 4 points (adjusted coefficient 6.80, 95% CI 1.57-12.04, p = 0.01). They show better neuropsychological recovery between 48-72 hours and 3 months, compared to patients in whom weaning fails (adjusted coefficient 7.60, 95% CI 3.09-12.11, p = 0.02). Patients who receive permanent CSF diversion (ventriculoperitoneal shunt) show significant neuropsychological improvement thereafter, catching up the delay in neuropsychological improvement between 14-28 days and 3 months post-aSAH. Neurological, disability, and HRQOL outcomes at 3 months were similar. These results show a temporary but clinically meaningful cognitive benefit in the first weeks after aSAH in successfully weaned patients. The resolution of this difference over time may be due to the positive effects of permanent CSF diversion and underlines its importance. Patients who do not show progressive neuropsychological improvement after weaning should be considered for repeat CT imaging to rule out chronic (untreated) hydrocephalus.

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

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. 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. 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 2.25days 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 2-16days). The mean number of days with an EVD after tumor resection was 6.35 ± 3.8 (range 0-16days). 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 6months 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). 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.

Incidence and management of postoperative pseudomeningocele and cerebrospinal fluid leak after Chiari malformation type I decompression.

The optimal surgical management of Chiari malformation type I (CM-I) remains controversial and heterogeneous. The authors sought to investigate patient-specific, technical, and perioperative features that may affect the incidence of CSF-related complications including pseudomeningocele and CSF leak at their institution. The authors performed a single-center, retrospective review of all adult patients with CM-I who underwent posterior fossa decompression. Patient demographics, operative details, and perioperative factors were collected via electronic medical record review. The authors performed Fisher's exact test and independent Student t-tests for categorical and continuous variables, respectively. Univariate regression analysis was performed to determine odds ratios. A multivariable regression analysis was performed for those factors with p < 0.10 or large effect sizes (OR ≥ 2.0 or ≤ 0.50) by univariate analysis. The STROBE guidelines for observational studies were followed. A total of 59 adult patients were included. Most patients were female (78.0%), and the mean body mass index was 32.2 (± 9.0). Almost one-third (30.5%) of patients had a syrinx on preoperative imaging. All patients underwent expansile duraplasty, of which 47 (79.7%) were from autologous pericranium. Arachnoid opening for fourth ventricular inspection was performed in 26 (44.1%) cases. CSF-related complications were identified in 18 (30.5%) of cases. Thirteen (22.0%) patients required readmission and 11 (18.6%) required intervention such as wound revision (n = 5), wound revision with CSF diversion (n = 4), CSF diversion alone (n = 1), or blood patch (n = 1). Three (5.1%) patients required permanent CSF diversion. Male sex (OR 3.495), diabetes mellitus (OR 0.249), tobacco use (OR 2.53), body mass index more than 30 (OR 2.45), preoperative syrinx (OR 1.733), autologous duraplasty (OR 0.331), and postoperative steroids (OR 2.825) were included in the multivariable analysis. No factors achieved significance by univariate or multivariable analysis (all p > 0.05). The authors report a single-center, retrospective experience of posterior fossa decompression for 59 adults with CM-I. No perioperative or technical features were found to affect the CSF-related complication rate. More standardized practices within centers are necessary to better delineate the true risk factors and potential protective factors against CSF-related complications.

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

IntroductionPediatric 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 methodsIn 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).ResultsMedian 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).ConclusionPerioperative 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.

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

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. 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. 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. 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.

DIPG-25. Patterns of cerebrospinal fluid diversion and survival in children with diffuse intrinsic pontine glioma: a report from the International Diffuse Intrinsic Pontine Glioma Registry

BACKGROUND: There are no standard practice guidelines for cerebrospinal (CSF) diversion for diffuse intrinsic pontine glioma (DIPG), nor clear understanding of potential for palliation and life-prolongation. We evaluated CSF diversion characteristics in children with DIPG to determine incidence, indications, symptom effects, and survival. METHODS: Data were extracted from subjects registered in the International DIPG registry (IDIPGR). Univariable analyses was performed using the Fisher’s exact test or Wilcoxon rank sum test. Survival was estimated using the Kaplan-Meier method. RESULTS: Evaluable patients (n=542) met criteria for DIPG diagnosis by central radiologic review; of those, 126 (23%) had permanent CSF diversion. Median time from diagnosis to diversion was 0.5 months (IQR 0.1-4.5 months). Those with permanent diversion were significantly younger (median 5.4 years vs 7.0 years, p<0.001) and had higher incidence of hydrocephalus at diagnosis (65.3% vs 11.9%, p<0.001). Permanent CSF diversion did not significantly impact overall survival (OS) (p=0.4), even amongst the 124 patients with hydrocephalus at presentation (p=0.20). Those with permanent diversion prior to radiation therapy demonstrated longer median OS than those in whom diversion was placed after radiation (14.3 vs 9.6 months, p=0.001). Patients reported significantly less headache and vomiting at last follow up after permanent CSF diversion compared to pre-diversion (p<0.0001 and p=0.001, respectively), however steroid use was also significantly higher at last follow-up after CSF diversion (p<0.001). CONCLUSIONS: Amongst an international cohort, DIPG patients who had permanent CSF diversion were significantly younger and had higher rates of hydrocephalus at initial presentation than those without permanent diversion. Symptoms of increased intracranial pressure improved in those with CSF diversion, although a direct effect may be confounded by increased steroid use. Permanent CSF diversion did not prolong overall survival in this large cohort of patients, even amongst those who presented with hydrocephalus.