Hydrocephalus in prematurity: does valve choice make a difference?

PURPOSE: Extremely premature neonates diagnosed with post-haemorrhagic hydrocephalus (PHH) are recognised to have particularly poor outcomes. This study assessed the impact of a number of variables on outcomes in this cohort, in particular the choice of shunt valve mechanism. METHODS: Electronic case notes were retrospectively reviewed of all premature neonates admitted to our centre for management of hydrocephalus between 2012 and 2021. Data included (i) gestational age, (ii) birth weight, (iii) hydrocephalus aetiology, (iv) surgical intervention, (v) shunt system, (vi) 'surgical burden' and (vii) wound failure and infection rate. Data was handled in Microsoft Excel and statistical analysis performed in SPSS v27.0 RESULTS: N = 53 premature hydrocephalic patients were identified (n = 28 (52.8%) female). Median gestational age at birth was 27 weeks (range: 23-36 + 6 weeks), with n = 35 extremely preterm patients and median birth weight of 1.9 kg (range: 0.8-3.6 kg). Total n = 99 programmable valves were implanted (n = 28 (28.3%) de novo, n = 71 (71.2%) revisions); n = 28 (28.3%) underwent n ≥ 1 pressure alterations, after which n = 21 (75%) patients had symptoms improve. In n = 8 patients exchanged from fixed to programmable valves, a mean reduction of 1.9 revisions per patient after exchange was observed (95%CI: 0.36-3.39, p = 0.02). Mean overall shunt survival was 39.5 weeks (95%CI: 30.6-48.5); 33.2 weeks (95%CI: 25.2-41.1) in programmable valves and 35.1 weeks (95%CI: 19.5-50.6) in fixed pressure (p = 0.22) with 12-month survival rates of 25.7% and 24.7%, respectively (p = 0.22). Shorter de novo shunt survival was associated with higher operation count overall (Pearson's R: - 0.54, 95%CI: - 0.72 to - 0.29, p < 0.01). Wound failure, gestational age and birth weight were significantly associated with shorter de novo shunt survival in a Cox regression proportional hazards model; gestational age had the greatest impact on shunt survival (Exp(B): 0.71, 95%CI: 0.63-0.81, p < 0.01). CONCLUSION: Hydrocephalus is especially challenging in extreme prematurity, with a shorter de novo shunt survival associated with higher number of future revisions. Programmable valves provide flexibility with regard to pressure setting, with the potential for fewer shunt revisions in this complex cohort.

Selective dorsal rhizotomy in non-ambulant children with cerebral palsy: a multi-center prospective study.

PURPOSE: Assess the effects of selective dorsal rhizotomy (SDR) on motor function and quality of life in children with a Gross Motor Function Classification System (GMFCS) level of IV or V (non-ambulatory). METHODS: This is a prospective, observational study in three tertiary neurosurgery units in England, UK, performing SDR on children aged 3-18 with spastic diplegic cerebral palsy, and a GMFCS level of IV or V, between 2012 and 2019. The primary outcome measure was the change in the 66-item Gross Motor Function Measure (GMFM-66) from baseline to 24 months after SDR, using a linear mixed effects model. Secondary outcomes included spasticity, bladder function, quality of life, and pain scores. RESULTS: Between 2012 and 2019, 144 children who satisfied these inclusion criteria underwent SDR. The mean age was 8.2 years. Fifty-two percent were female. Mean GMFM-66 score was available in 77 patients (53.5%) and in 39 patients (27.1%) at 24 months after SDR. The mean increase between baseline and 24 months post-SDR was 2.4 units (95% CI 1.7-3.1, p < 0.001, annual change 1.2 units). Of the 67 patients with a GMFM-66 measurement available, a documented increase in gross motor function was seen in 77.6% (n = 52). Of 101 patients with spasticity data available, mean Ashworth scale decreased after surgery (2.74 to 0.30). Of patients' pain scores, 60.7% (n = 34) improved, and 96.4% (n = 56) of patients' pain scores remained the same or improved. Bladder function improved in 30.9% of patients. CONCLUSIONS: SDR improved gross motor function and reduced pain in most patients at 24 months after surgery, although the improvement is less pronounced than in children with GMFCS levels II and III. SDR should be considered in non-ambulant patients.

Intracranial Empyemas in the COVID-19 Era: A New Phenomenon? A Paediatric Case Series and Review of the Literature.

INTRODUCTION: We present the largest series of paediatric intracranial empyemas occurring after COVID-19 infection to date, and discuss the potential implications of the pandemic on this neurosurgical pathology. METHODS: Patients admitted to our centre between January 2016 and December 2021 with a confirmed radiological diagnosis of intracranial empyema were retrospectively reviewed, excluding non-otorhinological source cases. Patients were grouped according to onset before or after onset of the COVID-19 pandemic and COVID-19 status. A literature review of all post-COVID-19 intracranial empyemas was performed. SPSS v27 was used for statistical analysis. RESULTS: Sixteen patients were diagnosed with intracranial empyema: n = 5 prior to 2020 and n = 11 after, resulting in an average annual incidence of 0.3% prior to onset of the pandemic and 1.2% thereafter. Of those diagnosed since the pandemic, 4 (25%) were confirmed to have COVID-19 on recent PCR test. Time from COVID-19 infection until empyema diagnosis ranged from 15 days to 8 weeks. Mean age for post-COVID-19 cases was 8.5 years (range: 7-10 years) compared to 11 years in non-COVID cases (range: 3-14 years). Streptococcus intermedius was grown in all cases of post-COVID-19 empyema, and 3 of 4 (75%) post-COVID-19 cases developed cerebral sinus thromboses, compared to 3 of 12 (25%) non-COVID-19 cases. All cases were discharged home with no residual deficit. CONCLUSION: Our post-COVID-19 intracranial empyema series demonstrates a greater proportion of cerebral sinus thromboses than non-COVID-19 cases, potentially reflecting the thrombogenic effects of COVID-19. Incidence of intracranial empyema at our centre has increased since the start of the pandemic, causes of which require further investigation and multicentre collaboration.

Multi-modality treatment approach for paediatric AVMs with quality-of-life outcome measures.

PURPOSE: Despite the potentially devastating and permanently disabling effects of paediatric arteriovenous malformations (pAVMs), there is a paucity of studies reporting long-term quality-of-life (QoL) outcomes in AVM patients. We aim to evaluate the management strategies for paediatric intracranial pAVMs in the UK and long-term QoL outcomes using a validated paediatric quality-of-life outcome measure. METHODS: In this single-centre case-series, we retrospectively reviewed a prospectively maintained database of all paediatric patients (i.e. 0-18 years old) with intracranial AVMs, who were managed at Alder Hey Children's Hospital from July 2007 to December 2021. We also collected the PedsQL 4.0 score for these patients as a measure of QoL. RESULTS: Fifty-two AVMs were included in our analysis. Forty (80%) were ruptured, 8 (16%) required emergency intervention, 17 (35%) required elective surgery, 15 (30%) underwent endovascular embolisation, and 15 (30%) patients underwent stereotactic radiosurgery. There was an 88% overall obliteration rate. Two (4%) pAVMs rebled, and there were no mortalities. Overall, the mean time from diagnosis to definitive treatment was 144 days (median 119; range 0-586). QoL outcomes were collected for 26 (51%) patients. Ruptured pAVM presentation was associated with worse QoL (p = 0.0008). Location impacted psychosocial scores significantly (71.4, 56.9, and 46.6 for right supratentorial, left supratentorial, and infratentorial, respectively; p = 0.04). CONCLUSION: This study shows a staged multi-modality treatment approach to pAVMs is safe and effective, with superior obliteration rates with surgery alone. QoL scores are impacted by AVM presentation and location regardless of treatment modality.

Long term quality of life outcomes following surgical resection alone for benign paediatric intracranial tumours.

PURPOSE: Survivors of paediatric intracranial tumours are at increased risk of psychosocial, neuro-developmental, and functional impairment. This study aimed to evaluate long-term health-related quality-of-life (HRQOL) outcomes in patients with benign paediatric brain tumours treated curatively with surgical resection alone. METHODOLOGY: This was a cross-sectional study of patients with benign paediatric intracranial tumours managed with surgery alone between 2000 and 2015. Eligible patients with a minimum of 5-years follow-up after surgery were identified. Validated health-related quality of life (HRQOL) questionnaires were administered: SF-36, QLQ-BN20, QLQ-C30 and PedsQL™. RESULTS: Twenty-three patients participated (median age at surgery 13 years; range 1-18; 12 male). The most common diagnosis was pilocytic astrocytoma (n = 15). Median time from surgery to participation was 11 years(range 6-19). Fourteen patients achieved A-level qualifications and two obtained an undergraduate degree. Twelve patients were employed, eight were studying and three were unemployed or volunteering. HRQOL outcomes demonstrated significant limitation from social functioning (p = 0.03) and cognitive functioning (p = 0.023) compared to the general population. Patients also experienced higher rates of loss of appetite (p = 0.009) and nausea and vomiting (p = 0.031). Ten patients were under transitional teenager and young-adult (TYA) clinic follow-up. TYA patients achieved higher levels of education (p = 0.014), were more likely to hold a driver's license (p = 0.041) compared to patients not followed-up through these services. CONCLUSIONS: Childhood brain-tumour survivors have a greater risk of developing psychological, neuro-cognitive and physical impairment. Early comprehensive assessment, specialist healthcare and TYA services are vital to support these patients.

Prevalence of dysphagia following posterior fossa tumour resection in children: the Alder Hey experience.

BACKGROUND: Surgery for posterior fossa tumours (PFTs) in children is associated with bulbar palsy and swallowing difficulties although this risk is not well defined in the literature and issues contributing to dysphagia following surgery are not fully understood. AIMS: This study aims to study the eating, drinking and swallowing function of children following PFT resection in a specialist paediatric neurosurgery centre. This included the frequency and duration of dysphagia, the risk of aspiration and the link between tumour type and dysphagia. MATERIALS AND METHODS: This is a retrospective review of children undergoing surgery for PFT between 2014 and 2019. Information was obtained from the patients' hospital and speech and language therapy (SLT) notes, oncology database and clinical letters. The International Dysphagia Diet Standardisation Initiative (IDDSI) Framework was used to describe food and fluid modifications. RESULTS: Seventy children had surgery to resect a posterior fossa tumour at Alder Hey from 2014 to 2019. Thirty-one children were included in the study following referral to SLT. Videofluoroscopy (VF) was undertaken at our institution in 68% (21/31) of cases. Fifty-two percent (11/21) of children aspirated or were considered at risk, and 55% (6/11) of those who aspirated showed silent aspiration. After 3 months, 43% (13/30) still required modified food and/or fluid textures, with this proportion reducing as time progressed. By tumour type, VF was performed in 5/7 medulloblastoma patients with 3/5 showing aspiration and 3/3 silently aspirating; in 8/9 patients with ependymoma with 4/8 patients aspirating with 2/4 showing silent aspiration; and 6/12 glioma patients with 4/6 aspirating with 1/4 showing silent aspiration. CONCLUSION: Swallowing difficulties, including silent aspiration, are an important complication of PFT resection. A proportion of children will need ongoing food and/or fluid modification. Further study into dysphagia following PFT resection is indicated.

Infant hydrocephalus: what valve first?

PURPOSE: To review the use of different valve types in infants with hydrocephalus, in doing so, determining whether an optimal valve choice exists for this patient cohort. METHODS: We conducted (1) a literature review for all studies describing valve types used (programmable vs. non-programmable, valve size, pressure) in infants (≤ 2 years) with hydrocephalus, (2) a review of data from the pivotal BASICS trial for infant patients and (3) a separate, institutional cohort study from Alder Hey Children's Hospital NHS Foundation Trust. The primary outcome was any revision not due to infection. RESULTS: The search identified 19 studies that were included in the review. Most did not identify a superior valve choice between programmable and non-programmable, small compared to ultra-small, and differential pressure compared to flow-regulating valves. Five studies investigated a single-valve type without a comparator group. The BASICS data identified 391 infants, with no statistically significant difference between gravitational and programmable subgroups. The institutional data from our tertiary referral centre did not reveal any significant difference in failure rate between valve subtypes. CONCLUSION: Our review highlights the challenges of valve selection in infant hydrocephalus, reiterating that the concept of an optimal valve choice in this group remains a controversial one. While the infant-hydrocephalic population is at high risk of valve failure, heterogeneity and a lack of direct comparison between valves in the literature limit our ability to draw meaningful conclusions. Data that does exist suggests at present that there is no difference in non-infective failure rate are increasing in number, with the British valve subtypes in infant hydrocephalus, supported by both the randomised trial and institutional data in this study.

Evolution of surgical attitudes to paediatric thalamic tumours: the alder hey experience.

PURPOSE: Attitudes to surgery for paediatric thalamic tumours have evolved due to improved preoperative imaging modalities and the advent of intraoperative MRI (iMRI) as well as enhanced understanding of tumour biology. We review the developments in our local practice over the last three decades with particular attention to the impact of iMRI. METHODS: We identified all paediatric patients from a prospectively maintained neuro-oncology database who received surgery for a thalamic tumour (n = 30). All children were treated in a single UK tertiary paediatric neurosurgery centre between January 1991 and June 2020. Twenty patients underwent surgical resection, the remainder (10) undergoing biopsy only. Pre-operative surgical intent (biopsy versus debulking, near-total resection, or complete resection) as well as the use of iMRI were prospectively recorded. Complications recorded in clinical documentation between postoperative days 0 and 30 were retrospectively graded using a modified version of the Clavien Dindo scale. The extent of resection with respect to the pre-determined surgical aim was also recorded. Data on patient survival and disease progression status were obtained retrospectively. RESULTS: In our series, there were 42 procedures (25 craniotomies, 17 biopsies) performed on 30 patients (17 male, with a median age of 8 at surgery). Of the 25 surgical resections performed, complete resection was achieved in 9 (36%), near-total resection in 10 (40%), and limited debulking in 6 (24%). The predetermined surgical aim was achieved or exceeded in 91.3% of cases. The proportion of craniotomies for which substantial resection was achieved, increased from 37.5 to 94.2% with use of iMRI (p = 0.014). Surgical morbidity was not associated with greater extent of surgical resection. High-grade histology is identified as the only independent significant factor influencing overall survival as calculated by Cox proportional hazards model (p = 0.006). CONCLUSION: We note a significant change in the rate and extent of attempted resection of paediatric thalamic tumours that has developed over the last 3 decades. Use of iMRI is associated with a significant increase in substantial tumour resection surgeries. This is not associated with any significant level of surgical morbidity. Improvements in pre- and intra-operative imaging alongside better understanding of tumour biology facilitate patient selection and a surgically more aggressive approach in selected cases whilst maintaining safety and avoiding operative morbidity.

Efficacy and safety of the Miethke programmable differential pressure valve (proGAV®2.0): a single-centre retrospective analysis.

PURPOSE: Achieving decompression without CSF over-drainage remains a challenge in hydrocephalus. Differential pressure valves are a popular treatment modality, with evidence suggesting that incorporation of gravitational units helps minimise over-drainage. This study seeks to describe the utility of the proGAV®2.0 programmable valve in a paediatric population. METHODS: Clinical records and imaging of all patients fitted with proGAV®2.0 valves and Miethke fixed-pressure valves between 2014 and 2019 at our tertiary centre were analysed. Patient demographics, indication for shunt and valve insertion/revision and time to shunt/valve revision were collected. Ventricular linear metrics (fronto-occipital horn ratio (FOHR) and fronto-occipital horn width ratio (FOHWR)) were collected pre- and post-valve insertion. Microsoft Excel and SPSS v24 were used for data collection and statistical analysis. RESULTS: Eighty-eight proGAV®2.0 valves were inserted in a population of 77 patients (n = 45 males (58%), mean age 5.1 years (IQR: 0.4-11.0 years)). A total of 102 Miethke fixed-pressure valves were inserted over the same time period. Median follow-up was 17.5 months (1.0-47.3). One (1.1%) proGAV®2.0 was revised due to over-drainage, compared to 2 (1.9%) fixed-pressure valves (p > 0.05). ProGAV®2.0 insertion resulted in a significant decrease in the mean number of revisions per patient per year (1.77 vs 0.25; p = 0.01). Overall shunt system survival with the proGAV®2.0 was 80.4% at 12 months, and mean time to revision was 37.1 months, compared to 31.0 months (95%CI: 25.7-36.3) and 58.3% in fixed-pressure valves (p < 0.01). Significant decreases were seen following proGAV®2.0 insertion in both FOHR and FOHWR, by 0.014 (95%CI: 0.006-0.023, p = 0.002) and 0.037 (95%CI: 0.005-0.069, p = 0.024) respectively. CONCLUSION: The proGAV®2.0 provides effective decompression of hydrocephalic patients, significantly reduces the number of valve revisions per patient and had a significantly greater mean time to revision than fixed-pressure valves.

Comparison of intraoperative and post-operative 3-T MRI performed at 24-72 h following brain tumour resection in children.

PURPOSE: Intraoperative MRI (ioMRI) is a valuable tool aiding paediatric brain tumour resection. There is no published evidence comparing the effectiveness of the final intraoperative MRI and early post-operative (24-72 h) MRI as baseline scans following brain tumour resection. We aimed to evaluate whether the final ioMRI scan could serve as the post-operative baseline scan after paediatric brain tumour resections. METHODS: This prospective study compared the final ioMRI scan with the immediate post-operative MRI scan performed 24-72 h post-surgery. We included 20 patients aged 6.6-21 years undergoing brain tumour resection using ioMRI and were suitable for MRI scan without general anaesthesia. The scans were independently evaluated by experienced local and external paediatric neuroradiologists. Identical sequences in the final ioMRI and the 24-72-h MRI were compared to assess the extent of resection, imaging characteristics of residual tumour, the surgical field, extent of surgically induced contrast enhancement, and diffusion abnormalities. RESULTS: In 20 patients undergoing intraoperative and early post-operative MRI, there was no difference between ioMRI and 24-72-h post-op scans in identifying residual tumour. Surgically induced contrast enhancement was similar in both groups. There were more abnormalities on diffusion imaging and a greater degree of oedema around the surgical cavity on the 24-72-h scan. CONCLUSION: The final 3-T ioMRI scan may be used as a baseline post-operative scan provided standard imaging guidelines are followed and is evaluated jointly by the operating neurosurgeon and neuroradiologist. Advantages of final ioMRI as a baseline scan are identified.

Reporting morbidity associated with pediatric brain tumor surgery: are the available scoring systems sufficient?

OBJECTIVE: Complications in pediatric neurooncology surgery are seldom and inconsistently reported. This study quantifies surgical morbidity after pediatric brain tumor surgery from the last decade in a single center, using existing morbidity and outcome measures. METHODS: The authors identified all pediatric patients undergoing surgery for an intracranial tumor in a single tertiary pediatric neurosurgery center between January 2008 and December 2018. Complications between postoperative days 0 and 30 that had been recorded prospectively were graded using appropriate existing morbidity scales, i.e., the Clavien-Dindo (CD), Landriel, and Drake scales. The result of surgery with respect to the predetermined surgical aim was also recorded. RESULTS: There were 477 cases (364 craniotomies and 113 biopsies) performed on 335 patients (188 males, median age 9 years). The overall 30-day mortality rate was 1.26% (n = 6), and no deaths were a direct result of surgical complication. Morbidity on the CD scale was 0 in 55.14%, 1 in 10.69%, 2 in 18.66%, 3A in 1.47%, 3B in 11.74%, and 4 in 1.05% of cases. Morbidity using the Drake classification was observed in 139 cases (29.14%). Neurological deficit that remained at 30 days was noted in 8.39%; 78% of the returns to the operative theater were for CSF diversion. CONCLUSIONS: To the authors' knowledge, this is the largest series presenting outcomes and morbidity from pediatric brain tumor surgery. The mortality rate and morbidity on the Drake classification were comparable to those of published series. An improved tool to quantify morbidity from pediatric neurooncology surgery is necessary.

The effect of GMFCS level, age, sex, and dystonia on multi-dimensional outcomes after selective dorsal rhizotomy: prospective observational study.

PURPOSE: Investigate the effect of age category (1-9 years vs 10-18 years), sex, Gross Motor Function Classification System (GMFCS) level, and presence of dystonia on changes in eight function test parameters 24 months after selective dorsal rhizotomy (SDR). METHODS: Prospective, single-center study of all children aged 3-18 years with bilateral cerebral palsy with spasticity who underwent SDR at a tertiary pediatric neurosurgery center between 2012 and 2019. A linear mixed effects model was used to assess longitudinal changes. RESULTS: From 2012 to 2019, 42 children had follow-up available at 24 months. Mean GMFM-66 scores increased after SDR (mean difference 5.1 units: 95% CI 3.05-7.13, p < 0.001). Statistically significant improvements were observed in CPQoL, PEDI Self-care and Mobility, 6MWT, Gillette, and MAS scores. There was no significant difference in the improvements seen for age category, sex, GMFCS level, and presence of dystonia for most of the parameters tested (5/8, 6/8, 5/8, and 6/8 respectively). CONCLUSION: SDR may improve gross and fine motor function, mobility and self-care, quality of life, and overall outcome based on extensive scoring parameter testing at 24 months. Atypical patient populations may benefit from SDR if appropriately selected. Multi-center, prospective registries investigating the effect of SDR are required.

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.

Management of paediatric hydrocephalous with Miethke fixed pressure gravitational valves. The Alder Hey Children's Hospital experience.

OBJECTIVE: The management of paediatric hydrocephalous remains challenging with the complication and revision rates being consistent in the literature. We hypothesise that the use of a fixed pressure gravitational valve for all de novo shunt insertions decreases the rate of functional revisions and that by implementing the routine use of gravitational valves in children, we would see a reduction in over-drainage and slit ventricle syndrome. METHODS: Retrospective data collection in a single centre, between February 2010 and August 2018. All patients undergoing fixed pressure gravitational Miethke valve insertion were included. We collected data on patients' demographics, reason for shunt insertion, type of valve and time to and reason for first revision. Data analysis was done with SPSS. RESULTS: A total of 235 patients were included in our study (124 males, 111 females), aged from 0 to 18.6 years (median 0.28). A total of 99 shunt revisions were documented, 30 of which secondary to ventricular catheter malfunction and 28 secondary to infection. The overall mechanical valve survival rates were 88.5%, 86.4% and 85.5% at 1, 2 and 5 years, respectively. Shunt revision due to over-drainage was documented in only 3 cases (1.3%). CONCLUSION: Our results are in agreement with existing literature regarding shunt failures secondary to all extrinsic factors to the valve (infection and mechanical failure). We have shown that the use of a Miethke fixed pressure valve for all de novo shunt insertions in paediatric hydrocephalus decreases the need for functional revisions with valve survival rates being superior to the ones described for other types.

Outcomes with respect to extent of surgical resection for pediatric atypical teratoid rhabdoid tumors.

PURPOSE: To evaluate overall survival for atypical teratoid rhabdoid tumors (ATRTs) in relation to extent of surgical resection. METHODS: The neurosurgical tumor databases from three UK Pediatric centers (University Hospital of Wales, Alder Hey and Royal Manchester Children's Hospital) were analyzed. Patients with a diagnosis of ATRT were identified between 2000 and 2018. Data was collected regarding demographics, extent of resection, complications, and overall survival. RESULTS: Twenty-four patients diagnosed with ATRT underwent thirty-eight operations. The age range was 20 days to 147 months (median 17.5 months). The most common location for the tumor was the posterior fossa (nine patients; 38%). Six patients (25%) underwent a complete total resection (CTR), seven (29%) underwent a near total resection (NTR), eight (33.3%) underwent a subtotal resection (STR), and three patients (12.5%) had biopsy only. Two-thirds of patients who underwent a CTR are still alive, as of March 2019, compared to 29% in the NTR and 12.5% in the STR groups. Out of the thirty-eight operations, there were a total of twenty-two complications, of which the most common was pseudomeningocele (27%). The extent of surgical resection (p = 0.021), age at surgery (p = 0.00015), and the presence of metastases at diagnosis (0.015) significantly affected overall survival. CONCLUSIONS: Although these patients are a highly vulnerable group, maximal resection is recommended where possible, for the best chance of long-term survival. However, near total resections are likely beneficial when compared with subtotal resections and biopsy alone. Maximal surgical resection should be combined with adjuvant therapies for the best long-term outcomes.