Third Ventriculostomy Research Articles

Repeated endoscopic third ventriculostomy (ETV). Role of advanced instruments for performing this minimally invasive surgery

This series of studies presents the results of repeated endoscopic third ventriculostomy (ETV) in patients with occlusive hydrocephalus. 33 cases of repeated ETV were considered as a material for the study: 7 adult patients aged 18 years and older (19 % (3 men, 4 women)) and 26 children aged 0 to 17 years (81 % (15 boys, 11 girls)). The average period of clinical observation after the surgery was 42,3 ± 2,7 months. 21 patients (64 %) had the effect from the surgery, they became shunt-independent. 23 repeated endoscopic third ventriculostomy were performed using standard rigid endoscopes (Gaab, Lotta, Little Lotta Endoscopes), the other 10 surgeries were performed using miniature semi-rigid needle endoscope. There were no postoperative neurological, endocrine and infectious complications in the studied group.

Management of Hydrocephalus in Brain Tumors to Fann Teaching Hospital in Dakar

Introduction: Tumoral hydrocephalus (TH) is an increasingly common pathology in our service. It is a diagnostic and especially therapeutic emergency. Its treatment is mainly surgical and the prognosis closely depends on the type of tumor. The objective of our study was to determine the efficiency of the various bypass procedures used for the treatment of hydrocephalus in patients with brain tumors. Patients and Methods: We conducted a retrospective study of 146 patients with tumoral hydrocephalus, collected from 1 January 2014 to 31 December 2018 (5 years) in the Neurosurgery Department of Fann Teaching Hospital. Results: The frequency of tumoral hydrocephalus cases in our series was rated at 25% of all hydrocephalus operated during this period with 29.2 cases per year. The sex ratio was 1.39 with a mean age of 35 years (range from 1 month to 77 years). Children under 15 accounted for 53.42%. Cerebral computed tomography (CT) was performed in 93.75% of patients and magnetic resonance imaging (MRI) in 20.83%. Tumors of the posterior fossa (PFT) accounted for 60.3% followed by ventricular tumors 15.5% and sellar 7.5%. Surgically, endoscopic third ventriculostomy (ETV), ventriculoperitoneal shunt (VPS), and external ventricular derivation (EVD) were performed respectively in 58.24%, 30.13% and 10.27% of cases. The surgical average time was 3 days with extremes of 24h and 150 days. Two patients benefited from a ventriculo –atrial shunt (VAS) complementary to the persistence of hydrocephalus. The main complications were ascites of great abundance in 4 patients and infections in 10 patients (6.84%). In our series, 30.82% (45 patients) received additional etiological treatment. The average time between the two interventions was 14 days. We noted 17 cases of death including 7 cases attributed to hydrocephalus. Conclusion: The endoscopic third ventriculostomy is currently the gold standard as an alternative to other methods in the management of tumoral hydrocephalus, but remains a palliative treatment. Etiological treatment is the core therapeutic approach for this hydrocephalus.

Endoscopic third ventriculostomy in posterior fossa tumor

Posterior fossa (PF) tumors are among the most frequent primary neoplasms in children. Proximity to the fourth ventricle, and therefore cerebrospinal fluid (CSF) pathways, predisposes children with PF tumors to the development of obstructive hydrocephalus. Some patients with PF tumors require a permanent CSF diversion procedure prior to or after tumor removal. However, management of hydrocephalus in children with resectable PF tumors is still controversial. In order to minimize the use of permanent shunts and to avoid associated complications, some investigators have advocated routine preoperative application of endoscopic third ventriculostomy (ETV) only in selected patients. We showed a clinical video case who experienced a preoperatively ETV before the surgical resection of their posterior fossa tumor. The patient is a 5 year-old boy presented with progressive headaches, vomits and somnolence. Young children with severe preoperative hydrocephalus and a midline tumor should be considered at risk when preoperative treatment decisions are made. *de Oliveira RS and Ballestero MFM contributed equally to this manuscript

Third ventriculostomy in fourth ventricle outlet obstruction

A seven years-old boy presented with headache and progressive drowsiness. MRI demonstrated obstruction at the foramen of Magendie and foramina of Luschka. Child underwent an endoscopic third ventriculostomy (ETV). The postoperative course was uneventful. MRI scan showed a marked decrease in the size of the ventricles, showing therefore that cerebrospinal fluid flow through the ventricular system and subarachnoid space was restored de Oliveira RS and Ballestero MFM contributed equally to this manuscript

Quadrigeminal cistern arachnoid cyst causing hydrocephalus.

The quadrigeminal cistern is an unusual location for these cysts. Quadrigeminal arachnoid cysts account for 5% to 10% of all intracranial arachnoid cysts. They are frequently diagnosed coincidentally on computed tomography (CT) or magnetic resonance imaging (MRI). They cause symptoms when they become sufficiently large to compress the adjacent brain structures. Endoscopic fenestration of the cyst with cystocisternostomy or cystoventriculostomy, when combined with third ventriculostomy, is the procedure of choice for such patients. A 14-month-old boywas referred to neurosurgery clinic due to increased head circumference. His had been in good health until age 8 months, between age 9 and 13 months his acquisition of developmental skills was slow. Magnetic resonance image (MRI) demonstarted enlargement of the supratentorial ventricular system secondary to a large quadri-geminal cistern arachnoid cyst compressing the brainstem, cerebellum, aqueduct of Sylvius and fourth ventricle. The cystic mass appeared hyperintense on T2 weighted-images (A, B), hypointense on T1-WI (C, D), similar to cerebrospinal fluid (CSF) signal, without enhancement after Gadolinium administration. The patient was operated by transventricular approach with endoscopic third ventriculocystostomy and endoscopic third ventriculostomy (ETV). The postoperative course was uneventful.

Endoscopic third ventriculostomy inpatient failure rates compared with shunting in post-hemorrhagic hydrocephalus of prematurity.

Endoscopic third ventriculostomy (ETV) has gained traction as a method for treating post-hemorrhagic hydrocephalus of prematurity (PHHP) in an effort to obviate lifelong shunt dependence in neonates. However, data remains limited regarding inpatient failures. A retrospective analysis of the NIS between 1998 and 2014 was performed. Discharges with age < 1year and ICD-9-CM codes indicating intraventricular hemorrhage of prematurity (772.1x) and ETV/shunt (02.22 and 02.3x) were included. Patients with ICD-9-CM codes for ventricular drain/reservoir (02.21) were excluded to prevent confounding. Time trend series plots were created. Yearly trends were quantified using logarithmic regression analysis. Kaplan-Meier curves were utilized to analyze time to treatment failure. Time to failure for each treatment was compared using log-rank. A total of 11,017 discharges were identified. ETV was more likely to be utilized at < 29weeks gestational age (p = 0.0039) and birth weight < 1000g (p = 0.0039). Shunts were less likely to fail in older and heavier newborns (OR 0.836 p = 0.00456, OR 0.828 p = 0.0001, respectively). Those initially shunted had lower failure rates compared with ETV (OR 0.44, p < 0.0001) but time to failure was longer with ETV (p = 0.04562). 79.5% of ETVs that failed were shunted after the first failure. Shunts were much less likely to undergo ETV if they failed (OR 0.21, p < 0.0001). Higher grade IVH was predictive of shunt failure but not ETV (OR 2.36, p = 0.0129). Although ETV can be effective in PHHP, it has a much higher initial failure rate than shunting and should thus be chosen based on a multifactorial approach.

Hydrocephalus due to aqueductal stenosis presenting with acute bilateral ptosis: case report

Hydrocephalus may cause Parinaud’s syndrome which consists of vertical gaze palsy, convergence palsy, lid retraction and pupil light-near dissociation. We are aware of only two prior reports of hydrocephalus presenting with bilateral ptosis. Both were cured by ventriculoperitoneal shunts. We report a 28-month-old girl who presented acute bilateral ptosis but full eye movements both sides. Neuroimages revealed chronic hydrocephalus and aqueductal stenosis. The bilateral ptosis resolved quickly after endoscopic third ventriculostomy (ETV).

Third ventricle floor bowing: a useful measurement to predict endoscopic third ventriculostomy success in infantile hydrocephalus.

Preoperative judgment who will benefit from endoscopic third ventriculostomy (ETV) in infantile hydrocephalus remains controversial and no sufficient clue exists. Although ETV success score (ETVSS) is a useful scale in predicting ETV success in hydrocephalus, its efficacy in infants younger than 1 year old has been limited. This study aimed to verify the efficacy of a newly defined sign, "third ventricle floor bowing (TVFB)," in predicting ETV success in infantile hydrocephalus for the first time and discuss the mechanism of this sign and its clinical meanings. Between January 2013 and April 2018, hydrocephalic infants (age ≤ 12 months) with third ventricle floor bowing were treated endoscopically in the Department of Neurosurgery, West China Hospital. The medical records of these patients were reviewed. Additionally, we undertook a detailed review of the reported data on the treatment of infantile hydrocephalus with endoscopic third ventriculostomy (ETV). A total of 42 infants underwent ETV alone in our institution, with a median age of 7.3 ± 3.8 months. Common etiologies included postinfectious (26.2%), arachnoid cyst (14.3%), aqueductal stenosis (11.9%), and congenital condition (11.9%). The complications included seizure (2.4%), CSF leak (2.4%), and subdural effusion (2.4%). During the average follow-up of 21.7 ± 13.1 months, the ETV success rate predicted by third ventricle floor bowing (TVFB) was 71.4%, which was higher than 6-month success rate predicted by the ETVSS (52.3%). However, it was difficult to reach statistical significance (P = 0.072) due to the limited sample size and further studies with larger sample size were needed. Our study suggests TVFB can serve as a useful method for selecting ETV candidates in infantile hydrocephalus preoperatively. And we speculate that good ventricle compliance and pressure difference between the ventricle and subarachnoid space are essential elements in ensuring ETV success.

Intraventricular Pressure in Non-communicating Hydrocephalus Patients Before Endoscopic Third Ventriculostomy.

BackgroundIn patients with non-communicating hydrocephalus impairment of cerebral compliance can occur pre- but also intraoperatively.MethodologyIn such patients (n = 6) undergoing endoscopic third ventriculostomy (ETV), the present study aimed to investigate the effect of ETCO2 (e.g 40 mmHg and 60 mmHg) and positive end-expiratory pressure (PEEP) (e.g. 6 cm and 12 cm H2O) on intraventricular pressure (IVP).FindingsBefore but not after ETV, hypercapnia in contrast to PEEP increased IVP(before ETV(PEEP-6/ ETCO2-40: 2.6 ± 2.4 mmHg) vs. (PEEP-6/ ETCO2-60: 12 ± 6.4 mmHg*); (PEEP-12/ ETCO2-40: 4.2 ± 4.1 mmHg) vs. (PEEP-12/ ETCO2-60: 13.7 ± 7.6 mmHg*), * significant, P ≤ 0.05;after ETV(PEEP-6/ ETCO2-40: 2.0 ± 1.2 mmHg) vs. (PEEP-6/ ETCO2-60: 4.4 ± 3.1 mmHg); (PEEP-12/ ETCO2-40: 1.6 ± 1.3 mmHg) vs. (PEEP-12/ ETCO2-60: 6.6 ± 2.6 mmHg), * significant, P ≤ 0.05).ConclusionPatients with non-communicating hydrocephalus showed that hypercapnia but not PEEP increases significantly IVP before but not after ETV.

Automatic volumetry of cerebrospinal fluid and brain volume in severe paediatric hydrocephalus, implementation and clinical course after intervention.

In childhood hydrocephalus, both the amount of cerebrospinal fluid and the brain volume are relevant for the prognosis of the development and for therapy monitoring. Since classical planar measurements of ventricular size are subject to strong limitations, imprecise and neglect brain volume, 3D volumetry is most desirable. We used and evaluated the robust segmentation algorithms of the freely available FSL-toolbox in paediatric hydrocephalus patients before and after specific therapy. Retrospectively 76 pre- and postoperative high-resolution T2-weighted MRI sequences (true FISP, 1 mm isovoxel) were analyzed in 38 patients with paediatric hydrocephalus (mean 4.4 ± 5.1 years) who underwent surgical treatment (ventriculo-peritoneal (VP) shunt n = 22, endoscopic third ventriculostomy (ETV) n = 16). After preprocessing, the 3D-datasets were skull stripped to estimate the inner skull surface. Following, a 2 class segmentation into different tissue types (brain matter and CSF) was performed. The volumes of CSF and brain were calculated. The method could be implemented in an automated fashion in all 76 MRIs. In the VP shunt cohort, the amount of CSF (p < 0.001) decreased. Consecutively brain volume increased significantly (p < 0.001). Following ETV, CSF volume (p = 0.019) decreased significantly (p = 0.012) although the reduction was less pronounced than after shunt implantation. Brain volume expanded (p = 0.02). A reliable automated segmentation of CSF and brain could be performed with the implemented algorithm. The method was able to track changes after therapy and detected significant differences in CSF and brain volumes after shunting and after ETV.

Analysis of Cerebrospinal Fluid Flowmetry in Evaluating the Efficiency of Endoscopic Third Ventriculostomy in Aqueductal Stenosis

Background: Endoscopic third ventriculostomy (ETV) approach was gaining popularity over shunt placement in obstructive hydrocephalus. Postoperative ETV assessment and patients follow up remains a matter of controversy and challenge to ensure efficiency and patency of ventriculostomy.Aim of the work: To assess whether cerebrospinal fluid (CSF) flow is restored after ETV and similarity to flow in normal aqueduct with patients clinical and ventricular size changes assessment.Patients and Methods: From April 2016 to April 2019, 30 patients with hydrocephalus due to aqueductal stenosis (AS) were treated with ETV. They were followed up for ventriculostomy patency within the 1st, 6th and 9th month after surgery and compared to 22 persons as a control group of normal aqueductal flow with phase contrast magnetic resonance imaging (PC MRI).Results: Twenty-three (23) patients restored pulsatile bidirectional pattern of CSF flow across the ventriculostomy similar to that of aqueductal flow. While one patient had no flow during the 1st follow up and 6 patients showed initial pulsatile flow then developed flow disturbance during the 2nd follow up period. Absolute stroke volume values showed significant statistical difference between ETV and control groups (p value < 0.001). The value of 85 μl showed sensitivity and specificity of 84.3% and 81.7%, respectively as a cutoff value of ETV efficiency.Conclusion: ETV is an efficient technique to restores the physiological pulsatile Cerebrospinal fluid flow. Absolute stroke volume was a good predictor of ETV efficiency.

Design and validation of a 3D-printed simulator for endoscopic third ventriculostomy.

Simulation-based training has been considered as the most promising curriculum for neurosurgical education to finally improve surgical skills with the greatest efficiency and safety. However, most of the simulators including physical models and virtual reality systems are relatively expensive, which limits their promotion. In this study, the authors tried to develop a realistic, low-cost, and reusable simulator for endoscopic third ventriculostomy (ETV) and evaluate its validity. A 3D-printed rigid skull with the ventricular system originated from a de-identified patient with obstructive hydrocephalus was constructed. The third ventricular floor was designed as a replaceable module. Thirty-nine neurosurgeons tested the simulator and a rating system was established to assess their performance. All participants filled out questionnaires to evaluate the simulator after training. Five neurosurgical students were recruited to finish the whole training for ten times in order to explore the learning curve of ETV. We found that (1) the more experienced surgeons performed obviously better than the rather inexperienced surgeons which verified that our model could reflect the ability of the trainees; (2) as the training progressed, the scores of the post-graduates increased and the fifth training average score was obviously higher than their first training average score. The feedback questionnaires showed the average scores for value of the simulator as a training tool and global rating were 3.15 and 3.54 (on a 4-point scale). Our model was practical for ETV training. The results of our program showed that our model could precisely reflect the operators' ability to perform ETV and could make it more efficient to master basic skills.

Prediction of endoscopic third ventriculostomy (ETV) success with preoperative third ventricle floor bowing (TVFB): a supplement to ETV success score.

Preoperative judgement of which children is likely to benefit from endoscopic third ventriculostomy (ETV) is still the most difficult challenge. This study aimed to compare the efficiency of third ventricular floor bowing (TVFB) and ETV success score (ETVSS) in selecting ETV candidates and achieve a better preoperative patient selection method for ETV based on our institutional experience. Children (≤ 16years old) with newly diagnosed hydrocephalus treated with ETV between January 2013 and June 2018 were included in this prospective study. Patients with TVFB will receive ETV procedure in the pediatric subgroup of our department. ETVSS was calculated in every patient. The ETVSS predicted ETV success rate and the actual ETV success rate in our institution were compared and further analyzed. One hundred twenty-nine children with TVFB were enrolled in our study. The mean age at ETV was 5.84 ± 5.17years (range, 0.04-16). Brain tumors, aqueductal stenosis, and inflammatory are the most common hydrocephalus etiologies. The most common complication was noninfectious fever (3.1%). During the average follow-up of 19.5 ± 14.95months, twenty-five patients had depicted ETV failure. The actual ETV success rate (81%) in our study was higher than the success rate (69%) predicted by ETVSS. TVFB is a pragmatic, efficient, and simple model to predict the ETV outcome. We suggest that for hydrocephalic patients with preoperative third ventricular floor bowing, ETV should be the first-treatment choice regardless of the ETV success score. And for patients without such sign, ETVSS should be applied to select ETV candidates.

Estudo Anatômico da Região Anterior do Terceiro Ventrículo em Pacientes Submetidos à Neurocirurgia Endoscópica

Introdução: A medicina atual tem se valido dos avanços científicos possibilitando o uso de equipamentos médicos que acessem o corpo humano com o mínimo de invasão em procedimentos cirúrgicos. Exemplo claro disso é a neurocirurgia endoscópica. Objetivo: Estudar a anatomia endoscópica do terceiro ventrículo em pacientes operados no Hospital de Clínicas da Universidade do Triângulo Mineiro. Materiais e métodos: Foi realizada a análise de vídeos e imagens intra-operatórios de 50 pacientes submetidos à terceiroventriculostomia endoscópica (TVE), no período de 2010 a 2017, sendo categorizados nos seguintes grupos: Grupo 1 –Assoalho delicado; Grupo 2 – Assoalho espesso; Grupo 3 – Assoalho parcialmente apagado; Grupo 4 – Assoalho balonado; Grupo 5 – Intervalo pré-pontino reduzido; Grupo 6 – Terceiro ventrículo estreito; Grupo 7 – Assoalho elevado; Grupo 8 – Corpos mamilares deslocados; Grupo 9 – Estenose do forame deMonro; Grupo 10 – Espessamento anterior aos corpos mamilares. Conclusão: A metodologia empregada demostrou-se adequada para o estudo anatômico endoscópico do terceiro ventrículo, e pode ser aplicada em estudos semelhantes.

Endoscopic Third Ventriculostomy in Cases of Hydrocephalus: An Institutional Experience

Abstract Background With the recent advances in optical and mechanical instrumentation, endoscopic third ventriculostomy (ETV) has emerged as the procedure of choice for the treatment of hydrocephalus in selected patients. Objective: To study the role of ETV in therapeutic management of hydrocephalus in a tertiary care center. Materials and Methods The present study was conducted in the Department of Neurosurgery at Dr. Ram Manohar Lohia Hospital. Endoscopic third ventriculostomy was performed as a therapeutic procedure in patients diagnosed with hydrocephalus requiring surgical intervention and admitted from June 2017 to July 2018. ETV success was defined by resolution or improvement in clinical symptoms and ETV failure was considered in patients whose symptoms either deteriorated or did not improve from the baseline and required ventriculoperitoneal shunt. Results A total of 85 patients were included in this study who underwent the therapeutic ETV. In the present study, the overall ETV success rate was 75.2% (64/85). 86.7% cases of aqueductal stenosis, 74.4% cases of post meningitis (including tubercular meningitis) hydrocephalus, and 71% of posterior fossa tumors showed resolution or improvement in clinical symptoms. Conclusion ETV is an effective treatment modality for obstructive hydrocephalus and with better results in post meningitis hydrocephalus and post tubercular meningitis hydrocephalus. However, more extensive studies dedicated to ETV with a larger sample size are required to further study its efficacy in various etiologies.

The role of third ventricle bowing in the success of endoscopic third ventriculostomy in pediatric and adult patients

ObjectivePreoperative third ventricle deformation (known as ‘bowing’) is associated with higher endoscopic third ventriculostomy (ETV) success. In children, the effect of bowing has not to date been systematically studied. Aim of of this study is to determine the effect of bowing on ETV success in adult and child patients. Patients and methodsIn this retrospective, monocentric study were included 135 (70 adults and 65 children) of 157 patients who underwent ETV between 2008–2016, with mean follow-up 4.3 years. Presence and extent of bowing and its impact on ETV outcome were evaluated. Third ventricular anatomy was assessed on pre- and postoperative MR imaging. ResultsIn patients > 6 months old, the ETV success rate was 91% in bowing-positive cases and 47.6% in bowing-negative cases. Among patients < 6 months old, ETV was successful in 37% of those with bowing and 36.4% of those without. Presence of bowing strongly indicates ETV success in patients older than 6 months (p < 0.000 5), including children of 7 months and older (p 0.001). This relationship was not confirmed in pediatric patients up to 6 months old (p 1.000). The extent of bowing does not influence ETV success (p 0.559). Bowing correction strongly correlates with ETV success (p < 0.000 5). ConclusionWe confirmed significant correlation between bowing and ETV success in patients over 6 months old. This relationship was not determined in those younger than 6 months and therefore we do not recommend bowing in ETV indication criteria for this patient cohort.

Neuroendoscopic Management of Hydrocephalus in Children

Objective: To determine the Neuroendoscopic management of hydrocephalus in children.Materials and Methods: The study was conducted at the Department of Neurosurgery, Peoples University of Medical and Health Science for women Nawabshah from January 2014 to May 2015. All of the patients with hydrocephalus diagnosed on history, clinical examination and CT scan included in the study. Subjects with co–morbidities such as uncontrolled diabetes, cardiac diseases or uremia were excluded. Patients with age of 6 months to 13 years either gender were included in the study. Aesculap rigid rod lens neuroendoscope with 0 degree was utilized. Warm ringers were utilized for irrigation, a Fogarty embolectomy catheter was utilized for ETV. Hemostasis was accomplished with irrigation, tamponade or coagulation. Endoscopic third ventriculostomy (ETV) was labeled successfully when characteristics of intracranial hypertension (ICP) clinically improved and the size of ventricular decreased on post-operative CT scan. All the data was recorded in the Proforma.Results: Thirty patients with male to female ration 2.5:1 were administered. Age ranged between 6 months and 12 years with a mean of 22.03 months. There were 15(%) cases of Tri Ventricular Hydrocephalus, 10 cases of Tetra Ventricular Hydrocephalus. Two cases of Dandy Walker Hydrocephalus, one case of Asymmetrical Ventricles Hydrocephalus and postoperative fever occurred in two subjects. CSF leak appeared in one patient who was managed conservatively. No operative mortality was found.ETV worked effectively for Hydrocephalus treatment in 99.9% patients included in the study.

Endoscopic Third Ventriculostomy Versus Shunt for Pediatric Hydrocephalus: A Systematic Literature Review and Meta-Analysis

Abstract INTRODUCTION Optimized management of pediatric hydrocephalus remains the subject of debate. Ventriculoperitoneal shunt is largely considered the standard of care. However, the advancements and introduction of new cerebrospinal fluid (CSF) diversion approaches including the use of endoscopic third ventriculostomy (ETV) offer appealing alternatives that have been reported in numerous observational series. METHODS This systematic literature review was performed according to the PRISMA guidelines. Eligible studies were identified through a search of PubMed until October 2018. A random-effects model meta-analysis was conducted and the I-square was used to assess heterogeneity. RESULTS Fourteen studies including 8419 patients were identified. Patients in the ETV group had a statistically significant lower risk of infection compared to shunt (OR: 0.19; 95% CI: 0.07-0.53; I2: 0%). All-cause mortality (OR: 0.77; 95% CI: 0.35-1.68; I2: 0%), postoperative CSF leak (OR: 1.53; 95% CI: 0.37-6.31; I2: 0%), and reoperation rates were similar between the 2 study groups. (OR: 0.72; 95% CI: 0.39-1.32; I2: 93.5%). Subgroup analyses for reoperation demonstrated that ETV in Africa (OR: 0.13; 95% CI: 0.03-0.48; I2: 0%) and Europe (OR: 0.39; 95% CI: 0.30-0.52; I2: 1.4%) was associated with significantly lower odds of reoperation compared to shunt, but not in USA/Canada (OR: 1.49; 95% CI: 0.85-2.63; I2: 86.2%). Metaregression analyses of age and duration of follow-up did not affect reoperation rates. CONCLUSION ETV was associated with a statistically significant lower risk of procedure-related infection compared to shunt. All-cause mortality, CSF leak, and reoperation rates were similar between the study groups. Subgroup analysis based on the geographic region showed that ETV is associated with statistically significant lower odds for reoperation in Europe and Africa, but not in USA/Canada. Future RCTs are needed to validate the results of this study and elucidate the cause of this heterogeneity.

Developmental Retrocerebellar Cysts: A New Classification for Neuroendoscopic Management and Systematic Review

Posterior fossa cystic malformations are diversely classified with considerable overlap without therapeutic relevance. These cysts posterior to the cerebellum, presenting in children younger than 5 years, are labeled developmental retrocerebellar cysts (DRCCs) under a new classification in relation to neuroendoscopy. DRCC was categorized as type 0 for asymptomatic enlarged cistern magna and was not treated. Among symptomatic cases, cysts with a compressed fourth ventricle were labeled type 1, whereas cysts in continuity with the fourth ventricle were termed type 2. They were further categorized as subtype B if hydrocephalus was greater relative to the cyst, or otherwise as subtype A. The literature was reviewed according to PRISMA guidelines. There were 13 children aged 3-48 months. Type 1A DRCC was noted in 5 patients, with onset before 6 months, 4 of whom (80%) had intracranial hypertension. All underwent suboccipital endoscopic deroofing and cisternostomy (SEDC), a new technique. Type 1B DRCC was seen in 2 patients, with onset at 8-9 months, who underwent endoscopic third ventriculostomy (ETV)+ endoscopic ventriculocystostomy (EVC). Type 2A DRCC was observed in 4 patients, with onset at 5-47 months, who underwent SEDC. Type 2B DRCC was noted in 2 patients, with onset 6-8 months, who underwent ETV. With a mean follow-up of 32months, all showed clinicoradiologic improvement. The application of our classification to other studies showed ETV/EVC to be successful in only 67% of type 1A DRCC and 72% of type 2A DRCC, compared with 100% efficacy of SEDC in our series. This is probably the first ever endoscopic classification of pediatric posterior fossa cyts, elucidating pathophysiology, presentation, and treatment. Patients with type 1 DRCC present early because of extraneous compression. Among patients with type 2 DRCC, posterior fossa compliance determines the degree of hydrocephalus. The newly described SEDC seems more appropriate for types 1A and 2A DRCC. ETV is adequate in type 2B DRCC and effective with EVC in type1B.

S1-05 SESSION 1: NEUROSURGERY HYDROCEPHALUS AND ITS TREATMENT IN CROUZON’S SYNDROME

Introduction: Hydrocephalus is frequently seen in Crouzon’s syndrome. The challenge is to treat the hydrocephalus while not impeding skull growth. We aim to show the hydrocephalus rate in our cohort of Crouzon’s patients as well as its treatment including endoscopic third ventriculostomy (ETV) and Ventriculo- peritoneal shunt (VPS). The need for more than one CSF diverting surgical procedure was documented. Methods: A departmental database search was performed to identify all Crouzon’s patients currently under our care. Records and op-notes were checked for initial craniofacial surgery, prevalence of hydrocephalus and its treatment. Results: We found 72 Crouzon patients that are currently under our care, 16 of which underwent surgery for hydrocephalus (22%). In 10 patients a VPS was inserted as initial hydrocephalus treatment, mean age 2y5m (2m-15y5m). In 6 patients firstly an ETV was performed, mean age 2y4m (1m-10y8m). In 3 out of these 6 ETV patients subsequently a VPS was needed due to unresolved hydrocephalus (50%). 12 out of the 13 patients (92%) who at some point underwent VPS insertion had to undergo at least on more shunt related procedure (1–4) Conclusions: Hydrocephalus is frequently seen in Crouzon’s syndrome, it was present in 22% of our 72 Crouzon’s patients. Most of these patients need more then one CSF-shunt related procedure (92% in our series). ETV was only sustainably effective in 50% of patients, however it delayed the insertion of a VPS shunt in all 6, thereby creating time for vault expansion surgeries to gain their maximal effect, since the presence of a shunt lowers the effect of vault expanding surgery in craniosynostosis.