An external validation of the ETVSS for both short-term and long-term predictive adequacy in 104 pediatric patients

Clinical and radiologic criteria to predict endoscopic third ventriculostomy success in non-communicating pediatric hydrocephalus

OBJECTIVE

Endoscopic third ventriculocisternostomy (ETV) became the relevant treatment option for non-communicating pediatric hydrocephalus. ETV success was predicted in relation to age, diagnosis, and previous shunt implantation. Radiological factors are usually taken for indication decision-making. The aim of this study is to investigate radiological signs of non-communicating hydrocephalus for ETV success in a single-center retrospective analysis.

PATIENTS AND METHODS

ETV interventions were collected from a 10-year period (2010-2019) from our institution. Clinical patient characteristics such as prematurity, age, diagnosis, and previous shunt treatment and follow-up in terms of possible shunt implantation or revision surgeries were investigated. Radiological data was retrieved from the in-house PACS system to analyze preoperative signs for non-communicating hydrocephalus such as ventricular size, pressure gradients at the third ventricle, and any signs of obstruction from internal towards external cerebral spinal fluid communication. Fisher's test was used to demonstrate the significance of each individual predictor. A multivariable model was built using the backward elimination method with multiple logistic regression.

RESULTS

From 136 ETV interventions, 95 met the inclusion criteria (age < 18 years; > 6-month follow-up; MR image data availability, treatment goal for shunt independence). In chi-square statistical evaluation of single parameters age > 6 months (OR 32.5; 95% CI 4.8-364), ventricular width (FOHR < 0.56; OR 6.1; 95% CI 2.2-16.3) and non-post-hemorrhagic hydrocephalus as underlying diagnosis (OR 13.1; 95% CI 1.9-163) showed significant increased odds ratio for shunt independence during follow-up. Logistic regression analysis for multiple parameters showed age > 6 months (OR 29.3; 95% CI 4.1-606) together with outward bulged lamina terminalis (OR 4.6; 95% CI 1.2-19.6), smaller FOHR (continuous parameter; OR 2.83 × 10-5; 95% CI 4.7 × 10-9-0.045), and non-4th-ventricular-outlet obstruction (4thVOO; OR 0.31; 95% CI 0.09-1.02) as significant factors for ETV success.

CONCLUSION

ETV has become a relevant treatment for non-communicating hydrocephalus, with typical MR image characteristics. Analyzing radiological markers as predictors for success smaller ventricular width and outward displaced lamina terminalis was relevant in combination with age > 6 months. Since the analysis is based on single-center experience, a larger cohort of patients with a multi-center approach should further investigate the combined clinical and radiological criteria.

Does machine learning improve prediction accuracy of the Endoscopic Third Ventriculostomy Success Score? A contemporary Hydrocephalus Clinical Research Network cohort study

PURPOSE

This Hydrocephalus Clinical Research Network (HCRN) study had two aims: (1) to compare the predictive performance of the original ETV Success Score (ETVSS) using logistic regression modeling with other newer machine learning models and (2) to assess whether inclusion of imaging variables improves prediction performance using machine learning models.

METHODS

We identified children undergoing first-time ETV for hydrocephalus that were enrolled prospectively at HCRN sites between 200 and 2020. The primary outcome was ETV success 6 months after index surgery. The cohort was randomly divided into training (70%) and testing (30%) datasets. The classic ETVSS variables were used for logistic regression and machine learning models. Predictive performance of each model was evaluated on the testing dataset using area under the receiver operating characteristic curve (AUROC).

RESULTS

There were 752 patients that underwent first time ETV, of which 185 patients (24.6%) experienced ETV failure within 6 months. For aim 1, using the classic ETVSS variables, machine learning models did not outperform logistic regression with AUROC 0.60 (95% CI: 0.52-0.69) for Naïve Bayes (highest machine learning model performance) and 0.68 (95% CI: 0.60-0.76) for logistic regression. After inclusion of imaging features (aim 2), machine learning model prediction improved but remained no better than the above logistic regression with the highest AUROC of 0.67 (95% CI: 0.59-0.75) attained using Naïve Bayes architecture compared to 0.68 (95% CI: 0.59-0.76) for logistic regression.

CONCLUSIONS

This contemporary multicenter observational cohort study demonstrated that machine learning modeling strategies did not improve performance of the ETVSS model over logistic regression.

Long-Term Success of Endoscopic Third Ventriculostomy in the Pediatric Population with Aqueductal Stenosis

OBJECTIVE

To evaluate the long-term success rate of endoscopic third ventriculostomy (ETV) in the treatment of hydrocephalus due to aqueductal stenosis in the pediatric population.

METHODS

Between January 2007 and June 2023, a total of 82 children underwent ETV surgery for hydrocephalus and met the inclusion criteria for our study. The children's medical records were reviewed, and cases requiring additional surgery in the months and years following surgery for ventriculostomy failure were reviewed.

RESULTS

The mean age was 5.35 years. Successful ETV was observed in 74 children with a successful ETV rate of 90%. The median follow-up was 6.75 years (2 months to 15.5 years). Eight children (10%) underwent additional surgery. In 7 cases, additional surgery was performed within 3 months, while in the remaining case; a delayed failure was noted (more than 3 years later). At 6 months and 3 years, the cumulative proportion of children with revision-free survival was 91%, declining slightly to 89% at 5 years.

CONCLUSIONS

ETV is highly effective in treating hydrocephalus in pediatric patients with aqueductal stenosis, with a 91% success rate at 6 months and 3 years. Although the success rate drops slightly to 89% at 5 years, it still demonstrates durability. Late failures are usually characterized by symptoms of increased intracranial pressure. While patients with a confirmed successful ETV at 6 months may be considered for reduced follow-up frequency, it is critical to educate them about the symptoms of intracranial hypertension and the importance of seeking medical attention promptly if such symptoms occur.

Compare the safety and efficacy of endoscopic third ventriculostomy and ventriculoperitoneal shunt placement in infants and children with hydrocephalus: a systematic review and meta-analysis

PURPOSE

Endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt placement are two surgical options used for treatment of non-communicating hydrocephalus. The purpose of this study was to compare the efficiency and safety of these techniques in pediatric patients.

MATERIALS AND METHODS

An extensive literature review regarding the clinical outcome, safety and efficiency of ETV and shunting in treatment of hydrocephalus was conducted in Medline, PubMed, Cochrane and Google Scholar databases up to 27 November 2015. Patient demographics, ETV and shunting success and failure rates were extracted.

RESULTS

A total of seven two-arm studies were included for quantitative analysis and 25 single-arm studies were included for systematic review. The two-arm studies recruited a total of 6995 patients: 1046 in the ETV group and 5949 in the shunt group. The pooled results showed that the 1 year success rate of ETV and shunt-placement procedure were similar (pooled RR = 0.870, 95% CI = 0.680-1.112, P = 0.266). The failure rate in the ETV treatment group was 0.9 times higher than in the shunt group; however, the results did not reach statistical significance (pooled RR = 0.893, 95% CI = 0.576-1.383, P = 0.611).

CONCLUSIONS

Both ETV and shunts are associated with similar 1 year success and failure rates. Therefore, there are no current indications to recommend one mode of treatment over the other. Future studies designed to assess the effectiveness of ETV and shunt procedures depending on patient's age and etiology are warranted.

Factors affecting endoscopic third ventriculostomy success in adults

BACKGROUND

Endoscopic third ventriculostomy (ETV) is a standard treatment in hydrocephalus of certain aetiologies. The most widely used predictive model is the ETV success score. This is frequently used to predict outcomes following ETV in adult patients; however, this was a model developed in paediatric patients with often distinct aetiologies of hydrocephalus. The aim of this study was to assess the predictive value of the model and to identify factors that influence ETV outcomes in adults.

METHODS

A retrospective study design was used to analyse consecutive patients who underwent ETV at a tertiary neurosurgical centre between 2012 and 2020. Observed ETV outcomes at 6 months were compared to pre-operative predicted ETV success scores. A multivariable Bayesian logistic regression analysis was used to determine the factors that best predicted ETV success and those factors that were redundant.

RESULTS

A total of 136 patients were analysed during the 9-year study. Thirty-one patients underwent further cerebrospinal fluid diversion within 6 months. The overall ETV success rate was 77%. Observed ETV outcomes corresponded well with predicted outcomes using the ETV success score for the higher scores, but less well for lower scores. Location of obstruction at the aqueduct irrespective of aetiology was the best predictor of success with odds of 1.65 of success. Elective procedures were also associated with higher success compared to urgent ones, whereas age under 70, nature and location of obstructive lesion (other than aqueductal) did not influence ETV success.

CONCLUSION

ETV was successful in three-quarters of adult patient with hydrocephalus within 6 months. Obstruction at the level of the aqueduct of any aetiology was a good predictor of ETV success. Clinicians should bear in mind that adult hydrocephalus responds differently to ETV compared to paediatric hydrocephalus, and more research is required to develop and validate an adult-specific predictive tool.

The role of the Liliequist membrane in the third ventriculostomy

Endoscopic third ventriculostomy (ETV) is a hydrocephalus treatment procedure that involves opening the Liliequist membrane (LM). However, LM anatomy has not been well-studied neuroendoscopically, because approach angles differ between descriptive and microsurgical anatomical explorations. Discrepancies in ETV efficacy, especially among children age 2 and younger, may be due to incomplete LM opening. The objective of this study was to characterize the LM anatomically from a neuroendoscopic perspective to better understand the impact of anatomical features during LM ostomy and the ETV success rate. Additionally, the ETV success score was tested to predict patient outcome after the intraoperatively difficult opening of LM. Fifty-four patients who underwent ETV were prospectively analyzed with a mean follow-up of 53.1 months (1-90 months). The ETV technical parameters of difficulty were validated by seven expert neurosurgeons. The pediatric population (44) of this study represents the majority of patients (81.4%). The overall ETV success rate was 68.5%. Anomalies on the IIIVT floor resulted in an increased rate of ETV failure. The IIIVT was anomalous, and LM was thick in 33.3% of cases. Fenestration of LM was difficult in 39% of cases, and the LM and TC were opened separately in 55.6% of cases. The endoscopic third ventriculostomy success score (ETVSS) accurately predicted the level of difficulty opening the LM (p = 0.012), and the group with easy opening presented greater durability in ETV success. Neurosurgeons should be aware of the difficulty level of the overture of LM during ETV and its impact on long-term ETV effectiveness.

External validation of the ETV success score in 313 pediatric patients: a Brazilian single-center study

The endoscopic third ventriculostomy (ETV) success score (ETVSS) was developed to predict the success rate of ETV at 6 months. In this study, the authors assessed the performance of this score for > 6 months, i.e., at 12 months, and provided external validation in Brazilian children. All children undergoing first ETV (without choroid plexus cauterization) at a Brazilian single institution for > 20 years were included in the study. The ETVSS was retrospectively calculated for each patient and compared with the actual success of the procedure observed at 6 and 12 months after the procedure. A total of 313 eligible children underwent initial ETV, 34.18% of whom had undergone shunt placement before ETV. The most common etiologies were aqueductal stenosis (45%) and non-tectal brain tumors (20.8%). ETV was successful at 6 months in 229 patients (73.16%) compared with the 61.3% predicted by the ETVSS. The overall actual success rate observed at 1 year after ETV was 65.1% (204 patients). The area under the receiver operating characteristic curve was 0.660 at 6 months and 0.668 at 1 year, which suggested a tendency for the ETVSS to underestimate the actual success rate of ETV at both timepoints. The ETVSS showed good success prediction in accordance with the actual ETV success rate and proved to be useful during the decision-making process of ETV.

The efficacy of endoscopic third ventriculostomy in children 1 year of age or younger: A systematic review and meta-analysis

PURPOSE

Hydrocephalus is a major cause of morbidity in the pediatric population, with potentially severe consequences if left untreated. Two viable strategies for management of non-communicating hydrocephalus are endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunting. However, there is uncertainty over the safety and efficacy of ETV in younger infants aged 1 year or below. In this systematic review, we aim to elucidate the success rate and procedural risks of ETV in this age group.

METHODS

A multi-database (PubMed, Embase, Web of Science) literature search between January 1990 and April 2018 was performed in accordance with PRISMA guidelines. Eligible studies were included if they (i) examined non-communicating hydrocephalus; (ii) quantified the success/failure rates of ETV; and (iii) assessed outcomes in children 1 year of age or younger.

RESULTS

A total of 19 articles with 399 patients were eligible for inclusion. Mean age at procedure was 4.2 months (range 34 weeks gestation to 12 months), with 116 females and 143 males. Commonest underlying aetiology was congenital aqueductal stenosis (AS) (60.4%). Remaining causes included post-haemorrhagic, post-infection, Chiari malformations, malignancies and others. Overall and AS mean success rates were 51.6% and 56.5% respectively. Overall complication rate was 10.0%, consisting mainly of CSF leak, infection, and haemorrhage. Younger age was significantly associated with poorer ETV success rate when divided into <6 months and 6-12 months of age (44.4 vs 66.7%; p = 0.0007). Underlying pathology had no significant association with ETV outcome when divided into AS and other pathologies (p = 0.53).

CONCLUSIONS

Age is significantly associated with ETV success rates. Pathology-dependent effects were not found in this age group. Despite a lower ETV success rate at younger ages (44.4 vs 66.7%), it offers a comparable safety profile that is independent of age. ETV remains a viable treatment option for non-communicating hydrocephalus for infants aged 1 year or younger.

Endoscopic third ventriculostomy success score in predicting short-term outcome in 68 children with hydrocephalus in a resource-limited tertiary centre in sub-Saharan Africa

Background

Endoscopic third ventriculostomy (ETV) is becoming a popular option of treatment in carefully selected patients with hydrocephalus (Drake et al., Childs Nerv Syst 25:467-472, 2009). The success or possible outcome of its application in treating hydrocephalus can be predicted by employing a preoperative scoring system. An example of such a system is the endoscopic third ventriculostomy success score (ETVSS). It could form a basis for decision-making and prognostication. This study aimed to evaluate ETVSS as a preoperative predictive tool in children with hydrocephalus who satisfy the inclusion criteria for the option of ETV procedure as treatment modality.

Methodology

This is a prospective hospital-based study of 68 children under 2 years of age that presented at the Lagos University Teaching Hospital (LUTH) out of 161 children with hydrocephalus from November 2014 to April 2016. The predicted ETVSS was calculated by the addition of patients’ age, presumed aetiology and prior shunting. These children were stratified into three groups according to ETVSS as higher score predicts better ETV outcome and vice versa. They were followed up for 6 months to determine the success rate of ETV.

Results

The age of the study population ranged from 0 to 24 months with a mean age of 5.52 ± 5.48 months. 69.1% of these patients were male and 30.9% were female with a male to female ratio of 2.2:1. The mean predicted ETVSS (48.82 ± 19.20%) and actual ETV success score (56.20 ± 15.10%) using the ANOVA were significantly related (p value < 0.05).

Conclusion

This study concluded that the early outcome of ETV in children below 2 years of age with hydrocephalus is directly related to the preoperative ETVSS.

Predicting endoscopic third ventriculostomy success in adult hydrocephalus: preliminary assessment of a modified ETV success score for adults (ETVSS-A) in a series of 47 patients

BACKGROUND

Endoscopic third ventriculostomy is an established treatment for noncommunicating hydrocephalus. In carefully selected patients, it can be adopted for the management of communicating variant; however controversy exists in regards to the definition of the appropriate candidates. Predictive score of Endoscopic Third Ventriculostomy Success (ETVSS) has been reported for pediatric and mixed populations only. Our purpose was to define a ETV success score for adult population (ETVSS-A), measuring the strength of correlation between preoperative score retrospectively evaluated and the success rates achieved in a class of adult patients.

METHODS

A retrospective analysis of 47 cases which received ETV procedure at our Institution between 2015 and 2018 was run. Demographic data,clinical history,preoperative and postoperative signs were reviewed and ETVSS-A was calculated. Thereafter ETVSS-A results were compared with the actual success rates.

RESULTS

29 patients(61,7%) presented unchanged or improvedclinical status with a mean ETVSS-A of 54.5%;18 patients(38,3%) worsened with mean ETVSS-A of 37,7%. We found that age,type of hydrocephalus and symptoms of admission are each apart important factors in predicting ETV success:older patients and those with non-obstructive hydrocephalus had the lowest predicted ETV success. In patients in whom ETV was actually successful, the pre-operative ETVSS-A was significantly higher as compared to those patients in whom we observed a poor surgical outcome.

CONCLUSIONS

From the results of this series, though small and retrospectively analyzed, it seems that ETVSS-A can be considered as a useful instrument to help neurosurgeon in predicting the ETV success and though define a more accurate surgical strategy in cases of hydrocephalus. Wider series and prospective studies are attended to validate these preliminary results.

Endoscopic third ventriculostomy and repeat endoscopic third ventriculostomy in pediatric patients: the Dutch experience

OBJECTIVE After endoscopic third ventriculostomy (ETV), some patients develop recurrent symptoms of hydrocephalus. The optimal treatment for these patients is not clear: repeat ETV (re-ETV) or CSF shunting. The goals of the study were to assess the effectiveness of re-ETV relative to initial ETV in pediatric patients and validate the ETV success score (ETVSS) for re-ETV. METHODS Retrospective data of 624 ETV and 93 re-ETV procedures were collected from 6 neurosurgical centers in the Netherlands (1998-2015). Multivariable Cox proportional hazards modeling was used to provide an adjusted estimate of the hazard ratio for re-ETV failure relative to ETV failure. The correlation coefficient between ETVSS and the chance of re-ETV success was calculated using Kendall's tau coefficient. Model discrimination was quantified using the c-statistic. The effects of intraoperative findings and management on re-ETV success were also analyzed. RESULTS The hazard ratio for re-ETV failure relative to ETV failure was 1.23 (95% CI 0.90-1.69; p = 0.20). At 6 months, the success rates for both ETV and re-ETV were 68%. ETVSS was significantly related to the chances of re-ETV success (τ = 0.37; 95% bias corrected and accelerated CI 0.21-0.52; p < 0.001). The c-statistic was 0.74 (95% CI 0.64-0.85). The presence of prepontine arachnoid membranes and use of an external ventricular drain (EVD) were negatively associated with treatment success, with ORs of 4.0 (95% CI 1.5-10.5) and 9.7 (95% CI 3.4-27.8), respectively. CONCLUSIONS Re-ETV seems to be as safe and effective as initial ETV. ETVSS adequately predicts the chance of successful re-ETV. The presence of prepontine arachnoid membranes and the use of EVD negatively influence the chance of success.

Robot-assisted endoscopic third ventriculostomy: institutional experience in 9 patients

OBJECTIVE The endoscopic third ventriculostomy (ETV) is an established and effective treatment for obstructive hydrocephalus. In its most common application, surgeons plan their entry point and the endoscope trajectory for the procedure based on anatomical landmarks, then control the endoscope freehand. Recent studies report an incidence of neural injuries as high as 16.6% of all ETVs performed in North America. The authors have introduced the ROSA system to their ETV procedure to stereotactically optimize endoscope trajectories, to reduce risk of traction on neural structures by the endoscope, and to provide a stable mechanical holder of the endoscope. Here, they present their series in which the ROSA system was used for ETVs. METHODS At the authors' institution, they performed ETVs with the ROSA system in 9 consecutive patients within an 8-month period. Patients had to have a favorable expected response to ETV (ETV Success Score ≥ 70) with no additional endoscopic procedures (e.g., choroid plexus cauterization, septum pellucidum fenestration). The modality of image registration (CT, MRI, surface mapping, or bone fiducials) was dependent on the case. RESULTS Nine pediatric patients with an age range of 1.5 to 16 years, 4 girls and 5 boys, with ETV Success Scores ranging from 70 to 90, underwent successful ETV surgery with the ROSA system within an 8-month period. Their intracranial pathologies included tectal tumors (n = 3), communicating hydrocephalus from hemorrhage or meningeal disease (n = 2), congenital aqueductal stenosis (n = 1), compressive porencephalic cyst (n = 1), Chiari I malformation (n = 1), and pineal region mass (n = 1). Robotic assistance was limited to the ventricular access in the first 2 procedures, but was used for the entirety of the procedure for the following 7 cases. Four of these cases were combined with another procedural objective (3 stereotactic tectal mass biopsies, 1 Chiari decompression). A learning curve was observed with each subsequent surgery as registration and surgical times became shorter and more efficient. All patients had complete resolution of their preprocedural symptoms. There were no complications. CONCLUSIONS The ROSA system provides a stable, precise, and minimally invasive approach to ETVs.

Endoscopic Third Ventriculostomy: Success and Failure

Endoscopic third ventriculostomy (ETV) has now become an accepted mode of hydrocephalus treatment in children. Varying degrees of success for the procedure have been reported depending on the type and etiology of hydrocephalus, age of the patient and certain technical parameters. Review of these factors for predictability of success, complications and validation of success score is presented.

Endoscopic third ventriculostomy in children: prospective, multicenter results from the Hydrocephalus Clinical Research Network

OBJECTIVE Endoscopic third ventriculostomy (ETV) is now established as a viable treatment option for a subgroup of children with hydrocephalus. Here, the authors report prospective, multicenter results from the Hydrocephalus Clinical Research Network (HCRN) to provide the most accurate determination of morbidity, complication incidence, and efficacy of ETV in children and to determine if intraoperative predictors of ETV success add substantially to preoperative predictors. METHODS All children undergoing a first ETV (without choroid plexus cauterization) at 1 of 7 HCRN centers up to June 2013 were included in the study and followed up for a minimum of 18 months. Data, including detailed intraoperative data, were prospectively collected as part of the HCRN's Core Data Project and included details of patient characteristics, ETV failure (need for repeat hydrocephalus surgery), and, in a subset of patients, postoperative complications up to the time of discharge. RESULTS Three hundred thirty-six eligible children underwent initial ETV, 18.8% of whom had undergone shunt placement prior to the ETV. The median age at ETV was 6.9 years (IQR 1.7-12.6), with 15.2% of the study cohort younger than 12 months of age. The most common etiologies were aqueductal stenosis (24.8%) and midbrain or tectal lesions (21.2%). Visible forniceal injury (16.6%) was more common than previously reported, whereas severe bleeding (1.8%), thalamic contusion (1.8%), venous injury (1.5%), hypothalamic contusion (1.5%), and major arterial injury (0.3%) were rare. The most common postoperative complications were CSF leak (4.4%), hyponatremia (3.9%), and pseudomeningocele (3.9%). New neurological deficit occurred in 1.5% cases, with 0.5% being permanent. One hundred forty-one patients had documented failure of their ETV requiring repeat hydrocephalus surgery during follow-up, 117 of them during the first 6 months postprocedure. Kaplan-Meier rates of 30-day, 90-day, 6-month, 1-year, and 2-year failure-free survival were 73.7%, 66.7%, 64.8%, 61.7%, and 57.8%, respectively. According to multivariate modeling, the preoperative ETV Success Score (ETVSS) was associated with ETV success (p < 0.001), as was the intraoperative ability to visualize a "naked" basilar artery (p = 0.023). CONCLUSIONS The authors' documented experience represents the most detailed account of ETV results in North America and provides the most accurate picture to date of ETV success and complications, based on contemporaneously collected prospective data. Serious complications with ETV are low. In addition to the ETVSS, visualization of a naked basilar artery is predictive of ETV success.

Is the endoscopic third ventriculostomy success score an appropriate tool to inform clinical decision-making?

INTRODUCTION

The endoscopic third ventriculostomy success score (ETVSS) is a model, which provides each patient with a prediction of the outcome of endoscopic third ventriculostomy. The objective of this study was to determine if there is clinical value to the use of the ETVSS in the decision for ETV.

METHODS

Prospectively collected data on all ETV procedures with the Republic of Ireland in children ≤16 years of age, totalling 112, from 2008 to 2014 was analysed. The percentage chance of success at six months was retrospectively calculated according to the ETVSS. A multivariable model, comprising the risk factors from the ETVSS - age, aetiology and previous shunt - was created and its performance compared to that of the ETVSS.

RESULTS

The ETVSS achieved an AUC of 0.61 (95% CI: 0.49-0.71) with a sensitivity and specificity of 50% and 76%, respectively, at its optimal cutoff. The ETVSS was not significantly well calibrated in this cohort and there was a limited net benefit on decision curve analysis in comparison with the strategy of performing ETV in all patients. The multivariable model achieved an AUC of 0.67 (95% CI: 0.56-0.78), was well calibrated and was associated with a superior net benefit over that of the ETVSS.

CONCLUSION

The ETVSS represents the future of patient risk stratification with an easy to use, individualised approach for each patient. The ETVSS has performed adequately in this study. However, through the addition of novel risk factors, the continuous updating of the model and recalibration where needed, the ETVSS can become a tool that the paediatric neurosurgeon cannot do without.

Long-term follow-up of endoscopic third ventriculostomy performed in the pediatric population

OBJECTIVE Endoscopic third ventriculostomy (ETV) is an effective treatment for obstructive hydrocephalus and avoids the risk for foreign-body infection associated with ventriculoperitoneal (VP) shunts. The short-term failure rate of ETV strongly depends on the indications for its use but is generally thought to be lower in the long term than that of VP shunts. However, few studies are available with long-term follow-up data of ETV for hydrocephalus in children. The authors reviewed the long-term success of ETV at their institution to investigate the rate of any late failures of this procedure. METHODS Between April 1998 and June 2006, 113 children (including neonates and children up to 16 years old) had primary or secondary ETV for different causes of hydrocephalus. The patients' medical records and the authors' electronic operation database were reviewed for evidence of additional surgery (i.e., repeat ETV or VP shunt insertion). These records were checked at both the pediatric and adult neurosurgical hospitals for those patients who had their care transferred to adult services. RESULTS The median length of follow-up was 8.25 years (range 1 month to 16 years). Long-term follow-up data for 96 patients were available, 47 (49%) of whom had additional ETV or VP shunt insertion for ETV failure. Twenty patients (21%) had a second procedure within 1 month, 17 patients (18%) between 1 and 12 months, 7 patients (7%) between 1 and 5 years, and 3 patients (3%) between 5 and 8 years. CONCLUSIONS In the authors' series, ETV had an initial early failure rate for the treatment of pediatric hydrocephalus as reported previously, and this rate significantly depended on patient age and hydrocephalus etiology. Once stabilized and effective, ETV appeared to be durable but not guaranteed, and some late decline in effectiveness was observed, with some ETV failures occurring many years later. Thus, successful ETV in children cannot be guaranteed for life, and some form of follow-up is recommended long term into adulthood.

International Infant Hydrocephalus Study: initial results of a prospective, multicenter comparison of endoscopic third ventriculostomy (ETV) and shunt for infant hydrocephalus

INTRODUCTION

The IIHS is an international, prospective, multicenter study to compare endoscopic third ventriculostomy (ETV) and shunt in infants (<24 months old) with symptomatic triventricular hydrocephalus from aqueductal stensosis. Recruitment started in 2004, and here, we present the first results of IIHS.

METHODS

IIHS utilized a prospective comprehensive cohort design, which contained both a randomized and a non-randomized arm. Patients received either an ETV or shunt, based on randomization or parental preference. Patients were followed prospectively for time to treatment failure, defined as the need for repeat CSF diversion procedure (shunt or ETV) or death due to hydrocephalus. Survival analysis was used to compare time to failure for ETV versus shunt. The trial was registered at clinicaltrials.gov (NCT00652470).

RESULTS

A total of 158 patients met eligibility criteria (median age at surgery 3.6 months, IQR 1.6-6.6 months) across 27 centers in 4 continents. Since only 52 patients (32.9 %) were randomized, all 158 patients were analyzed together (115 ETV, 43 shunt). Actuarial success rates for ETV vs shunt at 3, 6, and 12 months were as follows: 68 vs 95 %, 66 vs 88 %, and 66 vs 83 %. The 6-month ETV success rate of 66 % was slightly higher than would have been predicted by the ETV Success Score (57 %).The hazard ratio for time to treatment failure favored shunt over ETV (3.17, 95 % CI 1.45-6.96, p = 0.004), after adjusting for age at surgery, history of previous hemorrhage or infection, continent, and randomization status. Patients younger than 6 months of age appeared to do relatively worse with ETV than older patients.

CONCLUSIONS

The IIHS has provided the first prospective direct comparison of ETV and shunt for infant hydrocephalus. These initial results suggest that shunting has a superior success rate compared to ETV, although the success rate for both was relatively high. This patient cohort continues to be followed, and we will await the results of the important primary outcome of health status at 5 years of age.

Long-term results of endoscopic third ventriculostomy: an outcome analysis

OBJECT

Endoscopic third ventriculostomy (ETV) is the procedure of choice in the treatment of obstructive hydrocephalus. The excellent clinical and radiological success rates are well known. Nevertheless, very few papers have addressed the very long term outcomes of the procedure in very large series. The authors present a large case series of 113 patients who underwent 126 ETVs, and they highlight the initial postoperative outcome after 3 months and long-term follow-up with an average of 7 years.

METHODS

All patients who underwent ETV at the Department of Neurosurgery, Mainz University Hospital, between 1993 and 1999 were evaluated. Obstructive hydrocephalus was the causative pathology in all cases.

RESULTS

The initial clinical success rate was 82% and decreased slightly to 78% during long-term follow-up. Long-term success was analyzed using Kaplan-Meier curves. Overall, ETV failed in 31 patients. These patients underwent a second ETV or shunt treatment. A positive impact on long-term success was seen for age older than 6 months, and for obstruction due to cysts or benign aqueductal stenosis. The complication rate was 9% with 5 intraoperative and 5 postoperative events.

CONCLUSIONS

The high clinical success rate in short-term and long-term follow-up confirms ETV’s status as the gold standard for the treatment of obstructive hydrocephalus, especially for distinct pathologies. The patient’s age and underlying pathology may influence the outcome. These factors should be considered carefully preoperatively by the surgeon.

Predicting success of endoscopic third ventriculostomy: validation of the ETV Success Score in a mixed population of adult and pediatric patients

OBJECT

Endoscopic third ventriculostomy (ETV) has become the first line of treatment in obstructive hydrocephalus. The Toronto group (Kulkarni et al.) developed the ETV Success Score (ETVSS) to predict the clinical response following ETV based on age, previous shunt, and cause of hydrocephalus in a pediatric population. However, the use of the ETVSS has not been validated for a population comprising adults. The objective of this study was to validate the ETVSS in a "closed-skull" population, including patients 2 years of age and older.

METHODS

In this retrospective observational study, medical charts of all consecutive cases of ETV performed in two university hospitals were reviewed. The primary outcome, the success of ETV, was defined as the absence of reoperation or death attributable to hydrocephalus at 6 months. The ETVSS was calculated for all patients. Discriminative properties along with calibration of the ETVSS were established for the study population. The secondary outcome is the reoperation-free survival.

RESULTS

This study included 168 primary ETVs. The mean age was 40 years (range 3-85 years). ETV was successful at 6 months in 126 patients (75%) compared with a mean ETVSS of 82.4%. The area under the receiver operating characteristic curve was 0.61, revealing insufficient discrimination from the ETVSS in this population. In contrast, calibration of the ETVSS was excellent (calibration slope = 1.01), although the expected low numbers were obtained for scores < 70. Decision curve analyses demonstrate that ETVSS is marginally beneficial in clinical decision-making, a reduction of 4 and 2 avoidable ETVs per 100 cases if the threshold used on the ETVSS is set at 70 and 60, respectively. However, the use of the ETVSS showed inferior net benefit when compared with the strategy of not recommending ETV at all as a surgical option for thresholds set at 80 and 90. In this cohort, neither age nor previous shunt were significantly associated with unsuccessful ETV. However, better outcomes were achieved in patients with aqueductal stenosis, tectal compressions, and other tumor-associated hydrocephalus than in cases secondary to myelomeningocele, infection, or hemorrhage (p = 0.03).

CONCLUSIONS

The ETVSS did not show adequate discrimination but demonstrated excellent calibration in this population of patients 2 years and older. According to decision-curve analyses, the ETVSS is marginally useful in clinical scenarios in which 60% or 70% success rates are the thresholds for preferring ETV to CSF shunt. Previous history of CSF shunt and age were not associated with worse outcomes, whereas posthemorrhagic and postinfectious causes of the hydrocephalus were significantly associated with reduced success rates following ETV.