Prior CSF shunting increases the risk of endoscopic third ventriculostomy failure in the treatment of obstructive hydrocephalus in adults

Ventriculo - Gallbladder shunt

INTRODUCTION

Permanent liquor diversion is associated with a high risk of failure and often requires re-intervention. The ventriculo-gallbladder shunt (VGS) has been recognized as a last-resort alternative for treating hydrocephalus when the peritoneum or other distal sites are no longer suitable for receiving shunts. This article aims to report a case from a neurosurgery referral service in Brazil and review the literature on this issue.

METHODS

A systematic literature review was conducted in accordance with the PRISMA statement. The PubMed, Embase, and Web of Science databases were searched for data screening and extraction. The reported case was conducted with ethical approval from the neurosurgical hospital's ethics committee.

RESULTS

G.B.S, male, 43 years old, no comorbidities, who has been dealing with a 12-year history of hydrocephalus, with post-surgical chronic fungal meningitis. Two years ago, he underwent a ventriculoatrial shunt (VAS) placement due to multiple ventriculoperitoneal shunt (VPS) failures. Endocarditis was suspected, and the VAS was removed. As an alternative, VGS was implanted 6 months ago, and since then, there has been no need for a new system review. The gallbladder has an absorptive capacity of 1500 cc of liquid daily, which is more than the normal daily production of cerebrospinal fluid (CSF). Therefore, it is a good alternative when the ventriculoperitoneal shunt is not feasible due to postsurgical peritoneal adhesions or when there are contraindications for ventriculoatrial shunts.

CONCLUSION

VGS is an alternative for patients who cannot undergo the most common surgical interventions, such as VPS.

Long-Standing Overt Ventriculomegaly in Adults (LOVA): Diagnostic Aspects, CSF Dynamics with Lumbar Infusion Test and Treatment Options in a Consecutive Series with Long-Term Follow-Up

BACKGROUND

Long-standing overt ventriculomegaly in adults is a chronic form of hydrocephalus without a clear pathophysiological description and a consensus about the treatment. We present the results of endoscopic third ventriculostomy (ETV) in a consecutive series with a mean follow-up of 79 ± 23 months, highlighting how the preoperative lumbar infusion test could facilitate understanding the pathophysiology of the disease.

METHODS

We retrospectively collected data regarding clinical assessment, neuroradiological findings, and preoperative lumbar infusion tests in 22 symptomatic patients.

RESULTS

In the majority of cases, patients reported imbalance and gait disorders, and 8 subjects had headaches. The preoperative lumbar infusion test demonstrated a mean opening pressure of 13.95 ± 2.88 mm Hg, with plateau values ranging from 22 to 39 mm Hg. The resistance to outflow was 11.21 ± 2.00 mm Hg/mL/min. After the procedure, all patients reported improvement or halted progression in their presenting symptoms, whereas no significant reduction was demonstrated in Evans' index. One subject underwent a second ETV procedure after more than 2 years because of the failure of the endoscopic approach.

CONCLUSIONS

A progressive exhaustion of brain compliance plays an important role in explaining the dichotomy between severe ventriculomegaly and mild clinical symptoms in patients with long-standing overt ventriculomegaly in adults. The role of the aqueductal stenosis as a diagnostic criterion might be reconsidered. The preoperative infusion test data support this observation. Preoperative assessment should include not only clinical and neuroradiological evaluation but also the study of cerebrospinal fluid dynamics. ETV should be considered the treatment of choice because of its safety and efficacy. Long-term follow-up is mandatory.

Frameless radiosurgical third ventriculostomy: Technical report

Background:

We describe the technical report and results of the first image-guided, linear accelerator, frameless radiosurgical third ventriculostomy.

Methods:

We report a 20 years old man, with diplopia, balance disturbances, and limitation for gaze supraversion. Magnetic resonance imaging resonance imaging of the brain and cranial computed tomography showed showed a left thalamic-midbrain lesion that caused partial compression of the Silvio aqueduct and mild ventricular dilatation. The biopsy revealed the diagnosis of pleomorphic xanthoastrocytoma. Before radical treatment of the tumor with fractionated stereotactic radiotherapy, the patient underwent to frameless radiosurgical third ventriculostomy, on the TrueBeam STX® platform with the ExacTrac localization system. The target used was the one defined on the floor of the third ventricle, at the midpoint between the mammillary bodies and the infundibular recess. The prescription dose was 120 Gy, given using a monoisocentric technique of multiple noncoplanar circular arches. The geometric arrangement of the plan consisted of 15 arches, with a 4 mm cone, distributed over a 110° table.

Results:

There was symptomatic and image improvement two days after radiosurgery. On CT, a reduction in ventricular dilation was observed with a reduction in the Evans index from 0.39 (initial CT) to 0.29 (CT at 15 days). In 3.0T magnetic resonance image at 3 months, we showed the third ventriculostomy. There have been no treatment failures or complications.

Conclusion:

It is possible to effectively perform the frameless radiosurgical third ventriculostomy without associated morbidity in the short term.

Is endoscopic third ventriculostomy safe and efficient in the treatment of obstructive chronic hydrocephalus in adults? A prospective clinical and MRI study

BACKGROUND

In case of suspected normal pressure hydrocephalus, MRI is performed systematically and can sometimes highlight an obstruction of the flow pathways of the CSF (aqueductal stenosis or other downstream obstruction). It seems legitimate for these patients to ask the question of a treatment with endoscopic third ventriculostomy (ETV), even if the late decompensation of an obstruction may suggest an association with a CSF resorption disorder. The aim of this study was to evaluate clinical and radiological evolution after ETV in a group of elderly patients with an obstructive chronic hydrocephalus (OCH).

METHODS

ETV was performed in 15 patients with OCH between 2012 and 2017. Morphometric (callosal angle, ventricular surface, third ventricular width, and Evans' index) and velocimetric parameters (stroke volume of the aqueductal (SVa) CSF) parameters were measured prior and after surgery with brain MRI. The clinical score (mini-mental status examination (MMSE) and the modified Larsson's score, evaluating walking, autonomy, and incontinence) were performed pre- and postoperatively.

RESULTS

SVa was less than 15 μL/R-R in 12 out of the 15 patients; in the other three cases, the obstruction was located at a distance from the middle part of the aqueduct. Fourteen out of 15 patients were significantly improved: mean Larsson's score decreased from 3.8 to 0.6 (P ≤ 0.01) and mean MMSE increased from 25.7 to 28 (P = 0.084). Evans' index and ventricular area decreased postoperatively and the callosal angle increased (P ≤ 0.01). The mean follow-up lasted 17.9 months. No postoperative complications were observed.

CONCLUSION

ETV seems to be a safe and efficient alternative to shunt for chronic hydrocephalus with obstruction; the clinical improvement is usual and ventricular size decreases slightly.

Endoscopic Third Ventriculostomy in Noncommunicating Hydrocephalus: Report on a Short Series of 53 Children

Introduction:

Endoscopoic third ventriculostomy (ETV) is currently considered the best alternative to cerebrospinal fluid (CSF) shunt systems in the treatment of obstructive hydrocephalus. The aim of ETV is to communicate the third ventricle with the interpendicular cistern and create CSF flow which bypasses an obstruction to the circulation of the CSF.

Aims and Objectives:

The purpose of this study was to elucidate the indications, efficacy, safety and outcome Of ETV pediatric patients of noncommunicating hydrocephalus.

Material and Methods:

This study is a 3 year prospective study from June 2012 to May 2015. Records were kept for age, gender, etilogical factors, symptoms, signs, previous use of shunt or external ventricular device, imaging findings, and surgical complications (intraoperative and postoperative). Only those patients with age between 6months and 18 years with symptoms of intracranial hypertension and radiographic evidence of noncommunicating hydrocephalus were included in the study.

Results:

A total of 53 patients were studied, out of these 29 were boys and 24 were girls. The mean age of the patients was 6.6 years. Overall a total of 50 successful ETVs were done in 53 patients. The success rate is estimated to be 94%. There was no mortality. The average postoperative hospital stay was 4 days. The followup ranged from 6 to 16 months (mean, 12 months).

Conclusion:

ETV in children is a safe, simple and effective treatment and a logical alternative to shunting procedure for patients of noncommunicating hydrocephalus.

Role of Secondary Endoscopic Third Ventriculostomy in Children: Review of an Institutional Experience

BACKGROUND

Endoscopic third ventriculostomy (ETV) has become a standard and safe procedure for obstructive hydrocephalus. ETV can also play an important role in children presenting with shunt malfunction with an added advantage of shunt independence. Secondary ETV can be defined as either a redo endoscopic ventriculostomy done after primary ETV stoma closure or that done in cases presenting with shunt malfunction.

OBJECTIVE

The aim of our study was to evaluate the role of secondary ETV in the pediatric age group patients.

METHODS

This is a retrospective analysis of 36 children (<18 years) who underwent ETV after shunt malfunction and 4 children with ETV done after previous ETV stoma closure from 2004 until 2018. In all patients, the obstructive pattern suggesting aqueduct outflow obstruction was observed on MRI. Patients were followed up for a mean period of 4.25 years.

RESULTS

ETV was considered successful if the patient avoided a shunt insertion later on in their life. Considering this definition, a success rate of 72% was observed with secondary ETV for shunt malfunction whereas a success rate of 75% was observed after primary ETV failure without any major side effects in any of the patients.

CONCLUSION

ETV can be considered a primary treatment modality in children with shunt malfunction and has a good success rate in cases presenting with closure of previously performed ETV stoma.

Endoscopic third ventriculostomy for treatment of adult hydrocephalus: long-term follow-up of 163 patients

OBJECTIVE The efficacy of endoscopic third ventriculostomy (ETV) for the treatment of pediatric hydrocephalus has been extensively reported in the literature. However, ETV-related long-term outcome data are lacking for the adult hydrocephalus population. The objective of the present study was to assess the role of ETV as a primary or secondary treatment for hydrocephalus in adults. METHODS The authors performed a retrospective chart review of all adult patients (age ≥ 18 years) with symptomatic hydrocephalus treated with ETV in Calgary, Canada, over a span of 20 years (1994-2014). Patients were dichotomized into a primary or secondary ETV cohort based on whether ETV was the initial treatment modality for the hydrocephalus or if other CSF diversion procedures had been previously attempted respectively. Primary outcomes were subjective patient-reported clinical improvement within 12 weeks of surgery and the need for any CSF diversion procedures after the initial ETV during the span of the study. Categorical and actuarial data analysis was done to compare the outcomes of the primary versus secondary ETV cohorts. RESULTS A total of 163 adult patients with symptomatic hydrocephalus treated with ETV were identified and followed over an average of 98.6 months (range 0.1-230.4 months). All patients presented with signs of intracranial hypertension or other neurological symptoms. The primary ETV group consisted of 112 patients, and the secondary ETV consisted of 51 patients who presented with failed ventriculoperitoneal (VP) shunts. After the initial ETV procedure, clinical improvement was reported more frequently by patients in the primary cohort (87%) relative to those in the secondary ETV cohort (65%, p = 0.001). Additionally, patients in the primary ETV group required fewer reoperations (p < 0.001), with cumulative ETV survival time favoring this primary ETV cohort over the course of the follow-up period (p < 0.001). Fifteen patients required repeat ETV, with all but one experiencing successful relief of symptoms. Patients in the secondary ETV cohort also had a higher incidence of complications, with one occurring in 8 patients (16%) compared with 2 in the primary ETV group (2%; p = 0.010), although most complications were minor. CONCLUSIONS ETV is an effective long-term treatment for selected adult patients with hydrocephalus. The overall ETV success rate when it was the primary treatment modality for adult hydrocephalus was approximately 87%, and 99% of patients experience symptomatic improvement after 2 ETVs. Patients in whom VP shunt surgery fails prior to an ETV have a 22% relative risk of ETV failure and an almost eightfold complication rate, although mostly minor, when compared with patients who undergo a primary ETV. Most ETV failures occur within the first 7 months of surgery in patients treated with primary ETV, but the time to failure is more prolonged in patients who present with failed previous shunts.

Endoscopic Third Ventriculostomy Instead of Shunt Revision in Children Younger Than 3 Years of Age

OBJECTIVE

Endoscopic third ventriculostomy (ETV) is a valuable option in the treatment of shunt failure, but no clinical data exist for young children. The aim of this study was to elucidate the role of ETV in patients younger than 3 years of age with shunt malfunction.

METHODS

A cohort of 37 patients younger than 3 years of age with shunt malfunction underwent ETV instead of shunt revision. Patients' preoperative condition and medical history were studied to determine the impact of a number of variables on outcome. The Fisher exact test was used to assess differences among groups.

RESULTS

Median age at ETV was 21.6 months (8-36 months). Diagnosis was obstructive hydrocephalus in 24 patients and communicating hydrocephalus in 13. Median age at initial shunt placement was 3.2 months (10 days to 30 months). The etiology of shunt malfunction was obstruction (n = 27) or infection (n = 10). Overall ETV failure rate was 40.5% (15/37). Patients whose age at initial shunt placement was <6 months and/or who had a preterm birth history had higher relative rates of ETV failure. Other variables, including type of hydrocephalus, interval between initial shunt placement and ETV, history of intraventricular bleeding and/or infection, and etiology of shunt malfunction, did not significantly affect the final outcome.

CONCLUSIONS

Patients younger than 3 years with obstructive or communicating hydrocephalus may benefit from ETV in the event of shunt malfunction and have about a 60% probability of becoming shunt free.

Endoscopic Third Ventriculostomy in 250 Adults With Hydrocephalus

BACKGROUND:

Endoscopic third ventriculostomy (ETV) has been used predominantly in the pediatric population in the past. Application in the adult population has been less extensive, even in large neurosurgical centers. To our knowledge, this report is one of the largest adult ETV series reported and has the consistency of being performed at 1 center.

OBJECTIVE:

To determine the efficacy, safety, and outcome of ETV in a large adult hydrocephalus patient series at a single neurosurgical center. In addition, to analyze patient selection criteria and clinical subgroups (including those with ventriculoperitoneal shunt [VPS] malfunction or obstruction and neurointensive care unit patients with extended ventricular drainage before ETV) to optimize surgical results in the future.

METHODS:

We conducted a retrospective review of adult ETV procedures performed at our center between 2000 and 2014.

RESULTS:

The overall rate of success (no further cerebrospinal fluid diversion procedure performed plus clinical improvement) of 243 completed ETVs was 72.8%. Following is the number of procedures with the success rate in parentheses: aqueduct stenosis, 56 (91%); communicating hydrocephalus including normal pressure hydrocephalus, nonnormal pressure hydrocephalus, and remote head trauma, 57 (43.8%); communicating hydrocephalus in postoperative posterior fossa tumor without residual tumor, 14 (85.7%); communicating hydrocephalus in subarachnoid hemorrhage without intraventricular hemorrhage, 23 (69.6%); obstruction from tumor/cyst, 42 (85.7%); VPS obstruction (diagnosis unknown), 23 (65.2%); intraventricular hemorrhage, 20 (90%); and miscellaneous (obstructive), 8 (50%). There were 9 complications in 250 intended procedures (3.6%); 5 (2%) were serious.

CONCLUSION:

Use of ETV in adult hydrocephalus has broad application with a low complication rate and reasonably good efficacy in selected patients.

Endoscopic third ventriculostomy - effectiveness of the procedure for obstructive hydrocephalus with different etiology in adults

Introduction

After a time of domination of shunt placement, endoscopic third ventriculostomy (ETV) has been increasingly applied in treatment of obstructive hydrocephalus.

Aim

To assess the effectiveness of ETV in treatment of adults with three-ventricle hydrocephalus of different etiology.

Material and methods

Ninety-six patients with obstructive hydrocephalus were studied: 24 with primary aqueductal stenosis, 61 with brain tumor, and 2 with basilar tip aneurysm. In 9 patients the etiology of hydrocephalus remained undetermined. The assessment of treatment results was based on clinical and radiological criteria.

Results

Clinical improvement was observed in 74 (77.1%) patients, and radiological improvement in 52 (54.2%). One patient died. Follow-up of 24 patients with primary aqueductal stenosis has shown that in 20 (83.3%) of them clinical improvement has been stable, and in 14 (58.3%) radiological improvement has been observed. Two patients required shunt placement due to hydrocephalus recurrence 12–24 months after the ETV procedure. Among 9 patients with undefined hydrocephalus, 3 required shunt placement within 6 months after ETV (2 shunted previously). Endoscopic third ventriculostomy treatment in a patient with hydrocephalus caused by basilar tip aneurysm succeeded. The assessment of ETV effectiveness in oncological patients has been indirect in view of the underlying disease.

Conclusions

The best results of ETV treatment have been demonstrated for patients with primary aqueductal stenosis. Ventricle size cannot determine the effectiveness of treatment as an individual requirement. Endoscopic third ventriculostomy is effective in previously shunted patients although the prediction of outcome should be cautious. Endoscopic third ventriculostomy enables preparation for further therapy and is palliative treatment in oncological patients with secondary hydrocephalus.

Endoscopic third ventriculostomy in previously shunted children

Endoscopic third ventriculostomy (ETV) is a routine and safe procedure for therapy of obstructive hydrocephalus. The aim of our study is to evaluate ETV success rate in therapy of obstructive hydrocephalus in pediatric patients formerly treated by ventriculoperitoneal (V-P) shunt implantation. From 2001 till 2011, ETV was performed in 42 patients with former V-P drainage implantation. In all patients, the obstruction in aqueduct or outflow parts of the fourth ventricle was proved by MRI. During the surgery, V-P shunt was clipped and ETV was performed. In case of favourable clinical state and MRI functional stoma, the V-P shunt has been removed 3 months after ETV. These patients with V-P shunt possible removing were evaluated as successful. In our group of 42 patients we were successful in 29 patients (69%). There were two serious complications (4.7%)—one patient died 2.5 years and one patient died 1 year after surgery in consequence of delayed ETV failure. ETV is the method of choice in obstructive hydrocephalus even in patients with former V-P shunt implantation. In case of acute or scheduled V-P shunt surgical revision, MRI is feasible, and if ventricular system obstruction is diagnosed, the hydrocephalus may be solved endoscopically.

Endoscopic third ventriculostomy

Endoscopic third ventriculostomy (ETV) is considered as a treatment of choice for obstructive hydrocephalus. It is indicated in hydrocephalus secondary to congenital aqueductal stenosis, posterior third ventricle tumor, cerebellar infarct, Dandy-Walker malformation, vein of Galen aneurism, syringomyelia with or without Chiari malformation type I, intraventricular hematoma, post infective, normal pressure hydrocephalus, myelomeningocele, multiloculated hydrocephalus, encephalocele, posterior fossa tumor and craniosynostosis. It is also indicated in block shunt or slit ventricle syndrome. Proper Pre-operative imaging for detailed assessment of the posterior communicating arteries distance from mid line, presence or absence of Liliequist membrane or other membranes, located in the prepontine cistern is useful. Measurement of lumbar elastance and resistance can predict patency of cranial subarachnoid space and complex hydrocephalus, which decides an ultimate outcome. Water jet dissection is an effective technique of ETV in thick floor. Ultrasonic contact probe can be useful in selected patients. Intra-operative ventriculo-stomography could help in confirming the adequacy of endoscopic procedure, thereby facilitating the need for shunt. Intraoperative observations of the patent aqueduct and prepontine cistern scarring are predictors of the risk of ETV failure. Such patients may be considered for shunt surgery. Magnetic resonance ventriculography and cine phase contrast magnetic resonance imaging are effective in assessing subarachnoid space and stoma patency after ETV. Proper case selection, post-operative care including monitoring of ICP and need for external ventricular drain, repeated lumbar puncture and CSF drainage, Ommaya reservoir in selected patients could help to increase success rate and reduce complications. Most of the complications develop in an early post-operative, but fatal complications can develop late which indicate an importance of long term follow up.

Stereotactic versus endoscopic surgery in periventricular lesions

OBJECT

Endoscopic and stereotactic surgery have gained widespread acceptance as minimally invasive tools for the diagnosis of intracerebral pathologies. We investigated the specific advantages and disadvantages of each technique in the assessment of periventricular lesions.

METHOD

This study included a retrospective series of 70 patients with periventricular lesions. Endoscopic surgery was performed in 17 patients (mean age, 37 years; range, 4 months-78 years) and stereotactic biopsy in 55 patients (mean age, 63 years; range, 23-80 years), including two patients who underwent both procedures.

RESULTS

Hydrocephalus was present in 13/17 patients in the endoscopic group (77%) and in 11/55 patients in the stereotactic group (20%). Diagnosis was achieved in all patients in the endoscopic group and in all but one patient in the stereotactic group, in whom histological diagnosis was obtained by endoscopic biopsy during a second operation. In the endoscopic group, additional procedures performed included ventriculostomy (2/17), cyst fenestration (3/17), endoscopic shunt revision (3/17) and placement of Rickham reservoirs or external cerebrospinal fluid drains (6/17). Adverse events occurred in one patient after endoscopy (chronic subdural hematoma) and in two patients after stereotactic surgery (one mild hemiparesis and one transitory paresis of the contralateral leg).

CONCLUSIONS

Endoscopic and stereotactic surgery have distinct advantages and disadvantages in approaching periventricular lesions. The advantages of endoscopy encompass the possibility to perform additional surgical procedures during the same session (e.g. tumour reduction, third ventriculostomy, fenestration of a cyst). The visual control reduces the hazard of injury to anatomical structures and allows for a better control of bleeding although there is a considerable blind-out in such situations. The advantages of stereotactic surgery include a smaller approach and precise planning of the trajectory. It is usually performed under local anaesthesia. Both methods provide a safe and efficient therapeutic option in periventricular lesions with low surgical-related morbidity.

Minimally invasive neurosurgery for cerebrospinal fluid disorders

This article focuses on minimally invasive approaches used to address disorders of cerebrospinal fluid (CSF) circulation. The author covers the primary CSF disorders that are amenable to minimally invasive treatment, including aqueductal stenosis, fourth ventricular outlet obstruction (including Chiari malformation), isolated lateral ventricle, isolated fourth ventricle, multiloculated hydrocephalus, arachnoid cysts, and tumors that block CSF flow. General approaches to evaluating disorders of CSF circulation, including detailed imaging studies, are discussed. Approaches to minimally invasive management of such disorders are described in general, and for each specific entity. For each procedure, indications, surgical technique, and known outcomes are detailed. Specific complications as well as strategies for their avoidance and management are addressed. Lastly, future directions and the need for structured outcome studies are discussed.

Endoscopic Third Ventriculostomy Vs Cerebrospinal Fluid Shunt in the Treatment of Hydrocephalus in Children

BACKGROUND

Endoscopic third ventriculostomy (ETV) has preferentially been offered to patients with more favorable prognostic features compared with shunt.

OBJECTIVE

To use advanced statistical methods to adjust for treatment selection bias to determine whether ETV survival is superior to shunt survival once the bias of patient-related prognostic factors is removed.

METHODS

An international cohort of children (≤ 19 years of age) with newly diagnosed hydrocephalus treated with ETV (n = 489) or shunt (n = 720) was analyzed. We used propensity score adjustment techniques to account for 2 important patient prognostic factors: age and cause of hydrocephalus. Cox regression survival analysis was performed to compare time-to-treatment failure in an unadjusted model and 3 propensity score—adjusted models, each of which would adjust for the imbalance in prognostic factors.

RESULTS

In the unadjusted Cox model, the ETV failure rate was lower than the shunt failure rate from the immediate postoperative phase and became even more favorable with longer duration from surgery. Once patient prognostic factors were corrected for in the 3 adjusted models, however, the early failure rate for ETV was higher than that for shunt. It was only after about 3 months after surgery did the ETV failure rate become lower than the shunt failure rate.

CONCLUSIONS

The relative risk of ETV failure is initially higher than that for shunt, but after about 3 months, the relative risk becomes progressively lower for ETV. Therefore, after the early high-risk period of ETV failure, a patient could experience a long-term treatment survival advantage compared with shunt. It might take several years, however, to realize this benefit.

Cine phase-contrast MR images failed to predict clinical outcome following ETV

BACKGROUND

To predict success of endoscopic third ventriculostomy (ETV) in patients with obstructive hydrocephalus, we evaluated pre- and post- operative phase-contrast cine magnetic resonance images (PC MRI) on cerebrospinal fluid (CSF), cine flow in basal cisterns around the brain stem, and cervical medullar junction (CMJ) retrospectively.

METHODS

The study involved 102 patients with mean age of 36.74+/-23.25, and F/M = 1.55. All patients had PC MRI taken both pre- and post-operatively. A dynamic MRI video of PC MRI was reviewed at sagittal, axial, and coronal sections to determine cistern flows around the brain stem and CMJ. For quantitative analysis, quadrants were divided around midbrain axially to evaluate interpeduncular, quadrageminal, and ambient cisterns of both sides using scores of 0 to 60. Pre- and post- pontine and CMJ flows were shown in sagittal view and scored 0 to 20, and lateral cerebellopontine cisterns of both sides were measured on coronal image and scored 0 to 20.

RESULTS

No significant difference in CSF flow was seen from three individual views and total cine score, or between ETV success and failure groups by multivariate analysis of variance. Kaplan-Meier Analysis and Spearman's Correlation Test produced no relationship between MRI cine flow scores and interval period after surgery to ETV failure.

CONCLUSION

PC MRI cine flow failed to demonstrate significant differences between successful and failed ETV groups. This indicates in addition to achieving an adequate fenestration, CSF pathways beyond the basal cisterns around the brain stem and CMJ may play an essential role in achieving ETV success.

Endoscopic third ventriculostomy in the treatment of childhood hydrocephalus

OBJECTIVE

To develop a model to predict the probability of endoscopic third ventriculostomy (ETV) success in the treatment for hydrocephalus on the basis of a child's individual characteristics.

STUDY DESIGN

We analyzed 618 ETVs performed consecutively on children at 12 international institutions to identify predictors of ETV success at 6 months. A multivariable logistic regression model was developed on 70% of the dataset (training set) and validated on 30% of the dataset (validation set).

RESULTS

In the training set, 305/455 ETVs (67.0%) were successful. The regression model (containing patient age, cause of hydrocephalus, and previous cerebrospinal fluid shunt) demonstrated good fit (Hosmer-Lemeshow, P = .78) and discrimination (C statistic = 0.70). In the validation set, 105/163 ETVs (64.4%) were successful and the model maintained good fit (Hosmer-Lemeshow, P = .45), discrimination (C statistic = 0.68), and calibration (calibration slope = 0.88). A simplified ETV Success Score was devised that closely approximates the predicted probability of ETV success.

CONCLUSIONS

Children most likely to succeed with ETV can now be accurately identified and spared the long-term complications of CSF shunting.

Endoscopic third ventriculostomy: predicting outcome with phase-contrast MR imaging

PURPOSE

To determine whether phase-contrast magnetic resonance (MR) imaging measurements of preoperative cerebral blood and cerebrospinal fluid (CSF) hydrodynamics can be used as a biomarker of response to endoscopic third ventriculostomy (ETV).

MATERIALS AND METHODS

Approval from the local research ethics committee and written informed consent were obtained for this prospective study. Thirteen patients (six female patients, seven male patients; median age, 43 years) with chronic obstructive hydrocephalus, 12 of whom went on to undergo ETV, were imaged with phase-contrast MR imaging at 1.5 T to determine rates of total cerebral blood flow (CBF) and ventriculostomy defect, foramen magnum (FM), and cerebral aqueduct CSF flow. Ten control subjects (10 men; median age, 37 years) were similarly imaged. Correlations between measured values were assessed by means of Pearson correlation coefficients. Measurements were compared between groups with a Mann-Whitney test, and measurements before and after surgical intervention were compared with a Wilcoxon test for paired samples.

RESULTS

Rates of CBF (356 mL . min(-1) +/- 73 [standard deviation] vs 518 mL . min(-1) +/- 79, P < .001) and CSF flow in the FM (17.62 mL . min(-1) +/- 13.12 vs 36.35 mL . min(-1) +/- 8, P < .05) were significantly lower in patients than in control subjects.

CONCLUSION

ETV induces changes in brain volume and CBF that can be predicted by using simple metrics. These pilot results support a formal trial of these techniques in a larger prospective study.

Surgical management of adult hydrocephalus

The management of adult hydrocephalus spans a broad range of disorders and ages. Modern management strategies include endoscopic and adjustable cerebrospinal fluid shunt diversionary techniques. The assessment and management of the following clinical conditions are discussed: 1) the adult patient with congenital or childhood-onset hydrocephalus, 2) adult slit ventricle syndrome, 3) multicompartmental hydrocephalus, 4) noncommunicating hydrocephalus, 5) communicating hydrocephalus, 6) normal pressure hydrocephalus, and 7) the shunted patient with headaches. The hydrodynamics of cerebrospinal fluid shunt diversion are discussed in relation to mechanisms of under- and overdrainage conditions. A rationale for the routine implementation of adjustable valves for adult patients with hydrocephalus is provided based on objective clinical and experimental data. For the condition of normal pressure hydrocephalus, recommendations are offered regarding the evaluation, surgical treatment, and postoperative management of this disorder.