Endoscopic third ventriculostomy in idiopathic normal pressure hydrocephalus

Ventricular CSF proteomic profiles and predictors of surgical treatment outcome in chronic hydrocephalus

BACKGROUND

By applying an unbiased proteomic approach, we aimed to search for cerebrospinal fluid (CSF) protein biomarkers distinguishing between obstructive and communicating hydrocephalus in order to improve appropriate surgical selection for endoscopic third ventriculostomy vs. shunt implants. Our second study purpose was to look for potential CSF biomarkers distinguishing between patients with adult chronic hydrocephalus benefitting from surgery (responders) vs. those who did not (non-responders).

METHODS

Ventricular CSF samples were collected from 62 patients with communicating hydrocephalus and 28 patients with obstructive hydrocephalus. CSF was collected in relation to the patients' surgical treatment. As a control group, CSF was collected from ten patients with unruptured aneurysm undergoing preventive surgery (vascular clipping).

RESULTS

Mass spectrometry-based proteomic analysis of the samples identified 1251 unique proteins. No proteins differed significantly between the communicating hydrocephalus group and the obstructive hydrocephalus group. Four proteins were found to be significantly less abundant in CSF from communicating hydrocephalus patients compared to control subjects. A PCA plot revealed similar proteomic CSF profiles of obstructive and communicating hydrocephalus and control samples. For obstructive hydrocephalus, ten proteins were found to predict responders from non-responders.

CONCLUSION

Here, we show that the proteomic profile of ventricular CSF from patients with hydrocephalus differs slightly from control subjects. Furthermore, we find ten predictors of response to surgical outcome (endoscopic third ventriculostomy or ventriculo-peritoneal shunt) in patients with obstructive hydrocephalus.

Endoscopic third ventriculostomy compared to ventriculoperitoneal shunt as treatment for idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

BACKGROUND

The accepted treatment for idiopathic normal pressure hydrocephalus (iNPH) is the insertion of a ventriculoperitoneal shunt (VPS). Recently, some studies examined endoscopic third ventriculostomy (ETV) for the treatment of iNPH with controversial results. The aim of this systematic review and meta-analysis was to compare ETV to VPS regarding complications and outcome for the treatment of iNPH.

METHODS

We searched Medline, Embase and Scopus. Due to the scarcity of data, we did not include only randomized controlled trials, but also retro- and prospective studies. The primary outcome was failure of cerebrospinal fluid diversion method. Secondary endpoints were clinical postoperative improvement rate, morbidity and mortality.

RESULTS

Out of 311 screened studies, three were included in the quantitative analysis including one RCT and two retrospective cohort studies. No statistically significant difference concerning failure rate of CSF diversion method (ETV 27.5% vs. VPS 33.2%, RR 1.19, 95% CI [0.69-2.04], p = 0.52) or postoperative improvement was found (68% for ETV vs. 72.8% for VPS, RR 0.81, 95% CI [0.57-1.16], p = 0.26). ETV showed a significantly lower complication rate compared to VPS (7.5% vs. 51.1%, RR 0.25, 95% CI [0.08-0.76], p = 0.02).

CONCLUSION

ETV and VPS did not differ significantly regarding their failure rate for iNPH, while ETV showed a significantly lower complication rate than VPS. However, the data available is scarce with only one RCT investigating this important matter. Further well-designed trials are necessary to investigate the clinical outcome of ETV in iNPH.

TRIAL REGISTRATION NUMBER

PROSPERO (ID: CRD42020199173).

Prevalence and Trends in Management of Idiopathic Normal Pressure Hydrocephalus in the United States: Insights from the National Inpatient Sample

BACKGROUND

Over the past 2 decades, management of idiopathic normal pressure hydrocephalus (iNPH) has evolved significantly. In the current study, we sought to evaluate the national prevalence and management trends of iNPH in the United States using a national database.

METHODS

The National Inpatient Sample was queried for patients with an International Classification of Diseases diagnosis code for iNPH from 2007 to 2017. Trends in prevalence and procedure type were evaluated per 100,000 discharges and as a percentage of discharges, using weighted discharges. Utilization of procedure type across U.S. regions and hospital types was also compared.

RESULTS

From 2007 to 2017, 302,460 weighted discharges with any diagnosis code for iNPH, aged ≥60 years, were identified. Prevalence ranged from 0.04% to 0.20% (41/100,000 to 202/100,000) among admitted patients ≥60 years old, giving an average prevalence during the study duration of 0.18% (179/100,000). Of 66,759 weighted discharges with a primary diagnosis code of iNPH undergoing surgical management, ventriculoperitoneal shunt (72.0% of discharges, n = 48,977) was most commonly used; of these, 9.3% (n = 4567) were performed laparoscopically. This result was followed by lumbar peritoneal shunt (15.1% of discharges, n = 10,441). Up to 15.1% (n = 9990) of discharges reported only a lumbar puncture, assumed to be only diagnostic, for screening, or part of serial cerebrospinal fluid removal procedures. Significant discrepancies in procedure utilization were also identified among hospitals in the Western, Southern, Northeast and Midwest regions, as well as between urban and rural hospitals (P < 0.05).

CONCLUSIONS

We have summarized the national prevalence of iNPH, trends in its management over the previous decade and trends by region and hospital type.

Aqueductal Compression by Dilated Virchow-Robin Spaces in the Mesencephalic-Pontine Region Presenting with Symptoms Mimicking Normal Pressure Hydrocephalus: A Case Report and Review of Literature

BACKGROUND

Dilatation of Virchow-Robin spaces (dVRS) have been described in the development of hydrocephalic syndromes. We report an unusual case of a type III dVRS presenting as a mimic of normal pressure hydrocephalus (NPH), due to distortion at the level of the cerebral aqueduct.

CASE DESCRIPTION

A 59-year-old woman presented with mild traumatic brain injury and possible NPH, due to a history of progressive gait disturbance, recurrent falls, and cognitive decline over a year, in the context of ventriculomegaly. Detailed structural imaging of the brain revealed multiple dilated cystic lesions consistent with dVRS causing distortion at the level of the cerebral aqueduct. Cerebrospinal fluid examination was negative for infection. The patient was treated with endoscopic third ventriculostomy; at 12 months postoperatively, she demonstrated a sustained improvement in gait and stabilization of cognitive decline.

CONCLUSIONS

This is an illustrative case of a subacute obstructive hydrocephalus due to a collection of periaqueductal dVRS, leading to an insidious clinical presentation mimicking NPH. We reviewed the literature for key clinical presentations and describe neuroanatomical considerations as well as primary treatment strategies. Various hydrocephalic syndromes may present with classic symptoms from Hakim's triad; such symptoms are not specific to idiopathic NPH. Both endoscopic third ventriculostomy and shunting may be efficacious. In our case, dVRS may serve as both a cause of and compensatory mechanism in a subacute obstructive hydrocephalus of unknown etiology. Our case highlights the need to understand the neuroanatomy of aberrant cerebrospinal fluid spaces in hydrocephalic syndromes. Further studies of dVRS would provide valuable insights into the pathogenesis of hydrocephalus.

The 50 most cited publications in endoscopic third ventriculostomy: a bibliometric analysis

OBJECTIVEAlthough endoscopic third ventriculostomy (ETV) for the treatment of hydrocephalus was introduced in 1923, the method was relegated to the sidelines in favor of extracranial techniques. Since the 1990s to the beginning of the current century, however, ETV has undergone a remarkable resurgence to become the first-line treatment for obstructive hydrocephalus, and for some groups, the procedure has been applied for communicating hydrocephalus as well. In the present study, the authors identified the top 50 cited ETV works. These articles represent works of significance that document current practices and provide guidance for future inquiry.METHODSThe top 50 cited articles pertaining to ETV were identified using bibliometric data obtained with the Harzing's Publish or Perish software search engine. These high-impact works were evaluated for publication properties including year, country of authorship, category, and journal.RESULTSThe top 50 works were cited an average of 141.02 times with a mean of 9.45 citations per year. Articles published in 2005 were the most numerous in the top 50 group. These top articles were most frequently published in the Journal of Neurosurgery: Pediatrics. Most of the articles were clinical studies reporting on patients in the pediatric age group. The country of most authorship was the US, although many other countries were among the top 50 works.CONCLUSIONSThe present report discusses the bibliometric analysis of the top 50 ETV articles. This list may be useful to those interested in the progress and current status of this procedure.

The Liebau phenomenon: a translational approach to new paradigms of CSF circulation and related flow disturbances

PURPOSE

The aim of the study is to provide a comparison between Liebau's effect, underlying the working principles of impedance pumps, and the cerebrospinal fluid (CSF) circulation.

METHODS

Gerhard Liebau was a cardiologist with a specific interest in severe aortic regurgitation. Such interest drew his scientific attention to the flow-driven efficiency of valveless pumps. During one of his experiments, he assembled two rubber tubes of different sizes and documented how water could be aspirated against gravity when the tube of larger diameter underwent rhythmic compression. He subsequently tested an elastic tube connected to glass pipes of the same size on both ends, immersed in a water bucket. When the elastic tube was periodically pumped with a finger, a net flow could be observed in both directions; depending on the pumping site on the elastic tube, the flow was directed towards the most closely connected glass tube. The principles of a hydraulic system of different elasticity and compliance were also recently applied to the physiology and fluid dynamics of embryonic hearts.

RESULTS

Impedance pumps and the CSF dynamics model are both valveless systems and can both be activated by the effects of the cardiac cycle. The novel hydraulic model of impedance pumps was the foundation for the development of modern valveless micropumps and contributes to explain how the embryonic valveless tubular heart is capable of generating blood flow.

CONCLUSIONS

Liebau's effect and the mechanism of impedance pumps can enlighten some of the aspects of CSF dynamics and related flow disturbances.

Efficacy of endoscopic third ventriculostomy in old aged patients with normal pressure hydrocephalus

Normal pressure hydrocephalus (NPH) is a chronic disorder caused by interrupted CSF absorption or flow. Generally, shunt placement is first option for NPH treatment. Due to complications of ventriculo-peritoneal (VP) shunt placement, endoscopic third ventriculostomy (ETV) can be considered as an alternative treatment option. Here we report the efficacy of ETV especially in old aged patients with normal pressure hydrocephalus. Total 21 old aged patients with communicating hydrocephalus with opening pressure, measured via lumbar puncture, less than 20cm H₂O underwent ETV. 15 patients had primary/idiopathic NPH and 6 patients had secondary NPH. All patients were studied with a MRI to observe the flow void at aqueduct and the fourth ventricle outflow. And all of them underwent ETV. In a group with peak velocity was higher than 5cm/s, nine patients (75%) were evaluated was 'favorable' and three of them (25%) was scored 'poor'. In another group with peak velocity less than 5cm/s, three of them were scored 'poor' and two of them were scored 'stable'. None of them was evaluated as 'favorable'. We also evaluated the outcomes according to etiology: 12 patients (80% of the patients with primary NPH) were evaluated with 'favorable' after ETV treatment. Two patients (13.3%) were as 'stable'. And one patient was as 'poor' evaluated. Five patients (83.3%) among patients with secondary NPH were as 'poor' evaluated and one of them was stable and no patient was as 'favorable' evaluated. 4 patients, which was as 'poor' evaluated in the group with the secondary NPH, underwent additional VP shunt implantation. Overall, the outcomes of the group with the idiopathic NPH after ETV treatment were more favorable than of the group with the secondary NPH. Our study suggest that ETV can be effective for selected elderly patients with primary/idiopathic NPH, when they satisfy criteria including positive aqueduct flow void on T2 Sagittal MRI and the aqueductal peak velocity, which is greater than 5cm/s on cine MRI.

The Clinical Effect of Postoperative Hyperbaric Oxygen Therapy on Idiopathic Normal Pressure Hydrocephalus: A Retrospective and Comparative Analysis of 61 Patients with Ventriculoperitoneal Shunt

OBJECTIVE

The aim of the study was to examine the clinical effect of postoperative hyperbaric oxygen (HBO) therapy on symptoms and signs in the ventriculoperitoneal (VP) shunt insertion treatment of idiopathic normal pressure hydrocephalus (iNPH).

METHODS

We conducted a retrospective analysis of 61 patients treated at our institution for iNPH since 2007. Patients were stratified into 2 groups according to undergoing pure VP shunt with gravitational valves (group 1) or combined with postoperative HBO therapy (group 2). Clinical improvements as well as complications were compared between the 2 groups.

RESULTS

There was no significant difference between the 2 groups regarding age, sexual proportion, body mass index, education years, and the average Normal Pressure Hydrocephalus Scale score before the surgery, as well as the complication rate after the surgery (P > 0.05). On average, the total Normal Pressure Hydrocephalus Scale scores were both increased in the 2 groups at 1, 3, and 6 months after shunting, with no significant differences (P > 0.05). However, group 2 tended to increase more compared with group 1, especially 6 months later after shunting. The increase of cognitive functions was more significant in group 2 (P < 0.05).

CONCLUSIONS

HBO therapy combined with VP shunt is expected to improve the effect of iNPH treatment, especially for cognitive performance.

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.

Application of endoscopic third ventriculostomy for treating hydrocephalus-correlated Chiari type I malformation in a single Chinese neurosurgery centre

The correlation between hydrocephalus and Chiari type I malformation (CIM) has been debated since Chiari's first descriptions of CIM but some studies have shown that CIM and hydrocephalus (HCP) could cause symptoms/disease of each other or vice versa. Recent research has found that treatment focused on hydrocephalus with ventricle enlargement also provides alleviation of CIM and even of syringomyelia. However, the lack of consensus among previous studies left unanswered the question of how endoscopic third ventriculostomy (ETV) addresses CIM and why it fails. Ten symptomatic hydrocephalic patients associated with CIM underwent ETV from October 2002 to May 2012. The clinical features and neuroimaging of all patients were reviewed. Statistical analysis was applied to evaluate the changes in the tonsillar ectopia and the ventricle dilation after operation. The mean follow-up period of this series was 92 months (range 24-163 months). Eight patients (80%) remained shunt free or experienced symptom relief following ETV. The remaining two patients were identified as failures due to the deterioration of symptoms or subsequent hindbrain decompression. Endoscopic third ventriculostomy provides an effective treatment for hydrocephalus associated with CIM, which can relieve HCP and improve the symptoms of CIM in most patients. The clinical outcomes are related to the major cause of the tonsillar herniation.

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.

Operative planning aid for optimal endoscopic third ventriculostomy entry points in pediatric cases

OBJECT

Endoscopic third ventriculostomy (ETV) uses anatomical spaces of the ventricular system to reach the third ventricle floor and create an alternative pathway for cerebrospinal fluid flow. Optimal ETV trajectories have been previously proposed in the literature, designed to grant access to the third ventricle floor without a displacement of eloquent periventricular structures. However, in hydrocephalus, there is a significant variability to the configuration of the ventricular system, implying that the optimal ETV trajectory and cranial entry point needs to be planned on a case-by-case basis. In the current study, we created a mathematical model, which tailors the optimal ETV entry point to the individual case by incorporating the ventricle dimensions.

METHODS

We retrospectively reviewed the imaging of 30 consecutive pediatric patients with varying degrees of ventriculomegaly. Three dimensional radioanatomical models were created using preoperative MRI scans to simulate the optimal ETV trajectory and entry point for each case. The surface location of cranial entry points for individual ETV trajectories was recorded as Cartesian coordinates centered at Bregma. The distance from the Bregma in the coronal plane represented as "x", and the distance from the coronal suture in the sagittal plane represented as "y". The correlation between the ventricle dimensions and the x, y coordinates were tested using linear regression models.

RESULTS

The distance of the optimal ETV entry point from the Bregma in the coronal plane ("x") and from the coronal suture in the sagittal plane ("y") correlated well with the frontal horn ratio (FHR). The coordinates for x and y were fitted along the following linear equations: x = 85.8 FHR-13.3 (r ² = 0.84, p < 0.001) and y = -69.6 FHR + 16.7 (r ² = 0.83, p < 0.001).

CONCLUSION

The surface location of the optimal cranial ETV entry point correlates well with the ventricle size. We provide the first model that can be used as a surgical planning aid for a case specific ETV entry site with the incorporation of the ventricle size.

Endoscopic Third Ventriculostomy in Normal Pressure Hydrocephalus and Symptomatic Long-standing Overt Ventriculomegaly

Objectives:

The aim of this study is to define the role and effectiveness for an endoscopic third ventriculostomy (ETV) in patients with seconder normal pressure hydrocephalus(SNPH), idiopathic normal pressure hydrocephalus (INPH) and symptomatic longstanding overt ventriculomegaly (SLOVA).

Materials and Methods:

3 patients with SLOVA, 3 patients with INPH and 3 patients with SNPH underwent ETV were studied retrospectively. The patients had a follow-up of 1-6 years. Preoperative CT or/and MRI of the brain was done in all cases. Tap test was done in all cases. Clinical examination finding were classified according to the by Japanese Committee for Scientific Research (JCSS) on intractable Hydrocephalus. Patients were studied to evaluate of the patency of ventriculosthomy and aqueduclus slyvius by a Cine PC MR and CSF_DRİVE T2 Sequence MRI after 1-6 years.

Results:

Headache, gait disturbance and pollakiuria improved in three patients with SNPH underwent ETV, but dementia didn’t improve in one patient. Pollakiuria and headache improved in three patients with INPH underwent ETV but preoperative gait disturbance grade three remained unchanged in one patient. Headache improved in three patients with SLOVA underwent ETV. Preoperative gait disturbance grade 3 remained unchanged in one patient, but improved pollakiuria. We confirmed the patency of a third ventriculostomy and decreasing degrees of CSF flow into the aquaductus sylvius.

Conclusions:

In properly selected patients with SNPH, SLOVA and INPH who had headache, slight gait disturbance and pollakiuria, mainly those with a short duration of symptoms, ETV may provide good results.

Imaging normal pressure hydrocephalus: theories, techniques, and challenges

The pathophysiology of NPH continues to provoke debate. Although guidelines and best-practice recommendations are well established, there remains a lack of consensus about the role of individual imaging modalities in characterizing specific features of the condition and predicting the success of CSF shunting. Variability of clinical presentation and imperfect responsiveness to shunting are obstacles to the application of novel imaging techniques. Few studies have sought to interpret imaging findings in the context of theories of NPH pathogenesis. In this paper, the authors discuss the major streams of thought for the evolution of NPH and the relevance of key imaging studies contributing to the understanding of the pathophysiology of this complex condition.

Endoscopic transventricular exploration with biopsy of the basal cisterns and the role of endoscopic third ventriculostomy in patients suffering with basal cistern meningitis and consecutive hydrocephalus

OBJECTIVES

The purpose of this work is to elucidate the efficacy of endoscopic basal cisterns exploration, biopsy, and third ventriculostomy (ETV) in patients with basal cistern meningitis and arachnoiditis.

MATERIALS AND METHODS

The cases and videos of all patients in whom flexible neuroendoscopy was performed during the period of January 2005-June 2012 at the University Hospital 'Dr. Ignacio Morones Prieto' in San Luis Potosí, México. A group of 47 patients with radiological diagnosis of basal meningitis, arachnoiditis, and negative cerebrospinal fluid analysis were included.

RESULTS

From the 28 (60%) patients with histological diagnosis, 22 (47%) were made from biopsy from the arachnoid membranes of the basal cisterns only, 4 (9%) only from the cerebral cortex, and 2 (4%) from both sites. There were no complications related to the endoscopic procedure. In 23 patients from the 42 with hydrocephalus, ETV was successful. The grade of diagnostic accuracy of both biopsies in detect etiology was 68% (28 of 47 patients), the diagnostic accuracy of arachnoid biopsy was 60%, and diagnostic accuracy of convexity brain biopsy was 21% with 24 and 6 patients, respectively.

DISCUSSION

Endoscopic transventricular biopsy of the basal cisterns seems to be a safe and a relatively accurate procedure. As longs as frozen subarachnoid space was not seen, the possibilities of performing ETV in hydrocephalus condition are elevated depending on the causal micro-organism.

Comparison of outcomes between patients with idiopathic normal pressure hydrocephalus who received a primary versus a salvage shunt

Placement of a ventriculoperitoneal (VP) shunt is the treatment of choice for communicating hydrocephalus; however, the extent to which VP shunting is able to relieve symptoms in patients who had previously been treated with cerebrospinal fluid diverting therapy at an outside institution remains unclear. A retrospective review of patients with idiopathic normal pressure hydrocephalus treated with VP shunts at a single institution between 1993 and 2013 was conducted. Patients were classified as having received a primary VP shunt if they had not been previously treated with a VP shunt, ventriculoatrial shunt, lumboperitoneal shunt, or endoscopic third ventriculostomy. Patients were classified as having received a salvage VP shunt if they had been previously treated by one of these four modalities at an outside institution prior to their presentation to our institution. There were 357 patients who received a primary shunt and 33 patients who received a salvage shunt. Patients who had a salvage shunt placed had significantly higher odds of requiring a future revision (54% versus 41%; odds ratio=2.85; 95% confidence interval [CI]: 1.24-6.57; p=0.014). Patients who received a salvage shunt had statistically significantly lower rates of gait improvement at 6months in comparison to patients who received a primary shunt (relative risk=0.35; 95% CI: 0.14-0.87; p=0.025). Despite these findings, there was no significant difference at last follow-up in improvement in gait, continence, and cognition, indicating that outcomes for patients requiring a salvage shunt were comparable to patients receiving a primary shunt.

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.

Comparative analysis of endoscopic third ventriculostomy trajectories in pediatric cases

OBJECT

Endoscopic third ventriculostomy (ETV) has become a widely used method for CSF diversion when treating obstructive hydrocephalus. There are multiple recommendations on the transcortical ETV entry points, and some are specifically designed to provide a trajectory that avoids displacement to the eloquent periventricular structures. However, the morphology of the ventricular system is highly variable in hydrocephalus, and therefore a single best ETV trajectory may not be applicable to all cases. In the current study, 3 frequently quoted ETV entry points are compared in a cohort of pediatric cases with different degrees of ventriculomegaly.

METHODS

The images of 30 consecutive pediatric patients with varying degrees of ventriculomegaly were reviewed. Three-dimensional models were created using radiological analysis of anatomical detail and preoperative MRI scans in order to simulate 3 frequently quoted ETV trajectories for rigid neuroendoscopes. These trajectories were characterized based on the frequency and depth of tissue displacement to structures such as the fornix, caudate nucleus, genu of the internal capsule, and thalamus. The results are stratified based on ventricle size using the frontal horn ratio (FHR).

RESULTS

Eloquent areas were displaced in nearly all analyzed entry points (97%-100%). Stratifying the data based on ventricle size revealed that (1) lateral structures were more likely to be displaced in cases of intermediate ventriculomegaly (FHR < 0.4) using all 3 trajectories, whereas (2) the fornix was less likely to be displaced using more posteriorly placed trajectories for severe ventriculomegaly (FHR > 0.4). Allowing for minimal (2.4 mm) tissue displacement, a more posterior entry point was less traumatic for severe ventriculomegaly.

CONCLUSIONS

There is no single best ETV trajectory that fully avoids displacement of the eloquent periventricular structures. Larger ventricles require a more posteriorly placed entry point in order to reduce injury to the eloquent structures, and intermediate ventricles would dictate a medial entry point. These results suggest that the optimal entry point should be selected on a case-by-case basis after incorporating ventricle size.

Comparison of Intracranial Neuroendoscopic Procedures in Children versus Adults

BACKGROUND

The emphasis regarding intracranial neuroendoscopy has been traditionally advocated and focused on the role in pediatric patients, although a significant usage has developed in adult patients. In this study, we examine and contrast the role of predominantly intracranial neuroendoscopy in both a pediatric and adult population with a minimum postprocedure follow-up of 5 years.

METHODS

A retrospective review was conducted for patients in the two hospitals that manage neurosurgical care for Southern Alberta, Canada, undergoing neuroendoscopic surgery between 1994 and 2008. The pediatric group was defined as age ≤17 years and the adult group as age ≥18 years.

RESULTS

A total of 273 patients who underwent a total of 330 procedures with a mean postprocedure follow-up of 12.9 years were identified. There were 161 adult and 112 pediatric patients, and both groups underwent surgery by the same surgeons. The most common procedure was endoscopic third ventriculostomy, accounting for 55% of procedures. One postoperative death occurred in an adult patient. Endoscopic third ventriculostomy success 1-year postprocedure was 81%, with only three late-term failures. Postoperative infection was the most common serious complication (two pediatric/four adult patients). Adult and pediatric patients had similar major complication rates (4.2% vs 5.7%, p=0.547).

CONCLUSIONS

Neuroendoscopy overall had a similar role in both pediatric and adult neurosurgical populations, with the most commonly associated complication being infection. Neuroendoscopy is an important therapeutic modality in the management of appropriate adult patients.

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 (ETV) for idiopathic normal pressure hydrocephalus (iNPH)

BACKGROUND

Idiopathic normal pressure hydrocephalus (iNPH) is a type of communicating hydrocephalus also known as non-obstructive hydrocephalus. This type of hydrocephalus is caused by impaired cerebrospinal fluid reabsorption without any obstruction in the ventricular system and is associated with normal cerebrospinal fluid pressure. It is characterised clinically by gait disturbance, cognitive dysfunction, and urinary incontinence (known as the Hakim-Adams triad). The exact cause of iNPH is unknown. It may be managed conservatively or treated surgically by inserting a ventriculoperitoneal (VP) or ventriculoatrial (VA) shunt. However, a substantial number of patients do not respond well to surgical treatment, complication rates are high and there is often a need for further surgery. Endoscopic third ventriculostomy (ETV) is an alternative surgical intervention. It has been suggested that ETV may lead to better outcomes, including fewer complications.

OBJECTIVES

To determine the effectiveness of ETV for treatment of patients with iNPH compared to conservative therapy, or shunting of CSF using VP or VA shunts.To assess the perioperative and postoperative complication rates in patients with iNPH after ETV compared to conservative therapy, VP or VA shunting.

SEARCH METHODS

We searched for eligible studies using ALOIS: a comprehensive register of dementia studies, The Cochrane Central Register of Controlled Trials (CENTRAL) and several bibliographic databases such as MEDLINE (Ovid SP), EMBASE (Ovid SP), PsycINFO (Ovid SP), CINAHL (EBSCOhost) and LILACS (BIREME).We also searched the Database of Abstracts of Reviews of Effects (DARE) to identify potentially relevant reviews. The search strategy was adapted for other databases, using the most appropriate controlled vocabulary for each. We did not apply any language or time restrictions. The searches were performed in August 2014.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of ETV treatment of iNPH. Patients had to have at least two symptoms of the Hakim-Adams triad. Exclusion criteria were obstructive causes of hydrocephalus, other significant intracranial pathology and other confirmed causes of dementia. The eligible comparators were conservative treatment or shunting using VP and VA shunts.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results, selected eligible studies, assessed risk of bias and extracted data. We contacted trial authors for additional data.

MAIN RESULTS

Only one study met the inclusion criteria: an RCT comparing effectiveness of ETV and non-programmable VP shunts in 42 patients with iNPH. The study was conducted in Brazil between 2009 and 2012. The overall study risk of bias was high. The primary outcome in the study was the proportion of patients with improved symptoms one year after surgery, determined as a change of at least two points on the Japanese NPH scale. Due to imprecision in the results, it was not possible to determine whether there was any difference between groups in the proportion of patients who improved 3 or 12 months after surgery (3 months: odds ration (OR) 1.12, 95% confidence interval (CI) 0.26 to 4.76, n = 42; 12 months: OR 2.5, 95% CI 0.62 to 10.11, n = 38). We were unable to estimate the effect of treatment on other efficacy outcomes (cognition, balance, function, gait and mobility) because they were inadequately reported. Of the 26 patients in the VP shunting group, 5 developed subdural hematoma postoperatively, while there were no complications among the 16 patients in the ETV group (OR 0.12, 95% CI 0.01 to 2.3, n = 42), but the estimate was too imprecise to determine whether this was likely to reflect a true difference in complication rates. This was also the case for rates of further surgical intervention (OR 1.4, 95% CI 0.31 to 6.24, n = 42). There were no deaths during the trial. We judged the quality of evidence for all outcomes to be very low because of a high risk of selection, attrition and reporting bias and serious imprecision in the results.

AUTHORS' CONCLUSIONS

The only randomised trial of ETV for iNPH compares it to an intervention which is not a standard practice (VP shunting using a non-programmable valve). The evidence from this study is inconclusive and of very low quality. Clinicians should be aware of the limitations of the evidence. There is a need for more robust research on this topic to be able to determine the effectiveness of ETV in patients with iNPH.

Optimized surgical treatment for normal pressure hydrocephalus: comparison between gravitational and differential pressure valves

OBJECTIVES

In idiopathic normal pressure hydrocephalus (NPH) ventriculoperitoneal (VP) shunt insertion is the method of choice to improve cardinal symptoms such as gait disturbance, urge incontinence and/or dementia. With reduced compliance, the brain of the elderly is prone for overdrainage complications. This was especially true with the use of differential pressure valve implantation. The present study compares clinical outcome and complication rates after VP shunt insertion with differential pressure valves in the early years and gravitational valves since 2005.

METHODS

The authors reviewed patients treated at our institution for NPH since 1995. Differential pressure valves were solely used in the initial years, while the treatment regimen changed to gravitational valves in 2005. Clinical improvement/surgical success rates as well as complications were compared between the two groups.

RESULTS

Eighty-nine patients were enrolled for the present study. Mean age at the time of surgery was 73.5 ± 6.3 years. Male patients predominated with 73, compared with 16 female patients. Median follow-up time was 28 ± 26 months. Date of last follow-up was 1st October 2013. Forty-nine patients received a gravitational valve, while 40 were treated with differential pressure valves. In the gravitational group a significant improvement was observed after shunt insertion for gait disorder, cognitive impairment and urge incontinence (p < 0.0001, resp. p = 0.004), while a significant change in the differential pressure group was only seen for gait disorder (p = 0.03) but not for cognition or urinary incontinency (p > 0.05). The risk of hygroma as a sign of shunt overdrainage requiring surgical intervention was significantly higher in the differential pressure group (5 versus 0 in the gravitational group).

CONCLUSIONS

Patients with NPH treated with gravitational valves in the present cohort showed a more profound improvement in their initial symptoms, including gait disorder, cognitive impairment and urinary incontinency without the risk of overdrainage complications requiring surgical intervention when compared with patients who received differential pressure valves in previous years.

Obliteration of the choroid plexus after endoscopic coagulation

OBJECT

Endoscopic choroid plexus coagulation (CPC) with or without endoscopic third ventriculostomy (ETV) has been shown to be effective for selected patients with hydrocephalus. However, whether the effect of the coagulation is temporary and the choroid plexus regenerates or can be obliterated has remained largely unknown. The authors evaluate the effectiveness of CPC and report 3 cases of obliteration demonstrated by direct endoscopic observation.

METHODS

The authors retrospectively analyzed the surgical results of patients with hydrocephalus primarily treated by CPC with or without ETV. Charts were reviewed for demographic data, clinical presentations, surgical therapies, and clinical outcomes.

RESULTS

Eighteen patients with hydrocephalus were surgically treated using endoscopic CPC between July 2002 and July 2012. In 12 patients, ETV was concurrently performed. The etiology of hydrocephalus was posthemorrhagic in 5 patients, myelomeningocele in 3, postmeningitis in 2, congenital aqueductal stenosis in 1, hydranencephaly in 1, porencephaly in 1, and idiopathic in 5. The mean age at surgery was 8 months (range 0.3-24 months). The mean follow-up was 64 months. In 9 cases (50%), control of hydrocephalus was successful and the patients did not require further surgeries. In 9 patients (50%), treatment failed. Of these, 3 patients underwent repeat ETV 2, 3, and 38 months after the initial surgery. Endoscopic observation of the previous coagulation site revealed no regeneration of the choroid plexus in 2 patients, who underwent repeat ETV 2 and 3 months after CPC. In 1 patient who underwent repeat ETV 38 months after CPC, no regeneration of the choroid plexus, except for that in the proximity of the foramen of Monro, was observed.

CONCLUSIONS

Endoscopic CPC with or without ETV can be a safe and effective treatment alternative to shunt placement in infantile hydrocephalus. Obliteration of the choroid plexus can persist in the relatively long term following CPC, which may contribute to the long-term control of hydrocephalus in successful cases.

A modified method to enhance the safety of endoscopic third ventriculostomy (ETV)--transendoscopic pulse-waved microvascular Doppler-assisted ETV, technical note

INTRODUCTION

Endoscopic third ventriculostomy (ETV) is a simplified treatment relative to shunting for several types of hydrocephalus. The fatal complication of ETV is intraoperative hemorrhage due to arterial injury of the basilar artery, posterior cerebral arteries, and their perforators.

MATERIAL AND METHODS

Here, we present a modified technique of ETV by using a transendoscopic pulse-waved microvascular Doppler probe and videoscope head to avoid vascular injury behind the tuber cinereum (TC). The microvascular Doppler probe can detect the basilar artery complex through the TC.

CONCLUSION

Ventriculostomy with the probe head helps prevent vascular injury by informing the presence of invisible vessels under endoscopic view during perforation, and the method introduced here is certain to prove invaluable for enhancing the safety of ETV.

Updated physiology and pathophysiology of CSF circulation--the pulsatile vector theory

INTRODUCTION

Hydrocephalus is still a not well-understood diagnostic and a therapeutic dilemma because of the lack of sufficient and comprehensive model of cerebrospinal fluid circulation and pathological alterations.

CONCLUSIONS

Based on current studies, reviews, and knowledge of cerebrospinal fluid dynamics, brain water dynamics, intracranial pressure, and cerebral perfusion physiology, a new concept is deducted that can describe normal and pathological changes of cerebrospinal fluid circulation and pathophysiology of idiopathic intracranial hypertension.

Inferior Short-term Safety Profile of Endoscopic Third Ventriculostomy Compared With Ventriculoperitoneal Shunt Placement for Idiopathic Normal-Pressure Hydrocephalus

BACKGROUND:

In small series, endoscopic third ventriculostomy (ETV) has been shown to potentially have efficacy similar to that of ventriculoperitoneal shunting (VPS) for idiopathic normal-pressure hydrocephalus (iNPH). Therefore, some clinicians have advocated for ETV to avoid the potential long-term complications associated with VPS. Complication rates for these procedures vary widely based on limited small series data.

OBJECTIVE:

We used a nationwide database that provides a comprehensive investigation of the perioperative safety of ETV for iNPH compared with VPS.

METHODS:

We identified discharges with the primary diagnosis of iNPH (International Classification of Diseases, Ninth Revision code 331.5 [ICD-9]) with ICD-9 primary procedure codes for VPS (02.34) and ETV (02.2) from 2007 to 2010. We analyzed short-term safety outcomes using univariate and hierarchical logistic regression analyses.

RESULTS:

There were a total of 652 discharges for ETV for iNPH and 12 845 discharges for VPS for iNPH over the study period. ETV was associated with a significantly higher mortality (3.2% vs 0.5%) and short-term complication (17.9% vs 11.8%) rates than VPS despite similar mean modified comorbidity scores. On multivariate analysis, ETV alone predicted increased mortality and increased length of stay when adjusted for other patient and hospital factors.

CONCLUSION:

This is the first study that robustly assesses the perioperative complications and safety outcomes of ETV for iNPH. Compared with VPS, ETV is associated with higher perioperative mortality and complication rates. This consideration is important to weigh against the potential benefit of ETV: avoiding long-term shunt dependence. Prospective, randomized studies are needed.

Safety and efficacy of gravitational shunt valves in patients with idiopathic normal pressure hydrocephalus: a pragmatic, randomised, open label, multicentre trial (SVASONA)

OBJECTIVES

To investigate whether gravitational valves reduce the risk of overdrainage complications compared with programmable valves in ventriculoperitoneal (VP) shunt surgery for idiopathic normal pressure hydrocephalus (iNPH).

BACKGROUND

Patients with iNPH may benefit from VP shunting but are prone to overdrainage complications during posture changes. Gravitational valves with tantalum balls are considered to reduce the risk of overdrainage but their clinical effectiveness is unclear.

METHODS

We conducted a pragmatic, randomised, multicentre trial comparing gravitational with non-gravitational programmable valves in patients with iNPH eligible for VP shunting. The primary endpoint was any clinical or radiological sign (headache, nausea, vomiting, subdural effusion or slit ventricle) of overdrainage 6 months after randomisation. We also assessed disease specific instruments (Black and Kiefer Scale) and Physical and Mental Component Scores of the Short Form 12 (SF-12) generic health questionnaire.

RESULTS

We enrolled 145 patients (mean (SD) age 71.9 (6.9) years), 137 of whom were available for endpoint analysis. After 6 months, 29 patients in the standard and five patients in the gravitational shunt group developed overdrainage (risk difference -36%, 95% CI -49% to -23%; p<0.001). This difference exceeded predetermined stopping rules and resulted in premature discontinuation of patient recruitment. Disease specific outcome scales did not differ between the groups although there was a significant advantage of the gravitational device in the SF-12 Mental Component Scores at the 6 and 12 month visits.

CONCLUSIONS

Implanting a gravitational rather than another type of valve will avoid one additional overdrainage complication in about every third patient undergoing VP shunting for iNPH.

Tuber cinereum proximity to critical major arteries: a morphometric imaging analysis relevant to endoscopic third ventriculostomy

BACKGROUND

Arterial bleeding in the interpeduncular fossa is a dreaded complication of endoscopic third ventriculostomy (ETV). When the "safe zone" of the tuber cinereum (TC) is fenestrated, the basilar artery tip (BT) or its branches may be encountered below the third ventriclular floor. Major arterial injuries might be avoided by careful preoperative planning. We aimed to establish previously unavailable normal magnetic resonance imaging (MRI) and MR angiographic (MRA) morphometry and configuration of the BT and posterior cerebral artery P1 segments relative to the TC.

METHODS

We analyzed images of 82 patients with non-dilated ventricles (mean Evans' index 0.26), and lying in a neutral head position (mean cervico-medullary angle 141°). We cross-referenced axial MRAs with sagittal MRIs to measure distances of BT and P1 segments from the TC, and to classify the location of the BT in the interpeduncular and suprasellar cisterns. We correlated the sagittal areas of these cisterns and patients' ages with the TC-to-artery distances using regression analysis.

RESULTS

The BT, right P1 and left P1 segments were a mean 4.9 mm, 5.5 mm, and 5.7 mm respectively from the TC. Seventy-four percent of BTs were anterior to the mammillary bodies. These distances and locations did not correlate with age (mean 53 years) or size of basal cisterns.

CONCLUSIONS

The normal BT and P1 segments are anatomically close to the TC and potentially at risk during ETV in adults of all ages. The new morphometric data presented, along with cross-referencing of preoperative multiplanar images, could help reduce vascular complications during ETV.

Adjustment of the endoscopic third ventriculostomy entry point based on the anatomical relationship between coronal and sagittal sutures

Object

The coronal suture is often used as an empirical landmark for the entry point for endoscopic third ventriculostomy. The trajectory for the approach is often drawn based on midsagittal MRI findings. However, because the coronal suture is not perpendicular to the midline, this method may be inaccurate.

Methods

The junction of the coronal and sagittal sutures was exposed at the outer table of the cranium of 15 cadavers. An ideal coronal line was established perpendicular to the sagittal suture at the junction of the sagittal and coronal sutures. The distance from this ideal coronal line at the level of the coronal-sagittal junction to the actual coronal suture was measured at 1-cm intervals. The measured distance between the 2 planes was termed the distance to the coronal suture.

Results

The coronal suture bows forward as it moves from medial to lateral. From 1–6 cm lateral to the sagittal suture, the distance to the coronal suture was 0.1, 0.3, 0.5, 0.8, 1.0, and 1.4 cm, respectively. There was no significant difference between the right and left sides.

Conclusions

The position of a bur hole for endoscopic third ventriculostomy should be moved posteriorly with respect to the coronal suture the more laterally it is placed. Although the adjustment is small, it may be crucial. Failure to make this adjustment may result in suboptimal bur hole placement and increase the risk of morbidity.

Ventriculoperitoneal shunting versus endoscopic third ventriculostomy in the treatment of patients with hydrocephalus related to metastasis

Background:

Between 2005 and 2010, we treated patients with hydrocephalus related to cerebral metastases, who were not good candidates for surgical resection by either endoscopic third ventriculostomy (ETV) or ventriculoperitoneal shunting (VPS). Patients were excluded from ETV if they had a clinical history suggestive of non-obstructive hydrocephalus, including: (1) history of infection or ventricular hemorrhage and (2) leptomeningeal carcinomatosis. The rest of the patients were treated with VPS.

Methods:

We analyzed the clinical outcome of these patient cohorts, to determine whether the efficacy of VPS was compromised due to a history of infection, ventricular hemorrhage, or leptomeningeal carcinomatosis, and compared these results to those patients who underwent ETV.

Results:

Sixteen patients were treated with ETV and 36 patients were treated with VPS. The overall efficacy of symptomatic palliation was comparable in the ETV and VPS patients (ETV = 69%, VPS = 75%). In both groups, patients with more severe hydrocephalic symptoms such as nausea, vomiting, and lethargy were more likely to benefit from the procedure. The overall complication rate for the two groups was comparable (ETV = 12.6%, VPS = 19.4%), although the spectrum of complications differed. The overall survival, initial Karnofsky performance status (KPS), and three-month KPS, were similarly comparable (median survival: ETV 3 months, VPS 5.5 months; initial KPS: ETV = 66 ± 7, VPS = 69 ± 12; 3 months KPS: ETV = 86 ± 7, KPS = 84 ± 12).

Conclusion:

VPS remains a reasonable option for poor RPA grade metastasis patients with hydrocephalus, even in the setting of a previous infection, hemorrhage, or in those with leptomeningeal disease. Optimal treatment of this population will involve the judicious consideration of the relative merits of VPS and ETV.

Success criteria in pediatric neuroendoscopic procedures. Proposal for classification of results after 67 operations

PURPOSE

Controversial issues exist concerning criteria for patient selection and long-term success in pediatric neuroendoscopic procedures. We designed a classification of success grades applicable to high-pressure and chronic hydrocephalus and also to those cases in which different endoscopic maneuvers are performed during the same procedure. We then evaluated the success rate and complications in our series.

METHODS

A total of 59 patients underwent 67 neuroendoscopic procedures between January 2003 and January 2011. A retrospective study was made of the preoperative history, operative reports, and postoperative imaging findings and medical records. A 5-grade scale was developed to assess the type of success depending on clinical and radiological data. Complications related to the surgical procedure were also recorded.

RESULTS

Two patients were excluded from the success analysis due to insufficient follow-up time. The final results for the first procedures in 57 patients were complete and permanent success (grade I) in 49.1%, complete but transitory success (grade II) in 10.5%, partial success (grade III) in 12.3%, doubtful success (grade IV) in 5.3%, and failure (grade V) in 22.8%. In eight cases a second procedure followed the failure of the first: grade I success was achieved in seven cases (87.5%) and grade V in one case (12.5%). The highest success rates were achieved in cases of hydrocephalus caused by tumors or arachnoid cysts and the lowest in slit ventricle syndrome.

CONCLUSIONS

A common classification of degrees of success, such as that proposed here, would aid the development of comparative and cooperative studies.

Indication for endoscopic third ventriculostomy

BACKGROUND

Endoscopic third ventriculostomy (ETV) is increasingly prevalent among pediatric neurosurgeons as the initial treatment for hydrocephalus. The combination of ETV and choroid plexus cauterization (ETV/CPC) has improved the success rate among infants with hydrocephalus for whom ETV alone is much less successful. In parts of the developing world where there are economic and human resource constraints, this mode of treatment may be more appropriate than the routine use of shunts, which are prone to failures that require urgent surgical treatment. Here we review indications for the use of ETV or ETV/CPC as the primary treatment for hydrocephalus.

CONCLUSION

Primary treatment of hydrocephalus by ETV can avoid shunt-dependence and its complications for many patients. Optimal results depend upon proper patient selection and the use of combined ETV/CPC when treating infants.

Histological analysis of the third ventricle floor in hydrocephalic and nonhydrocephalic brains: application to neuroendocrine complications following third ventriculostomy procedures

OBJECT

Endocrine dysfunction following endoscopic third ventriculostomy (ETV) is rare, but it has been reported. In the present study the authors sought to determine the histological nature of the floor of the third ventricle in hydrocephalic brains to better elucidate this potential association.

METHODS

Five adult cadaveric brains with hydrocephalus were examined. Specifically, the floors of the third ventricle of these specimens were studied histologically. Age-matched controls without hydrocephalus were used for comparison.

RESULTS

Although it was thinned in the hydrocephalic brains, the floor of the third ventricle had no significant difference between the numbers of neuronal cell bodies versus nonhydrocephalic brains.

CONCLUSIONS

Although uncommon following ETV, endocrine dysfunction has been reported. Based on the present study, this is most likely to be due to the injury of normal neuronal cell bodies found in this location, even in very thinned-out tissue.

The constant flow ventricular infusion test: a simple and useful study in the diagnosis of third ventriculostomy failure

Object

The evaluation of third ventriculostomy function in hydrocephalic patients is challenging. The utility of the constant flow infusion test in predicting response to shunt insertion in normal-pressure hydrocephalus, as well as in identifying shunt malfunction, has been previously demonstrated. The object of this study was to evaluate its usefulness in determining whether a revision CSF diversion procedure was indicated in patients presenting with recurring symptoms and persisting ventriculomegaly after endoscopic third ventriculostomy (ETV).

Methods

The authors conducted a prospective study of all patients who, after undergoing ETV at their institution, presented postoperatively with recurring symptoms and persisting ventriculomegaly.

Results

Forty-six patients (mean age 40.7 years, including 11 patients younger than 18 years) underwent 56 constant flow ventricular infusion tests (VITs) at a mean of 24.7 months post-ETV. Thirty-three patients with resistance to CSF outflow (Rout) less than 13 mm Hg/ml/min underwent follow-up (median 17 months) and experienced resolution of symptoms. In 10 episodes Rout was greater than 13 mm Hg/ml/min; the patients in these cases underwent revisional CSF diversion. Two patients demonstrated high and frequent B (slow) waves despite a low Rout; these patients also underwent successful revisions. Patients who improved after surgery had increased B wave activity in the plateau phase of the VIT (p = 0.01). Thirty-four patients underwent MR imaging at the same time; 4 had high Rout despite evidence of flow across the stoma. These 4 patients underwent surgery and experienced resolution of symptoms. Of 9 patients without flow, Rout was less than 13 mm Hg/ml/min in 4; these patients were successfully treated conservatively.

Conclusions

The VIT is a useful and safe adjunct to clinical and MR imaging evaluation when ETV failure is suspected.

Complications of endoscopic third ventriculostomy: a systematic review

INTRODUCTION

Endoscopic third ventriculostomy (ETV) is an established treatment for hydrocephalus. Most studies focus on success rates, and complications are insufficiently charted. The aim of this study was to perform a systematic review of ETV complications.

METHODS

A Medline search discovered 24 series of ETV (seven in children, five in adults, and 12 in a mixed-age group) with detailed complications reports.

RESULTS

The analysis included 2,672 ETVs performed on 2,617 patients. The cause of hydrocephalus was aqueductal stenosis in 25.9%, tumor 37.0%, meningomyelocele-Chiari II 6.1%, posthemorrhagic 5.8%, postinfectious 1.4%, cysts 3.3%, Chiari I 0.4%, Dandy-Walker malformation 0.3%, cerebellar infarct 0.9%, normal pressure hydrocephalus 1.3%, and not recorded 16.8%. Overall complication rate was 8.8%. Permanent morbidity was 2.1%, neurologic in 1.2% (hemiparesis, gaze palsy, memory disorders, and/or altered consciousness), hypothalamic in 0.9% (diabetes insipidus, weight gain, or precocious puberty). Intraoperative hemorrhage was present in 3.9%, severe in 0.6% (including four cases [0.14%] of basilar rupture). Other surgical complications were 1.13% (three thalamic infarcts, six subdural, six intracerebral, and two epidural hematomas). Cerebrospinal fluid (CSF) infections occurred in 1.8%, CSF leak in 1.7%, anesthetic complications (bradycardia and hypotension) in 0.19% of cases. Postoperative mortality was 0.22% (six patients; sepsis two, hemorrhage three, and thalamic injury one). Another two children suffered delayed "sudden death" (after 25 and 60 months), caused by acute hydrocephalus due to stoma occlusion. There were no differences between pediatric and adult patients or short and long series (cutoff 100 patients). All deaths were reported in long series. Complication rates were insignificantly higher in short series.

CONCLUSIONS

Permanent morbidity after ETV is 2.1%, mortality is 0.22%. The incidence of delayed "sudden death" is 0.07%.

Neuroendoscopic diagnosis of central nervous system histoplasmosis with basilar arachnoiditis

OBJECTIVE

Histoplasmosis of the central nervous system (CNS) is seen in 10% to 20% of patients with disseminated histoplasmosis and/or in association with immunocompromised patients. Meningitis, arachnoiditis, and hydrocephalus are the most common clinical manifestations of CNS histoplasmosis. Patients with CNS histoplasmosis present similarly to other infectious etiologies, and confirmatory diagnosis is important in the management of these patients. However, diagnosis of CNS histoplasmosis can be difficult, and sometimes performing a parenchymal biopsy is necessary to confirm the diagnosis.

METHODS AND RESULTS

We describe the case of a 41-year-old man with HIV/AIDS who presented with the signs, symptoms, and radiologic evidence of basal meningitis and hydrocephalus. Cerebrospinal fluid (CSF) analysis from multiple lumbar punctures was negative. The patient underwent a neuroendoscopic procedure with diagnostic and therapeutic goals. Internal CSF diversion (endoscopic third ventriculostomy) and biopsy of the floor of the third ventricle and subarachnoid space were performed; surgical biopsies identified noncaseating granulomas, and ventricular CSF was positive for Histoplasmosis antibodies. The patient was treated with liposomal amphotericin B and itraconazole. The patient had resolution of his symptoms immediately after surgery, and 1-month follow-up computed tomography of the head demonstrated resolution of the hydrocephalus. At the last follow-up 12 months postoperatively, the patient has not required insertion of a ventriculoperitoneal shunt.

CONCLUSION

Clinicians should maintain a high index of suspicion for fungal basal meningitis in patients with AIDS and hydrocephalus. With nondiagnostic lumbar CSF sampling, neuroendoscopy can be considered as an alternative for diagnosis and treatment of basal meningitis and hydrocephalus.

Role of computerized tomographic cisternography in idiopathic normal pressure hydrocephalus

BACKGROUND

We prospectively evaluate the role of computerized tomographic cisternography (CTC) in idiopathic normal pressure hydrocephalus (iNPH).

METHODS

The cerebrospinal fluid kinetics of 70 patients who passed the entry criteria for the Study of iNPH on Neurological Improvement (SINPHONI) and underwent insertion of a shunt were studied.

RESULTS

Stasis of the contrast medium at the lateral ventricles over 24 h (positive ventricular stasis) was observed in 60 patients and at the Sylvian fissure or parietal sulci over 48 h (positive surface stasis) in 59 patients. Sixty patients showed a good response to shunt insertion. The sensitivities of CTC findings at the lateral ventricles and brain surface for shunt effectiveness were 81.7 and 86.7%, respectively; however, the specificities were 20 and 0%. Among the 60 patients who showed a good response to the shunt, 49 had positive surface stasis. Positive ventricular stasis was observed in 52 of the 60 patients, and both findings were observed in 44 patients. Three patients who responded to the shunt had negative stasis in both sites. The 11 patients who had negative surface stasis had significantly lower (p < 0.05) preoperative iNPH grading scale-R scores than the 49 patients with positive surface stasis; these patients were considered to be in an early stage of iNPH.

CONCLUSIONS

CTC did not provide additional diagnostic value for predicting the shunt response among patients selected using SINPHONI criteria. We suggest that factors other than disturbances in CSF circulation may be related to the pathogenesis of iNPH.

Complications of endoscopic third ventriculostomy

OBJECT

Endoscopic third ventriculostomy (ETV) is an established treatment for hydrocephalus. Most studies focus on success rate, and complications are insufficiently documented. The aim of this study was to perform a systematic review of ETV complications.

METHODS

A Medline search discovered 34 series of ETV with detailed complications reports (17 series involving exclusively pediatric patient populations, 6 series involving exclusively adults, and 11 series involving mixed adult and pediatric populations).

RESULTS

The analysis included 2985 ETVs performed in 2884 patients. The cause of hydrocephalus was aqueductal stenosis in 29.3% of patients, tumor in 37.6%, meningomyelocele in 7.6%, cysts in 2.6%, cerebellar infarct in 0.9%, Dandy-Walker malformation in 0.6%, and Chiari malformation Type I in 0.4%; 7.4% of the patients had posthemorrhagic hydrocephalus, 1.8% had postinfectious hydrocephalus, and 1.2% had normal pressure hydrocephalus. Hydrocephalus was due to other causes in 1.3% of cases and the cause was not reported in 9.8%. The overall complication rate was 8.5%. The rate of permanent morbidity was 2.38%; the rate of permanent neurological complications was 1.44% (hemiparesis, gaze palsy, memory disorders, altered consciousness), and the rate of permanent hormonal morbidity was 0.94% (diabetes insipidus, weight gain, precocious puberty). The rate of intraoperative hemorrhage rate was 3.7%; the rate of severe intraoperative hemorrhage was 0.6% (including a 0.21% rate of basilar rupture). The rate for intraoperative neural injury (thalamic, forniceal, hypothalamic, and midbrain injuries) was 0.24%. Central nervous system infections occurred in 1.81% of cases, CSF leak in 1.61%, and postoperative intracranial hematomas in 0.81% of cases. The early postoperative mortality rate was 0.21% (6 patients died; 2 of sepsis and 4 of hemorrhage). Another 2 children suffered delayed "sudden death" (one after 25 months and the other after 60 months), caused by acute hydrocephalus due to stoma occlusion. There were no significant differences between series involving pediatric or adult patient populations or series with fewer than 100 or more than 100 patients. All reported deaths were in series involving more than 100 patients.

CONCLUSIONS

Endoscopic third ventriculostomy can be regarded as a low-complication procedure, with an overall complication rate of 8.5%, permanent morbidity rate of 2.4%, mortality rate of 0.21%, and delayed "sudden death" rate of 0.07%.