Endoscopic third ventriculostomy in patients with cerebrospinal fluid infection and/or hemorrhage

LASER-ASSISTED ENDOSCOPIC THIRD VENTRICULOSTOMY

OBJECTIVE

Endoscopic third ventriculostomy is a well-known surgical option in the treatment of noncommunicating hydrocephalus. We studied complications and long-term success in 202 patients to demonstrate the safety and efficacy of laser-assisted endoscopic third ventriculostomy (LA-ETV) using a unique “black” fiber tip/diode laser combination for controlled tissue ablation.

METHODS

We studied 213 LA-ETVs, which were performed in 202 patients. Patients' ages ranged from 2 days to 83 years (mean age, 27 yr). The mean follow-up period for all patients was 2.7 years (range, 2 d to 12 yr). Hydrocephalus was caused by aqueductal stenosis in 65 patients, tumors in 67 patients, hemorrhages in 24 patients, myelomeningoceles in 20 patients, cysts in 15 patients, and other causes in 11 patients. The long-term effectiveness of LA-ETV was studied with Kaplan-Meier analysis.

RESULTS

Technically successful LA-ETVs were accomplished in 196 of the 202 patients (97%). The overall success rate for a functional LA-ETV was 68% at the 2-year follow-up evaluation. LA-ETV was more effective in patients aged 1 year and older (70% success rate) than in younger patients (59% success rate). Success rates were greater in patients with aqueductal stenosis or tumors as compared to other etiologies. Complications occurred in 22 procedures (10.3%). Only one patient (0.5%) experienced a major complication. No surgical mortalities or laser-related complications occurred.

CONCLUSION

This study demonstrates that LA-ETV is a safe and effective procedure that is comparable to other techniques for ETV. LA-ETV is most effective in patients aged 1 year and older and in patients with aqueductal stenosis and tumors, with a low major complication rate.

Hydrocephalus in children born in 1999-2002: epidemiology, outcome and ophthalmological findings

OBJECTIVE

The purpose of this study was to monitor incidence and outcome in children with hydrocephalus.

MATERIALS AND METHODS

This is a population-based prospective study of all the children with hydrocephalus born in western Sweden in 1999-2002. Etiological and clinical information was collected from records, neuroimaging and ophthalmological examinations. Comparisons with 208 children born in 1989-1998 were made.

RESULTS

The incidence was 0.66 per 1,000 live births, 0.48 for infantile hydrocephalus and 0.18 for hydrocephalus associated with myelomeningocele. The corresponding rates for 1989-1998 were 0.82, 0.49 and 0.33. Ventriculo-peritoneal shunt treatment was used in 42 of the 54 children and endoscopic third ventriculostomy in 12. Revisions were performed in 33 (61%). Neurological impairments were present in 63%, and they were more common in children born preterm than in those born at term. The radiological extent of parenchymal lesions correlated significantly with outcome. Ophthalmological abnormalities were found in 80%, including visual impairment in one third.

CONCLUSION

The incidence of post-haemorrhagic hydrocephalus in children born extremely preterm increased; a group running a high risk of neurological sequelae. Ophthalmological abnormalities were frequent and need to be assessed in all children with hydrocephalus. The high rate of morbidity and complications necessitates the further development of preventive and treatment methods.

The role of Ommaya reservoir and endoscopic third ventriculostomy in the management of post-hemorrhagic hydrocephalus of prematurity

OBJECTIVE

The aim of this study is to retrospectively evaluate a series of consecutive patients affected by post-hemorrhagic hydrocephalus in prematurity, treated with an implant of an Ommaya reservoir followed by ventriculo-peritoneal (VP) shunt and/or endoscopic third ventriculostomy (ETV) to evaluate the safety and efficacy of these treatment options in the management of the condition.

METHODS

Between 2002 and 2005, 18 consecutive premature patients affected by intra-ventricular haemorrhage (IVH) grades II to IV, presenting with progressive ventricular dilatation, were operated for implant of an intra-ventricular catheter connected to a sub-cutaneous Ommaya reservoir. Cerebrospinal fluid was intermittently aspirated percutaneously by the reservoir according with the clinical requirements and the echographic follow-up. The patients who presented a progression of the ventricular dilatation were finally operated for VP shunt implant or ETV according with the MRI findings.

RESULTS

One patient had grade II, 5 had grade III, and 12 had grade IV IVH. The mean age at IVH diagnosis was 5.2 days; the mean age at reservoir implant was 17.3 days. The Ommaya reservoir was punctured on an average basis of 11.4 times per patient (range 2-25), and the mean interval between aspirations was 2.7 days. The mean CSF volume per tap was 20 ml. One patient died for pulmonary complications during the study period. Out of the 17 survivors, 3 did not develop progressive ventricular dilatation, and their reservoir was removed; 14 developed progressive hydrocephalus, 5 of whom were implanted with a VP shunt and 9 received an ETV. Amongst the five shunted patients, two were re-admitted for shunt malfunction and had their shunt removed after ETV after 6.1 and 20.5 months, respectively. Amongst the nine patients who received an ETV, five had to be re-operated for VP shunt implant at an average interval of 2.17 months (range 9-172 days) because of increasing ventricular dilatation. Two of them had a redo third ventriculostomy with shunt removal at 11 and 25.1 months, respectively, after insertion. The first was reimplanted with a VP shunt 4 days later; the second remains shunt free. Therefore, at the end of the follow-up period, 10 out of 17 children affected by post-hemorrhagic hydrocephalus in prematurity were shunt free (59%).

CONCLUSIONS

The combination of Ommaya reservoir, VP shunt, and the aggressive use of ETV as a primary treatment or as an alternative to shunt revision allowed for a significant reduction of shunt dependency in a traditionally shunt-dependent population. Further studies are warranted to optimise the algorithm of treatment in these patients.

Factors affecting the outcome of neuroendoscopy in patients with tuberculous meningitis hydrocephalus: a preliminary study

BACKGROUND

In recent years, ETV has been found to be effective in patients with TBMH; however, its precise selection criteria are yet to be established. We carried out this study to identify the factors affecting the outcome of ETV in TBMH.

METHODS

Fourteen patients with TBMH (11 male patients and 3 female patients; mean age, 15.7 years; range, 9 months to 40 years) formed the study group. Various preoperative (clinical grade, ventricular morphology, basal exudates, and CNS tuberculoma) and perioperative (ependymal tubercles, third ventricular floor anatomy, exudates, and adhesions) factors were studied with regard to the result of ETV. Endoscopic third ventriculostomy could be performed on 13 patients; however, an unidentifiable third ventricular floor anatomy precluded ETV in the remaining patient. Endoscopic third ventriculostomy was assigned as "failed" if the patient needed shunt, required EVD, or died in the postoperative period. The average follow-up period for the patients was 5 months.

RESULTS

Endoscopic third ventriculostomy was successful in 9 of the 14 (64.2%) patients subjected to neuroendoscopy. Statistical analysis did not show any significant association of ventricular morphology (P = .109), basal enhancement on CT (P = .169), CNS tuberculoma (P = .169), and clinical grade (P = .057) with the result of ETV, probably because of the small number of cases. However, patients with severe hyponatremia, extra-CNS tuberculosis, an unidentifiable third ventricular floor anatomy, and adhesions in the prepontine cistern had a failed ETV. Patients with tuberculoma in the brain had a successful ETV.

CONCLUSIONS

Endoscopic third ventriculostomy is likely to fail in the presence of advanced clinical grade, extra-CNS tuberculosis, dense adhesions in prepontine cisterns, and an unidentifiable third ventricular floor anatomy. Tuberculoma in the brain in cases of TBMH may be associated with a successful ETV.

Complications following endoscopic intracranial procedures in children

BACKGROUND

The significant technological improvement of endoscopic instrumentation has allowed, in the last 10 years, a widespread diffusion of neuroendoscopic procedures. Nevertheless, severe, sometimes life-threatening, complications may occur during neuroendoscopic surgery, and the incidence and age specificity of complications in children have been underdescribed so far.

MATERIALS AND METHODS

Complications recorded in a prospectively collected database of pediatric patients undergoing neuroendoscopic procedures were analysed; the medical histories of the patients and the surgical procedures were reviewed.

RESULTS

Complications occurred in 32 out of 231 (13.8%) procedures performed for the management of obstructive hydrocephalus (137), multiloculated hydrocephalus (53), arachnoid cysts (29) and intraventricular tumors (12). Subdural hygroma occurred in 11 cases, seven requiring subdural shunting. In one of these cases, infection of the subdural space occurred and required a craniotomy. Cerebrospinal fluid (CSF) infection occurred in 11 cases. In one case, a frontal abscess developed and was managed with craniotomy. CSF leak occurred in nine cases, intraventricular haemorrhages in two, technical failures in seven, subcutaneous CSF collection (managed with lumbo-peritoneal shunt) in one, thalamic contusion and post-operative transient akinetic mutism in one. This patient suddenly died 6 months later, probably as a consequence of closure of the stoma. Two patients developed secondary compartmentalisation of the ventricles after complicated endoscopic third ventriculostomy. In nine cases, these complications were associated. Overall, no patient died after the procedure (operative mortality 0), one patient died 6 months after the procedure for unexplained events (sudden death rate 0.4%), and three patients presented permanent disability as a consequence of surgical complication (permanent morbidity 1.3%).

CONCLUSIONS

Complication rate of neuro-endoscopic procedures is not negligible even in experienced hands. The majority are minor complications which do not affect the final outcome, but sporadically major events may occur, leading to significant problems in surgical management and, occasionally, to permanent disabilities. Careful selection of patients on pre-operative imaging studies and intensive training of surgeons are mandatory to improve results.

Endoscopic Third Ventriculostomy in Pediatric Patients: The Canadian Experience

OBJECTIVE

Reports from relatively small series of pediatric patients predominantly from single centers have hampered accurate analysis of outcome from endoscopic third ventriculostomy. We combined patients from nine pediatric neurosurgery centers across Canada to obtain a better estimate of outcome and identify factors affecting success of the procedure.

METHODS

Databases were recoded for uniformity. Failure of the procedure was defined as any subsequent operation or death resulting from hydrocephalus. Time to failure was analyzed by Kaplan-Meier estimate and Cox proportional hazard analysis.

RESULTS

During a 15-year period (1989–2004), 368 patients underwent the procedure. The average age was 6.5 years, and 57% were male. Aqueduct stenosis and tumors were the most common etiology, comprising 34 and 29%, respectively. Twenty-two percent of the patients had been previously shunted. The 1- and 5-year success rates were 65 and 52%, respectively. Factors included in the Cox model were age, sex, etiology of hydrocephalus, previous surgery, center volume, and surgeon volume. By multivariate analysis, only age had a significant effect on outcome, with younger patients failing at higher rates, particularly neonates and infants.

CONCLUSION

Based on data from multiple Canadian centers, age seems to be the primary determinant of outcome in endoscopic third ventriculostomy in pediatric patients. Failure rates are particularly high in neonates and young infants; thus, the role of this procedure in this age group should be carefully considered.

Neuroendoscopic treatment of multiloculated hydrocephalus in children

OBJECT

The authors performed a retrospective analysis of data obtained in a series of 30 patients suffering from multiloculated hydrocephalus and treated endoscopically. The goal of the study was to evaluate the effectiveness of neuroendoscopic treatment as an alternative to the placement of multiple shunts to relieve intracranial hypertension, to simplify the shunt system, and to reduce the high rate of shunt revision.

METHODS

The endoscopic procedures included intraventricular septum fenestration, aqueductoplasty, Monro foraminoplasty, and third ventriculostomy. The patients were divided into two groups: Group A included 23 children in whom a shunt was already in place at the time of endoscopy, and Group B included seven children in whom a shunt had never been placed. The control of hydrocephalus by a single shunt placement or the absence of a shunt was achieved in 25 (83.3%) of 30 children. In Group A, five children no longer had shunts, 14 needed a single shunt, three required two shunts, and one required three shunts. The mean preendoscopy shunt revision rate in this group decreased from 2.07/year to 0.35/ year following the endoscopic procedure. Seven patients required endoscopic reoperations (endoscopic reoperation rate 0.31/year, total reoperation rate [shunt revisions plus endoscopic reoperation] 0.66/year). In Group B, three children did not require shunts, three needed a single shunt, and one required two shunts. Two patients required repeated endoscopic surgery (endoscopic reoperation rate 0.19/year), and two patients required shunt revisions (shunt revision rate 0.07/year) (total operation rate 0.26/year).

CONCLUSIONS

Neuroendoscopic procedures are a valid alternative to shunt revision in the management of multiloculated hydrocephalus. Early diagnosis comprising close monitoring with high-resolution magnetic resonance imaging and early treatment are the keys of success.

Analysis of the success and failure of endoscopic third ventriculostomy in infants less than 1 year of age

OBJECTIVES

In infants less than 1 year of age, the value of endoscopic third ventriculostomy (ETV) is controversial. It is believed to cause more morbidity and to have higher failure rates. We analyzed our data enlarging the reported pool of ETV outcome in infants less than 1 year of age.

MATERIALS AND METHODS

We performed 12 ETVs in ten patients younger than 1 year of age. All patients had predominant supratentorial hydrocephalus. We defined ETV success as a shunt-free follow-up of at least 12 months, however, allowing re-ETV.

CONCLUSION

ETV should be considered as initial treatment and carries low morbidity in these infants. As the immune system rapidly matures, postponing shunt implantation for several months or even weeks would make an ETV procedure worthwhile. On the other hand, as success probability rapidly increases 4 months after birth, re-ETV should always be considered first.

Endoscopy for tuberculous hydrocephalus

INTRODUCTION

The role of endoscopy in hydrocephalus due to infectious aetiology is unclear. Tuberculous hydrocephalus is a useful model to study because it presents particular challenges and the pathophysiology of the cerebrospinal fluid disturbance is well known.

MATERIALS AND METHODS

We present the results of 24 endoscopic operations in tuberculous meningitis.

RESULT

Endoscopic third ventriculostomy (ETV) was attempted in 17 patients: seven were successful, five failed, and five were not completed due to abnormal anatomy. There were five fenestration procedures, three of which were successful. Endoscopic biopsy of two tuberculomas failed to yield a bacteriological result. These operations were more difficult to perform than for hydrocephalus due to other aetiologies.

CONCLUSION

Although ETV is technically possible in this situation, it is imperative that the patients are adequately selected for the procedure to ensure optimal treatment and that the surgeon has experience with difficult cases.

[Recommendations of the European Stroke Initiative for the diagnosis and treatment of spontaneous intracerebral haemorrhage]

This article summarises the recommendations for the management of managing patients with intracerebral haemorrhage published in 2006 by the European Stroke Initiative (EUSI) on behalf of the European Stroke Council (ESC), the European Neurological Society (ENS), and the European Federation of Neurological Societies (EFNS).

Success and failure of endoscopic third ventriculostomy in young infants: are there different age distributions?

OBJECTIVE

Patient's age and etiology of hydrocephalus are the most important factors influencing the success rate of endoscopic third ventriculostomy (ETV). Failure rates are reported to be particularly high in the first year of age. On the basis of our own data and a metaanalysis of the literature, we try to further define the impact of age on ETV success in infants younger than 1 year.

MATERIALS AND METHODS

Only patients with a minimum follow-up of 12 months were considered. Between October 1994 and July 2004, 28 patients younger than 1 year underwent ETV in our institution. Age ranged from 8 to 311 days (median 96). The etiology of hydrocephalus was aqueductal stenosis (AS) in all patients (idiopathic in 13, posthemorrhagic in three, postmeningitic in four, and related to CNS or vascular malformation or to tumor in eight). ETV failure was defined as subsequent need for shunt implantation. The metaanalysis of the literature took into account reported series on ETV in infants with detailed data on age and etiology in every single patient.

RESULTS

In our own patients, ETV was successful in 13 patients and eventually failed in 15. In the ETV success group, the median age was 200 days and the mean age was 176 days (range 13-311 days). In the ETV failure group, the ages were 105 days (median), 117 days (mean), and 8-299 days (range). The differences were not statistically significant. Age distributions in both outcome groups showed a tendency of failures to occur more frequently in the first 2-4 months of life. The separate analysis of patients with idiopathic AS yielded similar figures and distributions. The data from the metaanalysis of the literature corresponded to our own results.

CONCLUSION

There is a clear impact of age on ETV failure rate even when excluding etiological factors. The probability of ETV success gradually increases during the first months of life. The consequence of these findings for decision-making as well as parental counseling is to try to weigh the age of the infant and its estimated impact on ETV success with other factors guiding the decision to perform ETV or shunt in the treatment of obstructive hydrocephalus.

The occurrence of obstructive vs absorptive hydrocephalus in newborns and infants: relevance to treatment choices

BACKGROUND AND OBJECTIVE

The classification of hydrocephalus in newborns and in infants is different from the classification in adulthood. This difference exists due to disparity in the source pathologies that produce the hydrocephalus, and the practical distinctions in prognosis and treatment choices. The objective of this paper is to present the spectrum of obstructive-communicating hydrocephalus, which is more complex in the pediatric group, and to propose the relevance of this particular classification to treatment options.

MATERIALS AND METHODS

The authors categorized infants with active hydrocephalus at time of presentation into the following four groups along the spectrum of communicating vs obstructive HCP. Group 1: patients with a purely absorptive (communicating) HCP. In these patients, tetraventricular dilatation is usually observed with occasional extraaxial fluid accumulation. An extracranial CSF diversion (shunt) is the treatment of choice. Group 2: patients with an obstructive component together with a persistent absorptive component. In these patients, a technically successful endoscopic procedure will not prevent progression of clinical symptoms of HCP. An extracranial CSF diversion (shunt) should be the treatment of choice even though some of these patients are currently treated by endoscopy. Group 3: patients with an obstructive component together with a temporary absorptive component. In these patients, a technically successful ETV should be followed by temporary CSF drainage [via LP, continuous spinal drainage (CLD), or ventriculostomy] with or without supplemental medical treatment (i.e., Diamox) for several days. Such temporary drainage may decrease failure rate in this subgroup. Group 4: patients with a purely obstructive HCP. In these patients, an endoscopic procedure (ETV) is the treatment of choice. According to this spectrum classification, the authors classify different entities with representative cases and discuss relevancy to treatment options and prognosis.

RESULTS

The data suggest that obstructive hydrocephalus in the very young population may be rather a combination of obstructive and absorptive problem. The outcome of the patient depends mainly not only on the basic pathology causing the hydrocephalus but also on the treatment that is chosen and its complications. While bleeding and infection represent the major causes for communicating hydrocephalus, patients with complex pathologies of congenital type and intra- or interventricular obstructions may reflect obstructive hydrocephalus. Treatment of these patients may be successful by shuntless procedures if the absorptive problem is not the major component. In transient absorptive hydrocephalus, temporary measures were effective in many cases leading to successful procedures of ETV and/or posterior-fossa decompression in selected cases.

CONCLUSIONS

Shuntless procedures are the dream of a pediatric neurosurgeon provided it solves the problem and does not imply unacceptable risk. However, the benefit has to be evaluated years after the procedure is performed, as only prospective multicenter studies will truly show which procedure may have the best overall results in the developing child. Until such studies are available, understanding the basic pathology or the combination of pathologies leading to hydrocephalus in a given child may open the window of opportunities for other than shunt surgery in many hydrocephalic children with major obstructive component.

The role of different imaging modalities: is MRI a conditio sine qua non for ETV?

OBJECTIVE

To describe the different imaging modalities used for the diagnosis and classification of hydrocephalus, their role in defining the optimal treatment of hydrocephalus and to define the optimal preoperative diagnostics for endoscopic third ventriculocisternostomy (ETV).

METHODS

An overview on available imaging modalities for hydrocephalus will be given and their pros and cons discussed. In addition, different aspects of the treatment of hydrocephalus by shunts and by ETV will be highlighted.

DISCUSSION

The role of the technical aspects of performing an ETV, the role of the surgeon's philosophy, the role of the urgency of the procedure, and the role of informed consent on the requirements for the imaging of the hydrocephalus will be discussed.

CONCLUSION

The authors conclude that MRI is a conditio sine qua non for ETV in elective surgical cases.

Is there an indication for ETV in young infants in aetiologies other than isolated aqueduct stenosis?

OBJECTIVES

The objective was to determine whether endoscopic third ventriculostomy (ETV) has a role in the management of obstructive hydrocephalus in aetiologies other than idiopathic aqueduct stenosis (AS) in infants.

MATERIALS AND METHODS

In addition to reviewing the literature, we performed a retrospective analysis of our endoscopy database, which was established in 1998, and analysed the outcome results of all cases of ETV in those under 1 year of age which were performed between 1998 and 2003. We included cases of idiopathic AS in the outcome analysis as a benchmark of successful outcome. Successful outcome was assessed by resolution of the presenting clinical features and shunt freedom.

RESULTS

Aetiologies that were identified included, in addition to idiopathic AS, suprasellar arachnoid cysts, AS in association with post-haemorrhagic hydrocephalus (PHH), post-infectious hydrocephalus (PIH), tumour-related hydrocephalus and a heterogenous group including Dandy-Walker malformation and other developmental anomalies. Suprasellar arachnoid cysts had a 100% outcome success. Idiopathic AS had a 50% outcome success and the successful outcome of PHH cases was poor at 18%. A statistical analysis revealed no effect of age at the time of ETV on the outcome in the aetiological groups.

CONCLUSIONS

The definitive initial neurosurgical management of suprasellar arachnoid cysts causing significant hydrocephalus is ETV, whereas that for PHH and PIH is probably that of a ventriculo-peritoneal shunt placement. We speculate that there may be a sub-group of AS cases, termed pure or idiopathic AS, which have a higher rate of successful outcome that may be durable from a younger age. The role of repeat ETV is controversial.

Assessment of the influence of operative factors in the success of endoscopic third ventriculostomy in children

OBJECTIVE

To determine if operative factors correlate with success of endoscopic third ventriculostomy (ETV) in the treatment of hydrocephalus.

MATERIALS AND METHODS

The ETV procedure video of 33 hydrocephalic children was reviewed. Mean age at operation was 76 months (range: 1-196). Success was defined as no need for shunt in the long term. We calculated the relative size of stoma as the percentage of stoma diameter to the distance between posterior clinoid-basilar artery. Factors analysed were: intra-operative haemorrhage, stoma size, thick/double third ventricular floor, pre-pontine adhesions presence, brisk cerebro-spinal fluid (CSF) flow through the stoma as well as hydrocephalus cause, previous shunt presence, CSF infection or haemorrhage and previous ETV. Analysis was performed using chi-square, linear regression, and one-way ANOVA.

RESULTS

Overall ETV success rate was 42%. Mean stoma size was 37%. For the entire group, none of the operative factors correlated statistically with success. Previous shunt presence adversely correlated with success (p=0.008). The highest success rate was in the aqueduct stenosis group. In patients without previous shunt (n=17), stoma size over 30% tended towards significance (p=0.094), CSF leak was adversely associated with ETV success (p=0.041) and mean stoma size was 41.3% in successful ETV and 27.8% in unsuccessful ETV (p=0.072). In patients with previous shunt (n=16), thin third ventricular floor was a negative predisposing factor (p=0.057).

CONCLUSION

This study did not demonstrate a correlation between the presence of pre-pontine adhesions, double or thickened floor of third ventricle and ETV success. In patients without previous shunt, stoma size may correlate with success. CSF leak was strongly associated with failure.

Evaluation and management of shunt infections in children with hydrocephalus

Shunt infections constitute one of the main risks of shunt surgery for hydrocephalus, which is the single most common type of surgery performed by pediatric neurosurgeons. Infectious complications are responsible for increased morbidity and mortality, lengthy hospitalizations, and high cost. Most modern series report infection rates approaching 10% of all shunt procedures. Despite the high incidence of this complication, optimal management is still unknown, and research on prevention has been hampered by single-institution series and small numbers. This article will review the history, causes, presentation, management, and outcome from shunt infections in children. Pitfalls in diagnosis and management will be reviewed. Finally, prevention strategies and research questions still remaining in this area will be outlined.

Complications and pitfalls of neuroendoscopic surgery in children

OBJECT

Neuroendoscopic surgery is being used as an alternative to traditional shunt surgery and craniotomy in the management of hydrocephalus and intracranial fluid-filled cavities. In this study, the authors evaluated the incidence and type of complications occurring after neuroendoscopic procedures that were performed in a consecutive series of pediatric patients at a single institution to determine the effectiveness of neuroendoscopy in such patients.

METHODS

Four hundred ninety-five neuroendoscopic procedures were consecutively performed in 450 pediatric patients at one institution over a 10-year period. Charts were retrospectively reviewed. A complication was defined as follows: 1) any postoperative neurological deficit that was not observed before surgery; 2) any event occurring during surgery that resulted in the procedure being aborted; or 3) any adverse event occurring within 7 days postsurgery that resulted in a modification of the normal postoperative care. However, headache, vomiting, and fever without cerebrospinal fluid (CSF) pleocytosis were not considered complications. Complications were observed in 40 (8.1%) of 495 procedures. Two patients had two complications. One patient died of diffuse brain edema following endoscopic biopsy sampling of a basal ganglia tumor (mortality rate 0.2%). Other complications observed were abandonment of the procedure in eight cases, CSF leakage in 11 (with associated wound infection in one), intraventricular hemorrhage in six (with external drainage needed in four), intraparenchymal hemorrhage in three, subdural collection in eight (with subdural-peritoneal shunt placement needed in seven), transient oculomotor palsy in two, and transient hemiparesis in one.

CONCLUSIONS

Many complications can be avoided by determining the correct diagnosis and using suitable techniques and instruments. Most complications can be managed conservatively and do not produce long-term morbidity. Complex procedures in most patients and simple procedures in patients with preoperative risk factors carry the highest hazard. Every attempt should be made to optimize the surgical technique. The most serious and potentially the most lethal complication remains arterial bleeding from injury to the basilar artery complex.

Recommendations for the Management of Intracranial Haemorrhage – Part I: Spontaneous Intracerebral Haemorrhage

This article represents the recommendations for the management of spontaneous intracerebral haemorrhage of the European Stroke Initiative (EUSI). These recommendations are endorsed by the 3 European societies which are represented in the EUSI: the European Stroke Council, the European Neurological Society and the European Federation of Neurological Societies.

Endoscopic third ventriculostomy

Among patients with idopathic aqueductal stenosis or impedance of cerebrospinal fluid (CSF) flow in the posterior fossa due to tumour, endoscopic fenestration of the floor of the third ventricle creates an alternative route for CSF flow to the subarachnoid space via the prepeduncular cistern. By reestablishing CSF flow, this procedure dissipates any pressure gradient on midline structures. This may obviate the need for traditional CSF shunt diversion techniques in such settings. Currently, endoscopic third ventriculostomy is indicated in approximately 25% of patients with hydrocephalus and can be performed instead of shunt placement. Appropriate patients are those with aqueductal stenosis (10%), obstructive tumours (10%), and obstructive cysts (5%). Additional recent data suggest the favorability of third ventriculostomy over shunt implantation in additional patient cohorts. Operative technique is discussed.

Endoscopic third ventriculostomy in children: early and late complications and their avoidance

INTRODUCTION

Endoscopic third ventriculostomy (ETV) is considered by many authors the initial surgical procedure of choice for the treatment of non-communicant hydrocephalus. However, this procedure has early and late complications that neurosurgeons must be aware of when performing it.

MATERIALS AND RESULTS

A retrospective study of infants and children treated with ETV at Children's Memorial Hospital (Chicago, IL) between 1993 and 2004 is presented. A total of 136 ETVs in 122 patients were performed with 8.8% early complication rate (hemorrhage, CSF leak, infection, diabetes insipidus, and seizures). There were no fatalities but one patient had severe neurological disturbances due to intracranial hemorrhage at the second ETV. We identified several significant factors that influence the late ETV failure rate: age under 12 months (p=0.012), cases performed early in our experience (p=0.009), patients with hydrocephalus without expansive lesions (p=0.026), patients that had an external ventricular drain (EVD) after ETV (p<0.005), and patients who developed early complications (p=0.035).

CONCLUSION

A careful patient selection and preoperative planning lead to better results of ETV. A higher early and late complication rate in children younger than 1-year-old were noted in our series. There is definitely a learning curve for this technique, and several technical considerations are helpful to avoid adverse events. Most of the early complications are transient, while potential devastating injuries can occur. Long-term follow-up is needed to identify delayed closure of the fenestration. Ventricular access devise is helpful for diagnostic and therapeutic purposes during the follow-up.

The International Infant Hydrocephalus Study: concept and rational

INTRODUCTION

During the recent meetings of the International Study Group on Neuroendoscopy and the International Society for Pediatric Neurosurgery, the consensus view emerged that there is a need to assess the value and efficacy of neuroendoscopic procedures against shunting in a scientific manner, to resolve long-lasting debates on the subject.

MATERIAL AND METHODS

A prospective randomized, controlled trial of endoscopic third ventriculostomy vs shunting in children presenting under the age of 2 years with pure aqueduct stenosis is been proposed and organized (the International Infant Hydrocephalus Study, IIHS). The participating surgeons must adhere to the philosophy of randomization and be suitably experienced in endoscopic techniques in infants. The primary outcome of the trial will be the overall health-related quality of life of these children at 5 years of age. Hence, the study is focusing on the effect of surgery on neurodevelopment, rather than the less important issue of shunt or stoma survival, that has been debated extensively with no conclusion so far. Intention-to-treat analysis will be performed according to the first surgery. Secondary outcomes such as complication and reoperation rate, total hospitalization time and cost, need for repeat imaging, and others will be analyzed as well.

RESULTS

Pure aqueduct stenosis is relatively rare, making recruitment problematic, but has been chosen to avoid other confounding factors that could influence outcome. More than 25 centers worldwide have committed already to patient recruitment to the study. It is anticipated that recruitment will last for 2 years, aiming for 91 patients per arm. The study has started recruiting patients already in some countries.

CONCLUSION

It is hoped that the trial will not only provide answers to unsettled debates on the value of neuroendoscopy but also create a network of collaborating pediatric neurosurgeons for future initiatives.

Endoscopic third ventriculostomy in the treatment of hydrocephalus in pediatric patients

Advances in surgical instrumentation and technique have lead to an extensive use of endoscopic third ventriculostomy in the management of pediatric hydrocephalus. The aim of this work was to point out the leading aspects related to this technique. After a review of the history, which is now almost one century last, the analysis of the endoscopic ventricular anatomy is aimed to detail normal findings and possible anatomic variations which might influence the correct conclusion of the procedure. The overview of modern endoscopic instrumentation helps to understand the technical improvements that have contributed to significantly reduce the operative invasiveness. Indications are analysed from a pathogenetic standpoint with the intent to better understand the results reported in the literature. A further part of the paper is dedicated to the neuroradiological and clinical means of outcome evaluation, which are still a matter of debate. Finally a review of transient and permanent surgical complications is performed looking at their occurrence in different hydrocephalus etiologies.

Retrospective analysis of 400 neuroendoscopic interventions: the Hungarian experience

Object

The authors present the results of 400 consecutive neuroendoscopic interventions performed by a single surgeon in 373 patients during the last 8 years.

Methods

The study is based on a retrospective analysis of a continuously updated electronic database that includes patient history and radiological files. The success rate of the interventions is calculated.

Conclusions

The underlying pathological condition was hydrocephalus of various origins. The success rate within patient groups is given and the factors leading to successful surgery are emphasized. Recommendations on indications for neuroendoscopic operations are discussed.

Endoscopic third ventriculostomy in adult patients

Endoscopic third ventriculostomy (ETV) has gained popularity and has become the treatment of choice for certain pediatric and adult hydrocephalic conditions. The authors report their experience with 36 adult patients and evaluate the long-term outcome and safety of ETV. They discuss several improvements to the surgical techniques that they have developed based on their experience, including the use of intraoperative Doppler imaging before fenestration to trace the location of vessels underlying the floor of the third ventricle. They also report the use of a Rickham reservoir and endoventricular stent in selected cases and discuss the indications for their use. In cases of obstructive hydrocephalus due to congenital or acquired aqueductal stenosis in adults, the success rate of ETV in avoidance of shunt placement is 72%. Twenty-two percent of the patients in this series in whom ETV was initially successful later experienced closure of the fenestration and recurrent symptoms at a mean interval of 3.75 years. Thus, in patients who undergo this treatment, long-term periodic follow-up review should be performed.

Success of endoscopic third ventriculostomy in children less than 2 years of age

Current literature reveals different opinions about the effectiveness of endoscopic third ventriculostomy in the treatment of hydrocephalus in children less than 2 years of age. Performing a retrospective evaluation of our own experience in this age group, we aimed to contribute to the growing data on the controversial issues related to this procedure in children. In a series of 97 endoscopic third ventriculostomy procedures, 25 were performed in children less than 2 years of age as an initial treatment for hydrocephalus. A retrospective analysis of our data revealed that the overall success rate of endoscopic third ventriculostomy in this age group was 56%. However, analysis of the results in subgroups with different etiologies of hydrocephalus showed that the success rate of the procedure was 83% in patients with defined anatomic obstruction, 66.6% in post-hemorrhagic hydrocephalus, 50% in infection related hydrocephalus and 41.6% in hydrocephalus accompanied by myelomeningocele. This article considers our data and the features of endoscopic third ventriculostomy procedure in this age group, with a detailed review of the literature. In our experience, the success of endoscopic third ventriculostomy is etiology related rather than age-dependent. We suggest that there are no grounds for denying children younger than 2 years this chance for a shunt-free life.

Air encephalography for hydrocephalus in the era of neuroendoscopy

INTRODUCTION

There is often uncertainty regarding the site of the cerebrospinal fluid (CSF) block in individual patients with hydrocephalus, leading to a significant failure rate for endoscopic third ventriculostomy (ETV) when performed for unconventional pathologies such as postmeningitic and posthaemorrhagic hydrocephalus. We describe the use of lumbar air encephalography (AEG) to refine the indications for ETV in such circumstances.

METHODS

Data from AEG studies used to guide indications for ETV were collected prospectively. The technique and protocol for AEG have been modified from the historical description of the procedure in the interest of safety and to minimise discomfort. In a separate evaluation, the level of the CSF block was determined by one of the authors, who was blinded to the results of the AEG, based on conventional computerised tomographic criteria. These results are compared with those obtained from the AEG.

RESULTS

Forty-five studies were performed over a 2-year period. Thirty-seven were preinterventional, the majority of which demonstrated communicating hydrocephalus. ETV performed in five cases of non-communicating hydrocephalus was successful in each. The prediction of the level of block based on CT criteria was poor.

CONCLUSION

It is often difficult to determine whether hydrocephalus is communicating or not with conventional imaging in the absence of a clearly demonstrable lesional obstruction to the CSF pathways. We have found AEG helpful in excluding patients with communicating hydrocephalus from an inappropriate ETV. On the basis of our experience, we consider the modified procedure safe as long as a strict protocol is followed.

Role of neuroendoscopy in the management of patients with tuberculous meningitis hydrocephalus

The role of neuroendoscopy in patients of tuberculous meningitis with hydrocephalus (TBMH) is not yet established. We present details of endoscopic morphology, and analyze outcome of Neuroendoscopy performed in 28 patients (15 males and 13 females, average age 23 years) of TBMH in last 2.5 years. Endoscopic procedures performed included endoscopic third ventriculostomy (ETV) alone (n=19), ETV with monroplasty (n=2), and septostomy (n=2), ETV with decompression/biopsy of tuberculoma (n=2) and with abscess drainage (n=1). Outcome was assessed on the basis of clinico-radiological improvement, need for external shunt and complications. Outcome was satisfactory in 14 (50%), acceptable in five (18%) and unsatisfactory in nine (32%) patients. Overall, 19 (68%) patients benefited from endoscopic intervention. Cerebrospinal fluid (CSF) leak (n=2) and per-operative bleeding (n=1) were the only complications encountered. Endoscopy appears to be helpful in a considerable number of patients with TBMH, and should be considered as the first surgical option for CSF diversion surgery in these patients. External shunt should be reserved for those who fail the endoscopic CSF diversion.

Long-term Reliability of Endoscopic Third Ventriculostomy

OBJECTIVE:

To describe the short-term operative success and the long-term reliability of endoscopic third ventriculostomy (ETV) for treatment of hydrocephalus and to examine the influence of diagnosis, age, and previous shunt history on these outcomes.

METHODS:

We retrospectively analyzed 203 consecutive patients from a single institution who had ETV as long as 22.6 years earlier. Patients with hydrocephalus from aqueduct stenosis, myelomeningocele, tumors, arachnoid cysts, previous infection, or hemorrhage were included.

RESULTS:

The overall probability of successfully performing an ETV was 89% (84–93%). There was support for an association between the surgical success and the individual operating surgeon (odds ratios for success, 0.44–1.47 relative to the mean of 1.0, P = 0.08). We observed infections in 4.9%, transient major complications in 7.2%, and major and permanent complications in 1.1% of 203 procedures. Age was strongly associated with long-term reliability. The longest observed reliability for the 13 patients 0 to 1 month old was 3.5 years. The statistical model predicted the following reliability at 1 year after insertion: at 0 to 1 month of age, 31% (14–53%); at 1 to 6 months of age, 50% (32–68%); at 6 to 24 months of age, 71% (55–85%); and more than 24 months of age, 84% (79–89%). There was no support for an association between reliability and the diagnostic group (n = 181, P = 0.168) or a previous shunt. Sixteen patients had ETV repeated, but only 9 were repeated after at least 6 months. Of these, 4 procedures failed within a few weeks, and 2 patients were available for long-term follow-up.

CONCLUSION:

Age was the only factor statistically associated with the long-term reliability of ETV. Patients less than 6 months old had poor reliability.

Long-term resolution of acute, obstructive, triventricular hydrocephalus by endoscopic removal of a third ventricular hematoma without third ventriculostomy. Case report and review of the literature

The authors describe a new extension of the use of neuroendoscopy beyond that which is ordinarily performed. The authors report on the resolution of acute, obstructive, triventricular hydrocephalus in a 42-year-old woman with hypertensive caudate hemorrhage that migrated into the ventricular system. The patient underwent emergency endoscopic removal of a third ventricular hematoma, which was obstructing the orifice of the aqueduct, and restoration of cerebrospinal fluid (CSF) flow but no third ventriculostomy. The authors believe that this is the first such case to be reported. In selected cases of third ventricular hemorrhage, endoscopic removal of the intraventricular hematoma may represent a useful and effective treatment option even in emergency conditions as well as a better alternative to prolonged CSF external ventricular drainage. A reduction in the duration of hospitalization is a beneficial consequence. The authors assert that third ventriculostomy is not always needed.

Endoscopic third ventriculostomy for chronic hydrocephalus after tuberculous meningitis

BACKGROUND

Cerebrospinal fluid diversion procedures are indicated in patients with hydrocephalus after tuberculous meningitis (TBM). We present 2 patients with hydrocephalus after TBM who were successfully treated with endoscopic third ventriculostomy (ETV).

METHODS

Two patients had been diagnosed with hydrocephalus after TBM and had undergone ventriculoperitoneal shunt surgery for the same. They presented with multiple episodes of shunt dysfunction. Endoscopic third ventriculostomy was performed (twice for one patient), and the patients were evaluated clinically and radiologically after the procedure.

RESULTS

On long-term clinical follow-up (3 and 2 years, respectively), both patients were asymptomatic after the ETV. The first patient was radiologically evaluated 7 months after the procedure and the second patient 2 years after the procedure. The first patient showed a decrease in ventricular size. The second patient did not show any significant change in the ventricular size.

CONCLUSION

Endoscopic third ventriculostomy can be considered as a safe and long-lasting solution for hydrocephalus after chronic TBM.

Endoscopic third ventriculostomy for obstructive hydrocephalus

The indications for neuroendoscopy are not only constantly increasing, but even the currently accepted indications are constantly being adjusted and tailored. This is also true for one of the most frequently used neuroendoscopic procedures, the endoscopic 3rd ventriculostomy (ETV) for obstructive hydrocephalus. ETV has gained popularity and widespread acceptance during the past few years, but little attention has been paid to the techniques of the procedure. After a short introduction describing the history of ETV, an overview is given of all the different techniques that have been and still are employed to open the floor of the 3rd ventricle. The spectrum of indications for ETV has been widely enlarged over the last years. Initially, the use of this procedure was restricted to patients older than 2 years, to patients with an obvious triventricular hydrocephalus, and to those with a bulging, translucent floor of the 3rd ventricle. Nowadays, indications include all kinds of obstructive hydrocephalus but also communicating forms of hydrocephalus. The results of endoscopic procedures in treating these pathologies are given under special consideration of shunt technologies. In summary, from the review of the publications since the first ETV performed by Mixter in 1923, this technique is the treatment of choice for obstructive hydrocephalus caused by different etiologies and is an alternative to cerebrospinal fluid shunt application.

Endoscopic third ventriculostomy in infants of less than 1 year of age: which factors influence the outcome?

OBJECTIVES

Endoscopic third ventriculostomy (ETV) is a successful method of treatment for obstructive hydrocephalus. In infants, however, it is reported to have a higher failure rate. On the basis of our own data and a meta-analysis of the literature, we try to define factors prognosticating potential failure in infants aged less than 1 year.

METHODS

Data were collected retrospectively. Between October 1994 and October 2002, 20 ETVs were performed in 16 patients younger than 1 year. Ages ranged from 8 to 311 days (median 103). Etiology was aqueductal stenosis in all 16 patients (idiopathic in 7, posthemorrhagic in 3, postmeningitic in 3, and related to CNS or vascular malformation in 3). ETV failure was defined as subsequent need for shunt implantation. For non-shunted patients, follow up was 16-52 months (median 25).

RESULTS

ETV was successful in 5 patients and eventually failed in 11. There was no mortality or permanent morbidity following ETV. In the successful cases, etiology was idiopathic aqueductal stenosis in 4 and postmeningitic aqueductal stenosis in 1; the median age was 206 days (range 82-311). In the 11 unsuccessful patients, it was idiopathic aqueductal stenosis in 3, posthemorrhagic in 3, postmeningitic in 2 and CNS/vascular malformation in 3 cases; median age was 94 days (range 8-299). Median time interval between (last) ETV and shunt was 38 days (range 2-70). The difference in median age between the success group and the failure group roughly corresponded to data gained from a meta-analysis of the literature. Four patients underwent a second ETV. In intraoperative ventriculoscopy, the stoma was closed or there were new membranes below the floor of the third ventricle and a second ETV was performed. But finally, all re-ETVs failed and the patients needed a shunt.

CONCLUSION

Factors indicating potential failure of ETV were very young age and etiology other than idiopathic aqueductal stenosis. Probability of success seems to increase during the first 2 or 3 months of life. Ventriculoscopy with the option of a second ETV should be regularly performed after failure of ETV.

Radiological assessment of hydrocephalus: new theories and implications for therapy

It is almost a century since Dandy made the first experimental studies on hydrocephalus, but its underlying mechanism has been unknown up to now. The conventional view is that cerebrospinal fluid (CSF) malabsorption due to hindrance of the CSF circulation causes either obstructive or communicating hydrocephalus. Analyses of the intracranial hydrodynamics related to the pulse pressure show that this is an over-simplification. The new hydrodynamic concept presented here divides hydrocephalus into two main groups, acute hydrocephalus and chronic hydrocephalus. It is still accepted that acute hydrocephalus is caused by an intraventricular CSF obstruction, in accordance with the conventional view. Chronic hydrocephalus consists of two subtypes, communicating hydrocephalus and chronic obstructive hydrocephalus. The associated malabsorption of CSF is not involved as a causative factor in chronic hydrocephalus. Instead, it is suggested that increased pulse pressure in the brain capillaries maintains the ventricular enlargement in chronic hydrocephalus. Chronic hydrocephalus is due to decreased intracranial compliance, causing restricted arterial pulsations and increased capillary pulsations. The terms "restricted arterial pulsation hydrocephalus" or "increased capillary pulsation hydrocephalus" can be used to stress the hydrodynamic origin of both types of chronic hydrocephalus. The new hydrodynamic theories explain why third ventriculostomy may cure patients with communicating hydrocephalus, a treatment incompatible with the conventional view.

Endoscopic third ventriculostomy in the management of obstructive hydrocephalus: an outcome analysis

Object. The purpose of this paper is to elucidate the safety and efficacy of, and indications and outcome prognosis for endoscopic third ventriculostomy (ETV) in 58 patients with obstructive hydrocephalus.

Methods. Between September 1999 and April 2003, 58 ETVs were performed in 58 patients with obstructive hydrocephalus (36 male and 22 female patients) at the authors' institution. The ages of the patients ranged from 5 to 67 years (mean age 35 years) and the follow-up period ranged from 3 to 41 months (mean duration of follow up 24 months). Patients were divided into four subgroups based on the cause of the obstructive hydrocephalus: 21 with intracranial tumors; 11 with intracranial cysts; 18 with aqueductal stenosis; and eight with intracranial hemorrhage or infection. Both univariate and multi-variate statistical analyses were performed to assess the prognostic relevance of the cause of the obstructive hydrocephalus, early postoperative clinical appearance, and neuroimaging findings in predicting the result of the ETV.

The survival rate was 87% at the end of the 1st year and 84% at the end of the 2nd year post-ETV. One month after ETV an overall clinical improvement was observed in 45 (77.6%) of 58 patients. If we also consider the successful revision of ETV in two patients, a success rate of 78.3% (47 of 60 patients) was reached. The ETV was successful in 17 (81%) of 21 patients with intracranial tumors, nine (82%) of 11 with cystic lesions, 16 (88.9%) of 18 with aqueductal stenosis, and three (38%) of eight with intracranial hemorrhage or infection. A Kaplan—Meier analysis illustrates that the percentage of functioning ETVs stabilizes between 75 and 80% 1 year after the operation. In a comparison of results 1 year after ETV, the authors found that the aqueductal stenosis subgroup had the highest proportion of functioning ETV (89%). The proportions of the tumor and cyst subgroups were 84 and 82%, respectively, whereas the proportion was only 50% in the ventriculitis/intracranial hemorrhage subgroup (strata log-rank test: χ2 = 7.93, p = 0.0475).

In the present study, ETV failed in eight patients (13.8%) and the time to failure after the procedure was a mean of 3.4 months (median 2 months, range 0–8 months). The logistic regression analysis confirmed an early postoperative improvement (within 2 weeks after ETV, significance [Sig] of log likelihood ratio [LLR] < 0.0001) and a patent stoma on cine phase—contrast magnetic resonance (MR) images (Sig of LLR = 0.0002) were significant prognostic factors for a successful ETV. The results demonstrated the multivariate model (B = − 53.7309, standard error = 325.1732, Wald = 0.0273, Sig = 0.8688) could predict a correct result in terms of success or failure from ETV surgery in 89.66% of observed cases. The Pearson chi-square test demonstrated that little reliance could be placed on the finding of a reduced size of the lateral ventricle (χ2 = 5.305, p = 0.07) on neuroimaging studies within 2 weeks after ETV, but it became a significant predictive factor at 3 months (χ2 = 8.992, p = 0.011) and 6 months (χ2 = 10.586, p = 0.005) post-ETV. Major complications occurred in seven patients (12.1%), including intraoperative venous bleeding in three, arterial bleeding in one, and occlusion of the stoma in three patients. The overall mortality rate was 10.3% (six patients). One of these patients died of pulmonary infection and another of ventriculitis. Four additional patients died of progression of malignant tumor during the follow-up period.

Conclusions. The results indicate that ETV is a most effective treatment in cases of obstructive hydrocephalus that is caused by aqueductal stenosis and space-occupying lesions. For patients with infections or intraventricular bleeding, ETV has considerable effects in selected cases with confirmed CSF dynamic studies. Early clinical and cine phase—contrast MR imaging findings after the operation play an important role in predicting patient outcomes after ETV. The predictive value of an alteration in ventricle size, especially during the early stage following ETV, is unsatisfactory. Seventy-five percent of ETV failures occur within 6 months after surgery. A repeated ventriculostomy should be considered to be a sufficient treatment option in cases in which stoma dysfunction is suspected.

Ventriculostomia endoscópica: influencia de factores predisponentes al fallo y evolución del tamaño ventricular

INTRODUCTION

Endoscopic third ventriculostomy is the treatment of choice for non communicating hydrocephalus at our institution. Several factors have been associated with failure of endoscopic third ventriculostomy. The goals of the study have been to evaluate the outcome, the influence of factors theoretically prone to failure of ventriculostomy and the evolution of ventricular size.

MATERIAL AND METHODS

Fifty-six patients (mean age 48.5 yrs) treated with an endoscopic third ventriculostomy during the period 1997-2002 were analysed retrospectively. Hydrocephalus was classified as acute (68%) and chronic forms. Etiology was classified in space-occupying lesions (59%), primary aqueductal stenosis (34%) and Chiari malformation (7%). The presence of the following factors theoretically prone to failure was considered: age below one year, history of mielomeningocele, cerebrospinal fluid (CSF) infection, intracranial haemorrhage, radiotherapy, craniotomy and previous treatment of hydrocephalus with a shunt. Ventricular size was measured linearly with four ventricular index pre- and postoperatively.

RESULTS

The global success rate was 71.4% (mean follow-up 26 months). Endoscopic third ventriculostomy for hydrocephalus secondary to cerebral metastases obstructing CSF pathways was associated with a higher risk of failure (p=0.006). None of the risk factors considered was associated with a higher risk of failure. The evolution of the ventricular size measured with linear methods is associated with outcome. Evans ratio, third ventricle index, cella media index and ventricular score decreased in patients whose outcome is satisfactory and increased in those cases deemed clinical failures (p< 0.05).

CONCLUSION

The risk of failure increases in patients with cerebral metastases close to CSF pathways, likely due to the concurrence of mechanisms other than obstruction. Changes in ventricular size are associated with outcome.

Intracerebroventricular passive immunization with anti-Abeta antibody in Tg2576

Current Alzheimer's disease (AD) research has established the fact that excessive genesis of Abeta derived from amyloidogenic processing of beta-amyloid (Abeta) precursor protein is fundamental to AD pathogenesis. There has been considerable interest in using immunization strategies for clearing excessive Abeta. Studies in animal models of AD have shown that active immunizations or systemic passive immunizations reduced cerebral plaque load and improved behavioral deficits. However, clinical translation of an active immunization strategy was interrupted because of evidence for meningoencephalitis produced in some patients who received Abeta vaccine. Studies in animal models have shown perimicrovascular hemorrhages and inflammation after sustained systemic immunizations in animals with vascular amyloid. In this light, our data showing the effects of a single intracerebroventricular (ICV) injection of anti-Abeta in the Alzheimer's Swedish mutant model Tg2576 are intriguing. We have previously demonstrated that a single ICV injection of anti-Abeta into the third ventricle of 10-month-old Tg2576 mice reduced cerebral plaques, reversed Abeta-induced depletion of presynaptic SNAP-25, and abolished astroglial activation as seen 1 month post-injection (Chauhan and Siegel [2002] J. Neurosci. Res. 69:10-23). The present report demonstrates that a single ICV injection of 10 microg anti-Abeta in 10-month-old Tg2576 mice reduced cerebral plaques, with decreased inflammation at this stage as evidenced by a reduced number of interleukin-1beta-positive microglia surrounding Congophilic plaques. Moreover, at this particular age, no microhemorrhage was discernible, as evidenced by the absence of hemosiderin deposition after a single ICV injection of anti-Abeta. This is the first report demonstrating absence of microhemorrhage and reduced inflammation after the ICV introduction of anti-Abeta in Tg2576 mice at 10 months of age. These facts indicate that, although invasive, ICV injection of anti-Abeta may be a safer method of vaccination in AD, possibly through reducing the vascular exposure to antibody. Further studies are warranted to determine the lasting effects of a single ICV anti-Abeta injection in animals with and without abundant plaque burden and at older ages.

Endoscopic adjuncts to intraventricular surgery

Recently, endoscopic intraventricular surgery has been performed successfully in several clinical series. Although the therapeutic results must be compared with conventional surgery, neuroendoscopy seems to be a safe surgical technique when performed by surgeons with appropriate experience and refined endoscopic tools. Rigid or flexible endoscopes equipped with various-sized working channels should be selected depending on the nature of the pathologic findings. The well-proven tenets of microsurgery must not be sacrificed for the sake of more rapid surgical time and noninvasiveness; thus, endoscopic surgery must adhere to the principles of microsurgery. The improved visualization and lower morbidity have established neuroendoscopy in the management of specific disease processes, such as obstructive hydrocephalus. Its further use in the management of intraventricular cysts and tumors is dependent on long-term follow-up and the development of even better instrumentation.