Neuroendoscopic surgery for specific forms of hydrocephalus

Clinical and surgical outcome of endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt (VPS) in patients with Long-Standing Overt Ventriculomegaly in Adults (LOVA): a systematic review

OBJECTIVES

The optimal surgical procedure for long-standing overt ventriculomegaly in adults (LOVA) remains controversial.

METHODS

A systematic search of three databases was performed for studies published between January 1999 and March 2022. This systematic review included 12 studies with a total of 318 patients with LOVA surgically treated. PRISMA guidelines were followed.

RESULTS

Gait disturbance (74.8%) and headache (59.7%) were the most common clinical presentation. Overall, the rate of postoperative clinical improvement at the last follow-up was 83.6% (95% CI 78.1-86.1). A lower rate of postoperative clinical improvement or halt of progression of presenting symptoms was observed after ETV (211/257 = 82.1% 95% CI 76.2-85.1%) compared with VPS (55/61 = 90.2% 95% CI 80.3-96.1%). Overall, surgical and postoperative complications were reported in 22/297 patients (7.5% 95% CI 4.4-20%) (11 studies). A higher rate of surgical complications was observed in patients treated with VPS (19.7% 95 CI 5.9-46.7%), compared with patients treated with ETV (4.3% 95% CI 2.1-10.9%). The overall rate of second surgery due to failure of first surgical approach (ETV or VPS) was 46/275 (16.7%).

DISCUSSION

This meta-analysis confirmed the efficacy of EVT and VPS in symptomatic patients with LOVA, reporting a roughly 84% of postoperative clinical improvement or halt of progression of symptoms. A higher rate of surgical complications was observed in patients treated with VPS compared with patients treated with ETV. In addition, roughly 18% of patients treated with ETV required a further VPS. These findings should be considered when advising LOVA patients regarding the management of hydrocephalus.

Clinical Outcome of Endoscopic Procedure in Patients with Shunt Malfunction

OBJECTIVE

The goal of this study was to analyze the clinical outcomes of endoscopic third ventriculostomy (ETV) and endoscopic septostomy when shunt malfunction occurs in a patient who has previously undergone placement of a ventriculoperitoneal shunt.

METHODS

From 2001 to 2020 at Seoul National University Children's Hospital, patients who underwent ETV or endoscopic septostomy for shunt malfunction were retrospectively analyzed. Initial diagnosis (etiology of hydrocephalus), age at first shunt insertion, age at endoscopic procedure, magnetic resonance or computed tomography image, subsequent shunting data, and follow-up period were included.

RESULTS

Thirty-six patients were included in this retrospective study. Twenty-nine patients, 18 males and 11 females, with shunt malfunction underwent ETV. At the time of shunting, the age ranged from 1 day to 15.4 years (mean, 2.4 years). The mean age at the time of ETV was 13.1 years (range, 0.7 to 29.6 years). Nineteen patients remained shunt revision free. The 5-year shunt revisionfree survival rate was 69% (95% confidence interval [CI], 0.54-0.88). Seven patients, three males and four females, with shunt malfunction underwent endoscopic septostomy. At the time of shunting, the age ranged from 0.2 to 12 years (mean, 3.9 years). The mean age at the time of endoscopic septostomy was 11.9 years (range, 0.5 to 29.5 years). Four patients remained free of shunt revision or addition. The 5-year shunt revision-free survival rate was 57% (95% CI, 0.3-1.0). There were no complications associated with the endoscopic procedures.

CONCLUSION

The results of our study demonstrate that ETV or endoscopic septostomy can be effective and safe in patients with shunt malfunction.

Loculated hydrocephalus: is neuroendoscopy effective and safe? A 90 patients' case series and literature review

INTRODUCTION

Loculated hydrocephalus is a complex condition in which different non-communicating compartments form within the ventricular system due to different etiology, mainly intraventricular hemorrhage and infection. Since the end of the twentieth century, neuroendoscopy has been explored as a therapeutic option for loculated hydrocephalus with non-univocal results.

METHODS

We performed a retrospective analysis of 90 patients who underwent endoscopic treatment for loculated hydrocephalus from January 1997 to January 2021 (mean age: 2 years, range 7-21). We included 37 (41.1%) children with multiloculated hydrocephalus, 37 (41.1%) with isolated lateral ventricle, 13 (14.4%) with excluded temporal horn, and 3 (3.3%) with isolated fourth ventricle. We compared our results with those available in literature.

RESULTS

A mean of 1.91 endoscopic procedure/patient were performed (only one endoscopy in 42.2% of cases). Complications of neuroendoscopy and of shunt surgeries were recorded in 17 (18.9%) and 52 (57.8%) children, respectively. Twenty-six (28.9%) children were shunt-free at the last follow-up, 47.8% have only one shunt.

DISCUSSION

The first goal of neuroendoscopy is to increase the rate of shunt-free patients but, when it is not possible, it aims at simplifying shunt system and reducing the number of surgical procedures. In our series, neuroendoscopy was able to achieve both these goals with an acceptable complication rate. Thus, our results confirmed neuroendoscopy as a valid tool in the long-term management of loculated hydrocephalus. Neuronavigation and intraoperative ultrasound could increase the success rate in cases with distorted anatomy.

Neuroendoscopic septostomy in unilateral and bilateral ventricular hydrocephalus

PURPOSE

This study describes the results of septostomy (SPT) in terms of success and analysis of follow-up in a series of pediatric patients diagnosed with unilateral ventricular hydrocephalus (UHV) and biventricular hydrocephalus (BVH).

METHODS

A total of 29 pediatric patients diagnosed with UVH or BVH were included in this study. In UVH, a neuroendoscopic SPT was performed (sometimes accompanied by NEFPFMO). In those diagnosed with BVH, an SPT combined with VPS was carried out. Demographic, etiological, clinical, and diagnostic variables and percentage of treatment success were collected.

RESULTS

SPT was successful during follow-up when no VPS was required in UVH and only unilateral VPS was implanted in BVH. At the time of surgery, 16 patients needed a ventriculoperitoneal shunt. The first SPT was successful in 22 patients, requiring a second surgery in 7 patients, from the oncology group diagnosed with BHV.

CONCLUSIONS

The surgical management of UVH and BVH still has some disclosure points to be reviewed. However, SPT seems to be a secure, non-traumatic, and efficient procedure.

Trapped Fourth Ventricle: Pathophysiology, History and Treatment Strategies

Trapped fourth ventricle is a clinic-radiological entity characterised by progressive neurological symptoms due to enlargement and dilatation of fourth ventricle secondary to obstruction to its outflow. There are several causative mechanisms for the development of trapped fourth ventricle, including previous haemorrhage, infection or inflammatory processes. However, this condition is most commonly observed in ex preterm paediatric patients shunted for a post-haemorrhagic or post-infective hydrocephalus. Until the introduction of endoscopic aqueductoplasty and stent placement, treatment of trapped fourth ventricle was associated with high rates of reoperation and complications resulting in morbidity. With the advent of new endoscopic techniques, supratentorial and infratentorial approaches for aqueductoplasty and stent insertion have revolutionised the treatment of trapped fourth ventricle. Fourth ventricular fenestration and direct shunting remain viable options in cases where aqueduct anatomy and length of obstruction is not surgically favourable for endoscopic approaches. In this book chapter, we explore the background, historical developments,$ and surgical treatment strategies in the management of this challenging condition.

Role of Endoscopy in Treatment of Complex Hydrocephalus in Children

Complex hydrocephalus or loculated hydrocephalus is a challenging problem in the field of pediatric neurosurgery. Early diagnosis and treatment are paramount in order to ensure success of treatment. Therefore, alertness is required among pediatricians who are dealing with premature children and children having meningitis and/or intraventricular hemorrhage. Disproportionate hydrocephalic changes in CT scan of the brain are suspicious, whereas gadolinium-enhanced multiplanar MR imaging (axial, sagittal, and coronal) is the best diagnostic modality. The definitive treatment is surgical, yet the approach remains a matter of debate. Cyst fenestration, communicating the isolated compartments together and with the ventricular system, is the main strategy of treatment. Cyst fenestration can be performed through either microsurgery or endoscopy, in order to improve the hydrocephalus, decrease number of shunts, and reduce shunt revision rates. However, the endoscopic procedure has an advantage over microsurgery of being simple and minimally invasive. It is evident that uniloculated hydrocephalus carries better prognosis than multiloculated hydrocephalus; this can be attributed to the initial pathological disease contributing to the ventricular compartmentalization. Because of the bad prognosis in multiloculated hydrocephalus, and because there are few numbers of patients available in any given center, a multicentric prospective study with long-term follow-up evaluating the results of outcome and quality of life is warranted.

Surgical Treatment of Long-Standing Overt Ventriculomegaly in Adults (LOVA): A Comparative Case Series between Ventriculoperitoneal Shunt (VPS) and Endoscopic Third Ventriculostomy (ETV)

Background: Long-standing overt ventriculomegaly in adults (LOVA) is an uncommon type of adult chronic hydrocephalus. In recent years, conflicting case series described different outcomes after treatment of LOVA with endoscopic third ventriculostomy (ETV) or ventriculoperitoneal shunt (VPS). The aim of this study is to report a single institutional surgical experience of patients with LOVA in order to evaluate the clinical outcome of those patients treated with one or, sometimes, both surgical procedures, analyzing the main clinical features of these patients, before and after surgery. Methods: We conducted a retrospective study on 31 patients with diagnosis of LOVA, who were treated in our University Hospital between December 2010 and October 2020. We reported gender, age, clinical presentation, surgical treatment, and clinical outcome according to the Kiefer index (KI). Evans’ index, head circumference, aqueductal stenosis and expanded/destroyed sella turcica were assessed on preoperative MRI. Results: The most common clinical manifestation was gait disturbances (100%) followed by urinary incontinence in 23 (74.2%) patients and cognitive deficits in 22 (71%) patients. On preoperative MRI, the overall mean Evans’s Index was 0.49, whereas the overall mean head circumference was 57.3 cm. Twenty-three patients (74.2%) had obliterated cortical sulci, 20 (64.5%) patients had aqueductal stenosis, and 22 (71%) patients had an expanded/destroyed sella turcica on preoperative MRI. Fifteen (48.4%) patients underwent ETV and sixteen (51.6%) were treated with VPS as first surgical procedure. Four (26.6%) out of fifteen patients treated with ETV required a subsequent VPS. The overall median age of patients was 64 (IQR: 54.5–74) and the overall median follow-up was 57 months (IQR 21.5–81.5). Overall morbidity was 22.5%. Mean recovery index (RI), according to KI, was 3.8 ± 4.3 and 2.2 ± 5.6 (p = 0.05) at last follow-up in patients treated with ETV and VPS, respectively. Conclusions: The choice of surgical treatment of LOVA remains under discussion. Although EVT is a tempting option for patients with LOVA, conversion to VP shunt is not uncommon.

Multiloculated hydrocephalus: Evolution of treatments and outcome

Multiloculated hydrocephalus has an overall dismal functional outcome; imaging, early diagnosis, and technological advancements have made new roads in its management. Thirty infants with multiloculated hydrocephalus were studied. Progressive enlargement of the head was the most common presentation in 77%; of these, 47% were treated for neonatal meningitis and septicemia and 20% had suffered birth trauma. The majority required a single ventriculoperitoneal shunt; nine of them required multiple shunts; and six were managed with endoscopic fenestration and endoscopic third ventriculostomy. On follow-up, shunt malfunction was the most common complication. Only 26% of the survivors could achieve normal, neuropsychological developments. The mortality in this series is 6.7%.

Longstanding overt ventriculomegaly in adults (LOVA) with patent aqueduct: surgical outcome and etiopathogenesis of a possibly distinct form of chronic hydrocephalus

Purpose

Longstanding overt ventriculomegaly in adults (LOVA) represents a form of chronic adulthood hydrocephalus with symptomatic manifestation in late adulthood. Based on the patency of the aqueduct, two different subcohorts of LOVA can be distinguished. Surgical treatments of this condition are also debated. Therefore, we analyzed preoperative characteristics and clinical outcome after different surgical treatments in a subgroup of LOVA patients with a patent aqueduct.

Methods

Eighteen LOVA patients with a patent aqueduct consecutively treated at our institution between July 2013 and December 2019 were analyzed for this study. Median age was 70 years. Preoperative radiological and clinical features, surgical procedures (ventriculo-peritoneal shunt or endoscopic third ventriculostomy), and outcomes were collected. Successful outcome was qualitatively defined as an improvement or a halt of progression of the presenting symptoms at follow-up, and quantitatively by changes in mRS and iNPHGS scales.

Results

Twelve patients underwent an ETV as a primary treatment, while 6 underwent VPS. A total of 22.2% of them were lost to follow-up. Median follow-up time was 38 months. Six patients (66.7%) in the ETV cohort achieved a successful outcome after treatment, with a complication rate of 11.1%. Two patients underwent rescue VPS after ETV failure with a good outcome. Four patients (100%) underwent primary VPS and achieved a satisfactory outcome after treatment, with a reported complications rate of 25%.

Conclusion

LOVA with patent aqueduct represents, in our opinion, a distinct clinical form of chronic hydrocephalus. For this subgroup, as well as for other forms of LOVA, ETV remains an acceptable first-line treatment option considering the good results, and the low complication rate, obtained in those patients and the hypothesis that hydrocephalus is due to an “intracisternal” obstruction.

Endoscopic treatment of complex multiloculated hydrocephalus in children, steps that may help to decrease revision rate

Background

Multiloculated hydrocephalus (MLH) is associated with increased intracranial pressure, with intraventricular septations, loculations, and isolation of parts of the ventricular system. Search continues for ideal surgical remedy capable of addressing the dimensions of the problem. We aimed to evaluate endoscopic septal fenestration and pellucidotomy combined with proximal shunt tube refashioning and further advancement into isolated loculations of the ventricular system containing choroid plexus.

Methods

This retrospective study was conducted on 55 patients with symptomatic complex MLH who underwent endoscopic surgery. The collected data included patients' age, gender, presenting manifestations, operative details, rate of remission of preoperative clinical and imaging signs, postoperative complications, redo surgery, or extra shunt hardware insertion. Patients were divided into Group A (underwent the standard technique of endoscopic multiseptal wide fenestration and final ventriculoperitoneal shunt insertion) and Group B (modified technique by adding extra side ports along the proximal shunt hardware).

Results

Groups A and B included 25 and 30 patients, respectively. The percentage of patients showing improvement of almost all manifestations was higher in Group B compared to Group A, with no significant difference (P > 0.05). Group B had lower rate of complications (20% vs. 36%, P = 0.231), insertion of two shunts (16.7% vs. 20%, P = 1.000), and redo surgery (20% vs. 44%, P = 0.097).

Conclusion

The modified technique was associated with better outcomes in terms of the use of single shunt and redo surgery. Launching randomized clinical trials to compare the two techniques are recommended to ascertain the efficacy of the modified technique.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Management of multiloculated hydrocephalus in children with emphasis on role of CT ventriculography

OBJECTIVE

The authors performed a retrospective review of children diagnosed with multiloculated hydrocephalus (MLH) in our institute. The goal was to analyze the different diagnostic and therapeutic modalities used with special emphasis on CT ventriculography (CTV).

METHODS

Male and female patients below the age of 18 years diagnosed with MLH were included. Cases of uniloculated hydrocephalus like entrapped temporal horn or isolated fourth ventricle were excluded. We used iohexol for CTV and gadodiamide for MR ventriculography. Neuroendoscopic procedures performed were endoscopic fenestration, endoscopic third ventriculostomy (ETV), endoscopic septostomy, endoscopic aqueductoplasty, or a combination of the above. The cohort was divided into two groups (endoscopic or shunt) based on initial surgical intervention.

RESULTS

A total of 52 patients were included, with 43 boys and 9 girls. The average age of presentation was 7.7 months. The most common predisposing factor for MLH was neonatal meningitis seen in 30 patients. Mean duration of follow-up was 39 months. CTV was used in 26 patients and MR ventriculography in three patients. In one patient, the diagnosis of MLH was ruled out after ventriculography. Patients who underwent ETV only had the best outcome with 71.4% success rate. At the end of follow-up, 14 patients (27%) were shunt independent.

CONCLUSIONS

The present study indicates that CTV helps to accurately define the anatomy of the ventricles and determine the site of physiological CSF obstruction. This helps in therapeutic planning and in avoiding misdiagnoses. Further, neuroendoscopy has the potential to lead to shunt independence in some patients.

Neural and vascular architecture of the septum pellucidum: an anatomical study and considerations for safe endoscopic septum pellucidotomy

OBJECTIVE

The septum pellucidum is a bilateral thin membranous structure representing the border between the frontal horns of the lateral ventricles. Its most examined components are the septal veins due to their surgical importance during endoscopic septum pellucidotomy (ESP), which is a well-accepted method for surgical treatment of unilateral hydrocephalus. It is widely accepted that the septum pellucidum contains nerve fibers as well, but interestingly, no anatomical study has been addressed to its neural components before. The aim of the present study was to identify these elements as well as their relations to the septal veins and to define major landmarks within the ventricular system for neurosurgical use.

METHODS

Nine formalin-fixed human cadaveric brains (18 septa pellucida) were involved in this study. A central block containing both septa pellucida was removed and frozen at -30°C for 2 weeks in 7 cases. The fibers of the septum pellucidum and the adjacent areas including the venous elements were dissected under magnification by using homemade wooden spatulas and microsurgical instruments. In 2 cases a histological technique was used to validate the findings of the dissections. The blocks were sliced, embedded in paraffin, cut in 7-µm-thick slices, and then stained as follows: 1) with H & E, 2) with Luxol fast blue combined with cresyl violet, and 3) with Luxol fast blue combined with Sirius red.

RESULTS

The septum pellucidum and the subjacent septum verum form the medial wall of the frontal horn of the lateral ventricle. Both structures contain nerve fibers that were organized in 3 groups: 1) the precommissural fibers of the fornix; 2) the inferior fascicle; and 3) the superior fascicle of the septum pellucidum. The area directly rostral to the postcommissural column of the fornix consisted of macroscopically identifiable gray matter corresponding to the septal nuclei. The histological examinations validated the findings of the authors' fiber dissections.

CONCLUSIONS

The nerve elements of the septum pellucidum as well as the subjacent septum verum were identified with fiber dissection and verified with histology for the first time. The septal nuclei located just anterior to the fornix and the precommissural fibers of the fornix should be preserved during ESP. Considering the venous anatomy as well as the neural architecture of the septum pellucidum, the fenestration should ideally be placed above the superior edge of the fornix and preferably dorsal to the interventricular foramen.

Surgical treatment of long-standing overt ventriculomegaly in adults (LOVA)

BACKGROUND

Longstanding overt ventriculomegaly in adults (LOVA) is characterised by chronic hydrocephalus presumed to begin during infancy, but arresting before becoming clinically detectable. Later in life clinical features of hydrocephalus ensue, typically in the 5th or 6th decades. Only a relatively small number of LOVA case series have been published, and ambiguity remains regarding optimal management. This case series describes a series of patients with LOVA treated successfully at a single neurosurgical institution using endoscopic third ventriculostomy (ETV).

METHODS

A series of 14 patients were diagnosed with LOVA using established clinical and radiological criteria. All patients underwent an ETV and their clinical conditions were followed up for up to 5 years post-operatively.

RESULTS

Fourteen patients (100 %) reported either improvement or halt of progression in their presenting symptoms 3 months after ETV; 93 % of patients (n = 13) did not require any further surgical intervention. One patient (7 %) reported deterioration in symptoms beyond 3 months post-operatively, which necessitated further surgery (ventriculoperitoneal shunt). These promising outcomes after ETV are mirrored in numerous other LOVA case series. Other works have analysed the value of CSF shunting procedures in LOVA, with mixed results. A direct, prospective comparison of outcomes after shunt procedures and ETV, with a specific focus on LOVA patients, is yet to be completed. A minority of patients fail to respond, or develop recurrence of symptoms, months or years after initial surgical intervention.

CONCLUSIONS

ETV is an attractive option for surgical treatment of LOVA. After surgical treatment for LOVA, long-term follow-up should be considered to screen for late recurrence of the condition.

Surgical management of arrested hydrocephalus: Case report, literature review, and 18-month follow-up

OBJECTIVE

Arrested hydrocephalus is stable ventriculomegaly without evidence of neurologic deterioration or symptoms. Management of arrested hydrocephalus in asymptomatic adults is controversial, with little clinical data. This case highlights the potential for decompensation in adults with arrested hydrocephalus and reviews the literature regarding pathophysiology and management of this clinical entity.

PATIENTS AND METHODS

A 39 year-old gentleman with arrested hydrocephalus incidentally found during work-up for new-onset seizure and managed conservatively for ten years presented with increasing headache, memory loss, gait instability and urinary and fecal incontinence. Stable massive triventriculomegaly was documented on serial brain imaging, and ophthalmologic exam revealed no papilledema.

RESULTS

The patient underwent endoscopic third ventriculostomy with immediate post-operative improvement of headache, resolution of incontinence, and cessation of seizures. At 15 months after surgery, neuropsychiatric testing demonstrated improvement in visuomotor skills, problem solving, verbal fluency and cognitive flexibility compared to his pre-operative baseline. At 18 months after surgery he remained seizure free with full continence and significant improvement in headaches.

CONCLUSION

Early recognition of arrested hydrocephalus and its potential for decompensation may prompt surgical treatment and prevent neurologic deterioration.

Hydrocephalus caused by unilateral foramen of Monro obstruction: A review on terminology

Background:

Hydrocephalus caused by unilateral foramen of Monro (FM) obstruction has been referred to in literature by many different terminologies. Precise terminology describing hydrocephalus confined to just one lateral ventricle has a very important prognostic value and determines whether or not the patient can be shunt free after an endoscopic procedure.

Methods:

Aiming to define the best term for unilateral FM obstruction, 19 terms were employed on PubMed database (http://www.ncbi.nlm.nih.gov/pubmed) as quoted phrases.

Results:

A total of 194 articles were found. Four patterns of hydrocephalus were discriminated as a result of our research term query and were divided by types for didactic purpose. Type A - partial dilation of the lateral ventricle; Type B - pure unilateral obstruction of the FM; Type C - previously shunted patients with secondary obstruction of the FM; and Type D - asymmetric lateral ventricles with patent FM.

Conclusion:

In unilateral FM obstruction hydrocephalus, an in-depth review on terminology application is critical to avoid mistakes that may compromise comparisons among different series. This terminology review suggests that Type B hydrocephalus, i.e., the hydrocephalus confined to just one lateral ventricle with no other sites of cerebrospinal fluid circulation blockage, are best described by the terms unilateral hydrocephalus (UH) and monoventricular hydrocephalus, the first being by far the most popular. Type A hydrocephalus is best represented in the literature by the terms uniloculated hydrocephalus and loculated ventricle; Type C hydrocephalus by the terms isolated lateral ventricle and isolated UH; and Type D hydrocephalus by the term asymmetric hydrocephalus.

Neuroendoscopic surgery for ventriculitis and hydrocephalus after shunt infection and malfunction: Preliminary report of a new strategy

If not controlled in the early stage, ventriculitis is difficult to treat neurosurgically and can lead to serious sequelae, a long course of treatment, and hospitalization. We report two cases of ventriculitis and progressive hydrocephalus after shunt infection. Both were successfully treated by neuroendoscopic septostomy in combination with thorough intraventricular irrigation through a single burr hole followed by single shunt revision. Although surgical intervention has not been established as a first-choice treatment for ventriculitis, including early-stage ventriculitis, prompt neuroendoscopic surgery appears effective for the management of ventriculitis and hydrocephalus after shunt infection. The strategy described in this report might be useful to avoid recurrent shunt infections and malfunctions, simplify a shunt, and reduce the overall duration of hospitalization.

Third ventricular schwannoma with hydrocephalus

Intraventricular schwannomas are rare, with only 20 cases reported in the literature to our knowledge, including two cases of schwannomas in the third ventricle. We report a 23-year-old man with a mass in the posterior portion of the third ventricle and obstructive hydrocephalus. The intraventricular mass was clearly visualized and removed by neuroendoscopic surgery, and endoscopic third ventriculostomy was simultaneously performed for the hydrocephalus. Histological and immunohistochemical assays of the surgical sample established a diagnosis of intraventricular schwannoma. The patient had a favourable outcome and no neurological deficits 1 year later. The schwannoma was distant from the choroid plexus, which supports the hypothesis that the schwannoma originated from ectopic neural crest cells that were displaced during embryogenesis.

Surgical management of complex multiloculated hydrocephalus in infants and children

OBJECTIVE

Multiloculated hydrocephalus may occur as a consequence of intraventricular hemorrhage or infection and is characterized by enlargement of multiple noncommunicating intraventricular and/or periventricular cysts. In this study, we report the outcomes of open and endoscopic fenestration for multiloculated hydrocephalus at our institution.

METHODS

Records of children who underwent endoscopic or open fenestration at St. Louis Children's Hospital from 1999 to 2011 were analyzed. The cause of MLH, operative parameters, length of hospital stay, and subsequent shunt intervention rate were recorded.

RESULTS

Twenty-five subjects were identified for study. Twelve subjects underwent open craniotomy and 13 underwent endoscopic fenestration. Endoscopic fenestration was associated with decreased blood loss, operative time, and length of stay (p = 0.003, 0.002, 0.02, respectively). Subjects undergoing craniotomy had an average of 5.1 ± 4.5 subsequent shunt-related interventions versus 3.1 ± 4.0 in the endoscopy group (p = 0.25). The craniotomy group's median subsequent shunt revision rate was 0.74 interventions per year versus 0.50 interventions per year in the endoscopy group (p = 0.51). Fifty percent of subjects in the open fenestration group required additional fenestration surgery compared to 38.5% in the endoscopic group (p = 0.70).

CONCLUSION

Both open and endoscopic fenestration appeared effective at improving shunt management. The endoscopic technique may offer advantages in operative time, blood loss, and length of hospital stay. These data suggest that endoscopic fenestration may be used as the initial approach for treatment of multiloculated hydrocephalus, with craniotomy and open fenestration used for more severe or refractory cases.

Ventricular endoscopy in the pediatric population: review of indications

INTRODUCTION

Neuroendoscopy has greatly impacted pediatric neurosurgery over the past few decades. Improved optics and microsurgical tools have allowed neuroendoscopes to be used for a multitude of neurosurgical procedures.

DISCUSSION

In this review article, we present the breadth of intraventricular neuroendoscopic procedures for the treatment of conditions ranging from hydrocephalus and brain tumors to congenital cysts and other pathologies. We critically discuss treatment indications and reported success rates for neuroendoscopic procedures. We also present novel approaches, technical nuances, and variations from recently published literature and as practiced in the authors' institution.

ETV as a last resort

INTRODUCTION

The field of neuroendoscopy is rapidly expanding with increasing indications for endoscopic third ventriculostomy (ETV).

DISCUSSION

As a treatment for hydrocephalus, ETV has the advantage of providing a more physiological cerebrospinal fluid diversion without shunt hardware which reduces the risk of recurrent infection and malfunction. The success rate of ETV has been increasing with decreasing morbidity and mortality.

CONCLUSION

Originally, ETV was indicated for cases of obstructive hydrocephalus, however the indications are expanding. To highlight this, we present a small series of cases were ETV is not traditionally indicated and was a treatment of last choice.

Endoscopic Transventricular Transaqueductal Magendie and Luschka Foraminoplasty for Hydrocephalus

BACKGROUND:

Routinely, hydrocephalus related to fourth ventricular outlet obstruction (FVOO) has been managed with ventriculoperitoneal (VP) shunting or endoscopic third ventriculostomy (ETV). Few reports on Magendie foraminoplasty exist, and Luschka foraminoplasty has not been described.

OBJECTIVE:

To present an alternative technique in the management of FVOO via an endoscopic transventricular transaqueductal Magendie and Luschka foraminoplasty and to discuss the indications, technique, findings, and outcomes.

METHODS:

Between 1994 and 2011, all patients who underwent endoscopic Magendie and Luschka foraminoplasty were analyzed.

RESULTS:

A total of 33 Magendie (28) and/or Luschka (5) foraminoplasties were performed in 30 patients. Twenty-three were adult and 7 were pediatric patients. The etiology of the FVOO was divided into primary etiologies (congenital membrane in 5 and atresia in 2) and secondary causes (neurocysticercosis in 14 patients, bacterial meningitis in 9). Fifteen (50%) had previously failed procedures. Intraoperative findings that led to Magendie/Luschka foraminoplasty were ETV not feasible to perform, nonpatent basal subarachnoid space, or primary FVOO. Minor postoperative complications were seen in 3 patients. Only 26 patients had long-term follow-up; 17 (65.3%) of these had clinical improvement and did not require further procedures. Nine (34.7%) did not improve. Eight required another procedure (7 shunts, and 1 endoscopic procedure). One patient died.

CONCLUSION:

Flexible neuroendoscopic transventricular transforaminal Magendie and Luschka foraminoplasty is feasible and safe. These procedures may prove to be viable alternatives to standard ETV and VP shunt in appropriate patients. Adequate intraoperative assessment of ETV success is necessary to identify patients who will benefit.

Hydrocephalus research update--controversies in definition and classification of hydrocephalus

Classification of hydrocephalus is the most crucial but the most complicated academic challenge within the hydrocephalus research field. The major difficulty in this challenge arises from the fact that the classification is based on almost all subjects in hydrocephalus research, i.e., definition and terminology of hydrocephalus, pathophysiology, hydrocephalus chronology, specific forms of hydrocephalus, associated congenital anomalies/syndrome and underlying conditions, diagnostic procedures for hydrocephalus, and treatment modalities in hydrocephalus. The current status of the classification of hydrocephalus in individual subgroups was reviewed and summarized from publications in the last 60 years (1950-2010), and discussed focusing on the variety of characteristics in hydrocephalus, with more and more new aspects recently disclosed not only in fetal and pediatric but also in adult hydrocephalus. A recently-reported classification of hydrocephalus, "Multi-categorical Hydrocephalus Classification" provides comprehensive coverage of the entire aspects of hydrocephalus with current important classification categories and subtypes.

Endoscopic septostomy through a standard precoronal ventricular access: feasibility and effectiveness

BACKGROUND

Although endoscopic septostomy is widely adopted in the treatment of unilateral or specific types of hydrocephalus, there is no consensus on surgical indications, technical aspects and postoperative outcome. In particular, the choice of the ventricular access has been recently debated. We investigated the results of endoscopic septostomy performed through a standard precoronal ventricular access using a rigid endoscope.

METHODS

Patients who underwent an endoscopic septostomy at our Institution from March 2001 to March 2011 were retrospectively identified. Clinico-radiological data and video recordings of the endoscopic procedures were reviewed.

RESULTS

Sixty-three patients (50 children and 13 adults) were collected. In adults, the obstruction of the cerebrospinal fluid (CSF) pathway was exclusively secondary to a tumor (neoplastic or pseudoneoplastic lesion). In the pediatric group hydrocephalus was most commonly due to a neoplasm (33 out of 50 patients), post-hemorrhagic and/or post-infectious hydrocephalus affecting 11 children and malformative hydrocephalus the remaining six children. We were able to perform the septostomy in all but two patients, presenting with a scarred multilayered septum secondary to post-hemorrhagic hydrocephalus. In 37 cases, one or more other endoscopic procedures were performed contemporarily. The mean follow-up was 24 months (min-max: 5-96 months). Overall, all but one patient benefited clinically and radiologically from the endoscopic septostomy. Two patients harboring a pineal/mesencephalic tumor experienced a late obstruction of the stoma secondary to neoplastic infiltration of the septum.

CONCLUSIONS

Endoscopic septostomy can be safely performed through a standard burr-hole. The effectiveness of this approach is testified by an early success rate of more than 95% and a long term success rate of 92%.

Multiloculated hydrocephalus: a review of current problems in classification and treatment

PURPOSE

Loculated hydrocephalus is a condition in which discrete fluid-filled compartments form in or in relation to the ventricular system of the brain. Both uni- and multiloculated variants exist, with marked differences in outcome. However, several competing and seemingly interchangeable nomenclatures exist, and none address the pathophysiological basis of the condition. To clarify current treatment options, we carried out a review of the literature.

METHODS

A protocol describing search strategy and inclusion criteria was prepared in advance, and a search of MEDLINE, the Cochrane Database of Systematic Reviews, and the U.S. NIH ClinicalTrials.gov database was carried out with the search terms: "multicystic," "multiloculated," "multicompartment," "uniloculated," and "loculated." All were used in conjunction with the search term "hydrocephalus."

RESULTS

A single study with a control group was found. Remaining reports are purely case series. Research efforts are hampered by unclear and seemingly interchangeable nomenclatures, which makes comparison between studies difficult. There is a paucity of studies of high methodological quality concerning choice of treatment. At the case series level, evidence is in favor of the neuroendoscopic approach.

CONCLUSIONS

In order to ensure a consistent nomenclature as well as to guide future research, we propose a new system of classification for loculated hydrocephalus. It acknowledges the differences between uniloculated and multiloculated hydrocephalus, and goes beyond a pure anatomical model. For future research, it enables us to clearly characterize subgroups, which is essential if we are to advance our understanding and level of care for this challenging group of patients.

Endoscopic management of complex hydrocephalus

BACKGROUND

The management of complex hydrocephalus is challenging. There is no consensus of the best treatment for isolated fourth ventricles, arachnoid cysts, and multiloculated hydrocephalus, although the avoidance of multiple shunts is desirable. We reviewed our experience with the use of endoscopic techniques to simplify complex multicompartmental hydrocephalus to determine its efficacy and safety.

METHODS

We performed a retrospective study of 114 consecutive adults and children undergoing endoscopic management of hydrocephalus by a single surgeon. The type of hydrocephalus and endoscopic procedure performed were recorded. The management algorithm for simplification of complex hydrocephalus is reviewed. All patients were followed up in the office or by telephone.

RESULTS

A total of 143 endoscopic procedures were performed on 114 patients with a mean age of 4.4 years (4 weeks to 32 years). The endoscopic procedures performed included cyst fenestration, septum pellucidotomy, endoscopic third ventriculostomy, aqueductal plasty with and without stent, and removal of cystercicotic cysts. Twenty-two (19.3%) patients had planned staged endoscopic procedures. Mean follow up was 65 months (range 33-122 months). Eighty-two (72%) patients were reduced to 1 shunt, shunt independence was achieved in 32 (28%) patients, and only 8 (11%) patients required shunt revision in the follow-up period.

CONCLUSIONS

Endoscopic simplification of complex hydrocephalus enables dependence on only a single shunt in the majority of patients, and a significant proportion achieve shunt independence. Endoscopic management should be considered before the placement of a second shunt, and some cases require staged endoscopic procedures to adequately communicate multicompartmental hydrocephalus.

Classification of hydrocephalus: critical analysis of classification categories and advantages of "Multi-categorical Hydrocephalus Classification" (Mc HC)

OBJECTIVE

Hydrocephalus is a complex pathophysiology with disturbed cerebrospinal fluid (CSF) circulation. There are numerous numbers of classification trials published focusing on various criteria, such as associated anomalies/underlying lesions, CSF circulation/intracranial pressure patterns, clinical features, and other categories. However, no definitive classification exists comprehensively to cover the variety of these aspects. The new classification of hydrocephalus, "Multi-categorical Hydrocephalus Classification" (Mc HC), was invented and developed to cover the entire aspects of hydrocephalus with all considerable classification items and categories.

MATERIALS AND METHOD

Ten categories include "Mc HC" category I: onset (age, phase), II: cause, III: underlying lesion, IV: symptomatology, V: pathophysiology 1-CSF circulation, VI: pathophysiology 2-ICP dynamics, VII: chronology, VII: post-shunt, VIII: post-endoscopic third ventriculostomy, and X: others. From a 100-year search of publication related to the classification of hydrocephalus, 14 representative publications were reviewed and divided into the 10 categories.

RESULTS AND DISCUSSION

The Baumkuchen classification graph made from the round o'clock classification demonstrated the historical tendency of deviation to the categories in pathophysiology, either CSF or ICP dynamics.

CONCLUSION

In the preliminary clinical application, it was concluded that "Mc HC" is extremely effective in expressing the individual state with various categories in the past and present condition or among the compatible cases of hydrocephalus along with the possible chronological change in the future.

Multiloculated hydrocephalus

OBJECTIVE

The study aims to assess the treatment of progressive multiloculated hydrocephalus. In a retrospective study, the authors reviewed their experience with different treatment modalities.

METHODS

We have retrospectively evaluated 93 patients with progressive multiloculated hydrocephalus operated between 1988 and 2010. They represented around 2% (93/4,565) of all patients surgically treated for nontumoral hydrocephalus during this period of time at our institution.

RESULTS

Ventricular septal fenestration was carried out by craniotomy in 27 patients, endoscopic septum pellucidum fenestration in 19, endoscopic ventricular septal fenestration in 18, choroid plexectomy-fulguration in 14 (8 endoscopically and 6 by craniotomy), and third ventriculostomy in 2. Hydrocephalus was resolved in 21 patients with shunting, placing two ventricular catheters as the only procedure. Out of the 72 remaining patients, 34 underwent only one treatment, 30 two treatments, and 8 three or more procedures. The majority of patients ultimately required CSF shunt placement with only one ventricular catheter.

CONCLUSIONS

(1) Multiloculated hydrocephalus is a severe disease in which no single treatment has clearly been shown to be superior. (2) The goal of treatment is to restore communication between isolated intraventricular compartments in order to create the possibility of the implantation of a simple shunt with only one intraventricular catheter. More than improving the quality of life the patient, the objective is to reduce the number of surgical procedures. (3) Given the complexity of multiloculated hydrocephalus, each patient must be studied individually, and no procedure proposed by the literature should be ruled out, no matter how old fashioned may appear.

Neuroendoscopic surgery for unilateral hydrocephalus due to inflammatory obstruction of the Monro foramen

OBJECTIVE

Unilateral hydrocephalus (UH) is characterized by enlargement of just one lateral ventricle. In this paper, the authors will demonstrate their experiences in the neuroendoscopic management of this uncommon type of hydrocephalus.

METHOD

The authors retrospectively reviewed a series of almost 800 neuroendoscopic procedures performed from September 1995 to July 2010 and selected seven adult patients with UH. Clinical and radiological charts were reviewed and analyzed.

RESULTS

Six patients had intraventricular neurocysticercosis and one patient had congenital stenosis of the foramen of Monro. Headaches were the most common symptom. A septostomy restored cerebrospinal fluid circulation. During follow-up period (65.5 months, range 3-109) no patient has presented clinical recurrence as well as no severe complications have been observed.

CONCLUSION

UH is a rare condition. A successful treatment can be accomplished through a neuroendoscopic approach avoiding the use of ventricular shunts.

Idiopathic bilateral stenosis of the foramina of Monro treated using endoscopic foraminoplasty and septostomy

Hydrocephalus caused by stenosis of the foramen of Monro is rare. The authors describe a 28-year-old female patient with bilateral foraminal stenosis treated using endoscopic septostomy and unilateral foraminal balloon plasty (foraminoplasty). The patient's hydrocephalus and symptoms resolved postoperatively. Endoscopic strategies may be employed as first-line therapy in this condition.

Neuroendoscopic fenestration of the foramen of Monro without septostomy for unilateral hydrocephalus following neonatal intraventricular hemorrhage

PURPOSE

Unilateral hydrocephalus is a rare type of hydrocephalus caused by germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH) in preterm infants. We present a case of posthemorrhagic unilateral hydrocephalus in a preterm infant that was successfully treated with neuroendoscopic fenestration of the foramen of Monro without septostomy.

CASE REPORT

Brain ultrasound of a female infant born at 26(+1) weeks gestation revealed delayed unilateral hydrocephalus in the frontal horn of the lateral ventricle after IVH. In this case, unilateral hydrocephalus appeared to be caused by chronic inflammatory changes, leading to membrane formation in the foramen of Monro. After neuroendoscopic foraminoplasty without septostomy, ventricular size decreased, and the patient's neurological status improved per the PREMIE-NEURO exam, a neurologic examination for preterm infants of gestational age 23-37 weeks.

CONCLUSIONS

This case demonstrates that simple repermeation of the foramen without fenestration of the septum pellucidum can successfully treat membrane-induced unilateral hydrocephalus. Also, because hydrocephalus can develop even after stabilization of GMH-IVH, close follow-up during the first year of life and beyond may reduce the likelihood of brain damage due to advanced hydrocephalus.

Simplified aqueductal stenting for isolated fourth ventricle using a small-caliber flexible endoscope in a patient with neurococcidiomycosis: technical case report

OBJECTIVE

Endoscopic aqueductoplasty and stenting are a preferred treatment for isolated fourth ventricle syndrome related to membranous aqueductal obstruction. We describe a technique using a small-caliber flexible endoscope that may address some limitations of current strategies.

CLINICAL PRESENTATION

A 39-year-old woman with hydrocephalus caused by neurococcidiomycosis and a functional right frontal ventriculoperitoneal shunt presented with vomiting and an isolated fourth ventricle. Magnetic resonance imaging showed an enlarged fourth ventricle and exuberant basilar arachnoiditis obstructing the outlet foramina of the fourth ventricle. Ventriculography indicated aqueductal obstruction.

INTERVENTION

Aqueductoplasty was planned to allow spinal fluid to flow from the fourth ventricle to the ventriculoperitoneal shunt. A stent-endoscope construct was prepared by feeding a flexible endoscope through a ventricular catheter cut 4 cm from the tip. The flexible endoscope was contoured to fit the anatomy of the aqueduct. Uncomplicated aqueductoplasty was performed through a single left frontal burr hole using the stent-endoscope construct to perforate a membranous veil and inspect the fourth ventricle. The stent was deployed over the endoscope using the proximal end of the catheter to deliver and secure the stent as the endoscope was withdrawn.

CONCLUSION

Aqueductoplasty and stenting using a small-caliber flexible endoscope is feasible. The endoscope can be contoured to suit the anatomy of the aqueduct and improves visualization of the leading edge of the stent during deployment. Furthermore, when the endoscope is used to create the perforation, the target is not obscured by the shaft of the device used to make the perforation.

Navigated endoscopic surgery for multiloculated hydrocephalus in children

OBJECT

Multiloculated hydrocephalus remains a challenging condition to treat in the pediatric hydrocephalic population. In a retrospective study, the authors reviewed their experience with navigated endoscopy to treat multiloculated hydrocephalus in children.

METHODS

Between April 2004 and September 2008, navigated endoscopic procedures were performed in 16 children with multiloculated hydrocephalus (median age 8 months, mean age 16.1 +/- 23.3 months). In all patients preoperative MR imaging was used for planning entry sites and trajectories of the endoscopic approach for cyst perforation and catheter positioning. Intraoperatively, a rigid endoscope was tracked by the navigation system. For all children the total number of operative procedures, navigated endoscopic procedures, implanted ventricular catheters, and drained compartments were recorded. In addition, postoperative complications and radiological follow-up data were analyzed.

RESULTS

In 16 children, a total of 91 procedures were performed to treat multiloculated hydrocephalus, including 29 navigated endoscopic surgeries. Finally, 21 navigated procedures involved 1 ventricular catheter and 8 involved 2 catheters for CSF diversion via the shunt. The average number of drained compartments in a shunt was 3.6 +/- 1.7 (range 2-9 compartments). In 9 patients (56%) a navigated endoscopic procedure constituted the last procedure within the follow-up period. One additional surgery was necessary in 3 patients (19%) after navigated endoscopy, and in 4 patients (25%) 2 further procedures were necessary after navigated endoscopy. Serial follow-up MR imaging demonstrated evidence of sufficient CSF diversion in all patients.

CONCLUSIONS

Navigated endoscopic surgery is a safe and effective treatment option for multiloculated hydrocephalus. The combination of the endoscopic approach and neuronavigation further refines preoperative planning and intraoperative orientation. The aim of treatment is to drain as many compartments as possible and as soon as possible, thereby establishing sufficient CSF drainage with few ventricular catheters in single shunt systems. Close clinical and radiological follow-up is mandatory because multiple revisions are likely.

Neuroendoscopic foraminal plasty of foramen of Monro

OBJECTIVES

The aims of this study were to describe and analyze the technique of neuroendoscopic foraminal plasty of foramen of Monro (NEFPFMO) in the treatment of isolated unilateral hydrocephalus (IUH) due to membranous occlusion, to evaluate its efficacy and safety, and to define the benefits of neuronavigational guidance of the procedure.

MATERIALS AND METHODS

Two symptomatic neonates with IUH, as a result of congenital atresia of foramen of Monro, underwent NEFPFMO plus neuroendoscopic septostomy in the first case and neuronavigational guidance in the second one. Clinical results were excellent in both neonates. The postoperative ventricular size decreased and the progressive IUH changed to the state of arrested hydrocephalus. The neuronavigation was precise.

CONCLUSION

NEFPFMO should be the primary treatment option in patients with IUH due to membranous occlusion of foramen of Monro. It reestablishes natural anatomical communication and provides real physiological cerebrospinal fluid flow. Neuronavigation is a useful adjunct of NEFPFMO.

Ventricular anatomy of hydrocephalus associated with myeloschisis and endoscopic third ventriculostomy

OBJECTS

To characterize the anatomical features of the ventricular regions in patients with myeloschisis and related to successful performance of endoscopic third ventriculostomy (ETV).

METHODS

Radiological and endoscopic findings of 21 myeloschisis patients were retrospectively reviewed. Radiological features that could interfere with endoscopic procedures were (1) a huge massa intermedia (12/19), (2) sloping of the third ventricular floor (3/10), (3) narrow anteroposterior length of the third ventricular floor (2/10), and (4) narrow prepontine cistern (8/21). Endoscopic findings were (a) a narrow foramen of Monro (0/3), (b) hypertrophy of the anterior commissure (1/3), (c) sloping of the third ventricle floor (1/3), (d) a huge massa intermedia (3/3), and (e) opaque third ventricular floor (3/3). These endoscopic findings did not interfere with endoscopic procedures by using the Oi-HandyPro neuroendoscope without the above-mentioned radiological features 3 or 4.

CONCLUSION

Narrow anteroposterior length of the third ventricular floor and narrow prepontine cistern are not infrequently observed. Preoperative evaluation and intraoperative inspection of these findings are very important in successful performance of ETV.

New transparent peel-away sheath with neuroendoscopic orientation markers

✓The peel-away sheath in neuroendoscopic surgery offers numerous advantages and has many potential applications. However, currently available nontransparent sheaths have a critical disadvantage in that disorientation can occur, given the limited visible operative field. To overcome this obstacle, the authors have developed and clinically applied a new transparent sheath with “navigational orientation markers.” The clear peel-away sheath provides a transparenchymal route, parenchymal protection, and, most importantly, direct visualization of the surroundings along the whole trajectory and at the distal edge. The navigational orientation markers add further benefits in terms of facilitating orientation in the endoscope trajectory, making this tool extremely useful in neuroendoscopic surgery.

Endoscopic stent placement for treatment of secondary bilateral occlusion of the Monro foramina following endoscopic third ventriculostomy in a patient with aqueductal stenosis

✓ Nontumoral bilateral occlusion of the Monro foramina is a rare clinical condition. Treatment includes shunt placement, endoscopic procedures, or both. The authors describe the case of a 22-year-old woman who had previously undergone placement of a ventriculoperitoneal shunt via a right frontal approach for management of triventricular dilation due to aqueductal stenosis. Six years postoperatively she presented with right-sided slit-ventricle syndrome and stenosis of the right Monro foramen, which was treated with an endoscopic third ventriculostomy and fenestration of the septum pellucidum. Two years later she presented with bilateral lateral ventricular dilation. Inspection of the right lateral ventricle with a fiberscope revealed occlusion of the septum pellucidum fenestration; on observation, the right Monro foramen was covered by thick, tough granulation tissue and the left was occluded by thin membranous tissue. Repeated fenestration of the septum pellucidum and left Monro foraminoplasty were therefore performed by perforating this thin tissue. A stent was then introduced into the third ventricle via the right lateral ventricle, the fenestration in the septum pellucidum, and the left Monro foramen.

The authors note that fiberscopes are in general more maneuverable than rigid endoscopes and conclude that they are particularly useful for the treatment of this type of hydrocephalus.

Risk reduction of subdural collections following endoscopic third ventriculostomy

OBJECT

To evaluate the efficacy and safety using fibrin glue and absorbable hemostats for packing the endoscopic tract in a pediatric population in the prevention of subdural fluid collections after endoscopic third ventriculostomy.

MATERIALS AND METHODS

Twenty-one endoscopic third ventriculostomies were performed in 20 hydrocephalic children with a mean age of 22 months over a 4-year period using uniformly this technique. Six children, with age ranged 6 days to 22 months (mean 9 months), had severe ventriculomegaly with thin brain mantle less than 10 mm. There was no mortality and no permanent morbidity related to the endoscopic procedure. One child developed an asymptomatic collection, which could be managed conservatively and was most likely attributed to the young age of the child and the assumed poor cerebrospinal fluid absorption ability. Lost compliance of the brain parenchyma may play an additional role, which was not related to the thickness of the brain mantle. No adverse effects regarding the material used for sealing were observed over a mean follow-up of 23 months.

CONCLUSIONS

Subdural fluid collections could be prevented in 20 out of 21 procedures by using this technique regardless of the thickness of the brain mantle, the application of mixture of fibrin glue and hemostatic agents seems to be safe, and we consider this technique effective in reducing the risk of this potential complication.

Neuronavigational endoscopic endonasal sellar and parasellar surgery using a 2-mm-diameter lens rigid-rod endoscope: a cadaver study

OBJECTIVE

Most of the endoscopes used for endonasal transsphenoidal surgery use 4-mm diameter lenses. The applicability of a newly developed neuroendoscope with a lens diameter of only 2 mm was tested in endonasal transsphenoidal pituitary surgery.

METHODS

The newly developed rigid-rod neuroendoscope with a 2-mm lens and an endoscope with a 4-mm lens were coupled with a navigation system and used for this comparative study. Comparison between the views obtained with these two devices was performed in a model and in formalin-fixed cadaver heads. A pure endonasal approach was used to reach and explore the sellar and parasellar regions. The navigation system was used to locate the same position in both lenses for image comparison.

RESULTS

The sellar and parasellar regions could be reached and explored using the new endoscope with the 2-mm lens and an oval-shaped irrigation and suction channel. The visual field appeared to be reduced compared with that of the 4-mm lens. However, this reduction was compensated by greater mobility and easier introduction and maneuvering of the instruments at the sellar level. Reduced image size and brightness were also found using the 2-mm lens compared with the 4-mm lens. These differences could be overcome by increasing the amount of light and enlarging the image but with subsequent reduction in image resolution.

CONCLUSION

The small diameter of this neuroendoscope resulted in good maneuverability and maintained a fine quality of vision. Children and patients with small nostrils are good candidates for the use of such a device.

Endoscope-assisted placement of a multiperforated shunt catheter into the fourth ventricle via a frontal transventricular approach

Object

Patients with symptomatic isolated fourth ventricle and multicompartmentalized hydrocephalus benefit from operative treatment, but the optimal surgical approach and technique have yet to be established. The authors report on their experience with the treatment of symptomatic adult patients by endoscope-assisted placement of a fourth ventricle shunt catheter via a frontal transventricular approach.

Methods

The authors describe a retrospective series of four patients treated for isolated fourth ventricle. The surgical technique is described in detail: use of a flexible endoscope with dual-port intraventricular access for direct visualization and for mechanical manipulation of a multiperforated panventricular catheter guided by frameless stereotaxy.

The transventricular approach allowed optimal catheter placement within the fourth ventricle. The use of the flexible endoscope permitted the neurosurgeon to use the endoscope as a tool to guide the ventricular catheter tip within the third ventricle and through the cerebral aqueduct. Clinical outcomes demonstrated neurological and radiographically verified improvement in all patients.

Conclusions

The endoscope-assisted dual-port technique provides a solution to the technical difficulties of fourth ventricle shunt placement. The multiple advantages of this technique include a single ventricular catheter shunt system that equalizes ventricular pressures, a frontal location for the ventricular catheter that facilitates valve placement and programming, and ventricular catheter placement within the fourth ventricle that does not allow the catheter to impinge on the fourth ventricle floor and makes the catheter less prone to obstruction.

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.

Endoscopic aqueductoplasty

OBJECTIVE

Endoscopic aqueductoplasty (EA) was considered as a good alternative to endoscopic third ventriculostomy (ETV) in selected patients. A personal experience on EA is presented in this paper.

MATERIALS AND METHODS

Forty-five patients with primary or secondary aqueductal stenosis underwent EA with or without a stent between June 2000 and June 2005. Age, gender, diagnosis, endoscopic procedures, complications, and outcome were reviewed. EA was considered successful when patients with noncommunicating hydrocephalus became shunt-free. When the patient did not need a fourth ventricular shunt after the EA with or without a stent, it was considered to be successful in patients with isolated fourth ventricle.

RESULTS

Fifteen patients were older than 18 years of age. EA, EA with stent, EA with ETV, and EA with stent in addition to ETV were performed in 11, 6, 11, and 17 patients, respectively. Out of 45 patients who had undergone EA with or without stent and ETV, 31 (69%) benefited from the endoscopic procedures. The type of the endoscopic procedure, diagnosis, and the age of the patients did not significantly affect the outcome.

CONCLUSION

EA with a stent can be performed in patients with isolated fourth ventricle and in patients with aqueduct stenosis in which ETV is not feasible. EA can be dangerous and useless in aqueduct stenosis (AS), and EA with ETV is even more useless. Those patients who have undergone EA should be closely followed up for a long period of time because restenosis of the aqueduct and stent migration may happen years after endoscopic surgery.

Endoscopic aqueductal stent placement for the treatment of a trapped fourth ventricle

OBJECT

Endoscopic aqueductal stent therapy has evolved into an important technique in the treatment of a trapped fourth ventricle (TFV). The authors analyzed five cases of symptomatic TFV treated by endoscopic aqueductal stent therapy and, on the basis of intraoperative findings, discuss aspects of TFV formation.

METHODS

Patients' ages ranged from 2 to 17 years (mean 9.2 years). Two patients underwent endoscopy via a coronal bur hole approach and three via a small suboccipital craniectomy. The mean follow-up period was 30 months (range 24-38 months). In four cases, a membrane occluding the orifice of the aqueduct and covering part of the walls of the ventricle was observed. Despite slit ventricles in four cases, there was no intraoperative evidence of aqueduct wall collapse. All procedures were successful, and all patients experienced positive outcomes. In one patient, Parinaud syndrome, rotatory nystagmus, and abducent nerve palsy developed postoperatively; these deficits resolved after a preexisting supratentorial shunt was upgraded. There were no cases of aqueduct reocclusion during the follow-up period.

CONCLUSIONS

Aqueductal stent therapy is an effective method of TFV treatment. Because it prevents aqueduct reocclusion by chronic inflammatory processes in postinflammatory hydrocephalus, it has been shown to be more efficient than aqueductoplasty alone and to be an important alternative to the placement of a fourth ventricle shunt. Intraventricular processes leading to membrane formation play an important role in occlusion of the cerebral aqueduct orifices and final isolation of the fourth ventricle in postinflammatory hydrocephalus.

Endoscopic aqueductal stenting via the fourth ventricle under navigating system guidance: technical note

OBJECTIVE

We report three patients with symptomatic isolated fourth ventricle after ventriculoperitoneal shunt placement for hydrocephalus associated with ventricular hemorrhage. All three patients were treated successfully with our new method of endoscopic aqueductal stenting under navigating system guidance.

METHODS

A therapeutic rigid endoscope was inserted through the thin cerebellar hemisphere, and endoscopic aqueductal stenting was performed via the enlarged fourth ventricle under navigating system guidance.

RESULTS

All three patients underwent successful procedures with good outcomes.

CONCLUSION

Our method of aqueductal stenting is a reasonable choice for initial treatment of patients with isolated fourth ventricle, and it entails less invasive neurosurgery.

Proposal of "evolution theory in cerebrospinal fluid dynamics" and minor pathway hydrocephalus in developing immature brain

BACKGROUND

The specificity of cerebrospinal fluid (CSF) dynamics in the immature brain still remains unknown. In our data previously published, the transependymal intraparenchymal CSF pathway (the minor pathway) plays a significant role in various degrees in the alternative CSF passage. Now, there is a growing consensus in the age differences in the outcome of neuroendoscopic ventriculostomy in treatment of non-communicating types of hydrocephalus. The authors discuss the clinical significance of the specific CSF dynamics and propose the new aspect of classification of hydrocephalus with a theory in the development of CSF from the pathophysiological point of view.

PATIENTS AND METHODS

Between January 2001 and March 2004, 122 hydrocephalic children were registered at the Jikei University Hospital Women's & Children's Medical Center (JWCMC), Tokyo. Our retrospective study for the efficacy of neuroendoscopic ventriculostomy confirmed the significantly high failure rate of neuroendoscopic ventriculostomy in treating hydrocephalus in neonates and infants with non-communicating hydrocephalus as the initial impression. The prospective CSF dynamic studies using cine-mode MRI and CT ventriculo-cisternography were then routinely started. Altogether, 9 out of 29 (31%) endoscopically treated cases needed shunt placement 3-30 weeks (mean 7.9 weeks) after the endoscopic procedure(s) (publication in preparation). Five out of 11 (45%) neonates/infants under 3 months, 3/5 (60%) infants at 7-12 months, 10/10 (100%) toddlers at 1-4 years and 3/3 (100%) schoolchildren at 5-17 years were cured, as in the condition of "post-endoscopic ventriculostomy arrested hydrocephalus". The pattern of ventriculo-cisternography in neonatal/infantile cases revealed intraparenchymal predominant pattern (minor pathway) of the CSF dynamics rather than passage in the major pathway.

DISCUSSION

The various basic investigations in rodents, cats and monkeys have suggested that CSF is absorbed not via Pacchionian bodies as the last end of the major pathway, which do not exist in these animals and are recognized after infantile period in human, but through the choroids plexus and the periventricular fenestrated venous capillaries into the deep venous channel. The high incidence of "failure to arrest hydrocephalus" by neuroendoscopic ventriculostomy in fetal, neonatal and infantile periods was considered to depend on the specific CSF dynamics, in which the major CSF pathway has not developed and the minor pathway has a significant role. PROPOSAL OF THEORY: We herein propose a new aspect of classification for hydrocephalus with special reference to the CSF circulation in the minor CSF pathway, i.e. "minor pathway hydrocephalus", differentiating the conventional classification by Dandy (communicating and non-communicating) or Russell (non-obstructive and obstructive) as "major pathway hydrocephalus". We also herein propose a hypothesis that the CSF dynamics develop in the theory of evolution from the immature brain, as in the animals with the minor CSF pathway predominance, towards matured adult human brain together with completion of the major CSF pathway: the "evolution theory in CSF dynamics".