Complications of endoscopic third ventriculostomy

Comparison of endoscopic third ventriculostomy versus cerebrospinal fluid shunt procedures for the treatment of pediatric hydrocephalus in Taiwan

PURPOSE

Pediatric hydrocephalus is the most common cause of surgically treatable neurological disease in children. Controversies exist whether endoscopic third ventriculostomy (ETV) or cerebrospinal fluid (CSF) shunt placement is the most appropriate treatment for pediatric hydrocephalus. This study aimed to compare the risk of re-operation and death between the two procedures.

METHODS

We performed a retrospective population-based cohort study and included patients younger than 20-years-old who underwent CSF shunt or ETV for hydrocephalus from the Taiwan National Health Insurance Research Database.

RESULTS

A total of 3,555 pediatric patients from 2004 to 2017 were selected, including 2,340 (65.8%) patients that received CSF shunt placement and 1215 (34.2%) patients that underwent ETV. The incidence of all-cause death was 3.31 per 100 person-year for CSF shunt group and 2.52 per 100 person-year for ETV group, with an adjusted hazard ratio (HR) of 0.79 (95% confidence interval [CI] = 0.66-0.94, p = 0.009). The cumulative incidence competing risk for reoperation was 31.2% for the CSF shunt group and 26.4% for the ETV group, with an adjusted subdistribution HR of 0.82 (95% CI = 0.70-0.96, p = 0.015). Subgroup analysis showed that ETV was beneficial for hydrocephalus coexisting with brain or spinal tumor, central nervous system infection, and intracranial hemorrhage.

CONCLUSION

Our data indicates ETV is a better operative procedure for pediatric hydrocephalus when advanced surgical techniques and instruments are available.

Neuroendoscopic access to the third ventricle in patients with narrow foramen of monro without stenosis/obstruction: role of foraminoplasty

OBJECT

One of the critical steps for the success of intraventricular neuroendoscopic procedures is the entry into the third ventricle and passage of the endoscopy system through the foramen of Monro (FM). A diameter larger than that of the instrument used is considered a prerequisite for safely performing the technique, as damage to this structure can lead to alterations in the fornix and vascular structures. When the foramen diameter is narrow and there is no obstruction/stenosis, the role of foraminoplasty in reducing the risk of complications has not been adequately assessed in the literature.

METHODS

A review of endoscopic procedures conducted at our center since 2018 was undertaken. Cases in which preoperative imaging indicated a FM diameter < 6 mm and foraminoplasty technique was applied were examined to determine the technical and functional success of the procedure. The technical success was determined by completing the neuroendoscopic procedure with the absence of macroscopic lesions in the various structures comprising the foramen and without complications in the follow-up imaging tests. Functional success was defined as the absence of cognitive/memory alterations during the 3-month postoperative follow-up. Additionally, a review of the various forms of foraminoplasty described in the literature is conducted.

RESULTS

In our cohort, six patients were identified with a preoperative FM diameter < 6 mm without obstruction or stenosis. Foraminoplasty was planned for these cases to facilitate various intraventricular neuroendoscopic procedures. In all instances, the technique was successfully performed without causing macroscopic damage to the structures comprising the foramen. Follow-up visits included various cognitive tests to assess potential sequelae related to microscopic damage to the fornix. None of the patients exhibited anomalies.

CONCLUSION

Foraminoplasty in patients with a narrow FM without signs of stenosis/obstruction is a useful technique to reduce the risk of complications during the passage of the endoscopy system through this structure, enabling the safe performance of neuroendoscopic procedures.

A case of rapid deterioration in a subacute period after endoscopic third ventriculostomy

Background: Although generally a safe procedure, serious postoperative complications after endoscopic third ventriculostomy (ETV) for obstructive hydrocephaly have been rarely reported, such as delayed obstruction of the stoma at the third ventricle floor.Case description: A 20-year-old male was referred to our department because of severe headache and diplopia. A pineal tumour and obstructive hydrocephaly were detected in preoperative imaging. After tumour biopsy and ETV, the reduction of ventricle size and improvement of headaches were immediately observed. On the seventh day, however, he developed a rapidly progressing consciousness disturbance due to severe hydrocephalus leading to urgent secondary ETV. The original ventriculostomy stoma at the third ventricle floor was completely occluded by scar adhesion. The patient recovered well as previously and received additional treatment.Conclusion: Although very rare, occlusion of the ventriculostomy stoma can postoperatively occur in the subacute period. Patients undergoing ETV for obstructive hydrocephalus due to a pineal tumour should be carefully monitored to avoid serious consequences.

Neuroendoscopic transventricular transchoroidal approach for access to the posterior zone of the third ventricle or pineal region

The endoscopic transventricular transchoroidal approach facilitates entry into the posterior part of the third ventricle, allowing a visualization field from the foramen of Monro to the pineal region through this anatomical corridor. Combined surgery to treat the target lesion and possible endoscopic third ventriculostomy (ETV) can be performed through a single burr hole. A detailed description of this surgical technique is given, and a series of cases from our center is presented. This retrospective study included patients with lesions in the pineal region or posterior zone of the third ventricle who underwent surgery between 2004 and 2022 in our center for tumor biopsy or endoscopic cyst fenestration. In nine cases, the transchoroidal approach was performed. Demographic and clinical variables were collected: sex, age at diagnosis, clinical presentation, characteristics of the lesion, pathological diagnosis, characteristics of the procedure, complications, subsequent treatments, evolution, follow-up time, and degree of success of the endoscopic procedure. The mean and range of the quantitative variables and frequency of the qualitative variables were analyzed, together with the statistical significance (p < 0.05). Surgical planning was carried out by performing a preoperative MRI, calculating the ideal entry point and trajectory for each case. The preoperative planning of the surgical technique is described in detail. Of our sample, 55.6% were women, with a mean age of 35 years (7-78). The most common clinical presentation was intracranial hypertension (55.6%), with or without a focus. Eight patients presented hydrocephalus at diagnosis. The most frequent procedure was endoscopic biopsy with ETV (66.7%). The pathological diagnosis varied widely. Procedure-related complications included one case of self-limited bleeding of the choroidal fissure at its opening and one intraventricular hemorrhage due to tumor bleeding in the postoperative period. Non-procedure-related complications comprised two ETV failures and one case of systemic infection, while late complications included one case of disease progression and one case of radionecrosis. Four patients died, one due to poor neurological evolution after post-surgical tumor bleeding and three due to causes unrelated to the procedure. The rest of the patients had a favorable evolution and were asymptomatic or stable. The transchoroidal approach through a single burr hole is a feasible and safe option for access to the posterior part of the third ventricle. Proper planning of each case is necessary to avoid complications.

Cerebrospinal fluid shunt malfunctions: A reflective review

PURPOSE

Pediatric hydrocephalus is a common and challenging condition. To date, the ventriculoperitoneal shunt (VPS) is still the main lifesaving treatment option. Nonetheless, it remains imperfect and is associated with multiple short- and long-term complications. This paper is a reflective review of the current state of the VPS, our knowledge gaps, and the future state of shunts in neurosurgical practice.

METHODS AND RESULTS

The authors' reflections are based on a review of shunts and shunt-related literature.

CONCLUSION

Overall, there is still an urgent need for the neurosurgical community to actively improve current strategies for shunt failures and shunt-related morbidity. The authors emphasize the role of collaborative efforts amongst like-minded clinicians to establish pragmatic approaches to avoid shunt complications.

Neuroendoscopy: history, endoscopes, and instrumentation

INTRODUCTION

Endoscopy was first employed in the surgical treatment of neurosurgical diseases early in the twentieth century, but did not become an established practice for a long time, mainly because of poor technology and clinical results. After a slow re-appearance in the 1980s, the 1990s saw an explosion of techniques and instrumentation. Continuing technological improvement has led to further expansion of surgical techniques and indications for use of neuroendoscopy.

DISCUSSION

The expansion of ventricular endoscopy has led to significant understanding of CSF disorders. Aqueduct stenosis as cause of hydrocephalus and arachnoid cysts are an example of pathologies, the concept and understanding of which now is considerably enhanced, due to the application of neuroendoscopy in their treatment. Management of loculated hydrocephalus has been facilitated considerably with the use of the endoscope. The concepts of aqueductoplasty, septostomy, and foraminoplasty of the foramina of Monro and Magendie emerged, which were previously unknown. Skull base surgery, especially surgery for craniopharyngioma, has seen dramatic improvement in results with the use of the endoscope. Coupling of the endoscope with neuronavigation has expanded technical capabilities even further. Overall, we can do a lot more with the endoscope now in comparison to 30 years ago.

CONCLUSION

We should always remember that the endoscope is only a tool. Its use has indications and limitations related to its design and our ability to extract the maximum, in the context of its shortcomings. Further technological advances will push surgical frontiers even more in years to come.

Extra-axial endoscopic third ventriculostomy: preliminary experience with a technique to circumvent conventional endoscopic third ventriculostomy complications

OBJECTIVE

Endoscopic third ventriculostomy (ETV) is mostly safe but may have serious complications. Most of the complications are inherent to the procedure's intra-axial nature. This study aimed to explore an alternative route to overcome inherent issues with conventional ETV. The authors performed supraorbital, subfrontal extra-axial ETV (EAETV) via the lamina terminalis.

METHODS

This prospective study began in October 2021 and included patients with obstructive triventricular hydrocephalus with a Glasgow Coma Scale score of 8 or more and a minimum follow-up of 3 months. Patients with multiloculated hydrocephalus and those younger than 1 year of age were excluded. The preoperative parameters etiology, symptoms, Evans' Index, frontal occipital horn ratio (FOHR), and third ventricle index were recorded. The surgical procedure is described. Postoperative evaluation included clinical (modified Rankin Scale [mRS]) and radiological assessment with CT and cine phase-contrast MRI. Preoperative and postoperative parameters were compared statistically.

RESULTS

Ten patients were included in this study. Six patients had acute hydrocephalus, and 4 had chronic hydrocephalus. After EAETV, all patients showed clinical improvement. An mRS score of 0 or 1 was achieved in 9 patients, but the mRS score remained at 4 in a patient with tectal tuberculoma. There was a significant reduction in Evans' Index, FOHR, and third ventricle index after EAETV (p < 0.05). The mean percent reduction in Evans' Index was 20.80% ± 13.89%, the mean percent reduction in FOHR was 20.79% ± 12.98%, and the mean percent reduction in the third ventricle index was 37.45% ± 14.74%. CSF flow voids were seen in all cases. The results of CSF flow quantification parameters were as follows: mean peak velocity 3.82 ± 0.93 cm/sec, mean average velocity 0.10 ± 0.05 cm/sec, mean average flow rate 46.60 ± 28.58 μL/sec, mean forward volume 39.90 ± 23.29 μL, mean reverse volume 34.10 ± 15.98 μL, mean overall flow amplitude 74.00 ± 27.61 μL, and mean stroke volume 37.00 ± 13.80 μL. One patient developed a minor frontal lobe contusion. The frontal air sinus was breached in 5 patients, but none had CSF rhinorrhea. Transient supraorbital hypesthesia was seen in 3 patients. No patient had electrolyte disturbance or change in thirst or fluid intake habits.

CONCLUSIONS

EAETV is a feasible, safe, and effective surgical alternative to conventional ETV.

Development of a 3D Printed Brain Model with Vasculature for Neurosurgical Procedure Visualisation and Training

BACKGROUND

Simulation-based techniques using three-dimensional models are gaining popularity in neurosurgical training. Most pre-existing models are expensive, so we felt a need to develop a real-life model using 3D printing technology to train in endoscopic third ventriculostomy.

METHODS

The brain model was made using a 3D-printed resin mold from patient-specific MRI data. The mold was filled with silicone Ecoflex™ 00-10 and mixed with Silc Pig^® pigment additives to replicate the color and consistency of brain tissue. The dura mater was made from quick-drying silicone paste admixed with gray dye. The blood vessels were made from a silicone 3D-printed mold based on magnetic resonance imaging. Liquid containing paprika oleoresin dye was used to simulate blood and was pumped through the vessels to simulate pulsatile motion.

RESULTS

Seven residents and eight senior neurosurgeons were recruited to test our model. The participants reported that the size and anatomy of the elements were very similar to real structures. The model was helpful for training neuroendoscopic 3D perception and navigation.

CONCLUSIONS

We developed an endoscopic third ventriculostomy training model using 3D printing technology that provides anatomical precision and a realistic simulation. We hope our model can provide an indispensable tool for young neurosurgeons to gain operative experience without exposing patients to risk.

Endovascular Management of a Basilar Artery Pseudoaneurysm After Iatrogenic Injury During Endoscopic Third Ventriculostomy: Case Report

Endoscopic third ventriculostomy (ETV) is a well-established neurosurgical procedure. However, it carries risks of intraoperative complications, among which major vascular injury is the most dangerous. Reportedly, prominent bleeding during ETV has been noted in <1% of cases. Herein, we describe a case of a 34-year-old woman with occlusive hydrocephalus caused by a quadrigeminal cistern arachnoid cyst, who developed a pseudoaneurysm after injury of the basilar artery apex during ETV. Complete obliteration of the pseudoaneurysm with endovascular balloon-assisted coiling was done on the first postoperative day, and the patient demonstrated gradual recovery, but approximately 4 weeks later, she suffered massive rebleeding, seemingly due to rupture of the weak pseudoaneurysm wall, which resulted in her death. Careful evaluation of sagittal T2-weighted magnetic resonance images before ETV may be invaluable for assessment of the basilar artery position in relation to the third ventricle floor. In addition, use of a blunt surgical instrument (instead of a sharp one or cautery) for fenestration may be safer for prevention of arterial injury. Finally, special care should be applied in cases with an opaque third ventricle floor and inability to visualize the basilar artery during ETV.

Endoscopic third ventriculostomy in previously shunt-treated patients

OBJECTIVE

Endoscopic third ventriculostomy (ETV) is an option for treatment of hydrocephalus, including for patients who have a history of previous treatment with CSF shunt insertion. The purpose of this study was to report the success of postshunt ETV by using data from a multicenter prospective registry.

METHODS

Prospectively collected data in the Hydrocephalus Clinical Research Network (HCRN) Core Data Project (i.e., HCRN Registry) were reviewed. Children who underwent ETV between 2008 and 2019 and had a history of previous treatment with a CSF shunt were included. A Kaplan-Meier survival curve was created for the primary outcome: time from postshunt ETV to subsequent CSF shunt placement or revision. Univariable Cox proportional hazards models were created to evaluate for an association between clinical and demographic variables and subsequent shunt surgery. Postshunt ETV complications were also identified and categorized.

RESULTS

A total of 203 children were included: 57% male and 43% female; 74% White, 23% Black, and 4% other race. The most common hydrocephalus etiologies were postintraventricular hemorrhage secondary to prematurity (56, 28%) and aqueductal stenosis (42, 21%). The ETV Success Score ranged from 10 to 80. The median patient age was 4.1 years. The overall success of postshunt ETV at 6 months was 41%. Only the surgeon's report of a clear view of the basilar artery was associated with a lower likelihood of postshunt ETV failure (HR 0.43, 95% CI 0.23-0.82, p = 0.009). None of the following variables were associated with postshunt ETV success: age at the time of postshunt ETV, etiology of hydrocephalus, sex, race, ventricle size, number of previous shunt operations, ETV performed at time of shunt infection, and use of external ventricular drainage. Overall, complications were reported in 22% of patients, with CSF leak (8.6%) being the most common complication.

CONCLUSIONS

Postshunt ETV was successful in treating hydrocephalus, without subsequent need for a CSF shunt, in 41% of patients, with a clear view of the basilar artery being the only variable significantly associated with success. Complications occurred in 22% of patients. ETV is an option for treatment of hydrocephalus in children who have previously undergone shunt placement, but with a lower than expected likelihood of success.

Agenesis of the right internal carotid artery and aqueductal stenosis in a child with hydrocephalus, the role of endoscopic third ventriculostomy: a case report

Agenesis of the internal carotid artery (aICA) is a rare congenital vascular condition that can affect one or both sides of the patient. Most patients remain asymptomatic, but ischemic/hemorrhagic stroke, intracranial aneurysm, and other neurologic findings can occur. CT scan can demonstrate the absence of the bony carotid canal and helps to differentiate a complete aICA from aplasia or hypoplasia. The association of aICA and aqueductal stenosis (AS) has never been reported in the literature. We report the case of a 9-year-old with agenesis of the right ICA associated with AS and hydrocephalus, which was treated successfully with an endoscopic third ventriculostomy (ETV). We review the literature looking for the association of the clinical findings and the evolution of the patient.

Specialised Surgical Instruments for Endoscopic and Endoscope-Assisted Neurosurgery: A Systematic Review of Safety, Efficacy and Usability

While there have been great strides in endoscopic and endoscope-assisted neurosurgical approaches, particularly in the treatment of deep-sited brain and skull base tumours, the greatest technical barrier to their adoption has been the availability of suitable surgical instruments. This systematic review seeks to identify specialised instruments for these approaches and evaluate their safety, efficacy and usability. Conducted in accordance with the PRISMA guidelines, Medline, Embase, CENTRAL, SCOPUS and Web of Science were searched. Original research studies that reported the use of specialised mechanical instruments that manipulate tissue in human patients, cadavers or surgical models were included. The results identified 50 specialised instruments over 62 studies. Objective measures of safety were reported in 32 out of 62 studies, and 20 reported objective measures of efficacy. Instruments were broadly safe and effective with one instrument malfunction noted. Measures of usability were reported in 15 studies, with seven reporting on ergonomics and eight on the instruments learning curve. Instruments with reports on usability were generally considered to be ergonomic, though learning curve was often considered a disadvantage. Comparisons to standard instruments were made in eight studies and were generally favourable. While there are many specialised instruments for endoscopic and endoscope-assisted neurosurgery available, the evidence for their safety, efficacy and usability is limited with non-standardised reporting and few comparative studies to standard instruments. Future innovation should be tailored to unmet clinical needs, and evaluation guided by structured development processes.

Failure of Endoscopic Third Ventriculostomy

Endoscopic third ventriculostomy (ETV) is an alternative to cerebrospinal fluid (CSF) shunting in the treatment of hydrocephalus. Careful patient selection is critical as patient age, etiology of hydrocephalus, and previous shunting have been shown to influence ETV success rates. Intraoperatively, patient anatomy and medical stability may prevent or limit the completion of the ventriculostomy procedure, and findings such as a patulous third ventricular floor or cisternal scarring may portend a lower chance of successful hydrocephalus treatment. Patients in whom a ventriculostomy is completed may still experience continued symptoms of hydrocephalus or CSF leak, representing an early ETV failure. In other patients, the ETV may prove a durable treatment of hydrocephalus for several months or even years before recurrence of hydrocephalus symptoms. The failure pattern for ETV is different than that of shunting, with a higher early failure rate but improved long-term failure-free survival rates. The risk factors for failure, along with the presentation and management of failure, deserve review.

Analysis of complications in intraventricular neuroendoscopy in children: proposal for a standardization system

Although intraventricular neuroendoscopy is considered a minimally invasive technique with good results, there is nevertheless a risk of developing certain complications. As no agreement apparently exists concerning the classification of these complications, we aim to propose a form of classification based on the results of our series, comparing them with recent publications. We undertook a retrospective study of 170 children who underwent intraventricular neuroendoscopy between 2003 and September 2020 at our center. Data were recorded on demographic and clinical variables: age, gender, presenting symptoms, etiology, number of procedures, type of procedure, and complications. Complications were divided into two main groups, intraoperative and postoperative, and in subgroups. The intraoperative complications included one group of systemic alterations and another group of surgical problems. The postoperative complications were divided into six groups: systemic, neurologic, hormone, fluid, hemorrhagic and death. A total of 202 neuroendoscopic procedures were performed in 170 children. The mean age at first surgery was 71 months (22-122). The most common etiology of the hydrocephalus was intraventricular tumors (32.9%), followed by aqueductal stenosis (13.5%). The most usual presenting sign was intracranial hypertension. The procedure most used was third ventriculostomy (62.9%). During the procedures, we experienced 5 surgical intraoperative complications (2.47% per procedure). In the postoperative period, there were 23.7% systemic complications per procedure, 12.87% neurologic, 8.41% hormone, 10.9% fluid, 0.5% hemorrhagic, and 0.99% for postoperative death. The rate of complications associated with intraventricular neuroendoscopy was similar in our series to those already published. Comparative studies require standardization for the analysis of neuroendoscopic complications.

How should we treat long-standing overt ventriculomegaly in adults (LOVA)? A retrospective cohort study

Long-standing overt ventriculomegaly in adults (LOVA) is a heterogenous group of conditions with differing presentations. Few studies have evaluated success rates of available surgical treatments, or ascertained the natural history. There is a need to assess the efficacy of both endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt (VPS) as first-line treatments. We conducted a retrospective, single-centre study of adults with LOVA at a tertiary neurosurgery centre in England, UK, aiming to identify presentation, management strategy, and outcome following treatment. A total of 127 patients were included (mean age 48.1 years, 61/127 male). Most patients were symptomatic (73.2%, n = 93/127, median symptom duration 10 months). The most common symptoms were gait ataxia, headache, and cognitive decline (52.8%, 50.4%, and 33.9%, respectively). Fourteen patients had papilloedema. Ninety-one patients (71.7%) underwent surgery (84 ETV, 7 VPS). Over a median follow-up of 33.0 months (interquartile range [IQR] 19.0-65.7), 82.4% had a clinical improvement after surgery, and 81.3% had radiological improvement. Clinical improvement rates were similar between ETV and VP shunt groups (82.1% vs 85.7%, p = 0.812). Surgical complication rates were significantly lower in the ETV group than the VP shunt group (4.8% vs 42.9%, p < 0.001). Of the patients treated surgically, 20 (22.0%) underwent further surgery, with 14 patients improving. This study demonstrates the efficacy of ETV as a first-line treatment for LOVA.

Frequency of success and complications of primary endoscopic third ventriculostomy in infants with obstructive hydrocephalous

OBJECTIVES

To determine the success rate and complications of primary endoscopic third ventri-culostomy (ETV) in infants with obstructive hydrocephalous.

METHODS

This case series was conducted at the Department of Neurosurgery, Medical and Teaching Institute, Lady Reading Hospital Peshawar from July 2016 to June 2018. All consecutive patients with age less than one year who underwent ETV for primary obstructive hydrocephalous, of both gender, were included in the study. The patients were followed up to six months after surgery. The data was entered in a specially designed Performa. Patients' data was analyzed using SPSS version 21.0.

RESULTS

We had total 21 patients with age less than one year during the study period. Male patients were 11 (52.4%). Success rate of ETV at six months of follow up was 12 (57.1%). Post-op complications observed were in 9.52% (2/21) cases. One patient had cerebrospinal fluid CSF) leak and the other had significant bleed.

CONCLUSION

ETV is successful in 57.1% of infants with obstructive type of hydrocephalous. The post op complications in case of ETV are lower than Ventriculo-peritoneal shunts. Therefore, ETV can be offered to infants having obstructive hydrocephalous.

Outcome of Initial 3 Years of Cranial Endoscopy at DG Khan Medical College and Teaching Hospital, Dera Ghazi Khan

OBJECTIVE

With the evolution of surgical approaches, endoscopic skull base surgery has emerged as a suitable alternative to many other invasive methods. The aim of this study was to investigate the efficacy and outcome of cranial endoscopy in treating various neurosurgical intracranial pathologies in terms of procedural success and complications.

METHODS

This observational, prospective case series was conducted at the Department of Neurosurgery of DG Khan Medical College from November 2017 to October 2020. The study enrolled 74 patients with indications for cranial neuroendoscopy. Clinical examination was performed, and a detailed history of the disease was obtained. Follow-up was conducted in the outpatient department. The collected data were analyzed using statistical analysis software.

RESULTS

Of 77 procedures performed, endoscopic third ventriculostomy, arachnoid cyst fenestration, septostomy, colloid cyst excision, endoscopic assisted ventricular catheter placement, and intraventricular tumor biopsy were performed in 53.3%, 18.2%, 10.4%, 7.8%, 6.5%, and 3.9% of patients. Aqueductal stenosis was identified as the most common cause of obstructive hydrocephalus. Seizures and cerebrospinal fluid leaks were the most commonly reported complications (12% and 8.1%, respectively). The observed mortality rate was 2.7%.

CONCLUSIONS

Neuroendoscopic surgery has become safe and effective, as surgeon experience and learning have lowered the risk of complications, and offers a low-cost alternative intervention.

Endoscopic Third Ventriculostomy - A Review

BACKGROUND

Endoscopic third ventriculostomy (ETV) has become a proven modality for treating obstructive and selected cases of communicating hydrocephalus.

OBJECTIVE

This review aims to summarize the indications, preoperative workup, surgical technique, results, postoperative care, complications, advantages, and limitations of an ETV.

MATERIALS AND METHODS

A thorough review of PubMed and Google Scholar was performed. This review is based on the relevant articles and authors' experience.

RESULTS

ETV is indicated in obstructive hydrocephalus and selected cases of communicating hydrocephalus. Studying preoperative imaging is critical, and a detailed assessment of interthalamic adhesions, the thickness of floor, arteries or membranes below the third ventricle floor, and prepontine cistern width is essential. Blunt perforation in a thin floor, while bipolar cautery at low settings and water jet dissection are preferred in a thick floor. The appearance of stoma pulsations and intraoperative ventriculostomography reassure stoma and basal cistern patency. The intraoperative decision for shunt, external ventricular drainage, or Ommaya reservoir can be taken. Magnetic resonance ventriculography and cine phase-contrast magnetic resonance imaging can determine stoma patency. Good postoperative care with repeated cerebrospinal fluid drainage enhances outcomes in selected cases. Though the complications mostly occur in an early postoperative phase, delayed lethal ones may happen. Watching live surgeries, assisting expert surgeons, and practicing on cadavers and models can shorten the learning curve.

CONCLUSION

ETV is an excellent technique for managing obstructive and selected cases of communicating hydrocephalus. Good case selection, methodical technique, and proper training under experts are vital.

Endoscopic third ventriculostomy and choroid plexus cauterization (ETV/CPC) for hydrocephalus of infancy: a technical review

In the twenty-first century, choroid plexus cauterization (CPC) in combination with endoscopic third ventriculostomy (ETV) has emerged as an effective treatment for some infants with hydrocephalus, leading to the favourable condition of 'shunt independence'. Herein we provide a narrative technical review considering the indications, procedural aspects, morbidity and its avoidance, postoperative care and follow-up. The CP has been the target of hydrocephalus treatment for more than a century. Early eminent neurosurgeons including Dandy, Putnam and Scarff performed CPC achieving generally poor results, and so the procedure fell out of favour. In recent years, the addition of CPC to ETV was one of the reasons greater ETV success rates were observed in Africa, compared to developed nations, and its popularity worldwide has since increased. Initial results indicate that when ETV/CPC is performed successfully, shunt independence is more likely than when ETV is undertaken alone. CPC is commonly performed using a flexible endoscope via septostomy and aims to maximally cauterize the CP. Success is more likely in infants aged >1 month, those with hydrocephalus secondary to myelomeningocele and aqueductal obstruction and those with >90% cauterized CP. Failure is more likely in those with post-haemorrhagic hydrocephalus of prematurity (PHHP), particularly those <1 month of corrected age and those with prepontine scarring. High-quality evidence comparing the efficacy of ETV/CPC with shunting is emerging, with data from ongoing and future trials offering additional promise to enhance our understanding of the true utility of ETV/CPC.

Endoscopic third ventriculostomy before surgery of third ventricle and posterior fossa tumours decreases the risk of secondary hydrocephalus and early postoperative complications

Endoscopic third ventriculostomy (ETV) is an effective treatment for obstructive hydrocephalus (HCP) at the level of third or fourth ventricle. To date, there is no consensus regarding its role as intervention preceding the operation of tumour removal. The aim of this prospective open-label controlled study is to assess if ETV prevents secondary HCP after tumour removal and if ETV influences the early results of tumour surgery. The study was performed on 68 patients operated for tumours of the third ventricle and posterior fossa. In 30 patients, ETV was performed several days before tumour removal, while in 38 patients, the tumour was removed during a one-stage procedure without ETV. Patients who did not receive ETV before the tumour removal procedure had a higher probability of developing postoperative HCP (n = 12, p = 0.03). They also demonstrated a substantially higher rate of early postoperative complications (n = 20, p = 0.002) and a lower Karnofsky score (p = 0.004) than patients in whom ETV was performed before tumour removal. The performance of external ventricular drainage in the non-ETV group did not prevent secondary HCP (p = 0.68). Postoperative cerebellar swelling (p = 0.01), haematoma (p = 0.04), cerebrospinal fluid leak (p = 0.04) and neuroinfection (p = 0.04) were the main risk factors of persistent HCP. Performance of ETV before tumour removal is not only beneficial for control of acute HCP but also prevents the occurrence of secondary postoperative HCP and may also minimize early postoperative complications.

Neurosurgical anatomy of the floor of the third ventricle and related vascular structures

PURPOSE

Anatomical knowledge of the floor of the third ventricle (FTV) is essential in avoiding surgical complications during endoscopic third ventriculostomy. The purpose of this study was to characterize the morphometry of FTV and related arteries, particularly the basilar artery (BA), as well as the factors that influence it.

METHODS

Twenty-six formalin-fixed adult brains and two hundred adult brain MRIs were studied focusing on FTV and related arteries. Dimensions of interest were measured using image analysis software. Morphometric data obtained were statistically analysed.

RESULTS

Distances between FTV, intermammillary sulcus (IMS), infundibulum, BA bifurcation, and posterior communicating arteries (PCoAs) were described on the cadavers and the MRIs. Distance between right and left PCoAs was greater at their anterior extremity (p < 0.001). Right PCoA was longer (p = 0.016). BA was lateralized in 58.4% of cases and its calibre was larger in males (p < 0.001). The distance from BA apex to FTV was inversely correlated with BA diameter (p < 0.001) and age (p = 0.004). Distance from IMS to infundibulum and the distance between both PCoAs were greater in MRI series when compared to cadaver series (p < 0.001).

CONCLUSIONS

A quantitative description of the morphometry of the region of the FTV and related vessels was obtained, helping neurosurgeons in planning their surgical approach. The distance from BA apex to FTV was shorter in individuals with larger BA calibre and in older subjects. MRI studies were qualitatively superior to cadaveric studies in evaluating the anatomy of this region.

Endoscopic third ventriculostomy for pediatric tumor-associated hydrocephalus

OBJECTIVE

Surgical options for managing hydrocephalus secondary to CNS tumors have traditionally included ventriculoperitoneal shunting (VPS) when tumor resection or medical management alone are ineffective. Endoscopic third ventriculostomy (ETV) has emerged as an attractive treatment strategy for tumor-associated hydrocephalus because it offers a lower risk of infection and hardware-related complications; however, relatively little has been written on the topic of ETV specifically for the treatment of tumor-associated hydrocephalus. Here, the authors reviewed the existing literature on the use of ETV in the treatment of tumor-associated hydrocephalus, focusing on the frequency of ETV use and the failure rates in patients with hydrocephalus secondary to CNS tumor.

METHODS

The authors queried PubMed for the following terms: "endoscopic third ventriculostomy," "tumor," and "pediatric." Papers with only adult populations, case reports, and papers published before the year 2000 were excluded. The authors analyzed the etiology of hydrocephalus and failure rates after ETV, and they compared failure rates of ETV with those of VPS where reported.

RESULTS

Thirty-two studies with data on pediatric patients undergoing ETV for tumor-related hydrocephalus were analyzed. Tumors, particularly in the posterior fossa, were reported as the etiology of hydrocephalus in 38.6% of all ETVs performed (984 of 2547 ETVs, range 29%-55%). The ETV failure rate in tumor-related hydrocephalus ranged from 6% to 38.6%, and in the largest studies analyzed (> 100 patients), the ETV failure rate ranged from 10% to 38.6%. The pooled ETV failure rate was 18.3% (199 failures after 1087 procedures). The mean or median follow-up for ETV failure assessment ranged from 6 months to 8 years in these studies. Only 5 studies directly compared ETV with VPS for tumor-associated hydrocephalus, and they reported mixed results in regard to failure rate and time to failure. Overall failure rates appear similar for ETV and VPS over time, and the risk of infection appears to be lower in those patients undergoing ETV. The literature is mixed regarding the need for routine ETV before resection for posterior fossa tumors with associated hydrocephalus.

CONCLUSIONS

Treatment of tumor-related hydrocephalus with ETV is common and is warranted in select pediatric patient populations. Failure rates are overall similar to those of VPS for tumor-associated hydrocephalus.

An Unusual But Possible Complication After Endoscopic Third Ventriculostomy

BACKGROUND

We present an unusual but possible complication after ETV for the treatment of acute hydrocephalus due to malfunction of a previously implanted V-P shunt.

CASE DESCRIPTION

A 12-year-old male patient was urgently operated upon by means of an endoscopic third-ventriculostomy and the positioning of a temporary external ventricular catheter because of the malfunction of a previously implanted V-P shunt; immediately after the operation, the tip of the external catheter caused an obstruction of the ostomy, which was resolved with the withdrawn of catheter for circa 1 cm, left closed and ultimately removed after 4 days. The patient did not present any further symptom and remained shunt-free at the last 2-year follow-up visit.

CONCLUSIONS

One should consider such occurrence in cases of early ETV failure when a ventricular catheter is left in situ, even though temporarily.

Patient and parental assessment of factors influencing the choice of treatment in pediatric hydrocephalus

OBJECTIVE

Choosing between competing options (shunt or endoscopic third ventriculostomy) for the management of hydrocephalus requires patients and caregivers to make a subjective judgment about the relative importance of risks and benefits associated with each treatment. In the context of this particular decision, little is known about what treatment-related factors are important and how they are prioritized in order to arrive at a treatment preference.

METHODS

The Hydrocephalus Association electronically distributed a survey to surgically treated hydrocephalus patients or their families. Respondents rated the importance of various surgical attributes in their decision-making about treatment choice, and also indicated their preference in hypothetical scenarios involving a trade-off between potential risks and benefits of treatment. Rank-order correlations were used to determine whether certain predictor variables affected the rating of factors or hypothetical treatment choice.

RESULTS

Eighty percent of 414 respondents rated procedural risks, minimizing repeat surgery, and improving long-term brain function as being very or extremely important factors when deciding on a treatment; 69% rated the need to implant a permanent device similarly. Parent-respondents rated procedural risks higher than patient-respondents. A majority of respondents (n = 209, 54%) chose a procedure with higher surgical risk if it meant that implantation of a permanent device was not required, and respondents were more likely to choose this option if they discussed both treatment options with their surgeon prior to their initial intervention (Spearman rho 0.198, p = 0.001).Although only 144 of 384 total respondents (38%) chose a less established operation if it meant less repeat surgery, patient-respondents were more likely to choose this option compared to parent-respondents (Spearman rho 0.145, p = 0.005). Likewise, patient-respondents were more likely than parent-respondents to choose an operation that involved less repeat surgery and led to worse long-term brain function (Spearman rho 0.160, p = 0.002), an option that was chosen by only 23 (6%) of respondents overall.

CONCLUSIONS

This study is the first exploration of patient/parental factors that influence treatment preference in pediatric hydrocephalus. Procedural risks, minimizing repeat operations, and the desire to maximize long-term cognitive function appeared to be the most important attributes that influenced treatment decisions that the survey respondents had made in the past. Patients and/or their caregivers appear to see some inherent benefit in being shunt free. It appears that fear of multiple revision operations may drive treatment choice in some circumstances.

Frame-Based Stereotactic Endoscopic Third Ventriculostomy-Toward Improved Precision and Minimizing Morbidities

BACKGROUND

Endoscopic third ventriculostomy (ETV) is a widely accepted treatment for obstructive hydrocephalus. For most practitioners, this procedure will be performed without navigation guidance. Without such guidance, the complications associated with the procedure have ranged from 1% to 8%. We hypothesized that the discrepancy between the surface bony anatomy and internal cranial anatomy contributes to the morbidities associated with ETV. We tested this hypothesis by comparing the position of the entry point defined by the classic Kocher's point relative to the ideal entry point that would result in no manipulation of the endoscope defined by frame-based stereotaxis.

METHODS

The cranial computed tomography scan of 58 patients who had undergone frame-based stereotactic ETV was reformatted into 3-dimensional renderings. The location of this entry point was compared with the Kocher point, as determined by the external bony anatomy.

RESULTS

Overall, >70% of the burr holes that provided an ideal trajectory to the third ventricle were ≥0.5 cm from the Kocher point in both the sagittal and the coronal planes. Median deviations of 0.74 and 0.81 cm in the coronal (P < 0.01) and sagittal (P < 0.0001) planes were observed.

CONCLUSION

The use of stereotactic endoscopic techniques increase the safety of third ventriculostomy by adding precision and reducing otherwise unnecessary surgical maneuvering.

Endoscopic Third Ventriculostomy: A Single-Center Experience in Greece

Endoscopic third ventriculostomy is an important tool in the treatment of various forms of adult hydrocephalus, and its use is evolving over the past years, proving in many cases more effective than the more traditional ventriculoperitoneal shunts. We present the experience from our department while comparing the results and complications with the international literature.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Neurocognitive Complications after Ventricular Neuroendoscopy: A Systematic Review

In recent years, neuroendoscopic treatment of hydrocephalus and various ventricular pathologies has become increasingly popular. It is considered by many as the first-choice treatment for the majority of these cases. However, neurocognitive complications following ventricular neuroendoscopic procedures may occur leading mostly to amnesia, which might have a grave effect on the patient's quality of life. Studies assessing neurocognitive complications after ventricular neuroendoscopic procedures are sparse. Therefore, we conducted a systematic review assessing the available literature of neurocognitive complications and outcome after ventricular neuroendoscopy. Of 1216 articles screened, 46 were included in this systematic review. Transient and permanent neurocognitive complications in 2804 ventricular neuroendoscopic procedures occurred in 2.0% (n = 55) and 1.04% (n = 28) of the patients, respectively. Most complications described are memory impairment, followed by psychiatric symptoms (psychosyndrome), cognitive impairment not further specified, declined executive function, and confusion. However, only in 20% of the series describing neurocognitive complications or outcome (n = 40) was neurocognition assessed by a trained neuropsychologist in a systematic manner. While in most of these series only a part of the included patients underwent neuropsychological testing, neurocognitive assessment was seldom done pre- and postoperatively, long-term follow up was rare, and patient's cohorts were small. A paucity of studies analyzing neurocognitive complications and outcome, through systematic neuropsychological testing, and the correlation with intraoperative lesions of neuronal structures (e.g., fornix) exists in the literature. Therefore, the neurocognitive and emotional morbidity after ventricular neuroendoscopic procedures might be underestimated and warrants further research.

Design and validation of a 3D-printed simulator for endoscopic third ventriculostomy

BACKGROUND

Simulation-based training has been considered as the most promising curriculum for neurosurgical education to finally improve surgical skills with the greatest efficiency and safety. However, most of the simulators including physical models and virtual reality systems are relatively expensive, which limits their promotion. In this study, the authors tried to develop a realistic, low-cost, and reusable simulator for endoscopic third ventriculostomy (ETV) and evaluate its validity.

METHODS

A 3D-printed rigid skull with the ventricular system originated from a de-identified patient with obstructive hydrocephalus was constructed. The third ventricular floor was designed as a replaceable module. Thirty-nine neurosurgeons tested the simulator and a rating system was established to assess their performance. All participants filled out questionnaires to evaluate the simulator after training. Five neurosurgical students were recruited to finish the whole training for ten times in order to explore the learning curve of ETV.

RESULTS

We found that (1) the more experienced surgeons performed obviously better than the rather inexperienced surgeons which verified that our model could reflect the ability of the trainees; (2) as the training progressed, the scores of the post-graduates increased and the fifth training average score was obviously higher than their first training average score. The feedback questionnaires showed the average scores for value of the simulator as a training tool and global rating were 3.15 and 3.54 (on a 4-point scale).

CONCLUSION

Our model was practical for ETV training. The results of our program showed that our model could precisely reflect the operators' ability to perform ETV and could make it more efficient to master basic skills.

A critical appraisal of Monro's erroneous description of the cerebral interventricular foramina: Age-related magnetic resonance imaging spatial morphometry and a proposed new terminology

Anatomic connections between the cerebral lateral and third ventricles have been mischaracterized since Monro's original erroneous description of his eponymous foramina (FoMs) as being only one T-shaped passage. Accurate knowledge of the in vivo three-dimensional (3D) configuration of FoM has important clinical neuroendoscopic, neurosurgical, and neuroimaging implications. We retrospectively analyzed volumetric high-resolution brain magnetic resonance imaging of 100 normal individuals to characterize the normal spatial anatomy and morphometry for each FoM. We measured the true anatomical 3D angulations of FoMs relative to standard neuroimaging orthogonal planes, and their minimum width, depth, and distance between the medial borders of bilateral FoMs. The right and left FoMs were separate, distinct, and in a V-shaped configuration. Each FoM was a round, oval, or crescent-shaped canal-like passage with well-defined borders formed by the semicircular concavity of the ipsilateral forniceal column. The plane of FoM was angled on average 56.8° ± 9.1° superiorly from the axial plane, 22.5° ± 10.7° laterally, and 37.0° ± 6.9° anteriorly from the midsagittal plane; all these angles changing significantly with increasing age. The mean narrowest diameter of FoM was 2.8 ± 1.2 mm, and its depth was 2.5 ± 0.2 mm. Thus, the true size and orientation of FoM differs from that depicted on standard neuroimaging. Notably, in young subjects, FoM has a diameter smaller than its depth, a configuration akin to a short, small canal. We propose that the eponym "Monro" no longer be associated with this structure, and the term "foramen" be abandoned. Instead, FoM should be more appropriately renamed as the "interventricular canaliculus," or IVC, for short.

Management of hydrocephalus after resection of posterior fossa lesions in pediatric and adult patients-predictors for development of hydrocephalus

The surgical management of hydrocephalus in patients with posterior fossa lesions (PFL) is critical for optimal patient outcome(s). Accordingly, it is prudent to identify patients in need of aggressive surgical intervention (i.e., ventriculoperitoneal [VP] shunting). To analyze prevalence of, and risk factors associated with, the development of post-operative hydrocephalus in both pediatrics and adults. A retrospective institutional analysis and review of patient records in those who had undergone PFL surgery was performed. In so doing, the authors identified patients that went on to develop post-operative hydrocephalus. The study included pediatric and adult patients treated between 2009 and 2017. Fifteen of 40 pediatric (37.5%) and 18 of 262 adult (6.9%) patients developed hydrocephalus after PFL surgery. The most common tumor entity in pediatrics was medulloblastoma (34%), astrocytoma (24.4%), and pilocytic astrocytoma (22%), whereas in adults, metastasis (29.5%), meningioma (22%), and acoustic neuroma (17.8%) were most common. Young age ≤ 2 years, medulloblastoma (OR 13.9), and brain stem compression (OR 5.4) were confirmed as independent predictors for hydrocephalus in pediatrics and pilocytic astrocytoma (OR 15.4) and pre-operative hydrocephalus (OR 3.6) in adults, respectively. All patients received VP shunts for hydrocephalus management and the mean follow-up was 29.5 months in pediatrics vs 19.2 months in adults. Overall complication rates related to VP shunts were 33.3% in pediatrics and 16.7% in adults, respectively. Shunt dependency and associated complications in pediatrics were noted to be higher than in adults. Given the identification of predictors for hydrocephalus, it is authors' contention that certain patients with those predictors may ultimately benefit from an alternative treatment regimen (e.g., pre-operative interventions) prior to PFT surgery.

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

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

Neurosarcoidosis Presenting with Obstructive Hydrocephalus Successfully Treated with Endoscopic Third Ventriculostomy

A 58-year-old Japanese woman complained of unstable gait and dizziness lasting for a month. She had been diagnosed histologically with pulmonary and cutaneous sarcoidosis and attended outpatient clinics for routine checkups. Head computed tomography and magnetic resonance imaging (MRI) indicated obstructive hydrocephalus caused by a contrast-enhanced lesion in the cerebral aqueduct. The patient underwent endoscopic third ventriculostomy and a biopsy of the lesion, leading to the diagnosis of neurosarcoidosis. This was a rare case of neurosarcoidosis presenting with obstructive hydrocephalus that was treated with endoscopic third ventriculostomy and diagnosed histologically via an intraoperative biopsy.

Intraventricular bone dust migration after neuroendoscopy: report of 2 cases

Neuroendoscopy has demonstrated safety and efficacy in the treatment of a host of pediatric neurosurgical pathologies. With the increase in its applicability, several associated complications have been described in the literature. A common practice in pediatric neurosurgery is the use of Gelfoam sponge pledget in the burr hole, followed by bone fragments and dust (obtained from the created burr hole), to cover the dural defect. This technique is used to enhance burr hole sealing and potentially prevent CSF leakage from the surgical site. Reports on intracranial bone dust migration associated with this technique are scarce. The authors report 2 cases of intracranial migration of bone fragments after an endoscopic third ventriculostomy and an endoscopic colloid cyst resection. The bone fragment migration was thought to be caused by negative pressure from a lumbar puncture in one case and external trauma to the head in the other. As endoscopy becomes more widely used, it is important to be aware of this potential complication that may in some cases require an intervention. A review of the cases reported in the literature is provided and a technique is suggested to help prevent this complication.

Low-cost endoscopic third ventriculostomy simulator with mimetic endoscope

OBJECTIVE Hydrocephalus affects approximately 1 in 500 people in the US, yet ventricular shunting, the gold standard of treatment, has a nearly 85% failure rate. Endoscopic third ventriculostomy (ETV) is an alternative surgical approach for a specific subset of hydrocephalic patients, but can be limited by the inability of neurosurgical residents to practice prior to patient contact. The goal of this study was to create an affordable ETV model and endoscope for resident training. METHODS Open-source software was used to isolate the skull and brain from the CT and MR images of a 2-year-old boy with hydrocephalus. A 3D printer created the skull and a 3D mold of the brain. A mixture of silicone and silicone tactile mutator was used to cast the brain mold prior to subsequent compression and shearing modulus testing. A mimetic endoscope was then created from basic supplies and a 3D printed frame. A small cohort of neurosurgical residents and attending physicians evaluated the ETV simulator with mimetic endoscope. RESULTS The authors successfully created a mimetic endoscope and ETV simulator. After compression and shearing modulus testing, a silicone/Slacker ratio between 10:6 and 10:7 was found to be similar to that of human brain parenchyma. Eighty-seven percent of participants strongly agreed that the simulator was useful for resident training, and 93% strongly agreed that the simulator helped them understand how to orient themselves with the endoscope. CONCLUSIONS The authors created an affordable (US$123, excluding 3D printer), easy-to-use ETV simulator with endoscope. Previous models have required expensive software and costly operative endoscopes that may not be available to most residents. Instead, this attempt takes advantage of open-source software for the manipulation and fabrication of a patient-specific mold. This model can assist with resident development, allowing them to safely practice use of the endoscope in ETV.

Endoscopic third ventriculostomy in children with a fiber optic neuroendoscopy

OBJECTIVE

Endoscopic third ventriculostomy (ETV) provides a shunt-free treatment for obstructive hydrocephalus children. With rapidly evolving technology, the semi-rigid fiber optic neuroendoscopy shows a potential application in ETV by blunt fenestration. A retrospective analysis of our experience is reviewed.

METHODS

The authors review infants and children who underwent ETV using this technique from June 2004 to June 2016 with radiological and clinical follow-up done by a single surgeon. Patients who underwent ETV with channel scope were excluded. Demographic variables and operative reports were collected. Improvement of preoperative symptoms and avoidance of additional cerebrospinal fluid (CSF) diversion procedures were considered a success. The ETV success score (ETVSS) was used to correlate with clinical outcomes.

RESULTS

A total of 79 patients were included with a mean age of 8.3 ± 5.5 years, and 40.5% were female. The mean clinical and radiographic follow-up was 38.6 ± 40.9 months. The overall complication rate was 6.3%, while 73.4% were considered successful. The ETV failure cases received conversion to ventriculoperitoneal shunt or redo of ETV with a median time of 2 months. The mean ETV success score was 74.3 ± 11.8 with positive correlation between success rate (P < 0.05). Kaplan-Meier failure-free survival rates of 30-day, 90-day, 6-month, 1-year, and 2-year were 89.9, 83.5, 78.5, 75.9, and 74.6%. Eight patients required redo ETV, and five of these patients required eventual shunt placements. Approximately 61.9% of failure occurred within 3 months. Patients with post-intraventricular hemorrhage (IVH) /infection, and age younger than 12 months had the poorest outcome (P < 0.05).

CONCLUSIONS

Blunt dissection of the third ventricle floor under endoscopic vision with the stylet tip of a fiber optic neuroendoscopy is safe and requires less equipment in the pediatric population. This technique is successful with an optimistic long-term outcome except for infants and the post-IVH and infectious subgroups.

Flow diversion of a recurrent, iatrogenic basilar tip aneurysm in a pediatric patient: case report

Endoscopic third ventriculostomy (ETV) is a common treatment for noncommunicating hydrocephalus. Although rare, vascular injury and traumatic pseudoaneurysm development during ETV have been reported. The authors present the case of a 13-year-old boy who underwent repeat ETV (rETV) for shunt and ETV failure, and who suffered an intraoperative subarachnoid hemorrhage due to iatrogenic injury to the basilar tip, with subsequent development of a pseudoaneurysm. Despite initial primary coil embolization, the aneurysm recurred and was definitively treated with flow diversion. In this report, the authors review complication rates associated with ETV and rETV as well as the emerging use of flow diversion and its applications in vessel reconstruction within the pediatric population.

An optimized technique of endoscopic third ventriculocisternostomy (ETV) for children with occlusive hydrocephalus

In this article, we present an optimized minimally invasive technique of ETV for children with occlusive hydrocephalus. The study comprises of 64 consecutive pediatric cases (34 boys and 30 girls aged from 1 month to 5 years) of occlusive hydrocephalus from various etiologies, which were treated with a modified technique of ETV. Mean clinical follow-up period after ETV was 24.2 ± 3.8 months. Application of the new technique made it possible to significantly reduce the length of the soft tissue incision for access, and the use of upgraded instruments allowed to perform a twist drill hole in the skull to less than half a usual size. Access to the brain and lateral ventricle was performed by blunt trephination of the dura without the need for significant corticectomy or coagulation, and yielded minimal damage to the brain, which is very important in patients of young age. Continued endoscopic control during the approach down to the lateral ventricle increases safety and decreases risk of injury, and can be performed in cases of pathologies affecting the anatomical relationships of the lateral and third ventricle. Mortality in our cohort was 0%, and there were no postoperative neurological, endocrinological, or infectious complications. Patency rates of the first ETV performed was 78%, with the remaining patients requiring additional surgical procedures for complicated settings. This new technique of minimally invasive ETV placement in pediatric patients is an effective and safe method to treat occlusive hydrocephalus and can be recommended for extensive clinical use.

Management of hydrocephalus in pediatric metastatic tumors of the posterior fossa at presentation

PURPOSE

Presence of metastases in newly diagnosed pediatric posterior fossa tumors (PFT) is not a rare situation, but optimal treatment of associated hydrocephalus in these children has remained undetermined.

METHODS

Twenty-nine children treated between January 2005 and December 2015 for a metastatic PFT associated with hydrocephalus constituted the study cohort. Patients were divided into three groups: ventriculoperitoneal shunt (VPS), endoscopic third ventriculostomy (ETV), and temporary ventricular drainage before or during tumor resection (PVD).

RESULTS

There were 4 VPS, 18 ETV, and 7 PVD. The global incidence of CSF diversion failure was 52%. No case of dysfunction or dissemination of metastatic cells occurred in the VPS group. Recurrence of hydrocephalus occurred in 55% of the ETV group. Presence of multiple macroscopic metastases and CSF metastatic cells after tumor surgery was associated with ETV failure. Fifty-seven percent of the children in the PVD group were reoperated after an average time of 53 days. Specific oncologic treatment was initiated earlier in the VPS group (11 days) compared to ETV (27 days) and PVD (23 days) groups.

CONCLUSIONS

ETV should be avoided in cases of multiple macroscopic metastases, and children who underwent ETV must be followed carefully when metastatic cells are present in CSF after tumor surgery. External ventricular drainage before or during surgical removal should not be considered as a final option to treat hydrocephalus. VPS remains a safe alternative in this situation and allows an early specific oncologic treatment.

Failure of ETV in patients with the highest ETV success scores

OBJECTIVE Endoscopic third ventriculostomy (ETV) is a surgical alternative to placing a CSF shunt in certain patients with hydrocephalus. The ETV Success Score (ETVSS) is a reliable, simple method to estimate the success of the procedure by 6 months of postoperative follow-up. The highest score is 90, estimating a 90% chance of the ETV effectively treating hydrocephalus without requiring a shunt. Treatment with ETV fails in certain patients, despite their being the theoretically best candidates for the procedure. In this study the authors attempted to identify factors that further predicted success in patients with the highest ETVSSs. METHODS A retrospective review was performed of all patients treated with ETV at 3 institutions. Demographic, radiological, and clinical data were recorded. All patients by definition were older than 1 year, had obstructive hydrocephalus, and did not have a prior shunt. Failure of ETV was defined as the need for a shunt by 1 year. The ETV was considered a success if the patient did not require another surgery (either shunt placement or a repeat endoscopic procedure) by 1 year. A statistical analysis was performed to identify factors associated with success or failure. RESULTS Fifty-nine patients met the entry criteria for the study. Eleven patients (18.6%) required further surgery by 1 year. All of these patients received a shunt. The presenting symptom of lethargy statistically correlated with success (p = 0.0126, odds ratio [OR] = 0.072). The preoperative radiological finding of transependymal flow (p = 0.0375, OR 0.158) correlated with success. A postoperative larger maximum width of the third ventricle correlated with failure (p = 0.0265). CONCLUSIONS The preoperative findings of lethargy and transependymal flow statistically correlated with success. This suggests that the best candidates for ETV are those with a relatively acute elevation of intracranial pressure. Cases without these findings may represent the failures in this highly selected group.