Rare Complications of CSF Diversion: Paradoxical Neuroimaging Findings in a Double, Chiasmic Case Report.

Two patients with CSF shunting systems exhibited symptoms of altered intracranial pressure. Initial neuroimaging led to misinterpretation, but integrating clinical history and follow-up imaging revealed the true diagnosis. In the first case, reduced ventricular size was mistaken for CSF overdrainage, while the actual problem was increased intracranial pressure, as seen in slit ventricle syndrome. In the second case, symptoms attributed to intracranial hypertension were due to CSF overdrainage causing tonsillar displacement and hydrocephalus. Adjusting the spinoperitoneal shunt pressure resolved symptoms and imaging abnormalities. These cases highlight the necessity of correlating clinical presentation with a deep understanding of CSF dynamics in shunt assessments.

Chronic Pediatric Headache as a Manifestation of Shunt Over-Drainage and Slit Ventricle Syndrome in Patients Harboring a Cerebrospinal Fluid Diversion System: A Narrative Literature Review.

The main subject of the current review is a specific subtype of headache, which is related to shunt over-drainage and slit ventricle syndrome, in pediatric patients harboring an implanted shunt device for the management of hydrocephalus. This clinical entity, along with its impairment regarding the quality of life of the affected individuals, is generally underestimated. This is partly due to the absence of universally agreed-upon diagnostic criteria, as well as due to a misunderstanding of the interactions among the implicated pathophysiological mechanisms. A lot of attempts have been performed to propose an integrative model, aiming at the determination of all the offending mechanisms of the shunt over-drainage syndrome, as well as the determination of all the clinical characteristics and related symptomatology that accompany these secondary headaches. This subcategory of headache, named postural dependent headache, can be associated with nausea, vomiting, and/or radiological signs of slim ventricles and/or subdural collections. The ultimate goal of our review is to draw clinicians' attention, especially that of those that are managing pediatric patients with permanent, long-standing, ventriculoperitoneal, or, less commonly, ventriculoatrial shunts. We attempted to elucidate all clinical and neurological characteristics that are inherently related to this type of headache, as well as to highlight the current management options. This specific subgroup of patients may eventually suffer from severe, intractable headaches, which may negatively impair their quality of daily living. In the absence of any other clinical condition that could be incriminated as the cause of the headache, shunt over-drainage should not be overlooked. On the contrary, it should be seriously taken into consideration, and its management should be added to the therapeutic armamentarium of such cases, which are difficult to be handled.

Positional shunt assist for slit ventricle syndrome.

PURPOSE: Hydrocephalus is one of the most common pathologies in pediatric neurosurgery. One of the causes of recurring events of headaches among shunted children is "slit ventricle syndrome" (SVS). Several potential treatments have been proposed, yet SVS often represents a treatment challenge. The goal of the current series is to present our experience with adding a positional shunt-assist (SA) (Miethke, Aesculap) for the treatment of SVS. METHODS: Clinical data was retrospectively collected from all consecutive children with SVS that were treated with SA (Miethke, Aesculap) at our center. Surgical and clinical outcomes as expressed by hospital visits, or need for additional surgery, were evaluated. RESULTS: Nine cases were included. Hydrocephalus etiology included IVH (6), postinfectious (1), and congenital syndromes (2). Average age at first shunt was 4 months. Primary shunt type was differential-pressure-valve in all. Average age at SVS onset was 4 years. Average age at SA placement was 5.5 years. There were no perioperative complications besides a single stich abscess. A 6-month follow-up period after SA was compared to a 6-month period prior to the SA: average hospital visits decreased from 2.4 to 0.6 per patient (p < 0.0002). 4/9 patients needed an LP or shunt revision before the SA surgery, while no procedure was indicated during the immediate 6-month follow-up. At the last follow-up, there was a significant reduction in the rate of ER visits compared to prior to surgery; however, the number of neurosurgical procedures did not significantly differ. CONCLUSION: Using a SA for SVS was associated with a short-term improvement of symptoms in the majority of cases, reduction in hospital visits, and reduced need for SVS-related procedures.

Effectiveness of subtemporal decompression for the management of slit ventricle syndrome.

OBJECTIVES: To assess the effectiveness of subtemporal decompression in the management of slit ventricle syndrome. METHODS: We conducted a retrospective review of all patients with slit ventricle syndrome (SVS) who underwent subtemporal decompression (STD) at our centre between 2010 and 2021. Cases were identified using the hospital database. Medical records for each patient were reviewed, including operative and radiological reports. RESULTS: Fifteen patients underwent STD for the management of SVS. Median age at time of STD was 9.18 years. Aetiology of hydrocephalus consisted of spinal dysraphism (5), idiopathic (4), post-infectious (1), post-haemorrhagic (3), secondary to tumour (1), and craniofacial anomalies (1). Median age at first shunt insertion was 3.4 months. Median pre-operative period assessed, from initial shunt insertion to STD, was 4.54 (interquartile range [IQR] 3.12-10.47) years. Twelve patients underwent ≥1 shunt revision prior to STD. All patients had a diagnosis of SVS at time of STD. Presenting symptoms, for the admission in which STD was performed, included nausea (9), vomiting (8), lethargy (8), headache (12), irritability (5), and visual disturbances (6). One third underwent shunt revision at the time of STD. Two patients developed post-operative complications requiring further surgery (meningitis requiring shunt revision: 1; wound debridement: 1). Three patients developed uncomplicated post-operative pyrexia, which was managed with antibiotics. Median duration of post-operative follow-up was 5.4 (IQR 1.73-8.54) years. Eleven patients underwent ≥1 shunt related procedure following STD. Wilcoxon signed-rank test demonstrated a significant difference in number of shunt related procedures before (median = 5, IQR 1-8) and after (median = 3, IQR 0-5) STD (Z = -2.083, p = .037). All patients reported subjective symptom improvement post-operatively. Thirteen patients experienced symptom recurrence at a median duration of 10 months post-operatively. CONCLUSIONS: STD was associated with a reduction in the amount of shunt related procedures required in this group of patients with SVS. Further study is required to confirm this association.

Subtemporal Decompression in Resistant Slit Ventricle Syndrome in Children: An Observational Study and Survival Analysis.

INTRODUCTION: Slit ventricle syndrome (SVS) remains a challenging problem in the early-shunted paediatric population. Various surgical and non-surgical treatments have been devised for this condition. However, there is currently no gold standard for its optimal management. Among various treatment modalities, subtemporal decompression (STD) is often performed as a last resort. We present our experience of STD in paediatric patients with SVS in whom initial treatment with programmable valves and anti-syphon device were not successful. METHODS: This is a single-centre retrospective observational study and survival analysis. Patients who underwent STD for SVS were included. Pre- and post-operative imaging data and clinical outcomes were collected. RESULTS: There were 20 patients (12 M, 8 F) with a mean age of 9 years (SD: 4) at first STD. 90% (n = 18) of patients had multiple shunt revisions pre-STD. At first STD, 70% (n = 14) and 30% (n = 6) of patients had unilateral or bilateral STD, respectively. STD led to a reduction in the frequency of shunt revisions in 60% (n = 12) of patients. The median time required before further STD, shunt surgery, or cranial vault surgery was 14 months. The median time before a further STD was required (either revision or contralateral side) was 89 months. At a median follow-up of 66.5 months (range: 1-159), 65% (n = 13) of patients had improvement in symptoms. CONCLUSIONS: A large proportion of patients with persistent SVS symptoms, refractory to multiple shunt revisions, benefitted from STD in combination with shunt optimization. It was also safe and well-tolerated. Therefore, in patients who have multiple failed shunts, STD may reduce the morbidity associated with further shunt revisions and can significantly improve symptomatology.

Noninvasive intracranial pressure monitoring throughout brain compliance guiding a ventriculoperitoneal shunt replacement in hydrocephalus-case report.

INTRODUCTION: Ventriculoperitoneal (VP) shunt is the primary therapy for hydrocephalus in children; however, this technique is amenable to malfunctions, which could be detected through an assessment of clinical signs and imaging results. Furthermore, early detection can prevent patient deterioration and guide clinical and surgical treatment. CASE PRESENTATION: A 5-year-old female with a premedical history of neonatal IVH, secondary hydrocephalus, multiple VP shunts revisions, and slit ventricle syndrome was evaluated using a noninvasive intracranial pressure monitor device at the early stages of the clinical symptoms, evidencing increased intracranial pressure and poor brain compliance. Serial MRI images demonstrated a slight ventricular enlargement, leading to the use of a gravitational VP shunt, promoting progressive improvement. On the follow-up visits, we used the noninvasive ICP monitoring device to guide the shunt adjustments until symptom resolution. Furthermore, the patient has been asymptomatic for the past 3 years without requiring new shunt revisions. DISCUSSION: Slit ventricle syndrome and VP shunt dysfunctions are challenging diagnoses for the neurosurgeon. The noninvasive intracranial monitoring has allowed a closer follow-up assisting early assessment of brain compliance changes related to a patient's symptomatology. Furthermore, this technique has high sensitivity and specificity in detecting alterations in the intracranial pressure, serving as a guide for the adjustments of programmable VP shunts, which may improve the patient's quality of life. CONCLUSION: Noninvasive ICP monitoring may lead to a less invasive assessment of patients with slit ventricle syndrome and could be used as a guide for adjustments of programmable shunts.

Development of the brain ventricular system from a comparative perspective.

The brain ventricular system (BVS) consists of brain ventricles and channels filled with cerebrospinal fluid (CSF). Disturbance of CSF flow has been linked to scoliosis and neurodegenerative diseases, including hydrocephalus. This could be due to defects of CSF production by the choroid plexus or impaired CSF movement over the ependyma dependent on motile cilia. Most vertebrates have horizontal body posture. They retain additional evolutionary innovations assisting CSF flow, such as the Reissner fiber. The causes of hydrocephalus have been studied using animal models including rodents (mice, rats, hamsters) and zebrafish. However, the horizontal body posture reduces the effect of gravity on CSF flow, which limits the use of mammalian models for scoliosis. In contrast, fish swim against the current and experience a forward-to-backward mechanical force akin to that caused by gravity in humans. This explains the increased popularity of the zebrafish model for studies of scoliosis. "Slit-ventricle" syndrome is another side of the spectrum of BVS anomalies. It develops because of insufficient inflation of the BVS. Recent advances in zebrafish functional genetics have revealed genes that could regulate the development of the BVS and CSF circulation. This review will describe the BVS of zebrafish, a typical teleost, and vertebrates in general, in comparative perspective. It will illustrate the usefulness of the zebrafish model for developmental studies of the choroid plexus (CP), CSF flow and the BVS.

External-internal cranial expansion to treat patients with craniocerebral disproportion due to post-shunt craniosynostosis: a case series.

INTRODUCTION: Secondary craniosynostosis subsequent to shunting is one of the late complications of ventricular shunt placement in the early childhood. Several interventions have been used to treat high intracranial pressure associated with this condition. This study aimed to evaluate the patients' clinical symptoms and head circumference before and after a method of decompressive craniotomy, coined as external-internal cranial expansion (EICE). METHODS: A retrospective study was conducted, and the patients who had undergone EICE for the treatment of post-shunt craniosynostosis between 2010 and 2020 were enrolled. This approach was a combination of a hinge multiple-strut decompressive craniectomy and internal cranial flap thinning by drill. Data, extracted from medical records, were used to evaluate the patients' symptoms and head circumferences before and 12 months after surgery. RESULTS: A total of 16 patients were enrolled in the study, of which eight were females. Before the surgery, 9 patients (56.2%) suffered from visual impairment, and all had intractable headache. Papilledema was recorded in all, with 3 cases having optic disc paleness. After cranial expansion, only two patients had headaches, diagnosed as migraine-type and psychosomatic headaches, respectively. In two patients, progressive visual impairments got worsening after surgery, which would be due to severe preoperative optic nerve atrophy. Patients' head circumferences significantly increased after the surgery (mean of 48.97 ± 4.28 cm vs. 45.78 ± 4.31 cm; P value < 0.0001). CONCLUSION: In lower resource countries, where newer technologies like distraction osteogenesis is not easily available, external-internal cranial expansion can be considered an effective alternative for patients with post-shunt craniosynostosis.

Shunt freedom in slit ventricle syndrome: using paradoxical ventriculomegaly following lumbar shunting to our advantage. Illustrative cases.

BACKGROUND: The authors present two cases of paradoxical ventriculomegaly after lumboperitoneal (LP) shunting in patients with slit ventricle syndrome (SVS). OBSERVATIONS: After placement of an LP shunt, both patients rapidly developed radiographic and clinically symptomatic ventricular enlargement. The then generous ventricular corridors allowed both patients to be treated by endoscopic third ventriculostomy (ETV) with concurrent removal of their LP shunt. The patients then underwent staged increases in their shunt resistance to the maximum setting and remain asymptomatic. LESSONS: The authors suggest that this paradoxical ventriculomegaly may have resulted from a pressure gradient between the shunt systems in the intra- and extraventricular spaces due to a noncommunicating etiology of their hydrocephalus. ETV may successfully exploit this newfound obstructive hydrocephalus and provide resolution of the radiographic and clinical hydrocephalus through allowing for improved communication between the cranial and lumbar cerebrospinal fluid spaces in SVS.

Visual acuity loss and sixth nerve palsy as the only manifestations of slit ventricle syndrome.

The case is presented of a girl diagnosed with obstructive hydrocephalus due to pilomyxoid astrocytoma, which required a ventriculoperitoneal shunt (VPS) at the age of 5 years and 10 months. Two months later, magnetic resonance imaging of the brain did not show ventriculomegaly or other signs of increased intracranial pressure. At the age of 6 years and 2 months, a rapid onset of bilateral visual acuity loss developed and she was diagnosed with slit ventricle syndrome. Despite valve revisions of the VPS, she developed an abrupt decline of visual acuity to hand motion at 10 cm. Fundus examination revealed bilateral optic atrophy. She did not report any other systemic symptoms suggesting increased intracranial pressure, such as headache, nausea, vomiting, lethargy, irritability, or altered levels of consciousness.

Pérdida de agudeza visual y parálisis de VI nervio craneal como únicas manifestaciones de un síndrome de colapso ventricular / Visual acuity loss and sixth nerve palsy as the only manifestations of slit ventricle syndrome

Se describe una niña con hidrocefalia obstructiva por un astrocitoma pilomixoide, que requirió implantar una derivación ventrículo-peritoneal (DVP) a los 5 años y 10 meses de edad. Dos meses después, la resonancia magnética cerebral no mostró ventriculomegalia ni otros signos de aumento de la presión intracraneal. A la edad de 6 años y 2 meses desarrolló una rápida disminución de la agudeza visual bilateral siendo diagnosticada de síndrome de colapso ventricular. A pesar de las revisiones valvulares de la DVP, se produjo una disminución abrupta de la agudeza visual a movimientos de mano a 10cm. El examen del fondo de ojo reveló atrofia óptica bilateral. No refirió otros síntomas sistémicos que sugirieran un aumento de la presión intracraneal, como dolor de cabeza, náuseas, vómitos, letargia, irritabilidad o niveles alterados de conciencia.

The case is presented of a girl diagnosed with obstructive hydrocephalus due to pilomyxoid astrocytoma, which required a ventriculoperitoneal shunt (VPS) at the age of 5 years and 10 months. Two months later, magnetic resonance imaging of the brain did not show ventriculomegaly or other signs of increased intracranial pressure. At the age of 6 years and 2 months, a rapid onset of bilateral visual acuity loss developed and she was diagnosed with slit ventricle syndrome. Despite valve revisions of the VPS, she developed an abrupt decline of visual acuity to hand motion at 10cm. Fundus examination revealed bilateral optic atrophy. She did not report any other systemic symptoms suggesting increased intracranial pressure, such as headache, nausea, vomiting, lethargy, irritability, or altered levels of consciousness.

Antisiphon device: A review of existing mechanisms and clinical applications to prevent overdrainage in shunted hydrocephalic patients.

Overdrainage of cerebrospinal fluid is one of the most notorious complications after ventriculoperitoneal shunt implantation. Siphon effect plays a major role in the development of overdrainage. Various overdrainage-preventing devices have been invented to counteract the siphon effect. Though some of the devices are designed to reduce the flow instead of providing antisiphoning effect, they are generally called antisiphon devices (ASDs). The basics of siphoning, the mechanisms and physical properties of currently available devices are described in this article. The clinical efficacy, shunt survival, and considerations on patient factors are also discussed. There are three kinds of ASD design, diaphragm, gravitational, and flow reducing devices. Flow reducing ASD is always open and the flow it controls is relatively stable. On the other hand, it may not provide sufficient flow in nocturnal intracranial pressure elevations. Diaphragm and gravitational devices are sensitive to the position of the patients. Diaphragm device is sensitive to the external pressure and the relative position of the device to the mastoid process. The gravitational device is sensitive to the angle between the axis of the device and the head. Many studies showed encouraging results with gravitational devices. Studies regarding diaphragm devices either showed better or similar outcomes comparing to differential pressure valves. Clinical studies regarding flow-reducing devices and head-to-head comparison between different mechanisms are warranted. This review aims to provide a useful reference for clinical practice of hydrocephalus.

Cerebral venous sinus thrombosis as a consequence of shunt hyperdrainage: a proposal of the pathophysiological mechanism and case report.

BACKGROUND AND AIM: Shunt dysfunction is a common event, especially in children who have this intervention performed early in life. The consequences of chronic shunt overdrainage can be multiple since the cerebral hydrodynamics is altered. A thrombotic event with consequent symptoms of intracranial hypertension is discussed in this article. MATERIAL AND METHODS: We performed a detailed review of cerebral hydrodynamics and intracranial pressure compensation mechanisms and how this can alter cerebral venous circulation. Next, we report the case of a 4-year-old child with such a clinical presentation that was conducted by our team. RESULTS: A child with a history of hydrocephalus treated with a ventriculo-peritoneal (VP) shunt in his early childhood presented with symptoms of intracranial hypertension, initial computed tomography (CT) demonstrating reduced-sized ventricles. Complementary investigation showed bilateral papilledema, cranial suture closure, changes compatible with Chiari type I, and venous sinus thrombosis (transverse and sigmoid, bilaterally). The case was managed conservatively with full anticoagulation with enoxaparin. Four months after the onset of symptoms, there was an improvement in the clinical and imaging status. CONCLUSION: A condition of severe headache in a patient with an apparently functioning shunt and small ventricles on initial CT should open up a range of diagnostic possibilities, with pseudotumor cerebri syndrome and cerebral venous sinus thrombosis being suggested. The therapeutic approach in these cases must be individualized.

Management of Slit Ventricle Syndrome: A Single-Center Case Series of 32 Surgically Treated Patients.

OBJECTIVE: Slit ventricle syndrome (SVS) is an iatrogenic disease occurring in patients with ventriculoperitoneal shunt. This article reports the management modalities and results in a case series from a single center. METHODS: We reviewed a series 48 hospitalized patients with severe SVS whom we managed in a 10-year period. Thirty-seven patients harboring programmable valves (P-valves) first underwent attempts at valve reprogramming. This treatment produced no effect in 21 patients, who therefore required surgical treatment. Surgery was also required by 11 patients without P-valve. Accordingly, 32 patients had to be operatively treated by shunt externalization followed by valve replacement or endoscopic third ventriculostomy basing on intracranial pressure and ventricular size. The new valve was either ProGav Mietke (Aesculap) or Medos Codman (Integra), each equipped with its own antisiphon system. In selected cases, a programmable antisiphon system (ProSa Mietke) was used. RESULTS: Surgical mortality was 3% and major morbidity accounted for 6%. Complete resolution was obtained in 55% of cases, improvement in 32%, and no effect or worsening in 13%. Only 1 patient became shunt free after endoscopic third ventriculostomy. Medos and ProGrav provided comparable outcomes, whereas ProSa was determinant in selected cases. Pediatric age, uncomplicated shunt courses, and short SVS histories were significantly favorable indicators. CONCLUSIONS: SVS management remains problematic. However, this study individuated factors that may improve the outcome, such as wider use of P-valves to treat hydrocephalus, timely diagnosis of overdrainage, and earlier and more aggressive indications to manage SVS.

Slit ventricle syndrome: Historical considerations, diagnosis, pathophysiology, and treatment review.

After the introduction of shunt treatment for the management of childhood hydrocephalus, a wide variety of complications related to this treatment modality have been recognized. The entity of slit ventricle syndrome (alternatively, symptomatic ventricular coaptation) is one of them, is frequently encountered in the pediatric population and its symptom complex resembles that of shunt failure. We conducted research on PubMed®, MEDLINE®, and Web of Science®, using the keywords: "slit ventricles," "slit ventricle syndrome," "SVS" and "ventricular coaptation." The aim of our review was to trace the advances made through the past decades, concerning our knowledge about the clinical characteristics, pathophysiology, and treatment options of this entity. The discrepancy among researchers about the offending etiology and the optimum treatment algorithm of this entity, as well as the necessity of an updated concept regarding shunt over drainage is analyzed. The multiple treatment modalities proposed and pathophysiologic mechanisms implicated for the treatment of slit ventricle syndrome illustrate the complexity of this entity. Consequently, the issue requires more detailed evaluation. In this review, we comment on all the main facets related to shunt over drainage and the resultant slit ventricle syndrome.

Risk factors for unchanged ventricles during pediatric shunt malfunction.

OBJECTIVE: Children whose ventricles do not change during shunt malfunction present a diagnostic dilemma. This study was performed to identify risk factors for unchanged ventricular size at shunt malfunction. METHODS: This retrospective 1:1 age-matched case-control study identified children with shunted hydrocephalus who underwent shunt revision with intraoperative evidence of malfunction at one of the three participating institutions from 1997 to 2019. Cases were defined as patients with a change of < 0.05 in the frontal-occipital horn ratio (FOR) between malfunction and baseline, and controls included patients with FOR changes ≥ 0.05. The presence of infection, abdominal pseudocyst, pseudomeningocele, or wound drainage and lack of baseline cranial imaging at the time of malfunction warranted exclusion. RESULTS: Of 450 included patients, 60% were male, 73% were Caucasian, and 67% had an occipital shunt. The median age was 4.3 (IQR 0.97-9.21) years at malfunction. On univariable analysis, unchanged ventricles at malfunction were associated with a frontal shunt (41% vs 28%, p < 0.001), programmable valve (17% vs 9%, p = 0.011), nonsiphoning shunt (85% vs 66%, p < 0.001), larger baseline FOR (0.44 ± 0.12 vs 0.38 ± 0.11, p < 0.001), no prior shunt infection (87% vs 76%, p = 0.003), and no prior shunt revisions (68% vs 52%, p < 0.001). On multivariable analysis with collinear variables removed, patients with a frontal shunt (OR 1.67, 95% CI 1.08-2.70, p = 0.037), programmable valve (OR 2.63, 95% CI 1.32-5.26, p = 0.007), nonsiphoning shunt at malfunction (OR 2.76, 95% CI 1.63-4.67, p < 0.001), larger baseline FOR (OR 3.13, 95% CI 2.21-4.43, p < 0.001), and no prior shunt infection (OR 2.34, 95% CI 1.27-4.30, p = 0.007) were more likely to have unchanged ventricles at malfunction. CONCLUSIONS: In a multicenter cohort of children with shunt malfunction, those with a frontal shunt, programmable valve, nonsiphoning shunt, baseline large ventricles, and no prior shunt infection were more likely than others to have unchanged ventricles at shunt failure.

Shunt Overdrainage: Reappraisal of the Syndrome and Proposal for an Integrative Model.

Although shunt overdrainage is a well-known complication in hydrocephalus management, the problem has been underestimated. Current literature suggests that the topic requires more examination. An insight into this condition is limited by a lack of universally agreed-upon diagnostic criteria, heterogeneity of published series, the multitude of different management options and misunderstanding of relationships among pathophysiological mechanisms involved. We carried out a review of the literature on clinical, radiological, intracranial pressure (ICP), pathophysiological and treatment concepts to finally propose an integrative model. Active prophylaxis and management are proposed according to this model based on determination of pathophysiological mechanisms and predisposing factors behind each individual case. As pathophysiology is progressively multifactorial, prevention of siphoning with gravitational valves or antisiphon devices is mandatory to avoid or minimize further complications. Shunt optimization or transferal and neuroendoscopy may be recommended when ventricular collapse and cerebrospinal fluid isolation appear. Cranial expansion may be useful in congenital or acquired craniocerebral disproportion and shunting the subarachnoid space in communicating venous hydrocephalus and idiopathic intracranial hypertension.

Visual acuity loss and sixth nerve palsy as the only manifestations of slit ventricle syndrome. / Pérdida de agudeza visual y parálisis de VI nervio craneal como únicas manifestaciones de un síndrome de colapso ventricular.

The case is presented of a girl diagnosed with obstructive hydrocephalus due to pilomyxoid astrocytoma, which required a ventriculoperitoneal shunt (VPS) at the age of 5 years and 10 months. Two months later, magnetic resonance imaging of the brain did not show ventriculomegaly or other signs of increased intracranial pressure. At the age of 6 years and 2 months, a rapid onset of bilateral visual acuity loss developed and she was diagnosed with slit ventricle syndrome. Despite valve revisions of the VPS, she developed an abrupt decline of visual acuity to hand motion at 10cm. Fundus examination revealed bilateral optic atrophy. She did not report any other systemic symptoms suggesting increased intracranial pressure, such as headache, nausea, vomiting, lethargy, irritability, or altered levels of consciousness.

Novel Endoscopic Technique for Inserting a Sheath into a Slit Ventricle: The Water-Slide Technique.

BACKGROUND: The efficacy and safety of endoscopic procedures for slit ventricle syndrome (SVS) have been presented in recent studies. However, inserting a sheath into a target ventricle is essential in the beginning of endoscopic procedures for SVS, and this maneuver is challenging owing to the quite narrow ventricular space. We report a novel flexible endoscopic technique, the water-slide technique, that can effectively guide a sheath into a slit ventricle without the use of other adjunctive devices, such as a neuronavigation system and an ultrasound machine. METHODS: Ten endoscopic procedures using the water-slide technique were performed in 9 patients with SVS. All patients had undergone ventriculoperitoneal shunt placement. Using the technique, the sheath was first placed on the flexible endoscope. The endoscope was then inserted into the lateral ventricle along the tract around the pre-existing ventricular catheter with irrigation of artificial cerebrospinal fluid via the working channel of the endoscope. After the endoscope reached the ventricle, the sheath was inserted into the ventricle along the endoscope. The endoscope was then used as a stylet. The endoscopic procedure was performed afterward. Continuous irrigation of artificial cerebrospinal fluid via the working channel is important when using this technique. RESULTS: In all cases, the sheath was successfully introduced to the slit ventricle without the use of adjunctive devices. There were no postoperative complications correlated with the maneuver. CONCLUSIONS: This novel endoscopic technique is effective and safe for inserting a sheath into a target ventricle in the management of SVS.

Cranial expansion and aqueductoplasty for combined isolated fourth ventricle and slit-ventricle syndrome: a surgical alternative.

INTRODUCTION: An isolated fourth ventricle (IFV) is a rare entity observed in shunted patients and its treatment is still uncertain. Endoscopic aqueductoplasty has shown good results for restoring CSF flux between the third and fourth ventricles. However, it needs some grade of ventricular dilation to be performed. Some patients affected by IFV show slit-ventricle morphology in CT/MRI. Usually, the rise of opening pressure or the shunt externalization gets enough ventricular dilation. However, the lack of intracranial compliance in some patients makes these options unsuitable and high-ICP symptoms are developed without ventricular dilation. METHODS: We present a two cases series affected by IFV with no ventricular dilation in radiological exams. ICP sensors were implanted, observing high-ICP and establishing the diagnosis of craniocerebral disproportion. A two-stage surgical plan based on a dynamic cranial expansion followed by a supratentorial endoscopic aqueductoplasty was performed. A physical and mathematical model explaining our approach was also provided. RESULTS: Chess-table cranial expansion technique was performed in both patients. Six/seven days after the first surgery, respectively, ventricular dilation was observed in CT. Endoscopic precoronal aqueductoplasty was then performed. No postoperative complications were described. IFV symptoms improved in both patients. Eighteen and 12 months after the two-stage surgical plan, the patients remain symptom-free and void of flow is still observed between the third and the fourth ventricles in MRI. CONCLUSION: The two-stage approach was a suitable option for the treatment of these complex patients affected by both craniocerebral disproportion and isolated fourth ventricle.