Prenatal dispositions and genetic analysis of monozygotic female twins with suprasellar cysts and hydrocephalus: A case report.

INTRODUCTION: We present a unique case of monozygotic female twins with virtually identical clinical and radiological presentations of supratentorial hydrocephalus and cystic formations from the suprasellar cistern. DISCUSSION: Evaluating genetic predispositions and prenatal exposures is crucial for hydrocephalus in twins. Familial cases imply a genetic contribution to the development of these anomalies, including chromosomal abnormalities and specific variants linked to arachnoid cyst formation in various syndromes. Extensive genetic analyses found no pathogenic variants in the twins. Prenatal exposure to anti-epileptic medication was known during pregnancy and may be associated with fetal abnormalities, but not central nervous system (CNS) malformations, and was therefore not considered the cause of the condition in the twins. The twins presenting simultaneously with hydrocephalus caused by suprasellar cysts (SAC) underwent a two-step surgical management: initial ventriculoperitoneal shunt (VPS) placement followed by fenestration. Postoperative imaging showed cyst reduction, but a secondary VPS was necessary in both cases. CONCLUSION: Genetic analysis is less likely to identify a monogenic etiology in non-syndromic cases of SACs, which are assumed to be multifactorial. There is no established evidence linking a teratogenic effect of anti-epileptic drugs to CNS malformations. Moreover, the surgical treatment of this complex condition constitutes a point of discussion.

Management of Pediatric Cavum Cysts: A Scoping Review and a Single Institution Case Series.

INTRODUCTION: Pediatric cavum cysts are a rare yet complicated pathology to manage. The literature is scarce, primarily consisting of case series, and lacking a consensus regarding clear management. In this scoping review, we aimed to compile existing information in the literature regarding the management of pediatric cavum cysts across the last 10 years. We also present our management of 19 patients, the largest case series to date, highlighting knowledge gaps surrounding the management of this salient pathology. METHODS: A literature search using PubMed and SCOPUS was conducted using the following search terms: (pediatric) AND (Cavum septum pellucidum) OR (cavum vergae) OR (cavum velum interpositum) AND (management). Eligibility criteria included peer-reviewed publication published in the last 10 years, pediatric population, cavum cyst, and English language. A retrospective search was conducted for all pediatric cavum cysts between 2013 and 2023 at our institution. Clinical and radiographic characteristics as well as intervention and outcome data were collected for both the scoping review and our cases. RESULTS: 330 total articles were populated using our search. 12 articles met our inclusion criteria. 41.7% (n = 5) of the articles were case series, 33.3% (n = 4) were case reports, 8.3% (n = 1) was a technical article, 8.3% (n = 1) was a systematic review, and 8.3% (n = 1) was a case questionnaire. Resolution of symptoms was noted in all articles of our scoping review, regardless of treatment modality. The average age in our case series was 9.84 years old and average age at diagnosis was 5.53 years old. 6 patients (31.6%) were female and 13 patients (68.4%) were male. 2 out of the 19 patients (10.5%) were surgically treated. CONCLUSION: There is no clear consensus on the management of cavum cysts. A prospective, multicenter study is needed to create standardized pediatric cyst management guidelines. The current thought is that surgical intervention should be saved for those patients with obstructive hydrocephalus and signs of intracranial hypertension.

Effectiveness of multiple endoscopic fenestrations for the treatment of Sylvian fissure arachnoid cysts: a multicenter study.

PURPOSE: Arachnoid cysts are usually asymptomatic lesions. However, they can sometimes cause intracranial hypertension, headache, seizures, focal neurological deficits, and bleeding. The most commonly used surgical techniques are microsurgical cyst fenestration/excision/drainage, cyst shunting, and endoscopic procedures. We aimed to investigate the success of different surgical techniques. METHODS: Between 2000 and 2021, patients with Sylvan fissure arachnoid cysts who received treatment via an endoscopic approach chosen as the first-line treatment in three centers were enrolled. All case notes and radiological studies were evaluated retrospectively. RESULTS: The study included 131 (female, n = 28; male, n = 103) patients with a mean age of 87.04 ± 66.76 (range, 0-216) months. Of the patients, 25 had Galassi type II left-sided arachnoid cysts, 33 had Galassi type II right-sided arachnoid cysts, 40 had Galassi type III left-sided arachnoid cysts, and 32 had Galassi type III right-sided arachnoid cysts. No difference was found between patients who underwent single and multiple fenestrations in terms of Galassi type, side, clinical outcome, and cyst size (p > 0.05). On the contrary, the rate of additional surgical intervention was lower in patients with multiple fenestrations than in those with single fenestration (36.10% vs. 5.30%; p < 0.001). CONCLUSION: Endoscopic fenestration of Sylvian fissure arachnoid cysts is a good alternative to open surgery or cystoperitoneal shunting, and the number of fenestrations made during this surgery decreases the need for a second surgical procedure.

Imaging characteristics and neurosurgical outcome in subjects with agenesis of the corpus callosum and interhemispheric cysts.

PURPOSE: To explore the relationships between clinical-radiological features and surgical outcomes in subjects with interhemispheric cysts (IHC) and corpus callosum anomalies. METHODS: We reviewed the clinico-radiological and neurosurgical data of 38 patients surgically treated with endoscopic fenestration, shunting, or combined approaches from 2000 to 2018 (24 males, median age 9 years). Pre- and postoperative changes in IHC volume were calculated. Outcome assessment was based on clinico-radiological data. Group comparisons were performed using χ2, Fisher exact, Mann-Whitney U, and Kruskal-Wallis tests. RESULTS: Median age at first surgery was 4 months (mean follow-up 8.3 years). Eighteen individuals (47.3%) required > 1 intervention due to IHC regrowth and/or shunt malfunction. Larger preoperative IHC volume (P = .008) and younger age at surgery (P = .016) were associated with cyst regrowth. At last follow-up, mean cystic volume was 307.8 cm3, with IHC volume reduction > 66% in 19/38 (50%) subjects. The neurological outcome was good in 14/38 subjects (36.8%), fair in 18/38 (47.3%), and poor in 6/38 (15.7%). There were no differences in the postoperative cyst volume with respect to either the type of first surgery or overall surgery type. Higher absolute postoperative IHC reduction was observed in subjects who underwent both IHC fenestration and shunting procedures (P < .0001). No differences in neurological outcome were found according to patient age at surgery or degree of IHC reduction. CONCLUSION: Endoscopic fenestration and shunting approaches are both effective but often require multiple procedures especially in younger patients. Larger IHC are more frequently complicated by cyst regrowth after surgery.

Endoscopic treatment of intracranial cysts in infants: personal experience and review of literature.

BACKGROUND: A wide variety of intracranial cysts is known to occur in infants. If symptomatic, they require treatment; the ideal surgical treatment and indications of surgery are yet a matter of discussion. Traditional treatment is either by cystoperitoneal shunting, or microsurgical fenestration. Endoscopic treatment is an alternative procedure that avoids the invasiveness of open craniotomy and the complications caused by shunting. METHODS: This article reviews the endoscopic treatment of intracranial cysts in infants. The author presents personal experience by reviewing the results of endoscopic treatment in different subgroups among his series of pediatric patients extending over 20 years. RESULTS: Different types of intracranial cysts in infants were discussed and the role of endoscopy in the management of these patients was reviewed. The author also presented the results of endoscopic treatment of a personal series including 87 infants with intracranial cysts operated by the endoscopic procedure. CONCLUSIONS: It has been recommended to use the endoscopic procedure in the treatment of intracranial cysts in infants, because it is effective, simple, minimally invasive, and associated with low morbidity and mortality rates. However, an important prerequisite is the presence of an area of contiguity with the subarachnoid cisterns and/or the ventricular system.

Surgical management of symptomatic cavum septum pellucidum cysts: systematic review of the literature.

Cavum septum pellucidum (CSP) and cavum vergae (CV) cysts are commonly found incidentally. They are usually asymptomatic but may present with symptoms related to obstructive hydrocephalus. There is no consensus about the management of symptomatic CSP and CV cysts. We present, to the best of our knowledge, the first systematic review of the different treatment options for symptomatic CSP and CV cysts. We conducted a literature review using PubMed database, searching for cases of symptomatic CSP and CV cysts managed surgically, and published until April 2019. Preoperative characteristics, surgical procedure, and postoperative outcome were analyzed using SPSS® software (Statistical Package for Social Sciences, IBM®). We found 54 cases of symptomatic CSP and CV cysts managed surgically (34 males, 20 females, 1.7/1 male to female ratio). Mean age was 24.3 ± 20.1 years. The most common presentation was headaches (34 patients, 62%), followed by psychiatric symptoms (27 patients, 49.1%). Preoperative radiological hydrocephalus was present in 30 patients (54.5%). The most common surgical procedure was endoscopic fenestration (39 patients, 70.9%), followed by shunting (10 patients, 18.2%), open surgery (3 patients, 5.5%), and stereotactic fenestration (1 patient, 1.8%). Complete resolution of symptoms was achieved in 36 patients (65.5%) and partial resolution in 7 patients (12.7%), and symptoms were unchanged in 2 patients. The present review suggests that surgical treatment could provide resolution of the symptoms in most of the cases, regardless of the procedure performed. Although mean follow-up was short among the studies, recurrence rate was low.

Positive outcome after endoscopic treatment of a symptomatic convexity arachnoid cyst in an elderly.

Cerebral convexity arachnoid cysts (ACs) only represent around 10-14% of the cysts. Symptomatic ACs in the elderly are rare. We present a 66-year-old woman with headache and a focal epileptic seizure. Imaging revealed a left parietal AC. Conservative management chosen but the patient's neurological condition worsened, and an endoscopic fenestration was then performed. Postoperatively, her symptoms completely resolved and MRI image showed significant shrinkage of the AC.

[Endoscopic fenestration of arachnoid cyst of posterior cranial fossa through third ventriculostomy]. / Endoskopicheskaya fenestratsiya arakhnoidal'noi kisty zadnei cherepnoi yamki cherez triventrikulostomu.

Arachnoid cysts (AC) are spaces with cerebrospinal fluid covered with arachnoid membrane. Most cysts are supratentorial and only 10-12% of ACs are found in posterior cranial fossa. This disease is usually diagnosed in childhood. In adults, ACs make up 1.4% of all focal lesions. ACs of posterior cranial fossa are often localized behind the cerebellum or in cerebellopontine angle. Most patients with cysts do not have permanent symptoms and should be followed-up. Surgery is indicated for cysts complicated by focal and hydrocephalic-hypertension symptoms. Microsurgical or endoscopic procedures are used. Surgical approach is determined by the closest location of cyst to brain surface. The authors report non-standard surgical approach for giant AC of posterior cranial fossa complicated by obstructive hydrocephalus, intracranial hypertension and visual function impairment. Endoscopic third ventriculostomy was followed by AC fenestration through ventriculostomy. Symptoms disappeared within 6 months after surgery.

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

OBJECTIVE: The authors performed a retrospective review of children diagnosed with multiloculated hydrocephalus (MLH) in our institute. The goal was to analyze the different diagnostic and therapeutic modalities used with special emphasis on CT ventriculography (CTV). METHODS: Male and female patients below the age of 18 years diagnosed with MLH were included. Cases of uniloculated hydrocephalus like entrapped temporal horn or isolated fourth ventricle were excluded. We used iohexol for CTV and gadodiamide for MR ventriculography. Neuroendoscopic procedures performed were endoscopic fenestration, endoscopic third ventriculostomy (ETV), endoscopic septostomy, endoscopic aqueductoplasty, or a combination of the above. The cohort was divided into two groups (endoscopic or shunt) based on initial surgical intervention. RESULTS: A total of 52 patients were included, with 43 boys and 9 girls. The average age of presentation was 7.7 months. The most common predisposing factor for MLH was neonatal meningitis seen in 30 patients. Mean duration of follow-up was 39 months. CTV was used in 26 patients and MR ventriculography in three patients. In one patient, the diagnosis of MLH was ruled out after ventriculography. Patients who underwent ETV only had the best outcome with 71.4% success rate. At the end of follow-up, 14 patients (27%) were shunt independent. CONCLUSIONS: The present study indicates that CTV helps to accurately define the anatomy of the ventricles and determine the site of physiological CSF obstruction. This helps in therapeutic planning and in avoiding misdiagnoses. Further, neuroendoscopy has the potential to lead to shunt independence in some patients.

A good choice for the patients with prior failed ventriculoperitoneal shunt treatment of suprasellar arachnoid cysts: endoscopic fenestration.

To investigate the effectiveness of endoscopic fenestration in the patients with prior failed ventriculoperitoneal (VP) shunt treatment of suprasellar arachnoid cysts (SACs). Between 2012 and 2018, four pediatric patients of SACs with previous failed VP shunt treatment were surgically treated using endoscopic ventriculocystocisternostomy (VCC) in our hospital. The clinical symptoms, imaging data, and surgical outcomes were collected and analyzed retrospectively. A literature review is provided with regard to the reasons of shunt failure and surgical outcome of further endoscopic fenestration in the previously reported patients of SACs with prior failed VP shunt. For the 4 cases, the initial clinical symptoms relieved or even disappeared after shunt placement, but, respectively, recurred 2, 6, 11, and 6 months later. MR scans were conducted when the clinical symptoms reappeared and showed a cyst had greatly enlarged after shunt placement. Furthermore, VP shunt-related slit ventricle was also demonstrated in 3 cases. Clinical improvement and cysts shrinkage occurred in all 4 patients after VCC. Slit ventricle and hydrocephalus were also resolved. Three patients had their shunt apparatus removed after VCC, and another patient's guardian refused to remove the shunt apparatus. Subdural hematoma occurred in one case after shunt apparatus removal. Four patients have been stable during follow-up period (mean follow-up 26.5 months). All the three patients whose VP shunt were removed were shunt independence. There were 24 patients who underwent endoscopic fenestration as an alternative to the failed VP shunt treatment in the published reports. Added our 4 patients to the published group, the effective rate of endoscopic fenestration for SACs following previous failed VP shunt treatment was approximately 93% (26/28). Of the 24 patients, the shunt apparatuses were in situ or reimplantation in 9 patients due to shunt dependence. The correction to recognize the SAC is the first condition to select the optimal management philosophy. The analysis of the series suggests endoscopic operation is still an effective and safe option in the SAC patients with previous failed VP shunt, and the shunt apparatus can be removed for some patients. The short interval time between shunt operation and endoscopic fenestration is conductive to return patients to the shunt-free state.

[Cysts of septum pellucidum, cavum vergae and cavum veli interpositi. Meta-analysis of 368 cases]. / Kisty prozrachnoi peregorodki, polosti Verge i promezhutochnogo parusa. Metaanaliz 368 klinicheskikh sluchaev.

OBJECTIVE: To review and systematize literature data on the incidence of cysts of septum pellucidum, cavum vergae and cavum veli interpositi, their clinical manifestations, indications for surgical treatment and optimal surgical approach. MATERIAL AND METHODS: An analysis included 72 manuscripts devoted to epidemiology, pathophysiology, clinical symptoms and results of surgical treatment of brain cysts. Case reports, series of cases, reviews and original studies were analyzed. RESULTS: Septum pellucidum cavity is always formed throughout an embryogenesis and persists in 20.34% of adults. Cavum vergae is observed in 2.32% of adults. Cyst of septum pellucidum is detected in 0.04% of adults. Analysis of 368 cases of cysts of septum pellucidum, cavum vergae and cavum veli interpositi has shown that clinical picture consists of headache (50% of cases), convulsive syndrome (23.6%), reduced intelligence (20.1%), behavioural disorders (15.8%), dizziness, nausea and vomiting (10.9%). Hydrocephalus occurs in 16.6% of cases. Endoscopic wall fenestration is preferred for cyst management. CONCLUSION: Brain cysts are rare and characterized by non-specific clinical manifestations. Symptomatic cyst is an indication for surgical treatment. Surgical treatment usually ensures regression of symptoms and low risk of complications.

Volume change of cranial arachnoid cysts after successful endoscopic fenestration in symptomatic children.

INTRODUCTION: Endoscopic fenestration remains a first-line treatment option for symptomatic arachnoid cysts. After fenestration, the cyst does not collapse but reaches an equilibrium state. The aim of this study was to evaluate the change in cyst volume following successful fenestration and symptomatic improvement. METHODS: Cyst volume was measured on serial MR scans of 4 children (1 female, 3 males) with symptomatic arachnoid cysts (middle fossa n = 2, choroidal fissure n = 1 and posterior fossa n = 1), who experienced symptom resolution after endoscopic fenestration. Average follow-up was 20.5 months (range 3-48). RESULTS: Significant cyst volume reduction was seen in all four patients. In patient 1, preoperative cyst volume was 336 cm3 and decreased to 194 cm3 at 7 months (42% reduction). In patient 2, preoperative volume was 12.64 cm3 and reduced to 1.51 cm3 at 3 months (88% reduction). In patient 3, preoperative volume was 105 cm3 and reduced to 72 cm3 in 2 months (30% reduction). In patient 4, preoperative volume was 125 cm3 and reduced to 54 cm3 at 7 months (56% reduction). All remained stable after 7 months and there has been no late increase in volume. CONCLUSIONS: Significant reduction in arachnoid cyst volume at the order of 30-40% is seen after successful endoscopic fenestration. The cyst volume appears to decrease gradually in the first 3-7 months and reaches a plateau after that. Complete resolution of symptoms in the presence of residual volume may indicate that cyst volume below a threshold may not correlate directly with clinical status.

Cerebral vasospasm after endoscopic fenestration of a temporal arachnoid cyst in a child-a case report and review of the literature.

INTRODUCTION: Intracranial arachnoid cysts (ACs) represent rare extra-axial CSF-containing lesions. Surgical management mainly depends on the cyst location and its size. Nevertheless, pure endoscopic fenestration represents a relatively straightforward and safe technique, and-in most cases-the treatment of choice for symptomatic intracranial ACs. The postoperative complication rate of the procedure is low including subdural hematomas, hygromas, and intraparenchymal hemorrhages. Symptomatic cerebral vasospasm after endoscopic treatment of ACs is a very uncommon event. CASE REPORT/RESULTS: To the authors' knowledge, this adverse event in children has not yet been reported in the literature yet. The authors present a case of a 9-year-old child developing an early symptomatic cerebral vasospasm with an insignificant secondary ischemia following endoscopic fenestration of a large temporal arachnoid cyst. DISCUSSION: The clinical approach, possible pathogenesis, and the therapeutic strategy is discussed particularly with regard to the literature.

Endoscopic surgery for intraventricular arachnoid cysts in children: clinical presentation, radiological features, management, and outcomes over a 12-year period.

PURPOSE: Less than 0.5% of arachnoid cysts are intraventricular in origin. We review our experience with endoscopic surgery for intraventricular arachnoid cysts in children. METHODS: This is a retrospective review of children with intraventricular arachnoid cysts who underwent surgery between 2005 and 2016. Clinical notes and imaging were reviewed. RESULTS: Twenty-nine patients with endoscopically treated intraventricular arachnoid cysts were identified (M/F = 17:12; median age = 1.47 years, range = 7 days-13 years). All had hydrocephalus at presentation, many had symptoms/signs of raised intracranial pressure, and five (17%) were asymptomatic. Cysts were treated with fenestration into the ventricle alone (ventriculocystostomy [VC], n = 14), fenestration into the ventricle and cisternostomy (ventriculocystostomy plus cisternostomy [VC + C], n = 14), or endoscopic third ventriculostomy alone (n = 1). Six (21%) patients experienced transient and/or conservatively managed complications. Further surgery was required in 12 (41%). Revision-free survival was significantly shorter with VC compared to VC + C (log rank p = 0.049), and the majority of VC/VC + C revisions (n = 8 of 11, 73%) were required within 6 months of initial endoscopic surgery. One (3%) patient died during follow-up, from unrelated pathology. After a median follow-up of 67.5 months in survivors (range = 5.5-133.5 months), 24 (83%) cases were clinically and radiologically stable without a shunt in situ. CONCLUSIONS: Endoscopic fenestration is safe and effective in most intraventricular arachnoid cysts. Additional cisternostomy at the time of cyst fenestration into the ventricle significantly improved revision-free survival in our cohort. Endoscopic surgery should be the first-line therapy when considering intervention for symptomatic intraventricular arachnoid cysts and for asymptomatic cysts increasing in size on serial imaging.

[«De novo¼ development of a suprasellar arachnoid cyst]. / Desarrollo «de novo¼ de un quiste aracnoideo supraselar.

Intracranial arachnoid cysts are fluid-filled cavities that arise within the cranial arachnoid, representing approximately 1%-2% of all intracranial lesions among the paediatric population. We present the case of a 2-year-old boy who presented with instability and episodes of ocular deviation. A computed tomography scan (CT scan) and magnetic resonance imaging (MRI) of the brain revealed a suprasellar cyst and obstructive hydrocephalus. At birth a transfontanellar ultrasound was normal. The cyst underwent endoscopic fenestration with complete remission of symptoms. In the review of the literature, we found only 6 previous cases of an intracranial arachnoid cyst whose origin was not clearly congenital or traumatic, and ours is the second case of a suprasellar arachnoid cyst to arise de novo. The clinical features, imaging characteristics and treatment of the previously reported cases are discussed.

Microsurgical Fenestration of Middle Fossa Arachnoid Cyst in a Pediatric Patient Through a Keyhole Approach with Endoscopic Inspection. 2-Dimensional Operative Video.

In recent decades, the management of middle fossa arachnoid cysts in pediatric patients has evolved significantly through the integration of novel techniques, such as the utilization of endoscopy systems1 and implementation of minimally invasive approaches like keyhole craniotomy.2,3 These cystic formations, occurring within the arachnoid membrane, may lead to neurologic impairments and raised intracranial pressure if left untreated.4 The utilization of endoscopy to aid microsurgical techniques or as a complement to them provides a level of visualization and manipulation of the cyst walls that is significantly more precise than the isolated use of a microscope.1 The keyhole craniotomy allows for reduced surgical trauma, smaller incisions, and quicker recovery times.5 In Video 1, we present the case of a 2-year-old patient with bilateral middle fossa arachnoid cysts exerting mass effect on the adjacent parenchyma. The patient was referred to our institution due to developmental delay and cognitive issues related to language and social interactions. On the basis of imaging findings and clinical correlation, we opted for a microsurgical fenestration with endoscopic inspection using a keyhole craniotomy to minimize complications and enhance the benefits of both techniques. Throughout the surgical video, tricks and considerations that contribute to the combined procedure's efficiency and ease of execution are highlighted and discussed. Postoperative images showed no complications, and the patient was discharged 3 days after surgery.

Management of entrapped temporal horn: Literature review and operative technique for endoscopic fenestration.

CONTEXT: Entrapment of the temporal horn (TH) is rare condition that can lead to increased intracranial pressure, but there is no consensus on a standard treatment. The aim of this study was to conduct a systematic literature review of the reported cases of TH entrapment and describe our operative technique for endoscopic fenestrations of the lateral ventricle into the basal cisterns. METHODS: We searched the databases Pubmed and Google scholar to find all studies reporting cases of entrapped TH and the subsequent treatment. Additionally, we report two illustrative cases of endoscopic fenestration with a step-by-step description of our surgical technique. RESULTS: Twenty-nine studies with a total of 67 patients were included in the analysis. The mean age was 36.5 years (SD± 21.9), and the female-to-male ratio was 1.5. The most frequent cause of TH entrapment was post-surgical scarring after tumor surgery (n= 30), and the most commonly reported treatment modality was endoscopic fenestration of the TH (n = 14). We observed an increasing use of endoscopic fenestration over time. CONCLUSION: Entrapped TH is a rare condition often requiring surgical treatment. Neuronavigation-guided endoscopic fenestration of the ventricle into the basal cisterns appears to be a safe, efficient, and device-free technique that has gained importance over the past years.

Modified Nasoseptal Flap Technique to Prevent the Recurrence of Rathke's Cleft Cyst.

Background: Rathke's cleft cysts (RCCs) are benign epithelial lesions arising from the Rathke's pouch remnants that fail to regress during embryogenesis. Some RCCs become symptomatic and require treatment. Cyst fenestration and drainage of its contents is the preferred procedure to treat symptomatic cases but carries a risk of recurrence. We propose the use of a novel modified nasoseptal flap technique to partially line the cyst wall to avoid recurrence. Methods: This was a prospective, observational study that included all RCC patients admitted to the Department of Neurosurgery, Aster Medcity, from April 2015 to May 2018. The modified nasoseptal flap technique was performed in all patients. They underwent preoperative and postoperative ophthalmological, endocrine, endoscopic, and MRI evaluations to look for recurrence. Results: Ten patients underwent the modified nasoseptal flap technique. The median follow-up was 36 months. Postoperatively, all patients were relieved from headaches. Moreover, their visual fields and pituitary functions normalized. None of the patients developed recurrence of RCC on follow-up brain MRI. On endoscopic examination, all patients had retained patency of the fenestra. The longest follow-up was 72 months. Conclusions: The modified nasoseptal flap technique maintains patency and avoids recurrence of RCCs on long-term follow-up.

Endoscopic fenestration of a giant frontal arachnoid cyst: Operative technique and anatomical nuances.

Endoscopic fenestration is best as it is minimally invasive and does not require hardware in the surgical site (Figure 1). This case shows the safety of endoscopic fenestration and the utility of operative adjuncts (J Korean Med Sci. 1999;14:443; Neurosurg Focus. 2005;19:E7).

Treatment of refractory giant suprasellar arachnoid cyst by endoscopic expansion of a fenestrated stoma.

Background: Although endoscopic ventriculo-cysto-cisternostomy is considered to be effective for suprasellar arachnoid cysts, we encountered a giant suprasellar arachnoid cyst that recurred despite surgery using this technique. Case Description: The patient was a 9-month-old boy. Magnetic resonance imaging revealed a huge suprasellar arachnoid cyst extending from the suprasellar region to the anterior skull base and both middle cranial fossa. First, an endoscopic procedure was performed to open the cyst wall between the right ventricle and the cyst and between the cyst and the prepontine cistern. Although the cyst initially shrank, it recurred over the next 2 months, and hence, we performed another endoscopic surgery. At the second surgery, both the previously opened stomas were found to be occluded. To reopen the cyst wall between the ventricle and the cyst, multiple holes were made with monopolar electrodes, and forceps were used to connect the holes by grasping and twisting the cyst wall so that the stoma was much larger than at the previous surgery. Postoperatively, the cyst shrank and the patient's head circumference stopped expanding. Conclusion: Following the treatment of large cysts, the stoma might become narrower as the cyst shrinks, resulting in obstruction. Using the technique reported here might prevent occlusion of large arachnoid cysts.