Endoscopic treatment of suprasellar arachnoid cysts

Intracranial arachnoid cysts: What is the appropriate surgical technique? A retrospective comparative study with 61 pediatric patients

Objective

Symptomatic intracranial arachnoid cysts (ACs) should be treated either through microsurgical (MS) or endoscopic surgical (ES) fenestration. Implantation of cysto-peritoneal shunt (CPS) system is another treatment option with decreasing indication. In our study, we compared the complication and revision rates between the three operative techniques in pediatric patients.

Methods

We included patients below 18 years with symptomatic intracranial ACs operated between 2004 and 2021. Initial symptoms, location, complication rate, clinical and radiological improvement, postoperative events and revision rate were compared retrospectively.

Results

Sixty-one patients; 33 (54.1%) MS operated (mean age 7.6 years), 18 (29.5%) ES operated (mean age 6.2 years) and 10 (16.4%) with CPS (mean age 3.0 years) were collected. The most common initial symptom was headache in 45.9%. 20 (32.8%) postoperative events were documented. The highest revision rate (60%) was seen in the CPS group compared to 33.3% in MS group and 16.7% in ES group. 31 patients harbored perisylvian ACs, 89% remained event-free after ES, 71% after MS and 20% after CPS. Clinical improvement immediately after surgery was observed in 58 patients (96.9% in MS, 88.9% in ES and 100% in CPS). A radiological volume reduction could be proven postoperative in 51 patients (78.8% MS, 88.9% ES and 90% CPS).

Conclusion

Endoscopic fenestration of AC is a safe and efficient technique which is being widely used nowadays with the highest event free survival compared to microsurgical fenestration especially in perisylvian arachnoid cysts. CPS shows on long terms the highest revision rate but carries the least surgical risks.

Postnatal Posterior Fossa Arachnoid Cyst: A Developmental Etiology to Be Considered

Intracranial arachnoid cyst is the most common cystic congenital anomaly in the brain. In this study, we discuss a pregnancy that had serial fetal ultrasound scans throughout the pregnancy and a fetal anomaly scan at 24 weeks of gestation that was normal. The child was born healthy with normal development, but 12 months onward the head began to enlarge. The magnetic resonance imaging of the brain showed a large posterior fossa arachnoid cyst with hydrocephalus. We discuss the postulation to explain this pathogenesis of the cyst. This case highlights that not all symptomatic arachnoid cysts are congenital despite the manifestation being as early as infancy.

Temporosylvian arachnoid cysts in children. Part 1: Cognitive profile of children with a temporal cyst and impact of the cyst in daily life. A prospective study in 100 consecutive children

OBJECTIVE

The aim of this study was to determine the cognitive profile of children with a temporal arachnoid cyst (TAC) and its impact on daily life.

METHODS

The authors prospectively analyzed the cognitive and psychological profiles of 100 consecutive children relative to age and cyst characteristics (side, cyst size, and cyst shape: convex or nonconvex) and their outcome 4 years later.

RESULTS

Mean IQs were normal but with high heterogeneity on Full Scale IQ (FSIQ; range 59-150); 29% of children had at least one Wechsler index below the norm, in particular, Processing Speed and Working Memory Indexes. Impairments were observed in language for 31% of children, as well as in verbal memory (28%), visual memory (23%), executive function (21%), and visual attention (24%). Half of the children (50%) needed rehabilitation for learning difficulties, and 26% had academic difficulties. The parental questionnaire BRIEF (Behavior Rating Inventory of Executive Function) revealed significant executive dysfunctions in daily life for 22% of the children. One-third of the patients (34%) required psychotherapy for anxiety or social disorders, with higher rates in patients with a right-sided cyst and older children. Cyst size had very little neuropsychological impact. Convex cysts were significantly associated with worse performance than nonconvex cysts on all Wechsler indexes and FSIQ, and in language, verbal memory, attention, and visuospatial skills. Children with a convex cyst had significantly more executive and behavior difficulties in daily life and more psychotherapy than other children. The effect of cyst shape was independent of Galassi type and cyst side. Children with a ruptured cyst or an incidentally discovered cyst usually had a good cognitive level. Four years later, children without initial disorders remained stable, whereas those with difficulties who did not undergo surgery needed more rehabilitation and school adaptations.

CONCLUSIONS

This large cohort study revealed a varied profile of children with a TAC: at initial assessment, 50% had neuropsychological difficulties and needed rehabilitation and/or psychotherapy for learning or behavior difficulties, and 50% had no difficulties, which may explain the debate about this pathology. Patients with neuropsychological difficulties had a heterogeneous profile with normal intelligence but selective cognitive and/or behavior disorders that may have a long-term impact on their quality of life, particularly those with a right-sided cyst. A neuropsychological evaluation is not always necessary for a cyst discovered incidentally, but early evaluation is essential in patients with academic, learning, or psychological disorders. When assessment shows selective disorders presumably linked to cyst location, surgery may be considered, particularly for convex cysts, as this study revealed more effects in association with cyst shape than with cyst size and significantly poorer performance with a convex cyst.

Cine MRI Is Useful for the Diagnosis of Intradural Arachnoid Cyst with Spinal Arachnoid Web: A Case Report

CASE

A 28-year-old woman developed gait disturbance due to lower limb weakness 3 years before presentation. Conventional magnetic resonance imaging (MRI) findings were inconclusive; therefore, we performed cine MRI, which confirmed the presence of a pulsatile cyst on the posterior thoracic spinal cord. The cyst compressed the spinal cord, and its pulsations synchronized with the patient's heartbeats. We resected the intradural arachnoid cyst and thickened arachnoid membrane. The gait disturbance improved after surgery.

CONCLUSIONS

Cine MRI can be used to identify a pulsating arachnoid cyst that cannot be visualized with a conventional MRI. Cine MRI is useful in patients with unexplained spinal symptoms.

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.

Results of Surgical Treatment in Patients with Intracranial Arachnoid Cyst During Last 5 Years in a Referral Center in a Developing Country: Shiraz, Iran

OBJECTIVE

To report the outcome of surgical intervention in patients diagnosed with arachnoid cyst (AC) during the last 5 years in Namazi Hospital, a tertiary center in Southern Iran.

METHODS

Hospitalization records of patients who had undergone surgical treatment of symptomatic intracranial AC in our center were surveyed retrospectively. Radiologic imaging was extracted from the picture archiving and communication system and analyzed. Postoperative evaluation of patients was conducted in neurosurgery clinic during their routine follow-up.

RESULTS

Twenty-nine patients (11 female, 18 male) with an age range of 13 days to 35 years were enrolled in this study. Most (62%) of all ACs were in the temporal area, 12% in the suprasellar region, 6% in the quadrigeminal region, 6% in the cerebellopontine angle, and 3% in the anterior frontal area. Twenty-six endoscopic intervention, 2 microsurgical resection, and 1 cystoperitoneal shunt were performed. All of the patients showed complete resolution or improvement in symptoms. Eighty-nine percent of patients also showed reduction in the cyst size. Ten patients had transient postoperative complications, which were resolved at the time of follow-up.

CONCLUSIONS

Diagnosis and appropriate surgical treatment of AC can alleviate the symptoms in patients who fulfill the criteria for surgery. Neuroendoscopy can provide a satisfactory result in symptomatic patients, whilst having less invasiveness and long-term complications. Reoperation should also be considered in situations where medical therapy fails to manage the complications.

Microsurgical Fenestration of Intracranial Arachnoid Cysts: Volumetric Analysis and Clinical Outcome

INTRODUCTION

There is paucity of data regarding change in arachnoid cyst (AC) volume following surgery. This study aimed at investigating the clinical outcome of ACs and applying 2 volumetric methods for determination of their volume change post microsurgical fenestration.

METHODS

Twenty-one ACs in 20 patients that underwent microsurgical fenestration were analyzed using 2 volumetric methods; the modified McDonald equation and the picture archiving and communication (PAC) system-based method. Patients were followed up for 23 ± 40.3 months.

RESULTS

The majority of the patients (13 or 65%) were children. Preoperative symptoms in children were mainly seizures and less commonly headache. Of the 20 patients, 12 (60%) had complete resolution of their preoperative symptoms with 8 (40.0%) showing partial improvement. Volumetric studies showed a mean reduction in AC size of 73.7% in children and 64.4% in adults using the PAC system versus 67.9% in children and 70.5% in adults using the modified McDonald equation method. There was no correlation between the percentage decrease in AC volume post surgery and degree of symptom improvement (49.2 ± 34.3% in patients with complete vs. 60.9 ± 40.3% in patients with only partial resolution of symptoms, p = 0.57).

DISCUSSION/CONCLUSION

Microsurgical fenestration is an effective approach for ACs with an excellent clinical outcome apparent in the complete or partial improvement of symptoms in all patients. Volumetric estimates of ACs and their change following surgery are feasible using the modified McDonald or PAC system methods. However, there is no correlation between the percentage decrease in AC volume after surgery and degree of clinical improvement.

Suprasellar arachnoid cysts in adults: clinical presentations, radiological features, and treatment outcomes

A tendency for suprasellar arachnoid cysts (SACs) to occur in young children is known. Data of adult SACs were rare in previous reports. The aim of this study is to discuss their clinical presentations, radiological features, and treatment outcomes based on 23 adult patients who underwent endoscopic fenestration in our hospital between January 2003 and December 2018. Preoperative cyst volume ranged from 12.3 to 72.5 cm³ (mean 39.8 ± 19.8). Endocrine disorders occurred in 7 (30.4%) patients. Hydrocephalus was observed in 20 patients. In the patients with hydrocephalus, the mean preoperative Evans' index (EI) (%) and frontooccipital horn ratio (FOHR) (%) were 44.8 (ranged 32.2-63.4) and 49.6 (ranged 36.7-59.8), respectively. A bivariate correlation showed significant positive association between preoperative cyst volume and preoperative EI or FOHR (Pearson correlation, r = 0.607, p = 0.005; r = 0.583, p = 0.007). The slit-valve phenomenon was observed in 13 (56.5%) patients. Pale/tenacious cyst walls were observed in 12 (52.2%) patients. Postoperatively, all patients achieved the improvement in clinical symptoms and a decrease in cyst size. The mean decreases in cyst volume, EI, and FOHR were 64.7%, 7.89%, and 5.8%, respectively. A bivariate correlation indicated the irrelevance between the postoperative cyst volume and postoperative EI or FOHR (Pearson correlation: r = 0.37, p = 0.11; r = 0.43, p = 0.054). These results reveal that there are a few differences in several aspects between adult patients and child patients. The severity of hydrocephalus is correlated with cyst size in adult patients. Additionally, the excellent outcomes in adult SACs can be obtained by endoscopic fenestration.

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.

Microsurgical, endoscopic, and shunt management of pediatric temporosylvian arachnoid cysts: a comparative study

OBJECTIVE

Arachnoid cysts (ACs) are most frequently located in the middle cranial fossa. Some patients are asymptomatic whereas others exhibit signs of increased intracranial pressure, seizures, or cognitive and behavioral symptoms. When ACs do require treatment, the optimal surgical technique remains controversial. This study was conducted to assess the most effective surgical treatment for these cysts.

METHODS

The authors retrospectively reviewed 240 temporal intracranial ACs managed over a 25-year period in their pediatric neurosurgical unit. Pre- and posttreatment results were clinically and radiologically assessed.

RESULTS

A majority of male patients (74.6%) with an overall median age of 6.9 years were included. The mean cyst size was 107 cm3; the Galassi classification showed 99 (41.3%) type I, 77 (32.1%) type II, and 64 (26.7%) type III cysts. Forty-four ACs (18.3%) were diagnosed after rupture. Surgical management was performed by microsurgery (28.3%), endoscopic cyst fenestration (14.6%), cystoperitoneal shunting (CPS; 16.2%), or subdural shunting (10%). Furthermore, 74 children (30.8%) did not undergo operations. After a mean follow-up of 4.1 years, the mean percentage decrease in cyst volume and the overall rate of clinical improvement did not significantly differ. The endoscopy group had earlier complications and a shorter event-free survival (EFS) time (EFS at 3 years = 67.7%, vs 71.5% and 90.5% for CPS and microsurgery, respectively; p < 0.007) and presented with more subdural hematomas compared to the microsurgery group (p < 0.005). The microsurgery group also showed a tendency for longer cystocisternostomy permeability than the endoscopy group.

CONCLUSIONS

Concerning the management of unruptured symptomatic temporal ACs, microsurgery appears to be the most effective treatment, with longer EFS and fewer complications compared to shunting or endoscopy.

Management of Neonatal Facial Paralysis due to Cerebellopontine Angle Arachnoid Cyst: A Case Report

Arachnoid cysts are benign, cerebrospinal fluid-filled collections that can be located in the brain or spinal cord. Arachnoid cysts form approximately 1% of all intracranial lesions. They are accepted as arachnoid developmental anomaly and arise from membrane splitting or duplication. Generally, lesion growth causes symptoms because of mass effect or obstruction. Arachnoid cyst growing mechanisms are a largely controversial issue. We report the case of a neonatal female patient who presented with congenital facial paralysis. Magnetic resonance imaging showed a right cerebellopontine angle arachnoid cyst causing severe mass effect on the brain stem. Cyst fenestration and cystocisternal shunt was performed through retrosigmoid suboccipital craniotomy.

Endonasal Endoscopic Treatment of Parasellar Arachnoid Cyst: Report of a Case

A 40-year-old man presented with intractable headache of 5-year duration and a 1-month history of intermittent cerebrospinal fluid (CSF) rhinorrhea. Magnetic resonance imaging showed a cystic lesion with signal characteristics similar to that of CSF. The patient underwent endonasal endoscopic surgery of the sphenoid sinus and the fistula was reinforced with facia, muscle, cartilage, and posterior septal flap while performing cystocisternostomy. The postoperative course was uneventful, CSF leakage stopped, and headache improved. Postoperative imaging revealed total collapse of the cyst cavity. Based on our findings, endonasal endoscopic treatment of the sellar and parasellar arachnoid cysts, if presenting into the sphenoid sinus, could be an acceptable minimally invasive alternative to the conventional modalities.

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.

La neuroendoscopia nel trattamento delle cisti aracnoidee Indicazioni e limiti

Gli autori descrivono 15 casi di cisti aracnoidee operate con tecnica endoscopica. Si tratta di 10 maschi e 5 femmine di età compresa fra 2 mesi e 80 anni con le seguenti localizzazioni cistiche: 6 della valle silviana, 2 soprasellari, 5 in fossa cranica posteriore, 1 della convessità frontale e 1 parietale interemisferica.

I risultati sono stati soddisfacenti con risoluzione dei sintomi clinici in 11 casi (73%) mentre sul piano radiologico una riduzione di volume della cisti si è ottenuta in 7 casi (46%). Vengono discussi vantaggi e limiti della tecnica endoscopica e le indicazioni in riferimento alla localizzazione cistica ed in confronto ai trattamenti tradizionali (craniotomia e shunt).

Neuroendoscopic Approach to Intracranial Ependymal Cysts

BACKGROUND

Intraparenchymal cysts without communication to the ventricles or the subarachnoid space are named ependymal or epithelial cysts. The estimated ratio of their incidence compared with arachnoid cysts is 1:10. Neurologic deficit can occur when the cyst exerts mass effect on its surroundings. We evaluated the success rate of endoscopic fenestration of intracranial ependymal cysts.

METHODS

Our prospectively maintained endoscopy database was screened for all cases of ependymal cysts. The charts were retrospectively reviewed for symptoms, surgery, postoperative course, and complications. Magnetic resonance imaging scans performed before and after surgery were analyzed.

RESULTS

We identified 6 patients harboring an intracranial ependymal cyst. The cyst location was frontoparietal, parietal, occipital, or mesencephalic. Patients presented with several symptoms according to the location of the cyst (i.e., epilepsy, hemiparesis, diplopia, hemianopsia). All patients were treated by navigation-guided endoscopic fenestration of the cyst to the ventricular system. Two complications occurred: a cerebrospinal fluid leak, which was managed surgically by wound revision without the need for cerebrospinal fluid shunting, and a chronic subdural hematoma, which occurred 6 weeks after surgery and required burr hole evacuation. Follow-up period ranged from 6 months to 9 years. Magnetic resonance imaging revealed that all cysts decreased in size. Symptoms improved in all patients.

CONCLUSIONS

Endoscopic fenestration of ependymal cysts to an adjacent ventricular cavity is a treatment option with excellent long-term results and minimal morbidity. It should be considered as the therapy of choice to avoid craniotomy and shunt dependence.

Rapid Visual Deterioration Caused by Posterior Fossa Arachnoid Cyst

Posterior fossa is a site next to the middle fossa where arachnoid cyst frequently occurs. Generally, most arachnoid cysts are asymptomatic and are found incidentally in most cases. Although arachnoid cysts are benign and asymptomatic lesions, patients with posterior fossa arachnoid cysts often complain of headaches, gait disturbance, and ataxia due to the local mass effects on the cerebellum. We observed a patient with a posterior fossa arachnoid cyst who had visual symptoms and a headache, but did not have gait disturbance and ataxia. We recommended an emergency operation for decompression, but the patient refused for personal reasons. After 7 days, the patient revisited our hospital in a state of near-blindness. We suspected that the arachnoid cyst induced the hydrocephalus and thereby the enlarged third ventricle directly compressed optic nerves. Compressed optic nerves were rapidly aggravated during the critical seven days; consequently, the patient's vision was damaged despite the operation. Considering the results of our case, it is important to keep in mind that the aggravation of symptoms cannot be predicted; therefore, symptomatic arachnoid cysts should be treated without undue delay.

Transaqueductal trans-Magendie fenestration of arachnoid cyst in the posterior fossa

BACKGROUND

Neuroendoscopy is currently recommended as the first choice to treat posterior fossa arachnoid cysts. It has proven to be effective, providing improved outcome, and safe, having a low complication rate. Compared to craniotomy and shunt placement, it has lower surgical morbidity, minimizing or avoiding risks of subdural fluid collections, shunt infection, malfunction, overdrainage, and dependence. Usually, rigid scopes maneuvered through a suboccipital approach are used. When symptomatic obstructive hydrocephalus develops, CSF diversion is the first aim of surgery.

METHODS

In these patients, a flexible scope introduced through a frontal burr hole allows not only immediate and efficient management of hydrocephalus with endoscopic third-ventriculostomy, but in selected cases also direct cyst inspection and fenestration. Navigation of an enlarged cerebral aqueduct is actually safe when performed by experienced neurosurgeons.

RESULTS

We describe the cystocisternostomy of a cisterna magna arachnoid cyst using a transaqueductal trans-Magendie approach.

CONCLUSIONS

This minimally invasive technique gives the possibility of performing both endoscopic third-ventriculostomy and cyst fenestration, which alone may not be enough to efficiently treat hydrocephalus.

A Novel Bilateral Approach for Suprasellar Arachnoid Cysts: A Case Report

The endoscopic method is used to treat suprasellar arachnoid cysts (SACs) but it is sometimes difficult to make sufficiently sized fenestrations. Creating a larger fenestration on the cyst wall is preferable to prevent closure of the stoma. In this paper, we report a novel endoscopic approach for SAC treatment in which we use bilateral burr holes to achieve a more extensive cyst fenestration. A 7-year-old girl was referred to our hospital because of incidentally detected hydrocephalus by computed tomography scans. Physical examination did not show any signs of intracranial hypertension, but a digital impression of her skull on X-ray implied chronic intracranial hypertension. Magnetic resonance imaging (MRI) revealed enlargement of both lateral ventricles and a cystic mass occupying the third ventricle. We performed cyst wall fenestration using a bilateral approach in which we created two burr holes to introduce a flexible endoscope and a rigid endoscope. The cyst wall was held by forceps with the flexible endoscope, and resection of the cyst wall was achieved by using a pair of scissors with the rigid endoscope. There were no postoperative complications, and MRI performed 1 year after treatment showed disappearance of the superior part of the cyst wall.

Suprasellar Arachnoid Cysts: Toward a New Simple Classification Based on Prognosis and Treatment Modality

BACKGROUND:

Suprasellar arachnoid cysts (SAC) represent between 9% and 21% of pediatric arachnoid cysts. Recent improvements in magnetic resonance imaging, as well as increasing prenatal diagnosis, have allowed more precise knowledge and follow-up.

OBJECTIVE:

To describe a novel classification of SAC.

METHODS:

We present 35 cases of SAC treated between 1996 and 2014. Patient records and imaging studies were reviewed retrospectively to assess symptomatology, radiological findings, treatment, and long-term follow-up.

RESULTS:

Fourteen SAC were diagnosed prenatally (39%). We observed 15 (43%) cases presenting hydrocephalus (SAC-1) removing Liliequist membrane downward. Lower forms (SAC-2) with free third ventricle were observed in 11 (31%) cases. Asymmetrical forms (SAC-3) with Sylvian or temporal extension were seen in the 9 (26%) remaining patients. Twenty-three (66%) patients were treated by ventriculocisternostomy, 3 (8.5%) by shunt surgery, and 3 (8.5%) by craniotomy. Six (17%) patients had no surgery, including 5 cases (14%) that had prenatal diagnosis. Outcomes were initially favorable in 26 cases (87%). Eight (22%) patients had endocrine abnormalities at the end of the follow-up, 3 (8.5%) had developmental delay, and 6 (17%) had minor neuropsychological disturbances.

CONCLUSION:

SAC are heterogeneous entities. SAC-1 may come from an expansion of the diencephalic leaf of the Liliequist membrane. SAC-2 show a dilatation of the interpeduncular cistern and correspond to a defect of the mesencephalic leaf of the Liliequist membrane. SAC-3 correspond to the asymmetrical forms expanding to other subarachnoid spaces. Surgical treatment is not always necessary. The recognition of the different subtypes will allow choosing the best treatment option.

A Novel Design for Steerable Instruments Based on Laser-Cut Nitinol

Objective. Omnidirectional articulated instruments enhance dexterity. In neurosurgery, for example, the simultaneous use of 2 instruments through the same endoscopic shaft remains a difficult feat. It is, however, very challenging to manufacture steerable instruments of the requisite small diameter. We present a new technique to produce such instruments by means of laser cutting. Only 3 coaxial tubes are used. The middle tube has a cutting pattern that allows the steering forces to be transmitted from the proximal to the distal end. In this way the steering part is concealed in the wall of the tube. Large diameter articulated instruments such as for laparoscopy might benefit from the excellent tip stability provided by the same economical technology. Method. Coaxial nitinol tubes are laser-cut with a Rofin Stent Cutter in a specific pattern. The 3 tubes are assembled by sliding them over one another, forming a single composite tube. In a surgical simulator, the neurosurgical microinstruments and laparoscopic needle drivers were evaluated on surgical convenience. Results. Simultaneous use of 2 neurosurgical instruments (1.5 mm diameter) through the same endoscopic shaft proved to be very intuitive. The tip of the steerable laparoscopic instruments (10 mm diameter) could resist a lateral force of more than 20 N. The angle of motion for either instrument was at least 70° in any direction. Conclusions. A new design for steerable endoscopic instruments is presented. It allows the construction in a range from microinstruments to 10-mm laparoscopic devices with excellent tip stability.

Current state and future development of intracranial neuroendoscopic surgery

Since the introduction of the modern, smaller endoscopes in the 1960s, neuroendoscopy has become an expanding field of neurosurgery. Neuroendoscopy reflects the tendency of modern neurosurgery to aim towards minimalism; that is, access and visualization through the narrowest practical corridor and maximum effective action at the target point with minimal disruption of normal tissue. Transventricular neuroendoscopy allows the treatment of several pathologies inside the ventricular system, such as obstructive hydrocephalus and intra-/paraventricular tumors or cysts, often avoiding the implantation of extracranial shunts or more invasive craniotomic approaches. Endoscopic endonasal transphenoidal surgery allows the treatment of pathologies of the sellar and parasellar region, with the advantage of a wider vision of the surgical field, less traumatism of the nasal structures, greater facility in the treatment of possible recurrences and reduced complications. However, an endoscope may be used to assist microsurgery in virtually any kind of neurosurgical procedures (endoscope-assisted microsurgery), particularly in aneurysm and tumor surgery. Basic principles of optical imaging and the physics of optic fibers are discussed, focusing on the neuroendoscope. The three main chapters of neuroendoscopy (transventricular, endonasal transphenoidal and endoscope-assisted microsurgery) are reviewed, concerning operative instruments, surgical procedures, main indications and results.

From the idea to its realization: the evolution of minimally invasive techniques in neurosurgery

Minimally invasive techniques in neurosurgery evolved in two steps. Many minimally invasive concepts like neuronavigation, endoscopy, or frame based stereotaxy were developed by the pioneers of neurosurgery, but it took decades till further technical developments made the realization and broad clinical application of these early ideas safe and possible. This thesis will be demonstrated by giving examples of the evolution of four minimally invasive techiques: neuronavigation, transsphenoidal pituitary surgery, neuroendoscopy and stereotaxy. The reasons for their early failure and also the crucial steps for the rediscovery of these minimally invasive techniques will be analysed. In the 80th of the 20th century endoscopy became increasingly applied in different surgical fields. The abdominal surgeons coined as first for their endoscopic procedures the term minimally invasive surgery in contrast to open surgery. In neurrosurgery the term minimally invasive surgery stood not in opposiotion to open procedures but was understood as a general concept and philosophy using the modern technology such as neuronavigation, endoscopy and planing computer workstations with the aim to make the procedures less traumatic.

Endoscopic treatment of quadrigeminal arachnoid cysts in children

OBJECT

Quadrigeminal arachnoid cysts (QACs) are rare, comprising approximately 5%-10% of all intracranial arachnoid cysts. The management of these cysts is challenging, and their optimal surgical treatment is controversial. This study evaluates the role of endoscopy in the treatment of QACs in children, focusing on some factors or technical aspects that might influence the outcome.

METHODS

Eighteen children with symptomatic QACs were the subject of this study. The group included 10 boys and 8 girls, with a mean age of 2.5 years. All patients had hydrocephalus. Surgical treatment included ventriculocystostomy (14 cases), endoscopic third ventriculostomy (14 cases), ventriculocystocisternostomy (2 cases), cystocisternostomy (2 cases), and removal of preexisting malfunctioning cystoperitoneal shunt (4 cases).

RESULTS

Significant clinical improvement occurred in 15 cases (83.3%). Postoperative MRI showed a reduction in the cyst size in 14 cases (77.8%), whereas in the remaining 4 cases (22.2%) the cyst size was unchanged. A postoperative decrease in ventricular size was encountered in 16 cases (88.9%). Minor intraoperative bleeding occurred in 1 case (5.6%), which stopped spontaneously without any postoperative sequelae. Postoperative subdural hygroma occurred in 3 cases (16.7%) and required a subduroperitoneal shunt in 2 cases. During follow-up (mean 45.8 months), a repeat endoscopic procedure was performed in 7 patients (all 4 patients with a prior shunt and 3 patients without a prior shunt), and new shunt placement was required in 5 patients (all 4 patients with a prior shunt and 1 patient without a prior shunt). Thus, none of the patients with a prior shunt was able to become shunt independent, whereas 92.9% of patients without a prior shunt were able to avoid shunt placement.

CONCLUSIONS

Arachnoid cysts of the quadrigeminal cistern and the associated hydrocephalus can be effectively treated by endoscopy. The procedure is simple, minimally invasive, and associated with low morbidity and mortality rates. The fact that all patients who previously received shunts required a repeat endoscopic procedure and that none of these patients was able to become shunt independent makes it clear that endoscopic treatment should be considered the first choice in the management of patients with arachnoid cysts in the quadrigeminal cistern.

Arachnoid cyst slit valves: the mechanism for arachnoid cyst enlargement

Arachnoid cysts are common, accounting for approximately 1% of intracranial mass lesions. Most are congenital, clinically silent, and remain static in size. Occasionally, they increase in size and produce symptoms due to mass effect or obstruction. The mechanism of enlargement of arachnoid cysts is controversial. One-way slit valves are often hypothesized as the mechanism for enlargement. The authors present 4 cases of suprasellar prepontine arachnoid cysts in which a slit valve was identified. The patients presented with hydrocephalus due to enlargement of the cyst. The valve was located in the arachnoid wall of the cyst directly over the basilar artery. The authors believe this slit valve was responsible for the net influx of CSF into the cyst and for its enlargement. They also present 1 case of an arachnoid cyst in the middle cranial fossa that had a small circular opening but lacked a slit valve. This cyst did not enlarge but surgery was required because of rupture and the development of a subdural hygroma. One-way slit valves exist and are a possible mechanism of enlargement of suprasellar prepontine arachnoid cysts. The valve was located directly over the basilar artery in each of these cases. Caudad-to-cephalad CSF flow during the cardiac cycle increased the opening of the valve, whereas cephalad-to-caudad CSF flow during the remainder of the cardiac cycle pushed the slit opening against the basilar artery and decreased the size of the opening. Arachnoid cysts that communicate CSF via circular, nonslit valves are probably more likely to remain stable.

The effectiveness of neuroendoscopic versus non-neuroendoscopic procedures in the treatment of lateral ventricular cysts: a retrospective medical record review study

Background

The aim of this study was to assess the effectiveness of neuroendoscopy compared with non-neuroendoscopic procedures for treating patients with arachnoid membrane cysts in the lateral ventricles.

Methods

The medical records of 28 patients with arachnoid membrane cysts in the lateral ventricles who were treated with neuroendoscopy and 39 such patients treated with non-neuroendoscopic techniques using classic treatment procedures were reviewed. The neuroendoscopic approach combined craniotomy, corticectomy, lesion resection and cyst ventriculostomy or cyst cisternostomy to restore normal cerebrospinal fluid circulation. The non-neuroendoscopic techniques included craniotomy, corticectomy, and lesion resection performed under a microscope. Clinical outcomes of symptoms and cyst size change on imaging were compared between the two treatment groups during follow-up (range: 1–5 years).

Results

Patients in the neuroendoscopy group had significantly less blood loss (P < 0.001) and shorter operative time (P < 0.001), better marked improvement in symptoms (64.3% vs. 5.1%, respectively), and a higher total resection rate (92.9% vs. 66.7%; P = 0.011) compared with the patients in the non-neuroendoscopy group. In the neuroendoscopy group there was no cyst recurrence whereas in the non-neuroendoscopy group 8 (20.5%) patients had cyst recurrence. However, all patients in the neuroendoscopy group had postoperative transient fever and 8 (28.6%) patients had subdural fluid accumulation which was treated and subsequently resolved during follow-up. These symptoms did not occur in the non-neuroendoscopy group.

Conclusion

We found that neuroendoscopic therapy for arachnoid cysts in the lateral ventricles was more efficacious than non-neuroendoscopic methods. Our results indicate that neuroendoscopy may produce better clinical outcomes than non-neuroendoscopic procedures in treating patients with arachnoid cysts in the lateral ventricles.

Transventricular endoscopic fenestration of intrasellar arachnoid cyst

BACKGROUND

To manage arachnoid cysts, incorporation with the normal circulation is the single most important determinant of success. Although the postoperative cerebrospinal fluid leakage rate is 3.9% for all cases of transsphenoidal surgery, it is 21.4% for intrasellar arachnoid cysts.

OBJECTIVE

To present a safe, relatively easy, and effective treatment option for very rare intrasellar arachnoid cysts.

METHODS

We performed a prospective study of intrasellar cystic lesions without a solid portion. Endoscopic exploration and fenestration were performed for all lesions under neuronavigational guidance. We analyzed presenting symptoms, endocrinological status, and magnetic resonance images.

RESULTS

There were 2 male and 4 female patients with a mean age of 45 years (range, 27-67 years). All patients presented with the visual disturbance of bitemporal hemianopsia. Four patients had endocrinological symptoms including galactorrhea, dysmenorrhea, and diabetes insipidus. Endoscopic fenestration of the cyst was successfully performed in all patients. All patients were confirmed to have a pure cystic lesion, namely an arachnoid cyst. The follow-up period was 10 months on average (range, 6-12 months). Visual disturbance improved in 5 patients. Endocrinological problems persisted in all patients for 3 months and then normalized, with the exception of the patient with diabetes insipidus. There was no evidence of recurrence in any of the 6 patients in the 12-month postoperative imaging studies (median follow-up of 10 months). Two patients showed syndrome of inappropriate antidiuretic hormone at 2 and 4 weeks after the operation, but antidiuretic hormones recovered to normal levels after this time point.

CONCLUSION

Endoscopic fenestration of an intrasellar arachnoid cyst is a safe and simple procedure without serious complications.

Endoscopic treatment of middle cranial fossa arachnoid cysts in children

OBJECT

Arachnoid cysts located in the middle cranial fossa are common, comprising about half of all intracranial arachnoid cysts. The management of these cysts is challenging, and the optimal surgical treatment is controversial. This study evaluates the role of endoscopy in the treatment of middle cranial fossa arachnoid cysts (MCFACs) in children, focusing on some factors or technical aspects that might influence the outcome.

METHODS

Thirty-two children with symptomatic MCFACs were the subject of this study. The group included 23 boys and 9 girls, with a mean age of 3.6 years. All patients underwent operations using a purely endoscopic cystocisternostomy procedure through a transtemporal approach.

RESULTS

Significant clinical improvement occurred in 28 cases (87.5%). Postoperative MR imaging showed a reduction in cyst size in 23 cases (71.9%), whereas in the remaining 9 cases (28.1%), the cyst size was unchanged. Minor intraoperative bleeding occurred in 3 cases (9.4%), which stopped spontaneously without any postoperative sequelae. Ipsilateral subdural hygroma occurred in 2 cases (6.3%) and resolved within a few weeks without surgery; transient oculomotor palsy occurred in 1 case (3.1%). During follow-up (mean 4.6 years), 3 patients (9.4%) experienced recurrence of symptoms and an increase in cyst size. Interestingly, all 3 patients who had recurrence had also experienced intraoperative bleeding at initial surgery. At a second endoscopic procedure, the fenestration was found to be closed in all 3 patients.

CONCLUSIONS

Endoscopic cystocisternostomy is recommended in the treatment of MCFACs in children because it is simple, minimally invasive, and effective. It maintains the basic strategy of cyst fenestration into the basal cisterns without the invasiveness of open craniotomy. This procedure reduces operative and recovery times and is associated with low morbidity and mortality rates.

Interhemispheric and quadrigeminal cysts

BACKGROUND

Interhemispheric and quadrigeminal cysts are rare lesions, similar in their propensity to present in young babies and to be associated with other central nervous system malformations, such as corpus callosum agenesia, holoprosencephaly, encephalocele, and neuronal heterotopias. Recently endoscopy has become increasingly popular in the treatment of arachnoid cysts, but experience with cysts located in the interhemispheric fissure and in the quadrigeminal cistern is limited.

METHODS

This study reviews the specific anatomy of interhemispheric and quadrigeminal cysts and their relationship with the ventricular system and subarachnoid cisterns to select the most appropriated treatment. It also reviews the literature on endoscopic treatment of interhemispheric and quadrigeminal cysts.

RESULTS

Interhemispheric and quadrigeminal cysts are not homogeneous, they have different extensions toward surrounding regions. In most cases it is presented as an area of contiguity between the cyst and ventricular system and/or subarachnoid cisterns, making endoscopic treatment feasible. The success rate for endoscopic treatment is not different from that reported in large series of arachnoid cysts elsewhere.

CONCLUSIONS

Endoscopic treatment should be considered the first-line option in the treatment of such lesions, even if some complications, such as subdural collections due to thinness of the cerebral mantle or subcutaneous CSF collections due to multifactorial associated hydrocephalus, must be expected.

Fenestration methods for Sylvian arachnoid cysts--endoscopy or microsurgery

INTRODUCTION

Two different approaches to fenestration, endoscopic and microsurgical, are in use for Sylvian arachnoid cysts (SACs), the most frequent among intracranial arachnoid cysts. We presented the clinical data and compared our results, with regard to technique and clinical success, with either microsurgical or neuroendoscopic fenestration of SACs.

MATERIALS AND METHODS

Twenty-nine patients who subjected to cysto-cisternostomy by the same team, using either of the two methods, were studied retrospectively.

RESULTS

Thirteen patients underwent microsurgery, and 16 had endoscopic cysto-cisternostomy. No reoperation was needed in either of these groups, i.e., full clinical and radiological success was achieved in both. The complication rate was 23% in the microsurgery patients and 47% in the endoscopic surgery group, with no statistically significant difference.

CONCLUSIONS

No relevant differences between the two methods are seen either in the published data or in our results. Adding our results to the published data, both techniques were reviewed in a discussion of the one that allows a better controlled or safer fenestration. We conclude that endoscopic fenestration of SACs is not superior to microsurgical cyst fenestration, and the latter seems safer.

De novo suprasellar arachnoid cyst: case report and review of the literature

PURPOSE

We present a case of a 4-year-old child who was incidentally found to have a suprasellar arachnoid cyst (SAC) after initial CT imaging at 6 weeks of age but who demonstrated no anomalies. This is only the sixth case of intracranial de novo ACs documented in the English literature and only the second case of SAC to arise de novo.

METHODS

Case review after an SAC was found on an MRI scan at 4 years of age which had not been present on a previous CT of the head.

RESULTS

Apparent de novo SAC formation in a healthy 4-year-old female without a history of intracranial infection, surgery or trauma.

CONCLUSION

The pathophysiology leading to the formation of the cyst might well be congenital, although there is some question as to how early in development the cysts are formed as our child was a 32-week GA preemie with an initial scan at 38 weeks GA. With the use of fast MRI scans instead of CT scans and the continued neuroimaging of premature infants, we can take a better look at the anatomy and better determine the timing of development of the SAC.

Endoscopic fenestrations for suprasellar arachnoid cysts

OBJECT

The endoscopic treatment of a suprasellar arachnoid cyst (SAC) consists mainly of ventriculocystostomy (VC) and ventriculocystocisternostomy (VCC). However, the most appropriate treatment for these cysts has not been fully determined yet. The authors report on the effectiveness of endoscopic VC for SACs communicating with the basal cisterns, which is demonstrated by preoperative CT cisternography.

METHODS

The authors retrospectively analyzed the surgical results of patients with an SAC treated using endoscopic fenestration. The patient charts were reviewed for demographic data, clinical presentations, surgical therapies, and clinical outcomes.

RESULTS

Six consecutive patients with SAC were surgically treated using endoscopic fenestration (VC or VCC) between March 2004 and February 2011. The mean age was 18.5 months (range 5 days to 37 months). Five patients were previously untreated, and 1 patient had previously undergone ventriculoperitoneal shunt placement. Five patients underwent preoperative CT cisternography, and communication between the SAC and the basal cisterns was demonstrated in 3 patients, very slight communication in 1, and no communication in 1. Four patients, including the 3 with communication between the SAC and basal cisterns, underwent VC. Two patients with very slight or no communication underwent VCC. In all patients the SAC decreased in size and hydrocephalus improved postoperatively. Five patients (3 treated with VC and 2 with VCC [83%]) have been stable without reoperation (mean follow-up 32.7 months). All 3 patients with an SAC communicating with the basal cisterns have been stable without reoperation following VC.

CONCLUSIONS

Preoperative cisternography may be useful for selecting the optimal endoscopic treatment method for SAC. If an SAC communicates with the basal cisterns, a VC could be an effective, safe, and simpler treatment option.

Endoscopy versus microsurgical cyst excision and shunting for treating intracranial arachnoid cysts

OBJECT

Endoscopic surgery is routinely used to treat intracranial arachnoid cysts. However, the indications and results with respect to the different cyst locations, compared with those of microsurgical fenestration and cyst shunting, deserve to be discussed.

METHODS

The authors review 18 patients with intracranial arachnoid cysts treated by pure endoscopic technique in their neurosurgical department. There were 10 male and 8 female patients ranging in age from 2 months to 48 years (median age 19.4 years). The cyst location was suprasellar in 5 cases, quadrigeminal in 5, cortical hemispheric in 2, sylvian region in 3, and posterior fossa in 3. The authors also reviewed the literature, comprising 61 reports for an overall number of 645 patients with intracranial arachnoid cysts treated by different surgical techniques. These techniques included microsurgical excision or fenestration by craniotomy, cyst shunting, and endoscopic fenestration. The surgical results of the different techniques according to the different cyst locations underwent statistical analysis.

RESULTS

The overall success rate (complete or partial clinical remission) in the authors' endoscopic series was 83.3% (15 of 18 cases), which is rather similar to that of 222 patients treated endoscopically and reported on in the literature (84.2%). In the overall endoscopic group, a higher success rate was found for cysts in the suprasellar (89.7%), quadrigeminal (88.5%), and posterior cranial fossa (83.3%) regions compared with sylvian (70%) and cortical and interhemispheric (75%) regions. The statistical comparison of the results of the endoscopic series with those of craniotomy and shunting revealed no significant differences for suprasellar, quadrigeminal, or posterior cranial fossa cysts, whereas the success rate of endoscopy is lower than that of other techniques for sylvian and cortical cysts.

CONCLUSIONS

Endoscopy is a safe and effective therapeutic modality for patients with intracranial arachnoid cysts. Cysts of the suprasellar and quadrigeminal regions and posterior fossa are the best indications for neuroendoscopy; on the other hand, cortical cysts are best treated by microsurgical fenestration or shunting. For sylvian cysts, the endoscopic procedure may be advocated in most cases.

Endoscopic treatment of suprasellar arachnoid cysts in children

OBJECT

Suprasellar arachnoid cysts (SACs) are rare, comprising approximately 10% of all intracranial arachnoid cysts. Although neuroendoscopic management is emerging as a safe effective alternative to microsurgery, the type of endoscopic surgery whether ventriculocystostomy (VC) or ventriculocystocisternostomy (VCC) is still controversial. This study evaluates the role of endoscopy in the treatment of SACs in children. It compares VC and VCC to determine which procedure is superior in the long term.

METHODS

Twenty-five children (14 boys and 11 girls; mean age 26 months) with symptomatic SACs associated with hydrocephalus are the subject of this study. According to the surgical procedure adopted, patients were divided into 2 groups. Patients in Group A (11 patients) underwent VC with a mean follow-up of 55 months, and those in Group B (14 patients) underwent VCC with a mean follow-up of 64.7 months.

RESULTS

Both procedures proved to be effective clinically and radiologically. The incidence of improvement of hydrocephalus-related symptoms was 63.6% in Group A compared with 85.7% in Group B. Improvement in cyst size and hydrocephalus after VC was 81.8% and 63.6%, respectively, compared with 100% and 85.7%, respectively, after VCC. There were no deaths or permanent morbidity, and no patient was left with a permanent shunt. Recurrence occurred in 3 cases after VC (27.3%), whereas no recurrence (0%) was encountered after VCC. At a second endoscopic procedure, the fenestration was found to be closed in all 3 recurrent cases.

CONCLUSIONS

An endoscopic procedure is recommended in the treatment of SACs in children because it is simple, effective, minimally invasive, and associated with low morbidity and mortality rates. Both procedures, VC and VCC, proved to be almost equally effective clinically and radiologically. Nevertheless, because of the statistically significant difference between the incidence of recurrence after VC and VCC during long-term follow-up, the author concludes that VCC should be considered as the procedure of choice in the treatment of these cases. The important finding of reclosure of the VC fenestration in the recurrent cases underscores the significance of performing cystocisternostomy at initial surgery to guard against cyst recurrence.

Cyst-ventricle stent as primary or salvage treatment for posterior fossa arachnoid cysts

OBJECT

The optimal treatment of symptomatic posterior fossa arachnoid cysts is controversial. Current options include open or endoscopic resection, fenestration, or cyst-peritoneal shunt placement. There are potential drawbacks with all options. Previous authors have described stenting a cyst into the ventricular system for supratentorial lesions. The current authors have used a similar strategy for posterior fossa cysts.

METHODS

The authors performed a retrospective review of 79 consecutive patients (1993-2010) with surgically treated intracranial arachnoid cysts.

RESULTS

The authors identified 3 patients who underwent placement of a stent from a posterior fossa arachnoid cyst to a supratentorial ventricle. In 2 patients the stent construct consisted of a catheter placed into a posterior fossa arachnoid cyst and connecting to a lateral ventricle catheter. Both patients underwent stent placement as a salvage procedure after failure of open surgical fenestration. In the third patient a single-catheter cyst-ventricle stent was stereotactically placed. All 3 patients improved clinically. Two patients remained asymptomatic, with radiographic stability in a follow-up period of 1 and 5 years, respectively. The third patient experienced initial symptom resolution with a demonstrable reduction of intracystic pressure. However, he developed recurrent headaches after 2 years.

CONCLUSIONS

Posterior fossa cyst-ventricle stenting offers the benefits of ease of surgical technique and a low morbidity rate. It may also potentially reduce the incidence of shunt-related headaches by equalizing the pressure between the posterior fossa and the supratentorial compartments. While fenestration is considered the first-line therapy for most symptomatic arachnoid cysts, the authors consider cyst-ventricle stenting to be a valuable additional strategy in treating these rare and often difficult lesions.

Intracranial Cysts Containing Cerebrospinal Fluid-Like Fluid: Results of Endoscopic Neurosurgery in a Series of 64 Consecutive Cases

BACKGROUND:

Intracranial cysts containing cerebrospinal fluid (CSF) may be developmental or acquired.

OBJECTIVE:

To analyze the results of endoscopic neurosurgery in the management of intracranial CSF cysts.

METHODS:

In a 7-year period, 64 consecutive patients underwent endoscopic neurosurgery for CSF cysts. Group 1 consisted of 13 patients with acquired cysts; group 2 included 51 patients with developmental cysts. In all cases, the cyst walls were fenestrated through small burr holes with frameless guided operative endoscopes. Follow-up ranged from 1 to 6 years (mean, 3.4 years).

RESULTS:

There were no mortality and no permanent morbidity, apart from a patient (1.6%) who remained neurologically intact but required ventriculoperitoneal shunting because of intraoperative hemorrhage. The planned fenestrations could be performed in all patients except 2, owing to thick, opaque cyst walls. In group 1, 6 patients fully recovered and remained intact throughout the follow-up, whereas 7 improved but had various degrees of neurological disabilities that were related to their initial diseases. Radiological results were excellent in all cases. In group 2, there were 7 asymptomatic patients who remained unchanged and 44 “symptomatic” patients: 40 (91%) clinically improved, 4 (9%) remained unchanged, and none worsened. Cyst size decreased in 37 patients (74%) and remained unchanged in 13 (26%).

CONCLUSION:

In this series, patients of different ages, harboring cysts of various sizes and locations, could be satisfactorily treated with endoscopic neurosurgery.

Interpeduncular arachnoid cysts in infants and children: insight into the entity based on a case series with long-term follow-up

OBJECTIVE

Arachnoid cysts occupying the suprasellar region comprise 10-15% of intracranial distribution. Unlike large suprasellar cysts, pure interpeduncular cysts (IPCs) are rare, and their natural history is unknown. We describe a small series of children diagnosed with IPC and their long-term natural history.

METHODS

A retrospective review was conducted of interpeduncular arachnoid cysts diagnosed over the years 2000-2010 at our center. Patients with clearly suprasellar cysts were excluded. Serial magnetic resonance imaging and long-term follow-up examinations were analyzed. Additionally, we conducted an extensive literature review focusing on the differences between suprasellar cysts and IPCs.

RESULTS

We identified three pediatric patients with "pure" IPC; all of these had a follow-up of more than 5 years, and none was operated. Only six additional cases were identified in the literature. In both our experience and in the literature review, IPCs proved stable over the course of time, both radiologically as well as clinically.

CONCLUSIONS

The clinical and radiological features of IPCs are not well defined. Variations in the relationship of arachnoid cysts in this area to Liliequist's membrane may explain the different subgroups that have been identified as well as the confusing nomenclature. IPCs are usually diagnosed as incidental findings or present with mild endocrine disorders. Associated findings of hydrocephalus, mass effect, and compression of neighboring structures, such as the chiasm, are not as frequent as with suprasellar cysts. Given the high likelihood of continuing stability, a conservative strategy of follow-up is recommended for pure IPCs that demonstrate preservation of the third ventricle.

The effectiveness of ventriculocystocisternostomy for suprasellar arachnoid cysts

OBJECT

The aim of this study was to report the long-term outcomes of patients receiving endoscopic ventriculocystocisternostomy (VCC) for suprasellar arachnoid cysts (SACs), and to analyze all published reports on outcomes of ventriculocystostomy (VC) versus VCC to compare the effectiveness of the 2 techniques.

METHODS

Eleven consecutive patients with previously untreated SACs were surgically treated using endoscopic VCC. Another 2 patients were treated with VCC following ventriculoperitoneal shunt placement. Clinical imaging data were recorded. An analysis was performed of all published patient outcomes following endoscopic VC or VCC for an SAC.

RESULTS

Developmental delay and progressive macrocephaly were the most common preoperative symptoms. At a mean clinical follow-up interval of 63 months, 10 of 11 patients undergoing primary VCC did not require reoperation. An analysis of the literature suggests that VCC may be more effective than VC. Of the 44 reported patients that underwent VC as a first treatment, 7 (16%) required reoperation, and 7 (8%) of 86 patients who underwent VCC as a first treatment required reoperation. When VC or VCC was performed following a prior surgical procedure, 4 of 11 patients undergoing VC had a treatment failure requiring reoperation. In contrast, only 2 of the 17 reported cases of VCC following a prior procedure required further treatment. The difference in reoperation rates following either primary or secondary VC was significantly higher than following primary or secondary VCC (p = 0.04).

CONCLUSIONS

The authors conclude that VCC is an effective and durable treatment for symptomatic SACs in most cases.

Neuroendoscopic treatment of arachnoid cysts of the quadrigeminal cistern: a series of 14 cases

OBJECT

In this paper, the authors' goal was to evaluate the role of neuroendoscopy in the treatment of arachnoid cysts of the quadrigeminal cistern.

METHODS

Between March 1995 and February 2008, 14 patients affected by arachnoid cysts of the quadrigeminal cistern were treated endoscopically. The cysts were classified according to their anatomical and radiological appearance. The most frequent form (Type I) extended infratentorially and supratentorially with a dumbbell shape. Type II cysts were confined to the infratentorial space and were associated with the most severe and acute form of hydrocephalus. Type III cysts presented a significant asymmetric expansion toward the temporal fossa. Ten patients underwent an endoscopic procedure as primary treatment and 4 as an alternative to shunt revision. In 6 cases, the first endoscopic procedure was ventriculocystostomy (VC) together with endoscopic third ventriculostomy (ETV). In the other 8 cases, the first endoscopic procedure was VC alone.

RESULTS

In the 6 cases in which VC was performed with an ETV, the procedure was successful, and the patients did not require further surgery. Of the 8 cases in which the first endoscopic procedure performed was VC without ETV, 7 underwent reoperation. Four of these patients underwent endoscopic procedures (by reopening the obstructed VC and performing ETV or cystocisternostomy) 2, 4, 4, and 5 months later with final success in all cases. Three patients (all of whom were previously treated using ventriculo- or cystoperitoneal shunts) required shunt reimplantation (complete failure). Subdural collection developed in 1 case, which was managed by transient insertion of a subduroperitoneal shunt. Neurological and developmental outcomes were good except for 1 patient who did not show improvement in preoperative developmental delay. No transient or permanent morbidity or mortality was observed.

CONCLUSIONS

The analysis of this series suggests that arachnoid cysts of the quadrigeminal cistern and the associated hydrocephalus can be effectively treated by endoscopy; this approach allows the patient to be shunt independent in more than 78% of the cases. If endoscopy is used as first option, the success rate of endoscopic procedures observed in this series was 90%. Endoscopic third ventriculostomy should be associated with a VC to offer the highest success rate with a single procedure.

Location, sidedness, and sex distribution of intracranial arachnoid cysts in a population-based sample

Object

The aim of this study was to examine the distribution of intracranial arachnoid cysts in a large and unselected patient population with special emphasis on sidedness and sex distribution.

Methods

In total, 299 patients with 305 arachnoid cysts were studied. These patients were consecutively referred to our department during a 20-year period from a well-defined geographical area with a stable population.

Results

There was a strong predilection (198 patients [66.2%]) for intracranial arachnoid cysts in the temporal fossa. Forty-two patients had cysts overlying the frontal convexity, 36 had cysts in the posterior fossa, and 23 patients had cysts in other, different locations. Of 269 cysts with clearly unilateral distribution, 163 were located on the left side and 106 on the right side. This difference resulted from the marked preponderance of temporal fossa cysts on the left side (left-to-right ratio 2.5:1; p < 0.0001 [adjusted < 0.0005]). For cysts in the cerebellopontine angle (CPA), there was preponderance on the right side (p = 0.001 [adjusted = 0.005]). Significantly more males than females had cysts in the temporal fossa (p = 0.002 [adjusted = 0.004]), whereas in the CPA a significant female preponderance was found (p = 0.016 [adjusted = 0.032]). For all other cyst locations, there was no difference between the 2 sexes.

Conclusions

Arachnoid cysts have a strong predilection for the temporal fossa. There is a sex dependency for some intracranial locations of arachnoid cysts, with temporal cysts occurring more frequently in men, and CPA cysts found more frequently in women. Furthermore, there is a strong location-related sidedness for arachnoid cysts, independent of patient sex. These findings and reports from the literature suggest a possible genetic component in the development of some arachnoid cysts.

Endoscopic Treatment of Arachnoid Cysts

BACKGROUND

Surgical treatment of arachnoid cysts remains under debate. Although many authors favor endoscopic techniques, others attribute a higher recurrence rate to the endoscope.

OBJECTIVE

The authors report their experience with endoscopic procedures for arachnoid cyst.

METHODS

All pure endoscopic procedures for arachnoid cysts performed by the authors were analyzed. Particular reference was given to surgical complications and patient outcome in relation to cyst location and endoscopic technique.

RESULTS

Sixty-six endoscopic procedures were performed in 61 patients (mean age, 28 years; range, 23 days to 74 years; 35 males, 26 females). The main presenting symptoms were cephalgia (61%), hemisymptoms (18%), and macrocephalus (18%). Cyst location was temporobasal (34%), suprasellar (21%), at the cisterna quadrigemina (18%), paraxial supratentorial (16%), and various (10%). Thirty cystocisternostomies, 14 ventriculocystostomies, 12 cystoventriculostomies, and 10 ventriculocystocisternostomies were performed. The overall clinical success rate was 90%. The endoscopic technique was abandoned in 4 cases (7%). Postoperative complications were found in 16%; there was only one permanent deficit (2%). Five recurrences (8%) occurred up to 7 years after the first procedure. Of the various locations, the temporobasal cysts were the most difficult to treat with lowest clinical success (81%), highest recurrence (19%), and highest complication rate (24%). Of the various endoscopic techniques, ventriculocystostomy and ventriculocystocisternostomy reached the highest success rates with 100%.

CONCLUSIONS

Endoscopic techniques provide very good results in arachnoid cyst treatment. The most frequent cyst location is the most difficult to treat. A long-term follow-up is recommended since recurrences can occur many years after the procedure.

Endoscopic management of cranial arachnoid cysts using extra-channel method

OBJECTIVE

Arachnoid cysts (ACs) can be cured by making the definite and wide communication between the cyst and arachnoid space using endoscopy, but often it is impossible only through the usual working-channel (intra-channel) procedures. We discuss and propose a more valuable endoscopic technique with the presentation of our series of cases.

METHODS

We treated 9 patients with cortical AC in various locations with extra-channel endoscopic techniques. The patients ranged in age from 3 years to 60 years (mean age, 37.2 yrs). The follow-up period ranged from 12 to 26 months (mean follow-up duration, 17.2 months). All patients had large AC compressing the adjacent brain with clinical symptoms or signs. The authors performed extensive fenestration via single burr hole with the aid of endoscope. Being bypassed the rigid endoscope, through the space between the shaft of endoscope and guiding cannula (extra-channel method), fenestration procedures were done in the dry fields.

RESULTS

Eight (88.9%) patients had been treated successfully with endoscope. One patient required shunt procedure. Among the eight patients who were treated with endoscopic procedure, 6 patients (66.7%) showed cyst reduction, and two (22.2%) showed disappearance of cyst.

CONCLUSION

We suggest that extra-channel method will be simple and easy to perform using more valuable instruments with wider working area, and may promise better results compared to the conventional intra-channel endoscopic procedures.

Arachnoid cysts do not contain cerebrospinal fluid: A comparative chemical analysis of arachnoid cyst fluid and cerebrospinal fluid in adults

Background

Arachnoid cyst (AC) fluid has not previously been compared with cerebrospinal fluid (CSF) from the same patient. ACs are commonly referred to as containing "CSF-like fluid". The objective of this study was to characterize AC fluid by clinical chemistry and to compare AC fluid to CSF drawn from the same patient. Such comparative analysis can shed further light on the mechanisms for filling and sustaining of ACs.

Methods

Cyst fluid from 15 adult patients with unilateral temporal AC (9 female, 6 male, age 22-77y) was compared with CSF from the same patients by clinical chemical analysis.

Results

AC fluid and CSF had the same osmolarity. There were no significant differences in the concentrations of sodium, potassium, chloride, calcium, magnesium or glucose. We found significant elevated concentration of phosphate in AC fluid (0.39 versus 0.35 mmol/L in CSF; p = 0.02), and significantly reduced concentrations of total protein (0.30 versus 0.41 g/L; p = 0.004), of ferritin (7.8 versus 25.5 ug/L; p = 0.001) and of lactate dehydrogenase (17.9 versus 35.6 U/L; p = 0.002) in AC fluid relative to CSF.

Conclusions

AC fluid is not identical to CSF. The differential composition of AC fluid relative to CSF supports secretion or active transport as the mechanism underlying cyst filling. Oncotic pressure gradients or slit-valves as mechanisms for generating fluid in temporal ACs are not supported by these results.

Are arachnoid cysts localized hydrocephali?

We report 2 cases of arachnoid cysts related to a head trauma. The first case involved a 1-year-old girl who developed an arachnoid cyst 7 months after suffering a head trauma due to a motor vehicle accident, and the second case involved a 1-year-old boy whose arachnoid cyst was first noted 2 months subsequent to his premature birth. We present the serial imaging for both cases. Choi and Kim [Pediatr Neurosurg 1998;29:260-266] postulated that head trauma in infancy may contribute to the pathogenesis of arachnoid cysts in some cases. In presenting our cases, we support this hypothesis, and further postulate that the arachnoid cysts may in fact be localized hydrocephali, triggered either by head trauma or by prematurity.

Treatment option for arachnoid cysts

OBJECTIVE

The objective of this study is to establish which treatment is the best operative intervention for arachnoid cyst.

MATERIALS AND METHODS

We reviewed a series of 209 cases with arachnoid cysts focusing on the effectiveness and safety. The cysts were treated with several surgical procedures including open surgery for fenestration, endoscopic fenestration, or cystoperitoneal shunting.

RESULTS

Follow-up imaging studies showed that 176 out of 209 arachnoid cysts (84.2%) reduced in size during a mean postoperative follow-up period of 6.9 years (range, 1 to 14 years). Although a cystoperitoneal shunt was the best method for early achieving an obliteration of the sylvian cyst (89%), it had the danger of shunt dependency (42%) in addition to four early complications. Although endoscopic fenestration tended to be less effective in reducing the size of a sylvian cyst, it was safe and particularly effective in completely obliterating a suprasellar, quadrigeminal, and prepontine cyst.

CONCLUSION

Although the shunt for arachnoid cyst can get the more rapid good radiological outcome, the shunt-related complication and dependency would be hazardous. We suggest that endoscopic or reduced open procedures offer the advantage of avoiding a large craniotomy or the known complications of a cystoperitoneal shunt in treatment of arachnoid cysts. We could get the nearly same surgical outcome without shunt complications with endoscopic or open procedures.