Endoscopic management of arachnoid cysts: an advancing technique

Early clinico-radiological outcomes following neuroendoscopic cysto-cisternostomy for middle cranial fossa arachnoid cysts: a prospective cohort study with illustrative cases

BACKGROUND

The dysmorphogenetic arachnoid cysts' pathomechanism is most favoured, and about 50% occur as middle cranial fossa cysts (MCFAC). Still being rare, management options are yet evolving. We described the clinico-radiological features, management and early outcomes of participants with MCFAC in our service.

METHODS

This prospective cohort study involved 29 pediatric participants recruited (from electronic health records, using ICD G93.0 D016080 for arachnoid cysts) between 01/01/2023 and 31/06/2023, following informed consent according to the ethical approval. All participants had neuro-imaging confirmed MCFAC. Baseline and follow-up data were retrieved and analyzed using summary (mean, standard deviation) and inferential (ANOVA, t-test) statistics.

RESULTS

They were averagely aged 6.2 ± 4.48 years and were mostly males (89.7%). 24.1% were asymptomatic. The commonest symptoms (n = 38) were headaches (23.7%), developmental delays (15.8%), eye complaints (15.8%) and cephalomegaly (7.9%). They were predominantly left-sided (89.7%). Galassi (G) 3 lesions were less (24.1%), with G2 and G1 lesions evenly sharing the rest. The average cyst volume was 58.4 ± 80.83cm3; there were significant differences (F = 4.682; p = 0.018) between the average volumes for G1 (14.4 ± 22.42cm3), G2 (61.7 ± 89.92cm3) and G3 (122.5 ± 94.37cm3) lesions. 44.8% of the participants had rigid-endoscopic cysto-cisternotomy (all between the ICA and oculomotor nerve into the interpeduncular cistern, using ventriculostomy forceps); including all G3, 50% of G2 and no G1 (had serial clinico-radiological observation) lesion. The average pre- (117.42cm3) and post-operative (53.48cm3) cyst volumes showed significant (t = - 2.797, p = 0.021) reductions.

CONCLUSION

Middle cranial fossa arachnoid cysts occur predominantly amongst males, in middle childhood and left-sided. The treatment-related patient series are largely symptomatic, unlike the largely asymptomatic, screening-related series. Higher Galassi grade lesions presented with progressively, significantly larger cyst volumes and higher likelihoods of surgery. The average post-operative cyst volume at follow-up averagely showed almost 60% reduction from the pre-operative. All participants reported clinical remission.

Long term clinical and radiological outcomes following surgical treatment of symptomatic cranial arachnoid cyst: A population based consecutive cohort study

OBJECTIVE

Symptomatic intracranial arachnoid cysts are treated mainly through surgical resection, endoscopic fenestration, or by implanting cystoperitoneal (CP) shunt. However, the use of a specific technique remains controversial. The purpose of this study is to discuss these surgical modalities in symptomatic patients with intracranial arachnoid cysts (ACs) and investigate which has better outcomes and less complications by comparing variable preoperative and postoperative parameters.

METHODS

An analysis of thirty-nine symptomatic patients who underwent intracranial arachnoid cyst surgery in the department of neurosurgery between 2009 and 2023 was performed. Patients were retrospectively compared based on age group, gender, anatomical location, laterality, type of intervention, clinical and volumetric changes, postoperative complications and outcome.

RESULTS

Of the 39 patients, 20 patients (51.28 %) received CP shunt. Eleven patients (28.2 %) underwent endoscopic fenestration, and 8 patients (20.5 %) had surgical resection. The age at the time of first operation ranged from 1 month to 59.9 years (mean age: 16.8 years), and the pediatric patients were 25 (64.1 %). The most common initial symptom was headache which was observed in 19 patients (48.7 %), followed by seizure in 12 patients (30.8 %), vomiting in 11 patients (28.2 %), visual dysfunction in 8 patients (20.5 %), drowsiness in 8 patients (20.5 %), visual symptoms in 8 patients (20.5 %), cognitive impairment in 4 patients (10.3 %), focal neurological deficits in 3 patients (7.7 %), and cranial nerve involvement in 1 patient (2.6 %). 24 patients (61.5 %) showed improvement while in 15 patients (38.5 %) the symptoms persisted or worsened. Postoperatively, patients were followed up for an average of one year. The highest improvement rate was noted in endoscopic fenestration with 9 improved patients (81.8 %), followed by surgical resection with 5 symptom-free patients (62.5 %). The worst outcomes were seen in cystoperitoneal shunt with only half of the patients were relieved (50 %). Complications developed in 2 patients (25 %) who underwent surgical resection, 5 patients (45.5 %) who had endoscopic fenestration, and 13 patients (65 %) who had cystoperitoneal shunting.

CONCLUSION

Endoscopic fenestration has the highest improvement rate, the lowest serious complications along with being the least invasive technique. These features make it the optimal modality in treatment of ACs. Surgical resection or cystoperitoneal shunt can be considered as secondary techniques when patients report unchanged or worsening symptoms.

Dynamic Workflow Proposal for Continuous Frameless Electromagnetic Neuronavigation in Rigid Neuroendoscopy

BACKGROUND

Ventriculoscopic neuronavigation has been described in several articles. However, there are different ventriculoscopes and navigation systems. Due to these different combinations, it is difficult to find detailed neuronavigation protocols. We describe, step-by-step, a simple method to navigate both the trajectory until reaching the ventricular system, as well as the intraventricular work.

METHODS

We use a rigid ventriculoscope (LOTTA, KarlStorz) with an electromagnetic stylet (S8-StealthSystem, Medtronic). The protocol is based on a modified or 3-dimensionally printed trocar for navigating the extraventricular step and on a modified pediatric nasogastric tube for the intraventricular navigation.

RESULTS

This protocol can be set up in less than 10 minutes. The extraventricular part is navigated by introducing the electromagnetic stylet inside the modified or 3-dimensionally printed trocar. Intraventricular navigation is done by combining a modified pediatric nasogastric tube with the electromagnetic stylet inside the endoscope's working channel. The most critical point is to obtain a blunt-bloodless ventriculostomy while achieving perfect alignment of all targeted structures via pure straight trajectories.

CONCLUSIONS

This protocol is easy-to-set-up, avoids head rigid-fixation and bulky optical-based attachments to the ventriculoscope, and allows continuous navigation of both parts of the surgery. Since we have implemented this protocol, we have noticed a significant enhancement in both simple and complex ventriculoscopic procedures because the surgery is dramatically simplified.

Arachnoid Cyst: An Asymptomatic Exuberance

A 66-year-old man presented to the emergency department with sudden onset of dysarthria, left central facial palsy, and left hemihypesthesia involving the tongue. The patient was hemodynamically stable (blood pressure of 153/84 mmHg and heart rate of 80 bpm) and normoglycemic, without a history of trauma or toxic exposure. Assuming an acute stroke, the patient immediately underwent a brain CT scan that revealed a large left-sided fronto-parieto-temporal arachnoid cyst, with approximately 9.5 x 5.1 cm of maximum diameters (anteroposterior and transversal), compressing the brain parenchyma and the ventricular system, with a right deviation of the median structures by about 5 mm. The patient had a complete spontaneous resolution of the initial symptoms while in the emergency department. He declined admission to the ward for observation and further investigation, choosing to be discharged against medical advice. Lately, the patient represented to the ED with a new episode, this time with worsening symptoms, and consented to a cystoperitoneal shunt insertion. The procedure was well tolerated, and the patient has been asymptomatic since surgery.

Interhemispheric arachnoid cyst

Background

Interhemispheric arachnoid cysts are uncommon and typically associated with other midline neurodevelopmental disorders, such as complete or partial agenesis of the corpus callosum.

Case Description

We report a case of a 27-year-old woman with worsening headache, memory deficit, and radiological progression of an interhemispheric arachnoid cyst. The treatment consisted of craniotomy for interhemispheric cyst fenestration into both the interhemispheric cistern and lateral ventricle. The postoperative course was unremarkable, with considerable clinical improvement and significant reduction in cyst size.

Conclusion

We successfully treat a patient with an enlarging arachnoid cyst and associated progressive symptoms with microsurgical fenestration.

Endoscopic Fenestration of Arachnoid Cysts Through Lateral Pontomesencephalic Membranotomy: Technical Note and Case Series

BACKGROUND

The ideal treatment method for cranial arachnoid cysts stills controversial, each of endoscopic and microscopic techniques has its pros and cons.

METHODS

We described cystocisternostomy technique for arachnoid cysts through fenestration medial to the edge of tentorium through lateral pontomesencephalic membrane and illustrated it's outcomes. We performed endoscopic lateral pontomesencephalic membranotomy in nine children with zero angled rigid endoscope (STORZ).The age ranged from eight months up to nine years. The cysts were Galassi type III in eight cases (five of them giant hemispheric) and Galassi type II in one case. Clinical presentations were delay in milestones, seizures, loss of consciousness, unsteady gait, and persistent headache.

RESULTS

The cysts decreased in size in five cases after three months and nearly disappeared after three and 15 months in two cases, and in 18 months in the other two. Preoperative symptoms improved in all cases. Insignificant subdural hygroma was found in five cases, one case developed hydrocephalus four months later treated with a ventriculoperitoneal shunt; contralateral massive subdural hematoma occurred in one case four months after surgery evacuated with two burr holes with good clinical outcome. There was neither cerebrospinal fluid leakage, cranial nerve palsy nor mortality.

CONCLUSIONS

The fenestration through the lateral pontomesencephalic membrane created a shortcut of cerebrospinal fluid flow to the basal cisterns especially cerebellopontine cistern and represents a reliable option with an acceptable success rate. It creates a good drainage to the large cysts.

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.

Posterior Fossa Arachnoid Cyst in a Pediatric Population is Associated with Social Perception and Rest Cerebral Blood Flow Abnormalities

Posterior fossa arachnoid cysts (PFAC) may produce not only neurological symptoms but also other symptoms still poorly understood such as behavioral and learning deficits, awkwardness, and difficulties in social interaction. These subtle social impairments have not been formally described and their underlying brain mechanisms remain unknown. In the present case-control study, we aimed to empirically characterize social impairments in a pediatric population with PFAC using eye tracking. In addition, we investigated putative functional cortical abnormalities in these children using arterial spin labeling magnetic resonance imaging. Overall, 15 patients with PFAC (3f, age = 9.4 ± 4 years) and 43 typically developing volunteer children (16f, age = 9.3 ± 3.6 years) were enrolled in this study. Eye tracking was used to record gaze patterns during visualization of social interaction scenes. Viewing times to faces of characters and non-social background were analyzed. A voxel-wise whole-brain analysis was performed to investigate rest cerebral blood flow (CBF) abnormalities. Significantly reduced viewing time to faces was observed in patients compared with controls (p < 0.01). A ROC curve analysis revealed that 30% of PFAC patients presented viewing time to the face lower than the cutoff, while none of the controls did. The whole-brain analysis revealed a significant decrease in rest CBF in PFAC patients compared with controls bilaterally in the superior temporal gyrus and the temporoparietal junction (TPJ) (p < 0.05 FWE). These results suggest that early life PFAC may have an impact on functional activity of the temporal lobe, which could be associated with social perception deficits.

A Recurrent Suprapituitary Ependymal Cyst Managed by Endoscopy-Assisted Transsphenoidal Surgery in a Canine: A Case Report

A 9-years-old spayed female mixed-breed dog was referred for the evaluation of intermittent head tremors, obtundation, long-standing blindness, and a tendency to seek confined spaces. The dog lost its vision 6 months before the current presentation. A menace response was absent on ophthalmological examination. Neurological examination did not show any abnormalities. A cyst measuring 16 × 18 × 14 mm was observed above the pituitary gland on magnetic resonance imaging. It extended toward the frontal area and compressed the optic chiasm and hypothalamic regions. A minimum preoperative database, including the findings of other required blood tests, was prepared. No abnormal laboratory findings were observed. Endoscopy-assisted transsphenoidal hypophysectomy was performed to remove the pituitary gland, drain the cyst, and partially excise the cyst wall. Normal pituitary gland tissue was observed on histopathology, and the mass was found to have a neuroendocrine or ependymal origin on cytology. Strict post-operative laboratory tests were performed at 1-h intervals for 24 h. An empty sella turcica region, and a collapsed and empty cyst wall was observed on follow-up magnetic resonance imaging. After 3 days of observation, the dog was discharged with a prescription of substitution therapy. However, the dog presented with the same signs and symptoms 73 days after the surgery. Cyst recurrence was apparent on magnetic resonance imaging. The owner requested euthanasia, and an ependymal cyst was observed on necropsy. To the best of our knowledge, we present the first case of an intra- and suprasellar ependymal cyst, and its surgical management in a canine. The findings from this case suggest that endoscopic transsphenoidal drainage and hypophysectomy could be a good surgical approach in cases where involvement of the pituitary gland is confirmed or strongly suspected on the basis of cytological and imaging findings.

Stereotactic Internal Shunt Placement in Congenital Intracranial Cysts

INTRODUCTION

Treatment of symptomatic intracranial cysts remains a controversial issue. We present a risk/benefit profile of a minimally invasive, not yet described, stereotactic internal shunt implantation technique. The provided data might serve as a reference against which other treatment modalities could be compared.

METHODS

From our prospective database, we identified a consecutive series of patients with symptomatic, untreated cysts who had undergone internal shunting from 2009 to 2017. We estimated the rates of clinical symptom improvement (RCSI), cyst reduction, total complications, and long-term complications. A minimal follow-up of 6 months was required. The prognostic factors were obtained from logistic regression models. Cyst recurrence-free survival was calculated using the Kaplan-Meier method. The outcomes data were compared with those from reported alternative treatment strategies using χ² statistics.

RESULTS

We included 38 patients. The cyst locations differed greatly and included the cerebellum (n = 2), brainstem (n = 5), and pineal area (n = 4). Cyst-associated hydrocephalus (n = 6) resolved after treatment. The 2-year cyst recurrence-free survival rate was 97%. The RCSI and rate of cyst reduction, total complications, and long-term complications was 91%, 97%, 11%, and 2.6%, respectively. We did not find any risk factors associated with the rate of total complications. The RCSI and rate of total and long-term complications compared favorably (P < 0.01) with the corresponding estimates of alternative treatments (P < 0.01).

CONCLUSIONS

The described stereotactic internal shunt implantation technique is safe and can be successfully applied for treatment of cystic formations in any location in the brain.

Management of Arachnoid Cysts: A Comprehensive Review

Arachnoid cysts are non-neoplastic, intracranial cerebrospinal fluid (CSF)-filled spaces lined with arachnoid membranes. Large arachnoid cysts are often symptomatic because they compress surrounding structures; therefore, they must be treated surgically. As several surgical management options exist, we explore the best approach according to each major type of arachnoid cyst: middle cranial fossa cyst, suprasellar cyst, intrahemispheric cyst, and quadrigeminal cyst.

Interactive navigation-guided ophthalmic plastic surgery: navigation enabling of telescopes and their use in endoscopic lacrimal surgeries

Purpose

The aims of this study were to report the preliminary experience of using telescopes, which were enabled for navigation guidance, and their utility in complex endoscopic lacrimal surgeries.

Methods

Navigation enabling of the telescope was achieved by using the AxiEM™ malleable neuronavigation shunt stylet. Image-guided dacryolocalization was performed in five patients using the intraoperative image-guided StealthStation™ system in the electromagnetic mode. The “look ahead” protocol software was used to assist the surgeon in assessing the intraoperative geometric location of the endoscope and what lies ahead in real time. All patients underwent navigation-guided powered endoscopic dacryocystorhinostomy. The utility of uninterrupted navigation guidance throughout the surgery with the endoscope as the navigating tool was noted.

Results

Intraoperative geometric localization of the lacrimal sac and the nasolacrimal duct could be easily deciphered. Constant orientation of the lacrimal drainage system and the peri-lacrimal anatomy was possible without the need for repeated point localizations throughout the surgery. The “look ahead” features could accurately alert the surgeon of anatomical structures that exists at 5, 10 and 15 mm in front of the endoscope. Good securing of the shunt stylet with the telescope was found to be essential for constant and accurate navigation.

Conclusion

Navigation-enabled endoscopes provide the surgeon with the advantage of sustained stereotactic anatomical awareness at all times during the surgery.

Congenital left temporal large arachnoid cyst causing intraorbital optic nerve damage in the second decade of life

AIM

Intracranial sylvian arachnoid cysts are often asymptomatic lesions. We present a 16-year-old female patient with progressive loss of vision together with an unusual visual field defect on the left eye accompanied by headache.

METHOD

A left frontotemporal sylvian arachnoid cyst was known since she was 9 months old, but observed ever since in the asymptomatic patient. Now, ophthalmological examination revealed bi-upper quadrant anopia on the left eye. Magnetic resonance imaging (MRI) and computed tomography showed erosion of the lateral orbital wall associated with intraorbital compression of the optic nerve by the cyst at the entrance into the optic canal. Microsurgical cyst fenestration to the basal cisterns was performed using a temporal mini-craniotomy.

RESULT

Full improvement of vision and visual field defects was observed in the follow-up. On postoperative MRI, an increase of the tissue surrounding the optic nerve in the conus and better delineation at the entrance of optic canal was noted.

CONCLUSION

Long-standing asymptomatic sylvian arachnoid cysts may suddenly produce severe unilateral visual deficits if the cyst erodes the lateral orbital wall. These deficits may rapidly revert to normal if surgical action is not delayed. If surveillance MRIs of sylvian arachnoid cysts show a narrowing of the conus diameter compared to the contralateral side, a yearly ophthalmological surveillance examination seems to be warranted in else wise asymptomatic patients.

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.

Posterior fossa arachnoid cysts in adults: Surgical strategy: Case series

Introduction and Aim:

The management of posterior fossa arachnoid cyst (PFAC) in adults is controversial. To review our cases and literature, propose a practically useful surgical strategy, which gives excellent long-term outcome in management of PFAC.

Materials and Methods:

We analyzed our case records of 26 large intracranial arachnoid cysts in adults treated over 12 years. Of them, we had 7 patients with symptomatic PFAC. Reviewed the literature of 174 PFAC cases (1973–2012) and added 7 of our new cases with a follow-up ranging from 3 to 12 years.

Results:

In 6 cases the PFAC was located in the midline. In the 7^th case, it was located laterally in the cerebello-pontine (CP) angle. All patients were treated surgically. Excision of the cyst was performed in 5 of these cases. Among the two intra-fourth ventricular cysts, in both the cases cysto-peritoneal shunt was performed. Postoperative computed tomography/magnetic resonance imaging showed variable decrease in size of the cyst even though clinically all patients improved. We propose a surgical strategy for the management of these cases which would aid the surgeon in decision making.

Discussion:

We observed that these PFACs can occur either in the midline within the fourth ventricle or retroclival region or extra-fourth ventricular region. It can also develop laterally in the CP angle or behind the cerebellum or as intracerebellar cyst. Importance of this is except for Midline Intra-fourth ventricular cyst/retroclival cyst, the rest all can be safely excised with excellent long term outcome. The treatment strategy for Midline Intra-fourth ventricular cyst/retroclival cyst can be either cysto-peritoneal shunt or endoscopic fenestration of the cyst.

Microsurgical fenestration and cystoperitoneal shunt through preauricular subtemporal keyhole craniotomy for the treatment of symptomatic middle fossa arachnoid cysts in children

INTRODUCTION

The optimal surgical treatment for symptomatic middle fossa arachnoid cyst is still controversial. The most leading therapeutic options include cyst shunting and fenestration (endoscopic, microsurgical). We present our experience on surgical treatments of arachnoid cysts.

PATIENTS AND METHODS

A retrospective data review of 16 children who underwent keyhole craniotomy for microsurgical fenestration and shunting of middle fossa arachnoid cysts between 1999 and 2012 was performed after institutional review board approval. The average patient age was 6.1 years. The average follow-up period was 36.5 months. There were ten male and six female patients in the series. Indications for surgery included intractable headaches (50%), increasing in cyst size (18.75%), and seizures (31.25%). All patient records were reviewed for their clinical presentation, classification, cyst resolution, symptom resolution, and cyst outcomes. After surgery, all patients underwent assessments of clinical and radiological improvement.

RESULTS

Postoperative complications were observed in two cases: progressively resolving monoparesia in one case and resolving epileptic seizure with monotherapy in the other. All patients had a satisfactory clinical outcome, and in 87.5%, there was either a decrease in the size or a complete disappearance of the MFAC. Nevertheless, three (18.75%) of all patients needed shunt revision because of shunt dysfunction. Complication related to surgical technique was cerebrospinal fluid leak which spontaneously resolved in one patient.

CONCLUSION

Microsurgical fenestration with keyhole craniotomy to provide passage between cysts to basal cisterns together with cystoperitoneal shunting during the same operation is still an effective and safe method in cases with symptomatic middle fossa arachnoid cysts in children.

Stricter indications are recommended for fenestration surgery in intracranial arachnoid cysts of children

PURPOSE

The indication of surgical treatment for intracranial arachnoid cysts (ACs) is a controversial issue. In this study, we reviewed surgical outcomes of intracranial ACs that were treated with endoscopic fenestration or microscopic fenestration, which are currently standard practices for surgical treatment of AC. In addition, we also evaluated the validity of current surgical indications.

METHODS

We analyzed pediatric patients under 18 years of age who underwent surgical management for intracranial AC between January 2000 and December 2011. Patients with a follow-up period of less than 1 year were excluded. A total of 75 patients were enrolled in this study. These patients were assessed by subjective symptoms and by a clinician's objective evaluation. The radiological assessment of AC after surgery was also evaluated.

RESULTS

The median age of patients at the initial operation was 5 years. The median follow-up period was 38 months. The goal of surgery was achieved in 28% (21/75) of patients. The radiological alteration of AC after initial fenestration surgery was diverse. The results of the clinical and radiological assessments did not always coincide. A total of 35 complications occurred in 28 patients. Subdural fluid collection was the most common unexpected radiological complication.

CONCLUSIONS

Our study showed that the fenestration procedure for AC produced unsatisfactory clinical improvements compared to the relatively high complication rate. Therefore, surgical treatment for AC should be strictly limited to patients who have symptoms directly related to AC.

Ventricular endoscopy in the pediatric population: review of indications

INTRODUCTION

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

DISCUSSION

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

Clinical and neuroimaging outcomes of surgically treated intracranial cysts in 110 children

Objective

The indications and optimal surgical treatments for intracranial cysts are controversial. In the present study, we describe long-term clinical and neuroimaging results of surgically treated intracranial cysts in children. The goal of this study is to contribute to the discussion of the debate.

Methods

This study included 110 pediatric patients that underwent surgeries to treat intracranial cysts. Endoscopic cyst fenestrations were performed in 71 cases, while craniotomies and cyst excisions (with or without fenestrations) were performed in 30 patients. Cystoperitoneal shunts were necessary for nine patients. Long-term results were retrospectively assessed with medical and neuroimaging records.

Results

Clinical and radiological improvement was reported in 87.3% and 92.8% of cases, respectively, after endoscopic neurosurgery, and in 93.3% and 100% using open microsurgery whereas 88.9% and 85.7% after shunt operation. There were no statistical differences in clinical outcomes (p=0.710) or volume reductions (p=0.177) among the different surgeries. There were no mortalities or permanent morbidities, but complications such as shunt malfunctions, infections, and subdural hematomas were observed in 56% of the patients that had shunt operations. A total of 13 patients (11.8%) underwent additional surgeries due to recurrences or treatment failures. The type of surgery performed did not influence the recurrence rate (p=0.662) or the failure rate (p=0.247).

Conclusion

Endoscopic neurosurgeries are less invasive than microsurgeries and are at least as effective as open surgeries. Thus, given the advantages and complications of these surgical techniques, we suggest that endoscopic fenestration should be the first treatment attempted in children with intracranial cysts.

Endoscopic treatment of interhemispheric arachnoid cysts

BACKGROUND

To describe the neuroendoscopic treatment of interhemispheric arachnoid cysts.

METHODS

Five children (aged 1-9 months) harboring interhemispheric arachnoid cysts underwent the procedure. The neuroendoscopic technique included cystoventriculostomy and cystocisternostomy. Imaging exams were compared before and after surgery, and the differences in cyst diameters were calculated. Head circumference and neurological development were also evaluated.

RESULTS

The cystoventriculostomy was performed through the lateral ventricle in 4 cases and through the third ventricle in 4 cases. An added cystocisternostomy was performed in 1 case. Cyst diameters were reduced in the anterior-posterior, lateral-medial and superior-inferior planes in 22, 31 and 31% of the cases, respectively. The rate of increasing head circumference slowed; however, all the children continued to show slight macrocrania. There were complications in 2 cases: cerebrospinal fluid fistula was managed by lumbar puncture in 1 case and subdural collection was treated with a shunt in another single case.

CONCLUSION

The neuroendoscopic approach to interhemispheric arachnoid cysts was effective with few complications.

The role of neuronavigation in intracranial endoscopic procedures

In occlusive hydrocephalus, cysts and some ventricular tumours, neuroendoscopy has replaced shunt operations and microsurgery. There is an ongoing discussion if neuronavigation should routinely accompany neuroendoscopy or if its use should be limited to selected cases. In this prospective clinical series, the role of neuronavigation during intracranial endoscopic procedures was investigated. In 126 consecutive endoscopic procedures (endoscopic third ventriculostomy, ETV, n = 65; tumour biopsy/resection, n = 36; non-tumourous cyst fenestration, n = 23; abscess aspiration and hematoma removal, n = 1 each), performed in 121 patients, neuronavigation was made available. After operation and videotape review, the surgeon had to categorize the role of neuronavigation: not beneficial; beneficial, but not essential; essential. Overall, neuronavigation was of value in more than 50% of the operations, but its value depended on the type of the procedure. Neuronavigation was beneficial, but not essential in 16 ETVs (24.6%), 19 tumour biopsies/resections (52.7%) and 14 cyst fenestrations (60.9%). Neuronavigation was essential in 1 ETV (2%), 11 tumour biopsies/resections (30.6%) and 8 cyst fenestrations (34.8%). Neuronavigation was not needed/not used in 48 ETVs (73.9%), 6 endoscopic tumour operations (16.7%) and 1 cyst fenestration (4.3%). For ETV, neuronavigation mostly is not required. In the majority of the remaining endoscopic procedures, however, neuronavigation is at least beneficial. This finding suggests integrating neuronavigation into the operative routine in endoscopic tumour operations and cyst fenestrations.

Minimally invasive neurosurgery for cerebrospinal fluid disorders

This article focuses on minimally invasive approaches used to address disorders of cerebrospinal fluid (CSF) circulation. The author covers the primary CSF disorders that are amenable to minimally invasive treatment, including aqueductal stenosis, fourth ventricular outlet obstruction (including Chiari malformation), isolated lateral ventricle, isolated fourth ventricle, multiloculated hydrocephalus, arachnoid cysts, and tumors that block CSF flow. General approaches to evaluating disorders of CSF circulation, including detailed imaging studies, are discussed. Approaches to minimally invasive management of such disorders are described in general, and for each specific entity. For each procedure, indications, surgical technique, and known outcomes are detailed. Specific complications as well as strategies for their avoidance and management are addressed. Lastly, future directions and the need for structured outcome studies are discussed.

Pinless frameless electromagnetic image-guided neuroendoscopy in children

OBJECTIVES

Frameless imaged-guided neuronavigation is a useful adjunct to neuroendoscopy in paediatric patients, especially those with abnormal or complex ventricular or cyst anatomy. The development of electromagnetic neuronavigation has allowed the use of image-guided navigation in the very young patient in whom rigid fixation in cranial pins is contraindicated. The technique and the authors' experience of its use in a series of paediatric patients are described.

MATERIALS AND METHODS

Nineteen paediatric patients were treated with endoscopic surgery at two paediatric neurosurgery centres over a period of 18 months. A total of 29 endoscopic procedures were performed. The cases were reviewed and surgical outcomes assessed. In all of the cases, the goal of surgery was realised successfully at the time of surgery, as confirmed by post-operative imaging. No technical failures were encountered. None of the patients suffered worsened neurological function as a result of their procedures.

CONCLUSION

Pinless, frameless electromagnetic neuronavigation was found to be a safe technique that can supplement endoscopic surgery in the very young patient. It allows the use of direct navigation of the endoscope in patients that are unable safely to undergo rigid cranial fixation in pins due to young age or thin skull vaults. This has proven to be a useful adjunct to neuroendoscopy in the subset of infants who have complicated or distorted ventricular anatomy and can improve the safety and accuracy of this type of surgery. It is also an alternative to optical neuronavigation in conjunction with neuroendoscopy in patients of any age.

Endoscopic treatment of middle fossa arachnoid cysts: a series of 40 patients treated endoscopically in two centres

PURPOSE

Middle fossa arachnoid cysts (MFAC) are a relatively common, benign pathology that pose a therapeutic challenge for both symptomatic and asymptomatic patients. The optimal surgical strategy and indication to treat are still debated by neurosurgeons. We reviewed our experience and results in a group of patients treated with endoscopic fenestration with the aim to assess indications to treat and clinical and neuroradiological results.

METHODS

The data on 40 patients operated with endoscopic fenestration for MFAC in two centres, "Anna Meyer" Children's Hospital, Florence, Italy, and Royal Liverpool Children's Hospital "Alder Hey", Liverpool, UK, between 2001 and 2007 were retrospectively reviewed with prospective follow-up. We analysed clinical and neuroradiological presentation, indications to treat, surgical technique, complications, and clinical and neuroradiological follow-up.

RESULTS

There were 30 males and ten females: mean age, 7.8 years; mean follow-up, 21 months. The neuronavigation system was used in 12 patients in the English cohort. Thirty-seven patients (92.5%) had a satisfactory clinical outcome. The cyst was reduced in size or completely disappeared in 29 patients (72.5%). There was no death or significant morbidity associated with the procedure. Four patients required further surgical treatment. Four patients experienced a post-traumatic intracystic bleeding after surgery.

CONCLUSION

Compared to microsurgical fenestration and cyst shunting, our experience with endoscopic fenestration was as effective and safe but less invasive. Each case must be assessed with its individual characteristics to define the optimal surgical strategy. Successful treatment may not reduce the risk of post-traumatic head injury haemorrhage.

Management of factitious disorders: a systematic review

BACKGROUND

The literature regarding the management of factitious disorder (FD) is diverse and generally of case reports or case series. To date there has been no systematic review of the effectiveness of management techniques.

METHODS

Systematic review of all evidence reporting the management and subsequent outcome in FD. Data were extracted and outcomes were assessed using an adaptation of the Global Improvement Scale. Results were analysed by parametric statistical tests; a meta-analysis was not possible.

RESULTS

Thirty-two case reports and 13 case series were eligible for inclusion. Analysis of the case reports found no significant difference in outcomes between confrontational and non-confrontational approaches [t(29) = 0.72, p = 0.48], between treatment with psychotherapy compared to no psychotherapy [t(30) = 0.69, p = 0.48], and when psychiatric medication had been prescribed compared with not [t(30) = 0.35, p = 0.73]. A trend was observed that a longer length of treatment lead to better outcomes, but this was not significant [F(5, 26) = 1.17, p = 0.35]. The consecutive case series demonstrated that many FD sufferers were not engaged in treatment and were lost to follow-up but did not provide any strong evidence regarding the effectiveness of different management approaches.

CONCLUSIONS

There is an absence of sufficient robust research to determine the effectiveness of any management technique for FD. The establishment of a central reporting register to facilitate the development of evidence-based guidelines is recommended.

Sylvian fissure arachnoid cysts: a survey on their diagnostic workout and practical management

BACKGROUND

The management of Sylvian arachnoid cysts in children is still a matter of debate. Diagnosis is often incidental, and symptoms are frequently aspecific in symptomatic cases. Suggested diagnostic investigation results have been often unclear. Surgical treatment is also controversial, pure, and assisted endoscopic cyst marsupialization having entered in the traditional debate between craniotomic and shunting approach

PURPOSE

The objective of the present study was to survey if (and, eventually, which) agreement points do actually exist between internationally recognized pediatric neurosurgery centers in the management of children with a controversial type of Sylvian arachnoid cyst (Type II cyst).

METHODS

Contributors were asked to answer to a six-separate-part multiple choice questionnaire related to the case of a 2.7-year-old boy with a Type II left Sylvian arachnoid cyst presented in different clinical situations. If surgery was indicated, it was asked which surgical procedure the authors would have suggested as first option.

RESULTS AND CONCLUSIONS

The option of the mere clinical observation was chosen by the majority of surgeons in case of asymptomatic clinical discovery. On the other hand, a constantly high percentage of participants suggested direct surgical treatment based on clinical manifestations or as a preventive measure justified by the risk of spontaneous or traumatic intracranial bleeding. The only diagnostic investigation result which significantly influenced the surgical indication was a localizing electroencephalography, if the child presented with seizures. The result is that in most cases the surgical indication was based on aspecific clinical manifestations and laboratory data. Craniotomy and arachnoid cyst marsupialization represented the preferred surgical option (66.6%), 28.8% of the participants suggesting pure or assisted endoscopic cyst marsupialization as primary surgical procedure. Cyst shunting was suggested by only three centers.