Effective shunt-independent treatment for primary middle fossa arachnoid cyst

Endoscopic Treatment of Intracranial Arachnoid Cysts: A Retrospective Analysis of a 25-Year Experience

BACKGROUND

Since the development of neuroendoscopy, pure endoscopic fenestration for intracranial arachnoid cysts (ACs) became more and more popular and is actually preferred by many neurosurgeons.

OBJECTIVE

To explore their techniques and experiences with endoscopic treatment of intracranial ACs over a 25-yr period.

METHODS

A total of 95 endoscopic procedures in 87 patients with 88 intracranial ACs performed at the authors’ departments between February 1993 and October 2018 were retrospectively analyzed. Particular respect was given to surgical technique, complications, patients’ outcome, and radiological benefit in relation to cyst location.

RESULTS

Patients’ ages ranged from 23 d to 81 yr (mean: 29.9 yr). Cysts were located temporobasal (n = 31; 35.2%), paraxial supratentorial (n = 14; 15.9%), suprasellar/prepontine (n = 14; 15.9%), quadrigeminal (n = 12; 13.6%), infratentorial (n = 11; 12.5%), and supratentorial intraventricular (n = 6; 6.8%). Four different endoscopic techniques were applied: cystocisternostomies (n = 48; 50.5%), ventriculocystostomies (n = 23; 24.2%), cystoventriculostomies (n = 14; 14.7%), and ventriculocystocisternostomies (n = 10; 10.5%). Pure endoscopic technique was feasible in 89 of the 95 surgeries (93.7%). Clinical improvement was documented after 82 surgeries (86.3%) and radiological benefit after 62 surgeries (65.3%). Recurrences developed in 8 cases (8.4%). Overall complication rate was 21.1% (n = 20), postoperative new shunt dependency was observed in 4.2% of the cases (n = 4).

CONCLUSION

Pure endoscopic AC fenestration is a safe, effective, and less invasive technique providing high success and low permanent complication rates. The most frequent temporobasal cysts are the most difficult to treat endoscopically. A long-term follow-up is recommended because recurrences may occur many years after first treatment.

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.

Nerve-Sheath-Risen Neuroglial Cyst: A Case Report and Review of the Literature

BACKGROUND

Neuroglial cysts are rare intracranial lesions that are believed to originate from the sequestration of neural tube lining during embryogenesis. They can present anywhere within the neuraxis; however, their most common location is the frontal lobe. Cerebellopontine angle (CPA) neuroglial cysts are extremely rare and to the best of authors' knowledge, there are no previous reports of a neuroglial cyst arising from cranial nerves.

CASE DESCRIPTION

The current study presented a male adolescent with the reoccurrence of an intracranial cyst with symptoms of diplopia and facial numbness primarily treated as CPA arachnoid cyst with fenestration of the cyst 12 months prior to admission to our center. Different magnetic resonance imaging (MRI) sequences showed a thin-walled extra-axial cyst at the right CPA without gadolinium (Gd)-enhancement. Direct visualization of the lesion revealed a cyst arising from the 5th cranial nerve sheath compressing the surrounding structures. The cyst was fenestrated and a biopsy was taken from the cyst wall. The pathological analysis along with specified histological markers indicated the neuroglial nature of the cyst.

CONCLUSION

The rising of a neuroglial cyst from the nerve sheath is a finding that brings other possible origins of neuroglial cysts into consideration.

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).

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.

[Microsurgical treatment of intracraneal arachnoid cysts]

Craniotomy and fenestration of membranes is one of the main treatment options for symptomatic arachnoid cysts. Open surgery advantages include, direct inspection of the cyst, biopsy sampling, fenestration in multilocular cysts and, in certain locations, cyst communication to basal cisterns. The aim of this paper is to review the advantages and disadvantages of this treatment modality for arachnoid cysts taking into account the different anatomical locations.

[Arachnoid cysts. Historical evolution of the concept and pathophysiological theories]

Arachnoid cysts of central nervous system are benign collections filled with a liquid that is equal o similar to cerebrospinal fluid, coated with a single layer or flattened arachnoid cells membrane, congenital or secondary to trauma, meningitis or hemorrhage. First described by Bright in 1931, its definition and possible pathophysiology has been debated to date. Our objective is to present a summary of this process.

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.

Pediatric intracranial arachnoid cysts: comparative effectiveness of surgical treatment options

PURPOSE

A variety of surgical approaches for the treatment of pediatric intracranial arachnoid cysts exist. In an effort to identify the optimal surgical treatment for this disorder, we developed a decision analytic model to evaluate outcomes of four surgical approaches in children. These included open craniotomy for cyst excision, open craniotomy for cyst fenestration, endoscopic cyst fenestration, and cystoperitoneal shunting.

METHODS

Pooled data were used to create evidence tables, from which we calculated incidence, relative risks, and summary outcomes in quality-adjusted life years (QALYs) for the four surgical treatments. Our study incorporated data up to 5 years postsurgery.

RESULTS

We analyzed 1,324 cases from 36 case series. There were no significant differences in outcome among the four surgical strategies. The QALYs (maximum of 5) for surgical approaches resulted in a range from 4.79 (for open craniotomy and excision) to 4.92 (for endoscopic fenestration).

CONCLUSIONS

Overall quality of life is comparable between patients undergoing open craniotomy for cyst excision or fenestration, endoscopic fenestration, and cystoperitoneal shunting up to 5 years after surgery. While each approach offers unique advantages and disadvantages, an individualized treatment strategy should be employed in the setting of surgical outcome equipoise.

Management of subdural hygromas associated with arachnoid cysts

OBJECT

Arachnoid cysts may occasionally be associated with subdural hygromas. The management of these concurrent findings is controversial.

METHODS

The authors reviewed their experience with arachnoid cysts and identified 8 patients with intracranial arachnoid cysts and an associated subdural hygroma. The medical records and images for these patients were also examined.

RESULTS

In total, 8 patients presented with concurrent subdural hygroma and arachnoid cyst. Of these 8 patients, 6 presented with headaches and 4 had nausea and vomiting. Six patients had a history of trauma. One patient was treated surgically at the time of initial presentation, and 7 patients were managed without surgery. All patients experienced complete resolution of their presenting signs and symptoms.

CONCLUSIONS

Subdural hygroma may lead to symptomatic presentation for otherwise asymptomatic arachnoid cysts. The natural course of cyst-associated subdural hygromas, even when symptomatic, is generally benign, and symptom resolution can be expected in most cases. The authors suggest that symptomatic hygroma is not an absolute indication for surgical treatment and that expectant management can result in good outcomes in many cases.

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.

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.

Arachnoid cysts of the middle cranial fossa accompanied by subdural effusions--experience with 60 consecutive cases

BACKGROUND

Subdural effusions (SDEs) can complicate arachnoid cysts of the middle cranial fossa (ACMFs). While there is a consensus that at least in adults asymptomatic ACMFs should not be operated, those with concomitant subdural and/or intracystic effusions are clinically apparent in the majority of cases and should be surgically treated. But it remains unclear, which surgical procedure is best.

METHODS

Since 1980, 60 out of 343 patients with an ACMF presented with accompanying SDEs. Four categories of SDEs were differentiated radiologically. This collective was controlled in a follow-up study up to 60 months after conservative or operative treatment by clinical and radiological means.

RESULTS

In 54 of the 60 patients, we saw an indication for surgical treatment. Twenty-nine patients received a burr hole, 13 cases were treated by craniotomy, seven by endoscopical means, three patients underwent shunting and two combined procedures. Six patients were treated conservatively. An excellent final clinical outcome was observed in 55 cases. While craniotomy succeeded best to reduce the cyst volume in postoperative CT, the final clinical outcome did not differ significantly compared with burr hole trepanation.

CONCLUSIONS

Patients with small effusions can be treated conservatively in selected cases. Based on our experience, we prefer a differentiated therapy. As first procedure, burr hole and subdural drainage were performed, leaving the cyst alone, seeming sufficient for the majority of cases. Craniotomy or endoscopical means should be reserved as treatment of choice for special cases, depending on category and acuteness of SDE and size/localisation of the ACMF.

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.

Acute intracranial hypertension and shunt dependency following treatment of intracranial arachnoid cyst in a child: a case report and review of the literature

Arachnoid cysts are developmental anomalies that represent 1% of all intracranial space occupying lesions. Treatment of symptomatic cases may include shunting of the cyst or an open fenestration of it, among other less acceptable surgical procedures. Each procedure has its own pros and cons. We present a case of the development of an acute intracranial hypertension during cysto-peritoneal shunt malfunction in a child. We describe the possible mechanism of these phenomena and, based on this report and by reviewing other case series in the literature, we raise the possibility that acute increase in intracranial pressure and the development of shunt dependency, although rare, are important complications of shunting an arachnoid cyst.

Limits of endoscopic treatment of sylvian arachnoid cysts in children

INTRODUCTION

The optimal surgical management of sylvian arachnoid cysts is debated. We present our experience in children who were treated endoscopically, focusing on the limits and complications of this approach.

MATERIALS AND METHODS

Seventeen children with a temporo-sylvian arachnoid cyst have been treated using a purely temporal endoscopic approach.

RESULTS

In all but one case, the recognition of anatomical landmarks was obtained at the insertion of the endoscope. In one child, the orientation and opening of the basal cisterns were more difficult due to the thickness and opacity of the membranes. Nevertheless, it was possible to perform the cysto-cisternostomy endoscopically in all children with several stomies in 13. In one child, a venous bleeding occurred. There were no other intraoperative complications. There were no postoperative cerebrospinal fluid leaks. In two patients, a symptomatic subdural collection developed which required a transient subdural-peritoneal shunt. No subdural collection was noted on a delayed follow-up (mean, 23 months). Preoperative symptoms related to the mass effect exerted by the cyst resolved in all children. Two children presented a recurrence, 12 and 20 months after endoscopic surgery, respectively. At the redo-endoscopy, the stomies were found to be closed. Their reopening resulted in the disappearance of the symptoms.

CONCLUSIONS

An endoscopic approach can be used safely in the management of sylvian arachnoid cysts. An effective opening of the deep arachnoid membranes into the basal cisterns could be performed in all patients with the resolution of the preoperative symptoms. However, the long-term efficacy of the stoma needs to be assessed.

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.

A population based study of intracranial arachnoid cysts: clinical and neuroimaging outcomes following surgical cyst decompression in adults

BACKGROUND

We have gradually adopted a liberal attitude towards surgical decompression of arachnoid cysts. This study describes the results from our institution.

METHODS

Long term clinical and neuroimaging results of 156 adult patients (aged > or = 16 years) operated on for arachnoid cysts in our department during the period January 1987 to September 2004 were assessed based on their medical and neuroimaging records, and on a questionnaire.

RESULTS

The clinical and/or neuroimaging results indicated that the cyst was successfully decompressed in all patients. 82% of patients were asymptomatic or had insignificant complaints at follow-up. 12% reported no symptom relief whereas 6% experienced worsening of symptoms. The cyst disappeared after surgery, or was reduced to < 50% of the preoperative volume, in 66% of cases. In another 24%, the postoperative volume was also reduced, but was larger than 50% of the original cyst volume. No reduction in fluid volume was observed in 10% of cases. There was no association between volume reduction and clinical improvement. A complication occurred in 26 patients (17%), all with temporal cysts, leading to reoperation in 11 patients (7.1%). In only two patients did the complication cause a permanent slight disability.

CONCLUSION

Decompression of arachnoid cysts yields a substantial clinical benefit with a low risk of severe complications.

A population-based study of intracranial arachnoid cysts: clinical and neuroimaging outcomes following surgical cyst decompression in children

OBJECT

If, when, and how children with arachnoid cysts should undergo surgery has been a matter of debate. In the present study the authors describe long-term clinical and neuroimaging results in children with intracranial arachnoid cysts, treated in accordance with the authors' policy of performing surgery in most of these cases.

METHODS

The study included 48 pediatric patients (age < 16 years of age) who underwent surgery for treatment of an arachnoid cyst at Haukeland University Hospital between January 1987 and September 2004. Forty-one patients underwent cyst fenestration to the basal cisterns and posterior fossa. Long-term results were assessed retrospectively on the basis of medical and neuroimaging records. Additional information was obtained by means of a check-box questionnaire completed by the patients and their parents. At their follow-up examinations, 82% of the patients had no or insignificant complaints, 14% reported no improvement, and 4% noted a worsening of symptoms. In 56% of the patients with appropriate imaging for analysis, the cyst was no longer visible on neuroimaging studies. In 23%, the postoperative fluid volume was reduced to less than 50% of the original cyst volume, and in another 19%, the volume was reduced but was larger than 50% of the original. The cyst was unchanged in only 2%. There was a significant association between a volume reduction greater than 50% and clinical improvement. Three patients (6%), all with temporal cysts, had minor complications that led to additional surgery in one patient. No complications caused permanent disability. Eight patients (17%) underwent additional surgery due to suspected or demonstrated treatment failure.

CONCLUSIONS

Most children who underwent cyst fenestration via a craniotomy experienced a good long-term outcome with no severe complications.

A population-based study of intracranial arachnoid cysts: clinical and neuroimaging outcomes following surgical cyst decompression in children

Object

If, when, and how children with arachnoid cysts should undergo surgery has been a matter of debate. In the present study the authors describe long-term clinical and neuroimaging results in children with intracranial arachnoid cysts, treated in accordance with the authors' policy of performing surgery in most of these cases.

Methods

The study included 48 pediatric patients (age < 16 years of age) who underwent surgery for treatment of an arachnoid cyst at Haukeland University Hospital between January 1987 and September 2004. Forty-one patients underwent cyst fenestration to the basal cisterns and posterior fossa. Long-term results were assessed retrospectively on the basis of medical and neuroimaging records. Additional information was obtained by means of a check-box questionnaire completed by the patients and their parents.

At their follow-up examinations, 82% of the patients had no or insignificant complaints, 14% reported no improvement, and 4% noted a worsening of symptoms. In 56% of the patients with appropriate imaging for analysis, the cyst was no longer visible on neuroimaging studies. In 23%, the postoperative fluid volume was reduced to less than 50% of the original cyst volume, and in another 19%, the volume was reduced but was larger than 50% of the original. The cyst was unchanged in only 2%. There was a significant association between a volume reduction greater than 50% and clinical improvement. Three patients (6%), all with temporal cysts, had minor complications that led to additional surgery in one patient. No complications caused permanent disability. Eight patients (17%) underwent additional surgery due to suspected or demonstrated treatment failure.

Conclusions

Most children who underwent cyst fenestration via a craniotomy experienced a good long-term outcome with no severe complications.

Pathogenesis and treatment of intracranial arachnoid cysts in pediatric patients younger than 2 years of age

Object

Arachnoid cysts can cause a variety of clinical signs and symptoms in infants. The authors sought to determine whether the clinical presentation of pediatric patients younger than 2 years old and harboring arachnoid cysts influenced the type of intervention that would be required.

Methods

A retrospective chart review was conducted for all patients younger than 2 years of age who had undergone craniotomy for fenestration of an arachnoid cyst at the Childrens Hospital Los Angeles between 1995 and 2006.

Forty-two patients were included in the study. The mean age was 10.4 months. The median follow-up time was 33 months. Clinical presentations were as follows: macrocephaly without ventriculomegaly (21 patients, 50%), hydrocephalus (six patients, 14%), and other symptoms (15 patients, 36%). After fenestration of the arachnoid cyst, 12 of 21 patients (57%) presenting with nonspecific macrocephaly required placement of a cystoperitoneal or ventriculoperitoneal shunt, compared with 1 of 15 patients (7%) presenting with other symptoms (p value = 0.0039). Five of six patients with hydrocephalus (83%) were shunt dependent following fenestration. Overall, 18 of 42 patients (43%) were shunt dependent after fenestration. Ten of these patients (55%) required revisions during the follow-up period.

Conclusions

Patients younger than 2 years of age and harboring an arachnoid cyst commonly present with macrocephaly. These patients are more likely to require shunts than are those presenting with other findings, such as seizu

Functional assessment of intracranial arachnoid cysts with TC99 m-HMPAO SPECT: a preliminary report

BACKGROUND

Many arachnoid cysts (AC) are detected incidentally in asymptomatic patients. Current neuroimaging methods provide only morphological details of the cysts, but they do not give information about cerebral function. While surgery is indicated in symptomatic patients, the management of asymptomatic individuals, who present with large cysts, is controversial.

STUDY OBJECTIVE

To ascertain the value of cerebral 99 mTc-HMPAO single photon emission computed tomography (SPECT) for detecting brain dysfunction in cases of intracranial ACs, aimed at allocating the patients for surgical or for conservative treatment.

PATIENTS AND METHODS

We studied prospectively 11 patients diagnosed with sylvian fissure ACs. The subjects underwent neurological examination, EEG, neuroimaging studies, neuropsychological testing, and cerebral perfusion studies with 99 mTc-HMPAO SPECT.

RESULTS

The patients' ages ranged from 2 to 42 years (median 16 years). The study group consisted of ten symptomatic patients with ACs and one patient with an incidental cyst. Seven patients showed diminished regional cerebral blood flow (rCBF) in their initial cerebral SPECT. Four individuals underwent surgery. Seven patients showed normalization of rCBF after surgical or conservative treatment.

CONCLUSIONS

Cerebral SPECT demonstrated impaired brain perfusion in 70% of symptomatic patients. The zone of decreased rCBF corresponded well with clinical symptoms and with neuroimaging findings. Patients exhibiting normal rCBF in SPECT studies remained or became asymptomatic during the follow-up time. Cerebral SPECT constitutes a valuable adjunct tool for correlating regional function with brain anatomy, and may be of help to allocate patients with ACs for surgical treatment or clinical observation. Further research on this field is warranted.

Arachnoid cysts in adults: long-term follow-up of patients treated with internal shunts to the subdural compartment

BACKGROUND

We have previously presented an alternative method for surgical decompression of intracranial arachnoid cysts. This minimally invasive method, with insertion of an internal shunt from the cyst to the subdural compartment, seemed to be an efficient and simple, and hence promising technique. The aim of the present study was to investigate the long-term results of this procedure.

METHODS

This study is a questionnaire-based retrospective study that includes 31 adult patients (>18 years) who were operated on in our department for an arachnoid cyst in the temporal fossa or overlying the frontal convexity with the internal shunt technique between April 1990 and October 2003. Follow-up ranged from 15 months to 14.8 years (mean = 8.2 years).

RESULTS

Of the patients, 83% were asymptomatic or had insignificant complaints at follow-up. A total of 17% reported no reduction of the preoperative complaints. No patient experienced worsening of the symptoms. The cyst was no longer visible on postoperative radiologic examinations in 37% of the patients. In 37%, the postoperative fluid volume was less than 50% of the original volume. In 13%, the cyst volume was reduced but the postoperative volume was greater than 50% of the original cyst volume. Thus, the cyst was unchanged in only 13% of the patients. There was no correlation between volume reduction and clinical improvement. A complication (subdural hygroma or hematoma) occurred in 7 patients, all with temporal cysts, leading to reoperation in 4. None of the complications caused permanent neurologic deficits or invalidity. Seven patients were reoperated on because of suspected or established treatment failure.

CONCLUSIONS

The internal shunt technique is a relatively simple, safe, and efficient alternative method for treatment of arachnoid cysts. It should be considered a valuable alternative in the treatment of arachnoid cysts.

Microsurgical Keyhole Approach for Middle Fossa Arachnoid Cyst Fenestration

OBJECTIVE

The optimal surgical treatment for symptomatic temporal arachnoid cysts is controversial. Therapeutic options include cyst shunting, endoscopic fenestration, and craniotomy for fenestration. We reviewed the results for patients who were treated primarily with craniotomy and fenestration at our institution, to provide a baseline for comparisons of the efficacies of other treatment modalities.

METHODS

A retrospective review of data for 50 children who underwent keyhole craniotomy for fenestration of temporal arachnoid cysts between 1994 and 2001 was performed after institutional review board approval. During that period, the first-line treatment for all symptomatic middle fossa arachnoid cysts was microcraniotomy for fenestration. Microsurgical dissection to create communications between the cyst cavity and basal cisterns was the goal. All patient records were reviewed and numerous variables related to presentation, cyst size and classification, treatment, cyst resolution, symptom resolution, follow-up periods, and cyst outcomes were recorded.

RESULTS

Fifty temporal arachnoid cysts in 50 treated patients were identified. The average age at the time of surgery was 68 ± 57.2 months. The follow-up periods averaged 36 months. There were 34 male and 16 female patients in the series. Twenty-six cysts were on the left side. Indications for surgery included intractable headaches (45%), increasing cyst size (21%), seizures (25%), and hemiparesis (8%). The symptoms most likely to improve were hemiparesis (100%) and abducens nerve palsies. Headaches (67%) and seizure disorders (50%) were less likely to improve. Nine patients exhibited progressive increases in cyst size in serial imaging studies. Those patients were monitored for a mean of 40 ± 23 months before intervention. In the entire series, 82% of patients demonstrated decreases in cyst size in serial imaging studies. Of those patients, 18% demonstrated complete cyst effacement. Overall, 83% of patients with Grade II cysts and 75% of patients with Grade III cysts exhibited evidence of decreases in cyst size in long-term monitoring. Two patients required shunting after craniotomy (4%). Hospital stays averaged 3.4 days. Total surgical times averaged 115 minutes. No significant blood loss occurred (5–50 ml). Complications included spontaneously resolving pseudomeningocele (10%), transient Cranial Nerve III palsy (6%), cerebrospinal fluid leak (6%), subdural hematoma (4%), and wound infection (2%).

CONCLUSION

A microsurgical keyhole approach to arachnoid cyst fenestration is a safe effective method for treating middle fossa cysts. This procedure can be performed with minimal morbidity via a minicraniotomy. Compared with an endoscopic approach, better control of hemostasis can be obtained, because of the ability to use bipolar forceps and other standard instruments. The operative time and length of hospital stay were not excessively increased.

Malformative intracranial cysts: diagnosis and outcome

INTRODUCTION

Prenatal investigations make it possible to follow up malformative intracranial cysts from their detection in utero through the postnatal period. By including those that will remain silent postnatally, precious information can be provided about their real natural history.

DIAGNOSIS

Contrary to common belief, the vast majority of these lesions, if not associated with other fetal anomalies, are benign in nature, remain clinically silent, do not evolve or even frequently regress spontaneously. They are compatible with a strictly normal life, whether requiring postnatal treatment or not.

TREATMENT

Surgery is rarely needed for the treatment of an evolving hydrocephalus or an expanding cyst.

PROGNOSIS

Clinical outcome is not correlated with cyst volume or location. Prognosis, therefore, does not rely upon brain deformation or translation but rather more upon brain integrity. To establish a correct prognosis all efforts must therefore aim to precisely analyze the brain anatomy. In this respect, fetal MRI is mandatory. Although chromosomal anomalies are rarely associated with isolated intracranial cysts, karyotype study is necessary.

CONCLUSION

The accuracy of diagnosis and prognosis depends mainly upon our ability to correctly interpret images, which in turn depends on the resolution of prenatal imaging and on experience. Median retrocerebellar fluid collections remain the most difficult to prognosticate, retrocerebellar cysts often being difficult to differentiate from mega cisterna magna and Dandy-Walker complex. In our hands, prenatal prognostication was correct in approximately 90% of the cases.

Arachnoid cysts of the posterior fossa

BACKGROUND

The surgical indications and management of posterior fossa arachnoid cysts (AC) are still controversial. Different surgical techniques and management have already been suggested for arachnoid cysts of the posterior fossa. AC involving the posterior fossa and especially the cerebellopontine angle may carry a high surgical morbidity because of the involvement of important neurovascular structures (e.g., brain stem and cranial nerves). Only long-term follow-up will determine the best surgical technique for such lesions.

METHODS

Between 1990 and 1996 a total of 12 patients underwent surgery for arachnoid cysts involving the posterior fossa. In seven cases AC were located within the cerebellopontine angle (CPA), in three cases in the CPA with major extension dorsal to the brainstem, and in two cases at the CPA extending into the internal auditory canal.

RESULTS

A suboccipital retrosigmoid approach was performed in all patients. Radical resection of the cyst could be accomplished in all but one case. There was no mortality. Major postoperative morbidity was present in one case because of an intraoperative air embolism in the semisitting position and strong adherence of the cyst wall to the surrounding neurovascular structures. Long-term follow-up (mean, 3.3 years) revealed improvement of most preoperative symptoms.

CONCLUSION

Open surgery and radical removal of the AC located at the posterior fossa, based on our retrospective analysis, provide very good long-term postoperative results. The suboccipital approach provides a good and safe exposure of vascular structures and cranial nerves in the CPA and allows radical resection of the cyst, reducing the chance of recurrence.

Arachnoid cysts associated with subdural hematomas and hygromas: analysis of 16 cases, long-term follow-up, and review of the literature

OBJECTIVE

Subdural hematomas and hygromas are infrequently encountered complications of arachnoid cysts of the middle cranial fossa and are particularly rare with cysts of other regions. Reports in the literature focus on casuistic observations. Therapeutic recommendations often include fenestration or extirpation of the cyst wall, in addition to evacuation of the space-occupying lesion. This study evaluates the results of and rationale for a more conservative approach, usually without cyst removal.

METHODS

Sixteen cases of complicated arachnoid cysts, from a total of 658 patients with subdural hematomas or hygromas, were analyzed retrospectively together with 75 other cases reported in the literature. Additionally, 94 magnetic resonance imaging scans from 89 patients with untreated arachnoid cysts, from a total of 11,487 examinations, were reviewed for signs of hemorrhagic complications.

RESULTS

Arachnoid cysts of the middle cranial fossa were found in 2.43% of patients with chronic subdural hematomas or hygromas. This indicated a fivefold greater prevalence of arachnoid cysts, compared with our magnetic resonance imaging-examined patient group. Only two patients with untreated cysts showed signs of hemorrhage in magnetic resonance imaging scans. An excellent or good therapeutic result was achieved with evacuation of the subdural fluid by drainage or craniotomy in 13 cases and with conservative treatment in two cases. Only one patient underwent additional fenestration of the cyst wall. No additional symptoms from the arachnoid cysts occurred in a follow-up period of up to 14 years after therapy.

CONCLUSIONS

We do not generally consider it necessary to perform cyst diversion or fenestration at the time of drainage of a hematoma or hygroma in previously asymptomatic arachnoid cysts.

Progesterone receptors in arachnoid cysts. An immunocytochemical study in 2 cases

We report 2 cases of arachnoid cysts, one with a retrocerebellar and the other with a left temporal localization, in which immunohistochemical studies had been conducted. The results of the immunohistochemistry on the presence of carcino-embryonic antigen (CEA) and glial fibrillary acidic protein (GFAP), and of the scanning- and transmission electron microscopy revealed the cyst lining to be identical to subdural neurothelium. Progesterone receptors were found in the nuclei of cells lining the cyst, which also suggests the similarity of the cyst lining to arachnoid granulations and meningiomas as derivatives of subdural neurothelium, which also possess progesterone receptors.

Neuroendoscopic approach to arachnoid cysts

A prospective study of seven consecutive patients with congenital arachnoid cysts treated endoscopically is reported. The ages of the patients at the time of diagnosis ranged from 6 to 47 years with three patients under 15 years. Two cysts were located in the posterior cranial fossa, four in the middle cranial fossa, and one in the suprasellar-prepontine area. The patients' symptoms included headache, seizures, vomiting, nausea, dizziness, balance problems, and precocious puberty. The authors performed cystocisternostomies and ventriculocystostomies via burr holes with the aid of a universal neuroendoscopic system. Minor bleeding was easily controlled by rinsing. In one case, the endoscopic procedure had to be abandoned because of significant bleeding, which obscured a clear operative view, and an open microsurgical cyst fenestration was performed. The follow-up review periods in this group of patients ranged from 15 to 30 months. There was no mortality or morbidity. Symptoms were relieved in five patients and improved in one. Precocious puberty in one case continued. In six cases, follow-up magnetic resonance images or computerized tomography scans revealed a decrease in the size of the cysts. Although the follow-up period is too short to make statements on long-term outcome, the authors recommend the minimally invasive endoscopic approach for treatment of arachnoid cysts as the first therapy of choice. Should the endoscopic procedure fail, established treatment options such as microsurgical fenestration or cystoperitoneal shunting can subsequently be performed without causing additional risk to the patient.

Supratentorial interhemispheric cysts associated with callosal agenesis: surgical treatment and outcome in 16 children

Cerebrospinal-fluid-filled interhemispheric cysts associated with callosal agenesis are relatively rare lesions, and have been subject to a varied and confusing terminology. From a pragmatic surgical point of view, we believe that the dorsal III ventricular cyst [35] and the giant interhemispheric cyst [23], although of different embryological origin, can be classified as one group. The most important condition that must be distinguished from interhemispheric cysts is the alobar form of holoprosencephaly. We describe the clinical symptomatology in 16 children who were surgically treated with a cysto-peritoneal shunt. The outcome, both neurologically and developmentally, was good in the large majority of cases, and compared favorably to similar cases in the older literature. It therefore seems reasonable, at the present state of knowledge and until further studies clarify the origin and natural history of these cysts, to treat them as early as possible in order to prevent gross developmental deficits.

Bilateral temporal arachnoid cysts in neurofibromatosis

The occurrence of bilateral temporal arachnoid cysts has been considered as a rare event. Unilateral arachnoid pouches have been reported in a few instances associated with neurofibromatosis. The authors describe a 5-year-old girl with bilateral temporal arachnoid cysts who presented obvious stigmata of van Recklinghausen's disease. To the best of our knowledge, this is the first time that this association has been described in the literature.