Fenestration methods for Sylvian arachnoid cysts--endoscopy or microsurgery

Endoscopy-assisted purely total outer wall excision for pediatric Sylvian arachnoid cysts

BACKGROUND

To present a novel endoscopy-assisted surgical strategy of Sylvian arachnoid cysts (ACs).

CASE PRESENTATION

Endoscopy-assisted surgery was performed on 9 children (May 2019-December 2021). All patients were evaluated with CT and/or MRI and had regular follow-up examinations. The procedure consisted of performing a small temporal craniotomy (2 cm) behind the hairline. After dural opening, the surgery was performed with the assistance of a rigid 30-degree transcranial endoscope, self-irrigating bipolar forceps, and other standard endoscopic instruments. Steps included total excision of the AC outer wall and dissection of arachnoid adhesion around the cystic edge to communicate the residual cyst cavity with subdural space. Compared with the microscopical procedure, a 30-degree transcranial endoscope provides a wider view, especially for the lateral part exposure of the outer wall. The average age of the patients was 27.7 months (range 13-44 months). The Sylvian AC was in the right hemisphere in three patients and six in the left, respectively. 1 patient suffered transient postoperative epilepsy. There was no mortality or additional postoperative neurological deficit in this series. All of the patients achieved significant clinical improvement after surgery. Radiological examination after the operation showed a significant reduction in all cases (100%, 9/9) and disappearance in one case (11.1%, 1/9). Postoperative subdural fluid collection occurred in six cases and completely resolved spontaneously in 9 months.

CONCLUSION

The study demonstrated the minimally invasive, safety, and effectivity of the endoscopy-assisted purely total outer wall excision.

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

PURPOSE

Arachnoid cysts are usually asymptomatic lesions. However, they can sometimes cause intracranial hypertension, headache, seizures, focal neurological deficits, and bleeding. The most commonly used surgical techniques are microsurgical cyst fenestration/excision/drainage, cyst shunting, and endoscopic procedures. We aimed to investigate the success of different surgical techniques.

METHODS

Between 2000 and 2021, patients with Sylvan fissure arachnoid cysts who received treatment via an endoscopic approach chosen as the first-line treatment in three centers were enrolled. All case notes and radiological studies were evaluated retrospectively.

RESULTS

The study included 131 (female, n = 28; male, n = 103) patients with a mean age of 87.04 ± 66.76 (range, 0-216) months. Of the patients, 25 had Galassi type II left-sided arachnoid cysts, 33 had Galassi type II right-sided arachnoid cysts, 40 had Galassi type III left-sided arachnoid cysts, and 32 had Galassi type III right-sided arachnoid cysts. No difference was found between patients who underwent single and multiple fenestrations in terms of Galassi type, side, clinical outcome, and cyst size (p > 0.05). On the contrary, the rate of additional surgical intervention was lower in patients with multiple fenestrations than in those with single fenestration (36.10% vs. 5.30%; p < 0.001).

CONCLUSION

Endoscopic fenestration of Sylvian fissure arachnoid cysts is a good alternative to open surgery or cystoperitoneal shunting, and the number of fenestrations made during this surgery decreases the need for a second surgical procedure.

Controversies in the Treatment of Arachnoid Cysts with Special Emphasis on Temporal Arachnoid Cysts

Intracranial arachnoid cysts (ACs) are benign lesions. The incidence in children is 2.6%. ACs are often diagnosed incidentally. Because of the broad use of CT and MR imaging, the frequency of AC diagnosis has increased. In addition, prenatal diagnosis of ACs is becoming more common. This places clinicians in a difficult situation with regard to the optimal treatment, since the presenting symptoms are often vague and operative management includes not negligible risks. It is generally accepted that conservative management is indicated in cases with small and asymptomatic cysts. In contrast, patients with definite signs of raised intracranial pressure should be treated. There are however clinical situations in whom the decision about the preferred treatment is difficult to make. Unspecific symptoms such as headaches and neurocognitive or attention deficits can be challenging to evaluate, whether they are related to the presence of the AC or not. The treatment techniques intent to establish a communication between the cyst and the normal cerebrospinal spaces or consist of a diversion of the cyst fluid by a shunt system. Which surgical method (open craniotomy for cyst fenestration, endoscopic fenestration, or shunting) is preferred differs between neurosurgical centers or the pediatric neurosurgeon in charge. Each treatment option has a unique profile of advantages and disadvantages which should be considered when discussing treatment with the patients or their caregivers.

Ruptured Sylvian arachnoid cysts: an update on a real problem

PURPOSE

Sylvian arachnoid cysts (SACs) are the most common type of arachnoid cysts and the most prone to undergo a rupture. This event is considered rare but potentially severe. No definite information is available on its occurrence or management. The goal of the present article is to provide an update on the epidemiological, etiological, and clinical aspects and the management of this peculiar clinical condition.

METHODS

A comprehensive review of the English literature of the last 40 years on this topic has been realized. Moreover, a personal series of children investigated and treated in the last 20 years is presented. These patients were managed as follows: (1) treatment of the subdural collection; (2) identification of candidates for surgical treatment of the residual cyst (brain MRI, perfusion brain MRI, prolonged invasive ICP monitoring (selected cases), EEG, neuropsychological tests); (3) surgical treatment of the cyst in the patients with pathological perfusion MRI and/or ICP measurement and/or clear neurophysiological and neuropsychological correlations.

RESULTS

A total of 446 patients (430 from the literature and 16 from the personal series), mainly children, adolescents, and young adults, have been analyzed leading to the following results: (1) SAC rupture is rare but not negligible (yearly risk of rupture: 0.04%; overall risk up to 10% in children affected by SCAs). Prophylactic surgery in asymptomatic cases is not advisable. (2) The mechanism of rupture is not known but an impact of SAC against the sphenoid wing and/or a direct injury on SAC through a thinned temporal bone, with possible laceration of the cyst wall vessels and/or tear of the bridging veins, can be hypothesized. A head injury is often not reported (may be misdiagnosed). (3) Subdural collection (hygroma > chronic hematoma) is the most common finding followed by intracystic bleeding, extradural hematoma, and other types of bleeding. Signs or symptoms of raised intracranial pressure are the most frequent ones. (4) The complication of the rupture is usually treated in emergency or in the acute period by burr hole or craniotomic evacuation of the subdural collection, although a conservative management is possible in some cases. Following the rupture, the majority of SACs are treated (70%), often at the same time of the complication, but no specific investigations are routinely performed to select candidates. According to our protocol, only 43.7% of SACs needed to be treated.

CONCLUSIONS

The "spontaneous" or posttraumatic rupture of SACs is a rare but potentially significant complication followed by a generally good outcome. The course of the cyst is independent from the outcome of the complication, consequently requiring specific investigations for individuating those lesions interfering with CSF dynamics and/or cerebral blood flow.

Predictors for the clinical prognosis of sylvian arachnoid cysts in children

Objectives

To investigate the potential factors affecting the clinical prognosis of intracranial sylvian arachnoid cysts(IAC) in children.

Methods

All patients with IAC admitted to our department from January, 1, 2015 to December, 31, 2016, were retrospectively reviewed. Patients were grouped based on surgical treatment (surgery cohort vs non-surgery cohort). The clinical and image outcome of the patients were followed routinely. The clinical characteristics and the prognosis of the patients were compared in different cohorts. Binary logistic regression analysis was applied to analyze the potential factors which may post an influence on the prognosis of the patients.

Results

Of 500 patients admitted to our department for IAC, 424 patients had good prognosis and 76 had poor prognosis, with no deaths occurred during the follow-ups. 68 patients had IAC related complications and 91 patients developed new symptoms during the follow-ups. There were significant differences (P < 0.05) between the 2 cohorts in below aspects: age, gender, Galassi subtype, whether the mother was a unipara, the maximum diameter of the cysts at the first visit and the last follow-up, headache, head circumference, temporal bulge, new symptoms, cysts rupture and hemorrhage, subdural effusion, and IAC disappearance. The mean changes in the maximum diameter of the IAC for the patients were marginally higher for the surgery cohort than for the non-surgery cohort (P < 0.01). Binary logistic regression analysis suggested that the number of symptom, no new symptoms during follow-up, surgical treatment, age, maximum diameter of cysts at first diagnosis were independent risk factors affecting the prognosis of patients (P < 0.05).

Conclusions

Patients older than 22.5 months, with the maximum diameter of IAC greater than 5.75 cm, who have multiple symptoms, born prematurely, develope new symptoms during the follow-ups and obvious symptoms after trauma need to conduct necessary surgical treatment in time. Patients with complications such as cysts rupture with hemorrhage and subdural effusion will acquire good prognosis after timely surgical treatment. IAC complete disappearance warrants no such important attention for the good prognosis.

Neuroendoscopic fenestration for intracranial unilocular cysts and isolated lateral ventricles: four pediatric cases

The purpose of treatment for unilocular intracranial cysts (UICs) is to release elevated intracranial pressure. Neuroendoscopic fenestration (NF) is one of the most effective and minimally invasive options for treating UICs, especially in young children; however, the optimal location and number of fenestrations, the necessity of using endoscopic third ventriculostomy (ETV) in combination with fenestration, and the course of treatment are not well known. We retrospectively reviewed the hospital records between 2012 and 2019. The patients were studied in terms of sex, age at surgery, preoperative symptoms, cyst localization and size, course of treatment, ventricular diameter, developmental assessment, anatomical location, and the number of fenestrations. There were four eligible patients in the relevant period: two boys and two girls. The median age at the time of surgery was 16 months. With regard to the location of the cysts, there were two cases of cavum velum interpositum (CVI), one case of quadrigeminal cistern, and one case of an isolated lateral ventricle. The most common preoperative finding was an enlarged head circumference. All the patients were treated with NF, including one case of reoperation after open head surgery. Postoperatively, we used the frontal and occipital horn ratio (FOHR) to evaluate the ventricular size. The average reduction in the FOHR was 0.003. In the most recent developmental assessment or examination during the follow-up period, two patients showed normal development, and two patients showed developmental delay. Based on our past experience and reports, we believe that it is recommended to perform two fenestrations for a single cyst. This is because it creates a flow of cerebrospinal fluid (CSF) within the cyst into normal CSF reflux. For lesions with obstruction of the aqueduct, such as cysts in the quadrigeminal cistern, ETV should be considered if it can be performed safely, in preparation for the worsening of hydrocephalus due to obstruction by enlargement of the cyst.

Intracranial arachnoid cysts in an infant: A technical note on the innovative use of navigation and flexible endoscopy for cyst fenestration

Background:

Intracranial arachnoid cysts (ACs) are a cerebral spinal fluid (CSF) collection within the meninges. They typically arise during embryologic development. Some are stable overtime with little consequence, but large or growing cysts may require surgical intervention. The optimal surgical technique is debated and may be more technically challenging in the infant age group.

Case Description:

Our unique case report details a 10-month-old (6 months corrected age) infant who presented with a drastic increase in head circumference and was found to have midline shift and three cysts – one large and two smaller ones. He was treated with an innovative surgical approach combining stereotactic introduction of a catheter to facilitate subsequent flexible endoscopy allowing three separate cysts to be treated through one small surgical incision with no complications and a stable examination on 2-year follow-up.

Conclusion:

Symptomatic ACs in the infant population that require treatment can be addressed with open surgery to fenestrate the cyst, endoscopic cyst fenestration, or cystoperitoneal shunting. Typically, surgeons must choose between a rigid endoscope which allows stereotactic navigation or a flexible endoscope which allows multiple trajectories but precludes navigation. Our case demonstrates that combining stereotactic ventricular placement before flexible endoscopy provides the benefit of both approaches and allows for successful endoscopic treatment in a young patient with durable results.

Surgical fenestration might not be the best option for very young patients with middle fossa arachnoid cysts

PURPOSE

Surgical fenestration is widely accepted as a primary treatment for middle fossa arachnoid cysts (MFACs) in pediatric patients. However, postoperative subdural effusion and/or hydrocephalus always affect treatment outcomes. In this study, we presented our experience of treating MFACs with surgical fenestration in pediatric patients and analyzed the cases complicated by postoperative subdural effusion and/or hydrocephalus, to give insight into the clinical characteristics predisposing the complications.

METHODS

We retrospectively analyzed 21 pediatric cases with MFACs treated by surgical fenestration suffering postoperative subdural effusion and/or hydrocephalus in our department from November 2011 to April 2019. We reviewed the clinical characteristics and treatment outcomes.

RESULTS

A total of 21 patients, among a total of 53 pediatric patients with MFACs treated by surgical fenestration, developed subdural effusion and/or hydrocephalus postoperatively. The mean age at the time of the initial surgery was 49 months. A total of 75% (6/8) of the patients under 2 years old and 13.3% (6/45) of the older patient group sustaining postoperative subdural effusion and/or hydrocephalus required further surgeries, respectively (Fisher's exact test, p = 0.001). Notably, among the 21 cases with postoperative subdural effusion and/or hydrocephalus, all the 6 patients under 2 years old needed additional surgeries, while of the other 15 older patients, only 40% (6/15) needed further surgical interventions (Fisher's exact test, p = 0.019).

CONCLUSION

The immature CSF absorption in MFAC patients younger than 2 years old might predispose them to the relatively serious postoperative subdural effusion and/or hydrocephalus. For very young patients with giant MFACs, surgical fenestration might not be the best option.

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.

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.

Intracerebral hematoma after endoscopic fenestration of an arachnoid cyst: A case report

RATIONALE

An intracranial arachnoid cyst is a relatively common congenital benign lesion. A small number of patients present with neurological symptoms. Endoscopic fenestration has become a common treatment for arachnoid cysts in recent years, but intracerebral hematoma after surgery is rarely reported.

PATIENT CONCERNS

A 60-year-old woman with an arachnoid cyst in the left parietal and occipital lobes showed obvious progressive neurological deficits. She had weakness in her right limbs for 2 years and a sudden convulsion in her left limbs.

DIAGNOSIS

An arachnoid cyst in the left parietal and occipital lobes was detected on magnetic resonance imaging.

INTERVENTION

Endoscopic fenestration was performed for the cyst. However, she developed an intracerebral hematoma after surgery, which was detected by computed tomography. Due to the exacerbation of the patient's condition in the early stage after surgery, reoperation was performed to remove the hematoma.

OUTCOMES

The patient was finally cured with no serious neurological deficits.

LESSONS

The rare complication of intracerebral hematoma after surgery for an arachnoid cyst can lead to a rapid deterioration in the patient's condition. More-adequate preoperative examination and neuronavigation should be conducted during surgery. Appropriate enlargement of the bone hole may help protect against this complication. Moreover, prompt reoperation for the intracerebral hematoma may improve the prognosis.

The effectiveness of microsurgical fenestration for middle fossa arachnoid cysts in children

OBJECTIVE

Although middle fossa arachnoid cysts (MFACs) are common, the optimal surgical treatment for these lesions remains controversial. In this study, we present our experiences of treating MFACs by microsurgical fenestration and evaluate its effectiveness.

METHODS

We performed retrospective review of 28 patients who underwent microsurgical fenestration for MFACs between May 2003 and December 2014. We reviewed patient characteristics and treatment outcomes including age, sex, symptoms, complicating hydrocephalus, Gallasi classification, change in cyst size after surgery, complicating subdural hygroma, symptom resolution, regrowth of the cyst, and reoperation (including additional CSF diversion).

RESULTS

Twenty-eight MFACs in 28 patients were investigated. The average age at the time of surgery was 61.6 months. The average follow-up duration was 53.5 months. After surgery, 19 (90.5 %) of 21 patients with symptomatic MFACs experienced improvements. The cysts decreased in size in all cases (100 %, 28/28) and disappeared in three cases (11 %, 3/28). None of the cases experienced regrowth of the cyst. Subdural hygroma was identified in 23 cases (82.1 %) at the immediate postoperative period. Hygroma was asymptomatic in all cases but one. Hygroma disappeared in 19 cases (83 %) and decreased in size in three cases (13 %) in the long term. Only one case (4 %) required an additional subdural-peritoneal shunt. The rate of CSF diversion after the fenestration was significantly higher in patients with preoperative ventricular dilation (p = 0.0002).

CONCLUSION

Microsurgical fenestration for pediatric MFACs was considered to be safe and effective. Although subdural hygroma developed in significant number of patients at the immediate postoperative period, it was mostly asymptomatic and disappeared or decreased in size in the long term.

[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.

The efficacy of neuroendoscopic treatment for middle cranial fossa arachnoid cysts assessed by MRI 3D segmentation and modeling

PURPOSE

The purpose of this study was to present a more precise and objective way to assess the effectiveness of neuroendoscopic application in the treatment of middle cranial fossa arachnoid cysts.

METHODS

Between March 2009 and December 2012, 28 patients affected by middle cranial fossa arachnoid cysts were initially treated with endoscopic fenestration at the three spaces. The volumes of the cysts on MR images at the time of pre-op and 4 months after surgery were reconstructed by 3D Slicer and quantitatively calculated to compare the volumetric changes. The possible predisposing factors of surgical outcomes were analyzed as well.

RESULTS

All the models of the cysts were successfully reconstructed, and the mean volume of the cysts was 135.77 ± 90.43 cm(3) before surgery and 93.08 ± 100.31 cm(3) after surgery at 4 months follow-up (t = 2.98, P = 0.006). The volumes of those two cases (7.14 %), presenting intracranial hypertension and ventricular dilation after surgery, were dramatically increased, whereas the others were decreased in 20 cases (71.43 %) or remained unchanged in 6 cases (21.43 %). There was significant difference on the age factor among the three result groups (P = 0.001).

CONCLUSIONS

The reconstruction of 3D for the assessment of the endoscopic fenestration outcomes is a feasible and precise way for clinical work. The variety of outcomes probably depends on age discrepancy.

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.