Shunt-independent surgical treatment of middle cranial fossa arachnoid cysts in children

The best operative intervention for children with arachnoid cysts remains the subject of controversy. Recent reports stress that craniotomy for cyst fenestration is associated with a low incidence of morbidity and mortality and may leave the child shunt-independent. Among a total of 66 intracranial arachnoid cysts operated on in the authors’ department from 1985 to 1997, 44 cases (67%) were located in the middle cranial fossa. A higher incidence in the first decade of life (53 cases) and a marked male predominance (45 cases) were recognized. Headache, cranial deformities, symptoms of raised intracranial pressure, and seizures constituted the most frequent features of the clinical presentation. To determine which treatment provides the greatest benefit with the lowest incidence of complications, the records of the 44 patients with arachnoid cysts in the middle cranial fossa were reviewed. The mean age of these patients was 4.6 years (range 0–16 years). Different types of initial surgical procedures were performed. In 33 patients with middle cranial fossa arachnoid cysts (MCFAC) the initial surgery took the form of craniotomy with excision of the cyst walls and fenestration into the basal cisterns. Shunting procedures were performed in 9 patients: cysto-peritoneal shunts (CPS) were placed in 4 patients and ventriculo-peritoneal shunts (VPS), in 3 patients, and cyst excision was performed in addition to CPS in 2 patients. Excision of the cyst membrane alone without fenestration was performed in 2 patients. The initial treatment was successful in terms of reduced symptoms and decreased cyst size, with no additional treatment needed for the cyst, in 79% (26/33) of patients who had undergone excision of the cyst walls and fenestration into the basal cisterns, compared with 66% (6/9) of patients who had undergone shunting procedures. Cyst membrane excision was not successful in any of the patients who underwent this procedure alone. No significant difference in morbidity was noted between these different treatment options. On follow-up CT scan and MRI, cysts of types I and II (Galassi classification) exhibited a steady tendency to reduction or obliteration. These results confirm that radical excision of the outer and inner membranes of the cyst wall with fenestration into the basal cistern is a safe and effective shunt-independent procedure for MCFAC, especially for those of types I and II. Received: 28 May 1999 Revised: 10 August 1999     

The clinical classification and treatment of middle cranial fossa arachnoid cysts in children

Objective

The optimal management for middle fossa arachnoid cysts (MFAC) remains controversial, but cystocistern fenestration is effective. MFACs are divided into non-communicating arachnoid cysts (NCIAC) and communicating arachnoid cysts (CIAC). This retrospective observational study evaluated the role of phase-contrast cine magnetic resonance imaging (PC-MRI) in the diagnosis and postoperative evaluation of MFACs and assessed surgical outcomes.

Methods

Twenty-eight children with MFAC that were diagnosed by conventional neuroradiology were enrolled. PC-MRI was performed preoperatively. The clinical manifestations, cyst volumes and PC-MRI data were analyzed, and the flow of cerebrospinal fluid (CSF) at the fistula was qualitatively evaluated.

Results

No communication with the adjacent subarachnoid space was found on preoperative PC-MRI in 20 patients, and they were diagnosed with NCIAC. A statistically significant decrease in cyst volume was observed in all 20 patients postoperatively. Symptoms resolved or improved in the 14 patients who were symptomatic preoperatively, and a positive CSF flow was found in all 20 patients postoperatively. PC-MRI diagnosed eight patients with CIAC, and the cyst sizes did not increase during follow-up.

Conclusions

Cystocistern fenestration is an effective treatment for children with lateral fissure IAC. PC-MRI can be used to determine the IAC type and to evaluate the effectiveness of cystocistern fenestration.     

Intraoperative subdural hematoma in a patient with arachnoid cyst in the middle cranial fossa

A case of arachnoid cyst in the middle cranial fossa complicated by intraoperative subdural hemorrhage is presented. Accumulation of cerebrospinal fluid (CSF) outside the outer wall of the arachnoid cyst was found to induce the rupture of well-developed, fragile leptomeningeal vessels at the base of the middle cranial fossa. This phenomenon is noteworthy as a pitfall in surgery for intracranial arachnoid cyst and suggest the bleeding source of subdural hematoma occasionally associated with this lesion.     

中颅窝蛛网膜囊肿的临床特点及外科治疗

目的 探讨中颅窝蛛网膜囊肿的临床特点及不同术式对其治疗的临床疗效.方法 回顾性分析第四军医大学西京医院神经外科自2001年5月至2008年5月收治的352例中颅窝蛛网膜囊肿患者(占同期收住的颅内占位性病变患者的2.58%)的临床资料、手术方式及预后情况,其中男性发病率明显高于女性(男:女为4.1∶1),以左侧居多(左∶右为3.6∶1),324例行囊肿切除术,28例巨大囊肿行囊肿-腹腔分流术.结果 术后平均随访3个月～3年.头痛就诊患者中75例(58.59%)术后头痛完全消失,41例(32.03%)明显缓解.癫痫发作患者中8例术后发作频率明显减少或程度减轻.行为异常、注意力不集中或学习困难患者中11例术后改善明显.头围增大和颞部局限性隆起就诊者术后头围及局部隆起无明显变化.影像学复查显示囊肿完全消失者46例(13.07%),囊肿部分消失者257例(73.01%),囊肿无明显变化者49例(13.92%).结论 中颅窝蛛网膜囊肿的临床特点为男性、左侧多发,年龄愈小手术效果越好,手术仅部分切除壁层即可;囊肿巨大时行分流手术效果好,分流管以中低压为佳.

Abstract：

Objective o investigate the clinical characteristics of middle cranial fossa arachnoid cyst (MCFAC) and its therapeutic effects with different surgical methods. Methods Three hundred and fifty-two patients with MCFAC (about 2.58% of patients with intracranial space occupying lesion),admitted to our hospital from May 2001 to May 2008, were chosen in out study; their clinical data,surgical approach and prognosis were analyzed retrospectively. The gender ratio of patient with MCFAC adopted resection of arachnoid cyst and arachnoid cyst-peritoneal shunt was performed in 28 patients.Results Follow-up was performed for 3 months to 3 years. The headache completely disappeared in 75 patients (58.59%) and partial remission in 41 (32.03%) after the operation. The frequency and degree of seizures obviously decreased in 8 of the patients with MCFIAC. Eleven patients with dystropy,attention-deficit disorder or difficulty of learning got improvement. The head circumference and local skull eminentia was stable. The cyst disappeared completely in 46 patients (13.07%), partially in 257 (73.01%) and no changes in 49 (13.92%). Conclusion The clinical features of MCFAC is that it mainly occur in the left side of male. The younger the patient with MCFAC is, the better the treatment effect in the surgical intervention is. good outcome can be achieved by resection of the parietal layer of arachnoid cysts. The indication of shunt with meso-low pressure shunt system is for larger arachnoid cyst.     

Effective shunt-independent treatment for primary middle fossa arachnoid cyst

The results of a prospective study on excision of the outer and inner membrane for symptomatic primary middle fossa arachnoid cysts in children are presented. During the period 1982–1989, among 48 cases of cyst in various locations, 18 symptomatic patients were treated by excision of both the outer and inner membranes with an opening to the basal cistern. The mean patient age was 3.2 years. All patients were evaluated by examinations, including magnetic resonance imaging (MRI), X-ray computed tomography (CT), quantitative CT cisternography (CTC), digital substraction angiography (DSA), N-isopropyl-p[123]iodoamphetamine single-photon emission CT (IMP-SPECT) and IQ. All showed abnormal cerebrospinal fluid flow dynamics. Significant complications included massive subdural effusion in two patients and transient pulmonary edema in one. There were no recurrences during the follow-up period (mean 4.7 years). Two morphological types were noted: type I, the classical anteromedial type where the cysts are attached directly to the adjacent parasellar cisterns, and type II, the anterolateral type, where the diagonally concave anterior temporal lobe covers the adjacent cisterns, making wide opening difficult. Type I accounted for 78% of all cases, and the reduction of the cyst volume with clinical improvement was remarkable within 6 months after surgery. Angiographically, 22% of cases showed tapering and retrograde filling of the superficial middle cerebral vein. This pattern is not included in Hacker's normal variations [18] and suggest mild but chronic compression of the developing brain. Even in patients with hemispheric cyst, the reconstituted brain showed sufficient cerebral perfusion on SPECT, suggesting that the nature of this disease entity is reversible developmental arrest. These results confirm that excision is a safe, effective shunt-independent procedure for middle-fossa arachnoid cysts, especially for those of type I.     

Assessment of endoscopic treatment for middle cranial fossa arachnoid cysts

Background

Endoscopic cystocisternotomy is one of three surgical methods used to treat middle cranial fossa arachnoid cysts. There is debate about which method is the best.

Objective

The aim of this study is to evaluate the effectiveness and safety of endoscopic cystocisternotomy for treatment of arachnoid cysts of the middle cranial fossa.

Methods

Thirty-two patients with arachnoid cysts of the middle cranial fossa who had undergone endoscopic cystocisternal fenestration between 2004 and 2009 were studied retrospectively. Data were obtained on clinical and neuroradiological presentation, indications to treat, surgical technique, complications, and the results of clinical and neuroradiological follow-up.

Results

Among the 27 patients with symptoms before surgery, 8 had disappearance of symptoms and 17 had improvement of symptoms. The cyst was reduced in size or it completely disappeared in 24 (75%) patients. The incidence rate of complications was 18.8%.

Conclusions

Endoscopic cystocisternal fenestration is an effective treatment for symptomatic arachnoid cysts of the middle cranial fossa and should be the initial surgical procedure.     

蛛网膜囊肿55例外科治疗临床分析

目的 探讨蛛网膜囊肿的手术指征和手术方法.方法 回顾性分析收治的55例蛛网膜囊肿患者,其中行囊肿切除术12例,囊肿大部分切除 蛛网膜下腔疏通术27例,囊肿部分切除 脑池分流术4例,囊肿-腹腔分流术9例,3例未行手术治疗.结果 术后症状均有不同程度好转,3例未手术者因囊肿为非"责任"病灶而采取针对性治疗好转.结论 蛛网膜囊肿在明确"责任"病灶的前提下应积极手术治疗,囊肿-腹腔分流术可作为首选的治疗方法.     

儿童蛛网膜囊肿伴癫癎的外科治疗(附13例报告)

目的 探讨儿童颅内蛛网膜囊肿（ａｒａｃｈｎｏｉｄ ｃｙｓｔ,ＡＣ）与癫癎的关系以及外科治疗方法。方法 手术治疗颅内蛛网膜囊肿伴癫癎的儿童１３例,其中额叶２例,顶叶１例,颞叶８例,枕叶２例,囊肿直径在３ｃｍ以下３例,３～６ｃｍ ９例,６ｃｍ以上１例,均采用颅内蛛网膜囊肿加致癎灶切除。结果 １３例病人中,完全不发作有４例,显著改善有７例,无变化２例。结论 儿童颅内蛛网膜囊肿伴癫癎具有脑皮质结构性异常,采用颅内蛛网膜囊肿加致癎灶切除效果较为理想。     

Hippocampal dysgenesis associated with temporal lobe hypoplasia and arachnoid cyst of the middle cranial fossa

We describe two children with left hippocampal dysgenesis in association with temporal lobe hypoplasia and arachnoid cyst of the middle cranial fossa. The hippocampus showed an abnormal globular shape and blurred internal structure in both patients. One of the patients had juvenile myoclonic epilepsy without evidence of seizure onset in the abnormal temporal region. The other patient did not have epilepsy; however, he showed developmental language disorder with a probable relationship to the left temporal abnormalities.     

Extradural hematoma complicating middle fossa arachnoid cyst

Two cases of post-traumatic extradural hematoma complicating an arachnoid cyst of the middle cranial fossa in children are described. While subdural and intracystic hemorrhages are well-known complications from this malformation, the association with extradural hematoma has never been previously reported in the literature. The pathogenetic mechanisms are discussed and the particular vulnerability of intracranial arachnoid cysts is stressed.     

A spontaneous bilateral subdural effusion in an 11-year-old boy with middle cranial fossa arachnoid cyst

An 11-year-old boy gradually developed headache, vomiting and diplopia over a period of 1 month. Repeated examinations of head CT scan revealed an arachnoid cyst in the right middle cranial fossa and bilateral subdural effusion of enlarging size. Papilledema was absent on admission, but it became evident after 1 week, and lumbar puncture disclosed very high pressure (800 mmH2O) of the cerebrospinal fluid. Fenestration of the cyst to the basal cisterms quickly alleviated his symptoms of intracranial hypertension as well as the bilateral subdural effusion on CT. Macroscopically, there was a small tear on the wall of the arachnoid cyst, and it probably served as a communication valve with the subdural space. Since he had no history of head trauma in the past few months, the reason of the tear formation was unclear. Intracranial arachnoid cyst is a relatively common congenital malformation of usually benign and non-pathogenic nature. However, it may occasionally cause non-traumatic subdural effusion and intracranial hypertension.     

儿童鞍上蛛网膜囊肿的手术治疗

目的探讨儿童鞍上蛛网膜囊肿的传统开颅手术及内镜下第三脑室底造瘘手术的治疗方法及疗效的比较。方法回顾分析2001年8月至2005年8月北京天坛医院收治的儿童鞍上蛛网膜囊肿患者44例,术前采用MRI明确诊断,分别采取传统开颅手术切除囊肿或者内镜下囊肿切开第三脑室底造瘘术,术后定期随访,观察疗效结果所有44例患者手术顺利,术后症状好转,MRI检查提示囊肿和脑室缩小,导水管通畅,无手术死亡,术后平均随访23个月,两组术后并发症发生率差异无统计学意义(P>0.05)。结论与传统的开颅囊肿剥除术相比,神经内镜手术具有创伤小、住院时间短、恢复快的独特优势,有望成为鞍上囊肿的首选治疗。     

儿童蛛网膜囊肿伴癫的外科治疗(附13例报告)

目的探讨儿童颅内蛛网膜囊肿(arachnoidcyst,AC)与癫的关系以及外科治疗方法.方法手术治疗颅内蛛网膜囊肿伴癫的儿童13例,其中额叶2例,顶叶l例,颞叶8例,枕叶2例,囊肿直径在3cm以下3例,3～6cm9例,6cm以上1例,均采用颅内蛛网膜囊肿加致灶切除.结果13例病人中,完全不发作有4例,显著改善有7例,无变化2例.结论儿童颅内蛛网膜囊肿伴癫具有脑皮质结构性异常,采用颅内蛛网膜囊肿加致灶切除效果较为理想.     

Asymptomatic large arachnoid cyst of the middle cranial fossa. A clinical and neuropsychological study

The authors studied a 26-year-old healthy subject in whom a large arachnoid cyst of the right middle cranial fossa was revealed by chance. As there were no subjective or objective neurological findings, we checked the existence of any neuropsychological impairment. In spite of this, the patient obtained a good general performance level and sometimes the hemisphere containing the cyst performed better, in accordance with the patient's handedness.     

Postnatal development and enlargement of primary middle cranial fossa arachnoid cyst recognized on repeat CT scans

The etiology and mechanism of expansion of primary intracranial arachnoid cysts have been much debated. A rare case of an 8-month-old boy is reported, in which postnatal development and enlargement of a middle cranial fossa arachnoid cyst was detected on follow-up CT scans. Based on intraoperative and histological findings, the cyst was found to be intra-arachnoid. The wall was excised completely, and the lobe adjacent to the cyst appeared normal apart from signs of atrophy. Histological study of the excised cyst revealed a common arachnoid membrane with neither ependymal nor inflammatory cells; the cyst fluid was similar to CSF. The etiology of the lesion remains unclear, but it was considered that the expansion of the cyst might have occurred through a ball-valve mechanism of the membrane in communication with the general subarachnoid space.     

Subdural hygroma in association with middle fossa arachnoid cyst: acetazolamide therapy

Intracranial arachnoid cysts are cerebrospinal fluid-filled collections between arachnoid layers. While many are silent, arachnoid cysts can become symptomatic if there is sudden expansion, haemorrhage or rupture with the development of subdural hygroma or subdural hematoma. Several studies have demonstrated the association of arachnoid cysts with subdural hygroma and subdural hematoma. We describe a 9-year-old girl with a moderate-sized middle-fossa arachnoid cyst and bilateral frontal subdural hygroma presenting with raised intracranial pressure. She was treated with acetazolamide which resulted in resolution of the subdural hygroma and relief of symptomatology.     

Symptomatic, expansive middle cranial fossa arachnoid cyst treated by a cysto-peritoneal shunt Case report and evaluation of treatment options

We report a symptomatic space-occupying arachnoid cyst in a 16-year-old boy. During the last two years, he was frequently absent from school because of headaches. Due to symptoms of nausea, fever and headache the patient was primarily referred to a surgical unit, where appendectomy was performed, revealing a normal appendix. Postoperatively, the patient complained of severe headache. Computed tomography (CT) of the head demonstrated a large left-sided middle cranial fossa arachnoid cyst. The patient was operated with insertion of a cysto-peritoneal shunt. A total regress of the clinical symptoms was seen at follow-up examination 3 months after shunting.