Endoscopic management of large multicompartmental intraventricular arachnoid cyst extending from foramen magnum to foramen of Monro

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.

Endoscopic surgery for intraventricular arachnoid cysts in children: clinical presentation, radiological features, management, and outcomes over a 12-year period

PURPOSE

Less than 0.5% of arachnoid cysts are intraventricular in origin. We review our experience with endoscopic surgery for intraventricular arachnoid cysts in children.

METHODS

This is a retrospective review of children with intraventricular arachnoid cysts who underwent surgery between 2005 and 2016. Clinical notes and imaging were reviewed.

RESULTS

Twenty-nine patients with endoscopically treated intraventricular arachnoid cysts were identified (M/F = 17:12; median age = 1.47 years, range = 7 days-13 years). All had hydrocephalus at presentation, many had symptoms/signs of raised intracranial pressure, and five (17%) were asymptomatic. Cysts were treated with fenestration into the ventricle alone (ventriculocystostomy [VC], n = 14), fenestration into the ventricle and cisternostomy (ventriculocystostomy plus cisternostomy [VC + C], n = 14), or endoscopic third ventriculostomy alone (n = 1). Six (21%) patients experienced transient and/or conservatively managed complications. Further surgery was required in 12 (41%). Revision-free survival was significantly shorter with VC compared to VC + C (log rank p = 0.049), and the majority of VC/VC + C revisions (n = 8 of 11, 73%) were required within 6 months of initial endoscopic surgery. One (3%) patient died during follow-up, from unrelated pathology. After a median follow-up of 67.5 months in survivors (range = 5.5-133.5 months), 24 (83%) cases were clinically and radiologically stable without a shunt in situ.

CONCLUSIONS

Endoscopic fenestration is safe and effective in most intraventricular arachnoid cysts. Additional cisternostomy at the time of cyst fenestration into the ventricle significantly improved revision-free survival in our cohort. Endoscopic surgery should be the first-line therapy when considering intervention for symptomatic intraventricular arachnoid cysts and for asymptomatic cysts increasing in size on serial imaging.

Endoscopic Management of a Fourth Ventricular Cyst

We report a case of a 12-year-old boy with previously shunted congenital hydrocephalus, presenting with a progressive headache, nausea, vomiting, and lethargy. In the brain magnetic resonance imaging, a large cyst was seen in the superior recess of the fourth ventricle extending through the cerebral aqueduct toward the third ventricle. Endoscopic dual fenestration of the cyst was performed successfully using the posterior suboccipital approach through the foramen of Magendie, which resulted in the relief of symptoms without any complications, and the patient was symptom-free in the subsequent follow-up visits for 4 years.

Transoccipital endoscopic fenestration of atrial cysts causing ventricular entrapment

OBJECT Cystic lesions in the atrium (trigone) of the lateral ventricle may become symptomatic due to obstruction of physiological CSF circulation and/or from mass effect on adjacent structures. A minimally invasive approach that not only allows for straightforward access to multiple regions of the atrial cyst wall, but also enables direct inspection of the entire lateral ventricular system, has not been elaborated. In this paper the authors describe their experience with the endoscopic transoccipital horn approach for treating cystic lesions in the atrium of the lateral ventricle. METHODS A retrospective review was performed of all patients who underwent endoscopic surgical treatment for cysts in the atrium of the lateral ventricle between 1999 and 2014. RESULTS The cohort consisted of 13 consecutive patients who presented with symptomatic lateral ventricular entrapment due to the presence of an atrial cyst. There were 9 male and 4 female patients, with a median age of 5 years. Headache was the most common complaint at presentation. The transoccipital horn approach facilitated successful cyst reduction and fenestration in all cases. Temporal and occipital horn entrapment was reversed in all cases, with reestablishment of a physiological CSF flow pattern throughout the ventricles. Hydrocephalus was also reversed in all patients presenting with this neuroimaging finding at presentation. No cyst or ventricular entrapment was noted to recur during a mean follow-up period of 36 months. No patient in the study cohort required repeat surgery or permanent CSF diversion postoperatively. CONCLUSIONS The endoscopic transoccipital horn approach represents a safe and effective treatment strategy for patients with symptomatic atrial cysts of the lateral ventricle. Using this minimally invasive technique, all poles of the lateral ventricular system can be visualized and the unobstructed flow of CSF can be confirmed after cyst resection obviating the need for additional diversion.