Endoscopic treatment of interhemispheric arachnoid cysts

Spontaneous regression of an interhemispheric arachnoid cyst: illustrative case

BACKGROUND

Intracranial arachnoid cysts are benign collections of cerebrospinal fluid that are often asymptomatic and discovered incidentally. An interhemispheric location of these lesions is rare, with only a few such cases reported in the literature. Though spontaneous regression of arachnoid cysts has been described in other locations, to date this phenomenon has not been reported in interhemispheric fissure cysts.

OBSERVATIONS

In this report, we describe a patient with a large, multiloculated interhemispheric arachnoid cyst diagnosed on prenatal ultrasound. She did not exhibit neurologic deficits or signs of increased intracranial pressure and was observed with serial imaging. After several years of observation, imaging revealed spontaneous and progressive decrease in the cyst size.

LESSONS

We illustrate a case of regression of an interhemispheric arachnoid cyst in a pediatric patient. To our knowledge, this is the first reported case of spontaneous shrinkage of an arachnoid cyst in this location. Although the current presentation is rare, this reporting adds to the current understanding of natural history of arachnoid cysts and provides an example of radiographical improvement without intervention of a cyst located within the interhemispheric fissure.

Surgical treatment of interhemispheric arachnoid cysts

OBJECTIVE

In children, interhemispheric arachnoid cysts (IHACs) are rare lesions often associated with corpus callosum dysgenesis. It is still controversial about surgical treatments for IHACs. We aim to report our experience with pediatric IHAC patients and evaluate surgical courses and neurological developments.

METHODS

Pediatric IHACs treated between 2001 and 2021 were reviewed retrospectively. IHAC was observed until they represented rapid cyst enlargement or neurological symptoms. Cyst fenestration was done by microscope or endoscope, depending on the IHAC's location. Cyst size and corpus callosum dysgenesis were evaluated with neuroimaging. Neurological development was assessed from medical records at the last follow-up.

RESULTS

Fifteen children received cyst fenestration surgery (mean age 11.4 months). Eleven patients (73.3%) under observation showed rapid cyst enlargement in a short period (median 5 months). Cysto-ventriculostomy (CVS) and cysto-cisternostomy (CCS) regressed the cyst size significantly (p = 0.003). The median follow-up duration was 51 months (range 14-178 months). Corpus callosum dysgenesis was observed in eleven patients (73.3%, complete = 5, partial = 6). Among eight patients (53.3%) having developmental delay, five patients (33.3%) showed speech delay, including one patient with intractable seizures.

CONCLUSION

Pediatric IHACs frequently present within 1 year after birth, with rapid cyst enlargement. CVS and CCS were effective in regressing the cyst size. Corpus callosum dysgenesis accompanied by IHAC might have a risk of language achievement; however, development delay could rely on multifactorial features, such as epilepsy or other brain anomalies.

Imaging characteristics and neurosurgical outcome in subjects with agenesis of the corpus callosum and interhemispheric cysts

PURPOSE

To explore the relationships between clinical-radiological features and surgical outcomes in subjects with interhemispheric cysts (IHC) and corpus callosum anomalies.

METHODS

We reviewed the clinico-radiological and neurosurgical data of 38 patients surgically treated with endoscopic fenestration, shunting, or combined approaches from 2000 to 2018 (24 males, median age 9 years). Pre- and postoperative changes in IHC volume were calculated. Outcome assessment was based on clinico-radiological data. Group comparisons were performed using χ², Fisher exact, Mann-Whitney U, and Kruskal-Wallis tests.

RESULTS

Median age at first surgery was 4 months (mean follow-up 8.3 years). Eighteen individuals (47.3%) required > 1 intervention due to IHC regrowth and/or shunt malfunction. Larger preoperative IHC volume (P = .008) and younger age at surgery (P = .016) were associated with cyst regrowth. At last follow-up, mean cystic volume was 307.8 cm³, with IHC volume reduction > 66% in 19/38 (50%) subjects. The neurological outcome was good in 14/38 subjects (36.8%), fair in 18/38 (47.3%), and poor in 6/38 (15.7%). There were no differences in the postoperative cyst volume with respect to either the type of first surgery or overall surgery type. Higher absolute postoperative IHC reduction was observed in subjects who underwent both IHC fenestration and shunting procedures (P < .0001). No differences in neurological outcome were found according to patient age at surgery or degree of IHC reduction.

CONCLUSION

Endoscopic fenestration and shunting approaches are both effective but often require multiple procedures especially in younger patients. Larger IHC are more frequently complicated by cyst regrowth after surgery.

Surgical treatment and clinical outcome of large pediatric interhemispheric cysts with callosal agenesis: A systematic literature review with four additional patients

OBJECTIVE

Large interhemispheric cysts (IHC) with partial or complete agenesis of corpus callosum (ACC) constitute a heterogeneous group of rare disorders. Neurosurgical treatment, in the terms of if, when and how to operate, remains unclear METHODS: We performed a surgical literature review of series or reports of IHCs with callosal anomalies; we evaluated whether revision surgeries were necessary and considered the dimensional change in the cyst postoperatively and the developmental outcome. We also reported our experience with sfour patients treated by programmable cysto-peritoneal (CP) shunting. Patients' clinical history, neuroradiological and neuropsychological performances were evaluated pre and post operatively.

RESULTS

The review included 133 patients with surgically-treated IHCs. Although most authors are in agreement to perform surgery if the patients present signs of raised ICP and to not intervene in those completely asymptomatic, for other signs and symptoms the debate is still open; only few authors performed cognitive tests pre and post-operatively. Shunting procedures were successful in 60% of our reviewed cases and often lead to a major cyst collapse. Craniotomy achieves good results but is extremely invasive. Endoscopy is minimally invasive and our review demonstrated a success rate of 66%. However, endoscopy does not ensue a complete cyst collapse. Our series and review seem to suggest a possible link between parenchymal re-expansion and cognitive outcome.

CONCLUSIONS

Early and effective surgery seems to obtain a greater cerebral parenchyma re-expansion and long-term cognitive evolution. Endoscopy is safe and reliable, but more data is needed on the impact of uncomplete cyst collapse on neurocognitive outcome.

Neuroendoscopic surgery in children: does age at intervention influence safety and efficacy? A single-center experience

OBJECTIVE The aim of this study was to review the safety of pediatric intraventricular endoscopy across separate age groups and to determine whether intraventricular endoscopy is associated with an increased risk of complications or reduced efficacy in infants younger than 1 year. METHODS In this retrospective cohort study, 286 pediatric patients younger than 17 years underwent intraventricular endoscopy at Great Ormond Street Hospital between December 2005 and December 2014. The primary diagnosis, procedure, and complications were recorded. RESULTS Neuroendoscopic surgery was performed in 286 pediatric patients (51 neonates 0-6 months [Group 1]; 37 infants 6-12 months [Group 2]; 75 patients 1-5 years [Group 3]; 54 patients 5-10 years [Group 4]; and 69 patients ≥ 10 years [Group 5]; male/female ratio 173:113). The most common procedures included endoscopic third ventriculostomy (ETV) in 159 patients and endoscopic fenestration of intracranial cysts in 64 patients. A total of 348 consecutive neuroendoscopic procedures were undertaken. Nine different complications were identified, of which postoperative seizures (1.7%), CSF leak (3.1%), CSF infection (2.4%), and intracranial hemorrhage (1.7%) were the most common. Specifically, no significant difference in complication rate (11.9%) or infection rate (2.4%) was observed among age groups (p = 0.40 and p = 0.91, respectively). In addition, there were no perioperative deaths; 30-day mortality was 1.1%. After neuroendoscopy for CSF diversion (n = 227), a significantly higher rate of shunt insertion was observed in the youngest group (Group 1, 63.0%) when compared with older groups (Group 2, 46.4%; Group 3, 26.3%; Group 4, 38.6%; and Group 5, 30.8%; p = 0.03). Similarly, for patients who underwent ETV as their initial neuroendoscopic procedure or in combination with additional surgical interventions (n = 171), a significantly higher rate of shunt insertion was also observed within young infants (Group 1, 67.9%; Group 2, 47.6%; Group 3, 19.6%; Group 4, 27.3%; and Group 5, 23.3%; p = 0.003). CONCLUSIONS Intraventricular endoscopy is a safe neurosurgical intervention in pediatric patients of all ages, although it might be associated with increased shunt rates after endoscopic surgery, specifically ETV, in younger infants.

Pediatric interhemispheric arachnoid cyst: An institutional experience

BACKGROUND

Interhemispheric arachnoid cysts (IHACs) are a rare type of congenital arachnoid cyst accounting for <5% of all cases. The optimum surgical management of symptomatic IHAC is still controversial, and there are no clear guidelines.

MATERIALS AND METHODS

Retrospective analysis of six pediatric patients of IHAC operated from 2012 to 2015 at our institute. There was definitive sex predisposition with all patients being males. Endoscopic cystoventriculostomy, cystocisternostomy, and cystoperitoneal shunt surgeries were performed in three patients each.

RESULTS

The median age at presentation was 13 months. The most common clinical presentations were macrocrania with rapidly increasing head size, seizures, infantile spasms, and developmental delay. The mean duration of follow-up was 24.16 months (range: 3-36 months). Cyst size decreased in all the patients on follow-up imaging. Head size stabilized in all the patients. None of the patients required a second surgical procedure till the last follow-up.

CONCLUSIONS

Both endoscopic cyst fenestration and shunt surgery are safe and effective in management of IHAC.