Surgical management of quadrigeminal cistern arachnoid cysts: case series and literature review

OBJECTIVE Quadrigeminal cistern arachnoid cysts (QACs) are congenital lesions that can cause pineal region compression and obstructive hydrocephalus when sufficiently large. Management of these cysts is controversial and rates of reintervention are high. Given the limited data on the management of QACs, the authors retrospectively reviewed 20 years of cases managed at their institution and performed a literature review on this topic. METHODS The authors performed a retrospective analysis of patients treated for QAC at their institution between 2001 and 2021. They also performed a literature review of studies published between 1980 and 2021 that reported at least 5 patients treated for QACs. Patient characteristics, radiographic findings, management course, and postoperative follow-up data were collected and analyzed. RESULTS A total of 12 patients treated for a QAC at the authors’ institution met the inclusion criteria for analysis. Median age was 9 months, mean cyst size was 5.1 cm, and 83% of patients had hydrocephalus. Initial treatment was endoscopic fenestration in 92% of these patients, 27% of whom had an endoscopic third ventriculostomy (ETV) performed concurrently. Reintervention was required in 42% of patients. Cases that required reintervention had a statistically significant lower median age at the initial intervention (5 months) than the cases that did not require reintervention (24.33 months; p = 0.018). There were no major complications. At a mean follow-up of 5.42 years, 83% of patients had improvement or resolution of their symptoms. A literature review revealed 7 studies that met the inclusion criteria, totaling 108 patients with a mean age of 8.8 years. Eighty-seven percent of patients had hydrocephalus at presentation. Ninety-two percent of patients were initially treated with endoscopic fenestration, 44% of whom underwent concurrent ETV. Complications occurred in 17.6% of cases, and reintervention was required in 30.6% of cases. The most frequent reason for reintervention was untreated or unresolved hydrocephalus after the initial procedure. CONCLUSIONS Endoscopic fenestration is the most common treatment for QACs. While generally safe and effective, there is a high rate of reintervention after initial treatment of QACs, which may be associated with a younger age at the first intervention. Additionally, identifying patients who require initial treatment of hydrocephalus is critically important, as the literature suggests that untreated hydrocephalus is a common cause of reintervention.

The Need for Head Space: Brachycephaly and Cerebrospinal Fluid Disorders

Brachycephalic dogs remain popular, despite the knowledge that this head conformation is associated with health problems, including airway compromise, ocular disorders, neurological disease, and other co-morbidities. There is increasing evidence that brachycephaly disrupts cerebrospinal fluid movement and absorption, predisposing ventriculomegaly, hydrocephalus, quadrigeminal cistern expansion, Chiari-like malformation, and syringomyelia. In this review, we focus on cerebrospinal fluid physiology and how this is impacted by brachycephaly, airorhynchy, and associated craniosynostosis.