Delayed subdural fluid collections after Ommaya reservoir placement

BACKGROUND: Delayed subdural fluid collections can occur after Ommaya reservoir placement and can cause neurological symptoms and interfere with treatment. We performed a retrospective chart review to study risk factors for delayed subdural fluid collections and clinical out-comes.METHODS: Retrospective chart review was performed for patients undergoing Ommaya reservoir placement between 2010-2019 at our institu-tion.RESULTS: Out of 53 patients who had Ommaya reservoir placement during the study period, 11 developed delayed subdural fluid collections (21%). HIV infection was the only statistically significant risk factor (P=0.001, Fisher's Exact Test). Thrombocytopenia, ventricle size, use of the reservoir, and suboptimal catheter placement were not associated with development of delayed subdural fluid collections. 2 patients, both HIV positive, required surgical evacuation.CONCLUSIONS: Delayed subdural fluid collections occur in a significant minority of patients after Ommaya reservoir placement, and some patients require surgical intervention. HIV infection is associated with a higher risk of development of delayed subdural fluid collections. This patient subpopulation may benefit from closer monitoring or adjustment of management protocols.