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 in order to study risk factors for delayed subdural fluid collections and clinical outcomes. Methods Retrospective chart review was performed for patients undergoing ommaya reservoir placement between 2010-2019 at our institution. 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 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.