Implementation of IRRAflow active irrigation in neurosurgical patients: A case series and literature overview

BACKGROUND: Active fluid management systems such as IRRAflow aim to overcome the limitations of passive external drains by enabling simultaneous automated irrigation and aspiration in a closed circuit. In acute and chronic subdural hematoma (a/cSDH), it enables active subdural irrigation, whereas in subarachnoid hemorrhage (SAH), intraventricular hemorrhage (IVH), and ventriculitis, it allows continuous ventricular CSF exchange and, when indicated, intrathecal administration of therapeutic agents. METHODS: A literature analysis identified studies reporting IRRAflow use for SAH, SDH, IVH, or ventriculitis. Additionally, a single-center retrospective series of 13 consecutive patients treated with IRRAflow was analyzed, focusing on clinical course, complications, and outcomes. RESULTS: Thirty studies comprising 345 patients were included in the literature analysis. In cSDH, clinical resolution was reported in 40 cases (90.9%), with recurrence in 3 patients (6.8%) and no reported infections or catheter obstructions. In aSDH, only 1/11 patient experienced clinical deterioration and required conversion to craniotomy. In IVH, outcomes were more variable, with complete resolution in 14/36 cases (38.9%), clinical improvement in 15/36 (41.7%), deterioration in 1/36 (2.8%), and death in 6 (16.7%). In ventriculitis, largely reported in case reports and small case series, resolution or improvement was achieved in 27/35 patients (77.1%), while mortality was 8/35 (22.9%). In aSAH, 7/23 (30.4%) patients died from complications of the hemorrhage. Vasospasm occurred in 7/23 (30.4%) patients, including two who subsequently died, while 2/23 (8.7%) required permanent shunting; both were survivors who had experienced vasospasm. No device-related complications were reported. Our institutional cohort included 6 patients with IVH, 4 with cSDH, and 3 with ventriculitis. Among the IVH cases, 3/6 patients died before discharge, 1 died during follow-up, whereas the other 2 had an mRS score of 3 and 2 at last follow-up. Among patients with cSDH, 3/4 achieved favorable functional recovery at follow-up, while 1/4 died before discharge because of complications unrelated to IRRAflow. Among the 3 patients with ventriculitis, 1 died following a complication related to urokinase infusion after adjunctive urokinase administration, whereas the remaining 2 (66.7%) achieved resolution or improvement. CONCLUSIONS: Both the institutional cohort and the literature search showed promising results for the use of IRRAflow in cSDH. Results on ventriculitis, aSAH and aSDH are still uncertain due to the small sample sizes. Regarding IVH, neither the exploratory review nor our institutional case series identified a clear clinical benefit associated with IRRAflow use. Nevertheless, the available evidence remains limited by predominantly observational, small and heterogeneous studies, precluding comparative conclusions.