Enhancing cerebrospinal fluid clearance in subarachnoid hemorrhage: A systematic review of combined ventricular and lumbar drainage

Introduction: Aneurysmal subarachnoid hemorrhage (aSAH) is a severe type of stroke associated with high rates of mortality and morbidity. Two major complications following aSAH are acute hydrocephalus and delayed cerebral ischemia (DCI) caused by severe vasospasm. While external ventricular drainage and lumbar drainage (LD) are typically used separately to manage hydrocephalus, the potential benefit of their combined use in reducing vasospasm risk remains underexplored. Methods: We conducted a systematic search on PubMed/MEDLINE and Scopus databases to identify relevant studies discussing double drainage systems in patients with severe aSAH-hydrocephalus. The search algorithm retrieved 1341 results. At the end of the exclusion phase, we included 4 studies in the final analysis. Results: We included 148 patients with post-aSAH hydrocephalus treated using dual CSF drainage. Treatment was reported in about 2/3 of patients and endovascular repair was in most of them. LD was typically placed early, though timing protocols varied. Drainage was maintained on average 0.5-16 days, with continuous drainage being most common. Complication rates varied: ischemia was reported in 18.9 % of patients, while vasospasm occurred in 22.3 % of cases when assessed clinically or angiographically. CSF infection was reported in up to 31.6 % of cases. Functional outcomes were generally favorable, with mean mRS scores at follow-up ranging from 1.0 to 2.4, depending on initial clinical severity. Conclusion: Patients with aSAH may benefit of dual CSF drainage, especially in case of massive bleeding. Preliminary data suggest that it may reduce vasospasm and improve outcomes by enhancing CSF clearance. However, the evidence is still limited by study variability and lack of direct comparisons. Until more data emerge, dual drainage should be reserved for high-risk patients.