Is Demonstration of ICH Stability by Repeated Cerebral Imaging Useful Enough to Start DVT Chemoprophylaxis After 24–48 Hours?

Background/Objectives: Venous thromboembolism (VTE) is a common and potentially preventable complication after hemorrhagic stroke, yet the optimal timing of pharmacologic prophylaxis remains uncertain because of concern for hematoma expansion or rebleeding. Repeat neuroimaging is frequently used to assess hemorrhage stability before initiating deep vein thrombosis (DVT) chemoprophylaxis, although the value of radiographic stability alone remains unclear. This review evaluates the evidence supporting imaging-guided initiation of prophylaxis after intracerebral hemorrhage (ICH) and aneurysmal subarachnoid hemorrhage (aSAH). Methods: A narrative review of the literature was performed focusing on hemorrhage expansion, thrombotic risk, repeat neuroimaging, and timing of pharmacologic prophylaxis in spontaneous ICH and aSAH. Observational studies, limited randomized data, and current guideline recommendations were assessed. Results: In spontaneous ICH, hematoma expansion risk is greatest within the first 24 h, whereas thrombotic risk increases over subsequent days because of immobility and systemic inflammation. Available evidence suggests that early low-dose anticoagulant prophylaxis may be safe in selected patients with stable hemorrhage, although definitions of stability vary and no prospective study has validated repeat imaging as an independent decision trigger. In aSAH, rebleeding risk depends more heavily on aneurysm securement and procedural factors than on imaging appearance alone. Conclusions: Repeat neuroimaging provides important reassurance after hemorrhagic stroke but does not fully capture ongoing biological risks. Current evidence supports a cautious, individualized approach in which radiographic stability informs, but does not independently determine, the timing of pharmacologic VTE prophylaxis.