Effect of enoxaparin (a low molecular weight heparin) given in a single or split dose, on stroke occurrence after unruptured brain aneurysm treatment utilising coils or stents

Thromboembolic events are frequent adverse events in neurointerventional procedures such as cerebral aneurysm coiling and stenting. Ischaemic lesions are visible on MRI diffusion weighted imaging (DWI). These can be further characterised as clinically evident or clinically silent. They are clinically evident ischaemic lesions(CEIL) if a neurological deficit is present, or clinically silent ischaemic lesions (CSIL) if not. Most ischaemic strokes occur 4-12 hours post procedure. The overall incidence of DWI lesions post endovascular cerebral aneurysm treatment has been reported as 49-60% and the literature suggests that they can increase the risk of dementia and cognitive decline. To assess the efficacy of enoxaparin (a low molecular weight heparin) in prevention of thromboembolic events, patients will be randomised to receive one of two enoxaparin dose regimens post elective endovascular aneurysm treatment: (A) subcutaneous enoxaparin 1mg/kg at T=0 and T=12hrs (split dose); or (B) subcutaneous enoxaparin 1.5mg/kg (single dose) at T=0. T=0 refers to the end of the endovascular procedure. Each patient will have pre and post-procedure MRIs. The primary outcome of interest is the proportion of patients who have thromboembolic events assessed by neurological examination at 24 hours and MRI at 48hrs. Secondary outcomes include the frequency of puncture site complications and haemorrhage assessed through clinical monitoring. We hope to learn which enoxaparin dose regimen should be recommended to neurointerventionists.