MMP9 and aneurysm: Early interventional embolization for IA patients can improve their complete embolization rate and reduce serum MMP-9, NSE, and MPO levels; delayed surgery, aneurysm in posterior circulation, aneurysm neck width >4.5 mm, Fisher grade III-IV, Hunt-Hess grade III-IV, and hypertension are closely associated with poor prognosis after interventional embolization in IA patients.