Urokinase cisternal irrigation therapy for prevention of symptomatic vasospasm after aneurysmal subarachnoid hemorrhage: a study of urokinase concentration and the fibrinolytic system.

BACKGROUND AND PURPOSE Cisternal irrigation therapy with urokinase (UK) was performed in multiple institutions to prevent symptomatic vasospasm. The efficacy and safety of this therapy were evaluated, and the optimal concentration of UK was estimated. METHODS This therapy was performed in 28 patients who underwent surgery within 72 hours of the onset of severe subarachnoid hemorrhage (Fisher's group 3, CT number [Hounsfield units] >60). After the aneurysm was clipped, irrigation tubes were placed in the Sylvian fissure (inlet) unilaterally and in the prepontine or chiasmatic cistern (outlet). Lactated Ringer's solution with UK (30, 60, or 120 IU/mL) was infused at a rate of 30 mL/h. The presence of symptomatic vasospasm was evaluated by changes in the clinical symptoms and the presence of a new low-density area on CT scan. Drained irrigation fluid and peripheral blood were examined chronologically to evaluate the fibrinolytic system. RESULTS Symptomatic vasospasm was observed transiently in 3 cases (10.7%) without any low-density area on CT scan. In the 120-IU/mL group, no symptomatic vasospasm occurred. Analysis of drainage fluid suggested that UK 120 IU/mL is effective. The mean values of total drained blood volume for the respective groups were as follows: 58 mL in 30 IU/mL, 106 mL in 60 IU/mL, and 143 mL in 120 IU/mL. No abnormal changes were observed in the coagulative and fibrinolytic systems after UK irrigation. CONCLUSIONS These results suggest that cisternal irrigation therapy with UK is safe and effective for the prevention of symptomatic vasospasm after aneurysmal subarachnoid hemorrhage.