Objective: The intra-arterial infusion of papaverine has been used for dilation of spastic cerebral vessels after aneurysmal subarachnoid hemorrhage, although its efficacy is controversial. Milrinone is an inotropic drug that dilates vessels by phosphodiesterase inhibition in a mechanism similar to that of papaverine. We examined the effects of intra-arterial and subsequent intravenous administration of milrinone on patients with symptomatic cerebral vasospasm.
Methods: Seven patients with cerebral vasospasm were enrolled in this study. Milrinone was delivered intra-arterially via catheter at a rate of 0.25 mg/min. The total delivered dose was between 2.5 and 15 mg. Radiological measurement of the middle cerebral artery diameter and cerebral blood flow was carried out before and after arterial infusion. Intravenous treatment followed at 0.50 or 0.75 microg/kg/min for up to 2 weeks from the onset of subarachnoid hemorrhage.
Results: Dilation of the vasospastic vessels occurred in all patients. The rate of cerebral blood flow was calculated in six patients and was increased in all. Subsequent intravenous infusion was effective in preventing a recurrence of symptomatic vasospasm in four of the seven patients.
Conclusion: It is suggested that milrinone was effective and safe for the treatment of cerebral vasospasm after subarachnoid hemorrhage in the patients in this series. Intra-arterial infusion with adjunctive intravenous infusion holds promise as a clinically advantageous treatment regimen.