Management of post-aneurysmal rupture vasospasm with intra-arterial nimodipine and milrinone therapy: a single-center study of 50 patients

Abstract Background Among the secondary complications of aneurysmal subarachnoid hemorrhage (aSAH), cerebral vasospasm stands as the leading contributor to delayed neurological deterioration, disability, and death. Angiographic evidence of vasospasm is detected in approximately 40–70% of affected individuals, with clinically symptomatic episodes occurring in 17–40%. Although systemic nimodipine administration and hemodynamic optimization form the mainstay of current treatment, a notable subset of patients exhibits vasospasm that proves resistant to these conventional approaches, thereby necessitating targeted endovascular rescue. The therapeutic potential of simultaneously delivering intra-arterial (IA) nimodipine and milrinone—a dual vasodilatory strategy exploiting complementary pharmacological pathways—has yet to be comprehensively evaluated. Objective To evaluate the safety and efficacy of combined IA nimodipine and milrinone infusion in patients with angiographic vasospasm refractory to maximal medical therapy following aSAH. Methods This retrospective, single-center study analyzed 50 consecutive patients with angiographically confirmed cerebral vasospasm following aSAH over a 3-year period (2022–2025). All patients underwent aneurysm securing (clipping or coiling) followed by combined IA nimodipine and milrinone infusion for refractory vasospasm. A total of 108 therapeutic digital subtraction angiography (DSA) sessions were performed. Primary outcomes included angiographic response and functional outcome assessed by the modified Rankin Scale (mRS) at discharge. Post-treatment outcomes were compared with published series using similar dual-agent approaches. Results Angiographic benefit was observed in 47 of 50 patients (94%). Immediate clinical improvement was noted in 18 patients (36%). A good functional outcome (mRS 0–2) was achieved in 41 patients (82%) at discharge. Among the 50 patients, 18 required three treatment sessions, 15 required two sessions, and 17 underwent a single session. The treatment mix included 20 patients (40%) treated with microsurgical clipping and 30 patients (60%) with endovascular coiling. No drug-related mortality was observed. Conclusions Concurrent IA delivery of nimodipine and milrinone constitutes a well-tolerated and efficacious endovascular rescue strategy for medically refractory post-aSAH vasospasm, producing angiographic reversal in 94% and discharge functional independence in 82% of treated patients. These findings are comparable to or better than existing single-agent and dual-agent series. Prospective multicenter trials are needed to confirm these observations and to establish an optimized treatment protocol.