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Background Endovascular treatment of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) relies on intra-arterial vasodilator delivery, yet the method of drug administration has remained unchanged for decades: manual hand-syringe injection with inherent variability in infusion rate, no objective volume documentation, and repeated syringe disconnections that risk air entrainment. The Nemoto Press Duo Elite is an FDA-approved dual-head power injector with programmable infusion capabilities. We describe a novel repurposing of this system for combined contrast administration and controlled intra-arterial vasodilator delivery during vasospasm treatment, and report the first clinical experience with this approach.Methods We performed a single-center retrospective review of consecutive patients treated for symptomatic cerebral vasospasm following aneurysmal SAH between September 2022 and July 2025. Nine patients (12 treatment sessions) were treated using the Nemoto injector and compared with 17 patients (19 sessions) receiving conventional manual syringe injection. The Nemoto system was configured with contrast in the A-side and a triple vasodilator cocktail (verapamil 50 mg, nicardipine 10 mg, nitroglycerin 1000 mcg in 125 mL heparinized saline) in the B-side, enabling programmable infusion at precise flow rates (0.1 mL/sec increments) through a closed sterile circuit. The procedural workflow cycled between A-side contrast delivery for diagnostic runs and B-side vasodilator infusion without syringe exchanges. We compared vasodilator regimens, procedural metrics, angiographic response, and complications.Results Groups were comparable in age (55.4±10.8 vs 58.2±10.7 years, p=0.829), sex (55.6% vs 70.6% female, p=0.667), and clinical severity as measured by Hunt-Hess and Modified Fisher grades. The Nemoto group presented with more severe vasospasm (66.7% severe vs 33.3%, p=0.125) and treated more arterial territories per session (2.2±0.7 vs 1.6±0.8, p=0.059). Adjunctive balloon angioplasty was performed in 41.7% of Nemoto sessions versus 15.8% of manual sessions.All 12 Nemoto sessions utilized the triple vasodilator cocktail (p<0.001 vs manual), while no manual sessions included nicardipine. Mean verapamil doses were comparable between groups (23.8±21.1 vs 22.9±32.9 mg, p=0.614). Procedural metrics did not differ significantly: fluoroscopy time (28.1±21.4 vs 42.2±32.4 min, p=0.283), radiation dose (1103.5±1055.9 vs 1956.9±1698.5 mGy, p=0.320), contrast volume (95.8±32.6 vs 114.7±39.4 mL, p=0.215), and total case time (135.6±57.9 vs 133.4±55.9 min, p=0.823).The Nemoto group achieved angiographic improvement in all 12 treated sessions (25.0% significant, 16.7% moderate, 58.3% mild) despite most involving severe vasospasm. In the manual group, 92.3% of evaluable sessions showed improvement (p=0.354). No complications related to vasodilator delivery occurred in any Nemoto session. Three manual sessions (15.8%) had complications, though all were related to the initial aneurysm treatment rather than vasodilator delivery. In-hospital mortality was numerically lower in the Nemoto group (11.1% vs 23.5%).Conclusion Repurposing the Nemoto dual-head power injector for intra-arterial vasodilator delivery during vasospasm treatment is feasible and safe, without increasing procedural time, radiation, or contrast burden. The closed-system architecture eliminates tableside syringe exchanges and facilitates routine use of a triple vasodilator cocktail with precise, programmable infusion parameters and digital volume documentation. This approach addresses longstanding limitations of manual injection including rate variability, lack of dose documentation, and air entrainment risk, while enabling standardized multi-agent protocols for multi-center adoption.Disclosures O. Gandhi: None. S. Almasri: None. N. Gaston: None. M. Rashad: None. S. Dumasia: None. N. Yu: None. W. Ahmed: None. J. Kim: None. G. Lanzino: None. L. Bagley: None. O. Choudhri: 2; C; Nemoto Kyorindo Co., Ltd.