Closed-Circuit Dual-Port Injector System for Fully Automated Contrast Delivery in Diagnostic Cerebral Angiography

Purpose: During diagnostic cerebral angiography, catheter navigation requires manual contrast “puff” injections, while subsequent 2D/3D runs often use automated power injectors. Using power injectors for navigation puffs has not been described. We present a closed-circuit dual-port injector system (Nemoto Press Duo Elite) that integrates both navigation puff delivery and diagnostic run injection into a single automated platform, eliminating all manual tableside contrast handling. A foot pedal interface enables operator-controlled puff timing, potentially reducing contrast waste and air embolism risk while improving single-operator ergonomics with future remote robotic implications. Materials and Methods: This retrospective comparative cohort study compared 19 consecutive patients undergoing diagnostic cerebral angiography with foot pedal-controlled puff injections (June–July 2023) to 19 historical controls using manual hand injections (May 2021). Both groups used 90% contrast concentration. Fluoroscopy time, radiation dose, contrast utilization, and safety outcomes were compared. Results: Groups were demographically matched (mean age 52.1±14.2 vs. 50.2±12.9 years; 73.7% female). All 38 procedures achieved diagnostic adequacy with no complications. The foot pedal group demonstrated significantly shorter procedure time per vessel (11.5±4.4 vs. 18.9±10.5 min/vessel, P=0.010) with no significant differences in fluoroscopy time (P=0.171), radiation dose (P=0.690), or contrast delivered (88.7±30.9 vs. 88.2±42.5 mL, P=0.966). A trend toward improved contrast efficiency was observed (23.4±9.4 vs. 27.4±10.4 mL/vessel, P=0.226). Despite undergoing significantly more 3D rotational runs (1.3±1.0 vs. 0.6±0.7, P=0.030), the foot pedal group maintained comparable safety metrics, strengthening the non-inferiority findings. Conclusion: A closed-circuit dual-port injector system integrating automated navigation puff delivery with diagnostic run injection demonstrates non-inferiority to manual injection for diagnostic cerebral angiography, with shorter procedure time per vessel (39% reduction, P=0.010), though interpretation is limited by differences in indication distribution. By eliminating manual tableside contrast handling, this approach enables precise digital contrast accounting and reduces air embolism risk, establishing a foundation for remote and robotic angiography applications.