In this work we propose an autonomous dual-arm system for needle insertion and central venous access. The system is composed of two Franka robotic arms that are precisely co-registered and collaborate to achieve accurate needle insertion by combining ultrasound and bioimpedance sensing to ensure robust deep vessels visualization and venipuncture detection. The proposed system performance is evaluated on a phantom trainer through experiments simulating the jugular vein access for cardiac catheterization purposes. Quantitative results show the system is able to localize the vein and perform autonomous needle insertion with high accuracy and placement error below 1.7mm, proving the potential of the technology for real clinical use.