© Springer International Publishing AG 2016. Endovascular procedures are challenging to perform due to the complexity and difficulty in catheter manipulation. The simultaneous recovery of the 3D structure of the vasculature and the catheter position and orientation intra-operatively is necessary in catheter control and navigation. State-of-art Simultaneous Catheter and Environment Modelling provides robust and real-time 3D vessel reconstruction based on real-time intravascular ultrasound (IVUS) imaging and electromagnetic (EM) sensing,but still relies on accurate registration between EM and pre-operative data. In this paper,a registration-free vessel reconstruction method is proposed for endovascular navigation. In the optimisation framework,the EM-CT registration is estimated and updated intra-operatively together with the 3D vessel reconstruction from IVUS,EM and pre-operative data,and thus does not require explicit registration. The proposed algorithm can also deal with global (patient) motion and periodic deformation caused by cardiac motion. Phantom and invivo experiments validate the accuracy of the algorithm and the results demonstrate the potential clinical value of the technique.