The use of Ventricular Assist Devices (VAD) is increasing in the context of refractory heart failure. Nevertheless, there is still a high rate of complications. This preliminary work analyzes more precisely the clinical needs and proposes a first solution for preoperative planning of device implantation. The proposed approach consists in representing within a common space the 3D mesh describing the device and the patient CT image, in order to interactively simulate the device positioning and detect collisions between the VAD and different kinds of surrounding anatomical structures (bones and right ventricle). CT scans from 3 adult patients who have previously received a VAD, were used for the experiments. We analyzed the influence of mesh precision on computation time and accuracy of collision detection. Results show that the proposed approach is compatible with fast and interactive simulation of virtual device positioning, in order to preoperatively plan its implantation. Such a solution could also facilitate the decision-making about the choice of the device taking into consideration the feasibility of implantation.