Treating total occlusions: Applying force for recanalization

Goal: The aim of this review was to analyze and review the state of the art devices for the endovascular treatment of chronic and acute total occlusions in the different vascular beds (coronary, peripheral, carotid, and intracranial arteries) based on the forces exerted on the occlusion during treatment. Methods: The literature search was executed in the databases of Scopus and Espacenet. Overall, 120 patents and 49 articles have been reviewed and categorized. Results: The identified treatment tools were divided into three treatment modalities: compression, resection, and conversion. A further subdivision was made based on the force direction, i.e., axial, radial, tangential, or energy conversion process (dissolving or state change). Conclusion: The working principles of the identified treatment tools relate strongly to the (biomechanical) properties of the occlusion and environment. In order to increase procedural success, especially in chronic occlusions, the applied force should be increased by applying buckling prevention methods, the penetration force decreased by smart tip design or dynamic loading, and the energy dissipation to the environment minimized. Significance: Insight in the working principles of the treatment tools and their effect on the environment can in future aid designers to overcome current challenges and develop new, innovative treatment tools.