For the recanalization of occluded arteries by means of plaque ablation an electrical technique, called spark erosion, has been developed. In vitro tests have shown that well-defined holes can be produced easily in fibrous, collagenous and lipid plaques, with minimal thermal side effects. As the method is not, by its nature, selective in vivo application will require an additional guidance technique to avoid arterial perforation. For this purpose, the potential use of tissue impedance as a sensing parameter has been tested. Main advantages of spark erosion are that it is a well controllable, low cost and highly effective tissue ablation technique.