 Introduction of ultrasound guidance made it possible to guide the needle directly to the vascular wall. But this procedure is considered very demanding, because of guiding the needle in an anatomical region with artifacts because of calcification, sudden movements e.g. because of swallowing and compromised coagulation antithrombotic medication. On the other side there are no clinical data proving the benefit of an additional perivascular infiltration with local anesthetic. Therefore, this investigation is testing the hypothesis, that an additional perivascular infiltration is associated with increased block quality. 