In the past ten years, there have been significant advances in the diagnosis and therapy of arterial vascular disease. While long-term morbidity can only be improved by changing the patient's life-style and removing any risk factors that may be present(hypertension, hyperlipidemia, obesity, diabetesmellitus, nicotine abuse), symptomatic relief may be obtained by various procedures. Besides conservative treatment of arterial occlusive disease (physical therapy, medical treatment) and surgical vascular interventions (thromboendarterectomy, bypass procedures), balloon catheters introduced percutaneously under local anesthesia have found increased application in virtually all areas for the dilatation and recanalization of obstructive lesions in the past few years. The technique of balloon dilatation, as introduced by Griintzig as a further development of the percutaneous interventions by Dotter and Judkins, is no longer the decisive issue. The main objective of present clinical research is to de termine the proper indications and patient selection for this procedure, which has found its place between conservative treatment and surgery. The contents of this Symposium should provide some guidelines for the indi cations and postprocedural therapy for the referring physician, the angiologist, and for the radiologist and cardiologist performing the dilatation. We owe our thanks to all the specialists involved, who have provided us with the benefits of their experience. Mrs. H. Beilmann and Dr. M. Wojtowycz con tributed substantially to the preparation of the text. I would like to thank them and the staff of Springer-Verlag for their conscientious work in the interest of composition and publication quality."

The number of patients with occlusive peripheral vascular disease of the lower ex- tremities is still growing as rapidly as the number of patients with coronary heart disease and cerebrovascular disease. Due to the increase in average life expectancy during the last few decades, more patients now need surgical vascular reconstruc- tion. This actually means a demand for more centers specializing in vascular surgery and equipped with intensive care facilities, since the number of patients with cardio- vascular and bronchopulmonary complications is increasing as well. In addition, the number of patients needing repeated vascular surgery has been growing. Therefore, the search for simple procedures to recanalize the arterial lumen which could be performed under local anesthesia is no surprise. Unfortunately peripheral vascular disease is still frequently treated by amputations. In 1967, the fIrst report in German on percutaneous recanalization of arteries with thrombotic occlusions and stenoses appeared in Rontgenfortschritte. The meth- od described in this report had been published by Dotter and Judkins in 1964. Today, 10 years after their report, more data have been systematically collected on this method in Europe than in the United States, where it was developed. Possibly an explanation of this state of affairs is that nonsurgical treatment is favored more in Europe than in the United States. The scientifIcally based angiology established by Ratschow served as the foun- dation for the development of diagnostic work-up and therapy in other directions beyond the questions of operability and surgical results.