In January 1980, the First Symposium on the Measurement of Tis sue Oxygen Pressure in Patients was held in Frankfurt. After a 4-year "rest period," the organizers of the 1984 symposium, Profes sor R. Huch of Zurich and Dr. J. Hauss of Munster, together with myself, extended another invitation to come to Frankfurt to find out what had gone on in the field of oxygen pressure measurement and its application in clinical medicine. As the following presentations will show, the application of oxygen pressure measurements has been broadened considerably. Furthermore, technological advances have been made, particularly with the increased use of computers. For various reasons, including technical ones, these methods have not been adapted as widely as one would want. Although con gresses on tissue oxygen pressure have been held in the last few years, the clinical aspect of tissue P0 measurement has not been 2 dealt with in such a concentrated and comprehensive way since 1980. It therefore seemed necessary to hold such a symposium, not only for scientific reasons, but also to enable a larger group of clini cians to gain insight into the importance of the possibilities these methods offer."

In recent years the treatment of kidney stones has taken on a new dimension, thanks to modem techniques. E. Schmiedt and Ch. Chaussy revolutionized the therapy of kidney stones with their extra corporeal shockwave lithotripsy. After percutaneous fistulization of the renal cavities by ultrasonically controlled puncture became a rou tine procedure, the obvious next step was to use the same approach, after dilating the track, to carry out intrarenal operations. Dr. Knut Korth has been using this operative technique for some time now. He has gained a great deal of experience, having treated hundreds of patients who have come to him from all parts of Europe. In this book he describes the endoscopic technique which he has used in 400 cases. He does not attempt to compare and contrast his method with others, but rather describes and discusses the route he has taken. The book hence takes on a very subjective character - in the positive sense of the word. Dr. Korth believes - and emphasi zes - that puncture should be performed by the urologist himself so that the final responsibility for an operation is not divided. Our own experience in exclusively urological operations without the help of a radiologist confirm this position. Korth has developed many ideas - some in the form of instru ments - for transcutaneous operations. He describes in detail the various procedures according to the type of stone, providing nume rous examples.