[Simultaneous antegrade-retrograde therapy for renal calculi].

The current guidelines recommend percutaneous nephrolithotomy (PCNL) as the first choice procedure for large stone masses. Complex stone situations, such as formed stones or large peripheral stone masses, however, often necessitate several access points and multiple stage procedures. In such cases open surgical stone removal is often used. An alternative is simultaneous antegrade-retrograde stone therapy in which PCNL is combined with flexible ureterorenoscopy (fURS). Both procedures complement each other in that fURS allows access to narrow calyces and PCNL the simple removal of buried concretions via the percutaneous shaft without excessive disintegration. Even difficult stone situations can be resolved simultaneously. Disadvantages are the high personnel and instrumental involvement (two endoscopic procedures with two endoscope towers and two operators) which is not adequately reflected in the diagnosis-related groups (DRG) remuneration system. Additionally simultaneous stone treatment is normally carried out in the supine lithotomy position so that even an experienced percutaneous surgeon is confronted with a new situation and a certain learning curve. Our own experiences and that of other working groups show, however, that the simultaneous approach represents an attractive and effective addition to minimally invasive stone therapy if the appropriate equipment and corresponding expertise are available.