Indications, prediction of success and methods to improve outcome of shock wave lithotripsy of renal and upper ureteral calculi.

OBJECTIVES

To clarify the current indications, factors influencing outcome and methods to predict and improve the results of shock wave lithotripsy for the treatment of renal and upper ureteral calculi.

MATERIAL AND METHODS

English literature on the Medline and MeSH databases was reviewed. Key words used for search included shock wave lithotripsy, calculi, stones, renal, kidney, ureter, efficacy, prediction, improvement and guidelines.

RESULTS

Shock wave lithotripsy still has certain indications for renal and upper ureteral stones. Major impact on outcome has the stone size, with a diameter of less than 20 mm being the cutoff point. Shock wave monotherapy should not be used for larger stones and should be combined with other treatment modalities such as percutaneous nephrolithotomy or ureteroscopy. Other factors influencing outcome include stone number, composition and location, existence of congenital abnormalities, obesity and bleeding diathesis. Nomograms, artificial neural networks and computed tomography are useful adjuncts in predicting the outcome. Potential methods of improvement are the decrease of shock wave rate, the progressive increase in lithotripter output, the use of two simultaneous or sequential pulses and the use of expulsive and chemolytic treatment.

CONCLUSION

Shock wave lithotripsy continues to be a significant part in the urologists armamentarium for the treatment of renal and upper ureteral stones.