Treatment of stone street after extracorporeal shock wave lithotripsy of staghorn calculi

Abstract

During ESWL monotherapy for staghorn calculi, the formation of a stone street in the ureter is often encountered, and can be a troublesome problem. At the Komaki Shimin Hospital, 75 patients with staghorn calculi were treated with ESWL monotherapy using a Dornier HM-3 lithotriptor between October 1987 and August 1992. Among them, three patients had involvement of both collecting systems. An indwelling double J catheter was always inserted during treatment. Our strategy for the treatment of stone street was as follows; observation was initially performed for one month after ESWL, as long as pyelonephritis and/or complete obstruction did not occur. In the patients without any improvement of the stone street, TUL or ESWL was then performed for removal. A stone street (stone fragments extending > or = 4 cm) was formed in 38 of 78 renal units (49%). In 14 cases (37%), it disappeared spontaneously. TUL was required in 14 unit (37%), ESWL in eight units (21%), and both procedures in two units (5%). In one unit (3%), renal function was severely damaged. In another unit, ureteric perforation occurred during the TUL procedure, and caused stone loss outside the ureter. To clarify the factors causing stone street, we compared the number of shock waves, the size of the stones, the severity of hydronephrosis and renal function in stone street formers and non-formers. However there were no significant differences among these factors. In conclusion, since it is impossible to predict stone street formation after ESWL monotherapy for staghorn calculi, patency of the indwelling double J catheter should be maintained and stone removal should be attempted after one month if necessary.