Comparative study of long-term stone recurrence after extracorporeal shock wave lithotripsy and open stone surgery for kidney stones.

Abstract

Extracorporeal shock wave lithotripsy (ESWL) has become the treatment of choice for most calculi of upper urinary tract and the need for open stone surgery (OSS) have considerably reduced. However, stone recurrence is often encountered as a long-term problem requiring re-treatment. In the present retrospective study, the recurrence rates of ESWL and OSS were compared in the treatment of kidney calculi. During the 1 year period of the present study, 43 patients were treated by OSS and 400 underwent ESWL (the Dornier MPL 9000 lithotriptor). The recurrence of stone was defined as reappearance of the stone on plain abdominal radiography during the follow-up period. Complete removal of all stone fragments was achieved in 51.2% of patients (n = 22) treated with OSS. In the ESWL group, the stone free rate was 56.7% (n = 237). The recurrence rate was 31.8% within a mean of 40 months (range 32-48 months) in the OSS group, whereas this figure was 13.9%, with a mean period of 46 months (range 42-48 months) in the ESWL group (P < 0.05). The mean periods of recurrence in ESWL and OSS groups were 20 (range 6-42 months) and 11 months (range 8-44 months), respectively (P < 0.05). However, the mean stone burdens of both groups were different (2.9 +/- 0.8 vs 1.4 +/- 1.1 cm). For comparable stone burdens, the recurrence rate was similar. In the ESWL group, stones in the lower calyx, multiple stones and larger stones showed a higher recurrence rate. The recurrence after OSS was also influenced by stone burden. The results of the present study demonstrate that stone burden may be the primary risk factor for stone recurrence after ESWL and OSS.