Outcomes of shockwave lithotripsy for upper urinary-tract stones: a large-scale study at a single institution.
OBJECTIVE
We investigated the risk factors having an impact on the achievement of stone-free status and on the success rate, as well as on the likelihood of recurrence, in patients undergoing shockwave lithotripsy.


METHODS
We evaluated the characteristics and outcomes of 3023 patients (3254 renal units) with upper urinary-tract stones who underwent SWL at the Funabashi Clinic over a 13-year period. We assessed the stone-free and success rates for 2844 patients (3061 renal units) 3 months post-SWL. We also determined the recurrence rate for the 1078 patients (1139 renal units) who had achieved stone-free status at that time.


RESULTS
Overall, stone-free status was achieved in 65.1% of patients, and the success rate was 85.7%. There were significant differences in the stone-free rates depending on patient age, history of urolithiasis, and presence of pyuria before SWL, as well as the number, location, size, and composition of the stones. Stones recurred in 326 of 1139 renal units (28.6%) during a mean follow-up of 36 months. The recurrence rates were 7.5%, 24.1%, and 33.0% after 1, 3, 5 years, respectively. Multiple stones, a history of urolithiasis, and stones located in the kidney or both kidneys plus the ureter significantly influenced recurrence. Multivariate analysis demonstrated that multiple stones were most significantly related to recurrence.


CONCLUSIONS
Treatment with SWL has a low morbidity and high effectiveness. The number and location of stones and a history of urolithiasis significantly influence recurrence. Further studies of prophylactic therapy are required, especially for patients with these factors.
Abe
Taku
T
Department of Urology, Graduate School of Medicine, Chiba University, Chiba, Japan. rt968@f8.dion.ne.jp
Akakura
Koichiro
K
Kawaguchi
Makoto
M
Ueda
Takeshi
T
Ichikawa
Tomohiko
T
Ito
Haruo
H
Nozumi
Kuniyoshi
K
Suzuki
Kazuhiro
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007669:Kidney Calculi / Q000628:therapy*; D008096:Lithotripsy; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012008:Recurrence; D012307:Risk Factors; D016896:Treatment Outcome; D014463:Ultrasonography; D014514:Ureteral Calculi / Q000628:therapy*; D014551:Urinary Tract / Q000000981:diagnostic imaging; D014567:Urography