Clinical comparison of extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy in treating renal calculi

Abstract

Study objective: To compare extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy for efficacy in treating renal calculi.

Design: Non-randomised multicentre cohort study with 3 month follow up and 13 month data collection period.

Setting: Lithotripter centre in London, tertiary referral hospital, and urological clinics in several secondary and tertiary care centres.

Patients: 933 of 1001 patients treated by lithotripsy at the lithotripter centre were compared with 195 treated by nephrolithotomy. Missing patients were due to incomplete collection of data. Age and sex distributions and characteristics of the stones were similar in the two treatment groups. Two patients died in the lithotripsy group. Three month follow up was achieved in about 84% of both groups (783/933 for lithotripsy; 163/195 for nephrolithotomy).

Interventions: The nephrolithotomy group had surgical nephrolithotomy alone. In the lithotripsy group 83% (774/933) had lithotripsy alone, 11% (103/933) had combined lithotripsy and nephrolithotomy, and 6% (56/933) had lithotripsy plus ureteroscopy. Single and combined lithotripter treatments were analysed as one group and compared with nephrolithotomy.

End point: Presence of stones three months after treatment.

Measurements and main results: Presence of residual stones was assessed by plain radiography, ultrasonography, or intravenous urography. After adjustment for age and size and position of stone for patients with single stones the likelihood of being free of stones three months after treatment was significantly greater in the nephrolithotomy group than the lithotripsy group (odds ratio 6.6; 95% confidence interval 3.0 to 14.6) and the response was particularly pronounced with staghorn calculi (62% (8/13) v 15% (141/96) patients free of stones after nephrolithotomy and lithotripsy, respectively). OTHER FINDINGS: 19%(146/775) of patients who had had lithotripsy had to be readmitted within three months after treatment compared with 14%(23/162) who had nephrolithotomy; and 64%(94/146) of readmissions after lithotripsy were for complications compared with 30%(7/23) of readmissions after nephrolithotomy.

Conclusions: Nephrolithotomy may be preferable to lithotripsy for treating renal stones and it may not be wise to invest heavily in lithotripsy facilities.