OBJECTIVE

To evaluate the effect of diuresis during extracorporeal shockwave lithotripsy (ESWL) treatment of ureteric calculi. The purpose is to improve stone fragmentation and clearance rates.

MATERIALS AND METHODS

One hundred and six consecutive patients with ureteric calculi at different levels were treated by ESWL using Siemens Lithostar 2 machine. Patients have been randomized into two treatment groups. The first group was treated by standard ESWL and included 54 patients. The second group was treated by ESWL with diuresis during the ESWL session. Shock waves were given at a rate of 90 shocks/minute with energy starting from 10 up to 18 KV. During the ESWL session the patient belonging to the second group received i.v. infusion of 500 ml normal saline containing 40 mg furosemide as a diuretic. The stone fragmentation and clearance rates were the two end points for evaluation.

RESULTS

The average number of sessions per stone was 1.92 and 1.5 and the average number of shocks per stone was 6295 and 5300 for the first and second treatment groups respectively. Stone fragmentation rate was 47/54 (87%) and 50/52 (96.2%) and the stone clearance (success) rate was 47/54 (87%) and 48/52 (92.3%) for the first and the second groups respectively. Analysis of the results in relation to stone location showed that the two treatment groups were comparable for upper and middle ureteric calculi. However for distal ureteric stones, the addition of diuresis during ESWL was associated with a lower mean number of ESWL sessions and shocks per stone compared with standard ESWL: 1.38 and 4950 for ESWL with diuresis compared with 2.9 and 8544 for standard ESWL respectively. The stone fragmentation and 3-month clearance (success) rates were clearly higher: 93.8% and 87.5% respectively for ESWL with diuresis compared with 70.6% (for both fragmentation and clearance) with standard ESWL.

CONCLUSIONS

Diuresis is a useful, inexpensive and safe adjunct to ESWL of ureteric stones. It markedly improves the results of ESWL treatment of distal ureteric stones compared with standard ESWL.