Piezolith extracorporeal shockwave lithotripsy: the Hotel-Dieu de France experience

Pelvicalyceal stone load: a factor affecting the outcome of extracorporeal shockwave lithotripsy for renal pelvic calculi

OBJECTIVES

To determine the effect of variations in pelvicalyceal volume on the results of extracorporeal shock wave lithotripsy (ESWL) and the relationship of stone load to estimated pelvicalyceal volume in patients with renal pelvic stones.

PATIENTS AND METHODS

In all, 204 patients with renal pelvic stones were treated primarily by ESWL. Exclusion criteria were radiolucent stones, dilatation of the renal collecting system, JJ stent insertion before ESWL and an inadequate follow-up. The surface area of the stones and the renal collecting system were measured using a grid of 1 mm2 divisions. The pelvicalyceal volume was calculated as 0.6 (area)1.27. To evaluate the treatment results a pelvicalyceal stone load (PSL) index, describing the relationship of stone load to total estimated pelvicalyceal volume, was defined as stone volume/renal collecting system volume.

RESULTS

The mean (range) pelvicalyceal volume of the patients was 13.24 (4.12-28.47) mm3 and the mean PSL index was 26.2%. The cumulative success rates according to the PSL decreased from 97% to 90% with increasing PSL, but remained at > 95% in patients with a PSL index of < 50%. In all, 184 sessions were applied and the session/patient ratio increased from 1.41 to 3.0 with increasing PSL. Complications were acute pyelonephritis in three and steinstrasse in five patients.

CONCLUSION

The PSL index appears to be a more accurate and reproducible method for predicting the outcome of ESWL, and has the advantage of considering the effect of pelvicalyceal anatomy.

Treatment of staghorn calculi by percutaneous nephrolithotomy and SWL: the Hotel Dieu de France experience

To evaluate the combined approach of percutaneous nephrolithotomy (PCNL) and extracorporeal shockwave lithotripsy (SWL) in the treatment of staghorn calculi, we carried out a retrospective review of 101 patients. The stone surface area ranged from 654 to 3042 mm2 (1535 mm2 on average). During PCNL, a single access tract was used in 22 patients, a double tract in 65 patients, and a triple tract in 14 patients. A double-J stent was placed percutaneously in 62 patients. Extracorporeal lithotripsy was scheduled at the patient's convenience on an outpatient basis approximately 2 weeks after PCNL. The mean hospital stay was 4.4 days. The combined approach showed a stone-free rate of 67% on the initial evaluation, an insignificant residual fragment rate of 26%, and a residual stone rate of 7%. With a follow-up of 52 months on average, the global stone growth rate was 17%, being 4.4% only among the stone-free group and 27% among the group with insignificant residual fragments. The global transfusion rate was 10%. Percutaneous stone debulking combined with SWL on an outpatient basis is an efficient, minimally invasive treatment for staghorn renal calculi. Reducing the number of access tracts, using the flexible nephroscope liberally, and placing a double-J stent frequently after PCNL increases the stone-free rate while reducing the morbidity and hospital stay.