Extracorporeal shock wave lithotripsy for the treatment of renal stones. Treatment policy is as important for success as type of lithotriptor and patient selection

Extracorporeal shock-wave lithotripsy or ureteroscopy as primary treatment for ureteric stones: a retrospective study comparing two different treatment strategies

OBJECTIVE

Our extracorporeal shock-wave lithotripsy (ESWL) lithotripter with ultrasound localization technique was replaced in 1999 by a Storz SLX-MX lithotripter with both X-ray and ultrasound detection possibilities. Before replacing our lithotripter, most ureteric stones were treated with ureteroscopy (URS); subsequently, almost all patients underwent ESWL as primary treatment. The aim of this retrospective study was to compare the results of these two treatment strategies in all consecutive patients attending our hospital in 1998 and 2000 for ureteric stone treatment.

MATERIAL AND METHODS

The medical records of all patients treated for ureteric stones in 1998 and 2000 were reviewed. In 1998, 173 ureteric stones were treated. Primary treatment was URS in 124 patients, push back/ESWL in 24, ESWL in 21 and open surgery in four. In 2000, 176 ureteric stones were treated: 158 with ESWL and 18 with URS. ESWL or URS monotherapy was defined as ESWL or URS, respectively as the only stone-treatment therapy, with or without the use of a ureteric catheter or nephrostomy tube. Treatment success was defined as a stone-free ureter.

RESULTS

In 1998, the success rate for URS monotherapy was 95%, with a retreatment rate (sessions per stone situation) of 1.06. Corresponding figures for ESWL monotherapy in 2000 were 90% and 1.69. All URS patients received general anaesthesia; ESWL patients received opiods. Complication rates were 6% for URS and 3% for ESWL. In the URS group, 4/8 complications were considered to be major.

CONCLUSION

ESWL should be considered the first-line treatment for ureteric stones because of its non-invasive nature, lack of a requirement for general anaesthesia and low complication rates.

Shockwave lithotripsy: dose-related effects on renal structure, hemodynamics, and tubular function

BACKGROUND AND PURPOSE

Shockwave lithotripsy (SWL) predictably damages renal tissue and transiently reduces function in both kidneys. This study characterized the effects on renal function of a supraclinical dose of shockwaves (SWs) (8000) in porcine kidneys and tested the hypothesis that such excessive treatment would intensify and prolong the resulting renal impairment.

MATERIALS AND METHODS

Pigs aged 6 to 7 weeks were anesthetized and assigned to one of three groups. Groups 1 (N=8) and 2 (N=6) each received 8000 SWs at 24 kV (Dornier HM3) to the lower-pole calix of one kidney. Group 3 (7 pigs) received sham treatment. Renal function was monitored for the first 4 hours after SW treatment in Group 1 and for 24 hours in Group 2. Plasma renin activity was measured in Groups 2 and 3.

RESULTS

The renal lesions produced by 8000 SWs comprised 13.8%+/-1.4% of the renal mass. In the 4-hour protocol, this injury was associated with marked reduction of the glomerular filtration rate (GFR), renal plasma flow (RPF), and urinary sodium excretion in both kidneys, although fractional sodium excretion was reduced only in the shocked kidneys. In the 24-hour protocol, GFR and RPF remained below baseline in shocked kidneys at 24 hours. Evidence of progressive ischemic injury was noted in shocked tissue at 24 hours after SW treatment.

CONCLUSIONS

These findings support the hypothesis that the severity of the renal injury caused by SWL is related to the number of SWs administered and demonstrate the connection in this relation between renal structure and function.

Estimating the effectiveness of various methods of evacuation of kidney stones, on the basis of data obtained on percentage of "stone free" and recurrent stone formation

Using the materials of more than 200 scientific papers of recent years in this review it has been carried out analysis of the effectiveness and also discussed the merits and demerits of various methods of treatment of urinary stone diseases (USD). With this purpose, for the first time it has been carried out analysis of treatment quality of USD using more important quantitative parameters of treatment efficacy: 1--percentage of "stone free"; 2--percentage of recurrent stone formation. It has been emphasized on the higher effectiveness of treatment in combination of the method of ESWL with the methods of ascending litholysis. It was shown that in order to solve problems such as etiology and pathogenesis of the disease, elaboration of quantitative risk factors of the disease, and search for effective measures on pro- and metaphylaxis of USD, and also elaboration of various (including therapeutics) medium and methods for complete and rapid evacuation of stones, it is needed to carry out intensively fundamental and applied researches in the field of urinary stone diseases.