Causes and prevention of calcium-containing renal calculi.

Kidney stones are common, and recurrences are the rule. At least 90% of patients with kidney stones probably have some identifiable metabolic risk factor. Effective prophylaxis is often available, but with the relatively low rate of recurrence, compliance with the treatment may be a problem. Studies are required to determine the cost-effectiveness of metabolic investigation and prophylactic therapy versus the possible need for repeated treatment by means of extracorporeal lithotripsy, especially in patients having a first calcium oxalate stone.     

Laser lithotripsy in the treatment of ureteral calculi.

We examined the effectiveness of laser lithotripsy with a flash-lamp-pumped tunable dye laser in the treatment of ureteral calculi that were too large for direct extraction and that could not be treated with or had not responded to extracorporeal shock-wave lithotripsy (ESWL) or forms of ureteroscopic lithotripsy other than laser lithotripsy. In 20 (74%) of the 27 patients the laser alone successfully fragmented the calculi into pieces small enough to pass spontaneously or to be easily extracted with a basket. In five (19%) laser lithotripsy was partially successful: another procedure (ESWL in three and fragment extraction with a basket in two) was needed. In two patients (7%) the stones could not be fragmented with the laser, and either ESWL or percutaneous antegrade extraction was performed. At follow-up 3 months after treatment there was no sign of stone fragments in 26 (96%) of the patients. We believe that laser lithotripsy is a safe and effective method of ureteral stone fragmentation.