Evaluation of the recurrent stone former.

For frequent stone formers, and even for some first-time stone formers interested in preventing future episodes of renal colic, a metabolic evaluation is necessary. The urologist, rather than members of other medical specialties, seems to have the primary responsibility of the medical management of stone disease. Thus, it is essential for the urologist to have a good working knowledge of the principles of metabolic evaluation and kidney stone prevention.

Does a slower treatment rate impact the efficacy of extracorporeal shock wave lithotripsy for solitary kidney or ureteral stones?

Purpose: We compared the efficacy of an SR (70 to 80 shocks per minute) and an FR (120 shocks per minute) for ESWL for solitary stones less than 2 cm located in the kidney or proximal ureter.

Materials And Methods: A total of 349 patients with a solitary, radiopaque kidney or ureteral stone underwent ESWL on a DoLi(R) 50 lithotriptor. Patients were grouped based on stone size, stone location and whether SR or FR treatment was performed.

Oxalate toxicity in cultured mouse inner medullary collecting duct cells.

Purpose: Oxalate, a metabolic end product and a major constituent of the majority of renal stones, has been shown to be toxic to renal epithelial cells of cortical origin. However, to our knowledge it is unknown whether inner medullary collecting duct (IMCD) cells, which are physiologically exposed to higher concentrations of oxalate, also behave in a similar manner.

Materials And Methods: A line of IMCD cells was exposed to oxalate (0.

Metabolic abnormalities and the medical management of calcium oxalate nephrolithiasis.

The lifetime prevalence of urolithiasis is approximately 12% for men and 7% for women in the United States and seems to be increasing; the cost of managing kidney stones continues to escalate. The most common kidney stones continue to be composed primarily of calcium and are an admixture of phosphate and oxalate. Of these, calcium oxalate stones are the most predominant.

Gender Differences among Hispanics and Caucasians in symptomatic presentation of kidney and ureteral stones.

Purpose: We determined gender differences in the symptomatic presentation of kidney and ureteral stones among the Hispanic population and compared it with presentation in the Caucasian population.

Patients And Methods: A retrospective chart review was performed on 443 patients seen in our Emergency Department or Urgent Care Center for symptomatic kidney or ureteral stones over a 5-year period. Demographic information was obtained, including sex, race, age, location of stone, stone size, and type of urologic intervention.

Is stone radiodensity a useful parameter for predicting outcome of extracorporeal shockwave lithotripsy for stones < or = 2 cm?

Purpose: Several factors determine the success of extracorporeal shockwave lithotripsy (SWL) for kidney stones: stone size, stone location within the collecting system, stone type, and the SWL machine used. It has been suggested that stone radiodensity, as determined either by plain radiography or computed tomography attenuation values, may be an independent predictor of SWL success. We examined the outcome of SWL for solitary stones less than or equal to 2 cm located within the renal pelvis, based on their radiodensity.

Effects of oxalate on IMCD cells: a line of mouse inner medullary collecting duct cells.

Oxalate, a metabolic end product and a major constituent of the majority of renal stones, has been shown to be toxic to renal epithelial cells of cortical origin. However, it is unknown whether inner medullary collecting duct (IMCD) cells that are physiologically exposed to higher concentrations of oxalate also behave in a similar manner. In the present study, we examined the effects of oxalate on IMCD cells.

The urinary response to an oral oxalate load in recurrent calcium stone formers.

Purpose: Dietary oxalate may contribute up to 50% to 80% of the oxalate excreted in urine. We studied the urinary response to an oral oxalate load in male and female idiopathic recurrent calcium oxalate stone formers with and without mild hyperoxaluria to evaluate the potential pathophysiological significance of dietary oxalate.

Materials And Methods: A total of 60 recurrent calcium stone formers underwent an oral oxalate load test.

Hyperuricosuric calcium nephrolithiasis.

Since the findings of Yü and Gutman [1], the hyperuricosuric calcium stone former is a unique clinical entity. While an impressive number of clinical and epidemiologic studies implicate hyperuricosuria in calcium stone formation, the exact physicochemical mechanism by which uric acid affects calcium oxalate crystallization has not been proven. Allopurinol decreases stone recurrences and is the drug of choice for patients with isolated HCN.

Is lower pole caliceal anatomy predictive of extracorporeal shock wave lithotripsy success for primary lower pole kidney stones?

Purpose: The management of lower pole kidney stones is controversial. We examined whether lower pole caliceal anatomy could predict the success of extracorporeal shock wave lithotripsy of primary lower pole kidney stones 20 mm. or less.

When is medical prophylaxis cost-effective for recurrent calcium stones?

Purpose: Medical management is generally recommended for recurrent calcium stones to prevent future episodes. However, in this era of extracorporeal shock wave lithotripsy and outpatient ureteroscopy it is not known whether medical prophylaxis is more cost-effective than treatment of recurrent stone episodes. The cost of medical prophylaxis was compared with the cost of clinically managing recurrent stone episodes, and the stone recurrence rate without prophylaxis (stone frequency) at which these 2 treatment approaches became cost equivalent was determined.

Comparison of intravenous sedation versus general anesthesia on the efficacy of the Doli 50 lithotriptor.

Purpose: We compared the impact of intravenous sedation versus general anesthesia on the efficacy of extracorporeal shock wave lithotripsy.

Materials And Methods: From November 1997 to May 1998, 295 patients with a single renal or upper ureteral radioopaque stone of less than 2 cm. were treated with the Doli 50 lithotriptor (Dornier Medical Systems, Marietta, Georgia).

A randomized outcomes trial of ureteral stents for extracorporeal shock wave lithotripsy of solitary kidney or proximal ureteral stones.

Purpose: Routine use of ureteral stents before extracorporeal shock wave lithotripsy of kidney stones between 10 and 20 mm. is controversial. We conducted a prospective randomized clinical trial to evaluate the outcome of ureteral stents for treating solitary kidney stones between 10 and 20 mm.

Economics of urolithiasis: cost-effectiveness of therapies.

The cost of treating urolithiasis with extracorporeal shockwave lithotripsy and endoscopic surgery continues to be a significant burden on a nation's healthcare economy. Cost-effectiveness evaluations of various medical and surgical treatment options for urolithiasis is a practical method of developing rational allocation strategies for limited economic resources. In this review, the cost-effectiveness of shockwave lithotripsy and that of endoscopic surgery in the management of kidney and ureteral stones are compared.

10-year experience with extracorporeal shockwave lithotripsy in the state of Colorado.

Purpose: To evaluate trends in the utilization of extracorporeal shockwave lithotripsy (SWL) and the potential need for medical prophylaxis of urolithaisis in the state of Colorado.

Materials And Methods: We examined patient and stone characteristics of individuals undergoing SWL for renal or upper-ureteral stones over a 10-year period (1987-1996) at the Kidney Stone Center of the Rocky Mountains. There were no significant changes in the in-state physician referral patterns nor SWL treatment criteria over this time interval.

Transport of oxalate across the rabbit papillary surface epithelium.

Purpose: The renal papilla and pelvic recesses of the mammalian kidney are thought to be the anatomical sites of initial kidney stone formation. We studied oxalate transport across the renal papillary surface epithelium.

Materials And Methods: In vitro oxalate transport across the papillary surface epithelium was studied by dissecting it off of the papilla and mounting it in a modified Ussing chamber.

Anatomic and metabolic risk factors for nephrolithiasis in patients with autosomal dominant polycystic kidney disease.

The prevalence of nephrolithiasis is considerably greater in patients with autosomal dominant polycystic kidney disease (ADPKD) than in the general population. We evaluated anatomic and metabolic factors that may be associated with an increased prevalence of nephrolithiasis in patients with ADPKD. We compared anatomic parameters among ADPKD patients with or without nephrolithiasis as diagnosed by ultrasonography, whereas metabolic factors were determined by 24-hour urinary chemical analysis.

Role of the renal collecting system in initial kidney stone formation.

Background: The anatomic site where the initial kidney stone grows to a clinically significant size is unknown.

Methods And Materials: We studied human forniceal anatomy by microdissection and correlated the anatomic findings with the clinical presentation of kidney stones. In addition, we examined crystal attachment sites within the collecting system by direct infusion of calcium oxalate crystals into the renal pelvis of rabbits.

Role of sex hormones in experimental calcium oxalate nephrolithiasis.

It is unclear why men have a higher incidence of calcium oxalate nephrolithiasis than women. This study examined the role of sex hormones on urinary oxalate excretion and kidney stone formation in an experimental model of urolithiasis. Adult male and female Sprague Dawley rats with different sex hormone modulations were given 0.

Examination of crystalluria in freshly voided urines of recurrent calcium stone formers and normal individuals using a new filter technique.

Purpose: We evaluated calcium oxalate (CaOx) and calcium phosphate (CaP) crystalluria in freshly voided urines of normal individuals (controls) and recurrent calcium stone formers (RSF) using a new filter technique.

Materials And Methods: Chemical analysis of urinary sediment retained by a 0.45 microm.

Comparison of comprehensive and limited metabolic evaluations in the treatment of patients with recurrent calcium urolithiasis.

Purpose: We compared diagnostic information from limited and comprehensive metabolic evaluations of recurrent calcium stone formers.

Materials And Methods: A total of 74 men and 45 women with recurrent calcium stones underwent comprehensive metabolic evaluation. The number of specific and total metabolic abnormalities diagnosed on 1 or 2 random 24-hour urinalyses were compared to those obtained on a comprehensive metabolic evaluation.

Cost-effectiveness analysis: application to endourology.

A literature review was conducted on the application of economic analysis to clinical medicine, particularly urology. The surgical management of urolithiasis and the treatment of ureteropelvic junction obstruction were used as specific disease examples to evaluate how cost-effectiveness analysis has been used to address the clinical concerns of practicing urologists. As the costs and outcomes of the treatment of kidney stone disease and ureteropelvic junction obstruction can be specifically defined, the application of cost-effectiveness analysis in these two areas meets most standards of economic analysis.