Correlation between the renal resistive index (RI) and nonenhanced computed tomography in acute renal colic: how reliable is the RI in distinguishing obstruction? (1/127)

OBJECTIVE: The purpose of this study was to determine the sensitivity of renal color Doppler sonography in differentiating obstructive and nonobstructive urinary calculi in patients with acute renal colic and to compare findings with nonenhanced helical computed tomography (CT). METHODS: Sixty-five patients referred to the emergency department with acute renal colic underwent nonenhanced CT and renal resistive index (RI) measurement with color pulsed Doppler sonography within 8 to 10 hours of the onset of the symptoms. Computed tomographic evaluation was based on the detection of urolithiasis and classification according to location and the presence of obstruction. The mean RI of each kidney and the difference between the mean RI (DeltaRI) of both kidneys were calculated and compared with CT findings. RESULTS: A total of 164 stones were identified. Computed tomography revealed obstruction in 33 patients. Mean RI values for the obstructive and nonobstructive groups were 0.64 and 0.63, respectively. Mean DeltaRI values were 0.01312 and 0.01000 in the obstructive and nonobstructive groups. The differences in the mean RI and DeltaRI for the patients with and without obstruction were statistically insignificant (P = .73). No significant relationship was found between the RI values, calculus location, and degree of obstruction. CONCLUSIONS: The RI is insensitive for detection of obstruction in patients with acute renal colic, and its value in routine practice seems quite controversial.  (+info)

Development of a urinary lithiasis localizer mechanism to couple ultrasound and extracorporeal lithotripsy equipment in canine model. (2/127)

INTRODUCTION: Due to the evolution of extracorporeal lithotripsy equipment (ESWL) and presently, the fact that most part of the equipment does not present ultrasound to localize urinary calculi, a system that allows adapting ultrasound equipment to ESWL equipment was developed, disposing only of fluoroscopy. Thus, this equipment was developed and was tested in urinary stones in canine models, to check its precision in relation to fluoroscopy. METHOD: Seven male dogs were utilized with the introduction, in the bladder through the ureteral route, of chalkstones, with initial localization by fluoroscopy, with a further ultrasound coincidence check localization of the vesical stones, being submitted to ESWL with a 3-hour, 21 days and 60 days follow-up after the procedure. RESULTS: Success of localization in all animals was verified presenting elimination of stones in the first micturitions, after ESWL. No complications were verified in those animals for 60 days. CONCLUSION: We verified that this equipment can lead to an update of the equipment that use only fluoroscopy, increasing in this way, their technical capacity in the treatment of urinary calculi, mainly in cases of non-radiopaque stones.  (+info)

Prevalence of urolithiasis in rural Thebes, Greece. (3/127)

INTRODUCTION: Worldwide, urolithiasis is the third most common urological disease affecting both males and females. Both genetic and environmental factors contribute to stone formation. The recurrence rate is approximately 50%, rising to 70% within 10 years and this condition represents a significant healthcare cost burden. An unusually frequent history of urolithiasis has been observed among patients from the rural area of Thebes, Viotia, Greece. OBJECTIVE: To determine the prevalence of urolithiasis in Thebes. METHODS: A representative sample of persons from the rural area of Thebes was questioned about the occurrence of urinary stones during their lifetime, and acute urolithiasis in 2005. A logistic regression model was used to contrast individuals with lithiasis to those without lithiasis. RESULTS: A total of 422 subjects participated in the study. We found a 15% prevalence of urolithiasis in the rural population of Thebes. The rate was slightly higher in men than in women in almost all age groups questioned, although this was not statistically significant. No case of urolithiasis was found in subjects under the age of 17 years. The prevalence of urolithiasis appeared to increase with age in both men and women. Those drinking bottled water were less likely to have lithiasis. CONCLUSION: The life time prevalence rate of urolithiasis observed in the rural area of Thebes was higher to that reported in other studies performed among males and females in the general population of Europe.  (+info)

Urothelial carcinogenesis in the urinary bladder of male rats treated with muraglitazar, a PPAR alpha/gamma agonist: Evidence for urolithiasis as the inciting event in the mode of action. (4/127)

Muraglitazar, a PPARalpha/gamma agonist, dose-dependently increased urinary bladder tumors in male Harlan Sprague-Dawley (HSD) rats administered 5, 30, or 50 mg/kg/day for up to 2 years. To determine the mode of tumor development, male HSD rats were treated daily for up to 21 months at doses of 0, 1, or 50 mg/kg while being fed either a normal or 1% NH4Cl-acidified diet. Muraglitazar-associated, time-dependent changes in urine composition, urothelial mitogenesis and apoptosis, and urothelial morphology were assessed. In control and treated rats fed a normal diet, urine pH was generally > or = 6.5, which facilitates formation of calcium-and magnesium-containing solids, particularly in the presence of other prolithogenic changes in rat urine. Urinary citrate, an inhibitor of lithogenesis, and soluble calcium concentrations were dose dependently decreased in association with increased calcium phosphate precipitate, crystals and/or microcalculi; magnesium ammonium phosphate crystals and aggregates; and calcium oxalate-containing thin, rod-like crystals. Morphologically, sustained urothelial cytotoxicity and proliferation with a ventral bladder predilection were noted in treated rats by month 1 and urinary carcinomas with a similar distribution occurred by month 9. Urothelial apoptotic rates were unaffected by muraglitazar treatment or diet. In muraglitazar-treated rats fed an acidified diet, urine pH was invariably < 6.5, which inhibited formation of calcium-and magnesium-containing solids. Moreover, dietary acidification prevented the urothelial cytotoxic, proliferative, and tumorigenic responses. Collectively, these data support an indirect pharmacologic mode of urinary bladder tumor development involving alterations in urine composition that predispose to urolithiasis and associated decreases in urine-soluble calcium concentrations.  (+info)

Urolithiasis associated with bilateral pelvic diverticula: a case report. (5/127)

We present a case of renal stone associated with bilateral pelvic diverticula. The initial diagnosis by ultrasonography and plain abdomen radiography (KUB) was urolithiasis with a 15-mm calculus in the right renal pelvis. The patient was referred for extracorporeal shock wave lithotripsy, but no stone fragments were yielded. So, further evaluations were performed by using repeated ultrasonography, intravenous urography, and computerized tomography, which revealed the presence of diverticula in both right and left renal pelvises with stone fragments within the right sided diverticulum. We concluded that intravenous urography and contrast-enhanced computerized tomography are essential for confirmation of diagnosis when ultrasonographic findings suggest the presence of renal cystic lesions, or when stone fragments are not yielded after extracorporeal shock wave lithotripsy.  (+info)

Prediction of unexpected emergency room visit after extracorporeal shock wave lithotripsy for urolithiasis - an application of artificial neural network in hospital information system. (6/127)

Extracorporeal shock wave lithotripsy (ESWL) for urolithiasis was developed for more than 30 years. It benefited most patients suffering from acute renal colic. The ESWL may be performed at outpatient based in most hospital in Taiwan. But the post-ESWL emergency room (ER) visits will be a painful experience for patient and the urologist,especially those patients visited ER immediately on the same day of ESWL. Though most guidelines for ESWL suggest the larger stone burden, the higher risk for post-ESWL ER visits,there are about 10% patients will come back to ER due to renal colic post-operatively. We use artificial neural network(ANN) to predict the post-ESWL ER visit for patient with urolithiasis. The result disclosed high sensitivity and specificity of prediction. In conclusion, it will decrease the rate of post-ER visit rate and patients' suffer by using ANN to predict the post-ESWL ER visits.  (+info)

Anesthesia for extracorporeal shockwave lithotripsy: Teikyo University Hospital experience using the third generation lithotripter. (7/127)

A single-board certified urologist with training and experience in anesthesiology was assigned to treat 502 patients (185 with renal stones, 317 with ureteral stones) using the Dornier Compact Delta lithotripter under general or epidural anesthesia. Data were obtained regarding stone location, stone size, shockwave use, stone-free rate, and complications. In all, 502 stones were treated with the Dornier Compact Delta lithotripter. Among renal stones, 73% were in the renal pelvis. Among ureteral stones, 60% were in the upper, 10% in the middle, and 30% in the lower ureter. Diameters of 61.8% of stones were less than 1 cm. The mean number of shocks was 3,471 at a mean power setting of 5. The stone-free rate for renal stones was 71.5%, while for ureteral stones this reached 99%. The efficiency quotient was calculated as 0.65. One patient with a renal stone developed perinephric hematoma requiring 3 units of transfusion. With a success rate higher than that reported for other lithotripters, the Dornier Compact Delta lithotripter represents a feasible treatment for urolithiasis. We stress that even in the third generation machines the lithotripsy under anesthesia can improve the treatment efficacy.  (+info)

Urolithiasis in HIV-positive patients treated with atazanavir. (8/127)

Among protease inhibitors, atazanavir has not been associated with urolithiasis in clinical studies. We describe 11 cases of atazanavir-associated urolithiasis in patients with human immunodeficiency virus (HIV) infection. Patients with low water intake, high urinary pH, and a prior history of urinary stones may have a higher risk of atazanavir-associated urine crystallization.  (+info)