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PubMed1994

Treatment of 150 ureteric calculi with the Lithoclast.

From May 1992 to October 1993, 150 ureteral stones, impervious to piezoelectric extracorporeal shock wave lithotripsy (ESWL) with ultrasound localization (EDAP LT.01), were treated with the Lithoclast. The maximum dimensions varied from 5 to 25 mm with a mean of 11 mm. 46 calculi were situated in the pelvic ureter, 82 in the abdominal ureter, and 22 were stuck in the ureteropelvic junction. There was no complete failure of fragmentation, but 39 abdominal calculi (48%) required additional treatment by ESWL due to migration of the fragments into the calyces. Apart from a few needle-sized perforations, ureteral tissue was not damaged by the Lithoclast. The use of this endoscopic lithotripter, which is highly efficient and painless, is, however, limited by the significant effect of retrograde propulsion of very mobile stones or fragments in the urinary tract.

Adolescent↗

PubMed1977

The presence of protein-bound gamma-carboxyglutamic acid in calcium-containing renal calculi.

The amino acid gamma-carboxyglutamic acid (Gla) is found in four blood-clotting proteins, in a bone protein, in kidney protein, and in the protein present in various ectopic calcifications. This paper reports the presence of Gla in the EDTA-soluble, nondialyzable proteins of calcium-containing renal calculi including calcium oxalate, hydroxyapatite, and mixed stores of apatite and struvite (MgNH4PO4). Calculi composed of pure struvite and those composed of only uric acid or cystine do not contain Gla. From calcium oxalate and hydroxyapatite stontes, a protein of about 17,000 daltons was obtained which contained about 40 residues of Gla per 1,000 amino acids. The amino acid composition of this protein had no apparent relationship to the Gla-containing bone protein or to the similarly-sized F1 fragment of prothrombin which contains about 64 residues of Gla per 1,000 amino acid residues. The Gla-rich protein in calcium-containing renal stones thus may be a different Gla-containing protein. These data as well as other studies demonstrating the presence of Gla in pathologically calcified tissues not normally containing Gla suggest that the Gla-containing proteins may be of considerable pathophysiological significance.

Adult↗

PubMed1984

Bacteriological and crystallographical analysis of urinary calculi: aid to patient management.

In an analysis, by both crystallographic and microbiological methods, of 50 urinary calculi recently removed by surgical operation, 33 proved to be of metabolic origin (mostly calcium oxalate and some uric acid or urate) and 17 of 'infective' origin (struvite, apatite or a mixture of the two). Metabolic stones were usually bacteriologically sterile or contained only small numbers (less than 10(3)/g of stone) of bacteria which did not produce urease, while infective stones always contained urease-producing organisms, usually Proteus mirabilis, in large numbers (greater than 10(5)/g). The combined approach of stone analysis by crystallography and microbiological culture yields more information than conventional techniques on which to base the treatment of urinary calculi and the prevention of their recurrence.

Adolescent↗

PubMed2004

Nondestructive analysis of urinary calculi using micro computed tomography.

BACKGROUND: Micro computed tomography (micro CT) has been shown to provide exceptionally high quality imaging of the fine structural detail within urinary calculi. We tested the idea that micro CT might also be used to identify the mineral composition of urinary stones non-destructively. METHODS: Micro CT x-ray attenuation values were measured for mineral that was positively identified by infrared microspectroscopy (FT-IR). To do this, human urinary stones were sectioned with a diamond wire saw. The cut surface was explored by FT-IR and regions of pure mineral were evaluated by micro CT to correlate x-ray attenuation values with mineral content. Additionally, intact stones were imaged with micro CT to visualize internal morphology and map the distribution of specific mineral components in 3-D. RESULTS: Micro CT images taken just beneath the cut surface of urinary stones showed excellent resolution of structural detail that could be correlated with structure visible in the optical image mode of FT-IR. Regions of pure mineral were not difficult to find by FT-IR for most stones and such regions could be localized on micro CT images of the cut surface. This was not true, however, for two brushite stones tested; in these, brushite was closely intermixed with calcium oxalate. Micro CT x-ray attenuation values were collected for six minerals that could be found in regions that appeared to be pure, including uric acid (3515 - 4995 micro CT attenuation units, AU), struvite (7242 - 7969 AU), cystine (8619 - 9921 AU), calcium oxalate dihydrate (13815 - 15797 AU), calcium oxalate monohydrate (16297 - 18449 AU), and hydroxyapatite (21144 - 23121 AU). These AU values did not overlap. Analysis of intact stones showed excellent resolution of structural detail and could discriminate multiple mineral types within heterogeneous stones. CONCLUSIONS: Micro CT gives excellent structural detail of urinary stones, and these results demonstrate the feasibility of identifying and localizing most of the common mineral types found in urinary calculi using laboratory CT.

Calcium Phosphates↗

PubMed2005

New chemolysis for urological calcium phosphate calculi - a study in vitro.

BACKGROUND: Advances in techniques have left very few indications for open surgical extraction of urinary stones currently. These advances notwithstanding, the search continues for medical approaches to urinary stone management. In this study, we perform an in vitro study analyzing the efficiency and prospect of two new complex solutions in urological calcium phosphate calculi dissolution. METHODS: Eighteen stones composed mainly of calcium phosphates were taken from patients who underwent kidney stone surgery. These stones were large enough (weight range 0.514-0.928 g) to be fragmented and matched equally into six groups. Chemolysis of phosphate stones was done with six different solvents and was repeated 3 times with 6 stones for each solution. At 24, 48 and 72 h, reduction in weight, percentage weight change, and dissolution rate; the dissolution rates at pH 5.0, 7.0 and 8.5 for each solution, using different cations (Na+, K+ or Ca2+), according to different dilutions (1:1, 1:2, 1:3, 1:4) of S1 and S2 were simultaneously determined. RESULTS: Calcium phosphate calculi were poorly dissolved by Phys and Art, and they had a low dissolution rate in pH 8.5 EDTA. The most effective solutions were S1, S2 and R, with 72 h mean dissolution rates: 5.75 +/- 0.44 mg/hr (S1), 5.2 +/- 0.63 mg/hr (S2), 4.55 +/- 0.46 mg/hr (R) (x +/- s, p < 0.01 R, S1 and S2 vs Phys, Art and EDTA; p < 0.05, S1 vs R, LSD-test). The mean percentage weight loss at 72 h was: 52.1 +/- 15.75 % (S1), 44.4 +/- 7.37 % (S2) and 40.5 +/- 3.67 % (R) ( x +/- s, p < 0.01 R, S1 and S2 vs Phys, Art and EDTA, LSD-test). Diluted twice, S1 and S2 had even better effectiveness than their initial solution. The additive of Na+, K+ or Ca2+ greatly reduced the dissolution rates of S1, S2. CONCLUSION: Our data indicate that test solutions S1 and S2 are effective solvents in the chemolysis of calcium phosphate stones. At twice dilutions, these solutions are even more useful in the treatment of stone disease.

Calcium Phosphates↗

PubMed1980

Calyceal calculi simulating gallstones.

Multiple faceted stones can develop in any sacular structure. Five cases of renal stones are described, four cases with calculi in calyceal diverticuli and one case with calculi in a hydronephrotic sac. Emphasis is on the remarkably similar radiographic appearance these cases of renal stones have with gallstones.

Adult↗

PubMed1980

Cystine calculi are radiopaque.

Cystine calculi are said to be either radiolucent or radiopaque. In the past, contamination of the calculi with calcium has been given as the reason for a radiopaque appearance. However, most cystine stones are pure cystine and contain essentially no calcium. When compared to adjacent fluids and tissues, they are radiopaque because of their higher physical density and their higher effective atomic number.

Cystinuria↗

PubMed1984

Detection of renal calculi: the value of tomography.

Two hundred patients were evaluated to determine the sensitivity of tomography in detecting calculous disease of the upper urinary tract. In all cases, patients had routine scout radiographs of the abdomen and five precontrast tomograms of the kidneys. Of the 200 patients, 28 (14%) had renal calculi. Of these, 11 (39%) had either unsuspected or more calculi detected on tomography than seen on abdominal radiographs. Patients with symptoms suggestive of calculous disease should be evaluated with tomography in addition to plain films in order to optimize the detection and the extent of calculous disease involving the urinary tract.

Evaluation Studies as Topic↗

PubMed1986

Distal ureteral calculi: diagnosis by transrectal sonography.

Eight patients were studied by both transrectal sonography and excretory urography for the presence of distal ureteral calculi. The sonographic diagnosis was correct in 5 of 5 true positives and 3 of 3 true negatives. Urography was correct in 4 of 5 true positives and 2 of 3 true negatives. None of the sonograms and two of the urograms were considered equivocal. Transrectal sonography appears to be a useful adjunct for the diagnosis of distal ureteral calculi when excretory urography is equivocal or contraindicated.

Adult↗

PubMed1998

Characterization of urinary calculi: in vitro study of "twinkling artifact" revealed by color-flow sonography.

OBJECTIVE: The "twinkling artifact" is a color-flow sonographic artifact described behind calcifications and presenting as a random color encoding in the region where shadowing would be expected on gray-scale images. Our purpose was to study the relationship between this twinkling artifact seen behind urinary stones on color-flow sonography and the morphology or biochemical composition of these urinary stones. MATERIALS AND METHODS: Forty-seven urinary stones were studied in vitro with color-flow sonography. Transmit frequency, color gain, velocity range, color filters, focal depth, and depth of field were changed during scanning. The twinkling artifact was graded 0 when absent, 1 when present but occupying a portion of acoustic shadowing, and 2 when occupying the entire acoustic shadowing. Stones were studied under a binocular magnifying glass to characterize the surface, and infrared spectrophotometry was used to determine the chemical composition. RESULTS: Calculi of calcium oxalate dihydrate and calcium phosphate always produced a grade 1 or grade 2 twinkling artifact. Absence of artifact was noted only for calcium oxalate monohydrate and urate stones. In 100% of grade 0 calcium oxalate stones, the monohydrate compound was predominant (>93%). In 100% of grade 2 calcium oxalate stones, the dihydrate compound was predominant (>75%). For calcium oxalate stones, the surface pattern was correlated with their composition. Sensitivity and specificity for absence of artifact, as indicative of calcium oxalate monohydrate, were 60% and 83%, respectively, for all stones and 56% and 100%, respectively, only for radiopaque stones. CONCLUSION: An in vitro relationship exists between the twinkling artifact and the morphology of urinary stones. Color-flow sonography could play a role in detecting dense calcium oxalate monohydrate calculi, which in turn may help predict fragmentability.

Artifacts↗

PubMed2000

Helical CT of urinary calculi: effect of stone composition, stone size, and scan collimation.

OBJECTIVE: Helical CT has become the preferred methodology for identifying urinary calculi. However, the ability to predict stone composition, which influences patient treatment, depends on the accurate measurement of the radiographic attenuation of stones. We studied the effects of stone composition, stone size, and scan collimation width on the measurement of attenuation in vitro. MATERIALS AND METHODS: One hundred twenty-seven human urinary calculi of known composition and size were scanned at 120 kVp, 240 mA, and a 1:1 pitch at different collimations. A model, based on the physics of helical CT, was used to predict the effect of scan collimation width and stone size on measured attenuation. RESULTS: At a 1-mm collimation, stone groups could be differentiated by attenuation: the attenuation of uric acid was less than that of cystine or struvite, which overlapped; these were less than the attenuation of calcium oxalate monohydrate, which was in turn lower than that of brushite and hydroxyapatite, which overlapped and showed the highest values. At a wider collimation, attenuation was lower and the ability to differentiate stone composition was lost. Attenuation also decreased with smaller stones. At a 10-mm collimation, some uric acid stones (<approximately 6 mm) and other stones (< approximately 4 mm) had very low attenuation, so low that they could remain undetected on helical CT. The model predicted well the degree that attenuation was affected by stone size and collimation width. CONCLUSION: Stone composition and stone size, relative to CT collimation, independently influenced CT attenuation. The effect of stone size and collimation generally conformed to the model's predictions. We determined that small stones with low attenuation can be overlooked on helical CT.

Humans↗

PubMed2001

Failure of holmium:yttrium-aluminum-garnet laser lithotripsy in two horses with calculi in the urinary bladder.

Holmium:yttrium-aluminum-garnet (Ho:YAG) laser lithotripsy was attempted in a mare and a gelding with calculi in the urinary bladder. The procedure was unsuccessful in producing adequate fragmentation of the calculi. In the gelding, pulsed dye laser lithotripsy was subsequently used to fragment the urolith. Manual removal of the urolith via the urethra was performed in the mare.

Animals↗

PubMed1990

The role of hyperoxaluria in the formation of calcium oxalate urinary calculi, and its association with other biochemical measurements.

The part played by hyperoxaluria in the formation of calcium oxalate urinary calculi was studied in 153 patients who had each been diagnosed as having calcium oxalate urinary calculi on one or more occasions. Seventy-seven of the patients excreted normal amounts of calcium (less than 6.2 mmol/d), and 76 had hypercalciuria (excretion greater than or equal to 6.2 mmol/d); each group was divided into a further two groups depending on whether the oxalate concentration was above or below 0.16 mmol/l. Pure calcium oxalate stones were more common in patients whose calcium excretion was normal, and mixed calcium oxalate and phosphate stones were more common among hypercalciuric patients. Urinary concentrations/day of magnesium, citrate, and phosphorus were significantly lower in the two groups in which the oxalate concentrations were below 0.16 mmol/l than in a normal control group, and magnesium and phosphorus were significantly lower in the two groups in which oxalate concentrations were less than 0.16 mmol/l than in the two in which they were above that value. The concentration of citrate was also lower, but not significantly so. In addition, the pH of the urine in patients with mixed stones was significantly higher in all groups than when the stones were composed of pure calcium oxalate.

Calcium Oxalate↗

PubMed1997

Prevalence of autoantibodies associated with glomerulonephritis, unaffected after extracorporeal shock wave lithotripsy for renal calculi, in a three-year follow-up.

Extracorporeal shock wave lithotripsy (ESWL) has become a useful tool in the treatment of renal calculi, but side effects may occur. Hitherto, two case reports have been published of an anti-glomerular basement membrane disease resulting in end-stage renal failure following ESWL treatment. In this prospective study of 59 consecutive patients undergoing ESWL for renal calculi, the prevalence of autoantibodies associated with glomerulonephritis was investigated before ESWL and at 3-year follow-up. The prevalences of antinuclear, anti-glomerular basement membrane, anti-neutrophil cytoplasmic and thyroid antibodies were found to be within the respective normal ranges prior to the first ESWL treatment and to be unaffected at follow-up.

Adult↗

PubMedDate not supplied

Ultrasonic parameters of renal calculi and gall bladder stones as a function of density.

In this investigation, ultrasonic parameters of complex renal calculi and gall bladder stones, in vitro are measured using a double-probe contact by pulse-echo technique. Due to the variation in the chemical composition of the stones, a large variation in the value of ultrasonic parameters is found. A correlation between ultrasonic parameters and various renal calculi and gall bladder stone pathologies are also discussed. The ultrasonic parameters are found to vary as a function of density of the specimen used.

Cholelithiasis↗

PubMed1986

Urinary calculi: microbiological and crystallographic studies.

Although referred to as "urinary calculus disease", the formation of stone in the urinary tract is not caused by a single etiological agent. As such, diverse clinical investigations to diagnose the cause of stone formation must be carried out and the course of management after diagnosis must inevitably be different in each case. This review will cover all aspects of calculus formation, but will give particular attention to calculi caused by infection of the urinary tract with urease-producing bacteria. This is a recurrent, potentially life-threatening disease which has led clinicians to refer to the condition as "stone cancer". Because the etiology of infection stones is so different from stones caused by metabolic disorders, the two disease patterns should be considered separately, a fact often overlooked in epidemiological studies of stone formation. The importance of analysis of calculi as an aid to management is thus emphasized; identification of stone type will help to indicate appropriate therapy. A review of methods of analysis will be covered, particularly crystallographic analysis. Inhibition of bacterial urease as a means of management of infection stones will be discussed together with problems encountered and brighter hopes for the future.

Anti-Bacterial Agents↗

PubMed1991

[Extracorporeal shock wave lithotripsy monotherapy in the treatment of staghorn calculi].

From October, 1987 to September, 1989, 53 staghorn calculi of 51 patients underwent extracorporeal shock wave lithotripsy (ESWL) monotherapy by using Dornier HM3 lithotriptor. All patients were treated with double J stenting preoperatively. Mean number of shock waves was 6092 and mean number of sessions was 2.1. In 52 out of 53 kidneys (98%), the stones were disintegrated completely. Complete removal of the stone were observed in 29 kidneys (55%) 3 months after the last ESWL treatment. Complications consisted of fever attack (more than 38 degrees C) (26 patients), ileus (2), subcapsular hematoma (2) and gastrointestinal hemorrhage (1). They could be conservatively treated except one case with percutaneous nephrostomy. Supplementary procedures for the stone street were necessary in 23 patients. They consisted of ESWL (16 patients) and transuretheral lithotripsy (7). The indication of this procedure for the treatment of staghorn calculi was also discussed.

Adult↗

PubMed1994

[Prognostic factors influencing the growth of renal calculi].

Factors influencing the growth of renal calculi were examined. In order to calculate the volume of stone on X-ray film, stones obtained from open operation or spontaneous passage were measured long (a) and short (b) diameter, and equation to obtain stone volume was assumed. Stone volume = 0.43 (pi ab (a + b))/12 + 0.04 was the mostly related to the volume measured by water volume, when size was less than 2 cm in diameter. Using the equation, factors influencing the growth of renal calculi of 136 kidney, which were followed over 6 months, were studied with monovariate analysis. Of the 136 kidneys, 36 have calcium oxalete stones, 54 have mixed stones with calcium oxalate and calcium phosphate, 3 have mixed stones with calcium oxalate and uric acid, and other 43 have stones with unknown composition. Uric acid stones, cystine stones and infectious stones were excluded in the study. Growth of stone was greater in male than in female. Pelvic stones grew rapidly than renal caliceal stones. The patients were divided into two groups by growth rate; non growing (< 10%/year), and growing group (> 10%/year), respectively. Excretion of urinary calcium was high in the growing group. Urinary magnesium/calcium was low in the growing group. When divided into two groups by growth volume; non growing (< 0.005 cm3/year), and growing group (> 0.005 cm3/year), respectively, excretion of urinary calcium was high in the growing group and urinary magnesium/calcium was low in the growing group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗