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PubMed2002

Simple classification of renal calculi closely related to their micromorphology and etiology.

BACKGROUND: Classification of renal calculi with clear correlation with the main urinary etiological conditions has been previously established. However, such information is complex and difficult to adapt to clinical routine practice. METHODS: A simple classification of renal calculi based on their structure and composition is proposed and applied to 2500 renal calculi to achieve the percentage of each category. The urines of 700 individuals chosen randomly have been analyzed and the results compared with those obtained with 51 healthy subjects. RESULTS: 12.9% calculi corresponded to calcium oxalate monohydrate papillary calculi, 16.4% to calcium oxalate monohydrate unattached calculi, 33.8% to calcium oxalate dihydrate calculi, 11.2% calcium oxalate dihydrate/hydroxyapatite mixed calculi, 7.1% hydroxyapatite calculi, 4.1% struvite calculi, 0.6% brushite calculi, 8.2% uric acid calculi, 2.6% calcium oxalate/uric acid mixed calculi, 1.1% cystine calculi and 1.9% various infrequent calculi. Based on the corresponding urinary analytical studies, each kind of calculus is related with the more frequently associated urinary alterations. CONCLUSIONS: An important aspect of this classification is the possibility to establish, by means of the correct study of the calculus, some of the main possible etiologic factors closely related to its formation.

Calcium Oxalate↗
PubMed2006

Role of uric acid in different types of calcium oxalate renal calculi.

AIM: The presence of uric acid in the beginning zone of different types of 'pure' calcium oxalate renal calculi was evaluated with the aim of establishing the degree of participation of uric acid crystals in the formation of such calculi. METHODS: The core or fragment of different types of 'pure' calcium oxalate renal calculi was detached, pulverized and uric acid extracted. Uric acid was determined using a high-performance liquid chromatography/mass spectrometry method. RESULTS: In calcium oxalate monohydrate (COM) papillary calculi with a core constituted by COM crystals and organic matter, 0.030+/-0.007% uric acid was found in the core. In COM papillary calculi with a core constituted by hydroxyapatite, 0.031+/-0.008% uric acid was found in the core. In COM unattached calculi (formed in renal cavities) with the core mainly formed by COM crystals and organic matter, 0.24+/-0.09% uric acid was found in the core. In COM unattached calculi with the core formed by uric acid identifiable by scanning electron microscopy (SEM) coupled to X-ray microanalysis, 20.8+/-7.8% uric acid was found in the core. In calcium oxalate dihydrate (COD) unattached calculi containing little amounts of organic matter, 0.012+/-0.004% uric acid was found. In COD unattached calculi containing little amounts of organic matter and hydroxyapatite, 0.0030+/-0.0004% of uric acid was found. CONCLUSIONS: From these results it can be deduced that uric acid can play an important role as inducer (heterogeneous nucleant) of COM unattached calculi with the core formed by uric acid identifiable by SEM coupled to X-ray microanalysis (these calculi constitute the 1.2% of all calculi) and in COM unattached calculi with the core mainly formed by COM crystals and organic matter (these calculi constitute the 10.8% of all calculi).

Calcium Oxalate↗
PubMed2002

US for detecting renal calculi with nonenhanced CT as a reference standard.

PURPOSE: To determine the sensitivity and specificity of ultrasonography (US) for detecting parenchymal and renal pelvis calculi and to establish the accuracy of US for determining the size and number of calculi. MATERIALS AND METHODS: A total of 123 US and computed tomographic (CT) examinations were compared retrospectively for the presence of renal calculi. The sensitivity of US was determined for individual calculi and at least one calculus per examination. Retrospective findings were compared with the original US interpretation. The sizes of calculi in longest axis were compared on US and CT images, and the US detection of calculi in the left and right kidneys was compared. The use of US for detecting the full extent of calculus burden was evaluated in patients with multiple calculi. RESULTS: US depicted 24 of 101 calculi identified at CT, yielding a sensitivity of 24% and a specificity of 90%. There was no substantial difference for the detection of calculi in the right and left kidneys. The sensitivity of US for any calculi in a patient was 44%, equal to that of the original US interpretation. US enabled identification of 39% of patients with multiple calculi and demonstrated all calculi in 17% of these patients. The mean size of calculi detected with US was 7.1 mm +/- 1.2 (95% CI); 73% of calculi not visualized at US were less than 3.0 mm in size. Calculus size based on US and CT measurements was concordant in 79% of cases and differed by a mean of 1.5 mm +/- 0.7. CONCLUSION: US is of limited value for detecting renal calculi.

Adolescent↗
PubMedDate not supplied

Renal calculi in dogs and cats: prevalence, mineral type, breed, age, and gender interrelationships (1981-1993).

Three hundred seventeen specimens of urinary calculi of renal origin from 214 female dogs and 103 male dogs, and 71 specimens of urinary calculi of renal origin from 38 female cats and 33 male cats were submitted for mineral analysis between July 1, 1981, and December 31, 1993. Among dogs, 45 breeds were affected with renal calculi. Thirty-three breeds and a crossbred group were represented among females, but 8 breeds and the crossbred group accounted for 81% of the total. Among male dogs, 30 breeds and a crossbred group were represented, but 7 breeds and the crossbred group accounted for 69% of the total. Among cats, 10 breeds and a crossbred group were represented. Dogs and cats with renal calculi were older than those of 2 comparison population groups. More than one-half of the renal calculi in both dogs and cats were from the 1st known episode of urolithiasis. The risk of formation of renal calculi was found to be higher for cats than for dogs, when compared to other stone-forming cats and dogs (approximately 4.95 per 100 stone-forming cats and 2.88 per 100 stone-forming dogs). Among dogs, breeds at highest risk of developing renal calculi were Miniature Schnauzers, Shih Tzus, Lhasa Aposos, Yorkshire Terriers, and female Pugs. Also at high risk were male Dalmatians and male Basset Hounds. Among small dogs, females generally were at higher risk of developing renal calculi than were males. Regardless of size, terrier breed males generally were at higher risk of developing renal calculi. Breeds of dogs at low risk for development of renal calculi included crossbreds. German Shepherd Dogs, Labrador Retrievers, Golden Retrievers, and female Dachshunds. When only 1 kidney was involved, the risk of left renal calculus was greatest for both dogs and cats, but bilateral renal involvement was relatively common in both species (19% and 9%, respectively). Among dogs, specimens composed of 1 mineral substance (e.g., struvite) occurred more often in males (58.3%) than in females (37.9%). Female dogs formed renal calculi containing struvite or oxalate more often than did males; males formed calculi containing urate more often than did females. Calculi containing oxalate, apatite, or some combination of these minerals predominated among cats; only 1 specimen from 38 female cats and only 4 specimens from 33 male cats contained neither oxalate nor apatite. Crossbred cats were significantly less likely to have renal calculi than were other breeds. A single renal calculus specimen was identified in several uncommon breeds including Tonkinese and Birman cats, and Affenpinscher, Clumber Spaniel, English Shepherd, and Field Spaniel dogs. No significant differences were observed between male and female dogs or between male and female cats with regard to mineral type of the specimen and the presence of urinary tract infection.

Age Distribution↗
PubMed2004

Drug-induced renal calculi: epidemiology, prevention and management.

Drug-induced calculi represent 1-2% of all renal calculi. The drugs reported to produce calculi formation may be divided into two groups. The first one includes poorly soluble drugs with high urine excretion that favours crystallisation in the urine. Among poorly soluble molecules, triamterene was the leading cause of drug-containing urinary calculi in the 1970s, and it is still currently responsible for a significant number of calculi. In the last decade, drugs used for the treatment of HIV-infected patients, namely indinavir and sulfadiazine, have become the most frequent cause of drug-containing urinary calculi. Besides these drugs, about twenty other molecules may induce nephrolithiasis in patients receiving long-term treatment or high doses. Calculi analysis by physical methods, including infrared spectroscopy or x-ray diffraction, is needed to demonstrate the presence of the drug or its metabolites within the calculi. The second group includes drugs that provoke urinary calculi as a consequence of their metabolic effects. Here, diagnosis relies on careful clinical inquiry because physical methods are ineffective to differentiate between urinary calculi induced by the metabolic effects of a drug and common metabolic calculi. The incidence of such calculi, especially those resulting from calcium/vitamin D supplementation, is probably underestimated. Although drug-induced urinary calculi most often complicate high-dose, long-duration drug treatments, there also exist specific patient risk factors in relation to urine pH, urine output and other parameters, which provide a basis for preventive or curative treatment of calculi. Better awareness of the possible occurrence of lithogenic complications, preventive measures based on drug solubility characteristics and close surveillance of patients on long-term treatment with drugs with lithogenic potential, especially those with a history of urolithiasis, should reduce the incidence of drug-induced nephrolithiasis.

Drug-Related Side Effects and Adverse Reactions↗
PubMed2004

Management of complex biliary tract calculi with a holmium laser.

The difficulty in managing complex biliary tract calculi is exemplified in patients with primary intrahepatic calculi. Standard surgical and endoscopic approaches often fail to clear calculi in these patients who have recurrent episodes of cholangitis. The success of the holmium laser for urologic calculi led us to adapt treatment strategies for primary and secondary biliary tract calculi where standard treatments had been unsuccessful. Our goals were to remove all calculi, prevent recurrent sepsis, and preserve hepatic parenchyma. Thirty-six patients with complex biliary calculi were treated. After sepsis was controlled and the extent of calculi was evaluated, appropriate access to and drainage of the biliary tract was achieved. Holmium laser lithotripsy was performed under video guidance using flexible choledochoscopes and a 200 micro laser fiber generating 0.6 to 1.0 joules at frequencies of 6 to 10 Hz. Lithotripsy procedures were repeated until cholangiography and cholangioscopy confirmed the clearance of calculi. Twenty-two patients of Asian descent with primary intrahepatic calculi and 14 patients with secondary intrahepatic calculi were treated. Access to the biliary tract could be accomplished through percutaneous catheter tracts, T-tube tracts, or the cystic duct during laparoscopic cholecystectomy. Biliary drainage was by biliary enteric anastomosis or endoscopic sphincterotomy. Complete stone clearance required an average of 3.9 procedures (range 1 to 15) for patients with primary intrahepatic calculi and 2.6 procedures (range 1 to 10) for patients with secondary intrahepatic calculi regardless of stone composition. No patient required hepatic resection and no complications or deaths were attributed to the holmium laser. Clearance of calculi can reliably and safely be achieved with a holmium laser regardless of stone composition or location while preserving hepatic parenchyma and preventing recurrent sepsis.

Adult↗
PubMed1999

Management of upper urinary tract calculi with ureteroscopic techniques.

OBJECTIVES: To evaluate our experience in treating 155 patients with upper urinary tract calculi ureteroscopically. The treatment of urinary calculi has remained the most frequent application of ureteroscopy. Miniaturization of semirigid and flexible ureteroscopes has permitted easier access to calculi throughout the urinary tract. METHODS: Ureteroscopic stone treatment was attempted in 155 patients with upper urinary tract calculi between November 1995 and March 1997. Fifty-nine (38.1%) patients had renal calculi, 82 (52.9%) ureteral, and 14 (9%) had both renal and ureteral calculi. Both semirigid and flexible ureteroscopes were used for treatment (rigid alone in 21 [13.5%], flexible in 64 [41.3%], and both rigid and flexible in 70 [45.2%] patients). Lithotripsy was required in 122 (79%) of the patients. The holmium:yttrium-aluminum-garnet laser was used in 113 (92.6%) of these patients. RESULTS: All patients with ureteral calculi (29 proximal, 19 mid, and 34 distal) were successfully cleared after one endoscopic procedure except for 1 patient with a proximal ureteral calculus who had a 4-mm residual fragment in the kidney. Of the 59 patients with renal calculi, 47 (79.7%) were totally clear of stones 1 month after treatment. The remaining 12 (20.3%) patients had evidence of residual calculi 3 to 4 mm or less in diameter. In patients with combined renal and ureteral calculi, 1 1 of 14 (78.6%) were rendered stone free. The remaining 3 (21.4%) patients had evidence of residual calculi 4 mm in diameter. Overall, 95% of the patients were treated in an outpatient setting. Morbidity was low, with no evidence of stricture. CONCLUSIONS: Ureteroscopy and laser lithotripsy in experienced hands are a safe and reliable method for the treatment of ureteral and even intrarenal calculi.

Adolescent↗
PubMed1993

[A clinical study on upper urinary tract calculi treated with extracorporeal shock wave lithotripsy (ESWL) monotherapy, with regard to bacteriuria before ESWL treatment].

To study a clinical problem in urolithiasis complicated with bacteriuria treated by extracorporeal shock wave lithotripsy (ESWL), we studied relationships between the frequency of bacteriuria and some clinical factors such as sex, location of, size of and composition of calculi in patients with upper urinary tract calculi. We also evaluated whether bacteriuria caused fever elevation after ESWL monotherapy. Six hundred seventy patients with upper urinary tract calculi, 440 renal calculi and 230 ureteral calculi, were subjected to the present study. The results were summarized as follows: 1) Bacteriuria was found in 40 of 440 patients with renal calculi (9%) and 12 of 230 patients with ureteral calculi (5%). 2) The frequency of bacteriuria was significantly higher in female (11%) than in male (6%) (p < 0.05). 3) Ten strains of Pseudomonas aeruginosa, 7 of Escherichia coli and 6 of Proteus mirabilis were isolated in patients with bacteriuria. 4) On the location of renal calculi in patients with bacteriuria, 37 out of 40 patients (93%) were found in R2. In contrast, bacteriuria was the most frequently found in DS 6 (19%), whereas the positive rates were about 10% in DS 3 (7%), DS 4 (*7%) and DS 5 (9%). The presence of bacteriuria was not related to the location of calculi or the size of calculi in patients with ureteral calculi. 5) Most of the calculi with bacteriuria were composed of magnesium ammonium phosphate or the mixture of calcium phosphate and carbonate with or without oxalate. 6) Patients with bacteriuria had a significantly higher rate of fever elevation after ESWL than those without bacteriuria (p < 0.01).

Adult↗
PubMed1995

[Experimental study of urinary calculi fragmentation with pulsed laser shockwave, based on their chemical composition].

OBJECTIVES: To attempt to classify the resistance of urinary calculi to shock waves according to the chemical composition of the calculi most frequently treated in clinical practice. METHOD: Seventy four urinary calculi obtained after surgery were submitted to shock waves produced by an experimental neodyme glass phosphate pulsed laser, at a frequency of 532 nanometres, delivering impulses of 4.8 Joules lasting 25 nanoseconds with a recurrence of 1 second. The calculi (25 homogeneous: 90% of one constituent, 49 heterogeneous: > 45% < 90% of one constituent) had to be fragmented down to 2 mm fragments. The total fragmentation energy (TFE) required was the parameter adopted to classify calculi and to compare the fragmentation of various chemical compositions studied by infrared spectrophotometry. The TFE of 25 homogeneous calculi were compared to a microhardness study performed on calculi with the same chemical composition. The fragmentation thresholds energy (TFE) was used to compare the fragmentation thresholds of each type of calculi. Statistical analysis by ascending multiple regression was performed to classify the various factors likely to influence fragmentation. RESULTS: Two groups were able to be significantly distinguished according to whether the TFE required to obtain 2 mm fragments was greater than 200 Joules (cystine, weddellite, brushite, uric acid) or less than 200 Joules (weddellite, carbapatite, struvite). Only cystine and whewellite significantly increased the fragmentation threshold. For the 125 homogeneous calculi, the correlation with microhardness demonstrated an inverse relationship between friability and increased microhardness. A crossover between microhardness and friability to shock waves was only observed for whewellite and cystine. For the 49 heterogeneous calculi, this study showed that when weddellite was the predominant component of a stone, the friability tended to increase. Struvite and whewellite significantly facilitated and decreased fragmentation of heterogenous calculi, respectively. CONCLUSIONS: This study allowed urinary calculi to be classified into three groups: friable (weddellite, carbapatite, struvite), intermediary (brushite, uric acid, whewellite) and resistant (cystine). Although this laser cannot be used clinically, the constants were similar to those of pulsed lasers available in clinical practice and the results of the study corresponded to those already observed empirically by other teams or observed experimentally on a single stone corresponding to each type of chemical composition. The clinical application of this study would be to prospectively compare the results with those observed in clinical lithotripsy.

Humans↗
PubMed1995

[Analytical evaluation of urinary calculi mineral composition].

Urolithiasis is the most frequent disease of urinary system. It affects about 3% of people of the productive age. One half of the hospitalized in Departments of Urology is made up of patients with urinary calculi. In some regions of the globe, urolithiasis is a very common pathological disorder. Upper Silesia being such a region in Poland. The objective of the paper is: 1) systematization of calculi according to their mineral composition with regard to eventual prophylaxis of urolithiasis, 2) comparison of mineral components of calculi in the aspect of pollutions for Upper Silesia and West Pomerania territories, and the effect of external factors on the constitution of the formed calculi, 3) making use of X-ray microanalysis in complex determinations of mineral compositions of stones, particularly the trace elements. For that purpose a total of 185 urinary calculi stemming from individuals of both sexes, aged 24 to 82 years were used. The content of calcium, magnesium, zinc and iron was determined by atom absorption method, that of aluminium, chloride, sulphur and copper by X-ray microanalysis method, fluoride by gas chromatographic method, phosphates and urates by colorimetric method. The content of cystine was defined by thermic decomposition and characteristic smell. The results were subjected to statistical analysis. With reference to the first task, the following chemical classification of stones has been suggested, namely; class I: ammonium stones being magnesium-ammonium phosphate, class II: stones with elevated calcium content, calcium oxalate, class III: stones with elevated magnesium content, class IV: calculi rich in calcium and magnesium, class V: calculi deficient in calcium and magnesium, class VI: organic uric stones, class VII: organic cystine stones. The second task consisted in comparing the mineral composition of stones from subjects inhabiting two remote from each other regions-industrialized Silesia and Pomerania (Tab. 10). The statistical analysis has revealed differences being statistically significant only with regard to calcium and magnesium in Silesia and Pomerania groups. Undoubtedly that is of importance when one takes into consideration that calcium and magnesium display high affinity to fluoride, the presence of which was detected in all the stones and which may influence the physicochemical properties of the urinary calculi, first of all their hardness and solubility. The third task consisted in evaluating the possibility of applying the X-ray microanalysis for searching the stone for further elements principally microelements. The performed study comprised 10 stones: Silesia region and Pomerania region, whose composition was compared pairwise. The pairs were selected in such a manner that they should have some features in common found out by previously described atom absorption methods. The established results concerning calcium, magnesium and phosphorus showed in general compatibility of results obtained by the two methods. However, by X-ray microanalysis method it was possible to detect further elements: sulphur, aluminium, chloride and copper. The following conclusions have been drawn, namely: 1) analytic examinations of mineral composition of urinary calculi are the base of their chemical composition with regard to eventual prophylaxis of urolithiasis, 2) a varied composition of urinary calculi from two different regions of Poland may be the reflection of actual state of natural environment pollution in those regions, 3) presence of fluoride in all the urinary calculi allows us to suppose that it is permanent element of urinary calculi.

Adult↗
PubMed1999

Holmium:YAG laser lithotripsy: A dominant photothermal ablative mechanism with chemical decomposition of urinary calculi.

BACKGROUND AND OBJECTIVE: Evidence is presented that the fragmentation process of long-pulse Holmium:YAG (Ho:YAG) lithotripsy is governed by photothermal decomposition of the calculi rather than photomechanical or photoacoustical mechanisms as is widely thought. The clinical Ho:YAG laser lithotriptor (2.12 microm, 250 micros) operates in the free-running mode, producing pulse durations much longer than the time required for a sound wave to propagate beyond the optical penetration depth of this wavelength in water. Hence, it is unlikely that shock waves are produced during bubble formation. In addition, the vapor bubble induced by this laser is not spherical. Thus the magnitude of the pressure wave produced at cavitation collapse does not contribute significantly to lithotripsy. STUDY DESIGN/MATERIALS AND METHODS: A fast-flash photography setup was used to capture the dynamics of urinary calculus fragmentation at various delay times following the onset of the Ho:YAG laser pulse. These images were concurrently correlated with pressure measurements obtained with a piezoelectric polyvinylidene-fluoride needle-hydrophone. Stone mass-loss measurements for ablation of urinary calculi (1) in air (dehydrated and hydrated) and in water, and (2) at pre-cooled and at room temperatures were compared. Chemical and composition analyses were performed on the ablation products of several types of Ho:YAG laser irradiated urinary calculi, including calcium oxalate monohydrate (COM), calcium hydrogen phosphate dihydrate (CHPD), magnesium ammonium phosphate hexahydrate (MAPH), cystine, and uric acid calculi. RESULTS: When the optical fiber was placed perpendicularly in contact with the surface of the target, fast-flash photography provided visual evidence that ablation occurred approximately 50 micros after the initiation of the Ho:YAG laser pulse (250-350 micros duration; 375-400 mJ per pulse), long before the collapse of the cavitation bubble. The measured peak acoustical pressure upon cavitation collapse was negligible (< 2 bars), indicating that photomechanical forces were not responsible for the observed fragmentation process. When the fiber was placed in parallel to the calculus surface, the pressure peaks occurring at the collapse of the cavitation were on the order of 20 bars, but no fragmentation occurred. Regardless of fiber orientation, no shock waves were recorded at the beginning of bubble formation. Ablation of COM calculi (a total of 150 J; 0.5 J per pulse at an 8-Hz repetition rate) revealed different Ho:YAG efficiencies for dehydrated calculus, hydrated calculus, and submerged calculus. COM and cystine calculi, pre-cooled at -80 degrees C and then placed in water, yielded lower mass-loss during ablation (20 J, 1.0 J per pulse) compared to the mass-loss of calculi at room temperature. Chemical analyses of the ablated calculi revealed products resulting from thermal decomposition. Calcium carbonate was found in samples composed of COM calculi; calcium pyrophosphate was found in CHPD samples; free sulfur and cysteine were discovered in samples composed of cystine samples; and cyanide was found in samples of uric acid calculi. CONCLUSION: These experimental results provide convincing evidence that long-pulse Ho:YAG laser lithotripsy causes chemical decomposition of urinary calculi as a consequence of a dominant photothermal mechanism.

Holmium↗
PubMedDate not supplied

Dried solidified blood calculi in the urinary tract of cats.

We have noted an increased number of calculi submitted to the Gerald V. Ling Urinary Stone Analysis Laboratory, University of California, Davis, that do not contain crystalline material but appear to be composed of dried solidified blood (DSB). Canine and feline laboratory records from 1986-2003 were reviewed for samples composed of >99% DSB. No calculi from dogs were found, but specimens from 49 cats were composed of >99% DSB, of which almost half (n = 22) had been submitted after 2001. The DSB calculi had been removed surgically or by postmortem examination from all areas of the upper and lower urinary tract. All samples were well formed and could be divided in half with Rongeur forceps. Detailed case information was available for 12 cats. Urinalyses were available for 9 of the 12 cats, and the mean specific gravity was 1.017 (range, 1.009-1.032). Red blood cells were reported in the sediment of all cats, with most containing >100 RBC/hpf. Ureteral obstructions but no radio-opaque calculi were visible by radiography, including radiographic contrast studies. Reports of ultrasound examinations were available for 10 cats, and discrete calculi were not recorded. In addition to polarized light microscopy, infrared spectroscopy and electron probe microanalysis were performed on a subset (n = 6, DSB calculi; n = 3, control calculi) of samples. Significantly more carbon, nitrogen, and sulfur (P = .012, P = .02, and P = .012, respectively) were present in the elemental analysis of the DSB calculi than in the control calculi, suggesting that the DSB calculi are primarily formed from organic material. At this time, we are uncertain why these DSB calculi become solidified, and we recommend that samples be submitted both in formalin and preservative free to further investigate their etiology.

Animals↗
PubMed1999

Unenhanced computerized axial tomography to detect retained calculi after percutaneous ultrasonic lithotripsy.

PURPOSE: We report our experience with unenhanced computerized axial tomography (CT) after percutaneous ultrasonic lithotripsy in patients thought to be at high risk for retained calculi. MATERIALS AND METHODS: CT was obtained in 121 patients (124 kidneys) within 12 to 36 hours of percutaneous ultrasonic lithotripsy for staghorn or large nonstaghorn renal calculi. Cases were grouped according to the CT findings as no retained calculi, insignificant retained calculi (fragments 1 to 3 mm.), retained calculi amenable to shock wave lithotripsy and retained fragments requiring second look percutaneous ultrasonic lithotripsy or flexible nephroscopy. RESULTS: No calculi were seen in 73 kidneys (59%) and retained calculi were identified in 51 (41%). Shock wave lithotripsy was used to treat 8 patients and another percutaneous ultrasonic lithotripsy or flexible nephroscopy was performed in 23 to remove retained stones. Insignificant calculi were noted in the remaining 21 patients. CONCLUSIONS: We believe that postoperative unenhanced CT is superior to plain renal tomography and is the best method to determine if a patient is stone-free after percutaneous ultrasonic lithotripsy. It helps to locate precisely those stones requiring a second percutaneous ultrasonic lithotripsy or nephroscopic extraction. An unenhanced renal CT devoid of calculi obviates routine postoperative second look flexible nephroscopy. We encourage others to consider this technique to define more accurately kidney stone status after percutaneous ultrasonic lithotripsy for large staghorn calculi or in any patient at high risk for retained calculi after percutaneous ultrasonic lithotripsy.

Adolescent↗
PubMed2002

Treatment of proximal ureteral calculi: holmium:YAG laser ureterolithotripsy versus extracorporeal shock wave lithotripsy.

PURPOSE: We compared the safety and efficacy of ureteroscopy with intracorporeal holmium:YAG laser lithotripsy and extracorporeal shock wave lithotripsy (ESWL) (Dornier Medical Systems, Inc., Marietta, Georgia) for proximal ureteral calculi. MATERIALS AND METHODS: A total of 67 patients underwent 81 primary procedures, including in situ ESWL with a DoLi 50 lithotriptor (Dornier Medical Systems, Inc.) or ureteroscopy combined with holmium:YAG laser lithotripsy for proximal ureteral calculi. RESULTS: Of the primary procedures 81 involved proximal ureteral calculi, including 35 done for calculi 1 cm. or greater. The initial stone-free rate in patients with calculi 1 cm. or greater was 93% for ureteroscopy combined with holmium:YAG laser lithotripsy and 50% for in situ ESWL. The efficiency quotient for treating proximal ureteral calculi 1 cm. or greater was calculated as 0.76 for ureteroscopic lithotripsy and 0.43 for ESWL. For proximal ureteral calculi less than 1 cm. the initial stone-free rate was 100% and 80% for ureteroscopic laser lithotripsy and ESWL, respectively. The efficiency quotient was calculated as 0.81 for ureteroscopic lithotripsy and 0.72 for ESWL for treating proximal ureteral calculi less than 1 cm. There were no major complications in either group and all procedures were performed on an outpatient basis. CONCLUSIONS: Our study demonstrates that ureteroscopy combined with holmium:YAG laser lithotripsy is an acceptable treatment modality for all proximal ureteral calculi and excellent results are achieved for calculi 1 cm. or larger. Although the stone-free rate was better for smaller stones with ureteroscopic laser lithotripsy, efficiency quotients were similar. Therefore, ESWL should remain first line therapy for proximal ureteral calculi less than 1 cm. because of less morbidity, and a lesser anesthesia and analgesic requirement.

Adult↗
PubMed1978

Effects of ethylenediaminetetraacetic acid-4 sodium solution on the surface of renal calculi and the uroepithelium.

Tetrasodium ethylenediaminetetraacetic acid is one of the most effective agents that dissolve renal calculi, especially calculi containing calcium. To study the dissolving process of calculi in solutions, with or without trypsin, serial thin sections of renal calculi composed of calcium oxalate and/or phosphate were prepared and observed by polarizing microscopy. The effects of the solution on the surface of human renal calculi and rat uroepithelium also were studied by scanning electron microscopy. A remarkable difference in solubility was noted between the crystalline and the amorphous components in struvite calculi. Under the polarizing microscope the dissolving effect of 5 per cent tetrasodium ethylenediaminetetraacetic acid solution on struvite after 30 minutes of incubation was equivalent to the use of saline for 24 hours. The effect of trypsin was not apparent. However, under the scanning electron microscope trypsin accelerated the dissolving effect of the tetrasodium ethylenediaminetetraacetic acid solution in struvite and calcium oxalate calculi. The contradictory findings of the ineffectiveness of trypsin on the thin sections as opposed to the pronounced changes seen on the surface of the calculi could be attributed to the difference in the exposed area. The results suggest that trypsin does not seem to dissolve calculi but mainly facilitates the solution to permeate the calculi. The cellular arrangement of the uroepithelium was preserved in tetrasodium solution and in 0.04 per cent trypsin tetrasodium ethylenediaminetetraacetic acid solution.

Animals↗
PubMed2000

Bladder calculi in children who perform clean intermittent catheterization.

OBJECTIVE: To examine the role of clean intermittent catheterization (CIC) as a possible predisposing risk factor for bladder calculi, assessing risk factors in patients with and without bladder augmentation, and to evaluate management options for bladder calculi in these patients. PATIENTS AND METHODS: The records of 403 patients who were using a regimen of CIC between January 1981 and March 1998 were reviewed to identify those forming bladder calculi; stones were diagnosed in 28 patients. The patients were categorized as: group 1, patients with no bladder augmentation who catheterized urethrally (227, group 1a) or via a Mitrofanoff conduit (18, group 1b); group 2, patients with augmented bladders who catheterized urethrally (100, group 2a) or via a Mitrofanoff conduit (58, group 2b). The incidence of bladder calculi in each group was determined and compared statistically where applicable. The success of the treatment options for stone management was reviewed. RESULTS: Bladder calculi developed in 5% of patients in group 1a, 8% in group 2a, 11% in group 1b, and 10% in group 2b; the incidence of calculi was not significantly different among the groups. Of these patients, 18 (64%) were asymptomatic at the time of diagnosis and significant bacteriuria was found in 23 (88%). Difficulty in catheterizing either the Mitrofanoff conduit or the native urethra was reported in 14 (50%) of these patients. Calculi were more often solitary (71%) and typically composed of struvite or apatite. Calculi were managed by open cystolithotomy in 15 patients (54%) and endoscopically in 13 (46%). Stones recurred in nine patients (32%) after treatment, comprising four of six patients treated endoscopically with electrohydraulic lithotripsy and in five of 15 after open cystolithotomy. The mean interval to recurrence was 22.8 months. CONCLUSION: These results suggest that patients on a regimen of CIC are at risk of developing bladder calculi but the incidence of calculi is not influenced by bladder augmentation. The presence of a Mitrofanoff conduit was associated with a slightly increased incidence of calculus formation. Open cystolithotomy was associated with a lower stone recurrence rate but there were too few patients to draw definitive conclusions.

Adolescent↗
PubMed1998

Supracostal percutaneous nephrolithotomy for upper pole caliceal calculi.

The incidence of upper pole calculi is 15% of all caliceal calculi. The management of such calculi has been simplified since the advent of extracorporeal shockwave lithotripsy (SWL). In our experience, however, there is a subset of upper pole caliceal calculi wherein certain features can render SWL less than adequate treatment, namely diameter >1.5 cm, narrowing of the caliceal infundibulum, either singly or combined, and morbid obesity. In such instances, percutaneous nephrolithotomy (PCNL) is indicated. Percutaneous access to an upper pole calix can be difficult by a subcostal track. The supracostal 12th rib approach provides direct and efficient access to an upper pole calix and is ideally suited for upper pole calculi. Twenty-one patients with large or complex upper pole calculi were treated by supracostal PCNL. The maximum diameter of the calculi ranged from 7 to 40 mm. Eight were branched (staghorn). There was one horseshoe kidney, and calculi were bilaterally represented in another patient. Two patients were morbidly obese. All procedures were performed in one stage under general anesthesia. Following cystoscopy and ureteral catheterization, the upper pole calix was accessed directly with the aid of C-arm fluoroscopy and retrograde ureteral contrast injection. The percutaneous tract was dilated to a maximum of 26 F, a working sheath was inserted, and the calculi were extracted after ultrasonic or pneumatic fragmentation. One patient required secondary SWL for residual fragments. There were no intrathoracic complications, and blood loss was minimal. Large or complex upper pole caliceal calculi, particularly in the morbidly obese, can be treated effectively by PCNL using supracostal percutaneous access.

Follow-Up Studies↗
PubMed2003

Prostatic calculi do not influence the level of serum prostate specific antigen in men without clinically detectable prostate cancer or prostatitis.

PURPOSE: Prostatic calculi are common but little is known of their effect on serum prostate specific antigen (PSA). We investigated whether prostatic calculi might influence serum PSA in men with clinically undetectable prostatic cancer or prostatitis. MATERIALS AND METHODS: Between November 1999 and November 2001, 581 consecutive patients underwent serum PSA determination and digital rectal examination. Of these patients 486 without detectable prostatic cancer, or a history or symptoms of prostatitis and with other specified exclusion criteria were included in the study. The detection and volume measurement of prostatic calculi, and the measurement of prostate volume were performed by transrectal ultrasonography. RESULTS: Prostatic calculi were detected in 198 of the 486 men (40.7%). Mean patient age, prostate volume and serum PSA were not significantly different in men with and without prostatic calculi. Prostate volume was significantly greater in patients with abnormally elevated serum PSA than in those with normal levels. However, no significant difference was found between the percent of men with prostatic calculi or the volumes of prostatic calculi in the 2 groups. Univariate logistic regression analysis indicated that the presence or volume of prostatic calculi was not a risk factor for elevated PSA. Multivariate analysis showed that age and prostate volume were associated with elevated PSA. CONCLUSIONS: The presence or volume of prostatic calculi had no significant effect on serum PSA. Our results suggest that the influence of prostatic calculi is irrelevant in men with elevated PSA.

Calculi↗