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PubMed1995

Biliary tract calculi in primary sclerosing cholangitis.

UNLABELLED: By conventional criteria the diagnosis of primary sclerosing cholangitis (PSC) is excluded if biliary tract calculi are present. OBJECTIVE: To compare patients with sclerosing cholangitis with and without calculi. METHODS: Retrospective review between 8/91 and 9/93 identified 63 patients with sclerosing cholangitis alone (Group A) and 22 patients with sclerosing cholangitis and biliary tract calculi (Group B). The mean follow-up was 13.6 months. Clinical features reviewed were age, sex, associated inflammatory disease (IBD), and clinical presentation. Cholangiographic features compared were site and extent of disease. Endoscopic stone extraction was reviewed for success and complications. RESULTS: Both groups had the following features in common: 1) mean age (45.9 vs 46.3 yr), 2) prevalence of IBD (68.3 vs 72.7%), 3) extent of bile duct strictures (intrahepatic: 28.5% vs 27.2%; extrahepatic: 12.7% vs 13.6%; both: 58.7% vs 54.5%). There were proportionately more women in Group B (45.5% vs 33.3%). Symptomatic presentation (pain, pruritus, jaundice, and cholangitis) was seen more often in Group B: 86.4% compared with Group A: 39.7% (specifically cholangitis was seen in 22.7% vs 4.7%). Among Group B, calculi developed subsequent (mean 40.2 months) after the diagnosis of sclerosing cholangitis in 77.3% of patients. The distribution of calculi was cholelithiasis: 7 (31.8%); choledocholithiasis: 9 (40.9%); and both: 6 (27.2%). Of the patients with choledocholithiasis alone, 78% had undergone previous cholecystectomy. Endoscopic stone extraction was successful in 13 (86.6%) of the patients with choledocholithiasis. Complications included mild pancreatitis in one patient and bleeding from sphincterotomy site in another patient which responded to sclerotherapy. In follow-up, only one patient had recurrent calculi and underwent successful stone extraction. CONCLUSION: We suggest that biliary tract calculi are a part of the spectrum of otherwise typical PSC and therefore their presence should not necessarily exclude the diagnosis.

Adult↗
PubMed1995

The case for primary endoscopic management of upper urinary tract calculi: I. A critical review of 121 extracorporeal shock-wave lithotripsy failures.

OBJECTIVES: To define those patients with upper urinary tract calculi who are more likely to have an unsuccessful outcome from extracorporeal shock-wave lithotripsy (ESWL). METHODS: A critical prospective analysis of 121 patients, referred to two university centers after ESWL had been exhausted as a treatment modality for upper urinary tract calculi, was performed. Patients were subdivided into the following groups: failure to clear fragments, failure to fragment, difficulty in calculus localization, and failure due to inherent upper urinary tract obstruction. Other important variables include the type of extracorporeal lithotriptor used, number of treatment sittings before referral, calculus location, calculus composition, patient body habitus, and the imaging leading to and associated with extracorporeal therapy. RESULTS: Large renal calculi (mean, 22.2 mm) and those within dependent or obstructed portions of the collecting system were frequently referred for endoscopic management after failed ESWL. Steinstrasse can be an extremely morbid complication from ESWL and in this series was associated with irreversible loss of renal function and ureteral stricture disease. Extracorporeal lithotripsy of infectious calculi can be associated with severe septic complication. Inadequate preoperative and intraoperative imaging and morbid obesity were also associated with failure. Second- and third-generation lithotriptors were represented in greater numbers than the Dornier HM-3 in this group of ESWL failures. CONCLUSIONS: ESWL remains the treatment of choice for moderately sized, uncomplicated renal calculi. Large calculi, those within obstructed or dependent portions of the collecting system, and those composed of calcium oxalate monohydrate, frequently fail ESWL. Training in the more technically challenging aspects of endoscopic lithotripsy must be encouraged.

Adolescent↗
PubMed2005

Recurrent vesical calculi, hypercalciuria, and biochemical evidence of increased bone resorption in an adult male with paraplegia due to spinal cord injury: is there a role for intermittent oral disodium etidronate therapy for prevention of calcium phosphate bladder stones?

STUDY DESIGN: Clinical case report with comments by colleagues from Sweden, Poland, Spain, Brazil, Japan, Belgium and Switzerland. OBJECTIVES: To discuss the role of disodium etidronate therapy for prevention of calcium phosphate vesical calculi in persons with spinal cord injury, who have hypercalciuria and biochemical evidence of increased bone resorption. SETTING: Regional Spinal Injuries Centre, Southport, UK. METHODS: A 21-year-old male sustained paraplegia (T-10; ASIA scale: A) in a road traffic accident in June 2001. He had an indwelling urethral catheter until the end of August 2001, when he started self-catheterisation. He developed bladder stones and electrohydraulic lithotripsy (EHL) was performed in May 2002. All stone fragments were removed. Recurrence of vesical calculi was noted in October 2002. These stones were fragmented by lithoclast lithotripsy in two sessions, in December 2002 and February 2003; all stone fragments were removed at the end of the second session. This patient reverted to indwelling catheter drainage when vesical calculi recurred. In September 2003, X-ray of the abdomen showed recurrence of vesical calculi. By February 2004, the stones had increased in size and number. EHL of vesical calculi was again performed in April 2004. Complete clearance was achieved. RESULTS: A 24-h urinalysis detected hypercalciuria--18.7 mmol/day (reference range: 2.5-7.5). Biochemical analysis of vesical calculus revealed calcium phosphate (85%) and magnesium ammonium phosphate (15%). Plasma C-terminal telopeptide (CTX) was increased - 1.06 ng/ml (reference range: 0.1-0.5 ng/ml). Free deoxypyridinoline/creatinine ratio (fDPD/Cr) in urine was also increased - 20.2 (reference range: 2.3-5.4). In April 2004, this patient was prescribed disodium etidronate 400 mg day. Nearly 3 months after commencing therapy with etidronate, plasma CTX decreased to 0.87 ng/ml. fDPD/Cr in urine also decreased to 12.4. After 4 months of etidronate therapy, 24-h urinary calcium excretion had decreased to 6.1 mmol/day. CONCLUSION: Etidronate (400 mg daily) is a very effective inhibitor of calcium phosphate crystallisation. Etidronate decreased urinary excretion of calcium, an important factor in prevention of calcium phosphate bladder stones. Etidronate therapy is not a substitute for other well-established methods for prevention of vesical calculi in spinal cord injury patients, for example, large fluid intake, avoiding long-term catheter drainage. Intermittent therapy with etidronate may be considered in selected patients, in whom hypercalciuria persists after instituting nonpharmacological therapy for an adequate period, for example, early mobilisation, weight-bearing exercises, and functional electrical stimulation. However, possible side effects of etidronate, and the fact that etidronate is not licensed in United Kingdom for prevention of urolithiasis, should be borne in mind.

Adult↗
PubMed2000

Extracorporeal shockwave lithotripsy of 2000 urinary calculi with the modulith SL-20: success and failure according to size and location of stones.

PURPOSE: We analyzed the successes and failures of SWL in the treatment of 2016 urinary calculi stratified according to size and position in the urinary tract. METHODS: All the patients were treated with a Modulith SL-20 (Storz Medical). RESULTS: The overall stone-free rate, regardless of the size and position of the stone, was 87.4%. The rate was different for kidney and ureteral stones. The stone-free rate observed for the different positions of the calculi within the kidney was upper calix 89.2%, middle calix 90.5% lower calix 84.8%, and renal pelvis 86.0%. For staghorn calculi, the stone-free rate was 60.0%. The stone-free rate for the different positions of calculi within the ureter was: upper ureter 84.3%, iliac ureter 82.4%, and pelvic ureter 91.0%. For calculi >24 mm, the retreatment rate increased, and the success rate dropped sharply. CONCLUSION: Extracorporal shockwave lithotripsy should be the first therapeutic option for urinary calculi of <24 mm regardless of their position in the urinary tract.

Adolescent↗
PubMed2005

Time to development of symptomatic urinary calculi in a high risk environment.

PURPOSE: While seasonal variation of stone disease is well described, the time to formation of urinary calculi is unknown. Because southwestern Asia is a high risk environment for stone disease, the date of entry into this region is a definitive beginning to a period of increased risk of urinary calculi. The recent influx of Department of Defense personnel into southwestern Asia provided the opportunity to observe stone disease in a cohort of healthy personnel during a well-defined period of increased risk of stone formation. MATERIALS AND METHODS: A database was constructed for all patients presenting with symptomatic urinary calculi to a single military hospital deployed to Kuwait from March through August 2003. Patient demographics, stone characteristics and time to formation of symptomatic urinary calculi were evaluated. RESULTS: A total of 182 patients were diagnosed with 218 symptomatic stones. Mean time to formation of symptomatic urinary calculi was 93 days with a standard deviation of 42 days. CONCLUSIONS: This study provides unprecedented information about the development of symptomatic urinary calculi in a high risk environment. While unique aspects of the population, environment and medical system created a singular opportunity to study stone disease, the results of this study are applicable to the general population.

Adult↗
PubMed2005

Role of computed tomography with no contrast medium enhancement in predicting the outcome of extracorporeal shock wave lithotripsy for urinary calculi.

OBJECTIVE: To evaluate the usefulness of urinary calculi attenuation values from non-contrast computed tomography (NCCT) in predicting the outcome of treatment by extracorporeal shock wave lithotripsy (ESWL). PATIENTS AND METHODS: We evaluated 112 patients with solitary renal and upper ureteric calculi of 0.5-2 cm undergoing ESWL. All patients had NCCT at 120 kV and 240 mA on a spiral CT scanner. During each ESWL session 3000 shock waves were given to a maximum of 3.0 kV. A final X-ray of the kidney, ureters and bladder was taken 12 weeks after the last ESWL session. Fragments of < or = 5 mm were regarded as clinically insignificant residual fragments (CIRF). The calculi retrieved were analysed by X-ray diffraction and the results assessed by comparing the mean density (as measured in Hounsfield units, HU) with the number of ESWL sessions and clearance. RESULTS: In all, 82 (76%) patients had complete clearance of stones and 26 (24%) had CIRF. There was a linear relationship between the calculus density and number of ESWL sessions required. Of patients with calculi of < or = 750 HU, 41 (80%) needed three or fewer ESWL sessions and 45 (88%) had complete clearance. Of patients with calculi of > 750 HU, 41 (72%) required three or more ESWL sessions, and 37 (65%) had complete clearance. The best outcome was in patients with calculus diameters of < 1.1 cm and mean densities of < or = 750 HU; 34 (83%) needed three or fewer ESWL sessions, and the clearance rate was 90%. The worst outcome was in patients with calculus densities of > 750 HU and diameters of > 1.1 cm; 23 (77%) needed three or more ESWL sessions and the clearance rate was only 60%. The calculus density was a stronger predictor of outcome than size alone. CONCLUSIONS: The use of NCCT for determining the attenuation values of urinary calculi before ESWL might help to predict the treatment outcome, and so might help in planning alternative treatment in patients with a likelihood of a poor outcome from ESWL.

Adult↗
PubMed2002

Ureteroscopic treatment of lower pole calculi: comparison of lithotripsy in situ and after displacement.

PURPOSE: Ureteroscopic management is a viable option for lower pole calculi less than 2 cm. Recently a technique was described to displace the calculus into a more accessible calix using a nitinol basket or grasper before lithotripsy. We compared the efficacy and safety of this technique with in situ treatment of small and intermediate lower pole calculi. MATERIALS AND METHODS: We retrospectively reviewed the records of 95 ureteroscopy cases performed at our institution from January 1997 through August 2001 for renal calculi located only in the lower pole. Preoperative patient characteristics, stone size, operative details, complications and outcomes were compared for calculi treated in situ and those displaced before treatment. RESULTS: Adequate followup was available on 78 patients. Patients in the displacement group were statistically older, more often had a preoperative indwelling ureteral stent and had a mean operative time that was 16 minutes longer (p = 0.04). Average stone diameter in the in situ and displacement groups was 8 and 10.3 mm., respectively (p = 0.04). In patients with radiographic followup greater than 1 month complete success was obtained for 77% of stones 1 cm. or less treated in situ versus 89% treated with displacement first (p = 0.43). For calculi greater than 1 cm. complete success was obtained for 2 of the 7 (29%) treated in situ versus all 7 (100%) treated with displacement (p = 0.005). CONCLUSIONS: When treating lower pole calculi 1 to 2 cm. via ureteroscopy, a higher success rate can be obtained with displacement into a more accessible calix before treatment.

Adult↗
PubMedDate not supplied

[Treatment of calculi not easily seen with radiology using extracorporeal shockwave lithotripsy. Value of contrast media].

Currently, most calculi can be treated with shockwave extracorporeal lithotrity regardless their location within the urinary apparatus or their physico-chemical features. In order to optimize results only medical criteria for patient's selection should be taken into account. Certain type of calculi can obstruct adequate radioscopic viewing by not allowing correct centring for shockwave emission. The problem can be overcome by using echography or other contrast procedures. Of a total 514 patients treated in our Unit with ESWL, execution of contrast procedures was necessary in 18 cases (3.5%) in order to allow adequate viewing of the calculi. Calculi in 10 patients were midly radiopacque, uric acid in 4, and bone-superimposed in the remaining 4. This technical manoeuvre allowed in all cases a good centring of the calculi. After a two months follow-up. lithiasis is absent in 15 patients and only 2 present expellable lithiatic fragments. It can therefore be concluded that the use of contrast procedures, both through i.v. or a catheter, is a simple, safe and well tolerated procedure allowing convenient viewing of those calculi, also followed by good results after ESWL treatment.

Adult↗
PubMed1987

[Local treatment of obstructive uric acid calculi].

Dissolution of uric acid calculi could be obtained by oral or parenteral urinary alcalinization, but this method cannot apply to the case of obstructive calculi. Nineteen obstructive calculi in 18 patients were treated by in situ alcalinization through a percutaneous nephrostomy catheter (PCN). Eight patients were initially anuric, 7 of whom from an obstructed solitary kidney and 1 from a bilateral obstructive lithiasis. Fifteen calculi were located in the ureter, 3 in the uretero-pelvic junction and 1 in the pelvis. After 48 h of urinary diversion through PCN, an isotonic sodium bicarbonate solution (14 g %) was continuously infused at an average flow rate of 2.8 l/24 h, through either an unique PCN, or a 2 PCN-irrigation circuit in the 7 cases with permanently obstructive calculus. Fifteen calculi (80%) were completely dissolved after 3 to 13 days of alcalinization (average 5.8 days). One large calculus was reduced by 3/4 and further removed by percutaneous lithotripsy. Three patients underwent ureterotomy after 9 to 11 days of uneffective treatment. Local alcalinization is an effective and non invasive treatment for obstructive uric acid calculi, and is logically associated with the necessary urinary diversion.

Aged↗
PubMed1998

Retrograde ureteropyeloscopic treatment of 2 cm. or greater upper urinary tract and minor Staghorn calculi.

PURPOSE: Upper urinary tract calculi that are too large to treat with extracorporeal shock wave lithotripsy are most commonly cleared with percutaneous endoscopic techniques. In a select group of patients who were poor candidates for percutaneous nephrostolithotomy we used retrograde endoscopic lithotripsy, and define the safety and efficacy of this modality in treating large, noninfectious stone burdens (2 cm. or greater). MATERIALS AND METHODS: A total of 51 patients with 66 large (2 cm. or greater) upper urinary tract stones were chosen for retrograde ureteroscopic surgery. Many of these patients had co-morbid conditions that precluded or complicated standard percutaneous treatment. Lithotripsy was based on the application of small diameter fiberoptic ureteroscopes and the holmium laser lithotriptor. Specifically, the 200 micro. laser fiber was used when lower pole renal access was required. Successful therapy was defined as total fragmentation of a stone burden with creation of fine sand and 2 mm. or smaller debris. Second look endoscopy was commonly performed in select patients with large branched calculi or stone burdens in excess of 3 cm. to rule out and treat large residual fragments. RESULTS: Of 51 patients 48 were treated solely in a retrograde ureteroscopic manner and in 3 either failure of lower pole access or infectious material encountered on initial endoscopy led to conversion to more standard percutaneous techniques. In 34 of 45 renal (76%), and 20 of 21 ureteral (95%) complete ureteroscopic fragmentation of the respective stone burden was accomplished after a single session. Second look endoscopy defined significant residual fragments requiring additional endoscopic lithotripsy in 8 of 15 large renal (53%) and 1 of 3 complex ureteral stone burdens. Success, that is complete pulverization of the stone burden to fine dust and small 2 mm. fragments, increased to 41 of 45 renal (91%) and all 21 ureteral calculi after these second look procedures. One patient required a third session to treat completely an exceptionally large (6 cm.) renal stone burden composed of pure cystine, thus increasing the overall success rate for renal calculi to 93%. Six-month followup data were available for 25 patients with large calculi treated ureteroscopically, of whom 15 (60%) had completely clear imaging, 6 (24%) had small lower pole debris that was decreasing on serial imaging and 4 (16%) had new stone growth which was, in part, related either to uncorrectable metabolic disorders or chronic renal scarring and urinary stasis. There were no intraoperative complications. Three postoperative complications included pyelonephritis in 1 patient, prostatic bleeding in 1 on anticoagulant therapy and a cerebral vascular accident 24 hours after the procedure in 1 with severe vascular disease. CONCLUSIONS: Large and complex upper urinary tract calculi can be addressed safely and efficiently with retrograde endoscopic techniques.

Adolescent↗
PubMed1997

Calculi in hydroceles: sonographic diagnosis and significance.

PURPOSE: This paper reviews the sonographic appearances of calculi found in hydroceles. METHODS: The records and sonograms of 350 patients who had scrotal sonography examinations at Salmaniya Hospital, Bahrain, between September 1992 and August 1994 were analyzed retrospectively. RESULTS: Seventy-eight hydroceles were identified. Of those, 32 contained calcareous particles or calculi. Calculi 3 mm or more in diameter were seen incidentally as movable echogenic foci in the hydrocele fluid in 15 patients who had projections and calcifications in the tunica vaginalis, skin thickening, and/or chronic epididymitis. These findings indicated that the likely cause of calculus formation was chronic scrotal inflammation leading to a disturbance in reabsorption of hydrocele fluid. During sonography, calculi in hydroceles were seen moving in the fluid between the tunica vaginalis layers; this distinguished them from other scrotal calculi or pathologic findings. CONCLUSIONS: With sonographic identification of calculi in hydroceles, further imaging and surgery may be avoided.

Adult↗
PubMedDate not supplied

Dissolution of struvite calculi by hemiacidrin solution.

Struvite calculi result from urinary tract infections secondary to urease-producing bacteria. To prevent recurrent infection and stone formation complete removal of struvite calculi is recommended. Two illustrative reports of patients with renal struvite calculi are presented in which 10% hemiacidrin (Renacidin) irrigation was instituted for stone dissolution. After surgical removal of the calculi a nephrostomy tube was placed in the renal pelvis. With confirmation of residual struvite calculi, 10% hemiacidrin irrigation was initiated. Urine cultures, electrolytes and nephrotomograms were performed and adverse effects monitored. Using strict aseptic technique and appropriate precautions, hemiacidrin irrigation safely dissolves struvite calculi.

Adult↗
PubMed2001

Ultrasound-guided piezoelectric extracorporeal shock wave lithotripsy of parotid gland calculi.

PURPOSE: The introduction of piezoelectric extracorporeal shock wave lithotripsy (ESWL) has changed therapy for salivary calculi. This method seems especially suitable for treating calculi in the parotid gland. The purpose of this study was to evaluate ESWL in patients with such calculi. METHODS: From November 1990 to November 1999, all patients with sialolithiasis of the parotid gland were treated with piezoelectric ESWL. Three different lithotriptors were used over the 9-year study period. Results were analyzed according to both the patients' clinical status and follow-up sonograms. RESULTS: In total, 42 patients (21 women, 21 men; mean age, 59 years) were treated with ESWL. The mean follow-up period for all patients was 63 months (range, 7-96 months). After ESWL had been performed, 71% of the patients were completely free of symptoms, and 21% had marked improvement of their symptoms. Sixty-seven percent were completely free of calculi, and 27% had a marked reduction in the size of their calculi. Adverse effects of ESWL included temporary glandular swelling (4 patients), blood-tinged salivary secretions (9 patients), petechiae on the skin surface (3 patients), and parotid abscess (1 patient). CONCLUSIONS: ESWL is an outpatient procedure that can be performed without anesthesia and with scarcely any discomfort for patients. Conventional surgical procedures such as subtotal parotidectomy may be almost entirely replaced by ESWL because of the excellent treatment results and a very low rate of complications associated with ESWL. ESWL should be considered the treatment of choice for parotid calculi.

Adult↗
PubMed1984

The bacteriology of the urine and renal calculi.

The bacteriological status of the pre-operative urine, removed calcium and the pelvic urine was studied in 63 consecutive patients undergoing removal of intrarenal calculi. The overall infection rates in the pre-operative urine, removed calculi and pelvic urine were 29%, 38% and 30% respectively. In patients with staghorn calculi, 58% of patients had an infected pre-operative M.S.S.U., and 82.5% of removed calculi demonstrated significant bacterial growth, with Proteus mirabilis being the predominant organism isolated. In patients with single or multiple oxalate calculi, 17% had an infected pre-operative M.S.S.U., and 22% of removed calculi demonstrated a significant bacterial growth. The findings would indicate that the presence of a positive M.S.S.U. in a patient with a renal calculus is an indication for surgical removal.

Adult↗
PubMed2004

Ureteroscopic holmium: YAG laser lithotripsy for managing ureteral calculi (a report of 168 cases).

The effectiveness and safety of ureteroscopic holmium: YAG laser lithotripsy for managing ureteral calculi was evaluated. Ureteroscopic holmium. YAG laser lithotripsy was performed in 168 ureteral calculi (upper 27 cases, middle 33 cases and lower 108 cases). The results showed that the stone-free rate was 92.6% in the upper ureteral calculi, 93.9% in the middle ureteral calculi and 94.4% in the lower ureteral calculi, respectively. The complication rate was 4.8% (8 cases). It was suggested that ureteroscopic holmium: YAG laser lithotripsy is a highly effective and safe treatment modality for managing ureteral calculi.

Adult↗
PubMed2006

Minimally invasive treatment of ureteral calculi in children.

A retrospective analysis was done to determine the efficacy of shock wave lithotripsy (SWL) and ureteroscopy in the treatment of paediatric ureteral calculi. We reviewed the records of 67 (35 boys, 32 girls) children (71 ureters) admitted to our clinic for treatment of ureteral calculi during 1990-2005. The initial treatment method was SWL in 80.3% (57 ureters), ureteroscopy in 11.3% (eight ureters) and open surgery in 8.5% (six ureters) of the renal units. The mean age of the patients was 10.67 +/- 4.4(1-16) years. The stone-free rates after SWL for upper, middle and lower ureteral calculi were 74.1, 100 and 75.9%, respectively. Increased stone diameter (P = 0.014) and/or burden (P = 0.002) were found to be significant factors that had an adverse affect on the stone-free rate after SWL while the success rates of SWL were independent of location. Including six patients (seven ureters) with failed SWL, a total of 14 patients (15 renal units) subjected to ureteroscopy for lower ureteral calculi yielded a stone-free rate of 93.3%. Thus, the overall stone-free rates after SWL, ureteroscopy and open surgery were found to be 75.4, 93.3 and 100%, respectively. Depending on the stone burden, SWL might be a good option for initial treatment of most ureteral calculi in children. Ureteroscopy offers a high success rate for lower ureteral calculi, including SWL failures.

Adolescent↗
PubMed2002

Determination of urinary calculi by binocular stereoscopic microscopy.

Because of the inadequacies of chemical methods for identifying urinary calculi, mineralogical methods have been developed, but these methods are sometimes time consuming and expensive. The aim of the study was to evaluate urinary calculi with binocular stereoscopic microscopy (BSM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and biochemical methods and to determine the specificity of BSM. A total of 30 pediatric patients with urinary calculi (17 girls and 13 boys), from 6 months to 19 years of age, were included in the study. The calculi obtained were evaluated with a Novex-AP 8 BSM, a Shimadzu 6000 XRD device, a Jeol JXA 733 SEM, and a biochemical kit from Merck. In 2 cases BSM rapidly determined that the material was not from the urinary system. Except for 2 cases, BSM results were identical to the results obtained by XRD. In 2 non-identifiable cases, the samples were struvite with an amorphous structure. The sensitivity of BSM was 93%. The small size of calculi did not permit biochemical analysis in 4 cases. In another group of 4 cases, the results of biochemical analysis did not agree with the XRD. In 7 cases, calcium phosphate was found by biochemical assay, although it was not confirmed by XRD. The sensitivity of biochemical analysis was 58%. BSM is more reliable than biochemical methods. BSM can be used for a rapid, reliable evaluation of the urinary calculi. It gives additional information about the nidus, the crystalline structure, and the order of deposition of components. The clinician can perform this investigation himself, obtaining very useful information about stone formation that allows an immediate start of medical treatment, decreasing recurrences.

Adolescent↗
PubMed1994

The influence of internal stone structure upon the fracture behaviour of urinary calculi.

In vitro extracoporeal shock wave lithotripsy (ESWL) on different types of urinary calculi, in combination with microfocus x-ray and microphotography, illustrates the importance of the internal stone structure. Calculi with a rough surface layered structure (calcium oxalate monohydrate) and untextured calculi (cystine) are characterized by a low stone fragility, whereas coarse-grain calculi (calcium oxalate dihydrate, struvite), and calculi with a smooth surface layered structure (uric acid), are very fragile. Shell-like fragmentation in layered calculi, with smooth surface of the crystalline laminations, suggests that the stone matrix influenced the propagation of the shock wave energy inside the stone.

Calcium Oxalate↗