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PubMed2003

The effect of indwelling endoprosthesis on stone size or fragmentation after long-term treatment with biliary stenting for large stones.

BACKGROUND: Endoscopic biliary stenting is often used for large or difficult common bile duct (CBD) stones, but the effect of indwelling endoprosthesis on size or fragmentation of stones after long-term treatment with biliary stenting has not been formally established. We compared the stone size or fragmentation of common bile duct stones after a long period of biliary stenting. METHODS: Endoscopic biliary endoprosthesis was performed for 49 high-risk patients with CBD stones too large or difficult to be extracted by conventional endoscopic means. Bile duct drainage was established in all the patients without complications. Of the patients, 24 died with endoprosthesis in situ all from causes unrelated to biliar disease; 22 underwent a second and three patients a third attempt at stone extraction. The largest stone diameter was >12 mm in all patients. RESULTS: In 11 of 25 patients (44%) the endoprosthesis allowed resolution of the problem of unextractable common bile duct stones. Four patients showed no existence of stent, and ERCP complete stone clearance from the CBD on programmized appointment after endoprosthesis insertion. Reduced size or fragmentation of stones was obtained in seven patients, and the stones could be removed endoscopically. The remaining 14 patients demonstrated no significant change in the size or fragmentation of their stones, and endoprostheses were replaced. CONCLUSIONS: These results suggest that endoscopic endoprosthesis for large or difficult CBD stones is an effective method to clear the duct in selected cases, as well as an important definitive treatment in high-risk patients.

Adolescent↗

PubMed1990

Piezoelectric lithotripsy: stone disintegration and follow-up results in patients with symptomatic gallbladder stones.

One hundred symptomatic patients with radiolucent gallbladder stones were treated with a new piezoelectric lithotripter and oral chemolitholytic agents. Stone disintegration was achieved in 99 of these patients (99%) with a mean (+/- SD) maximum fragment size of 5.1 +/- 4.1 mm. Significant differences were found when the mean (+/- SD) fragment sizes of single stones less than or equal to 20 mm (4.2 +/- 2.5 mm) were compared with those of single stones greater than 20 mm (5.8 +/- 3.4 mm; P less than 0.05) and multiple stones (6.2 +/- 3.8 mm; P less than 0.05), respectively. None of the patients required anesthesia, analgesics, or sedatives before or during the treatment. The stone-free rates for all patients followed up for up to 4-12 months (mean +/- SD, 10.7 +/- 2.9 months) were 18% (1 month), 25% (2 months), 38% (4 months), 52% (8 months), and 67% (12 months). Partly significant differences were obtained in stone-free rates for single stones (less than or equal to 20 mm) compared with larger stones (greater than 20 mm) and multiple stones (P less than 0.05), respectively. Serious adverse reactions (i.e., cholestasis and pancreatitis) were observed in only 3 patients (3%). These conditions were induced by fragment impaction in the common bile duct. In 2 of these patients, endoscopic retrograde cholangiopancreatography with endoscopic sphincterotomy was required. It is concluded that piezoelectrically generated shock waves are suitable for the effective and safe disintegration of gallbladder stones in humans. The anesthesia-free and analgesia-free shock-wave application opens up the possibility to perform biliary lithotripsy as an outpatient procedure. The stone-free rate achieved in combination with oral bile acids is most promising for single stones (less than or equal to 20 mm).

Adult↗

PubMed2006

Recurrent symptomatic common bile duct stones after endoscopic stone extraction in elderly patients.

BACKGROUND: Endoscopic sphincterotomy (EST) and stone extraction are established therapeutic procedures for common bile duct (CBD) stones. Little is known about the outcomes of EST for CBD stones among elderly patients. OBJECTIVES: To examine the rate and the risk factors (CBD dilation and/or angulation, periampullary diverticulum, and past open cholecystectomy) for recurrent symptomatic CBD stones after EST in the elderly. DESIGN AND PATIENTS: A total of 228 patients who underwent EST for CBD stones in the period 1997 to 2004 were included. Follow-up data were obtained from medical records and by questioning all the patients. The correlation between age and stone recurrence, as well as between age and the prevalence of risk factors for recurrence was calculated. In addition, a subgroup of 45 elderly patients aged > or =80 years was compared with a control subgroup of 51 young patients aged < or =50 years, in terms of stone recurrence and associated risk factors. SETTING: Single-center, retrospective study. INTERVENTIONS: Endoscopic sphincterotomy. MAIN OUTCOME MEASUREMENTS: Symptomatic CBD stone recurrence rate and frequency of risk factors for it. RESULTS: In the group of all patients, a correlation was found between the age and stone recurrence, as well as between age and the known risk factors for recurrent stones. In analyzing the 2 subgroups, CBD stones recurred in 20% of the elderly patients compared with 4% of the young patients. Risk factors for recurrent CBD stones were more common in the elderly, and so was the presence of multiple risk factors in the same patient. CONCLUSIONS: Recurrence of symptomatic CBD stones after endoscopic therapy was more frequent in the elderly patients because of an increased frequency of risk factors.

Adult↗

PubMed2006

Is pelvicaliceal anatomy a risk factor for stone formation in patients with solitary upper caliceal stone?

OBJECTIVES: To investigate the effect of pelvicaliceal anatomy on stone formation in patients with solitary upper caliceal stones. METHODS: The records of patients with solitary upper caliceal stones between 1996 and 2004 were reviewed. After the exclusion of patients with hydronephrosis, major anatomic abnormalities, noncalcium stones, metabolic abnormalities, history of recurrent stone disease, multiple stones, and previous renal surgery, 42 patients (24 male, 18 female) and 42 healthy subjects (22 male, 20 female) with normal results on intravenous pyelography (IVP) were enrolled into the study. With a previously described formula, upper pole infundibulopelvic angle (IPA), infundibular length (IL) and width (IW), and pelvicaliceal volume of the stone-bearing and contralateral normal kidney of patients and bilateral normal kidneys of healthy subjects were measured from IVP. RESULTS: Forty-two stone-bearing and 126 normal kidneys (42 contralateral, 84 healthy) were assessed. The mean stone size was 153.47 mm2 (range, 20 to 896 mm2). There were no statistically significant differences in terms of upper caliceal specifications between stone-bearing and normal kidneys. The mean (+/- standard deviation) pelvicaliceal volume of 42 stone-bearing and 126 normal kidneys was 2455.2 +/- 1380.2 mm3 and 1845.7 +/- 1454.8 mm3, respectively (P = 0.019). These values were 2114 +/- 2081.5 mm3 (P = 0.34) and 1709.5 +/- 989.1 mm3 (P = 0.001) for contralateral normal kidneys (n = 42) and normal kidneys of healthy subjects (n = 84), respectively. CONCLUSIONS: Explanation of the etiology of the upper caliceal stone by the anatomic features is very difficult, and these caliceal anatomic variables (IPA, IL, IW) seem not to be a significant risk factor for stone formation in the upper calyx.

Adult↗

PubMed2006

Retrograde intrarenal stone surgery for extracorporeal shock-wave lithotripsy-resistant kidney stones.

OBJECTIVE: The newer flexible ureteroscopes, 150-200-microm holmium YAG laser fibres and superflexible Dormia baskets have made it possible to reach and treat stones in all parts of the kidney. The object of this evaluation was to study the outcome of retrograde intrarenal stone surgery (RIRS) for extracorporeal shock-wave lithotripsy (ESWL)-resistant kidney stones. MATERIAL AND METHODS: A total of 38 consecutive patients (18 males, 20 females) participated in the study. All patients had undergone ESWL prior to RIRS without success. In all cases the stones could be reached with the endoscope. Calculi ranged in size from 3 to 20 mm (mean 9 mm). In 32 cases the stones were fragmented using a holmium YAG laser and in six the stones could be extracted using zero-tip Dormia baskets without fragmentation. Sixteen patients had lower calyceal calculi and eight had an abnormal anatomy of the upper urinary tract. Intravenous pyelography was performed 6-8 weeks after the treatment. RESULTS: In all cases the stones could be reached and fragmented to some extent. After a single RIRS procedure, 22/38 patients (58%) were completely stone-free at follow-up, and four (11%) had residual fragments < or = 4 mm in size that were expected to pass spontaneously. Of the remaining 12 patients, who initially had larger stones (mean 11.3 mm), the residual fragments ranged in size from 5 to 15 mm. Three patients underwent an additional RIRS procedure, after which they were all completely stone-free, resulting in an overall success rate of 76%. There were no major complications. CONCLUSIONS: RIRS is a safe procedure with a high success rate and a low complication rate for ESWL-resistant renal stones. Patients with larger stones (> 10 mm), those with stones in the lower pole and those with an abnormal renal anatomy may require more than one procedure.

Adult↗

PubMed2003

Removal of asymptomatic ipsilateral renal stones following rigid ureteroscopy for ureteral stones.

PURPOSE: To evaluate the feasibility and outcome of flexible ureteroscopic removal of small (<1-cm) asymptomatic renal stone(s) following rigid ureteroscopy for ureteral stones. PATIENTS AND METHODS: Ten female and nineteen male patients underwent rigid ureteroscopy and holmium lasertripsy for removal of ureteral stone(s). All had asymptomatic renal stone(s) on the same side, which were then removed using flexible ureteroscopy. The renal stones were either removed intact with a tipless Nitinol basket or fragmented with the laser to small pieces (<2 mm), with basket removal of larger fragments. The number and size of stones, total operative time, added time needed for flexible ureteroscopy, and intraoperative and postoperative complications were recorded. Follow-up at 1 month included a plain abdominal film and renal ultrasonography or noncontrast CT scan. RESULTS: Fifty-six renal stones with a mean size of 5.7 mm were treated. Fourteen patients had stones on the right side, and 15 had stones on the left. The mean total operative time was 56.5 minutes, with a mean added time of 16.7 minutes for flexible ureteroscopy. Stones were removed intact in 18 patients and fragmented in 8 patients, resulting in an immediate success rate of 90%. There were three failures. One-month follow-up confirmed all patients were either stone-free or had residual fragments <2 mm in diameter, with no new-onset hydronephrosis. CONCLUSIONS: Removal of small asymptomatic renal stones at the time of ureteroscopy for ureteral stones appears safe and effective and requires little additional operative time.

Female↗

PubMed1988

Dissolution of calcified cholesterol stones and of brown and black pigment stones of the gallbladder.

The influence of different solvents on cholesterol and pigment stones was investigated in vitro. Stone analysis was performed chemically, with infrared spectroscopy (IRS), scanning electron microscopy, energy-dispersive X-microanalysis (EDXA) and wave-length-dispersive X-microanalysis (WDXA). Each set of stones came from one source: eight human calcified cholesterol stones (CHS), eight fragments of bovine radiopaque Ca-bilirubinate stones (BBIL), and two complete BBIL. CHS and BBIL fragments were treated with (1) a buffered, alkaline 1% ethylenediamine tetraacetate solution (BA-EDTA; pH 9.5); (2) with BA-EDTA and monooctanoin preparation (GMOC) alternately; (3) with GMOC alone, and (4) with methyl-tert-butyl ether (MTBE). The complete BBIL were treated with BA-EDTA and MTBE. Furthermore, two human black pigment stones (BPS) were incubated in BA-EDTA. Calcified cholesterol stones are not dissolved by GMOC alone, nor by alternating treatment with BA-EDTA. They are dissolved by MTBE. MTBE is unsuitable for complete Ca-bilirubinate stones but MTBE, GMOC and GMOC/BA-EDTA alternately disaggregate stone fragments. This means that stone fragments behave differently from complete Ca-bilirubinate stones, which is important for further in vitro investigations. Ca-bilirubinate and black pigment stones are disaggregated in BA-EDTA. These results were confirmed with six CHS, 12 BBIL and 12 BPS from 5 further patients, incubated in the most eligible solvent for any individual stone type.

Animals↗

PubMed1999

Renal stones and primary hyperparathyroidism: natural history of renal stone disease after successful parathyroidectomy.

The aim of the study was to evaluate the risk of renal stone recurrence after successful surgical treatment of primary hyperparathyroidism (pHPT). Of 297 consecutive patients with surgically verified pHPT, 151 patients had had renal stone disease; a total of 113 patients were eligible for follow-up; and of these, 107 patients remained normocalcemic during follow-up and formed the study group. The number of new stones were calculated by subtracting the stones present on preoperative urograms from the number of stones on urograms after 1, 3, and 5 years and the number of stones passed or eliminated by intervention. Among 107 patients, 32 (30%) formed one to four new stones within 5 years. This recurrence rate is comparable to the expected recurrence rate in idiopathic stone formers. Primary hyperparathyroidism and renal stone disease are common. As all renal stone formers are screened for pHPT by serum calcium analysis, the two diseases might by coincidence be found in the same patients. A considerable number of patients with pHPT and renal stone disease therefore experience recurrence of their stone disease irrespective of the presence of normocalcemia after successful parathyroidectomy.

Adolescent↗

PubMed2007

Serum, urinary and stone zinc, iron, magnesium and copper levels in idiopathic calcium oxalate stone patients.

Many theories have been put forward to explain the mechanism of stone formation and growth. The aim of this study was to investigate the urinary, serum and stone levels of zinc, iron, magnesium, and copper in patients with calcium oxalate stones and to investigate urinary and serum element levels in healthy controls and to find a possible connection between the elements and calcium oxalate stone formation. A total of 104 patients with calcium oxalate stones ranging in age from 3 to 79 years (mean 44.0 +/- 18.1) and 77 healthy controls ranging in age from 18 to 77 (mean 44.2 +/- 17.9) were included in this study. The mean urinary iron and copper levels in stone patients were significantly higher than healthy controls (P = 0.000). The mean urinary zinc and magnesium levels in healthy controls were significantly higher than stone patients (P = 0.000). There was no significant difference in the serum levels of magnesium and copper in stone patients and healthy controls. Serum zinc and iron level were significantly high in healthy controls as compared to stone patients. Each stone had all 4 elements. Zn and Mg have inhibitory effect on calcium oxalate stone formation. Fe and Cu could be promotor of the calcium oxalate stone formation.

Adolescent↗

PubMed2000

Calcium phosphate supersaturation regulates stone formation in genetic hypercalciuric stone-forming rats.

BACKGROUND: Hypercalciuria is the most common metabolic abnormality observed in patients with nephrolithiasis. Hypercalciuria raises urine supersaturation with respect to the solid phases of calcium oxalate and calcium phosphate, leading to an enhanced probability for nucleation and growth of crystals into clinically significant stones. However, there is little direct proof that supersaturation itself regulates stone formation. Through successive inbreeding of the most hypercalciuric progeny of hypercalciuric Sprague-Dawley rats, we have established a strain of rats, each of which excrete abnormally large amounts of urinary calcium and each of which forms calcium phosphate kidney stones. We used these hypercalciuric (GHS) rats to test the hypothesis that an isolated reduction in urine supersaturation, achieved by decreasing urine phosphorus excretion, would decrease stone formation in these rats. METHODS: Thirty 44th-generation female GHS rats were randomly divided into three groups. Ten rats received a high-phosphorus diet (0.565% phosphorus), 10 a medium-phosphorus diet (0.395% phosphorus), and 10 a low-phosphorus diet (0.225% phosphorus) for a total of 18 weeks. The lowered dietary phosphorus would be expected to result in a decrease in urine phosphorus excretion and a decrease in urinary supersaturation with respect to the calcium phosphate solid phase. Every two weeks, 24-hour urine collections were obtained. All relevant ions were measured, and supersaturation with respect to calcium oxalate and calcium hydrogen phosphate were determined. At the conclusion of the experiment, each rat was killed, and the kidneys, ureters, and bladder were dissected en block and x-rayed to determine whether any stones formed. A decrease in stone formation with a reduction in urinary supersaturation would support the hypothesis that supersaturation alone can regulate stone formation. RESULTS: Decreasing the dietary phosphorus intake led to a progressive decrease in urine phosphorus excretion and an increase in urine calcium excretion, the latter presumably caused by decreased intestinal calcium phosphate binding and increased calcium absorption. With decreasing dietary phosphorus intake, there was a progressive decrease in saturation with respect to the calcium phosphate solid phase. Fifteen of the 20 kidneys from the 10 rats fed the high-phosphorus diet had radiographic evidence of kidney stone formation, whereas no kidneys from the rats fed either the medium- or low-phosphorus diet developed kidney stones. CONCLUSIONS: A decrease in urine phosphorus excretion not only led to a decrease in urine supersaturation with respect to the calcium phosphate solid phase but to an elimination of renal stone formation. The results of this study support the hypothesis that variation in supersaturation alone can regulate renal stone formation. Whether a reduction of dietary phosphorus will alter stone formation in humans with calcium phosphate nephrolithiasis remains to be determined.

Animals↗

PubMed2006

Efficacy of dretler stone cone in the treatment of ureteral stones with pneumatic lithotripsy.

INTRODUCTION: Ureteroscopic pneumatic lithotripsy has been used to treat ureteral calculi for more than 10 years. Owing to its low price and high degree of effectiveness, it has become the most popular ureteroscopic lithotripsy device in use worldwide. The major limitation of the technique is the occurrence of proximal fragment migration during intracorporeal lithotripsy. The Dretler Stone Cone is a new device developed to prevent stone migration during ureteroscopic lithotripsy. The aim of this study was to assess the efficacy and safety of this device during ureteroscopic pneumatic lithotripsy. PATIENTS AND METHODS: Twenty-three consecutive patients having ureteral stones were treated with a 10-Fr semirigid ureteroscope, a Stone Cone Nitinol Retrieval Device, and a pneumatic lithotriptor. In all patients Stone Cones were placed under visual guidance through the working channel of the ureteroscope. Outcomes of this device were then compared with the outcomes of 23 previous patients with stones of similar sizes and locations who had undergone ureteroscopic pneumatic lithotripsy prior to the Stone Cone being available at our clinic. RESULTS: All patients in the study group were stone-free after the procedure. No stone fragments were noted to migrate to proximal segments. CONCLUSIONS: The Dretler Stone Cone effectively prevents proximal stone migration and facilitates stone fragmentation during pneumatic lithotripsy with no risk of ureteral injury. It has only a small extra cost.

Equipment Design↗

PubMed2006

[Urinary stones in Western Algeria: study of the composition of 1,354 urinary stones in relation to their anatomical site and the age and gender of the patients].

INTRODUCTION: The prevalence of urinary stones runs parallel with the socioeconomic and health level of populations. Few data are currently available concerning the characteristics of urinary stones in Algeria. Based on our recruitment of stones derived from the main teaching hospital urology departments of Western Algeria, we defined the stone profile in this region of North Africa and its changes in relation to previous data. MATERIAL AND METHOD: A series of 1,354 stones derived from urology departments in Western Algeria was studied by IRTF spectroscopy. Analysis of the results concerned the crystalline composition and anatomical site of the stones and the age and gender of the patients. RESULTS AND DISCUSSION: Conventional surgery is the method of extraction most frequently used with 79.7% of operations contre 0.2% for extracorporeal lithotripsy. The male/female ratio has remained almost constant at 2.23. The anatomical site has changed with a predominance in the upper tract (77.4% of stones). The proportions of whewellite and weddellite have increased compared to our first series, from 48.1% to 50.3% and 13.1% to 16.7%, respectively, while phosphates decreased from 24.4% to 16.7%. The presence of struvite has not decreased over recent years, as 28.8% of stones contain this type of crystal. Anhydrous uric acid has slightly increased to 8.8% versus 6.2%. The proportions of ammonium urate and cystine have not changed (1.8% and 0.7%, respectively), but ammonium urate forms is less frequently the nucleus of stones than previously (2% versus 5.89%). The study of the nucleus showed that phosphates are predominant in 48.6% of cases versus 35.6% for oxalates. Carbapatite and struvite are more frequent in women, found in 50.8% and 6.7% of cases, respectively, than in man, found in 44.6% and 3.7% of cases, respectively. Calcium oxalate is predominantly found in the upper urinary tract (70.9%) rather than in the bladder (48.3%), regardless of gender. Calcium phosphate is more abundant in the upper tract of females with 23.7% of cases versus 10.7% in the bladder. It is equally distributed between the bladder and the upper tract in males (13.7% and 13.2%, respectively). Examination of the side affected by stones showed a predominance of the left side in both sexes. CONCLUSION: Analysis of these data shows that urinary stones in Western Algeria are tending to evolve in the same direction as in industrialized countries, but urinary tract infection remais a frequent cause of stones.

Adolescent↗

PubMed1979

Composition of renal stones and their frequency in a stone clinic: relationship to parameters of mineral metabolism in serum and urine.

Stone analyses (kidney, upper urinary tract) of the department of Urology, University of Erlangen, from a four-year-period (1974-1977) have been recorded with emphasis to stone composition, sex and age of the pertinent stone forming patients. During this time period there were no substantial changes as regards the per cent frequency of the various stone types. The most frequent type was calcium oxalate (CaOx), followed by uric acid, calcium phosphate (CaP), struvite and cystine. Stone analyses were mostly requested for patients between 46 and 55 years of age. Stone incidence in our clinic is calculated to be 1.22 times higher in males than females, especially beyond 36 years of age. The frequency peaks are: pure (= 100 per cent) CaOx 36-45 years; CaOx with additional mineral phases (mostly CaP) 46-55 years; uric acid 56-65 years; CaP 26-35 years. From those patients who underwent further investigations in searching for metabolic abnormalities serum concentrations, urine mineral clearances in fasting urine samples, and activity products of stone forming mineral phases in sequentially collected specimens from 24 h and 2 h fasting urine had been measured and compared with values from healthy control subjects. In urolithiasis (idiopathic) there is a normal parathyroid hormone blood level, a generally lower serum inorganic phosphate and magnesium concentration. In pure (= 100 per cent) CaOx and uric acid lithiasis serum uric acid and creatinine are higher than in controls, urine pH and calcium clearance in some groups are different too. Clearances of magnesium, uric acid, phosphate, sodium are within normal limits in urolithiasis. When expressing the propensity to form stones in terms of activity products, then only uric acid lithiasis deviates substantially from normal. All other stone types differ only slightly or not at all from each other and controls respectively. It is concluded that 1) in our geographic region the various stone types prevail in different age periods; 2) there are distinct alterations of parameters of mineral metabolism in urolithiasis; 3) measuring urine clearances may lead to assume falsely normal mean urine excretion of stone forming constituents.

Adolescent↗

PubMed1990

Extracorporeal lithotripsy of bile duct stones using ultrasonography for stone localization.

In 19 patients, extraction of bile duct stones through the papilla using a Dormia basket or a mechanical lithotripter was not possible following endoscopic sphincterotomy. After the insertion of a nasobiliary drain, extracorporeal lithotripsy was performed with intravenous sedation using an ultrasonographic stone localization system. The number and location of stones were first determined by retrograde cholangiography. At the time of lithotripsy, saline was injected in the bile ducts to modify the acoustic impedance of tissues surrounding the stones, and subsequent ultrasonography was effective in localizing all stones present in 4 of 5 (80%) patients with intrahepatic stones, and 13 of 14 (93%) with common bile duct stones. In 10 patients (53%), fragmentation was satisfactory and the bile ducts were cleared completely. The mean single stone diameter was significantly smaller in successful cases of fragmentation compared with failures (22.8 +/- 6.6 mm vs. 40 +/- 10 mm). The results in patients with multiple stones were significantly worse than those in patients with single stones of similar size (25% vs. 100% successful fragmentation). Reasons for this difference in results included the small size of the focal area and the reduced ability of ultrasonography (1) to adequately visualize multiple calculi individually and (2) to assess the degree of stone destruction. Care was taken to first await the resolution of infection or the correction of coagulation abnormalities when present; no morbidity following extracorporeal lithotripsy was observed. Despite its 3-step approach (endoscopic sphincterotomy, lithotripsy, and endoscopic extraction), the need for only intravenous sedation and the absence of patient immersion in water render this technique attractive for elderly and frail patients.

Adult↗

PubMed2002

Presence of lipids in urine, crystals and stones: implications for the formation of kidney stones.

BACKGROUND: Cell membranes and their lipids play critical roles in calcification. Specific membrane phospholipids promote the formation of calcium phosphate and become a part of the organic matrix of growing calcification. We propose that membrane lipids also promote the formation of calcium oxalate (CaOx) and calcium phosphate (CaP) containing kidney stones, and become a part of their stone matrix. METHODS: Human urine, crystals of CaOx and CaP produced in the urine of healthy individuals, and urinary stones containing struvite, uric acid, CaOx and CaP crystals for the presence of membrane lipids were analyzed. Crystallization of CaOx monohydrate at Langmuir monolayers of dipalmitoylphosphatidylglycerol (DPPG), dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylserine (DPPS), dioleoylphosphatidylglycerol (DOPG), palmitoyloleoylphosphatidylglycerol (POPG) and dimyristoylphosphatidylglycerol (DMPG) was investigated to directly demonstrate that phospholipid assemblies can catalyze CaOx nucleation. RESULTS: Urine as well as CaOx and CaP crystals made in the urine and various types of urinary stones investigated contained some lipids. Urine of both CaOx and uric acid stone formers contained significantly more cholesterol, cholesterol ester and triglycerides than urine of healthy subjects. However, urine of CaOx stone formers contained more acidic phospholipids. The organic matrix of calcific stones contained significantly more acidic and complexed phospholipids than uric acid and struvite stones. For each Langmuir monolayer precipitation was heterogeneous and selective with respect to the orientation and morphology of the CaOx crystals. Crystals were predominantly monohydrate, and most often grew singly with the calcium rich (10-1) face toward the monolayer. The number of crystals/mm2 decreased in the order DPPG> DPPC and was inversely proportional to surface pressure and mean molecular area/molecule. CONCLUSIONS: Stone forming conditions in the kidneys greatly impact their epithelial cells producing significant differences in the urinary lipids between healthy and stone forming individuals. Altered membrane lipids promote face selective nucleation and retention of calcium oxalate crystals, and in the process become a part of the growing crystals and stones.

1,2-Dipalmitoylphosphatidylcholine↗

PubMed1997

Laser fragmentation of pancreatic duct stones using a rhodamine laser with an automatic stone-tissue detection system. Basic in-vitro studies.

OBJECTIVES: The aim of our study was to examine the suitability of a rhodamine 6G laser with an integrated stone-tissue detection system (STDS) for fragmenting pancreatic stones. METHODS: A total of 64 pancreatic duct stones were measured for weight, diameter, main chemical components and in some cases for their computerized tomography density. Recognition of all stones was checked with the standard STDS or a prototype version. Number of fragmentation pulses, total fragmentation energies and correlation with the individual stone parameters were determined. The quality of the tissue-detection mode was evaluated in postmortem pancreata. RESULTS: The standard STDS detected only 45% of the pancreatic stones correctly. When using the prototype, the detection rate improved significantly up to 75% (P < 0.01). All laser pulses were cut off if tissue contact occurred. All the stones were completely disintegrated by the laser pulses. A slight correlation was found only between the required fragmentation energy and the stone weight (linear regression: R2 = 0.77); other factors had no significant impact. CONCLUSION: The rhodamine 6G laser is suitable for the fragmentation of pancreatic stones in vitro. The integrated STDS is less effective for pancreatic stones than reported for biliary stones.

Calculi↗

PubMed2004

Midstream urine culture and sensitivity test is a poor predictor of infected urine proximal to the obstructing ureteral stone or infected stones: a prospective clinical study.

PURPOSE: This prospective study was performed to determine if midstream urine (MSU) culture and sensitivity (C&S) alone could adequately predict infected urine proximal to the obstructing ureteral stone or the infected stones. Can pelvic urine C&S predict infected stones? MATERIALS AND METHODS: A prospective clinical study was performed on all patients undergoing ureterorenoscopy and lithotripsy for ureteral stones with obstruction between December 1, 2000 and January 31, 2002. We obtained MSU, renal pelvic urine and fragmented stones for culture and sensitivity. An analysis of the data was performed to assess statistical association. RESULTS: A total of 73 patients who fulfilled the criteria were recruited. Of these patients 25 (34.3%) had positive stone culture, 43 (58.9%) had positive pelvic urine and 21 (28.8%) patients had positive MSU C&S. Stone and pelvic C&S were positive simultaneously in 17 (23.3%) cases, MSU and stone C&S were positive in 8 (10.9%) cases, whereas pelvic and MSU C&S were positive in 13 (16.4%) cases (p = 0.03). MSU C&S had a sensitivity of 30.2% and specificity of 73% to detect pelvic urine C&S positivity. MSU C&S had a low positive predictive value and negative predictive value (NPV) in relation to infected pelvic urine (positive predictive value = 0.62, NPV = 0.42). Pelvic urine C&S had a NPV of 0.73 in detecting noninfected stones. CONCLUSIONS: The results of this study suggest that in obstructive uropathy secondary to a stone MSU C&S is a poor predictor of infected urine proximal to the obstruction and infected stones.

Adolescent↗

PubMed1984

Gall stones and mortality: a study of all gall stone related deaths in a single health district.

In a prospective study of gall stone related deaths in a single Health District, the biliary tract was examined at necropsy in 1701 cases and 8078 death certificates were searched. Gall stones were identified as the cause of death in only 21 cases (0.26%) but in 291 subjects found to have gall stones or cholecystectomy at necropsy, the mortality was 3.4%. The necropsy prevalence of gall stones in the adult population was 17.1% but nine out of 10 subjects with gall stones had not had a cholecystectomy and women were three times more likely to have had their gall stones removed than men. There were five postoperative deaths (mean age 60 years) with an operative mortality for cholecystectomy in the district of 1.2%. Death due to unoperated gall stones was identified in 16 subjects, most of whom were very elderly women (mean age 81) but carcinoma of the gall bladder was only found in one woman of 90 with gall stones. The prevalence of gall stones rose with age in both sexes but the cholecystectomy rate per head of population at-risk declined sharply in the seventh decade in women and the eighth decade in men. There are a large number of people with unoperated gall stones in the population but gall stone related deaths are very uncommon. The cholecystectomy rate in Britain, however, seems to be rising and it is suggested that if this trend continues there may be an increased number of deaths.

Adult↗