Clinical course and cystine stone formation during tiopronin treatment

The formation of stones in patients with cystinuria can be counteracted by reducing the urinary concentration of cystine and by increasing its solubility. Thirty-one patients with homozygous cystinuria and treated with tiopronin (2-mercaptopropionylglycine) were followed for between 0.4 and 12 years (median 8.8). With the aim of avoiding cystine concentrations above 1200 mol/l, the daily dose varied between 500 and 3000 mg (median 1500). The therapeutic effect was evaluated from the clinical symptoms and repeated radiographic examinations. The rate of stone formation during the treatment period was reduced by 60% in comparison with the pretreatment period (P< 0.001). The frequency of active stone removal was reduced by 72% (P< 0.05). The formation of new stones was associated with a higher cystine concentration than was the case during periods when stone formation and stone growth were excluded (P< 0.005). The probability of new stone formation increased with increasing concentrations of cystine up to 1100 mol/l, but stone formation was not accentuated above 1200 mol/l. There was no significant relationship between the 24 h excretion of cystine and stone formation.It is concluded that the formation of cystine stones can be efficiently counteracted during treatment with tiopronin, guided by analysis of the concentration of urinary cystine.     

Cystine calculi: correlation of CT-visible structure,CT number,and stone morphology with fragmentation by shock wave lithotripsy

Cystine stones are often highly resistant to shock wave lithotripsy (SWL), but it has been reported that cystine stones of "rough" morphology are actually quite susceptible to SWL. Based on the observation that rough cystine stones contain void regions that are visible by helical computed tomographic (CT) imaging, we hypothesized that the internal structure of cystine stones would correlate with the susceptibility of stones to SWL. Cystine stones with average diameters between 4 and 7 mm were scanned using micro and helical CT, classified morphologically according to published criteria, and broken in a research electrohydraulic lithotripter, with fragments sieved through a 2 mm mesh every 50 SWs. Stones with regions of low X-ray attenuation visible on helical CT required only 650 +/- 312 SW/g for total comminution, while those that did not show CT-visible internal structure required 1,046 +/- 307 SW/g (mean +/- SD, P < 0.004). In addition, both average and minimum values for CT number (in Hounsfield units, HU) correlated with SW/g to comminution (P < 0.003 and P < 0.0003, respectively), and these relationships were independent of stone size. This study also confirmed the relationship between the morphological criteria of Bhatta et al. (J Urol 142:937-940, 1989) and cystine stone fragility: Rough stones required 609 +/- 244 SW/g (n = 11), smooth stones 1,109 +/- 308 SW/g (n = 8), and stones intermediate in morphology 869 +/- 384 SW/g (n = 7; rough different from smooth, P < 0.005). In conclusion, cystine stones that appeared homogeneous by helical CT required 61% more SWs for comminution than did stones showing regions of low X-ray attenuation. These findings demonstrate the feasibility of using helical CT to identify cystine stones that will be susceptible to SWL.     

尿石红外光谱和电镜图像与尿石成因的相关性研究

目的 通过对尿路结石红外光谱和电镜图像的观察分析，对尿路结石的形成机制进行研究。方法 应用红外光谱仪对陕西地区140例尿路结石进行成分分析，并对其中典型结石进行扫描电镜超微结构观察。结果 尿路结石主要由一水草酸钙、二水草酸钙、碳酸磷灰石、羟基磷灰石、磷酸镁铵、尿酸、胱酸和基质构成，其中混合结石占76．5％；电镜下各种成分晶体具有不同的晶格特性，并按不同的排列方式混合分布。结论 尿路结石是由多种晶体和基质构成的混合性结石；尿路感染、尿液中的酸碱度的改变及各种晶体成分在尿液中的饱和度的升高，均可促使尿路结石的形成及生长。     

Influence of body size on urinary stone composition in men and women

A larger body size has been shown to be associated with increased excretion of urinary lithogenic solutes, and an increased risk of nephrolithiasis has been reported in overweight patients. However, the type of stones produced in these subjects has not been ascertained. Based on a large series of calculi, we examined the relationship between body size and the composition of stones, in order to assess which type of stone is predominantly favoured by overweight. Among 18,845 consecutive calculi referred to our laboratory, 2,100 came from adults with recorded body height and weight. Excluding calculi from patients with diabetes mellitus, as well as struvite and cystine stones, the study material consisted of 1,931 calcium or uric acid calculi. All calculi were analysed by infrared spectroscopy and categorized according to their main component. Body mass index (BMI) values were stratified as normal BMI (<25 kg/m²), overweight (BMI 25–29.9) or obese (BMI≥30). Overall, 27.1% of male and 19.6% of female stone formers were overweight, and 8.4 and 13.5% were obese, respectively. In males, the proportion of calcium stones was lower in overweight and obese groups than in normal BMI group, whereas the proportion of uric acid stones gradually increased with BMI, from 7.1% in normal BMI to 28.7% in obese subjects (P<0.0001). The same was true in females, with a proportion of uric acid stones rising from 6.1% in normal BMI to 17.1% in obese patients (P=0.003). In addition, the proportion of uric acid stones markedly rose with age in both genders (P<0.0001). The average BMI value was significantly higher in uric acid stone formers aged <60 years than in all other groups, whereas it did not differ from other groups in those aged ≥60 years. Stepwise regression analysis identified BMI and age as significant, independent covariates associated with the risk of uric acid stones. Our data provide evidence that overweight is associated with a high proportion of uric acid stones in patients less than 60 years of age, whereas beyond this limit, advancing age is the main risk factor.     

Comparison of renal function and metabolic abnormalities of cystine stone patients and calcium oxalate stone patients in China

Purpose

To compare renal function and metabolic abnormalities of cystine stone patients and calcium oxalate stone patients in China.

Methods

Between 2008 and 2011, thirty cystine stone patients were involved in our study, and an equal number of age- and gender pair-matched patients with calcium oxalate stones. Non-stone forming individuals were elected as controls. The evaluation included blood chemistry studies and 24-h urine collection in both groups of patients.

Results

The cystine stone patients had higher mean values of serum blood urea nitrogen, urate and creatinine levels than patients in other two groups. With respect to urine risk factors, cystine stone patients had higher urinary citrate and lower urinary oxalate and creatinine than calcium oxalate stone patients. When compared to non-stone forming individuals, cystine stone patients had higher urinary urate excretion and lower urinary creatinine excretion. Metabolic abnormalities could be demonstrated in 80 % of the cystine stone patients and in 100 % of the calcium oxalate stone patients. We also compared urine risk factors among cystine stone patients with different urine cystine excretion (<1 mmol/24 h, 1–2 mmol/24 h and >2 mmol/24 h). No significant difference was found in urine risk factors among three groups.

Conclusions

This study suggested that cystine stone patients were at greater risk for the loss of renal function than calcium oxalate stone patients, but the risk of the formation of calcium oxalate stones was lower. Our results also indicated that urinary cystine had little or no impact on the excretion of urine chemistries in cystine stone patients.     

Percutaneous chemolitholysis of cystine stone

Although cystine stone accounts for only 1-3% of renal calculi, many of the pure cystine stones usually can not be fragmented by ESWL and the residuals after PCNL is quite common. Percutaneous dissolution alone or combined with ESWL and PCNL could successfully dissolve these stones including all the residuals. This paper reported seven patients (8 pieces of renal and 2 pieces of ureteral stones) with cystine calculi in whom percutaneous renal irrigation or per-ureteral catheter irrigation with tromethamine-E (THAM-E) were performed for a relatively short period of time. All the stones disappeared completely or near completely. The authors recommend that percutaneous irrigation alone (including irrigation with ureteral catheter) or combined with PCNL and ESWL are the method of choice in the treatment of pure cystine stone of the kidney.     

Crystalline composition of urinary stones in recurrent stone formers

175 stones from 70 recurrent stone formers with each at least two stones available for analysis were studied crystallographically. The chance that a subsequent stone belonged to the same of five major stone groups was 65% but rose to 91% if three of these groups were considered as one (calcium stones). Other findings, however, indicate that distinction between the three groups of calcium stones is of interest. Thus, pure calcium oxalate stones (Ox) did not occur in the same patients as pure calcium phosphate stones (P). In comparable stones containing both the above types of components (OxP), the calcium phosphate content was significantly lower (average apatite content per stone 9%) in stones from patients who also had Ox stones than (37%) in those who had associated P stones. Also, the stone nucleus was frequently Ox in the OxP stones from the former and usually P in the OxP stones of the latter patients. Brushite occurred in 10% of the stones, which is more frequent than in unselected stone materials and largely due to a tendency for it to recur in a few patients. Patients who provide more than one stone for analysis appear to differ considerably in stone composition from stone patients in general, and inclusion of several stones from some patients will lead to bias in materials purporting to reflect stone composition in a population. When available, several stones from each patient should preferably be analysed. Exceptions may be made for cystine and, possibly, pure uric acid stone patients.     

Lower-caliceal stone clearance index to predict clearance of stone after SWL

BACKGROUND AND PURPOSE: There is no uniform consensus regarding the anatomic factors that influence the clearance rate of caliceal stones after SWL, as different authors have studied various independent factors separately. We correlated both favorable and unfavorable factors into a formula to predict the clearance rate. PATIENTS AND METHODS: A series of 56 consecutive patients (37 male, 19 female) with isolated lower-caliceal single stones (right 29, left 27) treated with SWL using the Dornier Compact Delta lithotripter were analyzed retrospectively. Of these, 40 patients had soft stones, and 16 patients had hard stones. The first stone-free rate (SFR) according to plain films and ultrasonography was analyzed by stone size, and a stone clearance index (SCI) formula was applied to see if there was any change in the SFR, especially for stones >2 cm. RESULTS: The formula, which correlated well with the clearance, is SCI = [(IVA x IW x stone type)/IH] - (stone size in mm(2)/10). Nearly all (90%) of the patients with an SCI of >0 cleared their stones within 3 months, and 87% of the patients with an SCI <0 cleared their stones after 3 months. Positive and negative predictive values were 93.33% and 76.9%, respectively. The accuracy of the correlation is 85.71%. CONCLUSIONS: The success of SWL for lower-caliceal stones can be predicted easily using the SCI. Stones of >200 mm(2) (>2 cm) surface area may still be suitable for SWL if the SCI is positive, whereas alternative treatment modalities should be considered if the SCI is a low negative value (<-7).     

A strategy of cystine stone management.

Simple mechanical disintegration of cystine calculi by extracorporeal shock wave lithotripsy and/or percutaneous nephrolithotomy is being performed widely around the world. However, it cannot be denied that the cystine calculus is one of the most difficult stones for mechanical disintegration. We previously reported the oral medical chemolysis of cystine calculi in 1982 and a third of the patients became stone-free. In another third of the patients the cystine component was replaced by apatite during the medical treatment and apatite stones formed in this manner are easily disintegrated. In view of the complications of mechanical disintegration, oral medical treatment for chemolysis should be recommended before simple destruction of cystine calculi.     

Impact of stone size, location, composition, impaction, and hydronephrosis on the efficacy of holmium:YAG-laser ureterolithotripsy

OBJECTIVES: The impact and outcome of holmium:YAG-laser (Ho:YAG) ureterolithotripsy in treating proximal and distal ureteral stones was investigated. METHODS: A total of 543 patients harbouring proximal (n=194) or distal (n=349) ureteral stones underwent semirigid Ho:YAG ureterolithotripsy. The degree of hydronephrosis; stone size, location, impaction, and composition; and complication and stone-free rates were recorded. RESULTS: Mean stone size for proximal and distal stones was 7.1+/-3.6 mm and 6.2+/-2.5 mm, respectively. The stone-free rate on the first postoperative day was 79.4% for proximal and 96.8% for distal stones (p<0.0001). For proximal stones <10mm and > or =10mm, respectively, the stone-free rate was 80.5% and 74.3% (p=0.4) and for distal stones 97.3% and 94.3% (p=0.2). Stone-free rates for radio-opaque versus radiolucent stones in proximal stones were 79.6% versus 77.9% (p=0.8) and 97.6% versus 96.2% in distal stones (p=0.5). Impaction correlated significantly with stone-free rates (p<0.0001). Stone-free rates for nonimpacted versus impacted proximal stones were 85.8% versus 67.2% (p=0.003) and for distal stones 99.2% versus 91.4% (p<0.003), respectively. The presence or degree of hydronephrosis did not correlate with treatment success (p=0.4, p=0.8). The presence of intraoperative complications correlated significantly with proximal compared to distal ureteral stone location (p=0.004). Auxiliary measures in proximal versus distal stones were performed in 20.6% versus 2.9% (p<0.0001). CONCLUSIONS: In this series, stone-free rates in Ho:YAG ureterolithotripsy were significantly higher in distal and nonimpacted stones but were independent of stone size and composition and the degree of hydronephrosis. Ureterolithotripsy in proximal stones was associated with higher intraoperative complication and retreatment rates compared to distal stones.     

Retrograde intrarenal surgery for the treatment of renal stones in children: Factors influencing stone clearance and complications

Background

Retrograde intrarenal surgery (RIRS) is a known option for the treatment of upper tract calculi with an excellent success. However, the reports of RIRS in prepubertal children are limited. In this study, we evaluated the factors which affected the success rate and the complications of RIRS at renal stone treatment in childhood.

Methods

We retrospectively reviewed the records of children under 14 years old who underwent RIRS for renal stone disease between January 2009 and December 2012. Patients’ age, gender, body mass index (BMI), stone size, stone location, stone number, intraoperative complications, stone free status, postoperative complications were recorded.

Results

There were 80 ureterorenoscopic procedures performed in 58 renal units of 47 children (23 males and 24 females). The patients’ ages ranged from 8 months to 14 years (mean age 4.7 ± 3.4 years). There was a difference in the distribution of symptoms in age groups. UTI was higher in the 1–4 years age group, abdominal pain was seen mostly in children aged 5–14 years. Multiple stones (included staghorn stone) were noted in 60.4% of patients. In 27.6% of patients, ureteral stones were accompanied by renal stones in our series. In the infancy group, cystine and staghorn stones were more frequently seen, mostly bilateral. After a single ureteroscopic procedure for intrarenal stones in children, we achieved stone free status in 50.9% of the ureters (n = 26). After the repeated sessions, the stone clearance rate reached to 85.1%.

Conclusion

Retrograde intrarenal surgery can be used as a first line therapy to treat renal stones in children. This is especially important if an associated ureteral stone is present that requires treatment; or in patients with cystinuria, which is not favorably treated with ESWL. Complications were seen more frequently in patients with cystine stones. Extravasation was noted more frequently in patients admitted with UTIs. There was a significant relationship between the conversion to open procedures and the age groups, with most procedures occurring in infancy. The parents should be informed about the probability of multiple procedures to achieve stone free status.     

Epidemiology and medical management of stone disease

Recurrent stone formation in the urinary tract is a common and important problem that must be considered in daily urological practice. With a prevalence of> 10% and an expected recurrence rate of approximately 50%, stone disease has an important effect on the healthcare system. It is generally agreed that patients with uric acid/urate, cystine or infection stones always should be treated pharmacologically. For calcium stone formers the treatment should be chosen according to the severity of the disease. Recurrence in patients with calcium-stone disease can be prevented with general or specific dietary and drinking advice, and with pharmacological therapy. For idiopathic calcium stone formers the most convincing therapeutic effects have been reported with thiazide and alkaline citrate.     

Improvement of stone comminution by slow delivery rate of shock waves in extracorporeal lithotripsy

AIM: The aim of this study was to investigate the effect of delivery rate of shockwaves (SW) on stone comminution and treatment outcomes in patients with renal and ureteral stones. METHODS: Patients with radio-opaque stones in the upper urinary tract that were treated by extracorporeal shock wave lithotripsy (ESWL) were divided into two groups according to delivery rate (120 or 60 SW/min). The effective fragmentation after one ESWL session and treatment success at 3 months after ESWL was compared between the two groups. RESULTS: Of 134 patients (84 men and 50 women), 68 patients were treated at a fast rate and 66 were treated at a slow rate. Thirty and 38 patients in the fast rate group and 28 and 38 in the slow rate group had renal and ureteral stones, respectively. After one ESWL session, effective fragmentation was noted more often in the slow group (65.2%) than the fast group (47.1%) (P = 0.035), particularly for smaller stones (stone area <100 mm(2)) (P = 0.005) and renal stones (p = 0.005). However, there was no significant difference in treatment success at 3 months after ESWL between the two groups. In univariate logistic regression analysis, slow SW rate and smaller stones were significant factors for effective fragmentation after one ESWL session. In multivariate analysis, slow SW rate and smaller stones were also independent factors. CONCLUSIONS: Slow SW rate contributed to better stone comminution than fast rate, particularly for small stones and renal stones. ESWL treatment at a slow SW rate is recommended to obtain efficient stone fragmentation.     

The role of bacteria in gallbladder and common duct stone formation

Debate continues as to the role that bacteria play in gallstone pathogenesis in Western countries. We therefore, examined gallbladder and common duct stones from 67 consecutive patients undergoing cholecystectomy and/or common bile duct exploration. Bile was cultured and stone cholesterol content was measured. Stones were examined by scanning electron microscopy (SEM) for bacteria. Individual calcium salts were classified by windowless energy-dispersive x-ray microanalysis. Gallbladder stones in 65 patients were identified as cholesterol in 46 (71%), black pigment in 17 (26%), and brown pigment in 2 patients (3%). Common bile duct stones from ten patients were cholesterol in 4, black pigment in 2, and brown pigment in 4 patients. The five patients with brown pigment stones were significantly (p less than 0.05) older, more likely to be men and to present with bile duct obstruction. Bile cultures were positive in 13% of patients with cholesterol stones, in 14% of those with black pigment stones, and in all of the patients with brown pigment stones (p less than 0.001). By SEM, bacteria were observed only within the calcium bilirubinate-protein matrix of brown pigment stones (p less than 0.001). In comparison to black pigment stones, brown stones were more likely to contain calcium palmitate (p less than 0.005) and cholesterol (p less than 0.001). We conclude that black and brown pigment stones have different pathogenic mechanisms and that bacterial infection is important only in the formation of brown pigment stones.     

Prevention of stone disease

In recent years stone disease has become more widespread in developed countries. At present the prevalence is 5.2 and 15% of men and 6% of women are affected. The increase is linked to changes in lifestyle, eating patterns and obesity which has become very common. The 'metabolic syndrome' includes all the diseases, e.g. hypertension, lipid imbalances, type 2 diabetes mellitus, gout and cardiovascular disease, which are concomitant in the majority of stone formers. Dietary patterns, besides leading to stone formation, also determine stone chemistry. With a diet that is rich in oxalates, calcium oxalate will constitute 75% of stones, struvite 10-20%, uric acid 5-6% and cystine 1%. As approximately 50% of patients with stones suffer recurrences, metabolic and/or pharmacological prophylaxis is recommended.     

结石红外光谱自动分析系统在尿路结石成分分析中的应用

目的 评价红外光谱自动分析系统检测尿路结石成分的临床应用价值.方法 尿路结石标本1450例.男1032例,女418例.年龄6个月～88岁.男性平均年龄(41.7±15.3)岁,女性(42.0±15.6)岁.肾结石875例(60.34%),输尿管结石504例(34.76%),膀胱结石71例(4.90%).均采用LIIR型结石红外光谱自动分析系统分析.解析结果均行红外光谱人工解析验证,必要时辅以偏光显微镜、X线衍射或化学方法进行验证. 结果在结石总体构成比上,一水草酸钙结石714例(49.24%),碳酸磷灰石结石444例(30.62%),无水尿酸结石93例(6.41%),二水草酸钙结石92例(6.34%),六水磷酸铵镁结石28例(1.93%),胱氨酸结石23例(1.59%),尿酸铵结石20例(1.38%),二水尿酸结石16例(1.10%),二水磷酸氢钙结石12例(0.83%),一水尿酸钠结石2例(0.14%),碳酸钙结石1例(0.07%),其他5例(0.34%).结石的组合成分上,混合性结石1053例(72.62%),单一成分结石仅397例(27.38%).混合性结石主要为含钙类结石.其中15例婴幼儿结石为食用三聚氰胺污染奶粉所致,成分为二水尿酸与尿酸铵的混合结石.验证结果表明,结石主要成分误检6例(0.41%),将无水尿酸误检为尿酸铵或碳酸磷灰石;漏检9例(0.62%),其中漏检六水磷酸铵镁或碳酸磷灰石7例,性质不明2例.在2种和3种成分的混合性结石中,含量相对低的成分各漏检6例和10例,均为六水磷酸铵镁或碳酸磷灰石. 结论结石红外光谱自动分析系统分析尿路结石成分具有准确、自动、快捷等优点,适合临床常规使用.

Abstract：

Objective To determine the value of applying LIIR Automatic Analysis System of Infrared Spectroscopy in analyzing urinary stone composition. Methods 1450 samples of urinary stones were collected from 1032 male and 418 female patients. The age of patients ranged from 6 months to 88 years. The mean ages were 41.7±15.3 and 42.0±15.6 years for male and female patients, respectively. Of 1450 stones, 875 cases were located in kidney (60.34%), 504 cases in ureter (34.76%) and 71 cases in bladder (4.90%). All stones were analyzed by LIIR Automatic Analysis System of Infrared Spectroscopy (Tianjin). Analysis results were reevaluated by the artificial analysis of spectrogram, if necessary, with polarization microscope, chemical analysis, and X-ray diffraction.Results Calcium oxalate monohydrate stones were found in 714 cases (49. 24%), carbonate apatite stones in 444 cases (30.62%), anhydrous uric acid stones in 93 cases (6.41%), calcium oxalate dihydrate stones in 92 cases (6. 34 % ), ammonium magnesium phosphate hexahydrate stones in 28 cases (1.93%), cystine stones in 23 cases (1.59%), ammonium urate stones in 20 cases (1.38%), uric acid dihydrate stones in 16 cases (1.10%), brushite stones in 12 cases (0.83%), sodium urate monohydrate stones in 2 cases (0. 14%), calcium carbonate stones in 1 cases (0. 07%), and other stone types in 5 cases (0. 34%). Most urinary stones were composed of 2 or more compositions, and pure stones were only observed in 397 cases (27.38%). Most of the mixed stones contained calcium and non-calcium mixed stone was rarely observed. In addition, 15 stones were found in infants who had consumed melamine-contaminated milk powder. These stones were composed of uric acid dihydrate and ammonium urate. The results of reevaluation by artificial analysis showed the following: among pure and mixed stones, false detection occurred in 6 cases (0.41%), of which the composition was ammonium urate or carbonate apatite determined by automatic system but the true composition was anhydrous uric acid. False negative detection occurred in 9 cases (0.62%), of which the composition was ammonium magnesium phosphate hexahydrate or carbonate apatite in 7 cases, but in other 2 cases the composition could not be determined by artificial analysis. The false negative detection of components with relatively low content occurred in 6 cases and 10 cases in stones with 2 components and 3 components, respectively. The undetected composition in these cases was ammonium magnesium phosphate hexahydrate or carbonate apatite. Conclusion Automatic Analysis System of Infrared Spectroscopy has many advantages in accuracy, automation and is quick in analyzing the composition of urinary stones, and is worthy of promotion in clinical use.     

改良输尿管硬镜钬激光碎石术治疗输尿管上段结石疗效观察

目的探讨使用改良的输尿管硬镜钬激光碎石术治疗输尿管上段结石的临床疗效。 方法选取2015年5月至2017年5月山西医科大学第一医院泌尿外科进行治疗的115例单侧输尿管上段单发结石（结石具体位置距肾盂输尿管连接部≤5 cm）患者,分别行改良输尿管硬镜碎石治疗（改良组,72例）和传统输尿管硬镜碎石治疗（对照组,43例）。与对照组相比,改良组输尿管硬镜进水阀与出水阀分别经三通连接进水管与负压吸引器,采取改良截石位,在封堵器的引导下置入输尿管硬镜,人工控制进水速度,利用200 μm细光纤碎石,通畅引流后小壶输注呋塞米。两组在年龄、性别、结石侧别、肾积水程度、结石距肾盂输尿管连接部距离和结石大小方面,差异无统计学意义（P>0.05）。比较两组患者的一期清石率及漂移率。 结果清石率方面,改良组为93.06％（67/72）,对照组为62.79％（27/43）,两组间差异有统计学意义（χ²=16.52,P<0.05）,漂移率方面改良组为5.56％（4/72）,对照组为41.86％（18/43）,两组间差异有统计学意义（χ²=22.94,P<0.05）,术中及术后均无输尿管穿孔、输尿管撕脱等严重并发症。 结论改良后的方法处理输尿管上段结石时,结石不易漂移入肾盂,结石一期清除率高,安全方便可行性强,尤其适用于没有输尿管软镜的基层医院。     

新疆南部维吾尔族尿石症患者病例对照研究

目的探讨新疆南部维吾尔族泌尿系结石发病的危险因素。方岳采用问卷调查的方式，研究了阿克苏地区90例维吾儿族泌尿系结石患者一般情况及生活习惯、饮食习惯，并对其结石成分进行分析。结果21—50岁为尿结石高发年龄组（74．4％），男性略多于女性，结石患者较对照组多口味偏咸，饮水量较少，差异有统计学意义（P〈0．001）；结石成分以草酸钙为主者81例（90．0％），磷酸钙结石1例（1．1％），尿酸结石5例（5．6％），磷酸镁铵结石2例（2．2％），胱氨酸结石1例（1．1％）。结论泌尿系结石发病主要受饮食习惯和饮水量的影响。     

The impact of new technology in the treatment of cystine stones

Cystinuric patients frequently require stone removing procedures because of their high tendency to have recurrent urinary calculi. In the last 20 years the morbidity of stone treatment has been reduced by the introduction of endourologic procedures and shock wave lithotripsy (SWL), but cystine stones are not amenable to all minimally invasive procedures. The aim of our study was to assess the impact of new technology in the treatment of cystine stones. The records of patients observed at our institutions from 1978 to 2005 were reviewed. We retrospectively analysed the previous stone histories of all the patients who presented at our institutions for stone treatment who resulted to be cystinuric at our metabolic work up. Patients were divided in two groups according to the date of our first observation: group A comprised patients observed from 1978 to 1989 who mainly experienced traditional stone treatment and group B patients observed from 1990 to present who were preferentially treated with minimally invasive therapeutic modalities. A total of 48 cystinuric patients were observed (31 in group A and 17 in group B). The mean age (38 ± 15 vs. 36 ± 13 years), the age at stone onset (21 ± 11 vs. 21 ± 12) and the annual recurrence rate (1.34 ± 2.38 vs. 1.16 ± 1.11 stones/year/pt) were not significantly different in the two groups. The male/female ratio was 18/13 and 8/9, respectively, in group A and B. In group A 16 patients underwent open surgical treatment for a total of 29 procedures (0.93 for patient) and four of them had nephrectomy; in group B only eight underwent open surgery but other seven had percutaneous surgery (0.47 + 0.41 procedure/patient). In group B 37 SWL treatments were performed (2.17 for patient) whereas patients in group A underwent only four SWLs. Renal function was impaired in six patients (19%) in group A with a patient requiring haemodyalitic treatment and in one patient (6%) in group B. Compared to the traditional stone treatment, after 1990 fewer cystinuric patients required open surgery and none underwent nephrectomy or developed severe renal failure. Our results indicate that the actual care of patients with cystine stones should still be improved requiring a comprehensive approach in order to avoid inappropriate SWL treatments and more attention to early diagnosis and preventive measures.     

Cystine stones: the impact of new treatment

The hardness and frequent recurrence of cystine stones present a special challenge to the urologist. In this study, 15 cystinuric patients (11 males, 4 females; mean age 36 years, range 17-54) were treated and followed up over a period of 30 months (range 2-40). Most patients had previous history of open surgery. The diagnosis of cystinuria was confirmed by metabolic studies and infrared spectrometry of stones. Over the follow-up period recurrence was observed in 23 instances in 11 patients, leading to 38 "stone treatments" on 74 cystine stones. The percutaneous approach was used alone in 9 cases and in association with extracorporeal shock wave lithotripsy (ESWL) in 9 cases. ESWL was used alone in 18 cases. Medical treatment included high fluid intake, alkalinisation and Thiola (tiopronin, N-(2-mercaptopropionyl)glycine) in 6 patients. The overall stone-free rate assessed 3 months after treatment was 44.7%, which compares poorly with the rate for non-cystine stones. The recurrence rate is very high and instrumental treatment should not therefore be used excessively; it is indicated only for stones that are symptomatic or refractory to intensive medical therapy.