Urinary stone composition in North-East Thailand

Stones removed from 120 adults and 22 children were analysed for chemical composition. Calcium oxalate was the main component of both adult (49%) and childhood (44%) stones. Calcium stones formed the major type in adults and were slightly more common in males, whereas urate/uric acid stones were predominant in children and were more common in girls. In adults, the stones were usually found in the upper urinary tract (UUT) and were mainly of calcium type (72%), while all three types were found in almost equal amounts in the lower urinary tract (LUT). Magnesium ammonium phosphate and urate/uric acid were the stones found mainly in the upper and lower urinary tracts respectively of children.     

广东东莞地区416例泌尿系结石成分分析

目的 应用红外光谱法测定东莞地区泌尿系结石化学成分,探讨本地区泌尿系结石患者的尿路结石成分特点,为本地区泌尿系结石的深化治疗、防止结石复发及预防提供科学依据.方法 收集经自行排出、碎石后排出或手术中取出的泌尿系结石标本416例,应用溴化钾压片技术的红外光谱法对其化学成分进行定性分析.结果 416例泌尿系结石患者中男性居多,占66.8%(278/416),女性占33.2%(138/416);上尿路结石占88.2%,下尿路结石(膀胱结石居多)占11.8%;结石成分定性分析共检测出一水草酸钙、二水草酸钙、碳酸磷灰石、无水尿酸、六水磷酸铵镁和尿酸铵6种化学成分.单一成分结石163例(一水草酸钙/无水尿酸/碳酸磷灰石/六水磷酸铵镁:98/56/6/3),占39.2%;混合成分结石253例,占60.8%,其中以草酸钙和碳酸磷灰石的混合结石为主(188/253).所有结石标本中草酸钙检出率最高,占80.5%(335/416),其次为碳酸磷灰石(49.3%)及无水尿酸(17.3%);膀胱结石成分以一水草酸钙或无水尿酸为主.结论 东莞为全国泌尿系结石最高发地区,其结石成分以草酸钙和碳酸磷灰石为主,单一成分结石亦占相当比例.尿路结石成分分析对了解结石成因可提供重要的线索,对临床制定个性化治疗方案、预防结石形成及复发具有重要意义.     

Ammonium acid urate calculi: a reevaluation of risk factors

PURPOSE: We reevaluate the demographic and metabolic risk factors for ammonium acid urate stones. MATERIALS AND METHODS: Since 1986, 23 women and 21 men ranging in age from 20 to 81 years (mean 48.7) were treated for stones partly composed of ammonium acid urate. Stone composition ranged from 2 to 60% ammonium acid urate (mean 24.1) of the total stone mass. No patient had a pure ammonium acid urate stone, although 11 (25%) had stones with ammonium acid urate as the predominant crystal. RESULTS: In the 44 patients 1 or more potential risk factors for ammonium acid urate were identified. Of the patients 11 (25%) had a history of inflammatory bowel disease with 10 (22.7%) having undergone ileostomy diversion, 6 (13.6%) admitted to a history of significant laxative use or abuse, 18 (40.9%) were morbidly obese, 16 (36.4%) had a history of recurrent urinary tract infections and 9 (20.5%) had a history of recurrent uric acid stones. CONCLUSIONS: Patients clearly at risk for stones with an ammonium acid urate component include those with a history of inflammatory bowel disease and ileostomy diversion or laxative abuse. Other factors that may potentially enhance ammonium acid urate stone formation include morbid obesity, recurrent uric acid calculi and recurrent urinary tract infection. A careful history followed by further metabolic evaluation is warranted in these patients.     

The aetiological and clinical pattern of childhood urolithiasis in Saudi Arabia

The clinical and aetiological pattern in 85 stone-forming children presenting to an integrated nephrourological service in Riyadh is reviewed. All patients were below the age of 15 years, the male to female ratio being 2∶1. Only 2 children presented with bladder calculi. The remaining all had upper tract stone and, in 12 cases, these were bilateral. Of 34 calculi recovered for analysis, one-third was predominantly calcium oxalate and a further third was composed of uric acid or urate. Four patients had cystine stones and the remaining 7 presented mixed calcium stones, 6 (17.6%) being struvite and infection-related. Of the 85 patients 55 were treated successfully with extracorporeal shock wave lithotripsy, 16 underwent surgery and 7 had their stones removed by endourological procedures. In the remaining 7 children, stones dissolved or were passed spontaneously during medical therapy. Nine children (10.6%) showed a primary metabolic defect leading to their stone formation, 10 (11.8%) had a predisposing anatomical anomaly and 15 (17.6%) presented with urinary tract infection. Of the remaining 51 patients (60%) with idiopathic disease, 6 showed hypercalciuria on investigation and 2 children may have formed their stones due to prolonged recumbency.     

Urolithiasis in Tunisian children: a study of 120 cases based on stone composition

The composition of urinary stones in children depends on socioeconomic conditions and hygiene, geographical area, and dietary habits. We analyzed urinary stones from 120 consecutive Tunisian children (81 males, 39 females) aged 5 months to 15 years. The stone was located in the upper urinary tract in 91 cases (76%). Stone analysis included both a morphological examination and an infrared analysis of the nucleus and the inner and peripheral layers. The main components of bladder calculi were whewellite (69%) and struvite (22%), whereas the main component of upper urinary tract calculi was whewellite (67%). The nucleus of bladder stones was composed of ammonium urate (45%), struvite (28%), cystine (10%), and carbapatite (7%). The nucleus of kidney and ureteral calculi was mainly composed of ammonium urate (38%), whewellite (24%), carbapatite (13%), or struvite (11%). Based on stone composition, urinary tract infection was involved in the nucleation or growth of a third of calculi. Endemic urolithiasis involving simultaneous nutritional, metabolic, and infectious factors, and defined by its nucleus composed of ammonium urate without struvite, represented 40% of cases. Exclusive metabolic factors – including genetic diseases such as primary hyperoxaluria, cystinuria, and hypercalciuria – were responsible for less than 25% of cases. Received: 6 March 1998 / Revised: 22 March 1999 / Accepted: 22 March 1999     

232例湖北地区泌尿系结石红外光谱成分分析

目的：分析湖北地区泌尿系结石化学成分的构成,为本地区结石的防治提供依据。方法：采用结石红外光谱自动分析系统对2011年11月～2012年8月期间收集到的湖北地区泌尿系结石232例进行成分分析。结果：232例结石中,各成分的检出率为：一水草酸钙（COM）85．34％,二水草酸钙（COD）62．93％,碳酸磷灰石（CA）24．14％,无水尿酸（UA）12．93％,二水磷酸氢钙（PH）4．31％,磷酸铵镁（MAP）6．90％,黄嘌呤1．29％,胱氨酸（CYS）1．29％,方解石0．86％,尿酸铵（AU）0．86％。含草酸钙成分结石86．21％,含磷酸钙成分结石28．45％,含磷酸铵镁成分结石6．90％,含尿酸成分结石13．79％,含胱氨酸成分结石1．29％。混合成分结石181例（78．02％）,尿路结石发病男性多于女性,男女比例为3．14：1。结论：湖北地区泌尿系结石以混合性结石为主,COM检出率最高,其次为COD。结石成分分析对于结石的防治有重要意义。     

Renal stones in the tropics

Urolithiasis is a problem that is generally increasing in the tropics as it is in most Western countries. There are 2 main types of the disorder-bladder stones in children, a form of the disorder that disappeared from Europe in the late 19th and early 20th centuries, and upper urinary tract stones in adults. The former has been decreasing in most countries in the so-called endemic bladder stone belt with gradual improvements in levels of nutrition. However, as living standards increase, particularly in the urban areas of the more affluent developing countries, so the incidence of upper urinary tract stones in adults is increasing. The types of stones formed depend mainly on the composition of urine, which, in turn, reflects the type of diet consumed in the countries concerned. The main factor that leads to the formation of bladder stones in children is a nutritionally poor diet that is low in animal protein, calcium, and phosphate, but high in cereal and is acidogenic. This leads to the formation of urine with a relatively high content of ammonium and urate ions and consequently to the formation of ammonium acid urate crystals and stones. In countries where there is also a high intake of oxalate from local leaves and vegetables, urinary oxalate is increased and, as a result, the ammonium acid urate stones often contain calcium oxalate as well. The stone problem in the tropics is compounded by low urine volumes resulting in some areas from poor drinking water, which causes chronic diarrhea, and in others from the hot climate and fluid losses through the skin. As nutrition improves in these countries, the formation of bladder stones gives way to upper urinary tract stones consisting of calcium oxalate, often mixed with calcium phosphate or uric acid, such as are formed in most Western countries.     

Urolithiasis in Okinawa, Japan: A relatively high prevalence of uric acid stones

AIM: The aim of the present study was to investigate the composition of urinary tract stones in patients from Okinawa, the most southern island group of Japan. METHODS: The study was conducted by 12 hospitals in Okinawa. A total of 1816 urinary tract calculi were obtained from 1816 patients (1323 males; 493 females). The patients had a mean age of 53 +/- 15.3 years (mean +/- SD). The calculi were examined to determine their chemical composition. Stone samples were analyzed by computed infrared spectrophotometer. RESULTS: Pure stones comprised 58.4% of the total, with calcium oxalate stones accounting for 40% (21% monohydrate [whewellite]; 6.6% dihydrate [weddellite]; and 12.4% combined monohydrate and dihydrate stones), uric acid/urate stones for 9.6%, calcium phosphate stones for 5.1%, and struvite stones for 3.7%. The other 41.6% of the stones consisted of calcium oxalate mixed with other components. The male-to-female ratio was 2.7:1. CONCLUSION: In our series, calcium oxalate stones accounted for 81.6% of the urinary tract calculi, while uric acid/urate stones accounted for 15.8%. Uric acid stones, predominantly the anhydrous and/or dihydrate forms, showed a relatively high prevalence. Calcium oxalate stones, predominantly in the form of whewellite, showed a high prevalence among pure calculi; while the predominant combinations among mixed calculi were weddellite + calcium phosphate and whewellite + uric acid/urate.     

The composition of urinary stones in the Sudan

Seventy-eight urinary stones from the Sudan were analysed quantitatively; 75.6% of upper urinary tract (UUT) stones and 37.8% of lower tract (LUT) stones were composed of pure calcium oxalate monohydrate. The composition of adult UUT stones in the Sudan is almost identical to that of similar stones from Leeds except that the former contain much more calcium oxalate and much less calcium phosphate. A smaller proportion of adult LUT stones from the Sudan contain magnesium ammonium phosphate and a larger proportion contain uric acid/urate than similar stones from Leeds. Juvenile LUT stones from the Sudan probably contain more calcium oxalate and less uric acid/urate than juvenile bladder stones in some other developing countries.     

Ammonium and sodium urates precipitating from synthetic urine and fine structure of urate renal calculi

A study of ammonium and sodium urate precipitation in vitro and the fine structure of several urate renal calculi was carried out to contribute to an understanding of the participation of ammonium and sodium urates in urolithiasis. Ammonium urate precipitated in vitro in two different morphologies: a typical spherulite morphology formed at high supersaturation and disorganized needle-like crystals formed at low supersaturation. In all cases sodium urate precipitated in vitro as bundles of curved fibrils, its crystallization being inhibited by calcium in concentrations between 20 and 60 mg/l depending on the sodium urate supersaturation. From a collection of 1300 renal calculi, only three had ammonium urate as their main component (0.2%), three were mixed calculi (0.2%) consisting of ammonium urate and calcium oxalate (two) or uric acid (one), and in one calculus ammonium urate was present as a minor component. Only in a mixed calculus of uric acid and calcium oxalate was sodium urate detected in a very low quantity. The study of the fine structure of the renal calculi constituted mainly by ammonium urate demonstrated similar patterns in which spherulites, needle-like individual crystals and an amorphous mass of ammonium urate with abundant organic matter in non-organized structures coexist. As minor components, struvite or calcium oxalate crystals were found. A general mechanism of the formation of such calculi is proposed. Received: 4 December 1997 / Accepted: 9 July 1998     

2015~2018年达州市尿路结石患者人口学特征及结石化学成分分析

目的对2015~2018年四川省达州地区尿路结石患者人口学特征及结石化学成分进行分析。方法选择2015年1月至2018年12月四川省达州市中西医结合医院进行治疗的583例尿路结石患者,经体外振动波碎石、手术、自排等方式获得结石标本583份进行研究。所有患者入组后均采集性别、年龄、居住地等一般资料,获取结石标本后以结石红外光谱自动分析系统对其化学成分进行分析。结果583例患者中单纯性结石289例(49.75%),二重混合性结石288例(49.40%),三重混合性结石6例(1.03%)。从结石成分分布上看草酸钙占比最高,为94.00%,其次是磷酸磷灰石37.04%、尿酸及尿酸铵14.92%。女性患者磷酸铵镁占比为4.31%,明显高于男性的1.35%(P<0.05)。其他成分不同性别患者分布情况差异无统计学意义(P>0.05)。60岁以下的患者结石成分为草酸钙占比为96.69%,明显高于60岁及以上者的89.55%(P<0.05)。其他成分不同年龄段患者分布情况差异无统计学意义(P>0.05)。城镇居民患者草酸钙、磷酸磷灰石占比分别为96.69%、40.38%,均明显高于农村居民的89.82%、28.74%(P<0.05)。其他成分不同居住环境患者分布情况差异无统计学意义(P>0.05)。结论四川达州地区尿路结石患者结石化学成分易草酸钙为主,其次为磷酸磷石灰石、尿酸及尿酸铵。不同性别、年龄、居住环境对尿路结石化学成分分布有一定的影响。     

以结石成分分析为基础的个体化指导方案在结石术后患者中的应用价值研究

目的探讨以结石成分分析为基础的个体化指导方案在结石术后患者中的应用价值。方法选取2016年1月至2017年1月在本院收治300例经内镜手术治疗的尿路结石患者为研究对象(观察组),所有患者均采取红外光谱自动分析法对尿结石标本进行化学成分分析,并以结石成分分析为基础给予个体化预防指导方案;另选取同期本院未进行结石成分分析的40例尿路结石患者为对照组,对比两组术后结石复发率。结果尿路结石标本中多为混合成分结石,2种成分混合结石占比38.67%,3种成分混合结石占比34.00%,单一成分结石占比27.33%。单一成分结石、混合成分结石及不同结石发生部位(上、下尿路结石)中,草酸钙结石均占比最高,其次为尿酸结石。术后3个月,两组结石复发率比较差异无统计学意义(P>0.05);术后半年、1年,观察组结石复发率低于对照组,差异有统计学意义(P<0.05)。结论红外光谱可简便、快速获取结石成分信息,结石成分复杂,多为草酸钙类结石与尿酸结石,结石成分分析是提出个体化预防指导方案的基础,可有效降低术后结石复发率。     

广东南海地区泌尿系结石患者结石成分分析(附986例报告)

【摘要】 目的 应用红外光谱法分析广东南海地区泌尿系结石患者的结石,为临床个性化防治泌尿系结石及复发提供理论依据。方法 通过自然排出、碎石后排出或手术取出获得结石样本986例,并应用红外光谱法对其行结石成分分析。结果 泌尿系结石患者男女比例为1.34∶1,51岁~60岁年龄阶段患者所占比例最高,上尿路结石发病人数明显多于下尿路结石,比例达9.49∶1。定性分析共检测出一水草酸钙、二水草酸钙、碳酸磷灰石、无水尿酸、六水磷酸镁铵和胱氨酸6种化学成分。混合成分结石647例,占总人数的65.6%;含钙结石853例,占86.51%。草酸钙检出率最高,占77.38%,其次是碳酸磷灰石(5.27%)和尿酸(13.29%)成分。结论 采用红外光谱法分析泌尿系结石成分,对于了解结石成因、预防结石形成和复发具有重要的意义。     

佛山市顺德地区原住居民与外来居民尿路结石成分差异性分析

目的分析广东佛山市顺德地区原住居民与外来居民尿路结石成分的差异性。方法选取顺德区新容奇医院泌尿外科2017年1月~2019年1月收治的300例尿路结石患者,根据居民来源分为原住居民组150例及外来居民组150例,利用红外光谱结石检测仪对尿路结石成分进行分析和比对。结果原住居民组含钙结石占比、纯尿酸结石占比高于外来居民组,感染性结石占比低于外来居民组,差异有统计学意义(P0.05),其他结石占比差异无统计学意义(P0.05);原住居民组中一水草酸钙占比高于原住居民组,差异有统计学意义(P0.05),二水草酸钙、一水草酸钙+二水草酸钙尿酸铵、无水尿酸、一水尿酸钠以及二水尿酸占比与外来居民组数值相当,差异无统计学意义(P0.05)。结论顺德地区原住居民与外来居民尿路结石成分存在较大差异性。     

微通道经皮肾镜取石术治疗上尿路结石的疗效及安全性评价（附4533例报告）

目的：探讨微通道经皮肾镜取石术（mPNI。）治疗上尿路结石的疗效和安全性。方法：1999年9月～2010年12月应用mPNI。治疗上尿路结石患者4533例,其中肾盂及。肾盏结石患者3434例,部分鹿角形肾结石患者324例,完全鹿角形肾结石患者38例,嵌顿性输尿管上段结石患者737例,结石大小12～103mm。采用肋上或肋下入路,经肾乳头穿刺后组肾盏建立手术通道。结果：4528例（99．8％）获得成功,手术时间30～185min,结石清除率分别为：输尿管上段结石99．2％,肾盏或’肾盂结石96．5％,部分鹿角形肾结石92．3％（联合ESWL）,完全鹿角形结石86．2％（联合ESWL）。并发症为输血,占1．39％;术后出血行高选择性肾动脉栓塞占O．13％,胸腔积液占O．13％,结肠损伤占0．11％,液体吸收综合征占O．11％,术后感染性休克占O．06％,无死亡及失肾。结论：采用mPNL治疗包括部分鹿角形肾结石在内的上尿路结石可获得较高的结石取净率,手术安全性高,在减少手术出血、降低输血率和其他并发症方面具有优势。     

Characteristics of patients with staghorn calculi in our experience

PURPOSE: To elucidate the factors contributing to staghorn stone formation in patients. MATERIALS AND METHODS: The records of 82 patients (44 men and 38 women) with complete staghorn calculi were reviewed retrospectively for clinical presentation, metabolic disturbances and anatomical abnormalities. RESULTS: There were 79 unilateral and three bilateral cases. The patient performance of the activities of daily life was assessed with the modified Rankin scale (MRS) and it was found that 69 patients were functionally independent (84.1%, MRS 0-1) and 10 patients had a severe disability (12.2%, MRS 4-5). Seven patients had chronic indwelling catheters (8.5%). A positive urine culture was found in 24.4% of patients. Analysis of stone composition revealed magnesium ammonium phosphate and mixed calcium oxalate-phosphate were the most frequently identified types of stone (32.1% and 22.2%, respectively). Urinary pH was low in patients with uric acid stones (mean 5.4). Hyperuricemia, cystinuria and hypercalciuria were found in 14.6%, 2.4% and 37.8%, respectively. Hypercalciuria was found more frequently in calcium-stone cases. Eleven patients (13.4%) showed structural abnormalities of the kidney. CONCLUSIONS: Our data show that the patients with severe disability, urinary tract infection and hypercalciuria could be recognized more frequently in staghorn calculi compared with common urolithiasis. However, in Western countries, the frequency of both urinary tract infection and struvite stones is much higher than in our data. Other Japanese authors have also reported the low frequency of struvite stones in staghorn calculi, suggesting that various factors other than urinary tract infection possibly contribute to the formation of staghorn calculi in Japan.     

延安地区泌尿系结石成分分析的研究

目的利用红外光谱法测定延安大学附属医院泌尿外科手术获得的泌尿系结石成分,探讨延安地区泌尿系结石成分与年龄、性别等关系,比较上、下尿路结石成分特点,分析延安地区泌尿系结石发生的流行病学情况,为临床制定有效的个体化治疗及预防措施提供参考依据。方法收集2013年1月至2017年1月在延安大学附属医院泌尿外科治疗1984例尿路结石患者的年龄、性别、结石部位等临床资料,对比分析延安地区泌尿系结石在不同年龄、不同性别、不同解剖部位的分布特点。结果在1984例泌尿系结石的患者中,按每10岁年龄大小分组排序,统计各年龄阶段泌尿系结石发病情况,男性患者有1346例,女性患者有638例,男性年龄(50.23±14.48)岁,女性年龄(47.87±14.51)岁,男、女患者比例约2.11∶1。在66~75岁年龄段,尿路结石发病率性别差异具有统计学意义(P<0.05)。结石成分以混合性结石为主,以混合性结石为主,共1582例,占79.76%。其中1665例(83.92%)为上尿路结石,上、下尿路结石的比例为5.22∶1,其余为肾结石合并膀胱结石。上尿路结石中男性1062例,女性603例,男女比例为1.76∶1;下尿路结石中男性284例,女性35例,男女比例为8.11∶1。青壮年(年龄≤45岁)泌尿系结石患者草酸钙为主结石、感染性结石多见;中老年(年龄>45岁)泌尿系结石者草酸钙为主结石、尿酸类结石多见。感染性结石患者性别差异具有统计学意义(P<0.05)。结论在延安地区男性较女性更容易患泌尿系结石。同时,不同年龄段结石构成成分具有差异。对于年龄≤45岁患者,主要以草酸钙为主结石、感染性结石多见,这与结石整体发病率基本一致;而对于年龄>45岁患者,主要以草酸钙为主结石、尿酸性结石多见。表明对于不同年龄段的结石患者,可以根据上述结果在结石的预防和治疗上综合考量,给予明确而更加合理的治疗。     

非增强螺旋CT平扫对上尿路结石成分预测的体内研究

目的 探讨非增强螺旋CT对体内上尿路结石化学成分的预测价值.方法 回顾性分析156例有结石标本的上尿路结石患者临床资料.所有患者在治疗前采用GE High speed CT/i螺旋CT机行非增强结石扫描,扫描参数为120 kV,320 mA,螺距0.6:1,扫描层厚为5 mm.在CT软组织窗测量结石平均CT值.将获取的结石样本采用红外光谱自动分析系统进行化学成分定性分析.经统计学分析,找出各种成分结石的相应CT值范围.结果 非增强螺旋CT扫描156例结石的软组织窗CT值范围为128～ 1663亨氏单位(hounsfield unit,HU).共发现纯结石57例,其中纯一水草酸钙结石28例,纯尿酸结石19例,纯羟基磷灰石10例,混合结石99例.一水草酸钙、尿酸、羟基磷灰石三种纯结石的软组织窗平均CT值分别为(915.4±142.9) HU、(469.7±55.1) HU、(868.4±168.8)HU.尿酸结石与一水草酸钙结石、尿酸结石与羟基磷灰石之间的CT值差异有统计学意义(P＜0.05).19例纯尿酸结石和137例其他成分结石的软组织窗平均CT值之间差异有统计学意义(P＜0.05).以结石的软组织窗平均CT值＜ 550 HU为标准诊断纯尿酸结石,其灵敏度为92.8％,特异度为98.1％,阳性预测值为88.5％,阴性预测值为99％,诊断符合率为98.1％.结论 非增强螺旋CT平扫用于判断上尿路结石成分效果满意.根据软组织窗CT值不同,可将体内尿酸结石与其他成分结石区分.软组织窗平均CT值＜550 HU可作为纯尿酸结石的诊断标准.     

Xanthine calculi in the patient with the Lesch-Nyhan syndrome associated with urinary tract infection

A Japanese boy with Lesch-Nyhan syndrome who passed xanthine calculi is reported. After pyelolithotomy for a left renal stone, made up of ammonium urate, associated with urinary tract infection, a high dose of allopurinol was given because of the persistence of pyuria. In the present case, the administration of a high dose of allopurinol, given for the prevention of ammonium urate stone formation in infected urine, induced xanthine calculi formation and we had difficulty in the management of this patient with Lesch-Nyhan syndrome associated with urinary tract infection. However, we believe it a basic necessity to cure our patient of his urinary tract infection and prevent recurrent ammonium urate stone formation because of the risk of renal deterioration.     

The severity of infection stones compared to other stones in the upper urinary tract

A retrospective study of the case records of 391 adult patients with spontaneously passed or surgically removed concrements from the upper urinary tract during the period 1982-1983 was performed. According to chemical analysis, 66% of the stones were calcium stones, 30% were infection stones, 4% were uric acid/urate stones and 1% were cystine stones. Of the infection stones 12 (10%) were staghorn calculi. The infection stones placed a greater strain on the patients than the calcium stones. Thus, infection stones were significantly more often recurrent stones and required surgery significantly more often than the calcium stones. Only 6% of the patients with infection stones had proved abnormalities predisposing to upper urinary tract infection. Urinary tract infection with a urease-producing microorganism was detected in only 52% of the patients with infection stones. As infection with a urease-producing microorganism is a prerequisite for the formation of infection stones in the urinary tract a careful microbiological investigation to find and treat the infection responsible for the stone formation is mandatory.