National trend of the incidence of urolithiasis in Japan from 1965 to 1995

BACKGROUND: A nationwide survey of urolithiasis in Japan was made in order to evaluate the chronological trend of upper urinary tract stones in the Japanese. It succeeded previous studies done in 1955, 1966, 1979, and 1990. METHODS: All outpatient visits to urologists that resulted in a diagnosis of first-episode upper urinary tract stones in the years 1990 and 1995 were enumerated, irrespective of admission and treatment. The study enrolled all of the Japanese Board of Urology-approved hospitals, thereby covering nearly all urologists practicing in Japan. The annual incidence by sex and age was estimated and compared with the incidences in the previous nationwide surveys. RESULTS: The age-adjusted annual incidence of first-episode upper urinary tract stones in 1995 was estimated as 68.9 per 100,000 (100.1 in men and 55.4 in women), a steady increase from 54.2 in 1965. The annual incidence has increased in all age groups, except in those of the first three decades. The peak age for both sexes has shifted in toward the older population's direction. Estimations of longitudinal changes between 1965 and 1995 showed that the annual incidence has more than doubled for the cohort of the 1965 census population (from 43.7 in 1965 to 110.9 in 1995) and that younger generations have had progressively higher annual incidences. CONCLUSIONS: The annual incidence of upper urinary tract stones in Japan has increased steadily over the past 30 years and will continue to do so in the near future, but it still is lower than in the United States.     

Surgical treatmnt for urolithiasis (in view of medical economics)

Surgical treatment for upper urinary stones has dramatically changed since extracorporeal shock wave lithotripsy (ESWL) was introduced in 1985 in Japan. Since then, the number of ESWL apparatus is increasing year by year, and there were about 800 ESWL apparatus available in Japan in 2001. On the other hand, the number of patients with upper urinary stones are also increasing in Japan, and the age-adjusted annual incidence of first-episode upper urinary tract stones in 1995 was estimated at 68.9 per 100,000 (100.1 in men and 55.4 in women), a steady increase from 54.2 in 1965. Under these circumstances, it would be very important to treat stone patients surgically even from an economical point of view, because the cost of ESWL is very expensive and more than 90% of the patients with urolithiasis are now treated by ESWL. In this paper, the medical economics of urolithiasis in Japan is discussed especially in the surgical treatment.     

泌尿系结石成分450例分析

目的分析泌尿系结石患者的发病年龄及性别特点,探讨结石部位与患者年龄及性别的关系,根据结石不同成分采用不同预防措施。方法应用化学分析法对450例尿路结石做成分分析,结合临床资料,对尿路结石患者发病年龄、性别、结石部位及结石成分做对比分析。姑杲男性患者321例,高发年龄21～60岁;女性129例,高发年龄41～60岁;男性发病率是女性的2．49倍。发病部位肾脏结石319例（70．8％）,输尿管结石115例（25．6％）,膀胱结石16例（3．6％）;单一成分结石275例（61％）,其中单纯草酸钙结石260例（57．7％）,两种及以上混合成分结石175例（39．0％）。结论尿路结石的发病率及发病年龄存在着明显的性别差异;尿路结石发病部位主要为上尿路结石;单一成分结石以草酸钙为主,约40％的尿路结石为两种及以上混合成分结石。     

Epidemiological characteristics of urolithiasis in Okhotsk coast area in Hokkaido

An epidemiological study of 422 stone-formers who visited our hospital from 1997 to 2001 was conducted. The mean annual prevalence and incidence of both upper and lower urinary tract stones were higher than what was found in a nationwide urolithiasis survey carried out in Japan in 1995. The incidence of upper and lower urinary tract stones was 90.8% and 9.2%, respectively. The frequency of lower urinary tract stones was higher than that found in the previously mentioned nationwide study. The male-to-female ratio of upper and lower urinary tract stones was 1.68:1 and 2.25:1, respectively. The frequency in females was higher in this study than that found in the nationwide survey. The peak age for incidence of upper urinary tract stones is 50s in males and females. In the treatment of upper urinary tract stones, ureteroscopic lithotripsy was carried out more often than shock wave lithotripsy (SWL), because our hospital had no SWL device. Many endoscopic lithotripsy procedures were performed to treat stones located in the lower urinary tract. Of the upper urinary tract stones 83.7% were composed of calcium, the incidence of uric acid stones was high (6.6%), whereas the incidence of infectious stones was low (1.9%). For lower urinary tract stones, the frequency of infectious stones was high (52.6%). In the present study, the epidemiological features were as follows: high annual prevalence and incidence, high frequency of lower urinary tract stones, high frequency in females, many endoscopic treatment procedures and high frequency of uric acid stones in the upper urinary tract.     

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.     

Clinical studies on childhood urolithiasis during the past 22 years

We have studied retrospectively 68 children who presented with urolithiasis between 1965 and 1986. Male to female ratio was 1.83 to 1 and the mean age was 9.5 years. Fifty four children (79%) had calculi in the upper urinary tract, 9 (13%) had in the lower, and 4 (6%) had calculi both in the upper and lower urinary tract. The most common presenting symptoms were gross hematuria (53%) and abdominal or flank pain (38%). Predisposing factors could be found only in 21 children (31%). Twenty four of the 68 patients (35%) had open surgery and 16 patients (24%) passed their stones spontaneously. Twenty one stones were analyzed by infrared spectroscopy. Infectious stone was more frequent than in adult cases. Among children five years old and younger, infectious stone was the most frequent. Among children over five years old, the number of idiopathic calcium stone has been on the increase with the years.     

Prevalence of upper urinary tract stones in Tajima, north Hyogo, Japan]

Toyooka Hospital is a central hospital in Tajima, a rural area in the northern part of Hyogo Prefecture. Because we possess the sole lithotripter in this area, almost all urolithiasis patients requiring treatment have been referred to our department. Based on the number of urolithiasis patients treated in our institution, we estimated the annual prevalence and incidence of upper urinary tract stones in the Tajima area. The mean annual prevalence of urolithiasis and incidence during the 1991-1993 period were 141 and 93 per 100,000, respectively. The male to female ratio was 2.0 to 1 in prevalence and 2.2 to 1.0 in incidence. Prevalence was highest in the sixties (245) and fifties (235), followed by the forties (205), seventies (162) and thirties (160). The incidence was highest in the fifties (169), followed by the forties (147), sixties (145) and thirties (118). In consideration of sex, the incidence was highest in males in the fifties and the forties. Of the patients with upper urinary calculi, 23.1% were treated by extracorporeal shock wave lithotripsy, while in 23.8% stones passed spontaneously and 50.9% were followed up without treatment. On stone analysis, calcium oxalate and/or calcium phosphate was present in 75.6%, uric acid in 16.4%, struvite and/or carbonate apatite in 5.6% and cystine in 1.4%. In summary, the prevalence and incidence of upper urinary tract calculi in the Tajima area were considerably higher than those in the nationwide survey on urolithiasis in Japan conducted in 1985.     

Epidemiological study on urolithiasis in Mie Prefecture. 1. Present status in 1985

To determine the present status of urolithiasis in Mie Prefecture, we analyzed the 1,314 patients of urolithiasis at 17 Departments of Urology and 2 Departments of Medicine in 1985. The ratio of male patients to female patients was 2.6 to 1. The most frequent incidence of urolithiasis was observed in Iinan county. The incidence of urolithiasis in the urban area was the same as that in the country. Most of the stones (96.9%) were in the upper urinary tract. The incidence of lower urinary tract calculi tended to be high in southern Mie Prefecture. The ratio of upper urinary tract calculi to lower urinary tract calculi in the urban area was the same as that in the country. The peak incidence in males was in the forties, while that in females was in the fifties. The average age was 44.5 years old. Ureterolithotomy was the most frequent (37.5%) surgical therapy, percutaneous nephrolithotomy and shock wave lithotomy done in 8.0% and 6.3%, respectively. The most frequent component of the urinary tract calculi was calcium oxalate and/or calcium phosphate (84.0%). The incidence increased in summer (April through September).     

Annual changes of the incidence and clinical characteristics of magnesium ammonium phosphate urinary stones

BACKGROUND: Magnesium ammonium phosphate (MAP) urinary stones account for the majority of staghorn stones and frequently cause a non-functioning kidney. In the present study, we examined the annual changes of the number and clinical characteristics of MAP stones. METHODS: The annual incidence of MAP stones was investigated in 2619 patients with urinary stones in whom composition of the stone was analysed at Chiba University Hospital between 1964 and 1999. In addition, the annual number of patients with MAP stones was examined at Funabashi Clinic. In a total of 644 patients with MAP stones, age and sex of the patients, location and size of the MAP stones, urinary cultures and etiological factors were analysed. RESULTS: The number of MAP stones in the lower urinary tract was relatively constant. In contrast, MAP stones in the upper urinary tract had dramatically decreased since 1989, resulting in an increase in the rate of MAP stones in the lower urinary tract. Age distribution of the MAP stone patients ranged from 10 years to > 80 years, with the majority aged 30-60 years. The proportion of larger MAP stones in the upper urinary tract increased. There was no significant difference in prevalence of urine cultures. Among etiological factors for MAP stones, difficulty on urination tended to be common in recent years. CONCLUSION: The number of MAP stones, especially in upper urinary tract, has been decreasing during the last decade. At present, treatment of urinary tract obstruction seems important for the management of MAP stones in lower urinary tract.     

广西地区尿石症患者年龄分布曲线特征及临床意义

目的 探讨尿石症患者发症年龄高峰及年龄分布曲线的形态与特征。方法 统计广西地区1994－1999年尿石症新发病患者1776例,按年龄每10岁一组划分,按性别及上下尿路结石部位分别统计并例表分析,描绘年龄分布曲线并作相关分析。结果 尿石症发病的高危年龄段为30－50 ,其中30－40岁为高峰,中位年龄为41.9岁;上下尿路结石发病年龄高峰分别为30－40岁及60－70岁。结论 尿石症发病年龄高峰及年龄 分布特征对临床诊治、预防尿石症及健康人群加强预防保健工作有重要意义。     

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。     

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。     

上尿路结石复发原因分析及其治疗(附42例报告)

目的:探讨泌尿系结石复发的原因及其处理措施。方法:回顾性分析2005年1月～2010年5月在我院接受治疗的42例上尿路复发结石患者临床资料,并对其尿石成分进行分析,对血、尿理化指标及代谢指标进行检测。结果:术后复发结石成分中,与原发结石成分相同者34例;与原发结石成分不同者8例,其中1例为尿流改道术后(草酸钙结石变为尿酸结石),1例为ESWL术后(草酸钙结石变为尿酸结石),3例为开放取石术后(草酸钙结石变为感染结石及尿酸结石),2例为输尿管碎石取石术后(尿酸结石变为感染结石)。在血、尿理化检测中,糖尿病8例,尿路感染7例,肥胖6例,甲状旁腺机能亢进3例。结论:根据复发性尿路结石的临床特点及诱发因素,采取针对性措施,选择合理的治疗方式,可以提高治疗效果。     

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.     

Mode of presentation and first line of management of non-recurrent urolithiasis in Kuwait

AIMS: To determine the incidence, mode of presentation, first line of management and composition of non-recurrent urolithiasis in Kuwait. METHODS: Consecutive patients admitted between January 1999 and December 2002 with non-recurrent urolithiasis were prospectively analyzed. RESULTS: The average annual incidence of hospital admission for non-recurrent urolithiasis in Kuwait was 43.44 per 100,000 population, representing men and women (ratio, 9:1) with a median age of 41.91 years. Of the hospital admissions for non-recurrent urolithiasis, 57.2% of cases were acute. Overall, the most predominant symptom was flank pain, while the least common symptom was acute urinary retention. Ureteroscopic stone manipulation was the most common initial treatment modality in the present series, as it was utilized in 43.3% and 37.09% for patients admitted on elective and emergency basis, respectively. Of the calculi available for chemical analysis, 91% contained calcium, 73% contained calcium oxalate, 17% contained mixed calcium and 1% contained calcium phosphate. The composition of the rest of the stones were urate in 7%, struvite in 1% and cystine in 1%. CONCLUSIONS: Urolithiasis is a common disease in the Kuwait region that mainly presents with flank pain. Ureteroscopic calculus removal is the most common modality of treatment. The majority of the calculi seen in Kuwait contained calcium.     

Urolithiasis in those patients with myelodysplasia

OBJECTIVE: To evaluate incidence and treatments of urolithiasis in myelodysplastic patients. PATIENTS AND METHODS: During the past 27 years 303 myelodysplastic patients, 160 men and 143 women, have been treated and 50 of them were operated on with bladder augmentation procedures. Their medical records were retrospectively reviewed. RESULTS: Urolithiasis occurred 20 times in 15 patients, 11 men and 4 women, where calculi developed 18 times in the bladder and twice in the kidney. Prevalence of urolithiasis was 20% (10/50) in those who had undergone bladder augmentation and 2% (5/253) in those who had not had this surgery, where the difference was statistically significant between the two groups (p < 0.01). Overall, 5% of all the patients suffered from stones in the urinary tract. Bladder calculi were endoscopically treated in 11 occasions or were resolved with suprapubic lithotomy in 4 cases. Small stones in the bladder were spontaneously delivered 3 times and extracorporeal shock wave lithotripsy (ESWL) was necessary for a renal calculus in one patient. The last patient having a renal stone has been put under care. Majority of stone compositions consisted of magnesium ammonium phosphate (MAP). CONCLUSION: It was found that urolithiasis was 10 times more prevalent in those patients operated on with enterocystoplasty than those without bladder augmentation and that intermittent clean catheterization and regular bladder irrigation were of necessity to prevent urolithiasis for those having enterocystoplasty.     

Urinary tract stone disease in modern Japan. Stone incidence, composition and possible causes in Osaka district

2,969 stones, obtained from affiliated hospitals as well as the Osaka University Urologic Clinic were analyzed by infrared spectrophotometry. 2,724 of the 2,969 stones were obvious upper urinary tract stones, and the composition of these 2,724 stones is reported. The incidence and possible cause of stones in 750 patients with upper urinary tract calculi, managed in Osaka University Urologic Clinic, are discussed, as well as the recent figures on urinary tract stone disease in Osaka district. These figures are representative of stone disease in Japan.     

Epidemiology of urolithiasis in Japan: a chronological and geographical study

A nationwide survey on urolithiasis in Japan between 1965 through 1987 was carried out, succeeding the previous 1955 and 1966 studies, in an effort to evaluate chronological and geographical changes in urolithiasis among the Japanese people who are relatively racially homogenous and living with similar customs and habits, which have changed dramatically from the old Japanese to westernized modes in a very short period after the Second World War. Incidence of calcium-containing urinary stones in the upper urinary tract has been increasing in Japan since the Second World War with increasing westernization of life-style and industrialization, with the annual incidence of urolithiasis steadily increasing from 53.8/100,000 general population in 1965 to 92.5 in 1985. According to the data, 5.4% of the population may be expected to develop a urinary calculus at least once in their life time. Analysis of 69,949 stones obtained during the years from 1978 to 1987 with infrared analysis showed that 79.4% were calcium oxalate and/or calcium phosphate stones, 7.4% were struvite with or without carbonate apatite, 5.2% were uric acid or urate, and 1.0% were cystine. In the era of new treatment modalities such as the endourological surgery and the extracorporeal shock wave lithotripsy, open surgical treatments were replaced with new types of treatment in about 75% of the cases in 1985.     

Recurrence of upper urinary tract calculi

Treatment of upper urinary tract stones has changed greatly. The recurrence of calculi after the discharge was studied in the 634 patients with urolithiasis admitted to our department during the 9 years up to the end of 1984. The recurrence rate in the 325 cases followed for more than 3 months after the disappearance of the original stones, was 15.6% after 2 years, 27.6% after 5 year and 51.4% after 8 years. In recurrent stone formers, the rate of recurrence thereafter was greater than that of primary stone formers. The growth of calculi was rapid in the renal stone former concomitant with urinary tract infection together with a past history of renal surgery. In relation to the composition of the stone, uric acid calculi tended to recur more often than calculi composed of other substances. In view of recurrence, pyelolithotomy is preferred to renal parenchymal incision.     

Outcomes of urethral calculi patients in an endemic region and an undiagnosed primary fossa navicularis calculus

Urethral calculus is a rare form of urolithiasis with an incidence lower than 0.3%. We determined the outcomes of 15 patients with urethral stone, of which 8 were pediatric, including an undiagnosed primary fossa navicularis calculus. Fifteen consecutive male patients, of whom eight were children, with urethral calculi were assessed between 2000 and 2005 with a mean of 19 months’ follow-up. All stones were fusiform in shape and solitary. Acute urinary retention, interrupted or weak stream, pain (penile, urethral, perineal) and gross hematuria were the main presenting symptoms in 7 (46.7%), 4 (26.7%), 3 (20%) and 1 (6.6%) patient, respectively. Six of them had accompanying urethral pathologies such as stenosis (primary or with hypospadias) and diverticulum. Two patients were associated with upper urinary tract calculi but none of them secondary to bladder calculi. A 50-year-old patient with a primary urethral stone disease had urethral meatal stenosis accompanied by lifelong lower urinary tract symptoms. Unlike the past reports, urethral stones secondary to bladder calculi were decreasing, especially in the pediatric population. However, the pediatric patients in their first decade are still under risk secondary to the upper urinary tract calculi or the primary ones.