Two cases of ammonium acid urate urinary stones related to anorexia nervosa and laxative abuse

We report two cases of urolithiasis related to anorexia nervosa and laxative abuse. Case 1: A 21-year-old woman was referred to our hospital because of left flank pain. A left ureteral stone, 10 x 6 mm in size, was successfully fragmented by extracorporeal shock-wave lithotripsy (ESWL), but she experienced repetitive formation of bilateral urinary stones and double J stent encrustation which required 13 sessions of ESWL, one session of transurethral ureterolithotripsy and one session of cystolithotripsy over a period of 5 years. All stones were comprised of pure ammonium acid urate. It was later revealed that she was diagnosed with anorexia nervosa at 15 years old and had suffered from laxative abuse (bisacodyl, 300-500 mg/day) ever since. Case 2: A 18-year-old woman was referred to our hospital because of left lower abdominal pain. A left renal stone, 15 x 10 mm in size, was successfully fragmented by ESWL, but she had double J stent encrustation which was managed by cystolithotripsy. All stones were comprised of pure ammonium acid urate. She was later diagnosed with anorexia nervosa and it turned out that she had suffered from an eating disorder and laxative abuse (bisacodyl, 200 mg/day) since the age of 15 years. Both patients had marked decrease in urine volume, hyponatremia and hypokalemia. Anorexia nervosa and laxative abuse should be suspected whenever a woman has an ammonium acid urate stone in sterile urine because the treatment of these disorders is crucial to the prevention of repetitive formation of urinary stones.     

A case of ammonium urate urinary stone

An 18-year-old female, who had undergone antireflux surgery for bilateral vesicoureteral reflux 5 years ago, was admitted to our department with complaints of fever and left-sided back pain. Bilateral renal stones and pyelonephritis were diagnosed after roentgenography, ultrasonography and urinalysis. Pyelonephritis was successfully treated with antibiotics and the left renal stone was completely disintegrated with extracorporeal shock wave lithotripsy. Spectrophotometric analysis revealed that the stone was composed of pure ammonium urate (AU). The patient had not experienced any episodes of urinary tract infection from the antireflux surgery until the present event, but had lost 20 kg in body weight during the last year due to a low-caloric diet and laxative abuse. AU urinary stones have been infrequently reported in Japan, and they are supposed to be associated with a low-caloric diet, laxative abuse, and anorexia nervosa.     

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.     

Anterior urethral diverticular stones and retrocaval ureter in male: a case report and review of literature in Japan]

A case of diverticular stones in the male anterior urethra with retrocaval ureter is reported. A 26-year-old man visited our hospital for examination, who had experienced spontaneous stone discharge a few days earlier. Computed tomographic (CT) scan with ureteral catheterization and urethrography revealed a retrocaval ureter and urethral diverticular stones. Resection of urethral diverticulum with 7 stones and right ureteroplasty were performed. The urethrography and drip infusion pyelography (DIP) 9 months after operation showed no abnormal findings. The largest stone was 28 x 22 x 20 mm in size and 20 g in weight. The main components were ammonium dihydrogen-urate (70%), carbonate apatite and struvite. Histological feature of the epithelium of the urethral diverticulum indicated normal skin with hairs. Pathological diagnosis was para-urethral dermoid cyst. Our case is the 67th case of the male urethral diverticular stones and the first case of those with retrocaval ureter in Japan.     

Silica calculi: a case report]

A 66-year-old female visited our university hospital with the chief complaint of right lower abdominal pain in July, 1984. Kidney-ureter-bladder roentgenograms disclosed the right ureter stone and several left renal stones. She passed the right ureter stone composed of calcium oxalate. Thereafter, she passed small stones twice and sand stones twice until September, 1985. The stone analysis revealed two of them as silica. Although most patients with silica stones reported in Japan had a history of long-term medication of magnesium trisilicate, this patient had not taken this drug. Silica stones are rare and fifteen cases including the present case have been reported in Japan.     

Dual-energy computed tomography for the differentiation of uric acid stones: ex vivo performance evaluation

We assessed the potential of dual-energy computed tomography (CT) for the differentiation between uric acid (UA)-containing and non-UA-containing urinary stones. Forty urinary stones of 16 different compositions in two sizes (< and >/= 5 mm) were examined in an ex vivo model. Thirty stones consisted of pure calcium oxalate (whewellite or wheddellite), calcium phosphate (apatite, brushite, or vaterite), ammonium magnesium phosphate (struvite), UA, ammonium acid urate, ammonium phosphate, sodium hydrogen urate, or cystine, and ten stones were of mixed composition (UA-sodium hydrogen urate, whewellite-urate, wheddellite-urate, whewellite-brushite, or whewellite-brushite-struvite). Scans were performed using dual-source CT in a dual-energy mode with the tubes simultaneously operating at 80 and 140 kV. Two readers analysed the data with respect to stone attenuation at each energy level. The stones were classified as UA- or non-UA-containing using manual attenuation measurements and software analysis results. Sensitivity, specificity, PPV, and NPV were calculated using crystallographic stone analysis as the gold standard. Twenty-six out of 40 stones (65%) contained no UA; 14 stones (35%) contained UA. When compared with UA-containing stones, the differences in attenuation values at 80 and 140 kV were significantly (P < 0.001) higher in stones containing no UA. The software automatically mapped 39/40 stones (98%). Only one (2%) 2 mm UA-stone was missed. The software correctly classified all detected stones as UA- or non-UA-containing. The attenuation values of the missed stone were manually plotted into the analysis sheet which allowed for the correct classification of the stone (containing UA). Therefore, the sensitivity, specificity, PPV, and NPV for the detection of UA-containing stones was 100%. Ex vivo experience indicates that differentiation between UA- and non-UA-containing stones can be accurately performed using dual-source dual-energy CT.     

A case of uretero-vaginal fistula with ureteral foreign body stone originated from the suture thread

A 32-year-old female was admitted to our hospital with the chief complaint of vaginal discharge of urine. She had undergone radical hysterectomy due to uterine cancer at another hospital by a gynecologic surgeon 5 years earlier. X-ray examination showed a stone-like shadow at the left ureter without hydronephrosis. She was diagnosed with ureterovaginal fistula with the left ureteral stone. Left ureterolithotomy and ureterovesiconeostomy was performed. The stone revealed a foreign body stone originating from the silk worm-gut which had penetrated accidentally the ureter when the vaginal wall was sutured at the previous surgery. Including our case, 15 cases of foreign body stones in the upper urinary tract were found in the Japanese literature and none of them were associated with ureterovaginal fistula.     

A case of urolithiasis associated with short bowel syndrome

We report a case of urolithiasis associated with short bowel syndrome. A 56-year-old woman was admitted to our hospital for asymptomatic bilateral renal stones. She had received extensive resection of small intestine due to strangulating obstructive ileus 7 years ago (residual intestine, only 20 cm). Subsequently, she was in a state of short bowel syndrome. Plain film of kidney, uteter, bladder and computed tomography revealed bilateral renal stones (right 4 mm, left 10 mm). The left renal stone was successfully treated by extracorporeal shock wave lithotripsy. Since the right renal stone was small, no treatment was performed. The stone fragments were composed of calcium oxalate and calcium phosphate, and excessive urinary excretion of oxalate (103.8 mg/day) was observed. In this patient, urolithiasis was diagnosed to be due to enteric hyperoxaluria caused by short bowel syndrome. To prevent the recurrence of stone formation, she was treated with oral administration of calcium lactate, sodium/potassium citrate and magnesium oxide. We review the Japanese literatures on urolithiasis with short bowel syndrome.     

Ammonium urate urinary stone: Its surface structure and incidence in Japan

We report on a middle-aged woman with a stone in the right kidney, derived from ammonium urate. Its surface structure was examined by scanning electron microscopy. Ammonium urate is a very rare component of urinary stones in industrialized countries, and they are thought to have an incidence of lower than 0.1% in Japan. The aetiology of ammonium urate-derived stones was investigated from an endemo-epidemiological viewpoint.     

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.     

Infrared spectroscopic analysis of urinary stones (including stones induced by melamine-contaminated milk powder) in 189 Chinese children

Aim

The aim of the study was to investigate the composition of the stones in Chinese children with urolithiasis, including peculiar stones induced by melamine-contaminated milk powder.

Materials and Methods

Between 1999 and 2009, 189 urinary stones from children of East China were received at our institution. Among them, 12 stones were received from pediatric stone formers with a history of consuming melamine-contaminated milk powder in 2008; and the remaining stones were defined as “natural” stones. All stones were analyzed by Fourier transform infrared spectroscopy.

Results

Among 177 “natural” stones, whewellite stone (49.72%) was observed most frequently followed by weddellite stone (15.25%), uric acid anhydrous stone (9.6%), carbapatite stone (9.04%), cystine stone (9.04%), ammonium acid urate stone (4.52%), struvite stone (2.26%), and sodium urate stone (0.56%). Twelve young children who consumed melamine-contaminated milk powder were younger than 3 years, and their stones were composed of a mixture of uric acid dihydrate and ammonium acid urate based on Fourier transform infrared spectroscopy. In addition, the stones were radiolucent and could be dissolved by urine alkalinization.

Conclusions

Our study emphasizes the relatively high rate of calcium oxalate stones and cystine stones, and the relatively low rate of struvite stones in Chinese children with urolithiasis. The stones caused by melamine-contaminated milk powder are composed of the mixture of uric acid dihydrate and ammonium acid urate.     

Relationship of frequency, age, sex, stone weight and composition in 15,624 stones: comparison of resutls for 1980 to 1983 and 1995 to 1998

PURPOSE: We studied the relationship of stone frequency and composition to age, sex and stone weight. MATERIALS AND METHODS: A retrospective study was performed of all 15,624 stones submitted for analysis with infrared and wet chemical methods in Newfoundland and Labrador from 1979 to 1998. RESULTS: There were 1,067 bladder stones of which 216 contained magnesium ammonium phosphate. The remaining 14,557 stones were from the kidney and ureter, and 11,707 were composed only of calcium oxalate and/or phosphate. Of the remaining 2,850 kidney and ureter stones magnesium ammonium phosphate was present in 573, uric acid/urate without magnesium ammonium phosphate in 1,109 and other compounds in 1,168. The 11,707 oxalate phosphate group was subdivided by infrared peak analysis based on oxalate-to-phosphate ratio into phosphate-ratio 1 or less, intermediate-1 to 10 and oxalate-10+. Oxalate comprised 65% of the 11,707 stones compared to 16% for phosphate. Women submitted 52% of phosphate stones compared with 28% of oxalate stones. From the first (1980 to 1983) to the last (1995 to 1998) complete 4-year study periods, there was a relative increase in oxalate and decrease in phosphate stones, associated with increasing age from decades 5 to 6 for oxalate and phosphate stones, except that the age peak for phosphate stones in women remained in decade 3. Median weight of 1, 828 phosphate stones was 43 mg. (mean 234) compared with 25 mg. (mean 98) for 7,634 oxalate stones. Male-to-female ratio was 0.91 for phosphate stones compared with 2.62 for oxalate stones. CONCLUSIONS: Phosphate stones were on average heavier and relatively more common in women, had an earlier age peak frequency in women than oxalate stones and became less frequent during our last 4-year study period. In contrast, oxalate stones were much more common, of lighter weight and became more frequent with time.     

A case of crossed fused kidney with simple ureterocele

A 32-year-old man consulted Osaka National hospital with chief complaints of dysuria and macrohematuria. DIP and CT revealed that the right kidney deviated to the lower pole of the left kidney and they fused together. The right ureter crossed over the supine. The calcified shadow existed in the lower end of the left ureter with cobra head image. He had no external anomalies. Under diagnosing crossed fused kidney (inverted L shaped) complicated the left ureterocele with a stone, transurethral incision of ureterocele (TUI) was performed. We made transverse incision and extracted stone, 7 mm in size (calcium oxalate 96% and calcium phosphate 4%). Three months later after the operation, IVP, CG and VCG revealed the down-sized ureterocele and no VUR. Crossed renal ectopia complicated many anomalies about 50%. Among them anomalies of the urinary tract was most frequent about 30%. But crossed renal ectopia with ureterocele wasn't reported so far in Japanese literature.     

Transurethral uretero-lithotripsy of ureteral stones in Osaka City University

During the 39 months since the introduction of transurethral lithotripsy (TUL) for the treatment of ureteral stones at our hospital in August 1985, TUL was performed a total of 200 times in 178 patients with ureteral stones. Among them, 111 patients had left ureteral stones and 65 had right ureteral stones, while 2 patients had ureteral stones in both sides. The stones were divided into upper ureteral stone (84 patients) and lower ureteral stone (94 patients) at above and below the iliac brim. 89% of the stones were less than 2 cm in diameter. Most of the patients were given lumbar anesthesia, and a guide wire was inserted into the ureter. The ureter was dilated with a ureteral bougie, and a 13F or 14F Storz ureteroscope was inserted. The stones were disintegrated by an ultrasound lithotripto and removed using forceps and a basket catheter. After the TUL procedure, a double J catheter was indwelled and removed within 5 days. The results were evaluated by DIP which was done 2 to 3 months after TUL. The success rate included residual stones less than 4 mm in diameter, as they could be spontaneously discharged. As a result, the success rate for upper ureteral stones was 53%, and it was higher for smaller stones. On the other hand, the success rate for lower ureteral stones was 85% and significantly higher. The main reasons for failure were the upper migration of the stones (60%) and inability to insert the ureteroscope up to the stone due to ureterostenosis and ureteral perforation (39%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Ammonium acid urate urinary stone caused by a low-caloric diet: a case report

A 32-year-old woman complained of right back pain and pyuria. The plain radiograph (KUB) and drip infusion pyelography (DIP) demonstrated a right renal stone and hydronephrosis. The stone was successfully treated using extracorporeal shock wave lithotripsy. Infrared spectrophotometry revealed that the stone was composed of pure ammonium acid urate. The patient had a 3-year history of excessive anorexia. The low-caloric diet was considered to have caused the disease.     

Acute renal failure due to bilateral ureteral stone impaction in an HIV-positive patient

A 51-year-old HIV-positive man treated with atazanavir for 9 months presented with anuria following right flank pain. Laboratory examination indicated renal insufficiency, and abdominopelvic computed tomography scanning showed bilateral hydroureteronephrosis, but no stones were visualized. Endoscopic procedures were performed to investigate the causes of ureteral obstruction and, if possible, to insert Double-J stents in the ureters. A yellowish stone composed of pure atazanavir was found at the right ureteral orifice, and retrograde pyelography revealed a filling defect in the left ureter found to be caused by an atazanavir stone. The patient’s renal function recovered after removal of these stones.     

A pediatric case of ammonium acid urate lithiasis with ulcerative colitis

A 13-year-old boy with ulcerative colitis was admitted to our hospital for the purpose of controlling diarrhea. He had received total colectomy and had been managed by intravenous hyper alimentation because of severe diarrhea (10 times/day). Oral intake had been prohibited except for fluid. Abdominal CT scan incidentally revealed two small calculi in the left kidney, which were left untreated. Two months later, one of them descended and was impacted into the urethra. Transurethral cystolitholapaxy showed the stone composition to be pure ammonium acid urate. Although ammonium acid urate lithiasis is rare in Japan, it should be reminded as a complication of chronic diarrhea secondary to inflammatory bowel disease in children.     

Laparoscopic pyelolithotomy in a horseshoe kidney

A 66-year-old woman had a 22 mm right kidney stone accompanied with a horseshoe kidney. The size of this stone had been increasing gradually from 7 mm to 22 mm during the past 5 years. Although apparent pelviuretic junction stenosis could not be identified by intravenous urography, external pelvis was dilated in both kidneys. Complete excretion of fragmented stones by extracorporeal shockwave lithotripsy seemed to be difficult because impaired urinary passage from the renal pelvis to the ureter was suspected. Percutaneous nephrolithotomy was also difficult due to malrotation of the pelvic-caliceal system and possible interposition of bowel loops between kidney and abdominal wall. Therefore, we chose laparoscopic pyelolithotomy. This procedure made it possible to remove the stone completely with minimum invasiveness. We assume that laparoscopic pyelolithotomy is a safe and effective approach for renal pelvic stone in case of horseshoe kidney.     

Percutaneous nephrolithotomy in horseshoe kidney

Two patients with renal pelvic stone in a horseshoe kidney who underwent a percutaneous nephrolithotripsy (PNL) are presented. Case 1 was a 36-year-old man with a 20 x 12 mm right renal pelvic stone in a horseshoe kidney. Case 2 was a 47-year-old man who had been followed up at our clinic for a horseshoe kidney and was found to have a 15 x 10 mm left renal pelvic stone. We found that percutaneous removal of renal pelvic stones can be performed safely in a horseshoe kidney. It appears that to remove stones from the renal pelvis in a horseshoe kidney 4 items must be considered. 1) The anatomical relationships of the horseshoe kidney to other viscera and blood vessels should be confirmed before surgery utilizing computerized tomography or ultrasound sonography. 2) The occlusion ureteral catheter should be inserted up to the renal pelvis to prevent small fragments from falling into the ureter. 3) The rigid nephroscopy should be introduced through the most appropriate calyx, so that its manipulation could be limited. 4) The fragmentation of stones should be performed from the peripheral surface of a stone to prevent from migrating into another calyx. We believe this is only the sixth and seventh documented cases involving a horseshoe kidney.     

Ureteral expanding stent: a new device for urolithiasis

BACKGROUND AND PURPOSE: We investigate a ureteral stent with radially expanding baskets producing passive dilation of the ureter for passage, capture, and removal of small ureteral stones. PATIENTS AND METHODS: Polyurethane ureteral stents were slit to open 15 to 17 baskets along the length. The baskets are designed to dilate the ureter passively and capture stones 相似文献