Ammonium Acid Urate Research Articles

The Effectiveness and Safety of Percutaneous Cystolithotripsy for Vesicle Calculus in Children: A Single-Center Study

Background: Primary bladder stones are common among children from developing countries but may be difficult to cure. Transurethral cystolithotripsy, open cystolithotomy, and shock wave lithotripsy are the treatment modalities for vesical calculi in children. Transurethral lithotripsy is less efficient in children because of the small caliber of the urethra. PCCL is a less intrusive and efficient procedure for removing bladder stones in pediatric patients. Objectives: The objective of the study was to determine the safety and efficacy of PCCL in children with bladder stones in third-world nations. Materials and Methods: There was a search for( PCCL) in pediatric individuals diagnosed with vesical calculus. 90% male and 10% female total of 120 patients enrolled in the single-center trial at the Department of Pediatric Urology at the Institute of Kidney Diseases between January 2021 to January 2022. The surgery was performed under a general anesthetic. After a thorough inspection, a suprapubic puncture of the lower urinary tract (by cystoscopy) was done. The tract was only dilated up to 14 Fr. The stone was fragmented using pneumatic lithotripsy after passing the nephroscope. After 36 hours per urethral catheter was removed. Results: In this study, the mean age of the patients was 4.2.14 years. The majority of patients were kids. The average gem was 9.3 millimeters in diameter. Successful stone fragmentation and retrieval took place in an average of 40 min. The only major problems seen during or after surgery were hematuria, infection, and moderate mucosal injury; all three were managed conservatively. In 108 out of 120 cases (90%), ammonium acid urate was found to be the primary constituent of the stones and the core. Conclusion: The success rate of percutaneous cystolithotripsy in the treatment of bladder stones in children is higher, and it is ready for immediate use. The operation is quick and causes minimal discomfort. Keywords: Effectiveness, Percutaneous , Cystolithotripsy, Vesical Calculus, Children

The Efficacy and Safety of Percutaneous Cystolithotripsy for Vesical Calculus in Children: A Single-Center Study

Purpose: The study aimed to assess the outcome and safety of PCCL in the pediatric population coming with bladder stones in developing countries.
 Methodology: Patients of pediatric age with vesical calculus were evaluated for PCCL. Department of Peads Urology Institute of Kidney Diseases Thirty participants were included in the single center study, with enrollment beginning in January 2000 and ending in August 2021. General anesthesia was used for the operation. Following a cystoscopy examination, a suprapubic puncture was performed, and the urethral tract was dilated to a maximum of 26 Fr. Pneumatic lithotripsy was used to break up the stone. A nephroscope was used to see where it was lodged so it could be removed. A percutaneous urethral catheter was inserted was taken out after 48 postoperative hours.
 Findings: The patients' median age was 4.1 (1-10). Patients tended to be men. The typical size of a gem was 10.1 millimeters. The average operational time to successfully remove the stones was just 30 minutes. Hematuria, infection, and mild mucosal damage were the only serious complications seen during or after surgery, and all were treated conservatively. Ammonium acid urate comprised the bulk of the stones and the nucleus in 26 cases (86%). Percutaneous suprapubic lithotripsy is a tested and reliable method with a high success rate for treating bladder stones in children. The procedure is short and has few adverse effects.

Quantitative phase analysis and microstructural characterization of urinary tract calculi with X-ray diffraction Rietveld analysis on a Caribbean island

In the twin-island state of Trinidad and Tobago, urinary stone analysis is not routinely performed. This study investigates, via powder X-ray diffraction, 52 urinary tract calculi collected from hospitals in Trinidad. Of these, 46 stones were analysed with Rietveld refinement for quantitative analysis and materials characterization. Refined unit-cell, microstructural and weight fraction parameters were obtained, with the last being used for stone classification. The results revealed seven distinct mineralogical phases of varying frequency: calcium oxalate monohydrate (COM, 58%), calcium oxalate dihydrate (COD, 23%), carbonated apatite (APA, 48%), brushite (BRU, 6%), struvite (STR, 42%), uric acid (UA, 23%) and ammonium acid urate (AAU, 19%). The average refined crystallite sizes were 1352 ± 90 Å (COM), 1921 ± 285 Å (COD), 83 ± 5 Å (APA), 1172 ± 9 Å (BRU), 1843 ± 138 Å (STR), 981 ± 87 Å (UA) and 292 ± 83 Å (AAU). Subsequently, 36.5% of stones were categorized as phosphates, 34.6% as oxalates, 13.5% as uric acid/urates and 15.4% as mixed compositions. The study findings highlight the importance of stone analysis as a necessary step towards disease management of local patients, and endorse the application of Rietveld refinement as a natural extension to diffraction-based kidney stone investigations.

Acute kidney injury due to ammonium acid urate stones in a patient with adenovirus gastroenteritis: a case report

BackgroundAdenovirus gastroenteritis is a common cause of diarrhea and vomiting in infants, resulting in prerenal acute kidney injury (AKI). However, postrenal AKI due to urinary stones associated with adenovirus gastroenteritis is extremely rare. Here, we describe postrenal AKI due to obstructive ammonium acid urate stones associated with adenovirus gastroenteritis.Case presentationA previously healthy 6-month-old boy had an 11-day history of severe diarrhea and a 5-day history of vomiting. His stool was positive for adenovirus antigens. We initiated fluid replacement therapy. On the second hospital day, he suddenly developed anuria. Abdominal computed tomography revealed bilateral hydronephrosis, left ureteral stones, and right bladder ureteral junction stones. Laboratory data showed that the creatinine level increased to 1.00 mg/dL. We diagnosed postrenal AKI due to obstructive bilateral urinary stones. Urination with stable urine volume resumed spontaneously after hydration. A few stones were found in the urine, which consisted of ammonium acid urate (> 98%). The serum creatinine level improved to 0.25 mg/dL. He was discharged nine days after admission.ConclusionsWe suggest that adenovirus gastroenteritis be considered in pediatric patients with postrenal AKI due to urinary stones.

Composition of urinary stones in children: clinical and metabolic determinants in a French tertiary care center.

As the epidemiology of urolithiasis is constantly evolving, analyzing the composition of stones is crucial to better understand the determinants of lithogenesis. The aim of this study was to describe the composition of stones of pediatric patients in a tertiary center. Clinical and metabolic data from all pediatric patients with at least one stone that was analyzed by Fourier transformed infrared spectroscopy (FTIR) in the Hospices Civils de Lyon between 2013 and 2017 were retrospectively collected. A total of 111 patients (sex ratio 1.4:1) were included; their median ([IQR]) age was 7.5 (3.1-10.5) years. The main component of stones was calcium oxalate (weddellite for 34 (31%) stones, whewellite 23 (21%)), calcium phosphate (carbapatite 32 (29%), brushite 6 (5%), amorphous calcium phosphate 3 (3%)), struvite 5 (5%), cystine 4 (4%), uric acid 2 (2%), and ammonium acid urate 2 (2%). A total of 20 (18%) stones were pure and 24 (22%) were infectious. Carbapatite stones were the most frequent in patients < 2 years and calcium oxalate stones in patients > 2 years old. Metabolic abnormalities (most frequently hypercalciuria) were found in 50% of tested patients and in 54% of patients with infectious stones. Congenital anomalies of the kidney and/or urinary tract (CAKUT) or neurogenic bladder were present in 9/24 (38%) patients with infectious stones and 12/16 (76%) patients with bladder stones.Conclusion: This study confirms that calcium oxalate stones are the most frequent among pediatric patients, which could reflect the nutritional habits of predisposed patients. In contrast, infectious stones are less frequent and occur mostly in association with anatomic or metabolic favoring factors.

Urates of colubroid snakes are different from those of boids and pythonids

Abstract Uricotelic species, such as squamate reptiles, birds and insects, effectively eliminate nitrogen as uric acid in a solid form commonly called urates. Observations made over a decade suggested that the voided urates produced by colubroids (modern snake species) exhibit remarkable differences from those of boids and pythons (ancient snake species). Here, we compare the urates generated by eight captive snake species fed the same diet. Although all fresh urates were wet at the time of excretion, those produced by modern snakes dried to a powdery solid, whereas those of ancient species dried to a rock-hard mass that was tightly adherent to surfaces. Powder X-ray diffraction and infrared spectroscopy analyses performed on voided urates produced by five modern and three ancient snakes confirmed their underlying chemical and structural differences. Urates excreted by ancient snakes were amorphous uric acid, whereas urates from modern snakes consisted primarily of ammonium acid urate, with some uric acid dihydrate. These compositional differences indicate that snakes have more than one mechanism to manage nitrogenous waste. Why different species use different nitrogen-handling pathways is not yet known, but the answer might be related to key differences in metabolism, physiology or, in the case of ancient snakes, the potential use of urates in social communication.

A Rare, Unusual Presentation of Newberyite Urolithiasis in Adolescent Female -A Case Report and Review of Literature

We report a rare case of newberyite (magnesium monohydrate phosphate trihydrate) urolithiasis in a young female with a past medical history significant for longstanding autoimmune hepatitis. She presented to the emergency department with newly diagnosed nephrolithiasis. Over the next 2 years, she had recurrent renal calculi and 3 urologic procedures. Notably, she did not have any history of urinary tract infections or genitourinary abnormalities. Her last stone analysis revealed the unusual combination of newberyite and ammonium acid urate. The pathophysiology of ammonium acid urate and newberyite stone formation as well as risk factors of development are discussed in this report.

Acute kidney injury caused by ammonium acid urate crystals in diabetic ketoacidosis at the onset of type 1 diabetes mellitus.

SummaryAmmonium acid urate (AAU) crystals are rare in industrialized countries. Furthermore, the number of children with diabetic ketoacidosis (DKA) who develop severe acute kidney injury (AKI) after hospitalization is small. We encountered two patients with AKI caused by AAU crystals during the recovery phase of DKA upon admission. They were diagnosed with severe DKA and hyperuricemia. Their urine volume decreased and AKI developed several days after hospitalization; however, acidosis improved in both patients. Urine sediment analysis revealed AAU crystals. They were treated with urine alkalization and diuretics. Excretion of ammonia in the urine and urine pH levels increased after treatment of DKA, which resulted in the formation of AAU crystals. In patients with severe DKA, the urine and urine sediment should be carefully examined as AAU can form in the recovery phase of DKA.Learning pointsAmmonium acid urate crystals could be formed in the recovery phase of diabetic ketoacidosis.Diabetic ketoacidosis patients may develop acute kidney injury caused by ammonium acid urate crystals.Urine and urine sediment should be carefully checked in patients with severe DKA who present with hyperuricemia and volume depletion.

Morphological and crystallographic analysis of kidney stones in Eastern Morocco

&lt;p&gt;&lt;strong&gt;Abstract&lt;/strong&gt;:&lt;strong&gt; &lt;/strong&gt;Renal lithiasis is a common disease in the eastern region of Morocco, as it threatens the public health because of its repetitive nature as well as the complications it can cause in the kidney. &lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Objective&lt;/strong&gt;: This study aims to investigate the morphological, molecular, and crystallographic characteristics of kidney stones affecting patients, specifically in the eastern region of Morocco.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods&lt;/strong&gt;: Morphological and constitutional analyses of 239 renal lithiases made it possible to identify the various crystalline forms present, to assess the structure of the stones and to determine the composition of their nucleation zone. &lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results&lt;/strong&gt;: It appears that calcium oxalate is the main component of the analyzed stones. It represents 70.5 % of the stones, which 55.5 % are majority whewellite and 15 % in weddellite. In comparison, calcium phosphates and magnesium (carbapatite and struvite) are the majority in only 8.9 % of cases, uric acid in 19.8 % of stones, and ammonium acid urate in 0.8 %. Calcium oxalate is predominant in the core of 52.5 % of the stones, carbapatite in 24.1 %, and uric acid in 20.3 % and struvite in 2.9 %. Most of the stones analyzed consist of a mixture of different crystalline constituents. Only 9.3 % of the stones analyzed have a homogeneous composition. Several types of associations were identified, the main ones being whewellite-carbapatite and whewellite-weddellite-carbapatite. &lt;strong&gt;Conclusion&lt;/strong&gt;:&lt;strong&gt; &lt;/strong&gt;The present study shows that calcium oxalate is the most common compound in the samples studied, followed by the uric acid compound.&lt;/p&gt;

Kidney Stone Composition in Third-World Areas: What Kashgar Tells Us?

To analyze urinary stone compositions in patients from Kashgar, China. We analyzed the components of urinary stones in 732 consecutive patients with urolithiasis admitted to the First and Second People's Hospital of Kashgar Prefecture, Xinjiang, from July 2014 to November 2016. The patients were divided into two groups by ages: group A, 0 to 18 years and group B, >18 years old. The distributions of various stone compositions were analyzed and correlated with the gender and age. The mean age of group A was 3.90 ± 4.09 years and that of group B was 39.88 ± 16.40 years. The overall gender ratio (male:female) was 2.27:1. Ammonium acid urate (AAU) stone was the most frequent stone, male 35.83% and female 33.48%. Female patients were significantly more common than male patients in calcium apatite stone (p = 0.004). Of all 732 cases, patients younger than 18 years were more than patients older than 18 years (58.47% vs 41.53%). The majority of the patients (77.87%) had the stone located in the upper urinary tract. Two peak ages for both genders were noted in 1 to 3 years and 19 to 40 years group of the patients. In group of 1 to 3 years patients, male were more than female (37.60% vs 24.55%, p = 0.001), whereas in the group of 10 to 18 years patients, female were more than male (10.71% vs 4.13%). AAU was the predominant stone component in group <1 year (70. 5%, p < 0.01, as compared with other groups.). Uric acid stone was more prevalent in group >60 years (66.8%, p < 0.01) than in other groups. Patients in 1 to 3 years were in the peak age group of AAU stones in both the upper and lower urinary tract. Most of the patients with urolithiasis diagnosed and treated in Kashgar are <18 years old, especially younger than 3 years old. The most frequent stone component in this area was AAU. More than 50% patients <18 years old had AAU stone. The mechanisms that could trigger the high prevalence of AAU stone in patients <18 years old are worth further investigation.

Composition of urinary calculi in infants: a report from an endemic country.

Pediatric urolithiasis remains endemic in low-resource countries where infants constitute 17-40% of all children with urolithiasis. This study reports socio-economic factors, medical history and chemical composition of urinary stones in 976 infants of up to 2years of age. Between 1992 and 2016, 976 infants presented to our institute with 1038 stones. Chemical composition of stones was analyzed by Fourier transformation infrared spectroscopy (FTIR). The mean age of infants was 19.5±5.74months with a M:F ratio of 5.5:1. Half (50%) of the infants were rural dwellers, 90% belonged to low socio-economic class and 70% were malnourished. A history of chronic diarrhoea was reported in 13% and urinary tract infections in 5%. The anatomic location was bladder in 487 (46.9%), kidney in 246 (23.6%), ureter in 142 (13.6%), urethra in 2 (0.2%) and 161 (15.5%) were passed spontaneously. Overall frequency of compounds in stones showed ammonium acid urate (AAU) in 772 (74.37%), calcium oxalate (CaOx) in 410 (39.5%). Uric acid (UA) in 119 (11.46%), calcium phosphate apatite (CaP) in 96 (9.25%), magnesium ammonium phosphate (Struvite) in 45 (4.34%), cystine in 12 (1.16%) and xanthine in 40 (3.85%). Frequency of compounds was similar in genders. Infants of age 0-6months had higher frequency of UA (28%), CaOx (50%) and low AAU (61%) as compared to 11, 39 and 75%, respectively, in 7-24months (p<0.049) (p<0.002) (p<0.001). Nucleus of stones showed pure AAU in 63 and 43% on the surface due to addition of CaOx, struvite and CaP. Our study has shown that AAU is a major component of stones in infants where the main risk factors are poverty, malnutrition, diarrheal diseases and dehydration.

Effect of Stone Size and Composition on Ultrasonic Propulsion Ex Vivo

To evaluate in more detail the effectiveness of a new designed more efficient ultrasonic propulsion for large stones and specific stone compositions in a tissue phantom model. In the first clinical trial of noninvasive ultrasonic propulsion, urinary stones of unknown compositions and sizes up to 10 mm were successfully repositioned. The study included 8- to 12-mm stones of 4 different primary compositions (calcium oxalate monohydrate, ammonium acid urate, calcium phosphate, and struvite) and a renal calyx phantom consisting of a 12 mm × 30 mm well in a 10-cm block of tissue-mimicking material. Primary outcome was the number of times a stone was expelled over 10 attempts, with ultrasonic propulsion burst duration varying from 0.5 seconds to 5 seconds. Overall success rate at expelling stones was 95%. All calcium oxalate monohydrate and ammonium acid urate stones were expelled 100% of the time. The largest stone (12 mm) became lodged within the 12-mm phantom calyx 25% of the time regardless of the burst duration. With the 0.5-second burst, there was insufficient energy to expel the heaviest stone (0.88 g), but there was sufficient energy at the longer burst durations. With a single burst, ultrasonic propulsion successfully moved most stones at least 3 cm and, regardless of size or composition, expelled them from the calyx. Ultrasonic propulsion is limited to the stones smaller than the calyceal space, and for each burst duration, related to maximum stone mass.

UROLITHIASIS IN FREE-RANGING AND CAPTIVE OTTERS (LUTRA LUTRA AND AONYX CINEREA) IN EUROPE.

Between 1996 and 1998, 477 dead otters from different Central European countries were examined for urolithiasis, including 449 free-ranging Eurasian otters (Lutra lutra) as well as 17 Eurasian otters and 11 Asian small-clawed otters (Aonyx cinerea) from captivity. In the free-ranging specimens, uroliths (sand or stones) were found in 105 animals (23.4%), with no significant difference (P = 0.77) between the sexes. Uroliths were not present in any juveniles (n = 26) and urolithiasis was not considered the main cause of death in any individual. In captive specimens, uroliths were found in 11 out of 17 Eurasian otters (64.7%; four males and seven females), and in 3 out of 11 Asian small-clawed otters (27.3%). Histology could not find any signs of inflammation in examined kidneys (n = 179) or urinary bladders (n = 66). Analyzed stones of free-ranging and captive Eurasian otters were composed mainly of ammonium acid urate. The stones of three captive Asian small-clawed otters consisted mainly of calcium oxalate. The difference in prevalence of uroliths between free-ranging and captive Eurasian otters was significant (P < 0.001). Nevertheless, the prevalence in free-ranging specimens of this study is higher than reported before. Differences between various habitats, environmental changes, and genetic predisposition all represent potential hypothetical explanations for these findings.

Profile of the Ammonium Acid Urate Stone Former Based on a Large Contemporary Cohort

To evaluate and profile ammonium acid urate (AAU) stone formers utilizing a large contemporary cohort. A retrospective review of all patients with documented AAU urolithiasis on stone analysis was performed from 1995 to 2013. A stone was considered AAU if it contained at least 10% of the total composition on stone analysis. Of 12,421 stones, a total of 111 AAU stones were identified in 89 patients. Seventy-two patients (81%) had mixed composition stones. Of the 89 AAU patients, 10 (11%) had chronic kidney disease, 12 (13%) had recurrent urinary tract infections, 8 (9%) had diabetes mellitus, 25 (28%) had a history of ileostomy or bowel resection, and 11 (12%) had significant diarrhea or inflammatory bowel disease. Additionally, 20 (22%) had prior prostate surgery with bladder neck contracture and 8 (9%) were managed with a chronic indwelling catheter. Surgical intervention was required in 74 patients (83%). At the median follow-up of 4.9 years, 19 patients (21%) had stone recurrence with a median time to recurrence of 22 months (interquartile range: 10.5-42.0). AAU stones are rare. In addition to previously described risk factors for AAU stone formation, patients with prior prostate surgery and bladder neck contracture or a surgically altered bladder may be at increased risk for formation. Furthermore, the long-term follow-up provided by this large AAU cohort demonstrates a significant risk for stone recurrence.

Prevalence of renal calculi in wolverine (Gulo gulo) from northwestern Canada

Renal calculi (kidney stones) are often reported in domestic animals and occasionally wildlife; however, prevalence is rarely reported for free-ranging wildlife. Our aim was to determine the prevalence of renal calculi in a large sample of free-ranging wolverine (Gulo gulo) from a harvested population in Yukon, Canada. We tested for an effect of sex, age, and body condition, on the presence of renal calculi. Macroscopic examination revealed renal calculi in 48 of 537 (8.9%) wolverine. Bilateralism was low, with only 6 of 48 (12.5%) affected wolverine having calculi in both kidneys. Calculi were found in similar prevalence between the sexes. A significantly higher percentage of adults (≥2 years old) had renal calculi than sub-adults (<2 years old). When considering adults alone, prevalence was 12.7% for males and 17.8% for females. The mean age of affected females was not statistically different than the sample population, but the mean age of affected adult males was 2 years older than unaffected adult males. Mean body condition scores for wolverine with and without calculi were not statistically different for females or males. Mineral composition was determined for calculi from 29 wolverine. Calculi from most wolverine (90%) were composed of 95–100% ammonium acid urate, with magnesium ammonium phosphate (struvite) and calcium phosphate (apatite) as minor (≤5%) constituents. Our study is one of the first to document the prevalence of renal calculi in a free-ranging population of wildlife. Prevalence of renal calculi in adult wolverine from northwestern Canada was substantial; however, the pathogenesis and clinical significance of nephrolithiasis in wolverine is unknown.

Vesical calculi in children

Vesical calculi occur due to increased urinary concentration & are commonly seen in children belonging to low socio-economic status. They are usually formed of ammonium acid urate, calcium oxalate or calcium phosphate. Vesical calculi constitute about 70% to 85% of paediatric urolithiasis & boys are affected more than girls. Primary vesical calculi occur in sterile urine & are associated with nutritional deficiency whereas Secondary calculi occur due to infection, obstruction or inflammation. Endemic calculi are associated with oxalate-rich diet. They usually present with hematuria, dysuria, frequent urinary tract infection, urinary urgency & bedwetting. The diagnostic modalities of vesical calculi are Urinalysis, urine dipstick test, serum Creatinine level, plain x-ray abdomen &Intravenous Pyelography. Sonogram is effective in identifying both radiolucent & radiopaque stones. Spiral CT scanning is highly sensitive & specific whereas Pelvic MRI orTechnetium-99m MAG-3 renal scanning yields poor resolution & are not recommended in the evaluation of bladder calculi. Treatment for vesical calculi depends on the size, composition & symptoms. The only effective medical treatment is urinary alkalization. Indications for surgery are failure of medical management, recurrent infections, acute urinary retention, suprapubic pain & significant gross hematuria. Open cystolithotomy was done earlier which is being replaced by cystolitholapaxy. With ongoing advances in instrumentation procedures like Transurethral optical litholapaxy are now applicable to children. Minimally invasive surgeries like extracorporeal lithotripsy, percutaneous nephrolithotripsy & urethroscopy have reduced open surgery to only 1- 4% of cases. Early diagnosis & appropriate management are essential for managing vesical calculi in children.

Clinical characteristics of rotavirus gastroenteritis with urinary crystals.

Rotavirus gastroenteritis is severe and often results in dehydration and pre-renal azotemia. In addition, some patients with acute obstructive uropathy due to ammonium acid urate stones, developing approximately 6-7 days after the onset of rotavirus gastroenteritis, have been reported, mainly in Japan. The pathophysiological mechanism responsible for stone formation has not been clarified. In the present study, we investigated the clinical characteristics of these patients, and analyzed the pathophysiology underlying the formation of urinary stones. A total of 164 patients were enrolled. All had acute gastroenteritis due to rotavirus infection and were treated at Osaka Medical College Hospital and affiliated hospitals between January 2009 and May 2011. All were younger than 15 years of age, and their laboratory data, including urinalysis, were available. Among the enrolled patients, 30 (20 boys and 10 girls aged 0.2-10 years; median, 1.5 years; interquartile range, 1-3 years) had crystals in their urine. Most of the patients were admitted approximately 2 days after onset of gastroenteritis and had hyperuricemia and aciduria. The crystals consisted mainly of uric acid, and rarely of ammonium acid urate. In order for ammonium acid urate stones to form in patients with acute obstructive uropathy associated with rotavirus gastroenteritis, prolonged continuous acidosis with hyperuricemia, might be necessary. Therefore, normalization of metabolic acidosis is important in order to prevent the onset of obstructive uropathy associated with rotavirus gastroenteritis.

Lithiases urinaires et pathologies digestives : une revue de la littérature

The aim of the study was to explain the relationship between urinary stones and bowel disease. A systematic review was performed on Medline, Embase and Cochrane using following keywords: urinary stones; urolithiasis; bowel; enteric and digestive. The literature selection was based on evidence and practical considerations. Fifty-three articles were selected. Three types of urolthiasis are mainly involved in digestive pathologies: calcium oxalate stones, uric acid and ammonium acid urate stones. Bowel pathologies responsible for stone disease are divided into small bowel diseases, colonic lesions and lack of an oxalate degrading bacteria (Oxalobacter formigenes) in the intestinal flora. Resulting in a decreased urine output, pH, hyperoxaluria, hypocitraturia or a hypomagnesurie. Blood and urinary explorations are the basis of diagnostic management. Bowel diseases can be responsible for urolthiasis. Understanding of the mechanisms, and metabolic evaluations can prevent recurrences. Increase fluid intake associated with specific supplementation and diet are the key of the treatment.

Four pediatric cases of ammonium acid urate crystal with nephrotic syndrome

Four pediatric cases of ammonium acid urate crystal with nephrotic syndrome

Endoscopic cystolithotomy by mini nephroscope: A preliminary study

Objective: To introduce a novel endoscopic surgical technique with mini-nephroscope by suprapubic transvesical route for cystolithotripsy in children. Material and methods: This was a non-randomized study with a series of 12 boys, between February 2012 and September 2013. Demographic, operative, and postoperative data were recorded. Our new endoscopic surgery technique could be performed in all patients. Complications were noted. Results: Mean age was 35.1 ± 8.6 months (19–46 months), the average stone size was 16.5 ± 5.2 mm (10–20 mm). Mean operation time was 28.9 min (21–40), and mean hospital stay was 2.2 (2–3) days. In all procedures, stones were successfully fragmented and extracted by the new surgical technique. There was no intraoperative and/or postoperative complication or urethral stricture during follow-up period. In stone analyses, the main components were ammonium acid urate, calcium oxalate, and struvite. Conclusions: The new endoscopic surgery technique is safe and effective for bladder stones in children. Thus, our technique can be a strong candidate for an alternative treatment of childhood bladder stones.