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Abstract
Uric acid nephrolithiasis appears to increase in prevalence. While a relationship between uric acid stones and low urinary pH has been for long known, additional association with various metabolic conditions and pathophysiological basis has recently been elucidated. Some conditions such as diabetes and metabolic syndrome disease, excessive dietary intake, and increased endogenous uric acid production and/or defect in ammoniagenesis are associated with low urinary pH. In addition, the phenomenon of global warming could result in an increase in areas with greater climate risk for uric acid stone formation. There are three therapeutic steps to be taken for management of uric acid stones: identification of urinary pH profiles, assessment of urinary volume status, and identification of disorders leading to excessive uric acid production. However, the most important factor for uric acid stone formation is acid urinary pH, which is a prerequisite for uric acid precipitation. This article reviews recent insights into the pathophysiology of uric acid stones and their management.
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Affiliation(s)
- Elisa Cicerello
- Unità Complessa di Urologia, Ospedale Ca' Foncello, Treviso, Italy
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Abou-Elela A. Epidemiology, pathophysiology, and management of uric acid urolithiasis: A narrative review. J Adv Res 2017; 8:513-527. [PMID: 28748117 PMCID: PMC5512151 DOI: 10.1016/j.jare.2017.04.005] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 04/16/2017] [Accepted: 04/25/2017] [Indexed: 12/31/2022] Open
Abstract
An in-depth comprehension of the epidemiology as well as pathophysiology of uric acid urolithiasis is important for the identification, treatment, and prophylaxis of calculi in these patients. Persistently low urinary pH, hyperuricosuria, and low urinary volume are the most important factors in pathogenesis of uric acid urolithiasis. Other various causes of calculus formation comprises of chronic diarrhea, renal hyperuricosuria, insulin resistance, primary gout, extra purine in the diet, neoplastic syndromes, and congenital hyperuricemia. Non-contrast-enhanced computed tomography is the radiologic modality of choice for early assessment of patients with renal colic. Excluding situations where there is acute obstruction, rising blood chemistry, severe infection, or unresolved pain, the initial management ought to be medical dissolution by oral chemolysis since this method has proved to be effective in most of the cases.
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Affiliation(s)
- A Abou-Elela
- Department Of Urology, Faculty Of Medicine, Cairo University, Kasr Al Ainy St., P.O. 11553, Cairo 11562, Egypt
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Torricelli FC, De S, Liu X, Calle J, Gebreselassie S, Monga M. Can 24-Hour Urine Stone Risk Profiles Predict Urinary Stone Composition? J Endourol 2014; 28:735-8. [DOI: 10.1089/end.2013.0769] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Fabio C.M. Torricelli
- Stevan B. Streem Center for Endourology & Stone Disease, Glickman Urological & Kidney Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Shubha De
- Stevan B. Streem Center for Endourology & Stone Disease, Glickman Urological & Kidney Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Xiaobo Liu
- Stevan B. Streem Center for Endourology & Stone Disease, Glickman Urological & Kidney Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Juan Calle
- Stevan B. Streem Center for Endourology & Stone Disease, Glickman Urological & Kidney Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Surafel Gebreselassie
- Stevan B. Streem Center for Endourology & Stone Disease, Glickman Urological & Kidney Institute, The Cleveland Clinic, Cleveland, Ohio
| | - Manoj Monga
- Stevan B. Streem Center for Endourology & Stone Disease, Glickman Urological & Kidney Institute, The Cleveland Clinic, Cleveland, Ohio
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Abstract
Uric acid stones are significantly more common among nephrolithiasis patients with type 2 diabetes, obesity, and/or the metabolic syndrome. The principal metabolic feature responsible for this association is an overly acidic urine, which leads to the precipitation of sparingly soluble uric acid crystals in urine and subsequent development of stones. The unduly acidic urine in uric acid stone formers is caused by a combination of excessive dietary intake of animal proteins and a defect in renal ammoniagenesis and/or excretion that leads to impaired buffering and amplifies the acidic urine caused by an increased acid excretion.
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Affiliation(s)
- Naim M Maalouf
- Department of Internal Medicine, and Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-8885, USA.
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Mokhless IA, Sakr MA, Abdeldaeim HM, Hashad MM. Radiolucent renal stones in children: combined use of shock wave lithotripsy and dissolution therapy. Urology 2009; 73:772-5. [PMID: 19193412 DOI: 10.1016/j.urology.2008.10.066] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Revised: 09/23/2008] [Accepted: 10/07/2008] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To provide a noninvasive efficient modality for the treatment of radiolucent renal stones in children. Uric acid calculi comprise a significant proportion of urinary stones. METHODS This study included 24 children (10 girls and 14 boys) with radiolucent renal stones. Of the 24 patients, 5 presented with bilateral renal stones, 8 with multiple stones, 4 with staghorn stones, and 7 with a solitary renal stone. Their age range was 2-12 years (mean 6.3 +/- 2.8). The stone size range was 12-65 mm in the largest diameter. All patients were treated with combined extracorporeal shock wave lithotripsy (ESWL) and medical therapy in the form of urinary alkalization using potassium sodium hydrogen citrate and allopurinol for the treatment of hyperuricosuria. Before ESWL, 3 patients had a percutaneous nephrostomy tube inserted and 2 patients had a ureteral stent placed to relieve obstruction. ESWL was performed with a Siemens Lithostar using either general anesthesia or intravenous sedation. The follow-up period after stone clearance was 12-36 months (mean 26 +/- 7.2). RESULTS The stone-free rate of 100% was achieved in all 24 patients after 3 months of combined use of extracorporeal shock wave lithotripsy and dissolution therapy. CONCLUSIONS Combined ESWL and dissolution therapy accelerated stone clearance and delayed stone recurrence. The use of ESWL and medical therapy as a combined modality is a safe and effective treatment of radiolucent renal stones in children.
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Affiliation(s)
- Ibrahim A Mokhless
- Section of Pediatric Urology, Department of Urology, Alexandria University, Alexandria, Egypt
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Abstract
Approximately one-fourth of urolithiasis patients are at high risk for recurrent stone formation or severe metabolic disturbances. These patients need specific metaphylaxis for effective stone prevention, adjusted to their individual metabolic risk. Recent recommendations for the pharmacological treatment of stone diseases are summarized in this article. For the different treatment options, evidence from the literature was assessed. In addition, a follow-up concept for pharmacologically treated high-risk stone formers is discussed.
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Affiliation(s)
- M Straub
- Urologische Klinik und Poliklinik der Technischen Universität München, Klinikum rechts der Isar, München.
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Straub M, Strohmaier WL, Berg W, Beck B, Hoppe B, Laube N, Lahme S, Schmidt M, Hesse A, Koehrmann KU. Diagnosis and metaphylaxis of stone disease. Consensus concept of the National Working Committee on Stone Disease for the upcoming German Urolithiasis Guideline. World J Urol 2005; 23:309-23. [PMID: 16315051 DOI: 10.1007/s00345-005-0029-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Accepted: 10/04/2005] [Indexed: 10/25/2022] Open
Abstract
This review draws the recent state of the art in metabolic diagnosis and metaphylaxis of stone disease. It is the basis for the consensus approval with the other medical societies and institutions in Germany involved in the guideline process of the new "Urolithiasis Guideline". The German Working Committee on Stone Disease reviewed critically the current literature in the field of urolithiasis-including the existing German and EAU-Guidelines as well as the Conference Book of the First International Consultation on Stone Disease. As far as possible the references were rated according to the EBM criteria. On this basis the expert group discussed all pathways and statements regarding the management of stone disease. The present review coincides with the consented guideline draft of the German Working Committee on Stone Disease. Occurrence of stone disease in the western world increases seriously. Modern lifestyle, dietary habits and overweight-problems of the affluent societies-emerge to be the important promoters of the "stone-boom" in the new millennium. This even affects children, whose stone prevalence is otherwise significantly less than that of adults. Criteria for the high risk group of stone formers were clearly defined. A diagnostic standard is formulated for the basic and the elaborate metabolic evaluation of a stone patient. Approximately 75% of all stone patients could anticipate stone recurrence with elementary reorientation of their lifestyle and dietary habits, summarized as general metaphylaxis. About 25% of the stone formers require additional pharmacological intervention to normalize their individual biochemical risk, precisely compiled for each stone type as specific metaphylaxis.
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Affiliation(s)
- M Straub
- Urolithiasis Research Group, Department of Urology and Pediatric Urology, University of Ulm, Prittwitzstrasse 43, 89075 Ulm, Germany.
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10
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Abstract
PURPOSE Uric acid calculi with or without a calcium component comprise a significant proportion of urinary stones. Knowledge of the pathophysiology of stone formation is important to direct medical treatment. The aim of this review is to provide an update on the epidemiology, pathophysiology and management of uric acid renal stones. MATERIALS AND METHODS A MEDLINE search was performed on the topic of uric acid stones. Current literature was reviewed with regard to the epidemiology, pathophysiology, associated medical conditions and management of uric acid stones. RESULTS The incidence of uric acid stones varies between countries and accounts for 5% to 40% of all urinary calculi. Hyperuricuria, low urinary output and acidic urine are well known contributing factors. However, the most important factor for uric acid stone formation is persistently acidic urine. Gout and myeloproliferative disorders are associated with uric acid stones. Why most patients with gout present with acidic urine yet only 20% have uric acid stone formation remains unclear. The pathophysiological basis for persistent urine acidity also remains unclear although various mechanisms have been proposed. Urinary alkalization with potassium citrate or sodium bicarbonate is a highly effective treatment, resulting in dissolution of existing stones and prevention of recurrence. CONCLUSIONS Acidic urine is a prerequisite for uric acid stone formation and growth. Medical management with urinary alkalization for stone dissolution and prevention of recurrence is effective and should be the cornerstone of treatment.
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Affiliation(s)
- Bijan Shekarriz
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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11
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Abstract
PURPOSE Uric acid calculi with or without a calcium component comprise a significant proportion of urinary stones. Knowledge of the pathophysiology of stone formation is important to direct medical treatment. The aim of this review is to provide an update on the epidemiology, pathophysiology and management of uric acid renal stones. MATERIALS AND METHODS A MEDLINE search was performed on the topic of uric acid stones. Current literature was reviewed with regard to the epidemiology, pathophysiology, associated medical conditions and management of uric acid stones. RESULTS The incidence of uric acid stones varies between countries and accounts for 5% to 40% of all urinary calculi. Hyperuricuria, low urinary output and acidic urine are well known contributing factors. However, the most important factor for uric acid stone formation is persistently acidic urine. Gout and myeloproliferative disorders are associated with uric acid stones. Why most patients with gout present with acidic urine yet only 20% have uric acid stone formation remains unclear. The pathophysiological basis for persistent urine acidity also remains unclear although various mechanisms have been proposed. Urinary alkalization with potassium citrate or sodium bicarbonate is a highly effective treatment, resulting in dissolution of existing stones and prevention of recurrence. CONCLUSIONS Acidic urine is a prerequisite for uric acid stone formation and growth. Medical management with urinary alkalization for stone dissolution and prevention of recurrence is effective and should be the cornerstone of treatment.
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Affiliation(s)
- Bijan Shekarriz
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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Harries SR, Fox BM, Williams MP. Nephrostomy failure due to tumour lysis syndrome. Clin Radiol 2000; 55:152. [PMID: 10657164 DOI: 10.1053/crad.1999.0071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- S R Harries
- The Department of Diagnostic Imaging, Derriford Hospital, Plymouth, Devon, U.K
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Abstract
Although they are two very distinct entities, uric acid and cystine stone disease share a common physico-chemical background, i.e. urinary supersaturation with respect to a compound that is poorly soluble in an acid milieu. Therefore, high-fluid intake and urine alkalinization, preferably by potassium citrate, are of utmost importance for prophylaxis. Urinary excretion of uric acid and cystine may be reduced by dietary measures as well as by drug therapy (allopurinol and thiols, respectively).
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Affiliation(s)
- B Hess
- Policlinic of Medicine, University of Berne, Switzerland
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Abstract
The mechanism of stone formation in the urinary tract is reviewed. Diet, urinary tract infection and metabolic disorders account for the different epidemiological patterns of stone formation. The diagnosis and management of renal tract calculi are discussed. Calcium stones are associated with hypercalciuria, urine acidification defects, the use of furosemide in premature babies, hypercalcaemia, hyperoxaluria, hyperuricosuria, an alkaline urine and hypocitraturia. Uric acid stones occur in acid urine, from increased purine synthesis with lympho- or myeloproliferative disorders or from several inborn errors of purine metabolism which can also cause xanthine or dihydroxyadenine stones. Cystinuria, inherited as an autosomal recessive disorder is best treated with a low sodium diet, a fluid intake exceeding 40 ml/kg per day maintaining urine pH between 7.5 and 8 and, if necessary, with oral penicillamine. Oxalate stones occur in relation to diet, bowel disease and primary inherited defects in oxalate metabolism. Urinary tract infection causing struvite and carbonate apatite formation is the commonest cause of stones in Europe.
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Affiliation(s)
- J Laufer
- Paediatric Nephrology Unit, Chaim Sheba Medical Centre, Sackler Faculty of Medicine, Tel Aviv University, Israel
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Hosking DH. The Use of K-Lyte (Potassium Citrate) in Uric Acid Lithiasis. Urolithiasis 1989. [DOI: 10.1007/978-1-4899-0873-5_257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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