Urinary stones is a pathology whose inci-dence and prevalence are increasing in developed and underdeveloped countries. Overall, in the United States the prevalence has been increased from 3.2% in 1980 to 10.1% in 2014. In Spain, this increase has also been significant, from 5% in 2005 to 14.6% in 2016. In the rest of the world happens in a similar way, where an average increase is observed in the last 15-20 years of approximately 5-7%. The decade of life between 40-60 years is usually the highest incidence of stones. Regarding sex, in recent years there has been a grow-ing in women, associated with a change in diet and obesity, and currently there are no differences between sex. It is a more frequent disease in the Western world, although there are countries in the Middle East such as Saudi Arabia where the prevalence is very high, around 20%. Respect the lithiasis composition, calcium oxalate continues to be the most frequent around 70-80%, with an increase in uric acid lithiasis in recent years and a decrease in infective lithiasis. In relation to the appear-ance of this pathology in children, it is rare in the first years of life, being more prevalent from 12-13 years of age and increasing in adolescence. It is usually more common in girls than in boys and in the Caucasian race compared to African Americans. There are no differenc-es in lithiasic composition with respect to adults, calcium oxalate being the most frequent composition, but with a prevalence of 50-60%. However, the causes and etio-pathogenic factors in children are less studied and well known than in adults.

INTRODUCTION: Kidney stone disease affects 1 in 10 persons at least once per life-time worldwide, in 2% the disease is recurrent. For the individual stone disease can be painful and lead even to chronic kidney disease, while the costs for the health system and economy can be very high. Thus, factors causing stone disease need to be identified in order to prevent or reduce the incidence of disease.AIM: This review will discuss major risk factors contributing to stone disease with special emphasis on genetic and dietary risk factors. RESULTS: Stone disease is multifactorial with a strong genetic component, gender-specific risks and prevalence, and a modifiable contribution of nutrition. The different factors contributing to the risk for developing stones are discussed.DISCUSSION: Urolithiasis is a frequent disorder affecting almost 10% of the population with a high risk of recurrence. Treatment and prevention have to be tailored to the individual causes of disease and require an assessment of underlying predispositions and interacting modifiable environmental factors.

Imaging in urolithiasis has a wide group of techniques, with different characteristics, limitations, and indications, which together allow the management of this prevalent pathology. Plain abdominal radiography and ultrasound are very accessible and inexpensive techniques that combined present an acceptable sensitivity and specificity. They are widely used for monitoring the evolution of stone disease and for evaluation after treatments (surgery or SWL). Ultrasound is the primary radiological diagnostic tool in the pediatric population and in pregnant women. CT has prevailed over IVP in the anatomical assessment of the urinary tract and the description of the characteristics of the lithiasis, although it shows a greater exposure to ionizing radiation, so the use of low and ultra-low dose CT is spreading. In this article we also discuss other imaging techniques such as Digital tomosynthesis, Fluoroscopy and DMSA Scintigraphy.

Analysis of urinary stones is an essential step in establishing the diagnosis and treatment of the stone patient. In fact, the need for an exhaustive study of the stones increases as the relationships between the type of stone and the etiological factors that predispose to this disease become evident. The enumeration (quali-tative or quantitative) of the major components that make up the kidney stone (calcium oxalate monohydrate, cal-cium oxalate dihydrate, uric acid, calcium phosphates, cystine), which is obtained by the most commonly used analytical method, infrared spectroscopy (IR), is no lon-ger enough to guide the urologist on the etiology of the disease. Only a detailed structural analysis and macro and micro components can provide key information on the etiology of the stone, and therefore, on the possible causes that have led to its formation. This study should conclude with a report that is provided to the Urologist. Obtaining this report involves a detailed study, sample by sample, which involves the systematic handling of stereoscopic microscopy, IR spectroscopy and scanning electron microscopy (SEM) with energy dispersive X-ray microanalysis (EDAX).

Kidney stones is a prevalent condition with a rising incidence in the last few decades. Disease relapse is an especially important issue, that requires further investigations in order to prevent new episodes. Adequate work up must be suited to patients´ charac-teristics such as age and the presence of risk factors for recurrence.An initial approach should focus on a thorough clinical history, with special attention to dietary habits, analy-sis of the stone composition when available, and basic blood and urine exams to guide further investigations.In this article, we aim to explain proper metabolic evalu-ation in kidney stone formers, explaining its indications, how to perform it and how to interpret it, in order to stablish an adequate treatment. Special attention will be given to: hypercalciuria, hy-peroxaluria, hyperuricosuria, hypocitraturia, hypomag-nesuria, hyperparathyroidism and the most frequent dis-turbances in urine analysis.

INTRODUCTION: Prevalence of urolithiasis is estimated between 5-15% with a clear trend to increasing in the industrialized countries. Stone recurrent patients show an increased risk of chronic renal disease which can potentially limit their life expectancy. OBJECTIVE: A review and summary of the different recommended treatment options to prevent urinary stone recurrence based on the type of calculi or urinary metabolic alterations in 24 h urine, according to recent guidelines and publications. CONCLUSIONS: Dietetic and pharmacologic measures, when addressed depending on the type of stone and results of metabolic evaluation have shown a decrease up to 60% of the recurrent clinical events. The increase of prevalence worldwide and the potential risk of chronic kidney disease in these patients clearly justify the need of increasing physiopathologic knowledge leading urolithiasis formation in order to develop new and more effective drugs for its prevention.

INTRODUCTION: Renoureteral colic (CRU) is the most common urological emergency, with a wide spectrum of severity that generates high morbidity and high health costs. However, there is no homoge-neous scheme of pharmacological treatment in its acute phase.AIMS: The main objective of our work is to evaluate the effectiveness and safety profile of the different drugs used in the treatment of CCR and to propose a practical treatment scheme. The secondary objectives are to eval-uate the role of fluid therapy in CRU and the treatment of CRU in pregnant women.MATERIAL AND METHODS: We have carried out a lit-erature search on PubMed using the MeSH terms “renal colic”, “treatment”, “anti-inflammatory drugs”, “antiemet-ic drugs”, “fluid therapy” and “pregnant”. The most rele-vant clinical trials, meta-analyses and systematic reviews published from 1 January 2005 to 15 September 2020 in Spanish, English and French were reviewed.RESULTS: In the different studies reviewed, non-steroidal anti-inflammatory drugs (NSAIDs) show better pain con-trol, with lower rescue doses and fewer side effects than treatment with opioids. However, fluid therapy has failed to demonstrate an impact on the treatment of CRU.CONCLUSIONS: The initial treatment for CRU is NSAIDs, reserving opioids for successive treatment lines. The control of vegetative cortex can be accomplished with Ondansetron as first choice.

INTRODUCTION: Medical Expulsive Treatment (MET) for ureteral stones has been questioned for the last few years. OBJECTIVES: The main goal of our study is to define the indications of MET, the different drugs that are used and their effectiveness and to propose a follow-up strategy. Secondary objectives include the effectiveness of MET in some special subgroups such as pregnant women and children and to assess aspects of MET cost-effectiveness compared with other options for ureteral lithiasis treat-ment (ureterorenoscopy or extracorporeal shock wave lithotripsy). MATERIAL AND METHODS: We have reviewed the most relevant clinical trials and meta-analysis evaluat-ing the impact of the different drugs available for MET. For the research we used some keywords like “medical expulsive treatment/therapy”, “ureteral lithiasis”, “uro-lithiasis”, “effectiveness”, “alpha-blockers” and “calci-um-antagonists”. MEDLINE database was used for the research (using the portal web Pubmed).RESULTS: Highest quality studies currently available show significant methodological limitations leading to heterogeneous and restricted evidence, which is only applicable to patients and lithiasis with specific condi-tions. Nevertheless, in general terms, it seems that MET can play a certain role in the expulsion of lithiasis ≥ 5 mm y ≤ 10 mm located in the distal ureter, although it has not been possible to demonstrate that any of the drugs used may have special superiority in terms of ef-fectiveness. In pregnancy and children, the recommen-dations of MET are also irregular. Finally, MET seems to be an alternative cost-effective compared to active options of treatment.CONCLUSIONS: Higher quality clinical trials are need-ed to reliably advice MET. With the current evidence, it appears that MET can improve the expulsion of distal ureteral lithiasis ≥ 5 mm and ≤ 10 mm, even though we have not found differences between the drugs that are available for MET.

OBJECTIVE: To determine if the stone free rate (SFR) can be used as a preventive method for urolithiasis recurrence and to describe which would be the best medical management of residual fragments.METHODS: Narrative overview of the most relevant articles published in PubMed and Scopus database about this subject, together with the experiences of personal practice.RESULTS: Residual fragments, when ≤4 mm, sometimes are included in the SFR definition. Most reports shown that these fragments may growth and cause complications and re-intervention when found in the follow-up of the patient that underwent any endourological procedure. The majority of the publications found show that the residual fragment medical management is necessary to assure a lower recurrence rate. CONCLUSION: Assuring a SFR can serve as a preventive method for recurrence, but not alone but in combination with medical therapy. Medical therapy is important in the follow-up and personalized for each patient. Drug therapy must be promoted if the patient continues to have the urolithiasis risk factors despite the dietary objectives have been reached.

OBJECTIVE: Urinary pH is a factor that influences in urinary lithogenesis. It can condition the het-erogeneous nucleation of calcium oxalate and the crys-tallization or dissolution of other substances such as uric acid, cystine and phosphates. Its exact and precise mea-surement is a tool to guide the treatment and prevention. The most accurate way to measure the pH is to use a glass electrode and a pH-meter, but this device is used in hospital’s environment and is not portable. Test strips are not adequate for proper measurement. Recently, a porta-ble and electronic device for measuring urinary pH has shown greater precision and accuracy in the measure-ment of urinary pH, with good acceptance by patients.METHOD: We carried out a bibliographic search in PUBMED and EMBASE using the terms “URINARY pH”, “Lithiasis”, “Uro-Lihitiasis”, “Urinary Stone”, “Urinary pH measurement”, in order to compile articles, books, ab-stracts and the most relevant clinical guides in English and Spanish on this topic.RESULTS: We select a total of 66 articles, 3 books, an abstract of a study unpublished presented at the Amer-ican urology congress and the European Guidelines on urolithiasis on the effect of pH on the formation and prevention of urolithiasis. Four articles deal specifically with the effect of urinary pH on urolithiasis, 5 articles deal with a new portable electronic device for measur-ing urinary pH, 5 articles dealt with the measurement of urinary pH with test strips and 1 article dealt with the modification of urinary pH to reduce fouling of double J catheters, 2 articles deal about the urinary acidification with oral methionine. The selected abstract deals with the new portable device for measuring urinary pH in cystin-uric patients. The 3 selected books have specific sections where the role of urinary pH in urolithiasis is discussed. Finally, in the European Urology Guidelines, the control of urinary pH is emphasized in the sections of prevention of urolithiasis formation, treatment of uric lithiasis, infec-tious/non-infectious phosphocalcic and cystine.CONCLUSIONS: Urinary pH is a recognized factor in the scientific-urological community for the study, monitor-ing, treatment and prevention of lithiasic patients. Urinary pH measurement is a very useful tool, but test strips are not suitable for pH measurement and medical decision making. Currently, several studies have evaluated a new device to achieve the measurement of urinary pH effec-tively and easily by the patient, keeping urinary pH in non-lithogenic ranges with the association of medical and non-medical treatments, and good acceptability from the patients.

Nutrition is tightly associated with the risk of stone events. Apart from genetic predisposition, a correct and balanced diet might prevent incident kidney stones.Several studies analyzed each dietary component and different diets to better understand their impact on stone recurrence.Fluids: High fluids intake is the most important factor for preventing kidney stones disease and for every 200 mL of water, the risk of stones is reduced by 13%. Soft drinks seems to be associated to a greater risk of stone events, whereas caffeine and citrus fruits juice are not.Calcium: Normally calcium intake with diet does not exceed 1.2 g/day. A balanced consumption of dairy products is capable of reducing oxalate intestinal absorption and urinary excretion compared to low calcium diet, being protective for stone disease.Oxalate: The exact amount of oxalate contained in different foods is difficult to estimate for its variability, even in the same aliment. In addition, the amount of oxalate consumed was shown to be only a minor risk factor for stone disease, whereas its intestinal absorption is strongly influenced by external factors, such as calcium intake. Dietary oxalate restriction is advisable only in patients with known elevated consumption.Sodium: High sodium intake is both associated with hypertension, heart disease and stone risk. Increased sodium consumption is directly associated to hypercalciuria in both calcium stone formers and healthy subjects. Although dietary sodium restriction to recommended values is always desirable in stone formers, it is difficult to achieve for its broad use in food preparation.Proteins: Animal proteins are associated to increased risk for stone formation, whereas vegetable and dairy proteins are not. Increased meat intake was associated to acidic urine pH, negative calcium balance and reduced anti-lithogenic urinary solutes excretion.Fruits and vegetables: Alkalizing foods are one of the most important factors for stone protection. Their consumption increases anti-lithogenic solutes as citrate, potassium and magnesium. A diet rich in fruits and vegetables is strongly recommended for stone formers.Uric acid: Elevated meat consumption is either associated to increased purine metabolism and acid load, favoring uric acid nephrolithiasis by reducing urine pH and increasing urinary excretion of uric acid, especially in patients affected by metabolic syndrome and diabetes.In conclusion, the most effective diet for stone protection is rich in fruits and vegetables, low in animal proteins and salt, with balanced dairy product consumption and obviously, with elevated fluid intake. These characteristics make vegetarian and Mediterranean diets protective and useful for stone formers, whereas western diet is at risk for stone formation.

Renal tubular acidosis (RTA) is a set of rare disorders in which the renal tubule is unable to excrete acid normally and thereby maintain normal acid-base balance, resulting in a complete or incomplete metabolic acidosis. In distal RTA (dRTA, also known as classical or type 1 RTA), there is a defect in excreting H+ ions along the distal nephron (distal tubule and collecting duct), leading to an alkaline urinary pH with calcium phosphate precipitation and stones. Causes of dRTA include genetic mutations, autoimmune disease, and some drugs.Clinical manifestations of the genetic forms of dRTA typically occur during childhood and may vary from mild clinical symptoms, such as a mild metabolic acidosis, hypokalaemia, and incidental detection of kidney stones, to more serious manifestations such as failure to thrive, severe metabolic acidosis, rickets and nephrocalcinosis. Progressive hearing loss may develop in patients with recessive dRTA, which, depending the causative gene mutation, can be present at birth or develop later in adolescence or early adulthood.Diagnosis of dRTA can be challenging, since it requires a high index of suspicion and/or measurement of urinary pH after an acid load, usually in the form of oral ammonium chloride; this should normally acidify the urine to pH below 5.3. In dRTA, urinary citrate levels are also low and patients are at increased risk of forming kidney stones from a combination of alkaline urine and low citrate. Ideally, affected patients need regular outpatient follow-up by a urologist and nephrologist. Thus, any patient found to have a calcium phosphate kidney stone, low urinary citrate, and raised urinary pH, especially with an early morning pH >5.5, should be evaluated for underlying dRTA. Patients with complete dRTA will have a low (<20 mmol/L) plasma or serum bicarbonate concentration, whereas in those with incomplete dRTA, bicarbonate levels are usually normal. Oral alkali as potassium citrate is still the mainstay of treatment in dRTA.

INTRODUCTION: Stone disease is a chronic condition in a high percentage of patients. Due to the high healthcare costs associated with the treat-ment of this pathology, chronicity approaches and strategies should be adapted and used in a similar way to other chronic diseases. One of the models applied for the management of these diseases with a significant im-pact on the consumption of health resources is the Kaiser Permanente model.MATERIAL AND METHODS: A chronic stone disease management project was developed and carried out in three different phases: Phase 1: identification of the target population of the program and design of the risk allocation model. The risk factors considered were CRG model (classification of risk groups or burden of morbidity) as a predictor of greater consumption of re-sources, anatomical risk factors, lithogenic risk factors, and hereditary factors associated with lithiasis. Phase 2: classification of patients according to risk and applica-tion of specific measures. The intervention measures will depend on the level of risk assigned: low, intermediate or high risk. Phase 3: analysis of indicators and results.RESULTS: An algorithm of risk allocation was designed, and a Kaiser pyramid drawn. A total of 59% of the patients were assigned to the low-risk group and 41% corresponded to high-risk (36.5%) or very high-risk pa-tients (4.5%). Preliminary results obtained at two years of follow-up show a reduction in global stone recurrence by 42.2% when compared with a control group (clas-sic follow-up). The overall adherence of the intervention group was 96.4% and the satisfaction of the patients included in the program was 9.93/10. CONCLUSIONS: A management model for chronic stone disease based on the Kaiser Permanente pyramid is feasible. The implantation of this model has prelimi-narily demonstrated its efficiency in chronic patients.

Patient reported outcome measures (PROMs) are essential to fully understand the impact of diseases and the effectiveness of treatment from a patient’s perspective. Generic and disease-specific tools have been used to assess the impact of nephrolithiasis on patients’ quality of life (QoL), as well as the impact of various treatment modalities. Additionally, various studies have investigated the factors that might determine the impact of the disease on the patients’ QoL. Here we review the available knowledge on this nascent topic and highlight the need for extensive future research in this crucial area.

The high prevalence and incidence of uri-nary stone disease, the severity of its symptoms, its high recurrence rate and resulting healthcare costs, make urolithiasis a chronic disease with significant impact on healthcare services and patient quality of life. There are several general tools available to assess health related quality of life in patients with chronic illnesses, as well as some specific ones directed to urinary stone disease, such as the ureteral stent symptom questionnaire. Patients with an obstructive ureteral stone or those indwelling a ureteral stent, often present symptoms that may affect their quality of life considerably. Patient education and counselling regarding stent-related symptoms, as well as medical treatment, may help improve their perception of quality of life.

Human microbiome understanding and its relationship with health has represented a revolution in biomedicine, facilitated by the emergence of new molecular microbiology techniques. Lithiasic pathology has not been alien to this new approach to etiological knowledge. As a result of this research activity, it has been possible to elucidate the importance of the intestine-kidney axis, understood as the impact of the intestinal microbiota on nephrourinary health. In this regard, the ability to use oxalate as an energy source by certain intestinal microorganisms has been used as a target for modulators of the intestinal microbiota in order to correct hyperoxaluria, both primary and secondary. However, the importance of the microbiome configuration, and its role in oxalocalcic lithiasis, transcends the existence of certain trophic networks. In particular, intestinal microbiome has the ability to promote tubular lesions resulting from oxidative stress caused by chronic low-grade inflammation, closely linked to the composition of the microbiota and the dialogue established with the immune system at the intestinal level.The importance of the urobiome, a stable microbial structure residing in the urinary tract, allowed to calibrate the importance of urinary microorganisms in lithiasic pathology, breaking with the paradigm of urine sterility in healthy conditions. Thus, recent studies suggest that the composition and structure of the urobiome have a crucial impact on infectious but also non-infectious lithiasis, since certain microorganisms can act as nucleants and promoters of the lithogenic process. Associated with the advances in the study of binomial microbiota and lithiasic pathology, new ways are opened for patient management, in terms of prevention and treatment, based on intervention on the microbiome. Future therapeutic arsenal, in addition to probiotics and prebiotics, will integrate consortia of different microbial groups and microbiota transplantation, both urinary and intestinal.

OBJECTIVE: The objective of this study is to present the content of existing Guidelines on medical management of urinary stone disease.MATERIALS AND METHODS: A search for current Guidelines from national and international urological Associations was performed in Societe International d’ Urologie and American Urological Association websites, along with a search in Pubmed/MEDLINE until 30/06/2020. Two authors performed an independent search and data extraction regarding medical management of acute renal colic, medical expulsive treatment, dietary modifications and pharmaceutical interventions for prevention of stone disease recurrence. Quality of Guidelines was assessed by the two reviewers using the AGREE II instrument. RESULTS: Literature search revealed 82 Associations, while eight of them provide recommendations/Guidelines on medical management of stone disease. Non-steroidal anti-inflammatory drugs or paracetamol are the most common 1st line treatment proposed for acute pain management, with opiates following next. Use of a-blockers is also indicated by most Guidelines for facilitating expulsion of distal ureteral stones 5-10 mm, after shockwave or laser lithotripsy or for alleviating stent-related symptoms. Adequate fluid intake, normal dietary calcium consumption and sodium restriction with varying daily limits, are universal dietary modifications from urological Associations on prevention of stone disease. Thiazides and alkaline citrates are proposed usually for calcium oxalate stone formers with differences in grading of the recommendations, while urinary alkalization with allopurinol or febuxostat as a second line treatment is a common treatment algorithm for urate stones, but with differences in target urine pH. European and American Urological Association Guidelines, along with National Institute for Health and Care Excellence recommendations were the most highly rated based on AGREE II.CONCLUSIONS: Despite methodological heterogeneity and subjective rating of recommendations, an acceptable degree of consensus was noted on Guidelines regarding medical management of stone disease.