Épidémiologie des lithiases urinaires

Sedation vs. general anesthesia in stone ureteroscopy: Comparison of efficacy and safety, a post COVID-19 report

INTRODUCTION

Ureterorenoscopy (URS) for ureteral or renal stones is traditionally performed under general anesthesia (GA). Sedation is an alternative to GA, allowing control of the level of consciousness, spontaneous ventilation, and faster recovery. Our aim was to compare sedation and GA for patients undergoing ureterorenoscopy. Endpoints were stone-free rate (SFR) and complication rates.

METHOD

Monocentric comparative retrospective study including all consecutive ureterorenoscopies for ureteral or renal stone. The inclusion period was dichotomized in two 6-months periods due to the COVID-19 pandemic: from January 1 to July 1, 2019 (URS under GA) and from January 1 to July 1, 2021 (URS under GA or sedation). Stone-free (SF) status was defined as the absence of stone or fragment>4mm after the first ureterorenoscopy. Complication rates were assessed according to the Satava (perioperative complications) and Clavien-Dindo (postoperative complications) classifications. Statistical analysis was performed by Chi-square test.

RESULTS

A total of 185 patients were included for a total of 206 ureterorenoscopies; 82 underwent ureterorenoscopy under GA and 103 under sedation. The median stone size was 10 [7-16] mm. In all, 150 (81%) patients had at least one intrarenal stone. The SFR was similar between the two groups (67% GA group, 69% sedation group, P=0.912). In the sedation group, the mean SFR in ureter was 83.7% vs. 92.5% in the GA group. In renal cavities, the mean SFR was 46.4% in the sedation group vs. 42.5% in the GA group. Satava grade I, IIa, and IIb complications were 5 (6%), 5 (6%), and 1 (1%) in the GA group and 6 (6%), 1 (1%), and 3 (3%) in the sedation group, respectively (P=0.214). The grade I, II, III, and IV Clavien complications were 6 (7%), 3 (4%), 0 (0%), and 2 (2%) in the GA group and 6 (6%), 4 (4%), 1 (1%), and 4 (4%) in the sedation group, respectively (P=0.928).

CONCLUSION

Our post COVID-19 study showed no difference in efficacy and safety between ureterorenoscopy under sedation and GA for patients with renal stones. Our results confirm the interest of the sedation procedure, particularly in the context of outpatient surgery.

LEVEL OF EVIDENCE: 4

Occupational hazard in urolithiasis patients in Qatar: A single-center cross-sectional study

BACKGROUND

Urolithiasis is one of the most prevalent urological diseases and is associated with a substantial economic burden. Its prevalence varies according to geographical location. Qatar is a Middle Eastern country located in the Afro-Asian Stone Belt. It has a dry and hot climate, which may predispose individuals working in these environments to form kidney stones (KSs).

METHODS

A population sample of 4204 patients was categorized into five occupational classes. The frequencies and correlations of these occupations with KS formation were calculated.

RESULTS

Among the total cases, 2000 presented with KSs, with the majority being of Asian descent (49%), followed by individuals of Middle Eastern descent (35.1%). Technicians accounted for 35.15% of KS cases followed by clerks (29.2%) and executives (14.6%). Among KS cases, 44% had a single stone, 30% had multiple stones, and 26% had two stones. In comparing both KS and non-KS groups, age, gender, occupation, and race were significantly associated with KS formation (p<0.05), while BMI did not show any significant correlation (p>0.05). Asian males aged 31-40, working as technicians, were significantly more prone to urolithiasis. In comparing age, BMI, and gender with stone characteristics, only age was found significantly associated with stone size (p<0.05). Occupation showed an impact on all studied stone characteristics. Clerks and technicians presented more frequently with stones within the 11-15 mm range, while executives more frequently presented with smaller stones (p<0.001). Stone density was more frequently <500 HU in workers, technicians and housewives and >500 HU in executives and clerks (p<0.001).

CONCLUSIONS

Our findings revealed an elevated risk of urolithiasis among certain occupational groups, particularly technicians, who frequently work outdoors in high-temperature environments. Alternatively, the sedentary nature of clerical and executive positions can also contribute to the risk of urolithiasis.

Hydration for Adult Patients with Nephrolithiasis: Specificities and Current Recommendations

Nephrolithiasis affects around 10% of the population and is frequently associated with impaired dietary factors. The first one is insufficient fluid intake inducing reduced urine volume, urine supersaturation, and subsequently urinary lithiasis. Kidneys regulate 24 h urine volume, which, under physiological conditions, approximately reflects daily fluid intake. The aim of this study is to synthesize and highlight the role of hydration in the treatment of nephrolithiasis. Increasing fluid intake has a preventive effect on the risk of developing a first kidney stone (primary prevention) and also decreases the risk of stone recurrence (secondary prevention). Current guidelines recommend increasing fluid intake to at least at 2.5 L/day to prevent stone formation, and even to 3.5-4 L in some severe forms of nephrolithiasis (primary or enteric hyperoxaluria or cystinuria). Fluid intake must also be balanced between day and night, to avoid urinary supersaturation during the night. Patients should be informed and supported in this difficult process of increasing urine dilution, with practical ways and daily routines to increase their fluid intake. The liquid of choice is water, which should be chosen depending on its composition (such as calcium, bicarbonate, or magnesium content). Finally, some additional advice has to be given to avoid certain beverages such as those containing fructose or phosphoric acid, which are susceptible to increase the risk of nephrolithiasis.

2022 Recommendations of the AFU Lithiasis Committee: Epidemiology, stone analysis and composition

The incidence of urinary lithiasis is rising steadily in industrialized countries, and its prevalence in the general population of France is estimated at 10%. Renal colic accounts for 1-2% of emergency department consultations. At a time when the new LASER stone fragmentation techniques available to urologists will lead to ever finer in situ pulverization of stones, the exact identification of the compounds that form the stone is essential for etiological diagnosis. Constitutional analysis by infrared spectrophotometry or X-ray diffraction is therefore recommended, to be complemented by morphological typing of the calculi. METHODOLOGY: These recommendations have been drawn up using two methods: the Recommendation for Clinical Practice (RPC) method and the ADAPTE method, depending on whether or not the issue was considered in the EAU recommendations (https://uroweb.org/guidelines/urolithiasis) [EAU 2022] and their adaptability to the French context.

Urinary Lithiasis Risk Assessment after Bariatric Surgery

Malabsorption is a consequence of gastric bypass (GB). GB increases the risk of kidney stone formation. This study aimed to evaluate the accuracy of a screening questionnaire for assessing the risk of lithiasis in this population. We performed a monocentric retrospective study to evaluate a screening questionnaire administered to patients who underwent gastric bypass surgery between 2014 and 2015. Patients were asked to answer a questionnaire that included 22 questions divided into four parts: medical history, episodes of renal colic before and after bypass surgery, and eating habits. A total of 143 patients were included in the study, and the mean age of the patients was 49.1 ± 10.8 years. The time between gastric bypass surgery and the completion of the questionnaire was 50.75 ± 4.95 months. The prevalence of kidney stones in the study population was 19.6%. We found that with a score of ≥6, the sensitivity and specificity were 92.9% and 76.5%, respectively. Positive and negative predictive values were 49.1% and 97.8%, respectively. The ROC curve showed an Area Under the Curve (AUC) of 0.932 ± 0.029 (p < 0.001). We developed a reliable and short questionnaire to identify patients at a high risk of kidney stones after gastric bypass. When the results of the questionnaire were equal to or greater than six, the patient was at a high risk of kidney stone formation. With a good predictive negative value, it could be used in daily practice to screen patients who have undergone gastric bypass and are at a high risk of renal lithiasis.

Learning curve in flexible ureteroscopy for renal stones: A propensity score-matched study

OBJECTIVE

To assess the learning curve and evaluate the impact of surgical experience related to the outcomes of flexible ureteroscopy (fURS) for upper urinary tract stones.

METHOD

We evaluated retrospectively lithiasis fURS performed in our institution between January 2004 and December 2020. Patients were divided into two groups by the number of procedures performed by surgeon. Group 1 (G1) included the first 50 procedures, and group 2 (G2) the next cases. These groups were matched on baseline characteristics by a propensity score. Stones free rate (SFR) and complication rate (CR) were compared. Learning curves were realized using logistic curve with 95% confidence interval.

RESULTS

After criteria exclusion and propensity score matching, 1548 procedures were analyzed (1:1, G1 and G2, n=774 procedures). A total of 29 surgeons were evaluated. The overall SFR was 68.4% without statistical difference between the two groups (G1=67.9% vs. G2=68.8%, P=0.72). The surgeon's experience was not associated with SFR (OR=1.15, 95% CI: 0.90-1.47), except in subgroup stones>2cm (OR=2.89, 95% CI: 1.29-6.46). The overall CR was 12.5%, mainly Clavien-Dindo grade I-II complications (96.2%). Surgical experience was not associated with CR (OR=1.06, 95% CI: 0.77-1.45). The overall logistic curves for probability of stone clearance and complication tended to be a flat slope.

CONCLUSION

Impact of surgical experience on fURS for UUTS was not associated with SFR and CR. However, for stones larger than 2cm, surgeon's experience tended to be associated with SFR, but without impact on overall complications.

LEVEL OF EVIDENCE: 3

Hydration and Nephrolithiasis in Pediatric Populations: Specificities and Current Recommendations

Renal lithiasis is less frequent in children than in adults; in pediatrics, lithiasis may be caused by genetic abnormalities, infections, and complex uropathies, but the association of urological and metabolic abnormalities is not uncommon. The aim of this study is to provide a synthesis of nephrolithiasis in children and to emphasize the role of hydration in its treatment. As an etiology is reported in 50% of cases, with a genetic origin in 10 to 20%, it is proposed to systematically perform a complete metabolic assessment after the first stone in a child. Recent data in the field reported increased incidence of pediatric urolithiasis notably for calcium oxalate stones. These changes in the epidemiology of stone components may be attributable to metabolic and environmental factors, where hydration seems to play a crucial role. In case of pediatric urolithiasis, whatever its cause, it is of utmost importance to increase water intake around 2 to 3 L/m² per day on average. The objective is to obtain a urine density less than 1010 on a dipstick or below 300 mOsm/L, especially with the first morning urine. Some genetic diseases may even require a more active 24 h over-hydration, e.g., primary hyperoxaluria and cystinuria; in such cases naso-gastric tubes or G-tubes may be proposed. Tap water is adapted for children with urolithiasis, with limited ecological impact and low economical cost. For children with low calcium intake, the use of calcium-rich mineral waters may be discussed in some peculiar cases, even in case of urolithiasis. In contrast, sugar-sweetened beverages are not recommended. In conclusion, even if parents and patients sometimes have the feeling that physicians do not propose "fancy" therapeutic drugs, hydration and nutrition remain cornerstones of the management of pediatric urolithiasis.

Quality of life of patients treated for kidney stones 10-20mm in diameter in terms of the type of operation performed: A qualitative study

INTRODUCTION

Urolithiasis is a common chronic disease whose effect on patients' quality of life (QOL) is considerable but depends on the treatment received, differing between types of surgery. Intrarenal stones can be treated with different techniques: extracorporeal shock wave lithotripsy (ESWL), flexible ureteroscopy (fURS), and mini percutaneous nephrolithotomy (mini-PCNL), with proportional success and complication rates. The aim of this study was to qualitatively explore the impact of the different techniques on patients' QOL and understand their experiences of treatment choices.

METHODS

Patients treated for medium-sized kidney stones (10-20mm in diameter) were interviewed in a semi-structured manner. The interview data were transcribed and analyzed by theme according to consolidated criteria for reporting qualitative research (COREQ) guidelines.

RESULTS

Data saturation was achieved after interviewing 15 patients. The mean interview time was 34min (standard deviation (SD), 6.8min). The mean patient age was 54 years (SD, 9.5 years). Eight patients underwent ESWL, 10 were treated with fURS, and 8 underwent mini-PCNL. Twenty-seven subthemes were coded and regrouped into eight major themes, namely: no sense of choice in the decision-making process for eleven patients; extremely negative experiences of double-J stents for fourteen patients; concern about the risk of recurrence or treatment failure for thirteen patients; complicated hygiene and dietary recommendations for nine patients; technique-dependent postoperative outcomes; relatively well-tolerated operations for thirteen patients; a poor experience of sick leave, often because of a double-J stent; different views regarding future operations. In fact, a third of patients would choose the most effective treatment, a third would choose the simplest procedure and the last third would trust their urologist. Patients' experiences of these operations are variable.

CONCLUSION

Urologists must support their patients by presenting the different treatment options with clear, appropriate, and unbiased information. This should ensure patients take part in treatment decisions as part of a personalized treatment plan.

LEVEL OF EVIDENCE: 3

Molecular Diagnosis of Primary Hyperoxaluria Type 1 and Distal Renal Tubular Acidosis in Moroccan Patients With Nephrolithiasis and/or Nephrocalcinosis

Nephrolithiasis (NL) and urolithiasis (UL) are usual reasons for hospitalization and presentation in pediatric outpatient departments and their incidence continues to rise worldwide. In Morocco, a previous epidemiological study done in the Fez region between January 2003 and November 2013 reported a prevalence of 0.83% of childhood UL. In two studies, heritability accounted for almost half of all NL or nephrocalcinosis (NC) prevalence. Genetic factors must be considered in the etiological diagnosis of urinary lithiasis in Morocco since the frequency of consanguineous marriages is high. Hereditary tubular disorders, especially distal renal tubular acidosis (dRTA) and Dent disease, and metabolic disorders like idiopathic hypercalciuria and hyperoxaluria are the most common causes of medullary NC. Primary hyperoxaluria type 1 (PH1), which can generate an early onset of NC, and often chronic kidney disease (CKD) should always be considered and thoroughly diagnosed. The aim of this work was to establish a molecular diagnosis of PH1 and dRTA and, thus, to predict and explain the disease phenotype in a cohort of 44 Moroccan patients with NL and/or NC by analyzing the AGXT and ATP6V1B1 genes that cause NL and/or NC when mutated. Disease phenotype was molecularly explained and solved in six of 44 individuals with NL and/or NC (13.6%). In the pediatric subgroup of individuals, a causative mutation in 16.2% was identified, whereas in the adult cohort no pathogenic mutation was detected. In our patients, PH1 was objectified in 67% of cases followed by dRTA in 33% of cases. We suggest that prompt detection and prophylactic treatment of UL are necessary to limit the risk of everlasting renal damage and thus prevent or delay the progression to CKD.

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.

Role of Citrus Fruit Juices in Prevention of Kidney Stone Disease (KSD): A Narrative Review

To explore the relationship between citrus fruit juices (oranges, grapefruits, and lemonades) and kidney stone disease (KSD).

METHODS

A systematic review was performed using the Medline, EMBASE, and Scopus databases, in concordance with the PRISMA checklist for all English, French, and Spanish language studies regarding the consumption of citrus fruit juices and the relationship to urinary stone disease. The main outcome of interest was the association of citrus fruit juices with KSD.

RESULTS

Thirteen articles met the criteria for inclusion in the final review. Three large epidemiological studies found that grapefruit juice was a risk factor for stone formation, while orange juice did not increase the risk for KSD. Ten small prospective clinical studies found that orange, grapefruit, and lemon juices all increased urinary citrate levels. Only orange and grapefruit juices had an alkalinizing effect and while lemon juice has a protective effect by raising urinary citrate levels, it lacked a significant alkalinizing effect on urine pH. Orange juice and grapefruit juices significantly increased urinary oxalate levels, while orange juice also had a high carbohydrate content.

CONCLUSION

While orange juice seems to play a protective role against stone formation, grapefruit was found to raise the risk of KSD in epidemiological studies but had a protective role in smaller clinical studies. Lemon juice had a smaller protective role than orange juice. Larger amounts of, as well as more accurate, data is needed before recommendations can be made and a high carbohydrate content in these juices needs to be taken into consideration.

Retrospective epidemiological study of urolithiasis in western Algeria over a period of 50 years

Background

Urolithiasis is a pathology that changes with time and with the evolution of human societies. The prevalence of this pathology has gradually increased during the last decades, especially because of dietary changes.

Methods

This work is a retrospective descriptive epidemiological study of the temporal type carried out at the level of the urology service of the University Hospital Center of Oran between the first January 1965 and December 31, 2014. The objectives of this work are to study the epidemiological profile of urolithiasis and to determine the evolutionary trend of the disease over time.

Results

This study confirms some current data in the direction of an increase in surgical activity concerning the treatment of urinary stones. The analysis over time shows us a significant decrease (p < 0.01) in the male predominance between 1965 and 2014 with a M/F ratio which decreased from 3.09 to 1.82, as well as an increase in the average age, rising from 28.8 years in the period 1965–1974 to 48.3 years between 2005 and 2014.

Conclusion

The analysis of epidemiological data is essential to better evaluate the evolution of the urolithiasis disease, which was affirmed in our study, where a constant evolution of the characteristics of the disease was revealed, testifying the change of the socio-economic level in Algeria.

Morpho-constitutional analysis of urinary stones from patients with urolithiasis in the Democratic Republic of Congo

Background

Urolithiasis is increasingly diagnosed worldwide. Stone analysis is an important part in the assessment of patients with urolithiasis. However, in sub-Saharan Africa, data on the composition of urinary stones are limited. This study aimed to describe the composition and sites of urinary stones and to investigate relationship between socio-demographic characteristics, clinical profile of patients, and the composition of urinary stones.

Methods

A retrospective analysis of 132 patients with urolithiasis who visited one of the seven hospitals in the Democratic Republic of Congo during eight years of study period (January 2010 to January 2018) was conducted. Stones were analyzed by infrared spectrophotometry.

Results

Most of stones analyzed (n = 82, 62.1%) originated from the upper urinary tract with a difference across gender (58.5% males vs. 41.5% females, p = 0.001). Only three stones (two from whewellite and one from anhydrous uric acid) were considered pure (2.3%), excluding the protein frame (less than 5%). Whewellite, proteins, and carbapatite were identified in 97.7%, 96.2%, and 80.3% of the stones analyzed, respectively; and in 91.7%, 89.4%, and 67.7% of the nuclei of the stones analyzed, respectively. Taking into account the proportion of each constituent in the stones analyzed, whewellite (68.9%), anhydrous uric acid (10.6%), and carbapatite (8.3%) were the main constituents in respectively 68, 9%, 10.6%, and 8.3% of the stones analyzed.

Conclusion

Whewellite, anhydrous uric acid, and carbapatite represented the most frequent main components of stones identified, suggesting that dietary hyperoxaluria could be an important factor in lithogenesis in the Democratic Republic of Congo.

Attitude and awareness of medicinal plants in treatment of kidney lithiasis in eastern Morocco: a retrospective study

Introduction: Kidney stone is a major public health problem. Over 5% of the population is affected by kidney stones, with causes a lifetime risk of transmitting renal lithiasis of about 8 to 10%.

Objective: The goal of our study is the attitude and awareness of lithiasis patients regarding the use of medicinal plants in eastern Morocco.

Methods: We carried out a study on lithiasis patients to retrospectively identify medicinal plants used in this disease, using a pre-established questionnaire. The study was carried out from 10 December 2017 to 28 February 2018.

Results: Our survey describes several medicinal plants used to treat renal lithiasis in eastern Morocco. Most patients used Herniaria hirsuta L., Zea mays L., Urtica dioica L., and Petroselinum crispum (Mill.) Fuss. This preliminary study showed that the first reason to use medicinal plants in half of lithiasis patients is to calm the pain and expel the stones. The primary source of plant use information is oral tradition. However 67% of lithiasis patients are unaware of the harmful and toxic effects that can appear.

Conclusion: Medicinal plants must, like medicines, comply with strict requirements and standard rules of use to which only the specialist in herbal medicine can respond and sensitize people to the dangers of irrational consumption of medicinal plants.

[Chemical composition of urinary stones and associated factors in the Democratic Republic of Congo]

To compare the chemical composition of the upper and lower urinary tract stones in Congolese patients, and to identify factors associated with the different types of stones. Stones from 119 patients originating from the upper tract and 75 from the lower tract were analyzed by infrared spectrophotometry. Among 119 patients with upper tract stones, age ranged from 10 to 81 years with a mean (SD) of 45.8 (13.6) years; males were the majority (55.5%). The main types of stones identified were whewellite (79%). For the 75 patients with lower apparatus stones, age ranged from 4 to 87 years with a mean (SD) of 51.6 (21.6) years; the majority were males (89.3%). The main types of stones were whewellite (44%) and anhydrous uric acid (22.7%). Overall, the factors associated with calcium oxalate included: site [4.95 (95% CI 2.35-10.44)] and diameter [3.03 (95% CI 1.45-6.25)]; patient's place of residence [0.05 (95% CI 0.01-0.29)] was associated with calcium phosphate. Infection stones were associated with; site [0.19 (95% CI 0.06-0.63)] and diameter [0.10 (95% CI 0.03-0.38)]. Finally, age 0.26 (95% CI 0.09-0.71) and stone site [0.23 (95% CI 0.07-0.68)] were associated with uric stones. The epidemiological and chemical profile of upper and lower tract stones were different. Several factors were associated with the chemical and crystalline composition of stones in the Democratic Republic of Congo.

Towards automatic recognition of pure and mixed stones using intra-operative endoscopic digital images

OBJECTIVE

To assess automatic computer-aided in situ recognition of the morphological features of pure and mixed urinary stones using intra-operative digital endoscopic images acquired in a clinical setting.

MATERIALS AND METHODS

In this single-centre study, a urologist with 20 years' experience intra-operatively and prospectively examined the surface and section of all kidney stones encountered. Calcium oxalate monohydrate (COM) or Ia, calcium oxalate dihydrate (COD) or IIb, and uric acid (UA) or IIIb morphological criteria were collected and classified to generate annotated datasets. A deep convolutional neural network (CNN) was trained to predict the composition of both pure and mixed stones. To explain the predictions of the deep neural network model, coarse localization heat-maps were plotted to pinpoint key areas identified by the network.

RESULTS

This study included 347 and 236 observations of stone surface and stone section, respectively; approximately 80% of all stones exhibited only one morphological type and approximately 20% displayed two. A highest sensitivity of 98% was obtained for the type 'pure IIIb/UA' using surface images. The most frequently encountered morphology was that of the type 'pure Ia/COM'; it was correctly predicted in 91% and 94% of cases using surface and section images, respectively. Of the mixed type 'Ia/COM + IIb/COD', Ia/COM was predicted in 84% of cases using surface images, IIb/COD in 70% of cases, and both in 65% of cases. With regard to mixed Ia/COM + IIIb/UA stones, Ia/COM was predicted in 91% of cases using section images, IIIb/UA in 69% of cases, and both in 74% of cases.

CONCLUSIONS

This preliminary study demonstrates that deep CNNs are a promising method by which to identify kidney stone composition from endoscopic images acquired intra-operatively. Both pure and mixed stone composition could be discriminated. Collected in a clinical setting, surface and section images analysed by a deep CNN provide valuable information about stone morphology for computer-aided diagnosis.

[Urinary stones in renal transplant recipients and donors: The French guidelines from CTAFU]

OBJECTIVE

To define guidelines for the management of kidney stones in kidney transplant (KTx) donor or recipients.

METHOD

Following a systematic approach, a review of the literature (Medline) was conducted by the CTAFU to report kidney stone epidemiology, diagnosis and management in KTx donors and recipients with the corresponding level of evidence.

RESULTS

Prevalence of kidney stones in deceased donor is unknown but reaches 9.3% in living donors in industrialized countries. Except in Maastrich 2 donors, diagnosis is done on systematic pre-donation CT scan according to standard french procedure. No prospective study has compared therapeutic strategies available for the management of kidney stones in KTx donor: ureteroscopy or an extra corporeal lithotripsy in case of living donor prior to donation, ex vivo approach (pyelotomy or ureteroscopy), ureterocopy in the KTx recipient or surveillance. De novo kidney stones result from a lithogenesis process to be identified and treated in order to avoid recurrences. The context of solitary functional kidney renders the prevention of recurrence of great importance. Diagnosis is suspected when identification of a renal graft dysfunction, hematuria or urinary tract infection with renal pelvis dilatation. Stone size and location are determined by computed tomography. There are no prospective, controlled studies on kidney stone management in the KTx. The therapeutic strategies are similar to standard management in general population.

CONCLUSION

These French recommendations should contribute to improve kidney stones management in KTx donor and recipients.

Toward improved endoscopic examination of urinary stones: a concordance study between endoscopic digital pictures vs microscopy

Objective

To improve endoscopic recognition of the most frequently encountered urinary stone morphologies for a better aetiological approach in lithiasis by urologists.

Materials and Methods

An expert urologist intraoperatively and prospectively (between June 2015 and June 2018) examined the surface, the section, and the nucleus of all encountered kidney stones. Fragmented stones were subsequently analysed by a biologist based on both microscopic morphological (i.e. binocular magnifying glass) and infrared (i.e. Fourier transform‐infrared spectroscopy) examinations (microscopists were blinded to the endoscopic data). Morphological criteria were collected and classified for the endoscopic and microscopic studies. The Wilcoxon–Mann–Whitney test was used to detect differences between the endoscopic and microscopic diagnoses. A diagnosis for a given urinary stone was considered ‘confirmed’ for a non‐statistically significant difference.

Results

A total of 399 urinary stones were included in this study: 51.4% of the stones had only one morphological type, while 48.6% were mixed stones (41% had at least two morphologies and 7.6% had three morphologies). The overall matching rate was 81.6%. Diagnostics were confirmed for the following morphologies: whewellite (Ia or Ib), weddellite (IIa or IIb), uric acid (IIIa or IIIb), carbapatite‐struvite association (IVb), and brushite (IVd).

Conclusions

Our preliminary study demonstrates the feasibility of using endoscopic morphology for the most frequently encountered urinary stones and didactic boards of confirmed endoscopic images are provided. The present study constitutes the first step toward endoscopic stone recognition, which is essential in lithiasis. We provide didactic boards of confirmed endoscopic images that pave the way for automatic computer‐aided in situ recognition.

Evaluation and comparison of scoring systems for predicting stone-free status after flexible ureteroscopy for renal and ureteral stones

OBJECTIVE

To evaluate four predictive scores for stone-free rate (SFR) after flexible ureterorenoscopy (f-URS) with holmium-YAG laser fragmentation of renal and ureteral lithiasis.

METHODS

We carried out a retrospective analysis of 800 f-URS procedures performed in our institution between January 2009 and December 2016. For each procedure, a single surgeon calculated the following scores: S.T.O.N.E score; Resorlu Unsal Stone Score (RUSS); modified Seoul National University Renal Complexity (S-ReSC) score; and Ito's score.

RESULTS

Overall SFR was 74.1%. Univariate analysis demonstrated that stone size (p<0.0001), stone volume (p<0.0001), stone number (p = 0.004), narrow lower pole infundibulopelvic angle (IPA) (p = 0.003) and lower pole location + IPA <45° (p = 0.011) were significantly associated with SFR. All scores differed between the stone-free and non-stone-free groups. Area under the curve of the receiving operator characteristics curve was calculated for each score: 0.617 [95%CI: 0.575-0.660] for the S.T.O.N.E score; 0.644 [95%CI: 0.609-0.680] for the RUSS; 0.651 [95%CI: 0.606-0.697] for the S-ReSC score; and 0.735 [95%CI: 0.692-0.777] for Ito's nomogram.

CONCLUSION

All four scores were predictive of SFR after f-URS. Ito's score was the most sensitive. However, the performance of all scores in this analysis was lower than in developmental studies.

[Inherited kidney stones: A nephrology center experience]

INTRODUCTION

Genetic factors must be considered in etiological diagnosis of urinary lithiasis. The aim of this study was to determine clinical, metabolic characteristics and the progression of hereditary urinary lithiasis in our patients.

METHODS

A retrospective study was conducted between 2008 and 2018 and 60 patients were included. Patients were referred to our department from pediatrics departments to be followed-up in adulthood in 9 cases, for etiological investigation in 42 cases and for chronic renal failure in 9 cases.

RESULTS

Thirty-five men and twenty-five women were enrolled in this study with a M/F sex ratio equal to 1.4. The mean age at the time of diagnosis of the hereditary character of the urinary lithiasis was 28.6years (3months-63years). The average delay between the onset of the lithiasis disease and the etiological diagnosis was 8years (0-42years). We noted 31 cases of cystinuria, 18 cases of primary hyperoxaluria type 1 with two mutations (I244T in 14 cases, 33-34 Insc in 23 cases) and 11 cases of renal tubulopathy. Fourteen patients were affected with chronic renal failure, of which five were in the end-stage renal disease. Crystalluria was positive in 62% of cases. The morpho-constitutional analysis of stones was performed in 37 cases and it contributed to the diagnosis in 29 cases. After an average follow-up of 16years, we noted normal renal function in 42 cases, chronic renal failure in 7 cases, hemodialysis in 10 cases all with primary hyperoxaluria and transplantation in 1 case.

CONCLUSION

The etiological diagnosis of hereditary urinary lithiasis in our study was made with considerable delay. Cystinuria was the most frequent etiology and primary hyperoxaluria was the most serious affection.

LEVEL OF EVIDENCE

4.

Idiopathic calcium nephrolithiasis with pure calcium oxalate composition: clinical correlates of the calcium oxalate dihydrate/monohydrate (COD/COM) stone ratio

Pure calcium oxalate is the most frequent type of idiopathic kidney stone composition. Fourier transform infrared spectroscopy (FT-IR) allows to detect the ratio of calcium oxalate dihydrate (COD) and monohydrate (COM) crystals in stones, but the clinical significance of this parameter remains uncertain. The objective of this observational study was to verify the association of clinical and laboratory parameters of kidney stone disease with COD/COM ratio in a group of 465 (322 M, age 46 ± 14) patients suffering from idiopathic calcium nephrolithiasis with pure calcium oxalate stones (≥ 97%). Each participant underwent a complete clinical examination, serum chemistry, 24-h urine collection for the determination of the profile of lithogenic risk, and had stones analyzed by FT-IR. Most (62%) of the stones had a COD/COM ratio ≤ 0.25, and the urine chemistry of the corresponding patients showed a low prevalence of urinary metabolic abnormalities. With increasing COD/COM ratio intervals (0-0.25, 0.26-0.50, 0.51-0.75, 0.76-1), a significant association was observed for the number of urological procedures, serum calcium, 24-h urinary calcium excretion, prevalence of hypercalciuria and relative calcium oxalate supersaturation, and a negative trend was detected for the age of the first stone episode (all p values < 0.05). A linear regression model showed that the only parameters significantly associated with COD/COM ratio were 24-h urinary calcium excretion (standardized β = 0.464, p < 0.001) and urine pH (standardized β = 0.103, p = 0.013). In pure calcium oxalate idiopathic stones, COD/COM ratio may reflect the presence of urinary metabolic risk factors, and represent a guide for the prescription of urinary analyses.

[The basis of endoscopic stones recognition, a prospective monocentric study]

INTRODUCTION

To evaluate by junior urologists the morphology of urinary stone using visual endoscopic recognition after expert teaching. Material From December 2017 to May 2018, surface and section stone pictures extracted from digital ureteroscopy had been submitted to description and recognition. Participants could take benefit from an expert coaching. Each stone was evaluated by a different coherence questionnaire (score 1-5).

RESULTS

Nine stones had been analyzed by 15 junior urologists. Mean score was initially 1.94/4 and then from 2.07 to 4.07/5 during the study. A perfect stone recognition and a matching etiological lithiasis research had been observed in 40.7% and 55.6% of cases respectively.

CONCLUSION

This first teaching experience of the urinary stone morphological endoscopic typing confirms the possibility to train urologists to gain this specific initial skill. Thereby, they could play a more important role in the etiological and diagnostic lithiasis research.

Retrograde intrarenal surgery: An expanding role in treatment of urolithiasis

During the past 3 decades, the surgical management of kidney stones has undergone many technological advances and one is the development of the flexible ureteroscopy. The development of this instrument as well as ancillary equipment such as baskets, graspers, and others, and improvements in lithotripsy with Holmium: YAG laser have led to expand its indications with diagnostic and therapeutic management of medical issues of the upper urinary tract such as urolithiasis and urothelial tumors. The objective of this review is to describe its indications and results in the different scenarios for the treatment of urinary stones.

[Result of treatment of urinary lithiasis for professional aptitude]

INTRODUCTION

Military people are inapt for presence of urinary stones. In this specific population, the treatment of stones is even more aggressive than for the general population without recommendation. The final decision about aptitude is the responsibility of the military doctor. Whereas, ureteroscopy has its place there and must done by any urologist.

METHODS

The purpose of this study was to estimate the results of treatments by ureteroscopy in this population. Success was defined by the complete absence of fragment visualized in the imaging of control operating comment and so the end of the inaptitude time.

RESULTS

Between 2009 and 2016, forty-two were treated for ureteral or renal calculi. The population comprises of 93% men, 35 years old on average. The stones were mainly multiple (more 2) and the medium size is 5mm; sixteen (42.9%) was at the left and eight (19%) was bilateral. In 78.8% (78) of the cases there was a stone in renal position whose 50% (39) still at the lower calyx. In total, 5% of the patients were stone-free in 2 sessions on average. The average deadline of inaptitude of the initial consultation in the resumption of work was of 6 months. In 4% of the cases there was a complication operating rank 4.

CONCLUSION

This study confirms the feasibility, the weak harmlessness of ureteroscopy and the lesser deadline of inaptitude. Every urologist can treat this specific population. The patient must be informed and accept the treatment because of excluding referential.

LEVEL OF EVIDENCE

4.

The study of the inhibitory effect of calcium oxalate monohydrate's crystallization by two medicinal and aromatic plants: Ammi visnaga and Punica granatum

INTRODUCTION

Urinary lithiasis is a recurrent disease defined by the presence of calculi in the urinary tract. Most urinary calculi have as a major component calcium oxalate which occurs mainly in two crystalline forms: Calcium oxalate monohydrate (whewellite) and calcium oxalate dihydrate (weddellite). The target behind, this work is to study the inhibiting effect of the calcium oxalate's crystallization by the extract of the Ammi visnaga and the Punica granatum.

METHODS

The inhibition of crystallization has been studied in vitro with both the absence and the presence of the different concentrations of the extracts of the two plants. This study consists in measurement, with the UV-Visible spectrophotometer, the temporal evolution of the optical density at λ equal to 620nm corresponding to the formation of the crystals due to the mixing of metastable solutions of calcium and oxalate. The characterization of the crystals is carried out in parallel by both the Fourier transform infrared spectra (FT-IR) and the observation of the crystals with the help of an optical microscope. In this respect, the inhibition percentages were calculated from the turbidity slopes in the presence and absence of the extract.

RESULTS

The results obtained were more effective, especially for Punica granatum with percentages of 97.8±0.12 and 83.46±1.34% against nucleation and aggregation, respectively, the order of Ammi visnaga was as follow: 73.25±0.81 and 59.44±3.3%. Thus, all correlation coefficients are greater than 0.95 and all coefficients of variation are less than 10%.

CONCLUSIONS

The prevention and treatment of urinary lithiasis and especially in the case of recurrence by plants remains an alternative choice for medical methods. This study justified the efficacy of the plants Ammi visnaga and in particular Punica granatum against the crystallization of calcium oxalate.

LEVEL OF EVIDENCE

3.

[Evaluation of stone size before flexible ureteroscopy: Which measurement is best?]

PURPOSE

To retrospectively assess the clinical utility in ureteroscopy (URS) planning of radiological parameters as predictor of stone-free status after a single flexible ureteroscopy.

MATERIAL

Sixty-seven patients with renal stones treated by flexible URS were retrospectively evaluated. To assess the clinical utility of radiological parameters, relationships between stone-free (SF) status and stone burden (maximal diameter, calculated area, calculated volume, cumulative diameter, and tridimentionnal volume [V3D]) were analyzed using the area under the receiver operating characteristics curve and logistic regression.

RESULTS

Maximal diameter (AUC=0.75), calculated area (AUC 0.79), calculated volume (AUC=0.79), cumulative diameter (AUC=0.80) and tridimensional volume (AUC=0.82) revealed ability to predict SF status after URS.

CONCLUSION

Stone burden evaluation is critical in predicting SF status after a single URS. Planar and volumetric measurements showed equal ability to predict SF status. V3D is more accurate but diameter measurement remains easier in clinical practice.

LEVEL OF EVIDENCE

4.

[Safety and feasibility of outpatient flexible ureteroscopy for urinary stones: A retrospective single-center study]

AIM

Management of urolithiasis has changed over the past decades. Outpatient surgery has become a major issue for healthcare systems. The aim of this study was to assess the feasibility of outpatient flexible ureteroscopy.

METHODS

A single-center retrospective study has been conducted including all patients who underwent an outpatient flexible ureteroscopy between January 2012 and December 2013. Failure of outpatient management was defined as length of hospital stay>12 hours or readmission within 48 hours after discharge. Univariate analysis was performed to seek for predictors of failure of outpatient management.

RESULTS

One hundred and fifty-seven patients who underwent a total of 174 procedures were included. They were mostly men (57.5 %), with a mean body mass index of 25.2kg/m² (±4.3). The stones were mostly unique (64.3 %), with a mean size of 14.2mm (±11.2). Eighty patients had a double J stent preoperatively (46.5 %), and mean operative time was 64.2 minutes (±34.1). An ureteral access sheath was used in 39 procedures (22.4 %). A double J stent was left postoperatively in 103 patients (59.1 %). In total, 165 procedures (94.8 %) were performed successfully as outpatient surgery. On postoperative imaging, the stone-free rate was 69.5 %. Postoperative complications occurred in 3.4 % of cases and were mostly minor (i.e. Clavien 1-2; 83.3 %). Predictive factors of failed outpatient management were male gender (P=0.04), BMI (P=0.03), and anticoagulants intake (P=0.003).

CONCLUSION

Outpatient flexible ureteroscopy for urinary stones is feasible and its low failure and complications rate may allow a wider spread of its use.

LEVEL OF EVIDENCE

4.

[Evaluation of the operating results and costs associated with the implementation of a flexible ureteroscopy activity within a university hospital center]

INTRODUCTION

The increasing use of flexible ureteroscopy (USSR) sets the cost problems inevitably associated with the fragility of these endoscopes. The aim of this work is to clear from a recent example (universitary hospital) results, costs during the implementation of this technique.

MATERIAL AND METHODS

This is a retrospective study conducted from December 2012 (date of introduction of the activity) in March 2015 concerning the USSR made in a French universitary hospital for stone disease. In this analysis, the cost of consumables was not evaluated, nor the costs of the operating theater or hospitalization.

RESULTS

One hundred forty-one hundred and thirteen patients USSR were conducted by seven surgeons. Seventeen breakages and failures have been identified and have led to the sending of the endoscope for repair. Breakage rate and failure was 12%. All failures were treated with a standard exchange of the device (including 4 standard exchanges made under warranty). The estimated average cost of outages was 3600 euros. This represents an average cost per procedure of about 625 euros (acquisition plus cost of failures) without counting the costs of sterilization or high-level disinfection. The impossibility of relocating the lower calyx stones is associated with an excess risk of breakage (odd ratio: 2.92 CI95: [1.02; 8.37]).

CONCLUSION

This study is novel because it focuses on the cost of implementing a technique in a French university hospital. The use of flexible ureteroscope to unique uses might be an interesting source of savings in the implementation of this technique. This remains to be evaluated.

LEVEL OF EVIDENCE

5.

NEPHROPROTECTIVE AND DIURETIC EFFECT OF NIGELLA SATIVA L SEEDS OIL ON LITHIASIC WISTAR RATS

Background and objective:

The purpose of the current investigation was to study the influences, preventive and diuretic, of Nigella sativa L. seeds oil (NSSO) on calcium oxalate (CaOx) urolithiasis induced in Wistar male rats.

Methodology:

Seeds of Nigella sativa L. (N.S) were analysed for the evaluation of the concentration of oxalate and calcium. Nigella sativa L. seeds oil is obtained by hydrodistillation and HPTLC densitometric method was adopted to determine the amount of thymoquinone (TQ) present.

Thirty male Wistar rats were divided into 5 groups (N=6). Group I, negative control, drank tap water. The other groups were II Positive control, III, IV and V received a treatment model inducing calcium oxalate urolithiasis for 28 days, using an aqueous solution involve 0.75% (EG) ethylene glycol and 1.0 % (AC) chloride ammonium. Rats in group III received in addition, 750 mg/kg Cystone from the beginning to the end of calculi induction experimentation.

However, rats in Groups IV and V received (NSSO) at 5 ml/kg b.w by gavage on days 1^st to 28^th and 15^th to 28^th days, respectively. On days 0, 7, 14, 21 and 28, body weights were measured and the 24-hour urine samples were accumulated and analysed for biochemical elements. On the 28^th day, blood samples were collected for the estimation of serum parameters including creatinine, BUN and uric acid.

All animals were sacrificed at the end of the experiment and the kidneys were detached for histopathological examination.

Results:

Administration of (NSSO) at 5 ml/kg body weight/dose/day for 28 days exerts a protective effect by reducing significantly (p <0.01) urinary and serum rates of calcium, phosphate and oxalate. This preventive diet could increase the volume of urine excreted.

Conclusion:

The nephroprotectrice and diuretic activity demonstrated by Nigella sativa L. gives a scientific basis that approves their traditional use like a remedy against urolithiasis.

List of Abbreviations:NSSO: Nigella sativa L. Seeds oil ; CaOx: Calcium Oxalate; N.S: Nigella sativa L.; HPTLC: High performance thin layer chromatography; TQ: Thymoquinone; N: Number; EG: Ethylene Glycol; AC: Chloride Ammonium BUN: Blood Urea Nitrogen; LD₅₀: Lethal Dose 50; b.w: body weight; H & E: Haematoxyline and Eosin; HPLC-UV:;Caph: calcium phosphate; FR: glomerular filtration rate

[Flexible ureterorenoscopy vs percutaneous nephrolithotomy for renal stone management: Retrospective study]

PURPOSE

The aim of this study was to evaluate the efficacy and tolerance of renal stone fragmentation by flexible ureterorenoscopy (URS), compared to percutaneous nephrolithotomy (PCNL).

MATERIAL AND METHODS

Patients treated between 1998 and 2010 by URS and PCNL for intrarenal stone were reviewed. Patients' and stones' characteristics were analyzed. The preoperative parameters were reported as well as the procedure's efficiency and its complications. Success was defined by the absence of residual lithiasis visualized on renal imaging at 6 months of follow-up.

RESULTS

Among 531 patients included, there were 159 PCNL and 372 URS. The mean duration of hospitalization after PCNL was 8±4.6 days and 3±1.7 days after URS. The mean stones' size was higher in the PCNL group (19.9±7.5mm) than for the URS group (9.7±5.6mm; P<0.0001). The stone-free rate was significantly better in the PCNL group for stones measuring between 10 and 20mm (P<0.0001) and for stones of more than 20mm (P=0.017). Postoperative complications were significantly more frequent (27 %) and more severe (8.8 % vs Clavien III and IV) in the PCNL, than in the URS group, respectively (P=0.0001).

CONCLUSION

PCNL is a successful technique for renal stone fragmentation. However, URS seemed more tolerated despite a lower stone-free rate.

LEVEL OF EVIDENCE

4.

[Composition of 359 kidney stones from the East region of Algeria]

PURPOSE

Determine stones composition of the upper urinary tract in the eastern region of Algeria.

METHODS

Our study focuses on a set of 359 stones of the upper urinary tract collected between January 2007 and December 2012 at hospitals in the eastern region of Algeria and analyzed by Fourier transform infrared spectroscopy.

RESULTS

The male/female ratio was only 1.32. Calcium oxalate prevailed in 68.5% of stones and 49.3% of nuclei, mainly as whewellite (51.8% of stones and 37.9% of nuclei vs 16.7% and 11.4% respectively for weddellite). Carbapatite prevailed in 15% of stones and 29.8% of nuclei. The struvite, identified in 11.1% of calculi, prevailed in 3.9% of stones and 3.1% of nuclei. Among purines, uric acid prevailed with frequencies quite close to 8.9% and 7% respectively in the stone and in the nucleus while the ammonium urate prevailed in only 0.3% of stones and 3.3% of nuclei. The cystine frequency was 3.6% in both stone and nucleus. The frequency of stone with umbilication was 26.2%. Whewellite was the main component of umbilicated stones with Randall's plaque.

CONCLUSION

Our results suggest that stones of the urinary tract in the Algerian east region resemble those observed in industrialized countries. Some features such as stones location, the whewellite prevalence, the frequencies of main components in both the stone and the nucleus as well as the formation of stones on renal papilla confirm this trend.

LEVEL OF EVIDENCE

4.

Decreased Radiation Exposure and Increased Efficacy in Extracorporeal Lithotripsy Using a New Ultrasound Stone Locking System

PURPOSE

To compare fluoroscopy duration, radiation dose, and efficacy of two ultrasound stone localization systems during extracorporeal shockwave lithotripsy (SWL) treatment.

PATIENTS AND METHODS

Monocentric prospective data were obtained from patients consecutively treated for renal stones using the Sonolith(®) i-sys (EDAP TMS) lithotripter, with fluoroscopy combined with ultrasound localization using an "outline" Automatic Ultrasound Positioning Support (AUPS) (group A), or the "free-line" Visio-Track (VT) (EDAP-TMS) hand-held three-dimensional ultrasound stone locking system (group B). Efficacy rate was defined as the within-groups proportion stone free or with partial stone fragmentation not needing additional procedures. Statistical analysis used Pearson chi-square tests for categoric variables, nonparametric Mann-Whitney tests for continuous variables, and linear regression for operator learning curve with VT. Continuous variables were reported as median (range) values.

RESULTS

Patients in group A (n=73) and group B (n=81) were comparable in baseline characteristics (age, kidney stone size, others) and in SWL application (duration, number of shocks, energy [Joules]). During SWL, the median (range) duration (seconds) of radiation exposure was 159.5 (0-690) in group A and 3.5 (0-478) in group B (P<0.001) and irradiation dose (mGy.cm(2)), 10598 (0-54843) in group A and 163 (0-13926) in group B (P<0.001). Fluoroscopy time significantly decreased with operator experience using VT. The efficacy rate was 54.5% in group A and 79.5% in group B (P=0.001).

CONCLUSION

VT significantly reduced fluoroscopy use during SWL and the duration and dose of patient exposure to ionizing radiation. Stone treatment efficacy was significantly greater with VT mainly because of a better real-time monitoring of the stone.