Machine learning models for screening clinically significant nephrolithiasis in overweight and obese populations.

PURPOSES: Our aim is to build and evaluate models to screen for clinically significant nephrolithiasis in overweight and obesity populations using machine learning (ML) methodologies and simple health checkup clinical and urine parameters easily obtained in clinics. METHODS: We developed ML models to screen for clinically significant nephrolithiasis (kidney stone > 2 mm) in overweight and obese populations (body mass index, BMI ≥ 25 kg/m2) using gender, age, BMI, gout, diabetes mellitus, estimated glomerular filtration rate, bacteriuria, urine pH, urine red blood cell counts, and urine specific gravity. The data were collected from hospitals in Kaohsiung, Taiwan between 2012 and 2021. RESULTS: Of the 2928 subjects we enrolled, 1148 (39.21%) had clinically significant nephrolithiasis and 1780 (60.79%) did not. The testing dataset consisted of data collected from 574 subjects, 235 (40.94%) with clinically significant nephrolithiasis and 339 (59.06%) without. One model had a testing area under curve of 0.965 (95% CI, 0.9506-0.9794), a sensitivity of 0.860 (95% CI, 0.8152-0.9040), a specificity of 0.947 (95% CI, 0.9230-0.9708), a positive predictive value of 0.918 (95% CI, 0.8820-0.9544), and negative predictive value of 0.907 (95% CI, 0.8756-0.9371). CONCLUSION: This ML-based model was found able to effectively distinguish the overweight and obese subjects with clinically significant nephrolithiasis from those without. We believe that such a model can serve as an easily accessible and reliable screening tool for nephrolithiasis in overweight and obesity populations and make possible early intervention such as lifestyle modifications and medication for prevention stone complications.

Comprehensive evaluation of patients with primary hyperoxaluria type 1: A nationwide study.

BACKGROUND: Primary hyperoxaluria type 1 (PH1) is characterized by increased endogenous oxalate production and deposition as calcium oxalate crystals. The main manifestations are nephrocalcinosis/nephrolithiasis, causing impaired kidney function. We aimed to evaluate the clinical characteristics and overall outcomes of paediatric PH1 patients in Turkey. METHODS: This is a nationwide, multicentre, retrospective study evaluating all available paediatric PH1 patients from 15 different paediatric nephrology centres in Turkey. Detailed patient data was collected which included demographic, clinical and laboratory features. Patients were classified according to their age and characteristics at presentation: patients presenting in the first year of life with nephrocalcinosis/nephrolithiasis (infantile oxalosis, Group 1), cases with recurrent nephrolithiasis diagnosed during childhood (childhood-onset PH1, Group 2), and asymptomatic children diagnosed with family screening (Group 3). RESULTS: Forty-eight patients had a mutation consistent with PH1. The most common mutation was c.971_972delTG (25%). Infantile oxalosis patients had more advanced chronic kidney disease (CKD) or kidney failure necessitating dialysis (76.9% vs. 45.5%). These patients had much worse clinical course and mortality rates seemed to be higher (23.1% vs. 13.6%). Patients with fatal outcomes were the ones with significant comorbidities, especially with cardiovascular involvement. Patients in Group 3 were followed with better outcomes, with no kidney failure or mortality. CONCLUSION: PH1 is not an isolated kidney disease but a systemic disease. Family screening helps to preserve kidney function and prevent systemic complications. Despite all efforts made with traditional treatment methods including transplantation, our results show devastating outcomes or mortality.

Extreme Reactive Thrombocytosis Caused by Obstructive Nephrolithiasis and Pyelonephritis.

Platelet counts in reactive thrombocytosis rarely exceed 1000 × 109/L. We present the case of a male patient, aged 80 years, with quiescent rheumatoid arthritis who was found to have a platelet count of 1011 × 109/L on routine laboratory testing. The patient was initially asymptomatic but developed leukocytosis to 23.1 × 109/L on hospital day 2. Diagnostic work-up revealed obstructive nephrolithiasis and pyelonephritis, and the thrombocytosis and leukocytosis gradually resolved with empiric antibiotic treatment and ureteral stent placement. Tests for myeloproliferative disorders, including JAK-2V617F mutation, BCR-ABL for chronic myeloid leukemia and acute lymphocytic leukemia, and myeloproliferative neoplasms (MPL/CALR), were negative. Physicians should be aware that in rare cases reactive thrombocytosis can exceed 1000 × 109/L, and that markedly elevated platelet counts in the setting of urinary tract infections may be an early sign of obstructive uropathy.

[Two cases of Dent disease type 1 with Bartter-like phenotype and literature review].

The clinical presentation, treatment, and follow-up of two boys with type 1 Dent disease who exhibited a Bartter-like phenotype were retropectively analysed. The related literature of pediatric patients with type 1 Dent disease who had hypokalemia and metabolic alkalosis was screened through databases such as PubMed, CNKI, and Wanfang until February 1, 2024, and common features among these patients were summarized through literature review. A total of 7 literatures were included, and 9 children were included in the analysis. All patients were male, presenting with significant low molecular weight proteinuria and hypercalciuria. Other prominent characteristic phenotypes included short stature (7/8), hypophosphatemia (8/9), and rickets (6/8). Seven previously reported patients had missense or nonsense mutations, while 2 patients in this study carried possible pathogenic mutations in the CLCN5 gene, c.315+2T>A (p.?) and c.584dupT (p.I196Yfs*6), respectively. Five patients were able to maintain blood potassium levels around 3 mmol/L with oral potassium chloride solution combined with non-steroidal anti-inflammatory drugs (ibuprofen or indomethacin). The follow-up showed that 2 patients developed chronic kidney disease stage 4 and stage 3 at the age of 13 and 21 years, respectively. The phenotypic overlap between Dent disease and Batter syndrome is considerable,with the distinguishing feature being the presence of significant low molecular weight proteinuria. Patients with type 1 Dent disease presenting with the Bartter-like phenotype have a high prevalence of short stature, hypophosphatemia, and rickets. Non-steroidal anti-inflammatory drugs can be used to correct hypokalemia in patients under periodic renal function assessment.

Genetic testing in children with nephrolithiasis and nephrocalcinosis.

BACKGROUND: Diagnosing genetic kidney disease has become more accessible with low-cost, rapid genetic testing. The study objectives were to determine genetic testing diagnostic yield and examine predictors of genetic diagnosis in children with nephrolithiasis/nephrocalcinosis (NL/NC). METHODS: This retrospective multicenter cross-sectional study was conducted on children ≤ 21 years old with NL/NC from pediatric nephrology/urology centers that underwent the Invitae Nephrolithiasis Panel 1/1/2019-9/30/2021. The diagnostic yield of the genetic panel was calculated. Bivariate and multiple logistic regression were performed to assess for predictors of positive genetic testing. RESULTS: One hundred and thirteen children (83 NL, 30 NC) from 7 centers were included. Genetic testing was positive in 32% overall (29% NL, 40% NC) with definite diagnoses (had pathogenic variants alone) made in 11.5%, probable diagnoses (carried a combination of pathogenic variants and variants of uncertain significance (VUS) in the same gene) made in 5.4%, and possible diagnoses (had VUS alone) made in 15.0%. Variants were found in 28 genes (most commonly HOGA1 in NL, SLC34A3 in NC) and 20 different conditions were identified. Compared to NL, those with NC were younger and had a higher proportion with developmental delay, hypercalcemia, low serum bicarbonate, hypophosphatemia, and chronic kidney disease. In multivariate analysis, low serum bicarbonate was associated with increased odds of genetic diagnosis (ß 2.2, OR 8.7, 95% CI 1.4-54.7, p = 0.02). CONCLUSIONS: Genetic testing was high-yield with definite, probable, or possible explanatory variants found in up to one-third of children with NL/NC and shows promise to improve clinical practice. A higher resolution version of the Graphical abstract is available as Supplementary information.

Genetic testing enables a precision medicine approach for nephrolithiasis and nephrocalcinosis in pediatrics: a single-center cohort.

OBJECTIVE: Hereditary factors are the main cause of pediatric nephrolithiasis (NL)/nephrocalcinosis (NC). We summarized the genotype-phenotype correlation of hereditary NL/NC in our center, to evaluate the role of genetic testing in early diagnosis. METHODS: The clinical data of 32 NL/NC cases, which were suspected to have an inherited basis, were retrospectively analyzed from May 2017 to August 2020. The trio-whole exome sequencing was used as the main approach for genetic testing, variants were confirmed by Sanger sequencing, and pathogenicity analysis according to protein function was predicted with custom-developed software. RESULTS: Causative monogenic mutations were detected in 24 of 32 NL/NC patients, and copy number variation was detected in one patient. A summary of manifestations in patients with inherited diseases revealed a significant degree of growth retardation, increased urinary excretion of the low-molecular weight protein, hypercalciuria, electrolyte imbalances, and young age of onset to be common in heredity disease. In addition, some patients had abnormal renal function (3 ppm 25). The most frequent pathology identified was distal renal tubular acidosis (with inclusion of SLC4A1, ATP6V1B1, and ATP6VOA4 genes), followed by Dent disease (CLCN5 and OCRL1 genes), primary hyperoxaluria (PH) (AGXT and HOGA1 genes) and Kabuki syndrome (KMT2D gene), which was more likely to present as NC or recurrent stone and having a higher correlation with a specific biochemical phenotype and extrarenal phenotype. CONCLUSION: The etiology of NL/NC is heterogeneous. This study explored in depth the relationship between phenotype and genotype in 32 patients, and confirmed that genetic testing and clinical phenotype evaluation enable the precision medicine approach to treating patients.

Changes in practice patterns of nephrolithiasis in the era of the coronavirus disease 2019 pandemic: a review.

PURPOSE OF REVIEW: The coronavirus disease 2019 (COVID-19) pandemic led to a drastic change in healthcare priorities, availability of resources and accommodation of different needs and scenarios. We sought to review the effect of the pandemic on different aspects of nephrolithiasis. RECENT FINDINGS: The pandemic resulted in a significant impact on management of patients with nephrolithiasis around the world. A significant decrease in patient presentation and differences in strategies of management to truncate exposure and surgery time and expedite patient discharge deferring definitive management has been noted. Moreover, new safety measures such as COVID-19 PCR testing prior to surgery and limiting any intervention for COVID-19 positive patients to only life-saving scenarios has been implemented. Different emergency triaging proposals are being used, mainly including high risk patients with septic shock or complete obstruction/renal injury. Moreover, the emergence of telehealth has changed outpatient practice dramatically with a significant adoption to minimize exposure. Lastly, the effect of COVID-19 on renal physiology has been described with significant potential to cause morbidity from immediate or delayed acute kidney. No physiological effect on stone formation has yet been described, and transmission through urine is rare. SUMMARY: The COVID-19 pandemic has markedly shifted the treatment of nephrolithiasis in many ways, including emergency triage, outpatient care, and definitive management. Although various approaches and algorithms proposed are meant to optimize management in the time of the pandemic, further studies are required for validation.

Preemptive liver transplant in two patients with primary hyperoxaluria type 1: Clinical significance of nephrolithiasis and nephrocalcinosis.

BACKGROUND: Although nephrolithiasis (NL) and nephrocalcinosis (NC) are very common features of primary hyperoxaluria type 1 (PH1), the long-term prognosis of NL and NC after preemptive liver transplantation (PLT) has not been elucidated. MATERIAL AND METHODS: We describe the cases of two chronic kidney disease (CKD) stage three patients with different clinical courses after PLT for PH1. RESULTS: The first patient underwent PLT at 7 years of age with an estimated glomerular filtration rate (eGFR) of 47.8 ml/min/1.73 m2 . Two years later, she experienced several episodes of obstructive pyelonephritis due to urolithiasis, and developed septic shock in one of these episodes. At the same time as these episodes, preexisting NL and NC progressively improved, with disappearance on X-ray disappeared at 8 years after transplantation. Her renal function has been maintained with an eGFR of 58.7 ml/min/1.73 m2 . The second patient received PLT at 10 years of age with an eGFR of 58.9 ml/min/1.73 m2 . Her renal function has been maintained with an eGFR of 65.9 ml/min/1.73 m2 . She had repeated urolithiasis which started to appear at 3 years after LT. The radiological findings still show bilateral NL and NC, but the stones in the renal pelvis have shown mild improvement. CONCLUSIONS: Regardless of the regression in NC seen on X-ray, long-term maintenance of the renal function in patients with PH1 with CKD stage 3 can be achieved with PLT. In patients with NL, there is a risk of serious complications due to posttransplant immunosuppressive therapy when obstructive pyelonephritis occurs after LT.

Use of prescription drug monitoring program to audit opioid prescribing patterns for patients with symptomatic nephrolithiasis.

INTRODUCTION The opioid epidemic is a growing problem in the United States. There is a high rate of opioid oversupply for treatment of symptomatic nephrolithiasis, partly due to patients being seen by multiple providers. In Pennsylvania, there are efforts to integrate a prescription drug monitoring program (PDMP) within the electronic medical record (EMR). The objectives of this study were to evaluate prescribing practices for opioids for symptomatic nephrolithiasis and the incidence of prescriptions not documented within the EMR. MATERIALS AND METHODS: Adults who presented for treatment of symptomatic nephrolithiasis were sequentially evaluated from May - October 2017 at Penn State Milton S. Hershey Medical Center. With IRB approval, we evaluated opioids prescribed in the EMR, which was compared to the PDMP for each stone episode. We calculated daily morphine milligram equivalents (MME) and total MME available to patients. RESULTS: A total of 301 patients were identified (52% male) with a mean age of 50.0 +/- 16.7 years and 249 (83%) of patients were prescribed narcotics with an average of 226.8 +/- 232.2 MME for their stone episode. Of patients that were prescribed narcotics, 19% had additional narcotics prescribed to them that were not entered into the EMR and later identified using PDMP. The average additional opioid prescribed was 371.8 +/- 404.2 total MME. CONCLUSIONS: The majority of patients presenting with symptomatic nephrolithiasis were prescribed an opioid. Approximately one-fifth of patients were receiving opioids from other providers that were not documented in the EMR at the time of their opioid prescription. PDMP, or similar resources, should be utilized by providers to minimize opioid use and reduce oversupplying patients.

The Impact of Dietary Modifications and Medical Management on 24-Hour Urinary Metabolic Profiles and the Status of Renal Stone Disease in Recurrent Stone Formers.

BACKGROUND: Dietary modifications and patient-tailored medical management are significant in controlling renal stone disease. Nevertheless, the literature regarding effectiveness is sparse. OBJECTIVES: To explore the impact of dietary modifications and medical management on 24-hour urinary metabolic profiles (UMP) and renal stone status in recurrent kidney stone formers. METHODS: We reviewed our prospective registry database of patients treated for nephrolithiasis. Data included age, sex, 24-hour UMP, and stone burden before treatment. Under individual treatment, patients were followed at 6-8 month intervals with repeat 24-hour UMP and radiographic images. Nephrolithiasis-related events (e.g., surgery, renal colic) were also recorded. We included patients with established long-term follow-up prior to the initiation of designated treatment, comparing individual nephrolithiasis status before and after treatment initiation. RESULTS: Inclusion criteria were met by 44 patients. Median age at treatment start was 60.5 (50.2-70.2) years. Male:Female ratio was 3.9:1. Median follow-up was 10 (6-25) years and 5 (3-6) years before and after initiation of medical and dietary treatment, respectively. Metabolic abnormalities detected included: hypocitraturia (95.5%), low urine volume (56.8%), hypercalciuria (45.5%), hyperoxaluria (40.9%), and hyperuricosuria (13.6%). Repeat 24-hour UMP under appropriate diet and medical treatment revealed a progressive increase in citrate levels compared to baseline and significantly decreased calcium levels (P = 0.001 and 0.03, respectively). A significant decrease was observed in stone burden (P = 0.001) and overall nephrolithiasis-related events. CONCLUSIONS: Dietary modifications and medical management significantly aid in correcting urinary metabolic abnormalities. Consequently, reduced nehprolithiasis-related events and better stone burden control is expected.

Linking 24-h urines to clinical phenotypes: what alternatives does the future bring?

PURPOSE OF REVIEW: The 24-h urine test is recommended as part of the metabolic evaluation for patients with nephrolithiasis to guide preventive interventions. However, this test may be challenging to interpret and has limits in its predictive ability. In this review, we summarize and discuss the most recent research on the opportunities and challenges for utilizing urinary biomarkers for kidney stone prevention. RECENT FINDINGS: Contemporary studies utilizing the 24-h urine test have improved our understanding of how to better administer testing and interpret test results. Beyond the standard panel of 24-h urine parameters, recent applications of proteomics and metabolomics have identified protein and metabolic profiles of stone formers. These profiles can be assayed in future studies as potential biomarkers for risk stratification and prediction. Broad collaborative efforts to create large datasets and biobanks from kidney stone formers will be invaluable for kidney stone research. SUMMARY: Recent advances in our understanding of kidney stone risk have opened opportunities to improve metabolic testing for kidney stone formers. These strategies do not appear to be mutually exclusive of 24-h urine testing but instead complementary in their approach. Finally, large clinical datasets hold promise to be leveraged to identify new avenues for stone prevention.

Artificial intelligence: the future of urinary stone management?

PURPOSE OF REVIEW: To investigate the application of artificial intelligence in the management of nephrolithiasis. RECENT FINDINGS: Although rising, the number of publications on artificial intelligence for the management of urinary stone disease is still low. Most publications focus on diagnostic tools and prediction of outcomes after clinical interventions. Artificial intelligence can, however, play a major role in development of surgical skills and automated data extraction to support clinical research. SUMMARY: The combination of artificial intelligence with new technological developments in the field of endourology will create new possibilities in the management of urinary stones. The implication of artificial intelligence can lead to better patient selection, higher success rates, and furthermore improve patient safety.

Inherited conditions resulting in nephrolithiasis.

PURPOSE OF REVIEW: Prevalence of pediatric urolithiasis is increasing, which is definitively visible in increasing numbers of presentations in emergency or outpatient clinics. In pediatric patients, a genetic or metabolic disease has to be excluded, so that adequate treatment can be installed as early as possible. Only then either recurrent stone events and chronic or even end-stage kidney disease can be prevented. RECENT FINDINGS: The genetic background of mostly monogenic kidney stone diseases was unravelled recently. In hypercalcuria, for example, the commonly used definition of idiopathic hypercalciuria was adopted to the genetic background, here three autosomal recessive hereditary forms of CYP24A1, SLC34A1 and SLC34A3 associated nephrocalcinosis/urolithiasis with elevated 1.25-dihydroxy-vitamin D3 (1.25-dihydroxy-vitamin D3) (calcitriol) levels. In addition either activating or inactivating mutations of the calcium-sensing receptor gene lead either to hypocalcemic hypercalciuria or hypercalcemic hypocalciuria. In primary hyperoxaluria, a third gene defect was unravelled explaining most of the so far unclassified patients. In addition, these findings lead to new treatment options, which are currently evaluated in phase III studies. SUMMARY: Kidney stones are not the disease itself, but only its first symptom. The underlying disease has to be diagnosed in every pediatric patient with the first stone event.

Application of whole-genome sequencing in a case study of renal tuberculosis in a child.

BACKGROUND: Urogenital tuberculosis (TB) is rare in children and usually develops due to reactivation of the foci in the genitourinary tract after the latency period following initial infection. Urogenital TB in children has no pathognomonic clinical features that can result in overlooking or misdiagnosing this clinical entity. Here, we report important findings regarding the pathogenesis and transmission of TB by using genotyping and whole-genome sequencing (WGS) in a study of renal TB case in a child. CASE PRESENTATION: A 13-year-old boy was admitted to the hospital because of high fever, severe dry cough, flank pain and painful urination. Abdominal ultrasonography and CT revealed an 8 mm calculus in the kidney, and clinical findings were initially interpreted as nephrolithiasis. Nevertheless, due to the atypical clinical presentation of kidney stone disease, additional investigations for possible TB were performed. The QuantiFERON®-TB Gold Plus test was positive, and the Mantoux test resulted in 15 mm of induration, confirming infection with Mycobacterium tuberculosis (Mtb). Chest X-ray was normal. Chest CT revealed calcified intrathoracic lymph nodes. The urine sample tested positive for acid-fast bacilli, and Mtb cultures were obtained from urine and bronchial aspirate samples, resulting in a final diagnosis of intrathoracic lymph node and renal TB. Contact investigation revealed that the child's father was diagnosed with TB when the child was 1 year old. Genotyping and WGS analysis of Mtb isolates of the child and his father confirmed the epidemiological link and pointed to the latency of infection in the child. CONCLUSIONS: This case report confirmed the development of active TB from calcified lesions in adolescent after 12 years of exposure, demonstrated the absence of microevolutionary changes in the Mtb genome during the period of latency, and proved the importance of appropriate evaluation and management to prevent the progression of TB infection to active TB disease. The use of WGS provided the ultimate resolution for the detection of TB transmission and reactivation events.

Prevalence of low molecular weight proteinuria and Dent disease 1 CLCN5 mutations in proteinuric cohorts.

BACKGROUND: Dent disease type 1 (DD1) is a rare X-linked disorder caused mainly by CLCN5 mutations. Patients may present with nephrotic-range proteinuria leading to erroneous diagnosis of focal segmental glomerulosclerosis (FSGS) and unnecessary immunosuppressive treatments. METHODS: The following cohorts were screened for CLCN5 mutations: Chronic Kidney Disease in Children (CKiD; n = 112); Multicenter FSGS-Clinical Trial (FSGS-CT) (n = 96), and Novel Therapies for Resistant FSGS Trial (FONT) (n = 30). Urinary α1-microglobulin (α1M), albumin (A), total protein (TP), and creatinine (Cr) were assessed from CKiD subjects (n = 104); DD1 patients (n = 14); and DD1 carriers (DC; n = 8). TP/Cr, α1M/Cr, α1M/TP, and A/TP from the CKiD cohort were compared with DD1 and DC. RESULTS: No CLCN5 mutations were detected. TP/Cr was lower in DC and CKiD with tubulointerstitial disease than in DD1 and CKiD with glomerular disease (p < 0.002). α1M/Cr was higher in DD1 than in CKiD and DC (p < 0.001). A/TP was lower in DD1, DC, and CKiD with tubulointerstitial disease and higher in CKiD with glomerular disease (p < 0.001). Thresholds for A/TP of ≤ 0.21 and α1M/Cr of ≥ 120 mg/g (> 13.6 mg/mmol) creatinine were good screens for Dent disease. CONCLUSIONS: CLCN5 mutations were not seen in screened CKiD/FSGS cohorts. In our study, a cutoff of TP/Cr > 600 mg/g (> 68 mg/mmol) and A/TP of < 0.3 had a high sensitivity and specificity to distinguish DD1 from both CKiD glomerular and tubulointerstitial cohorts. α1M/Cr ≥ 120 mg/g (> 13.6 mg/mmol) had the highest sensitivity and specificity when differentiating DD1 and studied CKiD populations.

Randomized Trial of Intravenous Lidocaine Versus Hydromorphone for Acute Abdominal Pain in the Emergency Department.

STUDY OBJECTIVE: We compare the efficacy and safety of intravenous lidocaine with that of hydromorphone for the treatment of acute abdominal pain in the emergency department (ED). METHODS: This was a randomized, double-blind, clinical trial conducted in 2 EDs in the Bronx, NY. Adults weighing 60 to 120 kg were randomized to receive 120 mg of intravenous lidocaine or 1 mg of intravenous hydromorphone. Thirty minutes after administration of the first dose of the study drug, participants were asked whether they needed a second dose of the investigational medication to which they were randomized. Patients were also stratified according to clinical suspicion of nephrolithiasis. The primary outcome was improvement in pain scores of 0 to 10 between baseline and 90 minutes. An important secondary outcome was need for "off-protocol" parenteral analgesics, including opioids and nonsteroidal anti-inflammatory drugs. RESULTS: We enrolled 154 patients, of whom 77 received lidocaine and 77 received hydromorphone. By 90 minutes, patients randomized to lidocaine improved by a mean of 3.8 points on the 0-to-10 scale, whereas those randomized to hydromorphone improved by a mean of 5.0 points (mean difference 1.2; 95% confidence interval 0.3 to 2.2). Need for off-protocol "rescue" analgesics occurred for 39 of 77 lidocaine patients (51%) and 20 of 77 hydromorphone patients (26%) (difference 25%; 95% confidence interval 10% to 40%). Adverse events were comparable between groups. Among the subset of 22 patients with nephrolithiasis, lidocaine patients reported a mean improvement of 3.4 points on the pain scale, whereas hydromorphone patients reported a mean improvement of 6.4 points (mean difference 3.0; 95% confidence interval 0.5 to 5.5). CONCLUSION: Intravenous hydromorphone was superior to intravenous lidocaine both for general abdominal pain and a subset of patients with nephrolithiasis. A majority of patients randomly allocated to lidocaine required additional analgesics.

"Inverted" positioning of renal allograft during kidney transplantation in children and adolescents: A single-institution comparative analysis.

Renal transplantation is the treatment of choice in children with end-stage renal failure. Limitations in patient anatomy or a short donor renal vein may necessitate intraoperative inversion of the kidney. There is little evidence to support the use of this surgical technique, and no evidence in the pediatric population. This study identifies the perioperative and post-operative outcomes of inverted renal transplants in pediatric patients. We reviewed all patients having a renal transplant between January 2012 and December 2016 and collected short- and long-term outcomes of patients who received an inverted allograft. Early graft function was defined as the time to reach creatinine nadir. During this time, our hospital performed 81 transplants, and 50 (62%) were from deceased donors, including the 6 (12%) patients who received inverted renal grafts. Half (3/6) were female, 5/6 (83%) were dialysis-dependent, and the median age at surgery was 13 years (range 9-16 years). There was no significant difference in mean creatinine nadir values (P = 0.518) and the time to creatinine nadir mean values (P = 0.190) between the upright and inverted renal transplant groups. There were also no significant differences in rates of post-operative complications between the upright and inverted allograft recipients. Inversion of renal allografts in pediatric patients is a viable surgical technique to compensate for shortcomings in patient anatomy or in special cases of renal transplantation involving a short donor renal vein. Future research should focus on outcomes of a larger group of pediatric inverted renal transplant patients.

Practice patterns of ureteral access sheath during ureteroscopy for nephrolithiasis: a survey among endourologists worldwide.

BACKGROUND: The use of ureteral access sheath (UAS) during ureteroscopy is controversial. We aimed to explore practice patterns of UAS during ureteroscopy for nephrolithiasis among endourologists worldwide. METHODS: A 15-question survey was designed using the SurveyMonkey® platform. The questions covered the background and professional experience of the potential respondents, indications for UAS insertion, UAS caliber and possible complications associated with its use. The questions were anonymously tabulated in order to determine practice patterns of UAS during ureteroscopy for nephrolithiasis among endourologists. The survey was then distributed via e-mail to all the Endourological Society members. RESULTS: 216 members responded. 99.53% of the respondents practice as endourologists, 63.4% are fellowship trained and 74.4% are at least 6 years post-fellow. 73.2% practice in an academic facility. 77.3% perform at least 100 ureteroscopies annually. 46 and 76% routinely use UAS for the treatment of ureteral and kidney stones, respectively. In both cases, the 12/14 access sheath is the most common. 42% use UAS in primary ureteroscopy. 90.3% believe that a double J stent insertion is not mandatory prior to UAS insertion. 79.1% think the use of UAS does not increase postoperative complications rate, and if the latter does encounter, then most likely it is either a ureteral stricture (93.2%) or pain (48%). CONCLUSIONS: UAS is commonly used by highly skilled endourologists during ureteroscopy. 12/14 UAS is mostly used. Ureteral stricture and post-operative pain are proposed as possible complications following UAS introduction, however pre-stenting is not mandatory as overall low complication rate is expected.

Risk Factors for Nephrolithiasis in Adults with Short Bowel Syndrome.

INTRODUCTION: Patients with short bowel syndrome (SBS) commonly develop nephrolithiasis. However, the risk factors for nephrolithiasis in patients with SBS remain unclarified. The present study aimed to identify the risk factors for nephrolithiasis in adults with SBS. METHODS: All eligible adults diagnosed with SBS and admitted to a tertiary referral center from December 2008 to 2018 were retrospectively identified from a prospectively maintained database. Patients' demographic and clinical characteristics were analyzed using univariate and multivariate analyses to identify the risk factors for nephrolithiasis. RESULTS: Of 231 adults with SBS, 42 (18.2%) developed nephrolithiasis. The mean age was 46.4 ± 17.8 years, the mean body mass index was 18.2 ± 3.8 kg/m2, and median duration of SBS was 11 months (range 2-324 months). Multivariate binary logistic regression analysis revealed that the independent risk factors for nephrolithiasis in adults with SBS were jejuno-ileal anastomosis and colon-in-continuity (OR 4.335; 95% CI 1.175-16.002; p = 0.028), prolonged duration of SBS (OR 1.008; 95% CI 1.002-1.014; p = 0.010), and increased serum creatinine concentration (OR 1.005; 95% CI 1.001-1.009; p = 0.012). CONCLUSIONS: Nephrolithiasis is common in adults with SBS. As nephrolithiasis can have adverse clinical consequences, patients with SBS should be closely monitored, and prophylactic interventions should be considered.