BACKGROUND

Staghorn calculi are complicated renal stones that are frequently linked to hydronephrosis, a parameter that can have a major impact on the results of surgery. Percutaneous nephrolithotomy (PCNL) is widely recognized as the gold standard for treating large kidney stones and staghorn calculi. Data on the effect of preoperative hydronephrosis on PCNL perioperative outcomes is still limited.

This study aimed to investigate the association between preoperative hydronephrosis and perioperative outcomes among patients undergoing PCNL in a tertiary government hospital in Manila.

A single-center prospective cohort study was conducted, involving 90 patients diagnosed with staghorn calculi and scheduled for elective PCNL. Patients were categorized into two groups based on the presence or absence of moderate-to-severe hydronephrosis as determined by preoperative imaging. Perioperative outcomes, including total operative time, access time, lithotripsy time, and perioperative complications such as bleeding and sepsis, were evaluated. Data were analyzed using linear and logistic regression models to assess associations between hydronephrosis and perioperative outcomes.

The presence of hydronephrosis was associated with a statistically significant reduction in access time (p = 0.036), likely due to the dilation of renal structures facilitating easier entry. However, hydronephrosis was linked to a borderline significant reduction in lithotripsy rate (p = 0.051), indicating potential challenges in stone fragmentation. No significant association was found between hydronephrosis and total operative time or perioperative complications, such as bleeding and sepsis.

While hydronephrosis may make kidney access and other technical aspects of PCNL easier, it may also make stone fragmentation more difficult. Larger stone size and stone location were significant predictors of longer operative times and slower lithotripsy rates, underscoring their critical role in surgical outcomes.

OBJECTIVES: To explore the association between Chinese visceral adiposity index (CVAI) and the risk of nephrolithiasis. METHODS: This cross-sectional study analyzed data from 78 438 Chinese adults who underwent ultrasound examinations during health screening at the Health Examination Center of Affiliated Hospital of Yangzhou University. Participants were divided into quartiles (Q1-Q4 groups) based on CVAI. Multivariate logistic regression models were utilized to evaluate the association between CVAI and nephrolithiasis risk, followed by subgroup analyses to further explore potential relationships. The performance of CVAI in predicting the risk of nephrolithiasis was evaluated using receiver operating characteristic (ROC) curves. RESULTS: Increased CVAI was significantly associated with a higher risk of nephrolithiasis, with prevalence rising from 3.36% in the Q1 group to 10.67% in the Q4 group (P<0.01). In adjusted models, CVAI was positively correlated with the prevalence rate of nephrolithiasis (OR=1.002, 95%CI: 1.001-1.004, P<0.01). The risks of nephrolithiasis in the Q2, Q3, and Q4 groups were 1.196-fold (95%CI: 1.069-1.338, P<0.01), 1.260-fold (95%CI: 1.109-1.433, P<0.01), and 1.316-fold (95%CI: 1.125-1.539, P<0.01) higher than in the Q1 group, respectively. Subgroup analysis revealed that CVAI was positively associated with the risk of nephrolithiasis in male participants, individuals aged <60 years, the hypertension group, populations with or without diabetes mellitus, and the normal body mass index subgroup. Genders and age had an interaction effect on the correlation between CVAI and the risk of nephrolithiasis development (both P<0.05). The ROC curve analysis demonstrated that CVAI exhibited superior predictive efficacy compared to waist circumference, body mass index, visceral adiposity index, weight-adjusted waist index, cardiometabolic index and body shape index, with an area under the curve of 0.622. CONCLUSIONS In Chinese adults, CVAI is positively associated with the risk of nephrolithiasis development, which may serve as a potential predictive marker for nephrolithiasis.
Humans ; Nephrolithiasis/etiology* ; Male ; Female ; Middle Aged ; Cross-Sectional Studies ; Adult ; Intra-Abdominal Fat ; Risk Factors ; China/epidemiology* ; Adiposity ; Aged ; Logistic Models ; Obesity, Abdominal/epidemiology* ; East Asian People

OBJECTIVES: To investigate the incidence of ipsilateral upper urinary tract stones after partial nephrectomy and its risk factors. METHODS: We retrospectively analyzed baseline patient characteristics (age, gender, and body mass index), smoking, alcohol consumption, comorbidities (hypertension, diabetes, hypertriglyceridemia, hyperuricemia, and cardiovascular diseases), preoperative tumor conditions (tumor diameter, multiple foci, location, hemorrhage, necrosis, cystic changes, and endophytic growth), preoperative glomerular filtration rate and intraoperative factors (renal collecting system damage, ischemia time, operation time, surgical approach, and estimated intraoperative blood loss) to identify the risk factors for ipsilateral upper urinary tract stones following partial nephrectomy in our center. RESULTS: The overall incidence of upper urinary tract stones following partial nephrectomy was 7.80% (112/1435). The incidence of ipsilateral upper urinary tract stones was significantly higher than those of contralateral stones (4.95% vs 1.46%, P<0.001) and bilateral stones (4.95% vs 1.39%, P<0.001). Intraoperative damage to the renal collecting system was identified as a significant risk factor for ipsilateral upper urinary tract stones (OR=4.550, 95% CI: 2.237-9.252, P<0.001). Diabetes was a probable risk factor for secondary ipsilateral upper urinary tract stones after partial nephrectomy (OR=2.419, 95% CI: 0.973-6.012, P=0.057). CONCLUSIONS The incidence of ipsilateral upper urinary tract stones after partial nephrectomy is higher than that of contralateral and bilateral stones. Intraoperative renal collecting system damage is a risk factor for secondary ipsilateral upper urinary tract stones after partial nephrectomy.
Humans ; Nephrectomy/methods* ; Retrospective Studies ; Risk Factors ; Male ; Female ; Case-Control Studies ; Middle Aged ; Aged ; Kidney Neoplasms/surgery* ; Adult ; Intraoperative Complications ; Kidney Tubules, Collecting/injuries* ; Propensity Score ; Incidence ; Kidney Calculi/etiology* ; Urinary Calculi/epidemiology*

OBJECTIVES: To investigate the causal relationship between gut microbiota and kidney stones. METHODS: Mendelian randomization analysis was conducted based on data from the MiBioGen consortium gut microbiota GWAS (exposure factors) and the IEU Open GWAS kidney stone dataset ukb-b-8297 (outcome variables) using the inverse variance weighted, MR-Egger regression, weighted median, weighted mode, and simple mode methods. Heterogeneity, pleiotropy, and leave-one-out sensitivity analyses were also performed. In the animal experiment, 12 male SD rats were randomized into control group with saline treatment and kidney stone model group treated with 1% ethylene glycol and 2% ammonium chloride for 28 consecutive days. Urine, blood, and intestinal samples of the rats were collected for testing the changes in renal function and intestinal barrier-related indicators, and kidney and colon pathologies were examined with histological staining and immunohistochemistry. The changes in diversity and abundance of gut microbiota were analyzed using 16S rRNA gene sequencing. RESULTS: Mendelian randomization analysis showed that decreased abundances of Lachnospiraceae NK4A136 group (OR=0.9974, 95% CI: 0.9948-0.9999, P=0.0393) and Gordonibacter (OR=0.9987, 95% CI: 0.9974-0.9999, P=0.0403) were associated with an increased risk of kidney stones without significant heterogeneity or horizontal pleiotropy, and sensitivity analyses suggested robustness of the results. The rat models of kidney stones exhibited significant renal function impairment and calcium oxalate crystal deposition, accompanied by decreased expressions of intestinal barrier-related proteins with lowered intestinal α- and β-diversity indices. Intestinal Gordonibacter abundance was significantly reduced in the rat models while the Lachnospiraceae NK4A136 group did not differ significantly between the control and model groups. CONCLUSIONS Decreased Gordonibacter abundance in gut microbiota is associated with an increased risk of kidney stones. The protective role of the Lachnospiraceae NK4A136 group against kidney stones as suggested by Mendelian randomization analysis fails to be supported by the experimental evidence and awaits further investigation.
Animals ; Kidney Calculi/microbiology* ; Gastrointestinal Microbiome ; Mendelian Randomization Analysis ; Rats, Sprague-Dawley ; Rats ; Male ; Disease Models, Animal ; Intestines/microbiology* ; RNA, Ribosomal, 16S/genetics*

Kidney stones are a urinary system disease with a high incidence,among which calcium oxalate stones are the most common.Metabolic disorders such as hypertension,diabetes,obesity,hyperlipidemia,and hyperuricemia can cause changes in oxalate,uric acid,and pH and calcium ion concentrations in the urine through multiple pathways including inducing oxidative stress and inflammatory responses by generating reactive oxygen species,ultimately affecting the formation of calcium oxalate stones.This article reviews the possible pathways and mechanisms by which metabolic diseases influence the formation of calcium oxalate stones,providing new ideas for the clinical prevention and treatment of calcium oxalate stones.
Humans ; Calcium Oxalate/metabolism* ; Kidney Calculi/etiology* ; Metabolic Diseases/complications*

This paper discusses the diagnostic and therapeutic approach to a patient with concomittant serious clinical conditions such as bilateral nephrolithiasis, and possible dual primary malignancies of the kidney and the urinary bladder.

A 62-year-old male presented with gross hematuria. Radiographic imaging revealed a large urinary bladder mass, bilateral hydronephrosis due to obstructive nephrolithiases, and a left solid renal mass. After appropriate cardiopulmonary optimization, the authors opted to do a preliminary transurethral resection of the bladder tumor. This was followed by staged therapies with right ultrasound-guided PCNL; a left partial nephrectomy with nephrolithotomy, and radical cystectomy with ileal conduit. Unfortunately, the patient did not survive the multiple surgeries and expired. The chronology of the various therapeutic procedures in cases of synchronous serious clinical conditions of the urinary tract such as nephrolithiasis, renal and bladder neoplasms need to be individualized and will dictate the outcome of the entire therapy.

Currently, the types of kidney stones before surgery are mainly identified by human beings, which directly leads to the problems of low classification accuracy and inconsistent diagnostic results due to the reliance on human knowledge. To address this issue, this paper proposes a framework for identifying types of kidney stones based on the combination of radiomics and deep learning, aiming to achieve automated preoperative classification of kidney stones with high accuracy. Firstly, radiomics methods are employed to extract radiomics features released from the shallow layers of a three-dimensional (3D) convolutional neural network, which are then fused with the deep features of the convolutional neural network. Subsequently, the fused features are subjected to regularization, least absolute shrinkage and selection operator (LASSO) processing. Finally, a light gradient boosting machine (LightGBM) is utilized for the identification of infectious and non-infectious kidney stones. The experimental results indicate that the proposed framework achieves an accuracy rate of 84.5% for preoperative identification of kidney stone types. This framework can effectively distinguish between infectious and non-infectious kidney stones, providing valuable assistance in the formulation of preoperative treatment plans and the rehabilitation of patients after surgery.
Humans ; Kidney Calculi/classification* ; Deep Learning ; Neural Networks, Computer ; Tomography, X-Ray Computed ; Imaging, Three-Dimensional ; Radiomics

OBJECTIVES

To describe the demographics of patients undergoing supine PCNL (s-PCNL) and prone PCNL (p-PCNL) at Veterans Memorial Medical Center (VMMC) and to compare different data collected between the two approaches.

Retrospective data collection was done through chart review of patients who underwent supine and prone PCNL at VMMC from 2018 to 2022. Information collected includes patient demographics, clinical profile, stone burden and laterality, surgical technique, hospital days, complications and management.

A total of 176 cases, 132 s-PCNL and 44 p-PCNL, were included. Demographic data show no statistical difference as to age and sex. There is no statistical difference in the stone burden, stone density, and Guy’s stone scores between the two groups. There was no statistical difference in the mean operative time and stone free rates between the two groups. Mean hospital stay was 6.11 days for s-PCNL and 6.76 for p-PCNL, with significant statistical difference in favor of s-PCNL. Complication rates were 15.2% for supine PCNL and 13.6% for prone PCNL. There was no statistical significant difference in Clavien-Dindo complications between the two groups. There was no mortality reported for both groups.

There is an observed increasing trend in the number of supine PCNL versus prone PCNL from 2018 to 2022. Supine PCNL is as effective and safe as prone PCNL. Supine PCNL appears to be more beneficial in terms of hospital stay in days. However, one limitation of the study its being retrospective and collated data which is the cause of the discrepancy in sample population size between the two groups.

With the improvement of people's living standards,the incidence of nephrolithiasis is increasing year by year.Nephrolithiasis poses a serious threat to the patients due to the unclear etiology,complicated composition of stones,and high recurrence rate after surgery.As the research on the pathogenesis and pathophysiology of nephrolithiasis keeps deepening in recent years,researchers have made achievements in the drug treatment,which has become a hot topic for urologists.This paper reviews the advances in the research on the possible formation mechanism and drug-induced litholysis and prevention for nephrolithiasis,aiming to provide theoretical references for subsequent clinical research.
Humans ; Nephrolithiasis/prevention & control*

Renal calculus is a common disease with complex etiology and high recurrence rate. Recent studies have revealed that gene mutations may lead to metabolic defects which are associated with the formation of renal calculus, and single gene mutation is involved in relative high proportion of renal calculus. Gene mutations cause changes in enzyme function, metabolic pathway, ion transport, and receptor sensitivity, causing defects in oxalic acid metabolism, cystine metabolism, calcium ion metabolism, or purine metabolism, which may lead to the formation of renal calculus. The hereditary conditions associated with renal calculus include primary hyperoxaluria, cystinuria, Dent disease, familial hypomagnesemia with hypercalciuria and nephrocalcinosis, Bartter syndrome, primary distal renal tubular acidosis, infant hypercalcemia, hereditary hypophosphatemic rickets with hypercalciuria, adenine phosphoribosyltransferase deficiency, hypoxanthine-guanine phosphoribosyltransferase deficiency, and hereditary xanthinuria. This article reviews the research progress on renal calculus associated with inborn error of metabolism, to provide reference for early screening, diagnosis, treatment, prevention and recurrence of renal calculus.
Infant ; Humans ; Hypercalciuria/genetics* ; Kidney Calculi/genetics* ; Urolithiasis/genetics* ; Nephrocalcinosis/genetics* ; Metabolism, Inborn Errors/genetics*