Long-Term Sodium Deficiency Reduces Sodium Excretion but Impairs Renal Function and Increases Stone Formation in Hyperoxaluric Calcium Oxalate Rats.

Excessive sodium intake is associated with nephrolithiasis, but the impact of sodium-deficient (SD) diets is unknown. Hence, we investigated the effects of short- and long-term SD diets on the expression of renal aquaporins and sodium transporters, and thus calcium oxalate (CaOx) crystal formation in hyperoxaluria rats. In a short-term sodium balance study, six male rats received drinking water and six received 0.75% ethylene glycol (EG) to induce hyperoxaluria. After a 30-day period of feeding on normal chow, both groups were treated with a normal-sodium diet for 5 days, followed by a sodium-free diet for the next 5 days. In a long-term SD study (42 days), four groups, induced with EG or not, were treated with normal-sodium water and sodium-free drinking water, alternately. Short-term sodium restriction in EG rats reversed the daily positive sodium balance, but progressively caused a negative cumulative water balance. In the long-term study, the abundant levels of of Na/H exchanger, thiazide-sensitive Na-Cl cotransporter, Na-K-ATPase, and aquaporins-1 from SD + EG rats were markedly reduced, corresponding to a decrease in Uosm, as compared to SD rats. Increased urine calcium, AP(CaOx)index, and renal CaOx deposition were also noted in SD + EG rats. Although the SD treatment reduced sodium excretion, it also increased urinary calcium and impaired renal function, ultimately causing the formation of more CaOx crystals.

Increased risk of chronic kidney disease in uric acid stone formers with high neutrophil-to-lymphocyte ratio.

Urolithiasis is associated with an increased risk of chronic kidney disease (CKD), irrespective of stone compositions. Chronic inflammation is an important factor for CKD progression. Neutrophil-to-lymphocyte ratio (NLR) has been recognized as a reliable biomarker of inflammation, yet its use in predicting renal deterioration in patients with urolithiasis remains limited. We aimed to explore whether the combination of stone composition and NLR could be useful as a predictor for CKD risk. A total of 336 stone formers with at least one stone submission for analysis were enrolled in the retrospective study. Stones were classified into uric acid and calcium groups. Renal functions were assessed at least one month after stone treatment. Uric acid stone formers had significantly lower estimated glomerular filtration rate (eGFR) compared with calcium stone formers (p < 0.001). NLR was significantly higher in uric acid stone formers (p = 0.005), and a significantly negative correlation (p < 0.001) between NLR and eGFR had been observed only in uric acid stone group. Univariate and multivariate logistic regression analyses showed that higher proportion of uric acid stone composition and higher NLR were both significantly associated with CKD risks. A nomogram integrating independent predictors was generated for CKD prediction, yielding an AUC of 0.811 (0.764-0.858). In conclusion, our study demonstrated that stone formers with higher proportion of uric acid composition and higher NLR levels were associated with higher CKD risk.

The Mayo adhesive probability score predicts postoperative fever and intraoperative hemorrhage in mini-percutaneous nephrolithotomy.

PURPOSE: Contemporary predictive tools for miniaturized percutaneous nephrolithotomy (mPCNL) mainly focus on stone clearance but not perioperative complications, especially infection and hemorrhage. This study aimed to evaluate whether the Mayo adhesive probability (MAP) score, an index of the perinephric fat characteristics, can predict postoperative fever and intraoperative hemorrhage in mPCNL. METHODS: This is a retrospective study recruiting 159 mPCNL patients from July 2018 to January 2022. MAP scores were recorded using preoperative computed tomography. Postoperative complications included postoperative fever and intraoperative bleeding, defined as hemoglobin drop. RESULTS: Over half patients had the MAP score ≧ 3. Men, elderly, chronic kidney disease, and diabetes were associated with a higher MAP score. The patients with a higher MAP score were more likely to have postoperative fever after mPCNL. On multivariate analysis, preoperative positive urine culture (OR 2.68) and a higher MAP score (OR 2.28) were both significantly associated with postoperative fever. ROC curves analysis of the combination of these two factors on predicting postoperative fever showed AUC values were 0.731 (0.652-0.810). Moreover, a higher MAP score (OR 2.30) and longer operative time (OR 2.16) were significantly associated with higher hemoglobin drop on multivariate analysis. CONCLUSION: A high MAP score was associated with postoperative fever and intraoperative hemorrhage in patients undergoing mPCNL. The MAP score can be a novel and easy predictive tool to help endourologists improve the awareness of mPCNL safety.

Nephrolithiasis is associated with the severity of coronary artery calcification, but not with coronary artery stenosis.

PURPOSE: Emerging data have indicated that nephrolithiasis is possibly associated with subclinical coronary artery disease (CAD). Considering that a significant proportion of obstructive CAD in non-elderly individuals occurs in those without detectable calcium score (CACS), this study aimed to investigate whether nephrolithiasis is still associated with CAD as assessed by coronary computed tomography (CT)-derived luminal stenosis [using Gensini score (GS)]. METHODS: A total of 1170 asymptomatic adults without known CAD who underwent health examinations were recruited. Nephrolithiasis was assessed using abdominal ultrasonography (US). Individuals with a self-reported stone history, but no evidence of nephrolithiasis were excluded. The CACS and GS were measured using 256-slice coronary CT. RESULTS: Nearly half of these patients had a CACS > 0 (48.1%), and a higher prevalence of nephrolithiasis was observed than in those who had zero CACS (13.1% vs. 9.7%). However, no significant intergroup difference in GS was detected. A greater proportion of stone formers than non-stone formers had a higher risk category, whereas no significant difference was noted in Gensini category. Multiple linear regression analyses showed that the CACS independently predicted the presence of nephrolithiasis after adjustment. Importantly, we found that stone formers had a nearly threefold higher risk than non-stone formers of developing severe coronary calcification (CAC > 400). CONCLUSIONS: Nephrolithiasis was significantly associated with coronary artery calcification presence and severity, but not coronary luminal stenosis in patients without known CAD. Accordingly, the relationship between stone disease and CAD remains controversial, and additional studies are imperative to validate these findings.

Gross hematuria as the presentation of ureteral paraganglioma: a case report and literature review.

BACKGROUND: Paraganglioma of genitourinary tract is uncommon, and origin from ureter is even rarer. We aim to present a case of paraganglioma from ureter in a 48-year-old female patient, who presented with gross hematuria. CASE PRESENTATION: We present a 48-year-old female who complained of gross hematuria for one week. A left ureteral tumor was found by image study. However, hypertension was unexpectedly recorded during diagnostic ureteroscopy survey. Due to persisted gross hematuria and bladder tamponade, she underwent left nephroureterectomy with bladder cuff resection. Blood pressure surged again when the tumor was surgically approached. Ureteral paraganglioma was confirmed according to pathological report. After the surgery, the patient recovered well, and no more gross hematuria was noted. She is now under regular follow-up at our outpatient clinic. CONCLUSION: Ureteral paraganglioma should be kept in mind not only when blood pressure fluctuates during operation, but also before we manipulate the ureteral tumor when gross hematuria is the only sign. Whenever the presumption of paraganglioma is raised, laboratory evaluation and anatomical or even functional imaging should be considered. The concomitant anesthesia consultation before the surgery should not be deferred, either.

Use of Urine N-Terminal Prohormone of Brain-Natriuretic Peptide (NT-proBNP) as a Non-Invasive Indicator for Renal Function Recovery after Surgical Relief of Hydronephrosis.

Cardiorenal syndrome is rarely discussed in patients with obstructive uropathy. On the other hand, there is currently no accurate and convenient clinical biomarker to predict the recovery of renal function after the resolution of ureteral obstruction. The purpose of this study is to explore the association between hydronephrosis and cardiorenal syndrome by measuring the change of the N-terminal prohormone of brain-natriuretic peptide (NT-proBNP), which is a biomarker typically used for cardiac failure, in patients receiving surgery to relieve obstructive uropathy. A total of 212 patients admitted for ureteroscopic (URS) procedures to relieve hydronephrosis were enrolled in this study. The severity of hydronephrosis as well as plasma and urine NT-proBNP levels were obtained before and after surgery. The results showed a significant correlation between urine NT-proBNP levels and renal function recovery following the resolution of hydronephrosis (OR 3.24, 95% CI 1.09−9.70, p = 0.035). Urine NT-proBNP could even predict the recovery of renal function with an area under the ROC = 0.775 (0.65−0.88, p < 0.001). In conclusion, urine NT-proBNP could be a useful early marker of renal function recovery after URS surgery, identifying patients whose renal and heart functions were compromised by the obstruction.

Ureterorenoscopic (URS) Lithotripsy and Balloon Dilation Cause Acute Kidney Injury and Distal Renal Tubule Damage: A Prospective Study.

Ureterorenoscopy (URS) is believed to be a safe and effective procedure for treating ureteral stones or ureteral strictures. Rapidly increasing intrarenal pressure during URS may have a negative impact on the kidney, but its effect on renal function is not well known. The aim of this study was to evaluate whether URS balloon dilation or lithotripsy could cause acute kidney injury (AKI), which was evaluated using urine neutrophil gelatinase-associated lipocalin (NGAL), and renal tubular damage, which was evaluated using urine α-glutathione S-transferase (GST) and πGST. This prospective study included 207 patients with a mean age of 53.8 years between September 2012 and June 2013. Four groups were included: the ureteral stricture group (group 1), the ureteral stone group (group 2), and two control groups. URS increased urine NGAL (uNGAL) levels on days 1 and 14 in both groups, and only elevated uGST levels were noted on day 14 after URS lithotripsy (URS). On day 14, the difference between low-grade and high-grade hydronephrosis was significant in group 1 (p < 0.001) compared to that in group 2 (p = 0.150). Multivariate logistic regression analysis revealed that age, baseline estimated glomerular filtration rate (eGFR), and stone size > 1.0 cm were associated with the complete recovery of hydronephrosis after URS on day 14. Patients with ureteral stones with preserved renal function had more AKI than those with impaired renal function. However, there was no significant difference in URS-related AKI between the ≤1 cm and >1 cm subgroups. In addition, urine αGST and πGST levels were both significantly higher in the stone > 1 cm subgroup than in the ≤1 cm subgroup. In conclusion, URS laser lithotripsy and balloon dilatation resulted in AKI and renal tubular damage on day 14, although post-URS double-J (DBJ) stenting was performed in every patient.

Preoperative Urine Analysis is An Effective Tool to Predict Fever After Miniaturized Percutaneous Nephrolithotomy on Large Renal Stones.

PURPOSE: To investigate the preoperative and intraoperative potential risk factors associated with miniaturized percutaneous nephrolithotomy (mPCNL) fever in the treatment of patients with large renal stones. MATERIALS AND METHODS: All patients with renal stones larger than 2.5 cm, who had undergone mPCNL, were included in the period between April 2018 and September 2019. Logistic regression analyses were performed to identify clinical variables associated with post-operative fever (>38°C). RESULTS: A total of 53 patients were enrolled for whom the median maximal stone length was 3.08 cm. 24 (45%) patients had a fever after mPCNL. Significantly more patients with urine WBC ≥ 27(/HPF) had a fever after surgery (p = 0.004). No significant between-group differences in urine cultures were found for the fever and non-fever groups (p = 0.094). Stepwise and multivariable logistic regression analyses all revealed that urine WBC ≥ 27(/HPF) is the only risk factor for developing post-mPCNL fever. Based on the highest body temperature, all of the patients were assigned into no fever, mild fever (37.5 ≤ Temp < 38.0), and fever groups, and an ordinal logistic regression analysis still supported the premise that the result of urine analysis is strongly associated with post-mPCNL fever. CONCLUSION: Large renal stones are challenging to treat and associated with severe complications. Approximately 45% of large renal stone patients treated via mPCNL developed a fever. Urine WBC can easily and directly predict the risk of fever.