Management of staghorn stones in special situations.

Staghorn stones have always been a challenge for urologists, especially in some special situations, such as horseshoe kidney, ectopic kidney, paediatric kidney, and solitary kidney. The treatment of these staghorn stones must be aggressive because they can lead to renal function loss and serious complications. The gold-standard management for staghorn stones is surgical treatment with the aim of clearing the stones and preserving renal function. Treatment methods for staghorn stones have developed rapidly, such as extracorporeal shock wave lithotripsy, retrograde intrarenal surgery, percutaneous nephrolithotomy and laparoscopy and open surgery. Whether the standard procedures for staghorn stones can also apply to these stones in special situations is still not agreed upon. The decision should be made individually according to the circumstances of the patient. In this review, we evaluates the previous studies and comments on the management of staghorn stones under special situations in the hope of guiding the optimal choice for urologists.

Risk factors for sepsis in patients with struvite stones following percutaneous nephrolithotomy.

PURPOSE: To describe the clinical characteristics of struvite stones and determine the preoperative predictors of sepsis in struvite patients undergoing percutaneous nephrolithotomy (PCNL). METHODS: A retrospective study of patients who underwent PCNL between April 2011 and March 2018 was performed. The data of the struvite stones and non-struvite stones groups were compared following propensity score matching. Subsequently, the struvite stones group was sub-divided for further analysis according to the Sepsis-3 definition: non-sepsis and sepsis groups. RESULTS: After matching based on age, gender, BMI, and number of access tracts, the comparative analysis showed that staghorn calculi and higher Guy's stone score were more frequently observed in non-struvite stone patients (n = 97), while a history of urolithiasis surgery (56.70%), preoperative broad-spectrum antibiotic therapy (53.61%), positive preoperative urine culture (55.67%), and sepsis (35.05%) after surgery were more common in patients (n = 97) with struvite stones (all P values < 0.05). Eighteen (18.56%) patients presented with multidrug-resistant (MDR) bacteriuria. Multivariate analysis demonstrated that the preoperative presence of MDR bacteriuria (OR = 3.203; P = 0.043) and increased serum creatinine (OR = 3.963; P = 0.010) were independent risk predictors of sepsis. The two factors were used to construct a nomogram to predict the probability of sepsis. The nomogram was well calibrated and had moderate discriminative ability (concordance index: 0.711). CONCLUSION: Our study revealed that patients with struvite stones were associated with a significantly high risk of calculi recurrence and sepsis after surgery. The presence of MDR bacteriuria preoperatively was a reliable factor to predict sepsis.

Safety of a Novel Thulium Fiber Laser for Lithotripsy: An In Vitro Study on the Thermal Effect and Its Impact Factor.

Introduction: To investigate the thermal effect on the water by a novel thulium fiber laser (TFL) designed for lithotripsy and evaluate the safety of this laser for clinical use. Materials and Methods: An in vitro experimental setup was constructed. A test tube filled with saline was immersed in an electric water bath, and a TFL fiber and a thermal probe were inserted into it. Saline was irrigated into the tube and pumped out synchronously at the same speed by two pumps, respectively, to maintain convection when needed. Then, continuous TFL firing of different power settings was imposed to saline in the tube for 60 seconds, on the conditions of different irrigation rates. The temperature was recorded every 5 seconds during the whole trial, and each trial was repeated five times. Safety threshold of temperature increase (STTI) was determined comparing with the deemed safe temperature of 43°C in vivo. Results: On condition of 0 mL/min irrigation rate, STTI was 6.5°C, and water temperature increase (WTI) caused by ≥15 W settings surpassed STTI after 20 seconds of laser firing; on condition of 15 mL/min irrigation rate, only WTI caused by the highest 30 W power setting surpassed STTI after 45 seconds of laser firing. When irrigation rate was added up to 25 and 50 mL/min, WTIs caused by all power settings were below STTIs in a 60-second experiment. High frequency and low pulse energy combinations caused a slightly higher WTI compared with low frequency and high pulse energy, given a constant power and irrigation rate. Conclusion: Power setting and irrigation rate collaboratively play a critical role in WTI during TFL lithotripsy, and it is safe to use TFL referring to the thermal effect as long as there is moderate irrigation, while TFL power should be lowered enough when irrigation is ceased.

Testosterone induces renal tubular epithelial cell death through the HIF-1α/BNIP3 pathway.

BACKGROUND: The morbidity of nephrolithiasis is 2-3 times higher in males than in females, suggesting that androgen plays a key role in nephrolithiasis. The death of renal tubular epithelial cells (TECs) is an important pathophysiological process contributing to the development of nephrolithiasis. Therefore, the aim of this study is to investigate whether androgen directly induces TECs apoptosis and necrosis and its underlying mechanisms in kidney stone formation. MATERIALS AND METHODS: We compared serum testosterone level between male and female healthy volunteers and kidney stone patients. The in vivo nephrolithiasis model was established using glyoxylic acid, and calcium deposits were detected by van Kossa staining. In the in vitro study using mouse TECs (TCMK-1 cells) and human TECs (HK-2 cells), apoptosis, necrosis, and the expression of BH3-only protein Bcl-2-like 19 kDa-interacting protein 3 (BNIP3) were examined incubated with different doses of testosterone using flow cytometry. Levels of apoptosis-related proteins transfected with the BNIP3 siRNA were examined by western blotting. The mitochondrial potential (ΔΨm) was detected by JC-1 staining and flow cytometry. We monitored BNIP3 expression in the testosterone-induced TECs injury model after treatment with hypoxia inducible factor 1α (HIF-1α) and/or hypoxia inducible factor 2α (HIF-2α) inhibitors to determine the upstream protein regulating BNIP3 expression. Additionally, ChIP and luciferase assays were performed to confirm the interaction between HIF-1α and BNIP3. RESULTS: Both male and female patients have significantly higher testosterones compared with healthy volunteers. More calcium deposits in the medulla were detected in male mice compared to female and castrated male mice. Testosterone induced TECs apoptosis and necrosis and increased BNIP3 expression in a dose-dependent manner. Testosterone also increased Bax expression, decreased Bcl-2 expression and induced a loss of ΔΨm. This effect was reversed by BNIP3 knockdown. HIF-1α inhibition significantly decreased BNIP3 expression and protected TECs from testosterone-induced apoptosis and necrosis. HIF-2α inhibition, however, did not influence BNIP3 expression or TECs apoptosis or necrosis. Finally, HIF-1α interacted with the BNIP3 promoter region. CONCLUSION: Based on these results, testosterone induced renal TECs death by activating the HIF-1α/BNIP3 pathway.

Endoscopic Balloon Dilatation in the Treatment of Benign Ureteral Strictures: A Meta-Analysis and Systematic Review.

BACKGROUND AND PURPOSE: Although balloon dilatation is one of the main endoscopic procedures used to treat benign ureteral strictures, its precise efficacy remains controversial. We aimed to identify, combine, and analyze existing published data to ascertain the efficacy of endoscopic balloon dilatation for benign ureteral strictures. METHODS: In December 2018, a literature search was performed using Medline, Embase, and Web of Science databases. We included reports in which the study population consisted of patients who underwent endoscopic balloon dilatation for the treatment of benign ureteral strictures. Technical, short-term, and long-term success rates (expressed as mean ± standard error) were adopted as the outcome measures. RESULTS: Using our search strategy, a total of 19 studies (all series reports) were included for analysis. Using a random-effects model, the pooled technical success rate of endoscopic balloon dilatation for benign ureteral strictures was found to be 89% ± 4%. Furthermore, the short-term success rate (i.e., 3 months after surgery) was 60% ± 10%, and the long-term success rate (i.e., 6-12 months after surgery) was 54% ± 14%. In the subgroup analysis, the success rate of endoscopic balloon dilatation for ≤2-cm benign ureteral strictures was significantly higher than that for >2-cm ones (odds ratio [OR]: 0.13; 95% confidence interval [CI]: 0.05-0.35). In addition, the success rate in cases with strictures of onset timing ≤3 months was relatively higher than that in cases with strictures of onset timing >3 months (OR: 0.46; 95% CI: 0.15-1.43). CONCLUSION: Our study indicates that endoscopic balloon dilatation has a high success rate in the treatment of benign ureteral strictures with length ≤2 cm and onset timing ≤3 months. However, there is still no consensus on balloon type, dilatation pressure, expansion number, postoperative ureteral stent type, and stent retention time for the balloon dilatation technique.

Novel laser positioning navigation to aid puncture during percutaneous nephrolithotomy: a preliminary report.

PURPOSE: Accurate puncture of the renal collecting system is crucial to the success of percutaneous nephrolithotomy and presents a technical challenge for urologists. Here, we introduced the Surgical Approach Visualization and Navigation (SAVN) system, a novel navigation system to assist puncture and reduce intraoperative radiation. MATERIALS AND METHODS: Twenty kidneys of 10 cadavers were randomly divided into two groups for renal calyx puncture. In the control group, traditional fluoroscopy was used for guidance, while SAVN system was used in the experimental group. Puncture duration, number of puncture attempts, total number of intraoperative fluoroscopies, and number of fluoroscopies during the puncture procedure were recorded. RESULTS: The puncture duration was 14.2 ± 2.5 s in SAVN group and 48.3 ± 7.1 s in conventional group (P < 0.05). One puncture attempt was needed for successful puncture in SAVN group, while more than one in conventional group (P = 0.28). The total number of intraoperative fluoroscopies was 3.3 ± 1.0 in SAVN group and 14.5 ± 3.1 in control group (P < 0.05),while the number of fluoroscopies during the puncture procedure was 0 and 11.2 ± 2.4, respectively (P < 0.05). CONCLUSIONS: The novel SAVN system has a simplified structure and is easy to use. It can be used to successfully assist with puncture of the renal calyx, thus reducing puncture duration and radiation dose.

Renal function changes after percutaneous nephrolithotomy in patients with renal calculi with a solitary kidney compared to bilateral kidneys.

OBJECTIVE: To evaluate renal function changes and risk factors for acute kidney injury (AKI) after percutaneous nephrolithotomy (PCNL) in patients with renal calculi with a solitary kidney (SK) or normal bilateral kidneys (BKs). PATIENTS AND METHODS: Between 2012 and 2016, 859 patients undergoing PCNL were retrospectively reviewed at Changhai Hospital. In all, 53 patients with a SK were paired with 53 patients with normal BKs via a propensity score-matched analysis. Data for the following variables were collected: age, sex, body mass index, stone size, distribution, operation time, perioperative outcomes, and complications. The complications were graded according to the modified Clavien-Dindo system. Univariable and multivariable logistic regression models were constructed to evaluate risk factors for predicting AKI. RESULTS: The SK and BKs groups were comparable in terms of age, sex ratio, stone size, stone location distribution, comorbidities, and American Society of Anesthesiologists Physical Status classification. The initial and final stone-free rates were comparable between the SK and BKs groups (initial: 52.83% vs 58.49%, P = 0.696; final: 84.91% vs 92.45%, P = 0.359). There was no difference between the two groups for complications, according to the Clavien-Dindo grades. The estimated glomerular filtration rate (eGFR) increased dramatically after the stone burden was immediately relieved, and during the 6-month follow-up eGFR was lower in the SK group compared with the BKs group. We found a modest improvement in renal function immediately after PCNL in the BKs group, and renal function gain was delayed in the SK group. Through logistic regression analysis, we discovered that a SK, preoperative creatinine and diabetes were independent risk factors for predicting AKI after PCNL. CONCLUSION: Considering the overall complication rates, PCNL is generally a safe procedure for treating renal calculi amongst patients with a SK or normal BKs. Follow-up renal function analysis showed a modest improvement in patients of both groups. Compared to patients with normal BKs, patients with a SK were more likely to develop AKI after PCNL.

C-reactive protein as a prognostic marker in chronic obstructive pulmonary disease.

The present study aimed to evaluate whether circulating C-reactive protein (CRP) levels are a biomarker of systemic inflammation and a significant predictor of future chronic obstructive pulmonary disease (COPD) outcome. During the study, 116 patients with stable COPD and 35 age- and gender-matched healthy subjects with normal pulmonary function were observed. Patient follow-up was also performed to evaluate the strength of the associations between CRP levels and future outcomes. The observations from the present study showed that serum CRP levels were significantly higher in stable COPD patients than in control subjects (4.48±0.83 vs. 1.01±0.27 mg/l, respectively; P<0.05). In addition, it was identified that a serum CRP concentration of >3 mg/l is a poor prognostic variable of COPD compared with a CRP concentration of ≤3 mg/l [hazard ratio (HR), 2.71; 95% confidence interval (CI), 1.05-6.99; P<0.05]. A quantitative synthesis of four studies including 1,750 COPD patients was performed and statistically similar results were obtained (HR, 1.54; 95% CI, 1.14-2.07; P<0.01). The present study showed that circulating CRP levels are higher in stable COPD patients and, therefore, may be used as a long-term predictor of future outcomes. These observations highlight the importance of high sensitivity CRP assays in patients with stable COPD.