The contemporary management of renal and ureteric calculi

Klotho alleviates oxidative stress and mitochondrial dysfunction through the Nrf2/HO-1 pathway, thereby reducing renal senescence induced by calcium oxalate crystals

Klotho is an antiaging protein that is primarily secreted by the kidneys. This study aimed to explore the protective effects of Klotho against calcium oxalate (CaOx) crystal-induced renal aging and the underlying mechanisms involved. We established a mouse model of CaOx crystal deposition via the intraperitoneal injection of glyoxylate (Gly) and constructed an in vitro model by stimulating HK2 cells with calcium oxalate monohydrate (COM). Renal aging levels were assessed through β-galactosidase (SA-β-gal) staining and the detection of senescence-associated markers. By overexpressing Klotho both in vitro and in vivo, we examined oxidative stress, mitochondrial function, and renal aging levels. We then evaluated the role of Nrf2/HO-1 signalling pathway-mediated oxidative stress in CaOx crystal-induced renal aging by applying the oxidative stress scavenger N-acetylcysteine (NAC) and overexpressing or inhibiting Nrf2 in HK2 cells. We subsequently overexpressed Klotho while inhibiting Nrf2 to confirm that Klotho exerts its protective effects through the Nrf2/HO-1 pathway. Finally, we measured the methylation levels of the Klotho promoter and assessed the degree of renal aging induced by CaOx crystals after the inhibition of Klotho DNA methylation. We found that the overexpression of Klotho alleviated CaOx crystal-induced oxidative stress and mitochondrial dysfunction, thereby reducing renal aging. NAC mitigated CaOx crystal-induced renal aging. The overexpression of Nrf2 alleviated CaOx crystal-induced oxidative stress and mitochondrial dysfunction, thus reducing renal aging, whereas the knockdown of Nrf2 exacerbated CaOx crystal-induced oxidative stress and mitochondrial dysfunction, leading to more severe renal aging. The combination of Klotho overexpression and Nrf2 knockdown reversed the protective effects of Klotho. CaOx crystals induced an increase in the DNA methylation levels of Klotho in the kidneys, and the inhibition of DNA methylation alleviated CaOx-induced renal aging. This study revealed that Klotho plays a crucial role in calcium oxalate crystal-induced kidney senescence by influencing kidney oxidative stress and mitochondrial function through the Nrf2/HO-1 pathway.

Efficacy and intrarenal pressure analysis of flexible and navigable suction ureteral access sheaths with flexible ureteroscopy in modified surgical positions for 2-6 cm upper urinary tract stones: a multicenter retrospective study

This multicenter retrospective study aimed to assess the efficacy, intrarenal pressure (IRP), and complications of retrograde intrarenal surgery (RIRS) using a flexible and navigable suction ureteral access sheaths (FANS-UAS) in the reverse Trendelenburg lithotomy position (RTLP) for treating kidney and upper ureteral stones measuring 2-6 cm. Conducted at six medical centers in Fujian Province from 2022 to 2024, the study included 231 patients with a median stone size of 26 mm. The immediate stone-free rate (ISFR) was 90.48%, while the SFR at postoperative day 30 was 95.67%. Only two patients developed postoperative fever, two patients had ureteral laceration and most experienced mild pain. Although surgical time increased with stone size, factors such as sex, infundibulopelvic angle (IPA), and stone density had little effect on duration, and there was no significant difference between ISFR and 30-day SFR. Importantly, all IRP measurements remained within normal limits. These findings suggest that RIRS with FANS-UAS in RTLP is a safe and effective approach for managing upper urinary tract stones of 2-6 cm, especially in 2-4 cm stones.

Feasibility of Performing Supine Percutaneous Nephrolithotomy for Solitary Renal Pelvic Stones (1.5-3 cm) Under Spinal Anaesthesia: A Single-Centre Study

Introduction Percutaneous nephrolithotomy (PCNL) procedure has evolved over the years and one such evolution has been the introduction of supine PCNL by Valdivia in 1987. This approach offers the added advantage of safe access in patients with compromised cardiovascular and pulmonary function. General anesthesia is the preferred anesthetic technique for PCNL. However, in the last decade, there has been an increase in the usage of regional anesthesia for this procedure. We share our experience of supine PCNL for solitary renal pelvic stones under regional anesthesia. Aim and objective To assess the feasibility, safety, and efficacy of supine PCNL for solitary renal pelvic stones sized 1.5 to 3 cm under spinal anesthesia. Material and methods This was a retrospective record review of 35 patients (21 male) who underwent supine PCNL under regional anesthesia between January 2022 till December 2022 at our institute. All patients had a solitary renal pelvic calculus sized 1.5-3 cm. Intraoperative and postoperative data were analyzed. Results The mean age of patients was 38.5 ± 15 years. The postoperative pain visual analog scale (VAS) score was <5 in 31 (89%) and >5 in 4 (11%) patients. The mean hospital stay was 3.33 ± 0.88 days. Mean fall in hemoglobin level was 0.49 ± 0.43 mg/dL. Postoperatively, mild hematuria occurred in three patients (8.5%) and fever occurred in two (5.7%) patients. There was no injury to adjacent organs in this series. Blood transfusion was required only in one patient. Complete stone clearance was achieved in all patients. Conclusion In experienced hands, supine PCNL under regional anesthesia is a feasible, safe, and effective approach with minimal morbidity.

Effects of stone density on alteration in renal resistive index after extracorporeal shock wave lithotripsy for non-obstructed kidney stones

Aim The doppler-based renal resistive index is a recently proposed technique for measuring changes in renal perfusion and predicting acute kidney damage. The purpose of this study was to look at the influence of stone density on the renal resistive index (RI) after extracorporeal shock wave lithotripsy (ESWL) in patients with non-obstructed kidney stones. Material and Method Between May 2020 and July 2021, 48 consecutive patients with unilateral renal calculi of  20 mm were treated with ESWL monotherapy. The patients' non-contrast computed tomography (NCCT) images were processed and grouped into two groups using Hounsfield units (HU) (Group 1, n=27,  1000 HU; Group 2, n=21,  1000 HU). The same radiologist performed Doppler ultrasonography on all cases before, one hour, and one week following ESWL. Measurement of the RI taken in the remote region (at least 20 mm from the stones). Patient age, gender, BMI, stone laterality, stone size, and stone position were investigated as potential predictors. Results The average stone size for Group 1 was 11.7 ± 3.3 mm and 12.1 ± 2.8 mm for Group 2. The mean RI values before ESWL for Group 1 and Group 2 were 0.54 and 0.53, respectively. On comparing the pre-treatment data with the 1 hour after SWL, a statistically significant increase was recorded in the RI value for both groups. However, there was no significant difference in RI values between groups 1 and 2 1 hour and 1 week following lithotripsy therapy. After one week, the mean RI returned to pretreatment levels, according to a follow-up doppler investigation. There was no association between stone density and RI (p > 0.05). Conclusion Stone density is a significant independent predictor of ESWL outcome; however, high stone densities detected with NCCT were not associated with a significant change in RI. Post-ESWL therapy alterations are present and reversible one week after the treatment.

Comparison of outcomes between flexible ureteroscopy and mini-percutaneous nephrolithotomy in the management of upper calyceal calculi larger than 2 cm

Objective

To compare the outcomes of FURSL and m-PNL in the management of upper calyceal calculi larger than 2 cm.

Methods

A total of 75 patients with upper calyceal calculi larger than 2 cm that were treated by FURSL (n = 37) or mini-PNL (n = 38) were retrospectively analysed. The mean age, sex, stone burden, operative time, complications, length of hospitalization, and stone-free rate (SFR) were compared between the groups. The success of the procedure was defined by the absence of residual stones or residual fragments smaller than 4 mm on computed tomography at 4 weeks postoperatively.

Results

The two groups had comparable preoperative parameters. The mean operative time was significantly longer in the mini-PNL group than in the FURSL group (87.8 vs. 69.8 min, p < 0.001). The length of hospitalization was greater in the mini-PNL group than in the FURSL group (2.5 vs. 1.3 days, p < 0.001). Although the perioperative complication rate was higher in the mini-PNL group (23.7%) than in the FURSL group (13.5%), this difference was not statistically significant (p = 0.258). The SFR for the mini-PNL group was 89.5%, and that of the FURSL group was 81.1%; the difference was not significantly different (p = 0.304).

Conclusions

Both FURSL and mini-PNL are effective and safe for the management of upper calyceal calculi larger than 2 cm. Of these two procedures, mini-PNL is less time consuming, FURSL is associated with faster recovery. FURSL can be considered a good alternative treatment in selected patients.

The learning curve for retrograde intrarenal surgery: A prospective analysis

INTRODUCTION

retrograde intrarenal surgery (CRIR) is an evolving tool. Its learning curve is not well established, despite the common use of flexible ureteroscopes today. Our aim is to estimate the number of procedures needed for one to perform RIRS consistently.

MATERIAL AND METHODS

a urology resident had his first 80 RIRS for nephrolithiasis analyzed quantitatively and qualitatively. The procedures were divided into 4 groups containing 20 surgeries each (I to IV), according to their order, for comparison.

RESULTS

there was no difference in stone sizes between groups. All qualitative variables varied significantly between groups (p<0.001), except between III and IV. In the quantitative analysis, there was a difference between groups I and IV in time for double-J catheter placement (p=0.012). There was an increasing difference in sheath placement time (p<0.001) and in total operative time (p=0.004). The time fot stone treatment (p=0.011) was significant only between groups I, II and III. There was difference in total sheath time only between groups I and III (p=0.023). Stone free status did not change between groups.

DISCUSSION

the differences between the qualitative and quantitative variables show the relation between number of surgeries performed and proficiency in the procedure. Intergroup comparisons show sequential optimization of parameters.

CONCLUSIONS

we found that 60 is a reasonable number of surgeries to be performed in order to reach the plateau of RIRSs learning curve.

Bilateral same-session flexible ureteroscopy for renal stones: a feasible method

A staged ureteroscopic procedure is generally preferred to treat bilateral renal stones. In this study, we evaluated the feasibility of bilateral same-session flexible ureteroscopy (BS-fURS) in renal stones. A total of 81 patients underwent bilateral BS-fURS between March 2014 and March 2021 for bilateral renal stones. The mean stone burden per patient was 17±4 (range 7-27 mm). The average stone density was 1240 HU (970 to 1510). We used 4 types of ureteroscopes: Olympus URF-V2 (34 cases), Storz Flex X2 (30 cases), single-use PUSEN PU 3022 (12 cases), and single-use PUSEN - PU 3033A (5 cases). We specifically set our Holmium laser for dusting, pop-corning, and fragmenting. We found 31 calcium oxalate monohydrate cases, 11 calcium oxalate dehydrate cases, 17 uric acid cases, and 22 magnesium ammonium phosphate cases. The mean operating time was 77 min. (range 52 to 85) for both renal units. The SFRs were evaluated between 1 and 3 months with computed tomography (fragments >3 mm were defined as residual). Double J stenting (6Fr.) was applied bilaterally in 8 cases (9.87%) and unilateral in 34 cases (41.97%). The overall SFRs after 1 and 2 procedures were 81.48% (66/81 cases) and 92.59% (75/81 cases), respectively. Postoperative complications after an overall 96 procedures were Clavien I-II (18.75%) and Clavien III (3.12%). Urinary tract infections were observed in 13 cases (16.04%) without any case of urosepsis. Our experience suggested some BS-fURS advantages as a single anesthetic session and potentially reduced cost associated with treatment. BS-fURS seem feasible, especially for medium-sized bilateral renal stones in high-volume centers.

A curva de aprendizado em cirurgia retrógrada intrarrenal: Uma análise prospectiva

RESUMO Introdução: a cirurgia retrógrada intrarrenal (CRIR) é ferramenta em evolução. Sua curva de aprendizado não está bem estabelecida, apesar do uso comum dos ureteroscópios flexíveis atualmente. O objetivo é estimar o número de procedimentos necessários para se realizar CRIR consistentemente. Material e Métodos: Um residente de urologia teve suas primeiras 80 CRIR para tratamento de nefrolitíase analisadas quantitativa e qualitativamente. Os procedimentos foram divididos em 4 grupos contendo 20 cirurgias cada (I a IV), de acordo com sua ordem, para comparação. Resultados: Não houve diferença nos tamanhos dos cálculos entre grupos. Todas as variáveis qualitativas apresentaram variação significativa entre os grupos (p<0,001), exceto entre III e IV. Na análise quantitativa houve diferença entre os grupos I e IV no tempo de colocação do cateter duplo J (p=0,012). Houve uma diferença crescente no tempo de colocação da bainha (p<0,001) e no tempo operatório total (p=0,004). O tempo para o tratamento do cálculo (p=0,011) foi significativo apenas entre os grupos I, II e III. Houve diferença no tempo total de bainha apenas entre os grupos I e III (p=0,023). Taxa livre de cálculos não se alterou entre os grupos. Discussão: as diferenças observadas entres as variáveis qualitativas e quantitativas evidenciam a relação entre o número de cirurgias realizadas e a proficiência no procedimento. As comparações intergrupo mostram otimização sequencial dos parâmetros. Conclusões: estima-se que 60 é um número razoável de cirurgias para que se atinja o platô da curva de aprendizado.

Superselective renal arterial embolization in treatment for severe renal hemorrhage after flexible ureterorenoscopy and laser lithotripsy (FURSL)

OBJECTIVE

Life-threatening renal hemorrhage after flexible ureterorenoscopy and laser lithotripsy (FURSL) is a rare complication. We aim to review our unit's experience with super-selective renal artery embolization as therapeutic options for such patients.

METHODS

From January 2015 to November 2021, total 1125 patients underwent the FURSL procedures in our unit. Patients with life-threatening renal hemorrhage were reviewed and the information of peri-operative, operative and post-operative were recorded.

RESULTS

Of the 1125 patients who underwent FURSL procedure, two patients with life-threatening renal hemorrhage were diagnosis; the age is 67 and 42 years old, respectively. Preoperative imaging examination showed that two patients had upper ureteral stone and renal stone ranging in size from 1.2 to 3.0 cm. Female patient placed the D-J stent for two weeks before FURSL. After the operation, both patients had the massive gross hematuria, significant drop of hemoglobin (Hgb), blood pressure lowering and needed to transfusion. CT scan showed that the male patient had an intrarenal hematoma. All these two were treated by super-selective renal artery embolization and had a successful outcome.

CONCLUSION

Life-threatening renal hemorrhage after FURSL is a rare and severe complication. Super-selective renal artery embolization is a safe and effective method for the treatment of patients with severe renal hemorrhage, preserving healthy renal parenchyma and renal function.

The clinical outcomes of flexible ureteroscopy and laser lithotripsy (FURSL) for treatment of the upper urinary tract calculi

PURPOSE

To evaluate efficacy and safety of flexible ureteroscopy and laser lithotripsy (FURSL) for treatment of the upper urinary tract calculi.

METHODS

We retrospectively analyzed 784 patients who underwent FURSL between January 2015 and October 2020 in our unit. All patients were preoperatively evaluated with urine analysis, serum biochemistry, urinary ultrasonography, non-contrast computed tomography and intravenous urography. The procedure was considered as successful in patients with complete stone disappearance or fragments < 4 mm on B ultrasound or computed tomography. The operative parameters, postoperative outcomes and complications were recorded and analyzed respectively.

RESULTS

The average operative time and postoperative hospital stay were 46.9±15.8 min and 1.2±1.1 days, respectively, among 784 patients. In addition, 746 patients were followed up and 38 patients were lost. In these patients, 700 (93.8%) cases met the stone removal criteria and 46 cases (6.2%) did not meet the stone removal criteria who need further treatment. The stone free rate (SFR) is 92.5%after 1-3 months and SFR of middle and upper calyceal calculi was higher than that of lower calyceal calculi significantly. The most common complications were fever (58/784, 7.4%), gross hematuria (540/784, 68.9%) and lpsilateral low back pain (47/784, 6.0%). The incidence rate of serious complication was 1.28%(10/784), including 5 cases of septic shock and 5 cases of subcapsular hematoma, which were cured after active treatment.

CONCLUSION

FURSL is a reliable treatment for small and medium calculi patients of upper urinary tract. The curative effect of stone removal is clear. The complications are few and the safety is high. However, there are certain limitations to the efficacy in treating larger stone and lower calyceal calculi.

The effectiveness and safety of Sun tip-flexible ureterorenoscope for the management of kidney stones: A protocol for systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Kidney stone is one of the urinary system diseases with a high incidence. In this study, we will evaluate the effectiveness and safety of Sun tip-flexible ureterorenoscope treating patients with kidney stone.

METHODS AND ANALYSIS

English and Chinese literature about Sun tip-flexible ureterorenoscope treatment for kidney stones published before October 31, 2020 will be systematic searched in PubMed, Embase, Web of Science, Cochrane Library, Open Grey, Clinicaltrials.gov, Chinese Clinical Trial Registry, WANFANG, VIP Chinese Science and Technology Journal Database, CNKI, Chinese biomedical document service system (SinoMed). Only randomized controlled trials (RCTs) of patients with kidney stones will be included. Literature screening, data extraction, and the assessment of risk of bias will be independently conducted by 2 reviewers, and the 3rd reviewer will be consulted if any different opinions existed. Systematic review and meta-analysis will be produced by RevMan 5.3 and Stata 14.0. This protocol reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) statement, and we will report the systematic review by following the PRISMA statement.

RESULTS

The current study is a protocol for systematic review and meta-analysis without results, and data analysis will be carried out after the protocol. We will share our findings in the fourth quarter of 2021.

CONCLUSION

This study will provide recommendations for the effectiveness and safety of Sun tip-flexible ureterorenoscope for patients with kidney stones (KS), which may help to guide clinician.

ETHICS AND DISSEMINATION

Ethical approval is not required as the review is a secondary study based on published literature. The results of the study will be published in peer-reviewed publications and disseminated electronically or in print.

PROTOCOL REGISTRATION NUMBER

INPLASY2020110099.

The effectiveness and safety of extracorporeal shock wave lithotripsy for the management of kidney stones: A protocol of systematic review and meta-analysis

BACKGROUND

Extracorporeal shockwave lithotripsy (ESWL) has gained worldwide popularity as one of the most commonly used minimally invasive management of urinary tract stones. The objective of this study was to evaluate the efficacy and safety of ESWL for patients with kidney stones (KS).

MATERIALS AND METHODS

This protocol established in this study has been reported following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. Web of Science, PubMed, Embase, Cochrane Library, China Biomedical Literature Database (CBM), China Knowledge Network Database (CNKI), Chinese Scientific Journal Database (VIP), and Wan Fang Database were searched for case-control studies in ESWL treating patients with KS until July 1, 2020. We will use a combination of Medical Subject Heading and free-text terms with various synonyms to search based on the Eligibility criteria. Two investigators independently reviewed the included studies and extracted relevant data. The relative risk (RR) and 95% confidence intervals (CIs) were used as effect estimate. I test, substantial heterogeneity, sensitivity analysis, and publication bias assessment will be performed accordingly. Stata 14.0 and Review Manger 5.3 are used for a meta-analysis.

RESULTS

The results will be published in a peer-reviewed journal.

CONCLUSION

The results of this review will be widely disseminated through peer-reviewed publications and conference presentations. This evidence may also provide helpful evidence of the efficacy and safety of ESWL treating patients with KS.

PROSPERO REGISTRATION NUMBER

CRD42019157243.

Early experience of Retrograde Intrarenal Surgery for Renal stone: A Descriptive Cross-sectional Study

Introduction:

Retrograde intrarenal surgery with improving skill and knowledge may be considered one of the first-line treatment options for removal of renal stones. The study is done to find the outcome of retrograde intrarenal surgery (RIRS) in patients with renal stone.

Method:

This descriptive cross sectional study was carried out on patients undergoing retrograde intrarenal surgery for renal stone at a tertiary care hospital December 2019 to March 2020. Ethical approval was taken from the institutional review committee (Ref. no.200120202). The Convenient sampling method was applied. Data was collected and analyzed in Statistical Package for the Social Sciences version 20.0. Point estimate at 95% confidence interval was calculated along with frequency and proportion for binary data.

Results:

Out of the 28 patients, the retrograde intrarenal surgery was successful in 27 (96.4%) cases. There were 16 (57.15%) females and 12 (42.86%) male patients with the mean age of 37.86±11.47 years. Most of the stones were in renal pelvis 18 (64.28%) followed by lower calyx 8(28.57%). The mean diameter of the stone was 11.47±3.33mm whereas most of the stones were on the right side 16 (57.15%). The mean hardness was 1155.21±265.34 Hounsfield units. Perioperative complications like failed access sheath placement in 2 (7.14%) cases, hematuria in 6 (21.43%) cases, fever in 6 (21.43%) cases, and septicemia in 4 (14.28%) cases.

Conclusions:

We found that the success rate of retrograde intrarenal surgery for the renal stone was acceptable and similar to other published studies . Retrograde intrarenal surgery is feasible for the treatment of kidney stones with acceptable complications and success rates.

The effectiveness and safety of extracorporeal shock wave lithotripsy for the management of kidney stones: A protocol of systematic review and meta-analysis

BACKGROUND

This study will assess the effectiveness and safety of extracorporeal shock wave lithotripsy (ESWL) for patients with kidney stones (KS).

METHODS

A comprehensive and systematic literature records search for studies will be conducted in MEDLINE, EMBASE, Cochrane Library, WANGFANG, VIP, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. All these databases will be searched from inception to the present without language limitation. Cochrane risk of bias tool will be used to assess the methodological quality for all included studies. Statistical analysis is performed using RevMan 5.3 software.

RESULTS

This study will provide synthesis of current evidence of ESWL for patients with KS through assessing primary outcomes of overall stone-free rate, and secondary outcomes of mean stone size (mm), pain intensity, urinary biochemical variables, mean hospital stay (day), quality of life, and adverse events.

CONCLUSION

This study will provide recommendations for the effectiveness and safety of ESWL for patients with KS, which may help to guide clinician.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019157243.

Conservative management of staghorn stones

INTRODUCTION

Since the seminal works by Singh and Blandy in the 1970s, the management of staghorn stones has almost exclusively involved surgical intervention. In contrast, a more recent study found that conservative management was not as unsafe as previously believed. The present review sought to examine the available literature to understand the implications of a conservative strategy.

METHODS

A systematic search of the literature was carried out using MEDLINE®, Embase™ and the Cochrane Central Register of Controlled Trials. All papers looking at management of staghorn calculi were reviewed and studies with a conservative management arm were identified. Outcomes of interest were recurrent or severe urinary tract infections, progressive renal deterioration, dialysis requirements, morbidity and disease specific mortality. Owing to the lack of relevant data, a descriptive review was carried out.

RESULTS

Our literature search yielded 10 suitable studies involving a total of 304 patients with staghorn stones managed conservatively. Progressive renal deterioration occurred in 0-100% of cases (mean 27.5%) with a higher rate among bilateral staghorn sufferers (44% vs 9%). Dialysis was required in 9% of patients (20% bilateral, 6% unilateral). The mean rate of severe infection was 8.7% and recurrent urinary tract infections occurred in as high as 50% of cases (80% bilateral, 41% unilateral). Disease specific mortality ranged from 0% to 67% (mean 20.5%).

CONCLUSIONS

It appears that conservative management of staghorn calculi is not as unsafe as previously thought and selection of patients with unilateral asymptomatic stones with minimal infection should be considered.

Tetracycline attenuates calcifying nanoparticles-induced renal epithelial injury through suppression of inflammation, oxidative stress, and apoptosis in rat models

Background

Calcifying nanoparticles (CNPs) has been associated with the occurrence and development of kidney stones, but the exact mechanism is not clear. This study aimed to establish a rat model of CNP-induced renal epithelial injury and assess the efficacy of tetracycline in preventing this injury.

Methods

Kidney stones from patients after percutaneous nephrolithotomy (PCNL) were collected to isolate and culture CNPs. Thirty Sprague-Dawley rats were divided into three groups: the sham group (G1), the CNP group (G2), and the CNP + tetracycline group (G3). Rats in G2 and G3 were given an intravenous injection of CNPs via the tail vein, while rats in G1 were given saline. Meanwhile, rats in G3 were given tetracycline by gavage twice a day at a dose of 25 mg/kg. After 8 weeks, the 24-h urine of all rats was collected, and all rats were sacrificed to obtain blood and kidneys.

Results

The results revealed that in G2, activities of antioxidant enzymes such as superoxide dismutase and catalase were significantly lower than those in G1, while malondialdehyde activity in G2 was significantly higher than that in G1 and both of them were inhibited by tetracycline co-treatment in G3. CNPs significantly increased expression of inflammatory cytokines, including monocyte chemotactic protein 1 and interleukin 6, which were largely alleviated in G3. CNPs significantly increased TUNEL-positive cells and the apoptosis activity of Bcl2-associated X protein but decreased B-cell lymphoma-2 level compared with that in G1, and was limited by tetracycline co-treatment in G3. Furthermore, CNPs led to notable renal tubular epithelial cell damage, hyaline cast formation, desquamation, swelling, vacuolization in histology, all of which were alleviated by tetracycline.

Conclusions

Tetracycline can attenuate CNP-induced renal epithelial injury through suppression of inflammation, oxidative stress, and apoptosis.

Effect of JJ stent on outcomes of extracorporeal shock wave lithotripsy treatment of moderate sized renal pelvic stones: A randomized prospective study

PURPOSE

To evaluate the effect of JJ stents on SWL treatment of moderate (15-25mm) renal pelvic stones.

MATERIALS AND METHODS

Between January 2016 and December 2017, a total of 152 adult patients who were planned to undergo SWL for a single radiopaque renal pelvic stone were included in the study. Patients with solitary kidney, congenital abnormality, skeletal tract abnormalities, previous urinary system surgery, hydronephrosis (grade 2 or more), untreated urinary tract infection, bleeding disorder, and suspected pregnancy were excluded. The remaining 114 patients were randomly divided into two groups; non-stented and stented. Twenty-two patients whose stone could not be fragmented despite 3 consecutive sessions were also excluded from the study. A total of 92 patients (54 non-stented and 38 stented) were included in the final analysis.

RESULTS

There was no significant difference in terms of age, sex, body mass index, renal parancyhimal thickness, hydronephrosis, skin-to-stone distance, Hounsfield units, and stone size between the groups. Success was significantly higher in the stented group than in the non-stented group (71% vs. 39%, P=.002). In stone-free patients, the number of emergency department visits and analgesic tablet consumption was significantly lower in the stented group than in the non-stented group (P<.001 and P<.001, respectively). In non- stone-free patients, analgesic tablet consumption was significantly lower in the stented group than in the non-stented group (P=.004).

CONCLUSIONS

Pre-stenting before SWL treatment of moderate sized renal pelvic stones has some advantages in terms of success, emergency service visits, and analgesic tablet consumption.

Noncontrast Computed Tomography Parameters for Predicting Shock Wave Lithotripsy Outcome in Upper Urinary Tract Stone Cases

Kidney stones are a major public health concern with continuously increasing worldwide prevalence. Shock wave lithotripsy (SWL) is the first line treatment choice for upper urinary tract calculi with ureteroscopy and has advantages of safety and noninvasiveness, but the treatment success rate of SWL is lower than that of other therapies. It is therefore important to identify predictive factors for SWL outcome and select a suitable treatment choice for patients with upper urinary tract calculi. In recent years, computed tomography (CT) has become the gold standard for diagnosis of upper urinary tract calculi. Several factors based on CT images, including skin-to-stone distance, mean stone density, stone heterogeneity index, and variation coefficient of stone density, have been reported to be useful for predicting SWL outcome. In addition, a new method of analysis, CT texture analysis, is reportedly useful for predicting SWL outcomes. This review aims to summarize CT parameters for predicting the outcome of shock wave lithotripsy in stone cases in the upper urinary tract.

Surgical management of urolithiasis - a systematic analysis of available guidelines

Background

Several societies around the world issue guidelines incorporating the latest evidence. However, even the most commonly cited guidelines of the European Association of Urology (EAU) and the American Urological Association (AUA) leave the clinician with several treatment options and differ on specific points. We aimed to identify discrepancies and areas of consensus between guidelines to give novel insights into areas where low consensus between the guideline panels exists, and therefore where more evidence might increase consensus.

Methods

The webpages of the 61 members of the Societé Internationale d’Urologie were analysed to identify all listed or linked guidelines. Decision trees for the surgical management of urolithiasis were derived, and a comparative analysis was performed to determine consensus and discrepancies.

Results

Five national and one international guideline (EAU) on surgical stone treatment were available for analysis. While 7 national urological societies refer to the AUA guidelines and 11 to the EAU guidelines, 43 neither publish their own guidelines nor refer to others. Comparative analysis revealed a high degree of consensus for most renal and ureteral stone scenarios. Nevertheless, we also identified a variety of discrepancies between the different guidelines, the largest being the approach to the treatment of proximal ureteral calculi and larger renal calculi.

Conclusions

Six guidelines with recommendations for the surgical treatment of urolithiasis to support urologists in decision-making were available for inclusion in our analysis. While there is a high grade of consensus for most stone scenarios, we also detected some discrepancies between different guidelines. These are, however, controversial situations where adequate evidence to assist with decision-making has yet to be elicited by further research.

Evaluation of selected Doppler parameters of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy

Introduction

Despite the risk of complications, which does not exceed several percent, extracorporeal shock wave lithotripsy (ESWL) causes morphological and functional changes in kidneys as a result of the effect of the generated shock wave energy on the renal parenchyma structure.

Material and methods

Forty-two patients were included in the study. The mean age in the studied group was 50.9 years (SD ±13.7). Extracorporeal lithotripsy treatments were carried out during the period from January 2014 to April 2014 using an electromagnetic shock wave generator. The spectrum of blood flow of the interlobar arteries of both the treated and the opposite kidney was investigated. On the basis of these spectrums, parameters such as: resistive index (RI), pulsatility index (PI) and acceleration time (AT) were calculated.

Results

The ESWL treatment causes a statistically significant increase of the RI parameter in the ipsilateral kidney (p <0.0001) as well as in the opposite kidney (p <0.0001). The RI value decreases after 92 hours after the treatment, reaching statistical significance in both kidneys (p <0.005). The PI parameter substantially increases after treatment in both kidneys (p <0.0001), and decreases after 92 hours (p <0.0001). Statistically significant correlations are shown between RI as well as the PI parameters and the patient's age.

Conclusions

Extracorporeal shock wave lithotripsy (ESWL) of renal stones causes temporary impairment of the renal perfusion in both ipsilateral and contralateral kidneys. The main factor that determines the value of the RI and PI parameters is the patient's age.

Is There A Difference Between Presence of Single Stone And Multiple Stones in Flexible Ureterorenoscopy And Laser Lithotripsy For Renal Stone Burden < 300mm2 ?

In this study, we aim to evaluate and compare the effectiveness of flexible ureterorenoscopy (f-URS) for solitary and multiple renal stones with < 300 mm2 stone burden. Patients' charts who treated with f-URS for kidney stone between January 2010 and June 2015 were reviewed, retrospectively. Patients with solitary kidney stones (n:111) were enrolled in group 1. We selected 111 patients with multiple kidney stones to serve as the control group and the patients were matched at a 1:1 ratio with respect to the patient's age, gender, body mass index and stone burden. Additionally, patients with multiple stones were divided into two groups according to the presence or abscence of lower pole stones. Stone free status was accepted as complete stone clearence and presence of residual fragments < 2 mm. According to the study design; age, stone burden, body mass index were comparable between groups. The mean operation time was longer in group 2 (p= 0.229). However, the mean fluoroscopy screening time in group 1 and in group 2 was 2.1±1.7 and 2.6±1.5 min, respectively and significantly longer in patients with multiple renal stones (P=0.043). The stone-free status was significantly higher in patients with solitary renal stones after a single session procedure (p=0.02). After third month follow up, overall success rate was 92.7% in Group 1 and 86.4% in Group 2. Our study revealed that F-URS achieved better stone free status in solitary renal stones < 300 mm2. However, outcomes of F-URS were acceptable in patients with multiple stones.

Minimally Invasive Percutaneous Nephrolithotomy versus Retrograde Intrarenal Surgery for Upper Urinary Stones: A Systematic Review and Meta-Analysis

Minimally invasive percutaneous nephrolithotomy (mini-PCNL) and retrograde intrarenal surgery (RIRS) are both alternatives for PCNL to treat renal calculi. This study is aimed at comparing the stone-free rate (SFR) and other surgery parameters of two approaches for treating upper urinary calculi. We performed this meta-analysis in September 2016 by searching studies about mini-PCNL and RIRS for treating upper urinary calculi in various databases, and RevMan v.5.3 was applied. Three randomized controlled trials and ten nonrandomized trials were included, involving a total of 1317 patients. Meta-analysis showed that mini-PCNL group led to a higher SFR [odds ratio: 1.96; 95% confidence interval: 1.46–2.64; P < 0.00001] but brought a larger postoperative decrease in hemoglobin levels compared with RIRS. RIRS provided a shorter hospital time. There was no significant difference in operation time. Higher postoperative complications were detected in the mini-PCNL, but the difference was not significant. Grade I and III complications did not vary between two procedures, but grade II complications were of lower incidence in RIRS group. In the light of these results, compared with RIRS, mini-PCNL provided significantly higher SFR and efficiency quotient for managing calculi; however, it resulted in higher incidence of postoperative complications, larger hemoglobin drops, and longer hospital stay.

Current ESWL practice and outcomes in the UK: A multicentre snapshot

Objectives:

The objective of this article is to investigate the current clinical practice and outcomes of extracorporeal shock wave lithotripsy (SWL) in the United Kingdom.

Patients and methods:

Patient demographics, stone characteristics and SWL protocols were collected prospectively for 30 consecutive new patient referrals at each of seven contributing UK institutions performing SWL. Final outcomes in terms of stone-free rates (SFRs), and complications were recorded.

Results:

Completed demographic data were available for 204 patients. Treatment protocols varied between centres. Mean patient age was 51 years. Over 70% of stones treated measured between 5 and 10 mm, and one-third were in the ureter, with two-thirds in the kidney, where the majority (31% overall) were in the lower pole. The overall cumulative SFR was 50.3% (range 33–70% between centres). SWL was notably more effective for ureteric stones (SFR 59.3% overall) than for renal calculi (SFR 45.6% overall). Complications were noted in six patients.

Conclusion:

This study provides a valuable snapshot of real-life clinical practice and demonstrates considerable variability in the application of SWL in the UK. The results support existing data which suggest that SWL is a safe and well tolerated treatment modality; however, overall SFRs were low.

Prevalence of kidney stones in mainland China: A systematic review

The data on the prevalence of kidney stones in mainland China are still lacking. We performed the present meta-analysis to assess the stone prevalence in mainland China from 1990 through 2016. A total of 18 articles were included. The pooled overall prevalence was 7.54% (95% CI, 5.94-9.15). The prevalence in age groups of <20 years, 20-29 years, 30-39 years, 40-49 years, 50-59 years, and 60 years and older was 0.27%, 3.15%, 5.96%, 8.18%, 9.14%, and 9.68%, respectively, showing that it increased with age. Moreover, the prevalence was 10.34% in males and 6.62% in females, with an odds ratio (OR) of 1.63 [95% CI: 1.51-1.76], indicating that males are more likely to suffer from this disease than females. However, urban areas (6.03%, 95% CI: 3.39-8.68) and rural areas (7.48%, 95% CI: 3.39-11.57) did not differ in the stone prevalence rate (OR = 0.84, 95% CI: 0.42-1.68). The prevalence in the year groups of 1991-2000, 2001-2010, and 2011 to date was 5.95%, 8.86%, and 10.63%, respectively, which indicated an increasing trend. Further high-quality surveys throughout mainland China are needed to confirm these findings.

Successful evacuation of large perirenal hematoma after extracorporeal shock wave lithotripsy (ESWL) - step 1 of the IDEAL recommendations of surgical innovation

Larger perirenal hematomas after extracorporeal shock wave lithotripsy (ESWL) are sometimes related to the loss of renal function due to compression of the normal renal tissue. After computed tomography-guided drainage and locally applied urokinase, the hematoma was fractionally evacuated. This procedure is a save and fast way to recover normal renal function.

Management of upper ureteral stones exceeding 15 mm in diameter: Shock wave lithotripsy versus semirigid ureteroscopy with holmium:yttrium-aluminum-garnet laser lithotripsy

Objectives:

We conducted a retrospective study to evaluate the efficacy and outcome of shock wave lithotripsy versus semirigid ureteroscopy in the management of the proximal ureteral stones of diameter exceeding 15 mm.

Methods:

During the 2009−2014 study period, 147 patients presenting with the proximal ureteral stones exceeding 15 mm in diameter were treated. Both shock wave lithotripsy and ureteroscopy with laser lithotripsy were offered for our patients. A 6/8.9 Fr semirigid ureteroscope was used in conjunction with a holmium:yttrium–aluminum–garnet laser. The stone-free rate was assessed at 2 weeks and 3 months post-treatment. All patients were evaluated for stone-free status, operation time, hospital stay, perioperative complications, and auxiliary procedures.

Results:

Of the 147 patients who took part in this study, 66 (45%) had undergone shock wave lithotripsy and 81 (55%) underwent ureteroscopy. At the 3-month follow-up, the overall stone-free rate in the shock wave lithotripsy group was 39/66 (59%) compared to 70/81 (86.4%) in the ureteroscopic laser lithotripsy group. Ureteroscopic laser lithotripsy achieved a highly significant stone-free rate (p = 0.0002), and the mean operative time, auxiliary procedures, and postoperative complication rates were comparable between the two groups.

Conclusion:

In terms of the management of proximal ureteral stones exceeding 15 mm in diameter, ureteroscopy achieved a greater stone-free rate and is considered the first-line of management. Shock wave lithotripsy achieved lower stone-free rate, and it could be used in selected cases.

Recent advances in lithotripsy technology and treatment strategies: A systematic review update

INTRODUCTION

Shock wave lithotripsy (SWL) is a well - established treatment option for urolithiasis. The technology of SWL has undergone significant changes in an attempt to better optimize the results while reducing failure rates. There are some important limitations that restrict the use of SWL. In this review, we aim to place these advantages and limitations in perspective, assess the current role of SWL, and discuss recent advances in lithotripsy technology and treatment strategies.

METHODS

A comprehensive review was conducted to identify studies reporting outcomes on ESWL. We searched for literature (PubMed, Embase, Medline) that focused on the physics of shock waves, theories of stone disintegration, and studies on optimising shock wave application. Relevant articles in English published since 1980 were selected for inclusion.

RESULTS

Efficacy has been shown to vary between lithotripters. To maximize stone fragmentation and reduce failure rates, many factors can be optimized. Factors to consider in proper patient selection include skin - to - stone distance and stone size. Careful attention to the rate of shock wave administration, proper coupling of the treatment head to the patient have important influences on the success of lithotripsy.

CONCLUSION

Proper selection of patients who are expected to respond well to SWL, as well as attention to the technical aspects of the procedure are the keys to SWL success. Studies aiming to determine the mechanisms of shock wave action in stone breakage have begun to suggest new treatment strategies to improve success rates and safety.

Review on Lithotripsy and Cavitation in Urinary Stone Therapy

Cavitation is the sudden formation of vapor bubbles or voids in liquid media and occurs after rapid changes in pressure as a consequence of mechanical forces. It is mostly an undesirable phenomenon. Although the elimination of cavitation is a major topic in the study of fluid dynamics, its destructive nature could be exploited for therapeutic applications. Ultrasonic and hydrodynamic sources are two main origins for generating cavitation. The purpose of this review is to give the reader a general idea about the formation of cavitation phenomenon and existing biomedical applications of ultrasonic and hydrodynamic cavitation. Because of the high number of the studies on ultrasound cavitation in the literature, the main focus of this review is placed on the lithotripsy techniques, which have been widely used for the treatment of urinary stones. Accordingly, cavitation phenomenon and its basic concepts are presented in Section II. The significance of the ultrasound cavitation in the urinary stone treatment is discussed in Section III in detail and hydrodynamic cavitation as an important alternative for the ultrasound cavitation is included in Section IV. Finally, side effects of using both ultrasound and hydrodynamic cavitation in biomedical applications are presented in Section V.

Supracostal Approach for PCNL: Is 10th and 11th Intercostal Space Safe According to Clavien Classification System?

The purpose of this study was to evaluate the success and morbidity of percutaneous nephrolithotomy (PCNL) performed through the 11th and 10th intercostal space. Between March 2005 and February 2012, 612 patients underwent PCNL, 243 of whom had a supracostal access. The interspace between the 11th and 12th rib was used in 204 cases (group 1) and between the 10th and 11th interspaces in 39 cases (group 2). PCNL was performed using standard supracostal technique in all patients. The operative time, success rate, hospital stay, and complications according to the modified Clavien classification were compared between group 1 and group 2. The stone-free rate was 86.8% in group 1 and 84.6% in group 2 after one session of PCNL. Auxiliary procedures consisting of ureterorenoscopy (URS) and shock wave lithotripsy (SWL) were required in 5 and 7 patients, respectively, in group 1; and in 1 patient each in group 2 . After the auxiliary procedures, stone-free rates increased to 92.6% in group 1 and 89.7% in group 2. A total of 74 (30.4%) complications were documented in the 2 groups according to modified Clavien classification. Grade-I complications were recorded in 20 (8.2%), grade-II in 38 (15.6%), grade-IIIa in 13 (5.3%), and grade-IIIb in 2 (0.8%) patients; grade-IVa was recorded in 1 (0.4%) patient. There were no grade-IVb or grade-V complications. Overall complication rate was 30.9% in group 1 and 28.2% in group 2. Supracostal PCNL in selected cases is effective and safe with acceptable complications. The modified Clavien system provides a standardized grading system for complications of PCNL.

Optimal Skin-to-Stone Distance Is a Positive Predictor for Successful Outcomes in Upper Ureter Calculi following Extracorporeal Shock Wave Lithotripsy: A Bayesian Model Averaging Approach

Objectives

To investigate whether skin-to-stone distance (SSD), which remains controversial in patients with ureter stones, can be a predicting factor for one session success following extracorporeal shock wave lithotripsy (ESWL) in patients with upper ureter stones.

Patients and Methods

We retrospectively reviewed the medical records of 1,519 patients who underwent their first ESWL between January 2005 and December 2013. Among these patients, 492 had upper ureter stones that measured 4–20 mm and were eligible for our analyses. Maximal stone length, mean stone density (HU), and SSD were determined on pretreatment non-contrast computed tomography (NCCT). For subgroup analyses, patients were divided into four groups. Group 1 consisted of patients with SSD<25^th percentile, group 2 consisted of patients with SSD in the 25^th to 50^th percentile, group 3 patients had SSD in the 50^th to 75^th percentile, and group 4 patients had SSD≥75^th percentile.

Results

In analyses of group 2 patients versus others, there were no statistical differences in mean age, stone length and density. However, the one session success rate in group 2 was higher than other groups (77.9% vs. 67.0%; P = 0.032). The multivariate logistic regression model revealed that shorter stone length, lower stone density, and the group 2 SSD were positive predictors for successful outcomes in ESWL. Using the Bayesian model-averaging approach, longer stone length, lower stone density, and group 2 SSD can be also positive predictors for successful outcomes following ESWL.

Conclusions

Our data indicate that a group 2 SSD of approximately 10 cm is a positive predictor for success following ESWL.

Flexible ureterorenoscopy results: Analysis of 279 cases

OBJECTIVE

In this study, the outcomes of 279 cases in whom we performed retrograde intrarenal surgery (RIRS) were evaluated retrospectively.

MATERIAL AND METHODS

RIRS was performed on 279 cases with the aid of access sheath of guidewire between March 2011 and February 2015. All patients were operated in the standard lithotomy position. A hydrophilic guidewire was inserted with the aid of rigid ureterorenoscopy and we checked whether there were any residual ureteral stones and other pathologies. Fluoroscopy was used routinely in all cases. Stone fragments smaller than 3 mm were left off but those bigger than 3 mm were removed by grasper after stone fragmentation. Controls of the patients were assessed by plain films (KUB), urinary tract ultrasonography (US) and/or computed tomography (CT) 1 month after the operation. Success rate of the procedure was defined as the stone-free status or presence of residual fragments less than 3 mm.

RESULTS

152 of the patients were male and 127 were female. The median ages of the male and female patients were 47.7 (1-86) ve 45.9 (3-79) years respectively. The median stone size was 13.5 mm (8-25). Preoperatively 34 (12.1%) patients had double-J ureteral stent. 19 (6.8%) patients were operated while they were still receiving antithrombotic and antiplatelet therapy Solitary kidney was present in 24 patients while the remaining patients had kyphoscoliosis (n=3), rotation anomaly (n=6), pelvic kidney (n=2), double collecting system (n=3), and horseshoe kidney (n=6). In 264 patients access sheath was used, in 15 patients operation was performed with the help of the guidewire. Double-J stents were inserted to 14 patients because of ureteral stricture and they underwent operation after 2 weeks later. Renal stones of 219 patients among all cases were fragmented completely and the patients were discharged as stone free (SF). Our success rate (SF or presence of clinically insignificant residual [CIRF]) was 78.4%. Stone size (p=0.029), stone number (p=0.01), stone location (p=0.023) had significant influence on the stone-free rate after RIRS The mean operation and floroscopy time was 62.5 min. (40-180) and 29.8 sec (4-96), respectively. The mean hospitalization time was 26.4 hours (12-72). Double J stents were placed to 253 patients for more stone burden and ureteral edema. Any complication was not observed for all cases except perioperative developed infection for two patients.

CONCLUSION

With advances in laser technology and flexible ureterorenoscopy, kidney stones can be treated with lower morbidity and high success rates.

Shock Wave Lithotripsy in Ureteral Stones: Evaluation of Patient and Stone Related Predictive Factors

Purpose:

To evaluate the patient and stone related factors which may influence the final outcome of SWL in the management of ureteral stones.

Materials and Methods:

Between October 2011 and October 2013, a total of 204 adult patients undergoing SWL for single ureteral stone sizing 5 to 15 mm were included into the study program. The impact of both patient (age, sex, BMI,) and stone related factors (laterality, location, longest diameter and density as CT HU) along with BUN and lastly SSD (skin to stone distance) on fragmentation were analysed by univariate and multivariate analyses. Results: Stone free rates for proximal and distal ureteral stones were 68.8% and 72.7%, respectively with no statistically significant difference between two groups (p=0.7). According to univariate and multivariate analyses, while higher BMI (mean: 26.8 and 28.1, p=0.048) and stone density values (mean: 702 HU and 930 HU, p<0.0001) were detected as statistically significant independent predictors of treatment failure for proximal ureteral stones, the only statistically significant predicting parameter for the success rates of SWL in distal ureteral stones was the higher SSD value (median: 114 and 90, p=0.012).

Conclusions:

Our findings have clearly shown that while higher BMI and increased stone attenuation values detected by NCCT were significant factors influencing the final outcome of SWL treatment in proximal ureteral stones; opposite to the literature, high SSD was the only independent predictor of success for the SWL treatment of distal ureteral stones.

Efficacy Management of Urolithiasis: Flexible Ureteroscopy versus Extracorporeal Shockwave Lithotripsy

OBJECTIVES

To evaluate the efficacy of flexible ureterscopy (fURS) and extracorporal shockwave lithotripsy (SWL) in the treatment of urolithiasis, complemented by a subgroup analysis of lower pole calyx.

METHODS

Retrospective analysis of patients treated by fURS or SWL was performed by independent variables such as gender, age, nephrolith size, double-J stent (DJ stent) and stone localisation.

RESULTS

Out of 326 patients, 165 were treated by SWL and 161 by fURS. Complete stone removal was achieved by fURS in 83.2% and by SWL in 43.0% (p < 0.001). Asymptomatic behaviour (88-89%) and complication rate (10-11%) were nearly the same in both methods. A higher retreatment rate for SWL was necessary; otherwise, an auxillary DJ stent was performed more often preoperative before fURS. The subgroup analysis of lower pole calyx confirmed these evaluations.

CONCLUSIONS

Complete stone-free removal was almost 8 times higher after fURS compared to SWL. The efficacy of fURS in treatment of urolithiasis is substantially higher than the efficacy of SWL.

Can a dual-energy computed tomography predict unsuitable stone components for extracorporeal shock wave lithotripsy?

Purpose

To assess the potential of dual-energy computed tomography (DECT) to identify urinary stone components, particularly uric acid and calcium oxalate monohydrate, which are unsuitable for extracorporeal shock wave lithotripsy (ESWL).

Materials and Methods

This clinical study included 246 patients who underwent removal of urinary stones and an analysis of stone components between November 2009 and August 2013. All patients received preoperative DECT using two energy values (80 kVp and 140 kVp). Hounsfield units (HU) were measured and matched to the stone component.

Results

Significant differences in HU values were observed between uric acid and nonuric acid stones at the 80 and 140 kVp energy values (p<0.001). All uric acid stones were red on color-coded DECT images, whereas 96.3% of the nonuric acid stones were blue. Patients with calcium oxalate stones were divided into two groups according to the amount of monohydrate (calcium oxalate monohydrate group: monohydrate≥90%, calcium oxalate dihydrate group: monohydrate<90%). Significant differences in HU values were detected between the two groups at both energy values (p<0.001).

Conclusions

DECT improved the characterization of urinary stone components and was a useful method for identifying uric acid and calcium oxalate monohydrate stones, which are unsuitable for ESWL.

Micropercutaneous nephrolithotripsy: initial experience

INTRODUCTION

For small renal calculi (< 2 cm) the currently available treatment options include extracorporeal shockwave lithotripsy (ESWL), retrograde intrarenal surgery (RIRS) and standard/mini percutaneous nephrolithotomy (PNL). A new method, microperc, has therefore been developed, in which a smaller tract size and smaller instruments were used.

AIM

To present our clinical experiences with micropercutaneous nephrolithotripsy (microperc) in the treatment of small renal calculi.

MATERIAL AND METHODS

We retrospectively evaluated patients with small renal calculi who underwent microperc between February and June 2013. A 4.8 Fr 'all-seeing needle' was used to achieve percutaneous renal access with the C-arm fluoroscopy guidance in the prone position. Holmium: YAG laser 272 µm fiber was used for stone fragmentation.

RESULTS

A total of 20 patients underwent the microperc procedure. The mean age of the patients was 46.5 ±13.8 years. The mean stone size was 13 ±3 mm. The stone-free rate (SFR) was 90% (18/20). Two patients had clinically significant residual fragments (≥ 4 mm). The mean operation and fluoroscopy times were 107.5 ±37 min and 45 ±40 s respectively. The mean postoperative drop in hemoglobin was 1.2 ±0.9 g/dl, and 1 patient required blood transfusion. The patients were discharged after an average hospitalization of 1.4 ±0.8 days. Two complications, urinary tract infection and blood loss requiring blood transfusion, were observed in 2 patients postoperatively.

CONCLUSIONS

We suggest that microperc should be considered for the treatment of small renal stones.

Prospective randomized comparison between superior calyceal access versus inferior calyceal access in PCNL for inferior calyceal stones with or without pelvic stones

The objective of this study is to assess the efficacy of superior calyceal access versus inferior calyceal access for inferior calyceal calculi with or without pelvic calculi. A total of 100 patients with inferior calyceal calculi or inferior calyceal calculi with pelvic calculi were included in this prospective randomized study. In 50 patients (Group 1), a fluoroscopy-assisted superior calyceal puncture was made, and in other 50 patients (Group 2), access was obtained through a fluoroscopy-assisted inferior calyceal puncture. The stone-free rates, hemoglobin drop, operative duration, requirement for additional tracts, complications, and auxiliary procedures in the two groups were compared. Stone clearance rates and hemoglobin drop values were better in group 1, though they were not statistically significant. The mean operative duration, number of tracts required, and the relook procedure rate were significantly in favor of Group 1. Only one patient (2%) in Group 1 developed hydropneumothorax related to supracostal puncture and required intercostal tube drainage. Superior calyceal puncture (supracostal or infracostal) provides favorable access to inferior calyceal stones, providing better and faster clearance with less requirement of secondary tracts and auxiliary procedures.

Simultaneous ureteroscopic lithotripsy and contralateral percutaneous nephrolithotomy for ureteral calculi combined with renal staghorn calculi

OBJECTIVES

To investigate the efficacy, safety, and cost-effectiveness of simultaneous ureteroscopic lithotripsy and contralateral percutaneous nephrolithotomy for ureteral calculi combined with contralateral renal staghorn calculi.

METHODS

The present prospective controlled trial had been registered with the Chinese Clinical Trial Registry (Registration number: ChiCTR-ONRC-13004146). Patients with ureteral calculi and contralateral renal staghorn calculi were enrolled into the staged (ureteroscopic lithotripsy first followed by a staged percutaneous nephrolithotomy) or the simultaneous (synchronous ureteroscopic lithotripsy and contralateral percutaneous nephrolithotomy) treatment group according to the odd or even number of the last hospitalization number. All patients signed informed consent. The primary outcomes were the stone-free rate and total hospital costs. The second outcomes were the operative and anesthesia times, the complication rate, and hospital stay.

RESULTS

A total of 51 patients were enrolled into the staged group and 52 patients were enrolled into the simultaneous group. There were no statistically significant differences in patients' characteristics. The overall stone-free rate was 94.1% in the staged group and 92.3% in the simultaneous group. No severe complication was observed. The total hospital stay of the staged group was longer, and it was negatively correlated to different procedures. The cost in the staged group was higher, and it was correlated with total operation time and postoperative hospital stay.

CONCLUSIONS

Simultaneous ureteroscopic lithotripsy and contralateral percutaneous nephrolithotomy represent safe and effective procedures, and they can be considered as a first-line treatment for selected patients presenting with ureteral calculi combined with contralateral renal calculi.

Incidence and Predictors for Ipsilateral Hydronephrosis Following Ureteroscopic Lithotripsy

OBJECTIVE

To review our experience in using ureteroscopy (URS) with lithotripsy for renal or ureteral calculi to determine the incidence and predictors of postprocedural ipsilateral hydronephrosis.

PATIENTS AND METHODS

Records of 324 URS cases for renal or ureteral calculi with imaging performed 4-12 weeks postprocedure were reviewed. Ipsilateral hydronephrosis was determined by computed tomography scan or renal ultrasound. Univariate and multivariate analyses determined the factors associated with hydronephrosis.

RESULTS

176 men and 148 women with a median age of 50 years were included. Median stone size was 6 mm and operative duration was 60 minutes; 30% of patients had multiple calculi; and 35% had undergone a prior ipsilateral URS. Overall, 49 of 324 patients (15%) had evidence of hydronephrosis, with 65% of these patients having symptoms and 40% requiring ancillary procedures. On multivariate analysis, increasing stone diameter (odds ratio [OR] 8.9, 95% confidence interval [CI] 1.9-23.8, P = .03), prior ipsilateral URS (OR 7.7, 95% CI 1.8-28.2, P = .006), longer operative duration (OR 6.5, 95% CI 1.8-16.3, P = .02), and renal colic symptoms (OR 48.3, 95% CI 14.7-71.4, P <.001) independently predicted hydronephrosis. Conversely, other factors including stone impaction at procedure, ureteral dilation, use of an access sheath, intraoperative perforation, or use of a stent did not associate with ipsilateral hydronephrosis.

CONCLUSION

In this contemporary cohort study, 15% of patients undergoing URS had evidence of ipsilateral hydronephrosis. Larger stone size, longer OR duration, prior ipsilateral URS, and recurrent colic were associated with an increased likelihood for this observation. Patients and stone cases with such characteristics likely warrant imaging modalities beyond plain radiography.

Minimally invasive surgical treatment for kidney stone disease

Minimally invasive interventions for stone disease in the United States are mainly founded on 3 surgical procedures: extracorporeal shock wave lithotripsy, ureteroscopic lithotripsy, and percutaneous nephrolithotomy. With the advancement of technology, treatment has shifted toward less invasive strategies and away from open or laparoscopic surgery. The treatment chosen for a patient with stones is based on the stone and patient characteristics. Each of the minimally invasive techniques uses an imaging source, either fluoroscopy or ultrasound, to localize the stone and an energy source to fragment the stone. Extracorporeal shock wave lithotripsy uses a shock wave energy source generated outside the body to fragment the stone. In contrast, with ureteroscopy, laser energy is placed directly on the stone using a ureteroscope that visualizes the stone. Percutaneous nephrolithotomy requires dilation of a tract through the back into the renal pelvis so that instruments can be inserted directly onto the stone to fragment or pulverize it. The success of the surgical intervention relies on performing the least invasive technique with the highest success of stone removal.

Strategies to optimize shock wave lithotripsy outcome: Patient selection and treatment parameters

Shock wave lithotripsy (SWL) was introduced in 1980, modernizing the treatment of upper urinary tract stones, and quickly became the most commonly utilized technique to treat kidney stones. Over the past 5-10 years, however, use of SWL has been declining because it is not as reliably effective as more modern technology. SWL success rates vary considerably and there is abundant literature predicting outcome based on patient- and stone-specific parameters. Herein we discuss the ways to optimize SWL outcomes by reviewing proper patient selection utilizing stone characteristics and patient features. Stone size, number, location, density, composition, and patient body habitus and renal anatomy are all discussed. We also review the technical parameters during SWL that can be controlled to improve results further, including type of anesthesia, coupling, shock wave rate, focal zones, pressures, and active monitoring. Following these basic principles and selection criteria will help maximize success rate.

Complications of Flexible Ureteroscopic Treatment for Renal and Ureteral Calculi during the Learning Curve

BACKGROUND

The flexible ureterorenoscope (URS) and associated devices have developed rapidly. However, despite its therapeutic benefits, URS may be associated with some complications. To the best of our knowledge, there are no studies discussing the complications of flexURS during the learning curve.

METHODS

A retrospective review of the records of patients who underwent flexURS from January 2005 to June 2013 was performed. To compare the complications after the introduction of flexURS, patients were divided into four groups based on the surgeon's training experience, that is, based on the number of cases performed by the surgeon. A total of 219 cases underwent flexURS. Groups 1, 2, 3, and 4 included 35, 50, 50, and 84 cases, respectively. The complications were classified using the Clavien system (I-IV).

RESULTS

The mean operation time and stone-free rate were significantly different (p < 0.001, p = 0.013, respectively). The total complication rates were 13.6, 10, 8.3, and 3.2%, respectively (p = 0.068). The more the surgeon's experience, the less was the complication rate. Despite our best efforts, the incidence of urosepsis was not reduced (p = 0.902).

CONCLUSIONS

To reduce severe complications, it is necessary to have performed about 100 cases. Increased surgeon experience tended to decrease the risk of severe complications, but the incidence of urosepsis was not reduced.

Simultaneous retrograde intrarenal surgery for ipsilateral asymptomatic renal stones in patients with ureteroscopic symptomatic ureteral stone removal

Background

Ipsilateral asymptomatic renal stone associated with symptomatic ureteral stone is not a rare event, and the recommended treatment policy was not declared clearly. This study was conducted to compare the outcomes of simultaneous retrograde intrarenal surgery (RIRS) and ureteroscopy to ureteroscopy alone for this clinical event.

Methods

415 patients with symptomatic ureteral stone and ipsilateral asymptomatic renal stones were reviewed to obtain two match groups, who were treating with simultaneous modality (group A, N = 72), or ureteroscopy alone (group B, N = 72). Matching criteria were ureteral and renal stone side, duration and location, the presence of pre-stented. Perioperative and postoperative characteristics were compared between the two groups.

Results

Mean stone burdens were similar between group A and B. Mean operative duration for group A and B were 72.4 ± 21.3 and 36.4 ± 10.2 min, respectively (P < 0.001). Mean hospital duration was 6.4 ± 2.9 and 5.3 ± 2.1 days in group A and B, respectively (P = 0.521). Ureteral SFR was 100% in each group. Renal SFR for RIRS was 86.1%. Complication rates in group A were higher (22.2% vs 13.9%), but the differences were not statistically significant (P = 0.358). In group A, complications were significantly less in pre-stented patients (3/25 vs 5/11, P = 0.04). Auxiliary treatment rate was significant higher in group B (69.4% vs 5.6%, P < 0.001) during follow-up (mean >18 months).

Conclusions

Simultaneous RIRS for ipsilateral asymptomatic renal stones in patients with ureteroscopic symptomatic ureteral stone removal can be performed safely and effectively. It promises a high SFR with lower auxiliary treatment rate, and does not lengthen hospital duration and increase complications.

Initial experiences with laparoscopy and flexible ureteroscopy combination pyeloplasty in management of ectopic pelvic kidney with stone and ureter-pelvic junction obstruction

To demonstrate the safety and efficacy of combine laparoscopy and flexible ureteroscopy to treat ectopic pelvic kidneys with ureteropelvic junction obstruction (UPJO) and stones. 16 patients of ectopic pelvic kidneys with ureteropelvic junction obstruction and stones were treated with laparoscopy and flexible ureteroscopy (FURS). The operative time, required dose of tramadol, visual analog pain scale (VAPS), postoperative day, stone-free rates (SFRs), perioperative complications, and serum creatinine were evaluated. The SFRs were evaluated with noncontrasted renal computed tomography (CT). Intravenous pyelography (IVP) and CT scan were used to evaluate the UPJO. Stone-free status was defined as absence of stone fragments in kidney or the size of that is less than 3 mm. Operation time from 118 to 225 min, average time (171 ± 28) min; lithotomy time from 16 to 45 min, average time (32 ± 6) min. Average tramadol required at the first day postoperation was (118 ± 49.6) mg; at the second day was (78 ± 24.8) mg. VAPS score at 24 h (5.0 ± 0.7), VAPS score at 48 h (2.5 ± 0.8). Postoperative day (3.9 ± 0.6) days. Stone-free rate was 100%. Average serum creatinine was (88.7 ± 24.3) mol/L before surgery and (92.8 ± 21.6) mol/L after surgery. No major complication. No stone and obstruction recurrence in the follow-up of average 29.3 months. Combined FUR and LC is a good option for patient of ectopic pelvic kidney with renal stone and UPJO. From our initial experience, the SFRs and the effect of pyeloplasty are satisfactory and without major complication, the operative time is acceptable.

Appropriate kidney stone size for ureteroscopic lithotripsy: When to switch to a percutaneous approach

Flexible ureteroscopy (fURS) has become a more effective and safer treatment for whole upper urinary tract stones. Percutaneous nephrolithotomy (PNL) is currently the first-line recommended treatment for large kidney stones ≥ 20 mm and it has an excellent stone-free rate for large kidney stones. However, its invasiveness is not negligible considering its major complication rates. Staged fURS is a practical treatment for such large kidney stones because fURS has a minimal blood transfusion risk, short hospitalization and few restrictions on daily routines. However, as the stone size becomes larger, the stone-free rate decreases, and the number of operations required increases. Therefore, in our opinion, staged fURS is a practical option for kidney stones 20 to 40 mm. Miniaturized PNL combined with fURS should be considered to be a preferred option for stones larger than 40 mm. Moreover, URS is an effective treatment for multiple upper urinary tract stones. Especially for patients with a stone burden < 20 mm, URS is a favorable option that promises a high stone-free rate after a single session either unilaterally or bilaterally. However, for patients with a stone burden ≥ 20 mm, a staged operation should be considered to achieve stone-free status.