Percutaneous nephrolithotomy versus retrograde intrarenal surgery: a systematic review and meta-analysis

Comparison of the efficacy and safety of shockwave lithotripsy, retrograde intrarenal surgery, percutaneous nephrolithotomy, and minimally invasive percutaneous nephrolithotomy for lower-pole renal stones: A systematic review and network meta-analysis

BACKGROUND

Shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), and minimally invasive PCNL are currently therapeutic options for lower-pole renal stones (LPS). However, the optimal treatment for LPS remains unclear. A comprehensive evaluation of the efficacy and safety of each intervention is needed to inform clinical decision-making. This study aimed at assessing the efficacy and safety of different interventions for LPS.

METHODS

PubMed, Embase, ScienceDirect, ClinicalKey, Cochrane Library, ProQuest, Web of Science, and ClinicalTrials.gov were searched from inception to December 6th 2018. Only randomized controlled trials (RCTs) including the patients treated for LPS were included. The frequentist models of network meta-analysis were used to compare the effect sizes. The primary outcome was stone free rate, and the secondary outcomes were overall complication rate, major complication rate, retreatment rate, and auxiliary procedure rate.

RESULTS

This study included 13 RCTs comprising 1832 participants undergoing 6 different interventions, including RIRS, PCNL, Mini-PCNL, Micro-PCNL, SWL, and conservative observation. PCNL had the best stone free rate (odds ratio [OR] = 3.45, 95% confidence interval [CI] = 1.30-9.12), followed by Mini-PCNL (OR = 2.90, 95% CI = 1.13-7.46). Meta-regression did not find any association of the treatment effect with age, sex, and stone size. Although PCNL tended to exhibit a higher complication rate, the difference of complication rate among various interventions did not achieve a statistical significance. SWL was the less effective and associated with higher retreatment rate compared with PCNL, Mini-PNCL, and RIRS.

CONCLUSIONS

PCNL was associated with the best stone free rate for LPS regardless of age, sex, and stone size. Each treatment achieved a similar complication rate compared with the others. Future large-scale RCTs are warranted to identify the most beneficial management for renal stones at a more complicated location.

A retrospective study comparing super-mini percutaneous nephrolithotomy and flexible ureteroscopy for the treatment of 20-30 mm renal stones in obese patients

Objective

This study aimed to compare the efficacy and safety of Super-mini percutaneous nephrolithotomy (SMP) and flexible ureteroscopy (F-URS) in the treatment of 20–30 mm renal stones in obese patients.

Methods

We conducted a retrospective analysis of outcomes of patients who underwent SMP and F-URS to treat 20–30 mm renal stones from August 2017 to September 2018. Patients with BMI >30 kg/m² were enrolled into this study. Forty-eight patients underwent SMP, while 104 patients underwent F-URS by the same surgeon. The patients’ demographic data, stone characteristics, perioperative parameters and outcomes, complications, stone-free rate (SFR) and overall costs were retrospectively assessed.

Results

No significant differences were found between the two groups in terms of age, gender, BMI, operation side, stone size, number, locations, stone compositions and CT value. The mean operation time was significantly shorter in the SMP group (p < 0.001), while the F-URS group had significantly shorter postoperative stays (p < 0.001) and lower complication rates (p < 0.001). Both groups had similar SFR at a 3-month follow-up (p = 0.190), while the SMP group achieved significant higher SFR 3 days after the operation (p < 0.001). The SMP group had a significantly lower overall cost and fewer stage-2 procedures than the F-URS group.

Conclusion

SMP and F-URS are equally effective in obese patients with 20–30 mm renal stones. However, F-URS offers the advantage of a lower complication rate, while SMP performed better in terms of operation time, tubeless rate, stage-2 procedures and overall costs.

Advantages of retrograde flexible ureteroscopy in determining the etiology of painless hematuria originating from the upper urinary tract

The present study investigated the use of retrograde flexible ureteroscopy (RFU) in the discrimination of the etiology of hematuria that originates from the upper urinary tract (UUT). The present study collected retrospective data for patients who presented with hematuria and cystoscopy-detected bleeding from the UUT between June 2006 and August 2018 in Ningbo First Hospital. All patients accepted RFU to determine the etiology of hematuria. Data regarding imaging examinations, surgery, pathology and complications were also collected and analyzed. In total, 65 patients (males, 38; females, 27) with a mean age of 63 years underwent RFU to determine the etiology of hematuria originating from the UUT. Using RFU, UUT tumors were found in 29 cases. Stones, polyps and atypical hyperplasia were found in two cases, and a definite diagnosis was not found in three cases. There were 17 cases without obvious abnormalities and nine cases were unable to undergo RFU due to ureteral stenosis. In patients who could not be diagnosed by imaging examination, 34.4% (11/32) were diagnosed with urothelial carcinoma by RFU, and these results were also confirmed by postoperative pathology. In the present study, no patient had severe complications after RFU. The present results suggested RFU may be used as a sensitive method to diagnose UUT tumors (78.4%; 29/37) and has strong specificity. RFU could be performed as a routine examination for patients with hematuria from the UUT.

Impact of case volume per year on flexible Ureteroscopy practice: an internet based survey

Background

To report current worldwide variation in techniques and clinical practice of flexible ureteroscopy (FURS) among endourologists of different case volumes per year.

Methods

Two invitations to complete an internet survey were emailed to Endourological Society members. Some of survey questions asked about indications of using FURS for renal and upper ureteral stones. Others were concerned with clinical practice of FURS (such as preoperative stenting, use of ureteral access sheath (UAS) and safety guidewire, technique of Laser lithotripsy and fragment retrieval, and post-FURS stenting. Responders were distributed into two groups; high-volume (> 100 cases/year) and low-volume surgeons (< 100 cases/year) and data were compared between both groups.

Results

Responses were received from 146 endourologists all over the world (62 high-volume and 84 low-volume). FURS for intrarenal stone > 20 mm was used by 61% of high-volume surgeons compared with 28.6% for low-volume (P < 0.001). Semirigid URS was used for upper ureteric stones in 68% among high-volume group and 82% in low-volume group (P = 0.044). UAS was used by 62% in low-volume group and 69% in high volume group (P = 0.516). Laser stone dusting was preferred by 63% in low-volume group versus 45% by high-volume (P = 0.031). More responders in low-volume group preferred to leave the stent for 6 weeks (P = 0.042).

Conclusions

The use of FURS for treating upper tract calculi has expanded by high volume endourologists to include large renal stones > 20 mm. Low-volume surgeons prefer to use semi-rigid URS for treatment of upper ureteral stones, to apply Laser stone dusting and maintain ureteral stents for longer periods.

Safety and efficacy of a single middle calyx access (MCA) in mini-PCNL

To compare outcomes of a single middle calyx access (MCA) with a single upper or lower calyceal access in mini-PCNL. From May 2015 through August 2018, patients' files who underwent a single renal access mini-PCNL were retrospectively reviewed. All patients underwent fluoroscopic-guided access (16-20 F) in the prone position. They were categorized into group 1 (MCA) and group 2 (either upper or lower calyceal access). Compared preoperative items included stone location, size, number and complexity (according to Guy's score). The compared outcome parameters were complication and stone-free rates. The study comprised 512 consecutive patients, 374 patients in group 1 and 138 in group 2. A single MCA was utilized to access 95% of proximal ureteral calculi, 89% for ureteropelvic junction stones, and 84% for stones present in the pelvicalyceal system and ureter. MCA was used in 89% of complete staghorn stones and 73% of multiple stones. the Stone-free rates (93% vs 90.6%, P = 0.350) and the complications rates (8% vs 7.2%, P = 0.772) were comparable between group 1 and 2 despite that MCA was used for most cases with complex stones. Complications severity were also comparable (P = 0.579). Mini-PCNL performed through a single MCA is effective and safe. This access can be used for the treatment of renal and upper ureteral calculi of different complexities and locations.

Percutaneous nephrolithotomy versus shock wave lithotripsy for high-density moderate-sized renal stones: A prospective randomized study

Context:

The management of renal stones of high density (>1000 Hounsfield units) on non-contrast computed tomography (NCCT), and moderate sized (15-25 mm) is still debatable.

Aims:

The aim of this study was to compare the outcomes of percutaneous nephrolithotomy (PCNL) and shock wave lithotripsy (SWL) for the high-density and moderate-sized renal stones regarding the stone-free rate (SFR), morbidity, and patients' quality of life.

Settings and Design:

This is a prospective randomized study.

Patients and Methods:

Eighty consecutive patients with renal stones, excluding those with lower calyceal stones, were randomized to receive either PCNL or SWL (40 in each arm). Patients were followed up by abdominal ultrasound and plain X-ray (NCCT if indicated) till clearance of stone. Outcomes, complications, costs, and SF-8 Health Survey scoring were recorded for each group.

Statistical Analysis:

We used Stata software, version 9.2 (Intercooled STATA®; StataCorp LP College Station, Texas, USA). Comparison of the two groups was made with regard to patient and stone criteria and the procedure details. Continuous variables were compared using the Mann–Whitney U-test with values shown as the median and interquartile range. Categorical variables were compared using the Pearson's Chi-square/Fisher's exact test. Multivariate logistic regression analysis was used to identify variables independently associated with the stone clearance after two sessions of SWL. P < 0.05 was considered statistically significant.

Results:

The basic characteristics of both groups were comparable. After a single treatment session, the SFR was 80% and 27.5% for PCNL and SWL, respectively (P < 0.001). The overall 3-month SFR was 87.5% versus 90%, respectively (P = 0.723). The median number of the required maneuvers was 1 (range: 1–3) for PCNL versus 2 (range: 1–4) for SWL (P < 0.001). The complication rate was 10% and 7.5%, respectively (P = 0.692). The cost of SWL was significantly lower (P < 0.001). On multivariate analysis, a single stone was an independent predictor for stone clearance after two sessions of SWL (odds ratio: 7.26, 95% confidence interval: 1.13–46.62, P = 0.037).

Conclusions:

PCNL for the dense, and moderate-sized renal stone provides higher initial success and lower re-treatment rates compared with SWL with comparable outcome after 3 months of therapy. However, SWL is an alternative, especially for a single stone.

Laser fibre, rather than the stone, may harm the scope: retrospective monocentric analysis of 26 pre- and intraoperative factors of flexible ureteroscope (fURS) damage

PURPOSE

The increasing number of flexible ureteroscopy procedures, the fragility of devices and their repair costs are a burden for urological departments worldwide. The objective was to investigate the impact of 26 pre- and intraoperative factors on reusable flexible ureteroscope (fURS) damage.

METHODS

All procedures were conducted with reusable fURS: Karl Storz Flex-X2 or Olympus URF-V. Statistical analysis was performed in RStudio (1.0.136) with Chi-square test and Mann-Whitney U tests (MWU).

RESULTS

In total, 416 flexible ureteroscopies, performed between September 2013 and June 2017, were analysed. 283 (68.03%) of these were for kidney stone surgery, and 133 (31.97%) for diagnostic purposes. In total, 39 (9.38%) devices were postoperatively deemed defective. The application of reusable laser fibre through fURS was more common in cases with documented defects [17/39 (43.59%) vs. 102/377 (27.06%), p = 0.047]. Other factors such as application of nitinol basket, biopsy via fURS, insertion of access sheath (UAS), as well as stone burden [median kidney stone maximal diameter: 6 mm (min 2.0; max 30.0) vs. 6 mm (min 1.0 vs. max 30.0)] showed no influence on fURS damage rate (p > 0.05). The infundibulopelvic angle (IPA) was steeper in cases with fURS damage as compared to cases without damage [median 44.0° (min 20.0; max 81.0) vs. 55.0 (min 7.0; max 122.0), p < 0.001].

CONCLUSIONS

Application of laser fibre via fURS can be considered as a risk factor of fURS damage. Stone burden, as well as the usage of not-sharp ended devices as nitinol baskets or forceps, is primarily not responsible for fURS damage.

Minimally invasive percutaneous nephrolithotomy versus retrograde intrarenal surgery in surgical management of upper urinary stones - A systematic review with meta-analysis

OBJECTIVE

The purpose of this study was to retrospectively assess the efficacy and safety of minimally invasive nephrolithotomy (MPCNL) versus retrograde intrarenal surgery (RIRS) in the management of upper urinary stones.

METHODS

A comprehensive literature review of articles that investigated the efficacy and safety of MPCNL and RIRS was conducted by systematically searching PubMed, EMBASE, and Cochrane Library in March 2019. Two reviewers searched the literature, independently extracted the data and evaluated the quality of the data according to the inclusion and exclusion criteria. A meta-analysis was performed by using Review Manager 5.3 software.

RESULTS

Eight randomized controlled trials (RCTs) involving 725 patients with upper urinary stones were analysed based on the inclusion criteria. While MPCNL has a better clinical efficacy than RIRS with respect to the stone-free rate (SFR) [RR = 1.11, 95% CI (1.05-1.17), p = 0.0005], MPCNL has a higher incidence of haematoma [RR = 3.09, 95% CI (1.44-6.66), p = 0.004] and longer hospitalization time [MD = 0.89 day, 95% CI (0.07-1.72), p = 0.04]. In addition, no significant difference in operative time [MD = 2.46 min, 95% CI (-17.99 to 22.92), p = 0.81] and postoperative pain score [MD = 0.74, 95% CI (-0.45 to 1.94), p = 0.22] were observed between the two methods. Overall, the evidence was insufficient to suggest a statistically significant difference in the adverse event profile for MPCNL compared with RIRS.

CONCLUSIONS

Our data suggest that MPCNL is an effective method for treating upper urinary stones, especially lower calyceal stones that are 1-2 cm in size. Compared to RIRS, MPCNL is associated with a longer hospital stay time and a higher incidence of haematoma. In addition, both methods have proven to be safe. Nevertheless, the findings should be further confirmed through well-designed prospective RCTs with a larger patient series.

Retrograde intrarenal surgery and percutaneous nephrolithotomy for the treatment of stones in horseshoe kidney; what are the advantages and disadvantages compared to each other?

Introduction

Kidney stones occur more frequently in patients with a horseshoe kidney (HSK) anomaly. Abnormal anatomy may make the stone removal procedures more difficult. Therefore we aimed to evaluate and compare retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) for the treatment of renal stones in the HSK anomaly.

Material and methods

In this descriptive study, patients with HSK anomaly who underwent RIRS and PCNL procedures were retrospectively evaluated. Demographic and renal stone characteristics, success and complications associated with the surgical methods were compared across patients.

Results

A total of 49 patients were evaluated, 28 underwent RIRS and 21 underwent PCNL. No differences were determined between the groups concerning the demographics of patients and stone characteristics. A single session and final stone-free rate was 71.4% and 85.7% in RIRS, 81% and 90.5% in PCNL (both p ≥0.05). However, RIRS had more re-treatment rate, while its mean length of hospital stay was shorter than PCNL (p = 0.035, p = 0.001). While no differences were detected between the associated complication rates, more of the complications encountered in the PCNL group were of a serious nature.

Conclusions

In the HSK anomaly, renal stones can be treated with RIRS and PCNL procedures with high success. With its minimal morbidity, low complication rates and the minor character of the associated complications, the RIRS procedure can sometimes be preferred to avoid complications related to PCNL in HSK anomaly with big sized kidney stones.

Prevalence and Predictors of Contrast-Induced Nephropathy (CIN) in Patients with ST-Segment Elevation Myocardial Infarction (STEMI) Undergoing Percutaneous Coronary Intervention (PCI): A Meta-Analysis

Background

Contrast-induced nephropathy (CIN) becomes more and more frequent after percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). There have been no reported meta-analyses to determine the role of these risk factors in predicting CIN in patients with STEMI undergoing PCI. So we made this meta-analysis to summarize the incidence of CIN in patients with STEMI undergoing PCI and to study associations between CIN and several risk factors that are mentioned in most prevention guidelines.

Hypothesis

The overall incidence of CIN in patients with STEMI undergoing PCI is not low. Many risk factors could influence the occurrence of CIN, such as hypertension, diabetes mellitus (DM), and lower estimated glomerular filtration rate.

Methods

Databases, including PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Chinese BioMedical (CBM), were searched for articles published before May 21, 2019, to identify all relevant studies on CIN. The pooled data were analyzed using either fixed-effects or random-effects models depending on heterogeneity (assessed via the I ² index).

Results

Twelve articles encompassing a total of 6342 patients were included. The overall pooled CIN incidence was 13.3% (95% CI: 10.4-17.1). The forest plots showed positive associations between CIN and the presence of hypertension, diabetes mellitus, history of prior myocardial infarction, age, damaged left anterior descending artery, Killip class ≥2, decreased left ventricular ejection fraction, lower estimated glomerular filtration rate, and left ventricular ejection fraction <40%; the odds ratios for these factors were 1.85 (95% CI: 1.57-2.18; p < 0.00001), 1.83 (95% CI: 1.47-2.29; p < 0.00001), 2.14 (95% CI: 1.46-3.14; p < 0.0001), 7.79 (95% CI: 5.24-10.34; p < 0.00001), 1.92 (95% CI: 1.15-3.22; p=0.01), 3.12 (95% CI: 2.21-4.40; p < 0.00001), -6.15 (95% CI: -9.52 to -2.79; p=0.0003), -15.06 (95% CI: -24.75 to -5.36; p=0.002), and 5.53 (95% CI: 1.10-27.95; p=0.04), respectively.

Conclusion

The overall incidence of CIN in patients with STEMI undergoing PCI was not low and was closely associated with hypertension, diabetes mellitus, history of prior myocardial infarction, age, damaged left anterior descending artery, Killip class ≥2, decreased left ventricular ejection fraction, lower estimated glomerular filtration rate, and left ventricular ejection fraction <40%.

The evolution of percutaneous nephrolithotomy: Analysis of a single institution experience over 25 years

INTRODUCTION

Over time, the incidence of nephrolithiasis has risen significantly, and patient populations have become increasingly complex. Our study aimed to determine the impact of changes in patient demographics on percutaneous nephrolithotomy (PCNL) outcomes.

METHODS

A retrospective analysis of a prospectively collected database was carried out from 1990-2015. Patient demographics, comorbidities, stone and procedure characteristics were analyzed. Multivariate logistic regression was used to evaluate differences in operative duration, complications, stone-free rate, and length of stay.

RESULTS

A total of 2486 patients with a mean age of 54±15 years, body mass index (BMI) of 31±8, and stone surface area of 895±602 mm² were analyzed; 47% of patients had comorbidities, including hypertension (22%), diabetes mellitus (14%), and cardiac disease (13%). Complication rate was 19%, including a 2% rate of major complications (Clavien grade III-V). There was a statistically significant increase in patient age, BMI, and comorbidities over time, which was correlated with an increased complication rate (odds ratio [OR] 1.15; p=0.010). The overall transfusion rate was 1.0% and remained stable (p=0.131). With time, both OR duration (mean Δ 16 minutes; p<0.001) and hospital length of stay (mean Δ 2.4 days; p<0.001) decreased significantly. Stone-free rate of 1873 patients with available three-month followup was 87% and decreased significantly over time (OR 1.09; p<0.001), but was correlated with an increased use of computed tomography (CT) scans for followup imaging.

CONCLUSIONS

Despite an increasingly complex patient population, PCNL remains a safe and effective procedure with a high stone-free rate and low risk of complications.

Nationwide Readmission Rates Following Percutaneous Nephrolithotomy: Does Age Matter?

Introduction/Objectives: Despite minimal evidence that evaluates the effect of age on percutaneous nephrolithotomy (PCNL) morbidity, pediatric and elderly patients are considered high-risk groups. Our objective was to assess the effect of the extremes of ages on PCNL readmission and postoperative complication rates. Methods: We identified all PCNL encounters in the 2013 and 2014 Nationwide Readmission Database. Encounters were divided into five age groups: pediatric (<18 years old), young adult (18-25 years old), adult (26-64 years old), geriatric (65-74 years old), and elderly (≥75 years old). Weighted descriptive statistics were used to describe population demographics. We fit an adjusted weighted logistic regression model for 30-day readmission and complication rates. Results: We identified 23,357 encounters. Testing average effect of pediatric and elderly encounters to all other age groups did not reveal a difference in odds for 30-day readmissions, but did result in increased odds for 30-day GU readmissions (odds ratio: 17.7 [95% confidence interval (CI): 2.65-118.9]; p = 0.003). Compared to all other age groups, elderly encounters had 7.5 (95% CI: 2.5-22.7; p = 0.0004) times the odds of a 30-day readmission and 68.3 (95% CI: 29.1-160.4; p < 0.0001) times the odds of a postoperative complication. Conclusions: When comparing the average effect of the extremes of ages to all other age groups, we did not find evidence to suggest a difference in odds for 30-day GU readmissions, but did find increased odds for complications. Further examination revealed that PCNL encounters of elderly patients had significantly increased odds for both readmission and complications, whereas PCNL encounters of pediatric patients did not.

Size is Not Everything That Matters: Preoperative CT Predictors of Stone Free After RIRS

OBJECTIVE

To define computed tomography (CT) predictors of residual fragments after retrograde intrarenal surgery (RIRS) for kidney stones up to 20 mm in patients never submitted to surgical procedures for stone removal.

METHODS

From August 2016 to August 2017, symptomatic adult patients with kidney stones less than 20 mm treated by RIRS had their pre- and postoperative CT prospectively evaluated in search for predictors of residual stone fragments. Stone size, stone volume, number of stones, stone density, and location were evaluated in preoperative CT and analyzed as predictors for residual stone fragments on 90 POD CT. Stone location was represented by the infundibulopelvic angle (IPA) measured for each stone on preoperative noncontrast CT using multiplanar reconstruction.

RESULTS

Ninety-two patients were successfully submitted to RIRS. Bilateral procedures were performed in 23 patients (25%) resulting in 115 renal units operated. Operative time was 54.5 ± 26.7 minutes (mean ± SD) and 96.7% (89/92) of the patients were discharged up to 12 hours after the procedure. Postoperative CT demonstrated stone-free in 86 of 115 (74.8%), 0-2 mm in 10 of 115 (8.7%), and > 2 mm residual fragments in 19 of 115 (16.5%) procedures. Logistic regression analysis revealed steep IPA was a predictor for any residual stone fragment after RIRS for kidney stones < 20 mm (P= .012). ROC curve showed that IPA < 41° was associated with a higher chance of residual fragments after RIRS.

CONCLUSION

IPA < 41° is associated with a higher chance of residual fragments after RIRS for kidney stones up to 20 mm.

Contemporary Trends in Percutaneous Nephrolithomy Across New York State: A Review of the Statewide Planning and Research Cooperative System

Introduction and Objectives: Percutaneous nephrolithotomy (PCNL) is a complex multistep surgery that has shown a steady increase in use for the past decade in the United States. We sought to evaluate the trends and factors associated with PCNL usage across New York State (NYS). Our goal was to characterize patient demographics and socioeconomic factors across high-, medium-, and low-volume institutions. Materials and Methods: We searched the NYS, Statewide Planning and Research Cooperative System (SPARCS) database from 2006 to 2014 using ICD-9 Procedure Codes 55.04 (percutaneous nephrostomy with fragmentation) for all hospital discharges. Patient demographics including age, gender, race, insurance status, and length of hospital stay were obtained. We characterized each hospital as a low-, medium-, or high-volume center by year. Patient and hospital demographics were compared and reported using chi-square analysis and Student's t-test for categorical and continuous variables, respectively, with statistical significance as a p-value of <0.05. Results: We identified a total of 4576 procedures performed from 2006 to 2014 at a total of 77 hospitals in NYS (Table 1). Total PCNL volume performed across all NYS hospitals increased in the past decade, with the greatest number of procedures performed in 2012 to 2013. Low-volume institutions were more likely to provide care to minority populations (21.4% vs 17.3%, p < 0.001) and those with Medicaid (25.5% vs 21.5%, p < 0.001). High-volume institutions provided care to patients with private insurance (42.1% vs 34.0%, p < 0.001) and had a shorter length of stay (3.3 days vs 4.1 days, p < 0.001). Conclusion: Our data provide insight into the patient demographics of those treated at high-, medium-, and low-volume hospitals for PCNL across NYS. Significant differences in race, insurance status, and length of stay were noted between low- and high-volume institutions, indicating that racial and socioeconomic factors play a role in access to care at high-volume centers.

Is the Efficacy and Safety of Retrograde Flexible Ureteroscopy in the Elderly Population Different from Non-elderly Adults?

Background and objectives The population of elderly adults is increasing globally, and due to metabolic changes related to advanced age, many elderly adults experience kidney stones. Flexible ureteroscopy (f-URS) is a minimally invasive procedure to treat kidney stones, but it is not free of complications. The goals of this study were to analyze the efficacy and safety of f-URS in the management of kidney stones in patients aged ≥60 years and compare the outcomes of this surgery with the outcomes of the same surgery in a younger population. Materials and methods We retrospectively reviewed patient data from 1750 patients who met our inclusion criteria and received f-URS at the urology clinic of our hospital from 2012 to 2017. Patients were assigned into two groups: those aged ≥60 years (Group 1, n=291) and those aged 19-59 years (Group 2, n=1459). The perioperative results were evaluated comparatively. We performed multivariable analyses for factors predicting complications. Results When we compared the groups on demographic attributes, we noted statistically significant differences in gender, body mass index (BMI), and American Society of Anesthesiologists scores. Stone size and operation time were higher in the ≥60-year age group (Group 1). Other stone characteristics and operative features were similar. Stone-free rates (SFR) after the first procedure were 88.0% in Group 1 and 89.2% in Group 2. SFR and success rates at three months were similar for both groups. The complication rates were similar, and multivariable regression analysis revealed the most important factor affecting the complications was the presence of residual stones in both groups. The second most important factor affecting the complication was the operation time in Group 1 and the number of stones in Group 2. Conclusion In our study, there were no significant differences in terms of results and complications among elderly and young patients after f-URS except for the duration of the operation. The prolongation of operation time results in worse outcomes in terms of perioperative complications in patients aged ≥60 years. f-URS is a relatively safe and efficient procedure, with a small risk of minor complications even in the elderly population, with increased comorbidity.

The Urological Association of Asia clinical guideline for urinary stone disease

The Urological Association of Asia, consisting of 25 member associations and one affiliated member since its foundation in 1990, has planned to develop Asian guidelines for all urological fields. The field of stone diseases is the third of its guideline projects. Because of the different climates, and social, economic and ethnic environments, the clinical practice for urinary stone diseases widely varies among the Asian countries. The committee members of the Urological Association of Asia on the clinical guidelines for urinary stone disease carried out a surveillance study to better understand the diversity of the treatment strategy among different regions and subsequent systematic literature review through PubMed and MEDLINE database between 1966 and 2017. Levels of evidence and grades of recommendation for each management were decided according to the relevant strategy. Each clinical question and answer were thoroughly reviewed and discussed by all committee members and their colleagues, with suggestions from expert representatives of the American Urological Association and European Association of Urology. However, we focused on the pragmatic care of patients and our own evidence throughout Asia, which included recent surgical trends, such as miniaturized percutaneous nephrolithotomy and endoscopic combined intrarenal surgery. This guideline covers all fields of stone diseases, from etiology to recurrence prevention. Here, we present a short summary of the first version of the guideline - consisting 43 clinical questions - and overview its key practical issues.

Predictive factors of infectious complications in the postoperative of percutaneous nephrolithotomy

OBJECTIVE

Infectious complications (IC) following percutaneous nephrolithotomy surgery (PCNL) can be life-threatening. Our objective was to analyse preoperative predictors of IC in PCNL.

MATERIALS AND METHODS

A total of 203 patients who underwent PCNL were included in a prospective study between January 2013 and February 2016. A postoperative IC was defined as urinary infection/pyelonephritis, systemic inflammatory response syndrome or sepsis. The variables analysed were age, gender, number, size(cm) and side of stone; Hounsfield units,diabetes (insulin dependent or not), preoperative culture, isolated bacteria, multitract, bodymass index and surgical time (min). A multivariate forward stepwise (logistic regression) was performed.

RESULTS

IC occurred in 30 patients (14.8%): 9 (4.4%) had urinary infection, 14 (6.9%) systemic inflammatory response syndrome and 7 (3.5%) sepsis. In addition, 13 (43.3%) had negative preoperative urine culture, 15 (50%) positive and in 2 (6.7%) was not available. On the logistic regression analysis, stone size (cm), insulin dependent diabetes and female sex were independently associated with increased risk of IC (odds ratio [OR] 1.03, 14.6 and 7.8, respectively; P=.0001).

CONCLUSIONS

Patients with large stone burdens, insulin diabetes condition and female gender, should be counselled properly regarding postoperative infection risks and closely followed up to diagnose IC (specially sepsis) soon enough. Negative preoperative urine culture seems not reliable enough to exclude an infectious complication according to our results.

Comparison of stone-free rates following shock wave lithotripsy, percutaneous nephrolithotomy, and retrograde intrarenal surgery for treatment of renal stones: A systematic review and network meta-analysis

OBJECTIVES

To perform a systematic review and network meta-analysis comparing stone-free rates following retrograde intrarenal surgery (RIRS), extracorporeal shock wave lithotripsy (SWL), and percutaneous nephrolithotomy (PCNL) treatments of renal stones.

MATERIALS AND METHODS

Clinical trials comparing RIRS, SWL, and PCNL for treatment of renal stones were identified from electronic databases. Stone-free rates for the procedures were compared by qualitative and quantitative syntheses (meta-analyses). Outcome variables are shown as risk ratios (ORs) with 95% credible intervals (CIs).

RESULTS

A total of 35 studies were included in this network meta-analysis of success and stone-free rates following three different treatments of renal stones. Six studies compared PCNL versus SWL, ten studies compared PCNL versus RIRS, fourteen studies compared RIRS versus SWL, and five studies compared PCNL, SWL, and RIRS. The quality scores within subscales were relatively low-risk. Network meta-analyses indicated that stone-free rates of RIRS (OR 0.38; 95% CI 0.22-0.64) and SWL (OR 0.12; 95% CI 0.067-0.19) were lower than that of PCNL. In addition, stone-free rate of SWL was lower than that of RIRS (OR 0.31; 95% CI 0.20-0.47). Stone free rate of PCNL was also superior to RIRS in subgroup analyses including ≥ 2 cm stone (OR 4.680; 95% CI 2.873-8.106), lower pole stone (OR 1.984; 95% CI 1.043-2.849), and randomized studies (OR 2.219; 95% CI 1.348-4.009). In rank-probability test, PCNL was ranked as No. 1 and SWL was ranked as No. 3.

CONCLUSIONS

PCNL showed the highest success and stone-free rate in the surgical treatment of renal stones. In contrast, SWL had the lowest success and stone-free rate.

Effects of fluid absorption following percutaneous nephrolithotomy: Changes in blood cell indices and electrolytes

Background and Aims:

Effects of fluid absorption on hematological profile in the immediate postoperative period in patients undergoing percutaneous nephrolithotomy (PCNL) have not been given due importance. Considering the limited number of studies available, we conducted this study to evaluate the changes in hemodynamics, complete blood count (CBC), and electrolytes in patients undergoing PCNL using normal saline for irrigation in the prone position. Furthermore, we evaluated the common factors known to affect the absorption.

Materials and Methods:

Forty American Society of Anesthesiologist Class I or II patients aged 18–65 years were recruited who underwent PCNL under general anesthesia. Heart rate, blood pressure (BP), CBC, and serum electrolytes were recorded preoperatively and just before extubation and compared using the Student's t-test. Correlation of these changes with height and total volume of irrigating fluid, total time of irrigation, duration of operation, and total intravenous fluids administered intraoperatively were performed using the Pearson's correlation coefficient.

Results:

There was a statistically significant fall in mean hemoglobin (12.5 g/dL to 11.5 g/dL), packed cell volume (38.6%–35.6%), platelet count (2.9 × 10⁵ cells/μL to 2.5 × 10⁵ cells/μL), and sodium ion concentration (Na⁺) (138.9 meq/L to 137.7 meq/L) in the immediate postoperative period as compared to that of the preoperative values. Rest of the blood indices and electrolytes did not show any significant change. There was a significant rise in postoperative heart rate and BP. Postoperative systolic BP showed a significant positive correlation with the total volume of irrigating fluid. No significant correlation was observed with height and total time of irrigation.

Conclusion:

This study reveals that there is a significant fall in hemoglobin and Na⁺ during PCNL in the immediate postoperative period. Only, total volume of irrigating fluid and total duration of surgery had a significant correlation with blood cell indices.

Oral dissolution therapy for renal radiolucent stones, outcome, and factors affecting response: A prospective study

Background:

Urolithiasis is a widespread problem, that affects up to 10% of population. Uric acid stones come second to calcium stones in prevalence (around 10% of urolithiasis). Potassium citrate is currently the treatment of choice for urine alkalization with minimal side effects and high tolerability.

Aims and Objectives:

This study is trying to present the outcome of oral dissolution therapy (ODT) for treating radiolucent renal stones and evaluating factors affecting its success in a prospective manner.

Materials and Methods:

Between 2015 and 2018, 147 patients with solitary radiolucent renal stones were offered ODT using potassium sodium hydrogen citrate (K citrate). The study included patients diagnosed by noncontrast computed tomography (NCCT) with stone size of 5–30 mm in the longest dimension and attenuation less than 600 Hounsfield units (HU). Patient compliance, blood pressure, creatinine level, K level, and tolerance to side effects were followed up at days 3, 7, and 15 and then monthly for 3 months. Follow-up renal ultrasound at 6-week intervals and a final NCCT at the end of treatment. Successful dissolution was defined as complete stone dissolution or residual that measures up to 2 mm in maximum length. Data were collected, tabulated, and analyzed using Stata 12.0 software (Stata Corporation, College Station, TX, USA).

Results:

One hundred and thirty-nine patients were included in the analyses. The age was 45.1 ± 10.5 years. DJ stent was used in 47 (33.8%) patients. Overall response rate was 64.8%. The stone location within the kidney (pelvic or calyceal) showed no difference between responders and non-responders. Stone longest diameter was smaller in responders (17 ± 5.7 mm) versus 19.2 ± 6.1 mm in nonresponders (P value = 0.039). The mean stone attenuation value (HU) was also lower in responders (347.4 ± 68.5 HU) versus (428.9 ± 84.0 HU) in nonresponders with P < 0.001. DJ insertions seemed to have marginal effect on stone dissolution on univariate analysis but found insignificant in multivariate analysis.

Conclusion:

ODT is safe and effective in the treatment of radiolucent renal stones. The efficacy was affected by stone density and stone size with more tendencies to failure with bigger stones and denser stones. Double J stent insertion may facilitate dissolution rate. There was no effect of the baseline urinarypH, hyperuricemia, or stone location on the dissolution rate of the stones.

A study on the clinical application of a patented perfusion and suctioning platform and ureteral access sheath in the treatment of large ureteral stones below L4 level

Purpose

The purpose of the study was to evaluate the efficacy and safety of a patented perfusion and suctioning platform and ureteral access sheath in the treatment of large ureteral stones (≥ 1.5 cm) below L4 level.

Methods

We recruited 122 patients with large ureteral stones below L4 level at our hospital from December 2014 to June 2017. The patients were randomly divided into the study and control groups. Multiple operative and perioperative parameters were compared between the two groups.

Results

The study group had shorter operation time, less cases of postoperative fever, lower serum levels of PCT, IL-6 and BET within 24 h after surgery, as well as less number of cases receiving secondary surgery than the control group. Moreover, the former had a significantly higher stone clearance rate than the latter (P < 0.05; t-test or χ² test).

Conclusions

The patented perfusion and suctioning platform and ureteral access sheath are safe and effective in treating large ureteral stones (≥ 1.5 cm) below L4 level.

Present indications and techniques of percutaneous nephrolithotomy: What the future holds?

The purpose of the review was to present the latest updates on percutaneous nephrolithotomy (PCNL) procedure in terms of indications and evolving techniques, and to identify the advantages and disadvantages of each modality. The data for this review were collected after a thorough PubMed search in core clinical journals in English language. The key words included “PCNL” and “PNL” in combination with “indications”, “techniques”, “review” and “miniaturized PCNL”. Publications relevant to the subject were retrieved and critically reviewed. Current European and American Urology Association Nephrolithiasis Guidelines were included as well. The indications for standard PCNL have been changed through the past decade. Despite evolution of the procedure, innovations and the development of new technical approaches, the indications for miniaturized PCNL have not been standardized yet. There is a need for well-constructed randomized trials to explore the indications, complications and results for each evolving approach. A continuous reduction of tract size is not the only revolution of the last years. There is constant ongoing interest in developing new efficient miniature instruments, intracorporeal lithotripters and sophisticated tract creation methods. We can summarize that, PCNL represents a valuable well-known tool in the field of endourology. We should be open minded to future changes in surgical approaches and technological improvements.

Flexible ureteroscopic holmium laser lithotripsy with PolyScope for senile patients with renal calculi

The present study reported the clinical experience of using a PolyScope with holmium laser lithotripter in managing renal calculi in senile patients. Between December 2013 and December 2016, 157 senile patients (69.1±6.1 years old) were treated with PolyScope holmium laser lithotripsy for renal calculi at Xin Hua Hospital (Shanghai, China). The mean stone digitized surface area was 154.2±57.7 mm² (range, 55.8–478.3 mm²). A thorough medical history investigation, and laboratory and radiological examination were followed by proper preoperative management. The PolyScope was then passed into the renal cavities following the position of the ureteral access sheath, with laser energy maintained at 1.0–2.0 J, frequency 10–15 Hz. The demographical and operative information of senile patients were compared with that of the 332 non-senile patients operated at the same period time. The average operative time was 54.6±13.2 min (range, 37–124 min). No major complications, including ureteral perforation or sepsis were encountered. The single session stone-free rate (SFR) was 81.5% and the overall SFR was 89.2%, similar to that of the non-senile group. PolyScope combined with holmium laser lithotripter is safe and effective in managing renal calculi in senile patients compared with non-senile patients, with considerately high SFRs and low complication rates.

Retrograde intrarenal surgery: An expanding role in treatment of urolithiasis

During the past 3 decades, the surgical management of kidney stones has undergone many technological advances and one is the development of the flexible ureteroscopy. The development of this instrument as well as ancillary equipment such as baskets, graspers, and others, and improvements in lithotripsy with Holmium: YAG laser have led to expand its indications with diagnostic and therapeutic management of medical issues of the upper urinary tract such as urolithiasis and urothelial tumors. The objective of this review is to describe its indications and results in the different scenarios for the treatment of urinary stones.

Postoperative Renal Outcomes of Patients Receiving Percutaneous Nephrolithotomy versus Pyelolithotomy: A Population-Based Cohort Study

The aim of this population-based cohort study was to explore postoperative renal outcomes of patients receiving pyelolithotomy versus percutaneous nephrolithotomy (PCNL). Data were retrieved from the Taiwan National Health Insurance Research Database. During the period from Jan 1, 1998, to Dec 31, 2012, there were 2549 and 21654 patients who underwent pyelolithotomy and PCNL, respectively. The postoperative incidence of new diagnosed end stage renal disease (ESRD) was statistically analyzed and compared between the pyelolithotomy and PCNL groups. The perioperative complications of two groups were also analyzed. In comparison to pyelolithotomy, PCNL achieved lower new diagnosed ESRD (1.38% versus 2.28%, p = 0.0004). Patients receiving PCNL had significantly higher rates of preoperative hypertension, diabetes mellitus, pulmonary disease, cerebrovascular disease, and coronary artery disease. The hospital stay was shorter in PCNL groups compared with pyelolithotomy groups (8.31 days versus 12.59 days, p = 0.0006). In conclusion, PCNL contributed to lower rates of new diagnosed ESRD and hospital stay when compared to pyelolithotomy.

Urinary tract stones in cystic fibrosis

Urinary tract stones are a common problem in a general population but increasingly so in cystic fibrosis (CF) patients as survival improves. Mechanisms of stone formation are discussed, particularly those unique to CF patients. Modalities of treatment and the decision making process in this choice is outlined as well as possible future preventative strategies.

Device-Related Adverse Events During Percutaneous Nephrolithotomy: Review of the Manufacturer and User Facility Device Experience Database

INTRODUCTION AND OBJECTIVES

Percutaneous nephrolithotomy (PCNL) is an established technique for removal of large stones from the upper urinary tract. It is a complex multistep procedure requiring several classes of instruments that are subject to operator misuse and device malfunction. We report device-related adverse events during PCNL from the Manufacturer and User Facility Device Experience (MAUDE) database using a recently developed standardized classification system.

MATERIALS AND METHODS

The MAUDE database was queried for "percutaneous nephrolithotomy" from 2006 to 2016. The circumstances and patient complications associated with classes of devices used during PCNL were identified. We then utilized a novel MAUDE classification system to categorize clinical events. Logistic regression analysis was performed to identify associations between device classes and severe adverse events.

RESULTS

A total of 218 device-related events were reported. The most common classes included: lithotripter 53 (24.3%), wires 43 (19.7%), balloon dilators 30 (13.8%), and occlusion balloons 28 (12.8%). Reported patient complications included need for a second procedure 12 (28.6%), bleeding 8 (19.0%), retained fragments 7 (16.7%), prolonged procedure 4 (9.5%), ureteral injury 2 (4.8%), and conversion to an open procedure 3 (7.1%). Using a MAUDE classification system, 176 complications (81%) were Level I (mild/none), 26 (12%) were Level II (moderate), 15 (7%) were Level III (severe), and 1 (0.5%) was Level IV (life threatening). On univariate analysis, balloon dilators had the highest risk of Level II-IV complications compared with the other device classes [odds ratio: 4.33, confidence interval: 1.978, 9.493, p < 0.001]. The device was evaluated by the manufacturer in 93 (42.7%) cases, with 54.8% of reviewed cases listing the source of malfunction as misuse by the operator.

CONCLUSIONS

PCNL is subject to a wide range of device-related adverse events. A MAUDE classification system is useful for standardized, clinically-relevant reporting of events. Our findings highlight the importance of proper surgeon training with devices to maximize efficiency and decrease harm.

The "all-seeing needle" micro-PCNL versus flexible ureterorenoscopy for lower calyceal stones of ≤ 2 cm

The objectives of the study are to compare the safety and efficacy of "all-seeing needle" optical puncture system micro-percutaneous nephrolithotomy (micro-PCNL) and flexible ureterorenoscopy (FURS) for the treatment of lower calyceal stones of ≤ 2 cm and to determine the advantages and disadvantages of each. 116 patients in total with lower calyceal stones of ≤ 2 cm were randomly divided into two equal groups, "all-seeing needle" optical puncture system micro-PCNL and FURS. In both groups, holmium laser was utilized for lithotripsy. The perioperative parameters were compared between the two groups. Compared to the "all-seeing needle" micro-PCNL group, the mean operative time was significantly longer in the FURS group (P = 0.000). However, there was no significant difference between the two groups with respect to mean hemoglobin reduction (P = 0.087), complications (P = 0.731) and LOS (P = 0.856). The overall SFR of the "all-seeing needle" micro-PCNL group and FURS group was 84.5% (49/58) and 79.3% (46/58), respectively, without any significant difference between the groups (P = 0.469). For treating lower calyceal stones of ≤ 2 cm, the "all-seeing needle" micro-PCNL group had shorter operative time than FURS, while no significant differences between the two groups with respect to mean hemoglobin reduction, complications, LOS and SFR were found.

Experiencia en el manejo de litiasis renal y ureteral con ureteroscopio flexible y láser holmium en un hospital público de Bogotá: estudio retrospectivo

Objetivos Discutir y evaluar la tasa libre de cálculos y las complicaciones de la ureterolitotomía endoscópica flexible con láser holmium en el manejo de cálculos ureterales y renales basada en la experiencia de un hospital público de iii nivel en Bogotá.

Material and Métodos Estudio retrospectivo en una muestra poblacional en pacientes con litiasis renal y ureteral, tratados con ureteroscopio flexible y láser holmium, evaluándose la tasa libre de cálculos, complicaciones postoperatorias y otros parámetros. El seguimiento se realizó con radiografía de abdomen y urotac al mes del postoperatorio, la tasa libre de cálculos se definió como ausencia de cálculos residuales < 4 mm en la imagen control.

Resultados Se realizaron 44 procedimientos en 43 pacientes con edad promedio de 45 años, tiempo quirúrgico promedio 91,2 min, la tasa libre de cálculos fue del 84% (37/44) en un solo evento quirúrgico; solo un paciente requirió una segunda intervención con posterior tasa libre de cálculos del 100%. La tasa libre de cálculos ureterales fue del 92% (24/26), cáliz superior 100% (2/2), cáliz medio 100%(1/1), cáliz inferior 78% (7/9) y calicial múltiple 50% (3/6). El porcentaje de complicaciones fue del 6,8%.

Conclusiones La ureterolitotomía endoscópica flexible con láser es un procedimiento efectivo y seguro en el manejo de litiasis renal y ureteral con baja incidencia de complicaciones. Observamos que en la mayoría de los pacientes con fragmentos residuales significativos estos se encontraban en cáliz inferior o se trataba de cálculos en múltiples cálices, explicándose por el difícil acceso al cáliz inferior y la carga litiásica.

Urinary Stone Disease: Diagnosis, Medical Therapy, and Surgical Management

Clinical suspicion of urolithiasis should be evaluated with low-dose computed tomography as the first-line imaging modality for nonpregnant, adult patients. A period of observation may be appropriate for ureteral stones less than 10 mm, and medical expulsive therapy may be beneficial for facilitating passage of distal ureteral stones. Regardless of stone type, patients should adhere to a low-sodium diet and attempt to achieve a urine volume of more than 2.5 L daily. Individuals with calcium stones should maintain a normal calcium diet, and if stones persist, citrate therapy or thiazide diuretics in the setting of hypercalciuria may be indicated.

Is retrograde intrarenal surgery the game changer in the management of upper tract calculi? A single-center single-surgeon experience of 131 cases

Introduction:

Success of any modality for stone disease needs to be evaluated in terms of Stone Free Rates (SFR), auxiliary procedures needed; complications and follow up. SFR in RIRS is subject to parameters like stone burden, location, number, hardness, composition; calyceal and ureter anatomy; use of ureteric access sheath (UAS); surgeon experience etc.

Methods:

The aim of this study is to evaluate the efficacy and safety of RIRS for managing upper tract stones. The objectives include evaluating SFR in RIRS in relation to stone burden, location and number. Other objectives include evaluating SFR after re RIRS in relation to stone burden, necessity of pre DJ stenting, use of UAS and post operative complication rate. 131 patients operated by single surgeon for single/multiple renal and/or upper ureteric stones were evaluated. Stone size > 3 mm on follow up CT KUB was considered as residual. Re RIRS was required for residual stones.

Results:

The overall SFR was 76%. SFR were statistically lower with stone burden > 1.5 cm, lower calyceal stones and single stones with stone burden > 1.5 cm. SFR was 90% after 2^nd RIRS and 98.5% after 3^rd RIRS procedure. No significant difference in SFR was noted between single v/s multiple stones, single calyx v/s multiple calyx stones and renal v/s upper ureteric stones. No major complication was noted.

Conclusion:

Larger stone burden and lower calyceal location are important factors deciding SFR in RIRS. With auxiliary procedure, RIRS is safe and effective compared to PCNL.

Is the Preoperative Level of Procalcitonin a Valid Indicator for Predicting Postoperative Fever After Percutaneous Nephrolithotomy?

OBJECTIVE

To evaluate the risk factors for postoperative fever and to identify the value of preoperative procalcitonin (PCT) in predicting postoperative fever after percutaneous nephrolithotomy (PNL).

PATIENTS AND METHODS

Patients who underwent PNL between January 2014 and March 2017 were studied. In total, 363 medical records with complete data were determined to be eligible for analysis. Patients were classified into a control or febrile group according to the presence of a body temperature over 38°C. Demographic and perioperative data were compared between the groups. Variables found to be statistically significant were included in a binary logistic regression analysis.

RESULTS

Ninety-one (25.1%) patients experienced postoperative fever. Univariate analysis revealed a statistically significant difference between postoperative fever and factors, such as sex (p = 0.009), preoperative fever (p < 0.001), stone burden (p < 0.001), pyuria (p = 0.013), urine culture (p < 0.001), and serum levels of C-reactive protein (CRP) (p = 0.003), PCT (p < 0.001), and interleukin-6 (IL-6) (p = 0.003). Binary logistic regression analysis indicated the presence of preoperative fever (p = 0.037), stone burden >353 mm² (p = 0.002), PCT >0.05 ng/mL (p < 0.001), or positive urine culture (p = 0.004) as independent risk factors for postoperative fever following PNL.

CONCLUSIONS

We concluded that patients with preoperative fever, stone burden >353 mm², PCT >0.05 ng/mL, or positive urine culture were more likely to develop postoperative fever and that routinely detecting PCT levels before PNL would be helpful in predicting postoperative fever.

Trends in the management of urolithiasis in Latin America, Spain and Portugal: results of a survey in the Confederación Americana de Urología (CAU)

OBJECTIVE

To describe the trends in the current management of urolithiasis in the Confederación Americana de Urología (CAU) setting to recognise patterns of clinical practice and identify educational needs.

MATERIAL AND METHOD

An online survey was created with 31 multiple-choice questions (Spanish and Portuguese) through www.caunet.org, which revealed demographic data, patterns of clinical practice and approaches for specific clinical conditions.

RESULTS

A total of 463 practitioners from Brazil, Mexico, Argentina, Spain, Colombia, Chile and other countries (3.96% of the members of CAU) completed the survey. All participants performed some type of urolithiasis treatment: 98.5% performed semirigid ureteroscopy (URS), 83.8% performed percutaneous nephrolithotomy (PCNL), 78.2% performed flexible URS, and 67.2% performed extracorporeal lithotripsy. The youngest physicians tended to perform PCNL (P<.001), and the proportion of users of flexible URS was greater in the Portuguese countries (P=.037). The main energy source was laser (60.7%). Small-calibre PCNL was performed by 15.3% of the respondents, more often in university hospitals (P<.01) and by older practitioners (P<.01). Only 3.2% of the respondents used percutaneous access to the kidney guided exclusively by ultrasound, especially the older practitioners (P<.001). The supine position was used by 40.4% of the respondents, more often in Spain (P<.001) and in the university setting (P=.017). PCNL without nephrostomy was practiced by 3.9% of the respondents. For flexible URS, 19.2% of the respondents did not use ureteral access sheaths, and the older practitioners preferred thinner calibre sheaths (P<.001).

CONCLUSIONS

The management of lithiasis in the CAU setting follows a profile similar to that recognised in the European and American clinical guidelines, although there are interesting variations based on the practitioner's age and preferences. We identified potential areas for improvement in small-calibre PCNL and ultrasound-guided puncture.

Systematic review and meta-analysis to compare success rates of retrograde intrarenal surgery versus percutaneous nephrolithotomy for renal stones >2 cm: An update

BACKGROUND

We performed a systematic review and meta-analysis comparing stone-free rates between retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL), using updated, more reliable evidence.

MATERIALS AND METHODS

Randomized controlled trials comparing RIRS and PCNL for >2 cm stones were identified from electronic databases. Stone-free rates for the procedures were compared by qualitative and quantitative syntheses (meta-analyses). Outcome variables are shown as risk ratios (RRs) with 95% confidence intervals (CIs).

RESULTS

Eleven articles were included in this study. Most recently published studies exhibited relatively low quality during quality assessment. For the meta-analysis comparing success (stone-free) rates between PCNL and RIRS, the forest plot using the random-effects model showed an RR of 1.11 (95% CI 1.02-1.21, P < .014) favoring PCNL. After determining the among-study heterogeneity, subgroup analysis was performed of 9 studies with less heterogeneity: the stone-free rate of PCNL was superior to that of RIRS using a fixed-effect model (RR 1.07, 95% CI 1.01-1.14, P < .019) for these studies.

CONCLUSIONS

RIRS can be a safe and effective procedure for selected patients with large renal stones. However, in this meta-analysis, the postoperative stone-free rate of PCNL was higher than that of RIRS in patients with >2 cm renal stones.

Small-calibre percutaneous nephrolithotomy (SC-PCNL). Therapeutic decision algorithm

INTRODUCTION

The progressive reduction in the calibre of the tract in percutaneous kidney surgery to the point of miniaturisation has expanded its use to smaller stones that until now have been treated with extracorporeal shock wave lithotripsy (ESWL) and retrograde intrarenal surgery (RIRS).

OBJECTIVE

To provide an update on the various techniques of small-calibre nephrolithotomy (SC-PCNL) analyse their efficacy, safety and indications and determine their degree of implantation at this time.

MATERIAL AND METHODS

We performed a review in PubMed of Spanish and English medical literature on the various techniques of SC-PCNL.

RESULTS

The use of SC-PCNL has reduced the morbidity associated with standard PCNL, particularly bleeding, and has enabled tubeless nephrolithotomy with greater safety. There are various techniques with blurred terminology (Miniperc, Microperc, Mini-microperc, Ultraminiperc), which differ in terms of gauge employed and in certain technical aspects that require their indications be specified. Currently, SC-PCNL competes with techniques that are less invasive than standard PCNL such as ESWL and the RIRS in treating small stones, but the role of SC-PCNL is still not sufficiently understood and continues to be the subject of debate.

CONCLUSIONS

The indications for PCNL are expanding to small stone sizes due to the miniaturisation of the technique. PCNL competes in this field with ESWL and RIRS. Larder studies are needed to establish the specific indications for PCNL in treating nephrolithiasis.

Clinical efficacy of percutaneous nephrolithotomy versus retrograde intrarenal surgery for pediatric kidney urolithiasis: A PRISMA-compliant article

BACKGROUND

Percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) are widely used for pediatric upper tract stones; however, comparisons of their clinical efficacies are needed.

METHODS

Literature searches for relevant articles were performed using PubMed, the Cochrane Central Register of Controlled Trials, Embase and the China CNKI database. Study quality was assessed by Jadad and Newcastle-Ottawa Scales. Standard mean differences (SMDs) or odds ratios (OR), and 95% confidential intervals (95% CIs) were pooled for meta-analysis. In addition, data was evaluated the quality of the body of evidence by means of grading of recommendations assessment, development, and evaluation (GRADE).

RESULTS

Data from 4 studies (231 PCNL, 212 RIRS cases) were analyzed. There was no significant difference in operation time (SMD: 1.39; 95% CIs: -0.049 to 2.82; P = .058), overall stone-free rate (OR: 3.72; 95% CIs: 0.55-25.22; P = .18), or complication rate (OR: 1.92; 95% CIs: 0.90-4.07; P = .091). PCNL cases had longer hospital stays (SMD: 1.22; 95% CIs: 0.95-1.50; P < .001), but showed a higher stone-free rate for stones greater than 20 mm (OR: 6.38; 95% CIs: 1.83-22.22; P = .004). For stones less than 20 mm, however, no significant difference between PCNL and RIRS was found (OR: 0.92; 95% CIs: 0.33-2.55; P = .87). The quality of evidence based on the GRADE system was low.

CONCLUSION

Results of our systematic review and meta-analysis suggest that, for the treatment of larger kidney stones (>20 mm) in pediatric patients, PCNL is a better option due to its higher stone-free rate, although RIRS may be associated with shorter hospital stays. A large-scale clinical trial is necessary to validate our findings.

Retrograde intrarenal surgery and micro-percutaneous nephrolithotomy for renal lithiasis smaller than 2 CM

INTRODUCTION

Microperc is the upgraded form of percutaneous nephrolithotomy miniaturization. The aim of this study is to compare prospectively microperc and retrograde intrarenal surgery for the treatment of renal stones smaller than 2 cm.

MATERIAL AND METHODS

A comparative prospective study of both techniques was carried out between January 2014 and June 2015. Thirty-five patients were divided in two groups: Group A, 17 patients treated by retrograde intrarenal surgery and Group B, 18 patients treated by microperc. Stone clearance was assessed using CT scan 3 months after surgery.

RESULTS

Both groups were statistically comparable as demographic variables and stone size was similar (16.76 mm Group A vs 15.72 mm Group B). Success rate, hospital stay and JJ stenting were similar for both groups. There was no statistically significant difference regarding post-operatory complications: 17.64% Group A vs 5.56% Group B (p=0,062), all of them Clavien I and II. Surgical time was statistically different (63.82 min Group A vs 103.24 min Group B) as well as hemoglobin drop (0.62 g/dl Group A and 1.89 g/dl Group B).

CONCLUSION

Microperc is an effective and safe procedure for the treatment of renal lithiasis smaller than 2 cm, which makes it a good alternative to retrograde intrarenal surgery for this stone size. However, more prospective studies that include a larger cohort are necessary to confirm our results.

The application of a novel integrated rigid and flexible Nephroscope in percutaneous nephrolithotomy for renal staghorn stones

Background

Renal staghorn stones are challenging for urologists to ensure maximum stone clearance and minimal morbidity. Percutaneous nephrolithotomy (PCNL) has become the gold standard treatment for renal staghorn stones. To assess the safety and efficacy of a novel integrated rigid and flexible percutaneous nephroscope(Rigi-flex nephroscope) in PCNL for renal staghorn stones.We present our initial experience with this new technique.

Methods

From March to July 2016, a prospective analysis of 3 patients with staghorn stones treated with Rigi-flex nephroscope in PCNLunder totally ultrasound guidance by paravertebral block (PVB) anesthesia was done. PCNL was performed with the rigid section of a 13-Fr Rigi-flex nephroscope firstly and the stones were disintegrated into fragments by holmium laser.Then the stones were removed by active flushout, followed by a search for residual stones in other inaccessible calyces with the flexible section. Finally, the residual stones were disintegrated into small fractions by holmium laser in situ or repositioned with a set of disposable retrieval baskets to pelvic or other accessible areas. The whole procedure was accomplished via only one nephrostomy tract. The operating time, stone-free rates (SFR), postoperative hemoglobin drop, complications, length of hospitalization, were recorded.

Results

The operation time were 89, 62 and 45 min, respectively, the postoperative hemoglobin drop was 1, 0.8 and 0.9 mg/dl, respectively.The postoperative Kidney-Ureter-Bladder (KUB) radiograph of the three patients showed no residual fragment >3 mm. No patients needed blood transfusion and suffered significant complications. The length of hospitalization was 9, 6 and 4 days, respectively. No patient needed multiple tracts PCNL or staged auxiliary measures one month after the operation.

Conclusions

The application of Rigi-flex nephroscope in PCNL under ultrasound guidance for staghorn stones has its unique advantages as monotherapy with increasing procedural stone free rate (SFR) via single nephrostomy tract, hence there is less morbidity as it does not require additional tracts dilation and staged auxiliary procedures combination. However, SFR should also be evaluated at a longer follow-up, particularly for staghorn stone, further large-scale multicenter prospective clinical trial are needed to verify its feasibility.

Contemporary Trends in Utilization and Perioperative Outcomes of Percutaneous Nephrolithotomy in the United States from 2003 to 2014

PURPOSE

To investigate the contemporary trends and perioperative outcomes of percutaneous nephrolithotomy (PCNL) by using a population-based cohort.

MATERIALS AND METHODS

Using the Premier Healthcare Database, we identified 225,321 patients in whom kidney/ureteral calculi were diagnosed and who underwent PCNL at 447 different hospitals across the United States from 2003 to 2014. Outcomes included 90-day postoperative complications (as classified by the Clavien-Dindo system), prolonged hospital length of stay, operating room time, blood transfusions, and direct hospital costs. Temporal trends were quantified by estimated annual percentage change (EAPC) by using least-squares linear regression analysis. Multivariable logistic regression was performed to identify predictors of outcomes.

RESULTS

PCNL utilization rates initially increased from 6.7% (2003) to 8.9% (2008) (EAPC: +5.60%, p = 0.02), before plateauing at 9.0% (2008-2011), and finally declining to 7.2% in 2014 (EAPC: -4.37%, p = 0.02). Overall (Clavien ≥1) and major complication (Clavien ≥3) rates rose significantly (EAPC: +12.2% and +16.4%, respectively, both p < 0.001). Overall/major complication and blood transfusion rates were 23.1%/4.8% and 3.3%, respectively. Median operating room time and 90-day costs were 221 minutes (interquartile range [IQR] 4) and $12,734 (IQR $9419), respectively. Significant predictors of overall complications include higher Charlson comorbidity index (CCI) (CCI ≥2: odds ratio [OR] 2.08, p < 0.001) and more recent year of surgery (2007-2010: OR 3.20, 2011-2014: OR 4.39, both p < 0.001). Higher surgeon volume was significantly associated with decreased overall (OR 0.992, p < 0.001) and major (OR 0.991, p = 0.01) complications.

CONCLUSIONS

Our contemporary analysis shows a decrease in the utilization of PCNL in recent years, along with an increase in complication rates. Numerous patient, hospital, and surgical characteristics affect complication rates.

A prospective multicenter European study on flexible ureterorenoscopy for the management of renal stone

Purpose

The aim of this study was to describe the outcomes and the complications of retrograde intrarenal surgery (RIRS) for renal stones in a multi-institutional working group.

Materials and Methods

From 2012 to 2014, we conducted a prospective study including all RIRS performed for kidney stones in 4 European centers. Demographic information, disease characteristics, and perioperative and postoperative data were gathered. Patients and stone data, procedure characteristics, results and safety outcomes were analyzed and compared by descriptive statistics. Complications were reported using the standardized Clavien system.

Results

Three hundred and fifty-six patients underwent 377 RIRS with holmium laser lithotripsy for renal stones. The RIRS was completed in all patients with a mean operative time of 63.5 min. The stone-free status was confirmed endoscopically and through fluoroscopic imaging after the first procedure in 73.6%. The second procedure was performed in twenty patients (5.6%) achieving an overall stone free rate of 78.9%. The overall complication rate was 15.1%. Intra-operative and post-operative complications were seen in 24 (6.7%) and 30 (8.4%) cases, respectively.

Conclusions

RIRS is a minimally invasive procedure with good results in terms of stone-free and complications rate.