Combined Electrohydraulic and Holmium:YAG Laser Ureteroscopic Nephrolithotripsy of Large (Greater Than 4 cm) Renal Calculi

Comparison of serum Kim-1 and Miox levels in patients that underwent percutaneous nephrolithotomy and flexible ureterorenoscopy

OBJECTIVE

Percutaneous nephrolithotomy (PNL) and retrograde intrarenal surgery (RIRS) are common surgical methods in the treatment of kidney stones. Possible effects on kidneys are an important factor in determining the surgical procedure and the surgical method. In our study, kidney injury molecule-1 (KIM-1) and myo-inositol oxygenase (MIOX) were used to compare acute kidney injury in patients that underwent PNL and RIRS.

MATERIAL AND METHOD

Eighty patients aged 20-75, who underwent PNL or RIRS in our urology clinic between November 2018 and February 2020 were included in the study. In this prospective study, the demographic characteristics, stone size, operation time, preoperative and postoperative hemoglobin and biochemistry values of the patients were recorded. About 5 cc blood samples taken from the patients before the operation and at the fourth hour after the operation were centrifuged and kept at -80°C, and the KIM-1 and MIOX levels were measured in the biochemistry department.

RESULTS

There was no difference between the groups in terms of demographic data; however, the operation time and length of hospital stay were significantly longer in the PNL group. The mean increase in MIOX was 10.583 ± 9.73 and 7.501 ± 16.46 ng/ml in the PNL and RIRS groups, respectively. Although there was a statistically significant increase in both groups, this increase was greater in the PNL group. A significant increase was observed only in the PNL group in the postoperative period (p = 0.003).

DISCUSSION AND CONCLUSION

The findings of the study suggest that the PNL procedure causes more damage to the kidneys than RIRS.

Retrograde intrarenal surgery for a staghorn renal calculus in a patient with solitary kidney and urinary tract deformity: a case report

Staghorn renal calculi are large, branched stones in the kidney that partially or completely fill the renal pelvis and renal calyces. Percutaneous nephrolithotomy (PCNL) is the gold standard treatment for staghorn calculi. However, we report a retrograde intrarenal surgery (RIRS) performed to treat a staghorn calculus in a patient with a solitary kidney and a deformed urinary tract. The 37-year-old male patient presented with right-sided lumbar pain. The computed tomography (CT) scan found a solitary kidney on the right side with an opaque 4.5 cm × 2.4 cm renal stone and grade I hydronephrosis. Additionally, a urinary tract deformity was observed, and it was secondary to the deformity of the pelvis caused by a previous pubis fracture, which significantly increased the risk and the difficulty of intrarenal surgery. A total number of 3 sessions of RIRS were conducted, and the patient was discharged 3 days after each session on average. The postoperative X-ray exam of the third session revealed that the renal stone was completely removed. The patient recovered well without any complications. This case demonstrates that RIRS is a safe and effective treatment of staghorn calculi with the presence of urinary tract deformation. This suggests RIRS may be of particular interest in minimizing the procedure-related damage of a solitary kidney.

Comparison of laparoscopic pyelolithotomy and retrograde intrarenal surgery in the management of large renal pelvic stones

BACKGROUND

To compare the clinical outcomes of laparoscopic pyelolithotomy (LP) and retrograde intrarenal surgery (RIRS) in the management of large renal pelvic stones.

PATIENTS AND METHODS

This study included patients who presented with a single renal pelvic stone sized ≥20 mm and who were treated primarily by LP or RIRS. The patients were grouped based on the surgical procedure they underwent. We retrospectively examined and compared the age, the longest axis, and the surface area of the stone, operation time, hospitalization time, complications, and stone-free rates of the two groups.

RESULTS

Of the 156 patients included in the study, 44 had LP, and 112 had RIRS. Patients who received LP (13 males, 31 females) had a median age of 54 (18-79) years, while those who underwent RIRS (46 males, 66 females) had a median age of 54.5 (18-79). Patients who received LP were found to have larger median stone size (30 mm vs 24 mm, P = .003), longer operation time (100 minutes vs 70 minutes, P = .007), lower complication rate (2% vs 8.9%, P = .063), longer median hospital stay (3 days vs 1 day, P < .001) and better stone-free rate at the third month (90.9% vs 67.9%, P < .001).

CONCLUSION

LP is a safe and efficient procedure that could be used as an alternative to RIRS in managing large renal pelvic stones.

Comparative outcomes of flexible ureteroscopy and mini-percutaneous nephrolithotomy for pediatric kidney stones larger than 2 cm

OBJECTIVES

To compare the outcomes of flexible ureteroscopy and mini-percutaneous nephrolithotomy for pediatric kidney stones larger than 2 cm and to show the learning curves for the two procedures.

METHODS

A prospectively managed database containing pediatric patients with kidney stones larger than 2 cm from June 2014 to October 2019 was analyzed. The primary outcomes were the efficacy and safety of flexible ureteroscopy and mini-percutaneous nephrolithotomy. Data on patient demographics, treatment details, stone-free rate, and complication rate were collected and compared. Learning curves were generated to estimate the effect of the surgeon's experience on surgical outcomes.

RESULTS

The final analysis included 113 pediatric patients who underwent surgery for kidney stones on a total of 126 sides. The stone-free rates for mini-percutaneous nephrolithotomy and flexible ureteroscopy were 80.9% (34/42) and 79.7% (67/84), respectively (P = 0.19). The complication rates for mini-percutaneous nephrolithotomy and flexible ureteroscopy were 52.5% (21/40) and 27.4% (27/73), respectively (P = 0.01). When stone mass was considered, the stone-free rates for mini-percutaneous nephrolithotomy and flexible ureteroscopy for stones with a high mass (>5000 HU*cm² ) were 83.3% (20/24) and 55.5% (10/18), respectively (P = 0.04). The learning curves showed that the stone-free rates for both mini-percutaneous nephrolithotomy and flexible ureteroscopy increased with the accumulation of cases. A higher stone-free rate could be achieved after approximately 20 mini-percutaneous nephrolithotomy cases and after approximately 50 flexible ureteroscopy cases.

CONCLUSIONS

Flexible ureteroscopy has an acceptable stone-free rate and a lower complication rate than mini-percutaneous nephrolithotomy when treating pediatric kidney stones larger than 2 cm. Mini-percutaneous nephrolithotomy is more applicable to stones with a high mass. The stone-free rates achieved after both mini-percutaneous nephrolithotomy and flexible ureteroscopy could be improved with number of cases accumulated.

A Novel Clinical-Radiomics Model Pre-operatively Predicted the Stone-Free Rate of Flexible Ureteroscopy Strategy in Kidney Stone Patients

Purpose: The purpose of the study is to develop and validate a novel clinical-radiomics nomogram model for pre-operatively predicting the stone-free rate of flexible ureteroscopy (fURS) in kidney stone patients. Patients and Methods: Altogether, 2,129 fURS cases with kidney stones were retrospectively analyzed, and 264 patients with a solitary kidney stone were included in a further study. For lower calyx calculi, a radiomics model was generated in a primary cohort of 99 patients who underwent non-contrast-enhanced computed tomography (NCCT). Radiomics feature selection and signature building were conducted by using the least absolute shrinkage and selection operator (LASSO) method. Multivariate logistic regression analysis was employed to build a model incorporating radiomics and potential clinical factors. Model performance was evaluated by its discrimination, calibration, and clinical utility. The model was internally validated in 43 patients. Results: The overall success rate of fURS was 72%, while the stone-free rate (SFR) for lower calyx calculi and non-lower calyx calculi was 56.3 and 90.16%, respectively. On multivariate logistic regression analysis of the primary cohort, independent predictors for SFR were radiomics signature, stone volume, operator experience, and hydronephrosis level, which were all selected into the nomogram. The area under the curve (AUC) of clinical-radiomics model was 0.949 and 0.947 in the primary and validation cohorts, respectively. Moreover, the calibration curve showed a satisfactory predictive accuracy, and the decision curve analysis indicated that the nomogram has superior clinical application value. Conclusion: In this novel clinical-radiomics model, the radiomics scores, stone volume, hydronephrosis level, and operator experience were crucial for the flexible ureteroscopy strategy.

Is plasma sterilization the modality of choice of sterilization today for endourological procedures such as ureterorenoscopy and retrograde intrarenal surgery? A single-center retrospective evaluation of 198 patients

Introduction:

The prevalence of infective complications among patients undergoing Retrograde Intrarenal Surgery (RIRS) for renal stone is 1.7%-18%, including fever, Systemic Inflammatory Response Syndrome (SIRS) and sepsis. The infectious complications of RIRS can be minimised by strict aseptic precautions and plasma sterilization. The Sterrad Next Generation (Sterrad NX) System, a low-temperature sterilizer represents the next generation of low-temperature hydrogen peroxide gas plasma sterilizers. This study was conducted to evaluate the efficacy of plasma sterilization among patients undergoing ureterorenoscopy (URS) and RIRS. The primary endpoint of this study was incidence of septicemia or related complications. Till date, there is no study on the incidence of infection rate in RIRS in relation to a specific mode of sterilization.

Material and Methods:

This is a retrospective study comprising of 198 patients undergoing URS and/or RIRS. The parameters studied were incidence of post-operative fever, Systemic Inflammatory Response Syndrome (SIRS), pyelonephritis or septicemic shock.

Results:

Out of 198 patients, incidence of post-operative fever was 3.5%, SIRS was 1.7%, pyelonephritis was 0.7% and septicemic shock was 0%. This is statistically significantly low septicemia rate among patients undergoing URS and /or RIRS as compared to the available literature. No health hazards of plasma sterilization were noted. No damage to the endoscopes or instruments was noted.

Conclusion:

Sterrad NX based on hydrogen peroxide gas plasma (HPGP) technology is highly efficacious, safe and the modality for sterilization of instruments, including heat labile instruments such as semi rigid, flexible and chip on the tip endoscopes and other EndoUrology armamentarium.

RIRS with Vacuum-Assisted Ureteral Access Sheath versus MPCNL for the Treatment of 2-4 cm Renal Stone

OBJECTIVE

Comparison of outcomes between RIRS with vacuum-assisted ureteral access sheath (V-UAS) and MPCNL in the treatment of renal stone.

MATERIALS AND METHODS

28 patients with 2-4 cm renal stone were treated using RIRS with 14/16 F V-UAS. The outcomes were compared to those who underwent MPCNL with 16 F Amplatz sheath using a matched-pair analysis in a 1 : 2 scenario. Matching criteria included stone size, location and laterality, gender, age, BMI, and degree of hydronephrosis. Patients' demographics, perioperative and postoperative characteristics, complications, stone-free rate (SFR), and auxiliary procedures were compared.

RESULTS

Mean operative times for the RIRS and MPCNL groups were 72.4 ± 21.3 minutes and 67.4 ± 25 minutes (P = 0.042). Postoperative pain was significantly less in the RIRS group. The initial SFR was 50% for the RIRS group and 73.2% for the MPCNL group (P = 0.035). The final SFR at postoperative three months improved to 89.3% for the RIRS group and 92.9% for the MPCNL group (P = 0.681). The auxiliary procedure rates were higher in the RIRS group (42.9% vs. 25%, P = 0.095). The overall complication rate in the RIRS group was lower, but the significant difference was not found.

CONCLUSION

In the treatment of 2-4 cm renal stone, using V-UAS in RIRS can improve surgical efficiency with lower postoperative early pain scores. Comparing with MPCNL, its initial SFR was more depressed, and there is still a trend towards requiring more auxiliary procedures to achieve comparable final SFR.

Efficacy and safety of fURS in stones larger than 20 mm: is it still the threshold?

Introduction

The aim of this article was to evaluate the safety and efficiency of flexible ureteroscopy (fURS) in the management of renal calculi larger than 20 mm.

Material and methods

A total of 92 cases with renal calculi were managed with fURS and divided into two groups depending on the size of the stones; <20 mm and >20 mm (Group 1 and Group 2, respectively). The groups were compared with respect to treatment-related parameters including success, complication rates, hospitalization period and need for auxiliary procedures with an emphasis on the rate of infections. Success rates were also compared in each group according to stone location.

Results

Overall success rates after 3 months showed that stone-free rates in both groups were 84.1% (< 20 mm) and 58.33% (>20 mm) respectively (p = 0.008). The success rates of upper/mid pole (100% vs. 80%) and pelvis stones (83.3% vs. 75%) showed no statistically significant difference (p = 0.5, p = 0.51 respectively). Success rates for stones located in the lower pole were 75% vs. 14.28% respectively (p = 0.008). The rate of infectious complications was significantly higher in cases undergoing fURS for relatively larger stones (22.9%) as compared to smaller calculi (6.8%) (p = 0.032). No complications were recorded in Group 1, while 2 cases in Group 2 (4.1%) developed ureteral stricture.

Conclusions

Despite the relatively low stone-free rates in lower pole stones, our current results indicate that fURS can be an effective and safe treatment alternative to PNL in larger renal stones (>20 mm) located in the pelvis and in the upper part of the calyceal system of the involved kidney.

Comparison between retrograde intrarenal surgery and percutaneous nephrolithotripsy in the management of renal stones: A meta-analysis

Percutaneous nephrolithotripsy (PCNL) is recommended as the first-line treatment for the management of kidney stones that are ≥2 cm in diameter. Retrograde intrarenal surgery (RIRS) has become increasingly preferred due to its high level of safety and repeatability, particularly in small stones. However, whether PCNL has superior efficacy and lower complication rates when compared with RIRS remains controversial. Therefore, the present meta-analysis was conducted to compare the clinical outcomes of patients treated with PCNL and RIRS as therapy for renal stones. Clinical trials published in PubMed, Web of Science, Excerpta Medica dataBASE (EMBASE), and the Chinese Biomedical Database (CBM) were systematically reviewed to evaluate the efficacy and safety profiles of patients with renal stones who were treated with PCNL or RIRS. Main outcomes measures included stone-free rate, operative time, hospital stay, and complication rate. Results were expressed as risk ratio (RR), or weighted mean difference (WMD) with 95% confidence intervals (CIs). Pooled estimates were calculated using a fixed-effects or random-effects model according to the heterogeneity among the studies. In total, 17 studies [4 randomized controlled trials (RCTs) and 13 cohort studies] involving 1,717 patients met the inclusion criteria, and were included in this meta-analysis. Pooled results showed that PCNL exhibited a significantly higher stone-free rate (RR=0.90, 95% CI: 0.86 to 0.95; P<0.001) but was associated with a longer hospital stay, when compared with RIRS (WMD=-2.72, 95% CI: -3.9 to -1.54; P<0.001). Operative time (WMD=7.86, 95% CI: -0.89 to 16.61; P=0.078) and complication rate (RR=0.71, 95% CI: 0.48 to 1.05; P=0.083) did not significantly differ between the groups. Subgroup analysis revealed that PCNL had a shorter operation time than RIRS in patients with stone sizes ≥2 cm (WMD=12.88, 95% CI: 4.77 to 20.99; P=0.002), and PCNL had a similar stone-free rate as RIRS when the estimates were pooled from RCTs (RR=0.88, 95% CI: 0.76 to 1.01; P=0.078). Compared with PCNL, RIRS had a significantly lower stone-free rate, shorter hospital stay, but a similar operation time and complication rate. Therefore, we propose that RIRS may be an alternative therapy to PCNL, with acceptable efficacy and complication rates for renal stones. Further large-scale, well-conducted RCTs are required to verify our findings.

Sheathless and fluoroscopy-free retrograde intrarenal surgery: An attractive way of renal stone management in high-volume stone centers

Objective

To evaluate the efficacy and safety of sheathless and fluoroscopy-free flexible ureterorenoscopic laser lithotripsy (FURSL) for treating renal stones.

Methods

Between May 2015 and May 2017, 135 patients with renal stones treated with sheathless and fluoroscopy-free FURSL were prospectively evaluated. Our technique involved a semi-rigid ureteroscopic assessment of the ureter, and the guidewire was left in situ to railroad the flexible ureteroscope. A holmium laser was used to fragment and dust the stones; fragments were neither grasped nor collected.

Results

The study population consisted of 135 patients including 85 males (62.96%) and 50 females (37.04%) with a mean age of 40.65 years (range: 3–70 years) were evaluated. The mean stone size was 17.23 mm (range: 8–41 mm). Complete stone-free status was achieved in 122 (90.37%) patients and clinically insignificant residual fragments (CIRF) in two (1.48%), while residual stones were still present in 11 (8.15%) patients. Postoperative complications occurred in 23 (17.4%) cases and were mostly minor, including fever in 17 (12.6%), pyelonephritis in four (3.0%), subcapsular hematoma in one (0.7%) and steinstrasse in one (0.7%). These complications were Clavien I-II, GI in 17 (12.6%) patients, GII in five (3.7%), and Clavien IIIb in one (0.7%). No major complications were observed. Stone size ≥2 cm, operative time ≥30 min, and lasing time ≥20 min were significantly associated with a higher rate of complications and lower stone-free rates upon univariate analysis (p<0.05).

Conclusion

Sheathless and fluoroscopy-free FURSL are effective and safe for renal stone management, especially for stones under 2 cm in diameter. This process is a feasible option for avoiding sheath complications, which can protect surgeons from the negative effects of radiation.

Propensity Score-Matched Analysis Comparing Retrograde Intrarenal Surgery with Percutaneous Nephrolithotomy for Large Stones in Patients with a Solitary Kidney

PURPOSE

To evaluate the clinical efficacy, safety, and cost of retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) in the treatment for large renal stones in patients with a solitary kidney.

PATIENTS AND METHODS

In this study, 117 patients with a solitary kidney who had undergone PCNL or RIRS for renal stones larger than 2 cm between January 2010 and December 2016 were retrospectively evaluated. The patients' demographic data, clinical characteristics, and perioperative outcomes were collected through a review of their medical records. Forty-three patients treated with PCNL were compared to 43 patients treated with RIRS by propensity score-matched analysis. The stone-free rate, retreatment rate, complication rate, and efficacy quotient (EQ) were assessed in both groups.

RESULTS

Initial stone-free rate of the PCNL group after a single procedure was significantly higher compared with the RIRS group (74.42% vs 34.88%, p < 0.001), whereas there was no significant difference in the final stone-free rate after repeated procedures (90.70% vs 88.37%, p = 0.713). PCNL had a significantly lower retreatment rate than RIRS (16.28% vs 63.79%, p < 0.001), and the PCNL group underwent fewer procedures than the RIRS group (p < 0.001). Thus, PCNL group had a higher EQ (78.00% vs 53.52%). Although cost per procedure of PCNL was significantly higher compared with RIRS (p < 0.001), the total costs were comparable. Complication rate of RIRS was lower compared with PCNL with no statistical significance (p = 0.193), and acute kidney injury rates were also comparable (PCNL vs RIRS: 13.95% vs 6.98%, p = 0.533).

CONCLUSIONS

With fewer repeated surgical procedures, higher EQ, and comparable total costs, PCNL is recommended as the first choice for the treatment of large renal calculi in patients with a solitary kidney. As for specific indications such as anticoagulant drugs, RIRS is a safer choice with fewer complications and acceptable final stone-free rate.

Factors affecting infectious complications following flexible ureterorenoscopy

In the present study, we aimed to clarify predictive factors that may cause postoperative infectious complications after flexible ureterorenoscopy (f-URS). In a 4-year prospective study, charts of patients who underwent f-URS between January 2014 and January 2018 for renal stone(s) in a tertiary academic center were reviewed. A standardized f-URS procedure was performed for all patients. Post-operative infectious complications including fever, sepsis and septic shock were categorized into same group. Patients with and without infectious complications were compared in the terms of preoperative, operative and post operative characteristics. In total, 463 patients who did not face infectious complications and 31 patients who faced infectious complications were enrolled into the study. The mean age was significantly lower in patients who did face infectious complications (34.8 vs 44.7 years old, p < 0.001). On the other hand, presence of renal abnormality was significantly more common in patients with infectious complications (12.3% vs 35.5%, p < 0.001). The mean operation time was 65.3 min in patients with infectious complications and significantly longer when compared with patients who did not face infectious complication (47.8 min, p < 0.001). Stone-free rate was significantly higher in patients without infectious complications (85.3% vs 77.5, p = 0.009). Multivariate regression analysis revealed that longer operation time ≥ 60 min, presence of renal abnormality and age ≤ 40 years were predictive factors for infectious complications following f-URS. The present study has demonstrated that operation time ≥ 60 min, presence of renal abnormality and patients with ≤ 40 years were significantly associated with infectious complications following f-URS.

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.

Ureteroscopy and laser stone fragmentation (URSL) for large (≥1 cm) paediatric stones: Outcomes from a university teaching hospital

INTRODUCTION

The treatment of large renal stones (≥1 cm) in paediatric patients is challenging. The usual treatment options include percutaneous nephrolithotomy (PCNL) or shockwave lithotripsy (SWL). There is a rise in the use of ureteroscopy and laser stone fragmentation (URSL) for paediatric stones; however, outcomes of treatment for large renal stones in this age group are still largely unknown.

OBJECTIVE

To investigate the outcome of URSL for large paediatric renal stones ≥1 cm treated at the present institution over the last 5 years.

METHODS

A retrospective review was performed of outcomes from the prospectively maintained stone database. Only paediatric patients undergoing ureteroscopic (rigid or flexible ureteroscopy (URS)) procedures for stones ≥1 cm were included. Patient demographics, operative details, stone burden, hospital stay, complications and stone clearance were recorded and analysed.

RESULTS

From April 2010 to June 2015, 18 paediatric patients with a mean age of 10.4 years (range 3.6-15) underwent 35 ureteroscopic procedures for large stones (≥1 cm). The stone location was in the kidney (n = 14), ureter (n = 1), and in both the kidney and ureter for the remaining three patients. Nine patients had multiple stones. There was a preceding history of PCNL in four patients, with one patient having URS combined with a PCNL. The mean follow-up was 2.7 years (range 0-5). A postoperative stent was inserted in 21 (60%) patients. The overall stone-free rate (SFR) was 89% for a mean of 1.8 procedures per patient (range 1-4) - see Summary Table below. There was an inability to access stone within a lower pole calyx in one patient, despite maximum deflection of the ureteroscope. No intra- or post-operative complications were noted, and mean hospital stay was 1.1 days (range 0-5).

DISCUSSION

Published papers in adult literature have shown that ureteroscopy and laser fragmentation (URSL) is a viable alternative to PCNL. Newer equipment and improved techniques have resulted in SFRs being comparable with PCNL. A recent systematic review reported an SFR of 91% for large adult stones (>2 cm) for a mean 1.45 procedures per patient, and an overall complication rate of 8.6%. The present study has also demonstrated excellent outcomes in the use of ureteroscopy and laser fragmentation for the management of large paediatric stones with no complications.

CONCLUSION

The results show that paediatric URSL for large stones achieves a good SFR with minimal morbidity and is a good treatment option in established endourological units.

The efficacy of performing shockwave lithotripsy before retrograde intrarenal surgery in the treatment of multiple or large (≥1.5 cm) nephrolithiasis: A propensity score matched analysis

Purpose

To investigate the effect of performing shockwave lithotripsy (SWL) before retrograde intrarenal surgery (RIRS) on the treatment outcomes of patients with nephrolithiasis.

Materials and Methods

The data of 189 patients with renal stones who underwent RIRS from July 2007 to July 2014 was reviewed retrospectively. Patients with stones larger than 1.5 cm were recommended to undergo SWL before RIRS. Patients were divided into 2 groups based on whether the preoperative SWL was performed (group 1, n=68) or not (group 2, n=121). The cohorts of the 2 groups cohorts were matched 1:1 using propensity score analysis. Patient, stone characteristics, operative parameters, and stone-free rates were compared.

Results

Patients in groups 1 and 2 were matched with respect to stone size, number, and location, leaving 57 patients in each group. After matching, no differences were identified between the 2 groups regarding age, body mass index, sex, stone composition, density and multiplicity. Compared to group 2 patients, patients in group 1 had fewer number of procedures performed (1.10 vs. 1.26, p=0.045) and higher stone-free rate (89.4% vs.73.6%, p=0.039). In multivariate analysis, Non lower calyceal location (odd ratio [OR], 8.215; 95% confidence interval [CI], 1.782–21.982; p=0.041), stone size (OR, 6.932; 95% CI, 1.022–18.283; p<0.001), and preoperative SWL (OR, 2.210; 95% CI, 1.058–7.157; p=0.019) were independent factors predicting a stone-free state after RIRS.

Conclusions

Performing SWL before RIRS may favor stone eliminations during surgery and increase the stone-free rate in selected patients.

Comparison of absorbed irrigation fluid volumes during retrograde intrarenal surgery and percutaneous nephrolithotomy for the treatment of kidney stones larger than 2 cm

Purpose

Irrigation-induced increase in intrarenal pressure is of concern because it may cause infection due to increased pyelovenous and pyelolymphatic absorption. This study is the first to compare prospectively the absorbed fluid volumes during percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for stones larger than 2 cm.

Materials and methods

General anesthesia was applied to all patients. Isotonic solution containing 1 % ethanol was used as irrigation fluid. Venous blood ethanol concentration was first measured with the start of irrigation and thereafter every 15 min until the patients left the recovery room. Absorbed fluid volumes were measured using the blood ethanol concentrations. Duration of irrigation, irrigated fluid volume, stone size and grade of hydronephrosis were also recorded.

Results

A total of 60 patients were included the study. Fluid absorption occurred in all patients. Minimum and maximum ranges of fluid absorption were 20–573 mL for RIRS and 13–364 mL for PCNL. The increase in fluid absorbed volume was observed as a result of the given amount of irrigating fluid used in the PCNL group. Also prolongation of operation led to a significant increase in absorption in the PCNL group. Increase in body mass index, stone size, and hydronephrosis did not affect fluid absorption significantly in either of the two operation techniques in correlation analyzes.

Conclusion

Both RIRS and PCNL are conducted under high pressure and can be accompanied potential complications such as SIRS. The fluid absorption confirmed in our study should be taken into consideration during RIRS and PCNL.

Outcomes of ureteroscopy for patients with stones in a solitary kidney: evidence from a systematic review

INTRODUCTION

Management of urolithiasis in a solitary functioning kidney can be clinically challenging. The aim of this article was to review the outcomes of URS for patients with stone disease in a solitary kidney and critically appraise the existing evidence and outcome reporting standards.

MATERIAL AND METHODS

We conducted a systematic review in line with PRISMA checklist and Cochrane guidelines between January 1980 and February 2015. Our inclusion criteria were all English language articles reporting on a minimum of 10 patients with a solitary kidney undergoing ureteroscopy for stone disease.

RESULTS

A total of 116 patients (mean age 50 years) underwent URS for stones in solitary kidney. For a mean stone size of 16.8 mm (range: 5-60 mm) and 1.23 procedures/patient, the mean stone free rate was 87%. No significant change in renal function was recorded in any of the studies although a transient elevation in creatinine was reported in 10 (8.6%) patients. A total of 33 (28%) complications were recorded a majority (n = 21) of which were Clavien grade I. The Clavien grade II/III complications as reported by authors were urosepsis, steinstrasse and renal colic. None of the procedures required conversion to open surgery with no cases of renal haematoma or ureteric perforation.

CONCLUSIONS

This contemporary review highlights URS as a viable treatment option for stone disease in patients with a solitary kidney. It is associated with superior clearance rates to SWL and fewer high-risk complications compared to PCNL.

Intrarenal Surgery vs Percutaneous Nephrolithotomy in the Management of Lower Pole Stones Greater than 2 cm

Purpose

To compare the efficacy of RIRS and PNL in lower pole stones ≥2 cm. Materials and and Methods: A total of 109 patients who underwent PNL or RIRS for solitary lower pole stone between April 2009 and December 2012, were retrospectively analyzed. Lower pole stone was diagnosed with CT scan. Stone size was assessed as the longest axis of the stone. All patients were informed about the advantages, disadvantages and probable complications of both PNL and RIRS before the selection of the procedure. Patients decided the surgery type by themselves without being under any influences and written informed consent was obtained from all patients prior to the surgery. Patients were divided into two groups according to the patients’ preference of surgery type. Group 1 consisted of 77 patients who underwent PNL and Group 2 consisted of 32 patients treated with RIRS. Stone free statuses, postoperative complications, operative time and hospitalization time were compared in both groups.

Results

There was no statistical significance between the two groups in mean age, stone size, stone laterality, mean follow-up periods and mean operative times. In PNL group, stone-free rate was 96.1% at first session and 100% after the additional procedure. In Group 2, stone-free rate was 90.6% at the first procedure and 100% after the additional procedure. The final stone-free rates and operative times were similar in both groups.

Conclusions

RIRS should be an effective treatment alternative to PNL in lower pole stones larger than 2 cm, especially in selected patients.

Evidence for Ureterorenoscopy and Laser Fragmentation (URSL) for Large Renal Stones in the Modern Era

Large renal stones (>2 cm) are managed with percutaneous nephrolithotomy (PCNL), which has a good stone-free rate (SFR) but a relatively high incidence of complications graded Clavien ≥ 3. We wanted to review the literature for the use of ureterorenoscopy and laser fragmentation (URSL) for the management of these stones. A systematic review was done from 1990 to April 2014 for all English language articles reporting on a minimum of 10 patients for stones >2 cm in size (done by 2 reviewers independently) in accordance with the PRISMA and Cochrane review guidelines. A total of 379 articles were identified and after screening for the titles (54) and abstracts (29), 12 papers (651 patients) were included. The male to female ratio was 356:232 with a mean age of 54 years (range 16-86 years). With a mean stone size of 2.7 cm (2-3.15 cm) and the mean operating time of 96 min (28-238 min); the SFR was 91 % (1.45 procedures/patient). The overall number of complications was 58 (8.6 %) of which 26 (4.5 %) were complications classed Clavien ≥ 3 (haematuria with subcapsular haematoma/clot retention-7; ureteral perforation-7; steinstrasse-5; sepsis/pyelonephritis-5; prostatitis-1; cerebrovascular accident-1). Ureterorenoscopy for large renal stones in the modern era has good SFR with a small risk of major complications.

Renal access through the inferior calyx is associated with higher risk of severe bleeding after percutaneous nephrolithotomy

INTRODUCTION

Hemorrhage is a major complication after percutaneous nephrolithotomy (PCNL). In the current study, we analyzed the risk factors for severe bleeding after PCNL.

MATERIAL AND METHODS

Medical records of 982 consecutive patients undergoing PCNL at the Department of Urology, the Third Xiangya Hospital, were reviewed. The type of stone included: solitary (n = 471), multiple (n = 192) and staghorn (n = 319). 139 patients had renal stones of solitary kidney or functional solitary kidney. The puncture site was the inferior calyx in 246 cases, the middle calyx in 651 cases, and the upper calyx in the remaining 85 cases.

RESULTS

The success rate (complete removal of the stone) was 92.8%, 73.4%, and 80.9% for solitary, multiple and staghorn stones, respectively. Severe bleeding occurred in 3.25% (8/246) of the cases with inferior calyx access, and 0.3% (2/651) in cases with middle calyx access. No severe bleeding occurred in patients with upper calyx access. The bleeding was controlled successfully with focal embolization under angiography in all 10 cases.

CONCLUSIONS

Severe postoperative bleeding after PCNL is associated with renal puncture via the inferior calyx, multiple renal stones and solitary kidney stones.

Flexible ureteroscopy for renal stones

OBJECTIVES

The objectives of this prospective study are to present our experience with retrograde intrarenal surgery (RIRS), and to analyze its results and complications.

MATERIAL AND METHODS

150 patients with renal stones were treated with RIRS. 111 cases showed single stones whilst multiple stones were observed in 39 cases. The mean size was 19.12mm (r: 5-74). Success rate was defined as the absence of residual stones or the presence of fragments ≤2mm.

RESULTS

in 21 (14%) patients RIRS could not be performed on first attempt because it was impossible to place the ureteral access sheath. The immediate success rate was 85.7%, and 91.6% at three months later. The average operating time was 85min (r: 25-220). Postoperative complications were observed in 22 cases (14.6%), although most of them were classified as Clavien 1 and 2 (19 cases), and only 2% (3 cases) showed Clavien 4 complications (sepsis requiring admission in the intensive care unit). 10 patients underwent a second procedure in order to complete the treatment. Thus, the number of procedures per patient was 1.06. There were no late complications.

CONCLUSIONS

the treatment of renal stones with flexible ureteroscopy using the ureteral access sheath shows a high successful rate with a low complication rate. In order to define its indication more precisely, randomized studies comparing RIRS with minimally invasive percutaneous nephrolithotomy procedures (miniperc and microperc) would be necessary.

Retrograde intrarenal surgery for kidney stones larger than 2.5 cm

PURPOSE OF REVIEW

The management of large intrarenal stones (>2 cm) is typically percutaneous nephrolithotomy. Although the stone-free rate (SFR) of such a procedure is high (up to 95%), the complications related mainly to the renal access are sometimes a concern. Because of the evolution in technology, it is nowadays possible to treat intrarenal stones with retrograde intrarenal surgery. It remains unclear weather or not retrograde intrarenal surgery (RIRS) may be effective also for the treatment of larger stones (>2 cm). The purpose of this review is to provide recent data on the ureteroscopic management of kidney stones larger than 2.5 cm.

RECENT FINDINGS

A systematic review of the literature for studies identified between January 2000 and September 2013 was performed. Only English language articles reporting on more than 10 cases treated with RIRS for intrarenal stones larger than 2.5 cm were considered for this review.Particular emphasis was given to studies published within the last 12 months. Of the 324 studies identified, only 10 were considered suitable for this review. There were a total of 441 patients with a mean stone size of 2.9 cm. The SFR with an average of 1.6 procedures was 89.3%. The overall complication rate was 8% with major complication rate of 1.9%.

SUMMARY

Although not supported by high evidence because of the absence of prospective randomized studies, it appears that in selected patients with large intrarenal stones, RIRS and laser lithotripsy may offer an acceptable efficacy with low morbidity.

Retrograde intrarenal surgery versus percutaneous nephrolithotomy for treatment of renal stones >2 cm: a meta-analysis

OBJECTIVE

To systematically review the efficacy and safety of retrograde intrarenal surgery (RIRS) versus percutaneous nephrolithotomy (PCNL) for the treatment of renal calculi >2 cm.

METHODS

We searched PubMed, Cochrane Library, Embase and the Chinese Biomedical Literature Database about RIRS and PCNL for the treatment of renal stones. The retrieval time ended in December 2013. All clinical trials were retrieved and their included references investigated. Two reviewers independently assessed the quality of all included studies, and the eligible studies were included and analyzed using the RevMan 5.2 software.

RESULTS

Two randomized controlled trials and six clinical controlled trials were included, involving a total of 590 patients. Our meta-analysis showed that there were not significant differences in stone-free rate (relative risk [RR] = 0.95, 95% confidence interval (CI) 0.88-1.02, p = 0.11) and fever (RR = 0.95, 95% CI 0.54-1.67, p = 0.85) between RIRS and PCNL. We found that hospital stay (weighted mean difference [WMD] = -2.10, 95% CI -3.08 to -1.11, p < 0.10) and bleeding (RR = 0.20, 95% CI 0.06-0.68, p = 0.01) were lower and operation time was longer (WMD = 19.11, 95% CI 7.83-30.39, p < 0.10) for RIRS.

CONCLUSION

RIRS is a safe and effective procedure. It can successfully treat patients with stones >2 cm with a high stone-free rate and significantly reduce hospital stay without increasing complications. RIRS can be used as an alternative treatment to PCNL in selected cases with larger renal stones. However, further randomized trials are needed to confirm these findings.

Safety and efficacy of retrograde intrarenal surgery for renal stones in patients with a solitary kidney: a single-center experience

BACKGROUND AND PURPOSE

The management of urolithiasis in patients with a solitary kidney is challenging for endourologists. This study was aimed at evaluating the safety and efficacy of retrograde intrarenal surgery (RIRS) in the treatment of such patients with renal stones.

PATIENTS AND METHODS

Between January 2010 and January 2014, we enrolled 45 patients who had a solitary kidney and underwent RIRS and holmium:yttrium-aluminum-garnet lithotripsy for the management of renal stones. We collected data pertaining to the preoperative patient characteristics, stone dimensions, and postoperative outcomes.

RESULTS

Sixty-eight procedures were performed in all. The mean stone diameter was 1.84±0.19 cm (range 0.5-6.0 cm), and the mean operative time, 76.4±40.14 minutes (range 18-190 min). The percentages of patients free of renal stones at the initial and final procedures were 64.44% and 93.33%, respectively. The mean number of procedures needed for the patients with renal stones of diameters ≥20 mm and <20 mm were 1.93 per patient and 1.23 per patient, respectively (P=0.009). Postoperative complications (graded by the Clavien system) were noted in 26.6% of the patients (12/45): Grade I complications, in 20% (9/45); grade II complications, in 4.4% (2/45); and grade III complication, in 2.2% (1/45). The grade III complication was anuria because of Steinstrasse, which necessitated emergency surgery.

CONCLUSIONS

RIRS for the removal of renal stones in patients with a solitary kidney affords a high success rate and low morbidity rate. For patients with large stones, however, a multistaged approach may be needed.

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

CONTEXT

Recent advances in technology have led to the implementation of mini- and micro-percutaneous nephrolithotomy (PCNL) as well as retrograde intrarenal surgery (RIRS) in the management of kidney stones.

OBJECTIVE

To provide a systematic review and meta-analysis of studies comparing RIRS with PCNL techniques for the treatment of kidney stones.

EVIDENCE ACQUISITION

A systematic literature review was performed in March 2014 using the PubMed, Scopus, and Web of Science databases to identify relevant studies. Article selection proceeded according to the search strategy based on Preferred Reporting Items for Systematic Reviews and Meta-analysis criteria. A subgroup analysis was performed comparing standard PCNL and minimally invasive percutaneous procedures (MIPPs) including mini-PCNL and micro-PCNL with RIRS, separately.

EVIDENCE SYNTHESIS

Two randomised and eight nonrandomised studies were analysed. PCNL techniques provided a significantly higher stone-free rate (weighted mean difference [WMD]: 2.19; 95% confidence interval [CI], 1.53-3.13; p<0.00001) but also higher complication rates (odds ratio [OR]: 1.61; 95% CI, 1.11-2.35; p<0.01) and a larger postoperative decrease in haemoglobin levels (WMD: 0.87; 95% CI, 0.51-1.22; p<0.00001). In contrast, RIRS led to a shorter hospital stay (WMD: 1.28; 95% CI, 0.79-1.77; p<0.0001). At subgroup analysis, RIRS provided a significantly higher stone-free rate than MIPPs (WMD: 1.70; 95% CI, 1.07-2.70; p=0.03) but less than standard PCNL (OR: 4.32; 95% CI, 1.99-9.37; p=0.0002). Hospital stay was shorter for RIRS compared with both MIPPs (WMD: 1.11; 95% CI, 0.39-1.83; p=0.003) and standard PCNL (WMD: 1.84 d; 95% CI, 0.64-3.04; p=0.003).

CONCLUSIONS

PCNL is associated with higher stone-free rates at the expense of higher complication rates, blood loss, and admission times. Standard PCNL offers stone-free rates superior to those of RIRS, whereas RIRS provides higher stone free rates than MIPPs. Given the added morbidity and lower efficacy of MIPPs, RIRS should be considered standard therapy for stones <2 cm until appropriate randomised studies are performed. When flexible instruments are not available, standard PCNL should be considered due to the lower efficacy of MIPPs.

PATIENT SUMMARY

We searched the literature for studies comparing new minimally invasive techniques for the treatment of kidney stones. The analysis of 10 available studies shows that treatment can be tailored to the patient by balancing the advantages and disadvantages of each technique.

Efficacy of percutaneous nephrostomy during flexible ureteroscopy for renal stone management

PURPOSE

Preoperative percutaneous nephrostomy (PCN) can be applied to urinary stone patients with pyelonephritis as well as obstructive uropathy; thus, some patients undergo flexible ureteroscopy (fURS) in the presence of a PCN tube. We evaluated the effectiveness of PCN during fURS for the management of renal stones.

MATERIALS AND METHODS

We retrospectively analyzed 130 consecutive patients who underwent fURS for renal stones between January 2009 and December 2011. All fURS procedures were performed by a single experienced surgeon. The patients were divided into two groups depending on the presence of PCN during the surgery: patients with PCN (group 1, n=41) and patients without PCN (group 2, n=89). To evaluate operative outcomes, we compared success rates, operative times, and complication rates. We defined success as the absence of any residual stones in the kidney or stone fragments less than 2 mm that were too small to be extracted during follow-up.

RESULTS

There were no significant differences in age, sex, body mass index, stone laterality, burden, or location between the two groups. The mean operative times of groups 1 and 2 were 50.1 and 58.3 minutes, respectively (p=0.102). The success rates of groups 1 and 2 were 95.1% and 82.0%, respectively (p=0.044). There was no statistically significant difference in the complication rate between groups 1 and 2 (p=0.888).

CONCLUSIONS

Flexible ureteroscopy in the presence of PCN produced a superior outcome in terms of the success rate without increasing the operative time or complication rate. PCN may be helpful to induce better outcomes of fURS.

Clinical effectiveness of the PolyScope™ endoscope system combined with holmium laser lithotripsy in the treatment of upper urinary calculi with a diameter of less than 2 cm

The aim of this study was to evaluate the clinical value of the PolyScope™ endoscope system in the treatment of upper urinary calculi with a diameter of <2 cm. A total of 86 patients hospitalized with upper urinary tract calculi were included. The patients were placed under general or spinal anesthesia and in a lithotomy position. Following the dilation of the ureter, a guide wire was inserted under the direct vision of an F8/9.8 rigid ureteroscope, and an F12/14 flexible ureteral access sheath was positioned along the guide wire. Holmium laser lithotripsy was subsequently performed, using an F8.0 ‘PolyScope’ modular flexible ureteroscope. Plain film of the kidney-ureter-bladder (KUB) was performed 1 day subsequent to the surgery, in order to determine the result of the lithotripsy and the position of the double-J stent which was inserted after after holmium laser lithotripsy. In addition, in certain patients, KUB radiography was performed 2–4 weeks subsequent to the surgery, and extracorporeal shockwave lithotripsy (ESWL) was performed if the diameter of the residual stones was >6 mm. Lithotripsy was successful in 77 patients and the duration of the surgery ranged between 25 and 80 min (mean duration, 42 min). Little bleeding was observed. Three patients presented with a slight fever following the surgery; however, no ureteral perforation, high fever or septicemia was observed among the patients following anti-inflammatory treatment. The stone-free rate (SFR) of the single-pass lithotripsy was 89.5% (77/86) and the SFR with ESWL was 96.5% (83/86). The study demonstrated that the F8 modular flexible ureteroscope was safe, convenient and effective for the lithotripsy of upper-tract calculi.

Utility and limitation of cumulative stone diameter in predicting urinary stone burden at flexible ureteroscopy with holmium laser lithotripsy: a single-center experience

PURPOSE

To retrospectively assess the clinical utility in ureteroscopy (URS) planning of cumulative stone diameter (CSD), which does not account for stone width or depth, as a predictor of URS outcome and compare it with stone volume.

MATERIALS AND METHODS

Patients with renal stones treated at a single institute by flexible URS were retrospectively evaluated. To assess the clinical utility of CSD, relationships between stone-free (SF) status and stone burden (CSD and volume) were analyzed using the area under the receiver operating characteristics (AUROC) curve. To identify stone number impact on CSD, the AUROC of CSD divided by stone number was evaluated. Correlation coefficients of CSD and stone volume were also calculated for groups by stone number.

RESULTS

In cases with CSD <20.0 mm, CSD and stone volume revealed equal ability to predict SF status. In cases with CSD ≥20.0 mm, stone volume showed higher predictive ability. The ROC curves for cases with ≥4 stones showed that CSD was less predictive of SF status than stone volume. The correlation coefficients of CSD and stone volume by stone number were 0.922 for 1 stone, 0.900 for 2-3 stones, and 0.661 for ≥4 stones.

CONCLUSIONS

In cases with CSD ≥20.0 mm or ≥4 stones, we should evaluate stone volume for a more predictive stone burden, and pretreatment non-contrast CT seems sufficient. In cases with CSD <20.0 mm or 1-3 stones, CSD was as valid a predictor of preoperative stone burden as stone volume, so preoperative kidney-ureter-bladder (KUB) films may be sufficient.

RIRS versus mPCNL for single renal stone of 2-3 cm: clinical outcome and cost-effective analysis in Chinese medical setting

The aim of the study was to compare the clinical outcome and the cost-effectiveness between retrograde intra renal surgery (RIRS) and mini-percutaneous nephrolithotripsy (mPCNL) for the management of single renal stone of 2-3 cm in Chinese medical setting. From May 2005 to February 2011, 115 patients with solitary renal calculi were treated either by RIRS or mPCNL. 56 patients were in RIRS group while 59 were in mPCNL group. Patients' demographics between the two groups, in terms of gender, age, BMI, history of ESWL as well as stone side, stone location and stone size were comparable. Peri-operative course, clinical outcome, complication rates and medical cost were compared. The effective quotient (EQ) of two groups was calculated. Data were analyzed using Fisher's exact test, Chi-square test and Student's t test. EQ for RIRS and mPCNL were 0.52 and 0.90. The initial stone-free rate (SFR) of RIRS group and mPCNL group was 71.4 and 96.6 %, respectively (P = 0.000). The mean procedure number was 1.18 in RIRS group and 1.03 in mPCNL group, respectively (P = 0.035). The operative time for RIRS was longer (P = 0.000) while the mean hospital stay was shorter (P = 0.000). There was no statistical difference in peri-operative complications between the groups. The initial hospitalization cost, laboratory and radiology test cost of RIRS group were lower (P = 0.000). However, counting the retreatment cost in the two groups, the total medical expenditure including the overall hospitalization cost, overall laboratory and radiology test cost and post-operative out-patient department (OPD) visit cost was similar between two groups. In conclusion, with similar total medical cost, mPCNL achieved faster stone clearance and lower retreatment rate without major complications, which implied higher cost-effectiveness for the treatment of single renal stone of 2-3 cm in Chinese medical setting. RIRS is also a safe and reliable choice for patients having contraindications or preference against mPCNL.

Flexible ureteroscopy and laser lithotripsy for stones >2 cm: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Urinary stones >2 cm are traditionally managed with percutaneous nephrolithotomy (PCNL). Recently, flexible ureteroscopy and laser lithotripsy) (FURSL) has been used to manage them with comparable results. In a comparative study of renal stones between 2 and 3 cm, FURSL was reported to need less second-stage procedures and be just as effective as PCNL. Our purpose was to review the literature for renal stones >2 cm managed by ureteroscopy and holmium lasertripsy.

MATERIALS AND METHODS

A systematic review and quantitative meta-analysis was performed using studies identified by a literature search from 1990s (the first reported large renal stones treated ureteroscopically) to August 2011. All English language articles reporting on a minimum of 10 patients treated with FURSL for renal stones >2 cm were included. Two reviewers independently extracted the data from each study. The data of studies with comparable results were included into a meta-analysis.

RESULTS

In nine studies, 445 patients (460 renal units) were reportedly treated with FURSL. The mean operative time was 82.5 minutes (28-215 min). The mean stone-free rate was 93.7% (77%-96.7%), with an average of 1.6 procedures per patient. The mean stone size was 2.5 cm. An overall complication rate was 10.1%. Major complications developed in 21 (5.3%) patients and minor complications developed in 19 (4.8%) patients. A subgroup analysis shows that FURSL has a 95.7% stone-free rate with stones 2-3 cm and 84.6% in those >3 cm (P=0.01), with a minor complication rate of 14.3% and 15.4%, respectively, and a major complication rate of 0% and 11.5%, respectively.

CONCLUSION

In experienced hands, FURSL can successfully treat patients with stones >2 cm with a high stone-free rate and a low complication rate. Although the studies are from high-volume experienced centers and may not be sufficient to alter everyday routine practice, this review has shown that the efficacy of FURSL allows an alternative to PCNL.

The most reliable preoperative assessment of renal stone burden as a predictor of stone-free status after flexible ureteroscopy with holmium laser lithotripsy: a single-center experience

OBJECTIVE

To examine which parameters should be measured to preoperatively determine the stone burden as predictors of stone-free (SF) status after a single flexible ureteroscopy (URS). Although several stone parameters reportedly influence the outcome of treatment for urinary stones, the most reliable indicators of stone burden remain unclear.

METHODS

Patients with renal stones treated by flexible URS with holmium laser lithotripsy between October 2009 and December 2011 at a single institute were retrospectively evaluated. The SF status was determined by kidney-ureter-bladder (KUB) films at postoperative day 1. Correlations of possible predictors with the SF status were analyzed using a logistic regression model.

RESULTS

According to the univariate analysis, the following variables were significantly associated with failed treatment: number of stones (P = .001), cumulative stone diameter (CSD) (P < .001), stone surface area (SA) (P < .001), stone volume (P < .001), and presence of lower pole calculi (P = .008). According to the multivariate analysis, the stone volume (P < .001) and the CSD (P = .015) were found to be independent predictors of SF status. The SA (P = .598) had no significant independent influence on the SF status.

CONCLUSION

Among the several parameters regarding the renal stone burden, the stone volume determined by noncontrast computed tomography and the CSD of the KUB were significantly and independently inversely related to the success rate of URS. Among the 3 parameters of stone burden, the SA was found to have a lower clinical utility and priority as a predictor of a SF status after URS.

The impact of pelvicaliceal anatomy on the success of retrograde intrarenal surgery in patients with lower pole renal stones

OBJECTIVES

To evaluate the impact of pelvicaliceal anatomy on the success of retrograde intrarenal surgery (RIRS) for lower pole renal stones and determine which of these factors can be used to select patients who will benefit from RIRS.

METHODS

We evaluated 67 patients who underwent RIRS between 2009 and 2010 for isolated lower pole renal stones. The infundibular length (IL), infundibular width (IW), pelvicaliceal height (PCH), and infundibulopelvic angle (IPA) were measured by preoperative intravenous urogram. Success was defined as either complete clearance or clearance with insignificant residual fragments≤3 mm in size at 2-months follow-up.

RESULTS

Mean IL was 26.7±7.9 and 28.2±5.3 mm, mean PCH was 20.7±6.6 and 23.2±4.9 mm in stone-free and non-stone-free patients, respectively. These were slightly larger in the non-stone-free group but not statistically significant (P=.140 and P=.072, respectively). Mean IW was 5.8±3.5 and 5.6±2.2 mm in stone-free and non-stone-free patients, respectively, which had no significant impact on the stone-free rate (P=.719). There were significant differences between the groups in terms of stone length (P=.001) and IPA (P=.003). The mean IPA was 49.37±11.83 and 37.61±13.22 mm in stone-free and non-stone-free patients, respectively.

CONCLUSIONS

In addition to the influence of stone size, lower pole anatomy, especially IPA, has a significant impact on stone clearance for lower pole stones after RIRS.

Outcomes of retrograde intrarenal surgery compared with percutaneous nephrolithotomy in elderly patients with moderate-size kidney stones: a matched-pair analysis

PURPOSE

The aim of our study was to evaluate the outcomes of retrograde intrarenal surgery (RIRS) in elderly patients with stones of moderate size.

PATIENTS AND METHODS

Between September 2008 and June 2011, a total of 28 patients over 65 years of age with single renal stones that measured 1.5 to 3 cm were treated with RIRS. The outcomes of these patients were compared with those of the patients who underwent percutaneous nephrolithotomy (PCNL) using matched-pair analysis (1:1 scenario). The matching parameters were the size and location of the stone as well as age, sex, body mass index, degree of hydronephrosis, presence of previous shockwave lithotripsy, and open surgery. SPSS version 16 was used for statistical analysis.

RESULTS

Stone-free rates after a single procedure were achieved in 82.1% of patients for the RIRS and 92.8% of patients for the PCNL group. The second flexible ureterorenoscopy procedure was performed for five patients in the RIRS group. Finally, stone-free rates during the third month of the follow-up period were 92.8% in the RIRS group and 96.4% in the PCNL group. The mean operative time per patient was 64.5 ± 20.9 minutes in the RIRS group after a total of 33 procedures, while it was 40.7 ± 10.7 minutes in the PCNL groups (P<0.0001). The overall complication rates for the RIRS and PCNL groups were 7.1% and 10.7%, respectively. Blood transfusions were needed in two patients in the PCNL group. Hospitalization time was significantly shorter in the RIRS group (26.5 ± 10.6 h per patient vs 60.0 ± 28.8 h; P<0.0001). In both groups, stones were most frequently composed of calcium oxalate (68.4% in the RIRS group and 77.7% in the PCNL group).

CONCLUSION

RIRS has a low complication rate and represents a safe and effective treatment alternative in selected geriatric patients with kidney stones of moderate size.

Can we avoid percutaneous nephrolithotomy in high-risk elderly patients using the Charlson comorbidity index?

OBJECTIVE

To determine whether Charlson comorbidity index (CCI) predicts the postoperative complications after percutaneous nephrolithotomy (PCNL) and could be a plausible option to avoid surgery and its potential risks in elderly patients with significant comorbidites.

METHODS

The data from 283 elderly patients (age ≥ 60 years) who underwent PCNL in 4 large referral hospitals were reviewed in the present multicenter study. For each patient, we evaluated pre-existing comorbidities and calculated the CCI score. The patients were classified to 3 CCI score categories (0, 1, ≥ 2) and compared regarding the stone-free and complications rates.

RESULTS

The mean patient age was 64.7, 65.6, and 67.7 years in the 3 groups. The stone-free rate after primary PCNL was 85.7% in group 1, 86.1% in group 2, and 75.0% in group 3. These rates increased to 90.8%, 95.4%, and 83.9% after a second intervention (P = .049). The overall postoperative complication rate was 38.8%. The most common complication was hemorrhage necessitating blood transfusion in 34 patients (12%), and we found an increased risk of hemorrhage associated with the CCI score (P = .011). Life-threatening medical complications developed in 7.6% of the patients in group 1, 12% of the patients in group 2, and 28.6% of the patients in group 3 (P = .001). A multivariate logistic regression analysis showed that a high CCI score, bleeding, and operative time had significant influence on the postoperative medical complication in this population.

CONCLUSION

Conservative management of asymptomatic large kidney stones appears to be a safe alternative to PCNL in elderly patients with significant comorbidites.

Flexible ureterorenoscopy versus miniaturized PNL for solitary renal calculi of 10-30 mm size

INTRODUCTION

The value of flexible ureterorenoscopy (fURS) and miniaturized PNL (mPNL) for larger renal calculi is under discussion. This non-randomized prospective study aimed to evaluate fURS and mPNL for solitary renal stones of 10-30 mm size.

MATERIALS AND METHODS

fURS was carried out in 21 patients with last generation 7.5F endoscopes. Ureteral access sheaths were used in 19 patients. For mPNL, an 18F modified Amplatz sheath with a 14F nephroscope were used (n = 25). The procedure was performed either tubeless with an antegrade stent or a nephrostomy. Outcome and complications of both procedures were assessed.

RESULTS

Patients' demographics and stone sizes were comparable (18 ± 5 vs. 19 ± 4 mm, P = 0.08). Patients in the fURS group had a higher mean BMI (31 vs. 27, P < 0.05). Total OR time was significantly longer for fURS (106 ± 51 vs. 59 ± 19 min., P < 0.001). More patients were stone-free after one single percutaneous treatment, while 2nd-stage treatments with fURS were common (total procedures 1.04 vs. 1.52, P < 0.001; immediate stone-free rate (SFR) 96% vs. 71.5%, P < 0.001). SFR after 4 weeks was 100% (mPNL) and 85.8% (fURS) (P < 0.01). Minor complications as classified by Clavien I or II occurred in 16 and 23.8%, mPNL and fURS, respectively, P = 0.13). No major complications (Clavien III-V) occured in both groups.

CONCLUSIONS

Our series supports both the concept of either percutaneous or retrograde endoscopic treatment for renal calculi with both modalities offering excellent safety. However, while for fURS, a significantly higher rate of 2nd-stage procedures was necessary, and mPNL led to faster and higher SFR without increasing complication rate.

Retrograde intrarenal surgery versus percutaneous nephrolithotomy in the management of lower-pole renal stones with a diameter of 15 to 20 mm

PURPOSE

To compare the outcomes of percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for 15 to 20 mm lower-pole (LP) renal calculi by evaluating stone-free rates and associated complications.

PATIENTS AND METHODS

The records of 79 patients who underwent either PCNL (n=42) or RIRS (n=37) by standard techniques for 15 to 20 mm LP renal calculi were reviewed retrospectively.

RESULTS

In the PCNL group, the stone-free rate was 92.8% (39/42 patients); this rate increased to 97.6% after a second intervention (shockwave lithotripsy in one and RIRS in one). After a single RIRS procedure, 33 of 37 (89.2%) patients were completely stone free. Two patients needed an additional procedure (rigid ureteroscopy in one and RIRS in one), after which they were all completely stone free, resulting in an overall success rate of 94.6%. Two patients had asymptomatic residual fragments <7 mm in the LP of the kidney, and these patients had been followed with ultrasonography of the kidney. For complications, there were minimal differences in both procedures, except for hemorrhage (necessitated transfusion) in three patients who were treated with PCNL. The overall stone-free rates and complication rates for PCNL were higher, but the differences were not statistically significant. Operative time was significantly longer in the RIRS group, and postoperative hospital stay was significantly longer in PCNL group.

CONCLUSION

PCNL and RIRS are safe and effective methods for medium-sized LP calculi. For selected patients, RIRS may represent an alternative therapy to PCNL, with acceptable efficacy and low morbidity.

Predictors of clinical outcomes of flexible ureterorenoscopy with holmium laser for renal stone greater than 2 cm

Objective. To evaluate the clinical outcome of flexible ureterorenoscopy (F-URS) with holmium laser in managing renal stone greater than 2 cm. Patients and Methods. Records of 120 patients (123 renal units) with renal stone greater than 2 cm who underwent F-URS with holmium laser iwere evaluated. The mean stone size was 26.3 mm. Patient and stone characteristics, perioperative outcomes and complications were evaluated. The outcome was determined at 4 weeks on plain radiograph (KUB) and Non-contrast CT scan (NCCT). Follow-up visit was up to 6 months to evaluate the clinical outcome and patients symptoms. Results. Stone burden was an independent predictor of FURS results. After first session of treatment, success rate was obtained in 72 renal units (58.5%). On the other hand, significant residual fragment was encountered in 51 renal units (41.5%). This was improved with “staged-therapy” to 87% and 96.7% after second and third session of treatment, respectively. Complications were recorded. They were managed in proper manner accordingly. Conclusion. This is an attractive, safe and effective technique. It is an ideal option for low volume complex stone with average burdens of 2 to 3 cm. Patient should be informed and consented about staged-therapy.