Retrograde intrarenal surgery for kidney stones larger than 2.5 cm

Comparison of the efficacy and safety of mini-percutaneous nephrolithotomy versus retrograde intrarenal surgery for the treatment of kidney stones in overweight or obese patients: a systematic review and meta-analysis

OBJECTIVE

To discuss the differences in the effectiveness and security of kidney stones in overweight or obese patients by mini percutaneous nephrolithotomy (MiniPCNL) and retrograde intrarenal surgery (RIRS).

MATERIALS AND METHODS

We exhaustively searched numerous databases, including PubMed, Embase, Web of Science, Cochrane Library, and CNKI, covering all records from their initiation date until September 2023. This included controlled trials focusing on the use of MiniPCNL and RIRS in the treatment of kidney stones in overweight or obese patients. The gathered data was then analyzed using the Review Manager 5.4 software.

RESULTS

9 studies including 1122 patients were included. Meta-analysis showed that: The MiniPCNL group had higher overall complications, grade I complications, length of hospital stay(LOS), first stone-free rate (SFR), and final SFR in obese patients, with no significant difference between the two groups in terms of operative time(OT), hemoglobin drop, and grade II complication rate. There were more overall complications, grade I complications, final SFR, and LOS with MiniPCNL in patients with stones > 2 cm compared to no significant difference in grade II complications. MiniPCNL performed in the prone position had higher final SFR, less OT, hemoglobin drop, and no statistically significant difference in overall complications or LOS. Sheaths using > 14 F had higher overall complication rates, final SFR, and LOS, and no statistical differences in OT and first SFR between the two modalities. In the MiniPCNL subgroup aged ≤ 50 years, there were higher first SFR, final SFR, and shorter OT, and in the MiniPCNL subgroup aged > 50 years, there were more OT, LOS, and hemoglobin drop, with no statistical difference in overall complications between the two groups.

CONCLUSION

Our study showed that MiniPCNL in obese patients had higher initial SFR and final SFR, fewer procedures, but more postoperative complications, LOS, and grade I complications compared with RIRS. Similar results were seen in patients in the prone position, with stones > 2 cm and age ≤ 50 years.

SYSTEMATIC REVIEW REGISTRATION

[ https://www.crd.york.ac.uk/PROSPERO/ ], identifier PROSPERO (CRD42023467284).

Does prior PCNL affect RIRS? A retrospective analysis of a single center data

PURPOSE

The aim of this study is to investigate the results and safety of retrograde intrarenal surgery (RIRS) in patients who have previously undergone percutaneous nephrolithotomy (PCNL).

METHODS

A retrospective analysis included patients who underwent RIRS for kidney stones between August 2018 and April 2023. Group 1 comprised 396 patients who underwent primary RIRS, while Group 2 included 231 individuals who had RIRS after previous PCNL. Evaluation parameters included preoperative characteristics, stone attributes, operative details, treatment outcomes, stone-free status, and complications. Statistical analysis utilized Student's t test, Mann-Whitney U test, and Pearson Chi-square test (p < 0.05).

RESULTS

The mean age, body mass index, stone number, mean stone burden, and SFS were not statistically different between the groups. Lower pole stones were identified in 144 patients in Group 1 and 88 patients in Group 2 (p = 0.315). In Group 1 and Group 2, the mean operation time and fluoroscopy time were 65.23 ± 18.1 min, 81.32 ± 14.3 min, 26.34 ± 8.31 s, 46.61 ± 7.6 s, respectively, showing statistically significant differences between the groups (p = 0.013, p < 0.001, respectively). Infundibulum stenosis was identified and treated with a laser in 12% of Group 2 cases. Complications occurred in 12 patients in Group 1 and 14 patients in Group 2 (p = 0.136).

CONCLUSION

A history of PCNL may contribute to extended operation times and increased fluoroscopy exposure in subsequent RIRS without significantly affecting postoperative SFS or complication rates.

Rigid ureteroscopic lithotripsy with a pressure-controlling ureteral access sheath for complex steinstrasse

OBJECTIVE

To evaluate the safety and efficacy of rigid ureteroscopic lithotripsy with a pressure-controlling ureteral access sheath (PC-UAS) for complex steinstrasse.

METHODS

Thirty-one consecutive patients (male: 18; female: 13) with steinstrasse were enrolled, six of whom had concurrent kidney stones. The mean cumulative stone size was 2.7 ± 1.3 cm. The patients were treated with rigid ureteroscopic lithotripsy using a PC-UAS. The cavity pressure parameters were set as follows: control value at -15 mmHg to -2 mmHg, warning value at 20 mmHg, and limit value at 30 mmHg. The infusion flow rate was set at 150-200 ml/min. A holmium laser (550 μm) was used to powderize the stone at 2.0-2.5 J/pulse with a frequency of 20-30 pulses/s. Analyses included cavity pressure, operative time, stone-free rates, and complications.

RESULTS

Among the 31 patients, 29 were successfully treated with PC-UAS, with nine requiring adjunctive flexible ureteroscopy for stone migration to the kidney. Two procedures were converted to percutaneous nephrolithotomies due to failure of sheath placement. The cavity pressure of all 29 patients was well-maintained below 20 mmHg, with clear vision. The mean operative time was 48.2 ± 17.7 min. No complications, such as ureteral perforation, mucosal avulsion, or hemorrhage, occurred. Two cases of Clavien-Dindo grade I complications occurred. No major complications (Clavien-Dindo grade II-V) occurred. The mean postoperative hospitalization time was 1.7 days. The stone-free rates 1 day and 1 month after surgery were 93.1% and 96.6%, respectively. One patient with residual stones underwent extracorporeal shockwaves.

CONCLUSIONS

Rigid ureteroscopic lithotripsy with PC-UAS can effectively control the cavity pressure, shorten the operation time, and improve the efficiency of broken stones, thus reducing the complication rate.

Could Use of a Flexible and Navigable Suction Ureteral Access Sheath Be a Potential Game-changer in Retrograde Intrarenal Surgery? Outcomes at 30 Days from a Large, Prospective, Multicenter, Real-world Study by the European Association of Urology Urolithiasis Section

BACKGROUND AND OBJECTIVE

The aim of this study was to evaluate the stone-free status (SFS) rate and complications after flexible ureteroscopy (fURS) for treatment of renal stones using a flexible and navigable suction (FANS) ureteral access sheath.

METHODS

Data for adults undergoing fURS in 25 centers worldwide were prospectively collected (August 2023 to January 2024). Exclusion criteria were abnormal renal anatomy and ureteral stones. All patients had computed tomography scans before and within 30 d after fURS with a FANS ureteral access sheath. SFS was defined as follows: grade A, zero fragments; grade B, a single fragment ≤2 mm; grade C, a single fragment 2.1-4 mm; and grade D, single/multiple fragments >4 mm. Data for continuous variables are presented as the median and interquartile range (IQR). Multivariable logistic regression was performed to evaluate predictors of grade A SFS.

KEY FINDINGS AND LIMITATIONS

The study enrolled 394 patients (59.1% male) with a median age of 49 yr (IQR 36-61). The median stone volume was 1260 mm3 (IQR 706-1800). Thulium fiber laser (TFL) was used in 45.9% of cases and holmium laser in the rest. The median lasing time was 18 min (IQR 11-28) and the median operative time was 49 min (IQR 37-70). One patient required a blood transfusion and 3.3% of patients had low-grade fever. No patient developed sepsis. Low-grade ureteral injury occurred in eight patients (2%). The grade A SFS rate was 57.4% and the grade A + B SFS rate was 97.2%, while 2.8% of patients had grade C or D SFS. Eleven patients underwent repeat fURS. Multivariable analysis revealed that a stone volume of 1501-3000 mm3 (odds ratio 0.50) and of >3000 mm3 (odds ratio 0.29) were significantly associated with lower probability of grade A SFS, while TFL use was associated with higher SFS probability (odds ratio 1.83). Limitations include the lack of a comparative group.

CONCLUSIONS AND CLINICAL IMPLICATIONS

fURS using a FANS ureteral access sheath resulted in a high SFS rate with negligible serious adverse event and reintervention rates.

PATIENT SUMMARY

We looked at 30-day results for patients undergoing telescopic laser treatment for kidney stones using a special type of vacuum-assisted sheath to remove stone fragments. We found a high stone-free rate with minimal complications.

Flexible Ureteroscopy with a Tip-Flexible Pressure-Controlling Ureteral Access Sheath for Renal Stones in Children

INTRODUCTION

The aim of this study was to evaluate the safety and efficacy of flexible ureteroscopy using a tip-flexible pressure-controlling ureteral access sheath (TFPC-UAS) for renal stones in children.

METHODS

Consecutive patients aged 5-18 years with renal stones of diameter 1-3 cm were enrolled between January 2022 and November 2023 at Ganzhou People's Hospital. The patients were treated with flexible ureteroscopy using the TFPC-UAS. The renal pelvic pressure (RPP) parameters were set as follows: control value at -10 mm Hg to 5 mm Hg, warning value at 20 mm Hg, and limit value at 30 mm Hg. The infusion flow rate was set to 100-120 mL/min. A holmium laser (276 μm) was used to fragment the stone at 2.0-2.5 J/pulse with a frequency of 20-30 pulses/s. The cases were analyzed for RPP, operative time, stone-free rate, and complications.

RESULTS

A total of 21 consecutive patients were included. Two patients were switched to percutaneous nephrolithotomy owing to sheath placement failure. The RPP was -4.6 ± 2.1 mm Hg. The mean operative time was 56.5 ± 17.1 min. The postoperative hospitalization time was 1.5 ± 0.3 days. The stone-free rates at 1 day and 1 month after surgery were 81.0% and 85.7%, respectively. Residual stones in 2 patients were cleared after extracorporeal shockwave lithotripsy. Three cases of Clavien I complications and one case of Clavien II complications occurred. No major complications (Clavien grade III-V) were observed.

CONCLUSIONS

Flexible ureteroscopy with a TFPC-UAS is safe and effective for renal stones in children.

Dynamic renal scans as a modality for follow-up of flexible ureteroscopy

OBJECTIVE

To determine whether dynamic renal scans - DTPA or MAG3 - routinely performed after flexible ureteroscopies (f-URS) could detect the development of an obstruction and thus promote prompt early intervention for kidney preservation.

PATIENTS AND METHODS

In this retrospective study, with all the data recorded prospectively between April 2010 and October 2023, 250 renal units in 242 patients with upper urinary tract stones (UUTS) who underwent ureterorenoscopy by one surgeon in the same medical center were evaluated. Stone-free rate (SFR) was defined as no residual fragments at all using an intraoperative "triple test". The following characteristics were examined: gender, BMI, age, Hounsfield unit, stone diameter, laterality, renal/ureteral stones, stone-free rate, and auxiliary procedures per renal unit. The Clavien-Dindo classification was used to report complications. Renal units with residual stones were scheduled for a 2nd f-URS. Post- flexible ureteroscopy ureteral obstruction and renal function were detected using renal scan DTPA or MAG-3. The primary outcome was renal/ ureteral obstruction.

RESULTS

The mean patient age was 53 years. The mean stone size was 12.3 mm. Stones in renal pelvis, upper, middle and lower calyces were treated in 9.2% (23), 27.6% (69), and 30.8% (77) of cases, respectively; 44% (110) ureteral stones were also treated. The single- and second-session SFRs were 94.8% and 99.7%, respectively. A third auxiliary procedure was needed in one renal unit (0.4%). The mean number of procedures per renal unit was 1.06 (264/250). Ureteral double-J stents were inserted in 53.6% (134) of the cases. In 37 (14.8%) cases, a stent was placed before surgery. Post-operative complications were minor, with readmission and pain control needed in only two patients (0.8%). No avulsion or perforation of the ureters was observed. In six patients with t1/2 between 10-20 minutes, a second renal scan revealed spontaneous improvement and no obstruction in five patients. One patient with large stones and a history of prior ureteroscopy developed a ureteral stricture (0.4%) and needed treatment with laser endoureterotomy.

CONCLUSIONS

Post-flexible ureteroscopy obstruction due to ureteral stricture is very rare. A routine renal scan post-operatively may be used in potentially high-risk patients.

Determining the Stone Free Rate of Retrograde Intrarenal Surgery. Which Radiological Technique? RIRSearch Study Group

OBJECTIVE

To evaluate the sensitivity and specificity of ultrasonography (USG) and kidney ureter bladder radiography (KUB) for the determination of stone-free status of retrograde intrarenal surgery (RIRS) according to different stone-free status definitions.

MATERIALS AND METHODS

The patients who underwent RIRS between September 2021 and September 2022 were prospectively included in the study. All patients underwent a KUB radiography, urinary system USG and noncontrast abdominal tomography at the postoperative first month of the surgery. The sensitivity, specificity, negative predictive factor, and positive predictive factor of USG and KUB on evaluating the stone-free rate were analyzed according to different stone-free status definitions.

RESULTS

A total of 178 patients were included in the study. The stone-free rates according to stone-free definitions as; residual stone <4 mm, <2 mm and no residual stone were 79.2%, 64.0%, and 56.7%, respectively. According to its definition as a residual stone <4 mm, the sensitivity and specificity of USG were 64.9% and 84.3%, respectively. The sensitivity of USG was 57.1% and 52.5% as the definitions were residual stone <2 mm and no residual stone, respectively. Addition of KUB to USG slightly increased the sensitivity but did not change the specificity.

CONCLUSION

USG had high specificity but low sensitivity for evaluating stone-free status after RIRS and addition of KUB did not increase the diagnostic efficacy. Although USG may be used in daily practice, it may overestimate the stone-free status and noncontrast abdominal tomography must be used during the clinical trials to document the exact stone-free rates of RIRS.

Comparison of traditional and suctioning ureteral access sheath during retrograde intrarenal surgery in the treatment of renal calculi

PURPOSE

This study aims to compare the efficiency and clinical outcomes between the suctioning ureteral access sheath (UAS) group and the traditional UAS group during retrograde intrarenal surgery (RIRS) for kidney stones and explore the impact of suctioning UAS on postoperative infectious complications.

METHODS

We retrospectively reviewed the clinical data of 162 patients with kidney stones who underwent RIRS with a traditional UAS (n = 74) or a suctioning UAS (n = 71) between March 2021 and May 2023.

RESULTS

The mean operative time in suctioning UAS group (39.03 ± 18.01 s) was significantly shorter than that (49.73 ± 20.77 s) in the traditional UAS group (P = 0.037). The mean postoperative hospital stay was significantly shorter in the suctioning UAS group (1.57 ± 0.82d) compared with the traditional UAS group (2.30 ± 1.6 2 d) (P = 0.032). The instant SFRs were significantly higher in the suctioning UAS group (88.73%) than in the traditional UAS group (75.68%) (P = 0.040). The overall SFR in suctioning UAS group (92.96%) was slightly higher than the traditional UAS group (85.14%). The incidence of overall complications was significantly higher in the traditional UAS group (35.14%) than in the suctioning UAS group (16.90%) (P = 0.013). In multivariate analysis, female patients (OR 0.053, P = 0.018), positive urine WBC (OR 10.382, P = 0.034), operative time > 60 min (OR 20.231, P = 0.032), and the application of traditional UAS (OR 0.042, P = 0.017) were independent risk factors associated with infectious complications.

CONCLUSION

We demonstrated that suctioning UAS provided a higher instant SFR and fewer postoperative infectious complications during RIRS, and patients with predictable risk factors for infectious complications could potentially benefit from the use of the suctioning UAS.

Optimizing Outcomes in Flexible Ureteroscopy: A Narrative Review of Suction Techniques

OBJECTIVE

The aim of this review is to summarize the existing suction systems in flexible ureteroscopy (fURS) and to evaluate their effectiveness and safety.

METHODS

A narrative review was performed using the Pubmed and Web of Science Core Collection (WoSCC) databases. Additionally, we conducted a search on the Twitter platform. Studies including suctions systems in fURS were included. Editorials, letters and studies reporting intervention with semirigid ureteroscopy, PCNL and mPCNL were excluded.

RESULTS

A total of 12 studies were included in this review. These studies comprised one in vitro study, one ex vivo study, one experimental study and eight cohort studies. The Pubmed and WoSCC searches identified three suction techniques (Irrigation/Suctioning system with control of pressure, suction ureteral access sheath (sUAS) and direct in scope suction (DISS)), and the Twitter search identified four of them. The overall results showed that suction is an effective and safe technique that improves stone-free rates, reduces operative time and limits complication rates after fURS.

CONCLUSIONS

The use of suctioning during common endourological procedures has been shown to improve safety and efficacy in several indications. However, randomized controlled trials are needed to confirm this.

Complete Stone Clearance after Retrograde Intrarenal Surgery among Patients with Urolithiasis in a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

Retrograde intra-renal surgery using flexible scopes and laser energy is a newer alternative in stone disease treatment armamentarium. It is claimed to be superior to other modalities for stone clearance, complications and hospital stay. The aim of this study was to find out the prevalence of complete stone clearance after retrograde intra-renal surgery among patients with urolithiasis in a tertiary care centre.

Methods

This was a descriptive cross-sectional study conducted in the Department of Urology in a tertiary care centre from 15 June 2021 to 14 May 2022 including adult patients with stone size up to 15 mm. Ethical approval was obtained from the Institutional Review Committee (Reference number: IRC-PA-143/2077-78). Convenience sampling was done. The prevalence of complete stone clearance (no residual fragment >4 mm) was calculated. Point estimation and 95% confidence interval were calculated.

Results

Among 42 patients, 36 (85.71%) patients (75.1-96.3, 95% Confidence Interval) achieved complete stone clearance. The mean age was 40.26±14.05 (16-74) years and the stone size was 1.27±0.19 (0.9 -1.5) cm. Similarly, the mean operating time was 51.55±9.34 (40-85) minutes and the hospital stay was 1.33±0.52 (1-3) days. Grade 3 ureteric injury occurred in one case. Residual fragments were seen in 6 cases (14.29%). Sepsis occurred in 4 cases (11.11%).

Conclusions

The prevalence of complete stone clearance was similar among patients undergoing retrograde intra-renal surgery in our study when compared to other studies conducted in similar settings.

Keywords

laser; miniaturization; postoperative complications.

Comparison Between Percutaneous Nephrolithotomy and Retrograde Flexible Nephrolithotripsy in Obese Patients with 2 - 4 cm Renal Stones

Background: Nowadays, because of remarkable advancements in retrograde intrarenal surgery (RIRS), modest attention toward this procedure as the second or alternative choice for renal stones treatment has been drawn. Objectives: In the present study, we compared RIRS and percutaneous nephrolithotomy (PCNL) outcomes in treating obese patients with 2 - 4 cm renal stones. Methods: Eighty-two patients who underwent PCNL (n = 40) and RIRS (n = 42) between June 2015 and December 2018 at the Department of Urology of Sina Hospital were enrolled in our retrospective cohort study. Results: After the first surgery session, stone-free rates for the RIRS group were 92.9% and for the PCNL group was 95% (P value = 0.52). The mean operation time for the RIRS and PCNL groups were 71.6 ± 11 and 93.3 ± 12.2, respectively (P < 0.001). The hospitalization stay for all of the PCNL group was more than 1 day (mean = 2.5 days); however, that for the majority of the RIRS group was less than 1 day (P < 0.001). The analgesic use in the RIRS group was significantly lower than in the PCNL group (9.0 ± 5.5, 61.8 ± 13.6, respectively; P < 0.001). The overall complication rates were higher in the RIRS group. However, none of them were statically significant (P > 0.05). Conclusions: According to satisfactory outcomes obtained in the RIRS groups, it can be concluded that RIRS can be applied as an alternative or even the first choice in obese patients with 2 - 4 cm renal stones.

Technique, Feasibility, Utility, Limitations, and Future Perspectives of a New Technique of Applying Direct In-Scope Suction to Improve Outcomes of Retrograde Intrarenal Surgery for Stones

Retrograde intrarenal surgery (RIRS) is accepted as a primary modality for the management of renal stones up to 2 cm. The limitations of RIRS in larger volume stones include limited visualization due to the snow-globe effect and persistence of fragments that cannot be removed. We describe a new, simple, cost-effective modification that can be attached to any flexible ureteroscope which allows simultaneous/alternating suction and aspiration during/after laser lithotripsy using the scope as a conduit to remove the fragments or dust from the pelvicalyceal system called direct in-scope suction (DISS) technique. Between September 2020 and September 2021, 30 patients with kidney stones underwent RIRS with the DISS technique. They were compared with 28 patients who underwent RIRS with a 11Fr/13Fr suction ureteral access sheaths (SUASs) in the same period. RIRS and laser lithotripsy were carried out traditionally with a Holmium laser for the SUAS group or a thulium fiber laser for the DISS group. There was no difference in age, gender, and history of renal lithiasis between the two groups. Ten (40%) patients had multiple stones in the DISS groups, whilst there were no patients with multiple stones in the SUAS group. Median stone size was significantly higher in the DISS group [22.0 (18.0−28.8) vs. 13.0 (11.8−15.0) millimeters, p < 0.001]. Median surgical time was significantly longer in the DISS group [80.0 (60.0−100) minutes] as compared to the SUAS group [47.5 (41.5−60.3) minutes, p < 0.001]. Hospital stay was significantly shorter in the DISS group [1.00 (0.667−1.00) vs. 1.00 (1.00−2.00) days, p = 0.02]. Postoperative complications were minor, and there was no significant difference between the two groups. The incidence of residual fragments did not significantly differ between the two groups [10 (33.3%) in the DISS group vs. 10 (35.7%) in the SUAS group, p = 0.99] but 10 (33.3%) patients required a further RIRS for residual fragments in the DISS group, whilst only one (3.6%) patient in the SUAS group required a subsequent shock wave lithotripsy treatment. Our audit study highlighted that RIRS with DISS technique was feasible with an acceptable rate of retreatment as compared to RIRS with SUAS.

External validation of Resorlu-Unsal stone score in predicting outcomes after retrograde intrarenal surgery. Experience from a single institution

Objective: Pre-operative assessment of renal stones is essential in selecting treatment options and achieving high success rates for retrograde intrarenal surgery (RIRS). Several nephrolithometric scoring systems have been developed using pre-operative clinical data and stone characteristics. Resorlu-Unsal stone score (RUSS) is composed of four different parameters, and each of them adds 1 point to the final score. One point is added in patients with stone size > 20 mm, lower calyceal stones and infundibulo-pelvic angle < 45°, stone number > 1, and abnormal anatomy, respec-tively. RUSS categorizes patients into four distinct groups and aims to predict stone-free rates (SFR) after RIRS. We externally validated RUSS and evaluated its predictive accuracy.Materials and Methods: We performed a retrospective analysis of patients who underwent RIRS for renal stones between January 2020 and December 2021. Patient age, pre-operative hydronephrosis, stone size, stone density as Hounsfield Unit(HU), operative time and RUSS were investigated as potential preoperative predictive factors for stone-free status. RUSS was applied to all patients, and the nomogram was externally vali-dated. Area under the curve (AUC) was used for clinical validity assessment.Results: The present study included a total of 79 patients. Mean patient age was 55.1 ± 15.4 years with a mean stone size was 14.2 ± 4.4 mm. Overall, 62/79 (78.4%) patients were stone free after the initial treatment. After applying RUSS, 36 (45.6%), 29 (36.7%), 10 (12.6%), and 4 (5.1%) patients had a score of 0, 1, 2, and 3, respectively. On multivariate logistic regression RUSS (OR = 0.220; 95%CI: 0.086-0.567; p = 0.002) was identified as the only predictor of postoperative stone-free status.Conclusions: RUSS is a user-friendly scoring system that may predict postoperative stone-free rate after RIRS with great effi-cacy and accuracy.

Sheathed flexible retrograde intrarenal surgery without safety guide wire for upper urinary tract stones

OBJECTIVES

To assess the success rate and intraoperative complications of flexible ureterorenoscopy (f-URS) in patients with upper urinary tract (UUT) stones using a ureteral access sheath (UAS) without a safety guide wire (SGW).

PATIENTS AND METHODS

Between April 2010 and March 2022, 464 renal units in patients with renal stones with and without concomitant ureteral stones (UUT), underwent ureterorenoscopy by one surgeon, and UAS was used in all of them. The primary endpoint was the stone-free rate (SFR). SFR was defined as no residual fragments at all. The following characteristics were examined: age, sex, laterality, renal/ureteral stones, stone diameter, SFR, Hounsfield unit, auxiliary procedures, double-J stent insertion, and intraoperative complications. This study was retrospective, with all the data recorded prospectively. Patients with residual stones were scheduled for the 2nd RIRS. The Clavien-Dindo classification was used to report complications.

RESULTS

The mean patient age was 52.9 years. The mean stone size was 13.1 mm. Lower pole, upper and middle calyces, renal pelvis and ureteral stones were found in 51.5% (239), 34.9% (162), 18.3% (85) and 46.9% (218) of cases, respectively. The mean diameter was 8.1 mm, 8 mm, 12.5 mm and 8.1 mm for the lower pole, upper and middle calyces, renal pelvis and ureteral stones, respectively. The single- and second-session SFRs were 90% and 100%, respectively. The mean number of procedures per renal unit was 1.1. Ureteral double-J stents were inserted in 45.7% (212) of patients. In 96 cases, a stent was placed before surgery. Postoperative complications were minor, with no avulsion or perforation of the ureters; readmission and insertion of a DJ stent occurred in one patient. Ureteral stricture developed in one patient (0.2%) and needed treatment with laser ureterotomy.

CONCLUSIONS

f-URS is a safe and effective mode of surgical management of renal and simultaneous renal and ureteral calculi using the ureteral access sheath without a safety guide wire. A guide wire should not be routinely used in these cases.

Evaluation of the optimal duration for retrograde intrarenal stone surgery to prevent postoperative complications

OBJECTIVE

To evaluate retrograde intrarenal surgery (RIRS) outcomes and to determine the effect of operative time on complications of RIRS.

METHODS

Patients undergoing RIRS for renal stones were evaluated. These patients were divided into two groups according to the operation time (Group 1<60 minutes and Group 2>60 minutes). Peroperative outcomes such as fluoroscopy time, stone-free rates, complications and duration of hospitalization were compared.

RESULTS

Group 1 consisted of 264 patients and Group 2 consisted of 297 patients. SFR rates, duration of hospitalization, and postoperative urinary tract infection rates were similar in both groups. Fluoroscopy time was 7.8±7.3 (0-49) sec in group 1 and 13.1±9.8 (0-81) sec in group 2. Complications according to modified Clavien-Dindo classification system (MCDCS) were 13 and 32 patients (Grade 1), 31 and 63 patients (Grade 2), 1 and 1 patient (Grade 3) in group 1 and 2, respectively. There was statistical difference between the two groups in terms of duration of fluoroscopy time and the MCDCS. Although duration of hospitalization and UTI rates were higher in group 2, no statistical significance was observed among groups.

CONCLUSION

Limiting the operation time to 60 minutes in RIRS seems to be important in reducing postoperative complications.

Retrograde Intrarenal Surgery Versus Miniaturized Percutaneous Nephrolithotomy for Kidney Stones >1cm: A Systematic Review and Meta-analysis of Randomized Trials

CONTEXT

Although miniaturized percutaneous nephrolithotomy (mPCNL) and retrograde intrarenal surgery (RIRS) are both options for treating >1cm kidney stones, controversies exist on whether one is more effective and safer than the other.

OBJECTIVE

To systematically appraise randomized trials comparing the effectiveness and safety of mPCNL and RIRS for treating >1cm kidney stones.

EVIDENCE ACQUISITION

A systematic search on PubMed/Medline, Web of Science, Embase, and ClinicalTrials.gov was conducted in August 2020 following the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA). Randomized trials comparing mPCNL and RIRS for >1cm kidney stones, and reporting stone-free rate (SFR), hemoglobin drop, transfusion rate, length of hospital stay (LOS), and/or complications, were included.

EVIDENCE SYNTHESIS

Eight studies compared mPCNL and RIRS, but one was not included due to its high risk of bias. SFR was higher for mPCNL (RR: 1.06 [95% coefficient interval {CI}, 1.01-1.10], p=0.008). Hemoglobin drop was higher for mPCNL (mean difference [MD]: 0.35 [95% CI, 0.05-0.65] g/dl, p=0.02); however, transfusion rates were similar (p=0.44). Complication rate was similar between mPCNL and RIRS (p=0.39), and the LOS was higher for mPCNL (MD: 1.11 [95% CI, 0.06-2.16] d, p=0.04). A subgroup analysis of lower pole stones showed that SFR was higher for mPCNL (RR: 1.09 [95% CI, 1.00-1.19], p=0.05).

CONCLUSIONS

Both approaches are effective and safe. Among these approaches, mPCNL has a higher SFR than RIRS for overall >1cm renal and lower pole stones, but longer LOS, and a higher hemoglobin drop that does not translate into higher transfusion rates. Complications are comparable.

PATIENT SUMMARY

Randomized trials have evaluated whether miniaturized percutaneous nephrolithotomy (mPCNL) or retrograde intrarenal surgery is more effective and safer for treating >1cm stones. After comparing the stone-free rate, hemoglobin drop, transfusion rate, length of hospital stay, and complications between both the approaches, mPCNL was found to be slightly more effective, but both were equally safe.

Stone free rate and clinical complications in patients submitted to retrograde intrarenal surgery (RIRS): Our experience in 571 consecutive cases

INTRODUCTION

The purpose of this study is to report the stone free rate (SFR) and clinical complications in patients submitted to retrograde intrarenal surgery (RIRS).

MATERIALS AND METHODS

A total of 571 procedures of upper urinary stones treated using flexible ureteroscopy and holmium laser lithotripsy from January 2014 to February 2020 have been analyzed. Overall SFR was evaluated after 3 months following the procedure by means of a non-contrast computed tomography. Success was considered as stone-free status or ≤ 0.4 cm fragments.

RESULTS

The overall SFR was 92.3% in group 1 (stone size: < 1 cm), 88.3% in group 2 (stone size: > 1 ≤ 2 cm), 56.7% in group 3 (stone size: 2-3 cm) and 69.6% in group 4 (multiple stones). Post-operative complications, according to the Clavien- Dindo (CD) classification system, were recorded in 32 (5.6%) procedures. The major complications recorded were: one case of subcapsular hematoma (SRH) associated with pulmonary embolism two days after the procedure (CD Grade IIIa) treated conservatively and one case of hemorrhagic shock 2 hour with multiple renal bleedings requiring urgent nephrectomy (CD Grade IVA).

CONCLUSIONS

The RIRS is an effective and safe procedure with a high SFR significantly correlated with the stone size; at the same time, RIRS could be characterized by severe clinical complications that require rapid diagnosis and prompt treatment.

Retrospective analysis of the factors affecting intraoperative and immediate postoperative complications of RIRS classified by the Clavien and Satava grading systems

BACKGROUND

To classify intraoperative and postoperative complications using the modified Clavien classification system(MCCS) and modified Satava classification system(SCS) and to evaluate the parameters associated with complications in patients undergoing retrograde intrarenal surgery(RIRS) for renal and proximal ureteral stones.

MATERIALS AND METHODS

We performed a retrospective analysis of 949 patients who underwent RIRS for renal stones and proximal ureteral stones at two institutions between March 2015 and June 2020. Intraoperative complications were assessed using SCS and postoperative complications were graded according to MCCS. Univariate and multivariate analyses were undertaken to determine predictive factors affecting complication rates.

RESULTS

The median stone size was determined as 13 mm (range 10-20 mm). The stone-free rate was 83.6% after the first intervention. Reprocedure was applied to 89 of the patients with residual stones and the final stone-free rate was 94.4% after reprocedure. According to SCS, the number of intraoperative events and complication incidences was 153(16.1%). MCCS revealed postoperative complications in 121(12.8%) patients. Major complications were observed in 18(1.9%) patients. The rate of complications was higher in patients with renal anomalies (9.9% vs 3.4%, p=0.001). Stone location, stone size, stone burden, stone number, stone density and residual fragments were determined to be associated with the development of complications (p<0.001,p<0.001,p<0.001, p<0.001,p=0.002 and p<0.001 respectively). In addition, the multivariate analysis revealed that only presence of residual fragments was a significant predictor of complication development for the patients with Grade≥3 complications according to MCCS (p=0.032). However, significant predictors were stone burden (p<0.001), stone density (p=0.002) and fluoroscopy time (p<0.001) for those with Grade≥2b complications according to SCS.

CONCLUSION

This study showed that abnormal kidney anatomy, operation time, stone burden and residual fragments were reliable predictors of complication development during and after RIRS. Appropriate preoperative management should be planned according to these predictors to prevent intraoperative and postoperative complications.

Massive retroperitoneal hematoma as an acute complication of retrograde intrarenal surgery: A case report

BACKGROUND

Retrograde intrarenal surgery (RIRS) has been proven to be a safe and effective treatment modality in large-scale quantitative studies. However, although its safety profile has been established, it also has a potential risk of life-threatening complications. We here describe our experience with a patient who developed a huge periureteral hematoma after RIRS with holmium laser lithotripsy.

CASE SUMMARY

A 73-year-old woman visited our center with a complaint of gross hematuria. An enhanced computed tomography (CT) scan revealed a 1.5-cm left renal pelvis stone with hydronephrosis. The patient underwent RIRS. During the surgery, a 12/14-Fr ureteral access sheath was applied and a 6-Fr ureteral catheter was indwelled thereafter. On postoperative day 1, she experienced aggravated left flank pain and left lower-quadrant tenderness without rebound tenderness. A follow-up CT scan was taken, which revealed a huge hematoma in the periureteral space, not in the perirenal space, with suspicious contrast medium extravasation. Immediate angiography was performed; however, it showed no evidence of active bleeding. She was conservatively managed with hydration and antibiotic and nonsteroidal anti-inflammatory drug therapy, and was discharged on postoperative day 7. However, she visited our outpatient department with recurrent left flank pain at 5 d from discharge. Ultrasonography confirmed that the double J-stent was intact. To rule out stent malfunction, the stent was changed. Decreased size of the hematoma was observed in the imaging studies, and conservative management for candiduria was performed for 1 wk.

CONCLUSION

Although RIRS is an effective and safe procedure for the management of renal stones, clinicians should be aware of its potential complications.

External validation of the R.I.R.S. scoring system to predict stone-free rate after retrograde intrarenal surgery

Background

The R.I.R.S. scoring system is defined as a novel and straightforward scoring system that uses the main parameters (kidney stone density, inferior pole stones, stone burden, and renal infundibular length) to identify most appropriate patients for retrograde intrarenal surgery (RIRS). We strived to evaluate the accuracy of the R.I.R.S. scoring system in predicting the stone-free rate (SFR) after RIRS.

Methods

In our medical center, we retrospectively analyzed charts of patients who had, between September 2018 and December 2019, been treated by RIRS for kidney stones. A total of 147 patients were enrolled in the study. Parameters were measured for each of the four specified variables.

Results

Stone-free status was achieved in 105 patients (71.43%), and 42 patients had one or more residual fragments (28.57%). Differences in stone characteristics, including renal infundibulopelvic angle, renal infundibular length, lower pole stone, kidney stone density, and stone burden were statistically significant in patients whether RIRS achieved stone-free status or not (P < 0.001, P: 0.005, P < 0.001, P < 0.001, P: 0.003, respectively). R.I.R.S. scores were significantly lower in patients treated successfully with RIRS than patients in which RIRS failed (P < 0.001). Binary logistic regression analyses revealed that R.I.R.S. scores were independent factors affecting RIRS success (P = 0.033). The area under the curve of the R.I.R.S. scoring system was 0.737.

Conclusions

Our study retrospectively validates that the R.I.R.S. scoring system is associated with SFR after RIRS in the treatment of renal stones, and can predict accurately.

Disposable versus Reusable Ureteroscopes: A Prospective Multicenter Randomized Comparison

Purpose

To compare reusable and disposable flexible ureteroscopes in terms of efficacy and safety for patients undergoing Retrograde Intrarenal Surgery (RIRS).

Patients and Methods

Patients with a renal stone eligible for RIRS were enrolled in this multicenter, randomized, clinical trial study. Patients were randomized into two groups: group A (90 patients) underwent RIRS with a reusable flexible ureteroscope and group B (90 patients) were treated with a disposable one.

Results

The patients’ demographics, stone features and pre-operative urine cultures were comparable between the groups. The Stone Free Rates (SFRs) were not significantly different (86.6% and 90.0% for group A and group B, respectively, p=0.11) and the mean cost for each procedure was comparable (2321 € in group A vs 2543 € in group B, p=0.09). However, the days of hospitalization and of antibiotic therapy were higher in group A (p ≤ 0.05). The overall complication rate in group A was 8.8% whilst in group B it was 3.3% (p ≤ 0.05); in particular, group A exhibited a greater number of major complications (Clavien score IIIa-V). The overall postoperative infection rate was 16.6% in group A and 3.3% in group B (p ≤ 0.05). Furthermore, none of the patients in group B developed urosepsis or had a positive blood culture, while 3 patients in group A did (p<0.05).

Conclusion

The use of disposable ureteroscopes is characterized by significantly lower post-operative complications and infection rates, while having comparable costs and SFRs vis à vis reusable ureteroscopes. Clinical Trial Registration Number: ISRCTN92289221.

The Application of Retrograde Intrarenal Surgery to Remove a Single Large Kidney Stone During Pregnancy

Purpose

To report the application and outcome of retrograde intrarenal surgery (RIRS) to remove a large kidney stone during pregnancy.

Patient and Methods

A 30-year-old woman presented with an infected kidney stone (3 cm in size) at 4 weeks of pregnancy. We decided to remove the stone due to the possibility of obstruction and infection and chose to carry out this procedure by RIRS. In order to avoid complications associated with anesthetic, the surgery was carried out after the infection had cleared and when the patient had entered the second trimester of pregnancy. First, we used an ureteral access sheath and semi-rigid ureteroscopy to evaluate the ureteral lumen. We confirmed that the ureteral access sheath had been positioned appropriately by direct visualization with a flexible ureterorenoscope. The procedure was then carried out with a radiation-free protocol and without fluoroscopy. Ho-YAG laser lithotripsy was used to fragment the stones, and these fragments were then removed in a stone basket. The patient required three sessions of RIRS to remove the stone in its entirety; during this time, the patient was 18-29 weeks into her pregnancy. During each session, we removed approximately 30% of the stone. The patient developed fever after the first operation but responded fully to antibiotics. There were no perioperative complications, and the patient only remained in hospital for 3 days. The male infant was delivered by caesarian section at 37 weeks of pregnancy without any health complications.

Results and Conclusion

We successfully removed a large kidney stone from a pregnant patient using an ureteral access sheath and RIRS without fluoroscopy. There were no complications indicating that this procedure can be carried out safely during pregnancy.

Comparative medico-economic study of reusable vs. single-use flexible ureteroscopes

PURPOSE

Reusable flexible-ureteroscopes (fURS) require personnel and budget for processing and repairing, whereas single-use fURS were recently developed. After exclusive reusable fURS since 2011, we experienced high repair costs and single-use fURS were therefore introduced in mid-2017. We aimed to evaluate economic and practical advantages and disadvantages of reusable versus single-use fURS.

MATERIALS AND METHODS

First, we evaluated the incidence of breakage and repairs of reusable fURS in 2017. We assessed the overall operational costs of reusable fURS including purchase, processing, and repairing in our institution from 2011 to 2017. Following our experience, we created a model to compare operation costs/procedure of single-use fURS with reusable fURS depending on repair costs.

RESULTS

In 2017, repair costs of reusable fURS increased by 345% compared with the period 2011-2016, causing: a median unavailability per reusable fURS of 200 days/year (100-249), median number of functioning fURS 0/5-3/5 per operating day, while unavailability of reusable fURS had become the first reason for cancellation of procedure. Since it was introduced, single-use fURS accounted for 59% of the flexible ureteroscopy activity. Taking into account the costs of processing, maintenance and repair, in 2011-2016 versus 2017, the single-use fURS was cost-effective compared with the reusable fURS until the 22nd procedure versus the 73rd procedure, respectively.

CONCLUSIONS

After years of exclusive reusable fURS, the rising incidence of breakage not only increased maintenance costs but also hampered daily activity owing to unavailability of the devices. The introduction of single-use with reusable fURS provided substantial help to maintain our activity.

Comparison among the available stone treatment techniques from the first European Association of Urology Section of Urolithiasis (EULIS) Survey: Do we have a Queen?

PURPOSE

The miniaturization of instruments has had an impact on stone management. The aims of this study were to highlight surgeon preferences among Retrograde Intra Renal Surgery (RIRS), Regular, Mini-, UltraMini- and Micro- Percutaneous Nephrolithotomy (PCNL) for urolithiasis and to compare the effectiveness and safety of these techniques in a real-life setting.

METHODS

A 12-item survey regarding endourological techniques was conducted through Survey Monkey among attendees of the 2013 European Association of Urology Section of Urolithiasis meeting. We asked responders to share data from the last 5 cases they performed for each technique. Procedures were stratified according to stone size and the centres' surgical volume. Techniques were compared in terms of effectiveness and safety. Analyses were performed on the overall group and a subgroup of 1-2 cm stones.

RESULTS

We collected data from a total of 420 procedures by 30, out of 78, urologists who received the survey (response rate 38%): 140 RIRS, 141 Regular-PCNL (>20 Ch), 67 Mini-PCNL (14-20 Ch), 28 UltraMini-PCNL (11-13 Ch) and 44 Micro-PCNL (4,8-8 Ch). Techniques choice was influenced by stone size and the centre's surgical volume. Effectiveness and safety outcomes were influenced by stone size, independently of the technique. The stone-free rate was significantly lower in Micro-PCNL compared to Regular-PCNL. This was not confirmed for 1-2 cm stones. All techniques presented a lower complication rate than Regular-PCNL, with Mini-PCNL being the most protective technique compared to Regular-PCNL.

CONCLUSIONS

Stone size seems to drive treatment choice. Miniaturized PCNL techniques are widely employed for 1-2 cm stones, in particular in higher surgical volume centres. Mini-PCNL and RIRS are growing in popularity for stones > 2 cm. Mini-PCNL seems to be a good compromise, being the most effective and safe procedure among PCNL techniques. RIRS is characterized by satisfactory stone-free and low complication rates.

Prediction of stone-free status after single-session retrograde intrarenal surgery for renal stones

OBJECTIVE

To determine the possible factors effecting stone-free status (SFS) after single-session retrograde intrarenal surgery (RIRS) for renal stones.

MATERIAL AND METHODS

We retrospectively analyzed the charts of 100 consecutive patients who underwent RIRS. Unilateral procedures performed for single renal stones were included in the study. The studied parameters included patient demographics, stone characteristics (size, volume, location and attenuation according to Hounsfield unit [HU]), operation time, presence of preoperative double-J stent (DJS), use of ureteral access sheath (UAS) and SFS.

RESULTS

The study population consisted of 100 patients where 43 of them were stone free and remaining 57 had residual stones. The mean age of the patients was 47.2±13.4 years. The mean stone size (largest dimension), stone attenuation and stone volume were 14.8±5.8 mm, 1010±416 HU and 937±929 mm³, respectively. The mean operative time was 60.8±24.2 minutes. Mean stone size, volume and HU were higher in the RS group compared to SF group but without any statistically significant difference, 15.2±6.1 vs. 14.2±5.3 mm, 1056±1037 mm³ vs. 780±745 mm³ and 1061±374 HU vs. 942±462 HU, respectively (p=0.490, p=0.135 and p=0.226). In multivariate regression analysis stone location and UAS use were found to be the significant predictors of SFS. Patients with lower pole stones are 2.25 times likely to have residual stones after RIRS compared to patient's having stones at other localizations (p<0.001).

CONCLUSION

Stone volume could be a more reliable parameter than stone size in predicting RIRS success. Lower pole stone location and UAS use could be considered the most significant predictors of SFS after single session RIRS for single renal stones.

Mortality from kidney stone disease (KSD) as reported in the literature over the last two decades: a systematic review

INTRODUCTION

Current trends show a rising incidence of kidney stone disease (KSD) globally, with a lifetime risk of 10% and increasing hospital admissions. However, it is not perceived as a life-threatening condition and there are no publications examining its mortality rate. The aim of this review was to report on the number of KSD mortalities in the literature from the past two decades, identify risk factors, and to summarize their key learning points.

METHODS

A search was conducted for full-text English language articles that reported on KSD associated mortality, following intervention or conservative treatment, published between 1999 and 2017, using PubMed, MEDLINE, EMBASE, Scopus, CINAHL, Clinicaltrials.gov, Google Scholar and The Cochrane Library. Study quality and risk of bias assessment was undertaken using a validated critical appraisal tool from the Joanna Briggs Institute.

RESULTS

Of the 2786 articles identified, 34 were included. Of the total number of reported mortalities (2550), 21% were related to intervention. Sepsis was the leading cause of mortality. Risk factors identified were patients with multiple co-morbidities, spinal cord injury or neurogenic bladder and high stone burden. The main recommendations suggested were to treat pre-operative UTI or use prophylactic antibiotics and to reduce operative duration. The included studies were of moderate to good quality.

CONCLUSION

Pre-procedural optimization of the patients is the key to avoiding KSD mortality, and care should be taken in patients with multiple co-morbidities. Surgeons should meticulously plan for patients with high stone burden to reduce their operative time, as mortality can be procedural related.

Subcapsular renal hematoma after retrograde ureterorenoscopic lithotripsy: our experience

BACKGROUND

Ureterorenoscopy is the current standard treatment for ureteral and kidney stones, also stones greater than 2 cm can be removed. Complications linked to infectious processes or ureteral damage are the most frequently reported. Subcapsular renal hematoma is an extremely rare complication following this procedure.

METHODS

We report the retrospective experience of two urological referral units for stones disease by analyzing incidence, risk factors and management of subcapsular renal hematoma.

RESULTS

Between May 2011 and December 2017, 2497 consecutive ureteroscopies for urolithiasis were performed by 8 skilled endourologists. A subcapsular renal hematoma was diagnosed in four cases (0.12%). Symptoms appeared few hours after intervention in two patients and after 14 postoperative days in the remaining two. In all cases CT scan revealed a subcapsular renal hematoma without signs of active bleeding. Conservative treatment was successful. Two patients required blood transfusion. One patient developed renal hypotrophy.

CONCLUSIONS

Subcapsular renal hematoma represents a rare but potentially serious complication after ureterorenoscopic lithotripsy. Its real incidence and etiology still need to be clarified. The elevated intrarenal pressures play an important role. Persistent hematuria, flank pain and hemoglobin drop should guide prompt investigation to reach an early diagnosis. In most cases a conservative management is sufficient.

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.

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.

The R.I.R.S. scoring system: An innovative scoring system for predicting stone-free rate following retrograde intrarenal surgery

Background

To establish and internally validate an innovative R.I.R.S. scoring system that allows urologists to preoperatively estimate the stone-free rate (SFR) after retrograde intrarenal surgery (RIRS).

Methods

This study included 382 eligible samples from a total 573 patients who underwent RIRS from January 2014 to December 2016. Four reproducible factors in the R.I.R.S. scoring system, including renal stone density, inferior pole stone, renal infundibular length and stone burden, were measured based on preoperative computed tomography of urography to evaluate the possibility of stone clearance after RIRS.

Results

The median cumulative diameter of the stones was 14 mm, and the interquartile range was 10 to 21. The SFR on postoperative day 1 in the present cohort was 61.5% (235 of 382), and the final SFR after 1 month was 73.6% (281 of 382). We established an innovative scoring system to evaluate SFR after RIRS using four preoperative characteristics. The range of the R.I.R.S. scoring system was 4 to 10. The overall score showed a great significance of stone-free status (p < 0.001). The area under the receiver operating characteristic curve of the R.I.R.S. scoring system was 0.904.

Conclusions

The R.I.R.S. scoring system is associated with SFR after RIRS. This innovative scoring system can preoperatively assess treatment success after intrarenal surgery and can be used for preoperative surgical arrangement and comparisons of outcomes among different centers and within a center over time.

The "old" 15 mm renal stone size limit for RIRS remains a clinically significant threshold size

PURPOSE

To investigate the performance of retrograde intrarenal surgery (RIRS) for the 1-2 cm renal stone size range in comparison to smaller stones.

MATERIALS AND METHODS

From a data base of 3000 ureteroscopies between 2004 and 2014, 635 consecutive patients underwent RIRS for renal stones. Patients were divided to three groups according to their renal stone size (<10, 10-15, 15-20 mm). Preoperative, operative, stone free rate (SFR) and follow-up data were analyzed and compared.

RESULTS

The SFR for the three groups was 94.1, 90.1 and 85%, respectively. Patients with renal stone size above 15 mm had a statistically significantly lower SFR. The efficiency quotient calculated for stones larger and smaller than 15 mm was 83.9 vs. 91.8%, respectively (p < 0.01). The mean operative time and hospital stay were longer for patients with renal stones larger than 15 mm (73.6 ± 29.9 vs. 53 ± 19.4 min, p < 0.01 and 2.2 ± 2 vs. 1.8 ± 1.8 days, p = 0.031, respectively). Moreover, the complication rate was almost two times higher (10 vs 5.4%, p = 0.08). Concomitant ureteral stones and older age were independent predictors of failure in the large stone group.

CONCLUSIONS

While the overall SFR following RIRS for renal stones up to 2 cm is generally high, the SFR for 15-20 mm stones is significantly lower, with a longer operating time and hospital stay, and a higher complication rate.

Single session vs two sessions of flexible ureterosopy (FURS) for dusting of renal pelvic stones 2-3 cm in diameter: Does stone size or hardness play a role in number of sessions to be applied?"

OBJECTIVE

To evaluate the stone hardness in predicting the need for single or two sessions of retrograde intrarenal surgery (RIRS) for renal pelvis stones of 2-3 cm in size.

MATERIAL AND METHODS

Ninety-six patients (64 male and 32 female) with only renal stones (2.5±0.3 cm) underwent RIRS using flexible 7.5 Fr ureteroscope (FURS). The stone hardness was evaluated by preoperative non-contrast computed tomography (NCCT). The patients were divided into two groups based on stone hardness: Group I (n=54) (hard stones - Hounsfield Unit (HU) >1000) and group II (n=42) (not hard stone - HU <1000). The stone-free rate, the operative time, any intra or postoperative complications and the need for second sessions of RIRS were evaluated.

RESULTS

All stones were successfully accessed. Intraoperative complications were not reported. The initial stone-free rate was 40% in Group I and 95% in Group II after a single session (p=0.01). A second session FURS was needed in 32 cases of Group I (40%) where postoperative CT showed significant residual stone fragments of 6±2 mm, and stone-free rate up to 100 percent. On the contrary only 2 cases from Group II underwent second session FURS (p=0.01). The operative times were 75±15 minutes in Group I and 55±13 minutes in Group II (p<0.01). Six patients (4 in group I and 2 in group II) had postoperative high-grade fever (Clavien Grade II).

CONCLUSION

Stone hardness had a significant impact on the decision of performing single versus two sessions of FURS for renal pelvic stones of 2-3 cm rather than the stone size alone.

Comparative analysis between percutaneous nephrolithotomy and flexible ureteroscopy in kidney stones of 2-3cm

INTRODUCTION

To compare percutaneous nephrolithotomy and flexible ureterorenoscopy for treating kidney stones between 2 and 3cm.

MATERIAL AND METHODS

A prospective, comparative, nonrandomised study was conducted with 108 patients with kidney stones between 2 and 3cm. Fifty-four patients underwent percutaneous nephrolithotomy and 54 underwent flexible ureteroscopy. We compared the following variables: lithiasis-free rate (%), surgical time, the need for an auxiliary process, postoperative complications, hospital stay, readmission rates and recovery time.

RESULTS

There were no differences in the lithiasis-free rate between the 2 surgical techniques (76% for ureteroscopy vs. 87% for nephrolithotomy; P=.1) or in the complications (29% for nephrolithotomy vs. 27% for ureteroscopy; P=.4). A larger number of auxiliary process were needed for the ureteroscopy group (20%) than for the nephrolithotomy group (7%) (P=.04). The surgical time was longer for the nephrolithotomy group (121±52min) than for the ureteroscopy group (93±42min) (P=.004). The ureteroscopy group had shorter hospital stays (2.1±1.6 vs. 3.9±1.9 days; P=.002), shorter convalescence (8.1±4.9 vs. 13.3±4.2 days; P=.005) and higher readmission rates (7.4% vs. 0%, P=.05) than the nephrolithotomy group.

CONCLUSIONS

Nephrolithotomy and ureteroscopy have similar efficacy for treating kidney stones measuring 2-3cm, with no differences in complications. Ureteroscopy results in shorter hospital stays, quicker recoveries but more readmissions and a greater need for auxiliary procedures.

Complications of retrograde intrarenal surgery classified by the modified Clavien grading system

The increase in the retrograde intrarenal surgery (RIRS) has been accompanied by the increase in complications. This study identified the factors that affected the severity of the complications using the modified Clavien classification system (MCCS). Three hundred and twenty-two consecutive RIRS performed by a single surgeon were analyzed. Data collection included demographics, clinical parameters, and perioperative and postoperative complications. The rate of adverse events for each of the Clavien grades was calculated, and statistical comparisons were made. The impact of each of the factors on the severity of the complications, based on the MCCS, was investigated using the univariate and multivariate analyses. The total complication rate was 26.1% (MCCS: I = 67.7%, II = 22.7%, IIIb = 7.2%, IVb = 2.4%). On the univariate analyses, the following factors affected complication: positive preoperative urine culture, operative time, irrigation rate, and stone burden. Multivariate logistic regression analysis demonstrated that positive preoperative urine culture, irrigation rate, and operative time were the significant factors affecting the complications. Most of the RIRS complications were in the lower Clavien grades and major complications were uncommon. Positive preoperative urine culture, irrigation rate, and operative time were the factors that affected complications.

A Novel Flexible Ureteroscopy with Intelligent Control of Renal Pelvic Pressure: An Initial Experience of 93 Cases

BACKGROUND

Flexible ureteroscopic lithotripsy (URS) is rapidly becoming a first-line therapy for patients with renal and ureteral calculi. Most current medical infusion devices can only monitor infusion flow and pressure, but not renal pelvic pressure (RPP).

PATIENTS AND METHODS

We designed a patented intelligent system to facilitate flexible URS that included an irrigation and suctioning platform and a ureteral access sheath (UAS) with a pressure-sensitive tip, enabling regulation of the infusion flow precisely and control of the vacuum suctioning by computerized real-time recording and monitoring of RPP. A stable RPP was ensured by pressure feedback technology. Ninety-three patients with renal or ureteral calculi participated in the study and received flexible URS. Gravel particles were sucked out automatically during the flexible URS. Patients were evaluated on postoperative days 1 and 30 by X-ray of kidneys, ureters, and bladder to assess stone-free status.

RESULTS

In 81 of the 93 patients, only one surgery was needed to remove the stone. There were nine cases who failed the first surgery due to difficulty in placing the UAS, but flexible URS was performed in these patients after indwelling a Double-J stent to the ureter with the calculus for 2 weeks. Three cases were converted to percutaneous nephrolithotomy due to significant ureteral stenosis. For the 90 patients who underwent flexible URS, the actual RPP was controlled under 20 mmHg with clear operative visualization. The stone-free rates at postoperative days 1 and 30 were 90.0% (81/90) and 95.6% (86/90), respectively. Clavien I complications were noted in 13 cases, while Clavien II complications were noted in two cases. No major complications (Clavien III-V) were noted.

CONCLUSIONS

Our patented system is technically feasible, safe, and efficient for treating upper urinary calculi. The advantages include breaking stones effectively and low complication rates because of its automatic control of RPP.

Retrograde Intrarenal Surgery is equally efficient and safe in patients with different American Society of Anesthesia physical status

OBJECTIVE

To assess the efficacy and safety of Retrograde Intrarenal Surgery to treat renal stones in patients with different American Society of Anesthesia (ASA) physical status.

MATERIAL AND METHODS

We performed a retrospective analysis of 150 patients who underwent Retrograde Intrarenal Surgery for renal stone between October 2013 and December 2014. Patients were categorized into three groups according to their ASA physical status: ASA Class 1 (Group 1, n = 23), ASA Class 2 (Group 2, n = 113) and ASA Class 3 (Group 3, n = 14). We documented and stratified the per-operative and postoperative complications according to modified Satava Classification System and Clavien-Dindo Classification.

RESULTS

The mean age of the patients was 44 years. The total stone-free rate was 81.2%. According to the groups, the stone-free rate was 75% in Group 1, 82.5% in Group 2, and 83.3% in Group 3 (p   =   0.340). Per-operative and postoperative complications were recorded in 12% (n = 18) and 5.3% (n = 8) of the patients. We did not find significant difference in terms of per-operative and postoperative complication rates among patients with different ASA physical status (p(per-operative) = 0.392 and p(postoperative) = 0.136).

CONCLUSIONS

Retrograde Intrarenal Surgery is an effective and safe surgery with high stone-free rates and low morbidity in patients with different ASA physical status.

Flexible ureterorenoscopy results: Analysis of 279 cases

OBJECTIVE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

Mini-percutaneous Nephrolithotomy vs Retrograde Intrarenal Surgery for Renal Stones Larger Than 10 mm: A Prospective Randomized Controlled Trial

OBJECTIVE

To compare miniaturized percutaneous nephrolithotomy (mini-PCNL) and retrograde intrarenal surgery (RIRS) in the management of renal stones >10 mm in a single session.

METHODS

Seventy patients presenting with renal stones >10 mm were randomized to a mini-PCNL or an RIRS group in a ratio of 1:1. Randomization was performed by a biostatistician and opened to the surgeon at the time of the patient's admission on the day before surgery. Patient and stone characteristics, perioperative outcomes, and complications were compared between the 2 groups. The primary end point of "stone-free" which was defined as no residual stone or stones <2 mm on computed tomography within 3 months postoperatively.

RESULTS

Thirty-five patients (mini-PCNL) and 33 (RIRS) were included in the final analysis. Mini-PCNL and RIRS had a stone-free rate of 85.7% and 97.0%, respectively (P = .199). Operation time (P = .148), hemoglobin decline (P = .323), and hospital stay (P = .728) were similar between the 2 groups. Pain visual analog score at 1 hour postoperatively (P = .029) and analgesic requirement (P = .050) were higher in the RIRS group. Two patients in the mini-PCNL group and 1 in the RIRS group had minor pelvic or ureter perforation. One patient in each of the 2 groups had hypertension and urinary tract infection.

CONCLUSION

Mini-PCNL and RIRS are safe and feasible surgical options to manage renal stones >10 mm. RIRS produced a slightly higher stone-free rate, but more immediate postoperative pain and higher analgesic requirement compared with mini-PCNL.

Flexible ureteroscopy: Technological advancements, current indications and outcomes in the treatment of urolithiasis

The last 3 decades have witnessed great improvements in the technology and clinical applications of many minimally invasive procedures in the urological field. Flexible ureteroscopy (fURS) has advanced considerably to become a widely utilized diagnostic and therapeutic tool for multiple upper urinary tract pathologies. The most common indication for fURS is the treatment of upper urinary tract stones with the aid of Holmium:Yttrium Aluminium Garnet (YAG) laser lithotripsy. Advancements in endoscope technologies and operative techniques have lead to a broader application of fURS in the management of urolithiasis to include larger and more complex stones. fURS has proved to be an effective and safe procedure with few contraindications. Continued progression in fURS may increase its clinical applicability and supplant other procedures as the first line treatment option for urolithiasis.

Retrograde intrarenal surgery with holmium-YAG laser lithotripsy in the primary treatment of renal lithiasis

INTRODUCTION

retrograde intrarenal surgery (RIRS) appears as a safe and effective technique as well as a good therapeutic alternative to extracorporeal shock wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PNL).

MATERIAL AND METHODS

descriptive study in 50 patients surgically treated between November 2012 and April 2013. Demographic, operative and postoperative data as well as early and late complications data were collected. The minimum follow-up of patients was one year. Surgery was performed under general anesthesia. Flexible ureteroscopy with ureteral access sheath and laser fragmentation were employed. Surgery success was defined as stone free rate in postoperative control test and at three months after surgery (simple radiography, abdominal ultrasound or CT without contrast).

RESULTS

mean age was 51.1±15.5 years old. The highest-frequency location was the lower calyceal group (26%), single stones were described in 58% of patients whilst multiple lithiasis were found in the 42%. Regarding the stone burden in 44% of the patients was low (<2 cm), and high (>3 cm) in 22% of the patients. The stone clearance rate was 89.7±17.5. Average surgery time was 96.6±35.2min. Complications were reported in 4 patients (8%), all of them early ones and minor in nature.

CONCLUSIONS

RIRS is an effective and safe option whose results are comparable to ESWL and PCNL. RIRS can be considered as first-line treatment. These results are corroborated by numerous studies. To strengthen these findings, prospective studies focusing on quality of life, length of stay, complications and cost-effectiveness of different treatments are needed.