Illumination matters Part II: advanced comparative analysis of flexible ureteroscopes in a kidney model by PEARLS

PURPOSE

The aim of the study was to evaluate illumination properties in an in-vitro kidney calyx model in saline.

DESIGN AND METHODS

We evaluated a series of contemporary flexible ureteroscopes including the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, as well as OTU WiScope using a 3D-printed closed pink kidney calyx model, submerged in saline. A spectrometer was used for illuminance and color temperature measurements at different openings located at center (direct light), 45° (direct and indirect light) and 90°(indirect light) to the axis of the scope.

RESULTS

Maximum illuminance was at the center opening for all scopes (range: 284 to 12,058 lx at 50% brightness and 454 to 11,871 lx at 100% brightness settings). The scope with the highest center illuminance (Flex-Xc) was 26 times superior to the scope with the lowest illuminance (Pusen 7.5Fr) at 100% brightness setting. For each scope, there was a peripheral illuminance drop ranging from - 43 to - 92% at 50% brightness and - 43% to - 88% at 100% brightness settings, respectively (all p < 0.01). Highest drop was for the P7 and the Pusen 9.2F. All scopes had illuminance skew, except the V3. All scopes had a warm color temperature.

CONCLUSION

Illumination properties vary between ureteroscopes in an enclosed cavity in saline, and differs at center vs 45° and 90° positions within scopes. Peripheral illuminance drop can be as high as - 92%, which is undesirable. This may affect the choice of ureteroscope and light brightness settings used in surgery by urologists.

Illumination matters part IV: blackout and whiteout in flexible ureteroscopy - first report on a phenomenon observed by PEARLS

PURPOSE

To date, no study has evaluated effects of varying brightness settings on image quality from flexible ureteroscopes submerged in saline. The aim was to evaluate blackout and whiteout occurrences in an in-vitro kidney calyx model.

MATERIAL AND METHODS

We evaluated a series of contemporary flexible ureteroscopes including the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, as well as OTU WiScope using a 3D-printed enclosed pink in-vitro kidney calyx model submerged in saline. Endoscopic images were captured with ureteroscope tip placed at 5 mm,10 mm and 20 mm distances. The complete range of brightness settings and video capture modes were evaluated for each scope. Distribution of brightness on a grayscale histogram of images was analyzed (scale range 0 to 255). Blackout and whiteout were defined as median histogram ranges from 0 to 35 and 220 to 255, respectively (monitor image too dark or too bright for the human eye, respectively).

RESULTS

Blackout occurred with the P7, Pusen 7.5F, 9.2F and WiScope at all distances, and V3 at 20 mm - with lowest brightness settings. Whiteout occurred with Flex-X2s, V3 and P7 at 5 mm and 10 mm, as well as with V3 and P7 at 20 mm - mostly with highest brightness settings. The Flex-Xc had neither blackout nor whiteout at all settings and distances.

CONCLUSION

Blackout or whiteout of images is an undesirable property that was found for several scopes, possibly impacting diagnostic and therapeutic purposes during ureteroscopy. These observations form a guide to impact a urologist's choice of instruments and settings.

Is "Kidney Stone Calculator" efficient in predicting ureteroscopic lithotripsy duration? A holmium:YAG and thulium fiber lasers comparative analysis

PURPOSE

This study aimed to evaluate the ability of Kidney Stone Calculator (KSC), a flexible ureteroscopy surgical planning software, to predict the lithotripsy duration with both holmium:YAG (Ho:YAG) and thulium fiber laser (TFL).

METHODS

A multicenter prospective study was conducted from January 2020 to April 2023. Patients with kidney or ureteral stones confirmed at non-contrast computed tomography and treated by flexible ureteroscopy with laser lithotripsy were enrolled. "Kidney Stone Calculator" provided stone volume and subsequent lithotripsy duration estimation using three-dimensional segmentation of the stone on computed tomography and the graphical user interface for laser settings. The primary endpoint was the quantitative and qualitative comparison between estimated and effective lithotripsy durations. Secondary endpoints included subgroup analysis (Ho:YAG-TFL) of differences between estimated and effective lithotripsy durations and intraoperative outcomes. Multivariate analysis assessed the association between pre- and intraoperative variables and these differences according to laser source.

RESULTS

89 patients were included in this study, 43 and 46 in Ho:YAG and TFL groups, respectively. No significant difference was found between estimated and effective lithotripsy durations (27.37 vs 28.36 min, p = 0.43) with a significant correlation (r =  + 0.89, p < 0.001). Among groups, this difference did not differ (p = 0.68 and 0.07, respectively), with a higher correlation between estimated and effective lithotripsy durations for TFL compared to Ho:YAG (r =  + 0.95, p < 0.001 vs r =  + 0.81, p < 0.001, respectively). At multivariate analysis, the difference was correlated with preoperative (volume > 2000 mm3 (Ho:YAG), 500-750 mm3 SV and calyceal diverticulum (TFL)), operative (fragmentation setting (p > 0.001), and basket utilization (p = 0.05) (Ho:YAG)) variables.

CONCLUSION

KSC is a reliable tool for predicting the lithotripsy duration estimation during flexible ureteroscopy for both Ho:YAG and TFL. However, some variables not including laser source may lead to underestimating this estimation.

Safety and feasability of ureteroscopy for pediatric stone, in children under 5 Years (SFUPA 5): A French multicentric study

INTRODUCTION

Ureteroscopy (URS) can be proposed as first-line therapy for the management of pelvic stones from 10 to 20 mm and for lower ureteric stones in children. However, little is known about the success and the morbidity of URS in young children. Ureteroscopic treatment may present matters in young children because of the small size of the pediatric kidney and the small size of the collecting system.

OBJECTIVE

To assess safety and efficacy of URS for the treatment of urinary stones in children aged of 5 years or less.

STUDY DESIGN

After the institutional ethical board approval was obtained, we conducted a retrospective, analytic, multicentric study that included all URS performed between January 2016 and April 2022 in children aged of 5 years or less. In this non-comparative case series, anonymized pooled data were collected from 7 tertiary care centers of pediatric patients. Endpoints were the one-session SFR at 3 months and per and postoperatives complications. Descriptive statistics were applied to describe the cohort.

RESULTS

Eighty-three patients were included. For them, 96 procedures were performed at the median age of 3.5 years (IQR: 0.8-5) and median weight of 14 Kg (6.3-23). Median stone size was 13 mm (4-45). There were 65 (67 %) renal stones treated with flexible URS, most of which were in the renal pelvis (30 %) and in the lower calix (33 %). A ureteral access sheath was used in 91 % procedures. Preoperative ureteral stent was placed in 52 (54 %) of patients. None of patients had ureteral dilatation. The single-session SFR was 67.4 % (56.3 and 89.2 % for flexible URS and semi-rigid URS respectively) and children require 1.4 procedures to achieve complete stone clearance. The overall complication rate was 18.7 %, most of them were minor (Clavien I-II). Intraoperative perirenal extravasation (Clavien IIIb) due to forniceal rupture was documented in 6.2 % of cases, related to an increased intrapelvic pressure (IPP) performed in a closed pelvicalyceal system.

DISCUSSION

Pediatric urologists should be aware of forniceal rupture based on the presence of extravasation of contrast during endourological procedures especially when they have difficulties to reach lower caliceal stone in small patient.

CONCLUSION

URS in patients aged of 5 years or less, is a complex minimally invasive procedure with reasonable efficacy and low morbidity. Intrarenal stones treated by RIRS in young children carries the risk of additional procedures to complete stone clearance.

Impact of ureteric access sheath use during flexible ureteroscopy: A comparative study on efficacy and safety

OBJECTIVES

This study evaluates the impact of using an access sheath (AS) during flexible ureteroscopy (fURS) for urolithiasis treatment, focusing on outcomes such as stone-free rate, operation time, and complications.

METHODS

This prospective, randomized study was carried out at Badr Hospital, Helwan University, and Ain Shams University hospitals from August 2021 to August 2022. Patients were systematically randomized into two groups (fURS with AS: 33 patients and without AS: 31 patients) and underwent preoperative and postoperative assessments, including lab tests and imaging. Possible procedure-associated risks, such as failed stone access, pain, bleeding, and sepsis, were monitored.

RESULTS

The two groups were found to be comparable in terms of demographic characteristics or preoperative stone findings (p > 0.05 for all). However, operation duration was shorter in the No Sheath group (79.4 ± 15.3 min vs. 90.4 ± 16.7 min in the Sheath group, p = 0.008). Intraoperative complication rates, including failed access, operation termination, ureteric injury, and bleeding, were comparable in both groups (p > 0.05). Postoperative stone-free rates (78.8% vs. 71.0%, p = 0.305) and mean residual stone size (2.7 ± 3.5 mm vs. 3.1 ± 3.1 mm, p = 0.687) showed no significant differences.

CONCLUSIONS

The present study suggests that fURS without an access sheath may offer an efficient and equally effective option for managing upper ureteric and renal stones. However, more studies with larger sample sizes and longer follow-up periods are required to validate these findings and to establish more precise indications for this approach.

Treatment of ureteropelvic junction obstruction in patients with renal calculi via laparoscopic pyeloplasty and flexible vacuum-assisted ureteral access sheath ureteroscopy: a multicenter retrospective observational study

BACKGROUND

Ureteropelvic junction obstruction (UPJO) is a common obstructive disease of the urinary tract. UPJO patients commonly exhibit coexistent renal calculi. The main aim of therapy is to relieve the obstruction and remove the stones at the same time.

METHODS

This retrospective study included 110 patients diagnosed with UPJO coexisting with multiple renal calculi at Shanxi Bethune Hospital and the First Hospital of Shanxi Medical University between March 2016 and January 2022. Patients were divided according to the methods used for dealing with UPJO and renal calculi. In Group A, patients underwent traditional open pyeloplasty and pyelolithotomy. In Group B, patients underwent percutaneous nephrolithotomy first and then laparoscopic pyeloplasty. In Group C, patients underwent flexible cystoscopy to remove stones and then laparoscopic pyeloplasty. In Group D, patients underwent flexible vacuum-assisted ureteral access sheath (FV-UAS)assisted flexible ureteroscopy (f-URS) and underwent laparoscopic pyeloplasty. The stones were broken up using a holmium laser. The pyeloplasty success rate, stone clearance rate, operation time, bleeding amount, complication occurrence rate, postsurgical pain, length of stay, and hospitalization cost were compared between the groups. The follow-up period was at least 2 years.

RESULTS

The use of f-URS and the FV-UAS, significantly increased the renal stone clearance rate and significantly reduced the complication incidence and operation time in UPJO patients with multiple coexisting renal calculi.

CONCLUSIONS

Laparoscopic pyeloplasty combined with f-URS and FV-UAS is safe and effective for treating UPJO in patients complicated by renal caliceal stones.

TRIAL REGISTRATION

Retrospectively registered.

Illumination matters Part III: Impact of light obstruction on illuminance from flexible ureteroscopes - a comparative PEARLS analysis

PURPOSE

Artifacts from poor ureteroscopes' light design with shadowing and dark areas in the field of view have been reported. The aim was to quantify effects of light obstruction in a kidney calyx model.

METHODS

We evaluated a series of contemporary flexible ureteroscopes including the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, as well as OTU Wiscope using an enclosed 3D-printed pink in vitro kidney calyx model submerged in saline, where the field of light was intentionally partially obstructed alternatively at 12, 3, 6, and 9 o'clock. A color spectrometer was used for illuminance measurements at a 45° opening position in the background of the model.

RESULTS

Overall and mean background illuminance for each obstructive situation were significantly different between scopes for both 50% and 100% brightness settings (ANOVA p < 0.001). At 50% brightness setting, almost all scopes had their highest and lowest background illuminance with the 6 o'clock and 3 o'clock obstructive situation, respectively. At 100% brightness setting, these became 6 o'clock and 12 o'clock obstructive situations. Considering each obstructive situation individually, the Flex-Xc was consistently the scope with highest background illuminance and the Pusen 7.5F the lowest. Background illuminance for each obstructive situation varied significantly for each scope individually, with the greatest range of variability for Pusen 7.5F and V3.

CONCLUSIONS

Illuminance performance of ureteroscopes within an obstructed calyx model differ significantly for various obstructive situations. Urologists should be aware of this to help guide their choice of ureteroscope.

A retrospective comparison of Sun's tip-flexible semirigid ureterorenoscopy, super-mini percutaneous nephrolithotomy and flexible ureteroscopy applied to treat upper urinary tract calculi

BACKGROUND

This retrospective study was conducted to compare the safety and efficacy of Sun's tip-flexible semirigid ureterorenoscopy (tf-URS), super-mini percutaneous nephrolithotomy (SMP) and flexible ureteroscopy (FURS) in treating upper urinary tract calculi, including upper ureteral or renal calculi.

METHODS

We included patients with upper ureteral calculi or renal calculi 1.0-2.0 cm in size, who underwent tf-URS, SMP or FURS, respectively. The indicators reflecting safety and efficacy were compared among the three surgical techniques.

RESULTS

SMP presented with higher single stone crushing success rate, but longer operation time and postoperative hospital stay, more blood loss, and higher postoperative pain score compared with FURS and tf-URS (P < 0.05). The hospitalization cost of tf-URS group was lower than that of SMP and FURS groups (P < 0.05). The incidence of postoperative fever in tf-URS group was significantly higher than that in SMP group (P < 0.05). No significant difference was found in mucosal injury, perirenal hematoma, and stone-free rate at 3 months after surgery (P > 0.05).

CONCLUSIONS

tf-URS and FURS have the advantages in minimal invasion, hospitalization cost, patient comfort, and hospital stay while SMP has higher stone-free rate. These three surgical techniques are safe, reliable and complementary, which should be selected according to the actual situation.

Confirmation of negative urine culture status after appropriate antibiotic treatment prior to endourological stone procedures: Is it really necessary?

To evaluate the necessity of confirmation for a negative urine culture test outcome after an appropriate antibiotic regimen for urinary tract infection (UTI) prior to endoscopic stone removal procedures. 170 cases receiving an appropriate antibiotic treatment for culture proven UTI based on test outcomes before endoscopic stone removal were evaluated in two groups: Group 1 (n = 85) Patients in whom a second urine culture test was performed to ensure "negative urine culture" status prior to the procedures after receiving antibiotic therapy and Group 2 (n = 85). Patients receiving the same antibiotic therapy without any additional urine culture test before the procedures. Cases were comparatively evaluated with respect to the statistical significance of post-operative infective complications (fever, sepsis), duration of hospital stay and readmission rates during early post-operative period. Our findings demonstrated no significant difference regarding the rate of infective complications (presence of fever, incidence of septic findings), hospitalization period and readmission rates between the two groups. Although the presence of a negative urine status has been confirmed by urine culture test in group 1 cases, no additional urine culture test was performed with this aim in group 2 cases (negative urine culture was confirmed only with urinalysis) and the outcomes regarding the infective problems were found to be similiar. Our current findings indicate that a second urine culture test may not be a "must" if the patients receive an appropriate antibiotic regimen based on the sensitivity test outcomes for a reasonable time period.

Left endoscopic combined intrarenal surgery with electrocoagulation hemostasis and right flexible ureteroscopic lithotripsy for bilateral upper urinary tract stones: a case report

Background

Percutaneous nephrolithotomy (PCNL) is the first-line treatment for large renal stones. However, multi-tract or staged procedures may be necessitated in bilateral or anatomically-complex stones to achieve stone clearance. Endoscopic combined intrarenal surgery (ECIRS) integrates the advantages of PCNL and retrograde intrarenal surgery. In this article, we detail a hybrid surgical technique adopted for the management of complex simultaneous bilateral upper urinary tract stones. In addition, we discuss the advantages and disadvantages of combining a variety of new techniques that may improve post-operative outcomes and patient satisfaction.

Case Description

We report the case of a 36-year-old male with a large left renal pelvis stone, right proximal ureteric stone, and bilateral renal stones. Biochemical results showed raised inflammatory markers but he denied pre-stenting and staged surgery. After receiving 3-day antibiotic prophylaxis, he underwent an elective hybrid procedure. Under split-leg prone position, we performed a hybrid procedure that included left ECIRS with tubeless single-tract mini PCNL and left flexible ureteroscopy, and right flexible ureteroscopic lithotripsy. Hemostasis was achieved by electrocauterization with a novel device. The patient made an uneventful recovery. Follow-up computed tomography (CT) at 1-month revealed complete stone clearance.

Conclusions

Unilateral ECIRS with tubeless single-tract mini PCNL with electrocoagulation hemostasis and adjacent retrograde intrarenal surgery in split-leg prone position is a safe, feasible, and efficient technique to manage large renal stones.

Comparison of percutaneous nephrolithotomy and flexible ureterorenoscopy in the treatment of single upper ureteral calculi measuring 1 to 2 centimeters: a retrospective study

PURPOSE

To compare the efficacy and safety of micropercutaneous nephrolithotomy (MPCNL) and flexible ureteroscopy (FURS) in the treatment of single upper ureteral calculi measuring 1 to 2 centimeters.

METHODS

This study is a retrospective analysis that combines a review of medical records with an outcomes management database. A total of 163 patients who underwent MPCNL and 137 patients who had FURS were identified between January 2017 and December 2021. Demographic data, operation time, hospitalization time, stone-free rate, and complication rate were collected and analyzed.

RESULTS

Preoperative general data of sex, age, BMI, serum creatinine, time of stone existence, stone hardness, stone diameter, preoperative hydronephrosis, and preoperative infection of the MPCNL group have no statistically significant difference with that of the FURS group. All MPCNL or FURS operations in both groups were successfully completed without any instances of reoperation or conversion to another surgical procedure. Patients who underwent MPCNL had a considerably reduced operation time (49.6 vs. 72.4 min; P<0.001), but a higher duration of hospitalization (9.1 vs. 3.9 days; P<0.001) compared to those who underwent FURS. The stone-free rate in the MPCNL group was superior to that of the FURS group, with a percentage of 90.8% compared to 71.5% (P<0.001). There was no statistically significant disparity in the rate of complications between the two groups (13.5% vs. 15.3%; P = 0.741).

CONCLUSION

Both MPCNL and FURS are viable and secure surgical choices for individuals with solitary upper ureteral calculi measuring 1 to 2 cm. The FURS procedure resulted in a shorter duration of hospitalization compared to MPCNL. However, it had a comparatively lower rate of successfully removing the stones and required a longer duration for the operation.There were no substantial disparities observed in the complication rate between the two groups.FURS is the preferable option for treating uncomplicated upper ureteral calculi, whereas MPCNL is the preferable option for treating complicated upper ureteral calculi.Prior to making treatment options, it is crucial to take into account the expertise of surgeons, the quality of the equipment, and the preferences of the patient.

TRIAL REGISTRATION

No.

Development and validation of a novel home-made bench-top training model for retrograde intrarenal surgery

PURPOSE

To develop and validate a low-cost homemade bench-top training model to facilitate retrograde intrarenal surgery (RIRS) training.

METHODS

The RIRS training model (G-Model) was developed using a surgical glove and a recycled ureter access sheath. Fifteen participants including 10 residents and 5 urologists were enrolled. Designed training curriculum for residents was carried out. Face validity, content validity, construct validity and criterion validity evaluation of the G-Model were carried out.

RESULTS

The global score of face and content validity was 4.15 ± 0.53 and 4.65 ± 0.29, respectively. For construct validity, the overall modified global rating scale (mGRS) score was significantly improved [12.5 (5.25) vs. 24.0 (5.25), p = 0.004], and the total task time was significantly shortened (39.5 ± 4.48 min vs. 24.1 ± 3.81 min, p < 0.001) within residents after G-Model training. The baseline mGRS score and total task time of residents were poorer than those of urologists [12.5 (5.25) vs. 32.0 (1.00), p < 0.001; 39.5 ± 4.48 min vs. 16.0 ± 1.58 min, p < 0.001]. Spearman correlation analysis revealed strong correlations between residents' G-Model and real patient performance.

CONCLUSION

The current study presented a valid low-cost easily accessible RIRS bench-top training model which could facilitate skill acquisition and translate to real-life scenario.

Miniaturization of flexible ureteroscopes: a comparative trend analysis of 59 flexible ureteroscopes

The purpose of this review is to analyze the trend in miniaturization of flexible ureteroscopes over the past decades, identify the advantages and disadvantages, and determine the correlation of individual parameters with release period. Flexible ureteroscopes mentioned in the literature or those commercially available were searched. To minimize the search bias, the instruments were grouped by release date time periods of < 2000 year, 2000-2009, 2010-2019, and 2020 onwards. The final review included only those instrument models for which data on tip size, overall shaft, working length and channel size had been determined. The correlation among features investigated as well as with release period was also determined. 59 models of flexible ureteroscopes (26 fiber optic and 33 digital scopes) were included. Among the different features investigated among fiber optic endoscopes, only the sizes of the distal tip and overall shaft positively correlated with each other. In contrast to their fiber optic counterparts, a strong positive correlation was observed between tip and channel sizes, whereas negative correlation was found between channel size and overall shaft size and working length of digital scopes. Only distal tip of fiber optic flexible ureteroscopes and overall shaft of digital endoscopes were significantly reduced over their evolution. With the development of technology, there has been an improvement of flexible ureteroscopes and one of the indicators of this trend is a decrease in their size. With a definite trend towards miniaturization over the past decades, a significant correlation was observed in tip size and overall shaft for fiber optic and digital endoscopes, respectively.

Comparison of traditional and novel tip-flexible suctioning ureteral access sheath combined with flexible ureteroscope to treat unilateral renal calculi

OBJECTIVES

To compare the safety and efficacy of novel tip-flexible suctioning ureteral access sheath (NTFS-UAS) and traditional ureteral access sheath (T-UAS) combined with flexible ureteroscope for treating unilateral renal calculi.

MATERIALS AND METHODS

The clinical data of 214 patients with unilateral renal calculi treated by NTFS-UAS (n = 102) and T-UAS (n = 112) combined with flexible ureteroscope from August 2021 to April 2022 were analyzed retrospectively. Demographic characteristics, stone-related parameters, operative time, stone-free rates (SFR), hospitalization time and complication rate (CR) were analyzed.

RESULT

No significant difference was observed between the two groups in terms of demographic characteristics, stone-related parameters, intraoperative CR, and hospitalization time. The operative time of NTFS-UAS group was significantly shorter than T-UAS group (55.25 ± 11.42 min vs. 59.36 ± 15.59 min; P = 0.028). The NTFS-UAS group obtained significantly higher SFR on 1 day postoperatively (86.3% vs. 75.0%; P = 0.038), and higher SFR on 30 days postoperatively than T-UAS group (91.2% vs. 81.3%; P = 0.037). The hemoglobin loss of NTFS-UAS group (- 0.54 ± 0.69 g/dl) was significantly lower than T-UAS group (- 0.83 ± 0.66 g/dl; P = 0.002). There was a significantly lower incidence of overall CR (11.8% vs. 22.3%; P = 0.041), and infectious CR (8.8% vs. 18.8%; P = 0.037) in the NTFS-UAS group.

CONCLUSION

Compared to T-UAS combined with flexible ureteroscope for treating unilateral renal calculi, NTFS-UAS had superiority in higher SFR on 1 day and 30 days postoperatively. Shorter operation time, lower hemoglobin loss, lower incidences of overall and infectious CR were observed in NTFS-UAS group.

REGISTRATION NUMBER AND DATE

ChiCTR2300070210; April 5, 2023.

Efficacy of simultaneous bilateral surgery using the oblique overriding position in the treatment of bilateral kidney stones

To compare the safety and the efficacy of simultaneous bilateral surgery in the oblique overriding position versus staging surgery in the treatment of bilateral renal calculi. A total of 46 patients with bilateral renal stones from May 2019 to January 2022 in our center were retrospectively analyzed, including 29 males and 17 females, with a mean age of 48 ± 13.6 years, body mass index of 24.6 ± 2.3 kg/m2, and uneven size of bilateral renal stones, with a mean diameter of 29.5 ± 9.1 mm on the side with the larger kidney stones (PCNL) and a mean diameter of 13.1 ± 3.2 mm on the side with the smaller kidney stones. The patients were divided into two groups for simultaneous and stepwise bilateral endoscopic surgery, and the operative time, anesthesia time, postoperative hemoglobin, blood creatinine, postoperative VAS pain score, Clavien complication rating, average hospital stay, and stone removal rate at one month after surgery were evaluated in both groups. The simultaneous group outperformed the other group in anesthesia time, operative time, VAS score, and mean number of days in the hospital, and there were no significant differences between the two groups in postoperative hemoglobin drop values, hematocrit elevation values, Clavien complication ratings, and stone clearance rate at one month. Both simultaneous surgery and staging surgery were safe and effective. Simultaneous surgery can effectively shorten the operation and anesthesia time, and reduce the postoperative pain and hospital days of patients while ensuring similar stone clearance rates.

Novel Endourological technique for a better navigation in incontinent urinary diversion (ileal conduit) during Double J stent removal

Introduction

Assessing ileal conduit for double J stents removal after radical cystectomy is not always a straightforward task as navigation inside the ileal loop can be challenging to manage due to the difficulty to maintain a waterfilled environment and its long and tortuous aspect.

Methods

We present a novel technique using a flexible ureteroscope that aims to ease this common demand with simple and readily available tools.

Results

This technique has been successfully utilized in 2 patients now. No complications were documented.

Conclusion

We propose a novel surgical technique to improve endoscopic navigation in incontinent ileal loop urinary diversion.

Does age impact outcomes of retrograde intrarenal surgery in the elderly? Results from 366 patients from the FLEXible ureteroscopy outcomes registry (FLEXOR)

BACKGROUND

There has been a consistent increase in the last decades in prevalence of renal stones in elderly.

AIMS

To evaluate outcomes of retrograde intrarenal surgery (RIRS) for renal stones in elderly and factors associated with postoperative complications and residual fragments (RFs).

METHODS

Data from 12 centers were retrospectively reviewed.

INCLUSION CRITERIA

 ≥ 75 years, renal stones only, normal renal anatomy. Patients were divided into three groups; Group 1: patients aged 75-79 years; Group 2: age 80-84 years; Group 3: age ≥ 85 years. Multivariable logistic regression analyses were performed to assess factors associated with perioperative complications, sepsis, and RFs.

RESULTS

366 patients were included. There were 189 patients in Group 1, 113 in Group 2, and 64 in Group 3. There was no difference between groups regarding stone features and total surgical time. Median length of stay was significantly longer in Group 3 (6.0 days, vs 2.0 days in Group 2 vs 2.5 days in Group 1, p = 0.043). There was no significant difference in postoperative complications and RFs between the groups. At multivariable logistic regression analysis, female gender (OR 2.82) and maximum stone diameter (OR 1.14) were associated with higher odds of sepsis, while surgical time (OR 1.12) and the use of a reusable ureteroscope (OR 6.51) with overall complications. Stone size (OR 1.23) was associated with higher odds of RFs.

CONCLUSION

RIRS showed safety and efficacy for kidney stones in elderly patients. Surgical time should be kept as short as possible to avoid higher odds of postoperative complications, particularly in females.

Comparison of Treatment Outcomes for Fluoroscopic and Fluoroscopy-free Endourological Procedures: A Systematic Review on Behalf of the European Association of Urology Urolithiasis Guidelines Panel

CONTEXT

Endourological procedures frequently require fluoroscopic guidance, which results in harmful radiation exposure to patients and staff. One clinician-controlled method for decreasing exposure to ionising radiation in patients with urolithiasis is to avoid the use of intraoperative fluoroscopy during stone intervention procedures.

OBJECTIVE

To comparatively assess the benefits and risks of "fluoroscopy-free" and fluoroscopic endourological interventions in patients with urolithiasis.

EVIDENCE ACQUISITION

A systematic review of the literature from 1970 to 2022 was performed using the MEDLINE/PubMed, Embase, and Cochrane controlled trials databases and ClinicalTrials.gov. Primary outcomes assessed were complications and the stone-free rate (SFR). Studies reporting data on ureteroscopy and percutaneous nephrolithotomy (PCNL) were eligible for inclusion. Secondary outcomes were operative duration, hospital length of stay, conversion from a fluoroscopy-free to a fluoroscopic procedure, and requirement for an auxiliary procedure to achieve stone clearance.

EVIDENCE SYNTHESIS

In total, 24 studies (12 randomised and 12 observational) out of 834 abstracts screened were eligible for analysis. There were 4564 patients with urolithiasis in total, of whom 2309 underwent a fluoroscopy-free procedure and 2255 underwent a comparative fluoroscopic procedure for treatment of urolithiasis. Pooled analysis of all procedures revealed no significant difference between the groups in SFR (p = 0.84), operative duration (p = 0.11), or length of stay (p = 0.13). Complication rates were significantly higher in the fluoroscopy group (p = 0.009). The incidence of conversion from a fluoroscopy-free to a fluoroscopic procedure was 2.84%. Similar results were noted in subanalyses for ureteroscopy (n = 2647) and PCNL (n = 1917). When only randomised studies were analysed (n = 12), the overall complication rate was significantly in the fluoroscopy group (p < 0.001).

CONCLUSIONS

For carefully selected patients with urolithiasis, fluoroscopy-free and fluoroscopic endourological procedures have comparable stone-free and complication rates when performed by experienced urologists. In addition, the conversion rate from a fluoroscopy-free to a fluoroscopic endourological procedure is low at 2.84%. These findings are important for clinicians and patients, as the detrimental health effects of ionising radiation are negated with fluoroscopy-free procedures.

PATIENT SUMMARY

We compared treatments for kidney stones with and without the use of radiation. We found that kidney stone procedures without the use of radiation can be safely performed by experienced urologists in patients with normal kidney anatomy. These findings are important, as they indicate that the harmful effects of radiation can be avoided during kidney stone surgery.

Flexible ureteroscopy for lower pole calculus: is it still a challenge?

PURPOSE

Flexible ureteroscopy (fURS) is steadily gaining popularity in the management of renal calculi, including those located in the lower pole (LP). Due to difficulty in accessing to the LP of kidney in minority of cases with fURS and reports of lower stone-free rate (SFR), it is still considered as a challenge in selected cases. The purpose of the review was to analyze the various aspects of fURS for LP stones.

METHODS

An extensive review of the recent literature was done including different factors such as anatomy, preoperative stenting, stone size, flexible scopes, types of lasers, laser fibers, suction, relocation, stone-free rates, and complications.

RESULTS

The significance of various lower pole anatomical measurements remain a subject of debate and requires standardization. Recent improvements in fURS such as single-use digital scopes with better vision and flexibility, high power laser, thulium fiber laser, smaller laser fiber, and accessories have significantly contributed to make flexible ureteroscopy  more effective and safer in the management of LP stone. The utilization of thulium fiber lasers in conjunction with various suction devices is being recognized and can significantly improve SFR.

CONCLUSIONS

With the significant advancement of various aspects of fURS, this treatment modality has shown remarkable efficacy and gaining widespread acceptance in management of LP kidney stones. These developments have made the fURS of LP stones less challenging.

Intrarenal pressure study using 7.5 French flexible ureteroscope with or without ureteral access sheath in an ex-vivo porcine kidney model

INTRODUCTION

7.5F digital fURS and 9.5/11.5F ureteral access sheaths (UAS), both conventional (cUAS) and vacuum-assisted (vaUAS), are commercially available. Irrigation increases intrarenal pressure (IRP). This study analyzes the IRP with various irrigation rates using 7.5F fURS without UAS or with either cUAS or vaUAS in an ex-vivo porcine model. Pyelo-tubular backflow was also studied during these experiments.

MATERIALS AND METHODS

11 porcine kidneys were used. 7.5F digital fURS was tested without UAS and with 9.5/11.5F cUAS and vaUAS. 6F pressure monitor catheters were placed into the upper and lower calyces. IRPs were recorded under different irrigation rates. When vaUAS was used, the air vent was either open or closed. 300 mmHg aspiration pressure was chosen. Lastly, contrasted irrigation fluid was delivered until IRP reached above 30 mmHg. Fluoroscopy images were obtained at 5 mmHg intervals over this threshold to study the pyelo-tubular backflow.

RESULTS

Using cUAS, IRP reached 30 mmHg with irrigation rates between 60 and 70 cc/min. Using vaUAS with vent closed, IRP never exceeded 10 mmHg with irrigation up to 120 cc/min. vaUAS with vent open performed marginally better than cUAS. fURS without UAS performed better than cUAS. Pyelo-tubular backflow became prominent at 40 mmHg.

CONCLUSION

In an ex-vivo porcine model, 7.5F fURS could be used safely without UAS with irrigation rates up to 120 cc/min. The safety margin dropped to 60-70 cc/min with cUAS. vaUAS with vent closed maintained IRP < 10 mmHg with irrigation rates up to 120 cc/min. Pyelo-tubular backflow was observed with IRP > 35 mmHg.

Occult renal artery pseudoaneurysm causing persistent hematuria after flexible Thulium fibered laser lithotripsy: A case report and literature review of rare but potentially fatal complication

Renal artery pseudoaneurysm may develop after laser flexible ureteroscopy stone lithotripsy (FURSL). Typical symptoms include flank pain, persistent hematuria, delayed refractory anemia, or hemorrhagic shock in case of pseudoaneurysm rupture. This complication of laser FURSL is very rare with only five cases reported in the literature as of April 2023, of which one involved Thulium laser. We report the case of a 65-year-old man with recurrent renal lithiasis who underwent FURSL using Thulium fibered laser (TFL) for 8 mm stone of left kidney upper pole. Persistent hematuria developed postoperatively, secondary to a pseudoaneurysm from a segmental branch of the left renal artery. It was diagnosed on arteriography performed for sudden hemorrhagic shock 27 days after surgery. Selective embolization with metallic micro-coils resolved hematuria. Although laser FURSL is often uncomplicated and TFL is regarded as safe, this complication should be suspected when refractory hematuria or hemodynamic instability follows the procedure. We report this case to add support to the current literature and outline procedural risk factors and useful precautions during the procedure.

Flexible ureteroscopy under local anesthesia for stone management: initial exploration and two-year experience

BACKGROUND

Flexible ureteroscopy (f-URS) is a minimally invasive surgical technique used for treating urinary tract stones. While general anesthesia (GA) is the standard method used, it comes with risks. Local anesthesia (LA) is a safer and more cost-effective alternative to GA, and its use in f-URS could potentially reduce patients' risks and increase accessibility to treatment. This study aims to investigate the feasibility, safety, and efficacy of using LA for f-URS in treating stones, as an initial experience in the diagnosis related group (DRG) era of China.

METHODS

Patients who met the inclusion and exclusion criteria and were continuously included in the study Between 2021 and 2023. We analyzed the stone free status, postoperative complication rate, hospitalization costs, and presented key points of the procedure performed under LA that we had summarized over the past two years.

RESULTS

A study of 614 patients undergoing f-URS under LA for urinary stones in our hospital showed 83.4% stone-free rate with a mean operative time of 44.12 ± 16.63 minutes; 18 patients experienced fever postoperatively, and 12 had ureteral injuries. No severe complication was reported. The cost of LA was found to be only 1.7% of the DRG payment, which is around $40. The highest VAS scores were observed during the sheath insertion, with STAI scores decreasing during and after surgery.

CONCLUSIONS

The study revealed that f-URS administered under LA was a well-tolerated, efficient, safe, and economical procedure. In the DRG era, this new anesthetic option for f-URS provides urologists with a more cost-effective alternative.

[Comparison of safety and effectiveness of active migration technique and in situ lithotripsy technique in the treatment of 1-2 cm upper ureteral calculi by flexible ure-teroscopy]

OBJECTIVE

To compare the safety and effectiveness of active migration technique and in situ lithotripsy technique in the treatment of 1-2 cm upper ureteral calculi by retrograde flexible ureteroscopy.

METHODS

A total of 90 patients with 1-2 cm upper ureteral calculi treated in the urology department of Beijing Friendship Hospital from August 2018 to August 2020 were selected as the subjects. The patients were divided into two groups using random number table: 45 patients in group A were treated with in situ lithotripsy and 45 patients in group B were treated with active migration technique. The active migration technique was to reposition the stones in the renal calyces convenient for lithotripsy with the help of body position change, water flow scouring, laser impact or basket displacement, and then conduct laser lithotripsy and stone extraction. The data of the patients before and after operation were collected and statistically analyzed.

RESULTS

The age of the patients in group A was (51.6±14.1) years, including 34 males and 11 females. The stone diameter was (1.48±0.24) cm, and the stone density was (897.8±175.9) Hu. The stones were located on the left in 26 cases and on the right in 19 cases. There were 8 cases with no hydronephrosis, 20 cases with grade Ⅰ hydronephrosis, 11 cases with grade Ⅱ hydronephrosis, and 6 cases with grade Ⅲ hydronephrosis. The age of the patients in group B was (51.8±13.7) years, including 30 males and 15 females. The stone diameter was (1.52±0.22) cm, and the stone density was (964.6±214.2) Hu. The stones were located on the left in 22 cases and on the right in 23 cases. There were 10 cases with no hydronephrosis, 23 cases with grade Ⅰ hydronephrosis, 8 cases with grade Ⅱ hydronephrosis, and 4 cases with grade Ⅲ hydronephrosis. There was no significant diffe-rence in general parameters and stone indexes between the two groups. The operation time of group A was (67.1±16.9) min and the lithotripsy time was (38.0±13.2) min. The operation time of group B was (72.2±14.8) min and the lithotripsy time was (40.6±12.6) min. There was no significant difference between the two groups. Four weeks after operation, the stone-free rate in group A was 86.7%, and in group B was 97.8%. There was no significant difference between the two groups. In terms of complications, 25 cases of hematuria, 16 cases of pain, 10 cases of bladder spasm and 4 cases of mild fever occurred in group A. There were 22 cases of hematuria, 13 cases of pain, 12 cases of bladder spasm and 2 cases of mild fever in group B. There was no significant difference between the two groups.

CONCLUSION

Active migration technique is safe and effective in the treatment of 1-2 cm upper ureteral calculi.

Improving Outcomes of Same-sitting Bilateral Flexible Ureteroscopy for Renal Stones in Real-world Practice-Lessons Learnt from Global Multicenter Experience of 1250 Patients

Background

Bilateral kidney stones are commonly treated in staged procedures.

Objective

To evaluate outcomes after same-sitting bilateral retrograde intrarenal surgery (SSB-RIRS) for renal stones.

Design setting and participants

Data from adults who underwent bilateral RIRS in 21 centers were retrospectively reviewed (from January 2015 to June 2022). The inclusion criteria were unilateral/bilateral symptomatic bilateral stone(s) of any size/location in both kidneys and bilateral stones on follow-up with symptom/stone progression. Stone-free rate (SFR) was defined as absence of any fragment >3 mm at 3 mo.

Outcome measurements and statistical analysis

Continuous variables are presented as medians and 25-75th percentiles. A multivariable logistic regression analysis was performed to evaluate independent predictors of sepsis and bilateral SFR.

Results and limitations

A total of 1250 patients were included. The median age was 48.0 (36-61) yr. Of the patients, 58.2% were prestented. The median stone diameter was 10 mm on both sides. Multiple stones were present in 45.3% and 47.9% of the left and right kidneys, respectively. Surgery was stopped in 6.8% of cases. The median surgical time was 75.0 (55-90) min. Complications were transient fever (10.7%), fever/infection needing prolonged stay (5.5%), sepsis (2%), and blood transfusion (1.3%). Bilateral and unilateral SFRs were 73.0% and 17.4%, respectively. Female (odds ratio [OR] 2.97, 95% confidence interval [CI] 1.18-7.49, p = 0.02), no antibiotic prophylaxis (OR 5.99, 95% CI 2.28-15.73, p < 0.001), kidney anomalies (OR 5.91, 95% CI 1.96-17.94, p < 0.001), surgical time ≥100 min (OR 2.86, 95% CI 1.12-7.31, p = 0.03) were factors associated with sepsis. Female (OR 1.88, 95% CI 1.35-2.62, p < 0.001), bilateral prestenting (OR 2.16, 95% CI 1.16-7.66, p = 0.04), and the use of high-power holmium:YAG laser (OR 1.63, 95% CI 1.14-2.34, p < 0.01) and thulium fiber laser (OR 2.50, 95% CI 1.32-4.74, p < 0.01) were predictors of bilateral SFR. Limitations were retrospective study and no cost analysis.

Conclusions

SSB-RIRS is an effective treatment with an acceptable complication rate in selected patients with kidney stones.

Patient summary

In this large multicenter study, we looked at outcomes after same-sitting bilateral retrograde intrarenal surgery (SSB-RIRS) for renal stones in a large cohort. We found that SSB-RIRS was associated with acceptable morbidity and good stone clearance after a single session.

Efficacy of pre-operative silodosin on flexible ureteroscopy procedure: A randomized controlled study

Objectives

To evaluate the impact of silodosin on stages of flexible ureteroscopy (F-URS) procedures, complications, and stone-free rate (SFR).

Patients and Methods

A prospective, randomized, controlled comparison research was conducted on 106 patients who were randomly allocated into two groups: the study group (52 patients) received F-URS with preoperative daily uptake of 8 mg silodosin for 10 days, and the control group (54 patients) received F- URS without silodosin uptake. Two patients were lost during the follow up in the study group and four patients were also lost in the controls.

Results

Operative time, application access sheath time (AAST), entrance to ureteric orifice time (ETUOT), and entrance to bladder time (ETBT) were significantly lower in the study group compared to controls. Meanwhile, F-URS time & laser time was higher in the study group compared to controls but without statistically significant difference. Complications were insignificalty different between both studied goups with no impact on SFR.

Conclusion

Before ureteroscopy, silodosin, an adjunctive alpha-blocker therapy, was successful in treating stones resulting in shortening the procedural time, with no impact on SFR or complication rate.

Analysis of the effect of holmium laser flexible ureteroscopic intrapelvic drainage in the treatment of parapelvic renal cysts

Objective

To explore the efficacy, safety, and feasibility of holmium laser flexible ureteroscopic intrapelvic drainage in the treatment of parapelvic renal cysts.

Methods

From September 2012 to February 2019, a total of 18 patients, aged from 28 to 62 (mean±standard deviation [SD]: 46.50±9.14) years, were diagnosed with parapelvic renal cysts and treated by holmium laser flexible ureteroscopic intrapelvic drainage. There were 10 males and eight females. All of the parapelvic renal cysts were unilateral, and two cases were complicated with pyelolithiasis. The diameters of the cysts ranged from 4.1 cm to 8.2 cm.

Results

All the patients completed the operation successfully in one stage without conversion to open surgery; in two cases, it was difficult to find the cysts during the operation, and the localization was completed by B-ultrasound and percutaneous injection of methylene blue. The mean operative time was 33.89 (SD: 9.68; range: 22-54) min, and the mean hospitalization time was 2.67 (SD: 0.91; range: 2-5) days. Three months and 6 months of follow-up were performed after surgery. The cysts disappeared in 13 (72%) cases, and the diameter of the cysts in five (28%) cases decreased by more than 50%.

Conclusion

Holmium laser flexible ureteroscopic intrapelvic drainage in the treatment of parapelvic renal cysts is simple, safe, and effective, and can be used as the first choice for the treatment of parapelvic renal cysts.

What is the appropriate gravel size during ureteroscopy lithotripsy? An in vitro evaluation

To propose the suitable diameter of calculus debris produced during flexible ureteroscopy lithotripsy (fURL). A glass tube was used to simulate the stone excretion process during Furl. Different stone diameters (0.50-1.00 mm, 0.25-0.50 mm, and 0.10-0.25 mm) with three sizes of flexible ureteroscopy (fURS) (7.5Fr, 8.7Fr, and 9.9Fr) and ureteral access sheath (UAS) (12/14Fr) with or without negative pressure suction were employed in the experiment. The intraoperative calculi excretion (ICE) was recorded according to the stones discharged from the gap between fURS and UAS. The ICE raised significantly in thinner fURS and UAS due to the smaller Ratio of Endoscope-Sheath Diameter (RESD). The gravel size ≤ 0.25 mm was conducive to drainage with traditional UAS, while using fURS with negative-pressure UAS could significantly improve ICE. The gravel size ≤ 0.5 mm was conducive to expulsion. We clarify that ICE during ureteroscopy relates to RESD and negative pressure suction. The proper size of the stone fragment is critical in ensuring the expulsion during fURL, ≤ 0.25 mm in traditional UAS and ≤ 0.50 mm in negative-pressure UAS, respectively.

Renal pseudoaneurysm after holmium laser lithotripsy with flexible ureteroscopy: an unusual case report and literature review

Pseudoaneurysms of the renal arteries are caused by focal rupture or perforation of the arterial wall, resulting in local bleeding. Such pseudoaneurysms can be observed in conditions such as nodular polyarteritis, penetrating or closed renal injury, and medically induced injuries (such as renal puncture biopsy, percutaneous nephrostomy, or partial nephrectomy). Flexible ureteroscopy (FURS) is performed entirely through the urethra to prevent potentially severe kidney damage. Because of this, almost no renal parenchymal hemorrhage occurs after FURS laser lithotripsy. Only four cases had been documented in the literature as of December 2022. In this report, we describe a 53-year-old man with a history of recurrent kidney stones who underwent FURS laser lithotripsy for bilateral kidney stones. The procedure was smoothly performed, and no active bleeding occurred. However, the patient developed recurrent macroscopic hematuria after discharge from the hospital, and renal angiography revealed a pseudoaneurysm in the distal right kidney. The pseudoaneurysm was treated with selective arterial embolization. Serious complications of FURS surgery are rare, particularly the formation of pseudoaneurysms. We report the present case to bring this potential complication to the attention of urologists.

The study of double-J stent free mode of flexible ureteroscopy and laser lithotripsy: a single centre experience

OBJECTIVE

To evaluate the effectiveness and safety of flexible ureteroscopy in the treatment of kidney and upper ureteral calculi under double-J stent free mode.

METHODS

Data from patients who underwent flexible ureteroscopy and laser lithotripsy between February 2018 and September 2021 were retrospectively and analysed. Cases were grouped according to pre- or postoperative use of the double-J stent (6 Fr): Post-F group (preoperative double-J stent but no postoperative double-J stent); Pre-F group (no preoperative stenting but with postoperative double-J stent); and Routine group (preoperative and postoperative double-J stenting).

RESULTS

A total of 554 patients (390 male and 164 female) were included. The mean operation time was similar between the three groups, with no statistically significant difference. Incidence of grade 0-1 ureteral injury was significantly higher in the Pre-F group versus other groups, but there were no significant between-group differences in other operation-related complications. During follow-up, stent-associated complications were observed in the Pre-F and Routine groups, but not in the Post-F group. Stone clearance rates were similar between all groups at 1, 3 and 6 months following surgery.

CONCLUSIONS

Flexible ureteroscopy using double-J stent free mode was found to be safe, feasible and effective in treating renal and upper ureteral calculi.

Ureteroscopic and flexible ureteroscopic lithotripsy: continuation or discontinuation of anticoagulant or antiplatelet drugs? A Chinese survey among urologists

PURPOSE

To evaluate the management of antithrombotic drugs made by different urologists before ureteroscopic lithotripsy and flexible ureteroscopy in stone patients undergoing active anticoagulant or antiplatelet therapy.

METHODS

A survey was distributed to 613 urologists in China, which included personal work information and views on the management of anticoagulants (AC) or antiplatelet (AP) drugs during the perioperative period of ureteroscopic lithotripsy (URL) and flexible ureteroscopy (fURS).

RESULTS

20.5% of urologists believed that AP drugs could be continued and 14.7% believed that AC drugs could be continued. 26.1% of the urologists who participated in more than 100 ureteroscopic lithotripsy or flexible ureteroscopy surgeries each year believed that AP drugs could be continued and 19.1% believed that AC drugs could be continued, compared with 13.6% (P < 0.01) and 9.2% (P < 0.01) of the urologists who performed less than 100 surgeries. Among the urologists with more than 20 cases undergoing active AC or AP therapy per year, 25.9% thought that AP drugs could be continued and 19.7% thought that AC drugs could be continued, compared with 17.1% (P = 0.008) and 11.5% (P = 0.005) of the urologists with less than 20 cases.

CONCLUSION

The decision on the continuation of AC or AP drugs before ureteroscopic and flexible ureteroscopic lithotripsy should be individualized. The experience in URL and fURS surgeries and in dealing with patients under AC or AP therapy is the influencing factor.

Indications, preferences, global practice patterns and outcomes in retrograde intrarenal surgery (RIRS) for renal stones in adults: results from a multicenter database of 6669 patients of the global FLEXible ureteroscopy Outcomes Registry (FLEXOR)

PURPOSE

To collect a multicentric database on behalf of TOWER research group to assess practice patterns and outcomes of retrograde intrarenal surgery (RIRS) for kidney stones.

METHODS

Inclusion criteria: age ≥ 18 years, normal renal/calyceal system anatomy, calculi of any size, number, and position.

STUDY PERIOD

January 2018 and August 2021. Stone-free status: absence of fragments > 2 mm, assessed post procedure according to the local protocol (KUB X-Ray and/or ultrasound or non-contrast CT scan).

RESULTS

Twenty centers from fifteen countries enrolled 6669 patients. There were 4407 (66.2%) men. Mean age was 49.3 ± 15.59 years. Pain was the most frequent symptom indication for intervention (62.6%). 679 (10.2%) patients underwent RIRS for an incidental finding of stones. 2732 (41.0%) patients had multiple stones. Mean stone size was 10.04 ± 6.84 mm. A reusable flexible ureteroscope was used in 4803 (72.0%) procedures. A sheath-less RIRS was performed in 454 (6.8%) cases. Holmium:YAG laser was used in 4878 (73.1%) cases. A combination of dusting and fragmentation was the most common lithotripsy mode performed (64.3%). Mean operation time was 62.40 ± 17.76 min. 119 (1.8%) patients had an intraoperative injury of the ureter due to UAS insertion. Mean postoperative stay was 3.62 ± 3.47 days. At least one postoperative complication occurred in 535 (8.0%) patients. Sepsis requiring intensive care admission occurred in 84 (1.3%) patients. Residual fragments were detected in 1445 (21.7%) patients. Among the latter, 744 (51.5%) patients required a further intervention.

CONCLUSION

Our database contributes real-world data to support to a better understanding of modern RIRS practice and outcomes.

Comparison of single-use flexible ureteroscopes with a reusable ureteroscope for the management of paediatric urolithiasis

INTRODUCTION

To compare the efficacy, side effects, and cost-effectiveness between a single-use digital flexible ureteroscope and a reusable flexible ureteroscope in the treatment of paediatric renal stones.

METHODS

This analytic, case-control, monocentric study included all patients undergoing flexible ureterosopies for stone treatment. Between April 2016 and February 2019, a reusable (Flex-X^C®, Karl Storz) flexible ureteroscope was used (control group), whereas a single-use (Uscope®, PUSEN Medical©) flexible ureteroscope was used in all procedures from March 2019 to April 2021. Clinical and procedural outcomes, operative times, complication rates, hospital stay, and costs per procedure were evaluated.

RESULTS

Forty-three cases using a reusable flexible ureteroscope and thirty-nine using a single-use flexible ureteroscope were included in the study. Demographic patient characteristics, stone burden, location and composition, preoperative presence of a double-J stent, procedural outcomes, mean length of postoperative hospital stay, and complications (4.6% versus 5%, p = 0.81) were comparable between the two groups. Median operative duration for stone removal was 93 min (20-170) with reusable versus 81 min (55-107) with the single-use scope (p = 0.18). Scope failure occurred four times with the reusable scope and in no case with the single-use. The total cost per procedure associated with the use of single-use scopes (798 Euros) was lower than a reusable scope (1483.23 Euros).

DISCUSSION

Single-use flexible ureteroscopes were created to bypass the problems incurred when reusable scopes were damaged and therefore not available for use in surgical procedures. Single-use flexible ureteroscopes are always immediately available and ready to be used, even in urgent cases, as they typically do not require maintenance or sterilization. Compared with their reusable counterparts, single-use flexible ureteroscopes have similar digital performance (270°), image quality and we found no difference in the success and complication rates. Cost analysis of a reusable flexible ureteroscope must consider the purchase price, maintenance and repair costs, and decontamination costs (including handling, detergent, bacterial culture, transportation, and storage costs). In contrast, only purchase price is included in cost analysis for single-use flexible ureteroscopes. Our study suggests that single-use flexible ureteroscopes may be associated with lower costs per procedure than their reusable counterparts.

CONCLUSION

Single-use flexible ureteroscopes are an interesting alternative to their reusable counterparts, particularly in terms of material resource management. Cost analyses conducted using a low volume of cases representative of a paediatric urology division favour the use of single-use ureteroscopes.

Pattern of key opinion leaders talks at major international urological meetings reflects the main differences in flexible ureteroscopy and PCNL diffusion

OBJECTIVE

To analyze the pattern of speaker activity related to both flexible ureteroscopy (fURS) and percutaneous nephrolithotomy (PCNL) during plenary sessions at the main (endo)urological international meetings over the last 10 years.

METHODS

We reviewed the meeting programs of the main endourological international meetings (EAU, AUA, WCE, and SIU) during 2011-2019. We detected all invited speakers at plenary sessions regarding fURS or PCNL. The proportion of fURS and PCNL talks was evaluated yearly during the study period. In order to analyze plenary session speaker composition, we estimated and compared the mean number of talks per speaker according to surgical technique. We also analyzed possible differences in age distribution according to the topic of the talk as well as the presence of young (i.e., < 45 years) speakers. Data were analyzed using descriptive statistics.

RESULTS

During the last 10 years, a total of 498 plenary talks were found. Of those, 260 (52.2%), 211 (42.4%), and 27 (5.4%) discussed PCNL, fURS, or both, respectively. PCNL was more frequently discussed at the beginning and the end of the study period. Mean [SD] number of talks per speaker was higher for PCNL (2.9 [3.4] vs 1.6 [1.4], p < 0.001), meaning that a wider variety of speakers was invited to give fURS talks. Speakers discussing fURS were younger (median [interquartile range, IQR] age 48 [44-56] vs 52 [47-60] years, p < 0.001), and a higher proportion of young speakers was observed in the fURS group (26% vs 15% p < 0.001). PCNL speakers were more commonly discussing fURS than fURS speakers discussing PCNL (23% vs 17%, p = 0.43).

CONCLUSIONS

We found a wider variety of speakers at fURS plenary sessions as compared to PCNL ones. It is easier and quicker to become an internationally recognized expert in the field of fURS rather than PCNL. PCNL speakers were able to master fURS more frequently than the other way around.

Comparison of dusting and fragmentation methods in the flexible ureteroscopic treatment of kidney lower calyx stones

To compare the long-term stone-free status of patients who underwent fragmentation of stones followed by active basketing versus stone dusting and spontaneous passage following flexible ureteroscopic treatment for lower calyceal stones. The dusting or fragmentation methods were randomly assigned to patients who were scheduled to undergo RIRS for only renal lower calyceal stones between February 2019 and May 2022, prospectively. Stone-free rates were determined after 3 months by non-contrast computed tomography and patient demography; preoperative and postoperative follow-up data of both groups were evaluated comparatively. While the fragmentation method was applied in 32 patients, the dusting method was applied in the remaining 31 cases. The two groups did not differ significantly regarding the demographic data and laboratory findings. Mean stone size was similar in both groups of cases. Operation time was significantly longer for fragmentation (93.23 ± 27.20 vs 78.43 ± 30.08, p = 0.045) and evaluation of the success rates after 3 months did show that patients in the dusting group had a higher rate of stone-free status when compared with the other group of cases (65.6 vs 87.1%, p = 0.043). Lastly, postoperative fever rates were not significantly different between the two groups (12.5 vs 9.7%, p = 0.518). Our findings showed that dusting the lower calyceal stones during fURS would reveal higher stone-free rates during long-term follow-up periods, and the mean operation time will be shorter in these patients.

Determinants of outflow rate through the ureteral access sheath during flexible ureteroscopy: an experimental in vivo study in an anesthetized porcine model

To evaluate the effect of different ureteroscope positions, saline pumping frequency, laser fiber diameter and ureteral access sheath (UAS) on outflow rate during flexible ureteroscopy (fURS). This study was performed in an anesthetized porcine model. The fURS setup included a manual pumping system, a 9.5 Fr single used-digital flexible ureteroscope and a ureteral access sheath (UAS). Outflow was collected and measured from the UAS during 1 min in all experimental settings. The evaluated variables were the position of the ureteroscope, the pumping frequency (2 s, 3 s or 5 s), the diameter of the used UAS (12/14 Fr or 14/16 Fr) and laser fiber (200 μm or a 272 μm). Ureteroscope position in the lower calyx was associated with significantly lower outflow rate (p < 0.05). The use of the 14/16 Fr UAS resulted in improved flow in the renal pelvis and upper calyx (p < 0.05) but not in the lower calyx. The use of a 200 μm laser fiber only improved flow in the upper calyx and when a 14/16 Fr UAS was being used. Pumping frequency did not show a significant correlation with outflow rate. The ureteroscope positioning and UAS size were important determinants of outflow rate through the UAS during fURS, while laser fiber diameter had a limited effect. In the lower calyx the outflow was minimal and was not improved by using a larger UAS.

score

OBJECTIVE

The original S.O.L.V.E. scoring system was modified using virtual reality technology, and a new H.L.P.E.S scoring system was constructed to improve the accuracy of predicting the stone-free rate after flexible ureteroscopy.

METHODS

We retrospectively analyzed clinical and virtual reality data of 150 patients with renal calculi who underwent flexible ureteroscopy at the First Affiliated Hospital of Chongqing Medical University, Chongqing, China, from September 2019 to January 2022. Factors affecting the stone-free rate were evaluated in univariate and multiple logical regression analyses. Factors were divided by cut-off value under the receiver-operating characteristic curve and scored accordingly to a well-known international scoring system. Area under the curve predicted the stone-free rate. The accuracy and superiority of the stone-free rate after flexible ureterorenoscopy was compared between this scoring system and the S.O.L.V.E, R.I.R.S, T.O.HO, and RUSS scores.

RESULTS

Multiple logistic regression showed that the stone surface area, renal pelvis volume, and length of the calyces funnel were correlated with stone-free rate (P < 0.01, P = 0.021, P = 0.019, respectively). The H.L.P.E.S. score included stone surface area (1-2 points), renal pelvis volume (1-2 points), length of calyces funnel (1-2 points), pelvic calyceal height (1-2 points), and essence of stone (1-2 points). The area under the receiver-operating characteristic curve of H.L.P.E.S. score was 0.927, which was higher than the S.O.L.V.E., R.I.R.S., T.O.HO, and RUSS scores.

CONCLUSION

H.L.P.E.S. scoring can effectively predict the stone-free rate after flexible ureteroscopy for renal calculi and is superior to other scoring systems.

One-Stage Flexible Ureteroscopy during Single-Tract Percutaneous Nephrolithotomy in the Treatment of Parallel Calyceal Stones

INTRODUCTION

The aim of this study was to compare the clinical safety and efficiency between one-stage flexible ureteroscopy (FURS) during single-tract percutaneous nephrolithotomy (PCNL) and multi-tract PCNL in the treatment of parallel calyceal stones.

METHODS

One hundred and twenty-five patients who had calyceal stones parallel to puncture channel from March 2017 to January 2021 were enrolled and assigned into two groups. Seventy cases received the treatment of FURS combined with single-tract PCNL under the oblique supine position (the Combined group), and 55 cases had multi-tract PCNL procedure under the prone position (the Multi-tract group). Demographic characteristics, clinical information, and surgical outcomes were analyzed.

RESULTS

Demographic variables and stone characteristics did not show statistical difference between the two groups. Compared with the Multi-tract group, there were longer operation time (p = 0.021), shorter postoperative hospitalization days (p = 0.003), smaller postoperative hemoglobin drop (p = 0.002), less incidence of moderate and severe postoperative pain (p = 0.001), and postoperative perirenal hematoma (p = 0.012) in the Combined group. No significant difference was found in the stone-free rate (SFR) and postoperative fever between the two groups (p = 0.880 and p = 0.324). More patients needed postoperative intervening embolization in the Multi-tract group (p = 0.048).

DISCUSSION/CONCLUSIONS

For most patients with parallel calyceal stones, one-stage FURS combined with single-tract PCNL procedure was a safer procedure for the reduction of complications and could achieve a comparative SFR compared to the multi-tract PCNL.

Ureteral calculi lithotripsy for single ureteral calculi: can DNN-assisted model help preoperatively predict risk factors for sepsis?

OBJECTIVES

To explore the utility of radiomics and deep learning model in assessing the risk factors for sepsis after flexible ureteroscopy lithotripsy (FURL) or percutaneous nephrolithotomy (PCNL) in patients with ureteral calculi.

METHODS

This retrospective analysis included 847 patients with treatment-naive proximal ureteral calculi who received FURL or PCNL. All participants were preoperatively conducted non-contrast computed tomography scans, and relevant clinical information was meanwhile collected. After propensity score matching, the radiomics model was established to predict the onset of sepsis. A deep learning model was also adapted to further improve the prediction accuracy. Performance of these trained models was verified in another independent external validation set including 40 cases of ureteral calculi patients.

RESULTS

The overall incidence of sepsis after FURL or PCNL was 5.9%. The least absolute shrinkage and selection operator (LASSO) regression analysis revealed 26 predictive variables, with an overall AUC of 0.881 (95% CI, 0.813-0.931) and an AUC of 0.783 (95% CI, 0.766-0.801) in external validation cohort. Judicious adaption of a deep neural network (DNN) model to our dataset improved the AUC to 0.920 (95% CI, 0.906-0.933) in the internal validation. To eliminate the overfitting, external validation was carried out for DNN model (AUC = 0.874 (95% CI, 0.858-0.891)).

CONCLUSIONS

The DNN was more effective than the LASSO model in revealing risk factors for sepsis after FURL or PCNL in single ureteral calculi patients, and females are more susceptible to sepsis than males. Deep learning models have the potential to act as gatekeepers to facilitate patient stratification.

KEY POINTS

• Both the least absolute shrinkage and selection operator (LASSO) and deep neural network (DNN) models were shown to be effective in sepsis prediction. • The DNN model achieved superior prediction capability, with an AUC of 0.920 (95% CI, 0.906-0.933). • DNN-assisted model has potential to serve as a gatekeeper to facilitate patient stratification.

The dilemma of 12/14F ureteral access sheath (UAS) usage: a case control study

BACKGROUND

The insertion of a ureteral access sheath (UAS) is a frequent procedure during flexible ureteroscopy (fURS) to facilitate kidney stone treatment. The aim of this study was to investigate the influence of 12/14 French (F) UAS on fURS outcomes.

METHODS

We performed a retrospective monocentric analysis of fURS procedures conducted at the Department of Urology (University Hospital Schleswig-Holstein, Lübeck, Germany) for kidney stone treatment via lithotripsy or basket stone retrieval between September 2013 and June 2017. Uni- and multivariate analyses were done with the help of RStudio (Version 1.0.136) software.

RESULTS

In total, 283 consecutive fURS were analyzed. UAS was applied in 98 cases (34.63%). The insertion of UAS was preferred in cases with multiple kidney stones and larger median maximal stone diameter (p < 0.05). UAS usage correlated with elevated radiation exposure in seconds (94 vs. 61; p < 0.0001), prolonged operation time in minutes (99 vs. 66, p < 0.0001), length of hospital stay over 48 h (LOS, 22.49% vs. 10.81%; p = 0.015), more frequent postoperative systemic inflammatory response syndrome (SIRS, 13.27% vs. 4.32%; p = 0.013) and lower postoperative stone-free rates (60.20% vs. 78.92%; p = 0.0013). Moreover, we conducted uni- and multivariate subgroup analysis for cases with multiple kidney stones (≥ 2) and comparable stone burden; UAS was inserted in 48.3% of these cases (71/147). On multivariate logistic regression, UAS insertion was statistically associated with prolonged operation time in minutes (101 vs. 77; p = 0.004). No statistical differences regarding radiation exposure, stone-free rates, postoperative SIRS rates or LOS were noted between UAS and non-UAS patients with multiple kidney stones of similar size (p > 0.05).

CONCLUSIONS

12/14F UAS does not seem to improve overall outcomes in fURS for kidney stones. In patients with multiple kidney stones it may be associated with elevated operation time without a clear benefit in terms of improved stone-free status or reduced perioperative complication rate. Further prospective randomized studies to specify the indications for UAS usage are urgently needed.

Comparison of flexible ureteroscopy and mini-percutaneous nephrolithotomy in the treatment for renal calculi larger than 2 cm: a matched-pair analysis

To compare the effectiveness and safety of flexible ureteroscopy and mini-percutaneous nephrolithotomy for renal calculi > 2 cm and perform subgroup analysis of stone length and age. Patients received mini-percutaneous nephrolithotomy or flexible ureteroscopy in Qilu Hospital of Shandong University from 2016.01 to 2021.03 with renal calculi > 2 cm were retrospectively analyzed. Propensity score matching was performed to get comparable patients. The postoperative hospital days, operation time, complication rate, and stone free rate were compared. The age and stone length were analyzed by subgroup. 162 in 313 patients were finally included. Each group had 81 cases. Outcomes such as intraoperative transfusion, stone free rate show no difference either. Flexible ureteroscopy had shorter postoperative hospital days (3.2 days vs 7.2 days, P < 0.001) and fewer complications (9, 11.1% vs 25, 30.9%, P = 0.002) compared to mini-percutaneous nephrolithotomy. The postoperative hospital days, and complication of the flexible ureteroscopy were significantly lower than those in the mini-percutaneous nephrolithotomy for renal stones ≤ 2.5 cm; when the stone length > 2.5 cm, the stone free rate of flexible ureteroscopy was lower than that of the mini-percutaneous nephrolithotomy group, but not statistically significant. The complications of flexible ureteroscopy in the young group (18-39 years old) were significantly lower than those in the mini-percutaneous nephrolithotomy group. For 2-2.5 cm renal stones, flexible ureteroscopy can achieve a similar stone free rate with shorter hospital stay, and lower complications. For larger stones, flexible ureteroscopy performed poorly. Flexible ureteroscopy may be a better option for younger patients with fewer complications.

Suctioning Flexible Ureteroscopy with Automatic Control of Renal Pelvic Pressure versus Mini PCNL for the Treatment of 2-3-cm Kidney Stones in Patients with a Solitary Kidney

OBJECTIVE

The aim of the study was to compare the treatment outcomes between suctioning flexible ureteroscopic lithotomy (SF-URL) with automatic control of renal pelvic pressure and minimally invasive percutaneous nephrolithotomy (MPCNL) for the management of 2-3-cm renal stones in patients with a solitary kidney.

MATERIALS AND METHODS

A total of 127 patients with a solitary kidney who underwent SF-URL (n = 57) or MPCNL (n = 70) for large renal stones (>2 cm) between June 2015 and October 2020 were consecutively analyzed. The stone characteristics, operative times, stone-free rate (SFR), hospital stays, and incidences of complications were compared.

RESULTS

There was a significantly shorter operative time with MPCNL than with SF-URL (43.4 ± 18.9 min vs. 61.8 ± 21.1 min, p = 0.012). SFR at 30 days were 80.7% (46/57) and 90.0% (63/70) for SF-URL and MPCNL, respectively (p > 0.05). The SFR at the 3-month follow-up was comparable in both groups (91.2% vs. 95.7%, p > 0.05). The hemoglobin decline value, hospital stay, serum cystatin C, and percentage of patients requiring blood transfusions in the SF-URL group were obviously better than those in the MPCNL group: (0.8 ± 0.4) versus (3.9 ± 2.7) g/dL (p = 0.007), (3.6 ± 1.5) versus (6.9 ± 3.1) days (p = 0.013), (1.02 ± 0.48) versus (2.54 ± 0.69) mg/L (p = 0.011), and 0 (0.0%) versus 7 (10.0%) (p = 0.016), respectively. The percentages of patients with thrombosis and perirenal hematoma in the MPCNL group were higher than those in the SF-URL group, but the difference was not statistically significant (p > 0.05).

CONCLUSION

For the treatment of 2-3-cm renal stones in patients with a solitary kidney, both SF-URL and MPCNL are effective. MPCNL has the advantage of a shorter operation time. However, SF-URL is characterized by less bleeding, shorter hospital stay, and less damage to kidney function.

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.

Factors affecting use of flexible ureteroscope in large renal stones; stone size or stone composition

Introduction

After advances in flexible ureteroscopes' design, accessories, and lithotripters, flexible ureteroscope has been used widely for the treatment of large renal calculi >2 cm.

Objectives

The objective was to evaluate the role of flexible ureteroscopy with laser lithotripsy in the treatment of large renal calculi >2 cm and find out which factor can affect the results.

Patients and Methods

Prospectively, we have studied 47 patients who have passed through flexible ureteroscopy with laser lithotripsy for renal calculi >2 cm. Preoperative, operative, and postoperative data were recorded. Results and complications were recorded, too.

Results

In 47 patients, the mean stone size is 26.2 ± 4.1 cm and the total stone-free rate (SFR) is 89.4%, while in stone size ≤3 cm, the SFR is 90.7%, and for stone size >3 cm, the SFR is 75%. Overall stone density is 1020 ± 286 HU. The SFR is 95.5% in stones ≤1000 HU and 84% in stones >1000 HU. The mean operative time is 99.2 ± 29.3 min. The intraoperative complications are 17%, while postoperative complications are 36% and all complications are mild.

Conclusion

Flexible ureterorenoscopy (FURS) is safe and effective for the treatment of large renal calculi >2 cm. Stones >3 cm may have lower results even after staged therapy.

3D printed model for flexible ureteroscopy training, a low-cost option for surgical training

INTRODUCTION

Training in experimental models is a valid option that improves the outcomes and shortens surgical learning curves. Our objective was to develop a 3D printed plastic model for teaching, training and education in flexible ureteroscopy, analyzing costs and suitability for the practice of this surgical technique.

METHODS

A 3D printed model was developed based on a CT scan from a real-life patient's upper urinary tract. Horos™ software was used for segmentation and an FDM-Ultimaker for 3D printing. Renal calyces were numbered to be identified, as in the European Association of Urology Endoscopic Stone Treatment training curriculum, Task 4. The following were used: Innovex single-use flexible ureteroscope (Palex) and nitinol baskets (Coloplast).

RESULTS

Printing time was 19 h, with a total cost of €8.77. The three-dimensional model allowed the insertion of the flexible ureteroscope and the exploration of the renal calyces by urologists in training as well as in current practice of the specialty without difficulty. The model also allowed the use of baskets and the mobilization and removal of previously placed stones.

CONCLUSION

We unveil a valid three-dimensional model for flexible ureteroscopy training exercises with reasonable costs, which will allow acquiring the necessary skills and confidence to initiate the procedure in a real-life scenario.

Retrograde intrarenal surgery versus percutaneous nephrolithotomy for treatment of renal pelvic stone more than 2 centimeters: a prospective randomized controlled trial

This study aimed at investigating the efficacy and safety of retrograde intrarenal surgery (RIRS) in treatment of renal pelvic stone larger than 2 cm against the percutaneous nephrolithotomy (PCNL). Between March 2018 and December 2020, 121 patients were randomized to undergo PCNL (60 patients), or RIRS (61 patients). Both groups were compared in terms of operative time, intraoperative complications. Postoperative complications were assessed based on Clavien-Dindo grading system. Stone-free rates were evaluated by CT scan 6 weeks after surgery. No significant difference were observed between both groups in perioperative criteria. The main operative time was slightly longer in PCNL group (105 vs 95 min, p = 0.49). Stone clearance was higher in PCNL, yet the difference was not significant. (53 patients in PCNL group had either complete clearance or residual fragments < 4 mm, compared to 49 in RIRS group (p = 0.22). Blood transfusion rate was 8.3% in PCNL compared to 1.6% in RIRS group, with a trend towards significance (p = 0.08). Post-operative fever was higher in RIRS, yet it fell just short of statistical significance (13.1% vs 5.0%, p = 0.12). Compared to PCNL, RIRS displayed acceptable efficacy with less risk of bleeding requiring transfusion. It can be applied to patients with large renal pelvic stone as an alternative to PCNL.

Preoperative hydronephrosis is a predictive factor of ureteral stenosis after flexible ureteroscopy: a propensity scores matching analysis

Objectives

Ureteral stenosis is a serious complication of flexible ureteroscopy. How to predict the possibility of stricture before surgery is an important topic. This research retrospectively studied the influence of preoperative hydronephrosis on ureteral stenosis after flexible ureteroscopy, to explore whether the preoperative hydronephrosis could predict postoperative ureteral stenosis.

Methods

We conducted a retrospective study on patients who received flexible ureteroscopy in our hospital for upper ureteral calculi from January 2015 to June 2018. Patients were followed-up for 36 months after surgery, and intraoperative and postoperative complications were recorded. We divided patients into the mild hydronephrosis group and moderate to severe hydronephrosis group. Preoperative clinical baseline data of the patients were adjusted by propensity matching score analysis. Differences of intraoperative ureteral injury, operative time, postoperative ureteral stricture, and SFR one month after surgery was statistically analyzed. Kaplan–Meier’s method and Log-rank test were used to compare the differences in the cumulative incidence of ureteral stenosis between the two groups. Cox regression was used to compare the hazard ratio of ureteral stenosis between the two groups.

Results

A total of 447 patients with 469 sides surgery were included, including 349 sides in the mild hydronephrosis group and 120 sides in the moderate to severe hydronephrosis group. Twenty-nine patients with 30 sides developed ureteral stenosis. Before and after propensity, the incidence of ureteral stricture matching analysis was 6.4% and 8%, respectively. There were statistical differences in ureteral stricture and injury, but the statistical differences in SFR and operation time were inconsistent. Kaplan–Meier showed a significant difference in the cumulative incidence of ureteral stenosis between the two groups.

Conclusions

Patients with moderate to severe hydronephrosis before surgery were more likely to have an intraoperative ureteral injury and postoperative ureteral stricture after FRUS. Preoperative hydronephrosis is an important predictor of ureteral stricture.

The value of procalcitonin for predicting urosepsis after mini-percutaneous nephrolithotomy or flexible ureteroscopy based on different organisms

PURPOSE

To assess the value of procalcitonin (PCT) as an early biomarker for predicting urosepsis caused by Gram-negative (GN) bacteria, Gram-positive (GP) bacteria and fungi following mini-percutaneous nephrolithotomy (mPCNL) and flexible ureteroscopy (FURS).

METHODS

A total number of 356 patients with positive preoperative UC (urine cultures) who underwent mPCNL and FURS between June 2017 and January 2021 were retrospectively analyzed. Univariable analysis and multivariable logistic regression analysis were conducted to compare the predictors for urosepsis caused by different organisms. Furthermore, the nomogram was established as a predicted model for urosepsis.

RESULTS

Among 356 positive UC, 265 (74.4%) were positive for GN bacteria, 77 (21.4%) for GP bacteria and 14 (3.9%) for fungal pathogens. Escherichia coli (48.9%) were the predominant pathogens and Enterococcus (54/77) were the most common GP bacteria. Multivariate logistic regression analysis showed that positive nitrite (OR 3.31, 95% CI 1.20-9.14; P = 0.021), operative time > 90 min (OR 3.10, 95% CI 1.10-8.75, P = 0.033) and postoperative PCT > 0.1 ng/mL (OR 56.18, 95% CI 15.20-207.64, P < 0.001) were associated with postoperative urosepsis originated in GN infections, while urosepsis caused by GP bacteria and fungi was not associated with PCT > 0.1 ng/mL (P = 0.198), only stone burden > 800 mm² (OR 3.69, 95% CI 1.01-13.53, P = 0.049) was an independent risk factor.

CONCLUSIONS

For patients with positive preoperative UC, postoperative PCT > 0.1 ng/mL was an independent risk factor of post-PCNL and post-FURS urosepsis caused by GN bacteria rather than GP bacteria and fungi.

[Single-use versus reusable flexible ureteroscope: Technical and medico-economic aspects]

INTRODUCTION

Sate of the art on the indications, methods of implementation and medico-economic considerations of reusable flexible ureteroscopes (URSr) vs single use (URSuu)?

METHOD

Review of the literature (Pubmed) on reusable and single-use ureteroscopes, as well as on the expertise of our center. A PubMed search and narrative review of the data was performed in July 2021. Only articles in French or English were selected.

RESULTS

The URSr and URSuu have similar technical characteristics and are suitable for the exploration of the upper urinary excretory tract: treatment of stones of the kidney <2cm or of the ureter. The URSr is the most common type of ureteroscope. URSuu are newer and associated with many advantages: no sterilization procedure, immediate availability of equipment in the operating room, reduced waste production at the institutional level. A hybrid use of URSr and URSuu currently seems to be the best compromise from a medico-economic point of view for high volume centers. In the case of a smaller activity or a secondary site, URSuu are more advantageous and the reduction in purchasing costs should accentuate this benefit.

CONCLUSION

URSr and URSuu are technically similar and allow identical treatment of upper urinary tract pathologies. Their complementary use optimizes the care of urology patients. The barrier to the exclusive use of URSuu remains their cost.

Impact of Preoperative Stenting on the Outcome of Flexible Ureterorenoscopy for Upper Urinary Tract Urolithiasis: A Systematic Review and Meta-Analysis

PURPOSE

This study aimed to investigate the effect of preoperative stenting (POS) on the perioperative outcomes of flexible ureterorenoscopy (fURS).

MATERIALS AND METHODS

A systematic review and meta-analysis was conducted based on the PRISMA statement. From the initially retrieved 609 reports, we excluded the ineligible studies at 2 stages. We only included studies that contained fURS patients with and without POS in the same report. Data of patients who underwent semirigid ureteroscope only were excluded from the analysis. The Newcastle-Ottawa Scale (NOS) system was applied for risk of bias assessment.

RESULTS

A total of 20 studies including 5,852 patients were involved. 48.5% of the patients had preoperative stent. Stone-free rate was significantly higher with prestenting; odds ratio (OR) was 1.98 (95% CI: 1.51-2.58) (Z = 5.02; p = 0.00001). It also displayed tendency toward lower complications; OR was 0.74 (95% CI: 0.52-1.05) (Z = 1.67; p = 0.09). POS significantly increased the use of ureteral access sheath; OR was 1.49 (95% CI: 1.05-2.13) (Z = 2.22; p = 0.03). Risk of bias assessment showed 13 and 7 studies with low and moderate risk, respectively.

CONCLUSIONS

POS clearly improves the stone-free rates after fURS. It might reduce the complications, especially ureteral injury. These findings might help solve the current debate and can be useful for urologists during patient counselling for a proper decision-making.