Effect of outflow resistance on intrarenal pressure at different irrigation rates during ureteroscopy: in vivo evaluation.

To maintain visualization and control temperature elevation during ureteroscopy, higher irrigation rates are necessary, but this can increase intrarenal pressure (IRP) and lead to adverse effects like sepsis. The IRP is also dependent on outflow resistance but this has not been quantitatively evaluated in a biological system. In this study, we sought to characterize the IRP as a function of irrigation rate in an in vivo porcine model at different outflow resistances. Ureteroscopy was performed in a porcine model with a 9.5 Fr prototype ureteroscope containing a pressure sensor. A modified ureteral access sheath (UAS) (11/13 Fr, 36 cm) was configured to adjust outflow resistance. IRP-irrigation rate curves were generated at four different outlet resistances representing different outflow scenarios. At lower irrigation rates, the pressure change in response to increased irrigation was gradual and non-linear, likely reflecting a "compliant" phase of the renal collecting system. Once IRP reached the range of 35-50 cm H2O, the pressure increased in a linear fashion with irrigation rate, suggesting that the distensibility of the collecting system had become saturated. The relationship between IRP and irrigation rate becomes linear during in vivo porcine studies once the initial compliance of the system is saturated. IRP is more sensitive to changes in irrigation rate in systems with higher outflow resistance. The modified UAS is a novel research tool which allows variance of outflow resistance to mimic different clinical scenarios. Knowledge of outflow resistance may simplify the decision to use an UAS.

Preoperative risk factors for complications after flexible and rigid ureteroscopy for stone disease: A French multicentric study.

BACKGROUND: With an increasing prevalence in industrialized countries, lithiasis represents a public health problem with significant economic cost. Ureteroscopy is nowadays the main treatment for kidney and ureteral stones with increasingly broad indications. While this treatment is relatively safe and effective, the complications can be severe. AIM: The aim of this study was to investigate the preoperative risk factors of complication in the 30 days following a rigid or flexible ureteroscopy in a large cohort of patients. METHODS: A retrospective multicenter study was conducted in 5 French centers between January 1st 2017 and 31st December 2018. All flexible and rigid ureteroscopies performed were included. All preoperative and per operative data were collected in an electronic database. Outcomes and complications within 30 days of the procedure were also collected. Univariate and multivariable analyses evaluated for potential predictors of postoperative complications. RESULTS: 1124 procedures were included. According to the occurrence of a postoperative complication, patients were divided into two groups, 109 in the group with complications. The majority of complications were minor, with only 13.7% classified as Clavien 3-4. In univariate analysis, ASA score>2 (odd ratio, OR=1.68, P=0.04), WHO performance status≥1 (OR=1.50, P=0.04) and neurologic disease (OR=2.78, P=0.005) were predictors of postoperative complications. In multivariable analysis, Charlson's score (OR=0.79, P=0.01) and ASA score>2 (OR=1.48, P=0.03) were independents risk factors of postoperative complication. Concerning major complications, in univariate analysis, cardiovascular disease (OR=3.71, P=0.032) and BMI (OR=0.87, P=0.02) were the only predictors of major complications after ureteroscopy. Only BMI was found In multivariable analysis (OR=0.86, P=0.01) CONCLUSION: Baseline characteristics and comorbidities of the patients, especially neurological diseases, were the main risk factors for short-term complications after ureteroscopy. Ureteroscopy remains a relatively safe and effective procedure. However, we advise surgeons to take precautions with fragile patients with multiple comorbidities or neurological disease.

Safety and Outcomes of using ureteric access sheath (UAS) for treatment of Pediatric renal stones: Outcomes from 2 tertiary endourology centers.

OBJECTIVE: To look at the safety and outcomes of using ureteral access sheath (UAS) for pediatric renal stones. The use of UAS is variable in urological practice with very little clinical work on their use in pediatric kidney stone disease. PATIENTS AND METHODS: Data was retrospectively collected from 2 large European tertiary endourology centers for all pediatric patients (≤16 years) with renal stones who underwent flexible ureteroscopy and lasertripsy (FURSL) via UAS. Data was collected on patient details, stone demographics and clinical outcomes of the FURSL procedure. RESULTS: Forty-eight patients with a mean age of 10.7 years were treated with FURSL for a mean single and cumulative stone size of 10.4 mm and 15 mm respectively, with two-third having multiple stones and stones in the lower pole. The initial and final stone free rate (SFR) was 66.7% and 100% respectively with 1.3 procedures/patient. One patient each had intra-operative grade 1 ureteric injury and post-operative UTI, with no other injuries or complications noted. Over a mean follow-up of 17 months, no other complications were noted. CONCLUSION: Ureteral access sheath is safe for treatment of pediatric renal stones with excellent outcomes and are especially useful for larger or multiple stones. While there does not seem to be any medium-term sequalae, to avoid risk of ureteral injury, we would suggest using the smallest size sheath possible. We would argue these procedures are best done in specialist high-volume endourology units for optimal results.

Risk Factors for a Complicated Postoperative Course in Flexible Ureteroscopy.

INTRODUCTION: The goal was to determine risk factors for Clavien-Dindo (CD) grade ≥2 complications, with special focus on early postoperative systemic inflammatory response syndrome (SIRS), for flexible ureteroscopy (fURS). MATERIALS AND METHODS: A retrospective monocentric statistical analysis relating to 32 factors was performed with the χ2 test, Mann-Whitney U tests, and multivariate logistic regression. RESULTS: In total, 416 consecutive fURS performed between September 2013 and June 2017 were analyzed; 283 (68.03%) of these were for stone surgery and 133 (31.97%) for diagnostic purposes. In 43 cases (10.34%), CD ≥2 occurred; 31 cases (72.09%) of these were SIRS. On multivariate logistic regression, positive preoperative urine culture and steep pyelographic and CT-based infundibulopelvic angle (IPA) have been confirmed as independent risk factors for both CD ≥2 and SIRS. Greater maximal median stone diameter and female gender were significantly associated only with a higher CD ≥2 prevalence, but not with SIRS. The influence of ureteral access sheath (UAS) on CD ≥ 2 or SIRS occurrence could not be confirmed on multivariate analysis. Perioperative antibiotic prophylaxis for patients with negative urine culture showed no difference regarding SIRS prevalence. CONCLUSION: Steep CT-based IPA can be considered as a new radiologic predictor of complicated postoperative course and SIRS. The role of UAS as well as indications for perioperative antibiotic prophylaxis should be determined in prospective studies.

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

INTRODUCTION: Kidney stone is one of the urinary system diseases with a high incidence. In this study, we will evaluate the effectiveness and safety of Sun tip-flexible ureterorenoscope treating patients with kidney stone. METHODS AND ANALYSIS: English and Chinese literature about Sun tip-flexible ureterorenoscope treatment for kidney stones published before October 31, 2020 will be systematic searched in PubMed, Embase, Web of Science, Cochrane Library, Open Grey, Clinicaltrials.gov, Chinese Clinical Trial Registry, WANFANG, VIP Chinese Science and Technology Journal Database, CNKI, Chinese biomedical document service system (SinoMed). Only randomized controlled trials (RCTs) of patients with kidney stones will be included. Literature screening, data extraction, and the assessment of risk of bias will be independently conducted by 2 reviewers, and the 3rd reviewer will be consulted if any different opinions existed. Systematic review and meta-analysis will be produced by RevMan 5.3 and Stata 14.0. This protocol reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) statement, and we will report the systematic review by following the PRISMA statement. RESULTS: The current study is a protocol for systematic review and meta-analysis without results, and data analysis will be carried out after the protocol. We will share our findings in the fourth quarter of 2021. CONCLUSION: This study will provide recommendations for the effectiveness and safety of Sun tip-flexible ureterorenoscope for patients with kidney stones (KS), which may help to guide clinician. ETHICS AND DISSEMINATION: Ethical approval is not required as the review is a secondary study based on published literature. The results of the study will be published in peer-reviewed publications and disseminated electronically or in print. PROTOCOL REGISTRATION NUMBER: INPLASY2020110099.

The feasibility of one-stage flexible ureteroscopy lithotripsy in solitary kidney patients with 1-3 cm renal stones and risk factors of renal function changes.

PURPOSE: To compare perioperative outcomes and long-term renal function changes between prior stenting (PS) and not prior stenting (NPS) before flexible ureteroscopy lithotripsy (f-URS) for solitary kidney patients. METHODS: Solitary kidney patients with 10-30 mm renal stones were enrolled in this historical control study. Perioperative parameters and complications were compared. Stone-free was defined as the absence of any residual stones on a CT scan. Renal function changes were evaluated by estimated glomerular filtration rate (eGFR) and adjusted for body surface area. A decrease in the eGFR over 20% was identified as 'deterioration' in renal function. The follow-up period was at least 6 months. Logistic regression was used to identify risk factors of renal function deterioration. RESULTS: Of the 76 patients included, 40 cases experienced prior stenting before f-URS. The average stone diameter was 16.8 ± 4.7 mm, ranging from 10.0 to 28.4 mm. Initial SFR was 85.0 and 83.3% in the PS and NPS groups, respectively (p = 0.842), while SFR after the second procedure was 97.5 and 94.4% (p = 0.926). Seven PS and 5 NPS patients developed complications (p = 0.666). At the postoperative 6 months, seven patients showed a deteriorated renal function. Surgical time in minutes was identified as a risk factor for renal function deterioration after the operation (OR = 1.061, 95% CI: 1.015-1.109, p = 0.009, per minute). CONCLUSION: It appears that one-stage f-URS without PS could be feasible for 10-30 mm renal stones in solitary kidney patients, and less surgical time might be beneficial to protect renal function.

In-vitro and in-vivo new evidence for Flexor® Vue™ deflecting endoscopic system use: optimization of the stone free rate (SFR) after flexible ureteroscopy and Ho:YAG laser lithotripsy.

To test in-vitro and in-vivo the Flexor® Vue™ deflecting endoscopic system (FVDES) as a new technology able to improve the removal of residual intrarenal fragments.This is an observational prospective "proof of concept" study performed in patients with renal calculi treated with flexible ureteroscopy and Ho:YAG laser lithotripsy (f-URS) in Humanitas Research Hospital (Rozzano, Italy). We assessed feasibility, efficacy and safety of FVDES as an in-vivo tool for removing residual fragments after f-URS. The stone-free rate (SFR) at 30 days post-operatively was evaluated using CT. An in-vitro model was developed to evaluate the FVDES when used for this purpose.Eleven patients (M/F ratio: 7/4, mean age 63.5 ± 8.3) were treated. The stones were located in the lower calyces and the renal pelvis in 3 and 8 patients, respectively. Mean stone size was 18 ± 3.2 mm. The procedure with FVDES was feasible and effective in all the patients. Mean operative time was 82 ± 13.7 min and median hospitalization was of 1.5 days. The SFR after 90 days was 81% (9/11). We reported no relevant complications (Clavien-Dindo > 2); one patient had fever and was treated with antibiotics. The experimental in-vitro model demonstrated the efficacy of FVDES, allowing the removal of about 90% of fragments.Our study showed that FVDES is effective when used as a tool for retrieval of residual fragments at the end of f-URS. This technology could ensure a complete cleaning of the intrarenal collecting system and represent a safe alternative to basketing.

Device profile of the LithoVue single-use digital flexible ureteroscope in the removal of kidney stones: overview of safety and efficacy.

Introduction: Flexible ureteroscopy is a commonly performed urologic procedure for visualization and treatment of the upper urinary tracts. Traditionally, ureteroscopy has been performed with reusable scopes, which have large initial purchasing costs. LithoVue was the first widely adopted single-use flexible ureteroscope clinically available in 2016 and has caused reevaluation of this paradigm. Areas covered: This review is an objective assessment of the LithoVue single-use ureteroscope based on available studies at the time of publication. The authors searched major databases for papers that included the term 'LithoVue' and included relevant papers. The state of the market, technical specifications, results from clinical studies and cost analyses, and competitors are discussed. Expert opinion: The LithoVue single-use flexible ureteroscope has comparable clinical performance to existing reusable ureteroscopes based on available data. Direct clinical comparisons to competing single-use ureteroscopes, many of which are relatively new, are limited. In numerous pre-clinical studies LithoVue performed favorably compared to available competitors. Cost analyses suggest that benefit of single-use ureteroscopes is institution-specific, and will likely be favorable at a low volume of cases and with high local costs for repairs of reusable scopes.

Semi-rigid ureteroscope as a dilator in renal stone ureteroscopic treatment.

INTRODUCTION: To determine the efficacy and safety of using the semi-rigid ureteroscope as the only ureteral dilator for primary ureteroscopy (URS) in the treatment of renal stones. MATERIALS AND METHODS: A retrospective review of primary URS for renal stone disease was performed on consecutive patients treated by a single provider from 2013 to 2017. Utilizing wire placement under fluoroscopic guidance and direct visual ureteroscopic dilation with a semi-rigid ureteroscope, primary outcome was successful completion of stone treatment. In addition, perioperative safety was evaluated. RESULTS: A total of 126 consecutive cases of primary URS using the semi-rigid ureteroscope as the only ureteral dilator were attempted for renal stone treatment. The renal stones were treated in 124 (98.4%) patients without other forms of active ureteral dilation. Two (1.6%) patients required ureteral stent placement for passive dilation despite attempted other dilating techniques. No intraoperative ureteral perforations were identified. Postoperative radiographic follow up was available for 67% patients with a 91% stone free rate and no hydronephrosis or ureteral strictures were detected. CONCLUSION: Utilizing direct visual semi-rigid ureteroscopic dilation with a semi-ridged ureteroscope prior to flexible ureteroscopy leads to successful primary ureteroscopy for renal stone treatment in most patients. This technique is an effective, safe and possibly cost-effective method of obtaining ureteral access to facilitate primary URS for renal stone treatment.

The Impact of Ureteral Access Sheath Use on the Development of Abnormal Postoperative Upper Tract Imaging after Ureteroscopy.

PURPOSE: Ureteral access sheaths are commonly used during ureteroscopy to facilitate stone removal, improve visibility and maintain low intrarenal pressures. However, the use of a ureteral access sheath can cause ureteral wall ischemia and ureteral tears, potentially increasing the risk of postoperative ureteral stricture and obstruction. We studied the impact of ureteral access sheath use on postoperative imaging studies. Secondary objectives included studying the impact of other intraoperative parameters on postoperative imaging studies. MATERIALS AND METHODS: A retrospective chart review was conducted of cases that underwent ureteroscopy for nephroureterolithiasis across 2 high volume institutions between January 2012 and September 2016. Patient demographics, cumulative stone size, operative time, use of ureteral access sheath, laser lithotripsy, basket extraction, preoperative ureteral stent and postoperative ureteral stent placement were extracted from the electronic medical record. Findings of followup renal ultrasound, kidney-ureter-bladder x-ray and/or computerized tomography at approximately 8 weeks after surgery were recorded. RESULTS: A total of 1,332 ureteroscopies were performed with 1,060 cases (79.6%) returning for routine upper tract imaging after ureteroscopy. Postoperative hydronephrosis was noted following 127 cases (12.0%). Factors predicting presence of hydronephrosis after ureteroscopy include lower body mass index (p=0.0016), greater cumulative stone size (p=0.0003), increased operative time (p <0.0001), preoperative ureteral stent (OR 1.49, p=0.0299) and postoperative ureteral stent placement (OR 6.43, p=0.0031). Postoperative hydronephrosis was not associated with use of ureteral access sheath, age, laser lithotripsy or basket extraction. CONCLUSIONS: Use of ureteral access sheath did not have a significant impact on development of postoperative hydronephrosis, suggesting ureteral access sheath is safe for use during ureteroscopy. Ureteral strictures remain rare following ureteroscopy, seen in only 1.0% of our cohort. With an observed prevalence of hydronephrosis of 12.0% on followup imaging at 8 weeks, routine upper tract imaging after ureteroscopy remains a valuable prognostic tool.

Risk Factors for Systemic Inflammatory Response Syndrome Induced by Flexible Ureteroscope Combined with Holmium Laser Lithotripsy.

OBJECTIVE: To investigate the risk factors of systemic inflammatory response syndrome (SIRS) induced by flexible ureteroscope combined with Holmium laser lithotripsy. Patients and Methods. The clinical data from 216 consecutive patients who had undergone flexible ureteroscope combined with Holmium laser lithotripsy between August 2015 and May 2019 were retrospectively analyzed. To identify the risk factors of systemic inflammatory response syndrome induced by flexible ureteroscope combined with Holmium laser lithotripsy, the cases were divided into two groups according to whether they developed postoperative SIRS: SIRS group (21 cases) and non-SIRS group (195 cases). Age, gender, body mass index, stone size, surgery time, stone location, hydronephrosis, urine culture, hospital stay, stone-free rate, ureteral access sheath, and diabetes mellitus were collected. Univariate analysis was performed to calculate the potential factors. In order to determine the independence of the various factors, factors that potentially contributed to SIRS were compared between the SIRS group and the non-SIRS group. Furthermore, multivariate logistic regression analysis was used to identify the risk factors of systemic inflammatory response syndrome induced by flexible ureteroscopic lithotripsy. RESULTS: All patients were successfully treated with flexible ureteroscopic lithotripsy. The incidence of SIRS after flexible ureteroscopic lithotripsy was 9.7%. The univariate analysis demonstrated the potential risk factors of systemic inflammatory response syndrome induced by flexible ureteroscopic lithotripsy were stone size (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (. CONCLUSIONS: Stone size, surgery time, urine culture, and ureteral access sheath are independent risk factors for SIRS induced by flexible ureteroscopic lithotripsy. Patients with these high-risk factors should be carefully evaluated to reduce systemic inflammatory response syndrome.

Single-Use Versus Reusable Digital Flexible Ureteroscopes for the Treatment of Renal Calculi: A Prospective Multicenter Randomized Controlled Trial.

Objective: To compare the efficacy and safety of a single-use digital flexible ureteroscope (f-URS) and a reusable digital f-URS (URF-V) for the treatment of renal stones in adults. Patients and Methods: In this randomized open-label noninferiority trial, we randomly selected patients with renal stones to receive ureteroscopy through a single-use digital f-URS (ZebraScope™; Happiness Workshop, Beijing, China) or a URF-V (Olympus, Tokyo, Japan). The primary endpoint was the 1-month postsurgical stone-free rate (SFR). The secondary efficacy endpoints assessed were the high-quality rate of images, the eligible rate of operability, the operative time, and the length of hospital stay. The safety outcomes assessed were the presence of postoperative complications, adverse events (AEs), and serious AEs (SAEs). The noninferiority margin was set at -10%. Results: In total, 126 patients completed the study (i.e., 63 patients in each group). The demographic and preoperative parameters were comparable between the two groups. The 1-month SFR was 77.78% for the ZebraScope group and 68.25% for the URF-V group (two-sided 95% confidence interval [CI]: -5.95 to 25.01). The high-quality rate of images and the eligible rate of operability were 100% in both groups (two-sided 95% CI: -5.27 to 5.35). There was no difference between the two groups in the operative time (p = 0.687), the length of hospital stay (p = 0.430), the presence of postoperative complications (p = 0.310), the presence of AEs (p = 0.709), and the presence of SAEs (p = 0.648). The most important and fatal SAE was acute urinary tract obstruction. Conclusion: The single-use digital f-URS (ZebraScope) appears to be at least noninferior to URF-V regarding the 1-month SFR, the high-quality rate of images, and the eligible rate of operability. Single-use digital f-URSs are an effective and safe alternative to URF-V.

Predictive risk factors of urinary tract infection following flexible ureteroscopy despite preoperative precautions to avoid infectious complications.

PURPOSE: Urinary tract infection (UTI) is a common complication after flexible ureteroscopy (fURS) despite technical precautions to avoid infectious complications. The aim was to investigate incidence and predictive risk factors of UTI following fURS procedure. PATIENTS AND METHODS: We conducted a retrospective study including consecutive fURS performed in our center from January 2015 to March 2019. The indications were: nephrolithiasis management and diagnosis and conservative treatment of upper urinary tract urothelial carcinomas (UTUC). Since 2015, we had technical precautions to avoid postoperative infectious complications: centralized collection of preoperative urine cultures which are examined daily by an urologist and a service provider, systematic use of ureteral access sheath and application of standardized antibiotic prophylaxis measures. The primary endpoint was occurrence of UTI within 15 days following fURS. RESULTS: Six hundred and four fURS were included for nephrolithiasis (n = 462) and UTUC management (n = 142). The median (IQR) age in the study cohort was 61(48-68) years, 268 female patients were included (44.4%), the median (IQR) Charlson score was 2(1-4) and single-use fURS were used in 186 cases (30.8%). Postoperative UTI occurred in 41 cases (6.7%). In multivariate analysis, female gender (OR 2.20 [1.02-5.02], p = 0.04), UTI within the last 6 months (OR 2.34 [1.12-5.11], p = 0.02), preoperative polymicrobial urine culture (OR 4.53 [1.99-10.56], p < 0.001) and increased operative time (OR 1.02 [1.002-1.031], p = 0.02) remain associated with postoperative UTI. CONCLUSIONS: In a large cohort study, female gender, prior UTI, increased operative time and preoperative polymicrobial urine culture were associated with the occurrence of postoperative UTI. Limiting operative time and improving our knowledge of polymicrobial urine cultures could reduce the infectious risk.

Flexible ureterorenoscopy to treat upper urinary tract stones in children.

Development of surgical expertise and technology has affected the way renal tract stones are treated. Our hypothesis was that flexible ureteroscopy (FURS) for upper tract stones in children produces good results. Our outcomes were reviewed. A retrospective case note review was performed for children with upper tract calculi who were treated by FURS. There were 56 stone episodes in 36 patients. Median age was 10.6 years. Stones were 3-23 mm (median 8 mm); 64.3% had multiple calculi. Median follow-up was for 17.1 months. After the first FURS there was stone clearance in 42/56 (75%). Although there were no immediate complications, two required re-admission; one with stent symptoms, the other with urinary infection. A second FURS was performed in 11, bringing the cumulative clearance to 89%, although this was often done as "another look" before stent removal. There was no statistically significant difference in stone clearance after first FURS for those with single stones (81.0%) compared to those with multiple stones (72.2%). Clearance rates of more than 70% after first FURS were achieved with stones of up to 17 mm. Unexpected disease was found and treated during FURS in 9 (16.1%) children. FURS is safe in children and good clearance rates are achieved. Multiple stones at different sites may be treated during the same treatment. In addition, FURS allows diagnosis and treatment of unexpected problems.

A Prospective Study Analyzing the Association Between High-grade Ureteral Access Sheath Injuries and the Formation of Ureteral Strictures.

OBJECTIVE: To assess the intermediate- and long-term effect of high-grade ureteral injuries from ureteral access sheaths. METHODS: Patients undergoing ureteroscopy for upper tract calculi were prospectively enrolled at 2 sites from 2010 to 2015. A 12/14 French sheath was used and the ureter was inspected with a flexible ureteroscope during withdrawal of the sheath and recorded. The videos were then evaluated by 2 blinded endourologists, and any injuries were graded per the Traxer ureteral injury scale. Only high-grade injuries were included. The primary endpoint was defined as ongoing hydronephrosis without an obstructing stone on follow-up imaging indicating a ureteral stricture. Logistic regression analysis was used to assess the relationship between hydronephrosis, ureteral injury, and other patient variables. RESULTS: Fifty-six patients were identified with high-grade ureteral injuries. Sixteen patients (28.6%) were female. Median age was 56.4 years (range 14-85). Median follow-up was 35.8 months (range 0-88). Three patients (5.5%) had hydronephrosis on follow-up imaging, only 1 of whom developed a de novo ureteral stricture. On univariate analysis, hydronephrosis was associated with a shorter stent duration (P = .11) and older age (P = .17). CONCLUSION: Endoscopically identified high-grade ureteral lesions following ureteral access sheath placement do not lead to clinically significant sequelae on intermediate term follow-up, with a stricture rate comparable to those without visible injuries of 1.8%.

Risk Factors for Ureteral Damage in Ureteroscopic stone Treatment: Results of the German Prospective Multicentre Benchmarks of Ureterorenoscopic Stone Treatment-Results in Terms of Complications, Quality of Life, and Stone-Free Rates Project.

BACKGROUND: The Post-Ureteroscopic Lesion Scale (PULS) is a validated, standardised scale that classifies iatrogenic ureteral lesions during ureteroscopy (URS). OBJECTIVE: To determine risk factors for the various PULS-grades caused by URS. METHOD: We prospectively investigated the independent influence of various risk factors in correlation with PULS-Grade 1+ and 2+ on 307 patients with ureterorenoscopic stone treatment from 14 German urologic departments. RESULTS: The following are the outcomes of the study: 117 (38.4%) and 188 (61.6%) of the calculi (median stone size 6 mm) were found in the kidney or ureter; 70% and 82.4% underwent preoperative or postoperative ureteral stenting; 44.3 and 7.2% received laser or ballistic lithotripsy; 60% of the patients presented with PULS grade 1+ and 8% with PULS grade of 2+. Only intracorporal lithotripsy revealed a significant independent risk factor for PULS grade 1+ or 2+. Both laser and ballistic therapies raised the probability of PULS grade 1+ by the factors 3.6 (p < 0.001) and 3.9 (p = 0.021), respectively. The ORs in conjunction with PULS grade 2+ were 3.1 (p = 0.038) and 5.8 (p = 0.014) respectively. Neither endpoint exhibited a significant difference regarding the lithotripsic procedure (laser vs. ballistic). CONCLUSION: Intracorporal lithotripsy is associated with a significant increase in damage to the ureter; further research is needed to determine its long-term effects.

Mini Versus Standard Percutaneous Nephrolithotomy: The Impact of Sheath Size on Intrarenal Pelvic Pressure and Infectious Complications in a Porcine Model.

OBJECTIVE: To determine how sheath and endoscope size affect intrarenal pelvic pressures and risk of postoperative infectious complications comparing "Mini" vs "Standard" percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: Uropathogenic Escherichia coli were grown and 109 of them were instilled into the porcine renal pelvis through retrograde access for 1 hour. Percutaneous access utilized a 14/16F 20 cm ureteral access sheath for the Mini arm and a 30F sheath for the Standard arm. Nephroscopy was simulated utilizing either an 8/9.8F semirigid ureteroscope or 26F nephroscope for 1 hour while intrarenal pelvic pressure was continuously monitored. Blood and tissue cultures of kidney, liver, and spleen biopsies were plated and incubated and positive cultures were confirmed with polymerase chain reaction. RESULTS: Intrapelvic pressures were higher in the Mini group, 18.76 ± 5.82 mm Hg vs 13.56 ± 5.82 mm Hg (p < 0.0001). Time spent above 30 mm Hg was greater in the Mini arm, 117.0 seconds vs 66.1 seconds (p = 0.0452). All pigs had positive kidney tissue cultures whereas spleen cultures were positive in 100% and 60% of pigs in the Mini and Standard arms, respectively (p = 0.0253); 90% and 30% had positive liver tissue culture in the Mini and Standard arms, respectively (p = 0.0062). Blood cultures were positive in 30% of pigs in the Mini arm compared with none in the Standard arm (p = 0.0603). CONCLUSION: Mini-PCNL was associated with higher intrarenal pressures and higher risk of end organ bacterial seeding in the setting of an infected collecting system. This suggests a higher potential for infectious complications in a clinical setting.

[Interrater reliability and clinical impact of the Post-Ureteroscopic Lesion Scale (PULS) grading system for ureteral lesions after ureteroscopy : Results of the German prospective multicenter BUSTER project]. / Interrater-Übereinstimmung und klinischer Nutzen der "Post-Ureteroscopic Lesion Scale" (PULS) zur Graduierung von intraoperativen Harnleiterverletzungen einer Ureterorenoskopie : Ergebnisse der deutschen prospektiv-multizentrischen BUSTER-Studie.

BACKGROUND: The Post-ureteroscopic Lesion Scale (PULS) was designed as a standardized classification system for ureteral lesions after uretero(reno)scopy (URS). This study evaluates its routine use and a possible clinical impact based on a representative patient cohort. MATERIALS AND METHODS: Data of 307 patients in 14 German centers within the BUSTER project were used to test 3 hypotheses (H): PULS score shows a high interrater reliability (IRR) after independent assessment by urologic surgeon and assistance personnel (H1); PULS score is correlated with the frequency of postoperative complications during hospital stay (H2); post-URS stenting of the ureter is associated with higher PULS scores (H3). RESULTS: Median age of patients was 54.4 years (interquartile range [IQR] 44.4-65.8; 65.5% male). Median diameter of index stones was 6 mm (IQR 4-8) with 117 (38.4%) pyelo-caliceal and 188 (61.6%) ureteral stones. Overall, 70 and 82.4% of patients had pre-stenting and post-URS stenting, respectively. Stone-free status was achieved in 68.7% after one URS procedure with a complication rate of 10.8% (mostly grade 1-2 according to Clavien-Dindo). PULS scores 0, 1, 2 and 3 were assessed in 40%, 52.1%, 6.9% and 1% of patients, respectively, when estimated by urologic surgeons. PULS score showed a high IRR between the urologic surgeon and assistance personnel (κ = 0.883, p < 0.001), but was not significantly correlated with complications (ρ = 0.09, p = 0.881). In contrast, a significant positive correlation was found between PULS score and post-URS stenting (ρ = 0.287, p < 0.001). A PULS score of 1 multiplied the likelihood of post-URS stenting by 3.24 (95% confidence interval 1.43-7.34; p = 0.005) as opposed to PULS score 0. CONCLUSIONS: Removal of upper urinary tract stones using URS is safe and efficacious. Real-world data provided by this study confirm a high IRR of the PULS score and its clinical impact on the indication for post-URS stenting. A future prospective randomized trial should evaluate a possible standardization of post-URS stenting based on PULS score assessment.

Clinical outcomes and costs of reusable and single-use flexible ureterorenoscopes: a prospective cohort study.

The purpose of this study is to analyze clinical outcomes and costs of single-use flexible ureterorenoscopes in comparison with reusable flexible ureterorenoscopes in a tertiary referral center. Prospectively, 68 flexible ureterorenoscopies utilizing reusable (Flex-X2S, Flex-XC, Karl Storz) and 68 applying single-use flexible ureterorenoscopes (LithoVue, Boston Scientific) were collected. Clinical outcome parameters such as overall success rate, complication rates according to Clavien-Dindo, operation time and radiation exposure time were measured. Cost analysis was based on purchase costs and recurrent costs for repair and reprocessing divided by number of procedures. In each group 68 procedures were available for evaluation. In 91% of reusable and 88% of single-use ureterorenoscopies stone disease was treated with a mean stone burden of 101 ± 226 and 90 ± 244 mm2 and lower pole involvement in 47 and 41%, respectively (p > 0.05). Comparing clinical outcomes of reusable vs. single-use instruments revealed no significant difference for overall success rates (81 vs. 87%), stone-free rates (82 vs. 85%), operation time (76.2 ± 46.8 vs. 76.8 ± 40.2 min), radiation exposure time (3.83 ± 3.15 vs. 3.93 ± 4.43 min) and complication rates (7 vs. 17%) (p > 0.05). A wide range of repair and purchase costs resulted in total to $1212-$1743 per procedure for reusable ureterorenoscopy whereas price of single-use ureterorenoscopy was $1300-$3180 per procedure. The current work provided evidence for equal clinical effectiveness of reusable and single-use flexible ureterorenoscopes. Partially overlapping ranges of costs for single-use and reusable scopes stress the importance to precisely know the expenses and caseload when negotiating purchase prices, repair prices and warranty conditions.

[A CASE OF RETROPERITONEAL HEMORRHAGE CAUSED BY THE INSERTION OF A URETERAL ACCESS SHEATH. A RARE COMPLICATION ASSOCIATED WITH FLEXIBLE TRANSURETHRAL LITHOTRIPSY (fTUL)].

A 77-year-old man with a right kidney stone was admitted to our hospital. A ureteroscope was introduced into the ureter without dilation under direct vision. We then performed flexible transurethral lithotripsy (f-TUL) using a ureteral access sheath and successfully fragmented the stone and extracted almost all the stone fragments without any complications. Just 3 hours after the operation, he suddenly developed right abdominal pain with a decrease in hemoglobin. A CT scan showed a retroperitoneal hemorrhage around the lower ureter. We herein describe a rare complication associated with flexible transurethral lithotripsy.