Ureteral Access Sheath Research Articles

Clinical determination of the natural distensibility of the human ureter: initial study.

To define the natural distensibility of the human ureter and evaluate the impact of other possibly favourable factors on ureteric distensibility. A total of 101 patients undergoing ureteroscopic stone removal or percutaneous nephrolithotomy underwent ureteric sizing using sequential passage of 37-cm urethral dilators in 2-F increments while attached to a unique force sensor. Insertion forces were limited to 6 N. After 6 N was attained, an appropriately sized ureteric access sheath was passed. At the conclusion of each procedure, Post-Ureteroscopic Lesion Scale score was determined. Urethral dilators were passed in 61% of patients at ≤14 F; 39% of patients accepted urethral dilators of ≥16 F. The mean dilator size was 14 F. Multivariate logistic regression analysis revealed that preprocedural ureteric stenting and antibiotic use favoured passage of 16-F dilators (odds ratio [OR] 5.16, 95% confidence interval [CI] 1.70-15.62 [P = 0.004] and OR 5.15, 95% CI 1.743-15.243 [P = 0.003], respectively). Neither tamsulosin nor prior urinary tract infection had an impact on ureteric size (OR 0.765, 95% CI 0.281-2.084 [P = 0.601], OR 1.049, 95% CI 0.269-4.089 [P = 0.945], respectively). Using continuous insertion force monitoring and a 6-N threshold, the majority of unstented adult human ureters within our patient population safely accommodated a 14-F dilator. Safe passage of a 16-F dilator at the 6-N threshold was more likely among patients with a preexisting indwelling ureteric stent or patients who were treated with antibiotics within a week of the procedure.

Effect of preoperative Silodosin on facilitating access sheath placement in retrograde intrarenal surgery. A randomized controlled studys

ABSTRACT Introduction to evaluate the effect of preoperative Silodosin on ureteric dilatation to facilitate ureteral access sheath (UAS) placement and reduction of ureteral wall injury in retrograde intrarenal surgery (RIRS). Methods one hundred and twenty patients with renal or ureteric stones were randomly allocated into 2 equal groups. Group A represents patients who received a 7-day preoperative single dose Silodosin before RIRS while Group B represents patients who received a placebo for the same regimen. Our primary outcome was to assess the success rate of (UAS) placement. Our secondary outcomes were to evaluate the perioperative complication rate, stone-free rate, hospital stay, and cost analysis. Results In our study, Silodosin showed a higher success rate for (UAS) insertion compared to placebo with a statistically significant difference (p-value = 0.04). Spontaneous UAS insertion in the Silodosin group was 58.3%, which was increased with active ureteric dilatation to 98.3%. Preoperative Silodosin led to less postoperative pain and analgesics requirements without impacting postoperative hospital stay or stone-free rate. There was less ureteric injury incidence in the Silodosin group compared to placebo with a statistically significant difference (p-value = 0.002). Conclusion Preoperative Silodosin facilitates UAS insertion with a protective role against ureteric injury compared to placebo.

Intelligent control of pressure based on ureteral access sheaths: renal pelvic pressure during flexible ureteroscope perfusion at different sites.

This study aimed to evaluate the accuracy and effectiveness of renal pelvic pressure (RPP) control during flexible ureteroscopic perfusion at various sites. Flexible ureteroscopy for the intelligent control of RPP was based on a ureteral access sheath (UAS) that integrated pressure measurement and suction functions (with automatic adjustment). Eleven consecutive patients with indurating nephrostomy tubes were enrolled. The nephrostomy tube was connected to a disposable invasive blood pressure sensor. The RPP was zeroed after the pressure stabilized. The flow rate and control value were set at 100ml/min and - 5 mmHg, respectively. An 8.5 Fr flexible ureteroscope was irrigated at the renal pelvis, as well as the upper, middle, and lower calyces of the kidney for 1min. All 11 patients with upper urinary tract calculi underwent successful UAS placement. Pressures measured by the sheath and fistula during perfusion were - 5.07 ± 1.41 and - 4.89 ± 1.07 mmHg at the renal pelvis, -5.16 ± 1.36 and - 5.12 ± 1.32 mmHg at the upper calyces, -4.98 ± 0.87 and - 5.39 ± 1.01 mmHg at the middle calyces, as well as -4.95 ± 1.56 and - 5.64 ± 1.24 mmHg at the lower calyces, respectively. There were no significant differences in pressure between the sheath and fistula groups or in sheath and fistula pressures among parts. The RPP fluctuated; however, all values were within the safe limit of 20 mmHg. The UAS-based pressure monitoring technology can accurately and reliably monitor and control RPP within a set range.

Development and validation of a predictive model for failure of ureteral access sheath placement in patients with ureteral calculi

ObjectiveThe Ureteral Access Sheath (UAS) has notable benefits but may fail to traverse the ureter in some cases. Our objective was to develop and validate a dynamic online nomogram for patients with ureteral stones who experienced UAS placement failure during retrograde intrarenal surgery (RIRS).MethodsThis study is a retrospective cohort analysis using medical records from the Second Hospital of Tianjin Medical University. We reviewed the records of patients with ureteral stones who underwent RIRS in 2022 to identify risk factors associated with UAS placement failure. Lasso combined logistic regression was utilized to identify independent risk factors associated with unsuccessful UAS placement in individuals with ureteral stones. Subsequently, a nomogram model was developed to predict the likelihood of failed UAS placement in this patient cohort. The model’s performance was assessed through Receiver Operating Characteristic Curve (ROC) analysis, calibration curve assessment, and Decision Curve Analysis (DCA).ResultsSignificant independent risk factors for unsuccessful UAS placement in patients with ureteral stones included age (OR = 0.95, P < 0.001), male gender (OR = 2.15, P = 0.017), body mass index (BMI) (OR = 1.12, P < 0.001), history of stone evacuation (OR = 0.35, P = 0.014), and ureteral stone diameter (OR = 0.23, P < 0.001). A nomogram was constructed based on these variables. Model validation demonstrated an area under the ROC curve of 0.789, indicating good discrimination. The calibration curve exhibited strong agreement, and the decision curve analysis revealed a favorable net clinical benefit for the model.ConclusionsYoung age, male sex, high BMI, no history of stone evacuation, and small diameter of ureteral stones were independent risk factors for failure of UAS placement in patients with ureteral stones, and the dynamic nomogram established with these 5 factors was clinically effective in predicting the outcome of UAS placement.

First clinical evaluation of a flexible digital ureteroscope with direct in scope suctioning system (Pusen DISS 7.5Ch): prospective multicentric feasibility study.

A new digital single-use flexible ureteroscope, Pusen direct in scope suction (DISS) 7.5Fr (PU3033AH), was evaluated with respect to manoeuvrability, suction quality, visibility and clinical efficiency. A prospective cohort study was conducted in six tertiary reference centers in Europe and Asia between February-April 2024. Adult patients who underwent flexible ureteroscopy and laser lithotripsy (fURSL) for urolithiasis were included. Demographic, intraoperative and follow-up characteristics were recorded. Quality parameters were rated by each surgeon using a Likert scale. a total of 57 fURSL were performed. Preoperative characteristics revealed a mean stone volume of 480.00mm3 (mean Hounsfield Unit- 998). 57.9%(n = 33) of the patients were pre-stented, and a ureteric access sheath was used in 64.9%(n = 37). Integrated-suction was deemed helpful in 94.7%(n = 54) fURSL as reported by the operators. An initial stone free rate (SFR) confirmed by postoperative imaging was achieved in 84.21%(n = 48). Quality parameters of the scope reached a mean Likert score of 4.5, with a "very good" mean evaluation for "scope placement", "visual quality", "irrigation", "deflection", "manoeuvrability", and "weight". "Suction quality" and "overall performance satisfaction" were rated "good". Comparing the Pusen DISS scope with other previously used scopes, overall satisfaction was rated 4.1. When asked if the surgeons would be willing to use the Pusen DISS 7.5Fr scope in the future, all the six surgeons answered positively. The DISS 7.5 Pusen ureteroscope displayed good visibility, manoeuvrability and suction quality, with excellent operative results. Further evaluation with larger comparative cohorts will help understand the potential of in-vivo use of integrated suctioning systems for fURSL.

Multicentre study comparing outcomes of RIRS using traditional suction ureteral access sheath (SUAS) and flexible and navigable suction UAS (FANS)

Objective: We aim to compare the stone-free rate (SFR), complications, and re-treatment rates in retrograde intrarenal surgery (RIRS) using a traditional suction ureteral access sheath (SUAS) with the more advanced flexible and navigable suction UAS (FANS). Materials and methods: Retrospective analysis was performed on patients who underwent RIRS using SUAS versus FANS across five institutions internationally as part of an audit. We analysed baseline and pre-operative characteristics such as stone location and density, intra-operative characteristics such as type of ureteroscope and laser, laser, and fluoroscopy time, as well as post-operative complications and residual fragments (RFs). Results: A total of 45 patients were included in each arm, with no significant difference in baseline characteristics. The commonest sheath size in the FANS group was 10–12 Fr (64.4%), while 11–13 Fr was preferred in SUAS (73.3%). Despite similar lasers (thulium fibre laser (TFL) and high-power holmium laser with MOSES), stone dusting (48.9%) and popcorning (95.6%) were carried out in FANS with minimal need for baskets (4.4%), while popcorning (64.4%) and basket extraction (40.0%) were required in SUAS. Although FANS had significantly longer operative times (65 minutes versus 55 minutes), it also had significantly higher rates of 100% SFR (80.0% versus 13.3%), and lower rates of clinically significant residual fragment (CSRF) (8.9% versus 53.3%), clinically insignificant residual fragment (CIRF) (11.1% versus 33.3%), and reintervention for CSRF (4.4% versus 37.8%). In addition, minor complications such as intra-operative oozing from mucosa not requiring intervention (8.9% versus 31.1%) and post-operative fever (11.1% versus 40.0%) were less common in FANS. On additional multivariate analysis, FANS was the only significant factor for higher SFR. Discussion and conclusion: The results of our study demonstrate that with its flexible and navigable tip, FANS proves advantageous over SUAS in terms of improving immediate SFR with negligible complications. By navigating the sheath into targeted individual calyces, fragments and dust are more successfully aspirated. FANS can therefore help to achieve the trifecta of high single-stage SFR, minimal minor and no major complications, and negligible reintervention rates. Level of evidence: Not applicable.

The efficacy of flexible ureteroscopy for large volume stones and hazards of ureteral access sheath usage: A prospective randomized study

ABSTRACT Objectives We aimed to assess the stone free rate of flexible ureteroscopy and laser lithotripsy (FURL) in upper urinary tract stones (UUTS) >20 mm and the risk of complications from ureteral access sheath (UAS) usage. Methods This is a prospective randomized clinical trial that included patients with UUTS larger than 20 mm who underwent FURL after randomization into two groups: group A (UAS) and group B (non-UAS). Data were collected for patients’ demographics, stone parameters, operative and postoperative complications, and the outcome of FURL regarding stone-free rate (SFR) and perioperative complications, with a 6-month follow-up. Stone clearance was defined as the absence of fragments or the presence of fragments smaller than 2 mm on follow-up CT scans of the urinary tract (CTUT). Results One hundred and fifty-nine patients were evaluated. The mean stone size was 27.08 ± 6.185 mm. Complete stone-free status was achieved in 84.9% of the patients. No significant difference was detected between both groups regarding operative time or SFR. The ureteric injury was identified in 13 (8.1%) patients (10 in group A and 3 in group B, p: 0.0481). Five of them, from group A, revealed hydronephrosis after stent removal. Postoperative pain and fever were documented in 50 and 22 patients, respectively, without significant differences between both groups. Postoperative sepsis occurred in 7 patients (2 in group A, 5 in group B, p: 0.380) who required supportive care. Conclusion FURL without UAS is a safe and efficient treatment for upper urinary tract stones larger than 20 mm in the form of lower risk of ureteric injury.

Operative outcomes 24 hours after retrograde intrarenal surgery for solitary renal calculi using a flexible and navigable suction ureteral access sheath. A prospective global multicenter study by the European Association of Urology Section on Urolithiasis.

Suction techniques showed potential to improve outcomes of retrograde intra-renal surgery (RIRS). We assessed the 24-hour stone-free rate (SFR) and complications after RIRS using flexible and navigable suction ureteral access sheaths (FANS-UAS). Sixteen centers prospectively contributed to data (August 2023-October 2023). Inclusion criteria: age ≥18 years, single renal stone, pre and 24-hour post-RIRS CT scan. Exclusion criteria were: ureteral stone, anomalous kidney, multiple stones. SFR was divided into: 1) grade A - no fragments; 2) grade B - fragments ≤2 mm; 3) grade C - fragments 2.1-4 mm; and 4) grade D - fragments >4 mm. A multivariable logistic regression analysis model was performed to assess factors associated with the odds of having grade A stone-free status. Data are expressed as median (interquartile range), absolute numbers and frequencies, odds ratio (OR), and 95% confidence interval (CI). One hundred forty-two patients with a median age of 52 years (40-61) were enrolled. 61.3% were males. Median stone volume was 1165 mm3 (656-1936). Median operative time was 48.5 (36.25-71.75) min. Transient fever (37°C-37.5°C) occurred in 10 (7%) patients. No sepsis case occurred. 96.5% of patients were stone-free (Grade A+B). Grade A SFR was 52.8%. All patients were discharged within 48 hours. Bone window (OR 3.156 95% CI 1.177-9.130, P=0.027) was the only factor significantly associated with higher odds of 100% SFR, while stone volume (OR 0.999, 95% CI 0.999-1.000, P=0.007) was significantly associated with lower odds. Imaging and clinical evidence demonstrate excellent perioperative outcomes just 24 hours post RIRS with FANS-UAS. The technique demonstrates a good safety profile, ability for immediate high SFR, and a low rate of infective complications.

Outcomes of Ureteroscopy and Laser Lithotripsy With and Without Ureteral Access Sheaths for the Treatment of Renal Calculi: A Systematic Review and Meta-analysis

Outcomes of Ureteroscopy and Laser Lithotripsy With and Without Ureteral Access Sheaths for the Treatment of Renal Calculi: A Systematic Review and Meta-analysis

The impact of preoperative ureteral stent duration on retrograde intrarenal surgery results: a RIRSearch group study.

A JJ stent placed before retrograde intrarenal surgery (RIRS) may ease the procedure. However, it is important to note that a prolonged duration of double J stent (DJS) placement before RIRS may increase the risk of postoperative urinary tract infection (UTI). Various publications have established this association, although the duration of the DJS before surgery is scarce. Our study investigates the relationship between the pre-stenting period and postoperative UTI and establishes a cut-off period to minimize this risk. We included a total of 500 cases with preoperative DJS prior to RIRS. The patients were divided into five groups according to their preoperative stenting duration (Group 1: 0-15 days; Group 2: 16-30 days; Group 3: 31-45 days; Group 4: 46-60 days; Group 5: >60 days). Demographic and clinical data of the patients, stone properties, operation data, perioperative and postoperative complications (including fever and UTI), hospitalization time, and stone-free rates (SFR) were compared. The groups contained 53, 124, 102, 63, and 158 patients. The demographics of the patients in each group were similar. There was no statistically significant difference between DJS duration, perioperative/postoperative complications, and SFR, except for the ureteral access sheath (UAS) insertion rate. (p = 0.001). The postoperative fever/UTI rate was the lowest in Group 1 (p = 0.046) compared to other durations. Stent duration does not impact SFR. Longer stents enhance UAS insertion success but increase postoperative infection risk. Our results suggest that RIRS should be performed within two weeks, ideally 20 days following stent insertion, to minimize postoperative infection risk.

The Evaluation of Intrarenal Pressure Using a Novel Single-Use Flexible Ureteroscope with Live Intrarenal Pressure Monitoring-An Experimental Study in Porcine Models.

(1) Background: This study aims to evaluate how different irrigation settings and the use of ureteral access sheaths (UASs) of varying sizes impact intrarenal pressure (IRP) during flexible ureteroscopy (fURS) procedures in pigs. (2) Methods: This study utilized three anesthetized female pigs. A novel flexible ureteroscope with the ability to continuously record live intrarenal pressure was used to perform ureteroscopy in different settings. Ureteroscopy was performed without UAS and with the use of 11/13 and 12/14 UAS at the ureteropelvic junction. Two different irrigation methods were employed for each parameter: one using gravity flow and the other using manual pumping with a commercial pump. IRP was also recorded with the presence of a laser fiber or lithotripsy basket. (3) Results: The recorded mean IRP during flexible URS without UAS was 28.25 (±11.2) under gravity irrigation; 35.46 (±10.08) under manual pumping; 22.5 (±3.05) and 30.75 (±5.79) with a laser fiber under gravity irrigation and manual pumping, respectively; and 16.45 (±1.27) and 17.27 (±3.69) with a lithotripsy basket under gravity irrigation and manual pumping, respectively. With an 11/13 UAS, the mean IRP was 15.41 (±8.57) and 19.33 (±4.26) under gravity and manual pumping irrigation, respectively; 14.56 (±2.50) and 18.64 (±5.13) with a laser in each irrigation setting, respectively; and 13.10 (±3.39) and 13.86 (±4.63) with a lithotripsy basket, respectively. With a 12/14 UAS, the mean IRP was 7.64 (±3.08) and 9.25 (±1.42) under gravity and manual pumping irrigation, respectively; 9.50 (±6.04) and 10.28 (3.46), respectively, in each setting when the laser fiber was used; and 5.32 (±1.57) and 6.26 (±1.79), respectively, when the lithotripsy basket was inserted. (4) Conclusion: Novel flexible ureteroscopes with integrated pressure sensors are both a feasible and reliable tool during fURS, giving the surgeon the ability to live-track the IRP. The results of the IRP measurements with and without UAS are in accordance with the current literature and exhibit a consistent pattern with previous studies.

First Worldwide Multicentric Series of Mini-Ecirs in Children: Outcomes from two Tertiary Endourology Centers.

Introduction: Endoscopic combined intrarenal surgery (ECIRS) is a combination of both retrograde and antegrade approaches for treatment of large or complex renal stones in one procedure, that are currently being treated with multiple tracts or sessions of percutaneous nephrolithotomy, increasing the complications. The aim of our study is to describe the clinical outcomes of Mini-ECIRS in a pediatric population. Material and Methods: A retrospective study was performed in pediatric patients with lithiasis disease treated with mini-ECIRS between 2006 and 2023 in 2 referral centers in Europe. Demographic data, clinical data, stone size and location, laser settings, intraoperative variables, stone-free rate (SFR) and complications were collected. Pearson's chi-squared test, Fisheŕs test and logistic regression, were performed. Results: A total of 32 mini-ECIRS were included. The mean age was 9,8 years, 56.3% girls. The mean size and volume of the stone were 21.5mm and 3298, 2mm3, 53.1% were multiple. Ureteral access sheath was used in 93.8% of the surgeries and only 37.5% had preoperative JJ stent. 53.1% of percutaneous access were with 14 Fr sheath. High power laser was the most frequent energy source for lithotripsy, including thulium fiber laser. The mean operative time was 166,6 minutes. There was one perforation of the collecting system that was managed with JJ stent and in the postoperative period 81.2% of the patients had no complications. Three presented fever, 1 developed urinary sepsis, and 1 required reintervention. The SFR was 75% and the size, volume, hardness, and complexity of the lithiasis, as well as the non-use of lithotripsy in the retrograde approach were statistically significant in decreasing the success of the surgery. Conclusions: ECIRS is a feasible, safe, and efficient procedure in children with complex renal lithiasis, decreasing the number of procedures needed for stone free. Multicenter studies are required to validate these results on a population scale.

Foley catheter after ureteroscopy and JJ stent placement: a randomised prospective European Association of Urology Section of Urolithiasis-Young Academic Urologists (EULIS-YAU) endourology study.

To evaluate the effects of inserting a Foley catheter after ureteroscopy (URS) and JJ stent placement on pain scores, voiding patterns, biochemical parameters and postoperative complications. A randomised clinical trial (1:1) with adult patients following unilateral URS + JJ stent placement was planned. In Group A, no Foley catheter was placed, in Group B, a Foley catheter was placed following URS + JJ stent placement. The primary objective was to evaluate effect of placing a Foley catheter on International Prostate Symptom Score (IPSS), Ureteric Stent Symptom Questionnaire (USSQ) score and postoperative biochemical parameters. The secondary objective was to evaluate postoperative complications. A total of 112 patients were included (56/group). A ureteric access sheath was used in each patient. Patients had similar demographic and surgical parameters. The pre- and postoperative biochemical analyses including white blood cell count, C-reactive protein, procalcitonin and creatinine levels were similar between the two groups. The IPSS were similar between the two groups. All the subdomains of the USSQ were similar between two groups except Total Body Pain score, which was lower in Group B. The visual analogue scale scores were similar. Complications were all Clavien-Dindo Grade I and II, and the complication rate was 5.4% and 8.9% in Group A and B, respectively. Placing a Foley catheter following URS + JJ stent placement did not show significant effects on postoperative biochemical parameters and voiding symptoms. However, a Foley catheter lowered the Total Body Pain score on the USSQ without having significant effects on VAS scores. The practice of placing a Foley catheter following URS and JJ stent placement should be based on surgeon's preference keeping in mind the potential positive effect on pain scores.

Application of 11/13Fr suctioning ureteral access sheath and 8.55Fr single-use digital flexible ureteroscope in one-stage flexible ureteroscopic lithotripsy: an initial experience of 900 cases.

To report our initial experience of one-stage flexible ureteroscopic lithotripsy(FURL) with 11/13Fr suctioning ureteral access sheath(UAS) and 8.55Fr single-use digital flexible ureteroscope(SDFU) in upper ureteral or renal calculi. We retrospectively collected the clinical data of 900 adult patients with upper ureteral or renal calculi treated by FURL with 11/13Fr suctioning UAS and 8.55Fr SDFU from January 2022 to April 2024. Demographics, peri- and postoperative outcomes were assessed. In all, 40 of 940 cases(4.26%) failed to introduce UAS and required second-stage FURL because of ureterostenosis and were excluded. Mean stones size of the remaining 900 eligible cases was 1.68 ± 0.58cm in greatest diameter. There were 228 cases of upper ureteral stone, 456 cases of renal stone and 216 cases of concomitant ureteral and renal calculi. The mean operation time was 52.20 ± 20.21min and the postoperative hospital stay was 2.87 ± 1.37 days. The stone-free rate of 1 month postoperatively was 89.56% and only 2.44% of patients with residue underwent additional reoperation. The rate of postoperative fever, postoperative pain needing analgesic and slight ureteral mucosal injury were 5.11%, 8.22% and 7.78%, respectively. None of patient suffered from severe complications, such as sepsis or ureteral perforation. It's practical and suitable for the vast majority of adult patients to undergo FURL in single session with 11/13Fr suctioning UAS without preoperative stenting. FURL with 11/13Fr suctioning UAS and 8.55Fr SDFU is feasible, reliable, safe, and efficient in the management of renal stone and upper ureteral stone.

Comparative efficacy and safety of intelligent pressure-controlled versus flexible vacuum-assisted ureteral access sheath for 2-4 cm renal calculi.

Retrograde intrarenal surgery (RIRS) is being increasingly used to treat 2-4 cm renal stones, which can be attributed to advances in flexible ureteroscopes and ureteral access sheaths (UASs). Despite the improvement and application of flexible vacuum-assisted (FV) and intelligent pressure-controlled (IPC) UASs, no studies have compared their therapeutic efficacy and safety. Therefore, this study aimed to compare the therapeutic efficacy and safety of IPC-UAS and FV-UAS in RIRS 2-4 cm renal stones. We included 96 and 103 patients who underwent IPC-UAS and FV-UAS RIRS, respectively, for 2-4 cm renal stones. Stone-free rate (SFR), operative time, and complications were compared between the two groups. The immediate SFR was 69.8% and 82.5% in the IPC-UAS and FV-UAS groups, respectively (P<0.05). There were no significant between-group differences in the 1-month SFR (84.4% vs. 84.5%, P>0.05). The IPC-UAS group had a shorter hospital stay (5.2±2.4 vs. 6.2±3.2 days, P=0.018) and lower cost (CNY13014.7±3240.7 vs. CNY14022.5±2301.6, P=0.012) than the FV-UAS group. There were no significant between-group differences in operative time or complications. Regarding RIRS for 2-4 cm renal stones, the IPC-UAS group can achieve a 1-month SFR similar to that of the FV-UAS group, with shorter hospitalization and lower cost. Additionally, the IPC-UAS is a promising device for efficient and safe RIRS, considering its intelligent pressure regulation. Our findings could inform optimal UAS selection for managing large renal calculi and demonstrate the utility of the novel IPC-UAS in improving outcomes of RIRS for 2-4 cm renal stones.

Pharmacological Modulation of Intrarenal Pressure in a Porcine Model Using a Novel Isoprenaline-Eluting Guidewire.

Introduction: Several complications of retrograde intrarenal surgery have been attributed to inadvertent increases in intrarenal pressure. We recently described the development of an innovative isoprenaline-eluting guidewire (IsoWire). The objective of this study was to investigate the impact of this IsoWire on the intrarenal pressure and evaluate its safety. Materials and Methods: This study was performed in 17 renal units using a porcine model. As controls, the intrarenal pressure, heart rate, and mean arterial pressure were measured for a duration of six minutes with a standard guidewire placed in the renal pelvis. For the experiment, the conventional guidewire was substituted with the IsoWire and the same parameters were measured. Blood samples were taken at one-minute intervals to measure plasma isoprenaline levels. This procedure was repeated on the opposite side. Results: The mean intrarenal pressure reduction was 29% (95% CI: 13%-53%). The mean isoprenaline effect time was 174 seconds. No changes in heart rate (p = .908) or mean arterial pressure (p = .749) were recorded after IsoWire insertion. Plasma isoprenaline levels were below the quantitation threshold. Isoprenaline concentrations in the plasma were below the quantification threshold. Ureteroscopy revealed no ureteral lesions. Conclusions: The IsoWire demonstrated a safe and effective reduction of intrarenal pressure. Additional research is necessary to determine whether ureteral smooth muscle relaxation generated by isoprenaline facilitates easier insertion of a ureteral access sheath, decreases the incidence of ureteral access sheath related ureteral lesions, or even encourage the practice of sheathless retrograde intrarenal surgery.

Impact of Pre-Operative Ureteroscopy on Bladder Recurrence Following Nephroureterectomy for UTUC.

(1) Introduction: Diagnostic ureteroscopy (URS) is an important component in the workup of upper tract urothelial carcinoma (UTUC). Whether URS was associated with increased recurrence in the bladder was not fully concluded. The current study aimed to evaluate the implication of URS on the incidences of intravesical recurrence following radical nephroureterectomy (RNU) in non-metastatic UTUC patients without prior history of bladder cancer via multi-institutional data. (2) Patients and Methods: Data were obtained from the Clinical Research Office of the Endourology Society Urothelial Carcinomas of the Upper Tract (CROES-UTUC) registry, a prospective, multicentre database. Patients with non-metastatic UTUC treated with RNU were divided into two groups: those undergoing upfront RNU and those having diagnostic URS prior to RNU. Intravesical recurrence-free survival (IVRS) was the primary endpoint, evaluated through Kaplan-Meier analysis and multivariate Cox regression. Cases with adequate follow-up data were included. (3) Results: The analysis included 269 patients. Of these, 137 (50.9%) received upfront RNU and 132 (49.1%) received pre-RNU URS. The URS group exhibited an inferior 24-month IVRS compared to the upfront RNU group (HR = 1.705, 95% CI = 1.082-2.688; p = 0.020). Multivariate analysis confirmed URS as the only significant predictor of IVR (p = 0.019). Ureteric access sheath usage, flexible ureteroscopy, ureteric biopsy, retrograde contrast studies, and the duration of URS did not significantly affect IVRS. (4) Conclusions: Diagnostic URS prior to RNU was found to be associated with an increased risk of IVR in patients with UTUC. The risk was not significantly influenced by auxiliary procedures during URS. Physicians were advised to meticulously evaluate the necessity of diagnostic URS.

Intrarenal pressure and flow rate profile using LithoVue™ elite: impact of different irrigation systems and working channel instruments.

To report real-time IRP and FR while performing flexible ureteroscopy in porcine kidney model utilizing LithoVue™ Elite (Boston Scientific®) with different irrigation systems, including automated pumps. Using an ex-vivo model of porcine kidney, IRPs were measured with LithoVue Elite. Ureteroscopic settings (US) were tested with all permutations of irrigation methods (IM), working channel occupant (WCO), and ureteral access sheaths (UAS). IMs included: Single Action Pumping System (SAPS™, Boston Scientific), Thermedx FluidSmart™ (Stryker®), and ENDOMAT™ (Karl Storz®). Pumps were tested at 50, 100, and 150mmHg. WCOs included a 1.9Fr zero-tip basket, 200µm, and 365µm laser fibers. UASs utilized 11/13Fr and 12/14Fr 36cm. 84 different US were tested (252 experiments). ENDOMAT had higher IRP but the same FR as Thermedx at the same US for 50 and 100mmHg (p < 0.01). SAPS had higher IRP and FR than pumps in all US studies (p < 0.01). There was positive correlation between pressure set by the pump and both IRP and FR (rho > 0.9). As the diameter of the WCO increased, lower IRP and FR were observed with the pumps (p < 0.01). With SAPS, IRP was similar regardless of WCO, but FR was decreased with the increased diameter of WCO (p = 0.81 and p < 0.01, respectively). There was significantly higher IRP when using 11/13Fr UAS than 12/14Fr (p < 0.01). IRP was higher with SAPS than automated pumps. ENDOMAT showed higher IRP than Thermedx when under 150mmHg. IRP and FR increase with higher pump pressure and decrease with larger diameter WCO. Likewise, a larger UAS significantly reduced IRP.

Suction use in ureterorenoscopy: A systematic review and meta‐analysis of comparative studies

AbstractObjectivesUreterorenoscopy is seeing a bloom of technological advances, one of which is incorporating suction. The objective of this study is to systematically review existing literature regarding suction use in rigid and flexible ureterorenoscopy and perform meta‐analysis of studies comparing suction versus no suction ureteroscopy or mini percutaneous nephrolithotomy (PCNL).MethodsA literature search was performed (November 2023) in MEDLINE, Embase and Cochrane CENTRAL. Study protocol was registered at PROSPERO (CRD42023482360). Comparative studies (observational and randomized) were eligible for inclusion if they compared suction versus no suction group and reported at least one primary outcome of interest (stone‐free or complication rate).ResultsSixteen studies (5 randomized and 11 observational), analysing 1086 and 1109 patients in standard and suction groups, respectively, were included. Final stone‐free rates (SFRs), overall and infectious complications and length of hospital stay exhibited significant improvement when suction was used. When mini‐PCNL was compared with flexible ureterorenoscopy with suction, no differences were found in terms of stone‐free and infectious complications rates.ConclusionsUreterorenoscopy is a commonly performed endoscopic procedure for urolithiasis treatment, the success of which is defined by SFRs and complication rates. Application of suction via ureteral access sheaths, ureteral catheters or scopes may provide improved SFRs, reduced overall and infectious complication rates, along with a reduction in length of hospital stay. Further randomized studies are needed to validate these findings and standardize indications and protocols.

Tip bendable suction ureteral access sheath versus traditional sheath in retrograde intrarenal stone surgery: an international multicentre, randomized, parallel group, superiority study

Retrograde intrarenal surgery (RIRS) is the main treatments for upper urinary tract stones. The Ureteral Access Sheath (UAS) serves as a supplementary tool, facilitating direct kidney access during RIRS. High quality of evidence comparing tip bendable suction ureteral access sheath (S-UAS) with traditional UAS in RIRS for the treatment of renal and ureteral stones is lacking. The purpose of the study is to compare the efficacy and safety of S-UAS with traditional UAS in RIRS for the treatment of renal or ureteral stones ≤30mm. An international, multicenter, and superiority randomized controlled trial included 320 intention-to-treat patients across 8 medical centers in China, the Philippines, Malaysia and Turkey from August 2023 to February 2024. The inclusion criteria were patients ≥18 years old with renal or ureteral stones ≤30mm. RIRS was performed using either S-UAS or traditional UAS. The primary outcome was the immediately stone-free rate (SFR). Secondary outcomes included SFR 3 months after operation, operating time, hospital stay, auxiliary procedures, complications (using the Clavien-Dindo grading system), and improvement in the Quality of Life (QoL) score. Differences between proportions [risk difference (RD)]/means [mean difference (MD)] and 95% confidence intervals (CI) were presented. This study is registered at ClinicalTrials.gov: NCT05952635. The S-UAS group demonstrated a significantly higher immediately SFR (81.3% versus 49.4%; RD 31.9%; 95% CI 22.5%-41.7%; p=0.004) compared to the traditional UAS group, as determined by the one-side superiority test. Additionally, the S-UAS group exhibited a higher SFR at 3 months post-operation (87.5% versus 70.0%; RD 17.5%; 95% CI 8.7%-26.3%; p<0.001), lower postoperative fever rate (RD-11.9%; 95% CI-18.7% to-4.9%; p<0.001), reduced use of stone baskets (RD-70.6%; 95% CI-77.8% to-63.5%; p<0.001), and better QoL improvement (MD 7.25; 95% CI 2.21-12.29; p=0.005). No statistically significant differences were observed in operation time, hospital stay, or the need for second-stage RIRS. In RIRS for upper urinary tract stones ≤30mm, S-UAS exhibited superior performance compared to traditional UAS, demonstrating higher SFR, reduced postoperative fever rate, and improved QoL outcomes. S-UAS emerges as a prudent and advantageous alternative to traditional UAS for RIRS. National Natural Science Foundation of China and Guangdong Province, and Zhejiang Medicine and Health Program.