Effect of nephrostomy sheath size on renal pelvic pressure during endoscopic combined intrarenal surgery: artificial kidney model study.

BACKGROUND: This study aimed to evaluate the intrarenal pelvic pressure in endoscopic combined intrarenal surgery using an artificial kidney model. METHODS: An artificial kidney model was created using the Urovac evacuator™. Four sizes of nephrostomy sheaths (MIP-L: 25/26 Fr, MIP-M: 16.5/17.5 Fr, MIP-S: 11/12 Fr, MIP-XS: 8.5/9.5 Fr) and two sizes of ureteral access sheaths (12/14 Fr and 10/12 Fr) were installed into the model. For each combination of nephrostomy and ureteral access sheath, renal pelvic pressure was measured with and without insertion of the retrograde flexible ureteroscope. Irrigation from the nephroscope was adjusted to 40-160 mmHg using an automatic irrigation device, and the irrigation of the ureteroscope was by spontaneous dripping at 80 cmH2O. Conditions were measured six times, and the renal pelvic pressure was compared in different conditions. RESULTS: Without ureteroscope insertion through the ureteral access sheath, the renal pelvic pressure never exceeded 30 mmHg. Meanwhile, when the ureteroscope was inserted, the renal pelvic pressure increased as the nephrostomy sheath and ureteral access sheath became narrower and as the irrigation pressure increased. Intrarenal pelvic pressure exceeded 30 mmHg when the irrigation pressure was increased in 12/14 Fr ureteral access sheath when MIP-XS was used, and in 10/12 Fr ureteral access sheath when MIP-XS and MIP-S were used. CONCLUSIONS: The use of a thin nephrostomy sheath in endoscopic combined intrarenal surgery can lead to increased intrarenal pelvic pressure. Although our results are from an artificial kidney model, special care is suggested to be required when using a retrograde flexible ureteroscope simultaneously in treatment of patients.

Play it safe: renal function after bilateral flexible ureteroscopy for kidney stones.

PURPOSE: We searched for perioperative renal function deterioration risk factors in patients that underwent bilateral flexible ureteroscopy (fURS) for kidney stones. METHODS: From August 2016 to February 2020, symptomatic patients > 18 years old with bilateral kidney stones up to 20 mm in each side were prospectively studied. Serum creatinine samples were collected on admission to surgery, immediate postoperative (IPO), on POD 3, 10, and 30. Estimated glomerular filtration rate (eGFR) was calculated using Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI) without a race coefficient. RESULTS: Thirty patients underwent bilateral fURS. Comparing to preoperative eGFR, median IPO and POD3 eGFR (p < 0.001) were significantly lower, and POD10 (p = 0.092) and POD30 (p = 0.648) were similar to preoperative eGFR. During follow-up, 22/30 (73.3%), 14/30 (46.7%), and 7/30 (23.3%) of the patients presented a decrease > 10% eGFR, > 20% eGFR, and > 30% eGFR, respectively. Multivariate analysis demonstrated that lower preoperative eGFR is a risk factor for eGFR < 60 mL/min/1.73 m2, p = 0.019 [1.021-1.263; 1.136]; ASA > 1 is a risk factor for decrease of eGFR > 10%, p = 0.028 [1.25-51.13; 8.00]; longer operative time is a risk factor for decrease of eGFR > 20%, p = 0.042 [1.00-1.05; 1.028]; and operative time ≥ 120 min is a risk factor for decrease of eGFR > 30%, p = 0.026 [0.016-0.773; 0.113]. CONCLUSIONS: Renal function suffers a reversible decrease after bilateral fURS. Our study suggests that adequate selection of patients and maintaining operative time < 120 min are relevant factors in preventing acute renal function deterioration following bilateral fURS.

Fluid dynamics within renal cavities during endoscopic stone surgery: does the position of the flexible ureteroscope and ureteral access sheath affect the outflow rate?

PURPOSE: To evaluate the impact of ureteroscope position within renal cavities as well as different locations of the tip of the ureteral access sheath (UAS) on fluid dynamics during retrograde intrarenal surgery (RIRS). MATERIALS AND METHODS: A prospective observational clinical study was performed. Measurements with a flexible ureteroscope placed in the upper, middle and lower calyces were obtained with the tip of the UAS placed either 2 cm below the pyelo-ureteric junction (PUJ), or at the level of the iliac crest. RESULTS: 74 patients were included. The outflow rates from the middle and upper calyxes were statistically significantly higher compared to the lower calyx, both with the UAS close to the pyelo-ureteric junction and at the iliac crest. When the UAS was withdrawn and positioned at the level of the iliac crest, a significant decrease in outflow rates from the upper (40.1 ± 4.3 ml/min vs 35.8 ± 4.1 ml/min) and middle calyces (40.6 ± 4.0 ml/min vs 36.8 ± 4.6 ml/min) and an increase in the outflow from the lower calyx (28.5 ± 3.3 ml/min vs 33.7 ± 5.7 ml/min) were noted. CONCLUSIONS: Our study showed that higher fluid outflow rates are observed from upper and middle calyces compared to lower calyx. This was true when the UAS was positioned 2 cm below the PUJ and at the iliac crest. Significant worsening of fluid dynamics from upper and middle calyces was observed when the UAS was placed distally at the level of the iliac crest. While the difference was statistically significant, the absolute change was not significant. In contrast, for lower calyces, a statistically significant improvement was documented.

Efficacy of flexible ureterorenoscopy with holmium laser in the management of calyceal diverticular calculi.

The purpose of this study was to evaluate the efficacy and safety of flexible ureteroscopy with holmium laser lithotripsy in the management of calyceal diverticular calculi. In this study, we retrospectively analyzed the clinical data of 27 patients with calyceal diverticular calculi admitted to the Department of Urology of the Zigong First People's Hospital from May 2018 to May 2021. Intraoperatively, the diverticular neck was found in all 27 patients, but flexible ureterorenoscopy lithotripsy was not performed in 2 cases because of the slender diverticular neck, and the success rate of the operation was 92.6%. Of the 25 patients with successful lithotripsy, the mean operative time was 76.9 ± 35.5 (43-200) min. There were no serious intraoperative complications such as ureteral perforation, mucosal avulsion, or hemorrhage. Postoperative minor complications (Clavien classification I-II) occurred in 4 (16%) patients. The mean hospital stay was 4.4 ± 1.7 (3-12) days. The stone-free rate was 80% at the 1-month postoperative follow-up. After the second-stage treatment, the stone-free rate was 88%. In 22 cases with complete stone clearance, no stone recurrence was observed at 5.3 ± 2.6 (3-12) months follow-up. This retrospective study demonstrated that flexible ureterorenoscopy with holmium laser is a safe and effective choice for the treatment of calyceal diverticular calculi, because it utilizes the natural lumen of the human body and has the advantages of less trauma, fewer complications, and a higher stone-free rate.

Initial Experience and Clinical Assessment of the Karl Storz FLEX-XC1 Single-Use Flexible Ureteroscope.

INTRODUCTION: The Karl Storz FLEX-XC1 is a novel single-use flexible ureteroscope that uses the same videographics platform as its reusable digital counterpart. We evaluated the technical performance of the FLEX-XC1 in its initial clinical use. METHODS: We reviewed a series of consecutive ureteroscopy procedures performed by 2 endourologists using the FLEX-XC1 for indications for which we typically use a single-use device: total stone burden > 15 mm or > 10 mm in the lower pole, anticipated case duration > 60 minutes, bilateral procedure, or upper tract urothelial cancer procedures. We assessed device tip deflection, intraoperative mechanical failure, and clinical outcomes for each case. Surgeons rated visual clarity, image quality, and maneuverability on a 1 to 5 Likert scale. RESULTS: Of 29 procedures using FLEX-XC1, 27 (93%) were successfully completed. Preoperative upward deflection was < 270° in 6 (21%) cases, and downward deflection was < 270° in 9 (31%) cases. Three types of intraoperative malfunctions occurred: rotational twisting of deflectable tip (4 cases, 13%), device not advancing through distal ureter (1 case, 3%), and working channel not accommodating a 365-µm laser (1 case, 3%). Visual clarity, image quality, and maneuverability were rated as 5 "very good" or 4 "good" in 100%, 100%, and 97% of cases, respectively. No device-specific or general 30-day complications were observed. CONCLUSIONS: The FLEX-XC1 showed comparable image quality and maneuverability to reusable digital devices. We observed incomplete deflection in up to 31% of cases and mechanical failure in 2 cases. The FLEX-XC1 may be advantageous in prolonged cases where maintaining visual clarity is paramount.

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.

The optimal ratio of endoscope-sheath diameter with negative-pressure ureteral access sheath: an in vitro research.

PURPOSE: To maintain safe intrarenal pelvic pressure (IPP), the combination of flexible ureteroscope (fURS) and traditional ureteral access sheath (T-UAS) should maintain a basic rule that is the ratio of endoscope-sheath diameter (RESD) ≤ 0.75. However, the negative-pressure ureteral access sheath (NP-UAS) may break the rule of negative pressure suction. This study aimed to examine the effect of NP-UAS on IPP and flow rate (FR) with varying RESD. METHODS: In a 3D-printed renal model, flexible ureteroscopy lithotripsy (fURL) was replicated. Six sizes of fURS paired with 12Fr T-UAS and NP-UAS resulted in six distinct RESDs of 0.63, 0.78, 0.87, 0.89, 0.90, and 0.91. While the irrigation pressure (IRP) was set between 100 and 800 cmH2O and the sucking pressure (SP) was set between 0 and 800 cmH2O, the IPP and FR were measured in each RESD. RESULTS: NP-UASs can reduce the IPP and increase the FR at the same RESD compared to T-UASs. The IPP decreased with increasing SP with NP-UAS. When RESD ≤ 0.78, T-UAS and NP-UAS can maintain IPP < 40 cmH2O in most circumstances. When RESD = 0.87, it is challenging for T-UAS to sustain IPP < 40 cmH2O; however, NP-UAS can do so. When RESD ≥ 0.89, it is difficult to maintain an IPP < 40 cmH2O even with NP-UAS. CONCLUSION: NP-UAS can decrease IPP and increase FR compared with T-UAS. To maintain a safe IPP, it is recommended that RESD < 0.85 when utilizing NP-UAS.

Factors affecting the intraoperative calculi excretion during flexible ureteroscopy lithotripsy: an in vitro analysis.

OBJECTIVE: To explore the parameters influencing intraoperative calculi excretion (ICE) during flexible ureteroscopy lithotripsy (fURL) using in vitro simulation experiments. METHODS: 3D-printed human kidney models were used to simulate the elimination of gravel during fURL. The factors influencing the ICE during fURL were analyzed by comparing the effects of different degrees of hydronephrosis (mild, moderate, and severe), surgical positions (supine and lateral position), ratios of endoscope-sheath diameter (RESD) (0.625, 0.725, and 0.825), gravel sizes (0.50-1.00 mm, 0.25-0.50 mm, and 0.10-0.25 mm), and ureteral access sheaths (UASs) (traditional UAS and negative-pressure UAS) on ICE. RESULTS: The impacts of various UAS, RESD, degree of hydronephrosis, surgical positions, and gravel sizes on ICE were all significant (p < 0.05). We found no evidence of multicollinearity for all the independent variables, and the linear regression equation fitted as ICE ( g / min ) = 0.102 + 0.083 ∗ UAS grade - 0.050 ∗ RESD grade - 0.048 ∗ hydronephrosis grade + 0.065 ∗ position grade - 0.027 ∗ gravel size grade (R2 = 0.569). CONCLUSION: Employing negative-pressure UAS, smaller RESD, milder hydronephrosis, lateral position, and smaller gravel size contribute to improved ICE during fURL. Among them, the adoption of negative-pressure UAS had the most substantial effects.

Comparing outcomes of single-use vs reusable ureteroscopes: a systematic review and meta analysis.

Flexible ureterolithotripsy is a frequent urological procedure, usually used to remove stones from the kidney and upper ureter. Reusable uretero-scopes were the standard tool for that procedure, but recent concerns related to sterility and maintenance and repair costs created the opportunity to develop new technologies. In 2016, the first single-use digital flexible ureteroscope was introduced. Since then, other single-use ureteroscopes were developed, and studies compared them with the reusable ureteroscopes with conflicting results. The purpose of this study is to describe the literature that compares the performance of single-use and reusable flexible ureteroscopes in retrograde intrarenal surgery for urinary stones. A Systematic Review was performed in October 2022 in accordance with the Cochrane Handbook and the Preferred Reporting Items for Systematic Reviews and MetaAnalyses (PRISMA). A search in MEDLINE, EMBASE, Web of Science, Google Scholar and LILACS retrieved 10,039 articles. After screening, 12 articles were selected for the Meta-Analysis. No differences were found in stone-free rate (OR 1.31, CI 95% [0.88, 1.97]), operative time (MD 0.12, CI 95% [-5.52, 5.76]), incidence of post-operative fever (OR 0.64, CI 95% [0.22, 1.89]), or incidence of post-operative urinary tract infection (OR 0.63 CI 95% [0.30, 1.32]). No differences were observed in the studied variables. Hence, the device choice should rely on the availability, cost analysis and surgeons' preference.

Semirigid ureteroscopy and tamsulosin therapy as dilatation methods before flexible ureteroscopy: evaluation and benefits.

OBJECTIVE: To evaluate the effect of semirigid ureteroscopy and tamsulosin therapy as dilatation methods before flexible ureteroscopy advancement to the renal collecting system. PATIENTS AND METHODS: This prospective study included patients with renal stones less than 2 cm who underwent retrograde flexible ureteroscopy and laser lithotripsy. The patients were randomized into two groups: group A patients were given a placebo for 1 week before flexible ureteroscopy, and group B patients were administered 0.4 mg of tamsulosin once daily for 1 week before surgery and underwent active dilatation using semirigid ureteroscopy before flexible ureteroscopy. The ability of the flexible ureteroscope to reach the collecting system in both groups during the same operative session was assessed. Operative outcomes and complications were collected and analyzed in both groups. RESULTS: A total of 170 patients were included in our study, with each group comprising 85 patients. In group B, the flexible ureteroscope successfully accessed the kidney in 61 patients, while in group A, the flexible ureteroscope was successful only in 28 cases (71.4% versus 32.9%). In group A, 33 (38.8%) patients had lower urinary tract symptoms compared to 17 (20.2%) patients in group B (P = 0.013). CONCLUSION: Using tamsulosin therapy and semirigid ureteroscopy as dilatation methods before flexible ureteroscopy increased the success of primary flexible ureteroscopy advancement to renal collecting system.

Environmental Impact of Flexible Cystoscopy: A Comparative Analysis Between Carbon Footprint of Isiris® Single-Use Cystoscope and Reusable Flexible Cystoscope and a Systematic Review of Literature.

Introduction: There is an absence of data on the environmental impact of single-use flexible cystoscopes. We wanted to review the existing literature about carbon footprint of flexible cystoscopy and analyze the environmental impact of the Isiris® (Coloplast©) single-use flexible cystoscope compared to reusable flexible cystoscopes. Methods: First, a systematic review on single-use and reusable cystoscope carbon footprint was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Second, carbon footprints of Isiris single-use flexible cystoscope and reusable cystoscope were analyzed and compared. Life cycle of the single-use flexible cystoscope was divided in three steps: manufacturing, sterilization, and disposal. For the reusable cystoscope, several steps were considered to estimate the carbon footprint over the life cycle: manufacturing, washing/sterilization, repackaging, repair, and disposal. For each step, the carbon footprint values were collected and adapted from previous comparable published data on flexible ureteroscope. Results: The systematic literature review evidenced total carbon emissions within a range of 2.06 to 2.41 kg carbon dioxide (CO2) per each use of single-use flexible cystoscope compared to a wide range of 0.53 to 4.23 kg CO2 per each case of reusable flexible cystoscope. The carbon footprint comparative analysis between Isiris single-use flexible cystoscope and reusable cystoscope concluded in favor of the single-use cystoscope. Based on our calculation, the total carbon emissions for a reusable flexible cystoscope could be refined to an estimated range of 2.40 to 3.99 kg CO2 per case, depending on the endoscopic activity of the unit, and to 1.76 kg CO2 per case for Isiris single-use cystoscope. Conclusion: The results and our systematic literature review demonstrated disparate results depending on the calculation method used for carbon footprint analysis. However, the results tend rather toward a lower environmental impact of single-use devices. In comparison to a reusable flexible cystoscope, Isiris compared favorably in terms of carbon footprint.

In vitro comparison of simulated intrapelvic pressure in an artificial kidney model during retrograde intrarenal surgery among various single-use ureteroscopes.

OBJECTIVES: This study compares intrapelvic pressure (IPP) during retrograde intrarenal surgery with various single-use flexible ureteroscopes (f-URS) in an artificial kidney model. METHODS: We created an artificial kidney model with a pressure sensor using a bladder evacuation device. The model was completely closed and the only backflow was on the side of the ureteroscope inside the ureteral access sheath (UAS). We tested five single-use f-URSs (LithoVue, Wiscope, PU3022A, PU3033A, and AXIS) with six different types of UAS (9.5/11.5-14/16 Fr). Using the automatic irrigation system, 30 s of irrigation was performed at various pressures (40-180 mmHg) and steady-state IPP was recorded. IPP was compared between the five single-use f-URSs. IPP cutoff value was determined at 30 mmHg. The diameter of the endoscope tip and the curved and shaft parts were also measured and recorded. RESULTS: The diameters of all parts were significantly different between single-use f-URSs. The maximum IPP tended to be higher in ureteroscopes with larger diameters of the proximal parts (curved part/shaft part). In LithoVue and Uscope PU3022A f-URSs, the maximum IPP did not exceed 30 mmHg when UAS ≥12/14 Fr was used. In AXIS and Wiscope f-URSs, it did not exceed the cutoff value when the UAS ≥11/13 Fr was used. In Uscope PU3033A f-URS, it did not exceed 30 mmHg when the UAS ≥10/12 Fr was used. CONCLUSIONS: Maximum IPP tended to be higher in f-URSs with larger diameters of the proximal part and the appropriate size of the UAS differed between various single-use f-URSs.

Clinical Application of Ureteroscope-Assisted Laparoscopic Surgery for Prostatic Utricle in Children.

Purpose: To investigate the use of ureteroscope-assisted laparoscopic surgery (UALS) in treating symptomatic prostatic utricle (PU) in children. Materials and Methods: Data on surgically treated cases of PU at the Department of Urology in Hunan Children's Hospital between September 2014 and September 2022 were retrospectively collected and analyzed. The diagnosis was confirmed by cystourethroscopy followed by ureteroscopy, and PU was excised by ureteroscope-assisted laparoscopy. Results: A total of 21 patients with PU were enrolled in this study. The median age of the patients at surgery was 8.1 (4.6-11.5) years. Karyotyping was available for 15 children: 13 (86.7%) were 46XY, 1 (6.7%) was 45X/46XY, and 1 (6.7%) was 45X/46XY/47XYY. The median length of the PU was 5.0 (4.1-7.1) cm. Nineteen patients underwent only ureteroscope-assisted laparoscopic excision, whereas 2 also had a perineal incision. All excisions were successfully performed. The median intraoperative blood loss was 25.0 (20.0-37.5) mL. The median hospital stay and follow-up durations were 18.0 (14.5-25.0) days and 24.0 (13.5-49.0) months, respectively. The patients reported no postoperative clinical symptoms. Conclusion: UALS allows for accurate patient positioning and thorough exposure of the anatomical structures, and it is a safe, effective, and minimally invasive treatment for PU in children.

The Effect of Ureteral Access Sheath Use/Caliber Change on Outcomes of Retrograde Intrarenal Surgery, Short-Term Kidney Functions, Radiation Exposure, Ureteroscope Lifetime, and Factors Predicting Insertion Failure: A RIRSearch Study.

Background: The aim of this study was (1) to explore effect of ureteral access sheath (UAS) use on primary retrograde intrarenal surgery (RIRS) outcomes, short-term kidney functions, radiation exposure, and ureteroscope lifetime (URS-LT) and (2) to reveal factors that predict UAS insertion failure. Materials and Methods: Patients (n = 1318) who underwent RIRS without UAS (Group 1), those who had operation with a <11-13 Fr (Group 2), and those with a ≥11-13 Fr UAS were matched (1:1:2) and compared. Stone-free rate (SFR), intra- and postoperative complications, acute kidney injury (AKI), fluoroscopy time, URS-LT, and UAS insertion failure were the outcomes. Results: SFR, which was highest in Group 3 (75%, 71% and 87.3%, respectively; P = .001), was significantly associated with use of ≥11-13 Fr (odds ratio [OR]: 4.2, P < .001), but was not with use of <11-13 Fr UAS (OR: 1.3, P = .3). Group 3 had less need for auxiliary procedure (15%, 16%, and 7.4%, respectively; P = .03). Five percent of patients had a risk of AKI, but only 0.3% developed AKI. Although UAS use was protective against creatinine increase (OR: 0.65, P = .02), increased risk of AKI was only associated with female gender (OR: 5.5, P < .001). Fluroscopy times were 5, 15, and 87 sn, respectively (P < .001). Short URS-LT was strongly associated with high frequency of lower calix stones (r = -0.94, P = .005), but URS-LT was not correlated with sheathless case rate (r = 0.59, P = .22). UAS insertion success in first attempt was more likely in younger (OR: 0.99, P = .03), hydronephrotic (OR: 3.4, P < .001), and female cases (OR: 1.5, P = .008). But absolute UAS insertion failure was associated with female gender (OR: 2.7, P = .017). Conclusions: Not any UAS use but a higher caliber UAS use may improve SFR and protect against AKI after RIRS. Although UAS insertion failure is seen mostly in men, it may be more challenging in women owing to less efficacy of preoperative Double-J stent.

Single use flexible ureteroscopes: a review of current technologies and cost effectiveness analysis.

PURPOSE OF REVIEW: Flexible ureteroscopy (fURS) has evolved into both diagnostic and therapeutic modalities. Our review discusses the cost-effectiveness of single use flexible ureteroscopes (su-fURS) and the use of these instruments in routine urological practice. RECENT FINDINGS: There are studies which support the use of su-fURS with an argument of both cost and clinical utility over reusable flexible ureteroscopes (ru-fURS). However, the cost may vary across countries, hence is difficult to compare the results based on the current literature. Perhaps therefore there is a role for hybrid strategy incorporating ru- and su-fURS, where su-fURS are employed in complex endourological cases with a high risk of scope damage or fracture to preserve ru-fURS, with the ability to maintain clinical activity in such an event. SUMMARY: While there seems to be some cost advantages with su-fURS with reduced sterilization and maintenance costs, the data supporting it is sparse and limited. This choice of scope would depend on the durability of ru-fURS, procedural volumes, limited availability of sterilization units in some centers and potential risk of infectious complications. It is time that cost-benefit analysis is conducted with defined outcomes for a given healthcare set-up to help with the decision making on the type of scope that best serves their needs.

Intrarenal pressures during flexible ureteroscopy: an insight into safer endourology.

OBJECTIVES: To assess intrarenal pressures (IRPs) and complication rates after flexible ureteroscopy (fURS), and to assess factors that contribute to raised IRPs and postoperative complications. PATIENTS AND METHODS: After informed consent patients underwent fURS under general anaesthesia. The transducer of a 0.3556 mm (0.014″) pressure guidewire was placed in the renal pelvis for live recording of IRPs. The fURS procedures were performed in a routine manner under antibiotic cover with the aim of dusting the calculus to completion. The operating surgeon was blinded to the live-recorded IRPs. RESULTS: A total of 40 fURS procedures were performed in 37 patients (26 male and 11 female). The mean age was 50.5 years. As a cohort, the mean of average IRPs was 34.8 mmHg and the mean of maximal IRPs was 128.8 mmHg. Pearson's correlation showed a significant inverse correlation between the mean IRP and age (r[38]: -0.391, P = 0.013). Three cases experienced postoperative deviations from uncomplicated recovery, with two being hypotensive and one case being both hypotensive and hypoxic. Three cases returned to the emergency department within 30 days of surgery, with two cases of flank pain and one case of urosepsis with positive urine cultures. The patient presenting with urosepsis had exhibited IRPs exceeding the mean. CONCLUSION: The IRPs changed significantly from normal baseline levels during routine fURS. The mean IRP during fURS correlates with patient age, but not with other factors. The IRP may be related to increased complication rates at fURS. Understanding factors that influence IRP will allow urologists to better manage this intraoperatively.

Perspectives on technology: to use or to reuse, that is the endoscopic question-a systematic review of single-use endoscopes.

OBJECTIVE: To compare clinical outcomes of single-use endoscopes with those of reusable endoscopes to better define their role within urology. METHODS: A systematic search of electronic databases was performed. All studies comparing the clinical outcomes of participants undergoing urological procedures with single-use endoscopes to those of participants treated with reusable endoscopes were included. Results are reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. RESULTS: Twenty-one studies in 3943 participants were identified. Six different single-use flexible ureteroscopes and two different single-use flexible cystoscopes were assessed. There were no differences in mean postoperative infection rates (4.0% vs 4.4%; P = 0.87) or overall complication rates (11.5% vs 11.9%; P = 0.88) between single-use and reusable endoscopes. For patients undergoing flexible ureteroscopy there were no differences in operating time (mean difference -0.05 min; P = 0.96), length of hospital stay (LOS; mean difference 0.06 days; P = 0.18) or stone-free rate (SFR; 74% vs 74.3%; P = 0.54) between the single-use and reusable flexible ureteroscope groups. CONCLUSION: This study is the largest to compare the clinical outcomes of single-use endoscopes to those of reusable endoscopes within urology, and demonstrated no difference in LOS, complication rate or SFR, with a shorter operating time associated with single-use flexible cystoscope use. It also highlights that the cost efficiency and environmental impact of single-use endoscopes is largely dependent on the caseload and reprocessing facilities available within a given institution. Urologists can therefore feel confident that whether they choose to 'use' or to 'reuse' based on the financial and environmental implications, they can do so without negatively impacting patient outcomes.