Search Results (30)

Background and Objectives: Ureteral kinking may hinder endoscopic access and reduce the success of ureteroscopic lithotripsy (URSL). This study evaluated whether kinking can be predicted preoperatively using non-contrast computed tomography (CT) by introducing a novel metric—Maximum Horizontal Ureteral Displacement (HUDmax)—and assessed its predictive value for procedural success. Materials and Methods: Data from 1261 patients who underwent URSL for a single ureteral stone were retrospectively analyzed. Patients were categorized into two groups based on whether the stone could be reached using a semirigid ureteroscope. Propensity score matching (1:2) was performed based on stone size and location, resulting in two matched cohorts: Group 1—Semirigid Inaccessible (SRI, n = 72), and Group 2—Semirigid Accessible (SRA, n = 144). Stone characteristics, ureteral wall thickness (UWT), and HUDmax were evaluated. Correlations between HUDmax and surgical parameters were analyzed, and the predictive value of HUDmax was assessed using receiver operating characteristic (ROC) analysis. Results: The SRI group showed significantly higher HUDmax values (median 2.36 mm vs. 1.2 mm, p < 0.0001). Semirigid access failure necessitated conversion to flexible ureteroscopy in all SRI cases, compared to 15% in the SRA group (p < 0.0001). Stone-free rates were significantly lower in the SRI group (45% vs. 82%, p < 0.0001), and the use of a double-J stent or nephrostomy placement was more frequent. Operative times were also longer in the SRI group (55 vs. 42 min, p < 0.0001). HUDmax correlated positively with operative time (r = 0.258, p = 0.005) but not with stone size, density, UWT, or hydronephrosis. ROC analysis showed HUDmax strongly predicted semirigid access failure (AUC: 0.805; cutoff: 1.58 mm), and moderately predicted stone-free status (AUC: 0.697; cutoff: 1.68 mm). Conclusions: Severe ureteral kinking constitutes a significant anatomical obstacle to the success of semirigid URSL. This study is the first to demonstrate that clinically relevant kinking can be predicted preoperatively using a non-contrast imaging modality, via the novel HUDmax parameter. Full article

Background/Objectives: Achieving renal access is a key step in percutaneous nephrolithotomy (PNL), with transpapillary access considered the safest anatomical approach. This prospective pilot study aimed to compare the effectiveness of freehand ultrasound-guided (F-UG) versus fluoroscopy-guided (FG) punctures in achieving anatomically accurate transpapillary access during supine PNL, confirmed by endoscopic visualization. Perioperative and postoperative outcomes were also evaluated. Methods: Forty-three patients undergoing supine PNL for renal pelvic or lower calyceal stones were prospectively enrolled and assigned to either the FG group (n = 23) or F-UG group (n = 20). Following renal access, intraoperative flexible ureteroscopy confirmed the anatomical nature of the puncture (transpapillary vs. nonpapillary). The puncture time, fluoroscopy time, operative time, complications (Clavien–Dindo classification), transfusion requirement, hospital stay, and one-month stone-free rates were recorded. Results: Transpapillary access was achieved in 95.7% of FG cases and 55.0% of F-UG cases (p = 0.003). Radiation exposure was significantly lower in the F-UG group (p < 0.001). Complication (15.0% vs. 0.0%) and transfusion rates (10.0% vs. 0.0%) were higher in the F-UG group but not statistically significant (p = 0.092 and p = 0.210, respectively). Other outcomes, including the operative time, hospital stay, and stone-free rates, were similar between groups. Conclusions: FG puncture is more effective for achieving transpapillary access, while F-UG significantly reduces radiation exposure. The endoscopic confirmation method may provide a reference for future comparative studies on access techniques in PNL. Full article

Background and Objectives: Flexible ureteroscopic surgery is a common minimally invasive procedure utilized for the management of various urological conditions. While effective, postoperative complications such as fever can occur, necessitating the identification of reliable biomarkers for early detection and management. In this study, we specifically evaluated the predictive performance of three preoperative hematologic indices: the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune–inflammation index (SII). Materials and Methods: By systematically comparing these biomarkers through receiver operating characteristic (ROC) curve analysis and logistic regression modeling, we aimed to identify the most accurate predictor of postoperative fever development. Our cohort included patients who developed postoperative fever, many of whom exhibited normal WBC counts, allowing us to evaluate the discriminatory power of alternative inflammatory biomarkers. Results: Among the 150 patients, 32 developed postoperative fever. Conventional WBC counts did not predict fever, with 91% of feverish individuals having normal WBC values. In the ROC curve analysis, NLR outperformed SII (AUC 0.847, cutoff 796) and PLR (AUC 0.743, cutoff 106), with an AUC of 0.996 at 2.96. A combined logistic model achieved 100% sensitivity and 91% specificity (AUC = 0.996). Conclusions: This study addresses a critical gap in perioperative monitoring by validating readily available complete blood count-derived ratios as clinically meaningful predictors of postoperative inflammatory responses. Full article

This work introduces a novel fiber Bragg grating (FBG)-based tactile sensor specifically developed for real-time force monitoring at the tips of flexible ureteroscopes. With a diameter of only 1.5 mm, the sensor features a dual-FBG configuration that effectively separates temperature effects from force signals, integrated with an innovative elastomer structure based on staggered parallelogram elements. Finite element analyses comparing traditional spiral and parallel groove designs indicate that the new configuration not only enhances axial sensitivity through optimized deformation characteristics but also significantly improves resistance to transverse forces via superior stress distribution and structural stability. In the sensor, a suspended lateral FBG is employed for thermal compensation, while an axially constrained FBG is dedicated to force detection. Calibration using a segmented approach yielded dual-range sensitivities of approximately 283.85 pm/N for the 0–0.5 N range and 258.57 pm/N for the 0.5–1 N range, with a maximum error of 0.07 N. Ex vivo ureteroscopy simulations further demonstrated the sensor’s capability to detect tissue–instrument interactions and to discriminate contact events effectively. This miniaturized solution offers a promising approach to achieving precise force feedback in endoscopic procedures while conforming to the dimensional constraints of standard ureteroscopes. Full article

Background: Renal lithiasis continues to represent a great challenge for modern urology in terms of minimally invasive management of lithotripsy procedures. The recent revolution of endoscopes with the miniaturization of instruments and the development of improved disposable ureteroscopes combined with recent suction methods such as suction access sheaths or direct in-scope suction (DISS^TM) systems promise to further improve the outcome of renal stone treatment. Methods: Considering this technological advance, this study aims to evaluate the results obtained by combining these methods in three groups: Group 1—Single-use 7.5 Fr flexible ureteroscope with standard access sheath, Group 2—Single-use 7.5 Fr flexible ureteroscope with direct in-scope suction (DISS^TM) with standard access sheath, Group 3—Single-use 7.5 Fr flexible ureteroscope with DISS^TM with suction access sheath. A total number of 105 consecutive patients were enrolled in the study, divided equally in each group. Several parameters were followed, such as size and location of the stones, operative time, duration of hospitalization, the need for ureteral stent insertion, residual fragments, and subjective evaluation of the lithotripsy environment visualization. Results: The best results were highlighted in Group 3 for almost all evaluated parameters. Significant improvements were indicated in terms of stone-free rates. Conclusions: Additional large studies are needed to support these initial results, but preliminary data indicate a valuable advantage for every urologist who treats urolithiasis. Full article

Background and Objectives: This study aimed to evaluate the recurrence rates at three years for upper tract urothelial carcinoma (UTUC) cases managed conservatively, using Narrow Band Imaging (NBI)-assisted flexible ureteroscopy and Holmium laser vaporization. Materials and Methods: The study group included 61 patients who were diagnosed with NBI-assisted visualization with superficial pyelo-calyceal urothelial tumor lesions, treated conservatively by the flexible ureteroscopic approach and Holmium laser vaporization, also assisted by NBI. This was compared with a control group with the same number of cases, which underwent the same procedure, but without NBI technology. Recurrence rates, the rate of patients who underwent nephroureterectomy, and cancer-specific survival were compared. Results: The relapse rate at 1 year was 3.3% in the study group, and respectively 8.2% in the control group (p < 0.05). Depending on the histological characteristics, at 1 year the relapse rates in the study group were 1.8% in patients with low-grade tumors and 20% in those with high-grade tumors. At 3 years, the relapse rate was 11.5% in the study group versus 18% in the control group, (p < 0.05): 7.1% in patients with low-grade lesions and 40% in patients with high-grade lesions versus 21.4% in patients with low-grade lesions and 100% in patients with high-grade lesions (both arms with statistically significant differences, p < 0.05). Cancer-specific survival was 93.4% in the study group versus 86.9% in the control group (p < 0.05). Conclusions: The recurrence rates at three years for the UTUC cases managed conservatively, using NBI-assisted flexible ureteroscopy and Holmium laser vaporization, were lower than in patients treated by the same technique without NBI assistance, both in low- and high-grade tumors. Cancer-specific survival was also significantly improved by the association of NBI visualization during diagnosis and laser vaporization. Full article

Manipulating a flexible ureteroscope is difficult, due to its bendable body and hand–eye coordination problems, especially when exploring the lower pole of the kidney. Though robotic interventions have been adopted in various clinical scenarios, they are rarely used in ureteroscopy. This study proposes a teleoperation system consists of a soft robotic endoscope together with a Guidance Virtual Fixture (GVF) to help users explore the kidney’s lower pole. The soft robotic arm was a cable-driven, 3D-printed design with a helicoid structure. GVF was dynamically constructed using video streams from an endoscopic camera. With a haptic controller, GVF can provide haptic feedback to guide the users in following a trajectory. In the user study, participants were asked to follow trajectories when the soft robotic arm was in a retroflex posture. The results suggest that the GVF can reduce errors in the trajectory tracking tasks when the users receive the proper training and gain more experience. Based on the NASA Task Load Index questionnaires, most participants preferred having the GVF when manipulating the robotic arm. In conclusion, the results demonstrate the benefits and potential of using a robotic arm with a GVF. More research is needed to investigate the effectiveness of the GVFs and the robotic endoscope in ureteroscopic procedures. Full article

The standard treatment procedures for managing renal calculi in the pediatric population are similar to those in adults. The application of flexible ureteroscopy has contributed to the increased popularity of retrograde intrarenal surgery (RIRS) as an alternative therapeutic modality that can be successfully applied in children. One of the most significant innovations of the last decade is the introduction of single-use flexible ureteroscopes (fURSs). In this case report, we present the case of a 2-year-old boy with multiple large calculi in his right kidney, which were successfully removed after a single session of RIRS using a 7.5 F single-use fURS and high-power laser settings. The total operative and lithotripsy times were estimated at 90 and 75 min, respectively. No complications were recorded. The hemoglobin loss was calculated at 0.3 mg/dL, while the creatinine level was decreased by 0.1 mg/dL. The urethral catheter was removed on the first postoperative day, and the patient was discharged. The management of multiple or large kidney stones is very challenging in the pediatric population under the age of three years. Convenient preoperative planning and the appropriate use of available equipment may lead to excellent outcomes accompanied by a reduced risk for complications. Full article

Nephrolithiasis, or kidney stone disease, is a significant global health issue in urology, requiring effective management strategies. The management of nephrolithiasis through flexible ureteroscopy (fURS) is increasingly gaining acceptance; however, it is associated with significant costs related to consumables, pharmacotherapy, specialized equipment, and general anesthesia (GA). Limited resources and the need to optimize the cost effectiveness ratio have driven the shift to day-case procedures, offering financial and operational benefits and improving patient satisfaction. This outpatient care approach addresses clinical and economic challenges. For same-day discharge, spinal anesthesia (SA) is essential for fURS, as GA does not permit safe immediate discharge. This retrospective study investigates the feasibility of same-day discharge following fURS procedures performed under SA. Analyzing data from 401 patients who underwent 414 fURS procedures between January 2020 and December 2023, this study aims to evaluate whether same-day discharge is a viable option compared to conventional fURS under GA. The primary objectives are to assess the outcomes, including efficacy, stone-free rate (SFR), pain management, and complication rates, in the context of same-day discharge. Additionally, this study seeks to identify patient and kidney stone characteristics that may influence the suitability of one-day fURS under SA. Outcomes will be measured using the Dindo–Clavien (D-C) classification and Visual Analog Scale (VAS) scores post-procedure. Full article

(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. Full article

(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. Full article

The ureteral access sheath (UAS) has been a boon and a bane in flexible ureteroscopy (FURS), with its merits and demerits well established. Its design and dimensions were instrumental in reshaping the way flexible scopes were used and were key adjuncts to establishing retrograde intrarenal surgery (RIRS) as a standard of care in the endourological management of renal stones. With the ever-changing landscape of RIRS over the decades shaped by technological advancements in lasers and flexible scopes, the UAS has also continuously evolved. The utility of suction in endourology has recently changed the way RIRS is performed and is a game changer for FURS outcomes. With strong clinical and experimental evidence to support its use, the UAS has undergone a transformative change in the recent past, with its ability to monitor intrarenal pressure and provide a superior vacuum-cleaner effect that improves the trifecta of RIRS, namely an improved single-stage stone-free rate (SFR), minimise complications, and reduce reinterventions. Our comprehensive review outlines the key clinical and experimental evidence and traces the developments that were key to modifying the traditional UAS into a flexible and navigable suction ureteric access sheath (FANS) and highlights how the design and modifications, in turn, influence the ability to push the boundaries of RIRS. Full article

New suction endoscopes, ureteral access sheaths (UAS) and catheters aim to improve the efficacy of flexible ureteroscopy and optimize its safety. Suction UAS with non-flexible tips have shown promising results, especially in maintaining low intrarenal pressure, but also in removing small debris and reducing the “snow globe” effect. In addition, suctioning UAS with a flexible tip offers the advantage of being able to be navigated through the pyelocaliceal system to where the laser lithotripsy is performed. It can also remove small stone fragments when the flexible ureteroscope is retracted, using the Venturi effect. Direct in-scope suction (DISS) involves aspirating dust and small stone debris through the working channel of a flexible ureteroscope, thus regulating intrarenal pressure and improving visibility. Steerable aspiration catheters are other devices designed to increase stone clearance of the pyelocaliceal system. They are inserted under fluoroscopic guidance into every calyx after retraction of the flexible ureteroscope, alternating irrigation and aspiration to remove dust and small gravels. Combining flexible-tip suction UAS and the DISS technique may offer some advantages worth evaluating. The advantage of using these instruments to achieve a low intrarenal pressure was demonstrated. The true practical impact on the long-term stone-free status is a matter requiring further studies. Full article

Objectives: To compare the rate and predictors of septic complications after shock wave lithotripsy (SWL) and flexible ureteroscopy and laser lithotripsy (FURS) in an Australian population. Methods: Hospital admission data were extracted from the Victorian Admitted Episodes Dataset (VAED) regarding all elective admissions for SWL and FURS for treatment of intrarenal stones from 2009 to 2018, inclusive. Sepsis was defined by the ICD-10 diagnostic code, A41. Results: There were 13 154 inpatient episodes analysed, comprising SWL (6033) and ureterorenoscopic laser lithotripsy (7121). Males made up 67.43% of SWL patients and 63.34% of FURS patients. Median age was 57 years in both groups. Median American Society of Anesthesiologists physical status classification grade (ASA grade) was 2 for both groups, but proportionally more FURS patients were ASA grade 3 to 4 (p < 0.001). Postoperative sepsis was more common in the FURS group (1.43% vs. 0.03%), as was intensive care unit admission (1.00% vs. 0.10%). Average length of stay was longer for FURS (1.43 days vs. 1.06 days). There were 4 inpatient deaths, all from the FURS group. FURS procedure, female sex, and a higher ASA grade were each independent predictors of sepsis. Conclusions: FURS may have a significantly higher relative risk of postoperative sepsis than SWL in high-risk patients as determined in this study. While overall risk is low, higher comorbidity (ASA grade 3 or 4) and female sex were independent predictors of sepsis. For these patients in particular, and when clinically appropriate, SWL may be considered as a potentially safer alternative to FURS. Full article