Ureteroscopic Lithotripsy Research Articles

Applications of flexible ureteroscope lithotripsy with negative pressure suction and percutaneous nephrolithotomy in the treatment of 2-3cm diameter renal calculi.

Renal calculus, or kidney stone disease, presents a significant healthcare challenge globally, necessitating diverse therapeutic interventions. Percutaneous nephrolithotomy (PCNL) and flexible ureteroscope lithotripsy (FURL) are prominent among these interventions, with PCNL favored for stones > 2cm and FURL for smaller stones and applications of flexible ureteroscope lithotripsy with negative pressure suction for stones 1.5-2.5cm have some benefit. From June 2019 to January 2024, 310 patients undergoing FURL with negative pressure suction or PCNL for 2-3cm renal calculi were retrospectively analyzed. The demographic and clinical data were collected, and outcomes including stone-free rates (SFR), postoperative complications, and surgical parameters were compared. Comparable SFR were observed between FURL and PCNL groups at 1-month follow-up, although PCNL was superior to FURL after immediately post-surgery. FURL exhibited significantly fewer complications overall (5.7% vs. 19.3%, p = 0.044), shorter hospital stays, and lower postoperative pain levels. The surgical parameters favored FURL, showing lower bleeding volumes, shorter catheter removal times, and less hemoglobin decrease postoperatively. Despite similar stone clearance efficacy at 1-month follow-up, FURL demonstrated superior safety and postoperative outcomes compared to PCNL for 2-3cm renal calculi. These findings highlight the potential advantages of FURL in reducing complications, enhancing recovery, and optimizing patient care pathways.

Complete intraureteral stent placement reduces stent-related pain in normotensive subjects and in diabetes: Subgroup analysis of a prospective randomized clinical trial

Purpose: Pain is a common symptom that is associated with ureteral stent placement, but its degree of perception might vary among individuals. Compared with conventional stent placement (C-SP), complete intraureteral stent placement (CIU-SP) has shown promise in reducing stent-associated pain. This study aimed to investigate the effect of patient characteristics and comorbidities on pain reduction after CIU-SP. Materials and methods: Patients who underwent ureteroscopic lithotripsy and stent placement were randomized into the CIU-SP and C-SP groups. Stent-associated symptoms were evaluated using the Ureteral Stent Symptom Questionnaire on day 7, immediately before stent removal. Stent-associated pain was determined by the answer to question P1 (yes or no). Subgroup analysis was conducted based on various patient characteristics and comorbidities. Results: Of the 103 randomized patients, 91 (45 in CIU-SP and 46 in C-SP) were included in the final analysis. Body pain was reported by 31 (68.9%) after CIU-SP and 41 (89.1%) after C-SP (P = 0.021). Compared with C-SP, CIU-SP significantly reduced pain in the normotensive population (66.7% versus 93.7%, P = 0.006) but not in hypertensive individuals (77.8% versus 76.9%, P = 1.000). Conversely, compared with C-SP, CIU-SP was associated with less pain in patients with diabetes (37.5% versus 88.9%, P = 0.05) but not in patients without diabetes (75.7% versus 89.2%, P = 0.221). Age, sex, stone laterality, body mass index, and smoking status did not influence the reduction of pain after CIU-SP. Conclusion: Compared with C-SP, CIU-SP was effective in reducing stent-associated pain, especially in normotensive and diabetic populations. These findings align with existing literature, which emphasized the potential impact of hypertension on decreased pain perception and highlighted the known association between diabetes and bladder hypersensitivity.

Efficacy analysis of tip-flexible suction access sheath during flexible ureteroscopic lithotripsy for unilateral upper urinary tract calculi.

This study aims to evaluate the efficacy of tip-flexible suctioning ureteral access sheath (TFS-UAS) compared to traditional ureteral access sheath (T-UAS) in flexible ureteroscopic lithotripsy (FURL) for unilateral upper urinary tract calculi. The study retrospectively compared outcomes from 103 cases using TFS-UAS and 138 using T-UAS treated with FURL for unilateral upper urinary tract calculi from January to October 2023. Assessed parameters included patient demographics, stone characteristics, preoperative urine cultures, ureteral pre-stenting, comorbidities, procedure time, stone-free rate (SFR), utilization of stone retrieval baskets, and postoperative Systemic Inflammatory Response Syndrome (SIRS) rates. The maximum angle of deflection was also measured when the flexible ureteroscope was located in different parts of the TFS-UAS with different diameters in vitro. The TFS-UAS group achieved a higher Immediate SFR (76.70% vs. 63.77%, p = 0.031) and final SFR (89.32% vs. 73.91%, p = 0.003) than the T-UAS group, especially in the lower calyx stones (80.00% vs. 41.18%, p = 0.018) and upper urinary tract calculi with a cumulative diameter of 2cm or larger (68.97% vs. 42.11%, p = 0.029). Notably, TFS-UAS with a 10 French (F) inside diameter size achieved a higher SFR (88.57% vs. 70.59%, p = 0.041) and a greater deflection angle than the 12.5F inside diameter size. No significant variations were observed in the operative duration, hospitalization duration and the occurrence of SIRS between the compared cohorts. TFS-UAS significantly improves SFR in FURL treatment of unilateral upper urinary tract calculi, particularly for stones located in the lower calyx or with a cumulative diameter of 2cm or greater, compared to T-UAS.

Novel scoring system for predicting stone-free rate after flexible ureteroscopy lithotripsy.

This study aims to investigate the factors affecting the stone-free rate (SFR) of flexible ureteroscopy and laser lithotripsy (fURSL) for renal stones and establish predictive models by identifying their prognostic factors. We retrospectively examined 252 patients with renal stones who were treated with fURSL between July 2020 and April 2022. We analyzed the relationship between the patient's clinical data (sex, age, and body mass index), stone status (side, size, location, stone/transverse process pixel ratio [STPR], and the CT value of stone [SCTV]), and SFR to determine the relevant factors and analyze their influence. Additionally, a nomogram was constructed based on these prediction results. A total of 252 patients were enrolled based on the inclusion and exclusion criteria. They were reviewed 7, 30, and 90 days postoperatively, with 46, 23, and 10 patients failing to discharge stones, respectively. Univariate Cox proportional hazard regression results revealed that the SFR was correlated with stone location, diameter (D1, diameter of stone measured by computed tomography [CT]; D2, diameter of stone measured by kidney-ureter-bladder abdominal radiography), SCTV, STPR, and operation time. Multivariate Cox proportional hazard regression was used to develop 2 predictive models for the SFR. The influencing factors of model 1 included D1, location, and SCTV, whereas those of model 2 were D2, location, and STPR. The results are shown in the nomogram. Receiver operating characteristic curves showed no significant difference between models 1 and 2 (P = .498), indicating that the nomogram was highly predictive. After 1000 resamples and internal self-validation, the C-indices of models 1 and 2 were 0.924 and 0.895, respectively, showing that the stone clearance predicted by the nomogram matched the actual situation. Stone location, size, and density (SCTV and STPR) were significant predictors of SFR after fURSL. The scoring system based on these factors may be used to guide optimal treatment strategy selection.

Comparison of laparoscopic-assisted flexible ureteroscopic lithotripsy with percutaneous nephrolithotripsy and flexible ureteroscopy lithotripsy: a case-control study and meta-analysis.

This study aims to compare the differences in stone clearance rate, infection rate, and bleeding risk among laparoscopic-assisted flexible ureteroscopic lithotripsy (LAFUL), percutaneous nephrolithotripsy (PCNL), and flexible ureteroscopic lithotripsy (FUL) through case-control studies and meta-analysis, to evaluate the safety and effectiveness of LAFUL. 1. Through systematic literature search, clinical studies related to LAFUL, PCNL, and FUL were screened, and data on stone clearance rate, infection rate, and bleeding events were collected and analyzed for three groups of patients, followed by meta-analysis. 2. Data of patients who met the single center inclusion criteria and received LAFUL (40 cases), PCNL (40 cases, FUL), and FUL (40 cases) treatments for kidney stones from January 2021 to December 2023 were collected. Using a case-control study method, relevant clinical data were analyzed using SPSS 26.0 software. A total of 31 studies involving 2974 patients were included. The results of case-control analysis showed the stone clearance rate in the LAFUL group (F = 225.19, P < 0.001) and the positive rate of postoperative urine bacterial culture (X2 = 4.558, P = 0.033). The results of meta-analysis showed the stone clearance rate (rate = 0.986, 95% CI 0.964-0.999) and blood transfusion rate (rate = 0, 95% CI 0-0.012) in the LAFUL group. LAFUL shows potential in improving the stone clearance rate and reducing the risk of postoperative infection and bleeding, suggesting it may have certain advantages in the treatment of renal calculi.

Microchannel percutaneous nephrolithotomy versus flexible ureteroscopic lithotripsy for the treatment of 1-2cm high hardness single upper ureteral stones: a propensity score-matched study.

The objective of this study was to compare the clinical efficacy and safety of microchannel percutaneous nephrolithotripsy (MPCNL) with flexible ureteroscopic lithotripsy (FURL) in the treatment of single upper ureteral stones with a diameter of 1-2cm and high hardness. This study retrospectively analyzed 89 patients diagnosed with a single upper ureteral stone with a 1-2cm diameter and a computed tomography value > 1000 Hounsfield units. A propensity score matching system matched this study with factors to minimize the effect of baseline differences between patients. Ultimately, 29 patients in each of the two groups were successfully matched. The stone-free rate was marginally higher in the MPCNL group than in the FURL group (93.10% vs. 86.21%), although the difference did not reach statistical significance (P = 0.666). Furthermore, the mean operative time in the MPCNL group, although slightly longer than that in the FURL group, did not demonstrate a statistically significant difference (P = 0.833). However, patients in the MPCNL group exhibited a significantly more substantial decrease in hemoglobin than those in the FURL group (P < 0.001) and a substantially more extended postoperative hospital stay (P < 0.001). Regarding perioperative complications, the incidence of moderate pain was higher in the MPCNL group than in the FURL group (P = 0.037). The difference in overall complication rates between the two groups did not reach statistical significance (P = 0.108). MPCNL and FURL are efficacious surgical procedures for treating single upper ureteral stones with a 1-2cm diameter and high hardness.

Safety of flexible ureteroscopic lithotripsy with 365μm fibers of Ho: YAG laser: a short-term follow-up.

Our previous study first reported the efficacy of FURL using 365μm fibers with holmium: yttrium aluminum garnet (Ho: YAG) laser lithotripsy. This study evaluates the 16-week safety of this procedure. A prospective cohort study was conducted, and the clinical characteristics of patients who underwent FURL using 365μm fibers with Ho: YAG laser were retrospectively collected. Descriptive statistics were reported, and logistic regression analysis was conducted to identify risk factors influencing the stone-free rate (SFR). Infection-related laboratory parameters, including white blood cell count (WBC), procalcitonin (PCT), and C-reactive protein (CRP), were collected. Regression analysis was conducted to identify risk factors for the development of urosepsis post-surgery. Additionally, a 16-week follow-up was conducted in outpatient clinics, and kidney function was assessed. A total of 274 patients participated in this study. The 4-week stone-free rate (SFR) following FURL with 365μm fibers of Ho: YAG laser was significantly associated with stone size and composition. No severe complications were observed following FURL procedures. There were no significant differences in white blood cell count (WBC), C-reactive protein (CRP), and procalcitonin (PCT) in peripheral blood before and after FURL procedures. Urosepsis was diagnosed in 1.82% of patients. Preoperative white blood cell count (WBC) in urine and preoperative urine culture results were identified as significant risk factors. Kidney function remained stable at 4 and 16 weeks following FURL. This prospective cohort study demonstrated the high safety of FURL with 365μm fibers of Ho: YAG laser, as infection-related parameters during the perioperative period showed no significant differences, and kidney function remained stable throughout the 16-week follow-up.

Bilateral duplex kidney and ureter with multiple stones: a case report

BackgroundBilateral duplicated kidney and ureter is a rare condition in urology, and it is even rarer for patients to have multiple stones simultaneously. We delineate the diagnostic and therapeutic trajectory of a patient presenting with bilateral duplex kidneys and ureters, characterized by the presence of multiple stones. Notably, the left kidney is a complete duplication, whereas the right kidney exhibits an incomplete duplication.Case presentationA 47-year-old male patient was diagnosed with bilateral duplex kidney and ureter combined with multiple stones. Ureteral flexible lithotripsy and percutaneous nephrolithotomy were performed successively in our hospital. On the postoperative five day, he was discharged from the hospital without apparent discomfort.The double J tube was pulled out one month later, and no stone recurrence was found after 3 months of follow-up.ConclusionsBilateral duplicated renal ureteral malformations combined with multiple stones are very rare. Stones can be removed by ureteroscopic lithotripsy or percutaneous nephrolithotripsy and sometimes multiple procedures are required, which should be chosen according to the patient’s relevant condition.

The association between novel negative pressure ureteroscopic lithotripsy combined with flexible ureteroscopy versus percutaneous nephrolithotomy on stone-free rates: implications for clinical practice and policy

The correlation between novel negative pressure ureteroscopic lithotripsy (NP-URL) combined with flexible ureteroscopy (FU) and percutaneous nephrolithotomy (PCNL) on stone-free rates (SFR) remains unclear. There is a lack of evidence from Chinese populations regarding the relationship between SFR and NP-URL combined with FU (NP-URL-FU) versus PCNL. We aimed to assess the association between NP-URL-FU and PCNL on SFR. We conducted a cohort study involving 166 participants with 2–4 cm kidney stones. Data on SFR (7 days and 2 months) were collected from all participants. Logistic regression analysis was used to substantiate the research objectives. NP-URL-FU versus PCNL showed an 86% decrease in the 7-day SFR (OR = 0.14, 95% CI 0.07–0.29). The results remained stable even after adjusting for potential confounders. However, no statistically significant association was found between the surgical method and the 2-month SFR. Further exploratory subgroup analyses showed no significant interactions, with all P values > 0.05. Among patients with 2–4 cm kidney stones, NP-URL-FU was associated with a lower risk of incident 7-day SFR than PCNL. However, no statistically significant difference was found in the long-term stone removal rate. Therefore, NP-URL-FU may be a viable alternative surgical option for patients seeking minimally invasive procedures.

Decision regret analysis in early URSL vs medical expulsive therapy 1 for ureteric calculi ≤ 1cm

BackgroundThe study assesses the decisional regret following Shared Decision-making (SDM) in patients selecting either early ureteroscopic lithotripsy (URSL) or medical expulsive therapy (MET) for ureteric stones ≤ 1 cm, with the aim to evaluate their decisional Conflict, satisfaction, and regret regarding their opted treatment choices.MethodsAdults aged more than 18 years with one stone up to 1 cm in either ureter were included. After SDM, the patients were allocated into their opted group viz. URSL or MET. Patients in each group were reassessed at “treatment completion”. Cambridge Ureteric Stone PROM (CUSP) questionnaire for HRQoL, Decision Regret Scale and the OPTION scale (SDM) were filled at treatment completion.Findings111 patients opted for MET, while 396 patients opted for early URSL. Mean stone size was larger in URSL group (7.16 ± 1.63 mm vs. 5.50 ± 1.89; p < 0.001). Decisional conflict was higher in patients opting for URSL (77.3% vs. 57.7%; p < 0.001). Stone-free rate at four weeks was higher in URSL group (87.1%vs68.5%, p < 0.001). Decisional regret was higher in patients opting for MET (33.24 ± 30.89 vs. 17.26 ± 12.92; p = 0.002). Anxiety, was higher in patients opting for MET (6.94 ± 1.89 vs. 5.85 ± 1.54; p < 0.001). Urinary symptoms and interference in patients’ travel plans and work-related activities were more in URSL group (6.21 ± 1.57 vs. 5.59 ± 1.46; p < 0.001 and 6.56 ± 1.59 vs. 6.05 ± 1.72; p < 0.001 respectively).InterpretationAfter SDM, decisional regret is higher in patients opting for MET mainly due protracted treatment duration with increased pain and anxiety during the treatment course and the need for additional procedure for attaining stone clearance and the. Despite higher decisional conflict, a larger proportion of patients opt for early URSL with the aim of avoiding anxiety and achieving early stone clearance.

Evaluation of changes in Mallampati grading in patients undergoing elective urological procedures in prone and lithotomy positions- A prospective observational study

Intubation often results in airway edema, which can lead to reintubation following planned extubation in the post-anesthesia care unit. In urological procedures like percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotripsy (URSL), the use of irrigation fluids may exacerbate these airway changes. This study aims to assess alterations in Mallampati grading in patients undergoing elective urological procedures, particularly in prone and lithotomy positions.This prospective observational study was conducted at a tertiary care hospital from May 2021 to September 2021. Sixty patients with ASA I and II classifications scheduled for elective PCNL in the prone position and URSL in the lithotomy position, with 30 patients in each group, were enrolled. We assessed the Modified Mallampati Grading (MPG) before the procedure and at postoperative intervals of 4 h, 8 h, 12 h, 24 h, and 48 h, noting any changes and the time required to return to the baseline. We also recorded the number of irrigation fluids used, intravenous (IV) fluids administered, surgery duration, and estimated blood loss to explore potential associations.MPG changed by at least one class in 36.6 % of patients in the prone position and 20 % of patients in the lithotomy position. Furthermore, MPG changed by two classes in 20 % of patients in the prone position and 3.3 % of patients in the lithotomy position. The absorption of irrigation fluids was identified as a potential cause of airway edema, with a significant p-value of 0.0001, leading to worsening of the MPG. Fortunately, in most patients, the changes in MPG returned to baseline values within 24 h.In conclusion, our study confirms that Mallampati grading may experience at least a one-class increase in both prone and lithotomy positions in most patients, and it typically reverts to baseline in about 24 h for most patients. These airway changes should be considered when re-intubating patients in the postoperative period.

Impact of Either Trendelenburg or Reverse Trendelenburg Positioning for Ureteroscopy Lithotripsy Procedures: A Systematic Review and Meta-Analysis.

Urologists encounter multiple challenges in managing ureteral stones with ureteroscopic laser lithotripsy. This meta-analysis assesses the effectiveness of alternative surgical positioning, Reverse Trendelenburg (RevTren) and Trendelenburg (Tren), in reducing stone migration and enhancing outcomes compared with standard dorsal lithotomy positioning. A systematic review was conducted following PRISMA guidelines, searching Medline, Embase, Scopus, Cochrane, and WoS up to March 2024. This review focused on studies evaluating RevTren or Tren positioning during ureteroscopic lithotripsy compared with standard dorsal lithotomy, analyzing end points such as stone migration, conversion rates, success rates, complications, and operative time. Of 137 studies identified, 8 met the inclusion criteria, encompassing 1374 patients. RevTren significantly reduced ureteral stone migration (odds ratio [OR], 0.20; 95% CI, 0.08-0.47), lowered the need for conversion to a flexible ureteroscope (OR, 0.28; 95% CI, 0.12-0.67), and improved success rates (OR, 2.90; 95% CI, 1.88-4.48). Tren increased migration of ureteral and calyceal stones toward upper renal calyces (OR, 2.12; 95% CI, 1.48-3.04) and achieved a higher success rate (OR, 3.56; 95% CI, 2.15-5.92). Complications were comparable across all positions. Adjusting patient positioning during ureteroscopic laser lithotripsy can enhance procedure outcomes. RevTren effectively reduces ureteral stone migration and the necessity for flexible ureteroscopes, whereas Tren facilitates ureteral and calyceal stone migration toward upper calyces, increasing success rates. Both positioning techniques offer significant advantages over standard positioning and can be safely adopted in clinical practice without compromising patient safety.

Novel Stanley Stent Symptom Status Score (s5 score) for predicting ureteral stent-related symptoms

Background It is a known fact that endourological procedures frequently require placement of double J (DJ) ureteral stent. These patients can have stent-related symptoms (SRS) after DJ stent placement which can be distressing with increased morbidity. Though intraoperative and postoperative factors for SRS have been studied, research work is deficient in preoperative prediction of these symptoms which is the need of the hour. Thus, we aim to find out the factors which can lead to SRS after ureteroscopic lithotripsy (URSL) surgeries. Further, we aim to establish a scoring system which will help us predict the possibility of SRS and take necessary actions to minimise them.Materials and methodsOur study includes 150 URSL cases with DJ stenting where we correlated various factors with the presence of SRS. Information regarding preoperative, intraoperative and postoperative factors which may lead to SRS were noted down. All patients completed Ureteral Stent Symptom Questionnaire (USSQ) to evaluate the symptoms at 1 and 3 weeks after stent placement and 1 week after removal of the stent. The statistical data were evaluated using SPSS 24 Statistics.ResultsIn our study, we found that SRS correlated statistically with factors namely body mass index (BMI) > 25 kg/m2, loin pain, stone size > 1 cm, haematuria, bilateral stone disease, incomplete distal curl, distal end crossing midline and these could predict the occurrence of SRS. Based on the significant preoperative factors, we constructed the Stanley Stent Symptom Status Score (S5 Score) which predicts the possibility of developing SRS.ConclusionThorough understanding of factors which can lead to SRS can help us take steps to reduce the morbidity related with this frequent procedure. Stanley Stent Symptom Status Score (S5 Score) predicts the occurrence of these symptoms preoperatively. This score is first of its kind which will pave the way for deeper understanding and prediction of these symptoms preoperatively.

Comparison of Moses laser and Raykeen laser in patients with impacted upper ureteral stone undergoing flexible ureteroscopic holmium laser lithotripsy

BackgroundTo compare the operative effect and clinical efficacy of the Moses laser mode and the Raykeen holmium laser energy platform powder mode under flexible ureteroscopic lithotripsy in patients with impacted upper ureteral stones.MethodsFrom March 2022 to September 2022, 72 patients were divided into a Moses laser group and a Raykeen laser group according to surgical method, with 36 patients in each group. CT and ureteroscopy confirmed that all patients had isolated impacted upper ureteral stones. The stone volume (mm3), stone density (Hu) and severity of hydronephrosis were measured by CT. Postoperative complications were evaluated using the Clavien–Dindo score.ResultsThere were no complications of ureteral stenosis related to the laser treatment. The operative time and lithotripsy time were lower in the Moses laser group than in the Raykeen laser group (P < 0.05). The stone-free survival rate did not differ significantly between the two groups (P = 0.722). Stone volume was found to be positively correlated with laser energy and lithotripsy time in both groups (P < 0.01). There was no significant correlation between laser energy and lithotripsy time or ureteral stone density (Hu) in the Moses laser group (P > 0.05) or the Raykeen laser group (P > 0.05).ConclusionsThe contact mode of Moses technology and the powder mode of Raykeen laser lithotripsy can be used for the ablation of a single impacted upper ureteral stone. The ablation speed was related to the stone volume and the severity of polyp hyperplasia, not the stone density. We recommend the use of the powdered mode as a therapeutic measure for the treatment of impacted upper ureteral stones in flexible ureteroscopic lithotripsy.

Initial Clinical Experience With a Novel Robotically Assisted Platform for Combined Mini-Percutaneous Nephrolithotomy and Flexible Ureteroscopic Lithotripsy.

We sought to evaluate the technical feasibility of performing a combined robotically assisted mini-percutaneous nephrolithotomy (PCNL) and flexible ureteroscopy (URS) procedure by a single urologist using the MONARCH Platform, Urology (Johnson & Johnson MedTech, Redwood City, California). In this prospective, first-in-human clinical trial, 13 patients underwent robotically-assisted PCNL for renal calculi at the University of California-Irvine, Department of Urology. Successful completion of the procedure was assessed as the primary endpoint. Postoperative adverse events were monitored for 30 days following the completion of the procedure. Stone ablation efficiency was evaluated on postoperative day 30 with low-dose 2-3 mm slice CT scans. Patients were classified according to the maximum length of their residual stone fragments as either absolute stone-free (Grade A), < 2 mm remnants (Grade B), or 2.1-4.0 mm remnants (Grade C). The combined robotic mini-PCNL and URS procedure was successfully completed in 12 of 13 procedures. No robotic device-related adverse events occurred. Preoperative stone burden was quantified by both maximum linear measurement (median 32.8 mm) as well as by CT-based volume (median 1645.9 mm3). Using the unique robotically assisted targeting system, percutaneous access was gained directly through the center of the renal papilla in a single pass in all cases. Median operative time was 187 minutes (range: 83-383 minutes). On postoperative day 30, a 98.7% (range: 72.9%-100.0%) volume reduction was achieved, with 5 Grade A (38.5%), 1 Grade B (7.7%), and 2 Grade C (15.4%). Three patients experienced complications (2 grade 1 and one grade 2 Clavien-Dindo). Our preliminary investigation demonstrates the safety, efficacy, and feasibility of a unique robotic-assisted combined mini-PCNL and URS platform.

Predictive factors for prolonged operative time in ureteroscopic lithotripsy for ureteral stones A retrospective cohort study.

A prolonged operative time of lithotripsy with ureteroscopy for urolithiasis increases the risk of infectious complications; however, few reports have investigated the factors prolonging the operative time for ureteral stones. We investigated the factors associated with longer operative time in ureteroscopy for ureteral stones. This retrospective cohort study analyzed patients who underwent retrograde ureteroscopic lithotripsy for ureteral stones and achieved an endoscopic stone-free status between April 2019 and July 2022. Patients were classified into two groups based on an operative time of ≥90 minutes or <90 minutes. We compared the patient and stone characteristics and surgical outcomes, and investigated the factors associated with a prolonged operative time. The cohort comprised 519 patients, with 58 patients in the group with an operative time of ≥90 minutes. Compared to the shorter operative time group, the longer operative time group had a significantly greater proportion of males, stone diameter, stone volume, and Hounsfield units of stone; additionally, the longer operative time group had higher prevalences of endoscopic findings of edema, polyps, and mucosa-stone adherence. Multivariable analysis showed that stone size >10 mm (odds ratio 4.05), polyps (odds ratio 2.40), and mucosal adherence (odds ratio 3.51) were significantly associated with an operative time exceeding 90 minutes. There were no significant differences between the two groups in the incidences of postoperative fever and systemic inflammatory response syndrome. Stone size, endoscopic findings of polyps, and mucosa-stone adherence were independent factors associated with a longer operative time.

Successful endourological treatment for a rare case of atazanavir-induced urinary stones.

Atazanavir, an anti-HIV drug, induces urinary stone formation. We herein report a case of atazanavir-induced bilateral ureteral stones treated with endourological procedures. A 47-year-old male patient on atazanavir was admitted with right flank pain. The patient's serum creatinine level was 3.60 mg/dL. Plain computed tomography showed bilateral hydronephrosis. The left upper ureter was obstructed by a 13 × 12 × 9-mm mass, which had very low CT attenuation values. The lower part of the right ureter was obstructed, but no mass was observed. Given his medical history, we suspected bilateral ureteral obstruction caused by drug-induced stones. A ureteral stent was successfully inserted on the right side, but not on the left side. Thereafter, a bilateral ureteroscopic lithotripsy was performed. Infrared spectrophotometry revealed that the stone component was atazanavir. Understanding the characteristics of these rare drug-induced stones will aid in the proper early diagnosis and treatment.

Optimizing the outcome of non-pre-stented flexible ureteroscopic lithotripsy regarding the quality of life, when to remove the stent?

ObjectivesTo investigate the safety of short-term stenting following flexible ureteroscopic lithotripsy (fURL) for patients without preoperative stents. Retaining double-J stent for 1–2 weeks after fURL is a common practice. At present, data on short-term stenting after non-pre-stented fURL is still lacking.Methods182 patients who met inclusion criteria were retrospectively divided into the 2-days group (2-day removal, 76 cases) and the 1-week group (1-week removal, 106 cases). The study endpoint was stent-associated adverse symptoms assessed by follow-up and completed validated questionnaires on postoperative days (POD) 7 and 12. A postoperative imaging review was performed 1 month after the surgery.ResultsNo statistical differences were found in the patients’ demographic and stone-related characteristics. The 2-days group showed fewer urinary tract symptoms and lower scores on the ureteral stent symptom questionnaire on POD 7: less backache during urination (p = 0.004), less hematuria (p = 0.031), less frequent urination (p = 0.004), lower urinary symptoms index (p < 0.001), lower general health index (p < 0.001), and lower performance index (p < 0.001). There were no significant differences in fever (p = 0.372), visual analogue scale score (p = 0.760), and painkiller requirements (p = 0.160) on POD 7. The average general health score and work performance score remained significantly higher in the 1-week group patients at 5 days after removal compared to the 2-days group patients at 5 days after removal. (p < 0.001, p = 0.005). Five patients in the 2-days group and 15 patients in the 1-week group returned to the emergency department for additional treatments. No patient required rehospitalization. Stone-free rates were 85.5% in the 2-days group and 80.2% in the 1-week group (p = 0.499), respectively, and none of the patients got aggravating hydronephrosis.ConclusionsCompared to the common 1-week stent removal option, short-term stenting after non-pre-stented fURL is safe, which can enhance the patient’s quality of life.

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.

Development and validation of a nomogram to predict impacted ureteral stones via machine learning.

To develop and evaluate a nomogram for predicting impacted ureteral stones using some simple and easily available clinical features. From June 2019 to July 2022, 480 patients who underwent ureteroscopic lithotripsy (URSL) for ureteral calculi were enrolled in the study. From the eligible study population between June 2019 and December 2020, a training and validation set was randomly generated in a 7:3 ratio. To further evaluate the generalization performance of the nomogram, we performed an additional validation using the data from January 2021 to July 2022. Lasso regression analysis was used to identify the most useful predictive features. Subsequently, a multivariate logistic regression algorithm was applied to select independent predictive features. The predictive performance of the nomogram was assessed using Receiver Operating Characteristic (ROC) curves, calibration curves and decision Curve Analysis (DCA). The Hosmer-Lemeshow Test was utilized to evaluate the overall goodness of fit of the nomogram. Multivariate logistic regression analysis showed that flank pain, hydronephrosis, stone length/width, HU below (Hounsfield unit density of the ureter center below the stone), HU above/below (HU above divided by HU below) and UWT (ureteral wall thickness) were ascertained as independent predictors of impacted ureteral stones. The nomogram showed outstanding performance within the training dataset, with the area under the curve (AUC) of 0.907. Moreover, the AUC was 0.874 in the validation dataset. The ROC curve, calibration curve, DCA curve and Hosmer-Lemeshow Test suggested that the nomogram maintains excellent clinical applicability and demonstrates commendable performance. Similar results were achieved in the test dataset as well. We established a nomogram that can be effectively used for preoperative diagnosis of impacted ureteral stones, which is of great significance for the treatment of this disease.