Break Wave Lithotripsy for Urolithiasis: Results of the First-in-Human International Multi-Institutional Clinical Trial.

PURPOSE: This study reports on a prospective, multicenter, single-arm, clinical trial utilizing the SonoMotion (San Mateo, California) Break Wave lithotripsy (BWL) device to fragment urinary stones. MATERIALS AND METHODS: Patients with a urinary stone underwent a single treatment of 30 minutes and peak negative pressure of 4.5 to 8 MPa. Subjects were contacted and outcomes assessed at 7, 14, and 35 days after treatment, with clinical follow-up and CT imaging 70 ± 14 days postprocedure. The primary objectives were to assess the safety (hematomas, complications, etc) and effectiveness of BWL (any fragmentation, residual fragments ≤4 mm or ≤2 mm, and completely stone-free rate) as assessed via noncontrast CT-kidneys, ureters, and bladder. RESULTS: Forty-four patients with a ureteral (43%) or renal (57%) stone were treated across 5 centers. Stone fragmentation occurred in 88% of cases; 70% had fragments ≤ 4 and 51% ≤ 2 mm, while 49% were completely stone free on CT; no serious adverse events were reported. Eighty-six percent of patients received either no analgesic medication at all (50%) or minor analgesia (36%). After determining optimal therapy settings, 36 patients were treated and the effectiveness improved exhibiting fragmentation in 92% (33/36), residual fragments ≤ 4 mm in 75% and 58% with fragments ≤ 2 mm with 58% completely stone free. Effectiveness was less in subjects with lower pole stones with 81% fragmentation, 71% having fragments ≤ 4 mm, 29% with fragments ≤ 2 mm, and 29% completely stone free; of distal ureteral stone patients, 89% were completely stone free. CONCLUSIONS: BWL offered safe and effective noninvasive stone therapy requiring little to no anesthesia and was carried out successfully in nonoperative environments. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03811171.

Bridging the knowledge gap: past, present and future of antibiotic use for ureteral stents.

OBJECTIVE: To evaluate the available literature on ureteric stent-related infections, the use of antibiotics and bacterial colonisation to identify the current incidence of stent-related infections, unveil knowledge gaps and generate potential hypotheses for future research. METHODS: A literature review was conducted using PubMed, Cochrane and urological association websites identifying relevant English literature published between 1983 and January 2024. RESULTS: There is a worldwide lack of guidelines for antibiotic prophylaxis for stent placement, exchange or extraction. In patients with a negative preoperative urine culture undergoing ureteroscopy and stent placement, it may be considered to only provide prophylaxis in presence of risk factors. However, in pre-stented patients a preoperative urine culture is important to guide prophylaxis during endourological surgery. During stent indwell time, antibiotic prophylaxis does not show any advantage in preventing urinary tract infections (UTIs). There is no strong evidence to support the use of antibiotics at time of stent removal. In the absence of any clear evidence, management strategies for treating UTIs in patients with ureteric stents vary widely. Stent exchange could be considered to remove the biofilm as a potential source of bacteria. Stent culture can help to guide treatment during infection as urine culture and stent culture can differ. CONCLUSION: In terms of good antibiotic stewardship, urologists should be aware that unnecessary use of antibiotics provokes bacterial resistance. There is a great need for further research in the field of antibiotic prophylaxis and stent-related infections to develop evidence that can help shape clear guidelines for this very common urological practice.

Retrograde intrarenal surgery for asymptomatic incidental renal stones: a retrospective, real-world data analysis.

OBJECTIVE: To determine surgical outcomes and stone-free rates (SFRs) when offering upfront retrograde intrarenal surgery (RIRS) to patients with asymptomatic incidental renal stones (AIRS), as active surveillance, shockwave lithotripsy or upfront intervention in patients with AIRS is still a debate among urologists. PATIENTS AND METHODS: This retrospective FLEXible Ureteroscopy Outcomes Registry (FLEXOR), supported by the Team of Worldwide Endourological Researchers (TOWER), examines adult patients who underwent RIRS. We analysed a subset of asymptomatic patients with renal stones on imaging who were treated with RIRS. Data includes patient characteristics, stone specifications, anaesthesia type, perioperative details, complications, and SFR. A multivariable logistic regression analysis was performed to assess factors associated with the SFR. RESULTS: Among 679 patients with AIRS, 640 met the inclusion criteria. The median age was 55 years, with 33.4% being female. In all, 22.1% had positive urine cultures. The median stone diameter was 12 mm, commonly in lower and interpolar locations. RIRS was preferentially performed under general anaesthesia using a reusable scope in 443 cases. Prophylactic antibiotics were administered to 314 patients. The median operation time was 58 min and the median laser time was 24 min. The SFR was 68.8%. The use of holmium laser (odds ratio [OR] 0.21, 95% confidence interval [CI] 0.06-0.63; P < 0.01) and multiple stones (OR 0.38, 95% CI 0.19-0.76; P < 0.01) were factors associated with lower odds of being stone free. Overall complications were minimal, with sepsis in 1.6% of patients. Re-interventions were performed in 76 cases (11.8%), with RIRS being the most common in 67 cases (10.6%). CONCLUSION: Our multicentre real-world study is the first of its kind that highlights the pros and cons of offering RIRS to patients with AIRS and demonstrates a favourable SFR with acceptable complications. Pre-emptively discussing potential re-intervention helps patients make informed decisions, particularly in cases involving large and multiple stones.

The impact of kidney stone disease on quality of life in high-risk stone formers.

OBJECTIVE: To assess the impact of kidney stone disease (KSD) and its treatment on the health-related quality of life (HRQOL) of high-risk stone formers with hyperparathyroidism, renal tubular acidosis, malabsorptive disease, and medullary sponge kidney. PATIENTS AND METHODS: The Wisconsin Stone Quality of Life questionnaire was used to evaluate HRQOL in 3301 patients with a history of KSD from 16 institutions in North America between 2014 and 2020. Baseline characteristics and medical history were collected from patients, while active KSD was confirmed through radiological imaging. The high-risk group was compared to the remaining patients (control group) using the Wilcoxon rank-sum test. RESULTS: Of 1499 patients with active KSD included in the study, the high-risk group included 120 patients. The high-risk group had significantly lower HRQOL scores compared to the control group (P < 0.01). In the multivariable analyses, medullary sponge kidney disease and renal tubular acidosis were independent predictors of poorer HRQOL, while alkali therapy was an independent predictor of better HRQOL (all P < 0.01). CONCLUSIONS: Among patients with active KSD, high-risk stone formers had impaired HRQOL with medullary sponge kidney disease and renal tubular acidosis being independent predictors of poorer HRQOL. Clinicians should seek to identify these patients earlier as they would benefit from prompt treatment and prevention.

International Alliance of Urolithiasis (IAU) guideline on staghorn calculi management.

BACKGROUND: The stone burden based management strategy reported in the guidelines published by different associations is well known for a long time. Staghorn calculi, representing the largest burden and most complex stones, is one of the most challenging cases to practicing urologists in clinical practice. The International Alliance of Urolithiasis (IAU) has released a series of guidelines on the management of urolithiasis. PURPOSE: To develop a series of recommendations for the contemporary management management of staghorn calculi and to provide a clinical framework for urologists treating patients with these complex stones. METHODS: A comprehensive literature search for articles published in English between 01/01/1976 and 31/12/2022 in the PubMed, OVID, Embase and Medline database is performed. A series of recommendations are developed and individually graded following the review of literature and panel discussion. RESULTS: The definition, pathogenesis, pathophysiology, preoperative evaluation, intraoperative treatment strategies and procedural advice, early postoperative management, follow up and prevention of stone recurrence are summarized in the present document. CONCLUSION: A series of recommendations regarding the management of staghorn calculi, along with related commentary and supporting documentation offered in the present guideline is intended to provide a clinical framework for the practicing urologists in the management of staghorn calculi.

Evaluating the Safety of Retrograde Intrarenal Surgery (RIRS): Intra- and Early Postoperative Complications in Patients Enrolled in the Global Multicentre Flexible Ureteroscopy Outcome Registry (FLEXOR).

PURPOSE: To assess the incidence of the most common intra- and early postoperative complications following RIRS in a large series of patients with kidney stones. METHODS: We conducted a retrospective analysis of patients with kidney stones who underwent RIRS across 21 centers from January 2018 to August 2021, as part of the Global Multicenter Flexible Ureteroscopy Outcome (FLEXOR) Registry. RESULTS: Among 6669 patients undergoing RIRS, 4.5% experienced intraoperative pelvicalyceal system bleeding without necessitating blood transfusion. Only 0.1% of patients, required a blood transfusion. The second most frequent intraoperative complication was ureteric injury due to the ureteral access sheath requiring stenting (1.8% of patients). Postoperatively, the most prevalent early complications were fever/infections requiring antibiotics (6.3%), blood transfusions (5.5%), and sepsis necessitating intensive care unit admission (1.3%). In cases of ureteric injury, a notably higher percentage of patients exhibited multiple stones and stone(s) in the lower pole, and these cases were correlated with prolonged lasing and overall surgical time. Hematuria requiring a blood transfusion was associated with an increased prevalence of larger median maximum stone diameters, particularly among patients with stones exceeding 20 mm. Furthermore, these cases exhibited a significant prolongation in surgical time. Sepsis necessitating admission to the intensive care unit was more prevalent among the elderly, concomitant with a significantly larger median maximum stone diameter. CONCLUSIONS: Our analysis showed that RIRS has a good safety profile but bleeding requiring transfusions, ureteric injury, fever, and sepsis are still the most common complications despite advancements in technology.

Comparison Between Holmium:YAG Laser with MOSES Technology vs Thulium Fiber Laser Lithotripsy in Retrograde Intrarenal Surgery for Kidney Stones in Adults: A Propensity Score-matched Analysis From the FLEXible Ureteroscopy Outcomes Registry.

PURPOSE: We evaluated stone-free rate and complications after flexible ureteroscopy for renal stones, comparing thulium fiber laser and holmium:YAG laser with MOSES technology. MATERIALS AND METHODS: Data from adults who underwent flexible ureteroscopy in 20 centers worldwide were retrospectively reviewed (January 2018-August 2021). Patients with ureteral stones, concomitant bilateral procedures, and combined procedures were excluded. One-to-one propensity score matching for age, gender, and stone characteristics was performed. Stone-free rate was defined as absence of fragments >2 mm on imaging within 3 months after surgery. Multivariable logistic regression analysis was performed to evaluate independent predictors of being stone-free. RESULTS: Of 2,075 included patients, holmium:YAG laser with MOSES technology was used in 508 patients and thulium fiber laser in 1,567 patients. After matching, 284 patients from each group with comparable baseline characteristics were included. Pure dusting was applied in 6.0% of cases in holmium:YAG laser with MOSES technology compared with 26% in thulium fiber laser. There was a higher rate of basket extraction in holmium:YAG laser with MOSES technology (89% vs 43%, P < .001). Total operation time and lasing time were similar. Nine patients had sepsis in thulium fiber laser vs none in holmium:YAG laser with MOSES technology (P = .007). Higher stone-free rate was achieved in thulium fiber laser (85% vs 56%, P < .001). At multivariable analysis, the use of thulium fiber laser and ureteral access sheath ≥8F had significantly higher odds of being stone-free. Lasing time, multiple stones, stone diameter, and use of disposable scopes showed significantly lower odds of being stone-free. CONCLUSIONS: This real-world study favors the use of thulium fiber laser over holmium:YAG laser with MOSES technology in flexible ureteroscopy for renal stones by way of its higher single-stage stone-free rate.

Sepsis prevalence and associated hospital admission and mortality after ureteroscopy in employed adults.

OBJECTIVE: To determine 30-day inpatient mortality, intensive care unit (ICU) admissions, inpatient admissions/readmissions, and yearly trends in sepsis prevalence and inpatient mortality after ureteroscopy (URS) in employed adults. MATERIALS AND METHODS: We performed a retrospective analysis of the IBM MarketScan Commercial Database to identify employed adults aged 18-64 years who underwent URS between 2015 and 2019. Patients were categorized as having no sepsis (controls), non-severe sepsis, or severe sepsis within 30 days of URS. The main outcomes included inpatient mortality, ICU admissions, inpatient admissions, readmissions, and annual rates of sepsis and associated inpatient mortality. RESULTS: Among 109 496 patients undergoing URS, 5.6% developed sepsis (4.1% non-severe, 1.5% severe). The 30-day inpatient mortality rates were 0.03%, 0.3% and 2.5% for controls, non-severe sepsis and severe sepsis, respectively (P < 0.001). In a multivariable analysis, diagnosis of sepsis regardless of severity (hazard ratio [HR] 17.2, 95% confidence interval [CI] 10.5-28.1; P < 0.001) or severe sepsis (HR 49.5, 95% CI 28.9-84.7; P < 0.001) increased the risk of 30-day inpatient mortality compared to no sepsis (controls). ICU admissions on the day of procedure (1.5%, 19.8% and 52.4%), inpatient admission rates (18.3%, 74.9% and 76.9%) and readmission rates (7.1%, 12.0% and 15.9%) were higher with severe sepsis and non-severe sepsis vs controls (all P < 0.001). During the study period, the prevalence of sepsis after URS increased from 4.7% to 6.6% (P < 0.001), while the associated mortality rate decreased from 0.7% to 0.2% (P < 0.001). CONCLUSION: Among working adults aged 18-64 years, sepsis after URS increases the risk of 30-day inpatient mortality, ICU and hospital admission, and hospital readmission. Although the prevalence of sepsis after URS is increasing over time, associated mortality rates are declining. Urologists should be aware of the potentially deadly consequences of sepsis after URS in younger patients.

Retrospective first-in-human use of the LithoVue™ Elite ureteroscope to measure intrarenal pressure.

OBJECTIVE: To report on our first-in-human experience using the LithoVue Elite™ ureteroscope (Boston Scientific Corp., Marlborough, MA, USA) to measure intrarenal pressure (IRP) during flexible ureteroscopy. PATIENTS AND METHODS: A single-arm retrospective observational analysis was performed in 50 consecutive patients undergoing ureteroscopic lithotripsy using the LithoVue Elite™ system with pressure sensing capability between April 2022 and February 2023 at two centres. A pressure bag set at 150 mmHg or hand irrigation with a 60-mL syringe was used for irrigation and a ureteric access sheath (UAS) was placed at the physician's discretion. Median and maximum IRPs, and relative cumulative time exceeding 20, 40, 60, 80, 100, 120, 140, 160, and 200 mmHg per total procedure time were analysed. The two-sample Mann-Whitney U-test was used, with statistical significance set at P < 0.05. RESULTS: The median (interquartile range [IQR]) patient age and body mass index (BMI) was 62.5 (46.7-68.2) years and 27.6 (23.3-32.1) kg/m2 , respectively. During the median (IQR) total procedure time of 31.9 (17.4-44.9) min, the median and maximum IRPs were 28.5 (20.0-47.5) and 174.0 (133.5-266.0) mmHg, respectively. IRP remained at <60 mmHg during 92% of the procedure times. Patients with Asian ethnicity, and those without pre-stenting or UAS use exhibited longer cumulative/total durations exceeding pre-defined IRP cut-off values. The smaller 10/12-F UAS did not lower pressures as much as the 11/13-F or 12/14-F UAS (P < 0.001). Age, diabetes, hypertension, preoperative α-blockade, stone size, and BMI did not show any statistically significant associations with IRP. CONCLUSIONS: The IRP can now be routinely measured during ureteroscopy. Patients had a median IRP of 28.5 mmHg and a maximum of 174 mmHg. Using a smaller UAS (10/12 F), Asian ethnicity, and tight ureters were found to have higher IRPs.

Indwelling stents cause obstruction and induce ureteral injury and fibrosis in a porcine model.

OBJECTIVES: To investigate global changes in ureters at the transcriptional, translational and functional levels, both while stents are indwelling and after removal and recovery, and to study the effects of targeting pathways that play a potential role. METHODS: Pig ureters were stented for varying amounts of time (48 h, 72 h, 14 days) and the impact on peristalsis, dilatation and hydronephrosis were assessed. RNAseq, proteomic, histological and smooth muscle (SM) function analyses were performed on ureteric and kidney tissues to assess changes induced by stenting and recovery. Pathway analysis was performed using Ingenuity Pathway Analysis software. To study the impact of possible interventions, the effects of erythropoeitin (EPO) and a Gli1 inhibitor were assessed. RESULTS: Stenting triggers massive ureteric dilatation, aperistalsis and moderate hydronephrosis within 48 h. Pathways associated with obstruction, fibrosis and kidney injury were upregulated by stenting. Increased expression of GLI1, clusterin-α (a kidney injury marker) and collagen 4A2 (a fibrosis marker) was found in stented vs contralateral unstented ureters. EPO did not improve peristalsis or contraction force but did decrease non-purposeful spasming seen exclusively in stented ureters. Tamsulosin administration increased contractility but not rate of peristalsis in stented ureters. CONCLUSIONS: Ureters respond to stents similarly to how they respond to an obstruction, that is, with activation of pathways associated with hydronephrosis, fibrosis and kidney injury. This is driven by significant dilatation and associated ureteric SM dysfunction. EPO and tamsulosin induced mild favourable changes in SM physiology, suggesting that targeting specific pathways has potential to address stent-induced complications.