Impact of previously failed extracorporeal shock wave lithotripsy on ureterorenoscopy outcomes in upper urinary tract stones: a prospective comparative study.

OBJECTIVE: We sought to prospectively evaluate the impact of previously failed SWL on subsequent URS outcomes in the treatment of upper urinary tract stones. MATERIALS AND METHODS: Between May 2021 and May 2023, one hundred thirty-six patients with proximal ureteral stones < 1.5 cm and renal stones < 2.5 cm who were candidates for URS were prospectively assigned to a non-SWL group, which included patients without a history of failed SWL before URS, and a post-SWL group, which included patients with a history of failed SWL before URS. The success rate was the primary outcome. The perioperative data of the two groups were compared. RESULTS: The stone-free rate was 83.3% in the post-SWL group versus 81.3% in the non-SWL group, and 8.3% in the post-SWL group versus 9.4% in the non-SWL group had clinically insignificant residual fragments. There was no significant difference in the stone-free rate or success rate between the groups. No significant differences in intraoperative fluoroscopy time, operative time, intraoperative stone appearance, perioperative complications, or the presence of embedded fragments in the ureteral mucosa were detected between the two groups. CONCLUSION: Compared with patients who underwent primary URS, patients who underwent salvage URS for upper urinary tract stones had similar stone-free rates, success rates, operative times, fluoroscopy times, and complication rates without any significant differences.

Effect of infundibulopelvic angle on outcomes of ureteroscopy: a systematic review and meta-analysis.

PURPOSE: The infundibulo-pelvic angle (IPA) is reportedly a predictor of successful ureteroscopy for lower pole renal stones, however there is uncertainty at which IPA success is likely. We therefore aimed to perform a meta-analysis and determine at which the angle of likely success and failure. METHODS: We performed a systematic review and meta-analysis as per Cochrane guidelines in accordance to the PRISMA statement. The review was registered with PROSPERO prior to commencement (ID: CRD42022296732). We included studies reporting on outcomes of ureteroscopy for lower pole stones, with IPA. We excluded patients undergoing alternative treatments for lower pole stones, anatomical abnormalities and studies with < 10 patients. We assessed bias with the Newcastle-Ottawa scale. We performed meta-analysis in R, and summarised the findings as per GRADE. RESULTS: Overall, there were 13 studies included, with 10 included for meta-analysis. These studies covered n = 1964 patients (71% stone free). Overall, the stone free patients had a significantly less acute mean IPA (52o ± 9o), compared to the non-stone free patients (39o ± 7o), on meta-analysis (REM MD = -13.0, 95% CI: -18.7 to -7.2, p < 0.001). On examination of forest plots, at IPA < 30o no patients were stone free, whilst > 50o all were stone free. Risk of bias was moderate, and certainty of evidence was 'very low'. CONCLUSION: With a very low certainty of evidence, we demonstrate that at an IPA of < 30o no patient is stone free, whilst > 50o all patients (in this review) are stone free. More evidence is therefore needed.

FIRE Stones: impact of forced diuresis on the residual fragment rate after flexible ureteroscopy for destruction of kidney stones with laser-protocol for a randomized controlled two-parallel group multicenter trial with blinding evaluation.

BACKGROUND: Lithiasis is a common and recurrent disease. Flexible ureteroscopy (fURS) is the cornerstone of laser treatment of kidney stones. Kidney stones destruction requires its laser pulverization into small fragments in order to remove them through the ureter or improve their spontaneous expulsion along the urinary tract. However, most of the time, all the micro-fragments and dust created cannot be extracted using our surgical tools and may stay intra-renally at the end of the procedure. Adjuvant treatments (such as forced diuresis, inversion or mechanical pressure) were previously described to improve the expulsion of stone fragments after extra-corporeal shock wave lithotripsy. Nevertheless, the impact of adjuvant treatment after fURS remains unclear and mainly theoretical. OBJECTIVE: The primary objective is to show that the injection of 40 mg of furosemide in slow intravenous during 10 min, after the procedure, increases the stone-free rate 3 months after a fURS for destruction of kidney stones with laser. METHODS/DESIGN: The study will be a two-parallel group randomized, controlled, multicentric trial with a blinding evaluation. Nine French departments of urology will participate. Patients will be randomized in 2 groups: the experimental group (injection of 40 mg of furosemide at the end of the surgery) and a control one (usual care). Patients will be followed up for 3 months (± 2 weeks) after the surgery. Then, we will perform a low dose abdomino-pelvic CT scan. The primary outcome is the stone-free rate at 3 months. A centralized review of the images will be performed by two specialized radiologists, in a blind and crossed way to allow a homogenization of the results. The secondary outcomes will include the rate of early post-operative urinary tract infection (UTI), the evaluation of post-operative pain, and the safety of the use of furosemide in patients treated by fURS for renal stone laser destruction. As secondary objectives, it is also planned to look at the effect of the prescription of an alpha-blocker as usual treatment on stone-free rate and to assess the agreement between the imaging analysis of the urologist and the specialized radiologist. DISCUSSION: Lithiasis is a public health problem. It affects about 10% of the general population. This prevalence is increasing (multiplied by 3 in 40 years), partly due to changes in the population's eating habits over the years. The lithiasis patient is a patient with a chronic disease requiring annual follow-up and who may suffer from multiple recurrences, with a recurrence rate at 5 years of 50%. Recurrences are partly due to residual fragments left in the kidneys at the end of the operation. Other risk factors for recurrence include dietary hygiene and the presence of an associated metabolic disease. The metabolic blood and urine tests recommended by the Association Française d'Urologie (AFU) can be used to manage these last two problems. As far as residual fragments are concerned, their presence leads to an early recurrence of stones because they form the bed for a new aggregation of crystals in the kidneys. Being able to reduce the rate of residual fragments in patients with the use of furosemide at the end of the intervention therefore seems essential in the management of recurrences in our patients. This will also improve our patients' quality of life. Indeed, lithiasis disease leads to chronic pain associated with acute pain that motivates consultations to the emergency for specialized management. This study is the first to evaluate the impact of forced diuresis with the use of furosemide on the stone-free rate after a fURS for destruction of kidney stone with laser. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05916963 , first received: 22 June 2023. EU Clinical Trials Register EudraCT Number: 2022-502890-40-00.

The Multidisciplinary Approach in the Management of Patients with Kidney Stone Disease-A State-of-the-Art Review.

Kidney stone disease has a multifactorial etiology, and evolving dietary habits necessitate continuous updates on the impact of dietary components on lithogenesis. The relationship between diseases influenced by lifestyle, such as obesity and diabetes, and kidney stone risk underscores the need for comprehensive lifestyle analysis. Effective management of kidney stones requires a multidisciplinary approach, involving collaboration among nutritionists, urologists, nephrologists, and other healthcare professionals to address the complex interactions between diet, lifestyle, and individual susceptibility. Personalized dietary therapy, based on each patient's unique biochemical and dietary profile, is essential and necessitates comprehensive nutritional assessments. Accurate dietary intake evaluation is best achieved through seven-day, real-time dietary records. Key factors influencing urinary risk include fluid intake, dietary protein, carbohydrates, oxalate, calcium, and sodium chloride. Personalized interventions, such as customized dietary changes based on gut microbiota, may improve stone prevention and recurrence. Current research suggests individualized guidance on alcohol intake and indicates that tea and coffee consumption might protect against urolithiasis. There is potential evidence linking tobacco use and secondhand smoke to increased kidney stone risk. The effects of vitamins and physical activity on kidney stone risk remain unresolved due to mixed evidence. For diseases influenced by lifestyle, conclusive evidence on targeted interventions for nephrolithiasis prevention is lacking, though preliminary research suggests potential benefits. Management strategies emphasize lifestyle modifications to reduce recurrence risks, support rapid recovery, and identify predisposing conditions, highlighting the importance of these changes despite inconclusive data.

Monitoring Intrarenal temperature changes during Ho: YAG laser lithotripsy in patients undergoing retrograde intrarenal surgery: a novel pilot study.

Ho: YAG laser lithotripsy is widely used for urinary stone treatment, but concerns persist regarding its thermal effects on renal tissues. This study aimed to monitor intrarenal temperature changes during kidney stone treatment using retrograde intrarenal surgery with Ho: YAG laser. Fifteen patients were enrolled. Various laser power settings (0.8 J/10 Hz, 1.2 J/12 Hz) and irrigation modes (10 cc/min, 15 cc/min, 20 cc/min, gravity irrigation, and manual pump irrigation) were used. A sterile thermal probe was attached to a flexible ureterorenoscope and delivered into the calyceal system via the ureteral access sheath. Temperature changes were recorded with a T-type thermal probe with ± 0.1 °C accuracy. Laser power significantly influenced mean temperature, with a 4.981 °C difference between 14 W and 8 W laser power (p < 0.001). The mean temperature was 2.075 °C higher with gravity irrigation and 2.828 °C lower with manual pump irrigation (p = 0.038 and p = 0.005, respectively). Body mass index, laser power, irrigation model, and operator duty cycle explained 49.5% of mean temperature variability (Adj. R2 = 0.495). Laser power and operator duty cycle positively impacted mean temperature, while body mass index and specific irrigation models affected it negatively. Laser power and irrigation rate are critical for intrarenal temperature during Ho: YAG laser lithotripsy. Optimal settings and irrigation strategies are vital for minimizing thermal injury risk. This study underscores the need for ongoing research to understand and mitigate thermal effects during laser lithotripsy.

RETROGRADE INTRARENAL LITHOTRIPSY USING DISPOSABLE FLEXIBLE URETEROSCOPE.

This research aims to characterize efficiency of a flexible ureteroscope that is of single use with regard to surgical time, absence of stone, and complications. From March 2022 to April 2023, the Basrah Urological Centre carried out this anticipated work. After excluding patients with untreated urinary tract infections, excessive blood urea, and ureteral strictures, the study involved ninety-eight patients. All patients were above 20 years of age. Patients were operated on by the same surgeon. This study involved 108 patients in this study composed of 42 (39.8%) men and 65 (60.2%) women. With a standard deviation of 10.9 years, the patient's mean age was 39.2 years. The total stone burden ranged from 6.9 to 14.5 mm, averaging 9.7±2.9 mm. The stone density ranged from 820-1411 HU, averaging 1000.8±279.3 HU. According to the current study, treating renal stones with a single-use flexible ureteroscope is less complicated and more successful.

Rigid ureteroscopic lithotripsy with a pressure-controlling ureteral access sheath for complex steinstrasse.

OBJECTIVE: To evaluate the safety and efficacy of rigid ureteroscopic lithotripsy with a pressure-controlling ureteral access sheath (PC-UAS) for complex steinstrasse. METHODS: Thirty-one consecutive patients (male: 18; female: 13) with steinstrasse were enrolled, six of whom had concurrent kidney stones. The mean cumulative stone size was 2.7 ± 1.3 cm. The patients were treated with rigid ureteroscopic lithotripsy using a PC-UAS. The cavity pressure parameters were set as follows: control value at -15 mmHg to -2 mmHg, warning value at 20 mmHg, and limit value at 30 mmHg. The infusion flow rate was set at 150-200 ml/min. A holmium laser (550 µm) was used to powderize the stone at 2.0-2.5 J/pulse with a frequency of 20-30 pulses/s. Analyses included cavity pressure, operative time, stone-free rates, and complications. RESULTS: Among the 31 patients, 29 were successfully treated with PC-UAS, with nine requiring adjunctive flexible ureteroscopy for stone migration to the kidney. Two procedures were converted to percutaneous nephrolithotomies due to failure of sheath placement. The cavity pressure of all 29 patients was well-maintained below 20 mmHg, with clear vision. The mean operative time was 48.2 ± 17.7 min. No complications, such as ureteral perforation, mucosal avulsion, or hemorrhage, occurred. Two cases of Clavien-Dindo grade I complications occurred. No major complications (Clavien-Dindo grade II-V) occurred. The mean postoperative hospitalization time was 1.7 days. The stone-free rates 1 day and 1 month after surgery were 93.1% and 96.6%, respectively. One patient with residual stones underwent extracorporeal shockwaves. CONCLUSIONS: Rigid ureteroscopic lithotripsy with PC-UAS can effectively control the cavity pressure, shorten the operation time, and improve the efficiency of broken stones, thus reducing the complication rate.

Urologists' opinion on treating asymptomatic stones: Would we treat ourselves as we treat our patients? Survey from European Association of Urology, Young Academic Urologists, Endourology and Urolithiasis working party.

Background/aim: Management of asymptomatic kidney stones is an ongoing debate with follow-up and treatment guidelines based on low-level evidence. Our aim was to evaluate current management of asymptomatic urinary stones. Materials and methods: A 70-question survey was designed in collaboration with European Association of Urology, Young Academic Urologists, Section of Uro-Technology and Section of Urolithiasis groups and distributed. Responders filled out hypothetical scenarios from 2 perspectives, either as treating physicians, or as patients themselves. Results: A total of 212 (40.01%) responses were obtained. Median responder age was 39 years. 75% of responders were interested in "urolithiasis". 82.5% had never experienced a renal colic, 89.6% had never undergone urolithiasis treatment.Overall, as the kidney stone scenarios got more complicated, the invasiveness of the treatment preference increased. As "the physician", responders preferred the conservative option in all situations more than they would choose as "the patient". For ureteral stones, conservative approach was most preferred for small stones and ureteroscopy became more preferred as the stone size increased.For smaller kidney stones, the most preferred follow-up schedule was 4-6 monthly, whereas for larger and complicated stones it was 0-3 monthly from both perspectives respectively. For all ureteral stone scenarios, 0-4 weekly follow-up was mostly preferred.Interestingly, having had a renal colic was an independent predictor of an interventional approach, whereas having had an intervention was an independent predictor of a conservative approach. Conclusion: Current treatment and follow-up patterns of asymptomatic urinary stones are in agreement with international guidelines on symptomatic stones.In most of the urolithiasis situations urologists chose a conservative approach for their patients compared to what they would prefer for themselves. Conversely, urologists, in the scenarios as "the patient", would like to have a more frequent follow-up schedule for their stones compared to how they would follow-up their patients.

Stone decision engine accurately predicts stone removal and treatment complications for shock wave lithotripsy and laser ureterorenoscopy patients.

Kidney stones form when mineral salts crystallize in the urinary tract. While most stones exit the body in the urine stream, some can block the ureteropelvic junction or ureters, leading to severe lower back pain, blood in the urine, vomiting, and painful urination. Imaging technologies, such as X-rays or ureterorenoscopy (URS), are typically used to detect kidney stones. Subsequently, these stones are fragmented into smaller pieces using shock wave lithotripsy (SWL) or laser URS. Both treatments yield subtly different patient outcomes. To predict successful stone removal and complication outcomes, Artificial Neural Network models were trained on 15,126 SWL and 2,116 URS patient records. These records include patient metrics like Body Mass Index and age, as well as treatment outcomes obtained using various medical instruments and healthcare professionals. Due to the low number of outcome failures in the data (e.g., treatment complications), Nearest Neighbor and Synthetic Minority Oversampling Technique (SMOTE) models were implemented to improve prediction accuracies. To reduce noise in the predictions, ensemble modeling was employed. The average prediction accuracies based on Confusion Matrices for SWL stone removal and treatment complications were 84.8% and 95.0%, respectively, while those for URS were 89.0% and 92.2%, respectively. The average prediction accuracies for SWL based on Area-Under-the-Curve were 74.7% and 62.9%, respectively, while those for URS were 77.2% and 78.9%, respectively. Taken together, the approach yielded moderate to high accurate predictions, regardless of treatment or outcome. These models were incorporated into a Stone Decision Engine web application (http://peteranoble.com/webapps.html) that suggests the best interventions to healthcare providers based on individual patient metrics.

External validation of a nomogram for outcome prediction in management of medium-sized (1-2 cm) kidney stones.

BACKGROUND: Stone nomogram by Micali et al., able topredict treatment failure of shock-wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) in the management of single 1-2 cm renal stones, was developed on 2605 patients and showed a high predictive accuracy, with an area under ROC curve of 0.793 at internal validation. The aim of the present study is to externally validate the model to assess whether it displayed a satisfactory predictive performance if applied to different populations. METHODS: External validation was retrospectively performed on 3025 patients who underwent an active stone treatment from December 2010 to June 2021 in 26 centers from four countries (Italy, USA, Spain, Argentina). Collected variables included: age, gender, previous renal surgery, preoperative urine culture, hydronephrosis, stone side, site, density, skin-to-stone distance. Treatment failure was the defined outcome (residual fragments >4 mm at three months CT-scan). RESULTS: Model discrimination in external validation datasets showed an area under ROC curve of 0.66 (95% 0.59-0.68) with adequate calibration. The retrospective fashion of the study and the lack of generalizability of the tool towards populations from Asia, Africa or Oceania represent limitations of the current analysis. CONCLUSIONS: According to the current findings, Micali's nomogram can be used for treatment prediction after SWL, RIRS and PNL; however, a lower discrimination performance than the one at internal validation should be acknowledged, reflecting geographical, temporal and domain limitation of external validation studies. Further prospective evaluation is required to refine and improve the nomogram findings and to validate its clinical value.

Gaps in kidney stone disease management: From clinical theory to patient reality.

With nephrolithiasis projected to affect 25% of the global population in the next three decades, there is an urgent call for innovative management strategies to prevent and reduce stone recurrence. This study aims to explore the evolving management needs in nephrolithiasis from both patient and healthcare provider perspectives. An expert-collaborative online survey comprising 10 targeted questions on kidney stone management was developed and disseminated. This survey was designed to gather comprehensive insights from patients, physicians and dietician and other person in the field of nephrolithiasis. Analysis of responses from 120 participants, including 45 nephrologists, 38 dieticians, 11 urologists, and 14 kidney stones patients followed in our hospital, revealed critical insights. A significant 97.5% emphasized the necessity of optimizing daily water intake, and 94.1% recognized the need for practical dietary modifications. Additionally, 88.3% of respondents found timely hydration reminders beneficial. Notably, monitoring urine color and pH was valued by 85% and 84.3% of the participants, respectively. A striking disparity emerged in the perception of fatigue and wellness monitoring, with 65% of patients prioritizing fatigue monitoring, a view less shared by healthcare professionals. Similarly, 71% of patients deemed wellness monitoring essential, highlighting a gap in understanding between patients and their caregivers. This study underscores the critical need for more tailored guidance on hydration strategies and the promise of remote urine parameters monitoring in nephrolithiasis management. The findings strongly advocate for a patient-centered approach, aligning medical recommendations with patient lifestyles and experiences, to enhance the effectiveness of nephrolithiasis management.

[The 1-cm lower calyx calculus: SWT, URS or Mini-PCNL? Guidelines vs. reality.] / Der 1 cm UKG-Stein: ESWL, URS oder Mini-PCNL? Leitlinien versus Realität.

Urinary stones of the upper urinary tract can be considered a widespread public health concern due to their high incidence and prevalence and their health policy-related and financial implications. A significant proportion of newly diagnosed kidney stones are lower-pole stones, i.e., stones affecting the lower calyx group of the renal pelvicalyceal system. These are often diagnosed by chance, i.e., as incidental findings during ultrasound or CT scans performed for other reasons, or as "secondary stones" detected during the diagnostic work-up of symptomatic urinary stones in other locations. Residual disintegrates after extracorporeal shock-wave lithotripsy (ESWL) or endoscopic stone therapy constitute a further, quantitatively significant group. These incidentally discovered lower-pole stones are often characterised by their small size and lack of symptoms. It stands to reason that some of these small, asymptomatic lower-pole stones do not always remain small and asymptomatic, and that treatment tends to become more complex with increasing size. There has been an astonishing lack of published studies with a high level of evidence over the last 20 years to provide a conclusive and reproducible answer to the question posed in this review. Small, asymptomatic stones can be monitored. Symptomatic and rapidly growing stones should be treated. There is a lack of valid risk factors allowing an identification of subgroups that should be treated prophylactically at the asymptomatic stage. In active therapy, a 10-to-20-year-old principle still holds true today: a high stone-free rate in one therapy session is offset by an increased complication rate, with increasing miniaturisation in endourology (retrograde and percutaneous) and increasingly effective laser disintegration shifting this basic principle more and more in favour of flexible URS and (mini, micro) PCNL. The range of indications for ESWL is undoubtedly becoming smaller, and this also applies to lower-pole stones. The results of an ongoing prospective randomised study comparing the different treatment modalities, albeit with recruitment difficulties, are still pending.