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.

Ureteroscopy for urolithiasis in bedridden patients: it is feasible and acceptable.

PURPOSE: To investigate the safety of transurethral ureteroscopy (URS) for urolithiasis in bedridden patients and to identify bedridden patient-specific risk factors for postoperative complications. METHODS: The patients who underwent URS for urolithiasis were divided into bedridden patients and good performance status (PS) patients, and the groups were compared regarding their clinical characteristics and postoperative complications. A multivariable logistic regression analysis was performed to evaluate independent predictors of postoperative febrile urinary tract infection (fUTI). RESULTS: A total of 1626 patients were included, 276 in the bedridden patient group, and 1350 in the good PS patient group. The bedridden patient group had a significantly higher age and higher proportion of females and had multiple comorbidities. In 77 patients (27.9%), 88 postoperative complications developed for the bedridden patient group. Clavien-Dindo grade III or IV complications were observed in only 8 patients. No grade V complications were observed. The most common complication was fUTI. The frequency of fUTI with grade III or IV for the bedridden patient group (2.2%) was higher compared with the good PS patient group (0.5%), but the difference was not statistically significant (p = 0.13). Bedridden patient-specific risk factors for fUTI included female sex, diabetes mellitus, cerebrovascular comorbidities, lower extremity contracture, and prolonged operative time. CONCLUSION: URS for urolithiasis is a feasible and acceptable procedure in bedridden patients, despite the moderate rate of postoperative complications. The identified risk factors provide a framework for risk stratification and individualized care in this unique patient population.

Comparison of novel flexible and traditional ureteral access sheath in retrograde intrarenal surgery.

OBJECTIVES: To compare the efficiency and safety of a novel flexible ureteral access sheath (f-UAS) and traditional ureteral access sheath (UAS) during retrograde intrarenal surgery (RIRS). PATIENTS AND METHODS: Between January 2022 and September 2022, a total of 152 consecutive cases with renal stones underwent RIRS with the f-UAS. Their outcomes were compared with those of another 152 consecutive cases undergoing RIRS with traditional UAS using a 1:1 scenario matched-pair analysis, with matching parameters including age and stone size. The f-UAS is a novel UAS with a 10-cm-long tube at the tip that can follow the bends of flexible ureteroscope (f-URS). RESULTS: Baseline characteristics were found to be similar between the two groups. The f-UAS group demonstrated significantly higher SFR (76.3% vs. 7.2%; P < 0.001) at 1 day postoperatively and a higher clearance rate of stone volume (98.11% vs. 91.78%; P < 0.001). The f-UAS group also had lower total complications rate (9.9% vs. 22.4%; P = 0.003), lower incidence of fever (5.9% vs 11.9%; P = 0.001), shorter operative times (56.5 min vs. 59.9 min; P = 0.047), and lower usage rate of baskets (17.1% vs. 100%; P < 0.001). There was no significant difference in SFR at 1 month postoperatively (P = 0.627) and in the length of postoperative hospital stay between the two groups (P = 0.225). CONCLUSION: Compared to the traditional UAS during RIRS, the f-UAS showed several advantages, including higher SFR at 1 day postoperatively, shorter operative times, lower incidence of complications, and less use of basket.

Comparison of percutaneous nephrolithotomy and flexible ureterorenoscopy in the treatment of single upper ureteral calculi measuring 1 to 2 centimeters: a retrospective study.

PURPOSE: To compare the efficacy and safety of micropercutaneous nephrolithotomy (MPCNL) and flexible ureteroscopy (FURS) in the treatment of single upper ureteral calculi measuring 1 to 2 centimeters. METHODS: This study is a retrospective analysis that combines a review of medical records with an outcomes management database. A total of 163 patients who underwent MPCNL and 137 patients who had FURS were identified between January 2017 and December 2021. Demographic data, operation time, hospitalization time, stone-free rate, and complication rate were collected and analyzed. RESULTS: Preoperative general data of sex, age, BMI, serum creatinine, time of stone existence, stone hardness, stone diameter, preoperative hydronephrosis, and preoperative infection of the MPCNL group have no statistically significant difference with that of the FURS group. All MPCNL or FURS operations in both groups were successfully completed without any instances of reoperation or conversion to another surgical procedure. Patients who underwent MPCNL had a considerably reduced operation time (49.6 vs. 72.4 min; P<0.001), but a higher duration of hospitalization (9.1 vs. 3.9 days; P<0.001) compared to those who underwent FURS. The stone-free rate in the MPCNL group was superior to that of the FURS group, with a percentage of 90.8% compared to 71.5% (P<0.001). There was no statistically significant disparity in the rate of complications between the two groups (13.5% vs. 15.3%; P = 0.741). CONCLUSION: Both MPCNL and FURS are viable and secure surgical choices for individuals with solitary upper ureteral calculi measuring 1 to 2 cm. The FURS procedure resulted in a shorter duration of hospitalization compared to MPCNL. However, it had a comparatively lower rate of successfully removing the stones and required a longer duration for the operation.There were no substantial disparities observed in the complication rate between the two groups.FURS is the preferable option for treating uncomplicated upper ureteral calculi, whereas MPCNL is the preferable option for treating complicated upper ureteral calculi.Prior to making treatment options, it is crucial to take into account the expertise of surgeons, the quality of the equipment, and the preferences of the patient. TRIAL REGISTRATION: No.

Physical Techniques to Remove Residual Stone Fragments in the Urinary System.

BACKGROUND: Although significant progress has been made in treatment techniques for renal and ureteral calculi, residual fragments (RF) persisting long after treatment pose a serious threat to patients' health. A variety of novel physical techniques and extraction devices are currently being developed to promote the removal of RF from the urinary system, and a series of in vivo experiments have demonstrated their safety and efficacy. SUMMARY: External physical vibration lithecbole, magnetic extraction, biocompatible stone adhesive-based methods, and ultrasonic propulsion technologies are examples of innovative therapies that can promote the clearance of RF and improve the stone-free rate. In conclusion, the physical treatment of these RF needs to be optimized and improved. They are a promising technique for improving the efficiency of endovascular urology, and further in vivo studies are needed to confirm their safety and efficacy. KEY MESSAGES: We have summarized the literature on removal of RF by physical methods in recent years, especially the new progress.

Flexible ureteroscopy for lower pole calculus: is it still a challenge?

PURPOSE: Flexible ureteroscopy (fURS) is steadily gaining popularity in the management of renal calculi, including those located in the lower pole (LP). Due to difficulty in accessing to the LP of kidney in minority of cases with fURS and reports of lower stone-free rate (SFR), it is still considered as a challenge in selected cases. The purpose of the review was to analyze the various aspects of fURS for LP stones. METHODS: An extensive review of the recent literature was done including different factors such as anatomy, preoperative stenting, stone size, flexible scopes, types of lasers, laser fibers, suction, relocation, stone-free rates, and complications. RESULTS: The significance of various lower pole anatomical measurements remain a subject of debate and requires standardization. Recent improvements in fURS such as single-use digital scopes with better vision and flexibility, high power laser, thulium fiber laser, smaller laser fiber, and accessories have significantly contributed to make flexible ureteroscopy  more effective and safer in the management of LP stone. The utilization of thulium fiber lasers in conjunction with various suction devices is being recognized and can significantly improve SFR. CONCLUSIONS: With the significant advancement of various aspects of fURS, this treatment modality has shown remarkable efficacy and gaining widespread acceptance in management of LP kidney stones. These developments have made the fURS of LP stones less challenging.

Vacuum-assisted dedusting lithotripsy in the treatment of kidney and proximal ureteral stones less than 3 cm in size.

PURPOSE: This study aimed to compare the outcomes of vacuum-assisted dedusting lithotripsy (VADL) using flexible vacuum-assisted ureteral access sheath (FV-UAS) versus traditional flexible ureteroscopic lithotripsy (fURL) in patients with kidney or proximal ureteral calculi less than 3 cm in size. METHODS: A total of 371 patients who successfully underwent fURL treatment were enrolled. These patients were divided into traditional fURL group and VADL group. Outcomes of both groups were compared using 1:1 propensity score-matched analysis. Stratified analyses based on stone size and location were also conducted. RESULTS: Finally, 103 well-matched patients in each group were identified. No septic shock or death occurred. The immediate stone-free rate (SFR) and follow-up SFR of VADL group were significantly higher (78.6% vs. 50.5%, p < 0.001; 94.2%% vs. 75.7%, p < 0.001). No difference was observed in postoperative fever rate (2.9% vs. 3.9%, p = 1.000) and duration of lithotripsy (37.7 ± 20.1 min vs. 40.3 ± 18.9 min, p = 0.235). For patients with stones ≤ 2 cm in size, the immediate SFR and follow-up SFR in VADL group were higher (86.7% vs. 60.6%, p < 0.001; 96.0% vs. 83.1%, p = 0.010). The same trend was observed in the 2-3 cm subgroup (57.1% vs. 28.1%, p = 0.023; 89.3% vs. 59.4%, p = 0.009). Although the in situ fragmentation strategy was employed more frequently in VADL group for lower pole stones, the SFR was still higher. Subgroup analyses did not reveal any significant differences in either infectious complications or duration of lithotripsy. CONCLUSION: VADL technique can significantly improve the postoperative SFR for the patients with kidney or proximal ureteral stones less than 3 cm in size treated by flexible ureteroscope.

Effect of ureteric access sheath on outcomes of retrograde intrarenal surgery for renal stone disease: a randomized controlled trial.

BACKGROUND: The need of ureteric access sheath (UAS) in retrograde intrarenal surgery (RIRS) has been controversial for gaining high success in terms of stone free rate (SFR), reducing operative times and complications. There has been lack of high level of evidence in the literature on this topic. MATERIALS AND METHODS: This prospective randomized controlled trial (RCT) was conducted in the Department of Urology, PGIMER, Chandigarh from July 2019 to Dec 2021. The effect of UAS on the outcome of RIRS (SFR, operative time and complications) for renal stone disease was assessed. Ninety patients were randomized into two groups: 41 patients in Group 1 (RIRS with UAS) and 40 patients in Group 2(RIRS without UAS) were finally analyzed after exclusion. All the patients underwent preoperative double J stent placement at least 10 days prior to the definitive procedure. Operative time was recorded and postoperative pain was assessed by visual analogue scale(VAS) at 6 and 24 h postoperatively. Complications and emergency visits were recorded up to one month post procedure. SFR was assessed at 1 month using noncontrast CT KUB. Success was defined as absence of any residual fragment more than 3 mm in maximum diameter. RESULTS: Demographic parameters (age, body mass index, and comorbidities) and preoperative parameters (stone burden, proportion of recurrent stone formers and proportion of patients with inferior calyceal stones) were comparable between the two groups. Operative times (45.49 vs 48.38 min; p - 0.484) and VAS scores at 6 and 24 h post-op (p - 0.577) were also comparable between Group 1 and Group 2. SFR was comparable in Group 1 and Group 2 (78.05% vs 80%, p - 0.829). Postoperative complications were higher in the UAS group, but not statistically significant (4.88% vs 0%; p - 0.157). CONCLUSION: The use of UAS during RIRS is not associated with improved SFR. RIRS can be performed safely without the use of UAS and without increasing postoperative complications.

Concerns about stone free rate and procedure events of percutaneous nephrolithotripsy (PCNL) for 2-4 cm kidney stones by standard-PCNL vs mini-PCNL- comparative randomised study.

BACKGROUND: To compare the efficacy and safety of standard percutaneous nephrolithotomy (PCNL) with mini- PCNL for kidney stones 2-4 cm. METHODS: Eighty patients were enrolled in a comparative study, they were randomly divided into mini-PCNL group (n = 40) and standard-PCNL (n = 40). Demographic characteristics, perioperative events, complications, stone free rate (SFR) were reported. RESULTS: Both groups showed no significant difference in clinical data about age, stone location, back pressure changes, and body mass index. The mean operative time was (95 ± 17.9 min) in mini-PCNL, and (72.1 ± 14.9 min). Stone free rate were 80% and 85% in mini-PCNL and standard-PCNL respectively. Intra-operative complications, post-operative need for analgesia, hospital stay were significantly higher in standard-PCNL compared to mini-PCNL (85% vs. 80%). The study followed CONSORT 2010 guidelines for reporting parallel group randomization. CONCLUSION: Mini-PCNL is an effective and safe treatment of kidney stones 2-4 cm, it has the advantage over standard-PCNL being has less intra-operative events, less post-operative analgesia, shorter hospital stay, while operative time and stone free rate are comparable when considering multiplicity, hardness, and site of stones.

Efficacy and safety of minimally invasive percutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of upper urinary tract stones (> 1 cm): a systematic review and meta-analysis of 18 randomized controlled trials.

BACKGROUND: The advantages and disadvantages of retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (mPCNL) for treatment of upper urinary tract calculi have not been conclusively determined. METHODS: In this meta-analysis, We comprehensively evaluated the performance of the two surgical approaches in treatment of upper urinary calculi. We searched the Pubmed, Embase, Cochrane and Web of science databases for randomized controlled trial (RCT) articles on RIRS and mPCNL upto December 2022. Data were extracted by two independent reviewers and subjected to the meta-analysis using the Stata 15.1 software (StataSE, USA). RESULTS: A total of 18 eligible RCTs involving 1733 patients were included in this study. The meta-analysis revealed that mPCNL of 1-2 cm or 2-3 cm stones had a higher stone clearance rate (RR:1.08, 95%CI (1.03, 1.14), p = 0.002) and shorter operation time (WMD : -10.85 min, 95%CI (-16.76, -4.94), p<0.001). However, it was associated with more hospital stay time (WMD :1.01 day, 95%CI(0.53, 1.5), p<0.001), hemoglobin drops (WMD :0.27 g/dl, 95%CI (0.14, 0.41), p<0.001), blood transfusion rate (RR:5.04, 95%CI(1.62, 15.65), p = 0.005), pain visual analogue score (WMD:0.75, 95%CI (0.04, 1.46), p = 0.037), hospital costs (SMD :-0.97, 95%CI (-1.19, -0.76), p<0.001) and major complications (RR:1.89, 95%CI(1.01, 3.53), p = 0.045). CONCLUSION: Therefore, in terms of surgical effects and operation time, mPCNL is superior to RIRS, but is inferior with regards to other perioperative parameters. These factors should be fully considered in clinical decision making.

Retrograde Intrarenal Surgery Learning Curves of Urology Residents Supervised by an Experienced Endourologist: An RIRSearch Study.

INTRODUCTION: Although retrograde intrarenal surgery (RIRS) is being performed with increasing frequency, there are only a limited number of studies about the learning curve (LC). This study aimed to analyze the LC of RIRS for five surgeons who underwent the same training. MATERIALS AND METHODS: The data of the 410 patients who underwent RIRS between April 2017 and 2022 in a single institution, which were performed consecutively by five surgeons, were analyzed. All 50 cases performed by each surgeon were included and numbered consecutively and separately, according to the date of the operation. The combined stone-free rate (SFR) was calculated for each surgeon's cases in the same row, and the LCs were created using moving average and cumulative sum (CUSUM) analyses. Separate multivariable analyses identified each period's (LC vs. beyond) characteristics. RESULTS: The LCs from the combined SFRs reached a plateau after approximately 50 cases for both the CUSUM and the moving average. The effect of stone burden on SFR was more evident in the first 50 cases compared to subsequent cases in the multivariable analyses (p = 0.001 and p = 0.047, respectively). Case order and stone density were independent factors in the first 50 cases (OR: 1.02 [95% CI 1.00-1.04], p = 0.04 and OR: 0.99 [95% CI 0.99-1.00], p = 0.04) but not significant in subsequent cases (OR: 0.97 [95% CI 0.94-1.00], p = 0.1 and OR: 1.00 [95% CI 0.99-1.00], p = 0.7, respectively). Compared to single locations except the lower calyx, the unfavorable effect of the multiple-stone localization on SFR grew in strength after the 50th case (OR: 0.42 [95% CI 0.23-0.78], p = 0.01 and OR: 0.20 [95% CI 0.09-0.46], p < 0.001, respectively). CONCLUSIONS: This is the first study reporting on the RIRS LCs of urology residents. While stone burden, density, and multiple-stone localization were the factors determining SFR in the learning period, after completing the LC, the effect of stone burden weakened and multiple-stone localization became stronger.

Safety and efficacy of ureteroscopy for urolithiasis in octogenarians.

OBJECTIVE: To examine the safety and efficacy of ureteroscopy (URS) for urolithiasis in octogenarians, and identify preoperative risk factors for the incidence of postoperative complications. METHODS: The patients who underwent URS for urolithiasis were divided into octogenarians and younger patients (age: <80 years), and the groups were compared regarding their clinical characteristics, intraoperative and postoperative complications, and stone-free rate. The predictors of postoperative complications were evaluated using logistic regression models. RESULTS: A total of 1207 patients were included, 166 in the octogenarian patient group and 1041 in the younger patient group. The proportion of female patients (p < 0.001), American Society of Anesthesiologists (ASA) score (p < 0.001), rate of preoperative pyelonephritis (p < 0.001), and diabetes mellitus (p = 0.003) were higher in the octogenarian group. No statistically significant differences were found between the two groups regarding stone size, location, and intraoperative complications. Postoperative complications, which reached a significant difference, were observed in 34 (20.5%) octogenarians and 117 (11.2%) younger patients (p = 0.002). However, age itself was not significantly associated with postoperative fever, the most frequent postoperative complication, in multivariate analysis. Female sex, ASA score of ≥3, history of diabetes mellitus, and prolonged operative time (≥120 min) were the significant predictors of fever. The stone-free rate in the octogenarian group was superior to that in the younger patient group (80.1% vs. 70.6%, respectively; p = 0.035). CONCLUSION: Our results suggest that URS for urolithiasis can be safely and effectively applied to octogenarians in selected cases.

A Prospective Study on the Impact of Clinical Factors and Adjusted Triple D System for Success Rate of ESWL.

Objective: Our study aimed to evaluate the success rate of ESWL and identify relevant treatment-specific factors affecting treatment outcomes, as well as to assess the accuracy of the updated Triple D scoring system and compare it with older systems. Material and Methods: A prospective study of 71 patients who received ESWL treatment for renal stones that were 5-15 mm in size was completed. The patient having no residual stones or residual stones lesser than 4 mm after ESWL was identified as a treatment success. Univariate and multivariate logistic regression and ROC curves were used to identify important factors for treatment outcomes. Results: Successful treatment was achieved for 66.2% of patients. The stone volume (SV), mean stone density (MD), and delivered power to the stone volume unit ratio (SMLI/SV) were defined as the most critical factors influencing ESWL success. An updated Triple D score system with a, SMLI/SV ratio could be an alternative to older systems and reach an even higher accuracy. A limitation of this study is the limited sample size due to the COVID-19 pandemic. Conclusions: Our results show that the three factors that most influence the success of ESWL are the stone size, mean stone density, and SMLI/SV ratio. Based on this, we present a simple updated triple D score system to predict ESWL success, which could be implemented in future clinical practice.

Learning curve in flexible ureteroscopy for renal stones: A propensity score-matched study.

OBJECTIVE: To assess the learning curve and evaluate the impact of surgical experience related to the outcomes of flexible ureteroscopy (fURS) for upper urinary tract stones. METHOD: We evaluated retrospectively lithiasis fURS performed in our institution between January 2004 and December 2020. Patients were divided into two groups by the number of procedures performed by surgeon. Group 1 (G1) included the first 50 procedures, and group 2 (G2) the next cases. These groups were matched on baseline characteristics by a propensity score. Stones free rate (SFR) and complication rate (CR) were compared. Learning curves were realized using logistic curve with 95% confidence interval. RESULTS: After criteria exclusion and propensity score matching, 1548 procedures were analyzed (1:1, G1 and G2, n=774 procedures). A total of 29 surgeons were evaluated. The overall SFR was 68.4% without statistical difference between the two groups (G1=67.9% vs. G2=68.8%, P=0.72). The surgeon's experience was not associated with SFR (OR=1.15, 95% CI: 0.90-1.47), except in subgroup stones>2cm (OR=2.89, 95% CI: 1.29-6.46). The overall CR was 12.5%, mainly Clavien-Dindo grade I-II complications (96.2%). Surgical experience was not associated with CR (OR=1.06, 95% CI: 0.77-1.45). The overall logistic curves for probability of stone clearance and complication tended to be a flat slope. CONCLUSION: Impact of surgical experience on fURS for UUTS was not associated with SFR and CR. However, for stones larger than 2cm, surgeon's experience tended to be associated with SFR, but without impact on overall complications.

[Mini-PCNL, micro-PCNL or RIRS: comparative efficacy and safety in renal stones up to 2 cm].

INTRODUCTION: One of the main trends in the evolution of endoscopic treatment of urolithiasis is the miniaturization of instruments. This is obvious in the development of minimally invasive percutaneous nephro-lithotomy (PCNL) and retrograde intrarenal surgery (RIRS). However, there are few studies comparing the efficiency and safety of these methods. AIM: To evaluate and compare the efficiency and safety of mini-PCNL, micro-PCNL and RIRS in the treatment of kidney stones up to 2 cm in size. MATERIALS AND METHODS: Between October 2020 and December 2022, a total 72 patients underwent minimally invasive endoscopic procedures in two centers, including RIRS (n=30), mini-PCNL (n=26) and micro-PCNL (n=16) using thulium fiber laser FiberLase U2. The efficiency of procedure (stone free rate [SFR]) was assessed using non-contrast-enhanced CT. SFR was considered as the absence of residual fragments > 4 mm. Complications (safety) were evaluated based on the Clavien-Dindo classification. RESULTS: The mean age of all patients was 47.7 (22-84) years. There were no significant differences between three groups in stone characteristics according to CT (maximum diameter, density, volume and number of stones, the presence of pelvicalyceal dilation). SFR was significantly different between the groups (p=0.034). The overall SFR was 81.9% (n=59). After RIRS, mini-PCNL, and micro-PCNL the SFR was 93.3%, 80.8%, and 62.5%, respectively. A significant difference was found between the RIRS and micro-PNL groups, with 2 out of 30 and 6 out of 16 patients requiring repeat procedure, respectively (p=0.026). The overall rate of complication of grades I-II, IIIa and IIIb according to Clavien-Dindo was 6.9%, 9.7% and 6.9%, respectively. A significant difference was found between the RIRS and micro-PCNL (p=0.021) for grade I-II complications. A rate of grade III complications was not differed between the groups. The operation time was higher for mini-PNL (79.8 (30-145) min), and it was shorter for RIRS (55.7 (30-155) min). The length of stay was lower in RIRS group (4.5 (1-12) days). CONCLUSION: The highest SFR was achieved in the RIRS group. In terms of the number of complications of I-II grades according to Clavien-Dindo, the duration of the procedure and the length of stay, RIRS also showed the advantage. There were no significant differences in efficiency and safety between the micro-PNL and mini-PNL. There are not enough studies comparing minimally invasive methods for treating kidney stones. It is necessary to continue research in this area in order to develop an optimal algorithm for choosing the method of endoscopic treatment.

Optimization of shockwave lithotripsy use for single medium sized hard renal stone with stone density ≥ 1000 HU. A prospective study.

PURPOSE: To identify shock wave lithotripsy (SWL) success predictors in hard renal stones (average stone density ≥ 1000 HU). MATERIALS: We prospectively evaluated patients who underwent SWL for hard renal stones between April 2018 and December 2020. Radiological parameters were identified, e.g., stone site, size, the average density in addition to stone core and shell mean density, and renal cortical thickness (RKT). SWL sessions were performed using Doli-S lithotripter till a maximum of 3-4 sessions with 2-4 weeks interval. Initial response to SWL included stone fragmentation and decreased stone size after the first SWL. Treatment success was considered if complete clearance of renal stones occurred or in case of clinically insignificant residual fragments ≤ 4 mm after 12 weeks follow up by NCCT. RESULTS: Out of 1878 patients who underwent SWL, the study included 157 patients with hard renal stones. Treatment overall success was found in 92 patients (58.6%) where 69 patients (43.9%) had complete stone clearance. On multivariate analysis, stone shell density < 901 HU, maximum stone size < 1 cm, RKT > 1.95 cm and initial treatment response were associated with increased the success rate after SWL for hard renal stones (P = 0.0001, 0.009, < 0.0001 and < 0.0001, respectively). CONCLUSION: In hard renal stones, treatment overall success was found in 58.6% where complete stone clearance was found in 43.9%. Stone outer shell fragility, lower stone size, increased RKT and initial response to SWL were associated with a higher success rate at 12-week follow-up.

A comparison among RIRS and MiniPerc for renal stones between 10 and 20 mm using thulium fiber laser (Fiber Dust): a randomized controlled trial.

PURPOSE: We performed a prospective randomized comparison among Retrograde IntraRenal Surgery (RIRS) and MiniPerc (MP) for stones between 10 and 20 mm to evaluate outcomes with the same laser device: Fiber Dust. METHODS: Patients with a single renal stone between 10 and 20 mm were randomized to RIRS (Group A) versus MP (Group B). Exclusion criteria were age < 18 or > 75, presence of acute infection, coagulation impairments, cardiovascular or pulmonary comorbidities. In both groups, the Fiber Dust laser was used. A CT scan after 3 months was performed. A negative CT scan or asymptomatic patients with stone fragments < 3 mm and a negative urinary culture were the criteria to assess the stone-free status. A statistical analysis was carried out to assess success, complication and retreatment rates and need for auxiliary treatments. RESULTS: Between January 2021 and January 2022, 186 patients were enrolled (90 in Group A and 96 in Group B). Mean stone size was 15.8 mm and 14.9 mm in Group A and B, respectively (p = 0.23). The overall stone-free rate (SFR) was 73.3% for Group A and 84.4% for Group B. A higher SFR was reached for upper calyceal stones in Group A (90.4%) lower calyceal stones in Group B (91.6%). Retreatment rate (p = 0.31) and auxiliary procedure rate (p = 0.18) were comparable. Complication rate was 5.5% and 5.2% for Groups A and B, respectively. CONCLUSIONS: RIRS and MP are both effective to obtain a postoperative SFR with Fiber Dust. According to the stone position one treatment is superior to the other one.

Urologists are optimistic surgeons: prevalence and predictors of discordance between intraoperative stone-free rate and cross-sectional imaging evaluation after vacuum-assisted mini-percutaneous nephrolithotomy.

PURPOSE: To assess how accurate are urologists in predicting stone-free status (SFS) after vacuum-assisted mini-PCNL (vamPCNL) compared to computed tomography (CT) and clinical predictors of discordant SFS. METHODS: Data from 235 patients who underwent vamPCNL were analysed. Patient's demographics, stones' characteristics and operative data were recorded. SFS was evaluated intraoperatively by the treating urologist (iSFS) and with non-contrast CT 3 months after vamPCNL (ctSFS). SFS was defined as no residual stones. Stone complexity was scored with the Guy's score. Descriptive statistics and logistic regression models were used to identify clinical factors associated with discordant SFS (namely iSFS not confirmed at CT). RESULTS: iSFS and ctSFS were 88.5% and 65.5%, respectively, with 54 (23%) cases resulting in discordant evaluation of SFS between the surgeon and CT imaging. Patients with discordant SFS had larger stone volume (p < 0.001), higher rate of multiple stones (p = 0.03) and higher rate of multiple calyceal groups affected by stones (p < 0.001) than those with concordant SFS. The use of flexible ureteroscopes to look for residual stones after lithotripsy was more frequently reported in cases with concordant SFS (p = 0.001). Multivariable logistic regression analysis revealed that stones in > 2 calyceal groups (OR 10.2, p < 0.001), Guy's score II (OR 5.8, p < 0.01) and not using flexible ureteroscopes after lithotripsy (OR 2.9, p = 0.02) were independent predictors of discordant SFS. CONCLUSION: One out of five patients is erroneously considered SF after vamPCNL. Urologist should carefully evaluate patients with multiple calyceal stones and consider using flexible ureteroscopes to complete lapaxy of migrated fragments in order to improve their prediction of SFS.

Rigid ureteroscopic lithotripsy in the lateral decubitus position for upper urinary tract stones.

BACKGROUND: The current study aimed to assess a novel ureteroscopic technique developed for treating upper urinary calculi based on a specially designed lateral decubitus body position that could avoid stone loss by adjusting to the effects of gravity. METHODS: This retrospective study examined patients with upper urinary calculi who were surgically treated from November 2008 to January 2020, using a new body position and a rigid ureteroscope. Clinical outcomes, stone-free rates, operative times and complications were evaluated, and factors that could influence treatment success were determined. RESULTS: In total, 1080 patients were included, and 1145 operations were performed. The maximum calculus diameters were 11.22 ± 5.01 mm. Operative times were 48.60 ± 27.44 min. A total of 1042 cases were successfully treated, with a stone-free rate of 91.00%. Multivariate analysis showed that female sex (OR = 2.135, 95% CI 1.332-3.422, P = 0.002), thin scope standby (OR = 1.643, 95% CI 1.074-2.514, P = 0.022), laser lithotripsy (OR = 5.087, 95% CI 2.400-10.785, P = 0.000) and stone size (OR = 0.946, 95% CI 0.912-0.981, P = 0.003) were independently associated with stone-free outcomes. In total, 2 ureteral perforations, 2 ureteric avulsions and 4 urosepsis cases were observed, but were all cured without sequelae. CONCLUSIONS: Ureteroscopic lithotripsy in the lateral decubitus position is a safe and effective technique for treating upper urinary tract calculi, especially upper ureteral calculi.

Mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy and its initial clinical application.

BACKGROUND: To assess the outcome of the mini-track, mini-nephroscopy, mini ultrasonic probe percutaneous nephrolithotomy for upper ureteral and kidney stones. METHODS: We collected data of 53 patients (55 kidney units) who underwent mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy between September 2020 and March 2021. The study included single and upper ureteral stones from 12 kidneys, multiple stones from 28 kidneys, and staghorn stones from 15 kidneys. RESULTS: The mean operative duration was 50.6 min, ranging from 15 to 200 min, whereas the mean lithotripsy and stone removal time was 17.2 min (3-45 min). Moreover, the mean postoperative length of stay was 4.0 days (1-7 days). Besides, the stone-free rate (SFR) of discharge was 89.1% (49/55). The mean hemoglobin drop was 15.3 mg/dL, ranging 1-32 mg/dL. Out of the total cases, only 4 of them displayed minor complications. The outcomes of < 40 mm versus ≥ 40 mm calculi were compared by performing subgroup analysis. The results demonstrated a longer operation duration (65.2 vs. 40.2 min), higher complication rate (13.0% vs. 3.3%), and lower SFR in the ≥ 40 mm calculi subgroup. CONCLUSIONS: In summary, mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy is an effective and safe method to treat patients with upper ureteral and kidney calculi. This is especially significant for the stone size of 20-40 mm, demonstrating excellent SFR and a lower complication rate.