Mini-percutaneous nephrolithotomy vs flexible ureteroscopy for 1-2 cm lower pole renal stones: a randomised controlled trial.

OBJECTIVE: To compare the safety and efficacy of flexible ureteroscopy (f-URS) and ambulatory tubeless mini-percutaneous nephrolithotomy (mini-PCNL) in the treatment of 1-2 cm lower calyceal renal stones. PATIENTS AND METHODS: Patients who underwent f-URS and mini-PCNL for the treatment of 1-2 cm lower calyceal renal stones between October 2020 and November 2023 were evaluated in a randomised controlled trial. A total of 72 patients were included in the study. All patients underwent a computed tomography renal colic scan preoperatively, on postoperative Day 1 (POD 1), and at 3 months follow-up. We compared perioperative outcomes, including operative time and hospital stay. Additionally, we evaluated follow-up outcomes, such as the stone-free rate (SFR) and complications. All patients were discharged home on the same operative day. RESULTS: There were no significant differences in preoperative baseline data between the two surgical groups. A significantly longer median operative time was reported in the mini-PCNL group (P = 0.04). The median hospital stay was 5 h and 4 h in the mini-PCNL and f-URS groups, respectively (P = 0.14). On POD 1, the SFR, defined as the absence of residual fragments measuring 0 cm, was 50% for mini-PCNL vs 11.1% for f-URS (P < 0.001). When a total cut-off of <4 cm was utilised, the SFR was 75% in the mini-PCNL group vs 22.2% in the f-URS cohort (P < 0.001). At 3 months follow-up, the SFR remained favourable for mini-PCNL at 72.2% vs 37.1% for f-URS (P = 0.003), with a cut-off of 0 cm, and it increased to 86.1% for mini-PCNL vs 65.7% for f-URS (P = 0.04) when a total cut-off of <4 cm was applied. There was no significant difference in postoperative complications between the two groups. Two patients (5.7%) in the f-URS group required re-treatment. CONCLUSIONS: Ambulatory tubeless mini-PCNL and f-URS are effective treatment options for 1-2 cm lower calyceal renal stones. Both techniques have a comparable hospital stay and complication rates, with a significantly better SFR with mini-PCNL.

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.

Can shear wave elastography predict the success of shock­wave lithotripsy used in renal stones treatment? A prospective study.

OBJECTIVE: To evaluate the usage of shear wave elastography (SWE) in the prediction of the success rate of shock­wave lithotripsy (SWL) treatment of renal stones. PATIENTS AND METHODS: In the present study, SWL was performed for 100 patients presented with renal stones in the duration from May 2022 to August 2023. The patients were divided into 2 groups SWL responders and non-responders. The study compared between the 2 groups in terms of baseline parameters of the patients as age, sex, body mass index (BMI), stone size, stone location, stone density (HU), skin-to-stone distance (SSD), the degree of hydronephrosis and the stone elastography values. RESULTS: There was no statistically significant relation between stone-free rate and degree of obstruction (p = 0.628), stone size (p = 0.390) upper calyceal location (p = 0.17), middle calyceal location (p = 0.66), and renal pelvis location (p = 1.0). Nevertheless, a statistically significant relation was found as regards lower calyceal location, stone density (HU), and stone Elastography values using multivariate analysis. CONCLUSIONS: Measurement of stone density by shear wave elastography (SWE) can be used as an alternative to HU in decision-making before SWL. SWL success depends mainly on stone site, HU, and SWE values.

A historical comparison of thulium fiber laser systems for stone lithotripsy: navigating toward safe and effective parameters.

INTRODUCTION AND OBJECTIVES: Medical device companies have introduced new TFL machines, including Soltive (Olympus, Japan), Fiber Dust (Quanta System, Italy), and TFLDrive (Coloplast, France). The primary objective of this study is to compare our initial clinical experiences with TFL using those devices. Through this historical comparison of Thulium Fiber Laser systems for stone lithotripsy, we aim to advance our understanding and approach toward achieving safe and effective TFL parameters. MATERIALS AND METHODS: The data for this comparative analysis were extracted from three distinct prospective series that were previously published, outlining our initial clinical experience with the Soltive (Olympus, Japan), FiberDust laser (Quanta System, Italy), and TFLDrive laser (Coloplast, France). Parameters such as stone size, stone density, laser-on time (LOT), and laser settings were meticulously recorded. Additionally, we assessed critical variables such as ablation speed (expressed in mm3/s) and Joules/mm3 for each lithotripsy procedure. RESULTS: A total of 149 patients were enrolled in this study. Among them, 120 patients were subjected to analysis concerning renal stones. Statistically significant differences were observed in the median (IQR) stone volume: 650 (127-6027) mm3 for TFLDrive, 1800 (682.8-2760) mm3 for Soltive, and 1125 (294-4000) mm3 for FiberDust (p: 0.007); while there were no differences regarding stone density among the groups. Significant variations were identified in median (IQR) pulse energy, frequency, and total power. The Soltive group exhibited lower energy levels (0.3 J vs. 0.6 J, p: 0.002) but significantly higher pulse frequency (100 Hz vs. 17.5 Hz, p: 0.003) and total power (24 W vs. 11W, p: 0.001) compared to the other groups. Laser-on time showed no substantial differences across all three groups. Additionally, a statistically significant difference was observed in median J/mm3, with the TFLDrive group using higher values (24 J/mm3, p: 0.001), while the Soltive group demonstrated a higher median ablation speed of 1.16 mm3/s (p: 0.001). The overall complication rate remained low for all groups, with comparable stone-free rates. CONCLUSION: By reducing pulsed frequency, we improved laser efficiency, but smaller volumes lead to decreased efficiency due to increased retropulsion and fragment movement. Further studies are needed to identify and establish the appropriate laser settings for this new technology.

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.

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.

Deep dental phenotyping and a novel FAM20A variant in patients with amelogenesis imperfecta type IG.

OBJECTIVES: To identify etiologic variants and perform deep dental phenotyping in patients with amelogenesis imperfecta (AI). METHODS: Three patients of two unrelated families were evaluated. Genetic variants were investigated by exome and Sanger sequencing. An unerupted permanent third molar (AI1) from Patient1 and a deciduous first molar (AI2) from Patient2, along with three tooth-type matched controls for each were characterized. RESULTS: All three patients harbored biallelic pathogenic variants in FAM20A, indicating AI1G. Of the four identified variants, one, c.1231C > T p.(Arg411Trp), was novel. Patient1 possessed the largest deletion, 7531 bp, ever identified in FAM20A. In addition to hypoplastic enamel, multiple impacted teeth, intrapulpal calcification, pericoronal radiolucencies, malocclusion, and periodontal infections were found in all three patients, gingival hyperplasia in Patient1 and Patient2, and alveolar bone exostosis in Patient3. Surface roughness was increased in AI1 but decreased in AI2. Decreased enamel mineral density, hardness, and elastic modulus were observed in AI1 enamel and dentin and AI2 dentin, along with decreased phosphorus, increased carbon, and increased calcium/phosphorus and carbon/oxygen ratios. Severely collapsed enamel rods and disorganized dentin-enamel junction were observed. CONCLUSIONS: We report a novel FAM20A variant and, for the first time, the defective mineral composition and physical/mechanical properties of AI1G teeth.

Flexible ureteroscopy with novel flexible ureteral access sheath versus mini-percutaneous nephrolithotomy for treatment of 2-3 cm renal stones.

OBJECTIVES: To assess and compare the effectiveness and safety of flexible ureteroscopy (f-URS) with a novel flexible ureteral access sheath (f-UAS) versus mini-percutaneous nephrolithotripsy (mini-PCNL) in treating 2-3 cm renal stones. METHODS: Retrospectively analyzed consecutive cases that underwent f-URS with f-UAS (12/14 Fr) from January 29, 2022, to November 30, 2022. Consecutive cases that underwent mini-PCNL (18 Fr) from June 5, 2021, to January 26, 2022, were selected as controls. The f-UAS is a novel device with a 10 cm anterior tip that passively bends along with the f-URS to enter the renal calyx. We analyzed demographic characteristics, stone parameters, operative time, stone-free rates (SFR), hospitalization time, and complication. RESULTS: A total of 96 consecutive cases that underwent f-URS with f-UAS and 96 consecutive cases that underwent mini-PCNL were included in the study. There were no significant differences between the two groups in terms of operative time (p = 0.06), stone volume clearance (p = 0.533) and complete SFR (p = 0.266) on the first postoperative day or residual Stone after 1 month (p = 0.407). We observed a significantly shorter postoperative hospital stay (1.4 days vs. 2.1 days; p < 0.001) and a lower decrease in hemoglobin levels (0.39 g/dL vs. 0.68 g/dL; p < 0.001) in the f-UAS group. The mini-PCNL group had a significantly higher overall complication rate (13.5%) compared with the f-UAS group (5.2%; p = 0.048). CONCLUSIONS: In the treatment of 2-3 cm renal stones, f-URS with a novel f-UAS may provide a superior alternative to mini-PCNL, potentially challenging its established status.

The effect of piezoelectric shockwave lithotripsy with 2- and 8-mm focus sizes on stone disintegration and renal injury.

OBJECTIVES: To compare the efficacy and safety of shockwave lithotripsy (SWL) using a narrow focus or wide focus for renal stones. PATIENTS AND METHODS: A double-blind randomised trial included adult patients with a solitary radio-opaque renal pelvic stone of 1-2 cm. Patients were randomised into two groups: narrow-focus (2 mm) SWL and wide-focus (8 mm) SWL. The stone-free rate (SFR) and presence of complications such as haematuria, fever, pain, and peri-renal haematoma were evaluated. Pre- and postoperative urinary markers (neutrophil gelatinase-associated lipocalin [NGAL] and kidney injury molecule 1 [KIM-1]) concentrations were compared to assess renal injury. RESULTS: A total of 135 patients were recruited for this study. The SFR after the first SWL session was 79.2% and 69.1% in narrow- and wide-focus groups, respectively. There was a comparable rise in the median 2-h NGAL concentration in both groups (P = 0.62). However, the rise in the median (interquartile range [IQR]) 2-h KIM-1 concentration was significantly higher in the narrow-focus group at 4.9 (4.6, 5.8) ng/mL compared with the wide-focus group at 4.4 (3.2, 5.7) ng/mL (P = 0.02). Nevertheless, the 3-day NGAL and KIM-1 urinary marker concentrations were significantly improved (P = 0.263 and P = 0.963, respectively). The overall SFR after three sessions was 86.6% and 86.8% in the narrow- and wide-focus groups, respectively (P = 0.77). Both groups were comparable for complications, apart from the median pain score and the percentage of high-grade haematuria, which were significantly higher in the narrow-focus group (P < 0.001 and P = 0.03, respectively). CONCLUSION: Narrow- and wide-focus SWL were associated with comparable outcomes and re-treatment rates. However, narrow-focus SWL was associated with significantly higher morbidity in terms of pain and haematuria.

Which is better, fluoroscopic-guided or ultrasonic-guided shock wave lithotripsy for pediatric renal stones? Prospective randomized comparative study.

OBJECTIVES: To compare the efficacy and clinical outcomes of two different stone localization modalities (fluoroscopic or ultrasonic) in SWL treatment of pediatric renal stones. PATIENTS AND METHODS: This study was conducted in the period between January 2021 and June 2022 and included 100 children aged 2-16 years who presented with radio-opaque renal pelvic stones < 20 mm. The children were divided in two groups: group I, US-guided (50 patients), and group II, FS-guided SWL (50 patients). SWL was applied under general anesthesia. The follow-up of the patients included a visit every two weeks up to three months. RESULTS: Even though group II's stone-free rate after one month of follow-up was higher than group I's (90% vs. 84%), no statistically significant difference was found between the groups (p = 0.749). While the success rate was higher in group II than in group I (92% vs. 86%), no statistically significant difference was observed between the two groups (p = 0.338). The complication rate was 28% (14 patients) and 12% (6 patients) in Groups I and II, respectively. However, no significant difference was found between the two groups (p = 0.132). CONCLUSIONS: SWL is a non-invasive and safe method for treating pediatric renal stones. We recommend the use of the ultrasonic focusing modality in SWL of the pediatric age group, which has similar success rates, avoiding radiation and low complication rate instead of the fluoroscopic focusing modality, which uses ionizing radiation during SWL.

A single center comparative study of two single use digital flexible ureteroscopy in the management of renal stones less than 2 cm.

PURPOSE: For renal stones < 2 cm, guidelines recommend the use of retrograde intrarenal surgery as a first line treatment option. Many available single use flexible ureteroscopy were found. We aim to compare the effectiveness of two single use flexible ureteroscopy; Pusen Uscope 3011 versus LithoVue in the management of renal stones less than 2 cm. METHODS: Our study prospectively included 60 patients equally divided in to two groups: Pusen group and LithoVue group during the period from June 2020 to June 2021. The included patients were above 18 years old. Perioperative details as operative time, fluoroscopy time, hospital stay, and complications were recorded. Stone free rate was assessed. Base purchase cost was also compared. RESULTS: There was no statistically significant difference between the two groups regarding age, gender, and body mass index (BMI), stones size, side, number and location. The perioperative evaluation and outcome had no statistically significant differences between the two groups regarding the operative time, hospital stay, access sheath use, and stone free rate or radiation exposure. Among all cases, we had 49 cases (81.6%) with no postoperative complications (21 cases for Pusen group and 28 cases for LithoVue group). The incidence of postoperative complications was significantly higher among Pusen group than LithoVue group (p = 0.02). Initial purchase cost for both FURS had no significant difference (P = 0.86). CONCLUSION: RIRS can be performed effectively with Pusen 3011 and LithoVue single use flexible ureteroscopy in patients diagnosed with renal calculi < 2 cm with superior outcomes with LithoVue.

Assessment of single-probe dual-energy lithotripters in percutaneous nephrolithotomy: a systematic review and meta-analysis of preclinical and clinical studies.

PURPOSE: To evaluate the safety and efficacy of single-probe dual-energy (SPDE) lithotripters in patients undergoing percutaneous nephrolithotripsy (PCNL) through a systematic review and meta-analysis. METHODS: We searched PubMed, Cochrane Library, Scopus and Embase databases until July 2022 for any preclinical or clinical studies, exploring the safety and efficacy of different SPDE lithotripters in patients undergoing PCNL. We performed a meta-analysis to compare stone-free rate, bleeding, or other complications and mean operative time between SPDE lithotripters and other lithotripters (PROSPERO: CRD42021285631). RESULTS: We included 16 studies (six preclinical, seven observational and three randomized with 625 participants) in the systematic review and four in the meta-analysis. Preclinical studies suggest that SPDE lithotripters are safe and effective for the management of renal stones. Among clinical studies, four studies assessed Trilogy with no comparative arm, two compared Trilogy or ShockPulse with a dual-probe dual-energy lithotripter, two compared Trilogy with a laser, one compared ShockPulse with a pneumatic lithotripter, and one directly compared Trilogy with ShockPulse. Comparing SPDE lithotripters to other lithotripters, no significant differences were demonstrated in stone free rate (OR 1.13, 95% CI 0.53-2.38, I2 = 0%), postoperative blood transfusion (OR 1.33, 95% CI 0.34-5.19, I2 = 0%), embolization (OR 0.45, 95% CI 0.02-12.06), operative time (WMD: 2.82 min, 95% CI -7.31-12.95, I2 = 78%) and postoperative complications based on the Clavien-Dindo classification. CONCLUSIONS: SPDE lithotripters represent a promising treatment modality for patients requiring PCNL. Despite the initial encouraging findings of preclinical and isolated clinical studies, it seems that Trilogy or ShockPulse provide similar efficiency compared to older generation devices.

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.

Does age impact outcomes of retrograde intrarenal surgery in the elderly? Results from 366 patients from the FLEXible ureteroscopy outcomes registry (FLEXOR).

BACKGROUND: There has been a consistent increase in the last decades in prevalence of renal stones in elderly. AIMS: To evaluate outcomes of retrograde intrarenal surgery (RIRS) for renal stones in elderly and factors associated with postoperative complications and residual fragments (RFs). METHODS: Data from 12 centers were retrospectively reviewed. INCLUSION CRITERIA: ≥ 75 years, renal stones only, normal renal anatomy. Patients were divided into three groups; Group 1: patients aged 75-79 years; Group 2: age 80-84 years; Group 3: age ≥ 85 years. Multivariable logistic regression analyses were performed to assess factors associated with perioperative complications, sepsis, and RFs. RESULTS: 366 patients were included. There were 189 patients in Group 1, 113 in Group 2, and 64 in Group 3. There was no difference between groups regarding stone features and total surgical time. Median length of stay was significantly longer in Group 3 (6.0 days, vs 2.0 days in Group 2 vs 2.5 days in Group 1, p = 0.043). There was no significant difference in postoperative complications and RFs between the groups. At multivariable logistic regression analysis, female gender (OR 2.82) and maximum stone diameter (OR 1.14) were associated with higher odds of sepsis, while surgical time (OR 1.12) and the use of a reusable ureteroscope (OR 6.51) with overall complications. Stone size (OR 1.23) was associated with higher odds of RFs. CONCLUSION: RIRS showed safety and efficacy for kidney stones in elderly patients. Surgical time should be kept as short as possible to avoid higher odds of postoperative complications, particularly in females.

Is the Supine Position Suitable for Ultrasound-Guided Percutaneous Nephrolithotomy in Patients with Complex Renal Stones?

INTRODUCTION: The aim of the study was to assess the safety and efficacy of ultrasound (US)-guided percutaneous nephrolithotomy (PCNL) for complex renal stones when performed in a modified supine position. METHODS: We retrospectively reviewed the charts of patients who underwent PCNL for complex renal stones at our institution between August 2018 and December 2021. During this time, 188 consecutive patients underwent US-guided PCNL in the prone position (P group, n = 129) or in the flank-free modified supine position (S group, n = 59). Patient demographics and intraoperative and postoperative data were analyzed. RESULTS: Successful renal access was achieved in all patients. The baseline demographics were comparable between the two groups. The numbers of renal access were significantly higher (2.1 ± 0.4 vs. 1.2 ± 0.2, p = 0.002), and the operation time was comparable (79.1 ± 14.6 min vs. 96.2 ± 19.6 min, p = 0.06) between the two groups. The postoperative hospital stay was also shorter in the P group (6.2 ± 1.5 d vs. 10.2 ± 1.7 d, p = 0.008). The postoperative hemoglobin loss was similar between the P and S groups (1.7 ± 0.4 g/dL vs. 1.8 ± 0.3 g/dL, p = 0.12). The stone-free rate was significantly lower in the S group (57.5% vs. 82.7%, p < 0.001). There were no embolization or septic complications. Twelve patients (20.3%) in the S group underwent simultaneous or staged retrograde flexible ureteroscopy to remove residual stones. CONCLUSION: US-guided PCNL in the modified supine position was a safe treatment for complex renal stones. However, the single-session stone clearance rate was not ideal. The supine flank-free position may be unsuitable for US-guided PCNL in patients with complex renal stones according to our preliminary findings.

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.

Comparison of low power and high power holmium YAG laser settings in flexible ureteroscopy.

PURPOSE: To compare the efficacy of conventional low power and high power holmium: yttrium aluminum-garnet (Ho: YAG) laser lithotripsy settings during retrograde intrarenal surgery (RIRS).  METHODS: The prospective study was conducted in patients undergoing RIRS for renal stones less than 2 cm diameter. Pulsed Ho:YAG laser (Lumenis® Pulse TM P120 H) was used for laser lithotripsy and the patients were randomized into low power (LP) and high power (HP) laser lithotripsy settings groups. The lasing duration, total laser energy used (Joules), laser energy used to ablate 1 mm3 of stone (Joules/mm3), operative duration, stone ablation speed (mm3/s) and stone free rate were compared. RESULTS: A total of 120 underwent RIRS with 63 and 57 patients in LP and HP group, respectively. Median stone volume and stone density were comparable between the groups. The total energy used and laser energy used to ablate 1mm3 of stone (Joules/mm3) were significantly higher in the HP group than in LP group (27.9 (16.4-46.2) J/ mm3 vs 9.7 (5.3-17.7) J/ mm3) (p < 0.01). Median (IQR) ablation speed were 0.8 (0.5-1.3) mm3/s and 0.6 (0.4-1) mm3/s in the LP and HP groups, respectively. The median lasing time, operative time and stone free rate were similar in both the groups. CONCLUSION: The total energy used and J/mm3 were lower in the LP group than in HP group with similar lasing duration, operative duration, ablation speed and stone free rate for renal stones less than 2 cm.

WiScope® single use digital flexible ureteroscope versus reusable flexible ureteroscope for management of renal stones: a prospective randomized study.

OBJECTIVES: To compare the clinical performance and surgical outcomes of the new digital single use flexible ureteroscope (WiScope®) with a reusable digital flexible ureteroscope. PATIENT AND METHODS: Our prospective study includes patients with renal stones less than 2 cm who underwent retrograde flexible ureteroscopy and laser lithotripsy. Patients were randomized into two groups: group A included patients who underwent laser lithotripsy using WiScope® Single use digital flexible ureteroscope and group B included patients who underwent laser lithotripsy using reusable flexible ureteroscope. Image quality, deflection, ease of insertion, maneuverability, and overall performance were assessed using either a visual analog or Likert scale. Operative outcomes and complications were collected and analyzed in both groups. RESULTS: A total of 242 patients were included in our study. There were 121 patients in the WiScope® group and 121 patients in reusable ureteroscope group. The WiScope® had higher maneuverability (9.3 ± 0.7 vs. 7.2 ± 0.8, P < 0.001) and less limb fatigue but had lower image quality when compared to reusable digital flexible ureteroscope (7.6 ± 0.9 vs. 9.2 ± 0.6, P < 0.001). There were no differences in operative time, complication rates and rates of relook ureteroscopy. CONCLUSIONS: The WiScope® single use flexible ureteroscope has comparable outcomes to the reusable flexible ureteroscope with regard to maneuverability, limb fatigue, and deflection. However, it has a lower image quality.

Super-mini percutaneous nephrolithotomy (SMP) vs retrograde intrarenal surgery (RIRS) in the management of renal calculi ≤ 2 cm: a propensity matched study.

OBJECTIVE: To compare the effectiveness and safety of Super-Mini PCNL (SMP) and Retrograde Intrarenal Surgery (RIRS) in the management of renal calculi ≤ 2 cm. PATIENTS AND METHODS: A prospective, inter-institutional, observational study of patients presenting with renal calculi ≤ 2 cm. Patients underwent either SMP (Group 1) or RIRS (Group 2) and were performed by 2 experienced high-volume surgeons. RESULTS: Between September 2018 and April 2019, 593 patients underwent PCNL and 239 patients had RIRS in two tertiary centers. Among them, 149 patients were included for the final analysis after propensity-score matching out of which 75 patients underwent SMP in one center and 74 patients underwent RIRS in the other. The stone-free rate (SFR) was statistically significantly higher in Group 1 on POD-1 (98.66% vs. 89.19%; p = 0.015), and was still higher in Group 1 on POD-30 (98.66% vs. 93.24%, p = 0.092) SFR on both POD-1 and POD-30 for lower pole calculi was higher in Group 1 (100 vs. 82.61%, p = 0.047 and 100 vs 92.61% p = 0.171). The mean (SD) operative time was significantly shorter in Group 1 at 36.43 min (14.07) vs 51.15 (17.95) mins (p < 0.0001). The mean hemoglobin drop was significantly less in Group 1 (0.31 vs 0.53 gm%; p = 0.020). There were more Clavien-Dindo complications in Group 2 (p = 0.021). The mean VAS pain score was significantly less in Group 2 at 6 and 12 h postoperatively (2.52 vs 3.67, 1.85 vs 2.40, respectively: p < 0.0001), whereas the mean VAS pain score was significantly less in Group 1 at 24 h postoperatively (0.31 vs 1.01, p < 0.0001). The mean hospital stay was significantly shorter in Group 1 (28.37 vs 45.70 h; p < 0.0001). CONCLUSION: SMP has significantly lower operative times, complication rates, shorter hospital stay, with higher stone-free rates compared to RIRS. SMP is associated with more early post-operative pain though.

Can trajectory nor-epinephrine infiltration reduce blood loss during percutaneous nephrolithotomy? A double-blinded randomized controlled trial.

PURPOSE: To determine the efficacy and safety of trajectory infiltration with 1:150 000 Norepinephrine (NE) in reducing blood loss during percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: This is a prospective randomized double-blinded placebo-controlled trial. In all, 140 consecutive patients underwent PCNL for the management of large renal calculi. They were randomly assigned (1:1) to one of either study groups, the NE-PCNL group (70 patients whose PCNL-trajectory was infiltrated by NE) or the Placebo group (saline PCNL) (70 patients whose PCNL tracts were infiltrated by normal saline). Procedure-related blood loss (the primary outcome) was assessed and statistically analyzed. Also, all other procedure-related events and complications were recorded and compared. RESULTS: The median blood loss was 378 ml (IQR: 252-504) in the NE-PCNL group versus 592 ml (IQR: 378-756) in the S-PCNL group (p < 0.0001). In addition, Hemoglobin and Hematocrit deficits were lower in NE-PCNL (p < 0.05). Patients who were randomized to the NE-PCNL group had a higher immediate stone-free rate (SFR) (80%) compared with those of the S-PCNL group (70%) (p = 0.034). However, no statistical differences were found in the final SFR. The reported overall complications between the 2 groups were similar (p > 0.05). Indeed, bleeding-related complications were 1 (1.4%) versus 10 (14.3%) for NE-PCNL and S-PCNL, respectively (p = 0.009). CONCLUSIONS: Trajectory infiltration of PCNL tracts by NE was found to be effective and safe in mitigation of PCNL-related blood loss. This step is a timeless and cost-effective as NE is readily available in surgical theaters and of very low cost.