Search

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., (© 2024 BJU International.)

Introduction: Associating minipercutaneous nephrolithotomy and retrograde flexible ureteroscopy (fURS) is called Mini Endoscopic Combined Intra-Renal Surgery (miniECIRS). It's a safe and efficient technique, also in children., Material and Methods: The video describes miniECIRS in a 12 month-old boy with an infectious pelvic left stone (16 mm) and multiple caliceal stones. The UAS used was a 10FR and the percutaneous access was a 14Fr with Clear-Petra® sheath., Results: The operative time was 180 min and blood losses were virtually absent. There were no intra- or post-operative complications and the patient was discharged at the 5th day. After 1 month, double J was removed having a stone free status., Conclusions: MiniECIRS with endoview puncture is a safe and efficient technique when performed by experienced hands. Therefore, it is an alternative to consider for the treatment of complex lithiasis in the pediatric population., Competing Interests: Conflict of interest None., (Copyright © 2024 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Objective: To identify the latest advances in suction devices and evaluate their effect in Retrograde intrarenal surgery (RIRS) and ureteroscopy for stones., Basic Procedures: A systematic literature search was performed on 4th January 2023 using Scopus, PubMed, and EMBASE. Only English papers were included; both pediatric and adult studies were accepted. Duplicate studies, case reports, letters to the editor, and meeting abstracts were excluded., Main Findings: Twenty-one papers were selected. Several methods have been proposed for suction use in RIRS, such as through the ureteral access sheath or directly to the scope. Artificial intelligence can also regulate this system, monitoring pressure and perfusion flow values. All the proposed techniques showed satisfactory perioperative results for operative time, stone-free rate (SFR), and residual fragments. Moreover, the reduction of intrarenal pressure (induced by aspiration) was also associated with a lower infection rate. Even the studies that considered kidney stones with a diameter of 20 mm or higher reported higher SFR and reduced postoperative complications. However, the lack of well-defined settings for suction pressure and fluid flow prevents the standardization of the procedure., Conclusion: Aspiration device in the surgical treatment of urinary stones favours a higher SFR, reducing infectious complications, as supported by the included studies. RIRS with a suction system provided to be a natural successor to the traditional technique, regulating intrarenal pressure and aspirating fine dust., (Copyright © 2023 AEU. Published by Elsevier España, S.L.U. All rights reserved.)

Introduction: Radiation via the use of imaging is a key tool in management of kidney stones. Simple measures are largely taken by the endourologists to implement the 'As Low As Reasonably Achievable' (ALARA) principle, including the use of fluoroless technique. We performed a scoping literature review to investigate the success and safety of fluoroless ureteroscopy (URS) or percutaneous nephrolithotomy (PCNL) procedures for the treatment of KSD., Methods: A literature review was performed searching bibliographic databases PubMed, EMBASE and Cochrane library, and 14 full papers were included in the review in accordance with the PRISMA guidelines., Results: Of the 2535 total procedures analysed, 823 were fluoroless URS vs. 556 fluoroscopic URS; and 734 fluoroless PCNL vs. 277 fluoroscopic PCNL. The SFR for fluoroless vs. fluoroscopic guided URS was 85.3% and 77%, respectively (p=0.2), while for fluoroless PCNL vs. fluoroscopic group was 83.8% and 84.6%, respectively (p=0.9). The overall Clavien-Dindo I/II and III/IV complications for fluoroless and fluoroscopic guided procedures were 3.1% (n=71) and 8.5% (n=131), and 1.7% (n=23) and 3% (n=47) respectively. Only 5 studies reported a failure of the fluoroscopic approach with a total of 30 (1.3%) failed procedures., Conclusion: The ALARA protocol has been implemented in endourology in numerous ways to protect both patients and healthcare workers during recent years. Fluoroless procedures for treatment of KSD are safe and effective with outcomes comparable to standard procedures and could become the new frontier of endourology in selected cases., (Copyright © 2023 The Author(s). Published by Elsevier España, S.L.U. All rights reserved.)

Introduction: Lithiasis in renal graft recipients might be a dangerous condition with a potential risk of organ function impairment., Evidence Acquisition: A systematic literature search was conducted through February 2023. The primary objective was to assess the incidence of lithiasis in kidney transplant (KT) recipients. The secondary objective was to assess the timing of stone formation, localization and composition of stones, possible treatment options, and the incidence of graft loss., Evidence Synthesis: A total of 41 non-randomized studies comprising 699 patients met our inclusion criteria. The age at lithiasis diagnosis ranged between 29-53 years. Incidence of urolithiasis ranged from 0.1-6.3%, usually diagnosed after 12 months from KT. Most of the stones were diagnosed in the calyces or in the pelvis. Calcium oxalate composition was the most frequent. Different treatment strategies were considered, namely active surveillance, ureteroscopy, percutaneous/combined approach, or open surgery. 15.73% of patients were submitted to extracorporeal shock wave lithotripsy (ESWL), while 26.75% underwent endoscopic lithotripsy or stone extraction. 18.03% of patients underwent percutaneous nephrolithotomy whilst 3.14% to a combined approach. Surgical lithotomy was performed in 5.01% of the cases. Global stone-free rate was around 80%., Conclusions: Lithiasis in kidney transplant is a rare condition usually diagnosed after one year after surgery and mostly located in the calyces and renal pelvis, more frequently of calcium oxalate composition. Each of the active treatments is associated with good results in terms of stone-free rate, thus the surgical technique should be chosen according to the patient's characteristics and surgeon preferences., (Copyright © 2023 The Author(s). Published by Elsevier España, S.L.U. All rights reserved.)

Introduction and Objectives: As well established flexible ureteroscopy (RIRS). There is still no evidence if gender can have any influence on the outcomes and complication when performing. This study aims to evaluate the role that gender has in performing flexible ureteroscopy from a large series of patients., Methods: This study retrospectively analyzed patients who underwent RIRS for renal stones from January 2018 to August 2021 within the multicentric FLEXOR registry. Demographics, stone characteristics, perioperative findings, results and complications were analyzed and compared between gender groups., Results: A total of 6669 patients were included, 66.1% were male and 33.9% were female. Stone characteristics was comparable between groups. Female patients had significant higher fever and positive urine culture rates (12% vs. 8% and 37% vs. 34%). Also, females had a slight longer hospital stay (3.8 vs. 3.5 days; P < 0.001) and more residual fragments after the procedure (23.03% vs. 20.97 (P = 0.032). Overall complications were slightly significantly higher in women (15.74% vs. 14% (P = 0.042)) mainly at the expense of fever rates (6.9% vs. 5.7%) whereas the risk of sepsis was similar in both groups. A multivariate analysis showed that larger stone size, multiple and lower pole stones seem to have a negative impact in the incidence of residual stones and complications., Conclusion: Our real life global study reflects that female gender may have a correlation with a slightly increased residual fragment rate and overall low grade complications. However, women can safely be treated with RIRS with no increased the rate of sepsis with appropriate care., (Copyright © 2023. Published by Elsevier España, S.L.U.)

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., (© 2023. The Author(s).)

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

Objectives: To compare the outcomes of using low-power (up to 30 W) vs high-power (up to 120 W) holmium lasers in retrograde intrarenal surgery (RIRS) in children and to analyze if lasering techniques and the use of access sheath have any influence on the outcomes. Methods: We retrospectively reviewed data from 9 centers of children who underwent RIRS with holmium laser for the treatment of kidney stones between January 2015 and December 2020. Patients were divided into two groups: high-power and low-power holmium laser. Clinical, perioperative variables and complications were analyzed. Outcomes were compared between groups using Student's t -test for continuous variables, and Chi-square and Fisher's exact test for categorical variables. A multivariable logistic regression analysis model was also performed. Results: A total of 314 patients were included. A high-power and low-power holmium laser was used in 97 and 217 patients, respectively. Clinical and demographic variables were comparable between both groups, except for stone size where the low-power group treated larger stones (mean 11.11 vs 9.70 mm, p  = 0.018). In the high-power laser group, a reduction in surgical time was found (mean 64.29 vs 75.27 minutes, p  = 0.018) with a significantly higher stone-free rate (SFR) (mean 81.4% vs 59%, p  < 0.001). We found no statistical differences in complication rates. The multivariate logistic regression model showed lower SFR in the low-power holmium group, especially with larger ( p  = 0.011) and multiple stones ( p  < 0.001). Conclusion: Our real-world pediatric multicenter study favors high-power holmium laser and establishes its safety and efficacy in children.

Purpose: To evaluate the perioperative outcomes of retrograde intra-renal surgery (RIRS) for lower pole stones (LPS) and factors affecting stone-free rate (SFR)., Methods: Data from 20 centers were retrospectively reviewed. Inclusion criteria were adult patients, normal renal anatomy, and LPS. Exclusion criteria were bilateral surgery, concomitant surgery for ureteral stones. SFR was defined as a single residual fragment (RF) ≤ 2 mm and evaluated 3-months after surgery. A multivariable logistic regression analysis was performed to assess factors associated with RF. Statistical significance was set at p value < 0.05., Results: 2946 patients were included. Mean age and stone size were 49.9 years 10.19 mm, with multiple LPS in 61.1% of cases. Total operation and laser time were 63.89 ± 37.65 and 17.34 ± 18.39 min, respectively. Mean hospital stay was 3.55 days. Hematuria requiring blood transfusion and fever/urinary infections requiring prolonged antibiotics occurred in 6.1% and 169 5.7% of cases, while sepsis with intensive-care admission in 1.1% of patients. On multivariate analysis, Multiple stones (OR 1.380), stone size (OR 1.865), and reusable ureteroscopes (OR 1.414) were significantly associated with RF, while Thulium fiber laser (TFL) (OR 0.341) and pre-stenting (OR 0.750) were less likely associated with RF., Conclusions: RIRS showed safety and efficacy for LPS with a mean diameter of 10 mm. This procedure can achieve a satisfactory SFR in pre-stented patients with a single and smaller stone, particularly with TFL use., (© 2023. The Author(s).)

Background: Endourologic interventions for urolithiasis in patients with anomalous kidneys can be challenging, and comparisons between these interventions are not well studied. We aim to compare the safety, outcomes and complications of retrograde intrarenal surgery (RIRS) versus percutaneous nephrolithotomy (PCNL) in patients with urolithiasis in anomalous kidneys., Methods: A propensity score-matched pair analysis (PSM) was performed on pooled patient data from 20 centers. 569 patients with anomalous kidneys (horseshoe kidney [HSK], ectopic kidney, malrotated kidney) and urolithiasis who received either PCNL or RIRS as the primary modality of intervention from 2010 to 2020 were analyzed. Patients were matched based on calculated propensity scores by a regression model using age, sex, comorbidities, stone size, and renal anomaly type as co-variates. Multivariate logistic regression of factors (mode of treatment [PCNL or RIRS], comorbidities, stone size) and their effects on outcomes of stone-free rate (SFR), need to abandon surgery due to intraoperative difficulty, postoperative hematuria and sepsis and were analyzed when applicable., Results: After PSM, there were a total of 127 pairs in each group. Overall, PCNL conferred a higher SFR compared to RIRS (OR=3.69, 95% CI 1.91-7.46, P<0.001), particularly in HSK (OR=3.33, 95% CI 1.22-9.99, P=0.023), and ectopic kidneys (OR=18.10, 95% CI 3.62-147.63, P=0.002), with no significant difference in malrotated kidneys. There was no significant difference in postoperative sepsis observed. Surgery was abandoned more often in RIRS than PCNL (6.3% vs. 0%, P=0.014). Although PSM provides a robust analysis due to baseline differences in the unmatched cohorts, this study was limited by an inevitable degree of selection bias., Conclusions: While both modalities are safe and efficacious, PCNL yields better SFR than RIRS in patients with anomalous kidneys, with no difference in postoperative sepsis rates. Patients may benefit from personalized management best carried out in high volume endourology centers.

Introduction: Percutaneous nephrolithotomy (PCNL) is one of the main approaches for the treatment of large and complex stones in pediatric patients. The patient position for PCNL has been classically divided into prone or supine and the prone position is more commonly used. One of the most feared complications of this surgical technique is colon injury and the objective of this work is to evaluate the incidence of retrorenal colon (RRC) both supine and prone position, in pediatric patients, through radiological images., Materials and Method: A retrosepctive review was performed of all abdominal CT scans performed in one center, in patients under 18 years since 2017 to 2019. The ideal path for percutaneous puncture was traced in the upper, middle, and lower calyces of both kidneys in the prone and supine positions and contact with the kidney and adjacent organs was evaluated, with a uro-radiologist. Chi-square test and Student's t test were applied., Results: 50 CT-scans were performed on 44 children. Patients had a mean age of 12.6 years and 71.4% were male. Twenty-five scans were performed in the prone and 25 in the supine position. The incidence of RRC for the left kidney (LK) was significantly higher in the lower calyx in prone position than in the supine position, 28% vs 4% (p = 0.049), and the right kidney (RK) presented RRC only in the prone position. The liver was the most frequent retrorenal organ (97.7%) for the RK, with a non-significant difference by position, while for the LK the spleen was the most frequent (61.1%)., Discussion: Colon injury is one of the most morbid complication in PCNL and one of the reasons to perform a CT scan before surgery, on which its incidence appears to be <1% in adults. The present study revealed RRC to be present in three (12%) patients in the supine position and seven (28%) patients in the prone position (p=0.15). These results were slightly higher from those reported in adults (supine: 1.7%-10%; prone: 6.8%-20%), but there are no reports in the literature on this issue to allow appropriate comparison. This is the first study to attempt to assess the incidence of RRC in children according to position., Conclusion: The incidence of RRC for an ideal puncture was significantly higher in the lower calyx of the left kidney in the prone position than in the supine position, and in the right kidney, the RRC only occurred in the prone position., (Copyright © 2022 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Purpose: To evaluate the learning curve of the simplified fluoroscopic biplanar (0-90º) puncture technique for percutaneous nephrolithotomy., Methods: We prospectively evaluated patients with renal stones treated with percutaneous nephrolithotomy by a single institution's fellows employing the simplified bi-planar (0-90º) fluoroscopic puncture technique for renal access. The learning curve was assessed with the fluoroscopic screening time and the percutaneous renal puncture time. Data obtained were compared to a subset of patients operated by a senior surgeon., Results: Eighty-nine patients were included in the study. Forty patients were operated by fellow-1, 39 by fellow-2, and 10 patients by the senior surgeon. Demographic data of all patients between groups were homogeneous, with no difference in gender (p = 0.432), age (p = 0.92), stone volume (p = 0.78), puncture laterality (p = 0.755), and body mass index (p = 0.365). The mean puncture time was 7.5, 4, and 3.1 min for fellow-1, fellow-2, and expert, respectively. The mean fluoroscopic screening time for the puncture was 10, 11, and 5.1 s for fellow-1, fellow-2, and the expert, respectively. Stone cases, both fellows needed to complete 10 procedures to match the senior surgeon in the mean puncture time (p = 0.046); meanwhile, the fluoroscopic screening time was equal even before to complete 10 procedures., Conclusion: This study suggests that with the simplified biplanar (0-90º) puncture technique, the fluoroscopic screening time used in the learning process is brief. A novice fellow could require to complete ten cases to flatten the learning curve treating complex stone cases, and a flat learning curve is seen since the beginning when treating simple renal stones., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To compare the safety and efficacy of RIRS in patients ≥ 80 years to a younger population., Methods: We retrospectively compared the data from patients ≥ 80 years of age undergoing RIRS with the data of a group of patients from 18 and < 80 years. Perioperative outcomes, complications and emergency department visits were compared between two groups., Results: A total of 173 patients were included in the study. Mean age was 44 (27-79) and 81 years-old (80-94), for younger and elderly group, respectively. Elderly patients had higher ASA scores (≥ 3) (28.6% vs 75.8%; p = 0.0001) and Charlson comorbidity index (1.99 vs 7.86; p = 0.0001), more diabetes (p = 0.006) and respiratory comorbidities (p = 0.002). No statistical difference was found between two groups in stone size (p = 0.614) and number (p = 0.152). Operative time (74.48 vs 102.96 min; p = 0.0001) and duration of hospitalisation (1.7 vs 2.9 days; p = 0.001) were longer for the elderly. Intraoperative complication rate did not show differences between the two groups (p = 0.166). Postoperative complications rates were similar between the cohorts (7.7% vs 9.5%; p = 0.682). The success rates were 67.5% in the younger group and 71.4% in the elderly group (p = 0.584). No difference was seen in stone recurrence (p = 0.73). A higher rate of visits to the emergency department was found in younger cohort (23.6% vs 11.6%; p = 0.046), mostly duo to stent-related symptoms., Conclusions: Despite the higher rate of comorbidity in the elderly group, RIRS was a safe procedure with similar complication rate and outcomes at an expense of higher operative time and hospital stay., (© 2020. Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Kidney stones are one of the longest known and most common diseases in the urinary tract, with a prevalence that ranges from 1% to 20%. Many phytotherapeutic and herbal medicines have been described for the treatment and prevention of kidney stones., Objective: The aim of this study was to perform a comprehensive review of publications on various phytotherapeutic and herbal medicines, including both clinical and animal studies., Results: Phytotherapy may influence the risk of recurrence of calcium oxalate and uric acid stones. The most solid evidence relates to Phyllanthus niruri, one of the most studied phytotherapeutics; findings suggest that it interferes with calcium oxalate crystallization, reduces hyperoxaluria and hyperuricosuria, and increases the efficacy of shock wave lithotripsy due to reduced crystallization, without significant adverse effects. Theobromine has been shown to reduce the crystallization of uric acid in patients and appears to be a promising supplement to treat such stones., Conclusion: Many phytotherapeutic and herbal agents have been studied for the treatment of urolithiasis, most of them only in a small number of patients or in animal models. Further randomized clinical trials are needed to evaluate the effects of these agents on kidney stones., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Non-contrast CT scan (NCCT) is becoming the standard imaging modality in urinary stone disease. Radiation dose remains an issue, especially for those patients who may need to undergo several CT scans for this indication during their lifetime. Low-dose and ultra-low-dose protocols exist, but there is limited data on the relationship between the minimum radiation dose capable of detecting stone fragments and stone composition., Methods: Seven different kinds of human kidney stone were selected. Fragments of 1, 2, 4 and 7 mm were obtained for each stone. Four fragments of the same material were placed in a porcine kidney. A CT scan was then used to scan the kidney at decreasing dosages of 140, 70, 30, 15 and 7mAs. The scans were repeated for each type of stone. Images were reviewed by two radiologists independently with the intent of identifying the stone composition and providing information on its position, dimensions and Hounsfield units (HU)., Results: All types of stone were visible at all settings. Only the 1-mm uric-acid fragment was not detected by both radiologists at 7 and 15 mAs. Dose Length product (DLP) decreased with the reduction in mAs. In terms of HU a statistically significant difference was observed between calcium-based and non-calcium-based stones. Stone dimensions and HU were not affected by the reductions in mAs., Conclusions: Ultra-low-dose CT has a good detection rate for all kinds of stone, even when the fragment size is small. Only small uric acid fragments need higher energy settings in order to be detected. When the stone composition is known after surgery for urolithiasis, the most appropriate CT scan setting could be suggested by the urologist during their follow-up.

Purpose: The purpose of this study was to evaluate the popcorn technique using a wide range of holmium laser settings and fiber sizes in a systematic in vitro assessment., Materials and Methods: Evaluations were done with 4 artificial stones in a collection tube. A fixed ureteroscope was inserted through a ureteral access sheath to provide constant irrigation flow and the laser was placed 1 mm from the bottom. Combinations of 0.5 to 1.5 J, 10 to 20 and 40 Hz, and long and short pulses were tested for 2 and 4 minutes. We used 273 and 365 μm laser fibers. All tests were repeated 3 times. The stones were weighed before and after the experiments to evaluate the setting efficiency. Significant predictors of a highly efficient technique were assessed., Results: A total of 144 tests were performed. Mean starting weight of the stones was 0.23 gm, which was consistent among the groups. After the experiment the median weight difference was 0.07 gm (range 0.01 to 0.24). When designating a 50% reduction in stone volume as the threshold indicating high efficiency, the significant predictors of an efficient popcorn technique were a long pulse (OR 2.7, 95% CI 1.05-7.15), a longer duration (OR 11.4, 95% CI 3.88-33.29), a small (273 μm) laser fiber (OR 0.23, 95% CI 0.08-0.70) and higher power (W) (OR 1.14, 95% CI 1.09-1.20)., Conclusions: Higher energy, a longer pulse, frequencies higher than 10 Hz, a longer duration and a smaller laser fiber predict a popcorn technique that is more efficient at reducing stone volume., (Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Objective: Cystine renal stone is the only clinical consequence of cystinuria, an autosomal recessive hereditary disease that affects an average of 1 out of 7,000 newborns, and whose geographical distribution varies significantly. The diagnosis and treatment of this condition is reviewed in the light of the advances in genetics and molecular biology., Methods: The evolution of current knowledge about this disease is reviewed., Results/conclusions: The advances over the last 8 years have led to the characterization, at the present time, of two genes responsible for this disease, which demonstrates its polygenic origin. By phenotype, cystinuria can be classified into two types: type 1 and non-type 1. Both types show genetic and biochemical, but not clinical differences. From the therapeutic viewpoint, the main objective is to eliminate existing calculi and, above all, prevent recurrence by acting on the pathophysiologic mechanisms of renal cystine. Experience shows that despite the correct use of our current therapeutic armamentarium and the application of the general guidelines discussed in this paper, some cystinuric patients still maintain an important stone-forming activity. Patient clinical evaluation and a genetic study of both patient and family will be decisive for phenotyping.

Objective: Although residual lithiasis after the application of shock waves is a situation that coexists with the procedure, in some cases it can be considered to be a failure of ESWL. The natural history and outcome of 244 cases of residual renal stone followed over a 5-year period are analyzed, and the approach based on a pre-established classification is discussed., Methods: Of 1,407 patients treated by ESWL for renal lithiasis during 1995, 244 cases with a renal calculus larger than 3 mm were followed for a period of 5 years after treatment and evaluated by clinical, radiological, ultrasound and analytical methods., Results: At 3 months post-ESWL, 1,013 cases (72%) were completely stone-free and 394 (28%) showed residual stone; of these, 244 (62%) had residual stone fragments greater than 3 mm. At 5 years, 190 (78%) remained stable and the remaining 54 (22%) showed stone regrowth that warranted additional treatments: 52 ESWL, 1 PNL and 1 partial nephrectomy. Despite the retreatments, only 42% became completely stone-free., Conclusions: A classification of residual renal stone can be established based on the data obtained to orient the approach in each case, although the frequency of residual stone can be reduced by the appropriate indication of ESWL. Once a renal stone has formed retreatments with ESWL cannot ensure complete elimination of the stone.

Objective: To review our series of lithiasis associated with megacalyosis, a rare disease entity., Methods/results: The clinical records of patients treated from 1976 to 1994 were reviewed. Of 39 cases of megacalyosis, 27 were associated with lithiasis and was slightly more prevalent in males (59.3%). Struvite and whewelite calculi were more prevalent and 40.7% also had urinary tract infection, E. coli, Pseudomonas and Proteus being the most frequent pathogens. ESWL with hyperhydration was the most frequently utilized treatment., Conclusions: Megacalyosis is an embryogenic anomaly of Malpighi's pyramids that is associated with lithiasis in 69.2% of our series, frequently localized to the left side. We have found no significant difference according to sex or a hereditary component. IVP is the principal diagnostic method for megacalyosis. The frequent association of urinary tract infection should be taken into account when instituting treatment.

From 1989 to 1993, 11,535 extracorporeal shock wave lithotripsy (ESWL) sessions were performed in 6,066 patients in our centre. In contrast, simple or extended pyelolithotomy was the treatment of choice in a small group of patients. The object of this paper is to review the results and complications of this type of operation. A total of 57 pyelolithotomies was performed, including 33 extended pyelolithotomies, in 55 patients (26 men and 29 women). The mean age of the series was 50 years (range: 5-77). The operated kidney was the left kidney in 34 cases and the right kidney in 23 cases. The mean interval between the diagnosis and the operation was 31 months. 64% of the patients had history of stone disease (33 ipsilateral and 2 bilateral). Thirteen patients had already been treated by ESWL (10 patients), percutaneous nephrolithotomy (PNL) (2 cases) and one case had previously undergone pyelolithotomy. A urinary tract infection was observed in 26 patients (47%). The incision consisted of lumbotomy in 40 patients (71%), or a subcostal incision in 12 cases. The mean operating time was 161 minutes (range: 90-245) and the mean intraoperative bleeding was 500 ml. Thirteen patients were transfused (23%). The renal artery had to be clamped in 9 cases (for an average of 19 minutes). After a mean follow-up of 20 month, 50.8% of patients were stone-free. 49% of patients presented residual caliceal fragments on the immediate postoperative X-ray. One patient had to be treated by percutaneous nephrolithotomy and ESWL. 12 cases (41% of patients with residual fragments) required subsequent treatment by ESWL and the remaining patients with residual fragments were asymptomatic and did not receive any further treatment. The immediate postoperative complication rate was 17% and 10% of patients developed late postoperative complications. Simple or extended pyelolithotomy remains an effective treatment for stones of the renal pelvis, either on its own or associated with ESWL. However, the possibility of serious complications demands meticulous patient selection.

Two hundred seventy patients undergoing resection of renal or lumbar ureteral stones with percutaneous nephrolithotomy (PNL) were reviewed. The observed complications were of three types: circulatory, respiratory and metabolic (reabsorption syndrome). The rate of patients with any complication was 38.9% (104 patients). The most common type were circulatory complications, found in 75 patients (27.7%). Respiratory complications developed in 22 patients (8.1%), and the remaining 2 patients (0.74%) had reabsorption syndrome. Six cases of severe complications developed (2.22%), i.e.: one electromechanical dissociation, one ventricular tachycardia, one reabsorption syndrome and two severe difficulties for ventilation. In addition, one patient died (0.37%).

Calculus formation in the renal transplanted patient is uncommon and usually represents a late complication of secondary hyperparathyroidism. A case report of a gouty patient with a transplanted cadaveric kidney is presented. The patient presented without hypercalcemia, or urinary infection, or renal tubular acidosis, or ureteral obstruction, or ingestion of antacids, or metabolic disease, or previous graft lithiasis. Five months after transplantation, a large stone within the renal pelvis was observed on an x-ray film. The radiotransparent nucleus, the patient's past history and the acute gouty arthritis he presented in the immediate postoperative period suggested that the nucleus of the calculus might be mainly composed of uric acid. These facts have drawn our attention to the control of the purine metabolism in the renal transplanted patients who have a past history consistent with gout.