Glycolate oxidase-1 gene variants influence the risk of hyperoxaluria and renal stone development.

PURPOSE: Oxalate is an excellent calcium ion attractor with great abundance in the human body, and the liver is the major source of oxalate. The Glycolate oxidase-1 (GOX1) gene is solely responsible for the glycolate and glyoxylate metabolism and produces oxalate. This study has been designed to comprehend the association of genetic variants of the GOX1 gene with the risk of hyperoxaluria and renal stone disease in the Indian population. METHOD: The present study is a candidate gene approach prospective case-control study carried out on 300 participants (150 cases and 150 controls) at Muljibhai Patel Urological Hospital, Gujarat, India. Biochemical parameters, including serum levels of calcium, creatinine, parathyroid hormone, and 24-h urine metabolites, were performed. The genotyping of GOX1 gene variants rs6086287, rs2235250, rs2255183, and rs2294303 was performed using a customized TaqMan assay probe by RT-PCR. RESULT: Parathyroid hormone, serum creatinine, and urine metabolites were significantly elevated in nephrolithiasis compared to healthy individuals. All mutated homozygous genotypes GG (rs6086287), TT (rs2235250), GG (rs2255183), and CC (rs2294303) were significantly associated with a high risk of renal stone disease. Individuals diagnosed with hyperoxaluria and carrying TG (rs6086287), AG (rs2255183), and TT (rs2294303) genotypes have a significantly high risk of renal stone disease. Moreover, haplotype analysis and correlation analysis also confirmed the strong association between genetic variants and nephrolithiasis. CONCLUSION: Genetic variants of the GOX1 genes were associated with renal stone disease. In the presence of risk genotype and hyperoxaluria, the susceptibility to develop renal stone disease risk gets modulated.

Zero-echo time MRI: an alternative method for the diagnosis of urinary stones in children.

OBJECTIVES: To evaluate the potential of zero-echo time-magnetic resonance imaging (ZTE-MRI) in the assessment of urolithiasis and compare ZTE-MRI with computed tomography (CT) in pediatric patients. MATERIALS AND METHODS: This was a single-center, prospective cross-sectional study conducted between April 2023 and December 2023. 23 patients (12 girls, 11 boys; mean age: 12.3, range 1-18) with urinary tract stones detected on non-enhanced abdominal CT were enrolled. The images were evaluated independently by two radiologists for the presence, and number of stones in the kidneys, ureters, and bladder. In the second session, two radiologists evaluated whether urinary tract stones could be detected by MRI compared to CT, and the maximum diameter of the stones was measured. The CT and MRI results were compared with the Wilcoxon test. The agreement between the results of the observers was examined using Spearman's rho correlation coefficient and the intraclass correlation coefficient. RESULTS: A total of 58 urinary tract stones were detected by CT and 39 of these were detected by MRI. Most of the stones that MRI could not detect were < 5 mm and the detection sensitivity of MRI increased in correlation with stone size (p < 0.001). There was poor intermodality agreement for stones < 5 mm, substantial agreement for stones 5-10 mm, and almost perfect agreement for stones > 10 mm. Interobserver agreement for stone detection on MRI was almost perfect for stones > 10 mm and 5-10 mm and was substantial for stones < 5 mm. CONCLUSION: ZTE-MRI is a promising modality for detecting urinary stones without radiation exposure in children. CLINICAL RELEVANCE STATEMENT: Zero-echo time-magnetic resonance imaging is a potential method for identifying urinary stones in children and other populations who are particularly sensitive to radiation. KEY POINTS: Urinary system stone disease in children is increasing and imaging is needed for managing urolithiasis. Zero-echo time-magnetic resonance imaging (ZTE-MRI) had an accuracy of 81.8% and 93.7% for stones larger than 5 mm and 10 mm, respectively. ZTE-MRI is a potential non-irradiating method for the diagnosis and management of urolithiasis.

Flexible Ureteroscopy with a Tip-Flexible Pressure-Controlling Ureteral Access Sheath for Renal Stones in Children.

INTRODUCTION: The aim of this study was to evaluate the safety and efficacy of flexible ureteroscopy using a tip-flexible pressure-controlling ureteral access sheath (TFPC-UAS) for renal stones in children. METHODS: Consecutive patients aged 5-18 years with renal stones of diameter 1-3 cm were enrolled between January 2022 and November 2023 at Ganzhou People's Hospital. The patients were treated with flexible ureteroscopy using the TFPC-UAS. The renal pelvic pressure (RPP) parameters were set as follows: control value at -10 mm Hg to 5 mm Hg, warning value at 20 mm Hg, and limit value at 30 mm Hg. The infusion flow rate was set to 100-120 mL/min. A holmium laser (276 µm) was used to fragment the stone at 2.0-2.5 J/pulse with a frequency of 20-30 pulses/s. The cases were analyzed for RPP, operative time, stone-free rate, and complications. RESULTS: A total of 21 consecutive patients were included. Two patients were switched to percutaneous nephrolithotomy owing to sheath placement failure. The RPP was -4.6 ± 2.1 mm Hg. The mean operative time was 56.5 ± 17.1 min. The postoperative hospitalization time was 1.5 ± 0.3 days. The stone-free rates at 1 day and 1 month after surgery were 81.0% and 85.7%, respectively. Residual stones in 2 patients were cleared after extracorporeal shockwave lithotripsy. Three cases of Clavien I complications and one case of Clavien II complications occurred. No major complications (Clavien grade III-V) were observed. CONCLUSIONS: Flexible ureteroscopy with a TFPC-UAS is safe and effective for renal stones in children.

First 100 Reported Cases of Supine Percutaneous Nephrolithotomy in Malaysia: An Alternative Effective and Safe Approach to Treat Renal Stones.

Background: Supine percutaneous nephrolithotomy (s-PCNL) offers great benefits from urological and anaesthetic points of view. We present the first evaluation of the outcomes of s-PCNL in Malaysia. Our aim was to explore the safety and efficacy of s-PCNL. Methods: Institutional review board approval was obtained from the National Medical Research Register (NMRR ID-21002225-WLP). We retrospectively reviewed 115 patients with renal pelvis stones who underwent single renal access during s-PCNL between November 2020 and May 2023. Patients who underwent simultaneous ipsilateral or contralateral endourological procedures were included. The data were analysed to determine stone-free rates (SFR), major complication rates, blood transfusion rates, operative times and lengths of hospital stay (LOS). Results: The SFR was higher for the single middle calyceal renal access (MCA) group than for the lower calyceal renal access (LCA) or upper calyceal renal access (UCA) groups (OR: 1.76; 95% confidence interval [CI]: 0.63, 4.92). In total, 0, 1 and 2 patients had major complications in the UCA, MCA and LCA groups, respectively (P = 0.453). One of the 115 patients (0.9%) needed blood transfusion. Subgroup analysis revealed mean operative times of 76.3 min and 78.6 min for patients who underwent sole s-PCNL (PCNL-only group) and those who had simultaneous ipsilateral and contralateral endourological procedures (PCNL-plus group), respectively (P = 0.786). The overall mean LOS was 2.9 days. Conclusion: s-PCNL is a safe and effective alternative treatment for renal stones. We would recommend s-PCNL for patients who require an ipsilateral/contralateral endourological procedure (URS/RIRS) because it is time-efficient. All renal accesses are safe. Single MCA is recommended for complete stone clearance.

Learning Curve for Endoscopic Combined Intra-Renal Surgery Using Vacuum-Assisted Device.

INTRODUCTION: The aim of the study was to provide data related to endoscopic combined intra-renal surgery learning curve using minimally invasive techniques with vacuum-assisted devices. Minimal data exist on the learning curve for these techniques. METHODS: We conducted a prospective study monitoring the training of a mentored surgeon learning ECIRS with vacuum assistance. We use varied parameters for improvements. After collection of peri-operative data, tendency lines and CUSUM analysis were used to investigate the learning curves. RESULTS: 111 patients have been included. Guy's Stone Score 3 and 4 stones 51.3% of all cases. The mostly used percutaneous sheath was 16 Fr (87.3%). SFR was 78.4%. 52.3% patients were tubeless, and 38.7% achieved trifecta. High-degree complication rate was 3.6%. Operative time improved after 72 cases. We observed a decrease of complications throughout the case series, with improvement after 17 cases. In terms of trifecta, proficiency was reached after 53 cases. Proficiency seems achievable in a limited number of procedures, but results did not plateau. Higher number of cases might be necessary for excellence. DISCUSSION: A surgeon learning ECIRS with vacuum assistance can obtain proficiency in 17-50 cases. The number of procedures required for excellence remains unclear. Exclusion of more complex cases might positively affect the training, reducing unnecessary complications.

Evaluation of the safety and efficiency of color Doppler ultrasound-guided percutaneous nephrolithotomy in clinical practice: results from a retrospective study.

This study evaluated the clinical value of color Doppler ultrasound-guided percutaneous nephrolithotomy (PCNL) in avoiding bleeding caused by punctured blood vessels. Herein, we retrospectively included patients who underwent color Doppler ultrasound-guided PCNL or PCNL using the conventional channel technique from August 2018 to August 2022. The clinical characteristics of patients during surgery, complications, and hospital stay were recorded and compared. Overall, 228 patients were enrolled, with 126 patients (age, 47.6 ± 13.2 years; men: 57.14%) in the color Doppler ultrasound-guided PCNL group and 102 patients (age, 46.6 ± 12.3 years) in the B-mode ultrasound-guided puncture group. The total operation time (63.5 ± 15.5 vs. 61.3 ± 16.3 min, p = .5236) and stone clearance rate (86.50% vs. 83.33%, p = .7139) were similar between the two groups. However, the puncture time for the color Doppler ultrasound-guided PCNL group was longer than that for the B-mode ultrasound-guided puncture group (5.1 ± 2.3 vs. 2.6 ± 1.6 min, p = .0019). Moreover, the length of postoperative hospital stay in the color Doppler ultrasound-guided PCNL group reduced significantly by ∼1 day compared with that in the B-mode ultrasound-guided puncture group (4.5 ± 1.6 vs. 5.6 ± 2.1 days, p = .0087). The blood transfusion rate (1.58% vs. 4.9%, p = .0399), sedation-related adverse event rate (0.79% vs. 2.9%, p = .0332), perineal hematoma incidence (0% vs. 2.94%, p < .0001), and serum decreased hemoglobin levels (12.2 ± 9.7 vs. 23.5 ± 10.1 g/L, p < .001) after color Doppler ultrasound-guided PCNL were significantly lower than those after B-mode ultrasound-guided puncture. The stone clearance rate was similar between the two groups, with a similar operation time. Moreover, color Doppler ultrasound-guided PCNL shortened the postoperative hospital stay and decreased Hb levels, blood transfusion rate, and perineal hematoma incidence.

Ureteropelvic junction obstruction and renal calculi: Simultaneous treatment by robot-assisted laparoscopic pyeloplasty and transcutaneous retrograde flexible ureteroscopy. Technique description and early outcomes.

BACKGROUND: Ureteropelvic junction obstruction (UPJO) and renal calculi are associated in 20 to 30% of cases and treatment is mandatory. The simultaneous surgical management is a therapeutic challenge that is still a source of controversy. We describe our technique combining robot-assisted laparoscopic pyeloplasty and transcutaneous retrograde flexible ureteroscopy (fURS), assessing the feasibility of simultaneous treatment through an original technique. METHODS: This single centre series reports our initial experience with 12 patients. From January 2014 to September 2018, 12 patients underwent robot-assisted laparoscopic pyeloplasty with simultaneous fURS for UPJO and renal calculi. Mean age was 46 years (24-68). 92% had multiple renal stones and the mean cumulative stone diameter was 31,3mm. Robot-assisted pyeloplasty was performed with peroperative transcutaneous retrograde fURS through a ureteral access sheath introduced in an incision on the bassinet through a subcostal trocar. Stone extraction was performed using a basket. RESULTS: All patients underwent surgery successfully, achieving UPJ repair and complete stone extraction. Mean operating time was 92,5min (85-110). All reported Clavien-Dindo complications were grade 1. Non-contrast enhanced abdominal CT performed 1 month after surgery confirmed the absence of residual stones in all patients. Mean follow-up time was 10 months with no recurrence of UPJO. CONCLUSION: This small series confirms the feasibility with good surgical results of concomitant robot-assisted laparoscopic pyeloplasty and transcutaneous retrograde fURS stone extraction. No major complications were observed. This technique is easily reproducible but requires 2 experienced urologists to be achieved in a contained operative time.

Outcomes and lessons learnt from practice of retrograde intrarenal surgery (RIRS) in a paediatric setting of various age groups: a global study across 8 centres.

PURPOSE: To analyse and report the practice, outcomes and lessons learnt from a global series of retrograde intrarenal surgery (RIRS) in a paediatric multicentre series. METHODS: A retrospective review of anonymized pooled data gathered globally from 8 centres in paediatric patients (≤ 18 years of age) who had renal stones and underwent RIRS from 2015 to 2020 was performed. Patient demographics, perioperative parameters, stone characteristics, complications and stone-free rate (SFR; defined as endoscopically stone free and/or residual fragments < 2 mm on follow up imaging) were analysed. The cohort was stratified into 3 groups by age: < 5 years (Group A), 5-10 years (Group B) and > 10 years (Group C). Overall, post-operative complication rate was 13.7%. Chi-square comparisons were used for categorical variables; analysis of variance (ANOVA) or Kruskal-Wallis tests were used for continuous variables. RESULTS: 314 patients were analysed. The mean age was 9.54 ± 4.76 years. Groups A, B and C had 67 (21.3%), 83 (26.4%) and 164 (52.2%) patients, respectively. Mean stone size was 10.7 ± 4.62 mm. Pre-stenting was performed in 155 (49.4%) of patients, ureteral access sheaths (UAS) was used in 54.5% of patients with majority (71%) utilizing holmium laser for stone fragmentation. All complications were minor (Clavien-Dindo grade 1 and 2). SFR was 75.5%. CONCLUSIONS: RIRS is acceptable as a first-line intervention in the paediatric population with reasonable efficacy and low morbidity. Complications are slightly higher in patients < 5 years of age, which should be taken into account while counselling patients.

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.

Hem-o-Lok clip migration into renal pelvis and stone formation as a long-term complication following laparoscopic pyelolithotomy: a case report and literature review.

BACKGROUND: Hem-o-Lok clips (HOLCs) are widely used in minimal access urological operations due to the advantage of vascular control and suture stabilization. In rare cases, however, they can develop problems themselves. Migration of HOLCs into the collecting system is a fairly rare complication after laparoscopic pyelolithotomy. To date, only two cases were reported in the literature. CASE PRESENTATION: This article describes a case of 51-year-old man with a complaint of left flank pain. He had a medical history of ipsilateral retroperitoneal laparoscopic pyelolithotomy at another hospital 8 years ago. Non-contrast CT scan demonstrated a renal stone in the left ureteropelvic junction complicated by mild hydronephrosis. A straight foreign body was found near the renal pelvis, with part of it wedging into renal pelvic wall. A percutaneous nephrolithotomy (PNL) was performed for this patient. After some fragmentation, a HOLC was found in the kernel of the stone. With an alligator plier, the clip was totally removed out of the collecting system. The postoperative period and follow-up were uneventful. CONCLUSIONS: HOLC migration into renal pelvis is a rare complication following laparoscopic pyelolithotomy. It could act as nidus for stone formation under extended exposure to urine. Using HOLCs to stabilize the anastomotic suture near renal pelvis should be avoided to prevent this complication. Instead, knotting is a better choice under such condition. The secondary calculi and dislodged HOLCs can be removed through PNL by an alligator plier after laser lithotripsy.

Gas-containing renal stones: a red flag for renal infection.

BACKGROUND: Gas in the renal excretory system is described as a consequence of recent procedures but it can be a sign of severe conditions such as fistulas or infections; however, gas-containing renal stones are only rarely encountered. PURPOSE: To describe the association of gas-containing renal stones and urinary tract infection. MATERIAL AND METHODS: We performed a retrospective evaluation of the clinical and imaging findings in a series of six patients with gas-containing renal stones and compared our findings with those of patients with gas-containing renal stones reported in the literature. Urine and stone cultures were used as a diagnostic standard for urinary tract infection. RESULTS: Including the present series, there is a total of 21 patients with gas-containing renal stones in the literature. Based on clinical presentation, urinary tract infection could be suspected in 10 (57%) patients, while urine and/or stone cultures showed infection in 18 of 19 (95%) patients, with only one case with no bacterial growth in both (5%); in the remaining patient the information was not available. CONCLUSION: Gas-containing renal stones are a rarely reported entity usually diagnosed with computed tomography. They are a radiological sign often associated with urinary tract infection that can also be encountered in patients with non-specific renal symptoms.

Counter-Irrigation as a Novel Technique versus the Standard Technique in Percutaneous Nephrolithotomy: A Prospective Randomized Trial.

OBJECTIVE: This study aimed to evaluate the efficacy of our counter-irrigation technique versus the standard technique in percutaneous nephrolithotomy (PCNL) by assessment of the stone-free rate after the procedures and its safety in terms of comparing the intraoperative time, Hb deficit, blood transfusion, length of hospital stay, auxiliary procedures, and perioperative complications with that of the standard one. METHODS: This prospective randomized trial was conducted on patients with renal stone 2-3 cm in diameter without contraindications to PCNL. The patients were randomized into group A in which the counter-irrigation technique has been performed and group B who were managed by the standard technique. The preoperative characteristics including demographic data and stone parameters were compared between both groups. The primary outcome was the stone-free rate assessed by noncontrast spiral CT after 3 months. The secondary outcome included intraoperative time, Hb deficit, blood transfusion, hospital stay, auxiliary procedure required, and rate of complications. RESULTS: Forty-eight patients were included in this study. Overall, no significant difference was observed between both groups regarding preoperative characteristics, Hb deficit, and complication rate. Operative time was significantly shorter in group B (p = 0.001). None of our patients required blood transfusion. The stone-free rates at 3 months were significantly better in group A (95% for group A and 70% for group B, p = 0.04). CONCLUSIONS: Our results indicate that our counter-irrigation technique has lower stone migration with subsequent significantly better stone-free rate versus the standard technique. We can recommend this technique as a potentially valid option for cases with large stone burden when the access to the upper calyx is feasible to minimize significant residual fragments.

Double-Sheath Vacuum Suction Minimally Invasive Percutaneous Nephrolithotomy for Management of Large Renal Stones.

OBJECTIVES: This study aimed to describe a novel double-sheath vacuum suction minimally invasive percutaneous nephrolithotomy (mini-PCNL) to overcome the deficiencies of the conventional procedure. PATIENTS AND METHODS: Between March 2019 and December 2019, 65 patients (37 males and 28 females) with a mean age of 41 years (range 23-69) underwent mini-PCNL with double-sheath vacuum suction. It consisted of an F20 Y-shaped sheath as an outer sheath and an F16 Y-shaped sheath as an inner sheath, in which the inner sheath was longer than the outer sheath. The oblique arm of the outer sheath and the inner sheath was connected to the perfusion inflow and the vacuum suction, respectively. A 550-µm holmium-YAG laser was introduced for stone fragmentation through the working channel of the mini-nephroscope, which was no longer connected to the perfusion fluid. RESULTS: All procedures were successful. Mean operation time was 50.2 min (range 39-83). Mean hemoglobin decrease was 5.2 g/L (range 1.0-15.5), and no patient needed a blood transfusion. One patient (1.5%) with low fever (<38°C) at day 1 had returned to normal at day 2 without administration of antibiotics. There were no Clavien grade 2-4 complications. Mean postoperative hospital stay was 2.4 days (range 2-6). The initial stone-free rate of PCNL was 81.53% (53 of 65 patients). One month after surgery, the final stone-free rate increased to 90.77% (59/65 patients). CONCLUSIONS: The double-sheath vacuum suction mini-PCNL is a safe and effective modality for large renal stones, which might increase the efficiency of stone extraction with low intrapelvic pressure.

Evaluation of the optimal duration for retrograde intrarenal stone surgery to prevent postoperative complications.

OBJECTIVE: To evaluate retrograde intrarenal surgery (RIRS) outcomes and to determine the effect of operative time on complications of RIRS. METHODS: Patients undergoing RIRS for renal stones were evaluated. These patients were divided into two groups according to the operation time (Group 1<60 minutes and Group 2>60 minutes). Peroperative outcomes such as fluoroscopy time, stone-free rates, complications and duration of hospitalization were compared. RESULTS: Group 1 consisted of 264 patients and Group 2 consisted of 297 patients. SFR rates, duration of hospitalization, and postoperative urinary tract infection rates were similar in both groups. Fluoroscopy time was 7.8±7.3 (0-49) sec in group 1 and 13.1±9.8 (0-81) sec in group 2. Complications according to modified Clavien-Dindo classification system (MCDCS) were 13 and 32 patients (Grade 1), 31 and 63 patients (Grade 2), 1 and 1 patient (Grade 3) in group 1 and 2, respectively. There was statistical difference between the two groups in terms of duration of fluoroscopy time and the MCDCS. Although duration of hospitalization and UTI rates were higher in group 2, no statistical significance was observed among groups. CONCLUSION: Limiting the operation time to 60 minutes in RIRS seems to be important in reducing postoperative complications.

Innovative way to break the stone: Master lithoclast for bilateral simultaneous Percutaneous Nephrolithotomy.

The objective of our study was to evaluate the efficacy of Master Lithoclast, also known as trilogy lithoclast, in simultaneous bilateral Percutaneous Nephrolithotomy (PCNL). The study was a prospective case series, involving 40 patients undergoing bilateral simultaneous PCNL, with 20 (50%) males and 20 (50%) females. The mean age of subjects was 32.9±7.9 years. In Guy's stone scoring 7(17.5%) patients classified in Group I, 28 (70%) in group II and the remaining 5(12.5%) patients were placed in group III. Total operative time observed was 74.8±17.9 minutes. Complete stone clearance was observed in 30 (75%) patients. In conclusion, study data confirmed that Master Lithoclast provides faster stone clearance and is unaffected by the composition of stones, ease of usability, and improved tissue safety with reduced chances of fragments blocking are key factors.

MINIMALLY INVASIVE PERCUTANEOUS NEPHROLITHOTRYPSY IN THE TREATMENT OF PATIENTS WITH KIDNEY STONES.

OBJECTIVE: The aim: To evaluate the outcomes and complications rate of minipercutaneous nephrolithotripsy (MPCNL) for renal stones treatment. PATIENTS AND METHODS: Materials and methods: MPCNL was performed to 123 patients with kidney stones from January 2020 till November 2021. All operations were performed under endotracheal inhalation anesthesia. After the ureteral catheter was introduced ultrasound controlled punction of kidney collecting system and work channel dilation were performed. Stones were fragmented by holmium laser. The fragments extracted passively with fluid flow through the outer sheath. Operation ended by introduction of nephrostomy tube 14Ch. RESULTS: Results: In total 135 MPCNLs were performed in 123 patients. The average duration of operations was 55±5,4 minutes and stone size was 1,6±0,2 sm. 12 patients were per¬formed simultaneous MPCNL on both sides. The simultaneous MPCNL duration amounted 105±8,1 min. In 3 (2,2%) cases residual stones were observed. The average hospital stay was 1,31±0,2 days. The renal drainage was removed in 24 ± 3,2 hours after operation. Acute pyelonephritis was presented in 4 (3,3%) and postoperative bleeding in 2 (1,6%) patients, which were stopped by antibacterial and hemostatic drugs with drainage occlusion respectively. CONCLUSION: Conclusions: To advantages of MPCNL belong short hospital stay, high safety level, insignificant intraoperative and postoperative bleeding, good operation field visualization, opportunity of quick removal of renal drainage, ureteral and urethral catheters. Benefit in patients with severe comorbidities, opportunity of simultaneous bilateral MPCNL and almost complete postoperative pain absence allow to consider MPCNL the operation of choice in kidney stone management.

[Safety and efficacy of percutaneous nephrolithotomy in patients with neurogenic bladder]. / Néphrolithotomie percutanée chez les patients neurologiques : efficacité et morbidité à long terme.

INTRODUCTION: To assess the efficacy and morbidity of percutaneous nephrolithotomy (PNLT) in the treatment of renal stones in patients with neurogenic lower urinary tract dysfunction (NLUTD). METHODS: Retrospective, monocentric study including all patients with NLUTD who had undergone PNLT between 2005 and 2017. Pre-operative clinical data (neurological condition, voiding mode, preoperative urine culture…), peri-operative and post-operative data (success and morbidity) were collected from the patients' charts. Success was defined by the absence of residual fragment (RF), on imaging or intraoperative endoscopy. Partial efficacy was defined by the presence of RF lower than 4mm. Early complications were reported according to the Clavien-Dindo classification. RESULTS: In all, 53 PNLTs were performed, in 35 patients, mostly with spinal cord injury. The success and partial efficacy rates were 66.0% and 71.7% respectively. The failure rate was correlated with increased stone burden (P=0.03), increased size of the largest stone (P=0.02), and the presence of complex stones (P<0.02). The rate of early complications was 41.5%, with 27.3% major, mostly septic, and bleeding. The retreatment rate within 3 years was 41.5%. CONCLUSION: In patients with NLUTD, PNLT allows a high success rate, but with a significant rate of retreatment and infectious complications. However, NLPC remains the gold standard in this population, especially for renal stones larger 20mm, allowing a higher success rate than ureteroscopy and a lower retreatment rate.

[The tale of two stones in an obstructed partial duplex kidney: case presentation].

Duplex renal systems is a common anomalies. Incidence rate of 0.8% in healthy adult population and 2-4% in patients investigated for urinary tract symptoms. Urolithiasis management for patients with anomalies is complex and require proper imaging and planning. We have a patient with a partial duplex collecting system presented with a right renal calculus in a non-functioning lower moiety and multiple distal ureteric calculi. Preoperative planning done and surgery performed with good outcome without any early and late complications.

Double-sheath vacuum suction versus vacuum-assisted sheath minimally invasive percutaneous nephrolithotomy for management of large renal stones: single-center experience.

PURPOSE: To compare double-sheath vacuum suction minimally invasive percutaneous nephrolithotomy (DS-mini-PCNL) with vacuum-assisted mini-PCNL (VS-mini-PCNL) and to better define the potential benefits of DS-mini-PCNL. METHODS: Between July 2019 and May 2020, 117 patients with large radiopaque renal stones underwent mini-PCNL. Of these, 63 underwent DS-mini-PCNL and 54 underwent VS-mini-PCNL. For VS-mini-PCNL, a F20 Y-shaped sheath was used and the oblique arm of the sheath was connected to the vacuum suction. For DS-mini-PCNL, the oblique arm of a F20 Y-shaped sheath (the outer sheath) and a F16 Y-shaped sheath (the inner sheath) was connected to the perfusion inflow and the vacuum suction, respectively. A 550-µm holmium-YAG laser was used for stone fragmentation. RESULTS: Compared with VS-mini-PCNL group, DS-mini-PCNL group had significantly shorter operative time (35.78 ± 7.77 min vs. 44.56 ± 13.19 min; P = 0.000) and significantly lower fever rate (1.6% vs. 11.1%; P = 0.048). It was not significantly different between the two groups despite the higher initial stone-free rate seen for DS-mini-PCNL group relative to VS-mini-PCNL group (87.7% vs. 81.5%, P = 0.346). Auxiliary procedure rates were 4.8% (three patients) in DS-mini-PCNL group and 16.7% (nine patients) in VS-mini-PCNL group, with a significant difference (P = 0.034). The difference in the final stone-free rate between the two groups was rendered insignificant (93.8% vs. 89.1%, P = 0.510). CONCLUSIONS: DS-mini-PCNL is a safe and effective modality for large renal stones, which could increase the efficiency of stone extraction and decrease infectious complications compared with VS-mini-PCNL.

Tea and coffee consumption and pathophysiology related to kidney stone formation: a systematic review.

OBJECTIVE: To explore the mechanisms behind the potential protective effect of coffee and tea consumption, regarding urinary stone formation, previously demonstrated in large epidemiological studies. METHODS: A systematic review was performed using the Medline, Cochrane library (CENTRAL) and Scopus databases, in concordance with the PRISMA statement. English, French and Spanish language studies, regarding the consumption of caffeinated and decaffeinated coffee and tea, and the relationship to urinary stone formation were reviewed. Meta-analyses, systematic reviews, case reports and letters, unpublished studies, posters and comments abstracts were excluded. RESULTS: As per the inclusion criteria, 13 studies were included in the final review. The major findings show that caffeine increases urinary excretion of calcium, sodium and magnesium, in addition to a diuretic action with consumption > 300-360 mg (approximately four cups of coffee). Together with other components of coffee, this beverage might have potential protective effects against the formation of urinary stones. Tea exerts many protective effects against stone formation, through the accompanying water intake, the action of caffeine and the effects of components with antioxidant properties. CONCLUSION: Caffeine has a hypercalciuric effect, balanced partially by a diuretic effect which appears after consumption of large quantities of caffeine. The current available literature supports in general, a potentially protective role for tea against stone formation, mainly for green tea. Additional standardization in this field of research, through specification of tea and coffee types studied, and their respective compositions, is needed for further clarification of the relation between coffee, tea and urinary stones.