Association between NDUFS1 from urinary extracellular vesicles and decreased differential renal function in children with ureteropelvic junction obstruction.

BACKGROUND: Ureteropelvic junction obstruction (UPJO) is the most common cause of pediatric congenital hydronephrosis, and continuous kidney function monitoring plays a role in guiding the treatment of UPJO. In this study, we aimed to explore the differentially expressed proteins (DEPs) in the urinary extracellular vesicles(uEVs) of children with UPJO and determine potential biomarkers of uEVs proteins that reflect kidney function changes. METHODS: Preoperative urine samples from 6 unilateral UPJO patients were collected and divided into two groups: differential renal function (DRF) ≥ 40% and DRF < 40%.We subsequently used data-independent acquisition (DIA) to identify and quantify uEVs proteins in urine, screened for DEPs between the two groups, and analyzed biofunctional enrichment information. The proteomic data were evaluated by Western blotting and enzyme-linked immunosorbent assay (ELISA) in a new UPJO testing cohort. RESULTS: After one-way ANOVA, a P adj value < 0.05 (P-value corrected by Benjamin-Hochberg) was taken, and the absolute value of the difference multiple was more than 1.5 as the screening basis for obtaining 334 DEPs. After analyzing the enrichment of the DEPs according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment combined with the protein-protein interaction (PPI) network results, we selected nicotinamide adenine dinucleotide-ubiquinone oxidoreductase core subunit S1 (NDUFS1) for further detection. The expression of NDUFS1 in uEVs was significantly lower in patients with DRF < 40% (1.182 ± 0.437 vs. 1.818 ± 0.489, P < 0.05), and the expression level of NDUFS1 was correlated with the DRF in the affected kidney (r = 0.78, P < 0.05). However, the NDUFS1 concentration in intravesical urine was not necessarily related to the change in DRF (r = 0.28, P = 0.24). CONCLUSIONS: Reduced expression of NDUFS1 in uEVs might indicate the decline of DRF in children with UPJO.

Propensity score matched analysis of treatment outcomes in pediatric ureteropelvic junction obstruction: a comparison between horseshoe and non-horseshoe kidneys.

BACKGROUND: Pediatric hydronephrosis poses distinct challenges, particularly in cases involving horseshoe kidneys (HSK). This retrospective study compares treatment outcomes between HSK and non-horseshoe kidneys (NHSK) in pediatric ureteropelvic junction obstruction (UPJO) patients. METHODS: A retrospective cohort study included 35 patients with HSK and 790 patients with NHSK undergoing pyeloplasty. Preoperative, intraoperative, and postoperative parameters were evaluated. Propensity score matching (PSM) balanced patient characteristics in the NHSK group. RESULTS: In comparison with NHSK, HSK exhibited a higher crossing vessel incidence (51.6% vs. 5.12%, P < 0.001) and smaller preoperative anteroposterior pelvic diameter (APD). Post 6 and 12 months, NHSK maintained a larger APD, with a higher P/C ratio at 12 months. PSM retained significantly higher crossing vessel incidence in HSK (51.6 vs. 3.61%, P < 0.001). Laparoscopic pyeloplasty (LP) in HSK showed lower postoperative length of stay (LOS). Postoperative ultrasound parameters favored NHSK. In HSK and NHSK with crossing vessels, HSK demonstrated higher complications even post-PSM (38.5% vs. 0%, P = 0.039). CONCLUSIONS: The study emphasizes the importance of recognizing crossing vessels in HSK-related hydronephrosis. Surgical success, although comparable between HSK and NHSK, requires tailored approaches. This investigation contributes valuable insights to pediatric urology, emphasizing personalized management for optimal outcomes.

Diagnosis and Management of Ureteropelvic Obstruction in Kidney Transplant Recipients and Outcomes of Foley Y-V Pyeloplasty.

OBJECTIVES: To evaluate the etiology and diagnostic tools for ureteropelvic obstruction in kidney transplant recipients, we investigated the short-term and long-term outcomes of Foley Y-V pyeloplasty. MATERIALS AND METHODS: We retrospectively reviewed 10 patients who underwent kidney transplant followed by additional interventions to treat obstructive ureteral pathologies between 2016 and 2020. We enrolled 4 patients who had received intervention to treat ureteropelvic obstruction. For these 4 patients, serum creatinine and estimated glomerular filtration rate levels were recorded at baseline, during the symptomatic period, and long-term. In this single center study, we investigated diagnostic tools and management strategies for ureteropelvic obstruction and assessed performance of Foley Y-V nondismembered pyeloplasty in kidney transplant recipients. RESULTS: Among 4 patients, graft function (assessed by serum creatinine and estimated glomerular filtration rate) worsened significantly (P = .03) in the symptomatic period of ureteropelvic obstruction in all patients; however, graft function levels improved rapidly to levels similar to baseline (P = .07) after Y-V pyeloplasty. In addition, no statistically significant difference was detected between baseline and longterm graft functions afterY-V pyeloplasty in follow-up (P = .28). CONCLUSIONS: Diagnosis and management of ureteropelvic obstruction in kidney transplant recipients are challenging due to rarity and lack of an ideal management algorithm.There is no specific diagnostic tool to discriminate this pathology from other ureteral pathologies; therefore, a regimen of conventional imaging modalities and diuretic renogram combined with endoscopic evaluation is more reliable. Moreover, nondismembered Foley Y-V pyeloplasty is effective and safe for graft function in the short-term and long-term.

The association between renal pelvis urine density and the risk of severe infectious complications in patient with symptom-free hydronephrosis after shock wave lithotripsy: a multi-center prospective study.

Finding reliable and easy-to-obtain predictors of severe infectious complications after shock wave lithotripsy (SWL) is a major clinical need, particular in symptom-free hydronephrosis. Therefore, we aim to prospectively investigate the predictive value of Hounsfield units (HU) in renal pelvis urine for the risk of severe infectious complications in patients with ureteral stones and symptom-free hydronephrosis after SWL. This multi-center prospective study was conducted from June 2020 to December 2023. The HU of renal pelvis urine was measured by non-enhanced computed tomography. The severe infectious complications included systemic inflammatory response syndrome, sepsis, and septic shock. Binary logistic regression models assessed the odds ratios (ORs) and 95% confidence intervals (CIs). Finally, 1,436 patients with ureteral stones were enrolled in this study. 8.9% (128/1,436) of patients experienced severe infectious complications after SWL treatment. After adjusting confounding variables, compared with the patients in the lowest renal pelvis urine density quartile, the OR (95% CI) for the highest quartile was 32.36 (13.32, 78.60). There was a positive linear association between the HU value of renal pelvis urine and the risk of severe infectious complications after SWL (P for trend < 0.001). Furthermore, this association was also observed stratified by age, gender, BMI, stone size, stone location and hydronephrosis grade (all P for interaction > 0.05). Additionally, the nonlinear association employed by restricted cubic splines is not statistically significant (nonlinear P = 0.256). The AUROC and 95%CI of renal pelvis urine density were 0.895 (0.862 to 0.927, P value < 0.001). The cut-off value was 12.0 HU with 78.59% sensitivity and 85.94% specificity. This multi-center prospective study demonstrated a positive linear association between HU in renal pelvis urine and the risk of severe infectious complications in patients with ureteral stones and symptom-free hydronephrosis after SWL, regardless of age, gender, BMI, stone size, stone location, and hydronephrosis grade. These findings might be helpful in the SWL treatment decision-making process.

Prone vs supine percutaneous nephrolithotomy: does position affect renal pelvic pressures?

The purpose of this study was to measure and compare renal pelvic pressure (RPP) between prone and supine percutaneous nephrolithotomy (PCNL) in a benchtop model. Six identical silicone kidney models were placed into anatomically correct prone or supine torsos constructed from patient CT scans in the corresponding positions. A 30-Fr renal access sheath was placed in either the upper, middle, or lower pole calyx for both prone and supine positions. Two 9-mm BegoStones were placed in the respective calyx and RPPs were measured at baseline, irrigating with a rigid nephroscope, and irrigating with a flexible nephroscope. Five trials were conducted for each access in both prone and supine positions. The average baseline RPP in the prone position was significantly higher than the supine position (9.1 vs 2.7 mmHg; p < 0.001). Similarly, the average RPP in prone was significantly higher than supine when using both the rigid and flexible nephroscopes. When comparing RPPs for upper, middle, and lower pole access sites, there was no significant difference in pressures in either prone or supine positions (p > 0.05 for all). Overall, when combining all pressures at baseline and with irrigation, with all access sites and types of scopes, the mean RPP was significantly higher in the prone position compared to the supine position (14.0 vs 3.2 mmHg; p < 0.001). RPPs were significantly higher in the prone position compared to the supine position in all conditions tested. These differences in RPPs between prone and supine PCNL could in part explain the different clinical outcomes, including postoperative fever and stone-free rates.

Ureteral duplicity with a left ureterocele: a case report.

An intravesical ureterocele is a rare condition in which a terminal ureter terminates in a cystic dilation of the bladder. We present the case of a 42-year-old female who presented with irritative lower urinary tract symptoms and left lower back pain. Computed tomography (CT) urography revealed ureteral duplication with a ureterocele complicated by upper tract obstruction. Treatment involved endoscopic ureterocelotomy, which successfully relieved symptoms and resolved renal obstruction.

Effect of nephrostomy sheath size on renal pelvic pressure during endoscopic combined intrarenal surgery: artificial kidney model study.

BACKGROUND: This study aimed to evaluate the intrarenal pelvic pressure in endoscopic combined intrarenal surgery using an artificial kidney model. METHODS: An artificial kidney model was created using the Urovac evacuator™. Four sizes of nephrostomy sheaths (MIP-L: 25/26 Fr, MIP-M: 16.5/17.5 Fr, MIP-S: 11/12 Fr, MIP-XS: 8.5/9.5 Fr) and two sizes of ureteral access sheaths (12/14 Fr and 10/12 Fr) were installed into the model. For each combination of nephrostomy and ureteral access sheath, renal pelvic pressure was measured with and without insertion of the retrograde flexible ureteroscope. Irrigation from the nephroscope was adjusted to 40-160 mmHg using an automatic irrigation device, and the irrigation of the ureteroscope was by spontaneous dripping at 80 cmH2O. Conditions were measured six times, and the renal pelvic pressure was compared in different conditions. RESULTS: Without ureteroscope insertion through the ureteral access sheath, the renal pelvic pressure never exceeded 30 mmHg. Meanwhile, when the ureteroscope was inserted, the renal pelvic pressure increased as the nephrostomy sheath and ureteral access sheath became narrower and as the irrigation pressure increased. Intrarenal pelvic pressure exceeded 30 mmHg when the irrigation pressure was increased in 12/14 Fr ureteral access sheath when MIP-XS was used, and in 10/12 Fr ureteral access sheath when MIP-XS and MIP-S were used. CONCLUSIONS: The use of a thin nephrostomy sheath in endoscopic combined intrarenal surgery can lead to increased intrarenal pelvic pressure. Although our results are from an artificial kidney model, special care is suggested to be required when using a retrograde flexible ureteroscope simultaneously in treatment of patients.

Area of hydronephrosis is a useful predictive factor of impacted ureteral stones.

Ureteroscopic lithotripsy for impacted stones is challenging, but it is important to predict impacted stones preoperatively. Hydronephrosis, which is evaluated by a grading system, is often apparent in impacted stones. However, the currently used grading system is a qualitative evaluation. We, therefore, focused on a quantitative evaluation: the area of hydronephrosis. The aim of this study was to investigate whether the area of hydronephrosis could predict impacted stones more accurately than Society for Fetal Urology grade. We retrospectively identified 160 patients who underwent ureteroscopic lithotripsy for ureteral stones at our hospital between January 2014 and April 2022. Impacted stones were defined as stones fixed to the ureteral wall that could not be moved by means of ureteroscopic manipulation or water pressure. Of the 160 patients, 54 (33.8%) had impacted stones. Comparing patient characteristics, there were significant differences in stone size, ureteral wall thickness, Society for Fetal Urology grade, renal pelvic width and area of hydronephrosis (all P < 0.01). Receiver operating characteristic analysis showed that area of hydronephrosis was the more significant predictive value (area under the curve 0.781) compared with Society for Fetal Urology grade (area under the curve 0.676, P < 0.01). Multivariate analysis revealed that significant independent predictive factors of impacted stones were thicker ureteral wall thickness and larger area of hydronephrosis (both P < 0.01). The area of hydronephrosis and ureteral wall thickness were significant predictors of impacted stones in patients undergoing ureteroscopic lithotripsy for ureteral stones. These factors may be useful for selecting the treatment and preoperative settings.

Low anterolateral incision for single-port extraperitoneal robot-assisted pyeloplasty: description of technique and initial experience.

PURPOSE: This study aims to describe the surgical steps for the single-port low anterolateral extraperitoneal approach to pyeloplasty, report its feasibility, and share the initial outcomes of our experience. METHODS: We analyzed all consecutive patients who underwent single-port low anterolateral extraperitoneal pyeloplasty due to ureteropelvic junction obstruction (UPJO). The surgical steps included a pure single-port approach through a 3.5 cm low anterolateral incision two fingerbreadths above the superior pubic ramus. The ureter was localized and followed cranially, a dismembered pyeloplasty was performed, and a running ureteropelvic anastomosis was completed. No drains were placed. The urinary catheter was removed upon discharge, and the ureteral stent after 3-5 weeks. RESULTS: A total of eight cases (two adults and six children) were completed successfully, without complications or conversions. Median operative time, console time, and estimated blood loss were 208.5 min, 114.5 min, and 10.0 ml, respectively. All patients were discharged within 24 h, except for one that required urinary output observation due to retention. There were no major postoperative complications. The median pain score at discharge was 0/10. Only one patient was prescribed PRN opioids at discharge. The readmission rate was 0.0%. All patients were asymptomatic on their last follow-up with no definitive obstruction on imaging, and no requirement for additional procedures or stents. CONCLUSION: Single-port low anterolateral extraperitoneal pyeloplasty is a feasible alternative for surgical treatment of UPJO in adult and pediatric patients with improved recovery outcomes.

New infundibulopelvic angle measurement method can predict stone-free rates following retrograde intrarenal surgery.

To enhance the accuracy of predicting stone-free rates after retrograde intrarenal surgery, we devised a novel approach to assess the renal infundibulopelvic angle. We conducted a retrospective review of patient records for those who underwent retrograde intrarenal surgery for renal stones between April 2018 and August 2019. Patient demographics, stone characteristics, and perioperative data were recorded. Subsequently, we introduced a modified angle measurement called the pelvic stone angle and evaluated its predictive performance for stone-free rates by comparing it with the traditional method in scoring systems. A total of 43 individuals were included in this study. Notable differences in stone burden and Hounsfield unit measurements were found between stone-free and non-stone-free patients. The pelvic stone angle demonstrated a good model fit when used in scoring systems, performing equally well as the conventional approach. The area under the receiver operating characteristic curve for the R.I.R.S. scoring system using the pelvic stone angle and the conventional approach did not show a significant difference. In conclusion, the predictive ability of the pelvic stone angle for stone-free rates was comparable to the old measurement method. Moreover, scoring systems using the pelvic stone angle exhibited a better model fit than those using the conventional approach.

Treatment of ureteropelvic junction obstruction in patients with renal calculi via laparoscopic pyeloplasty and flexible vacuum-assisted ureteral access sheath ureteroscopy: a multicenter retrospective observational study.

BACKGROUND: Ureteropelvic junction obstruction (UPJO) is a common obstructive disease of the urinary tract. UPJO patients commonly exhibit coexistent renal calculi. The main aim of therapy is to relieve the obstruction and remove the stones at the same time. METHODS: This retrospective study included 110 patients diagnosed with UPJO coexisting with multiple renal calculi at Shanxi Bethune Hospital and the First Hospital of Shanxi Medical University between March 2016 and January 2022. Patients were divided according to the methods used for dealing with UPJO and renal calculi. In Group A, patients underwent traditional open pyeloplasty and pyelolithotomy. In Group B, patients underwent percutaneous nephrolithotomy first and then laparoscopic pyeloplasty. In Group C, patients underwent flexible cystoscopy to remove stones and then laparoscopic pyeloplasty. In Group D, patients underwent flexible vacuum-assisted ureteral access sheath (FV-UAS)assisted flexible ureteroscopy (f-URS) and underwent laparoscopic pyeloplasty. The stones were broken up using a holmium laser. The pyeloplasty success rate, stone clearance rate, operation time, bleeding amount, complication occurrence rate, postsurgical pain, length of stay, and hospitalization cost were compared between the groups. The follow-up period was at least 2 years. RESULTS: The use of f-URS and the FV-UAS, significantly increased the renal stone clearance rate and significantly reduced the complication incidence and operation time in UPJO patients with multiple coexisting renal calculi. CONCLUSIONS: Laparoscopic pyeloplasty combined with f-URS and FV-UAS is safe and effective for treating UPJO in patients complicated by renal caliceal stones. TRIAL REGISTRATION: Retrospectively registered.

Single port robot-assisted pyeloplasty: An early comparative outcomes analysis.

BACKGROUND: The treatment paradigm for ureteropelvic junction obstruction (UPJO) has shifted towards minimally invasive pyeloplasty. A comparison Single Port (SP) and Multi Port (MP) robot-assisted pyeloplasty (RAP) was performed. METHODS: Data from consecutive patients undergoing SP RAP or MP RAP between January 2021 and September 2023 were collected and analysed. Co-primary outcomes were length of stay (LOS), Defense and Veterans Pain Rating Scale (DVPRS), and narcotic dose. The choice of the robotic system depended on the surgeon's preference and availability of a specific robotic platform. RESULTS: A total of 10 SP RAPs and 12 MP RAPs were identified. SP RAP patients were significantly younger [23 years (20-34)] than MP RAP [42 years (35.5-47.5), p < 0.01]. No difference in terms of OT (p = 0.6), LOS (p = 0.1), DVPRS (p = 0.2) and narcotic dose (p = 0.1) between the two groups was observed. CONCLUSIONS: SP RAP can be implemented without compromising surgical outcomes and potentially offering some clinical advantages.

Focus on Upper Urinary Tract Stones Combined with Parenchymal Infiltrative Renal Pelvis Cancer.

INTRODUCTION: Upper urinary tract stones combined with parenchymal infiltrative renal pelvic cancer are challenging to detect on imaging and to evaluate the differential diagnosis. CASE PRESENTATION: The symptoms and diagnoses in three cases of parenchymal infiltrative renal pelvic cancer and upper urinary tract stones that occurred between June 2019 and June 2022 were reviewed. Primary symptoms of lumbar discomfort and hematuria were evident in all 3 patients. Preoperative computed tomography (CT) abdominal imaging revealed that all three cases had hydronephrosis along with renal stones, while the other two cases only had localized hypoenhancement of the renal parenchyma, which was only thought to be limited inflammatory changes in the renal cortex as a result of the combination of renal pelvis infection. After percutaneous nephrolithotomy or ureteroscopic lithotripsy, a combined renal pelvis tumor was discovered in all of these instances. Radical tumor surgery was later performed. One patient who had several tumor metastases passed away 6 months after surgery. A case with multiple metastases was discovered 15 months after surgery and survived with the help of the current chemotherapy. A case with a bladder tumor recurrence was discovered 16 months after surgery and had transurethral bladder tumor electrosurgery and routine bladder perfusion chemotherapy. CONCLUSION: Upper urinary tract stones and parenchymal infiltrative pyel carcinoma have atypical imaging, easily confused with infectious diseases. CT or computed tomography urography (CTU) must be considered by urologists. Patients who have a CT with local renal parenchyma density should be suspected of having parenchymal invasive renal pelvis carcinoma; a needle biopsy ought to be performed; and repeat biopsies may be performed if necessary. High-risk individuals need multiple, sufficient biopsies as needed and a comprehensive intraoperative assessment of the renal pelvic mucosa.

Retroperitoneoscopic Simple Nondismembered Pyeloplasty with Da Vinci Si Assistance to Prevent Alignment Shift.

Aims: Retroperitoneoscopic simple nondismembered pyeloplasty (SNDP) with da Vinci Si assistance was developed because of a possible risk for alignment shift after retroperitoneoscopic diamond-shaped bypass pyeloplasty (Diamond-Bypass; DP). Outcomes of SNDP and DP were compared. Materials and Methods: For SNDP, a small longitudinal incision is made on the border of the dilated pelvis and narrowed ureter at the ureteropelvic junction (UPJ). Extending this incision toward the pelvis allows identification of mucosa while maintaining the integrity of surrounding tissues that are so thin and fragile that they will not influence lumen alignment. Data for DP were obtained from a previously published article. Results: For SNDP (n = 3), mean age at surgery was 2.67 years (range: 1-4), mean operative time was 176 minutes. Mean postoperative Society of Fetal Urology (SFU) grades for hydronephrosis were 1.2, 0.7, and 0.6, 1, 2, and 3 months after stent removal, respectively. Postoperative diethylenetriaminepentaacetic acid (DTPA) was normal (n = 3). For DP (n = 5) mean age at surgery was 4.3 years (range: 1-14), mean operative time was 189 minutes. Mean postoperative SFU grades were 2.8, 2.2, and 1.6, respectively. Postoperative DTPA was normal (n = 4) and delayed (n = 1). All SNDP and DP were asymptomatic by 3 months after stent removal. Conclusion: Both SNDP and DP have favorable outcomes. If the UPJ is located at the lowest end of the renal pelvis, SNDP may improve hydronephrosis more quickly.

Robotic pyeloplasty: Technological global panacea or geo-surgical nightmare?

To the Editor, Pelvi-ureteric junction obstruction (PUJO) is a well-recognised clinical entity characterised by functionally significant impairment of drainage of urine at the level of the pelvi-ureteric junction due to extrinsic or intrinsic obstruction and is encountered both by adult and paediatric urologists alike. Management of PUJO has been surgical historically, and the gold standard has been an open Anderson-Hynes dismembered pyeloplasty [...].

Experimental study of a new technique for minimally invasive percutaneous nephrolithotomy: intelligent pressure-controlled minimally invasive percutaneous nephrolithotomy.

BACKGROUND: To test the reliability and safety of a newly invented technique for minimally invasive percutaneous nephrolithotomy, intelligent pressure-controlled minimally invasive percutaneous nephrolithotomy (IPC-MPCNL). METHODS: Eighteen kidneys of nine female pigs were randomly divided into three groups. Those in Groups A and B underwent IPC-MPCNL through the new system composed of a pressure-measuring MPCNL suctioning sheath and an irrigation and suctioning platform with pressure feedback control. The infusion flow rate was 500 ml/min in Group A and 750 ml/min in Group B. Those in Group C underwent MPCNL at an infusion flow rate of 500 ml/min. The renal pelvic pressure (RPP) monitored by a ureteral catheter and that monitored by the pressure-measuring sheath in Groups A and B were compared. The RPP in Group C was monitored by a ureteral catheter. RESULTS: The RPP measured by the pressure-measuring sheath and that measured by the ureteral catheter in Group A was - 5.59 ± 1.95 mmHg and 4.46 ± 2.08 mmHg, respectively. The RPP measured by the pressure-measuring sheath and that measured by the ureteral catheter in Group B was - 4.00 ± 2.01 mmHg and 5.92 ± 2.05 mmHg, respectively. Hence, the RPPs measured by the pressure-measuring sheath in Groups A and B were consistent with those measured by the ureteral catheter. The RPP in Group C was 27.75 ± 5.98 mmHg (large fluctuations). CONCLUSIONS: IPC-MPCNL can be used to accurately monitor the RPP and maintain it within a preset safe range via suction. The new technique and the new system are safe and reliable.

Kidney collecting system anatomy applied to endourology - a narrative review.

OBJECTIVE: To evaluate the surgical anatomy of the kidney collecting system through a narrative review of the literature, highlighting its importance during diagnosis and its approach during surgical procedures for the treatment of renal stones. MATERIAL AND METHODS: We carried out a review about the anatomy of the kidney collecting system. We analyzed papers published in the past 40 years in the databases Pubmed, Embase and Scielo, and we included only papers in English and excluded case reports, editorials and opinions of specialists. RESULTS: Renal collecting system could be divided in four groups: A1 - kidney midzone (KM), drained by minor calyx that are dependent on the superior or the inferior caliceal groups; A2 - KM drained by crossed calyx, one draining into the superior caliceal group and another draining into the inferior caliceal group; B1 - KM drained by a major caliceal group independent of both the superior and inferior groups; and B2 - KM drained by minor calyx entering directly into the renal pelvis. Some details and anatomic variations of the collecting system are related to clinical and radiological aspects, particularly perpendicular calyces, interpyelocalyx space, position of calyces in relation to renal border, classification of the renal collecting system, infundibular diameter and the angle between the lower infundibulum and renal pelvis. CONCLUSION: The knowledge of intra-renal collecting system divisions and variations as the angle between the renal pelvis and lower infundibula, position of the calices in relationship with renal edge and the diameter and position of the calyces are important for the planning of minimally invasive renal surgeries.

Intrinsic ureteric obstruction secondary to endometriosis: a rare clinical entity causing obstructive uropathy and renal failure.

Ureteral endometriosis is rare and can be a silent clinical entity, which can potentially lead to serious complications such as obstructive uropathy, sepsis and renal failure. A high clinical suspicion is required especially in childbearing age groups due to non-specific presentation such as renal colic, recurrent urinary tract infection (UTI), renal failure or asymptomatic hydronephrosis.A woman in her 40s presented with febrile UTI and flank pain. She reportedly suffered from recurrent UTIs in the past. Initial workup revealed an infected, obstructed left renal collecting system with gross hydronephrosis and hydroureter to the distal ureter on a significant gynaecological background of severe endometriosis requiring hysterectomy in the past.CT showed chronic obstructive changes and soft tissue nodules within the renal pelvis with no radio-opaque stones. She underwent emergent ureteric stent insertion. Functional imaging demonstrated only 1% contribution of the left kidney with a preserved estimated glomerular filtration rate of 65 mL/min/1.73 m2Endoscopic evaluation of ureters found extensive soft tissue lesions throughout the dilated left collecting system with biopsy-confirmed endometriosis. Subsequently, she underwent laparoscopic nephroureterectomy due to extensive ureteric involvement and chronically obstructed non-functioning kidney. Histopathology demonstrated completely obstructing ureteral endometriosis.Ureteric obstruction secondary to endometriosis can be due to extrinsic or intrinsic disease. In addition to initial assessment with CT urogram MRI may be helpful to evaluate soft tissue thickening. Endoscopic assessment with ureteroscopy and biopsy is required for tissue diagnosis. Surgery is often the treatment of choice, ranging from ureteroureterostomy, ureteroneocystostomy or nephroureterectomy in severe cases.Ureteral endometriosis is a rare clinical entity, clinicians should remain vigilant about common presentations of this rare entity, early diagnosis and prompt treatment is crucial to prevent progression to renal failure.