Ureteropelvic junction obstruction in the first three months of life: is sex a prognostic factor?

OBJECTIVE: Ureteropelvic junction obstruction (UPJO) is a blockage that occurs at the point where the renal pelvis (the part of the kidney where urine collects) meets the ureter (the tube that carries urine from the kidney to the bladder). This study compared outcomes between male and female patients with UPJO. PATIENTS AND METHODS: 402 UPJO patients diagnosed and treated before the age of three months were divided into two groups: males and females. The following information was extracted: age at diagnosis, age at surgery, the parenchymal thickness of the UPJ and contralateral sides (preoperatively and at 1 and 3 years postoperatively), pelvic diameter, and kidney function. RESULTS: There were 287 male and 115 female patients (a ratio of 2.5:1). The parenchymal thickness (PTs) at diagnosis and surgery were 5(4) mm and 5(3) mm in males, respectively. In females, these values were 5(3) mm and 6(5) mm, respectively. There was a significant decrease in male PT at the time of surgery compared to diagnosis (p<0.05). After the first postoperative year, PTs were 8(4) mm and 9(4) mm in males and females, respectively, and after the third postoperative year, PTs were 9(4) mm and 10(4.75) mm in males and females, respectively. CONCLUSIONS: Among patients diagnosed with UPJO during the first three months of life, males had a more severe disease course than females. Additionally, females experienced better clinical improvement during the long-term postoperative period.

Laparoscopic assisted dismembered pyeloplasty versus open pyeloplasty in UPJO with poorly function kidney in pediatrics.

BACKGROUND: The management of UPJO with poor function kidney, less than 10%, has been the subject of debate for more than a decade. Some authors have recommended nephrectomy, while others favor renal salvage (pyeloplasty). We report our experience with laparoscopic assisted pyeloplasty in pediatric patients with poorly functioning kidneys in comparison with an open approach. MATERIALS AND METHODS: A retrospective study was conducted to review 65 patients who were diagnosed with hydronephrosis and had impaired renal function due to UPJO. The study was conducted in the pediatric surgery departments of Al-Azhar University Hospital and Fattouma Bourguiba University Hospital of Monastir over a period of 20 years. Limited to pediatric patients with UPJO with ≥ Grade III hydronephrosis, antero-posterior pelvic diameter ≥ 20 mm, as well as a renal function equal to or less than 10%, was corrected by laparoscopic assisted or open pyeloplasty. RESULTS: There were 40 cases in group A who underwent laparoscopic assisted pyeloplasty, and 25 cases in group B who underwent open pyeloplasty. There were no complications or difficulties during the operation. The mean operative time in group A was 90 ± 12 min, while in group B, it was 120 ± 11 min. The renal assessment parameters significantly improved in both groups. In group A, the mean split renal function was 7.9 ± 1.3% and increased to 22.2 ± 6.3%. In group B, the mean split renal function was 8.1 ± 1.1% and increased to 24.2 ± 5.1%. However, the differences between both groups in terms of pre-operative and post-operative renal functions were statistically insignificant. CONCLUSION: Laparoscopic assisted pyeloplasty is an effective treatment for patients with poorly functioning kidneys, especially those with less than 10% function. While this surgical procedure requires shorter operative times, it yields functional outcomes that are comparable to open approach.

Epidemiology of Infantile Ureteropelvic Junction Obstruction in the US.

OBJECTIVE: To describe sex- and diagnosis-specific comorbidities, outcomes, and secular trends associated with ureteropelvic junction obstruction (UPJO) in a large, real-world population diagnosed with hydronephrosis in infancy. MATERIALS AND METHODS: We identified all infants ≤1 year old with ≥1 claim in the Optum Clinformatics 2007-2020 nationwide population database and used univariable and multivariable Cox regression analyses to estimate associations of demographic and clinical characteristics of infants with a UPJO diagnosis with surgical status. RESULTS: Of 22,349 infants with hydronephrosis (1.1% of infants; males-1.4%, females-0.7%), 1722 (7.7%; 7.9%-males, 7.2%-females) had UPJO. Follow-up was ≥1 year in 1198 (70%) and ≥3 years in 555 (32%) cases, and UPJO repair was performed in 542 children (31.5%; 32.3%-males, 29.5%-females); 77.7% within 1 year and 97.3% within 3 years. UPJO repair was associated with prior urinary tract infection (UTI) (hazard ratio (HR) 1.41, 95% confidence interval (CI) 1.12-1.76) and South (HR 1.42, 95% CI 1.14-1.78) or Midwest (HR 1.60, 95% CI 1.26-2.04) geographic region but did not change over time. CONCLUSION: This population-based study provides a real-world view of postnatally diagnosed hydronephrosis, focusing on UPJO, for which 522 cases (∼1/3) had ≥3 years continuous coverage. UPJO-associated comorbidities were more common in females, and the frequencies of UPJO-associated surgery and comorbidities were higher than in other studies. Other than UTI, no other associated kidney or urinary tract diagnoses were associated with UPJO repair. We identified unique sex- and diagnosis-specific differences in associated comorbidities and interventions in children diagnosed with UPJO in the first year of life.

Spontaneous resolution and the role of endoscopic surgery in the treatment of primary obstructive megaureter: a review of the literature.

The megaureter accounts for almost a quarter of all urinary tract dilations diagnosed in utero and is the second leading cause of hydronephrosis in newborns, following pyeloureteral junction obstruction. The current standard treatment for progressive or persistent, symptomatic primary obstructive megaureter is ureteral anti-reflux reimplantation, which can be associated with ureteral remodeling or plication. Due to the associated morbidity, postoperative recovery challenges, and the complications that may arise from the open surgical approach, there has been a natural inclination towards validating new minimally invasive techniques. This study reviews the literature, extracting data from three major international databases, from 1998 to 2022. Out of 1172 initially identified articles, only 52 were deemed eligible, analyzing 1764 patients and 1981 renal units. Results show that 65% of cases required surgical intervention, with minimally invasive techniques constituting 56% of these procedures. High-pressure endoscopic balloon dilation was the preferred endourologic technique. The degree of ureterohydronephrosis is considered one of the factors indicating the need for surgery. There is an inverse relationship between the diameter of the ureter and the likelihood of spontaneous resolution. Conditions such as renal hypoplasia, renal dysplasia, or ectopic ureteral insertion strongly indicate a poor prognosis. Endoscopic surgical techniques for treating primary obstructive megaureter can be definitive, firstline treatment options. In selected cases, they might be at least as effective and safe as the open approach, but with advantages like quicker recovery, fewer complications, shorter hospital stays, and reduced costs.

Primary repair vs Delayed staged repair in infants with primary obstructive megaureters and their long term outcomes - A single centre experience.

BACKGROUND: There is paucity of literature in the management of infants with primary obstructive megaureters undergoing upfront primary repair with an extravesical technique of ureteral re implantation (with or without ureteral tailoring). OBJECTIVE: To compare 2 different approaches in the management of infants with unilateral primary obstructive megaureters. STUDY DESIGN: This was a retrospective analysis of a prospectively maintained data base between 2005 and 2021. Infants <1 year with unilateral primary obstructive megaureter were included. They were divided into 2 groups: those who underwent an upfront extravesical ureteric reimplantation with or without ureteral tailoring during infancy -Primary Repair (PR), and those who initially underwent a low end cutaneous ureterostomy during infancy followed by take down of ureterostomy and intravesical ureteric reimplantation after 1 year of age -Delayed staged repair (DSR). Children presenting with sepsis, in whom a diversion was imperative, were excluded. All children were followed up annually after their definitive repair with a renal ultrasound, diuretic renogram, estimated glomerular filtration rate and assessment of voiding dysfunction if present. The 1st year and 3rd year follow up details were collated and analysed. Failure was defined as persistent obstructive pattern on renogram with worsening differential renal function or presence of high grade reflux with recurrent breakthrough urinary tract infection; both of which necessitated a redo reimplantation following the definitive surgery. RESULTS: There were 18 infants in Primary repair and 16 infants in Delayed Staged Repair. Urinary tract infections was the commonest presenting symptom amongst both groups i.e. > 50%.The post operative complication rate was 11% in Primary repair and 31% in Delayed Staged Repair. One child in each of the groups (2 girls) required redo reimplantation (5.8%). At the end of the 3rd year follow up (from the definitive repair) there was significant reduction in the hydronephrosis, improvement in the differential renal function with no evidence of obstruction and improvement in the estimated glomerular filtration rate amongst all in both groups which was statistically significant i.e. p < 0.05. The success rate was 94.4% in Primary Repair and 93.75% in Delayed Staged Repair. The mean follow up was 9.7 years amongst those undergone Primary Repair and 9 years amongst those undergone Delayed Staged Repair. DISCUSSION AND CONCLUSION: Primary extravesical ureteral reimplantation may be considered as the preferred line of management of unilateral obstructed megaureters during infancy.

Electromechanically Functionalized Ureteral Stents for Wireless Obstruction Monitoring.

While millions of ureteral stents are placed in patients with urinary tract issues around the world every year, hydronephrosis still poses great danger to these patients as a common complication. In the present work, an intelligent double-J ureteral stent equipped with a micro pressure sensor and antenna circuitry is investigated and prototyped toward enabling continuous wireless monitoring of kidney pressure to detect a ureteral obstruction and the resultant hydronephrosis via the indwelling stent. This electromechanically functionalized "intelligent" ureteral stent acts as a radiofrequency resonator with a pressure-sensitive resonant frequency that can be interrogated using an external antenna to track the local pressure. The prototype passes mechanical bending tests of up to 15 cm radius of curvature and shows wireless sensing with a sensitivity of 3.1 kHz/mmHg in artificial urine, which represents 25× enhancement over the preceding design, using an in vitro model with test tissue layers and a pressure range that functions within the conditions found in hydronephrotic conditions. These promising results are expected to propel intelligent ureteral stent technology into further clinical research.

Outcomes of robotic-assisted pyeloplasty in symptomatic versus asymptomatic patients.

OBJECTIVE: To evaluate the outcome of robotic-assisted laparoscopic pyeloplasty (RAP) in symptomatic patients with ureteropelvic junction obstruction (UPJO) versus patients who were incidentally found to have UPJO. METHODS: We retrospectively reviewed the records of 141 patients who underwent RAP at Massachusetts General Hospital between 2008 and 2020. Patients were categorized into symptomatic group and asymptomatic group. We compared patient demographics as well as preoperative and postoperative symptoms and functional renal scans. RESULTS: The study population included 108 patients in the symptomatic group and 33 patients in the asymptomatic group. Mean age was 46 ± 17 years with average follow-up time of 12 ± 18 months. Asymptomatic patients had significantly higher rate of definite obstruction (80% versus 70%) and equivocal obstruction (10% versus 0.9%) on preop renogram (P: 0.001). There was no significant difference in the preop split renal function in symptomatic versus asymptomatic group (39 ± 13 versus 36 ± 13 P: 0.3). Following RAP, 91% of symptomatic patients achieved symptom resolution, while four asymptomatic patients (12%) developed new symptoms postoperatively. Compared to preoperative renogram, RAP resulted in improvement in renogram indices in 61% of symptomatic versus 75% of asymptomatic patients (P: 0.2). CONCLUSION: Although asymptomatic patients had worse obstructive indices on renogram, both symptomatic and asymptomatic groups had comparable improvement in renal function following robotic pyeloplasty. RAP is a safe and efficacious minimally invasive option to offer symptom resolution in symptomatic patients and improve obstruction in both symptomatic and asymptomatic patients with UPJO.

Ureteropelvic junction obstruction in children by polar vessels: histological examination result.

In children, ureteropelvic junction obstruction (UPJO) is mostly caused by intrinsic factors (IUPJO) such as abnormal amounts of muscle and collagen deposition; extrinsic UPJO are rare and often due to crossing vessels (CVs). What is not clear is whether there is also intrinsic UPJ pathology in patients with CV. The aim of our study was to compare the histology of the two types of obstruction and to determine whether these histologic features are distinguishable enough to enable to identify the cause of obstruction based on histologic appearance alone. We retrospectively reviewed pathology reports of 38 children with UPJO that underwent surgery in our hospital from 2008 to 2022. The intrinsic and extrinsic groups consisted of 18 and 20 patients, respectively. After ematoxylin-eosin and Gomori's trichrome staining the specimens were scored for fibrosis and muscular hypertrophy in histhopatology, and CD117 antibody were used to detect interstitial Cajal-like cells. In our study, histological analyses revealed no differences between the CV and IUPJO specimens in terms of presence and degree of fibrosis and muscular hypertrophy; likewise, for presence of interstitial Cajal-like cells.

Association of the Hydronephrosis Severity Score With Likelihood of Pyeloplasty: A Large Prospective Database Analysis.

OBJECTIVE: To apply and reproduce this scoring system in our prenatal hydronephrosis population with ureteropelvic junction obstruction (UPJO)-like hydronephrosis (HN), specifically looking at determining better HHS cutoffs that would allow for stratification into three risk categories: spontaneous HN resolution, observation, and surgery. METHODS: A prospectively collected prenatal hydronephrosis database was reviewed to extract UPJO-like HN patients. Children with vesicoureteral reflux, primary megaureter, bilateral HN, and other associated anomalies were excluded. Only patients who had an ultrasound and mercaptoacetyltriglycine renal scan at a minimum of 2-time points were included. Hydronephrosis Severity Score was calculated at the initial, interim, and last follow-up clinic visits. Scores were analyzed regarding its usefulness to determine which patients would have been more likely to undergo pyeloplasty. RESULTS: Of 167 patients, 131 (78%) were male, 119 (71%) had left UPJO-like, and 113 (67%) had a pyeloplasty. The median age at baseline was 2months (interquartile range 1-4). According to initial (first clinic visit) Hydronephrosis Severity Score, 5/36 (14%) patients with a 0-4 score, 93/116 (80%) with a 5-8 score, and 15/15 (100%) with a 9-12 score underwent pyeloplasty, respectively (P < .01). CONCLUSION: The proposed HHS system for UPJO-like HN patients is reproducible, however, cut-off values need to be reassessed to accurately reflect true risk categories, as the purpose of this system is to differentiate those who have HN severe enough to require intervention from those who can be managed nonsurgically. Changing risk groups to mild (0-3), moderate (4-6), and severe (7-12) allowed for better discrimination between patients who underwent surgical intervention from those who did not in our dataset.

Rapport de cas Suspected congenital unilateral ureteral atresia and hydronephrosis in a 6-year-old dog.

A 6-year-old neutered male giant schnauzer dog was presented to an emergency clinic with stranguria and pollakiuria. On physical examination, the abdomen was generally and non-painfully distended. Diagnostic imaging revealed several large, anechoic, fluid-filled, space-occupying lesions from the cranial to caudal abdomen placing extramural pressure on the bladder and urethra and apparently causing the clinical signs. Unilateral ureteral atresia with secondary ipsilateral hydronephrosis and hydroureter were diagnosed on post-mortem examination. Due to a lack of history of abdominal surgery or trauma and the absence of scarring or stenosis of the ureter, the condition was suspected to be congenital. Key clinical message: Although rare, hydronephrosis and hydroureter secondary to a congenital ureteral defect should be considered when a dog is presented with abdominal distension and several peritoneal and retroperitoneal space-occupying lesions on diagnostic imaging.

Atrésie urétérale unilatérale congénitale suspectée et hydronéphrose chez un chien de 6 ans. Un chien schnauzer géant mâle castré âgé de 6 ans a été présenté à une clinique d'urgence avec une strangurie et une pollakiurie. À l'examen physique, l'abdomen était distendu de manière générale et non-douloureuse. L'imagerie diagnostique a révélé plusieurs grandes lésions anéchoïques, remplies de liquide et occupant de l'espace de l'abdomen crânien à caudal, exerçant une pression extra-murale sur la vessie et l'urètre et causant apparemment les signes cliniques. Une atrésie urétérale unilatérale avec hydronéphrose ipsilatérale secondaire et hydro-uretère ont été diagnostiqués lors de l'autopsie. En raison d'un manque d'antécédents de chirurgie abdominale ou de traumatisme et de l'absence de cicatrices ou de sténose de l'uretère, la condition a été suspectée d'être congénitale.Message clinique clé :Bien que rares, l'hydronéphrose et l'hydro-uretère secondaires à une anomalie urétérale congénitale doivent être envisagées lorsqu'un chien présente une distension abdominale et plusieurs lésions péritonéales et rétropéritonéales occupant de l'espace à l'imagerie diagnostique.(Traduit par Dr Serge Messier).

Ureteropelvic junction obstruction (UPJ) due to congenital crossing of the renal vessels (CRV): Comparison of the pre- and postoperative features of UPJO with and without CRV.

We evaluated the differences in demographic characteristics of patients with and without underlying crossing renal vessels (CRVs) operated for unilateral symptomatic ureteropelvic junction obstruction (UPJO). We identified the features of patients who had undergone open, laparoscopic and robotically assisted laparoscopic pyeloplasty at our institution from July 2000 to January 2021. The ratio of renal parenchymal thickness (RPT; ratio between the kidney with UPJO and the healthy kidney), pelvic diameter and kidney functions were recorded. A total of 641 patients were operated for UPJO; 448 were male (69.8%) and 193 (30.1%) were female; 257 had right-side (40%) and 384 (60%) left-side disease. Fifty-eight patients (9%) were found to have CRV (operated on to treat CRV). The age at diagnosis was 6.51 ± 5.09 years in the CRV (+) group and 1.82 ± 1.37 years in the CRV (-) (p < 0.001). The age at surgery was 8.00 ± 4.71 and 4.27 ± 3.54 years, respectively (p < 0.001). At the time of diagnosis, the RPT measurement was significantly better in CRV (+) compared to CRV (-) group (0.71 ± 0.2 vs. 0.64 ± 0.23, p = 0.043) and initial renal functions were 45.53 ± 8.99% and 42.99 ± 11.65% in CRV (+) and (-) groups respectively. At the time of surgery, the RPTs were 0.60 ± 0.24 and 0.63 ± 0.21 in CRV (+) and (-) groups and these values were also correlated with split renal functions (36.28 ± 15.81% and 41.80 ± 14.26%, respectively). Renal functions were significantly decreased in CRV (+) group (p = 0.027). Significant parenchymal improvements were noted during the first postoperative year. The RPTs were 0.71 ± 0.2 and 0.77 ± 0.19 in the CRV (+) and CRV (-) groups, respectively (p = 0.27) in that time; the improvements continued to increase to postoperative third year (0.74 ± 0.20 and 0.78 ± 0.19 respectively; p = 0.939). In patients with CRVs, renal functions seemed to be preserved in the early stages, however it should be kept in mind that sudden obstruction and loss of kidney function might develop in the follow up period.

Clues for the early loss of renal function in congenital hydronephrosis: Analysis of renal pelvis collagen ratio, diuresis renography and upper urinary tract morphology.

INTRODUCTION: Diagnosing real urinary obstruction and surgical decision making for the operative correction of urinary obstruction, are still problematic in congenital hydronephrosis (CH). Compliance of the renal pelvis is one of the important defense mechanisms of renal parenchyma against urinary obstruction. We observed early loss of function in some cases of CH with low and moderate anteroposterior diameter of the renal pelvis (APDRP). OBJECTIVE: To evaluate structural properties of the renal pelvic tissue of patients with CH and the relation of these structural properties with renal function and Anteroposterior diameter of the renal pelvis. STUDY DESIGN: Ureteropelvic junction (UPJ) excised during UPJ obstruction operations from 2013 to 2019 were evaluated histopathologically. The patients were divided into the two groups according to initial renal function, i.e. group with initial preoperative differential renal function (DRF) less than 35% and group with initial DRF greater than 35%. The percentage of collagen to whole tissue area were analyzed using image processing program. The relationship between DRF and tissue collagen ratio, SFU and APDRP was evaluated. RESULTS: There were 5 patients in the DRF <35% group and 16 patients in the DRF >35% group. However, APDRP's of the DRF <35% group were also significantly lower than the DRF >35% group. The collagen distribution in the muscle layer was more prominent in the DRF <35% group. Proportionally, percentage of collagen stained surface was significantly higher in DRF <35% group. DISCUSSION: There are numerous histopathological studies evaluating the cause of UPJ obstruction. Besides these studies that are oriented to etiology, there are many studies comparing the histopathological changes at UPJ with surgical outcome and prognosis. In the present study, we found that renal pelvis collagen ratio was significantly increased in patients with lower APDRP and with severe renal function loss. This increase in the collagen content in the renal pelvis have been shown to affect the compliance negatively and decrease APDRP, which leads to a faster loss of renal function. Thus, pelvic structural changes accompanying UPJ obstruction may aggravate urinary obstructive process. CONCLUSION: Increased renal pelvis collagen ratio negatively affects the expansion of the renal pelvis, which is one of the protective mechanisms of the renal parenchyma, and may be one of the triggering mechanisms of early loss of renal function.

Inverted-Y Ureteric Duplication With Paraureteric Diverticulum Presenting With Bladder Outlet Obstruction in an Infant- A Diagnostic Dilemma.

The ectopic ureter and paraureteric diverticulum are 2 known common urological anomalies of pediatric patients. Another rare entity is inverted-Y ureteric duplication. We report a case of a 3-month-old boy presented with bladder outlet obstruction, where surgical excision of large bladder diverticulum with left ureter and small kidney was done. Histopathology confirmed the presence of inverted-Y ureteric duplication with left dysplastic kidney. The report defines the first case of infantile bladder outlet obstruction having the co-existing congenital genitourinary anomaly of inverted Y-partial ureteric duplication with obstructive ectopic ureter and ipsilateral paraureteric diverticula.

[A comparative study of transcolonic and paracolic laparoscopic pyeloplasty in children with UPJO].

OBJECTIVE: Comparing the laparoscopic pyeloplasty via the mesocolon and para-colonic gutter approach for the treatment of pediatric pelvi-ureteric junction obstruction (UPJO) induced simple hydronephrosis, and analyzing the potential factors influencing surgical outcomes. METHODS: Clinical data of 71 children with UPJO who underwent laparoscopic pyeloplasty at the Department of Urology of the Second Hospital of Hebei Medical University from January 2020 to January 2023 were analyzed. The patients, aged 0.25 to 18 years, were divided into two groups: 30 cases underwent the transcolonic route (mesangial group) and 41 cases underwent the transcolonic paragutter route (paragrow group). RESULTS: showed that both surgical approaches had similar outcomes in terms of operation completion, smooth process, absence of laparotomy, operation time, intraoperative blood loss, postoperative feeding time, and postoperative drainage tube indwelling time, total hospitalization cost, surgical effect, and satisfaction. Common complications such as postoperative fever and abdominal pain were managed with drug treatment or observation, with no need for secondary surgery or fatal complications. Factors such as age, body mass index, preoperative symptoms, severity of hydronephrosis, and ABO blood group classification did not impact the surgical outcome. CONCLUSIONS: There was no statistically significant difference between laparoscopic pyeloplasty and another surgical method in terms of various surgical outcomes for children with ureteropelvic junction obstruction. Factors such as age, body mass index, preoperative symptoms, severity of hydronephrosis, and ABO blood group classification did not have a significant impact on the surgical outcome.

Severe Ureteral Endometriosis Complicated with Hydronephrosis: A Case Report.

BACKGROUND Endometriosis is a disease characterized by endometrial tissue appearing outside the uterus, mainly involving the peritoneum and pelvic organs. Ureteral endometriosis (UE) is rare, typified by deep infiltrating endometriosis involving the ureter and can result in ureteral obstruction, proximal hydroureter, hydronephrosis, and impairment of renal function. Symptoms may be insidious and nonspecific and may lead to a prolonged disease course. We describe a patient with UE complicated by hydronephrosis. CASE REPORT A 42-year-old woman was admitted to the Urology Department with the incidental discovery of right hydronephrosis. After a thorough examination, she underwent right ureteral mass resection and right ureteral stump anastomosis. The pathology report indicated endometriosis. The patient was given 6 doses of gonadotropin-releasing hormone agonist immediately after surgery, followed by an intrauterine levonorgestrel-releasing system. Postoperative follow-up showed that no recurrence was observed in this year. Here, we briefly summarize the epidemiology, pathogenesis, clinical presentation, imaging, treatment, and prognosis of the disease. CONCLUSIONS UE should be listed as one of the differential diagnoses of unexplained hydronephrosis in women of childbearing age, and those with dysmenorrhea should be cognizant of this disease. Active surgical treatment and long-term management should be carried out to obtain better prognosis.

Could CA 19-9 be a useful biomarker in the diagnosis, prognosis, and prediction of adequate relief in lower urinary tract obstructions?

INTRODUCTION: posterior urethral valves represent an important cause of childhood chronic kidney disease. The identification of biomarkers that indicate early kidney damage and even adequate clearance could reduce how many patients head towards kidney failure. OBJECTIVE: this study evaluated how this easy-analysis biomarker (CA 19-9) could help identifying potential renal damage and adequate clearance in obstructive uropathies. METHODS: 46 female Wistar rats were divided into 5 groups, with different patterns of partial urinary tract obstruction: group control; group OIV: infravesical obstruction; group OIVd: infravesical obstruction with reversion, obstruction relief 7 postoperative days later; group OUu: unilateral ureteral obstruction; group OUb: bilateral ureteral obstruction. The CA 19-9s performance was compared to another biomarker: Ngal. Determination of basal CA 19-9 and Ngal in urine and blood and serum creatinine levels was performed in the rats prior to surgery (T0) and after 14 days (T1). Group OIVd underwent intermediate (Ti) collection before clearance. RESULTS: the urinary concentration of CA 19-9 increased in groups OIV, OIVd and OUb; elevation at T1 and Ti, reached statistical significance compared to the T0 value (p<0,05). Changes in urinary CA 19-9 were more expressive in infravesical obstruction groups (AUC 0.81). Obstruction relief in group OIVd promoted significant urinary CA 19-9 reduction (p<0,05) in the final evaluation. CONCLUSIONS: CA 19-9 urinary concentration increased in partial urinary tract obstruction. Its best performance was in the bladder neck obstruction group, in which the elevation was detected early (6 days after infravesical obstruction) and the CA19-9 urinary concentration declined after clearance.

A systematic review of underlying genetic factors associated with ureteropelvic junction obstruction in stenotic human tissue.

OBJECTIVE: Genetic factors are implicated in the development of ureteropelvic junction obstruction (UPJO). The aims of this study were: 1) condense and examine the existing data in studies containing information regarding differential gene expression in tissues from patients with UPJO and 2) investigate associations between genetic markers and their related pathways. MATERIALS AND METHODS: A systematic review of studies published between January 2000 and September 2021 was conducted using the following databases: Ovid/Medline, PubMed, Wiley Cochrane Central Register of Controlled Trials, Web of Science, and Scopus. Of 249 studies, 10 were included in the final analysis. The search was performed using the terms "ureteropelvic junction obstruction", "genetic", "gene", and "gene expression". Literature pertaining to differential gene expression in UPJO patients as compared to healthy controls was identified. Studies containing gene expression and quantification of molecular data carried out directly on stenotic tissue samples were selected for analysis. Gene network connections and functional analyses were then determined using MetaScape software. RESULTS: From the ten studies identified for analysis, fifteen genes were noted as differentially expressed. In UPJO patients, nine genes were upregulated (ET1, ACTA2, MCP-1, TGFB1, NFKB1, IL-6, HIF1A, S100A1, SYP) and six were downregulated (ADM, NOS2, EGF, PDGFRA, UCHL1, NGFR). These genes were principally involved in HIF-1 signaling pathway, blood vessel development, positive regulation of signaling receptor activity, and Ras signaling pathway. CONCLUSIONS: A potential link exists between genes related to hypoxia, excessive fibrous tissue formation, and inflammation in the development of UPJO, and these connections merit more detailed, tissue level investigations in UPJO patients. The outcomes of this systematic review may lay the groundwork for the development of future targeted therapies and novel biomarker detection for treatments, early detection, and possible prediction and prevention of development of UPJO.

Initial observational management of hydronephrosis in infants with reduced differential renal function and non-obstructive drainage parameters.

INTRODUCTION: Hydronephrosis secondary to ureteropelvic junction (UPJ) obstruction is a common finding in infants with prenatally-diagnosed hydronephrosis and often results in pyeloplasty due to obstructive drainage parameters and/or renal function compromise. However, little is known regarding the natural history of hydronephrosis with reduced differential renal function (DRF) but non-obstructive drainage. OBJECTIVE: We sought to explore our experience with initial observational management of these patients. STUDY DESIGN: A retrospective review of our institutional database of all diuretic MAG-3 renal scans obtained between 2000 and 2016 was performed. We included patients with antenatally-detected unilateral hydronephrosis ≥ SFU grade 2, first MAG-3 scan prior to 18months of age, DRF <40% and post-furosemide half-time (T1/2) <20 min. Exclusion criteria were: hydroureter, VUR, solitary kidney, duplication anomalies. Outcomes of interest were a progression of T1/2 ≥ 20 min and/or further decline in DRF >5%. RESULTS: Of 704 patients with unilateral hydronephrosis, 91 had DRF≤40%, of which 29 (18 boys, 11 girls) met our inclusion criteria and were followed for a mean of 2.8 years (1.4 months-6.6 years). Mean age at first sonogram was 2.3 months. 2 patients had SFU grade 2, 16 had grade 3, and 9 had grade 4 hydronephrosis, and 2 unknown grade. Median half-time on initial MAG-3 scan across all patients was 10 min (3-20 min). Initial MAG3 scan was performed at a median of 2.3 months of age (0.3-17 months). 22/29 patients had >1 MAG3 scan. Of the 7 remaining, 5 were lost to follow-up and 2 demonstrated improvement in hydronephrosis. Worsening drainage occurred in 10/22(45%), median final T1/2 was 45.5 min 8 of these underwent pyeloplasty and 2 were lost to follow up. 4/22 patients (18%) had progressive decline in DRF (mean 8.3%, range 6-10%). 3/4 maintained non-obstructive drainage patterns and stable/improved hydronephrosis, and 1 underwent pyeloplasty. 13/18 remaining patients had stable DRF and 5 had improvement in DRF. 7(39%) of these underwent surgery for worsening drainage (Summary Figure). Overall, 7/29(24%) patients had sufficient resolution of hydronephrosis to be discharged from our care, 8(28%) are under continued observation, 9(31%) underwent pyeloplasty, and 5(17%) were lost to follow-up. In the observational group [median follow-up 4.5 years (3.7-6.6 years)], all 8 demonstrated improved non-obstructive drainage (T1/2 <20 minutes) and/or improvement in hydronephrosis. 4/10(40%) with DRF <35% underwent pyeloplasty versus 5/19(26%) with DRF 35-40%(p=0.67). CONCLUSION: Initial observational management of unilateral hydronephrosis with reduced DRF and nonobstructive drainage is recommended as most kidneys maintain nonobstructive drainage and do not demonstrate further decline in DRF. Even when DRF decreases, the majority remain non-obstructive. Worsening drainage over time more often leads to the decision for pyeloplasty rather than change in DRF.

The Use of Neutrophil Gelatinase-Associated Lipocalin (NGAL) as a Diagnostic and Prognostic Biomarker in Urinary Tract Obstruction: a Systematic Review.

PURPOSE OF REVIEW: The early recognition of urinary tract obstruction (UTO) is vital in order to prevent mortality and morbidity associated with an acute kidney injury (AKI) and progression to irreversible kidney damage. Urinary biomarkers such as neutrophil gelatinase-associated lipocalin (NGAL) have been recognised as an accurate tool in the timely diagnosis of AKI, but its role in the detection, prognosis and subsequent monitoring of a variety of obstructive uropathies has not yet been explored. We performed a systematic review of literature in accordance with Cochrane methodology from inception to August 2021. RECENT FINDINGS: Eleven studies were included in which urine and serum NGAL were measured (616 patients) presenting with multiple UTO aetiologies. Four investigated kidney stone disease (KSD) exclusively, whilst other studies identified other causes of UTO including pelviureteric junction obstruction (PUJO), retroperitoneal fibrosis (RPF) and ureteric strictures. Six studies monitored NGAL levels after surgical intervention to relieve the obstruction. Nine studies demonstrated a significant increase in both urine and serum NGAL levels in UTO, often in a more sensitive and timely manner than serum creatinine. Subclinical unilateral UTO could be recognised by urinary NGAL levels even in the absence of changes in serum creatinine. Following surgical intervention, a reduction in urinary and serum NGAL was seen in all but two studies. NGAL levels decreased acutely by 14% in 2 h and showed a long-term reduction of 78% in 6 months. Readily available but not yet widely accepted, NGAL has the potential to be a less invasive, low-cost diagnostic test for urinary tract obstructions as a whole. Not only can it be used as a marker of treatment success but also to monitor for obstruction recurrence or progression. Further research is required to acknowledge urinary biomarkers such as NGAL as a potential replacement to standard renal function monitoring tests in the context of obstructive uropathy.

Prognostic factors for overall survival in malignant ureteral obstruction.

INTRODUCTION: To identify prognostic factors for overall survival (OS) in patients with malignant ureteral obstruction (MUO) from gynecologic malignancy (GM), with the goal of improving patient selection for urinary diversion. MATERIALS AND METHODS: Retrospective review of 126 patients with MUO from GM at two academic centers from 2011-2019. Factors related to OS identified by Cox regression proportional hazard model. In patients with incomplete survival data (n = 30), hospice was used as a surrogate for death. Multivariate models and receivers operating characteristics (ROC) curves were created for hemoglobin and albumin values. RESULTS: Overall median survival was 6.2 months. On univariate analysis, age at diagnosis, Charlson Comorbidity Index (CCI) ≥ 8, advanced clinical stage, ascites, pleural effusion, albumin, and hemoglobin were associated with poor OS. OS was higher for those receiving ureteral stenting as compared with no intervention. There was no survival difference based on hydronephrosis grade, stent failure (SF), or creatinine at the time of intervention. On multivariate analysis, albumin < 2.85 g/dL and hemoglobin < 9.6 g/dL were predictive of poor OS. CONCLUSIONS: OS in patients with MUO due to GM is poor. Several prognostic factors for poor survival including low serum albumin and hemoglobin were identified. Ureteral stenting was associated with improved OS compared to observation, but selection bias likely contributed to this result. Additional studies are needed to clarify this finding. These data can be utilized to counsel patients regarding outcomes after urinary diversion in the setting of MUO and perhaps avoid additional procedures in some of these patients who will not derive meaningful benefit.