Risk of urinary tract infection in patients with hydroureter: An analysis from the Society of Fetal Urology Prenatal Hydronephrosis Registry

The conundrum of high-grade hydronephrosis with non-obstructive drainage on diuretic renography

BACKGROUND

Patients with high grade hydronephrosis (HN) and non-obstructive drainage on mercaptoacetyltriglycine (MAG-3) diuretic renography (renal scans) can pose a dilemma for clinicians. Some patients may progress and require pyeloplasty; however, more clarity is needed on outcomes among these patients.

OBJECTIVE

Our primary objective was to predict which patients with high-grade HN and non-obstructive renal scan, (defined as T ½ time <20 min) would experience resolution of HN. Our secondary objective was to determine predictors for surgical intervention.

STUDY DESIGN

Patients with prenatally detected HN were prospectively enrolled from 7 centers from 2007 to 2022. Included patients had a renal scan with T ½<20 min and Society for Fetal Urology (SFU) grade 3 or 4 at last ultrasound (RBUS) prior to renal scan. Primary outcome was resolution of HN defined as SFU grade 1 and anterior posterior diameter of the renal pelvis (APD) < 10 mm on follow-up RBUS. Secondary outcome was pyeloplasty, comparing patients undergoing pyeloplasty with patients followed with serial imaging without resolution. Multivariable logistic regression was used for analysis.

RESULTS

Of the total 2228 patients, 1311 had isolated HN, 338 patients had a renal scan and 129 met inclusion criteria. Median age at renal scan was 3.1 months, 77% were male and median follow-up was 35 months (IQR 20-49). We found that 22% (29/129) resolved, 42% of patients had pyeloplasty (54/129) and 36% had persistent HN that required follow-up (46/129). Univariate predictors of resolution were age≥3 months at time of renal scan (p = 0.05), T ½ time≤5 min (p = 0.09), SFU grade 3 (p = 0.0009), and APD<20 mm (p = 0.005). Upon multivariable analysis, SFU grade 3 (OR = 4.14, 95% CI: 1.30-13.4, p = 0.02) and APD<20 mm (OR = 6.62, 95% CI: 1.41-31.0, p = 0.02) were significant predictors of resolution. In the analysis of decision for pyeloplasty, SFU grade 4 (OR = 2.40, 95% CI: 1.01-5.71, p = 0.04) and T ½ time on subsequent renal scan of ≥20 min (OR = 5.14, 95% CI: 1.54-17.1, p = 0.008) were the significant predictors.

CONCLUSIONS

Patients with high grade HN and reassuring renal scan can pose a significant challenge to clinical management. Our results help identify a specific candidate for observation with little risk for progression: the patient with SFU grade 3, APD under 20 mm, T ½ of 5 min or less who was 3 months or older at the time of renal scan. However, many patients may progress to surgery or do not fully resolve and require continued follow-up.

The construction of a nomogram to predict the prognosis and recurrence risks of UPJO

Objective

This study was conducted to explore the risk factors for the prognosis and recurrence of ureteropelvic junction obstruction (UPJO).

Methods

The correlation of these variables with the prognosis and recurrence risks was analyzed by binary and multivariate logistic regression. Besides, a nomogram was constructed based on the multivariate logistic regression calculation. After the model was verified by the C-statistic, the ROC curve was plotted to evaluate the sensitivity of the model. Finally, the decision curve analysis (DCA) was conducted to estimate the clinical benefits and losses of intervention measures under a series of risk thresholds.

Results

Preoperative automated peritoneal dialysis (APD), preoperative urinary tract infection (UTI), preoperative renal parenchymal thickness (RPT), Mayo adhesive probability (MAP) score, and surgeon proficiency were the high-risk factors for the prognosis and recurrence of UPJO. In addition, a nomogram was constructed based on the above 5 variables. The area under the curve (AUC) was 0.8831 after self cross-validation, which validated that the specificity of the model was favorable.

Conclusion

The column chart constructed by five factors has good predictive ability for the prognosis and recurrence of UPJO, which may provide more reasonable guidance for the clinical diagnosis and treatment of this disease.

Ureteroinguinal Herniation with Consecutive Ureteral Stricture in a 2-Month-Old Infant: Case Report

Inguinal herniation of ureter is an uncommon finding among children, with scarce reported cases in the literature to date, that can potentially lead to obstructive uropathy. We report a case of ureteroinguinal herniation discovered during an inguinal hernia repair in a patient with antenatally ultrasound finding of hydronephrosis. A 2-month-old infant with antenatal left hydronephrosis presented with left inguinal mass. Preoperative ultrasound showed an anechoic tubular image producing a mass effect on the left testicle, with suspected bladder herniation and/or dilated ureter toward the inguinal canal. An open surgical inguinal exploration was performed, where the left inguinal canal revealed a peritoneal sac and sliding of the dilated left ureter behind the sac, with a significant change in diameter, corresponding to the paraperitoneal variant of ureteroinguinal herniation. Ligation of the sac and replacement of the ureter into the retroperitoneum were performed, with improvement in the hydronephrosis observed on the ultrasound 1 month after the intervention. However, 6 months later, hydronephrosis worsening as well as the obstructive pattern observed in the diuretic renogram required removal of the stenotic ureteral segment and reimplantation of the healthy proximal segment in the bladder by open approach (Cohen's reimplantation). Follow-up ultrasound of the renal tract showed no dilatation of the upper renal tract and the renal function tests were normal. Currently, the patient is 2 years old and he remains asymptomatic. In conclusion, s igns of ureteral obstruction such as hydronephrosis in patients with inguinal herniation may suggest the possibility of an ureteroinguinal hernia. Preoperative diagnostic suspicion is essential.

Meta-analysis of perioperative outcomes and safety of percutaneous nephrostomy versus retrograde ureteral stenting in the treatment of acute obstructive upper urinary tract infection

Background

The debate regarding the optimal drainage method for acute obstructive upper urinary tract infection persists, focusing on the choice between percutaneous nephrostomy (PCN) and retrograde ureteral stenting (RUS).

Aims

This study aims to systematically examine the perioperative outcomes and safety associated with PCN and RUS in treating acute obstructive upper urinary tract infections.

Methods

A comprehensive investigation was conducted using the Medline, Embase, Web of Science, and Cochrane databases up to December 2022, following the guidelines of the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. The utilized keywords included 'PCN', 'RUS', 'acute upper obstructive uropathy', and 'RCT'. Inclusion criteria encompassed studies providing accurate and analyzable data, which incorporated the total subject count, perioperative outcomes, and complication rates. The assessed perioperative outcomes included fluoroscopy time, normalization of temperature, normalization of serum creatinine, normalization of white blood cell (WBC) count, and operative time. Safety outcomes encompassed failure rate, intraoperative and postoperative hematuria, postoperative fever, postoperative pain, and postoperative nephrostomy tube or stent slippage rate. The study protocol was prospectively registered at PROSPERO (CRD42022352474).

Results

The meta-analysis encompassed 7 trials involving 727 patients, with 412 assigned to the PCN group and 315 to the RUS group. The outcome of the meta-analysis unveiled a reduced occurrence of postoperative hematuria in the PCN group [odds ratio (OR) = 0.54, 95% confidence interval (CI) 0.30-0.99, p = 0.04], along with a decreased frequency of insertion failure (OR = 0.42, 95% CI 0.21-0.81, p = 0.01). In addition, the RUS group exhibited a shorter fluoroscopy time than the PCN group (mean difference = 0.31, 95% CI 0.14-0.48, p = 0.0004).

Conclusion

Given the significant impact of hematuria and catheterization failure on postoperative quality of life, the preference for PCN appears more advantageous than RUS.

The role of circumcision in preventing urinary tract infections in children with antenatal hydronephrosis: Systematic review and meta-analysis

INTRODUCTION

Circumcision has been reported to reduce the risk of urinary tract infections (UTIs) in boys with antenatal hydronephrosis (HN). Our aim was to compare the incidence of UTIs in circumcised vs. uncircumcised boys with antenatal HN by conducting a systematic review and meta-analysis.

STUDY DESIGN

A comprehensive search was performed until December 2022. Comparative studies were evaluated according to Cochrane collaboration recommendations. Assessed measures included: UTIs, continuous antibiotic prophylaxis (CAP) use, renal outcomes, and circumcision complications. Odds ratios (OR) and mean difference with 95% confidence interval (CI) were extrapolated from available data. Random-effects meta-analysis were performed.

RESULTS

Twenty-three studies describing 9093 boys with antenatal HN were identified, including 4677 uncircumcised and 4416 circumcised boys. Overall effect estimates demonstrate that circumcised boys have significantly reduced odds of developing any UTI [OR 0.26, 95%CI 0.21, 0.32; p < 0.001]]. In addition, there a significantly reduced odds of developing UTI when circumcised and on CAP [OR 0.19, 95% CI 0.13, 0.30; p < 0.001]. When stratifying by etiology, circumcision reduced the odds of UTI in boys with isolated HN [OR 0.33, 95% CI 0.16, 0.68; p = 0.003], vesicoureteral reflux [OR 0.23, 95% CI 0.13, 0.42; P < 0.00001], or with posterior urethral valves [OR 0.29, 95% CI 0.13, 0.64; p = 0.002].

DISCUSSION

Circumcision reduces the incidence of UTIs in boys with antenatal HN. This review is limited by the varied definitions of UTIs and inconsistent reporting on HN etiology, renal outcomes, and circumcision complications.

CONCLUSIONS

Circumcision should be considered in boys with antenatal HN to prevent the risk of developing UTI. Further research is warranted to individualize the prophylactic role of circumcision for patients with HN.

Antibiotic Prophylaxis for the Prevention of Urinary Tract Infections in Children: Guideline and Recommendations from the Emilia-Romagna Pediatric Urinary Tract Infections (UTI-Ped-ER) Study Group

Background: Urinary tract infection (UTI) represents one of the most common infectious diseases and a major cause of antibiotic prescription in children. To prevent recurrent infections and long-term complications, low-dose continuous antibiotic prophylaxis (CAP) has been used. However, the efficacy of CAP is controversial. The aim of this document was to develop updated guidelines on the efficacy and safety of CAP to prevent pediatric UTIs. Methods: A panel of experts on pediatric infectious diseases, pediatric nephrology, pediatric urology, and primary care was asked clinical questions concerning the role of CAP in preventing UTIs in children. Overall, 15 clinical questions were addressed, and the search strategy included accessing electronic databases and a manual search of gray literature published in the last 25 years. After data extraction and narrative synthesis of results, recommendations were developed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology. Results: The use of CAP is not recommended in children with a previous UTI, with recurrent UTIs, with vesicoureteral reflux (VUR) of any grade, with isolated hydronephrosis, and with neurogenic bladder. CAP is suggested in children with significant obstructive uropathies until surgical correction. Close surveillance based on early diagnosis of UTI episodes and prompt antibiotic therapy is proposed for conditions in which CAP is not recommended. Conclusions: Our systematic review shows that CAP plays a limited role in preventing recurrences of UTI in children and has no effect on its complications. On the other hand, the emergence of new antimicrobial resistances is a proven risk.

Circumcision reduces urinary tract infection in children with antenatal hydronephrosis: Systematic review and meta-analysis

INTRODUCTION

Urinary tract infection (UTI) is more prevalent in boys with antenatal hydronephrosis (ANH). Circumcision is known to lessen the risk of UTI. This study was performed to examine the associations between circumcision and UTI among patients with ANH.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards were followed for conducting this systematic review and meta-analysis. PubMed, ScienceDirect, EMBASE, and Cochrane Library databases were searched through August 4th, 2022 to identify eligible studies. The risk of bias was measured using the Newcastle-Ottawa Scale (NOS). Review manager 5.4 was used for all analysis.

RESULTS

A total of 21 studies involving 8,968 patients with ANH were included in the meta-analysis. The incidences of UTI were 18.1% in the uncircumcised group and 4.9% in the circumcised group. From analysis, circumcision had significant protective effect against UTI with pooled OR of 0.28 (95% CI 0.23-0.32). The significant protective effects were also found in subgroup analysis of hydronephrosis etiology, including vesicoureteral reflux (pooled OR of 0.24; 95% CI 0.17-0.32), obstructive hydronephrosis (pooled OR of 0.34; 95% CI 0.21-0.53), and posterior urethral valve (pooled OR of 0.28; 95% CI 0.16-0.52).

CONCLUSION

Our meta-analysis showed that circumcision was associated with a decreased incidence of UTI in children with ANH. This benefit was consistent irrespective of the underlying cause of hydronephrosis.

Continuous antibiotic prophylaxis in isolated prenatal hydronephrosis

BACKGROUND

Prenatal hydronephrosis (PNH) is one of the most common congenital anomalies and can increase the risk of developing a urinary tract infection (UTI) in the first two years of life. Continuous antibiotic prophylaxis (CAP) has been recommended empirically to prevent UTI in children with PNH, but its use has been controversial.

OBJECTIVE

We describe the incidence of UTI in children with isolated PNH of the renal pelvis without ureteral dilation. Our objective was to compare patients receiving and not receiving CAP and determine whether CAP is beneficial at preventing UTI in children with isolated PNH.

STUDY DESIGN

Children with confirmed PNH were enrolled between 2008 and 2020 into the Society for Fetal Urology Hydronephrosis Registry. Children with isolated dilation of the renal pelvis without ureteral or bladder abnormality were included. The primary outcome was development of a UTI, comparing patients who were prescribed and not prescribed CAP.

RESULTS

In this cohort of 801 children, 76% were male, and 35% had high grade hydronephrosis (SFU grades 3-4). CAP was prescribed in 34% of children. The UTI rate among all children with isolated PNH was 4.2%. Independent predictors of UTI were female sex (HR = 13, 95% CI: 3.8-40, p = 0.0001), intact prepuce (HR = 5.1, 95% CI: 1.4-18, p = 0.01) and high grade hydronephrosis (HR = 2.0, 95% CI: 0.99-4.0, p = 0.05; Table) on multivariable analysis. For patients on CAP, the UTI rate was 4.0% compared to 4.3% without CAP (p = 0.76). The risk of UTI during follow-up was not significantly different between patients who received CAP and patients who were not exposed to CAP; adjusting for sex, circumcision status and hydronephrosis grade (HR = 0.72, 95% CI: 0.34-1.5, p = 0.38). In sub-group analysis of patients at higher risk of UTI (uncircumcised males, females and high grade hydronephrosis), CAP use was not associated with a statistically significant reduction in UTI.

CONCLUSIONS

The overall UTI rate in children with isolated PNH is very low at 4.2%. In the overall population of patients with isolated PNH, CAP was not associated with reduction in UTI risk, although the limitations in our study make characterizing CAP effectiveness difficult. Clinicians should consider risk factors prior to placing all patients with isolated PNH on CAP.

Prenatal Hydronephrosis: Bridging Pre- and Postnatal Management

Urinary tract dilation (UTD), including hydronephrosis (HN) is the most common prenatally detected anomaly and affects up to 1-2% of pregnancies. Postnatally, it resolves without surgical intervention in approximately 75-80% of children, however this may take several years to occur, necessitating repeated clinic visits and additional invasive testing for many. For the remainder, a surgical intervention will be offered to relieve obstruction or to correct vesicoureteral reflux. During the monitoring period, many of these infants will be offered continuous antibiotic prophylaxis for the prevention of urinary tract infections, however this remains a controversial topic among pediatric urologists and nephrologists. Herein, we present an up-to-date review of the early management of prenatally detected UTD including timing of postnatal imaging, the use of antibiotics, when circumcision may be beneficial and long term outcomes of the most common HN etiologies. We also propose a decision making tool to help guide the care of infants with UTD. This article is protected by copyright. All rights reserved.