Conservative management of primary non-refluxing megaureter during the first year of life: A longitudinal observational study

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.

ACR Appropriateness Criteria® Antenatal Hydronephrosis-Infant

Antenatal hydronephrosis is the most frequent urinary tract anomaly detected on prenatal ultrasonography. It occurs approximately twice as often in males as in females. Most antenatal hydronephrosis is transient with little long-term significance, and few children with antenatal hydronephrosis will have significant obstruction, develop symptoms or complications, and require surgery. Some children will be diagnosed with more serious conditions, such as posterior urethral valves. Early detection of obstructive uropathy is necessary to mitigate the potential morbidity from loss of renal function. Imaging is an integral part of screening, diagnosis, and monitoring of children with antenatal hydronephrosis. Optimal timing and appropriate use of imaging can reduce the incidence of late diagnoses and prevent renal scarring and other complications. In general, follow-up neonatal ultrasound is recommended for all cases of antenatal hydronephrosis, while further imaging, including voiding cystourethrography and nuclear scintigraphy, is recommended for moderate or severe cases, or when renal parenchymal or bladder wall abnormalities are suspected. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Does the presence of non-refluxing hydroureter impact the management and outcome of high-grade hydronephrosis?

INTRODUCTION

We aimed to evaluate the impact of non-refluxing hydroureter on the initial management of high-grade hydronephrosis (HGH) management. Moreover, we evaluated the occurrence of febrile urinary tract infection (fUTI) and surgical intervention for conservatively managed units.

METHODS

Patients' charts with postnatal hydronephrosis from 2008-2014 were retrospectively reviewed. We included patients who presented in the first year of life. All included patients had HGH (Society of Fetal Ultrasound [SFU] grades 3 and 4) and all were non-refluxing using voiding cystourethrogram (VCUG). We categorized renal units into two groups: with hydroureteronephrosis (HUN) and without hydroureter (isolated hydronephrosis [IH]). We recorded the initial management. We evaluated the impact of non-refluxing hydroureter on hydronephrosis fate, fUTI, and change to surgery for those managed conservatively.

RESULTS

We included 169 patients (180 units). IH was diagnosed in 146 units (137 patients), whereas 34 units (32 patients) had HUN. Median followup was 42.9 months. A total of 25.3% (37/146) of IH units had initial surgical management in comparison to 5.1% (2/34) of HUN units (p=0.01). During conservative management, nine HUN patients (30%) and 11 IH patients (10.7%) experienced fUTI (p=0.009). Surgical intervention after failed conservative management was indicated for 12 IH units (11%) and six HUN units (18.8%) (p=0.25). Anteroposterior diameter (APD) worsening was significantly associated with the change to surgery in IH group (p=0.003). More than half (52.3%) of IH units resolved during conservative management in comparison to 18.7% of HUN (p<0.001). HUN had longer time to resolution (log rank=0.004).

CONCLUSIONS

IH units had more initial surgical interventions. The fUTI rate was much higher in association with dilated ureter even under antibiotic coverage. HUN was associated with less and slower resolution rate.

Primary Non-refluxing Megaureter: Analysis of Risk Factors for Spontaneous Resolution and Surgical Intervention

Background: The risk of febrile urinary tract infection (fUTI) in children with primary non-refluxing megaureter (PM) has been extensively studied in the literature, however, a paucity of information exists regarding risk factors for surgical intervention and spontaneous resolution. We sought to analyze data from our prospectively collected PM cohort to determine risk factors that would predict surgery and resolution in this population. Methods: Patients with PM were identified from our prospectively-collected prenatal hydronephrosis (HN) database from 2008 to 2017. Primary outcomes included surgical intervention and hydroureter resolution. Spontaneous resolution was defined as ureteral dilation <7 mm at last follow-up. Age at presentation, gender, development of fUTI, HN grade [low (SFU I/II) vs. high (SFU III/IV)], anteroposterior diameter (APD) measurements and ureteral diameter at baseline and last follow-up were recorded. Univariate and multivariable analyses (binary logistic and Cox regression) were performed. Results: Of 101 patients, 86 (85%) were male, and 80 (79%) had high grade HN. Median age at baseline and last follow-up were 2 (0-23) and 29 (2-107) months, respectively. Overall, 23 (23%) patients underwent surgery at a median age of 22 (3-35) months. Mean ureteral diameter was larger in surgical patients vs. those treated non-surgically (14 ± 4 vs.11 ± 3 mm; p < 0.01). Of the 78 (77%) non-surgical patients, 43(55%) showed resolution of their ureteral dilation at a median age of 24(4-56) months. Survival analysis demonstrated that 12 patients resolved by year 1, 22 by year 2, 30 by year 3, 40 by year 4, and 43 by year 5. However, when considering resolution as APD <10 mm, 62(79%) children resolved their HN by last follow-up (29 months). Univariate and multivariable analyses (Table 1) revealed that high-grade HN at baseline, development of fUTI, and ureteric dilation ≥14 mm were significant risk factors for surgical intervention. Cox regression (Figure 2) found that ureteral dilation <11 mm was the only independent risk factor significantly associated with PM resolution (Table 2). Conclusion: Patients with PM and high-grade HN, as well as individuals with ureteral dilation ≥14 mm and fUTI were more likely to undergo surgical intervention. Ureteral dilation <11 mm was the only independent risk factor significantly associated with spontaneous resolution of PM.

Diuresis renography in the evaluation and management of pediatric hydronephrosis: What have we learned?

Diuresis renography (DR) is widely used in the evaluation of hydronephrosis and hydroureter in infants and children. The goal of this provocative nuclear imaging examination should be to detect the hydronephrotic kidneys at risk for loss of function and development of pain, hematuria, and urinary tract infection. The reliability of DR is dependent on the acquisition and processing of the data as well as interpretation and utilization of the results. In this review, the key concepts of standardized DR and pitfalls to avoid are highlighted.

Incidence of urinary tract infections in infants with antenatally diagnosed hydronephrosis-A retrospective single center study

OBJECTIVE

To evaluate the incidence of urinary tract infections (UTIs) in infants with antenatal hydronephrosis (AHN).

MATERIALS AND METHODS

A cohort of AHN patients admitted to our institution between 2003 and 2013 were identified. Altogether 192 patients with nonrefluxing hydronephrosis (HN, n=135), nonrefluxing hydroureteronephrosis (HUN, n=21), or vesicoureteral reflux (VUR, n=36) were identified. Patients with complex anomalies or neonatal decompression of the urinary tract were excluded. Information about UTIs diagnosed among the AHN patients was collected and compared with data from 58 controls.

RESULTS

During the median follow-up time of 2.6 (0.3-11.2) years, 24 (13%) patients (15 (10%) males and 9 (19%) females) and 2 (3%) controls experienced at least one UTI (p=0.033). Eighteen (69%) UTIs were febrile. The males had the first UTI at significantly younger age than the females (0.3, 0.0-1.7years vs. 1.0, 0.4-4.8years, p=0.010). UTI was detected in 15 (63%) patients with grade 4-5 VUR, in 8 (6%) patients with HN, and in one (5%) patient with HUN (p-values <0.001, 0.726 and >0.999 against the controls). None of the patients with grade≤3 VUR had UTI. Fifty-eight percent of the patients with UTI were on antimicrobial prophylaxis. In five (12%) cases UTI appeared within one week after voiding cystourethrography (VCUG).

CONCLUSIONS

Infants with AHN and grade 4-5 VUR had the highest risk of UTI. UTIs tented to be more common in females than in males; however, males experienced UTI at younger age than females. VCUG caused UTI in 2.3% in our material.

LEVEL OF EVIDENCE

III.

Antibiotic prophylaxis for prevention of urinary tract infections in prenatal hydronephrosis: An updated systematic review

INTRODUCTION

While continuous antibiotic prophylaxis (CAP) is currently recommended to prevent urinary tract infections (UTIs) in infants with prenatal hydronephrosis (HN), this recommendation is not evidence-based. The objective of this study was to systematically determine whether CAP reduces UTIs in the HN population.

METHODS

Applicable trials were identified through an electronic search of MEDLINE (1946-2015), EMBASE (1980-2016), CINAHL (1982-2016), and CENTRAL (1993-2016) and through a hand search of American Urological Association (AUA) (2012-2015) and European Society for Pediatric Urology (ESPU) (2012-2015) abstracts, as well as reference lists of included trials. The search strategy was not limited by language or year of publication. Eligible studies compared CAP to no CAP in patients with antenatal HN, <2 years of age, and reported development of UTI and HN grades. Two independent reviewers performed title and abstract screening, full-text review, and quality appraisal.

RESULTS

Of 1518 citations screened, 11 were included, contributing 3909 patients for final analysis. Of these, four (36%) were considered high-quality when assessed by the Newcastle Ottawa Scale. Meta-analysis of the non-randomized trials (n=10) provided similar pooled UTI rates, regardless of CAP use: 9.9% (95% confidence interval [CI] 8.4-11.4%) for CAP and 7.5% (95% CI 6.4-8.6%) for no CAP.

CONCLUSIONS

This systematic review and meta-analysis suggests there may be value in providing CAP to infants with high-grade HN; however, due to the very low-quality data from non-randomized studies, important clinical variables, such as circumcision status, were unable to be assessed.

[Therapeutic mega-ureter primitive before one year of life, retrospective study of 20years]

INTRODUCTION

What is the proper way to manage complicated primary mega-ureter in infants under the age of one. This has already been discussed in the literature but the controversy remains.

OBJECTIVE

Evaluate the long-term results of the management of mega-ureter based support under the age of one.

MATERIAL AND METHODS

Single-center retrospective study from 1990 to 2010. All children under one year found were evaluated including clinical examination, ultrasound, scintigraphy and cystography. They were divided into two groups: group 1: children operated on before the age of one year, group 2 non-operated or operated children after the age of one year. We analyzed the long-term evolution of these children on the following criteria: reflux, pyelonephritis, changes in dilation, renal function, need for surgical revision or secondary surgery, and impact on bladder function.

RESULTS

In total, 54 patients were included in group 1 and 56 patients in group 2. In a median follow-up of 12 years. A total of 101 boys and 9 girls (sex-ratio 11.22). There were 57 left MUP (52%), 22 right (20%) and 31 bilateral (28%). A total of 71% of antenatal diagnosis. No difference on the emergence of complications: 25 (group 1) versus 31 (group 2) OR=0.69; 95% (0.307; 1.574); P=0.44. No difference between secondary surgery and revision surgery: group 1=12, group 2=22, OR=0.45; 95% CI (0.17, 1.09); P=0.06. No difference for daytime incontinence: OR=1.04; 95% CI (0.14; 7.64); P=0.67. Seventy-six children (69%) were finally made, 12 children operated twice (10.9%) and 34 children (31%) never made.

CONCLUSION

The main challenge of the MUP of management is the preservation of renal function. Sixty-nine percent of our children received surgery due to impaired renal function lower than 30% of urethral dilatation greater than 10mm associated with reflux or recurrent pyelonephritis. Clinical monitoring, regular ultrasound and isotopic testing are necessary and should be extended to adulthood.

LEVEL OF EVIDENCE

5.

Primary non-refluxive megaureter in children: single-center experience and follow-up of 212 patients

PURPOSE

Primary non-refluxing megaureter (pMU) is a multifaceted and challenging congenital pathology of the urinary tract. We report our 23-year experience with this anomaly in terms of presentation, diagnostic work-up and management.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 212 children diagnosed with pMU between 1986 and 2009 at our institution. Mean follow-up was 45.17 (0-192) months.

RESULTS

Of the total, 168 (79 %) children presented with upper urinary tract dilation on perinatal ultrasound screening. In 44 (21 %) patients, the diagnosis was made following diagnostic work-up of a urinary tract infection (UTI, 18 %) or flank pain (3 %). In total, 203 of 254 pMUs (79.9 %) were successfully treated conservatively during the 23-year observation period. Forty-eight children (23 %) underwent ureteric reimplantation. UTIs occurred in 91 of 212 children (43 %). Of these, 41 (45 %) occurred despite antibacterial infection prophylaxis. Within the past three decades, there has been a marked shift from surgical toward conservative therapy at our institution.

CONCLUSION

Neonatal renal ultrasound is the method of choice to timely identify children with pMU and, alongside dynamic renography, to monitor the clinical course. Nowadays, only a minor subset of children with asymptomatic course requires surgical correction. Antibacterial prophylaxis has the potential to reduce the risk of febrile UTIs. Prospective randomized studies are warranted to provide evidence of the beneficial effect of antibacterial prophylaxis.

Urinary tract infections in children with prenatal hydronephrosis: A risk assessment from the Society for Fetal Urology Hydronephrosis Registry

INTRODUCTION

Risk factors for urinary tract infection (UTI) in children with prenatal hydronephrosis (PNH) are not clearly defined. Our study aim was to describe incidence and identify factors associated with UTI among a cohort of children diagnosed with PNH.

MATERIAL AND METHODS

Patients with confirmed PNH from four medical centers were prospectively enrolled in the Society for Fetal Urology (SFU) hydronephrosis registry between 9/2008 and 10/2015. Exclusion criteria included enrollment because of UTI, associated congenital anomalies, and less than 1-month follow-up. Univariate analysis was performed using Fisher's Exact test or Mann-Whitney U. Probability for UTI was determined by Kaplan-Meier curve.

RESULTS

Median follow-up was 12 (IQR 4-20) months in 213 patients prenatally diagnosed with hydronephrosis. The majority of the cohort was male (72%), Caucasian (77%), and 26% had high grade (SFU 3 or 4) hydronephrosis. Circumcision was performed in 116/147 (79%) with known status, 19% had vesicoureteral reflux (VUR), and 11% had ureteral dilatation. UTI developed in 8% (n = 18), 89% during their first year of life. Univariate analysis found UTI developed more frequently in females (p < 0.001), uncircumcised males (p < 0.01), and the presence of parenchymal renal cyst (p < 0.05). Logistic regression found renal cyst to no longer be significant, but female gender a significant risk factor for development of UTI (p < 0.001). Regression analysis stratified by gender found neither hydronephrosis grade nor parenchymal renal cyst to be significant risk factors for UTI development among females. However, hydronephrosis grade and circumcision status were significant risk factors for development of UTI among males (p < 0.05 and p < 0.01, respectively).

CONCLUSION

Identification of factors associated with UTI in patients with PNH is still progressing; however, several observational studies have identified groups that may be at increased risk of UTI. Use of prophylactic antibiotics (PA), degree of kidney dilation, gender, and circumcision status all have been reported to have some degree of impact on UTI. A previous study identified risk factors for UTI as female gender, uncircumcised status, hydroureteronephrosis, and VUR, and reported that prophylaxis provided a protective effect on prevention of UTI. Our data mirror those in some respect, identifying an association of UTI with female gender and, among males, uncircumcised status, and high grade hydronephrosis. However, we were unable to demonstrate an association between UTI and the use of PA, presence of VUR, dilated ureter, or renal duplication in this observational registry.

From Research Question to Conducting a Randomized Controlled Trial on Continuous Antibiotic Prophylaxis in Prenatal Hydronephrosis: A Rational Stepwise Process

INTRODUCTION AND OBJECTIVES

Continuous antibiotic prophylaxis (CAP) use to prevent urinary tract infections (UTI) in infants with prenatal hydronephrosis (HN) remains controversial. Lack of consensus guidelines and diverse practice patterns for postnatal management of HN highlight the dire need for higher level of evidence studies. Herein, we aim to describe the steps from developing a well-defined research question to execute a multicentered randomized controlled trial (RCT) to address the issue of CAP use in patients with prenatal HN.

MATERIALS AND METHODS

The steps involved were (1) choosing the proper research question, (2) survey of practice patterns and establishing clinical equipoise, (3) systematic review of the literature, (4) reviewing own practice, (5) longitudinal prospective study, (6) pilot study, (7) cost-utility analysis, and (8) definitive RCT (clinical trials registry number: NCT01140516). An update of our previous systematic review was conducted using two electronic databases and gray literature from 2010 to 2015. Eligibility criteria included studies of children <2 years old with postnatally confirmed prenatal HN, receiving CAP or not, and reporting on development of UTIs, capturing information on voiding cystourethrogram result and HN grade. Full-text screening was conducted by two independent reviewers. UTI rates in patients with high-grade HN were compared across different study designs. Finally, blinded comparative analysis of UTI rates between placebo and treatment groups was carried out using chi-square test.

RESULTS

UTI rates in patients with high-grade HN by their respective study design were: 25% for systematic review, 20% for retrospective study, 21% for prospective and pilot studies, and 13% for the definitive RCT thus far. Regardless of the type of study design, patients with hydroureteronephrosis had significantly higher (threefold to sixfold) UTI rates than those with isolated HN. Our updated systematic review yielded 486 citations, of which 9 (n = 1987 infants) observational studies met eligibility criteria.

CONCLUSION

UTI rates in patients with high-grade HN dropped from 25% in observational studies to 13% in our RCT. This decline in UTI rate demonstrates that study designs lacking strategies to minimize bias are more prone to overestimate treatment effects. These findings highlight the importance of conducting methodologically sound RCTs to answer clinically meaningful questions, such as the one presented here.