Probability of urinary tract infection in infants with ureteropelvic junction obstruction: is antibacterial prophylaxis really needed?

Febrile urinary tract infection after Double-J stent removal is associated with restenosis after laparoscopic pyeloplasty: A propensity score matched analysis of 503 children

OBJECTIVE

To analyze the association between the febrile urinary tract infection (fUTI) after Double-J (DJ) stents removal and restenosis after laparoscopic pyeloplasty (LP).

STUDY DESIGN

We retrospectively reviewed the clinical data of patients who were treated with transperitoneal LP for ureteropelvic junction obstruction from 2016 to 2020. Patients were divided into two groups according to whether they developed fUTI after DJ stent removal within 48 h. The 1:3 Propensity Score Matched (PSM) method was used to balance confounding variables.

RESULTS

503 patients were included in the study. 28 (5.57%) patients developed fUTI after DJ stent removal. Compared with the non-fUTI group, age was younger, and weight was lower (P < 0.05) in the fUTI group. Restenosis occurred in 11 (2.2%) patients, of which six patients developed fUTI after DJ stent removal. The revision surgery rate in the fUTI group was significantly higher than in the non-fUTI group (21.4% vs. 1.1%, P < 0.01). After PSM, the results remained consistent. For 492 patients without restenosis, 22 patients developed fUTI. Compared with the non-fUTI group, the larger anteroposterior diameter (APD) and higher APD/cortical thickness (P/C) ratio were observed in the fUTI group at three months and six months postoperatively (P < 0.05), but the difference vanished at 12 months and 24 months after surgery (Figure).

DISCUSSION

FUTI after DJ stent removal is not uncommon after LP, and surgeons are often concerned about the possibility of restenosis. In the present study, although our results demonstrated a significant association between them, restenosis patients comprise only about 20% of fUTI patients. Based on our clinical observations, fUTI is often developed in children from 1 to 6 years of age, and the younger patients may be afraid of voiding because of the postoperative pain after DJ stent removal. Besides, intraoperative manipulation of DJ stent removal may lead to transient edema in the anastomotic site, causing the fUTI. For patients who develop fUTI after DJ stent removal but without persistent symptoms, the transient worsening of hydronephrosis during the early postoperative period may not impact long-term outcomes (As shown in Figure). Additional follow-up is needed to prevent the deterioration of renal function.

CONCLUSIONS

Our result demonstrated that fUTI after DJ stent removal is associated with restenosis after LP. For fUTI patients without restenosis, APD and P/C ratio exhibited transient worsening at three months and six months postoperatively, decreasing gradually during follow-up. Patients who develop fUTI after DJ stent removal should be monitored.

Role of antibiotic prophylaxis in antenatal hydronephrosis: A systematic review from the European Association of Urology/European Society for Paediatric Urology Guidelines Panel

BACKGROUND

The benefits and harms of continuous antibiotic prophylaxis (CAP) versus observation in patients with antenatal hydronephrosis (ANH) are controversial.

OBJECTIVE

The aim was to determine the effectiveness of CAP for ANH, and if beneficial to determine the best type and regimen of antibiotic and the most harmful to provide guidance for clinical practice.

METHODS

A systematic literature search was performed in databases including Medline, Embase, and Cochrane in June 2015. The protocol was prospectively registered to PROSPERO (CRD42015024775). The search started from 1980, when maternal ultrasound was first introduced into clinical practice. Eligible studies were critically evaluated for risk of bias using Revman software. The outcomes included reduction in urinary tract infections (UTI), drug-related adverse events and kidney functions.

RESULTS

Of 797 articles identified, 57 full text articles and six abstracts were eligible for inclusion (2 randomized controlled trials, 11 non-randomized comparative studies, and 50 case series). It remains unclear whether CAP is superior to observation in decreasing UTIs. No conclusion could be drawn for drug-related adverse events and kidney function because of lack of data. Children who were not circumcised, with ureteral dilatation, and high-grade hydronephrosis may be more likely to develop UTI, and CAP may be warranted for these subgroups of patients. A majority of the studies had low-to-moderate quality of evidence and with high risk of bias.

CONCLUSIONS

The benefits of CAP in a heterogeneous group of children with ANH involving different etiologies remains unproven. However, the evidence in the form of prospective and retrospective observational studies has shown that it reduces febrile UTI in particular subgroups.

Associations of Initial Society for Fetal Urology Grades and Urinary Tract Dilatation Risk Groups with Clinical Outcomes in Patients with Isolated Prenatal Hydronephrosis

PURPOSE

There are limited comparative data on the predictive value of the 2 most commonly used classification systems, that is SFU (Society for Fetal Urology) hydronephrosis grades and urinary tract dilatation risk groups, in regard to the future risk of surgical intervention and the development of febrile urinary tract infection. We explored this topic in infants with isolated hydronephrosis.

MATERIALS AND METHODS

After screening 938 patients with prenatal hydronephrosis from 2009 to 2016 we selected 322 patients with ureteropelvic junction obstruction-like hydronephrosis for study. Hydronephrosis grades were prospectively collected at baseline, surgery and last followup. Gender, circumcision status, antibiotic prophylaxis and renal pelvis anteroposterior diameter were captured. The primary outcome was pyeloplasty and the development of febrile urinary tract infection. Comparative analyses between SFU grades/urinary tract dilatation groups and the primary outcome were performed with the Fisher exact and log rank tests.

RESULTS

Mean ± SD age at presentation was 3.3 ± 2.6 months and mean followup was 22 ± 19 months. Pyeloplasty was performed in 32% of patients with SFU III/IV vs 31% with urinary tract dilatation 2/3. The rate of febrile urinary tract infection in patients with SFU III/IV was similar to that in those with urinary tract dilatation group 2/3 (8% vs 10%). Children with SFU III/IV showed a significantly higher rate of surgery than those with SFU I/II (32% vs 2%, p <0.01). Similar findings were seen when using urinary tract dilatation groups to compare patients at low risk (1) vs moderate/high risk (2/3).

CONCLUSIONS

Both grading systems equally allowed for proper risk stratification and prediction of clinical outcomes based on baseline ultrasound. They correctly separated most infants who underwent surgery or in whom febrile urinary tract infection developed from those who could be treated nonsurgically. Use of the new urinary tract dilatation classification should not affect how families of children with isolated hydronephrosis are counseled regarding surgical intervention and the risk of febrile urinary tract infection.

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.

Economic analysis of continuous antibiotic prophylaxis for prevention of urinary tract infections in infants with high-grade hydronephrosis

BACKGROUND

For infants with hydronephrosis, continuous antibiotic prophylaxis (CAP) may reduce urinary tract infections (UTIs); however, its value remains controversial. Recent studies have suggested that neonates with severe obstructive hydronephrosis are at an increased risk of UTIs, and support the use of CAP. Other studies have demonstrated the negligible risk for UTIs in the setting of suspected ureteropelvic junction obstruction and have highlighted the limited role of CAP in hydronephrosis. Furthermore, economic studies in this patient population have been sparse.

OBJECTIVE

This study aimed to evaluate whether the use of CAP is an efficient expenditure for preventing UTIs in children with high-grade hydronephrosis within the first 2 years of life.

STUDY DESIGN

A decision model was used to estimate expected costs, clinical outcomes and quality-adjusted life years (QALYs) of CAP versus no CAP (Fig. 1). Cost data were collected from provincial databases and converted to 2013 Canadian dollars (CAD). Estimates of risks and health utility values were extracted from published literature. The analysis was performed over a time horizon of 2 years. One-way and probabilistic sensitivity analyses were carried out to assess uncertainty and robustness.

RESULTS

Overall, CAP use was less costly and provided a minimal increase in health utility when compared to no CAP (Table). The mean cost over two years for CAP and no CAP was CAD$1571.19 and CAD$1956.44, respectively. The use of CAP reduced outpatient-managed UTIs by 0.21 infections and UTIs requiring hospitalization by 0.04 infections over 2 years. Cost-utility analysis revealed an increase of 0.0001 QALYs/year when using CAP. The CAP arm exhibited strong dominance over no CAP in all sensitivity analyses and across all willingness-to-pay thresholds.

DISCUSSION

The use of CAP exhibited strong dominance in the economic evaluation, despite a small gain of 0.0001 QALYs/year. Whether this slight gain is clinically significant remains to be determined. However, small QALY gains have been reported in other pediatric economic evaluations. Strengths of this study included the use of data from a recent systematic review and meta-analysis, in addition to a comprehensive probabilistic sensitivity analysis. Limitations of this study included the use of estimates for UTI probabilities in the second year of life and health utility values, given that they were lacking in the literature. Spontaneous resolution of hydronephrosis and surgical management were also not implemented in this model.

CONCLUSION

To prevent UTIs within the first 2 years of life in infants with high-grade hydronephrosis, this probabilistic model has shown that CAP use is a prudent expenditure of healthcare resources when compared to no CAP.

Anatomy and Physiology of the Urinary Tract: Relation to Host Defense and Microbial Infection

The urinary tract exits to a body surface area that is densely populated by a wide range of microbes. Yet, under most normal circumstances, it is typically considered sterile, i.e., devoid of microbes, a stark contrast to the gastrointestinal and upper respiratory tracts where many commensal and pathogenic microbes call home. Not surprisingly, infection of the urinary tract over a healthy person's lifetime is relatively infrequent, occurring once or twice or not at all for most people. For those who do experience an initial infection, the great majority (70% to 80%) thankfully do not go on to suffer from multiple episodes. This is a far cry from the upper respiratory tract infections, which can afflict an otherwise healthy individual countless times. The fact that urinary tract infections are hard to elicit in experimental animals except with inoculum 3-5 orders of magnitude greater than the colony counts that define an acute urinary infection in humans (105 cfu/ml), also speaks to the robustness of the urinary tract defense. How can the urinary tract be so effective in fending off harmful microbes despite its orifice in a close vicinity to that of the microbe-laden gastrointestinal tract? While a complete picture is still evolving, the general consensus is that the anatomical and physiological integrity of the urinary tract is of paramount importance in maintaining a healthy urinary tract. When this integrity is breached, however, the urinary tract can be at a heightened risk or even recurrent episodes of microbial infections. In fact, recurrent urinary tract infections are a significant cause of morbidity and time lost from work and a major challenge to manage clinically. Additionally, infections of the upper urinary tract often require hospitalization and prolonged antibiotic therapy. In this chapter, we provide an overview of the basic anatomy and physiology of the urinary tract with an emphasis on their specific roles in host defense. We also highlight the important structural and functional abnormalities that predispose the urinary tract to microbial infections.

[Childhood ureteropelvic junction obstruction in a regional treatment center: spectrum and therapy]

BACKGROUND

Ureteropelvic junction obstruction is the most frequent malformation of the upper urinary tract and treatment with conservative or operative management remains controversial. In this study we present the retrospective analysis of 129 children with ureteropelvic junction obstruction who underwent conservative or operative management.

MATERIAL AND METHODS

A total of 129 children with ureteropelvic junction obstruction, who were treated in the department of pediatric nephrology at the University of Essen from 1998-2005, were included into the analysis. Clinical charts were reviewed for the parameters urinary tract infections (total number, severity, bacteriology), antibiotics, ultrasound, Tc-99 diuresis renography, and management (conservative or operative). Statistical analysis was performed using the SPSS software (Version 11.0) RESULTS: A total of 89 urinary tract infections was observed in 52 children. The mean width of renal pelvis was 3.04 ± 1.33 cm in the operative group and 1.98 ± 1.2 cm in the conservative group (p=0.001, ANOVA test). Tc-99 diuresis renography was performed in 70 children of which 46 children received primarily conservative management and 24 children were operated. In the conservative group 6 children underwent pyeloplasty later on due to aggravation of renal function. In 59 out of 129 cases diuresis nephrography was not performed due to only mild ectasia.

CONCLUSIONS

This study demonstrates that conservative management is safe in children with ureteropelvic junction obstruction with no or only little constricted renal function, if a close-meshed surveillance protocol is followed and parental compliance is given.

Revised guidelines on management of antenatal hydronephrosis

Widespread antenatal screening has resulted in increased detection of anomalies of the kidneys and urinary tract. The present guidelines update the recommendations published in 2000. Antenatal hydronephrosis (ANH) is transient and resolves by the third trimester in almost one-half cases. The presence of oligohydramnios and additional renal or extrarenal anomalies suggests significant pathology. All patients with ANH should undergo postnatal ultrasonography; the intensity of subsequent evaluation depends on anteroposterior diameter (APD) of the renal pelvis and/or Society for Fetal Urology (SFU) grading. Patients with postnatal APD exceeding 10 mm and/or SFU grade 3-4 should be screened for upper or lower urinary tract obstruction and vesicoureteric reflux (VUR). Infants with VUR should receive antibiotic prophylaxis through the first year of life, and their parents counseled regarding the risk of urinary tract infections. The management of patients with pelviureteric junction or vesicoureteric junction obstruction depends on clinical features and results of sequential ultrasonography and radionuclide renography. Surgery is considered in patients with increasing renal pelvic APD and/or an obstructed renogram with differential renal function <35-40% or its subsequent decline. Further studies are necessary to clarify the role of prenatal intervention, frequency of follow-up investigations and indications for surgery in these patients.

Update on recent guidelines for the management of urinary tract infections in children: the shifting paradigm

PURPOSE OF REVIEW

Recent guidelines on the management of urinary tract infections (UTIs) in children have seen a shift from aggressive imaging studies and the use of prophylactic antibiotics to a more restrictive and targeted approach. This review focuses on new additions to the literature on management of UTI from January 2011 to September 2012.

RECENT FINDINGS

The causal relationship between UTI-vesicoureteral reflux (VUR) and renal scarring has been challenged by several studies. Concerns about unnecessary exposure to ionizing radiation, invasiveness of some of the procedures, and risk of infection have also been raised. With improved prenatal ultrasound, a 'top-down' approach to investigating febrile UTI in children using renal bladder ultrasound alone as an initial study has become popular. Several studies have reported that prophylactic antibiotics and imaging studies after first UTI can be reduced substantially without affecting the risk of recurrent UTI or renal scarring.

SUMMARY

The use of targeted imaging approach in evaluating febrile UTI in children may lead to improved resource use and reduction of potential harmful procedures and interventions, without affecting outcomes of UTI in children. Providers using current guidelines should endeavor to collect practice-based evidence to validate and inform future guidelines.

Antibiotic prophylaxis for urinary tract infections in antenatal hydronephrosis

BACKGROUND AND OBJECTIVE

Continuous antibiotic prophylaxis (CAP) is recommended to prevent urinary tract infections (UTIs) in newborns with antenatal hydronephrosis (HN). However, there is a paucity of high-level evidence supporting this practice. The goal of this study was to conduct a systematic evaluation to determine the value of CAP in reducing the rate of UTIs in this patient population.

METHODS

Pertinent articles and abstracts from 4 electronic databases and gray literature, spanning publication dates between 1990 and 2010, were included. Eligibility criteria included studies of children <2 years old with antenatal HN, receiving either CAP or not, and reporting on development of UTIs, capturing information on voiding cystourethrogram (VCUG) result and HN grade. Full-text screening and quality appraisal were conducted by 2 independent reviewers.

RESULTS

Of 1681 citations, 21 were included in the final analysis (N = 3876 infants). Of these, 76% were of moderate or low quality. Pooled UTI rates in patients with low-grade HN were similar regardless of CAP status: 2.2% on prophylaxis versus 2.8% not receiving prophylaxis. In children with high-grade HN, patients receiving CAP had a significantly lower UTI rate versus those not receiving CAP (14.6% [95% confidence interval: 9.3-22.0] vs 28.9% [95% confidence interval: 24.6-33.6], P < .01). The estimated number needed to treat to prevent 1 UTI in patients with high-grade HN was 7.

CONCLUSIONS

This systematic review suggests value in offering CAP to infants with high-grade HN, however the impact of important variables (eg, gender, reflux, circumcision status) could not be assessed. The overall level of evidence of available data is unfortunately moderate to low.