Urinary tract infection after voiding cystourethrogram

Nuclear medicine and pediatric nephro-urology: a long-lasting successful partnership

Congenital anomalies of the kidney and urinary tract, as well as urinary infections, are very frequent in children. After the clinical and laboratory evaluation, the first imaging procedure to be done is a renal and bladder ultrasound, but afterwards, a main contribution comes from nuclear medicine. Through minimally invasive and sedation-free procedures, nuclear medicine allows the evaluation of the functional anatomy of the urinary tract, and the quantification of renal function and drainage. If pediatric dosage cards provided by scientific societies are used, radiation exposure can also be low. In the pediatric conditions previously mentioned, nuclear medicine is used both for initial diagnosis and follow-up, mostly in cases of suspicion of ureteropelvic or ureterovesical junction syndromes, as well as vesicoureteral reflux or renal scars of febrile infectious episodes. Pediatric nephro-urology constitutes a significant workload of pediatric nuclear medicine departments. The following paragraphs are a revision of the renal radiopharmaceuticals, as well as the nuclear nephro-urology procedures - dynamic and static renal scintigraphy, and direct and indirect radionuclide cystography. A summary of the techniques, main indications, interpretation criteria and pitfalls will be provided. Some future directions for the field are also pointed out, among which the most relevant is the need for nuclear medicine professionals to use standardized protocols and integrate multidisciplinary teams with other pediatric and adult health professionals that manage these life-long pediatric pathologies, which are recognized as an important cause of adult chronic kidney disease.

High-grade Vesicoureteral Reflux in Patients With Anorectal Malformation From the ARM-Net Registry: Is Our Screening Sufficient?

BACKGROUND

Vesico-ureteral reflux (VUR) is a common associated urological anomaly in anorectal malformation (ARM)-patients. High-grade VUR requires antibiotic prophylaxis to prevent urinary tract infections (UTI's), renal scarring and -failure. The exact prevalence of high-grade VUR in ARM patients is unknown. Hence, the aim of this study was determining the incidence of high-grade VUR in ARM-patients, and its associated risk factors.

METHODS

A multicenter retrospective cohort study was performed using the ARM-Net registry, including data from 34 centers. Patient characteristics, screening for and presence of renal anomalies and VUR, sacral and spinal anomalies, and sacral ratio were registered. Phenotypes of ARM were grouped according to their complexity in complex and less complex. Multivariable analyses were performed to detect independent risk factors for high-grade (grade III-V) VUR.

RESULTS

This study included 2502 patients (50 % female). Renal screening was performed in 2250 patients (90 %), of whom 648 (29 %) had a renal anomaly documented. VUR-screening was performed in 789 patients (32 %), establishing high-grade VUR in 150 (19 %). In patients with a normal renal screening, high-grade VUR was still present in 10 % of patients. Independent risk factors for presence of high-grade VUR were a complex ARM (OR 2.6, 95 %CI 1.6-4.3), and any renal anomaly (OR 3.3, 95 %CI 2.1-5.3).

CONCLUSIONS

Although renal screening is performed in the vast majority of patients, only 32 % underwent VUR-screening. Complex ARM and any renal anomaly were independent risk factors for high-grade VUR. Remarkably, 10 % had high-grade VUR despite normal renal screening. Therefore, VUR-screening seems indicated in all ARM patients regardless of renal screening results, to prevent sequelae such as UTI's, renal scarring and ultimately renal failure.

TYPE OF STUDY

Observational Cohort-Study.

LEVEL OF EVIDENCE

III.

National Trends in Voiding Cystourethrograms During Hospitalization for Young Infants With Urinary Tract Infections

OBJECTIVES

The American Academy of Pediatrics published a guideline in 2011 recommending against the routine use of voiding cystourethrogram (VCUG) in infants aged 2 to 24 months with first febrile urinary tract infection (UTI); however, the rates of VCUG for infants aged <2 months are unknown. The objective of this study was to determine the trend in VCUG performance during index hospitalization among infants aged 0 to 2 months with UTI.

METHODS

This retrospective cohort study included infants aged birth to 2 months hospitalized with a UTI from 2008 to 2019 across 38 institutions in the Pediatric Health Information System. Outcome measures included recurrent UTI within 1 year, vesicoureteral reflux diagnosis within 1 year and antiurinary reflux procedure performed within 2 years. Trends over time were compared between preguideline (2008-2011) and postguideline periods (2012-2019) using piecewise mixed-effects logistic regression.

RESULTS

The odds of VCUG decreased by 21% per year in the preguideline period (adjusted odds ratio, 0.79; 95% confidence interval, 0.77-0.81; P < .001) versus 20% (adjusted odds ratio, 0.80; 95% confidence interval, 0.77-0.83; P < .001) in the postguideline period. The preguideline and postguideline difference was not statistically significant (P = .60). There was no difference in the postguideline odds of UTI within 1 year (P = .07), whereas the odds of vesicoureteral reflux diagnosis (P < .001) and antiurinary reflux procedure performance (P < .001) decreased.

CONCLUSIONS

VCUG performance during hospitalization has declined over the past decade among young infants hospitalized with UTI. Further work is needed to determine the optimal approach to imaging in these young infants.

Clinical Outcomes of Voiding Cystourethrogram and Antibiotic Prophylaxis

Background Urinary tract infections (UTIs) are a prevalent and potentially serious bacterial infection observed among children. Presently, the primary use of diagnostic imaging for UTI is to pinpoint young patients who are at a high risk of developing renal scarring. The most significant procedure for pediatric urology fluoroscopic evaluation is voiding cystourethrogram (VCUG). VCUG-acquired UTIs continue to be an important concern and the purpose of this study is to assess the clinical outcomes of antibiotic prophylaxis on VCUG-associated UTIs. Methods This retrospective study included all patients who underwent VCUG procedures performed from the year 2014 to 2021. All data were retrieved from the medical registries and databases. Radiological and laboratory investigations related to the VCUG procedures were thoroughly reviewed. Patients were considered to have post-procedure UTI if urological symptoms including fever and dysuria along with positive urine culture were exhibited within four weeks after the VCUG study. Patients with incomplete medical records were excluded from the analysis. Results This study consisted of 147 participants. Continuous antibiotic prophylaxis (CAP) was observed in 57 (38.8%) participants of them 35 (23.8%) participants suffered from UTI while urine culture and sensitivity testing were performed among 142 (96.6%) participants before VCUG which came negative and only five (3.4%) had a positive result. Overall, the results of the Chi-square test of association revealed a significant association between sex and vesicoureteral reflux (VUR), indicating that the prevalence of VUR differs between males and females. However, no significant associations were observed between VUR and UTI, urine culture and sensitivity results, hydronephrosis, type of catheter, or choice of antibiotic. Conclusion In conclusion, this study contributes valuable insights into the clinical outcomes of antibiotic prophylaxis on VCUG-associated UTIs. Despite the prophylaxis rate of 38.8%, UTIs were still observed in a significant proportion of children undergoing VCUG. This calls for further research to identify additional risk factors, optimize prophylaxis strategies, and enhance the overall safety and efficacy of VCUG procedures in children.

Prospective evaluation of a pediatric urodynamics protocol before and after limiting urine cultures

PURPOSE

While our institution has historically obtained a urine culture (UCx) from every child at the time of urodynamics (UDS), no consensus exists on UDS UCx utility, and practice varies widely. This study aims to prospectively study our symptomatic post-UDS UTI rate before and after implementing a targeted UCx protocol.

MATERIALS AND METHODS

A 2-part prospective study of patients undergoing UDS at one pediatric hospital was undertaken, divided into Phase 1 (7/2016-6/2017) with routine UCx at the time of UDS and Phase 2 (7/2019-6/2020) after implementation of a protocol limiting UCx at the time of UDS to only a targeted subset of patients. The primary outcome was symptomatic post-UDS UTI, defined as positive UCx ≥10ˆ4 CFU/mL and fever ≥38.5 °C or new urinary symptoms within seven days of UDS.

RESULTS

A total of 1,154 UDS were included: 553 in 483 unique patients during Phase 1 and 601 in 533 unique patients during Phase 2. Age, sex, race, ethnicity, and bladder management did not differ significantly between phases. All 553 UDS in Phase 1 had UCx at the time of UDS, compared to 34% (204/601) in Phase 2. The rate of positive UCx decreased from 39% in Phase 1-35% in Phase 2. Three patients developed symptomatic post-UDS UTI in each study period, resulting in a stable post-UDS UTI rate of 0.5% (3/553) in Phase 1 and 0.5% (3/601) in Phase 2. These patients varied in age, sex, UDS indication, and bladder management. Four of the six (67%) patients had positive UCx at the time of UDS, one had a negative UCx, and one had no UCx under the targeted UCx protocol. Predictors of symptomatic post-UDS UTI could not be evaluated.

DISCUSSION

In the largest prospective study to date, we found that symptomatic post-UDS UTI was <1% and that UCx at the time of UDS can safely be limited at our hospital. This reduction has important implications for cost containment and antibiotic stewardship. We will continue iterative modifications to our protocol, which may eventually include the elimination of UCx at the time of UDS in all groups.

CONCLUSIONS

This 2-part prospective evaluation at one pediatric hospital determined that the symptomatic post-UDS UTI rate remained <1% with no identifiable predictors after limiting previously universal UCx at the time of UDS to only a targeted subset of patients.

Culture-positive urinary tract infection following micturating cystourethrogram in children

Objective

To determine the incidence of culture-positive urinary tract infection (UTI) after micturating cystourethrogram (MCUG). We further wanted to identify risk factors for developing a culture-positive UTI following MCUG.

Methods

A retrospective review of the available medical records of 500 paediatric patients who underwent MCUG in Perth, Western Australia was performed.

Results

Seven (1.4%) patients comprised of four females and three males developed a febrile, culture-positive UTI within 14 days following MCUG. Significant association was found for female patients, patients with neurogenic bladder, and patients with previous culture-positive UTI as developing a culture-positive UTI following MCUG. Multivariate logistic regression determined that patients were more likely to develop culture-positive UTI within 14 days following MCUG if they had a known history of UTI (odds ratio: 5.0, 95% confidence interval: 1.5–17.3, p=0.010) or had a neurogenic bladder (odds ratio: 4.2, 95% confidence interval: 1.0–17.9, p=0.049).

Conclusion

The incidence of patients who developed a febrile, culture-positive UTI following MCUG was low at 1.4%. Statistically significant and independent associations for the development of culture positive UTI were found in patients with neurogenic bladder and patients with previous culture-positive UTI. Further prospective studies are necessary to determine necessity of prophylactic antibiotics for high-risk patients, e.g., patients with neurogenic bladder or previous culture-positive UTI.

Incidence of post-procedure symptomatic urinary tract infection in children undergoing micturition cystourethrogram in the absence of antibiotic cover

Context

Prophylactic antibiotics are usually not recommended for an in and out catheterization. However procedures involving similar catheterizations like micturition cystourethrogram (MCUG) and cystometrogram are being performed under prophylactic antibiotic cover.

Aims

We aim to find the incidence of symptomatic urinary tract infections following MCUG done in children without antibiotic cover.

Settings and design

A retrospective cross sectional study was conducted on 398 patients who underwent MCUG from January 2015 to January 2016. The median age was 24 months and here were 272 males and 126 females, with 102 of them being infants.

Methods and material

Urine microscopy or culture was checked before performing the MCUG and only those without UTI were included in the study. Those with symptomatic and culture proven UTI within 2 weeks post-MCUG were defined as having post-procedure UTI (ppUTI). The incidence of post-procedure UTI was calculated and was compared with other studies.

Statistical analysis used

Data was entered in Microsoft Excel and analyzed using SPSS. Categorical variables were summarized as percentage and continuous variables were summarized as mean with standard deviation.

Results

Symptomatic procedure induced UTI were seen in only 3 of the 398 (0.75%) patients with a 95% CI of 0.02–0.008.

Conclusions

Strict adherence to aseptic precautions while performing an MCUG and prompt initiation of appropriate therapy when indicated may help obviate the need for routine administration of pre procedure antibiotics before MCUG.

Antimicrobial Prophylaxis for Urologic Procedures in Paediatric Patients: A RAND/UCLA Appropriateness Method Consensus Study in Italy

The main aim of surgical antimicrobial prophylaxis (SAP) in urologic procedures is to prevent bacteraemia, surgical site infections (SSIs), and postoperative urinary tract infections (ppUTIs). Guidelines for SAP in paediatric urology are lacking. Only some aspects of this complex topic have been studied, and the use of antibiotic prophylaxis prior to surgical procedures seems to be more often linked to institutional schools of thought or experts’ opinions than to rules dictated by studies demonstrating the most correct and preferred management. Therefore, the aim of this Consensus document realized using the RAND/UCLA appropriateness method is to provide clinicians with a series of recommendations on SAP for the prevention of bacteraemia, SSIs, and ppUTIs after urologic imaging and surgical procedures in paediatric patients. Despite the few available studies, experts agree on some basilar concepts related to SAP for urologic procedures in paediatric patients. Before any urological procedure is conducted, UTI must be excluded. Clean procedures do not require SAP, with the exception of prosthetic device implantation and groin and perineal incisions where the SSI risk may be increased. In contrast, SAP is needed in clean-contaminated procedures. Studies have also suggested the safety of eliminating SAP in paediatric hernia repair and orchiopexy. To limit the emergence of resistance, every effort to reduce and rationalize antibiotic consumption for SAP must be made. Increased use of antibiotic stewardship can be greatly effective in this regard.

Diagnosis and grading of vesicoureteral reflux on voiding cystourethrography images in children using a deep hybrid model

BACKGROUND AND OBJECTIVE

Vesicoureteral reflux is the leakage of urine from the bladder into the ureter. As a result, urinary tract infections and kidney scarring can occur in children. Voiding cystourethrography is the primary radiological imaging method used to diagnose vesicoureteral reflux in children with a history of recurrent urinary tract infection. Besides the diagnosis of reflux, it is graded with voiding cystourethrography. In this study, we aimed to diagnose and grade vesicoureteral reflux in Voiding cystourethrography images using hybrid CNN in deep learning methods.

METHODS

Images of pediatric patients diagnosed with VUR between 2016 and 2021 in our hospital (Firat University Hospital) were graded according to the international vesicoureteral reflux radiographic grading system. VCUG images of 236 normal and 992 with vesicoureteral reflux pediatric patients were available. A total of 6 classes were created as normal and graded 1-5 patients.

RESULTS

In this study, a hybrid-based mRMR (Minimum Redundancy Maximum Relevance) using CNN (Convolutional Neural Networks) model is developed for the diagnosis and grading of vesicoureteral reflux on voiding cystourethrography images. Googlenet, MobilenetV2, and Densenet201 models are used as a part of the hybrid architecture. The obtained features from these architectures are examined in concatenating process. Then, these features are classified in machine learning classifiers after optimizing with the mRMR method. Among the models used in the study, the highest accuracy value was obtained in the proposed model with an accuracy rate of 96.9%.

CONCLUSIONS

It shows that the hybrid model developed according to the findings of our study can be used in the diagnosis and grading of vesicoureteral reflux in voiding cystourethrography images.

INCIDENCE OF URINARY TRACT INFECTION AFTER CYSTOGRAPHY

Objective:

Cystography an invasive procedure with potential complications such as urinary infection (UI). There are few studies about the incidence of complications associated with this procedure. The purpose of this study is to evaluate the incidence of post-cystography urinary infection (UI.).

Methods:

Retrospective study with a review of clinical records of patients under 15 years of age, followed in this hospital, who underwent cystography (radiologic or indirect radionuclide) between 2009 and 2018. Post-cystography UI was defined when it occurred until seven days after the procedure. Descriptive and nonparametric statistics were applied to assess possible predictive factors related with post-cystography UI.

Results:

In the study period, 531 cystograms were undertaken (55% indirect radionuclide and 45% radiologic). The mean age at the procedure was 11.5 months; 62% were boys. Every patient had a previous negative urine culture; 50% were under antibiotic prophylaxis at the time of the procedure. The most common indication for the procedure was the post-natal study of congenital hydronephrosis/other nephrological malformation (53%), followed by the study of febrile UI (31%). Vesicoureteral reflux (VUR) was diagnosed in 40% of procedures. Post-cystography UI occurred in 23 cases (incidence of 4.3%). The most frequent microorganism was E. coli (52%). The presence of VUR was significantly associated with the occurrence of post-cystography IU.

Conclusions:

The incidence of post-cystography UI was low in our sample. The presence of VUR was significantly associated with the occurrence of post-cystography UI. The authors highlight the importance of an adequate catheterization technique and the need for clinical surveillance after the procedure.

Updated Italian recommendations for the diagnosis, treatment and follow-up of the first febrile urinary tract infection in young children

AIM

Our aim was to update the recommendations for the diagnosis, treatment and follow-up of the first febrile urinary tract infection in young children, which were endorsed in 2012 by the Italian Society of Pediatric Nephrology.

METHODS

The Italian recommendations were revised on the basis of a review of the literature published from 2012 to October 2018. We also carried out an ad hoc evaluation of the risk factors to identify children with high-grade vesicoureteral reflux or renal scarring, which were published in the previous recommendations. When evidence was not available, the working group held extensive discussions, during various meetings and through email exchanges.

RESULTS

Four major modifications have been introduced. The method for collecting urine for culture and its interpretation has been re-evaluated. We have reformulated the algorithm that guides clinical decisions to proceed with voiding cystourethrography. The suggested antibiotics have been revised, and we have recommended further restrictions of the use of antibiotic prophylaxis.

CONCLUSION

These updated recommendations have now been endorsed by the Italian Society of Pediatric Nephrology and the Italian Society for Pediatric Infectivology. They can also be used to compare other recommendations that are available, as a worldwide consensus in this area is still lacking.

Urinary Tract Infection in Children

BACKGROUND

Urinary Tract Infection (UTI) is a common infection in children. Prompt diagnosis and appropriate treatment are very important to reduce the morbidity associated with this condition.

OBJECTIVE

To provide an update on the evaluation, diagnosis, and treatment of urinary tract infection in children.

METHODS

A PubMed search was completed in clinical queries using the key terms "urinary tract infection", "pyelonephritis" OR "cystitis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature and the pediatric age group. Patents were searched using the key terms "urinary tract infection" "pyelonephritis" OR "cystitis" from www.google.com/patents, http://espacenet.com, and www.freepatentsonline.com.

RESULTS

Escherichia coli accounts for 80 to 90% of UTI in children. The symptoms and signs are nonspecific throughout infancy. Unexplained fever is the most common symptom of UTI during the first two years of life. After the second year of life, symptoms and signs of pyelonephritis include fever, chills, rigor, flank pain, and costovertebral angle tenderness. Lower tract symptoms and signs include suprapubic pain, dysuria, urinary frequency, urgency, cloudy urine, malodorous urine, and suprapubic tenderness. A urinalysis and urine culture should be performed when UTI is suspected. In the work-up of children with UTI, physicians must judiciously utilize imaging studies to minimize exposure of children to radiation. While waiting for the culture results, prompt antibiotic therapy is indicated for symptomatic UTI based on clinical findings and positive urinalysis to eradicate the infection and improve clinical outcome. The choice of antibiotics should take into consideration local data on antibiotic resistance patterns. Recent patents related to the management of UTI are discussed.

CONCLUSION

Currently, a second or third generation cephalosporin and amoxicillin-clavulanate are drugs of choice in the treatment of acute uncomplicated UTI. Parenteral antibiotic therapy is recommended for infants ≤ 2 months and any child who is toxic-looking, hemodynamically unstable, immunocompromised, unable to tolerate oral medication, or not responding to oral medication. A combination of intravenous ampicillin and intravenous/intramuscular gentamycin or a third-generation cephalosporin can be used in those situations. Routine antimicrobial prophylaxis is rarely justified, but continuous antimicrobial prophylaxis should be considered for children with frequent febrile UTI.

Antibiotics for urethral catheterization in children undergoing cystography: retrospective evaluation of a single-center cohort of pediatric non-toilet-trained patients

Antibiotics are often used to prevent post-catheterization urinary tract infections (UTIs) in patients undergoing cystography. However, there is no universally accepted protocol and the literature data are conflicting. We aimed to determine prevalence and risk factors of post-cystography UTIs in non-toilet-trained children. We retrospectively evaluated 216 non-toilet-trained children not assuming antibiotics when undergoing cystography. Only the patients with dilated vesico-ureteral reflux (VUR) assumed antibiotics just after the exam (within 15 min). One hundred eleven patients without vesico-ureteral reflux (VUR) and 29 patients with non-dilated VUR did not receive post-procedure antibiotics and did not develop UTIs. Out of the 76 patients who showed a dilated VUR and received post-procedure antibiotics, only 5 (6.6%) developed a UTI. The most significant factor associated with post-cystography UTIs was the presence of dilated VUR (p = 0.005) with the presence of bilateral VUR also being significant (p = 0.02).Conclusion: Patients without dilated VUR or bilateral VUR could not benefit from antibiotic prophylaxis for cystography. What is Known: • There is no universally accepted protocol about antibiotic administration in children undergoing cystography. • Literature data are conflicting. What is New: • Among 216 non-toilet-trained children undergoing cystography, 111 patients without vesico-ureteral reflux (VUR) and 29 patients with non-dilated VUR did not receive post-procedure antibiotics and did not develop UTIs. Out of the 76 patients who showed a dilated VUR and received post-procedure antibiotics, only 5 (6.6%) developed a UTI. • The most significant factor associated to post-cystography UTIs was the presence of dilated VUR (p = 0.005) with presence of bilateral VUR also being significant (p = 0.02).

Pediatric voiding cystourethrography: An essential examination for urologists but a terrible experience for children

Voiding cystourethrography is the most important fluoroscopic examination in pediatric urology for the investigation of lower urogenital tract diseases, such as vesicoureteral reflux or urethral stricture. However, this invasive procedure imposes a significant burden on children and their parents, and recently there has been a paradigm shift in the diagnosis and treatment of vesicoureteral reflux. In the 2011 revision, the American Academy of Pediatrics guidelines on urinary tract infection recommended abandoning routine voiding cystourethrography after the first febrile urinary tract infection. In 2014, the randomized intervention for children with vesicoureteral reflux study recommended discontinuation of routine continuous antibiotic prophylaxis for vesicoureteral reflux. The time is now ripe to radically reconsider indications for voiding cystourethrography and the procedure itself.

The association between continuous antibiotic prophylaxis and UTI from birth until initial postnatal imaging evaluation among newborns with antenatal hydronephrosis

INTRODUCTION

There is a lack of consensus regarding the use of continuous antibiotic prophylaxis (CAP) during the interval between birth and initial postnatal imaging in infants with a history of antenatal urinary tract dilation (AUTD).

OBJECTIVE

To determine the incidence of urinary tract infection (UTI), and the association between CAP use and UTI during the interval between birth and the first postnatal renal ultrasound (RUS) in infants with AUTD.

STUDY DESIGN

A single-institution, retrospective cohort study of newborns with a history of AUTD. Infants undergoing RUS within 3 months of birth for an indication of 'hydronephrosis' between 2012 and 2014 were identified. A random sample of 500 infants was selected; six were excluded for concomitant congenital anomalies. Baseline patient (sex, race, insurance) and clinical characteristics (circumcision status, UTD risk score, receipt of CAP, UTI prior to RUS, age at UTI, and age at RUS) were collected via retrospective chart review. Descriptive statistics were calculated. To adjust for receipt of CAP, propensity score adjusted univariate logistic regression for UTI based on CAP status was performed.

RESULTS

Among the 494 infants with AUTD, 157 (32%) received CAP. Infants with normal/low-risk UTD scores were less likely to receive CAP than those with medium/high-risk UTD (23% vs 77%; P < 0.001). There was no difference in CAP based on sex, insurance, or circumcision status (among 260/365 males with known circumcision status). Overall, seven infants (1.4%) developed UTI prior to imaging: six (1.8%) without CAP vs one (0.64%) with CAP (P = 0.44). The median age at UTI was 59 days (range 2-84); among those with UTI, initial imaging occurred significantly later (66 vs 28 days; P = 0.001). The propensity score adjusted odds of developing UTI with CAP (vs without) was 0.93 (95% CI 0.10-8.32; P = 0.95). The Summary Figure describes the infants with UTI.

CONCLUSION

The incidence of UTI prior to initial neonatal imaging in newborns with AUTD was low. Use of CAP was not associated with UTI incidence after adjusting for UTD severity. Routine use of CAP in newborns with AUTD prior to initial imaging may be of limited benefit in most patients.