Value of renal pelvic diameter and urinary tract dilation classification in the prediction of urinary tract anomaly

Urinary tract dilation classification system for predicting surgical management and urinary tract infection in neonates and young infants: a systematic review and meta-analysis

BACKGROUND

The urinary tract dilation classification system has recently been developed to ensure a unified approach to describe urinary tract dilation in neonates and young infants. However, the predictive value of this system for surgical intervention or urinary tract infection (UTI) has not yet been evaluated in a meta-analysis.

OBJECTIVE

This systematic review and meta-analysis aimed to evaluate the utility of a postnatal urinary tract dilation classification system for predicting surgical management or a UTI occurrence.

MATERIALS AND METHODS

As the urinary tract dilation classification system was introduced in 2014, we searched Embase and PubMed databases for studies published between January 2014 and December 2022. Original articles that reported surgical interventions or UTI episodes according to postnatal urinary tract dilation grades were included. The pooled odds ratio (OR) was calculated, using either the fixed-effects or random-effects model, given the lower urinary tract dilation grades as the base category. The quality of the included studies was evaluated using the Newcastle-Ottawa scale.

RESULTS

Of the 285 articles reviewed, eight (comprising 2,165 children) were included in the analysis. The studies were of medium-to-high quality. Pooled analysis demonstrated that urinary tract dilation P3 (combined OR, 21.41; 95% confidence interval [CI], 15.72-29.17) and urinary tract dilation P2-P3 (combined OR, 65.17; 95% CI, 33.08-128.38) were associated with surgical intervention. The urinary tract dilation P3 (combined OR, 2.11; 95% CI, 1.56-2.85) and urinary tract dilation P2-P3 (combined OR, 3.36; 95% CI, 2.43-4.63) were associated with UTI episodes.

CONCLUSION

The postnatal urinary tract dilation classification system is useful for predicting the need for surgical management and UTI episodes in infants with hydronephrosis.

Outcomes of children with isolated antenatal hydronephrosis

BACKGROUND

Antenatal hydronephrosis (ANH) is one of the most common abnormalities detected during prenatal ultrasound. There is significant variability in the postnatal management of ANH. Our objective was to report the outcomes of patients with ANH, spontaneous resolution rates, surgical intervention rates, and factors contributing to these parameters.

METHODS

A total of 227 patients and 264 renal units with ANH were included in this study. We used the renal pelvis anteroposterior diameter and the Society for Fetal Urology grading system to classify and compare ANH as mild, moderate, and severe.

RESULTS

The patients' median follow-up period was 48 months (with a minimum of 6 months and a maximum of 136 months). Of the 264 renal units, 123 (46.6%) had mild, 101 (38.26%) had moderate, and 40 (15.15%) had severe antenatal hydronephrosis. The spontaneous resolution rate was 91.9% in the mild hydronephrosis group (n = 113), 81.2% (n = 82) in the moderate hydronephrosis group, and 37.5% (n = 15) in the severe hydronephrosis group. The patients with higher hydronephrosis grades required a longer time to resolve. Only one patient with a posterior urethral valve had reduced estimated glomerular filtration. None of the patients had proteinuria or hypertension.

CONCLUSION

Although the outcome of the patients with mild hydronephrosis was excellent, there was a progression of the disease, especially within the first 6 months, and 6% of our cases required surgical intervention. Additional prospective studies are needed to define the risk of urinary tract abnormalities with any degree of ANH.

2021 update on the urinary tract dilation (UTD) classification system: clarifications, review of the literature, and practical suggestions

In 2014, a multidisciplinary consensus on the classification of pre- and postnatal urinary tract dilation (UTD classification) was developed. Its goal was to provide a standardized system for evaluating and reporting urinary tract dilation both in the prenatal and postnatal periods. In this review, we summarize insights learned from the implementation of the UTD classification system since its inception, providing clarifications on common points of confusion. In addition, we review current literature in the clinical validation of the UTD classification system to provide credence for its use in managing fetuses and children with urinary tract dilation.

Functional Magnetic Resonance Urography in Ureteropelvic Junction Obstruction: Proposal for a Pediatric Quantitative Score

BACKGROUND

Ureteropelvic junction obstruction (UPJO) is one of the most frequent causes of congenital hydronephrosis. It is essential to distinguish UPJO which needs surgical treatment. fMRU combines high quality morphological details of the kidney and excretory pathways with functional data.

OBJECTIVE

This study aims to introduce a new radiological score based on fMRU findings to be able to differentiate surgical from non-surgical kidneys.

MATERIALS AND METHODS

We retrospectively selected patients with hydronephrosis due to UPJO who underwent fMRU (January 2009-June 2018). A multidisciplinary team identified a list of fMRU morpho-functional predictive variables to be included in the analysis. To evaluate the role of different independent variables in predicting the outcome, a multivariable logistic regression model has been performed; the outcome variable was the surgical intervention. For each predictive variable, Odds Ratio and 95% Confidence Intervals were calculated. The likelihood ratio test was used to assess the significance of the variables. Using the regression model, we assigned a numerical value to each predictive variable, rounding up the beta-coefficients. The cut-off value of the total score was obtained from the ROC curve analysis.

RESULTS

A total of 192 patients were enrolled, corresponding to 200 pathological kidneys. All of them underwent fMRU; 135 were surgically treated, while 65 underwent ultrasound or MRU follow-up. Predictive variables significantly associated with surgery resulted to be the urographic phase, the presence of abnormal vessels, and a baseline anterior-posterior pelvic diameter >23 mm. Beta coefficients of the logistic regression model were then converted in scores. The ROC curve of the score showed high sensitivity (84.3%) and specificity (81.3%) with a cut-off > 2.5.

CONCLUSIONS

We propose a new fMRU score able to identify surgical vs. non-surgical kidneys with UPJO.