Exacerbation of Congenital Hydronephrosis as the First Presentation of COVID-19 Infection in Children: A Case Series

Background:Congenital hydronephrosis is one of the most common abnormalities of the upper urinary tract, which can be exacerbated by a variety of intrinsic or extrinsic triggers. The urinary tract system is one of the major organs complicated by COVID-19 infection. Case presentations:Here we report five patients with an established diagnosis of congenital hydronephrosis, who presented with acute abdominal pain and fever and an abrupt increase in the anteroposterior pelvic diameter (APD). Patients had a previous stable course and were under regular follow-up with serial ultra-sonographic studies. They underwent surgery or supportive treatment due to the later exacerbation of hydronephrosis. Based on the clinical and imaging findings, no plausible etiologies for these exacerbation episodes, including infection, nephrolithiasis or abdominal masses, could be postulated. The common aspect in all these patients was the evidence of a COVID-19 infection. Conclusions:Infection with COVID-19 in children with antenatal hydronephrosis may exacerbate the degree of hydronephrosis and renal APD in ultrasonography, which itself may be mediated by the increase in inflammatory mediators.

Antenatal hydronephrosis: a five-year retrospective study

Introduction: Antenatal hydronephrosis (ANH) is common in fetal ultrasounds. Though mostly transient, it can be associated with congenital abnormalities and kidney injury. The authors went to assess the evolution of children with ANH and identify risk groups. Methods: Retrospective cohort study of children with ANH from 2013‑2017. Renal pelvis anteroposterior diameter (APD) of 4 and 7mm or more in the second and third trimester, respectively, defined diagnosis of ANH. APD also defined severity stratification. The primary out‑ comes included occurrence of urinary tract infection (UTI) and congenital anomalies of the kidney and urinary tract (CAKUT). Results: We identified 198 cases, with male predominance (76.8%) and a 2.1% incidence. It resolved antenatally in 12.1%, with a lower mean value of APD in these cases (p=0.017), and persisted in 43.4%. CAKUT were found in 8.6% of the patients. At least 1 episode of UTI occurred in 9.1% of patients during follow‑up. The degree of ANH in the 3rd trimester was related to postnatal persistence and degree (p<0.001) and the postnatal degree was related to the occurrence of UTI (p=0.008). The 3rd trimester and postnatal degree were also associated to the presence of CAKUT (p=0.036; p=0.001), although not with vesicoureteral reflux (VUR). The persistence of ANH through the 2nd and 3rd trimester was related to postnatal persistence (p=0.002) and degree (p=0.007), and the presence of CAKUT excluding VUR (p=0.034). The optimal cut‑off for the APD in the 3rd trimester to predict the occurrence of negative outcomes (CAKUT and/or UTI), through a receiver operating characteristic (ROC) curve, was 8.225mm with 76% sensitivity and 59% specificity. Discussion: ANH is frequent and reflects a wide range of conditions, requiring follow‑up. Most cases resolve spontaneously and require no further intervention other than ultrasounds. 3rd trimester and postnatal degree are related to prognosis, allowing the definition of risk groups and the improvement of patient management.

Reliability of Sonography for the Prediction of Vesicoureteral Reflux in Children With Mild Hydronephrosis

Objectives: Postnatal evaluation of vesicoureteral reflux (VUR) remains controversial in patients with antenatal hydronephrosis (HN). The objective of this study was to identify the significance of mild postnatal HN as a marker of VUR and its severity. Materials and Methods: Sonographic findings of 248 children (351 kidneys) with persistent postnatal HN were evaluated for the incidence and severity of primary VUR. Results: The majority of patients had mild (67.8%) HN, followed by moderate (27.6%) and severe (4.6%) HN. VUR was identified in 14.7% of patients with mild HN, 18.5% of patients with moderate HN, and 18.7% of patients with severe HN. About 11.44% of patients with mild HN had low-grade VUR, followed by moderate (45.71 %) and severe grades (42.85%). Conclusion: A large number (89%) of patients with mild HN had moderate to severe VUR. In this cohort, renal sonography was not a reliable method for the prediction of VUR and its severity in patients with mild postnatal HN. However, it was reliable for high grades of VUR. These results are limited due to the study design and the inability to generalize these findings. These results should be replicated across other multiple clinics, thereby recruiting more variety of patients, to validate these study recommendations.

Evaluation of the Patients with Antenatal Hydronephrosis Diagnosed Ureteropelvic Junction Obstruction with the Hydronephrosis Severity Score

Objective: Ureteropelvic junction obstruction is the main cause of obstructive antenatal hydronephrosis. Although surgery is the traditional treatment modality, there is still no consensus on surgical indications. We aimed to analyse the patients referred as antenatal hydronephrosis and diagnosed with ureteropelvic junction obstruction with Hydronehprosis Severity Score that has been developed by Babu at al. Method: The patients who were admitted with antenatal hydronephrosis in 2013-2018 and diagnosed as ureteropelvic junction obstruction and followed up in our clinic for at least one year were evaluated. The cases with unilateral hydronephrosis were included. Those with vesicoureteral reflux, horseshoe kidney, hydroureter, ureterovesical junction obstruction were excluded. Renal ultrasonography and nuclear scintigraphy results were re-evaluated. They were grouped as mild (0-4), moderate (5-8) and severe (9-12) based on scoring of three parameters; differantial renal function, drainage curve pattern and US grade. Clinical outcomes were also classified in three groups; resolution (grade 1-no hydronephrosis), persistance (grade 2-3 hydronephrosis) and surgical intervention. The relation between the scores and clinical outcomes were analysed. Results: A total of 57 patients were evaluated. 2 with horseshoe kidney, 4 with vesicoureteralreflux, 7 with bilateral hydronephrosis, 4 with ureteric outlet obstruction, 12 with incomplete records were excluded. Finally, 28 patients were included. Hydronephrosis was resolved in 4 (14.2%), persisted in 5 (17.8%) and surgical intervention was required in 19 (67.8%) patients. 1/5 patients with mild, 15/20 patients with moderate and 3/3 patients with severe HSS underwent surgery. 77.2% of the patients with a total score of ≥6 initially required surgical intervention at their follow-up. Conclusion: HSS may provide a significant predictive value for surgical intervention for the patients classified as “mild” or “severe” at the initial evaluation. In the “moderate” group, the risk increases in the patients with HSS≥6. Existing data should be evaluated with larger case series.

Postnatal management of children with antenatal hydronephrosis

Background Postnatal management of infants with antenatal hydronephrosis (ANH) is still one of the most controversial issues. The majority of infants with ANH are asymptomatic with only few children who develop renal insufficiency. Thus, the biggest challenge for pediatric urologists is to distinguish children who will require further investigations and possible intervention prior to the development of symptoms, complications or renal damage in a cost effective manner without exposing them to the hazards of unnecessary investigations. Main body In this review article, literature on ANH were reviewed to present the current suggestions, recommendations, guidelines and their rational for postnatal management of ANH. It is agreed that a large portion of infants with ANH will improve; thus, the protocol of management is based mainly on observation and follow-up by ultrasound to detect either resolution, stabilization or worsening of hydronephrosis. The first 2 years of life are critical for this follow-up as the final picture is mostly reached during that period. Advanced imaging using voiding cystourethrography or renal scintigraphy are required for children at risk. Then, surgical intervention is selected only for a subgroup of these infants who showed worsening of hydronephrosis or renal function. Conclusions The protocol of management is based mainly on observation and follow-up by US to detect either resolution, stabilization or worsening of hydronephrosis. Postnatal evaluation should be performed for any neonate with a history ANH at any stage during pregnancy even if it was resolved during third trimester. Exclusion of UTI should be performed by urinalysis for all cases followed by urine culture if indicated. Serum creatinine should be performed especially in patients with bilateral ANH. US is the initial standard diagnostic imaging technique. Other imaging modalities like VCUG and nuclear renal scans may be required according to the results of the US evaluation. The most important items in decision making are the presence of bilateral or unilateral hydronephrosis, presence or absence of hydroureter, presence of lower urinary tract obstruction and degree of hydronephrosis on the initial postnatal US. Then an intervention is selected only for a subgroup of these patients who showed deterioration in renal function or degree of hydronephrosis or were complicated by UTIs. All these recommendations are based on the available literature. However, management of ANH is still a controversial issue due to lack of high evidence-based recommendations. Randomised controlled studies are still needed to provide a high level evidence for different aspects of management.