We appreciate Dr. Salvatore and Dr. Carmelo’s interest in our article [1]. As they have stated, our cohort consists of patients with AP diameter ≤ 20 mm and < SFU Grade IV, which is the most common group of children we see in daily practice [2]. The idea of our manuscript came up with the question ‘How long should we need to follow-up this group of children?’ that we came across at the first postnatal visit. As these patients are very less likely to undergo surgery, the duration of follow-up should be kept minimal to reduce costs and parental anxiety without compromising patient health. Our results indicate that complete resolution may be expected to happen in 3 years, while many patients will show regression of hydronephrosis in the first year of life.
With regard to AP diameter and SFU classification systems, they both have advantages and disadvantages; however, they are the most commonly used tools for assessing hydronephrosis. AP diameter is a relatively reliable method as a numerical value is given. However, it can be affected by hydration status and bladder fullness. Besides, it gives no information about caliceal dilatation and parenchymal status.
In their nicely written study, the authors have investigated a challenging patient group that has poor drainage but good differential renal function [3]. As they have concluded, poor drainage patterns might not always indicate obstruction. Previously, Koff et. al also showed that T1/2 might be inaccurate due to exaggerated enlargement of renal pelvis when assessing children < 2 years of age [4]. Of note, patients with SFU Grade III in our study underwent scintigraphic evaluation.
Consequently, we think serial ultrasonography is the key for the evaluation of antenatal hydronephrosis and scintigraphic evaluation should be considered in cases with peripheral caliceal dilatation, and/or increase in AP diameter or degree of hydronephrosis.
References
Arena S, Romeo C (2019) Isolated antenatal hydronephrosis with renal pelvis antero-posterior diameter </= 20 mm. Eur J Pediatr 178:1443. https://doi.org/10.1007/s00431-019-03430-8
Elmaci AM, Donmez MI (2019) Time to resolution of isolated antenatal hydronephrosis with anteroposterior diameter </= 20 mm. Eur J Pediatr 178:823–828. https://doi.org/10.1007/s00431-019-03359-y
Arena S, Chimenz R, Antonelli E, Peri FM, Romeo P, Impellizzeri P, Romeo C (2018) A long-term follow-up in conservative management of unilateral ureteropelvic junction obstruction with poor drainage and good renal function. Eur J Pediatr 177:1761–1765. https://doi.org/10.1007/s00431-018-3239-2
Koff SA, Binkovitz L, Coley B, Jayanthi VR (2005) Renal pelvis volume during diuresis in children with hydronephrosis: implications for diagnosing obstruction with diuretic renography. J Urol 174:303–307. https://doi.org/10.1097/01.ju.0000161217.47446.0b
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Ethical approval
This article does not contain any studies with human participants or animals performed by any of the authors.
Additional information
Communicated by Peter de Winter
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
This is a reply to the article https://doi.org/10.1007/s00431-019-03430-8
Rights and permissions
About this article
Cite this article
Dönmez, M.İ., Elmacı, A.M. Reply to correspondence “Isolated antenatal hydronephrosis with renal pelvis antero-posterior diameter ≤ 20 mm”. Eur J Pediatr 178, 1921 (2019). https://doi.org/10.1007/s00431-019-03473-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00431-019-03473-x