Predictive value of cortical transit time on MAG3 for surgery in antenatally detected unilateral hydronephrosis caused by ureteropelvic junction stenosis
Introduction
The postnatal course of antenatally detected hydronephrosis (ANH) caused by ureteropelvic junction (UPJ) stenosis varies from spontaneous resolution to the progressive deterioration of renal function, and a not inconsiderable number of children with UPJ stenosis can have serious long-term consequences such as loss of renal function [1]. Although the management paradigm has shifted gradually from early surgery to a more conservative approach consisting of active surveillance and selective surgery, postnatal management of ANH caused by UPJ stenosis remains controversial [2], [3], [4]. The main challenge of its management is preserving renal function by identifying children who require early surgical intervention from those for whom watchful waiting may be appropriate because of the potential for spontaneous resolution without a significant loss of renal function [5], [6]. Although many studies have examined the predictive factors of functional deterioration [4], different criteria for surgical intervention and the variable use of diagnostic tools to assess renal function have contributed to the controversy in the management of ANH caused by UPJ stenosis.
A few recent studies showed that cortical transit time (CTT) on a technetium-99m mercaptoacetyltriglycerine (MAG3) diuretic renogram could successfully predict functional deterioration in children with UPJ stenosis [7], [8], [9], [10]. These studies showed a significant correlation between CTT and the clinical outcomes of children with UPJ stenosis. However, the true advantage of CTT as a prognostic factor of the clinical course of ANH caused by UPJ stenosis remains questionable. Therefore, we assessed the impact of initial CTT on a MAG3 scan for surgical need in children with unilateral ANH caused by UPJ stenosis.
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Material and methods
We retrospectively reviewed the medical records of the children with unilateral ANH caused by UPJ stenosis who were managed at our institution between January 2006 and December 2014. Ninety-nine children with significant unilateral hydronephrosis (maximal anteroposterior diameter [APD] of the renal pelvis >10 mm) on an initial postnatal ultrasonography (USG) conducted 1–2 weeks after birth were consecutively included in this study. Patients were excluded if they had ipsilateral or contralateral
Results
Thirty-three children with unilateral ANH caused by UPJ stenosis were identified in this study. The mean follow-up duration was 31.8 months. The male to female ratio was 25:8 and the left to right ratio was 27:6. The mean APD on initial USG was 17.7 mm and the SFU grade of hydronephrosis on initial USG was grade I in 0 (0%), grade II in nine (27.3%), grade III in eight (24.2%), and grade IV in 16 (48.5%) patients. The initial SRF of the affected kidney was 50.7% and the drainage pattern was
Discussion
Many factors have been suggested as predictors related to the future deterioration of renal function in children with unilateral ANH caused by UPJ stenosis [1], [11], [12], [13], [14]. However, the main obstacle in this conservative era is that none of these parameters measured by conventional tools including USG, a diuretic renogram, magnetic resonance imaging, or even biological markers, has given us a reliable predictive value [12], [14]. Therefore, it is critical to identify which
Conclusions
In this study, we observed that CTT on the initial MAG3 scan is an independent predictor of surgical need in children with unilateral ANH caused by UPJ stenosis. CTT as a promising predictor in UPJ stenosis may help clinicians to decide whether to pursue surgical treatment before significant renal deterioration occurs, to plan follow-up duration and frequency, and to counsel families.
Conflict of interest
None declared.
Funding
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2015R1D1A3A03020378).
References (17)
- et al.
Prediction of the outcome of antenatally diagnosed hydronephrosis: a multivariable analysis
J Pediatr Urol
(2012) Postnatal management of antenatal hydronephrosis using an observational approach
Urology
(2000)- et al.
Round table on the management of renal pelvic dilatation in children
J Pediatr Urol
(2009) - et al.
The postnatal management of hydronephrosis diagnosed by prenatal ultrasound
J Urol
(1990) - et al.
Predicting the clinical outcome of antenatally detected unilateral pelviureteric junction stenosis
Urology
(2013) - et al.
Cortical transit time as a predictive marker of the need for surgery in children with pelvi-ureteric junction stenosis: preliminary study
J Pediatr Urol
(2013) - et al.
Diagnostic accuracy of renal pelvic dilatation for detecting surgically managed ureteropelvic junction obstruction
J Urol
(2013) - et al.
Predictive value of decreased renal pelvis anteroposterior diameter in prone position for prenatally detected hydronephrosis
J Urol
(2012)
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Hyun Tae Kim and Sung Kwang Chung contributed equally to this work.