Isolated low grade prenatally detected unilateral hydronephrosis: do we need long term follow-up?

Abstract

Purpose:To assess the need for postnatal evaluation and the medium term outcome in patients with isolated unilateral low grade prenatally detected hydronephrosis.Materials and Methods:We prospectively selected 424 patients (690 kidney units) with a prenatal diagnosis of urinary tract dilatation between 2010 and 2013. We included only those patients with isolated unilateral low-grade hydronephrosis who underwent at least 2 postnatal ultrasound examinations. The Society for Fetal Urology (SFU) grading system was utilized for assessment of the hydronephrosis. We excluded patients with bilateral dilation or other urological abnormalities. The fate of hydronephrosis including resolution, stability or worsening was documented.Results:A total of 66 infants (44 boys and 22 girls) with antenatally diagnosed unilateral urinary tract dilation (23 right and 43 left) were identified. Ultrasounds showed SFU grade 1 hydronephrosis in 32 patients (48%) and SFU grade 2 hydronephrosis in 34 (52%). After a mean follow-up period of 32 months (range 12 to 60), 37 patients (56%) had complete resolution of hydronephrosis while the remaining 29 were stable (44%). None of our patients developed UTIs during follow-up and none required surgical intervention.Conclusions:Prenatally detected, isolated unilateral low-grade hydronephrosis usually have a favorable prognosis. All cases in our cohort showed either stability or resolution of hydronephrosis without any harmful consequences. Based on our findings on medium-term in this category of patients, long-term follow-up is not warranted.

Antenatally detected urinary tract dilatation: a 12–15-year follow-up

“…It is difficult to compare our results with other studies in aspects other than those mentioned above [5, 7-10, 17, 19, 28], as different definitions of pre-and postnatal UTD and different endpoints and outcomes were used. Also, most of these studies [5,[7][8][9][10]28] are registry or cohort studies with patients included over a prolonged period but with data analyzed cross-sectionally at a certain time point and the results not differentiated based on length of follow-up.…”

“…Many studies have tried to define which children with antenatally diagnosed UTD will eventually need surgery, and most authors agree that children with low-grade UTD (Society for Fetal Urology (SFU) grades 1 and 2) will probably not need surgery for UTD-related issues [ 4 , 8 – 10 ]. In our study, no child from subgroup A and six children from subgroup B (6/40, 15%) needed UTD-related surgery, which is consistent with these studies.…”

“…Only few studies have followed children with antenatally detected UTD for longer than a median of 2 years [5,7,8], and even fewer for longer than a median of 10 years [9,10]. In these studies, the included cases had a wide range of follow-up times [5,[7][8][9][10], and some of them only examined subgroups of children [7,8,10].…”

“…Only few studies have followed children with antenatally detected UTD for longer than a median of 2 years [5,7,8], and even fewer for longer than a median of 10 years [9,10]. In these studies, the included cases had a wide range of follow-up times [5,[7][8][9][10], and some of them only examined subgroups of children [7,8,10]. To meet the need for a study of an unselected cohort with a long follow-up [11], we conducted this 12-15-year re-evaluation of children antenatally diagnosed with UTD, born in 2003-2005, and followed according to a standardized protocol during the first 2 years of life [12][13][14].…”