We conducted a 10-year (2005-2015) retrospective review of all operated cases of PUV, who had antenatal hydronephrosis. Antenatal ultrasound findings, clinical features, age at confirmation of diagnosis, biochemical abnormalities, surgical management and follow-up data were analyzed. Initial investigations included urinalysis, renal functions parameters (urea, creatinine and electrolytes) and renal ultrasound. The diagnosis was made by micturating cystourethrogram (MCU) and confirmed on cystourethroscopy.

The surgical treatment was cystourethroscopy and PUV ablation; diversion was reserved for patients where ablation was not advisable/feasible. Postoperatively, all patients received prophylactic oral antibiotics and oxybutynin (0.2 mg/kg/day), which was discontinued after toilet training, and when timed voiding was possible.

The renal function (nadir creatinine) was analyzed in relation to oligohydramnios, gestational status at delivery, age at intervention, mode of therapy (diversion/PUV ablation), presence of vesicoureteral reflux (VUR) and preoperative infection. Initial creatinine of more than 0.6 mg/dL was considered as raised, and patients with nadir creatinine of more than 1.2 mg/dL at 6 months were considered to be at risk of progression to chronic renal insufficiency.

We managed 218 patients with PUV during the study period. Ninety-two (42.5%) had antenatal hydronephrosis; 81 of these were analyzed for this study (minimum of 6 months follow-up). Out of 81 children, 11 were excluded (2 died before treatment, one moved overseas after treatment, and 8 patients had insufficient data).

The mean (SD) gestational age at antenatal diagnosis was 34 (4.48) weeks, and mean (SD) age at intervention was 124 (147) days. The mean (SD) follow-up period was 39.2 (27.6) months, and mean (SD) age at last follow-up was 43.4 (28) months. Twenty-five patients (33%) had VUR.

Sixty patients (85%) were managed by primary valve ablation and 15% underwent diversion, of which eight have been undiverted during follow-up. Two patients are still on diversion and two of the diverted patients died of renal failure.

The mean (SD) initial and nadir creatinine was 0.87 (0.98) mg/dL and 0.41 (0.35) mg/dL, respectively. Initial creatinine was raised in 24 (30%) patients. After treatment, 12 (15%) patients had nadir creatinine >1.2 mg/dL with a trend towards higher creatinine on follow-up (Fig. 1).

Fig. 1 The correlation between peak creatinine and nadir creatinine over time.

Fifty-two patients could be assessed for voiding function. Three patients underwent ablation of residual valve and four of the toilet-trained patients had bladder dysfunction at last follow-up. On nuclear renal scans, eight patients had poorly functioning unilateral renal units (<10% function), and three underwent unilateral nephroureterectomy for recurrent urinary tract infections (UTI).

In our series of children antenatally diagnosed with posteriod urethral valves, thirty percent presented with raised peak creatinine (>0.6 mg/dL). Vesicoureteral reflux (VUR) was present in one-third of patients. Majority of our patients were managed by endoscopic valve ablation and 15% needed diversion due to persisting sepsis or progressive renal failure with electrolyte abnormalities.

More than two-thirds of PUV are detected antenatally [7], but this proportion is less in developing countries [8]. The classical ultrasound features of PUV (hydronephrosis, distended/thickened bladder with dilated posterior urethra and oligohydramnios) are present in about one-third of scans [9]. As antenatal ultrasonography is not specific for PUV [10], careful postnatal evaluation is warranted.

The treatment is mainly endoscopic valve ablation, and diversion is used for those with persisting sepsis or failed endoscopic therapy. In a series of 65 cases of antenatally diagnosed PUV [11], 97% were managed by valve ablation alone. Conservative management is advocated for VUR in PUV as majority resolve with time. Heikkila, et al. [12] reported that almost half of 197 patients with PUV had resolution of VUR within 2 years after treatment.

The renal outcome of PUV is largely based on nadir creatinine; a recent study [13] showed that nadir level after treatment is reached by six months. The functional outcome is better for prenatally diagnosed PUV [14], and bladder function improves with longer follow-up.

PUV can present with antenatal hydronephrosis or postnatally with bladder outflow obstruction. Endoscopic valve ablation is the main modality of treatment and diversion is reserved if the former fails or is contraindicated. The prognosis of patients with mild disease and normal renal function is good, and in those with intermediate severity disease, postnatal therapy improves the outcome.

Acknowledgements: Dr Sreekumaran MI, who was part of the team in clinical management. Dr Biju George, for help in statistical analysis.

Contributors: TPJ: clinical management of patients, supervised the data collection and contributed to critical review of the article; VKG: helped in manuscript editing and clinical management; PRB: helped in manuscript editing and clinical management; KVSK: Data collection, data analysis and manuscript drafting.

Funding: None; Competing interest: None stated.