Primary obstructive megaureter in children; 10 years' experience from a tertiary care center

Abstract

Introduction: Primary obstructive megaureter (POM) is a congenital dilatation of the ureter due to an adynamic segment of vesicoureteric junction obstruction. Surgical intervention is needed if nuclear scan shows obstructive curve. We analyzed our data and outcome of conservative and surgical treatment in such cases at our tertiary care hospital.

Materials and methods: We evaluated all cases of POMs during the study period. Investigations included ultrasonography (USG), voiding cystourethrogram, diethylene pentacetic acid (DTPA) scan, and dimercaptosuccinyle acid scan. In antenatal cases, any pelvic dilatation ≥12 mm after 6 weeks were subjected to reonography. Patients with anterior-posterior pelvic diameter (APPD) ≥12 mm had to undergo DTPA scan to look for DRF and drainage. Follow-up USG was done in all cases of mild-to-moderate hydroureteronephrosis, with APPD <12 at 3 months interval.

Results: A total of 270 megaureters were registered and treated during the study period (2008-2019). The total number of patients included was 50 (64 ureters). The mean age of presentation in these 30 children was 21.78 ± 18.1 months (range 1-72 months) and the mean weeks of gestation in antenatal cases at presentation as megaureter was 24 ± 7 weeks (range 13-37 weeks). The mean weight of babies was 2.72 ± 0.7 g. The duration of follow-up ranged from 16 to 1W12 months. The mean APPD on the affected side was 19.99 ± 10.3 mm (range 11-43 mm). The mean ureteric diameter was 1.67 ± 0.33 mm (range 0.78-2.66 cm). The mean split function of patients with POM was 34.88% ± 11.5% on the affected side. Twenty patients (40%) had spontaneous resolution over a mean time period of 24.1 ± 11.1 months. Thirty patients underwent surgical procedures. In three children, HTN was observed over a mean follow-up period of 3 years.

Conclusion: The babies with POM need a close follow-up. Surgery is indicated in prolonged t_½/T_max on renal scan, function <40% at the initial scan, or >5% split function deterioration in the subsequent renal scan.

Keywords: British Association of Psediatric Urologists; differential renal function; glomerular filtration rate; hydroureteronephrosis; primary obstructive megaureters; ultrasonography; vesicoureteric reflux.

Figure 1

Fetal antenatal hydronephrosis at 23 weeks of gestation

Figure 2

Fetal ultrasonography shows dilated distal ureter

Figure 3

Adilated distal ureter with tapering near vesicoureteric junction

Figure 4

Magnetic resonance urography showing narrowed vesicoureteric junction with bilateral dilated obstructed ureters

Figure 5

HPE of the excised vesicoureteric junction segment showing smooth muscle hyperplasia

Bar Chart 1

Gestational age of 20 patients diagnosed in the antenatal period

Figure 6

Intraoperative picture showing distal stenosing segment

Figure 7

Intraoperative picture showing dilated tortuous ureters

Bar Chart 2

The time period for resolution of megaureters