Spontaneous resolution of antenatally diagnosed ureterocele.

Sir,

Ultrasound scan report in first week of life, in a full-term female neonate with antenatally diagnosed ureterocele (ADU), revealed left duplex kidney with upper moiety hydronephrosis, ureterocele of 5mm diameter in left bladder base and normal right kidney. The ureterocele wall was thick in ultrasound [Figure 1]. Voiding cystourethrogram (VCUG) showed no vesicoureteric reflux. Dimercaptosuccinic acid (DMSA) scan showed 45% left kidney function and nearly 20% function in upper moiety. The baby was managed conservatively.

Figure 1

(Left half) Coronal ultrasound scan shows the dilated upper moiety (black arrows) and lower moiety (white arrows) of the left kidney. The right half marked-A shows the small intravesical ureterocele with a well-defined wall (white arrow)

Ultrasound three to six monthly showed stable hydronephrosis in early infancy and its reduction subsequently. Diuretic renogram (DR) showed good drainage and function in all renal moieties.

By three years, the left upper pole hydronephrosis disappeared with reduction in ureterocele size. By six years, both hydronephrosis and ureterocele were not seen. Cystoscopy (at various bladder volumes) did not show any ureterocele. Crescentic left upper pole ureteric orifice was seen supero-lateral to bladder neck with periodic urine efflux.

Periodic ultrasound scans till age of ten showed no hydronephrosis and ureterocele. VCUG was not repeated as the girl neared puberty.

Only 39 patients with successful non-operative ureterocele management have been documented.[123] Poor function of involved renal moiety and associated multicystic kidney favor spontaneous ureterocele resolution (SUR). Progressive atrophy of renal moiety explains the SUR.[123]

Smooth muscle distribution in ureterocele wall varies.[4] In our patient, the thick ureterocele rim on ultrasound suggests good muscle distribution. SUR with good function of renal moieties is known.[23] This may be explained by normal urine flow causing dilatation of ureterocele orifice. The dilatation is possibly facilitated by adequate muscle in ureterocele wall.

Investigation and management of ureterocele are tailored to the requirement of the individual patient.[1235] Early DR helps to exclude obstruction in the renal moieties,[15] but requires consistently precise definition of regions of interest which is difficult in infants with duplex system.[5] Initial ultrasound and DMSA have been used for anatomical/functional assessment, respectively with serial ultrasound to monitor preservation of renal parenchyma.[235] In our patient, progressive hydronephrosis reduction with good function in all renal moieties shown by DMSA and subsequent DR ruled out obstruction.

In ADU managed conservatively, serial monitoring for at least 5 years after SUR is safe.[235]