Ultrasound follow-up of an unusual giant urinoma in a newborn

Urinoma, defined as an encapsulation of urine caused by urine extravasation into the perirenal space either through rupture of a calyceal fornix or a tear in the renal parenchyma, is an uncommon finding in prenatal diagnosis and the neonatal period. Urinoma can be associated with any urinary tract obstruction, or, as reported in several published cases, related to vesicoureteral reflux, kidney dysplasia, or complication arising during amniocentesis. We report on a newborn with a perinatal urinoma, with initial slight corpusculated fluid associated with nonobstructive and nonrefluxing megaureter, and no signs of kidney dysplasia. Close sonography follow-up of the urinoma allowed complex differential diagnoses, including cystic, septated, and solid perirenal masses, due to dissimilar and peculiar ultrasound images during urinoma evolution stages.

Prenatal drainage of fetal urinoma with polyhydramnios: a case report and literature review

The appearance of fetal urinoma is rare in prenatal care, especially when associated with polyhydramnions. Many previous reports have concluded that the visualization of a prenatal urinoma is probably a sign of underlying renal dysplasia or poor function. Thus, the management of the reported cases, conservative treatment or uniroma drainage, has not been unified. In this paper, we present two cases of prenatally detected urinoma with prenatal drainage to improve the prognosis.

Fetal urinoma and prenatal hydronephrosis: how is renal function affected?

OBJECTIVE

In our study, the functional prognosis of kidneys with prenatal urinomas were investigated.

MATERIAL AND METHODS

Between 2006 and 2010, fetal urinomas were detected in 19 fetuses using prenatal ultrasonography (US), and the medical records were reviewed retrospectively. Of the 19 cases, the follow-up data were available for 10 fetuses. The gestational age at diagnosis, prognosis of urinomas, clinical course and renal functions were recorded. Postnatal renal functions were assessed with renal scintigraphy.

RESULTS

Unilateral urinomas and increased parenchyma echogenicity in the ipsilateral kidney were detected in all of the fetuses. Of the 10 fetuses with follow-up data, the option of termination was offered in 6 cases of anhydramnios, including 3 cases with signs of infravesical obstruction (a possible posterior urethral valve (PUV) and poor prognostic factors and 3 cases with unilateral hydronephrosis and increased echogenicity in the contralateral kidney. Only one family agreed the termination. The other 5 fetuses died during the early postnatal period. The average postnatal follow-up period in the 4 surviving fetuses was 22.5 months (8-38 months). One patient with a PUV underwent ablation surgery during the early postnatal period. In the postnatal period, none of the 4 kidneys that were ipsilateral to the urinoma were functional on scintigraphic evaluation. The urinomas disappeared in 3 cases. Nephrectomy was performed in one case due to recurrent urinary tract infections.

CONCLUSION

In our study, no function was detected in the ipsilateral kidney of surviving patients with urinomas. Upper urinary tract dilatation accompanied by a urinoma is a poor prognostic factor for renal function.

The fetal urinoma revisited

The fetal urinoma is a rare but important diagnosis, as it indicates substantial underlying obstruction with implications for the functionality of the affected kidney. This case series describes a single center's experience with the diagnosis and management of fetal urinomas. All 25 cases were diagnosed or referred to our medical center over an 11-year period. Most cases were secondary to either posterior urethral valves or ureteropelvic junction obstruction. Fetal interventions, including percutaneous drainage of the urinoma and cystoscopic alleviation of bladder outlet obstruction, were performed in 4 cases.