A large unilateral contained urinoma in a fetus: an indication for intrauterine urinary shunting

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 impact of perinatal urinoma formation on renal function: our experience and review of the literature

INTRODUCTION

A urinoma is a fluid mass consisting of extravasated urine in the perirenal space. Its impact on renal function was analysed.

METHODS

All cases of prenatal and neonatal urinoma reported in the literature were analysed as well as two cases recently observed in our department.

RESULTS

A review of all prenatally diagnosed urinomas revealed 25 cases, for a total of 30 renal units. The cause of obstruction was: lower urinary tract (LUT) obstruction in 16 cases (62.5%), upper urinary tract (UUT) obstruction in seven cases (29.5%) and unknown in two cases (8%). A preserved renal function was found in only 30% of all cases. Furthermore, prognosis for renal function was better in posterior urethral valve (PUV) patients than in uretero-pelvic junction obstruction (UPJO) patients. In addition, we analysed 35 published cases of urinoma with a neonatal onset, without prenatal diagnosis, and secondary to LUT obstruction in 27 cases (77%), UUT obstruction in seven cases (20%), while the underlying cause was unknown in one cases (3%). A preserved renal function was observed in 84% of cases with UUT obstruction and in 80% of cases presenting a LUT obstruction.

CONCLUSIONS

Prognosis concerning renal function seems to be mainly related to two factors: age at presentation and underlying diagnosis. Decompression of the urinary tract by urine extravasation produces the best results in terms of preservation of the renal function in LUT obstruction (75% in prenatal and 84% in postnatal cases); UUT obstruction however is associated with a good prognosis in the neonatal period (80% of preserved renal function) but with a severe impairment (only 20% of preserved renal function) in prenatally detected cases.

Antenatal isolated hydronephrosis associated with urinoma

Two cases of prenatally identified urinoma associated with an isolated hydronephrosis are presented, and the pathophysiology and prognosis of this rare condition are discussed. The presence in utero of a peri-renal collection associated with an isolated hydronephrosis seems to be a sign of significant renal dysplasia. These urinomas disappear spontaneously, thus drainage is not necessary, except in the case of compression of surrounding structures. The functional prognosis of these kidneys seems to be most unfavourable.

Fetal urinoma: two new cases and a review of the literature

OBJECTIVE

To evaluate the functional prognosis of kidneys affected prenatally by urinomas.

METHODS

This was a retrospective review of cases of fetal urinoma reported in the literature, as well as two of our own cases.

RESULTS

Twenty-three patients with a prenatal diagnosis of urinoma (five bilateral) were included in the analysis. Postnatal ipsilateral renal function was observed in only six of the 28 renal units (i.e. around 20%).

CONCLUSIONS

Although the precise causes of urinomas are still unknown, this review shows that in the event of a fetal urinoma, the probability of a non-functional dysplastic ipsilateral kidney lies at around 80%. In-utero puncture only appears to be justified in cases where fluid accumulation has mass effects on adjacent major structures.

Enlarged fetal bladder: Differential diagnosis and outcomes

The sonographic finding of an enlarged fetal bladder may simply be a transitory normal variant, but it may also be secondary to reflux or to obstructive, neurogenic, or myopathic causes. In this report, we describe the cases of 3 fetuses with an enlarged bladder, each of which had a different cause. The first fetus had posterior urethral valve obstruction, the second, a ruptured neurogenic bladder, and the third, megacystic-microcolon-intestinal hypoperistalsis syndrome. When sonographic examination reveals an enlarged fetal bladder, the ureter, kidneys, genitalia, and spine should be evaluated carefully. Although sonography is good at identifying urinary tract abnormalities, it often cannot provide the specific diagnosis or cause. We recommend frequent sonographic monitoring to evaluate such fetuses for persistence of or changes in bladder enlargement and for changes in the volume of amniotic fluid because these signs may be indicators of abnormalities of renal function and risk factors for a poor prognosis. Analysis of fetal electrolyte levels can also aid in determining the prognosis and whether the condition is amenable to therapeutic intervention.

Magnetic resonance imaging of fetal urinoma

Extrarenal collections of urine have long been associated with obstructive uropathy and may preserve renal function by acting as a "popoff" valve. Although urinary extravasation manifested as urinary ascites carries a favorable prognosis, perinephric urinomas occurring prenatally are associated with poor renal function in most cases. We report the case of a baby girl with a urinoma diagnosed by fetal magnetic resonance imaging and discuss the significance of this radiologic finding.

Posterior urethral valves causing urinomas: two case reports

The cases of two male babies with posterior urethral valves complicated by the formation of urinomas are reported. Early diagnosis and treatment of this condition is important, as morbidity and mortality from resultant renal failure can be significant if it is unrecognized.

Spontaneous resolution of an in utero perirenal urinoma associated with posterior urethral valves

Ultrasound imaging of a 26-week-gestation fetus demonstrated a large, nonemptying bladder. At 27 weeks, a distended, thick-walled bladder, left hydronephrosis, and a perirenal urinoma were present, without ascites. Observation was undertaken, as the amniotic fluid volume was normal. At 29 weeks, the left perirenal fluid collection persisted but, at 30 weeks, was absent. After delivery at 36 weeks, no ultrasound evidence for perirenal urinoma or ascites was present. Isotope renal scan showed preserved renal function bilaterally. This case illustrates that in utero urinomas associated with posterior urethral valves can resolve spontaneously, with preservation of renal function.