Fetal Urinoma in Females without Obstructive Uropathy

Abstract

Objective: Prenatal diagnosis of urinomas has long been established with underlying obstructive uropathy generally responsible for urinary extravasation. Because urinoma formation represents a pop-off mechanism in cases of posterior urethral valves, the number of affected males greatly exceeds the number of females. Fetal urinoma has rarely been reported without obstruction and in females it has only been described as a consequence of a complicated amniocentesis. Methods: Three cases of fetal urinoma in female fetuses without any dilatation of the urinary tract are described. Since the fetus remained healthy, they were all conservatively managed. Results: Two urinomas resolved after birth and 1 exhibited significant regression. In the second case, a compressed kidney was visualized with fetal MRI. Renal function was impaired in cases 1 and 3 and absent in case 2 (the kidney was no longer visualized). Conclusions: Fetal urinomas can occur even in the absence of urinary tract obstruction and in a low-pressure system as is found in female fetuses. Fetal MRI may help both visualize the ipsilateral kidney and differentiate the mass from other conditions. In a healthy fetus, fetal urinomas can be conservatively managed, but renal function after birth is often absent or impaired. Whether or not in utero aspiration may be beneficial for the preservation of renal function remains unclear.

The Fetal Urinoma Revisited

“…Thus, it seems safe to speculate that the etiology of the obstruction does not dictate whether spontaneous resolution will occur. Additional case reports have described resolution shortly after birth 13 . However, regression of the urinoma should be approached with caution, as it may reflect oliguria secondary to severe renal dysplasia rather than improvement in urine drainage or the obstruction itself.…”

Post-traumatic urinoma in two cats: Imaging diagnosis

“…In human medicine, urinomas are often described as consequences of blunt trauma, urinary tract obstruction by uroliths, intra-abdominal malignancy, retroperitoneal fibrosis or post instrumentation (Titton et al 2003;Goldwasser et al 2018). This condition is also described in foetuses mostly because of the urine extravasation after the rupture of the kidney second to an underlying urinary tract obstruction or trauma (Gorincour et al 2006;Zaccara et al 2011;Yitta et al 2014).…”

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

“…[10] The occurrence of fetal urinomas has also been reported following a traumatic amniocentesis. [4] Additionally, Zaccara et al [11] reported three cases of fetal urinomas in female fetuses without an identifiable obstructive uropathy.…”

“…The postnatal function of kidneys with urinomas and PUV has been previously reported to be between 20% and 71%. [6][7][8][9][10][11][12][13][14][15][16] In 1990, Fernbach et al [1] described 5 cases with PUV, in which renal function was preserved in the presence of a urinoma. However, later studies have not identified any protective effect for urinomas in PUV patients.…”