Prenatal diagnosis of bladder exstrophy by fetal MRI

A case report of single umbilical artery combined with fetal bladder exstrophy in singleton pregnancy and related literature review

BACKGROUND

According to prenatal ultrasonographic studies, single umbilical artery may be present alone or in association with other fetal abnormalities. So far, the exact pathogenesis of bladder exstrophy is unclear. Some scholars believe that bladder exstrophy and cloacal exstrophy should be regarded as a disease spectrum to explore their pathogenesis. If bladder exstrophy and cloacal exstrophy are regarded as the same disease spectrum, then we can speculate that the single umbilical artery should have the probability of being accompanied by bladder exstrophy at the same time.

CASE PRESENTATION

For the first time, we report a rare case of fetal bladder exstrophy with single umbilical artery in single pregnancy. This patient underwent targeted color Doppler ultrasound at 26 weeks of pregnancy which first suspected bladder exstrophy with single umbilical artery and fetal MRI for diagnosis at 38 + 3 weeks of pregnancy which confirmed the suspicion. After the diagnosis was confirmed, the patient was scheduled for a multidisciplinary discussion. Ultimately the patient opted for induced fetal demise at 38 + 5 weeks of pregnancy and the physical appearance of the fetal demise affirmed previous ultrasound and MRI examination results.

CONCLUSIONS

Our report is the first finding of single umbilical artery combined with bladder exstrophy in a singleton pregnancy. Accordingly, our case enhances the evidence that cloacal exstrophy and bladder exstrophy should be treated as the same disease spectrum. In addition, we conducted a literature review on the diagnostic progress of single umbilical artery combined with bladder exstrophy, hoping to provide useful references for the diagnosis of this disease.

Prenatal Diagnosis of Bladder Exstrophy and OEIS over 20 Years

OBJECTIVE

To examine the prenatal diagnosis rates of bladder exstrophy (BE) and Omphalocele-Exstrophy-Imperforate anus-Spinal Defect Syndrome (OEIS) in a large cohort of patients over a 20-year period. We hypothesized that prenatal diagnosis rates improved over time due to evolving techniques in fetal imaging.

METHODS

A multi-institutional database was queried to identify BE or OEIS patients who underwent primary closure between 2000 and 2020. We retrospectively determined prenatal or postnatal diagnosis. Those with unknown prenatal history were excluded. Multivariable logistic regression was used to investigate temporal pattern in rate of prenatal diagnosis while adjusting for sex and treating institution.

RESULTS

Among 197 BE and 52 OEIS patients, 155 BE and 45 OEIS patients had known prenatal history. Overall prenatal diagnosis rates of BE and OEIS were 47.1% (73/155) and 82.2% (37/45), respectively. Prenatal diagnosis rate was significantly lower in BE compared to OEIS (P <.0001). The prenatal diagnosis rate for BE significantly increased over time (OR 1.10; [95%CI: 1.03-1.17]; P = .003). Between 2000 and 2005, the prenatal diagnosis rate of BE was 30.3% (10/33). Between 2015 and 2020, prenatal diagnosis rate of BE was 61.1% (33/54). Prenatal diagnosis rate for OEIS did not change over time. Rates of prenatal diagnosis did not differ by sex or treating institution.

CONCLUSION

Rates of prenatal diagnosis of BE and OEIS are higher than previously reported. Prenatal diagnosis rate of BE doubled in the last 5 years compared to the first 5 years of the study period. Nonetheless, a significant proportion of both BE and OEIS patients remain undiagnosed prior to delivery.

Key anatomic findings on fetal ultrasound and MRI in the prenatal diagnosis of bladder and cloacal exstrophy

INTRODUCTION

Prenatal determination of bladder exstrophy (BE) or cloacal exstrophy (CE), known also as the omphalocele-exstrophy-imperforate anus-spinal anomaly complex (OEIS), is challenging. Distinguishing between BE and CE is important because children with CE have many more challenges initially and during their lifetime. An accurate diagnosis is critical when counselling expectant parents. We hypothesized that there are key imaging features that can distinguish BE from CE, and that there are areas of diagnostic concordance and discordance between fetal ultrasound (fUS) and fetal MRI (fMRI) among these entities.

MATERIALS AND METHODS

We queried a single institutional IRB-approved registry of children with BE and CE to identify those with accessible fetal imaging from 2000 to 2018, and formal interpretations were collected. Two pediatric radiologists performed independent retrospective blinded review of the images. Criteria evaluated included: genitalia, kidneys, bowel appearance, presence of anal dimple, location of insertion of umbilical cord into the abdomen relative to the abdominal wall defect, umbilical vessels, bladder protuberance, presence of omphalocele, and spine/neural cord abnormalities. We evaluated concordance between radiologic interpretations and postnatal diagnosis, as well as between specific findings in the two diagnostic modalities.

RESULTS

Twenty-one infants born between 2000 and 2018 with BE or CE had fetal imaging for review: 15 had both fUS and fMRI, 2 had fUS alone, and 4 fMRI alone. There was 100% concordance between fUS and fMRI in evaluating kidneys, presence of anal dimple, location of abdominal insertion of umbilical cord relative to the defect, number of umbilical vessels, and spine abnormalities/level of neural cord termination. The following discrepancies were observed: 1) genitalia and bowel appearance, and bladder protuberance in 1/15 (6.7%); 2) presence of an omphalocele in 2/15 (13.3%). Of the initial radiologic interpretations, 4/17 (23.5%) of fUS and 2/19 (10.5%) of fMRI erroneously were interpreted as on the OEIS spectrum when the post-natal diagnosis was BE. Errors in diagnosis were due to a protuberant bladder plate extending beyond the plane of the abdominal wall with bowel loops posteriorly mimicking an omphalocele. In all of these BE cases, the abdominal wall defect was located inferior to the umbilical cord insertion on the abdominal wall.

CONCLUSION

An everting bladder plate with bowel loops posterior to the plate in classic BE may be misdiagnosed as CE. Identification of the location of umbilical cord insertion relative to the abdominal wall defect, with fetal US or MRI, results in the correct differentiation between BE and CE.

Repeated successful vaginal delivery in a pregnant woman with unrepaired ectopia vesicae and split pelvis: a case study

Abstract

Ectopia vesicae, or bladder exstrophy, is a rare malformation, more frequently found in males. Very few cases of pregnancy with unrepaired ectopia vesicae have been reported in literature. The majority of these pregnant women with ectopia vesicae have terminated their pregnancies by cesarean section due to malpresentation, preterm labor or other indications. Clemetson concluded that cesarean section was the preferable method of term delivery to avoid postpartum prolapse. We have a different opinion on this because we had an interesting case. A woman with unrepaired ectopia vesicae had two successful vaginal deliveries, in 2009 and 2019 respectively. She recovered well and did not have any symptoms or signs of pelvic organ prolapse (POP) so far.

Case presentation

Let us present this woman with ectopia vesicae who had four pregnancies; two spontaneous abortions and two vaginal deliveries. In 2009, she had a successful vaginal delivery at Yantai Harbor Hospital where the first author worked at that time. She met the first author again surprisingly, during her third trimester in 2019. She had a spacious pelvis and pendulous abdomen. In this fourth pregnancy, the fetus changed its presentation frequently. Still, she had the second vaginal delivery successfully. She recovered fully after delivery and did not have any symptoms or signs of POP. As far as we know, this is the first case that a patient with ectopia vesicae who has been observed for such a long time after multiple vaginal deliveries.

Conclusions

Doctors must evaluate the risk of vaginal delivery or cesarean section and consider maternal-neonatal health. Prior to this, women with repaired or unrepaired ectopia vesicae usually delivered their babies by cesarean section. Our practice shows that vaginal delivery is also a safe and feasible choice for some of these patients, especially for those with unrepaired, mild types of ectopia vesicae who experience no other dangerous or uncomfortable symptoms.

Prenatal and postnatal imaging techniques in the evaluation of disorders of sex development

Imaging of the reproductive tract is challenging and requires a general knowledge of congenital variations in anatomy. The anatomy of the developing fetus, whether a male phenotype or female phenotype, is also a dynamic process with many changes occurring during gestation. Families may ask details about the genitalia during prenatal imaging and when variations in what is thought to be normal are present, further investigation is sometimes needed to make sense of what is seen. This overview will describe categories of disorders of sex development (DSD), whether chromosomal or structural or both, and the current state of imaging of these anomalies.

Isolated bladder exstrophy in prenatal diagnosis

PURPOSE

Isolated classic bladder exstrophy (CBE) is the most common variant of the bladder-exstrophy-epispadias complex (BEEC). The BEEC represents a spectrum ranging from isolated epispadias over CBE to the most severe form, cloacal exstrophy. We report on a series of 12 cases with CBE diagnosed prenatally and illustrate the spectrum of prenatal ultrasound findings with comparison to prior published reports on this entity.

METHODS

This was a retrospective study involving 12 fetuses with CBE at two large tertiary referral centers in Germany over a 14-year period (2004-2018).

RESULTS

Median diagnosis was made with ultrasound in 24 + 5 (IQR_25,75: 21 + 2, 29 + 0) weeks of gestation. All fetuses presented with the pathognomonic findings non-visualization of the fetal bladder and protruding abdominal mass below the umbilical cord insertion. All fetuses showed normal kidney anatomy and normal amniotic fluid throughout pregnancy. Epispadia was visible prenatally on ultrasound in 6/8 male fetuses. 1/12 Parents opted for termination of pregnancy, 11/12 fetuses were live born and received reconstructive surgery.

CONCLUSIONS

Isolated CBE is an extremely rare prenatal sonographic finding. Prenatal diagnostics should exclude additional malformations within the spectrum of cloacal malformations.

The Pubic Diastasis Measurement, a Key Element for the Diagnosis, Management, and Prognosis of the Bladder Exstrophy

OBJECTIVE

To demonstrate the feasibility of measuring the fetal pubic diastasis (PD) distance on antenatal ultrasound in normal fetuses and to compare it to fetuses with bladder exstrophy.

METHODS

Firstly, a prospective multicentric study was conducted to determine the feasibility of the PD ultrasound measurement during the second half of pregnancy. Secondly, data from a single center were used to develop a nomogram for PD values in normal fetuses. Thirdly, retrospective PD measurements were collected from fetuses with bladder exstrophy, diagnosed in seven French Multidisciplinary Centers for Prenatal Diagnosis (MCPDs).

RESULTS

Operators from several MCPDs examined 868 fetuses and found that overall PD ultrasound measurement was feasible in 71% of cases and that the ossification of pubic points increased to be always visible from 27 weeks of gestation onward. Performed in a single center by a referring operator on 1,539 fetuses, the feasibility reached 94.74%. Both set of measurements were concordant (mean PD distance value of 5.42 ± 1.8 mm). Interestingly, all 23 fetuses with bladder exstrophy showed a significantly larger PD distance (mean 15.74 ± 3.9 mm).

CONCLUSION

PD measurement in the fetus is feasible and reliable in the second half of gestation and can be used to support the antenatal diagnosis of bladder exstrophy with PD values exceeding 10 mm.

When Closure Fails: What the Radiologist Needs to Know About the Embryology, Anatomy, and Prenatal Imaging of Ventral Body Wall Defects

Ventral body wall defects (VBWDs) are one of the main categories of human congenital malformations, representing a wide and heterogeneous group of defects sharing a common feature, that is, herniation of one or more viscera through a defect in the anterior body wall. Gastroschisis and omphalocele are the 2 most common congenital VBWDs. Other uncommon anomalies include ectopia cordis and pentalogy of Cantrell, limb-body wall complex, and bladder and cloacal exstrophy. Although VBWDs are associated with multiple abnormalities with distinct embryological origins and that may affect virtually any system organs, at least in relation to anterior body wall defects, they are thought (except for omphalocele) to share a common embryologic mechanism, that is, a failure involving the lateral body wall folds responsible for closing the thoracic, abdominal, and pelvic portions of the ventral body wall during the fourth week of development. Additionally, many of the principles of diagnosis and management are similar for these conditions. Fetal ultrasound (US) in prenatal care allows the diagnosis of most of such defects with subsequent opportunities for parental counseling and optimal perinatal management. Fetal magnetic resonance imaging may be an adjunct to US, providing global and detailed anatomical information, assessing the extent of defects, and also helping to confirm the diagnosis in equivocal cases. Prenatal imaging features of VBWDs may be complex and challenging, often requiring from the radiologist a high level of suspicion and familiarity with the imaging patterns. Because an appropriate management is dependent on an accurate diagnosis and assessment of defects, radiologists should be able to recognize and distinguish between the different VBWDs and their associated anomalies. In this article, we review the relevant embryology of VBWDs to facilitate understanding of the pathologic anatomy and diagnostic imaging approach. Features will be illustrated with prenatal US and magnetic resonance imaging and correlated with postnatal and clinical imaging.

Disorders of the bladder and cloacal anomaly

The incidence of congenital urachal, bladder, and cloacal anomalies is low. Urachal remnants are the result of failure or delay in obliteration of the allantois. Exstrophy of the bladder or cloaca can be diagnosed on prenatal ultrasonography and represent a deviation from the normal embryologic sequence. Persistent cloaca is an anomaly occurring in girls, in which a common cavity exists into which the intestinal, urinary, and reproductive tracts all open. It is also often diagnosed on prenatal imaging.