Prenatal diagnosis and postnatal outcome of closed spinal dysraphism

OBJECTIVE

To evaluate the prenatal diagnosis of closed dysraphism (CD) and its correlation with postnatal findings and neonatal adverse outcomes.

METHODS

A retrospective cohort study including pregnancies diagsnosed with fetal CD by prenatal ultrasound (US) and magnetic resonance imaging (MRI) at a single tertiary center between September 2011 and July 2021.

RESULTS

CD was diagnosed prenatally and confirmed postnatally in 12 fetuses. The mean gestational age of prenatal imaging was 24.2 weeks, in 17% the head circumference was ≤fifth percentile and in 25% the cerebellar diameter was ≤fifth percentile. US findings included banana sign in 17%, and lemon sign in 33%. On MRI, posterior fossa anomalies were seen in 33% of cases, with hindbrain herniation below the foramen magnum in two cases. Mean clivus-supraocciput angle (CSA) was 74°. Additional anomalies outside the CNS were observed in 50%. Abnormal foot position was demonstrated prenatally in 17%. Neurogenic bladder was present in 90% of patients after birth.

CONCLUSION

Arnold Chiari II malformation and impaired motor function can be present on prenatal imaging of fetuses with CD and may be associated with a specific type of CD. Prenatal distinction of CD can be challenging. Associated extra CNS anomalies are frequent and the rate of neurogenic urinary tract dysfunction is high.

An Algorithmic Approach to Complex Fetal Abdominal Wall Defects

OBJECTIVE. The purpose of this article is to describe the imaging findings associated with complex fetal abdominal wall defects and provide an algorithmic method for arriving at a final diagnosis. CONCLUSION. Fetal ventral abdominal wall defects are a complex group of conditions with a broad spectrum of associated multisystem anomalies and manifestations. Correct characterization and classification of these defects require not only familiarity with imaging findings but also a systematic approach to avoid diagnostic confusion.

Misdiagnosis of a cloacal exstrophy variant as urorectal septum malformation in a fetus by ultrasound: A case report

Cloacal exstrophy variants are comprised of a wide range of characteristics, of which there are four primary features, including omphalocele, bladder exstrophy, an imperforate anus and spina bifida. The existing literature regarding the differential diagnosis from alternative urinary diseases prenatally are limited. If the bladder is present, defects in the ventral wall may not be visualized with prenatal ultrasound in certain conditions, including oligohydramnios, and differential diagnosis from urorectal septum malformation sequence is a challenge. In order to improve the diagnosis of cloacal exstrophy variants, the present study investigated the misdiagnosis of a cloacal exstrophy variant as a urorectal septum malformation in a fetus by ultrasound and analyzed the reasoning of diagnosis in detail.

Evaluation of the development of the fetal anal sphincter with tomography ultrasonography imaging

The aim of the study described here was to examine the potential of tomography ultrasonography imaging (TUI) in evaluation of the fetal anal sphincter. In this prospective cross-sectional study of the fetal anal sphincter with TUI, 326 singleton pregnancies (mean age = 28 y, range: 22-38 y) were scanned at 19-40 wk of gestation. The fetal anal region and ischium were revealed in 320 of 326 patients (98.2%). The normal fetal anal sphincter diameter and ischial space reached maximums of 15 and 39 mm, respectively. The normal fetal anal sphincter diameter and the ischial space were plotted as a function of gestational age (GA) on a linear curve, and the regression equations for normal fetal anal sphincter diameter and ischial space as a function of GA in weeks were obtained. A scatterplot was also created that revealed a significant positive relationship between normal fetal anal sphincter diameter and ischial space. On the basis of these criteria, imperforate anus was diagnosed in one fetus. Ultrasonographic assessment of the fetal anal sphincter and the ischium with TUI is feasible. The reference values reported in this article may be useful in prenatal diagnosis of fetal anal sphincter abnormalities.

Fetal MRI of cloacal exstrophy

BACKGROUND

Prenatal ultrasonographic (US) diagnosis of cloacal exstrophy (CE) is challenging.

OBJECTIVE

To define the fetal MRI findings in CE.

MATERIALS AND METHODS

We performed a retrospective review of eight patients with CE. Imaging was performed between 22 weeks and 36 weeks of gestation with US in four and MRI in eight fetuses. Abdominal wall, gastrointestinal/genitourinary, and spine and limb abnormalities detected were compared with postnatal evaluation.

RESULTS

US failed to display CE in one of the four fetuses. Fetal MRI confirmed CE in all eight fetuses by demonstrating absence of a normal bladder and lack of meconium-filled rectum/colon, associated with protuberant pelvic contour and omphalocele. These findings correlated postnatally with CE, atretic hindgut and omphalocele. One fetus had imaging before rupture of the cloacal membrane, showing a protruding pelvic cyst. Absent bladder was noted in the remaining seven fetuses. Confirmed skin-covered spinal defects were noted in seven fetuses, low conus/tethered cord in one and clubfoot in three. Six fetuses had renal anomalies, two had hydrocolpos and one had ambiguous genitalia.

CONCLUSION

Fetal MRI provides a confident diagnosis of CE when a normal bladder is not identified, there is a protuberant abdominopelvic contour and there is absence of meconium-filled rectum and colon. Genitourinary and spinal malformations are common associations.

Prenatal findings of omphalocele-exstrophy of the bladder-imperforate anus-spinal defects (OEIS) complex

Omphalocele-exstrophy of the bladder (cloaca)-imperforate anus-spinal defects (OEIS) complex describes a rare grouping of more commonly occurring component malformations. We report two cases of OEIS complex diagnosed prenatally by ultrasound and magnetic resonance imaging (MRI). In both cases, OEIS complex was suspected by conventional sonography in the second trimester, and fetal MRI was performed at 27 and 32 weeks of gestation. Conventional sonography revealed low abdominal wall mass, spina bifida, absent bladder and ambiguous genitalia, but those findings were inconclusive. Using fetal MRI, we were able to detect omphalocele, imfraumbilical mass connected to gut tract, absent bladder, ambiguous external genitalia and spinal defect. Our findings suggest that fetal MRI is a useful tool for prenatal diagnosis of OEIS complex. MRI helps prenatal counseling and planning of postnatal early treatment strategy.

Prenatal diagnosis and postnatal outcome of fetal spinal defects without Arnold-Chiari II malformation

OBJECTIVE

To determine the prenatal evolution/natural history and postnatal outcome of fetuses diagnosed with a neural tube defect (NTD) lacking the Arnold-Chiari-II malformation (ACM II).

MATERIAL AND METHODS

This retrospective study reviewed 16 fetuses evaluated with ultrasound (US) and MRI at a single referral center from 1/2000 to 8/2007. Follow-up studies and available postnatal outcomes were reviewed.

RESULTS

Postpartum diagnosis was terminal myelocystoceles 7/16 (44%); myelomeningoceles (MMCs) 3/16 (19%); lipomyelomeningoceles 2/16(13%); and thoracic myelocystocele 1/16 (6%). Three patients (19%) were lost to follow-up or termination of pregnancy. Two prenatally diagnosed 'closed' NTD were postnatally found to be MMCs. Three of the myelocystoceles had additional omphalocele, bladder extrophy, imperforate anus and spinal defect (OEIS complex). For the total cohort, impaired lower extremity function was seen in 38%, impaired bladder function in 64%, and ventriculoperitoneal shunting in 8%. Four fetuses with a myelocystocele developed hindbrain herniation in the third trimester of pregnancy. The preterm delivery rate was 38%. Five of eight (63%) neonates with postnatally diagnosed myelocystoceles had mothers with a body mass index over 30.

CONCLUSION

Prenatal differentiation between closed and open NTD is not always possible. Postnatal outcome of isolated myelocystocele and MMC seems to be more favorable than for an NTD with ACM II (shunt requirement). Incontinence is the major childhood morbidity. Maternal obesity may be a risk factor for closed NTDs.

Contemporary postnatal surgical management strategies for congenital abdominal wall defects

Early definitive closure of abdominal wall defects is possible in most cases. Staged reduction does offer distinct advantages, and mortality and morbidity may be better. Risk stratification may produce outcome and tailor management of difficult cases in the form of a clinical pathway. Stem cell technology may, in the future, offer the ideal allogenic prosthesis in complex cases.