Case Report
Body stalk anomaly complicated by complex congenital heart disease: first-trimester ultrasonic diagnosis and fetal autopsy
https://doi.org/10.21203/rs.3.rs-2006469/v1
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Body stalk anomaly (BSA) is a relatively rare and severe congenital malformation. Most reported heart anomalies occurring in combination with BSA are ectopic hearts. We herein report a rare case of BSA complicated by complex congenital heart disease prenatally diagnosed in the first trimester by ultrasound and confirmed by autopsy. This case emphasizes that in addition to the typical anomalies, cardiac structural abnormalities are also worthy of attention in cases of BSA.
Body stalk anomaly
congenital heart disease
first trimester
prenatal diagnosis
ultrasound
Body stalk anomaly (BSA) is a relatively rare and severe congenital malformation that is characterized by large anterior abdominal wall defects, an absent or extremely short umbilical cord, and kyphoscoliosis [1]. BSA is a fatal malformation mainly because of its severe structural abnormalities, such as abdominal wall defects and pulmonary hypoplasia [2]. With the exception of an ectopic heart, BSA with congenital heart disease (CHD) has rarely been reported, and few researchers have studied the detailed intracardiac structure in such cases. We herein report a rare case of BSA complicated by complex CHD diagnosed in the first trimester by prenatal ultrasound and confirmed by autopsy.
A 20-year-old healthy primigravida (G1P0) was referred to our hospital because of a suspected fetal anomaly at 12 weeks of gestation. Prenatal ultrasound revealed kyphoscoliosis (Fig. 1A); a large anterior thoracic and abdominal wall defect with organs including the heart, left lung, liver, and stomach herniating into the extra-embryonic coelom (Fig. 1B); and a short umbilical cord. Additionally, discordant connections at both the atrioventricular and ventriculoarterial junctions were detected with a vascular ring (Fig. 1B–D). Based on the ultrasound findings, we considered a diagnosis of BSA with CHD of congenitally corrected transposition of the great arteries (cc-TGA) with a vascular ring. Considering the grave prognosis, the parents opted for termination of the pregnancy.
Fetal autopsy revealed kyphoscoliosis with a short umbilical cord and organs herniating into the extra-embryonic coelom through a large anterior thoracic and abdominal wall defect, consistent with the ultrasonic findings. The dysplastic left upper limb was joined to the left waist by connective tissue. Ruptured amniotic bands were attached to the right foot and fingers of both hands (Fig. 2A). In addition, the left lung was hypoplastic and single-lobed with absence of an oblique fissure (Fig. 2B). Cardiac autopsy confirmed cc-TGA (Fig. 2C) and revealed that the vascular ring was characterized by double aortic arches (DAA) with the left ductus arteriosus (Fig. 2D) encircling the trachea and esophagus. The fetal karyotype was 46, XY. A heterozygous nonsense mutation in NFE2L2 (NM_006164.5:exon5:c.1465C > T:p.Q489*) and a heterozygous deletion non-frameshift mutation in SON (NM_032195.3:exon3:c.5859_5921del:p.S1978_R1998del) were found by whole-exome sequencing. According to the autopsy findings, the definitive diagnosis was BSA complicated by cc-TGA and DAA.
BSA is a rare deformity with a prevalence of 0.12 in 10,000 live and still births [3]. Its pathogenesis is not clear, but there are currently three main hypotheses [4]: premature rupture of the amniotic membrane (i.e., the amniotic membrane ruptures before the extra-embryonic coelom cavity closes), extensive destruction of blood vessels during early embryonic development, and abnormal early embryonic development resulting in disturbances in the embryonic folding process. The multiple ruptured amniotic bands and the herniation of multiple intra-thoracic and intra-abdominal organs into the extra-embryonic coelom in our case support the hypothesis of amniotic membrane rupture before obliteration of the coelomic cavity.
BSA is a fatal malformation, and no effective intrauterine interventions have been established. No reports in the literature to date describe healthy living individuals with BSA2,3. The main cause of death in reported cases of BSA is severe structural malformations such as gastroschisis and pulmonary dysplasia [2]. CHD is the most common congenital defect, but reports of BSA complicated by CHD are very rare. Except for cardiac ectopia, which occurs in 36–50% of cases [5, 6], few scholars have conducted detailed studies on the cardiac structure of fetuses with BSA. The present case involved a fetus with BSA combined with severe CHD, including cc-TGA and DAA. We believe that CHD may also be a structural malformation contributing to the poor prognosis of BSA, and attention should be paid to evaluation of the cardiac structure when diagnosing BSA.
Ultrasound examination is the most important method for prenatal diagnosis of BSA, and it is also the main method of evaluating the fetal heart structure. The quality of prenatal diagnosis of fetal abnormalities has advanced with improved resolution of ultrasound images. A scan of the fetal anatomy in the first trimester allows for the detection of approximately half of all major structural anomalies, including those of the central nervous system, cardiovascular system, and gastrointestinal system [7, 8]. cc-TGA is a rare congenital cardiac anomaly constituting less than 1% of all CHDs [9] and is associated with discordant atrioventricular and ventriculoarterial connections. Ultrasound diagnosis of BSA in early pregnancy has been widely reported, whereas fetal cc-TGA is mostly diagnosed by fetal echocardiography in the second and third trimesters. To the best of our knowledge, this is the first report of the combination of BSA with cc-TGA and DAA diagnosed before 14 weeks of gestation.
In summary, we have herein reported the first case of BSA complicated by complex CHD. In addition to the typical anomalies, CHD is also worthy of attention in cases of BSA. Once fetal BSA is detected, fetal echocardiography should be considered. Early accurate diagnosis is helpful for prenatal consultation with parents and postnatal medical support for neonates.
Disclosure
No author has any potential conflict of interest. Written informed consent was obtained from the patient for publication of this case report and accompanying images. The identity of the patient has been protected.
Acknowledgments
This study was supported by the National Key R&D Program of China (2017YFC0211705, 2017YFC0113905), the Key R&D Program of Science and Technology Department of Sichuan Province (2019YFS0403, 2019YFS0037), and the Popularization and Application Project of the Sichuan Health and Family Planning Commission (17PJ415). The authors are very grateful to the patient’s parents, who contributed the images in this article. The authors also thank Angela Morben, DVM, ELS, from Liwen Bianji (Edanz) (www.liwenbianji.cn), for editing the English text of a draft of this manuscript.
No competing interests reported.
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