Keywords
fetal - fistulas - left-sided inferior vena cava
Case Study
A 32-year-old, gravida 2 para 1 woman was referred to our center for fetal echocardiography
at 30+4 weeks of gestation following routine ultrasound screening because of cardiomegaly.
Family history was negative for congenital heart malformations, and there was no history
of medication use during pregnancy. The cardiothoracic ratio was 0.49, and there was
no sign of hydrops. Echocardiography showed normal segmental anatomy and a perimembranous
ventricular septal defect. On detailed examination, it was noted that the dilated
intra-abdominal part of umbilical vein coursed into the liver like a helix. Doppler
imaging demonstrated a 28 × 24 mm vascular structure in the middle part of the liver
and revealed a “saw-toothed” arterial flow pattern with an extremely high-peak velocity
(240 cm/s) in the lesion ([Fig. 1]). Subtle examination of the lesion on sagittal and transverse views using color
and power Doppler revealed that the following vessels were in continuity with the
lesion: an arterial vessel originating directly from the abdominal aorta, portal veins,
and a dilated umbilical vein ([Fig. 2]). Moreover, the subrenal inferior vena cava (IVC) ran upward along the left side
of the aorta and then anteriorly crossed the aorta at the level of the kidney to join
the normal IVC on the right ([Fig. 3]). All three hepatic arteries and ductus venosus were visible and coursed normally.
Cordocentesis yielded a normal karyotype (46, XY). The pregnancy was uneventful and
showed no sign of hydrops, and spontaneous vaginal delivery occurred at 37 weeks'
of gestation. An extended right hepatectomy was successfully performed at the age
of 3 months. There were no complications, and sonography showed no obvious residual
lesions upon follow-up after 3 months.
Fig. 1 Doppler revealed “saw-toothed” arterial flow pattern with extremely high-peak velocity
(240 cm/s) in the lesion.
Fig. 2 Doppler imaging demonstrated a vascular structure in the middle part of the liver.
The following vessels were in continuity with the lesion: an arterial vessel originating
directly from the abdominal aorta, portal veins, and dilated umbilical vein. Ao, abdominal
aorta; Sp, spine; St, stomach; UV, umbilical vein.
Fig. 3 The arrows demonstrate the course of IVC: the subrenal IVC ran upward along the left
side of aorta, and then crossed the aorta anteriorly at the level of the kidney to
join the normal IVC on the right. Ao, abdominal aorta; IVC, inferior vena cava; St,
stomach.
Discussion
Congenital arteriovenous shunts in the liver of fetuses are very rare, especially
when involved with the abdominal aorta.[1] Portal hypertension and/or congestive heart failure are the main presentations in
postnatal life. Although the progress of the arteriovenous malformation in the fetus
depends on the size of the lesion, the related arteries and the associated anomalies,
most published isolated cases showed good outcomes including spontaneous closure[2] and successful surgery.[3]
This anomaly has mostly presented alone, with a few cases been associated with other
congenital defects, such as duodenal atresia and trisomy 21.[1] To the best of our knowledge, the combination of defects described in this case,
namely, aorta-porto-umbilical vein fistulas with a left-sided IVC, has not been previously
reported. Left-sided IVC is a rare form of IVC malformation. A search of the literature
found only one published report on the prenatal diagnosis of left-sided IVC in which
the left-sided subrenal IVC continued as an azygos/hemiazygos vein with interrupted
IVC.[4] Left-sided IVC, although frequently asymptomatic, may result in Nutcracker syndrome
postnatally due to left-sided IVC compression.[5]
Prenatal ultrasonography can facilitate the prenatal detection, provide close observation,
and evaluate the complications and hemodynamic status of such lesions.
