Congenital anomalies of the venae cavae: embryological origin, imaging features and report of three new variants

Abstract

Due to the complexity of their developmental stages, the venae cavae may undergo a very large number of congenital anomalies. All the possible abnormalities which, to our knowledge, have been observed in the literature are reported, differentiating those of the superior vena cava and the azygos system, those of the inferior vena cava and the complex anomalies that concern the venous system as a whole. Moreover, we present three new variants: a right double inferior vena cava with azygos continuation of the posterior-medial vein; an agenesis of the superior vena cava with drainage through the azygos and hemiazygos veins to the inferior vena cava; and a double inferior vena cava with hemiazygos and azygos continuation of the left one.

Evaluation of left renal vein and inferior vena cava variations through routine abdominal multi-slice computed tomography

“…In our study, this variation was found in 2 (0.3%) cases. In 1 case of azygos continuation of the IVC, the patient also had situs ambiguous-heterotaxy syndrome [9]. It is vital to be aware of the presence of a LRV and IVC variation prior to surgical interventions or the implantation of vena cava filters because this may prevent possible haemorrhages and potentially fatal complications.…”

‘Tobacco pipe’ sign in the fetus: patent left superior vena cava with absent right superior vena cava

“…Compared to an LSVC with a patent RSVC, an LSVC with absent RSVC is larger in size and the coronary sinus is even more dilated 7 . Furthermore, the innominate vein is patent and not absent 1 . We report on a case of LSVC and absent RSVC detected in a fetus at 19 weeks' gestation.…”

“…Anomalies of the superior vena cava (SVC) include the presence of two veins as the right SVC (RSVC) and persistent left SVC (LSVC) 1 , the presence of an LSVC with an absent RSVC 2,3 and the very rare condition of the absence of both the right and left SVC 4 . In most cases with two SVCs the innominate vein connecting the jugular vein with the opposite SVC is absent 1,5 .…”

“…In most cases with two SVCs the innominate vein connecting the jugular vein with the opposite SVC is absent 1,5 . Absent RSVC with LSVC is often an isolated anomaly 3,6 .…”

“…Pregnancy is associated with high levels of cell-free DNA (cfDNA) in the maternal circulation, and around 5% of the DNA is fetal in origin 1 . The exact source of cfDNA is uncertain, with some evidence supporting a placental 2,3 and other a fetal 4 origin.…”