Unique Medley of Cardinal Veins: Duplicated Superior and Inferior Venae Cavae With Left Renal Agenesis and Hemiazygos Continuation of Left Inferior Vena Cava With Drainage Into Left Atrium

Abstract

Congenital anomalies of the superior and inferior vena cava result from abnormal embryogenesis of cardinal veins. Duplication of superior vena cava (SVC) occurs in 0.3% of the general population of which only 8% drain into the left atrium. The prevalence of double inferior vena cava (IVC) is around 0.2–3%. The reported incidence of unilateral renal agenesis ranges from 1:1100 to 1:5000, and the association of double IVC with renal agenesis has been reported in only 11 cases in the literature. The conglomeration of such rare anomalies incidentally noted in a single patient is reported in this study. A 32-year-old man was referred to our department for Computed Tomography (CT) scan of the thorax. The patient was found to have dorsal kyphoscoliosis with hemivertebrae. The SVC was duplicated with the right SVC draining into the right atrium and the left SVC draining into the left atrium. The left kidney was not visualized in the abdomen. There was dual IVC with no intercommunicating interiliac vein. The right IVC maintained its normal course, while the left IVC continued as hemiazygos vein and joined left SVC in the thorax. Also noted was the aberrant origin of the right subclavian artery. This is the first reported case of combined superior and inferior vena caval anomalies along with left renal agenesis in a single patient in the literature. A review on the embryological basis is also described in this article.

Beware of a duplicate superior vena cava

“…This allows right sided emboli to be transferred into systemic circulation which can have dire consequences, such as ischemia or stroke and even death. 1,2,4,5 It is important for physicians to be aware of these congenital cardiac abnormalities and to be able to identify them prior to surgery and catheter placement. Identification of a dilated coronary sinus on imaging should raise suspicion for PLSVC and confirmatory tests should be performed.…”

“…The incidence increases up to 10% in patients who have congenital heart disease. [1][2][3][4][5] A persistent left SVC occurs when the left common cardinal and precardinal veins fail to obliterate, resulting in a patent left SVC and duplicate SVC. Most PLSVCs drain into the coronary sinus and right atrium and are asymptomatic.…”

“…Most PLSVCs drain into the coronary sinus and right atrium and are asymptomatic. [1][2][3][4][5] A duplicate SVC is usually unrecognized and can cause confusion during catheter placement if the guidewire or catheter fails to cross the midline on imaging. Irritation of the coronary sinus from catheter placement can cause hypotension, arrhythmia, and myocardial ischemia.…”

Right Superior Vena Cava Agenesis and Persistent Left Superior Vena Cava: Literature Review and Case Report

“…Right superior vena cava (RSVC) agenesis and persistent left superior vena cava (PLSVC) are rare congenital anomalies of the venous system, with reported incidences varying across different populations. The prevalence of RSVC agenesis has been estimated to range from 0.3% to 0.5% in the general population, while the prevalence of PLSVC is reported to be approximately 0.3% to 0.5% as well (Kannappan & Sakthi Velavan, 2023 (Vignesh & Bhat, 2022).…”

“…Typically, the right anterior cardinal vein regresses, while the left anterior cardinal vein incorporates into the coronary sinus and left brachiocephalic vein, ultimately forming the left superior vena cava (Mori et al, 2022). However, in RSVC agenesis, the right anterior cardinal vein fails to develop properly, leading to the absence or hypoplasia of the right superior vena cava (Vignesh & Bhat, 2022). Conversely, PLSVC results from the persistence of the left anterior cardinal vein, creating an additional venous pathway draining directly into the right atrium or coronary sinus (Kahramanoglu et al, 2023).…”