CASE 10522 Published on 06.01.2013
0

Persistent left superior vena cava: MR evaluation

Section

Cardiovascular

Case Type

Anatomy and Functional Imaging

Authors

Sperandio Massimiliano, Da Ros Valerio, Nano Giovanni, Ricci Aurora, Cama Valentina, Simonetti Giovanni

Via f. Corridoni 31
00046 Grottaferrata, Italy
Email:valeriodaros@hotmail.com
Connected authors
Patient

72 years, female

Categories
Area of Interest Anatomy ; Imaging Technique MR
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Clinical History
A 72-year-old woman presented to our department to undergo a Cardiac-MR evaluation for suspicion of a retrocardiac left atrial mass. She suffered from high cholesterol levels well controlled by medical therapy and a left bundle branch block. She had never undergone surgery.
Imaging Findings
The woman underwent echocardiography (not shown) 12 days before at another institution as a routine check. The woman reported that the examination didn’t show any significant cardiac abnormality but highlighted the existence of a retrocardiac left atrial mass. Cardiac-MR evaluation was performed using a 1.5 T scanner with an ECG-gated study triggered with every heartbeat, using a five-element phased-array coil. The study documented the absence of the right superior vena cava with the presence of persistence left superior vena cava (PLSVC) which opened at the level of the coronary sinus (Fig 1-2). The coronary sinus was dilated. The PLSVC ran in a retro-cardiac left para-aortic course, in the physiological seat of the hemiazygos vein. The PLSVC continued with the left inferior vena cava which drained both renal veins. Also the absence of the azygos vein was documented (Fig 3).
Discussion
The left superior vena cava is an embryological counterpart of the normal right-sided superior vena cava and the incidence of its persistence is uncommon [1]. PLSVC incidence reported in the literature is 0.3–0.5% in the general population and 3–5% in congenital heart disease patients [1-12].
In the early embryonic stage of the systemic and pulmonary veins system development, the anterior cardinal veins, which drain the head, neck, and arm, unite with the posterior cardinal vein and enter the heart as the right and left horns of the sinus venosus [10, 13]. During normal growth most of the left-sided cardinal system disappears, leaving only the coronary sinus and a remnant known as the ligament of Marshall. Simple failure of obliteration of the left anterior cardinal vein results in the PLSVC. This usually drains into the right atrium via the coronary sinus as was the case in our patient. On rare occasions, when developmental arrest occurs at an earlier stage, the coronary sinus is absent and the PLSVC drains directly into the left atrium producing a right-to-left shunt or directly into the right atrium [2, 5, 6, 10]. Most cases of PLSVC have been reported as incidental findings during central venous catheter placement, pacemaker [3–6] and implantable cardioverter defibrillator (ICD) implantation [14], and during thoracic surgery for various reasons [13, 15]. Transthoracic echocardiogram (TTE) is usually the mainstay tool for diagnosing PLSVC [7, 9, 10, 16, 17]. Even if TTE gives a readily available bedside confirmatory test that is non-invasive, inexpensive [16, 17] and it helps to identify other cardiac anomalies that might be associated, it could be not always exhaustive in the diagnosis of PLSVC, as demonstrated in this case. This become more evident especially in presence of a not optimal acoustic window or when it is necessary to delineate the insertion site of the PLSVC. The recognition of this anomaly is of main importance in venous catheterisation, pacemaker implantation or for thoracic surgery. In spite of a higher cost of the method, MR provides a simple, noninvasive evaluation of these developmental venous anomalies also due to its superb natural contrast between rapidly flowing blood and surrounding structures.
Differential Diagnosis List
Persistent left superior vena cava
Aneurysm of sinus of valsalva
Overriding aorta
Final Diagnosis
Persistent left superior vena cava
Case information
URL: https://www.eurorad.org/case/10522
DOI: 10.1594/EURORAD/CASE.10522
ISSN: 1563-4086
Figure 1

MR study

MR study
Cine MR images on 4-chamber show PLSVC and its course in the para-aortic left retrocardiaca
MR study
Cine MR images on 4-chamber show PLSVC and its course in the para-aortic left retrocardiaca
MR study
Cine MR images on 4-chamber show PLSVC and its course in the para-aortic left retrocardiaca
Figure 2

MR study

MR study
Balanced image, in sagittal view, shows the presence of the PLSVC descending on the left side of the mediastinum and the absence of the superior right vena cava
Figure 3

MR with 3D reconstructions

MR with 3D reconstructions
The image shows the absence of the superior right vena cava and the presence of PLSVC, anterior view
MR with 3D reconstructions
The image shows the absence of the superior right vena cava and the presence of PLSVC, posterior view