Persistent Left Superior Vena Cava (SVC)

Fig. 1: Portable chest radiograph shows a right PICC line coursing from the right arm to the left side of the mediastinum (arrows).
Fig. 2: Coronal chest CT image performed with injection of the right antecubital vein shows dense contrast in the right axillary, subclavian, left brachiocephalic vein to the left SVC (arrowheads). There is no right SVC.

Persistent Left SVC

• Persistence of left anterior cardinal vein
• 0.3% of normal population; 4.4% in patients with congenital heart disease
• In most cases, the right SVC is also present (82% - 90%) (i.e. double SVC)
• Left SVC courses lateral to the aortic arch, main pulmonary artery, anterior to the left hilum and typically enters the coronary sinus that drains into the right atrium
• In some cases, left SVC enters the left atrium. Left SVC draining into the left atrium is highly associated with intracardiac defects (commonly ASD)

Significance of left SVC

• Need to know before performing SVC-pulmonary artery anastomosis
• Need to know before performing open heart operation

Reference:

1. Shumacker HB, King H, Waldhausen JA. The persistent left superior vena cava. Surgical implications, with special reference to caval drainage into the left atrium. Ann Surg 1967;165:797-805.

2. Webb WR, Gamsu G, Speckman JM, et al. Computed tomographic demonstration of mediastinal venous anomalies. AJR 1982;139:157-161.