The anterior cardinal veins are paired transient embryologic venous vessels which deliver venous return to the heart starting at about 4 weeks of gestation 1.
The anterior cardinal veins begin their embryological development as symmetric venous channels draining blood from the cranial structures of the embryo. They anastomose with the posterior cardinal veins inferiorly to form the common cardinal veins (ducts of Cuvier), which drain into the sinus venosus 2. At approximately 8 weeks of gestation, the left brachiocephalic vein forms from an anastomosis between the thymicothyroic veins and connects the left and right anterior cardinal veins 3. After this left-right connection forms, asymmetry develops when the caudal portion of the left anterior cardinal vein begins to involute, which redirects blood flow to the proximal right anterior cardinal vein which persists to become the right-sided superior vena cava (SVC) 1. The caudal portion of the left anterior cardinal artery forms the oblique ligament and vein of Marshall after involution 4. The more cranial portions of the bilateral anterior cardinal veins persist and form the internal jugular veins 1. During the course of their development and involution, the anterior cardinal veins form multiple normal permanent structures, as well as potentially some anomalous structures.
Failure of the left anterior cardinal vein to involute is the most common developmental variation in the central venous system with an incidence of 0.3% in the general population, which increases to 4.4% in patients with other cardiac defects 5. Failure of the left anterior cardinal vein to involute results in a left sided superior vena cava, and in 8% of these cases, drainage of the left sided superior vena cava into the left atrium 5. Failure of involution is usually related to a failure of the anastomosis of the left and right anterior cardinal veins through the brachiocephalic vein 3.
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- 2. Bradley M. Patten. Human Embryology. McGraw-Hill, 1968 [Google Books].
- 3. Jacob M, Sokoll A, Mannherz HG. A case of persistent left and absent right superior caval vein: An anatomical and embryological perspective. Clinical anatomy (New York, N.Y.). 23 (3): 277-86. doi:10.1002/ca.20945 - Pubmed
- 4. Fang CC, Jao YT, Han SC, Wang SP. Persistent left superior vena cava: multi-slice CT images and report of a case. International journal of cardiology. 121 (1): 112-4. doi:10.1016/j.ijcard.2006.08.099 - Pubmed
- 5. Miraldi F, di Gioia CR, Proietti P, De Santis M, d'Amati G, Gallo P. Cardinal vein isomerism: an embryological hypothesis to explain a persistent left superior vena cava draining into the roof of the left atrium in the absence of coronary sinus and atrial septal defect. Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology. 11 (3): 149-52. Pubmed