ABSTRACT
When one considers that venous anatomical variations are common, it is surprising that
congenital venous malformations are seen quite uncommonly in specialist venous clinics.
There is a wide spectrum of congenital variation-absence of major veins, incomplete
development, multiple vessels, dextra-position of vessels and hereditary diseases.
Attempts are being made to map the genetic signatures for these venous malformations
but no single chromosome or gene has yet been implicated. There is however evidence that
some of the hereditary forms are associated with some chromosomal defects, but the
findings have not been consistent. Awareness of these anomalies, such as double inferior
vena cava, left side inferior vena cava, etc., have implications in surgical practice,
especially for vascular surgeons and radiologists. Some of these such as venous aneurysm,
agenesis, congenital and hereditary anomalies, etc., are associated with complications
such as varicose veins, thrombosis, embolism, and the secondary effects of venous
thrombosis-venous hypertension leading to chronic venous disease.
