Double Left Renal Vein- A Rare Anomaly

Abstract

During routine dissection for the students from 2006 -2011, an adult male cadaver was observed to have double left renal vein. Both the veins were opening into the inferior vena cava. One is preaortic and the other is post aortic channel forming a ring around the aorta called circumaortic, or persistent renal collar. Double left renal vein is a rare developmental anomaly, but carries immense surgical importance. Injury to the postaortic channel during surgery may lead to severe haemorrhage.So profound knowledge is necessary for this variation. The embryological aspect and the clinical importance of the case are discussed here. KEY WORDS: Double left renal vein, retro-aortic vein, renal collar, abdominal aortic aneurysm. INTRODUCTION:Congenital anomalies of Inferior Vena Cava (IVC) and its tributaries are known to anatomists since 1793 (1). It is commonly recognized in symptomatic patients. The embryogenesis of the IVC is a complex process involving the formation of several anastomoses between three paired embryonic veins. It results into numerous variations in the basic plan of venous return from abdomen and lower limbs (2).The right and left renal vein drains blood into inferior vena cava from each kidney. The left renal vein is longer than the right renal vein and drains blood from the left gonad and left suprarenal gland as well. The left renal vein crosses the front of abdominal aorta below the origin of superior mesenteric artery (3).Here a case of double left renal vein and its embryological basis is discussed.