Retroaortic Left Renal Vein: An Incidental Finding During Cadaver Dissection.

Developmental variations are frequently observed during the course of dissection in the gross anatomy laboratory and serve as valuable learning experiences for students. In part, because of the insights and motivation derived from such discovery opportunities, the classical method of teaching anatomy by cadaver dissection is still the preferred way of teaching in most medical schools in U.S. and globally. However, the shortage of qualified educators, and the resource intensive nature of the operating and maintaining gross anatomy laboratories have prompted consideration of alternative resources. Some U.S. medical schools have already adopted virtual dissection tools. Use of high quality plastinated specimens has been explored by some universities. Still, replacing cadaver dissection with virtual dissectors and computer-generated images deprive students of beneficial learning experiences where they encounter structural variation. For instance, it has been reported that about 10% of clinical malpractice is attributed to the ignorance of anatomical variations. Here we report an example of an instructive congenital variation. The left renal vein normally passes through the angle between the aorta and superior mesenteric artery to drain into the inferior vena cava. Yet congenital variations in the position of left renal vein have previously been reported. During the cadaver dissection by first-year medical students, we discovered a case where the left renal vein passed between the aorta and the lumbar vertebrae in an elderly female cadaver donor. This unusual position of left renal vein is termed retroaortic left renal vein (RLRV), which has a reported incidence from 0.5% to 3.6%. Careful dissection revealed the course of left renal vein and its relation with the surrounding structures. Noticeable compression of the LRV between the aorta and vertebral column was observed. The left kidney was smaller in size compared to the right kidney and darker in appearance. No significant change was observed in the renal parenchyma. The donor had significant plaque accumulation at the bifurcation of the common iliac arteries no other vascular congenital anomalies that can accompany a retroaortic left renal vein were noted in this donor. This study highlights the educational importance of learning about morphologic variations and their potential impact on adjacent organs.