Abstract

Discectomy for decompression of lumbar disc herniation is one of the most common techniques. Perforation of the anterior anulus fibrosus and anterior longitudinal ligament with major vascular injuries is rare. However, serious complications may occur due to the proximity of the intervertebral disc to adjacent neurovascular structures. Life threatening vascular injuries, such as injuries to the aorta, inferior vena cava, common iliac arteries and veins has been reported. The major vessels, including the abdominal aorta, the inferior vena cava, the common iliac arteries and veins were situated directly anterior to the lumbar spine. These vessels, especially veins, are prone to injury during lumbar discectomy and a lesion of major arteries will cause profuse bleeding, which may progress rapidly fatal. Possible perforations which can occur during lumbar discectomies at different levels and angles and in different approaches to the spine were defined. The vascular anatomy of the anterior aspect of the lumbar vertebral bodies was variable from one cadaver to another. In general, the aorta was located in the midline and the inferior vena cava was situated to the right of the aorta. The aortic bifurcation was usually positioned immediately anterior to the body of the L4 vertebra and less frequently at L3-4 and L4-5 disc spaces. Commonly at L5-S1 level, the right common iliac vein crossed L5-S1 disc on right of the midline and the right common iliac artery overlaps the right common iliac vein. The left common iliac vein usually coursed lateral to the L5-S1 level but rarely coursed directly over the disc space. The left common iliac vein and artery run adjacent to them with no overlap on the left of midline. The inferior vena cava and the common iliac veins have a larger diameter and lie closer to the discs than the arteries and form a broad vascular band, especially at the L4-5 disc level. Because veins have considerably thinner walls than arteries, particularly the left common iliac vein which is adherent to the L5-S1 disc, it seems that veins were accidentally hit and punctured more often than arteries in anterior perforations. The median sacral artery crossed the anterior aspect of the L5-S1 disc near the midline traveling with the median sacral vein.Considerable variations have been found in previous anatomic and radiological studies of the abdominal aorta, inferior vena cava and their branches. Injury to the great vessels anterior to the intervertebral disc should always be kept in mind during disc surgery and the imaging techniques are useful in understanding the true relationships of the vascular anatomy with the intervertebral disc space. Injury to adjacent vascular structures during approaches to lumbar intervertebral discs is important and detailed anatomic knowledge of relationships is beneficial to decrease surgical complications.