Abstract
BACKGROUND: Minimally invasive lateral lumbar interbody fusion is a technique that has become increasingly popular for the treatment of degenerative lumbar spine disease; however, the pertinent surgical vascular anatomy has not been examined in detail. The goal of this study is to examine the anatomy of the lower lumbar and median sacral arteries, which are important determinants of these surgical outcomes. METHODS: This is an observational, experimental study based on cadaveric models, including 20 embalmed adult human cadavers. The following measurements were made: length of the lumbar and median sacral arteries, vertical distance between the third and fourth lumbar arteries and the superior end plate of the corresponding vertebrae, anterior vertebral body height, and intervertebral disc height. RESULTS: Our sample showcased considerable variability regarding vascular anatomy around the lower lumbar spine. In 10% of specimens, the abdominal aorta bifurcated at the level of the L3-L4 intervertebral disc, and 20% showed variations in vena cava origin. Regarding the lumbar arteries, in 10% of the sample, the fourth lumbar artery was absent on the right side, and 10% presented a fifth lumbar artery. The median sacral artery was present in all cadavers; however, in 15% of specimens, it originated from a common trunk that also gave rise to the fourth pair of lumbar arteries. Anterior vertebral body height was smaller in L3 comparing with L5 (P = 0.003), and there was a significant cephalocaudal increase in the anterior intervertebral disc height in the analyzed levels (P < 0.001). Bilaterally, the distance between the fourth lumbar arteries and the superior end plate of the L4 vertebral body was shorter than this distance at the L3 vertebral body (P < 0.001 and P = 0.002 on the right and left, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: These data may be useful in spine surgery planning and operative management. These anatomic variations should be identified beforehand to prevent difficulties during surgery and possible complications.