A Morphometric Study of Cadavers for the Anterior Approach to the Lower Lumbar Spine.

Aim: To explore the relationship between the retroperitoneal vasculature and anterior surface of the lower spine, and to establish values for aiding in prediction of the pertinence of anterior approach at the L4-L5 and L5-S1 intervertebral discs.

Material and methods: The study included 13 fresh human cadavers. After exploration of the abdominal cavity and removal of the visceral organs, the vasculature, and anterior spinal surface were revealed beneath the lower extension of the perirenal fascia. Morphometric measurements of the great vessels and the intervertebral discs were obtained. All measurements were analyzed and presented as mean and standard deviation. Differences in the values between sexes were assessed.

Results: The anterior height of the L4-L5 and L5-S1 intervertebral disc was 6.8 ± 0.81 mm and 6.7 ± 0.99 mm, respectively. The widths of the aorta, inferior vena cava, right and left common iliac arteries, and right, and left common iliac veins were 16.4 ± 3.58, 20.6 ± 3.36, 11.5 ± 2.32, 11.5 ± 2.43, 14.7 ± 3.13, and 15.5 ± 3.27 mm, respectively. The mean aortic bifurcation angle was 45.5°. The aortic bifurcation was located above the lower endplate of the L4 vertebrae in 53.8% of the cadavers. The area of the interarterial and interiliac trigones was 14.6 ± 5.33 cm < sup > 2 < /sup > and 7.1 ± 4.35 cm2, respectively. No statistically significant differences were noted between the sexes.

Conclusion: An elaborate radiological examination of the vasculature should be performed prior to surgery to avoid unwanted vascular complications during the anterior approach. Knowing the area of the interarterial and interiliac triangles and the aortic bifurcation location could be aid in assessing the safe working zone.