Magnetic Resonance Image Findings of Lumbar Prevertebral Aortocaval Structures in Korean Spinal Disorder Patients

ABSTRACT

OBJECTIVE: The purpose of this study is to evaluate the level of lumbar spine corresponding to the prevertebral major vascular structures and the distance of the prevertebral available disc space (DPADS) of L5-S1 between the common iliac arteries and veins with preoperative magnetic resonance imaging (MRI) study. METHODS: Three hundred and forty seven lumbar MRI films (200males and 147females) from spinal disorder patients were reviewed. The patients' age ranged 14 to 86 years (mean 45 years). The patients were divided into eight groups by 10-year interval from a teen to the eighties. There were evaluated age-related locational changes in the level of lumbar spine corresponding to the aortic bifurcation (AB) and the origin of inferior vena cava (OIVC). In addition, DPADS of L5-S1 between the common iliac arteries and veins were measured. RESULTS: The common sites of the AB for the entire subject group were at the upper body of L4 (from the upper body of L3 to the lower body of L5). The common sites of the OIVC for the entire subject group were at the level of the L4-L5 disc space (from the upper body of L4 to the lower body of L5). The age-related changes in the location of the AB with a downward shift were statistically significant (p< 0.05). Similarly, age-related changes were observed in the OIVC, although this was more prominent in females (p<0.05). The average DPADS of L5-S1 was 34.48+/-10.00 mm. There were 27 cases(7.8%) who had the DPADS less than 20mm, and this narrow DPADS could make it very difficult to access the anterior disc space of L5-S1 because recently the popularly used anterior lumbar fusion materials were over 10 mm in diameter. CONCLUSION: These results may be helpful to minimize potential vascular injury and morbidity in anterior lumbar spinal surgery.