A MORPHOMETRIC STUDY OF VENTRAL NERVE ROOTS AND RETROPERITONEAL VESSELS IN RELATION TO A MINIMALLY INVASIVE LATERAL APPROACH TO DETERMINE SAFE WORKING ZONE

Abstract

Background: The minimally invasive lateral retroperitoneal transpsoas approach is a new method that was designed to minimize problems related with standard or minimally invasive anterior or posterior lumbar spine techniques. The current work used magnetic resonance imaging to determine the anatomic location of the ventral root and retroperitoneal arteries in respect to the vertebral body and to establish the anatomical safe zones. We examined lumbar spine MRI in 50 individuals retrospectively (L1-L2 to L5-S Method: 1 levels). The ventral root and surrounding major arteries were identied using axial T1 and T2 scans. Axial MR scans were utilized to determine the anterior-posterior (AP) diameter of the vertebral endplate, the overlap between the ventral root and the posterior border of the vertebra, and the overlap between the retroperitoneal big vessels and the anterior edge of the vertebra. The safe zone was then determined. From L1–L2 Results: to L5–S1, the mean AP diameter of the vertebral body and the overlap of the vertebral body with the nerve roots and retroperitoneal arteries grew gradually. When we examined the extent of overlap of retroperitoneal arteries with the ventral border of the lower vertebral body endplate, we discovered that the right vascular structures were more posterior than the left vascular structures. The safe working zone was 81.86 percent of the lower endplate of the sagittal diameter of the vertebral body at L1–L2, 70.03 percent at L2–L3, 69.32 percent at L3–L4, 50.08 percent at L4–L5, and 17.92 percent at L5–S1 levels. The Conclusion: retroperitoneal transpsoas method is a less invasive and more efcient alternative to the conventional posterior, open lumbar procedures. It can be used to treat trauma, degenerative disc disease, adult degenerative scoliosis, spondylosis with instability, spondylolisthesis, lumbar stenosis, and neighboring segment failure.