An MRI study of the oblique corridor and the trajectory to the L1-L5 intervertebral discs in the lateral position.

November 5, 2019

OBJECTIVE:

This study investigated the retroperitoneal oblique corridor and trajectory of L1-L5 as the lateral surgical access to the intervertebral discs in the Chinese population, and detected the potential relationship between the corridor or trajectory and vertebral parameters, including disc axis, psoas muscle and retroperitoneal vessel.

METHODS:

Seventy MRI studies performed from January 2017 to January 2019 were investigated. The oblique corridor was defined as the distance between the left lateral border of the retroperitoneal vessel and the anterior border of psoas. The trajectory was defined as the distance between the retroperitoneal vessel and lumbar plexus.

RESULTS:

The oblique corridor analysis to L1-L5 discs have the following mean distances: L1-2 13.36 mm, L2-3 13.36 mm, L3-4 12.37 mm, and L4-5 10.36 mm. There was no difference in the L1-L5 corridor between genders. And the position of retroperitoneal vessel was negatively correlated with the corridor width. The trajectory measurements to L1-L5 discs have the following mean distances: L1-2 27.44 mm, L2-3 30.86 mm, L3-4 30.73 mm, L4-5 24.36 mm. Moreover, the vertebral parameters, including the disc axis and the psoas muscle, were positively correlated with the trajectory width. Otherwise, the position of retroperitoneal vessel was negatively correlated with the trajectory width.

CONCLUSIONS:

Compared with previous studies, the safe surgical area of the Chinese is generally smaller than that of Caucasian. The position of the retroperitoneal vessel is the vital potential to limit the corridor and trajectory. The preoperative assessment of vertebral parameters, especially vascular structure, is essential for planning surgical process.