Anatomical study of diaphragmatic crura and segmental vessels for lumbar spinal surgery

Observational cadaveric anatomical study.

To investigate the anatomical relationship between the segmental vessels and the diaphragmatic crus, aiming to reduce the risk of segmental vessel injury.

Total en bloc spondylectomy and lateral lumbar interbody fusion are advanced surgical procedures associated with segmental vessel injury. Previous research suggests these injuries may arise from anatomical variations where segmental vessels intersect intervertebral discs. At upper lumbar levels, the diaphragmatic crus lies adjacent to the vertebral bodies, and its relationship with segmental vessels may increase vascular risk. Although this proximity has been noted, no study has specifically examined the detailed anatomy of the crus in relation to segmental vessels. Clarifying this relationship is critical for surgical planning and safety.

Fifteen Thiel-embalmed human cadavers (three males, 12 females; mean age 90.1 years) were dissected. Segmental arteries and veins from L1 to L5 and both crura were identified and measured. Crus origin, width, and distance from the vertebral midline were assessed. Data were analyzed using paired t-tests and Wilcoxon signed-rank tests.

The right crus was broader, originated more caudally, and was positioned closer to the vertebral midline along the ventral surface of the vertebral body than the left crus, especially at L1-L3. Segmental arteries and the left segmental vein coursed between the crus and vertebral bodies, whereas the right segmental vein consistently passed ventral to the crus.

The diaphragmatic crus shows laterality in origin, width, and position, with distinct relationships to segmental vessels. Recognizing these anatomical features may help surgeons minimize vascular injury and improve safety during lumbar spinal surgery.