Anatomy of the diaphragmatic crura and other paraspinal structures relevant to en-bloc spondylectomy for lumbar spine tumours

Abstract Introduction En-bloc spondylectomy in the lumbar spine is a challenging procedure mainly due to a complex prevertebral anatomy. The aim of our study is to describe the anatomy of the diaphragmatic crura and surrounding vascular and neural structures which may be iatrogenically injured during the surgical resection. Materials and methods Ten embalmed specimens were meticulously dissected. Widths of the diaphragmatic crura, abdominal aorta, cisterna chyli, thoracic duct, sympathetic trunks, and inferior vena cava as well as their distances from the midline were measured at nine levels (L1 to L4 vertebra and adjacent intervertebral discs). Results The right crus was attached to the L2–L4 vertebral bodies and L2/3 intervertebral disc, while the left crus inserted onto L1–L3 vertebrae. The thoracic duct arose commonly at the level of L2 vertebra and overlaid the right crus at the L3 vertebra and L2/3-disc levels. The cisterna chyli was present in 70% of specimens and overlapped with the left crus at the same levels. Both sympathetic trunks emerged underneath the crura at the L1/2 discs or L1 vertebra level. The aorta overlapped with the crura at all levels. Conclusion The L3 level appears to be the riskiest for spondylectomy due to the overlap of both diaphragmatic crura with the thoracic duct and cisterna chyli, respectively. Spondylectomy at the L2 level also brings the risk of lymphatic structures injury while injury to the left sympathetic trunk may be the main issue at the L1 level.