Methods: Five formalin-embalmed human cadavers were used. We assessed the proportion of segmental arteries and veins that intersected the IVD in the L2–L5 range and their course on the anterior part of the spinal column. Results: The segmental arteries and veins commonly intersect the anterior part of the IVD (artery, 28.1%; vein, 42.1%). Seven of 10 (70%) segmental arteries at L2 intersected the IVD, but only one artery intersected the IVD at L3 and L4. The proportions of segmental veins that intersected the IVD were 60%, 50%, and 16.7% at L2, L3, and L4, respectively. Conclusions The segmental arteries and veins frequently intersect the IVD in the anterior part of the spinal column. Therefore, it is necessary to consider these individual anatomical features to prevent vascular damage during lateral lumbar interbody fusion surgery.

Methods: HFCs were obtained from patients with LSS who underwent surgery. HFCs were stimulated by tumor necrosis factor-α (TNF-α) and a p38 MAP kinase inhibitor, SB203580. Phosphorylation of the p38 MAP kinase was analyzed by western blotting. The concentration of interleukin-6 (IL-6) in the conditioned medium was measured by enzyme-linked immunoassay and IL-6 messenger RNA expression levels were determined by real-time polymerase chain reaction. Results: TNF-α induced the phosphorylation of p38 MAP kinase in a time-dependent manner, which was suppressed by the p38 MAP kinase inhibitor, SB203580. TNF-α also stimulated IL-6 release in both a time- and dose-dependent manner. On its own, SB203580 did not stimulate IL-6 secretion from HFCs; however, it dramatically suppressed the degree of IL-6 release stimulated by TNF-α from HFCs. Conclusions This is the first report suggesting that TNF-α stimulates the gene expression and protein secretion of IL-6 via p38 MAP kinase in HFCs. A noted association between tissue hypertrophy and inflammation suggests that the p38 MAP kinase inflammatory pathway may be a therapeutic molecular target for LSS.

Methods: HFCs were obtained from patients with LSS who had undergone decompression surgery. The cells were stimulated with TGF-β and pretreated with either the p38 mitogen-activated protein (MAP) kinase inhibitor SB203580 or the p44/42 MAP kinase inhibitor FR180204. IL-6 secretion in the cell culture medium and IL-6 messenger RNA (mRNA) expression levels were analyzed using an enzyme-linked immunoassay and real-time polymerase chain reaction, respectively. Results: TGF-β administration resulted in a dose- and time-dependent stimulation of IL-6 release. Treatment with SB203580 and FR180204 markedly suppressed TGF-β–induced IL-6 secretion from HFCs. Moreover, these inhibitors suppressed IL-6 mRNA expression in response to TGF-β stimulation. Conclusions Our findings indicate that TGF-β induces IL-6 protein secretion and gene expression in HFCs through the activation of p38 or p44/42 MAP kinases. These results suggest a potential association between IL-6–mediated inflammatory response and tissue hypertrophy in LSS, and we provide insights into molecular targets for therapeutic interventions targeting LSS-related inflammation through our analysis of the MAP kinase pathway using HFCs.