Morphobiochemical parallels in evaluating the condition of the spinal soft tissue vascular flow in patients with neurofibromatosis type I

Abstract

Purpose To compare and analyze structural changes in the vascular bed of the spine skin, paravertebral muscles in the zone of surgical intervention (at the apex of the spine deformity), as well as serum concentrations of vascular endothelial growth factors and their receptors in patients with kyphoscoliosis due to neurofibromatosis type I (NF-I). Material and methods The work is based on the results of examining a continuous cohort of patients with NF-I (n = 12). During the examination the concentrations of vascular endothelial growth factors (VEGF, VEGF-А, FGF-basic) and receptors for these factors (VEGF-R2, VEGF-R3) were determined in blood serum using the immunoenzyme analysis. Histological techniques of light and scanning electron microscopy were used for studying the biopsy material of the spine skin and paravertebral muscles obtained in the projection of the spine deformity apex during surgical correction of kyphoscoliosis. Results Concentration of VEGF and VEGF-A was 8 % (р = 0.00908) and 417 % (р = 0.00392) higher than reference values, respectively. VEGF-R2 receptor was 215 % (р = 0.00622) and exceeded the level of reference values. On the contrary, VEGF-R3 receptor concentration was 58.1 % (р = 0.00415), lower than the relative reference values. FGF-basic growth factor in blood serum was within control values (р = 0.05613). Changes in the histostructure of the vascular walls of largeand medium-size arteries and veins, fibrosis and obliteration of some vessel lumens, hyperemia of venous and capillary microvessels, formation of inflammatory infiltrates in adventitia of large-and medium-size vessels and in perivascular spaces, hemorrhages were revealed in bioptates of the spine skin. Pathological changes in muscles manifested themselves as fibrosis and constriction (up to complete obliteration) of the lumens of arterial vessels, increase in the diameter of thinwalled venous vessels, increase in their permeability leading to widespread extensive hemorrhages. Conclusion Increased concentration of vascular endothelial growth factors and their imbalance with receptors in patients with NF-I are combined with pathohistological structural changes in the vascular system of the spine skin and paravertebral muscles due to the inflammatory process present. The obtained results should be taken into account both in surgical treatment of this complex disease manifestations, and when planning treatment and rehabilitation measures in general.