The Expression of Matrix Metalloproteinase according to Hydrostatic Pressure in Varicose Veins

ABSTRACT

PURPOSE: The expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) caused by hydrostatic pressure stress is important in the development of varicose veins (VVs). This study was performed to analyse the expression of various MMPs and TIMPs according to the hydrostatic stress and the anatomical level of human great saphenous vein (GSV). METHODS: Forty-nine vein samples were obtained from 10 patients with VVs (control group), and 34 samples from 7 VV patients after 1-hour hydrostatic stress just before surgery (stress group) at each anatomical site (proximal, Hunter, Dodd, and Boyd perforators) of GSV. Light microscopic examination and immunohistochemistry for MMP-1, -2, -9, -13 and TIMP-1, -2 were performed. RESULTS: Intimal hyperplasia, fragmentation and loss of elastic fibers, infiltration of collagen fibers, and disorganization of medial muscle layers were evident in most vein samples. The degree of vein wall degeneration was not different between the 2 groups, and the anatomical sites of GSV. By immunohistochemistry, the expression of MMPs and TIMPs was not significantly different according to the group and the site. The expression of MMP-9 was more intense than that of other MMPs and TIMPs in all samples. MMP-9 was well localized to endothelial cells, medial muscle layers, and adventitial vasa vasorum. CONCLUSION: There are no distinct differences in the varicose vein samples after short-term postural blood stasis compared to the resting group. MMP-9 may be the key enzyme of the venous wall remodeling.