Angiogenic study in Graves' disease treated with thyroid arterial embolization.

PURPOSE To investigate angiogenesis in the thyroid of Graves' disease (GD) treated with thyroid arterial embolization through analysis of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and microvessel density (MVD). MATERIALS AND METHODS Forty-two GD patients were treated with thyroid arterial embolization and followed up for 1-68 months after embolization. Before embolization and at 7 days, 3, 6, 12, 36 and 48 months following embolization, TT3, TT4, FT3, FT4, TSH and thyroid stimulating antibody (TSAb) were tested respectively. Thyroid biopsy was performed under the guidance of computed tomography for immunohistochemical staining of VEGF and bFGF, and MVD within the thyroid gland was marked by CD34. RESULTS VEGF and bFGF were mostly expressed in the cytoplasm and on the cell membrane. The expression of VEGF was increased (P < 0.05) at < or = 6 months compared with before embolization and decreased (P < 0.05) at > or = 1 year compared with either at < or = 6 months or before embolization. The expression of bFGF was not statistically different at < or = 6 months compared with before embolization but was decreased (P < 0.05) at > or = 1 year compared with either at ?6 months or before embolization. Thyroid MVD marked by CD34 had similar changes to those of the VEGF expression after embolization. There was a positive correlation between VEGF and bFGF (P < 0.05) and between VEGF or bFGF and MVD (P < 0.05). Thyroid hormones mostly returned to normal and TSAb was decreased in longer follow-up. CONCLUSION Thyroid arterial embolization can decrease the expression of VEGF, bFGF and MVD. Consequently, angiogenesis within the GD thyroid will be decreased in the long term after embolization and may serve as the basis for reduced thyroid size and function.