The influence of low molecular weight heparin on neointimal proliferation in cultured human saphenous vein

Abstract

To investigate the effect of low molecular weight heparin (LMWH) on neointimal proliferation in cultured human saphenous vein, a model of human vein graft intimal hyperplasia. Dose ranging LMWH concentration study. Culture Laboratory, Department of Surgery. Fifteen segments of human long saphenous vein were incubated at 37 degrees C for 14 days in culture medium with 30% foetal calf serum. LMWH was added to one of the paired segments at 1, 10 and 100 micrograms/ml (five veins each dose). 5-bromo-2-deoxyuridine (Brd-U) was used to label proliferating cells. Neointimal thickness (micron and proliferation index (% labelled neointimal cells). Neointimal thickness and proliferation index were both significantly reduced by LMWH at 100 micrograms/ml [control vs. LMWH, reduction in thickness 21 microns vs. 7 microns (median difference 12 microns, 95% conf. int. 6-18), reduction in proliferation index 33% to 6% (median difference 19%, 95% C.I. 4-32)]. High dose LMWH reduces neointimal proliferation in cultured human saphenous vein. The practical clinical application of these results may require the use of non anticoagulant heparin-like molecules and/or local drug delivery systems.