ABSTRACT
Objective:The aim of this study was to identify fibrinogen ( FG ) on the development of intimal hyperplasia ( IH ), using an organ culture model. Methods：Segments(n=9 ) of human saphenous vein ( HSV ) wereharvested during coronary artery or infrainguinal vein bypass surgery. The culture medium supplemented with FG (from0 mg/ml to 5 mg/ml ). The proliferation of smooth muscle cell ( SMC ) quantified by 5′-Bromodeoxyuridine (5′-BrdU) uptake in the final four days of the culture period. Histologic analysis and computerized morphometric analysis were used to determine intimal and medial thickness and area，then the intima/media thickness ratio and intima/media area ratio were calculated. Monoclonal antibodies to 5′-BrdU were used as an immunohistochemical maker for proliferating SMC. Results：Addition of FG ( 2.5 mg/ml ) to the cultured medium caused a significant increase in median ( range ) of intima/media thickness ratio and intima/media area ratio of these segments when compared with the normal cultured vein segments ( Wilcoxon paired rank test )：0.387versus 0.215（P=0.017 ）and 0.396 versus 0.229（P=0.015 ），respectively. Addition of FG ( 5.0 mg/ml ) to the cultured medium also caused a significant increase in median ( range ) of intima/media thickness ratio and intima/media area ratio of these segments when compared with the normal cultured vein segments: 0.421 versus 0.215（P=0.008 ）and 0.382 versus 0.229 （P=0.011 ），respectively. However，there were no significant differences in the two vein segments which 2.5 mg/ml or 5.0 mg/ml FG in cultured medium (P>0.05 ).In addition, there was no significant difference in the median ( range ) of intima/media thickness ratio and intima/media area ratio of the segments which FG ( 0.5 mg/ml ) in cultured medium when compared with the normal cultured vein segments ( P>0.05 ). These were supported by SMC proliferation index using staining with 5′-BrdU. Conclusion：High concentration FG at local preianastimotic area may an important factor for IH and early postoprative vein graft restenosis or occlusion.