Objective:To observe the effect of fractionated preoperative irradiation on neointima of the replaced ePTFE blood vessel prosthesis in dogs.
Methods :Eigteen mongrel dogs were equally divided into irradiated group and control group at radom according to whether or not preoperative irradiation was given. Six weeks after preoperative irradiation, subrenal abdominal aorta and inferior vena cava of the irradiated group were replaced by ePTFE blood vessel prosthesis. Specimens were harvested at 4 weeks after operation, and H-E staining, immunohistochemistry test of PCNA and CD34 were done.
Results:Two dogs died after operation. Three grafts implanted into IVC in irradiated group and 2 in control group were completely occluded, but no graft was obstructed in AA. The neointima of vascular graft formed completely, but the coverage of vascular endothelial cells was incomplete in both groups. The expression of CD34 of irradiated group was statistically less than control group in the middle of the graft (P<0.05), while there were no statistical difference at the distal and proximal anastomosis. The intimal thickness in distal, proximal and middle of the graft was thinner in irradiated group than that in control group (P<0.05). The PCNA proliferation in irradiated group was lower than in control group (P<0.05).
Conclusions:Fractionated preoperative irradiation showed inhibition of the intima hyperplasia 4 weeks after vessels replacement and has no negative effect in patency of graft both in veins and aortas.