Effect Of Preoperative Irradiation On Neointima Of The Venous Prosthetic Vascular Graft After AA And IVC Prosthetic Vessel Co-replacement In Canine

Objective To observe the effect of preoperative irradiation on neointima of the venous prosthetic vascular graft after abdominal aorta and inferior vena cava prosthetic vessel co-replacement.Methods 18 mistus dogs' subrenal abdominal aorta(AA) and inferior vena cava (IVC) were marked by silver clips,and then all dogs were randomly divided into 2 groups including the irradiated group and the control group which associated or not preoperative external radiation(28Gy) on the marked AA and IVC.Six weeks after radiation both marked vessels were co-replaced by ePTFE prosthetic grafts. All the animals were sacrificed at 4 weeks after operation for histological and immunohistochemical examination of the neointima of the venous prosthetic vascular graft.Results1. 2 dogs of irradiated group died in peri-operative period and still one died 5 days after vessels replacement.2. 3 cases in irradiated group and 2 cases in control group were completely occluded.And a few thrombosis occured in 1 case of each group,but still patent.3. The neointima of vascular graft formed completely, and the coverage of vascular endothelial cell was incomplete in both groups.The neointima at the distal anastomosis was statistically thinner than that at the proximal anastomosis (p<0.05).And the intimal thickness in irradiated group isthinner than that in control group(p<0.05)4. The PCNA proliferation in irradiated group was less than controlgroup(p<0.05). The PCNA proliferation at the middle of vascular graftwas less than the place at the anastomosis(p<0.05), and that on the distalanastomosis was less than at the proximal anastomosis(p<0.05).Conclusions1.No disunion, rupture was found at the anastomosis after preoperativeexternal beam radiation at a does of 28Gy.2.Preoprative irradiation showed inhibition of the intima hyperplasia 4weeks after vessels replacement.3.Preoprative irradiation has no negative effect in patency of graft inveins.4.The study helps judge whether a patient who have had Preoprativeirradiation can received tumor radication accompanied with prostheticvascular replacement of veins.