Prevention of Intimal Hyperplasia by Single-dose Pre-insertion External Radiation in Canine-vein Interposition Grafts

Abstract Objectives: to evaluate the efficacy of single-dose pre-insertion gamma radiation of vein grafts in the prevention of intimal hyperplasia. Methods: femoral artery interposition grafts with internal jugular vein were inserted in 12 mongrel dogs. The animals were randomly divided into two groups. Immediately before graft replacement, jugular veins were treated with a single dose of cobalt-60 radiation at 14 Gy or received no radiation (control group). Six weeks after graft insertion, the vein grafts were pressure-perfusion fixed and harvested for the histomorphometric analysis. Quantitative data on anastomotic stenosis were calculated from Gilman parameters after cross-sectional image analysis. Results: vein grafts treated with radiation demonstrated significantly decreased neointima formation compared with grafts in the control group. The mean Gilman parameter for the control group was 1.09 S.E.M. 0.34 mm and for the radiotherapy group was 0.65 S.E.M. 0.23 mm (p 0.05). All vein grafts in the radiotherapy group had a decreased amount of intimal and cellular infiltration. Conclusion: single-dose external pre-insertion gamma radiation of vein grafts reduced the amount of intimal hyperplasia in this animal model.