Prevention of intimal hyperplasia by single-dose pre-insertion external radiation in canine-vein interposition grafts

Objectives: to evaluate the efficacy of single-dose pre-insertion gamma rad iation of vein grafts in the prevention of intimal hyperplasia. Methods: femoral artery interposition grafts with internal jugular vein wer e inserted in 12 mongrel dogs. The animals were randomly divided into two g roups. Immediately before graft replacement, jugular veins were treated wit h a single dose of cobalt-60 radiation at 14 Gy or received no radiation (c ontrol group). Six weeks after graft insertion, the vein grafts were pressu re-perfusion fixed and harvested for the histomorphometric analysis. Quanti tative data on anastomotic stenosis were calculated from Gilman parameters after cross-sectional image analysis. Results: vein grafts treated with radiation demonstrated significantly decr eased neointima formation compared with grafts in the control group. The me an Gilman parameter for the control group was 1.09 S.E.M. 0.34 mm and for t he 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 infil tration. Conclusion: single-dose external pre-insertion gamma radiation of vein graf ts reduced the amount of intimal hyperplasia in this animal model.