Inhibition of Intimal/Medial Hyperplasia by Perindopril in Canine Vein Grafts

We used a canine model to assess the efficacy of an angiotensin-converting enzyme inhibitor (perindopril) at modulating intimal/medial hyperplasia in vein bypass grafts. Fourteen beagle dogs were divided into medicated and control groups and underwent bilateral grafting of external jugular veins into the common carotid artery. Samples of normal veins were obtained from the control group during vein grafting. Vein grafts were harvested 1 week and 4 weeks after surgery in both groups. Subsequently, intimal/medial thickness was measured by staining with hematoxylin and eosin; antibodies for proliferating cell nuclear antigen were employed to determine the degree of cellular proliferation; apoptotic cells were detected using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling method. In the medicated group, the intimal/medial cross-sectional area was significantly smaller and increased 8- to 9-fold in comparison to the control group, which increased 12- to 20-fold. There was a significantly higher rate of cell proliferation in the control group, whereas the medicated group showed a significantly higher rate of apoptotic cells. These data support the efficacy of perindopril at reducing intimal/medial hyperplasia in arterialized vein grafts during a short postoperative period.