Experimental assessment of new stent technologies: validation of a comparative paired rabbit iliac artery study model

Preventing coronary in-stent restenosis is a major challenge for physicians and industry. To assess new stent technologies, a comparative paired iliac artery model in rabbits is proposed. One tubular stent was implanted in each external iliac artery in 12 rabbits (i.e., 24 stents). An artery overdilatation level of 20% was strictly observed. Restenosis was examined at 30 days by angiography, intravascular ultrasound (IVUS) examination, and histomorphometry. On quantitative angiography, the mean loss of angiographic diameter was 9.8 +/- 4.4% in the right as compared to 9.3 +/- 55% in the left artery (p = 0.75). On IVUS, the volume of intrastent neointimal proliferation was 26.6 +/- 4.9 mm(3) in the right and 25.8 +/- 3.5 mm(3) in the left artery (p = 0.58). In histomorphometry, the neointimal proliferation area was 0.78 +/- 17 mm(2) in the right and 0.76 +/- 0.17 mm(2) in the left artery (p = 0.87). Intrastent neointimal proliferation was comparable between the left and right arteries of all rabbits. The model has three main advantages: (1) arterial dilatation and thus arterial wall aggression are controlled, (2) pairing makes each animal its own control subject, and (3) the statistical power for comparative testing is maximized. The model enables the effect of a new drug-delivery device to be assessed.