Changes in wall mechanics after endovascular stenting in the rabbit aorta:comparison of three stent designs

OBJECTIVE, The aim of this study was to evaluate changes in the wall mechan ics of small-diameter arteries after endovascular placement of three differ ent stents. SUBJECTS AND METHODS. Five self-expandable stents (Wallstent), five balloon -expandable noncovered Palmaz stents. and three balloon-expandable covered stents (Jostent) were placed in the infrarenal aorta of 13 New Zealand whit e rabbits. Systolic blood pressure changes. blood-flow velocity, systolic d iameter. and diameter changes were measured and used to calculate the diame ter compliance, the distensibility coefficient, and the pulsatility index. RESULTS. Compliance (10(-3) mm kPa(-1)) was 75.3 +/- 20.1 before stenting a nd reached 94.7 +/- 42.2 upstream, 38.8 +/- 14.2 at the stent level (p < 0. 05), and 70.8 +/- 23.2 downstream from the stent. Distensibility (10(-3) kP a(-1)) was 24.3 +/- 6.3 before stenting and reached 27.8 +/- 10.3 upstream, 10.5 +/- 4.4 at the stent level (p < 0.001), and 21.9 +/- 8.6 downstream f rom the stent. Compliance and distensibility were significantly lower at th e stent level than upstream and downstream ii, < 0.05). Aortic diameter inc reased significantly at the stent level from 3.11 +/- 0.40 mm before to 3.7 6 +/- 0.42 mm after stenting. No significant difference was found among the three stent designs fur all the studied data. CONCLUSION. Regardless of the three tested stent designs, endovascular sten ting produces a significant decrease in arterial wall compliance of the rab bit aorta.