Wall mechanics of the stented rabbit aorta: long-term study and correlation with histological findings.
OBJECTIVE
To evaluate long-term changes in arterial wall mechanics induced by stenting of the rabbit aorta.


METHODS
Eighteen New Zealand white rabbits had initial stent deployment (3x8 mm Multilink) at 110% of the pre-stenting abdominal aortic diameter. Group A (n=10) had no postdeployment stent expansion and group B (n=8) had 30% overdilation of the stent. A noninvasive B-mode ultrasound examination coupled with image processing allowed measurement of diameters at systole and diastole and the calculation of diameter compliance. Measurements were performed before stenting and compared to those recorded immediately after stenting and at 3 months at 3 locations: upstream from the stent, at the stent level, and downstream from the stent. Measurements were also compared among measurement sites. The pathological study included measurement of intimal thickening and calculation of an injury score.


RESULTS
At the stent level, diameter compliance was significantly lower after initial stenting and at 3 months than before stenting (group A: p<0.005; group B: p<0.001) and than downstream or upstream from the stent (group A: p<0.0001, group B: p<0.005). No significant difference in diameter compliance was found between groups A and B. In group B, intimal thickening and the injury score were greater than in group A (p<0.05 and p<0.0001, respectively).


CONCLUSIONS
Endovascular stenting of the rabbit aorta impairs wall mechanics. Performing 30% overdilation of the stent does not worsen this impairment but induces greater in-stent intimal hyperplasia.
Vernhet
Hélène
H
Laboratory of Cardiovascular Physiology, Faculty of Medicine, Montpellier I University, Montpellier, France.
Demaria
Roland
R
Pérez-Martin
Antonia
A
Juan
Jean Marie
JM
Oliva-Lauraire
Marie Claire
MC
Marty-Double
Christiane
C
Sénac
Jean Paul
JP
Dauzat
Michel
M
D000818:Animals; D001011:Aorta / Q000473:pathology / Q000502:physiology* / Q000601:surgery*; D004548:Elasticity; D008297:Male; D011817:Rabbits; D015607:Stents; D013997:Time Factors