Helene Vernhet-Kovacsik MD, PhD, Abstract Co-Author: Nothing to Disclose

Roland Demaria, Abstract Co-Author: Nothing to Disclose

Gerald Gahide, Presenter: Nothing to Disclose

Marie Claire Oliva-Lauraire, Abstract Co-Author: Nothing to Disclose

Isabelle Guiraud, Abstract Co-Author: Nothing to Disclose

Michel Dauzat, Abstract Co-Author: Nothing to Disclose

Despite improvements in stent design, restenosis is not completely eliminated, especially at the stent edges. The aim of this study was to evaluate changes in endothelium dependent relaxation induced by stent placement in small caliber arteries, and evaluate their relationship with morphological and biomechanical data.

Eight New-Zealand white rabbits had initial stent deployment (3mm x 8mm ACS Multilink) in the infra renal aorta. Eight weeks later, arterial wall distensibility was non invasively evaluated from B-mode ultrasound measurements of systolic-diastolic diameter changes. The aorta was then excised for histology (injury index and inflammatory response) and histomorphometry studies 20 mm upstream (CS), immediately upstream (UpS), immediately downstream (DownS) from the stent, and at the proximal (ProxS), mid (MidS) and distal part (DistS) of the stent. Ex vivo assessment of endothelial vasomotor function was performed at UpS and DownsS.

Distensibility was lower at MidS than UpS (p<0.0003) and DownsS (p<0.0001), and lower at DownsS than UpS (p<0.05). Intima surface was greater at ProxS than MidS (p<0.0004) and DistS (p<0.01), and at DistS than MidS (p< 0.009). Endothelium-dependent relaxation to acetylcholine was lower at UpS (p<0,02) and DownsS (p<0,015) than at CS. No correlation was found between UpS or DownsS endothelium-dependent relaxation and neither ProxS or DistS intimal surface, nor inflammation score, or distensibility mismatch (UpS – S and S-DownsS distensibility differences). A significant correlation (r=0.72; p<0.05) was found between DownsS endothelium-dependent relaxation and the DistS injury score.

Balloon-expandable stent placement induces endothelial dysfunction in arterial segments adjacent to the stent, without correlation with stent-induced biomechanical changes and wall remodelling.

Vernhet-Kovacsik, H, Demaria, R, Gahide, G, Oliva-Lauraire, M, Guiraud, I, Dauzat, M, Endothelial Dysfunction at Stent Edges: Role of Arterial Wall Mechanics, In-stent Intimal Hyperplasia, and Remodelling.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4416401.html