Background
The vascular trauma imposed by the stent is intimately linked to the in-stent restenosis (ISR). Besides the deep injury, the circumferential stretch injury has been recently identified as factor of neointimal development. This study investigated the importance of circumferential stretch and deep injury to the ISR in the animal diseased arteries.
Methods
Bare metal stents were deployed in the rabbits’ atherosclerotic iliac arteries and harvested for histology. The neointimal area was correlated with either deep injure score at each strut site (DIS, score 0–3 as IEL intact, IEL ruptured, media ruptured, EEL ruptured) or a novel stretch injure score at each interstrut area (SIS, score 0–5 as IEL intact, 2/3 IEL lacerated, medial lacerated and EEL lacerated).
Methods
Bare metal stents were deployed in the rabbits’ atherosclerotic iliac arteries and harvested for histology. The neointimal area was correlated with either deep injure score at each strut site (DIS, score 0–3 as IEL intact, IEL ruptured, media ruptured, EEL ruptured) or a novel stretch injure score at each interstrut area (SIS, score 0–5 as IEL intact, 2/3 IEL lacerated, medial lacerated and EEL lacerated).
Results
With no significant difference shown in the neointima area ( P =.345), ISR ( P =.420) or inflammation score ( P =.407) between the plaque-rich and nonplaque vessels, the former had significantly lower DIS ( P =.002) and higher SIS ( P =.021) (data shown in Fig. 1 ). The neointimal thickness was only found to be significantly, but weakly, correlated with either SIS in plaque-rich vessels ( r =0.313, P =.015) or DIS in nonplaque vessels ( r =0.322, P =.003).
