Impact of Coronary Stent Fracture on Restenotic Neointimal Tissue Characterization After Drug-Eluting Stent Implantation

Abstract

SummaryAlthough drug-eluting stents (DESs) reduce the rates of in-stent restenosis (ISR) and subsequent target lesion revascularization, stent fracture (SF) after DES implantation has become an important concern because of its potential association with restenosis and stent thrombosis. We aimed to assess the pathogenic impact of SF on in-stent restenotic neointimal tissue components after DES implantation. We analyzed 43 consecutive patients (14 with SF and 29 without SF) with ISR requiring revascularization after DES implantation between January 2008 and March 2014. For evaluation of in-stent tissue components, integrated backscatter intravascular ultrasound (IB-IVUS) was performed. SF was defined as complete or partial separation of stent segments observed using plain fluoroscopy or intravascular ultrasound. On volumetric IB-IVUS analyses, patients with SF had a significantly higher percentage of lipid tissue volume within the neointima and a significantly lower percentage of fibrous tissue volume than those without (37.3 ± 18.9% versus 24.9 ± 12.4%, P = 0.02, and 61.2 ± 18.3 versus 72.6 ± 12.1%, P = 0.04, respectively). Moreover, SF was positively correlated with the percentage of lipid volume on multiple linear regression analysis after adjustment for confounding factors (β = 0.36, P = 0.03). The interval from stent implantation was similar in both groups (47.0 ± 28.7 versus 37.7 ± 33.3 months; P = 0.39). In conclusion, SF is associated with larger lipid tissue volume within the neointima after DES placement, suggesting a contribution to the development of neoatherosclerosis and vulnerable neointima. Thus SF might lead to future adverse coronary events.(Int Heart J 2017; 58: 861-867)

A Novel Rabbit Model for In-Stent Neoatherosclerosis

“…However, researchers have reported several mechanisms for ISR, such as glucose fluctuation and stent fracture. 13,19) This demonstrates that ISR is still problematic. An improved animal model is required.…”

“…Compared with the interventional method, 13) our improved method requires less laboratory staff and less time. The interventional method requires radiography, which harms the staff and the rabbits.…”

“…Besides, other researchers reported that irregular protrusion post-DES implantation and stent fracture were also associated with subsequent neoatherosclerosis formation. 12,13) However, certain mechanisms of neoatherosclerosis are still unclear, so we should attach more importance to the further study of neoatherosclerosis, and an appropriate animal model that allows clear scanning of the arterial wall is required.…”

“…12) Another method is to separate the common carotid artery and perform aortic arteriography on the bilateral common carotid arteries by transcatheterization of the right femoral artery with a cut-down technique. 13) However, both of these models have disadvantages. The former method destroys the normal anatomical structure and greatly affects the hemodynamics.…”

Stent Recoil in Overlapping Stent 18 Years After Wiktor Stent Implantation

“…Stent fracture, including stent recoil after stent implantation, sometimes causes target lesion revascularization. 1,2) Although the exact mechanism is unknown, the change in angulation of the lesion after stenting, total stent length, vessel tortuosity, the stent design, and overlapping stent are associated with the stent deformation. 3,4) A previous study demonstrated acute recoil was observed in 8.2% of 77 consecutive patients, while late recoil was not observed after WS implantation in the patients' native coronary arteries.…”