Comparison of Vascular Responses Following New‐Generation Biodegradable and Durable Polymer‐Based Drug‐Eluting Stent Implantation in an Atherosclerotic Rabbit Iliac Artery Model

Abstract

BackgroundIncomplete endothelialization is the primary substrate of late stent thrombosis; however, recent reports have revealed that abnormal vascular responses are also responsible for the occurrence of late stent failure. The aim of the current study was to assess vascular response following deployment of biodegradable polymer‐based Synergy (Boston Scientific) and Nobori (Terumo) drug‐eluting stents and the durable polymer‐based Resolute Integrity stent (Medtronic) in an atherosclerotic rabbit iliac artery model.Methods and ResultsA total of 24 rabbits were fed an atherogenic diet, and then a balloon injury was used to induce atheroma formation. Synergy, Nobori, and Resolute Integrity stents were randomly implanted in iliac arteries. Animals were euthanized at 28 days for scanning electron microscopic evaluation and at 90 days for histological analysis. The percentage of uncovered strut area at 28 days was lowest with Synergy, followed by Resolute Integrity, and was significantly higher with Nobori stents (Synergy 1.1±2.2%, Resolute Integrity 2.0±3.9%, Nobori 4.6±3.0%; P<0.001). At 90 days, inflammation score was lowest for Synergy (0.27±0.45), followed by Nobori (0.62±0.59), and was highest for Resolute Integrity (0.89±0.46, P<0.001). Foamy macrophage infiltration within neointima (ie, neoatherosclerosis) was significantly less with Synergy (0.62±0.82) compared with Nobori (0.85±0.74) and Resolute Integrity (1.39±1.32; P=0.034).ConclusionsThe biodegradable polymer‐coated thin‐strut Synergy drug‐eluting stent showed the fastest stent strut neointimal coverage and the lowest incidence of neoatherosclerosis in the current animal model.

A comparison of Drug Eluting Stents with different coatings in rabbit iliac artery model

“…The lowest value of uncovered area was for Control (0.9%±0.6%) and the difference between Stent #1 and Stent #2 was found significant (2.75%±2.38 vs. 1.37%±1.14%, P=0.01). The obtained results are consistent with the results published earlier [10] for atherosclerotic rabbit iliac artery model. The edges of prepared samples of stented vessel were also investigated.…”

Early-Phase Vascular Healing of Bioabsorbable vs. Durable Polymer-Coated Everolimus-Eluting Stents in Patients With ST-Elevation Myocardial Infarction ― 2-Week and 4-Month Analyses With Optical Coherence Tomography ―

“…26 In fact, in an animal experiment using rabbits, S-EES showed the fastest neointimal coverage of stent struts as compared with other DES. 27 These study results are consistent with our findings in terms of more rapid neointimal coverage in S-EES. Recent clinical trials have coronary syndrome patients) was superior to bare-metal stents with respect to the occurrence of major adverse cardiac events without increasing the risk of stent thrombosis.…”

In-Stent Restenosis due to Stent Recoil After Third-Generation Drug-Eluting Stent Implantation

“…Therefore, the struts of the third-generation DES Synergy stent are thinner (74-μm thick) than those of previous-generation stents including second-generation DES (more than 80-μm thick) to improve clinical outcomes after PCI. In fact, the Synergy stent promoted faster stent-strut neo-intimal coverage and reduced the incidence of neo-atherosclerosis compared to a second-generation DES in an atherosclerotic rabbit model [ 9 ], and has been associated with an excellent clinical outcome [ 1 ]. However, thin stent struts may reduce its radial strength and increase the incidence of SR [ 8 ].…”