A Novel Rabbit Model for In-Stent Neoatherosclerosis

Global research trends in in-stent neoatherosclerosis: A CiteSpace-based visual analysis

BACKGROUND

Recent studies have shown that in-stent neoatherosclerosis (ISNA/NA) is an important cause of late stent failure. A comprehensive understanding of the current state of research in this field will facilitate the analysis of its development trends and hot frontiers. However, no bibliometric correlation has been reported yet. Here, we analyze the relevant literature since the emergence of the concept and provide valuable insights.

METHODS

Publications were collected from the Web of Science Core Collection (WoSCC) and PubMed. Microsoft Excel, SPSS and CiteSpace were used to analyze and present the data.

RESULTS

A total of 498 articles were collected, with Japan and Cardiovasc Res Fdn being the main publishing forces in all country/region and institutions. J AM COLL CARDIOL is the journal with the most published and co-cited articles. According to co-citation analysis, optical coherence tomography, thrombosis, implantation, restenosis, drug-eluting stent, and bare metal stent have become more and more popular recently.

CONCLUSION

ISNA is a niche and emerging field. How to reduce the incidence of ISNA and improve the late patency rate of coronary stents may remain a hot spot for future research. The pathogenesis of ISNA also needs to be explored in more depth.

Animal Models of Neointimal Hyperplasia and Restenosis: Species-Specific Differences and Implications for Translational Research

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Neointimal hyperplasia is the major factor contributing to restenosis after angioplasty procedures.

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Multiple animal models exist to study basic and translational aspects of restenosis formation.

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Animal models differ substantially, and species-specific differences have major impact on the pathophysiology of the model.

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Genetic, dietary, and mechanical interventions determine the translational potential of the animal model used and have to be considered when choosing the model.

The process of restenosis is based on the interplay of various mechanical and biological processes triggered by angioplasty-induced vascular trauma. Early arterial recoil, negative vascular remodeling, and neointimal formation therefore limit the long-term patency of interventional recanalization procedures. The most serious of these processes is neointimal hyperplasia, which can be traced back to 4 main mechanisms: endothelial damage and activation; monocyte accumulation in the subintimal space; fibroblast migration; and the transformation of vascular smooth muscle cells. A wide variety of animal models exists to investigate the underlying pathophysiology. Although mouse models, with their ease of genetic manipulation, enable cell- and molecular-focused fundamental research, and rats provide the opportunity to use stent and balloon models with high throughput, both rodents lack a lipid metabolism comparable to humans. Rabbits instead build a bridge to close the gap between basic and clinical research due to their human-like lipid metabolism, as well as their size being accessible for clinical angioplasty procedures. Every different combination of animal, dietary, and injury model has various advantages and disadvantages, and the decision for a proper model requires awareness of species-specific biological properties reaching from vessel morphology to distinct cellular and molecular features.

A heparin-rosuvastatin-loaded P(LLA-CL) nanofiber-covered stent inhibits inflammatory smooth-muscle cell viability to reduce in-stent stenosis and thrombosis

Background

An endovascular covered-stent has unique advantages in treating complex intracranial aneurysms; however, in-stent stenosis and late thrombosis have become the main factors affecting the efficacy of covered-stent treatment. Smooth-muscle-cell phenotypic modulation plays an important role in late in-stent stenosis and thrombosis. Here, we determined the efficacy of using covered stents loaded with drugs to inhibit smooth-muscle-cell phenotypic modulation and potentially lower the incidence of long-term complications.

Methods

Nanofiber-covered stents were prepared using coaxial electrospinning, with the core solution prepared with 15% heparin and 20 µM rosuvastatin solution (400: 100 µL), and the shell solution prepared with 120 mg/mL hexafluoroisopropanol. We established a rabbit carotid-artery aneurysm model, which was treated with covered stents. Angiography and histology were performed to evaluate the therapeutic efficacy and incidence rate of in-stent stenosis and thrombosis. Phenotype, function, and inflammatory factors of smooth-muscle cells were studied to explore the mechanism of rosuvastatin action in smooth-muscle cells.

Result

Heparin–rosuvastatin-loaded nanofiber scaffold mats inhibited the proliferation of synthetic smooth-muscle cells, and the nanofiber-covered stent effectively treated aneurysms in the absence of notable in-stent stenosis. Additionally, in vitro experiments showed that rosuvastatin inhibited the smooth-muscle-cell phenotypic modulation of platelet-derived growth factor-BB induction and decreased synthetic smooth-muscle-cell viability, as well as secretion of inflammatory cytokines.

Conclusion

Rosuvastatin inhibited the abnormal proliferation of synthetic smooth-muscle cells, and heparin–rosuvastatin-loaded covered stents reduced the incidence of stenosis and late thrombosis, thereby improving the healing rates of stents used for aneurysm treatment.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00867-8.