Introduction
Stroke remains main causative factor of mortality and disability worldwide (1,2). The aging of the population at >65 years is positively associated with the crude mortality and incidence of stroke, according to the World Health Organization, while western countries are among the regions with the highest mortality rates due to stroke (3-5). Carotid artery disease, a subcategory of peripheral artery disease, is associated with the incidence of stroke (1,6-8). Medical treatment and interventional management with carotid endarterectomy or carotid artery stenting (CAS) are the main axes in the management of carotid artery disease (Fig. 1) (1,6). However, to the best of our knowledge, no randomized trial comparing the interventional approaches has been conducted to date to prove the superiority of CAS, while studies are under way to shed some light on its application and outcomes (9-11).
In the latest guidelines, researchers have noted the need for presenting newer evidence regarding the management of carotid stenosis, the prevention of stroke, the timing of interventions, as well as novelties regarding endovascular techniques (1,6,12,13). A bibliometric analysis would permit the assessment of the currently available literature and reflect the synchronous trends in a number of different aspects, such as carotid stenting, which remains an evolutionary field. Such an analysis depicts the association between institutions and authors, and estimates the publication rates among countries and journals. Along this line, vascular specialists may have easier access to current literature trends and information to design future studies.
The primary aim of the present study was to identify the knowledge routes in CAS using bibliometrics, a systematic and reproducible statistical analysis (9). The secondary aims were to examine the research front on the topic under study and produce a social network of the associated scientific community.
Discussion
In this analysis, CAS literature progression was summarized over a 25-year period. CAS remains a critical issue in vascular surgery. The application of minimal and novel interventions, such as TCAR, and technology evolution regarding stents and embolic protection devices, such as reversed flow, will probably affect the application of CAS in the future. Current recommendations have not established the role of CAS in carotid stenting management (1,6). At 10 years after the initial studies, randomized trials continue to evolve regarding the role of CAS in carotid stenosis management (17). The annual growth rate of CAS literature is >20%, indicating current interest. Over the past few years, analogous bibliometric analyses have been performed regarding carotid artery stenosis, reflecting the interest of the vascular and other scientific communities in this field (18-20).
The top three studies include the initial randomized trial in CAS, the guidelines of the European Society of Cardiology, and a multicenter study. In 2001, the first multicenter randomized trial, the CAVATAS study, presented the comparative results of angioplasty versus endarterectomy in patients with carotid and vertebral stenosis (1,247 citations) (15). The authors concluded that carotid or vertebral angioplasty presented similar major risks and effectiveness in stroke prevention during the initial 3 years of follow-up (21). The European Society of Cardiology published in 2011 recommendations regarding the management of atherosclerotic carotid and vertebral, mesenteric, renal, upper, and lower extremity artery disease (1,145 citations) (16). The revision of these recommendations was published in 2017 with the collaboration of the European Society of Cardiology and Vascular Surgery (6). CAS recommendations present the same level of evidence (level of evidence IIb) (6,21). However, the ‘high volume center’ criterion was replaced by plaque characteristics and life expectancy (6,21). Carotid plaque is among the word trends, indicating the focus of research on the role of the plaque in stroke risk stratification and indications for surgical treatment. The top three studies also include the multicenter study of Wholey et al (16), published in 2000. The purpose of that article was to review CAS placement worldwide using a survey of multiple questions regarding patient selection, techniques, and CAS outcomes (16). In total, 5,210 procedures and 4,757 patients were included in that analysis. Early experience in CAS demonstrated highly acceptable results in terms of minor and major cerebral events and mortality (16).
Vascular surgery, cardiovascular disease and neuro-interventional journals were the hosts of all records. Stroke, CAS and stent were the most commonly used key words, followed by carotid stenosis and angioplasty. The word growth and trend topics based on the key words of authors revealed that CAS is an evolutionary issue with an increased impact in vascular surgery literature. Notably, an increasing interest has risen regarding the application of TCAR, which is associated with a low morbidity and mortality rate (22-24). As endovascular management gains popularity among specialists from different scientific fields, it appears that CAS literature will probably serve future studies.
In terms of collaboration analysis, an extensive network among 20 institutions is provided regarding CAS publications. A total of three large collaboration networks were identified, including universities from the USA and two smaller ones represented by Japanese institutions. Other important collaborations were observed between European countries, such as the United Kingdom, France, Germany and the USA. Collaboration among Universities, specialists and countries is the cornerstone of medical evolution, as well as vascular surgery. Multidisciplinary approaches gain popularity, facilitate patient management, ameliorate outcomes and reduce complications in other fields of vascular medicine (25,26). The role of the multidisciplinary approach is further emphasized in the available recommendations (1,6).
The present study has certain limitations, which should be mentioned. The current analysis provides a holistic view of the scientific research of CAS from 1994 to 2023. The inclusion of most articles and reviews limited the inherent bias of this analysis. However, missing significant publications cannot be precluded, as time for citation accumulation may be required. As only corresponding authors were included in the analysis, the performance of other coauthors could not be analyzed.
In conclusion, CAS remains an area of high interest among specialties, with a publication growth rate estimated at >20% per year. As numerous questions remain to be answered, the need to determine the role of CAS may drive further research and, subsequently, publications.