Keywords
Intracranial Aneurysm - Subarachnoid Hemorrhage - Endovascular Procedures - Bibliometrics
Palavras-chave
Aneurisma Intracraniano - Hemorragia Subaracnóidea - Procedimentos Endovasculares
- Bibliometria
INTRODUCTION
Endovascular technology has been used to embolize intracranial aneurysms (IAs) since
the Guglielmi detachable coil (GDC) was introduced for clinical use in 1990.[1] Currently, an increasing number of patients with ruptured or unruptured IAs are
being treated with endovascular therapy. The endovascular treatment methods for IAs
include simple coil embolization, stent-assisted embolization, and placement of Flow
Diversion Device. According to the international multi-center randomized controlled
study (International Subarachnoid Aneurysm Trial, ISAT), endovascular treatment was
better than neurosurgical clipping and reduced the mortality and disability rate of
IAs patients. Moreover, the complication rate of endovascular treatment was lower
than that of craniotomy. But the rebleeding rate was higher than craniotomy.[2]
[3] To our knowledge, endovascular therapy is more suitable for patients with advanced
age, weak physique, or severe organic diseases who cannot tolerate craniotomy, as
well as for patients with posterior circulation, wide neck, or huge IAs.
Many researchers have focused on research reports on the endovascular treatment of
IAs. We have learned that bibliometric analysis is an analytical method that provides
comprehensive knowledge about a particular area of study and identifies current research
hotspots or research directions. We aim to provide a new perspective through bibliometric
analysis to understand the overall research status of endovascular treatment of IAs.
The impact of a research report can be evaluated by the number of citations. An overview
of the research area can be obtained through bibliometric analysis of the most cited
literature. There have been many reports of bibliometric analysis in many fields.
However, the bibliometric analysis dedicated to endovascular treatment for IAs has
not been reported. Therefore, the purpose of this study is to understand the development
in the field of endovascular treatment of IAs and to use bibliometric methods to analyze
the characteristics of the 100 most cited articles in the field.
METHODS
This study was a bibliometric analysis, so ethical approval was not required.
Search strategy
Web of Science (WOS) is an online database platform. It can provide information on
the annual/total number of citations, authors, publication year, source journals,
article types, citation indexes, etc. We searched the literature on endovascular treatment
of IAs from the 1950s to the present day on WOS ([Figure 1]).
Figure 1 The flow chart of this study.
In this study, the following secondary IAs were excluded: traumatic, infectious, and
aneurysms secondary to radiotherapy or surgery. The articles were ranked based on
the number of citations. The top 100 most cited articles were selected for analysis,
and the full texts of these 100 articles were downloaded for analysis.
Information collection and analysis
We analyzed the top 100 most cited articles, and the following information of each
article was obtained ([Figures 2]
[3]
[4]
[5], [Table 1]
[2]
[3]
[4]): (1) the number of articles published each year; (2) the number of articles published
in each country over the years; (3) the cooperative network relationship between countries;
(4) the number of citations per year; (5) the details of the top 100 most cited articles
(publication year, journal, first author, number of citations/number of citations
per year); (5) the details of journals (number of citations, number of articles, average
number of citations per article); (6) country of the main author; (7) article category
(clinical research, review, basic research, guideline, commentary, expert consensus,
protocol); (8) productive authors (number of articles, position on author list); (9)
productive institutions (number of articles, citations).
Figure 2 The annual citation number of the top 100 most cited articles.
Figure 3 Number of articles per year for the top 100 most cited articles.
Figure 4 Annual number of the top 100 most cited articles in some countries (countries with
more reports).
Figure 5 The schematic diagram of cooperation network between countries.
Table 1
Journals publishing the top 100 most cited articles on endovascular treatment of intracranial
aneurysms
|
Journal
|
Citations (n)
|
Number of articles
|
Annual number of citations
|
Impact factor
|
|
Journal of Neurosurgery
|
150
|
24
|
6.3
|
3.96
|
|
Stroke
|
69
|
20
|
3.5
|
7.19
|
|
American Journal of Neuroradiology
|
68
|
15
|
4.5
|
3.38
|
|
Neurosurgery
|
90
|
15
|
6.0
|
4.85
|
|
Radiology
|
39
|
8
|
4.9
|
7.93
|
|
Lancet
|
40
|
5
|
8.0
|
60.39
|
|
Acta Neurochirurgica
|
6
|
2
|
3.0
|
1.81
|
|
Neuroradiology
|
7
|
2
|
3.5
|
2.24
|
|
Annals of Neurology
|
3
|
1
|
3.0
|
9.04
|
|
IEEE Transactions on Medical Imaging
|
1
|
1
|
1.0
|
6.68
|
|
Journal of NeuroInterventional Surgery
|
2
|
1
|
2.0
|
4.46
|
|
Journal of Neuroradiology
|
10
|
1
|
10.0
|
2.42
|
|
Lancet Neurology
|
4
|
1
|
4.0
|
30.03
|
|
Neurological Research
|
0
|
1
|
0
|
2.40
|
|
Neurology
|
5
|
1
|
5.0
|
8.77
|
|
Plos One
|
9
|
1
|
9.0
|
2.74
|
|
Surgical Neurology
|
6
|
1
|
6.0
|
0
|
Table 2
Publication area distribution of the top 100 most cited articles on endovascular treatment
of IAs
|
Country
|
Number of articles
|
|
USA
|
57
|
|
France
|
14
|
|
England
|
9
|
|
Canada
|
8
|
|
Germany
|
7
|
|
Netherlands
|
6
|
|
Turkey
|
5
|
|
Argentina
|
4
|
|
Hungary
|
4
|
|
Scotland
|
4
|
|
Switzerland
|
4
|
|
Finland
|
3
|
|
Japan
|
3
|
|
China
|
2
|
|
Australia
|
1
|
|
Belgium
|
1
|
|
Ireland
|
1
|
|
Spain
|
1
|
|
USSR
|
1
|
Table 3
Institutions that contributed 5 or more of the top 100 most cited articles
|
Institution
|
Number of articles
|
Citations (n)
|
|
University of California system
|
15
|
50
|
|
State University of New York (SUNY) system
|
10
|
48
|
|
New York University
|
8
|
87
|
|
State University of New York (SUNY) Buffalo
|
8
|
48
|
|
University of California Los Angeles
|
8
|
27
|
|
Barrow Neurological Institute
|
7
|
78
|
|
University of California San Francisco
|
7
|
27
|
|
David Geffen School of Medicine at UCLA
|
6
|
27
|
|
Elisabeth-TweeSteden Ziekenhuis (ETZ)
|
6
|
21
|
|
Mayo clinic
|
6
|
22
|
|
University of Oxford
|
6
|
60
|
|
Université de Paris
|
5
|
1
|
Table 4
Authors who contributed 5 or more of the 100 most cited articles
|
Author
|
Number of articles
|
Position on author list (number of articles)
|
|
Fiorella D
|
9
|
FA (4); FourA (1); SixA (1); SevA (1); TenA (1); 15thA (1)
|
|
Vinuela F
|
9
|
FA (1); SA (2); TA (2); Four A (1); SixA (1); EA (1)
|
|
Lanzino G
|
8
|
FA (1); SA (3); TA (2); FourA (1); TenA (1)
|
|
Duckwiler GR
|
8
|
SA (1); TA (3); FourA (3); 27thA(1)
|
|
Molyneux AJ
|
8
|
FA (4); TA (2); FifA (1); 55thA (1)
|
|
Nelson PK
|
7
|
FA (1); FourA (2); SevA (1); EA (1); NA (1); 22th A (1)
|
|
Albuquerque FC
|
6
|
SA (2); TA (2); FifA (1); 14th A (1)
|
|
Goblin YP
|
6
|
TA (1); FourA (3); FifA (1); SixA (1)
|
|
Hopkins LN
|
6
|
FourA (1); FifA (1); SixA (1); SevA (1); EA (1); 15thA (1)
|
|
Van Rooij WJ
|
6
|
SA (2); TA (3); FourA (1)
|
|
Guglielmi G
|
5
|
SA (2); TA (1); FifA (2)
|
|
Higashida RT
|
5
|
FA (2); SA (1); FourA (1); FifA (1)
|
|
kallmes DF
|
5
|
SA (1); FourA (2); FifA (1); SixA (1)
|
|
Mcdougall CG
|
5
|
FourA (1); SixA (2); EA (1); 14thA (1)
|
|
Sluzewski M
|
5
|
FA (4); SevA (1)
|
|
Wakhloo AK
|
5
|
FA (2); SA (1); TA (1); SevA (1)
|
Abbreviations: EA, eighth author; FA, first Author; FifA, fifth author; FourA, fourth
author; NA, ninth author; SA, second author; SevA, seventh author; SixA, sixth author;
TA, third author; TenA, tenth author.
The extraction of the above-mentioned information was completed by two reviewers (neurointerventional
physicians). If there was a dispute, the task was handed over to the third reviewer
(senior neurointerventional physician), who made the final decision.
RESULTS
The overall situation
A total of 7,504 articles were retrieved. The top 100 most cited articles that met
the inclusion criteria for analysis were selected. The details of the top 100 most
cited articles are shown in [Supplementary Table S1]. The top 100 most cited articles were cited 281.3 times on average (range, 135–2254).
The most cited articles on endovascular treatment of IAs
The most cited article was the manuscript titled “International Subarachnoid Aneurysm
Trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2,143 patients
with ruptured intracranial aneurysms: a randomized trial,” which was published in
Lancet in 2002. It has been cited 2,254 times, with an average of 112.7 citations
per year.
The annual citations number
As shown in [Figure 2], the annual number of citations of these articles increased in the beginning and
then decreased over time. These articles were cited with the most in 2012.
Time of publication, publication area distribution, annual number in some countries,
and cooperation between countries
As shown in [Figure 3], these top 100 most cited articles were mainly published during 1998–2013. The number
of articles published in the top contributing countries are shown in [Figure 4]. It was not difficult to see that, in the field of endovascular treatment of IAs,
the United States produced the most articles every year.
The countries with the top 100 most cited articles are listed in [Table 3]. The United States has published the most articles (57), with a significantly higher
number of articles than France. The United States cooperated the most with other countries
as shown in the schematic diagram of cooperation network ([Figure 5]).
Journals publishing the top 100 most cited articles
The journals that have published the most number of articles are shown in [Table 1]. Among them, the Journal of Neurosurgery has published the most articles (24), with
a total of 150 citations. It was followed by the Journal of Stroke, which published
20 articles, with a total of 69 citations.
High-yield countries/individuals
The institutions with more output (≥ 5 articles) are shown in [Table 3]. The University of California system has the most output, with a total of 15 articles
published. Studies from the University of California system have been cited 50 times.
The authors with more output (≥ 5) are shown in [Table 4]. Fiorella et al. have published four highly cited articles.
Article category
Among the top 100 most cited articles, most (86) of them were clinical studies, only
8 were review studies, 3 were basic studies, and 2 were commentary articles.
DISCUSSION
The rupture of IAs can cause subarachnoid hemorrhage leading to disastrous consequences
in patients.[4] With the advancement of interventional therapy technology, the endovascular treatment
of IAs has become an important treatment method.[5]
The purpose of this study was to review the most highly cited articles in the field
of endovascular treatment of IAs, and to explore the characteristics of research studies
in this field. To the best of our knowledge, the bibliometric analysis of intracranial
aneurysmal subarachnoid hemorrhage has been reported.[6] However, the bibliometric analysis dedicated to the endovascular treatment of IAs
has not been reported yet. The bibliometric analysis in this study is a contrived
in-depth summary based on previous work. We reviewed the 100 most cited reports in
the field of endovascular treatment of IAs as the basis for understanding this type
of treatment. Next, we will discuss the results of the bibliometric analysis. It should
be noted that the focus of this study is to describe the bibliometric characteristics.
The characteristics of the citation number per year and the publication time of the
top 100 most cited articles
The number of annual citations gradually increased from 1986 to 2013 ([Figure 2]). The top 100 most cited articles were mainly published between 1997 and 2013. This
was also a period with rapid development of endovascular treatment of IAs. During
this period, the technology of interventional materials developed rapidly. Practitioners
in this field also communicated with each other more conveniently with the development
of the internet and social media. These reasons may have led to higher production
of the top 100 most-cited articles during that period.
After 2013, the number decreased gradually. This was consistent with the general literature
being cited. These reports attracted more and more physicians' interest in the early
stage as the technique became more popular. Gradually, the endovascular treatment
for IAs became well known to many physicians and less attention was paid to this field.
In addition, with the emergence of new treatment equipment and technologies, people's
attention to traditional endovascular treatment technologies gradually decreased.
Journals that published more articles
As shown in [Table 1], the top 100 most cited documents were mainly published in the publications Journal
of Neurosurgery, Stroke, American Journal of Neuroradiology, etc. Among them, the
Journal of Neurosurgery is a classic journal that publishes clinical and basic research
on neurosurgery. It has published 24 of the top 100 most cited reports on endovascular
treatment of IAs. Most of the highly cited reports were published in professional
journals, which may be due to the fact that readers of comprehensive journals lack
sufficient interest in reports on intravascular therapy of IAs compared with the readers
of professional journals.
Main contributing countries and the cooperation network between these countries
As shown in [Table 2], the United States published the highest number of papers among the top 100 ones,
and that number was significantly higher than those of other countries. Developing
countries have published fewer articles of the top 100 most cited articles. As shown
in [Figure 5], the United States was the hub of the collaboration network, which is similar to
other bibliometric analysis results.
The United States is the largest economy in the world and provides economic support
to medical research worldwide. There are also many scientific and technological innovations
in the United States that may accelerate the production of highly cited documents
in this field. Other countries also seek to cooperate with the United States to promote
their own development in this field.
It should be noted that although the United States has contributed the most in number,
this does not mean that it has made the greatest contribution to this field. For example,
the International Subarachnoid Aneurysm Trial (ISAT) is a multi-center study, and
its research branch did not include the United States.
Productive institutions and individuals
As shown in [Table 3], the University of California system has the largest academic output. As the first
author, Fiorella et al. have published the four most cited articles. Most of these
highly accomplished individuals were affiliated with the United States and European
institutions. There are fewer institutions and individuals from developing countries.
This difference may be due to the higher investment in scientific research in western
developed countries, which results in strong innovation capabilities and a good academic
atmosphere in these countries compared with developing countries.
Analysis of research type
Among the top 100 most cited reports, clinical studies accounted for 86%, followed
by review reports (8%), and basic research (3%). Some clinical research reports have
provided high-quality data for clinical decision-making. For example, the International
Unruptured Intracranial Aneurysm (ISUIA) study and the ISAT, are examples of multi-center
and multi-country cooperation and provided an important reference for the establishment
of intravascular treatment norms for IAs. The ISUIA showed that if the diameter of
the aneurysm exceeds 7 mm, the risk of rupture is increased.[3]
[7]
We noted that there are few basic research reports. So, it is necessary to strengthen
the cooperation in basic research. For instance, we should cooperate to explore the
mechanism of hemodynamic changes after endovascular treatment of IAs. A deep understanding
of pathogenesis may be beneficial to increase the long-term occlusion rate.
Limitations of this study
In this study, we only analyzed literature reports in English. This may omit contributions
made by non-English authors. Besides, we selected the top 100 most cited articles
based on the number of citations, this may underestimate some important articles and
overestimate those articles that appeared in the list. Furthermore, the results of
bibliometric analysis will change with the update of the number of citations. Moreover,
the number of citations used as a reference basis for the influence of the article
may not be completely accurate. In the future, it may be more accurate if we can combine
multiple indicators to comprehensively judge the influence of the article and then
analyze the bibliometrics characteristics of the literature.
In conclusion, this study highlights the top 100 most cited reports in endovascular
treatment of IAs. The bibliometric analysis provides insight into the development
and growth trend in endovascular treatment of IAs. This study can help researchers
to better understand the global overview of this disease and provide information about
promising areas of research and potential collaborations.
