Knowledge mapping of surgical smoke from 2003 to 2022: a bibliometric analysis

Purpose The purpose of this study is to identify and characterize the literature on surgical smoke, visualize the data and sketch a certain trending outline. Methods In the Web of Science Core Collection (WoSCC), all the data were acquired from January 1st 2003 to December 31st 2022. VOSviewer and CiteSpace were employed to visualize data, based on publications, bibliographic coupling, co-citation, or co-authorship relations. Microsoft Excel 2019 was used to comb and categorize all the statistics. Result A total 363 of journal papers were retrieved. The publication number was in a slow but steady growth between 2003 and 2019, followed by a sharp surge in 2020, and then the publication kept in a productive way. Surgical endoscopy and other interventional techniques was the most active journal on surgical smoke. USA played an important role among all the countries/regions. There were 1847 authors for these 363 papers, among whom 44 authors published more than three articles on surgical smoke. “Surgical smoke”, “covid-19” and “surgery” were the top 3 appeared keywords, while the latest hot-spot keywords were “COVID-19”, “virus”, “transmission”, “exposure” and “risk”. There were 1105 co-cited references and 3786 links appeared in all 363 articles. Among them, 38 references are cited more than 10 times. The most co-cited article was “Detecting hepatitis B virus in surgical smoke emitted during laparoscopic surgery.” Based on the titles of references and calculated by CiteSpace, the top 3 cluster trend network are “laparoscopic surgery”, “COVID-19 pandemic” and “surgical smoke”. Conclusion According to bibliometric analysis, the research on surgical smoke has been drawing attention of more scholars in the world. Increasing number of countries or regions added in this field, and among them, USA, Italy, and China has been playing important roles, however, more wide and intense cooperation is still in expectation. Supplementary Information The online version contains supplementary material available at 10.1007/s00464-023-10641-6.

of articles and publications.It analyzes certain topic or domain in journals, countries, funding agencies, keywords, contribution or cooperation of authors and ultimately gives a comprehensive overview as well as study trending for readers [16][17][18].VOSviewer and CiteSpace are both bibliometric tools, which visualize the selected papers related to certain field based on co-author, co-occurrence, countries/regions cooperation, and so on.The former can be quick to create a bibliometric network graph, where Network Visualization, Overlay Visualization, and Density Visualization presenting the relationship and centrality of different items [19].CiteSpace is a functionally designed bibliometric tool.It focuses on cluster-labeling, node-adjusting, paper information reviewing, and topicextracting in LLR, LSI, MI algorithm [20].CiteSpace is helpful to reveal new technologies, hot spots and trends, as well as explore the key paths and frontier developments in scientific research fields [21].
There are literature reviews [1,[22][23][24][25] or systematic reviews [26,27] about surgical smoke, however, no bibliometric analysis had been done to give a qualitatively and quantitatively analyzing panorama related to surgical smoke.Therefore, this paper uses two kinds of bibliometric software-VOSviewer and CiteSpace, in order to identify and characterize the English literature on surgical smoke, visualize the data in the latest 20 years and sketch a certain trending outline in the field, helping the following researchers with potential topic and hot spots.

Data collection
In the Web of Science Core Collection (WoSCC), all the data were searched and acquired from January 1st 2003 to December 31st 2022.Retrieved method and strategies were used as [TS = ("surgical smoke" OR "surgical plume" OR "surgical aerosol" OR "surgical particle" OR "surgical gas" OR "surgical smog")].The inclusion criteria were as follows: (1) peer-reviewed published original articles; (2) reviews; (3) language in English, meanwhile we excluded meeting abstracts, news items, letters, editorial materials, corrections, and other languages articles.
Totally 485 articles were obtained before 122 ones excluded.At last, we get 363 eligible publications, including 299 articles and 64 reviews (Fig. 1).All "Full Record and Cited References" of the data were exported in format ".xls" and ".txt" for further analysis.

Data analysis
Bibliometric software CiteSpace 6.2.4 Advanced [28] and VOSviewer version 1.6.19[29] were used to construct and visualize data, based on citation, bibliographic coupling, cocitation, or co-authorship relations.We used Microsoft Excel 2019 to comb, count, and categorize all the statistics, then displayed in chart.

Annual publications and citations
From Fig. 2A, we could see the publication number of each year was in a slow but steady growth between 2003 and 2019 without data collected in 2004 and 2005.However, 2020 witnessed the sharp surge with the top publication number up to 92, still more than the following 2 years' counts as were 80 and 58.This was due to the pandemic of Corona Virus Disease 2019 (COVID-19), which had been testified to spread via aerosol.Consequently, surgical smoke drew the experts' attention to protecting medical staff from infecting in each surgery of COVID-19 patients.All of this was also reflected in Fig. 2B about citation-2020 was still at the peak with 2143 citations while the number in other years fluctuated around 100-300 except 2008, 2009, 2010, 2022 (below 100).The number of 2020 occupied more than 1/3 of the total citation number (n = 6024) between 2003 and 2022.

Journal analysis
During 2003 to 2022, 205 journals have published articles on surgical smoke.We pick out the top ten journals among  them as is shown in Table 1 and Fig. 3. Surgical endoscopy and other interventional techniques (SURG ENDOSC, IF:3.5), with 22 papers on its list, is the most active journal in this field.SURG ENDOSC is a publication of Springer which helps meet different patients' needs.The third one Annals of Surgery (8 publications, IF:10.3) has the highest IF out of the top ten, which provides the international medical community with information on significant contributions to the advancement of surgical science and practice.These three journals published 89 articles, covering nearly a quarter of all the eligible data (n = 363).

Contributions of countries/regions to global publication
A total of 363 papers are from 54 countries/regions.We select the top 11 published countries/regions as are shown in  4E is a co-citation review.We could tell that most color of lines was close to red and connection became more intense.In fact, 2020 was a bursting yearthe most articles (n = 92) were published, meanwhile, 12 countries published their first articles (n = 44), creating the biggest link net of countries' co-citation as in Fig. 4F.

Funding agencies analysis
A total of 217 funding agencies published articles of surgical smoke.

Analysis of authors
There are 1847 authors for these 363 articles between 2003 and 2022.We get 44 authors (Table 4) and their 166 articles on surgical smoke after changing "the minimum number of documents of an author" to 3.Among them, there are 2 authors publishing the most papers (n = 8), 2 authors of 7 papers, 2 authors of 5 papers, 12 authors of 4 papers, and 26 authors of 3 papers.All the articles are divided into five groups based on the author's publication.The articles in    expecting to see teamwork on surgical smoke between more authors, deeply and massively.

of keywords
A total of 1321 keywords were extracted, among which 96 keywords appeared at least 5 times, 45 keywords appeared at least 10 times, and 24 appeared at least 20 times.We extracted the top 20 appeared keywords in Table 5. "Surgical smoke" (n = 230) ranked first, followed by "covid-19" (n = 79) and "surgery" (n = 61).Figure 6A and B are based on the keywords appeared more than 10 times.The line between two circles means co-occurrence in papers, and thickness of the line is positively relative to the link strength.In Fig. 6A, red cluster denotes the management about surgical smoke; green cluster is the physico-chemical influence, while yellow and blue clusters are about the biological hazard.Figure 6B shows the gradually change of hot-spot keywords, and the latest hot-spot keywords is "COVID-19," "virus," "transmission," "exposure," and "risk," taking the place of "laparoscopy," "infection," and "smoke evacuation." Figure 6C is a top 20 keywords of strong citation burst."Electrocautery smoke" has a longest citation burst (n = 13), followed by "chemical composition" (n = 10) and "mutagenicity" (n = 9).Nevertheless, "transmission" and "systematic review" are latest appeared and still lasting in citation burst.Figure 6D, created and counted by CiteSpace, gives us an annual vision on keywords.All the 17 terms are deduced by the software indicate different themes in the last 20 years."Covid-19," "cancer," "surgery," and "smoke evacuation" stand for the hot spots in the past 5 years.

Co-cited references and reference burst
Based on the data from CiteSpace, there are 1105 co-cited references and 3786 links we obtained in all 363 articles.Among them, 38 references are cited more than 10 times, while 18 references are cited more than 20 times shown in Fig. 7A and B. All these 38 references are published later than 2013 and more specifically, 20 of them are published later than 2019.The most co-cited article is Han Deok Kwak authored "Detecting hepatitis B virus in surgical smoke emitted during laparoscopic surgery" published on Occupational and environmental medicine.It even has a frequency of up to 47 co-citations in 2020 due to the affecting characteristics of COVID-19 virus.We listed the top 10 co-cited reference in Table 6 on surgical smoke.Topics like "COVID-19," "surgical smoke hazard," and "surgical smoke evacuation or prevention" are included in these references.From Fig. 7C, the strongest citation bursts are shown red in the right blue bar.As time went by, the citations of older references became fewer and fewer, which could be explained by knowledge updating.The difference is that most of the references have had its citation burst in 2 years and ended after 5-year publication, but the reference from Kwak HD came to its burst citations after 3 years and didn't meet its end after 6-year publication.This result matches to and complementarily explains what has showed in Fig. 7A and B. All data are analyzed to created a cluster trend network and selected the top 10 clusters as in Fig. 7D, based on the titles of references by CiteSpace.This picture tells us the hot-spot trend in the past 20 years on surgical smoke.Of all the clusters, "laparoscopic surgery" ranked first, with "COVID-19 pandemic" and "surgical smoke" as second and third.Circle with purple rings in the outer layer denote crucial references between clusters.Reading these articles might be helpful to know the macroscopic trend view on surgical smoke in the latest 20 years.All the relative references have been listed in Table 7.

Discussion
In this study, we retrieved 363 eligible publications from 54 countries or regions in WoSCC on surgical smoke with time limited in 20 years (from January 1st 2003 to December 31st 2022).VOSviewer, CiteSpace, and Excel 2019 were used to collect and visualize the data to present the dynamic change and research trend in surgical smoke.Bibliometric analysis was performed in journals, countries/regions, funding agencies, authors, key words, and references.It is found that the yearly publication number and citation has increased in a low speed until a big surge occurred in 2020, a bursting year proved to reach the peak both in the publication and citation during the past 20 years.No doubt this phenomenon has something to do with the COVID-19 Pandemic.COVID-19 broke out at the year end of 2019, then instantly but extensively transmitted worldwide in 2020, and caught incomparably supreme attention of medical staff, epidemiological specialist, and even human beings on the earth.Many scholars from different regions turned to the studies about prevention and protection against COVID-19.In the field of surgical smoke, 230 papers have been published in the latest 3 years (between 2020 and 2022), compared with 133 papers published in previous 17 years (from 2003 to 2019).Still, the former is nearly twice more than the latter.
In all the countries or regions, USA has made the greatest contribution to surgical smoke, with the biggest number both in publication and citation.It is also the earliest and continuously researching country in this field.As the second most published and cited country, Italy owns the highest scores in average citation by its outstanding performance in publication after 2020.China, ranking the third in publication, has the most published funding agency: National Natural Science Foundation of China.Meanwhile, Finland, began its research at 2018, though, had 7 funding agencies with over three papers, and consequently ranked first in terms of funding agency number.As more countries joined in this field since 2020, more studies and co-operations will be performed to acquire new material or better equipment,  and eventually eliminate hazard from surgical smoke in the future.
In the aspect of authors, Roine, A and Oksala, N, who worked together in the same Finnish group with Karjalainen, M; Kontunen, A and Vehkaoja, A, are both the most published authors.In their study, they verified there were significant differences in particles of surgical smoke when electrosurgical devices worked on different tissues.Liver produced the most particles, followed by renal tissues and skeletal muscle, while fat, lung tissue, cerebral gray and white matter, and skin produced considerably less particulate mass [30].What's more, they introduced Differential Ion Mobility Spectrometry (DMS) and invented Automatic Tissue Analysis System (ATAS) to differentiate tissues originated from ten different organs and discriminate benign and malignant tissues based on surgical smoke, which might help clinical surgeons with margin assessment in the future [31][32][33].When it comes to citation, Zhu, Xueqiong, who worked together with Hu, Xiaoli in China, ranks first by surgical smoke among gynecologists.They proved the prevalent presence of HPV DNA in surgical smoke during cervical operation, moreover, HPV DNA sampled from surgeon's nasal epithelial was tested positive, though not infected [6,34].This study echoed and explained the suspicious HPVinfectious two carcinoma cases happened to male gynecologists [35].
The latest hot spot key words is about "COVID-19" and "virus," while "surgical smoke evacuation" is of great importance to prevent occupational exposure in surgery.The study trend might be about "surgical smoke" during "laparoscopic surgery" in the background of COVID-19.The most cocited reference is "Detecting hepatitis B virus in surgical smoke emitted during laparoscopic surgery" [36], written by Kwak HD and published on OCCUPATIONAL AND ENVI-RONMENTAL MEDICINE in 2016.The team collected a median volume gas of 375 L, with a high-efficient collector named Biosampler attached to the 5 mm trocar outlet, then the samples were transferred to laboratory in less than 1 h to get analyzed by using nested PCR. 10 of the 11 cases discovered HBV in surgical smoke.This is the first article about HBV isolation from surgical smoke of laparoscopy, which provide a feasible method to detect virus in a virus-infection surgery.Based on the potentially risky characteristics that virus could be transmitted through mucosal membrane into circulatory system, scholars adopted comprehensive measures to prevent the novel coronavirus from contaminating operating room, as in "Minimally Invasive Surgery and the Novel Coronavirus Outbreak: Lessons Learned in China and Italy" [37], the second most co-cited article, which told us to pay attention to the professionals' health and occupational safety besides patients'.While the third most co-cited article, "Awareness of surgical smoke hazards and enhancement of surgical smoke prevention among the gynecologists" gives us a relatively overall description about surgical smoke with protective measures included.
From the most co-cited and crucial references, we conclude four ways to minimize the risk of surgical smoke: Firstly, use wall suction with an in-line filter.Evacuating surgical smoke with wall suction is common practice, but the shortcoming is that the smoke might cycle into environment anywhere.So, wall suction with an in-line filter is recommended, which is convenient and adequate for many surgeries [38].The distance should be within 2-3 cm from smoke source for effectiveness [39].It can also be used in laparoscopic surgery to preventing smoke built up by attaching to an partially opened trocar [40].Secondly, apply smoke evacuator with filter.This method can be used in procedure generating larger volume of smoke [41].Additionally, there has been laparoscopy-used device with filter inside to evacuate automatically when smoke is detected, which proved effective for surgical smoke [13].Thirdly, personnel protection equipment should be required.The high efficiency particulate air (HEPA) filter, like N95 respirator, ought to be used for respiratory protection when necessary.Surgical masks can filter the vast majority of noxious chemicals in surgical smoke [22] but can not block particles less than 5 μm.In another word, mutagenic, carcinogenic gases, or viable biologic particles, if less than 5 μm, could be breathed in [40].While N95 respirator could filter over 95% 0.3-μm-sized particles, and reduce the inhalation exposure to surgical smoke by over two orders of magnitude [42].Disadvantage is that wearers may suffer from respiratory discomfort due to the tight closure and high-efficient filtration.At last, more efforts should be made in further training for surgical teams about surgical smoke, in approach of curriculum, examination or short video, in order to raise awareness of collective occupational security, work together and reduce occupational exposures [22,40,41].

Strengths and limitations
This study is the first one, to our knowledge, that comprehensively describe the document characteristics and study trends about "surgical smoke" by bibliometrics.Additionally, two kinds of widely used bibliometric software were employed to create document maps and visualize research data in each way, objectively showing the trends and hot spots and giving readers a general idea about surgical smoke.Nevertheless, this study have limitations.First, for the analysis of the bibliometric software, all articles were retrieved merely from WoSCC and the language was restricted to only English, therefore, certain important studies collected in other databases or in other languages might be omitted; secondly, we only selected data published in the last 20 years, some classic literature could not be covered, leading to certain biased results.

Conclusion
According to bibliometric analysis, the research on surgical smoke is drawing attention of more scholars in the world.Increasing number of countries or regions added in this field, and among them, USA, Italy, and China are playing important roles, however, more wide and intense cooperation is still in expectation.Particularly, under the influence of COVID-19, biological adverse of surgical smoke has been up to the premiere hotspot.With more studies that prove virus exists in surgical smoke, plus previous studies that chemical matters in surgical smoke are hazardous to human, there are more studies on protection or prevention from surgical smoke, but effective and simple measures or devices might still need further developing and examining.

Fig. 1 Fig. 2 A
Fig. 1 Flow chart of data collection

Fig. 3
Fig. 3 Density visualization of journals.Colors range from blue to green to yellow.The closer the color of the point to yellow, the higher the item weighs (Color figure online)

Fig. 4 A
Fig. 4 A Network visualization between countries/regions.The cluster of different color is determined by co-citing relationship.The closer two countries/regions are located to each other, the stronger their relatedness is.The strongest co-citation links between are represented by line.The higher the weight of an item, the larger the label and the circle of the item.B Average citation of countries/regions.The colors denote the average citation number in the right lower bar.C Average publish year of different countries/regions.Color of the circle denote the average publish year as in the right lower bar.D

Fig. 5 A
Fig. 5 A Percentage of documents from five publishing groups.B Authors' network visualization of co-authors.C Countries'/regions' network visualization of co-authors

Fig. 6 A
Fig. 6 A Network analysis of keywords co-occurrence.B Co-occurrence analysis of key words and time superposition.C Top 20 keywords of strong citation burst.D Terms from keywords cited more than 20 times.One circle means a keyword, inside which the color

Table 1
Publication number and impact factor of the top ten most-published journals

Table 3
ish funding agencies played a highlighted part in this field.There are 7 funding agencies of Finland appeared in this table, followed by USA (4 funding agencies included).China and Switzerland both have 2 agencies on the list while Korea has 1.

Table 3
Top 16 funding agencies of surgical smoke

Table 4
Authors of no less than three papers and document count and citations

Table 5
Co-occurrence and link strength of the top 20 keywords

Table 6
Top 10 co-cited references on surgical smoke