REVIEW ARTICLE An Investigation of Topics and Trends of Tracheal Replacement Studies Using Co-Occurrence Analysis Fariba Ghorbani, MD, PhD, 1 Mansoureh Feizabadi, PhD, 2 Roya Farzanegan, MD, PhD, 1 Esmaeil Vaziri, PhD, 3 Saeed Samani, PhD, 4 Seyedamirmohammad Lajevardi, 5 Lida Moradi, PhD, 4 and Mohammad Behgam Shadmehr, MD 1 This study evaluated tracheal regeneration studies using scientometric and co-occurrence analysis to identify the most important topics and assess their trends over time. To provide the adequate search options, PubMed, Scopus, and Web of Science (WOS) were used to cover various categories such as keywords, countries, organizations, and authors. Search results were obtained by employing Bibexcel. Co-occurrence analysis was applied to evaluate the publications. Finally, scientific maps, author’s network, and country contributions were depicted using VOS- viewer and NetDraw. Furthermore, the first 25 countries and 130 of the most productive authors were determined. Regarding the trend analysis, 10 co-occurrence terms out of highly frequent words were examined at 5-year intervals. Our findings indicated that the field of trachea regeneration has tested different approaches over the time. In total, 65 countries have contributed to scientific progress both in experimental and clinical fields. Special keywords such as tissue engineering and different types of stem cells have been increasingly used since 1995. Studies have addressed topics such as angiogenesis, decellularization methods, extracellular matrix, and me- chanical properties since 2011. These findings will offer evidence-based information about the current status and trends of tracheal replacement research topics over time, as well as countries’ contributions. Keywords: trachea, scientometrics, replacement, transplantation, therapeutic substitution, regeneration, trends Introduction T racheal stenosis is caused by many different eti- ologies. Postintubation tracheal stenosis (the most common cause), congenital strictures, tracheomalacia, as well as direct tracheal traumas are very much challenging in the field of thoracic surgery. 1 Most of these lesions are treatable with conventional methods of surgery, that is, re- section and anastomosis. Bronchoscopic dilatation, core out of granulation tissues, and laser therapy are also among the methods that can be employed in some cases. 2 The idea of using tracheal substitutes was raised by Belsey’s opinion, which in turn was based on the impossi- bility of tracheal resection more than 2 cm. 3 However, studies conducted from 1950 to 1970 showed that this limitation could be tackled. 4 At the moment, considering the experimental progress in the field of tracheal surgery, it is feasible to resect one half of the tracheal lesion in adults and one third in children, and make a safe anastomosis. For the lengthier lesions, tracheal substitutes will be required. Other factors such as age, regional anatomy, pathology, and pre- vious treatments also affect this limitation. 5 Therefore, many studies have been conducted to provide proper tra- cheal substitutes with very limited success. In this regard, the aim of these studies varies over time. Herein is a review of these dynamic attempts. Stents and prostheses Different types of prostheses made of materials such as stainless steel, silicon (Montgomery T-tube, Dumon, Rush, Orlowski), Teflon, Vitallium, glass, polyethylene, Avalon, and poly (vinyl alcohol) have been tested on animals and human beings in some cases. However, the most popular are 1 Tracheal Diseases Research Center (TDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2 Sabzevar University of Medical Sciences, Faculty of Medicine, Sabzevar, Iran. 3 University of Zabol, Faculty of Humanities, Department of Information Science and Knowledge Studies, Zabol, Iran. 4 Department of Tissue Engineering & Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran, Iran. 5 Faculty of Health, York University, Toronto, Canada. TISSUE ENGINEERING: Part B Volume 23, Number 2, 2017 ª Mary Ann Liebert, Inc. DOI: 10.1089/ten.teb.2016.0254 118 Downloaded by Guangxi University for Nationalities from online.liebertpub.com at 02/24/18. For personal use only. brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by Sabzevar University of Medical Sciences Electronic Publications