Relevance. The frozen elephant trunk technique is recognized as a safe and effective method of surgical treatment for aneurysms and dissections of the thoracic aorta. The hybrid prostheses, available on the territory of the Russian Federation, are foreign-made, characterized by a high price, and, accordingly, unpopular. Due to unavailability of domestic hybrid prostheses in the home market, the development of domestic prosthesis is the key point to further progress in aortic surgery in the Russian Federation. Aim . The aim of the study was to evaluate the implantation characteristics of prototype hybrid thoracic aorta prosthesis in the pig model and the transformation of the prosthesis in the postoperative period. Material and Methods . The hybrid prosthesis consists of two parts including the vascular part and a stent graft. The prosthesis is made of Dacron and Z-shaped nitinol wire stents. A Landrace pig aged six months with body weight of 120 kg underwent open reconstruction of the descending aorta through the left-sided lateral thoracotomy, under conditions of extracorporeal bypass with a roller pump from the left subclavian artery to the descending aorta. The animal was removed from the experiment after six months as planned. The macro- and microscopic evaluation of the removed implant was performed. Results . The technical success of implantation of hybrid stent graft prototype was confirmed. Macroscopy of the stent graft, removed after six months, demonstrated a complete coverage of the neointimal inner surface of the synthetic prosthesis. The lumen of the product was patent. Histological examination revealed the neointima presented as a structured connective tissue without signs of inflammation. The luminal surface was lined with a single layer of evenly spaced endotheliocytes. The thickness of the neointima in the vascular part was significantly greater than in the stent-graft part ( p = 0.0121). Conclusion. The study demonstrated the technical feasibility of implantation of the prototype hybrid prosthesis developed by Angioline Research LLC. The effectiveness of sealing impregnation was confirmed by the absence of active signs of bleeding during the perioperative and early postoperative stages. The prosthesis demonstrated satisfactory bio- and hemocompatibility.

Background .The availability of drug-eluting stents with evidence-based clinical safety and efficacy produced in the Russian Federation is one of the relevant goals for successful treating of patients with coronary artery disease, including acute coronary syndrome. Aim To confirm clinical rationale and experimental feasibility of the first Russian drugeluting stent, Calypso (Angioline, LLC, Russian Federation), for the clinical practice. Methods. The study included four phases. The first phase was aimed at selecting the optimal stent platform with superior healing properties. Then, the selected Russian coronary stents based on the optimal platforms underwent preclinical studies. The third phase included the clinical assessment using optical coherence tomography (OCT) in order to confirm the preclinical results. The last phase was focused on assessing clinical safety and efficacy of the Russian coronary stent based on the comparative analysis of angiographic findings within the 12-months follow-up. Results. At the first phase, biodegradable polymer sirolimus-eluting stent showed superior healing properties in comparison with the healing score of 18±14.97 for Orsiro stents (Biotronik, Germany) versus 25.6±1.0 for Xience stents (Abbott Vascular, USA) versus 32.5±20.3 for Synergy (Boston Scientific, USA), p<0.001. The Russian stent consistently demonstrated a high healing profile in preclinical and OCT clinical studies. The results of the comparative clinical study proved the clinical safety and efficacy of the Russian stent that was similar to the best foreign stents. None of the differences in the incidence of binary restenosis were found between the groups (p<0.05). Conclusion. The biodegradable polymer sirolimus-eluting stent Calypso manufactured in the Russian Federation demonstrated superior neointimal healing pattern with no signs of chronic inflammation in the experiment. This stent reported high neointimal healing properties according to the clinical OCT study. According to the angiographic findings, the incidence of binary restenosis between the Russian biodegradable polymer sirolimus-eluting stent and durable polymer everolimuseluting stents was similar at the 12-months follow-up (p>0.05).

Background. Since 1996, thrombolytic therapy with tissue plasminogen activator has traditionally been the first-line treatment for patients with ischaemic stroke. However, the results of recent randomised trials have shown the advantage of mechanical thrombectomy over thrombolytic therapy for successful revascularisation of brain arteries and improvement of clinical outcomes. Owing to the development of endovascular surgery, mechanical thrombectomy has now become an effective and safe method for treating ischaemic stroke resulting from the occlusion of large cerebral arteries.Aim. The main aim of this study was to develop a prototype for a combined transcatheter system to be used for mechanical thrombectomy.Methods. During the implementation of the project, we first analysed the data on the problems to justify the choice of standard sizes of a stent retriever and an aspiration catheter and to determine the basic set of physical–mechanical, functional and biomedical characteristics of the system. A prototype of a combined transcatheter system for mechanical thrombectomy, which comprises an aspiration catheter and a stent retriever, was manufactured. Moreover, preclinical tests were conducted to study the physical properties of the developed prototype and assess its effectiveness. Results. Data from preclinical tests showed a level of radial stiffness of the prototype that was comparable to that of a similar device on the market, satisfactory visualisation under angiography and high efficiency while performing mechanical thrombectomy in vitro and in vivo tests.Conclusions. Studies on the prototype of the combined transcatheter system for thrombectomy have shown positive results in preclinical trials.Received 5 December 2019. Revised 18 December 2019. Accepted 20 December 2019.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.

Актуальность. С 1996 г. тромболитическая терапия с тканевым активатором плазминогена традиционно была первой линией лечения пациентов с ишемическим инсультом. Однако результаты последних рандомизированных исследований показали преимущество механической тромбэктомии над тромболитической терапией как в реваскуляризации артерий головного мозга, так и в улучшении клинических результатов. Благодаря развитию эндоваскулярной хирургии механическая тромбэкстракция является эффективным и безопасным методом лечения ишемического инсульта, возникающего вследствие окклюзии крупных церебральных артерий. Цель. Разработка прототипа комбинированной транскатетерной системы для внутрисосудистой тромбэктомии. Методы. Проведен анализ данных по проблематике для обоснования выбора типоразмеров стента-ретривера и аспирационного катетера, а также для определения основного набора физико-механических, функциональных и медико-биологических характеристик системы. Изготовлен прототип комбинированной транскатетерной системы для механической тромбэктомии из церебральных сосудов, состоящий из аспирационного катетера и стент-ретривера. Изучены физические свойства прототипа, оценена его эффективность. Результаты. Доклинические испытания показали сопоставимую радиальную жесткость опытного образца с аналогичным устройством на рынке, удовлетворительную визуализацию рентгеноконтрастных меток под ангиографической установкой, а также высокую эффективность тромбэктомии в испытаниях in vitro и in vivo. Выводы. Прототип комбинированной транскатетерной системы для тромбэктомии продемонстрировал положительные результаты доклинических испытаний.

We present here the results of experimental and theoretical grounding of the design of the first Russian aortic valve bioprosthesis for sutureless implantation. A carcase of superelastic titanium nickelide was tested by simulation and empirical methods and consistent results were obtained. Methods for modeling the biological material and synthetic sleeving on the carcase were developed.

The review deals with the evolution of interventional coronary procedures and development of the state-of-art coronary stent market. Emphasis in the review is placed on comprehensive analysis of technical characteristics of the world’s most popular coronary stents versus a Russian bioresorbable sirolimus-eluting stent “Calipso”.Received 13 January 2017. Accepted 17 March 2017.Conflict of interest: Kudryashov A.N., Trebushat D.V. are “Angioline” Company employees, the producer of “Kalipso” coronary stent. Kretov E.I. served as executive editor of “Endovascular surgery” section. All other authors declare no conflict of interest.

The aim of the investigation is the development of the heart valve prosthesis and transcatheter delivery system for the replacement of a failed mitral biological prosthesis. Materials and Methods. Calculations and construction of three-dimensional models and drawings have been performed in the Computer-Aided Design environment CATIA V5 (Dassault Systemes, France). The process of the product shaping has been simulated by the terminal element analysis in Abaqus Software (Dassault Systemes, France). Prototypes of the stents have been made of nitinol tubes by Angioline Interventional Device company (Novosibirsk, Russia) using a laser cutting technique with outer diameter of 7.0 mm and wall thickness 0.5 mm (Vascotube GmbH, Germany). Bioprosthetic leaflets and the cover have been cut using a laser station Melas-Cardio (Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk). The valve assemblage has been hand-made using surgical sutures 8/0. Results. The self-expanding biological prosthesis design is based on the anatomy of the left heart, considering the presence of previously implanted bioprosthesis in the mitral position. The nitinol stent of cellular structure consists of a cuff, the body and the outlet part. It is round-shaped that corresponds to the shape of a standard suture bioprostheses. One-third of the cuff adjacent to the mitral-aortic contact area forms a 70-degree angle to the mitral annulus plane. In the outlet part there are three hook retainers of the previously implanted bioprosthetic leaflets. For prosthesis repositioning during implantation there are two-way (on the cuff and on hook retainers) retainers and complementary latches in the central catheter of the delivery system, they providing the connection of the valve with the delivery system in both transapical and transatrial access. The valve is provided with radiopaque markers to facilitate the positioning. Valve leaflets and the cover have been made of porcine pericardium treated with epoxy compound. The cover coats the inner surface of the stent cuff and a part of the body. Conclusion. We developed the prototype of a device for the redo transcatheter mitral valve implantation. Further preclinical testing is necessary to evaluate a safety of the medical device.