17 research outputs found
Myectomy versus alcohol septal ablation in patients with hypertrophic obstructive cardiomyopathy
OBJECTIVES: There is very little evidence comparing the safety and efficacy of alcohol septal ablation versus septal myectomy for a septal reduction in patients with hypertrophic obstructive cardiomyopathy. This study aimed to compare the immediate and long-term outcomes of these procedures. METHODS: Following propensity score matching, we retrospectively analysed outcomes in 105 patients who underwent myectomy and 105 who underwent septal ablation between 2011 and 2017 at 2 reference centres. RESULTS: The mean age was 51.9 ± 14.3 and 52.2 ± 14.3 years in the myectomy and ablation groups, respectively (P = 0.855), and postoperative left ventricular outflow tract gradients were 13 (10-19) mmHg vs 16 (12-26) mmHg; P = 0.025. The 1-year prevalence of the New York Heart Association class III-IV was higher in the ablation group (none vs 6.4%; P = 0.041). The 5-year overall survival rate [96.8% (86.3-99.3) after myectomy and 93.5% (85.9-97.1) after ablation; P = 0.103] and cumulative incidence of sudden cardiac death [0% and 1.9% (0.5-7.5), respectively P = 0.797] did not differ between the groups. The cumulative reoperation rate within 5 years was lower after myectomy than after ablation [2.0% (0.5-7.6) vs 14.6% (8.6-24.1); P = 0.003]. Ablation was associated with a higher reoperation risk (subdistributional hazard ratio = 5.9; 95% confidence interval 1.3-26.3, P = 0.020). At follow-up, left ventricular outflow tract gradient [16 (11-20) vs 23 (15-59) mmHg; P < 0.001] and prevalence of 2+ mitral regurgitation (1.1% vs 10.6%; P = 0.016) were lower after myectomy than after ablation. CONCLUSIONS: Both procedures improved functional capacity; however, myectomy better-resolved classes III-IV of heart failure. Septal ablation was associated with higher reoperation rates. Myectomy demonstrated benefits in gradient relief and mitral regurgitation elimination. The results suggest that decreasing rates of myectomy procedures need to be investigated and reconsidered. © The Author(s) 2020. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved
Long-Wave Instability of Advective Flows in Inclined Layer with Solid Heat Conductive Boundaries
We investigate the stability of the steady convective flow in a plane tilted
layer with ideal thermal conductivity of solid boundaries in the presence of
uniform longitudinal temperature gradient. Analytically found the stability
boundary with respect to the long-wave perturbations, find the critical Grashof
number for the most dangerous among them of even spiral perturbation.Comment: in Russian, 18 pages, 5 figures, submited to Appl. mechanics and
physics, RAS Siberian brunch, Novosibirsk, Russia; Key words: advective flow,
oblique layer, a longitudinal temperature gradient, long-wave instabilit
Myectomy versus alcohol septal ablation in patients with hypertrophic obstructive cardiomyopathy
Meshalkin National Medical Research Center
We present three cases of successful transatrial transcatheter valve-in-valve implantation in patients with bioprosthetic mitral valve dysfunction. Patients with a high surgical risk, with severe heart failure due to bioprosthetic mitral valve dysfunction, were implanted with transcatheter prostheses using the transatrial approach.Transesophageal echocardiography and fluoroscopy-guided transcatheter mitral prosthetic valve positioning was performed. With a cardiac pacing at 180 bpm, a transcatheter valve was implanted. The transcatheter valves functioned properly after surgery. The patients were discharged in satisfactory condition
РЕКОНСТРУКЦИЯ ВЫХОДНОГО ОТДЕЛА ПРАВОГО ЖЕЛУДОЧКА ВО ВРЕМЯ ПРОЦЕДУРЫ РОССА: СРАВНЕНИЕ ЛЕГОЧНЫХ АЛЛОГРАФТОВ И КСЕНОПЕРИКАРДИАЛЬНЫХ КОНДУИТОВ
Aim The aim of this study was to compare the results of right ventricular outflow tract reconstruction during the Ross procedure with pulmonary allografts versus diepoxide-treated pericardial xenografts. Methods Between 1998 and 2015, 793 adult patients underwent the Ross procedure. The right ventricular outflow tract reconstruction was performed with pulmonary allografts in 185 patients, diepoxide-treated pericardial xenografts in 402 patients. Two groups of patients (122 patients in each group) were allocated using «propensity score matching»: the allograft group (pulmonary allograft) and the xenograft group (xenograft). Surgical results in two groups were assessed. Results The overall early mortality rate in both groups was 2.5%. The mean follow-up was 5,1±2,6 years in the allograft group and 5,2±2,8 years in xenograft group (p = 0,692). The 5-year survival rate did not differ between the study groups (93,7±2,6% in the allograft group versus 94,02±2,4% in the xenograft group, p = 0.748). The peak pressure gradients across the right ventricular outflow tract in early and mid-term follow-up were significantly higher in the xenograft group. Two patients in the xenograft group underwent redo surgeries due to the graft failure. There were no reoperations in the allograft group (p = 0,176). The freedom from right ventricular outflow tract reoperations was 96,3±2,7% for the xenograft group. Conclusion The diepoxide-treated pericardial xenografts demonstrates acceptable haemodynamic results at the mid-term follow-up and could be considered as an alternative to allografts for right ventricular outflow tract reconstruction during the Ross procedure in adults. Further study focused on the assessment of the longterm results are required.Цель Сравнить результаты применения легочных аллографтов и эпоксиобработанных ксеноперикардиальных кондуитов во время процедуры Росса. Материалы и методы В период с 1998 г. по 2015 г. 793 взрослым пациентам (≥18 лет) выполнена процедура Росса. В 185 случаях для реконструкции выходного отдела правого желудочка использовались легочные аллографты, в 402 – эпоксиобработанные ксеноперикардиальные кондуиты. C помощью методики «propensity score matching» были сформированы две сопоставимые группы по 122 пациента: группа ЛА (легочный аллографт) и группа КГ (ксенографт). Проведен сравнительный анализ результатов оперативного лечения в обеих группах. Результаты Ранняя летальность составила 2,5% в обеих группах. Средний срок наблюдения для группы ЛА составил 5,1±2,6 лет, для группы КГ – 5,2±2,8 лет (p = 0,692). Группы не различались по показателю отдаленной выживаемости: 93,7±2,6% и 94,02±2,4% через 5 лет после операции, для групп ЛА и КГ соответственно (p = 0,748). Пиковый градиент на выходном отделе правого желудочка в раннем и среднеотдаленном послеоперационном периодах был статистически значимо выше в группе КГ. В группе КГ выполнено 2 повторные операции по поводу дисфункции ксенокондуита, в группе ЛА повторных операций не было (р = 0,176). Свобода от реопераций на выходном отделе правого желудочка в группе КГ составила 96,3±2,7%. Заключение Эпоксиобработанные ксеноперикардиальные кондуиты демонстрируют удовлетворительные гемодинамические показатели в среднеотдаленном периоде и могут быть использованы в качестве альтернативы легочным аллографтам при реконструкции выходного отдела правого желудочка во время процедуры Росса у взрослых. Необходим анализ отдаленных результатов
ТКАНЕИНЖЕНЕРНЫЙ МАТРИКС, МОДИФИЦИРОВАННЫЙ БИОЛОГИЧЕСКИ АКТИВНЫМИ МОЛЕКУЛАМИ ДЛЯ НАПРАВЛЕННОЙ РЕГЕНЕРАЦИИ ТКАНЕЙ
Search of an ideal polymer for the preparation of the artificial scaffolds is an important goal of vascular tissue engineering. Biofunctionalization of the scaffolds may assist in creation of the bioactive environment at the site of implantation. Combination of biodegradable polymers and growth factors may be an appropriate approach for the directed regeneration of the vascular tissues.Purpose. To assess tissue reaction to nonwoven scaffolds prepared from poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/polycaprolactone (PCL) with vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and stromal-derived growth factor-1α (SDF -1α) implanted into the rat pericardial sac.Materials and methods. Nonwoven PHBV/PCL scaffolds with and without VEGF, bFGF, and SDF -1α were prepared using electrospinning and implanted into the rat pericardial sac for 2 weeks, 1, 2, and 3 months with the further histological examination.Results. Implantation of the scaffolds did not cause any inflammatory reaction. We detected an active neoangiogenesis in both PHBV/PCL/VEGF and PHBV/PCL/SDF -1α scaffolds and adjacent tissues at all the time points. Moreover, we observed a considerable cell infiltration and production of extracellular matrix in PHBV/PCL/SDF -1α scaffolds. PHBV/PCL/bFGF scaffolds were colonized by fibroblasts and were surrounded by a connective tissue capsule. Therefore, growth factors retained their bioactivity in the tissues during the whole time of the experiment.Conclusions. Incorporation of the growth factors into biodegradable polymers is an appropriate approach for the creation of thetissue engineered scaffolds for directed tissue regeneration. VEGF, bFGF, and SDF -1α may be used for the creation of biodegradable vascular graft promoting de novo formation of the vascular tissue after the implantation.Важной задачей тканевой инженерии кровеносных сосудов является поиск материалов для изготовления искусственного матрикса, применяемого в качестве основы для восстановления тканей. Особый интерес представляет модификация матриксов для создания биологически активной среды в месте имплантации. Возможным решением данной проблемы может стать комбинирование биодеградируемых полимеров, ростовых факторов и хемоаттрактантных молекул.Цель. Оценить реакцию окружающих тканей на нетканные матриксы из полигидроксибутирата/валерата (ПГБВ) и поликапролактона (ПКЛ) с VEGF, bFGF и SDF -1α, имплантированные на переднюю поверхность сердца крыс.Материалы и методы. Нетканные матриксы ПГБВ/ПКЛ, немодифицированные и модифицированные сосудистым эндотелиальным фактором роста (VEGF), основным фактором роста фибробластов (bFGF) или хемоаттрактантной молекулой SDF -1α, изготавливали методом двухфазного электроспиннинга и имплантировали на переднюю поверхность сердца крыс сроком на 2 недели, 1, 2 и 3 месяца. По истечении срока наблюдения матриксы эксплантировали с прилежащими тканями и проводили гистологическое исследование.Результаты. Имплантация пустых и биофункционализированных ПГБВ/ПКЛ-матриксов не вызывала местной воспалительной реакции. В матриксах с VEGF и прилежащих к ним тканях отмечали активный ангиогенез на протяжении 3 месяцев. Образцы этой группы отличались умеренной клеточной инфильтрацией. ПГБВ/ПКЛ+bFGF-матриксы были значительно заселены фибробластами и окружены наиболее выраженной соединительнотканной капсулой. В матриксах с инкорпорированным SDF -1α наблюдали активную инфильтрацию клетками, синтезирующими внеклеточный матрикс, и неоангиогенез с образованием более крупных кровеносных сосудов относительно всех исследуемых образцов. Таким образом, инкорпорированные молекулы после высвобождения из матрикса проявляли биологическую активность в окружающих тканях в течение всего эксперимента.Заключение. Введение ростовых факторов и хемоаттрактантных молекул в биодеградируемые полимеры позволяет создавать тканеинженерные матриксы, обладающие бионаправленностью своего действия. Данный подход с использованием VEGF, bFGF и SDF -1α может быть использован в разработке функционально активного биодеградируемого сосудистого графта, способствующего формированию in situ ткани de novo после имплантации
The first experience of implantation of the transcatheter aortal valve prosthesis “MedLab-KT”
Aim. Transcatheter aortic valve replacement in patients with high and extremely high risk has become a routine procedure in many cardiac surgery clinics. Until recently, there were no transcatheter prostheses produced within Russia. This article analyzes the results of applying the first domestic transcatheter aortic valve prosthesis MedLabKT. Material and methods. In the period from June 2018 to October 2018, 7 operations of transcatheter aortic valve replacement were made using the MedLabKT prosthesis. In all cases, implantation was performed by transapical access.Results. We noted one death. In all cases, paraprosthetic regurgitation was not registrated or was not significant. There are no cases of dislocation of the prosthesis. There were no complications associated with access. In one case, implantation was complicated by myocardial infarction.Conclusion. The first experience of implantation demonstrated the efficacy and safety of using the MedLabLT prosthesis for transcatheter aortic valve replacement. The analysis of longterm results is required
Stability of steady thermal convection in a tilted rectangular cavity in low-mode approximation
The results of transcatheter mitral valve replacement
Mitral insufficiency is one of the most common valvular pathology. In almost half of the patients, standard mitral valve replacement using extracorporeal circulation cannot be used due to the high risk of complications. In recent years, for this category of patients a method for transcatheter mitral valve replacement has been proposed. Now it is known about a few transcatheter prostheses for implantation into the native mitral valve that are at the stage of preclinical or clinical trials. This article analyzes the results of the clinical use of prostheses for transcatheter mitral valve replacement