Transcatheter surgery of residual right ventricular outflow tract stenosis

Over the past 40 years, various types of prostheses have been developed for right ventricular outflow tract reconstruction. However, conduit stenosis and insufficiency due to valve degeneration occur frequently, decreasing the lifetime of patients. Transcatheter stenting of conduits does not always give favorable results and can lead to severe pulmonary regurgitation. The novel method of percutaneous pulmonary valve implantation is a good alternative to the surgical intervention according to data on long-term survival and quality of life

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

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

CHOICE OF THE IMPLANTABLE SUPPORT RINGS IN CONNECTIVE TISSUE DYSPLASIA AND SEVERE MITRAL REGURGITATION

Aim. To analyze the results of valve-securing surgery on mitral valve in connective tissue dysplasia.Material and methods. From 2011 to 2014 y., totally 171 patient included, with isolated mitral regurgitation. Patients were randomized to 2 groups. Mean age in the Group D — ring, and Group C — flex, was 57 [42;65] and 54 [41;63] year old, respectively (p=0,092). Part of males was 69 and 67% in the groups, respectively.Results. There were no cases of 30-day mortality. During 24 months of follow-up, in D ring and C flex groups, survival was 96,0±2,3% (95% CI 88,6-98,7%) and 94,3±2,8% (95% CI 85,5- 97,9%), resp. (р=0,899); no re-operation — 97,0±2,1% (95% CI 88,4-99,3%) and 100%, resp. (р=0,044); no return of significant mitral regurgitation 80,8±6,5% (95% CI 64,0-90,3%) and 92,8±3,1% (95% CI 83,4-97,0%), resp. (р=0,002).Conclusion. Application of flexible C flex rings in valve-securing operations makes it to achieve better results in middle-long-term post-operation period comparing to the usage of semi-hard support rings in patients with connective tissue dysplasia and severe mitral regurgitation

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

RADIOFREQUENCY DENERVATION OF PULMONARY ARTERY IN SURGERY OF DYSPLASTIC MITRAL VALVE DEFECTS WITH SEVERE PULMONARY HYPERTENSION

Pulmonary hypertension is an increase of pulmonary artery mean pressure for more than 25 mmHg at rest, measured by direct tensometry, and it includes a broad spectrum of diseases. Mechanisms of pulmonary hypertension are a connection of diverse vicious circles determining chronic progression of the disease, progradient worsening of patient’s condition and serious decline in life quality, and premature death. Severe pulmonary hypertension significantly raises risk of perioperation mortality and closely correlates with long-term survival. We propose an original technics of pulmonary artery denervation during one-stage cardiosurgical interventions, that confirmed its safety. Radiofrequency ablation of pulmonary artery in patients with dysplasia of connective tissue and high combined (precapillary and postcapillary) pulmonary hypertension, undergoing surgery for severe sympthomatic mitral insufficiency, is an effective procedure. An assessment is needed for short- and long-term results. Further studies will make it to know, whether the achieved hemodynamical benefits do turn to better clinical outcomes

THREE-DIMENSIONAL MODEL OF LEFT CHAMBERS OF THE HEART BASED ON ECHOCARDIOGRAPHY DATA: AN INSTRUMENT FOR DEVELOPMENT OF TRANSCATHETER VALVES

Aim. Comparative analysis of the acquired with EchoCG method parameters of the left chambers of the heart and of mitral valve in normal state and in restrictive type of failure with further building up three-dimensional models of these variants of the fibrous anulus geometry, and of the left atrium, left ventricle and its outgoing tract.Material and methods. The study was done using 3D transthoracal and transesophageal EchoCG on Philips iE33 (Philips Healthcare, USA) in 30 patients with unchanged mitral valve (n=15) and in ischemic mitral regurgitation (n=15). Spatial configuration of the anulus fibrosus was investigated, and mitral valve, spatial and volumetric parameters of the left atrium and left ventricle. Data was processed in SciLab 4.1.2 software and exported to CATIA 5 modelling system, where the acquired curves were combined to 2 solid thin-wall models, and after linking of the surfaces — to a hard-bodied model with required thickness of the walls.Results. All studied parameters revealed significant differences (p<0,001) in groups comparison. In restrictive type of insufficiency, sizes of fibrous anulus increase: intercomissural diameter by 22%, front-back — by 13%, perimeter — by 28%, surface — by 79%. End systolic and diastolic volumes of the LV increase more than 2 times, which is related with more prominent sphericity of the LV, than normally. Increase of LA more than 1,5 times also combines with its geometry change towards sphere. Three dimensional computer model of the left heart chambers changed as a result of ischemic mitral failure, is created. The model can be implemented in creation, analysis and prediction of medical devices for the position and/or realized as the full-sized mockups, test systems and phantoms for development and education.Conclusion. The investigation of mitral valve characteristics and of the left heart chambers by method of 3D transthoracal and transesophageal echocardiography makes it to obtain the baseline data necessary for creation of 3D computed models of the anatomic area normal and disordered. Such models can be implemented in the development of implanted devices constructions, preliminary tests of medical devices and in training