Total cavopulmonary connection with a new bioabsorbable vascular graft: First clinical experience.

OBJECTIVES To assess safety and clinical performance of a novel bioabsorbable vascular graft in pediatric patients with univentricular cardiac malformation who received surgical correction via an extracardiac cavopulmonary conduit. METHODS The implanted graft material is designed to attract patient's own cells and proteins, which trigger a cascade of physiological events leading to endogenous tissue restoration. As the graft resorbs progressively after implantation, components of native tissue including collagen, endothelial lining, and capillary blood vessels develop and organize into a natural tissue. Five patients (aged 4-12 years) received this new vascular graft as interposition between the inferior vena cava and the pulmonary artery. They were followed up to 12 months after surgery. The conduit was assessed by echocardiography, computed tomography and magnetic resonance imaging, including 4-dimensional flow. RESULTS All patients recovered from the procedure without complications. No device-related adverse events were reported. Two patients required interventional occlusion of aortopulmonary collaterals. At 12 months, there was a significant improvement in the patients' general condition. Imaging studies demonstrated anatomical (conduit diameter, length and wall thickness) and functional (blood flow pattern) stability of the bioabsorbable grafts in all patients with no significant changes at 12 months compared with early postoperative data. CONCLUSIONS Initial clinical experience with a novel absorbable graft underlines the potential of this new material to improve cardiac and vascular surgical procedures. In addition, better biocompatibility may reduce permanent implant-related complications. A longer follow-up is needed to assess the long-term effectiveness of biodegradable vascular grafts, including their ability to grow

Analysis of structure of intraventricular blood flow based on studies of architectonics of trabecular layer in left ventricle

Aims To overcome numerous contradictions in the knowledge of the blood transportation, a hypothesis was supposed asserting the swirling pattern of blood flow in the heart and main vessels which resembles tornado-like flows and which is widespread in nature. These flows can be exhaustively described by the exact solutions of the nonstationary hydrodynamic Navier-Stokes equations and the continuity equations for the class of viscous swirling flows offered by Kiknadze - Krasnov. Materials and methods Using morphometric studies of human and canine left ventricular casts and Multislice Computed Tomography it has been shown that the trabeculae in the ventricular cavity are oriented along the streamlines of the tornado-like flow of appropriate dimension. Moreover, this principle covers both the diastolic trabeculae of the inlet part of the left ventricle and the systolic trabeculae of the outlet part of the left ventricle. Results It is concluded that the main trabeculae function consists in the structural organization of the intraventricular tornado-like swirling flow of Kiknadze – Krasnov type. Conclusion The hydrodynamic analysis of the blood flow laws is indispensable for the development of new diagnostics criteria in cardiology, cardiac surgery optimization, the design of new implantable and paracorporal devices contacting with blood flow and mathematical and physical modeling of circulation

Simultaneous surgical correction of atrial fibrillation and aortic valve replacement: immediate results after surgery

Aim — To assess the results of simultaneous surgical correction of atrial fibrillation and aortic valve replacement. Materials and Methods — The retrospective analysis was held for the period of 2009-2016 of patients with atrial fibrillation (AF) and pathology of the aortic valve after combined operations. 68 patients were included in the study, the average age was 56 (51; 64) years; men 53%, women 47%. All patients were in III-IV functional class by NYHA classification. The duration of AF was 34 (24; 58) months. AF: persistent in 70,6%, paroxysmal in 29,4%. Calculated risks comprised: Euro Score II – 3,8 (2,4; 5,6), the risk of in-hospital mortality and the risk of total mortality by Ambler - 5,5 (3; 7,3) and 8 (6; 9), respectively. Results ― The average number of simultaneous procedures per one patient was – 4 (4; 4), minimum – 3, maximum – 5. In 100% cases was performed aortic valve and mitral valve correction and Maze IIIB procedure. CABG was performed in 20,6% of cases and tricuspid valve repair was performed in 67,6%. The total duration of operations was 6.3 ± 1.4 hours, the time of CPB: 208 (168; 224) min, aortic clamping time: 126 (119; 151) min. In-hospital mortality was 4.4%. The main non-lethal complications in the early postoperative period were heart failure, respiratory and renal insufficience, hemorrhage and transient neurological disorder. Conclusions ― There are few data demonstrating experience in performing of such complex surgical cases due to the severity of patients and small number of institutions having such experience. In our series of hospital mortality observations correlated with the calculated and accounted for 4.4%, which is an acceptable result in this group of patients

Our new tornado-compatible aortic valve prosthesis: notable results of hydrodynamic testing and experimental trials

Aims A shortcoming common to all existing designs of mechanical cardiac valve prostheses is an increased trombogenicity caused, among other factors, by the lack of hydrodynamic compatibility between the luminal part of the prosthesis and the patterned blood flow. The aim of the study is to design and test our new mechanical aortic valve prosthesis to exclude life-long anticoagulation treatment. Materials and methods Standard hydrodynamic tests of the new prosthetic valve have been carried out for comparing with the other existing valve designs. A new method for the heart valve prosthesis testing in a tornado-like flow has been developed. The valve function has been verified in a swine excluding the anticoagulation treatment during the period of time exceeding six months. Results The significant advantage of the new prosthesis in the standard hydrodynamic tests has been demonstrated. The tests in the tornado-like flow have shown that only this prosthesis allows maintaining the pattern, the head and flow rate characteristics of the tornado-like jet. Upon implanting the new prosthesis in the aortic position in a swine, the good performance of the valve without anticoagulation therapy has been confirmed in the course of more than six months. Conclusion Obtained has been the evidence of the merits of the new mechanical aortic valve owing to the due consideration of the hydrodynamic peculiarities of the aortic blood flow and the creation of the design providing the proper hydrodynamic compatibility

Accelerated Growth, Differentiation, and Ploidy with Reduced Proliferation of Right Ventricular Cardiomyocytes in Children with Congenital Heart Defect Tetralogy of Fallot

The myocardium of children with tetralogy of Fallot (TF) undergoes hemodynamic overload and hypoxemia immediately after birth. Comparative analysis of changes in the ploidy and morphology of the right ventricular cardiomyocytes in children with TF in the first years of life demonstrated their significant increase compared with the control group. In children with TF, there was a predominantly diffuse distribution of Connexin43-containing gap junctions over the cardiomyocytes sarcolemma, which redistributed into the intercalated discs as cardiomyocytes differentiation increased. The number of Ki67-positive cardiomyocytes varied greatly and amounted to 7.0–1025.5/106 cardiomyocytes and also were decreased with increased myocytes differentiation. Ultrastructural signs of immaturity and proliferative activity of cardiomyocytes in children with TF were demonstrated. The proportion of interstitial tissue did not differ significantly from the control group. The myocardium of children with TF under six months of age was most sensitive to hypoxemia, it was manifested by a delay in the intercalated discs and myofibril assembly and the appearance of ultrastructural signs of dystrophic changes in the cardiomyocytes. Thus, the acceleration of ontogenetic growth and differentiation of the cardiomyocytes, but not the reactivation of their proliferation, was an adaptation of the immature myocardium of children with TF to hemodynamic overload and hypoxemia