ObjectiveTo compare the outcomes of mechanical prosthetic versus bioprosthetic replacement of tricuspid valve. Methods We retrospectively analyzed the clinical data of 344 patients underwent tricuspid valve replacement (TVR) in Guangdong General Hospital between January 2000 and December 2010. There were 227 female and 117 male patients with their age of 8-74 (42.0±13.3) years. We allocated the patients into two groups: 168 patients (48.8%) at age of 37.0±11.6 years underwent mechanical tricuspid valve replacement (the MTVR group) and 176 (51.2%) patients at age of 46.0±13.4 years underwent biological tricuspid valve replacement (the BTVR group). Follow-up data were obtained via patients' visiting the outpatient clinic, telephone or mail contacts. ResultsThe mean follow-up time was 5.7 years (ranged from 2 months to 12.6 years). In the BTVR group, 149 patients survived to discharge from hospital, and 144 patients were followed-up successfully, giving a 96.6% follow-up rate. Early mortality (within 30 days post-operation) occurred in 29 patients (16.5%), and 14 patients (7.9%) died after 30 days post-operation. Eighteen bioprosthetic valve degeneration was found during follow-up, and infective endocarditis in 3 patients. In the MTVR group, 152 patients survived to discharge from hospital, 142 patients (93.4%) were followed-up. Early mortality in 13 patients (7.7%), and 14 patients (8.3%) died after 30 days post-operation. Nineteen patients suffered from mechanical prosthesis obstruction, no infective endocarditis patients was found in the MTVR group. There was no statistical difference between the BTVR group and the MTVR group in mortality rate (24.4% versus 16.1%, P=0.054) and in reoperation rate (4.2% versus 9.9%, P=0.051), respectively．There were statistical differences in long-term survival rates between the BTVR group and the MTVR group with 1 year survival rate(78% vs. 89%), 5 years survival rate(74% vs. 86%), and 10 years survival rate (66% versus 78%) with P value at 0.003. ConclusionsThis study suggests that the type of implanted prosthesis in tricuspid replacement does not affect long-term outcomes or the reoperation rate. The survival rate is higher in the MTVR group than that in the BTVR group, which may contribute to younger age in the MTVR group. There is a tendency in higher infective endocarditis incidence in the BTVR group than that in the MTVR group.
ObjectiveTo study the hemocompatibility of bioprosthetic heart valve materials respectively based on glutaraldehyde and non-glutaraldehyde treatment. MethodsFresh bovine pericardium was treated with glutaraldehyde or non-glutaraldehyde after adipose tissue was removed. To evaluate the hemocompatibility of the two bioprosthetic heart valve materials, hemolysis test, in vitro fibrinogen adsorption experiment, platelet adhesion experiment, thrombin-antithrombin complex (TAT) test, complement activation assay and ex vivo circulation experiment were performed. ResultsThe hemolysis test results demonstrated that both of the materials showed hemolytic rates lower than 5%. The results of TAT test and complement activation assay showed no statistical differences among the two materials and the blank control group. Compared to the bioprosthetic heart valve materials with glutaraldehyde-based treatment, the materials with non-glutaraldehyde-based treatment showed significantly decreased fibrinogen adsorption, platelet adhesion and thrombosis. ConclusionCompared to the bioprosthetic heart valve materials with glutaraldehyde-based treatment, the materials with non-glutaraldehyde-based treatment show better hemocompatibility.
ObjectiveTo study the biocompatibility of bioprosthetic heart valve material with a non-glutaraldehyde-based treatment, and to provide the safety data for the clinical application. MethodsAll the tests were conducted according to GB/T16886 standards. The in vitro cytotoxicity was determined by methyl thiazolyl tetrazolium assay. Fifteen guinea pigs were divided into a test group (n=10) and a control group (n=5) in the skin sensitization test. Three New Zealand white rabbits were used in the intradermal reactivity test. Five sites on both sides of the rabbit back were set as test sites and control sites, respectively. In the acute systemic toxicity test, a total of 20 ICR mice were randomly assigned to 4 groups: a test group (polar medium), a control group (polar medium), a test group (non-polar medium) and a control group (non-polar medium), 5 in each group. Forty SD rats were divided into a test group (n=20) and a control group (n=20) in the subchronic systemic toxicity test. ResultsThe viability of the 100% extracts of the bioprosthetic heart valve material with a non-glutaraldehyde-based treatment was 75.2%. The rate of positive reaction was 0.0%. The total intradermal reactivity test score was 0. There was no statistical difference in the body weight between the test group and control group in the acute systemic toxicity test. There was no statistical difference in the body weight, organ weight, organ weight/body weight ratio, blood routine test or blood biochemistry between the test group and control group in the subchronic systemic toxicity test. ConclusionThe bioprosthetic heart valve material with a non-glutaraldehyde-based treatment has satisfying biocompatibility, which conforms to relevant national standards. The material might be a promising material for application in valve replacement.
Objective To investigate the biological and biomechanical characteristics of acellular porcine aortic valve with dye mediated photo oxidation so that a new and better bioprosthetic valve materials can be obtained. Methods Thirty porcine aortic valves were divided into three groups with random number table. Acellular valves (n=10) were stabilized by dye mediated photo oxidation in dye mediated photo oxidation group; acellular valves (n=10) were stabilized by glutaraldehyde in glutaraldehyde group; and acellular valves (n=10) were acellularized only in acellular valves group. Thickness, appearance, histology, water content, shrinkage temperature, breaking strength and soluble protein level of acellular porcine aortic in three groups were tested respectively. Results There were light blue, soft, flexible and unshrinking valves in dye mediated photo oxidation group. Compared to valves in glutaraldehyde group, valves in dye mediated photo oxidation group had lighter thickness（0.26±0.09mm vs. 0.38±0.08mm，Plt;0.05）, more water content（86.30%±4.03% vs. 71.10%±3.23%，Plt;0.05）, and lower shrinkage temperature （76.30±0.70℃ vs. 87.70±0.30℃，Plt;0.05）; while these indexes had no statistically significant differences compared to those in acellular valves group. At the same time, compared to valves in acellular valves group, valves in dye mediated photo oxidation group had more breaking strength（17.33±2.65 mPa vs. 9.11±0.95 mPa，Plt;0.05） and lower soluble protein level（0.039%±0.013% vs. 0.107%±0.024%，Plt;0.05）; while these indexes had no statistically significant differences compared to those in glutaraldehyde group. Conclusion Acellular porcine aortic valve stabilized by dye mediated photo oxidation has nice biological and biomechanical characteristics.
Along with the coming of aged society, the prevalence of heart valvular disease is significantly increasing, and the use of bioprosthetic valves for treating patients with severe valve disease has increased over the last two decades. As a consequence, a growing number of patients with surgical bioprosthesis degeneration is predicted in the near future. In this setting, valve-in-valve (ViV) transcatheter aortic/mitral valve replacement (TAVR/TMVR) has emerged as an alternative to redo surgery. A deep knowledge of the mechanism and features of the failed bioprosthetic heart valve is pivotal to plan an adequate procedure. Multimodal imaging is fundamental in the diagnostic and pre-procedural phases. The immediate and mid-term clinical and hemodynamic results have demonstrated the safety and feasibility of ViV techniques, but the development of these techniques faces several specific challenges, such as coronary obstruction, potential post-procedural mismatch and leaflet thrombosis. This article reviews the current status and prospects of ViV-TAVR technology in the treatment for biological valve degeneration, and suggests that ViV-TAVR should be promoted and implemented in existing medical centers with good surgical aortic valve replacement experience, so as to provide better treatment for patients.
Objective To explore morphological recellularization level of bioprosthetic valve scaffold (BVS) and to provide researching means for fabricating tissue engineered heart valve in vitro.Methods The homograft bioprosthetic aortic tube valve was selected as BVS, which was conserved by liquid nitrogen, and its endothelial cells (ECs) were removed by 0.1% sodium dodecylsulphate (SDS). As implantation cells, the endothelial cells (ECs) differentiating from human bone marrow mesenchymal stem cells (MSCs) in vitro were implanted with high-density seeding (gt;10 5 cells/cm2) on the BVS, which was covered by fibronectin (80 μg/ml) in advance. The complex structure was statically cultured in DMEM (high glucose) with 20% FBS and VEGF (10 ng/ml) for about 20 days in vitro and stained by 0.5% AgNO3. The morphological structure was observed and photographed by stereomicroscope to detect the recellularization level. Results The ECs of the bioprosthetic valve were notonly removed completely, but also the collagen fiber and elastic fibers were reserved. The ECs differentiating from MSCs were successfully implanted on the HBS, whose recellularization levels on 7th, 14th and 20th day were 73%, 85%, and 92% respectively. Conclusion AgNO3 staining technique is effective, convenient, and economic in evaluating the recellularization level of BVS. It is an effective method in morphological observation for fabricating tissueengineered heart valve in vitro.
ObjectiveTo analyze clinical experience and outcomes of video-assisted thoracoscopic surgery (VATS)for bioprosthetic mitral valve replacement (MVR). MethodsWe retrospectively analyzed 32 patients who underwent VATS bioprosthetic MVR in the Department of Cardiovascular Surgery of Guangdong General Hospital from March to December 2013. There were 14 males and 18 females with a mean age of 55.6±17.3 years (range, 19 to 80 years), mean body weight of 55.7±9.7 kg (range, 37 to 78 kg) and mean body surface area of 1.67±0.16 m2 (range, 1.30 to 1.95 m2). Five patients had atrial fibrillation. There were 20 patients in New York Heart Association (NYHA)functional class Ⅱ, 11 patients in class Ⅲ, and 1 patient in class Ⅳ. There were 16 patients with rheumatic mitral valve disease, 11 patients with degenerative mitral valve disease, 4 patients with infective endocarditis and 1 patient with associated congenital heart disease. ResultsVATS bioprosthetic MVR was successfully performed for all the patients, including 27 patients with Medtronic Hancock Ⅱ Bioprosthesis and 5 patients with Medtronic Mosaic Bioprosthesis. Concomitantly, tricuspid valvuloplasty was performed for 13 patients and atrial septal defect repair was performed for 1 patient. There was no in-hospital death, low cardiac output syndrome or left ventricular rupture. Postoperative echocardiography showed good bioprosthetic function in all the patients without paravalvular leakage. Postoperative cardiac function significantly improved compared with preoperative cardiac function. There were 9 patients in NYHA functional class Ⅰ, 17 patients in class Ⅱ, and 6 patients in class Ⅲ. Left atrial diameter and left ventricular end-diastolic diameter examined postoperatively and 3 months after surgery were significantly smaller than preoperative values. Left ventricular ejection fraction (LVEF)examined postoperatively and 3 months after surgery was significantly lower than preoperative LVEF. ConclusionsVATS bioprosthetic MVR is a minimally invasive, safe and feasible procedure with a low postoperative morbidity. Incision size can be significantly reduced with a special type of bioprosthesis.
Commissural misalignment of biological valve and autologous valve during transcatheter aortic valve replacement may affect the filling of coronary artery, reduce the feasibility of redo-aortic valve intervention and damage the valve function, which will adversely affect long-term prognosis of patients. Some studies have obtained achievement by changing the axial direction of valve and using individualized computer simulation technology to improve the alignment technology. However, there are still many unknown problems about the impact of commissural misalignment on patients, and accurate commissural alignment techniques still need to be further explored. This article systematically expounds the possible impact of commissural misalignment between biological valve and autologous valve in transcatheter aortic valve replacement, possibly effective accurate commissural alignment techniques and related research progress.
Biological valves can lead to structural valve degeneration (SVD) over time and due to various factors, reducing their durability. SVD patients need to undergo valve replacement surgery again, while traditional open chest surgery can cause significant trauma and patients often give up treatment due to intolerance. Research has shown that as an alternative treatment option for reoperation of thoracic valve replacement surgery, redo-transcatheter aortic valve replacement for SVD is safe and effective, but still faces many challenges, including prosthesis-patient mismatch, high cross valve pressure difference, and coronary obstruction. This article aims to review the strategies, clinical research status and progress of redo-transcatheter aortic valve replacement in SVD patients.