Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. It is characterized by an interventricular communication with an overriding aorta, subpulmonary obstruction, and consequent right ventricular hypertrophy. The potential for late complications is an important concern for growing number of survivors after surgical repair, although long-term survival rates are excellent. Progressive pulmonary valve regurgitation leading to right heart failure and arrhythmias are common late complications and major reasons of mortality. In this review, we focus on research progress of pathogenesis and treatment of late complications after TOF repair, and the importance of long-term follow-up is emphasized.
Hybrid cardiovascular surgical procedure is an emerging concept that combines the skills and techniques of minimally invasive surgery and interventional catheterization. It allows surgeons to use interventional equipment and techniques during operations, which are traditionally used by physicians, in order to reduce the magnitude of therapeutic interventions and to increase therapeutic effectiveness. This review provides a snapshot of the main application and progress of current hybrid procedures in the field of cardiovascular surgery, including the hybrid therapy of coronary artery disease, congenital heart disease and thoracic aortic aneurysm, also discusses the precondition with which the hybrid procedure should ideally be performed.
Abstract: Objective Using Amplex red fluorometric assay to detect the lysyl oxidase (LOX) enzyme activity in tissue engineered heart valve (TEHV). Methods Porcine aortic valves were decellularized with trypsin+ethylene diaminetetraacetic acid(EDTA), TritonX-100, and RNaseⅠ＋DNaseⅠ, then they were seeded by myo-fibroblasts that harvested from rats. Then they were fed with Dulbecco’s modified Eagle medium (DMEM) which contained high glucose for 27 days, they were fed with phenol red-free and serumfree DMEM for 24 hours, and the medium was harvested and used for LOX enzyme activity assays with the Amplex red fluorometric assay. And reverse transcription-polymerase chain reaction (RT-PCR) technique was used to analyze the expression of LOXmRNA in TEHV. Results All the samples produced measurable amounts of active LOX enzyme. The fluorescence units were 45.60±1.66, and the corresponding concentration of LOX enzyme were 0.123±0.003μg/ml. At the same time, all the samples expressed LOXmRNA. The expression of LOXmRNA was corresponding to the results of the Amplex red fluorometric assay. Conclusion It is feasible to detect the LOX enzyme activity in TEHV with the Amplex red fluorometric assay. And this assay gives a way to reflect that LOX plays an important role in collagen cross-linking of extracellar matrix in TEHV.
Objective To develop a tissue engineering scaffold by using 4arm branched polyethylene glycol-VS (PEG-VS) crosslinked with decellularized valved conduits (DVC), and to research on its mechanical and biological functions. Methods The valved aortic conduits of rabbits were taken and decellularized by trypsin method and then were crosslinked with 4arm branched PEG-VS to construct the composite scaffolds (CS). The functions of decellularized valved conduits and the composite scaffolds were tested by mechanics test system. Thirty New Zealand white rabbits were equally and randomly assigned to one of the three groups: the control group, the DVC group, and the CS group. Valved aortic conduits, decellularized valved conduits and composite scaffoldswere transplanted into the common carotid artery of the abovementioned three groups of rabbits respectively. Twentyeight days after the operation, patency of the transplants was tested by Color Doppler ultrasound; micromorphology and inflammatory infiltration were observed by hematoxylin eosin（HE） staining andscanning electron microscope (SEM)，and endothelialization of composite scaffolds was detected by immunofluorescent staining. Results A series of biomechanical analyses revealed that the composite scaffolds had highly similar mechanical properties as fresh tissue, and had superior elastic modulus (P=3.1×10-9) and tensile strength (P=1.1×10-6) compared with decellularized valved conduits. Color Doppler ultrasound revealed that the graft patency for the CS group was better than the control group (P=0.054) and the DVC group (P=0.019), and the intraaortic thrombosis rate and distortion rate decreased significantly. HE staining and SEM showed that the endothelialization of composite scaffolds in the CS group was significantly higher than the other two groups with the endothelial cells evenly distributed on the scaffolds. The [CM(159mm]immunofluorescent staining indicated that the positive rate of the endothelial cell marker CD34 was higher than the other two groups. Conclusion The composite scaffolds using 4arm branched PEGVS crosslinked with DVC have great mechanical and biological properties.
Objective To observe whether Cyclo-RGDfK (Arg-Gly-Asp-D-Phe-Lys) could enhance the adhesion of myofibroblast to decellularized scaffolds and upregulate the expression of Integrin αVβ3 gene. Methods Myofibroblast from the rat thoracic aorta was acquired by primary cell culture. The expression of Vimentin and α-smooth muscle actin(α-SMA) has been detected by immunoflurescent labeling. Decellularized valves have been randomly divided into three groups (each n=7). Group A (blank control): valves do not receive any pretreatment; Group B: valves reacted with linking agent NEthylN(3dimethylaminopropyl)carbodiimide hydrochloride (EDC) for 36 hours before being seeded; Experimental group: Cyclo-RGD peptide has been covalently immobilized onto the surface of scaffolds by linking agent EDC. The fifth generation of myofibroblast has been planted on the scaffolds of each group. The adhesion of myofibroblast to the scaffolds was evaluated by HE staining and electron scanning microscope. The expression of Integrin αVβ3 was quantified by halfquantitative reverse transcriptionpolymerase china reaction (RT-PCR). Results We can see that myofibroblast has exhibited b positive staining for Vimentin and α-SMA. Besides, it has been shown that the expression of Integrin αVβ3 was much higher in the experimental group than that of the group A and group B(Plt;0.05). There was no statistically difference in group A and group B (P=0.900). Conclusion RGD pretreatment does enhance the adhesive efficiency of seeding cells to the scaffolds and this effect may be related to the upregulation of Integrin αVβ3.
Objective To analyze and explore the risk factors of secondary tricuspid regurgitation (TR) after left-sided valve surgery (left cardiac valve replacement or valvuloplasty) using meta-analysis, so as to provide evidence for clinical diagnosis and treatment of secondary TR. Methods We electronically searched databases including PubMed, MEDLINE, CBM, CNKI, VIP, for literature on the risk factors of secondary TR after left-sided valve surgery from 1995 to 2012. According to the inclusion and exclusion criteria, we screened literature, extracted data, and assessed methodological quality. Then, meta-analysis was performed using RevMan 5.0 software. Results A total of 6 case-control studies were included, involving 437 patients and 2 102 controls. The results of meta-analysis showed that, the risk factors of progressive exacerbation of secondary TR after left-sided valve surgery included preoperative atrial fibrillation (OR=3.90, 95%CI 3.00 to 5.07; adjusted OR=3.04, 95%CI 2.21 to 4.16), age (MD=5.36, 95%CI 3.49 to 7.23), huge left atrium (OR=5.17, 95%CI 3.12 to 8.57; adjusted OR=1.91, 95%CI 1.49 to 2.44) or left atrium diameter (MD=4.85, 95%CI 3.18 to 6.53), degradation of left heart function (OR=2.97, 95%CI 1.73 to 5.08), rheumatic pathological change (OR=3.06, 95%CI 1.66 to 4.68), preoperative TR no less than 2+ (OR=3.52, 95%CI 1.26 to 9.89), and mitral valve replacement (MVR) (OR=2.35, 95%CI 1.68 to 3.30). Sex (OR=1.54, 95%CI 0.94 to 2.52) and preoperative pulmonary arterial hypertension (OR=1.28, 95%CI 0.77 to 2.12) were not associated with secondary TR after left-sided valve surgery. Conclusion The risk factors of progressive exacerbation of secondary TR after left-sided valve surgery include preoperative atrial fibrillation, age, huge left atrium or left atrium diameter, degradation of left heart function, rheumatic pathological change, preoperative TR no less than 2+, and MVR. Understanding these risk factors helps us to improve the long-time effectiveness of preventing and treating TR after left-sided valve surgery.