Preclinical Testing of Living Tissue-Engineered Heart Valves for Pediatric Patients, Challenges and Opportunities.

Pediatric patients with cardiac congenital diseases require heart valve implants that can grow with their natural somatic increase in size. Current artificial valves perform poorly in children and cannot grow; thus, living-tissue-engineered valves capable of sustaining matrix homeostasis could overcome the current drawbacks of artificial prostheses and minimize the need for repeat surgeries. To prepare living-tissue-engineered valves, we produced completely acellular ovine pulmonary valves by perfusion.

Challenges in Perioperative Animal Care for Orthotopic Implantation of Tissue-Engineered Pulmonary Valves in the Ovine Model.

Background: Development of valvular substitutes meeting the performance criteria for surgical correction of congenital heart malformations is a major research challenge. The sheep is probably the most widely used animal model in heart valves regenerative medicine. Although the standard cardiopulmonary bypass (CPB) technique and various anesthetic and surgical protocols are reported to be feasible and safe, they are associated with significant morbidity and mortality rates.

Exploring Current Evidence on the Past, the Present, and the Future of the Heart Team: A Narrative Review.

Introduction: Including healthcare professionals dealing with cardiovascular diseases, Heart Team is a concept/structure designed for selecting diagnostic strategies, facilitating therapeutic decisions, and improving cardiovascular outcomes in patients with complex heart pathologies, requiring input from different subspecialties and the necessity of a multidisciplinary approach. The aim of this narrative review is to search for and to summarize current evidence regarding Heart Team and to underline the future directions for the development of this concept.

Methods: We searched the electronic database of PubMed, SCOPUS, and Cochrane CENTRAL for studies including Heart Team.

[Surgical ventricular reconstruction for ischemic left ventricular aneurysm. Early and medium-term outcomes for two surgical techniques].

Introduction: Left ventricular aneurysm is a severe complication of acute myocardial infarction, which contributes significantly to mortality and morbidity associated with this pathology. Despite the progress of correction techniques, there are still controversies about the optimal approach addressing this pathology.

Aim: The aim of this study was to analyse short and medium term outcomes of left ventricular reconstruction for ischemic left ventricular aneurysm using two surgical techniques (endoventricular patch plasty and liniar suture) in order to determine if one of these techniques has supperior results.

Functional Heart Valve Scaffolds Obtained by Complete Decellularization of Porcine Aortic Roots in a Novel Differential Pressure Gradient Perfusion System.

There is a great need for living valve replacements for patients of all ages. Such constructs could be built by tissue engineering, with perspective of the unique structure and biology of the aortic root. The aortic valve root is composed of several different tissues, and careful structural and functional consideration has to be given to each segment and component.

Indication for transplantation in a patient with univentricular heart.

Surgical correction of the univentrivular heart is an achievement of the last 4-5 decades. The Fontan pathway is nowadays an established but continuously improving surgical technique.Nevertheless, attrition of the univentricular heart is a well known process, its timing depending on several factors:technique, time of operation, type of ventricle aso.

First heart transplantation in a small child in Romania.

Heart transplantation is a life-saving procedure for irreducible heart failure in children as in adults. Worldwide there is a great amount of experience with this procedure, while Romania is only at the beginning. The authors are presenting the experience concerning the first small child heart transplantation in Romania, underlining the pre-operative and posttransplantation experience.

[Type B aortic dissection--endovascular stent-graft repair. Case report].

The treatment of aortic dissections type B Stanford using endovascular stents represents one of the newest advances in the treatment of this diseases, less invasive alternative to classic surgical repair. Aortic stent-grafts initially were used in treatment of abdominal aortic aneurysms, and then to treat aneurysms, dissections and traumatic ruptures of the descending aorta, with good early and mid-term outcomes. Thoracic aortic aneurysms are frequently diagnosed in mid-age or elderly patients who have arterial hypertension, coronary artery disease, chronic obstructive pulmonary disease.

The diagnosis, morphological particularities, and surgical technique in a case of intravascular leiomyoma extended to the right heart chambers.

Intravenous leiomyoma is a benign smooth muscle cell tumor of uterine origin that may grow into the pelvic veins and the inferior vena cava. It usually affects premenopausal women and the majority (90%) are parous. Because cardiac involvement is present in up to 10% of cases, it may be misdiagnosed as a primary cardiac tumor or a venous thrombus-in-transit.

[Tetralogy of Fallot--new appearance of an old technique].

Unlabelled: Tetralogy of Fallot represents one of the most frequent congenital heart disease in medical practice and a "corner stone" of any paediatric surgical team due to great anatomic and functional variability and clinical aspects. This paper presents a retrospective study of surgical experience in patients with tetralogy of Fallot admitted in Paediatric Cardiovascular Centre of Târgu Mureş, Romania, between 2005, October to 2009, January.

Method: There where retrospectively studied medical records of patients who undergo a surgical procedure: age, morphologic diagnosis, symptoms and type of surgical procedure, intraoperative data, postoperative follow-up and complications.

Effects of Atorvastatin on some inflammatory parameters in severe primary hypercholesterolemia.

Recent publications have reanimated the point of view that there exist links between atherosclerosis--inflammation and hypercholesterolemia. The aim of our study was to investigate the possible influence of statins on some inflammatory parameters in persons with severe primary hypercholesterolemia (PHC). The effects of the HMG CoA reductase inhibitor--Atorvastatin--on serum lipids, apoproteins, C reactive protein (CRP), soluble Intercellular Adhesion Molecule (sICAM), lipid peroxides, antibodies to oxidized LDL (Ab oxLDL) and homocystein were evaluated in 21 persons (52.

Factors associated with atrial fibrillation in patients with mitral stenosis: a cardiac catheterization study.

Atrial fibrillation (AF) is frequently found in association with rheumatic mitral valve disease. To study the interrelation of factors contributing to the risk of AF in patients with mitral stenosis, we examined a cardiac catheterization database of a series of 314 patients. Patients with AF were older, 53.

Matrix metalloproteinases in the pathology of natural and bioprosthetic cardiac valves.

Degenerative dysfunction of cardiac valves may be accounted for by uncontrolled extracellular matrix degradation processes in which matrix metalloproteinases could play a major role. In this study, 24 pathologic human valves and 26 pericardial-derived bioprostheses were analysed for metalloproteinases by gelatin zymography. Compared to controls, human stenotic valves and bioprostheses explanted because of either calcifying or noncalcifying degeneration revealed three notable biochemical aspects: (1) an amplification in the levels of metalloproteinase 9 (gelatinase B), suggestive of its active role in valvular pathology; (2) minimal modifications in the gelatinolytic levels of metalloproteinase 2 (gelatinase A), indicative of a constitutive secretion; and (3) activation products derived from both gelatinase A and B.

Biochemical pathways of tissue degeneration in bioprosthetic cardiac valves. The role of matrix metalloproteinases.

Degeneration processes that affect bioprosthetic heart valves made from glutaraldehyde treated bovine pericardium are poorly understood. The present study undertook the identification and characterization of matrix metalloproteinases (MMPs) in extracts obtained from 28 pericardial derived bioprosthetic heart valves explanted at surgery. A lysosomal marker was used to assess the incidence of infiltrating extracellular matrix degrading cells.

New evolution in mitral physiology and surgery: mitral stentless pericardial valve.

The human adult mitral valve, with a mean diastolic area of up to 7.6 cm2, excess leaflet surface area for coaptation in systole, mitral annulus-papillary muscle continuity, and systolic constriction of the posterior left ventricular wall around the mitral annulus functions in concert with other components of the left side of the heart. Mitral valve replacement with an artificial valve that interferes with the normal physiology could account for less than adequate late results.

Large animal model of ischemic mitral regurgitation.

A large animal model of ischemic mitral regurgitation (MR) that resembles the multiple presentations of the human disease was developed in sheep. In 76 sheep hearts, the anatomy of the coronary arterial circulation was determined by observation and polymer casts. Two variations, types A and B, which differed by the vessel that supplied the left ventricular apex, were found.

Detection of remnant proteolytic activities in unimplanted glutaraldehyde-treated bovine pericardium and explanted cardiac bioprostheses.

The presence and activity of proteolytic enzymes has been investigated in vitro on soluble and insoluble preparations obtained from both unimplanted and implanted glutaraldehyde-treated bovine parietal pericardium. Using detection by colorimetric techniques, soluble preparations were shown to hydrolyze enzyme substrates that are characteristic for trypsin-like proteases, cathepsin-like proteases, and collagenase. As detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in gradient gels and gel filtration on Sepharose CL-6B, insoluble (pellet) preparations degraded denatured type I collagen in a time-dependent pattern, producing low-molecular-weight fragments.

Mapping of glutaraldehyde-treated bovine pericardium and tissue selection for bioprosthetic heart valves.

Glutaraldehyde-crosslinked bovine pericardium is widely used in bioprosthetic heart valve fabrication. In an attempt to set a scientific basis for more reproducible tissue selection, we produced and analyzed topographical maps of glutaraldehyde-treated bovine pericardium. Whole pericardia were divided into specific anatomical areas and their thickness was measured and mapped on templates.

Pathogenesis of ischemic mitral insufficiency.

We developed a new animal model of ischemic mitral insufficiency in sheep and used it to test the hypothesis that the combination of posterior papillary muscle infarction and left ventricular dilatation was required to produce mitral regurgitation after acute inferior myocardial infarction of moderate size. In 12 sheep, ligation of the first two circumflex marginal coronary arteries infarcted 23% of the left ventricular mass, increased left ventricular cavitary area from 13.2 +/- 1.

Lysine-enhanced glutaraldehyde crosslinking of collagenous biomaterials.

Crosslinking of collagenous biomaterials currently employs the use of glutaraldehyde. The putative enhancement of glutaraldehyde crosslinking by lysine was investigated in three model systems: bovine pericardium, collagen membranes, and bovine serum albumin. Repetitive sequential treatment of bovine pericardium with glutaraldehyde and lysine and finally with formaldehyde produced a matrix which, by the two criteria used (shrinkage temperature and urea/SDS soluble collagen), was shown to be more highly crosslinked than pericardium fixed in glutaraldehyde alone.

The significance of the lung biopsy in congenital cardiovascular malformations.

The microscopic changes of pulmonary arteries in 18 patients with congenital cardiovascular malformations were studied on lung biopsies and appreciated by the Heath-Edwards' scale. A correlation between the nature of the malformation and the patient's age on the one hand, and the severity of arterial lesions on the other hand, was observed, suggesting the utility of the lung biopsy for a better prognosis of the surgical corrective intervention. The role of inflammatory factors in the genesis of arterial changes leading to hypertension is also discussed.