OBJECTIVES Decellularization is an alternative method for processing biological tissues with decreased antigenicity and resistance to calcification. The aim of this study was to characterize the properties of decellularized (dCell) bovine pericardium fixed with 0.1% glutaraldehyde (GA) and to evaluate outcomes of bioprosthetic valves constructed with this tissue when implanted in the mitral position of juvenile sheep. METHODS Bioprosthetic mitral valves were constructed with fresh bovine pericardium fixed in 0.5% GA (control group) or dCell bovine pericardium fixed in 0.1% GA (study group). Before implantation, samples were submitted to histological (haematoxylin–eosin, Movat and 4′,6-diamidino-2-phenylindole), biochemical (residual deoxyribonucleic acid and α-gal epitopes) and biomechanical characterization. Valves were implanted (n = 8 in each group) as a mitral valve replacement for 180 days in sheep and explants were re-evaluated histologically and for calcification with radiological studies and calcium content determination. RESULTS Unimplanted dCell pericardia exhibited a well-preserved extracellular matrix with absence of cells, a 77% reduction in deoxyribonucleic acid levels and with no detectable α-gal epitopes. When compared to controls, they had lower ultimate tensile strength (7.3 ± 5.4 vs 10.2 ± 3.0 mPa, P = 0.04) and greater percentage elongation in the longitudinal direction (29 ± 6.5% vs 23.8 ± 5.1%, P = 0.02). After 180 days in mitral position, dCell valves showed pliable leaflets without macroscopic signs of calcification. Histologically, dCell leaflets had intact collagen fibres, better tissue remodelling and a significant 89% reduction in calcium content. CONCLUSIONS This study demonstrates that bioprosthetic valves constructed with dCell bovine pericardium fixed in low GA concentration were resistant to calcification and may thereby improve long-term durability of the tissue.
Background: Minimally invasive cardiovascular operations have been proposed as an alternative method to correct several cardiac congenital and acquired heart diseases, with the aim to reduce morbidity and mortality.Objectives: Describe the two years initial experience with minimally invasive operations, with emphasis on technical aspects and the learning curve.Methods: Between July 2009 and March 2012, 95 patients were operated using minimally invasive operations. Mean age was 55 ± 15 years and 53% were females. The operations performed were atrial septal defect closure (25), aortic valve replacement (32), mitral valve repair (23), mitral valve replacement (12), excision of atrial myxoma (2) and resection of subaortic membrane (1). The incision was a mini right thoracotomy in 87 cases and ministernotomy in 8.Results: Early mortality was 4.2%. Mean size of the incision was 6.3 ±1.2 cm. Extension of the original thoracotomy was necessary in only one case. Two patients suffered a stroke, and the mean total blood loss was 470 ± 277 ml. There were no cases of incision infection and 67% the patients had no major morbidity. Conclusions
RBCCV 44205-905Ácido L-glutâmico na prevenção da calcificação de pericárdio bovino fixado em glutaraldeído: estudo em ratos L-glutamic acid in the prevention of the calcification of bovine pericardial fixed in glutaraldehyde: study in rats Abstract Objective: To evaluate the efficiency of L-glutamic acid to prevent calcification of glutaraldehyde bovine pericardium implanted in rats' subcutaneous tissues.Methods: Fifty four Wistar rats were divided in six groups according to the type of the bovine pericardium implanted. At first, all pericardia were initially cross-linked with 0.5% glutaraldehyde (GDA) fixative for 72 h. In Group I, after the initial fixation, the pericardia were preserved in 0.2% GDA fixative until the implantation, whereas in Group II they were stocked in Paraben solution. In Groups III and IV, after the initial fixation in 0.5% GDA fixative, the pericardia were treated with 8% L-glutamic acid at pH 7.4 and 3.5, respectivelly, being subsequently stocked in Paraben solution. Groups V and VI were similar to III and IV, except for the concentration of L-Glutamic acid which was 0.8%. Explantation was done at 15, 30, and 60 days, and the specimens submitted to histological analysis with Hematoxylin and eosin (HE) and Von Kossa stains, besides calcium quantification with atomic spectrofotometry.Results: Microscopic analysis demonstrated severe and progressive calcification in groups I, II, and III, whereas in groups IV, V, and VI calcification, when present, was mild and focal. Spectrofotomety confirmed these findings, revealing calcium contents of 1.93µg/mg of tissue at 60 days in the control group. Groups IV and VI showed the least calcium contents (0.063 e 0.066, respectively).Conclusions: The use of L-glutamic acid in segments of bovine pericardium with glutaraldehyde fixative was effective in preventing the calcification when implanted in rats' subcutaneous tissues up to 60 days.Descriptors: Glutamic acid. Glutaral. Pericardium. Calcinosis. 304FERREIRA, ADA ET AL -L-glutamic acid in the prevention of the calcification of bovine pericardial fixed in glutaraldehyde: study in rats Bras Cir Cardiovasc 2007; 22(3): 303-309 particularly in developing countries, in which the usage of the biological prostheses is more frequent. RevThe aim of the present study was to analyze the efficacy of L-glutamic acid in concentrations of 0.8% and 8%, pH values ranging from 3.5 (acid) to 7.4 (physiologic), in the prevention of the segments calcification of the bovine pericardium with glutaraldehyde fixative and implanted in the subcutaneous tissue of young rats. METHODSThis study was carried out at the following Labs:
The Premium bioprosthetic aortic valve demonstrated very satisfactory clinical and echocardiographic results up to 4 years, similar to other commercially available, third-generation bioprosthetic valves.
Late outcomes with the Ross Operation were associated with an excellent long-term survival and a low incidence of reoperations and late morbidity. We consider this procedure the best option for the surgical treatment of aortic valve disease in children and young adults.
Descelularização como método anticalcificante em próteses valvares de pericárdio bovino sem suporte: estudo em ovinosDecellularization as an anticalcification method in stentless bovine pericardium valve prosthesis: a study in sheep Work performed at the Cardiac Surgery Department at Santa Casa Hospital, PUCPR, Curitiba, Parana, Brazil. Methods:The valved tubs were implanted in pulmonary artery position in sheep by 180 days. The animals were divided in two groups of eight animals: control groupglutaraldehyde-preserved bovine pericardium and the study group -decellularized bovine pericardium with 0.1% SDS and glutaraldehyde-preserved. After explantation the tubs were analized by x-ray macroscopy, hematoxilin-eosin, alizarin-red and Russel-Movatz pentacromic histology. The calcium content was measured by flame atomic absorption spectrometry.Results: There was no early mortality, but two animals in each group died during the study. All cusps in the control group were severely calcified and in some points in the conduits, while the decellularized group did not show macroscopic calcification. Data were proved by x-ray and histologycal exams. The matrix was preserved in histologycal analysis in decellularized group, without gross calcification.
Efeito da descelularização com SDS na prevenção da calcificação em pericárdio bovino fixado em glutaraldeído. Estudo em ratosEffect of SDS-based decelullarization in the prevention of calcification in glutaraldehydepreserved bovine pericardium. Study in rats Abstract Objective: The aim of this study was to investigate the SDS-based decellularization process as an anticalcification method in glutaraldehyde-preserved bovine pericardium in subcutaneous rat model.Methods: Pericardium samples with 0.5 cm 2 area and divided into four groups: GDA group: 0.5% glutaraldehydepreserved pericardium (GDA); GDA-GL group: GDA + 0.2% glutamic acid (GL); D-GDA group: decellularized (D) pericardium with 0.1% SDS + GDA, and D-GDA-GL group: decellularized pericardium + GDA + 0.2% glutamic acid. Afterwards these samples were implanted in 18 rats in subcutaneous position up to 90 days. Each animal received samples of the four groups. The explants were performed at 45 and 90 days. The explants were subjected to histology in glass slides stained with hematoxilin-eosin and alizarin red, morphometry evaluation and the calcium content was measured by flame atomic absorption spectrometry. Results
IntroductionDue to late complications associated with the use of conventional prosthetic heart valves, several centers have advocated aortic valve repair and/or valve sparing aortic root replacement for patients with aortic valve insufficiency, in order to enhance late survival and minimize adverse postoperative events.MethodsFrom March/2012 thru March 2015, 37 patients consecutively underwent conservative operations of the aortic valve and/or aortic root. Mean age was 48±16 years and 81% were males. The aortic valve was bicuspid in 54% and tricuspid in the remaining. All were operated with the aid of intraoperative transesophageal echocardiography. Surgical techniques consisted of replacing the aortic root with a Dacron graft whenever it was dilated or aneurysmatic, using either the remodeling or the reimplantation technique, besides correcting leaflet prolapse when present. Patients were sequentially evaluated with clinical and echocardiographic studies and mean follow-up time was 16±5 months.ResultsThirty-day mortality was 2.7%. In addition there were two late deaths, with late survival being 85% (CI 95% - 68%-95%) at two years. Two patients were reoperated due to primary structural valve failure. Freedom from reoperation or from primary structural valve failure was 90% (CI 95% - 66%-97%) and 91% (CI 95% - 69%-97%) at 2 years, respectively. During clinical follow-up up to 3 years, there were no cases of thromboembolism, hemorrhage or endocarditis.ConclusionsAlthough this represents an initial series, these data demonstrates that aortic valve repair and/or valve sparing aortic root surgery can be performed with satisfactory immediate and short-term results.
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