IDAGENE APARECIDA CESTARI
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina
LIM/65, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/65, Hospital das Clínicas, Faculdade de Medicina - Líder
6 resultados
Resultados de Busca
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conferenceObject Comparative Study between Cavopulmonary Anastomosis Associated with Left Ventricular Assist Device Support and Biventricular Circulatory Assistance in Acute Biventricular Failure(2012) SANTOS, L. A. S.; MOREIRA, L. F. P.; BENICIO, A.; CESTARI, I.; MATTOS JR., E.; STOLF, N. G.Purpose: Right ventricular failure during left ventricular assist device (LVAD) support can result in severe hemodynamic compromise with high mortality. This study investigated the acute effects of cavopulmonary anastomosis on LVAD performance and right ventricular myocardial compromise in comparison with biventricular circulatory support, in a model of severe biventricular failure. Methods and Materials: LVAD support was performed by means of centrifugal pump implantation in 21 anesthetized pigs (20-30 kg) with biventricular failure obtained by ventricular fibrillation induction. Animals were randomized to be submitted to modified cavopulmonary anastomosis, to biventricular circulatory support or to control group. They were maintained under circulatory support and hemodynamic monitoring for 3h. Venous lactate and cytokines serum levels were also determined. Endocardium samples of the ventricles were collected and analyzed by electronic microscopy. Results: Ventricular fibrillation was responsible for acute LVAD performance impairment after 180 min in the control group. Cavopulmonary anastomosis resulted in non-significant improvement of LVAD pump flow in relation to control group (+55±14 ml/kg/min, p=0.072), while animals under biventricular support maintained higher LVAD flow performance (+93±17 ml/kg/min, p=0.012). Mean arterial pressure remained constant only in biventricular group (p<0.001), which also presented significant decrease of right atrial and ventricular pressures. Similar increases in lactate and cytokines levels were observed in the three groups. Ultrastructural analysis documented the presence of higher levels of myocardial mitochondrial swelling in control group (p=0.018). Conclusions: Concomitant use of cavopulmonary anastomosis during LVAD support in a pig model of severe biventricular failure resulted in non-significant improvement of hemodynamic performance and it did not effectively replace the use of biventricular support.- Effect of the bileaflet inlet valve angle on the flow of a pediatric ventricular assist device: Experimental analysis(2022) LEMOS, Bernardo Luiz Harry Diniz; BORTOLIN, Vitor Augusto Andreghetto; AMARAL, Rodrigo de Lima; MAZZETTO, Marcelo; CESTARI, Idagene Aparecida; MENEGHINI, Julio RomanoBackground Mechanical heart valves (MHV) and its fluid dynamics inside a pulsatile pediatric ventricular assist device (PVAD) can be associated with blood degradation. In this article, flow structures are analyzed and compared by an experimental investigation on the effect of bileaflet MHV positioned at varying angles in the inlet port orifice of a PVAD. Methods Time-resolved particle image velocimetry was applied to characterize the internal flow of the device. St Jude Medical bileaftlet valves were used on the inlet orifice and positioned at 0 degrees, 15 degrees, 30 degrees, 45 degrees, 60 degrees, and 90 degrees in relation to the centerline of the device. Three planes with bidimensional velocity magnitude fields were considered in the analysis with visualization of diastolic jets, device wall washing patterns and flow circulation during emptying or systole of the pump. Also, the washing vortex area, and vertical velocity probabilities of regurgitant flows in the inlet valve were evaluated. Results The results show that a variation in the angle of the MHV at the inlet port produced distinct velocities, fluid structures, and regurgitant flow probabilities within the device. MHV positioned at an angle of 0 degrees generated the strongest inlet jet, larger vortex area during filling, more prominent outgoing flow, and less regurgitation compared to the angles studied. The presence of unfavorable fluid structures, such as small vortices, and/or sudden flow structure interruption, and/or regurgitation, were identified at 45 degrees and 90 degrees angles. Conclusions The 0 degrees inlet angle had better outcomes than other angles due to its consistency in the multiple parameters analyzed.
- In Vitro Evaluation of Pediatric Hollow-Fiber Membrane Oxygenators on Hemodynamic Performance and Gaseous Microemboli Handling: An International Multicenter/Multidisciplinary Approach(2017) WANG, Shigang; CANEO, Luiz F.; JATENE, Marcelo B.; JATENE, Fabio B.; CESTARI, Idagene A.; KUNSELMAN, Allen R.; UNDAR, AkifThe objective of this study was to compare the hemodynamic performances and gaseous microemboli (GME) handling ability of two pediatric oxygenators in a simulated pediatric cardiopulmonary bypass (CPB) model and the importance of adding an arterial filter in the circuit. The circuit consisted of a Braile Infant oxygenator or a Maquet Quadrox-I Pediatric oxygenator without integrated arterial filter (parallel arrangement), 1/4 in. ID tubing A-V loop, and a 12-Fr arterial cannula, primed with lactated Ringer's solution and packed red blood cells. Trials were conducted at flow rates ranging from 500 to 2000 mL/min (500 mL/min increment) at 35 degrees C and 28 degrees C. Real-time pressure and flow data were recorded using a custom-based data acquisition system. ForGME testing, 5 cc of air was manually injected into the venous line. GME were recorded using the Emboli Detection and Classification Quantifier (EDAC) System. An additional experiment using a separate arterial filter was conducted. There was no difference in the mean circuit pressure, pressure drop, total hemodynamic energy level, and energy loss between the two oxygenators. The venous line pressures were higher in the Braile than in the Quadrox group during all trials (P < 0.01). GME count and volume at pre-/post oxygenator and pre-cannula sites in the Quadrox were lower than the Braile group at high flow rates (P<0.05). In the additional experiment, an arterial filter captured a significant number of microemboli at all flow rates. The Braile Infant oxygenator has a matched hemodynamic characteristic with the Quadrox-i Pediatric oxygenator. The Quadrox-i has a better GME handling ability compared with the Braile Infant oxygenator. Regardless of type of oxygenator an additional arterial filter decreases the number of GME.
conferenceObject Biomechanical Properties of the Porcine Trachea before and after Decellularization for Airway Transplantation(2021) GUIMARAES, A. B.; CORREA, A. T.; PEGO-FERNANDES, P. M.; MAIZATO, M. J.; CESTARI, I. A.; CARDOSO, P. F.- Behavior of Lyophilized Biological Valves in a Chronic Animal Model(2013) MAIZATO, Marina J. S.; TANIGUCHI, Fabio P.; AMBAR, Rafael F.; PITOMBO, Ronaldo N. M.; LEIRNER, Adolfo A.; CESTARI, Idagene A.; STOLF, Noedir A. G.Glutaraldehyde is used in order to improve the mechanical and immunogenic properties of biological tissues, such as bovine pericardium membranes, used to manufacture heart valve bioprostheses. Lyophilization, also known as freeze-drying, preserves biological material without damage by freezing the water content and removing ice by sublimation. Through this process, dehydrated products of high quality may be obtained; also, the material may be easily handled. The lyophilization process reduces aldehyde residues in biological tissue previously treated with glutaraldehyde, thus promoting reduction of cytotoxicity, increasing resistance to inflammation, and possibly decreasing the potential for tissue calcification. The objective of this study was to chronically evaluate the calcification of bovine pericardium heart valve prostheses, previously lyophilized or not, in an animal model. Six-month-old sheep received implants of lyophilized and unlyophilized heart valve prostheses in the pulmonary position with right bypass. The study followed 16 animals for a period of 90 days. Right ventricle-pulmonary artery (RV/PA) transvalvular pressure gradient was evaluated before and immediately after implantation and before explantation, as were tissue calcium, inflammation intensity, and thrombosis and pannus formation. The t-test was used for statistical analysis. Twelve animals survived to the end of the experiment, but one of the animals in the control group had endocarditis and was excluded from the data. Four animals died early. The mean RV/PA gradient on implantation was 2.0 +/- 1.6 mm Hg in the control group and 6.2 +/- 4.1 mm Hg in the lyophilized group (P = 0.064). This mean gradient increased at explantation to 7.7 +/- 3.9 mm Hg and 8.6 +/- 5.8 mm Hg, respectively (P = 0.777). The average calcium content in the tissue leaflets after 3 months was 21.6 +/- 39.1 mg Ca2+/g dry weight in the control group, compared with an average content of 41.2 +/- 46.9 mg Ca2+/g dry weight in the lyophilized group (P = 0.478). In this experimental study there was no reduction of calcification after lyophilization. However, histological analysis showed less inflammation over the lyophilized tissue when compared with the control.
- In Vitro and In Vivo Evaluation of Lyophilized Bioprosthetic Valve(2011) MAIZATO, Marina J. S.; HAYASHIDA, Sergio A.; TANIGUCHI, Fabio P.; HIGA, Olga Z.; PITOMBO, Ronaldo N. M.; CESTARI, Idagene A.; LEIRNER, Adolfo A.; STOLF, Noedir A. G.Freeze-drying of biological tissues allows for dry storage and gamma ray sterilization, which may improve their use as a medical prosthesis. The objective of this study was to evaluate the rehydration characteristics and hydrodynamic performance of prosthetic valves before and after lyophilization. Two size 23 bovine pericardium aortic valve prostheses from different manufacturers were evaluated in a Shelhigh (Union, NJ, USA) pulse duplicator (80 ppm, 5 L/min) before and after lyophilization. Flow and transvalvular pressure gradient were registered in vitro and in vivo, and images of opening and closing of the prosthesis were obtained in the pulse duplicator in a digital camera. Rehydration was evaluated by comparison of dry valve weight with valve weight after 15 min, and 1, 24, 48, and 72 h in saline solution, inside the pulse duplicator. In vivo performance was assessed by surgical implantation in Santa Ines young male sheep in the pulmonary position after 30 min rehydration with 0.9% saline. Transvalvular pressure gradient and flow measurements were obtained immediately after implantation and 3 months after surgery when valves were explanted. Captured images showed a change in the profile opening and closing of valve prosthesis after lyophilization. The gradient measured (in vitro) in two valves was 17.08 +/- 0.57 and 18.76 +/- 0.70 mm Hg before lyophilization, and 34.24 +/- 0.59 and 30.40 +/- 0.97 mm Hg after lyophilization. Rehydration of both lyophilized valves was approximately 82%. Drying changed the profile of the opening and closing of valve prostheses, and increased on average by 83% the gradient in vitro tests. The result of the in vivo tests suggests maintaining pressure levels of the animal with the lyophilized prostheses within acceptable levels.