NATHALI CORDEIRO PINTO
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina
LIM/11 - Laboratório de Cirurgia Cardiovascular e Fisiopatologia da Circulação, Hospital das Clínicas, Faculdade de Medicina
LIM/11 - Laboratório de Cirurgia Cardiovascular e Fisiopatologia da Circulação, Hospital das Clínicas, Faculdade de Medicina
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- The use of a high-power laser on swine mitral valve chordae tendineae(2016) PINTO, Nathali Cordeiro; CHAVANTES, M. Cristina; ZEZELL, Denise; DEANA, Alessandro; BENETTI, Carolina; MARCOS, Rodrigo Labat; LOPES, Luciana Almeida; MARTINS, Rodrigo A. B. Lopes; AIELLO, Vera Demarchi; JATENE, Fabio Biscegli; POMERANTZEFF, Pablo M. A.Worldwide, rheumatic fever remains a significant cause of mitral valve insufficiency. It is responsible for approximately 90 % of early childhood valvular surgeries in Brazil. Elongated or flail chordae are frequently responsible and require surgical correction. The purpose of this study was to analyze and compare the histological tissues of the mitral valve chordae and the mechanical resistance generated by the chordae, both with and without the application of a high-power laser. Twenty normal porcine mitral valve chordae were measured and divided randomly into the following two groups: control group (not subjected to a high-power laser) and laser group (subjected to photonic irradiation). Laser surgery was performed under controlled conditions, using following parameters: lambda = 980-nm wavelength, power = 3 W, and energy = 60 J. A mechanical test machine was used in combination with a subsequent histological study to measure chordae tensile properties. A histological analysis demonstrated a typical collagen bundle arrangement in the control group; however, under a particular reached temperature range (48), the collagen bundles assumed different arrangements in the laser group. Significant reductions in the chordae tendineae lengths and changes in their resistance in the laser group were observed, as these chordae exhibited less rigid fibers. The chordae tendineae of normal porcine valves subjected to a high-power laser exhibited its length reduction and less stiffness compared to the control group. A histological analysis of the laser treatment specimens demonstrated differences in collagen bundle spatial organization, following slight changes into tissue temperature.
- Descriptive Analysis of In Vitro Cutting of Swine Mitral Cusps: Comparison of High-Power Laser and Scalpel Blade Cutting Techniques(2017) PINTO, Nathali Cordeiro; POMERANTZEFF, Pablo Maria Alberto; DEANA, Alessandro; ZEZELL, Denise; BENETTI, Carolina; AIELLO, Vera Demarchi; LOPES, Luciana Almeida; JATENE, Fabio Biscegli; CHAVANTES, M. CristinaBackground and objectives: The most common injury to the heart valve with rheumatic involvement is mitral stenosis, which is the reason for a big number of cardiac operations in Brazil. Commissurotomy is the traditional technique that is still widely used for this condition, although late postoperative restenosis is concerning. This study's purpose was to compare the histological findings of porcine cusp mitral valves treated in vitro with commissurotomy with a scalpel blade to those treated with high-power laser (HPL) cutting, using appropriate staining techniques. Materials and methods: Five mitral valves from healthy swine were randomly divided into two groups: Cusp group (G1), cut with a scalpel blade (n = 5), and Cusp group (G2), cut with a laser (n = 5). G2 cusps were treated using a diode laser (lambda = 980 nm, power = 9.0 W, time = 12 sec, irradiance = 5625 W/cm(2), and energy = 108 J). Results: In G1, no histological change was observed in tissue. A hyaline basophilic aspect was focally observed in G2, along with a dark red color on the edges and areas of lower birefringence, when stained with hematoxylin-eosin, Masson's trichrome, and Sirius red. Further, the mean distances from the cutting edge in cusps submitted to laser application and stained with Masson's trichrome and Sirius red were 416.7 and 778.6 mu m, respectively, never overcoming 1mm in length. Conclusions: Thermal changes were unique in the group submitted to HPL and not observed in the cusp group cut with a scalpel blade. The mean distance of the cusps' collagen injury from the cutting edge was less than 1mm with laser treatment. Additional studies are needed to establish the histological evolution of the laser cutting and to answer whether laser cutting may avoid valvular restenosis better than blade cutting.