MICROSCOPIA ELECTRONICA DE BARRIDO PDF

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Study of the parietal coronary sinus valve under scanning electron microscopy. The cardioplegic solution is retrogradly perfused through the coronary sinus, the main vein of the heart, and it is useful since the coronary venous system has shown to be free of any obstructing atherosclerotic disease.

The opening of the coronary sinus occurs directly in the right atrium and an ostial valve at this level has long been related. However, a parietal valve in the coronary sinus has renewed the interest in this study. These valves could make difficult a perfect perfusion of the cardioplegic solution, particularly when low coronary sinus pressures are used. In order to understand the morphology of the parietal valve of the coronary sinus we decided to perform a study of the valve under SEM.

Six fragments of the coronary sinus containing the parietal valve were taken from adult individuals, post mortem , with no gross cardiac pathologies. The samples were submitted to the usual techniques of Scanning Electron Microscopy.

The parietal valve of the coronary sinus showed a half-moon shape, with a well defined structure. Its endothelium was arranged in parallel lines, similar to a stem of a tree, where we could evidence the nuclei of the endothelial cells. Under the endothelial layer we found abundant collagen and elastic fibers. Owing to its developed form seen under SEM, the parietal valve of the coronary sinus must play an important role in guiding the blood flow through the coronary sinus to the right atrium in physiological conditions and could raise difficulties to the flow of the cardioplegic solution during the retrograde cardioplegia.

Heart; 2. Coronary Sinus; 3. Subsequent studies on retroperfusion through coronary sinus have continued to fascinate generations of researchers, and have introduced a new era which today again appears to be on the threshold of allowing aplication in clinical trials. Three decades have elapsed since the first serious clinical application of coronary sinus interventions were attempted. Over the last few years a renewed interest and a new demand for protecting myocardial schemia via the coronary sinus have been developed.

Today coronary sinus intervention is generally understood as a method of temporary protection of ischemic myocardium via the coronary venous system and include retroinfusion of a cardioplegic solution during cardiac arrest in surgery, retroperfusion of pharmaceutical agents, and manipulation of the venous blood drainage by pressure- controlled intermitent coronary sinus occlusion MOHL, Coronary sinus cardioplegia is now the most widely used technique of myocardial preservation.

The delivering of the cardioplegic solution through the coronary sinus is useful since the coronary venous system has shown to be free of any obstructing atherosclerotic disease.

They advance the cannula as far as it goes into the coronary sinus. The opening of the coronary sinus occurs directly in the right atrium and an ostial valve at this level has long been related MOORE, In another study of anatomical human hearts he emphasizes that the regulation of the blood stream in the coronary sinus is performed by a system of simple valves SHORMANOV, Although the existence of one-way valves at the orifices of the major tributary veins of the coronary sinus has long been noted in anatomy textbooks, there is little details of their morphofuntional characteristics.

In order to investigate the presence of such structures we studied under scanning electron microscopy the morphology of the vein valves of the coronary sinus and tried to establish some functional correlation. The samples were washed in a 0. The material was rinsed in 0. Rinsed again in 0. Its endothelium was arranged in parallel lines Fig. Under the endothelial layer we found abundant elastic fibers Fig. In the sub-endothelial layer we could still find a monocyte resting on elastic fibers.

Shows the elastic fibers ef of the sub-endothelial layer. This technique offers a number of potential advantages: it avoids trauma to the coronary ostia, minimally interferes with surgical procedures, and affords access of cardioplegia to the myocardium distal to acutely occluded coronary arteries.

A possible reason for a prolonged time to diastolic arrest with retrograde cardioplegia may have to do with the existence of one-way venous valves at the entrances of the major tributary veins of the coronary sinus.

Anatomic variations, which are much more common in coronary veins than arteries further complicate the prediction on an optimal range of coronary venous perfusion PAN- CHIH et al. We did not find any report in the literature about a SEM study of the parietal valve of the coronary sinus. In another study of anatomical human hearts he enphasizes that the regulation of the blood stream in the coronary sinus is performed by a system of simple valves.

In the ligth of the growing interest in experimental and clinical use of retrograde cardioplegia for myocardium protection both animal and human cadaver hearts were examined to assess the incidence and morphology of one-way coronary vein valves by PAN-CHIH et al. We also believe based in the SEM study that the regulation of the blood stream through the coronary sinus is facilitated by the parietal valve.

The observations made by these authors could be explained by the existence of the parietal valve, for us described, in the coronary sinus. Further hemodynamic studies must be done in order to determine more accurately the influence of these valves in patients submitted to retrograde cardioplegia. La desembocadura del seno coronario ocurre directamente en el atrio derecho, donde una valva ostial es referida a este nivel.

Seno coronario; 3. Fone-Fax: 55 and E-mail: neprates biomed. Retrograde Continuos Warm Blood Cardioplegia. Die foramina Thebesii im Herzen des Menschen.

Sitzungsberichte der Matematisch Naturwissenschaftlichen Klasse der Kaiserlichen. Akademie der Wissenschaften, 82 , The momentum of coronary sinus interventions clinically.

Circulation, 77 1 , Guanabara-Koogan, , p Hemodynamic Significance of the Coronary Vein Valves. Anatomic data of the human coronary sinus. Technique and pitfalls of retrograde continuos warm Blood Cardioplegia.

Pathways of venous blood outflow from the canine myocardium and structures participating in its regulation. Adaptative structures of the cardiac venous bed, normal and at certain defects of its development. Servicios Personalizados Revista. Casilla D Temuco mdelsol ufro.

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Study of the parietal coronary sinus valve under scanning electron microscopy. The cardioplegic solution is retrogradly perfused through the coronary sinus, the main vein of the heart, and it is useful since the coronary venous system has shown to be free of any obstructing atherosclerotic disease. The opening of the coronary sinus occurs directly in the right atrium and an ostial valve at this level has long been related. However, a parietal valve in the coronary sinus has renewed the interest in this study. These valves could make difficult a perfect perfusion of the cardioplegic solution, particularly when low coronary sinus pressures are used. In order to understand the morphology of the parietal valve of the coronary sinus we decided to perform a study of the valve under SEM.

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