First Time Experimental Implanting of Locally Developed Left Atrium Occluders

Aim. To develop and preclinically test an occluder of the left atrium appendage (LAA) in experiment on big animals, as prevention treatment of ischemic strokes. Material and methods . The study was done on the pigs “big white” breed, n=7, mass 98±4 kg. The locally Russian-made device and placement equipment were used. The length of occluder itself, packed, is48 mm, opened — 28-32 mm and diameter 31-35 mm. The occluder was placed into LAA via puncture of femoral vein and interatrial septum under x-ray and ulltrasound control. After implanting of the occluder, during 16 weeks the behavior and appetite of animals were controlled. In prospective study the blood was collected for inflammatory response control, and ultrasound examination of the heart. Controls were 3 swings. In 16 weeks the animals were withdrawn from experiment for morpho-functional investigation of the heart. For cytotoxicity study, histology was done of limphatic nodes, liver and kidneys. Results. By ultrasound imaging it was shown that occluder placement did not significantly influence hemodynamics of animals. Blood tests showed nonsignificant changes during the first weeks after surgery, with normalized values in 12 weeks. Autopsy and microscopy did not show significant inflammatory and degenerative changes in the heart, as in internal organs. There was satisfactory “ingrowth” of the occluder with smooth plain surface of endocardium from the side of the left atrium. Conclusio n. The experience of occluder preclinical test showed its construction and functional effectiveness for the aim of further usage in patients with high risk of cardioembolic strokes due to LAA thrombosis. The procedure of occluder implanting is simple if the personnel is skilled enough and there is proper equipment.