The plastinated porcine heart specimen for learning echocardiography

With recent developments in echocardiography, most operators need to be familiar with cross-sectional cardiac anatomy. However, the precise spatial relationships of the components of the heart can be difficult to understand. Plastination has been known as an excellent technique that helps to keep anatomical specimens in a dry, firm, shape-preserved condition. In this paper, the method of producing plastinated pig heart specimens for learning echocardiography is described. The final specimens show the detailed structure of the heart, which provides students and beginners who are training for echocardiography a better chance of developing a three-dimensional understanding of the heart. Introduction It is widely accepted that echocardiography is one of the noninvasive and very useful tools for diagnosing cardiovascular disease. However, its usefulness and the correct diagnosis depends on both the proper skills and the well-understanding of the heart. The precise spatial relationship of the components of the heart can be difficult to understand for students and beginners. Therefore, anatomic drawings, atlases, and models that correspond to standard ultrasound images are necessary to assist echocardiographic interpretation. However, from among the other artificial models of the heart, it is difficult to find instructional materials suitable for students or beginners who have just begun to study echocardiography. The plastination method has been used to process cadaveric material and make it into dry, odorless, and durable specimens that can be handled without gloves [1-3]. From this standpoint, the potential value of plastination is increasingly appreciated [4-9]. It is possible to produce a plastinated specimen of a porcine heart, cut off the suitable cross-section surfaces for standard echocardiographic images, and make a comparison while performing echocardiography. Procedure Material The heart of a pig subjected to meat processing with no morphological abnormalities on macroscopic inspection was used. Dilatation under hydrostatic pressure The heart was flushed with tap water to remove blood clots. Color injection into the coronary vessels For the injection into the coronary arteries (left anterior descending artery, left circumflex artery, and right coronary arteries), colored silicone KE24 (Shin-Etsu Chem. Co., Tokyo, Japan), red, blue, and yellow, respectively, was used. Fixation under hydrostatic pressure In order to provide a proper shape, short polyethylene tubes of the appropriate dimensions were inserted into the veins of the veins, the vena cavas, the aorta, and the pulmonary artery. After putting the cork stoppers on the veins of lung and the vena cavas, dilatation and fixation were performed with filled 10% formalin solution (10 parts 3538 wt. % formaldehyde solution in water and 90 parts tap water) through the two tubes inserted into the aorta and the pulmonary artery with hydrostatic pressure. The aorta and the pulmonary artery were plugged to keep the fixative inside, and then the heart was immersed in a solution of 10% formalin for 7 days. After fixation, all cork stoppers and tubes were removed, and the heart was then immersed in running tap water for 12-24 hours. Dehydration under hydrostatic pressure To dehydrate, the precooled heart was freeze-substituted with pure acetone with three changes every week. To degrease, if necessary, the dehydrated heart was left at room temperature without removing it from acetone for an additional week. Impregnation in a vacuum chamber The heart was then transferred into the silicone KE108, and vacuum impregnation in the freezer for 1-3 days was started. Hardening and aftercare The heart was taken out of the silicone, excess silicone was wiped off, and it was finally mounted on a supporting device to dry out and Correspondence to: Hiromi Suenaga, Ph.D, Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan, Tel: +81 836 22 2133; Fax: +81 836 22 2133; E-mail: [email protected]