Biomechanical properties studying of atherosclerotic aortic wall with micro and macrocalcifications

Abstract

Objective: In the aortic wall calcification occurs as a pattern of micro- and macrocalcification changing significantly aortic wall biomechan­ical properties. The aim of the work is biom echanical properties studying of aortic wall in the conditions of macro and microcalcification. Method: 18 atherosclerotic aorta tissue samples with histologically verified different calcification patterns were studied. The samples were divided into 3 groups: control - without calcification man ifistation (6), with micro calcification - calcium deposits to 4.99 mm (6), macrocalcification - calcifications <5 mm (6). Hydrostatic test stand was to study tissue samples strength, using the principle of equal distribution of pressure and its gradual increase on the sample surface. The experimental stand consists o f metal con­tainer, filled with liquid under pressure o f 5-8 bar, pressure conduit, a regulating valve, model m anom eter (accuracy class 0.4) and test chamber with fastening mechanisms o f aorta samples. Moments of aortic w all ru p tu re and th e manometer index were fixed on the camera. Results: For the control group pressure o f aorta wall rupture was 389,19 ± 60,11 kPa. For aorta with microcalcifications rupture pressure w as 1 2 8 ,6 3 ± 2 5 ,3 4 k P a , at th e sam e tim e , th e a o r ta w ith macrocalcification patterns rupture pressure was 344,0 ± 35,88 kPa. Conclusion: Aorta samples with macrocalcifications are significantly more stable to h y d r o d y n a m ic p r e s s u r e , tha n a o r ta w ith microcalcifications (p < 0.01). Moreover, the resistance to pressure in the case o f macrocalcifications is not significantly different from the control group (p> 0.05)