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MATERIAL TESTING SYSTEM 186

Blood Vessel Tensile Strength Tests

People think, move, and act to sustain life, and the consistent vital energy source behind this is our blood vessels.
There are a variety of vascular diseases including arterial sclerosis; aortic aneurisms and phlebeurysms in which an "bump" is present in the vessel; and arterial obstructions and thrombophlebitis in which the blood vessels become clogged. Grafting of artificial blood vessels is sometimes used to remedy these vascular diseases.

Modern artificial blood vessels make widespread use of tubes knitted from nonallergic fibers, and nonwoven vessels created by drawing techniques. In contrast, on the regenerative medical front, artificial blood vessels are being developed that offer functions closer to those of natural blood vessels.
Various types of investigations are being conducted to determine the extent to which these artificial blood vessels mimic natural blood vessels.
This report introduces the results of strength tests for a variety of blood vessels (carotid arteries, jugular veins, aortas, inferior vena cava), as well as urinary tracts, and decellularized urinary tracts (urinary tracts from which the cellular components have been chemically removed: in regenerative medicine, this is utilized as artificial blood vessels, with the aim of regeneration through dissemination of one's own cells).
The tests were conducted with the Shimadzu table-top precision universal tester, the Autograph AG-X (Fig. 1). 
Fig. 2 shows the tensile test for a dog’s carotid artery.

 

Fig. 3 shows the tensile test results for artificial blood vessels (decellularized urinary tracts), while
Fig.4 shows the tensile test results for a dog’s urinary tract.
From Figs. 3 and 4 and Table 1, it is evident that the dog’s urinary tract has the higher maximum test force and displacement, due to higher strength and elasticity. However, the measurement data may change when the cells have been disseminated.

 

Table 1

Sample Details	Maximum Test Force N	Maximum Displacement mm	Maximum Stress N/mm2
Artificial Blood Vessels (Decellularized Urinary Tract)	6.75	11.37	3.75
Dog’s Urinary Tract	11.45	23.89	5.78

 

Figs. 5 and 6 are diagrams of test force versus displacement for a dog's aorta and inferior vena cava respectively. From a comparison of these figures, it is evident that the aorta is stronger in terms of withstanding blood pressure. While the vein is not as strong, it demonstrates considerable elasticity.

 

 

In evaluating blood vessel strength, more detailed evaluations are made possible by combining measures of elastic modulus and energy with tensile strength. The Shimadzu table-top tester AG-X is capable of quantifying these physical characteristics of blood vessels.