Table 4. Common animal models for evaluation of artificial blood vessels in vivo.

Animal model	Characteristics	Application inner diameter (mm)	Common length (mm)	Longest implantation period	Implantation site	References
Sheep	Similar cardiovascular physiology, endothelialisation mechanisms and thrombogenicity mechanisms to humans. Suitable size and long-term studies possible. Higher incidence of hypercoagulability.	4-6 4-6	80-100 60-100	9 months 3 months	Carotid artery Arteriovenous graft	48, 74 129
Pig	Similar vascular physiology and anatomy to humans. Well established as a model for assessing vascular grafts. Mount an extensive immune response to implanted tissues.	3-6 3-6	30-100 10-100	6 months 4 weeks	Iliac artery Carotid artery	130 52
Dog	Lack of spontaneous endothelialisation and immune response restricts study lengths. Ease of accessing vessel due to thin skin. Thrombogenicity mechanisms and vessel viscoelastic properties differ from humans.	3-6 3-6	30-50 30-50	6 months 1 year	Abdominal artery Carotid artery	131 119
Baboon	Physiology and cardiovascular anatomy are the most similar to humans. Suitable for a wide range of non-invasive imaging techniques adapted from humans. High cost and ethical concerns associated with using primates in medical research.	3-6	30-50	6 months	Arteriovenous graft	26
Rabbit	Similar endothelialisation rates and thrombogenicity mechanisms to humans. Demanding higher anticoagulant function. Limited to short-term studies.	1-4 1-4 1-4	5-30 5-30 5-30	12 months 2 weeks 3 months	Carotid artery Femoral artery Abdominal artery	94, 132 133 134
Rat	Large sample size. Wide variety of transgenic lines. Allows exploration of genetic/molecular mechanisms.	1-3 1-3	5-30 5-10	18 months 12 weeks	Abdominal artery Carotid artery	73, 135 136
Mouse	Ideal for biocompatibility and cell infiltration studies.	0.5-1	3-10	6 months	Carotid artery	137