Creation of Abdominal Aortic Aneurysms in Sheep by Extrapolation of Rodent Models: Is It Feasible?

Verbrugghe, Peter; Verhoeven, Jelle; Clijsters, Marnick; Vervoort, Dominique; Coudyzer, Walter; Verbeken, Eric; Meuris, Bart; Herijgers, Paul

doi:10.1016/j.avsg.2018.02.041

Cited by 4 publications

(3 citation statements)

References 31 publications

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“…Nowadays, sheep (Ovis aries) are the most commonly used animal for preclinical evaluation of heart valve substitutes, primarily because of the similarities in cardiovascular anatomy and physiology to humans (17). Furthermore, they are known for their rapid postoperative recovery, ease of establishing vascular access, moderate weight gain and docile nature, facilitating perioperative care and follow-up investigations (18,19). As the ratio between mean systemic and pulmonary arterial pressures (75-100 mmHg and 15-17 mmHg in sheep, respectively) in sheep is similar to that in humans, a comparable relative increase in autograft diameter and wall stress can be expected (19,20).…”

Section: Existing Animal Models Of the Ross Proceduresmentioning

confidence: 99%

Back to the root: a large animal model of the Ross procedure

Hoof¹,

Claus²,

Jones³

et al. 2021

Ann Cardiothorac Surg

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The excellent clinical outcome of the Ross procedure and previous histological studies suggest that the pulmonary autograft has the potential to offer young patients a permanent solution to aortic valve disease.We aim to study the early mechanobiological adaptation of the autograft. To this end, we have reviewed relevant existing animal models, including the canine models which enabled Donald N Ross to perform the first Ross procedure in a patient in 1967. Two research groups recently evaluated the isolated effect of systemic pressures on pulmonary arterial tissue in an ovine model of a pulmonary artery interposition graft in the descending aorta. While this model is ideal to study the artery's biological response and the effect of external support, it does not recreate the complex environment of the aortic root. The freestanding Ross procedure has been performed in pigs and sheep before. These studies offered valuable insights into leaflet growth and histological remodeling, yet may be less relevant to adults undergoing the Ross procedure, as pronounced autograft dilatation was achieved by using small, rapidly growing animals. Therefore, a large animal model remains needed to determine the ideal conditions and surgical technique to ensure longterm autograft remodeling and valve function. We set out to develop an ovine model of the Ross procedure performed as a freestanding root replacement, acknowledging that the sheep's specific anatomy and the setting of an animal laboratory would mandate several modifications in surgical strategy. This article describes the development, surgical technique and early outcomes of our animal model while highlighting opportunities for further research.

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Section: Existing Animal Models Of the Ross Proceduresmentioning

confidence: 99%

Back to the root: a large animal model of the Ross procedure

Hoof¹,

Claus²,

Jones³

et al. 2021

Ann Cardiothorac Surg

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“…Future studies, are also required to assess the long-term results of this model while measuring the AAAs with ultrasound. This model should also be trialed in larger animals although there have been many reports of failures when applied to larger animals ( 2 , 21 ). However, a trial in larger animals is needed to confirm that the AAAs in the present model are similar to human AAAs with infrarenal symmetric fusiform shape.…”

Section: Discussionmentioning

confidence: 99%

A novel animal model of abdominal aortic aneurysm by mechanical injury

Kim,

Park,

Kim

et al. 2024

Exp Ther Med

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The present study established a novel and reproducible animal model to study abdominal aortic aneurysms. In total, 22 adult Lewis rats underwent a procedure to produce mechanical injuries at the infrarenal aorta which was opened temporarily. The aortas were injured 6 times and repaired. Those rats were divided into 2 groups and the aortic aneurysm tissue was harvested after 42 (6-week group) or 63 (9-week group) days and evaluated for the progression of aortic aneurysms. In the 6-week group, changes in the aneurysm were observed in 6/10 (60%) rats and the mean maximum diameter of the aorta demonstrated a 119% increase in size from the baseline measurement. In the 9-week group, changes in the aneurysm were observed in 8/11 (88%) rats and the mean maximum diameter of aorta demonstrated a 133% increase in size. Additional findings from the aortic aneurysm tissue were found microscopically, including the destruction of the tunica media and the elastic fiber. The present study demonstrated that this novel animal model for the development of abdominal aortic aneurysms (AAAs) produced by mechanical injury may have high reproducibility and similar gross and microscopic morphology to humans. This model could be helpful to investigate the treatment of AAAs.

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“…The somatic growth is acceptable and adult weight is around 45-100kg for female sheep, well within the husbandry limits even for the adult animals. Their docile nature allows extensive perioperative care and follow-up investigations with minimal or no sedation [7,9]. Sheep anatomy is comparable to human with similar annulus size, systemic and pulmonary pressures [10].…”

Section: Type Of Animalmentioning

confidence: 99%

Development of an Orthotopic Pulmonary Valve Replacement Porcine Model for Mechanical Heart Valve Thrombosis Research

Langenaeken,

De Meester,

Hecke

et al. 2023

Preprint

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Objective Animal models play a vital role in preclinical cardiovascular testing of materials. While sheep have traditionally served as the standard for preclinical cardiovascular testing, pigs are considered a superior option due to a more comparable coagulation system. This study aimed to compare the thrombogenicity of sheep and pigs in a pulmonary valve replacement model. Methods Pigs (n = 12) and sheep (n = 5) underwent pulmonary valve replacement using a bileaflet mechanical valve without any antithrombotic postoperatively. The follow-up period extended to 5 months or until valve thrombosis. Valve performance was evaluated through by cardiac ultrasounds complemented by post-mortem macro- and microscopical analysis of the valve and downstream organs. Results In the pig cohort, terminal valve thrombosis occurred in all but one animal within a month. In the sheep cohort, all animals completed the 5-month follow-up period and post-mortem examination revealed thrombi-free valves with both leaflet mobile. Conclusion Sheep demonstrated insufficient thrombogenicity to induce mechanical valve thrombosis, while pigs exhibited rapid and substantial thrombosis on mechanical valves. These findings support the recommendation to transition to pigs as the standard model for valve thrombosis research.

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Creation of Abdominal Aortic Aneurysms in Sheep by Extrapolation of Rodent Models: Is It Feasible?

Cited by 4 publications

References 31 publications

Back to the root: a large animal model of the Ross procedure

Back to the root: a large animal model of the Ross procedure

A novel animal model of abdominal aortic aneurysm by mechanical injury

Development of an Orthotopic Pulmonary Valve Replacement Porcine Model for Mechanical Heart Valve Thrombosis Research

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