Histological changes in chronic experimental aneurysms surgically fashioned in sheep

Area of Science:

• Vascular surgery
• Cardiovascular research
• Animal models

Background:

• Surgically created venous pouch saccular aneurysms were used to study long-term hemodynamic effects.
• Previous research has not fully explored the chronic pathological changes in such models.

Purpose of the Study:

• To investigate the long-term hemodynamic effects on vessel walls after creating experimental aneurysms.
• To assess the pathological changes in these aneurysms over time and their similarity to human vascular diseases.

Main Methods:

• Experimental venous pouch saccular aneurysms were surgically fashioned on common carotid arteries of sheep.
• Vessel walls were examined up to seven years postoperatively.

Main Results:

• Aneurysms became more spherical and enlarged at variable rates.
• Venous sac changes mimicked human phlebosclerosis, with wall sclerosis and loss of mural architecture.
• Lipid accumulation, calcification, intimal tears, mural dissection, and thrombosis occurred, similar to human atherosclerosis.

Conclusions:

• The sheep carotid artery aneurysm model demonstrates pathological changes comparable to human vascular disorders.
• This model is suitable for studying atherosclerosis and the effects of hemodynamic stress on vessel walls.