Differences in Collagen Type Distribution in Ruptured Aortas

Differences in collagen type distribution in ruptured aortas of Friesian horses, vs aortas of healthy Friesian and Warmblood horses

Introduction
Ruptures in the aortic arch near the ligamentum arteriosum are more prevalent in Friesian horses compared to Warmblood horses (I). Collagen is a very important strength-providing element of the aortic wall and collagen disorders have been suggested to play a role in the pathogenesis of aortic rupture in humans (II). This study aimed at investigating collagen types 1 and 3 within the aortic wall of affected Friesian horses, unaffected Friesian horses and Warmblood horses.

Material and Methods
The study population encompassed 20 affected Friesian horses (1-10 years old), 30 unaffected Friesians (0-9 years) and 28 Warmblood horses (0-10 years). Full thickness aortic wall biopsies harvested from the thoracic aorta, approximately 30 cm distal of the ligamentum arteriosum, were stained immunohistochemically for collagen 1 and 3. Area percentages in 3 randomly chosen fields of the intima, media and adventitia were determined by image analysis and semiquantitatively scored. The area percentage differences between groups were investigated using a mixed model with horse as random effect and group, layer and their interaction as categorical fixed effects. […]