Vascular remodeling and its role in the pathogenesis of ascites in fast growing commercial broilers

• Published in: Research in veterinary science Vol. 86; no. 3; pp. 479 - 484
• Main Authors: Nain, S., Wojnarowicz, C., Laarveld, B., Olkowski, A.A.
• Format: Journal Article
• Language: English
• Published: England Elsevier India Pvt Ltd 01-06-2009; Elsevier Limited
• Subjects: Abdomen; animal anatomy; Animals; Aorta - pathology; Aorta - ultrastructure; arteries; Ascites; Ascites - mortality; Ascites - pathology; Ascites - veterinary; blood pressure; Blood vessels; Blood Vessels - pathology; Broiler; broiler chickens; cardiomyopathy; Chickens - growth & development; congestive heart failure; Coronary vessels; Councils; Elasticity; Growth - physiology; Growth rate; Heart failure; Heart Failure - mortality; Heart Failure - pathology; Heart Failure - veterinary; hemodynamics; Microscopy, Electron, Scanning; microstructure; Pathogenesis; Pathology; permeability; poultry diseases; Poultry Diseases - mortality; Poultry Diseases - pathology; Pulmonary arteries; Retrospective Studies; smooth muscle; Survival Analysis; vascular remodeling; vascular tissues; Veins & arteries; Vena Cava, Inferior - pathology; Vena Cava, Inferior - ultrastructure; Veterinary medicine; Heart failure; Blood vessels; Ascites; Broiler
• ISSN: 0034-5288; 1532-2661
• DOI: 10.1016/j.rvsc.2008.08.008

This study examined the putative role of blood vessel pathology in the development of ascites in broilers. Major blood vessels (aorta, brachiocephalic arteries, pulmonary arteries, and vena cava) from normal commercial male broiler chickens, and broilers that developed congestive heart failure (CHF) with or without ascites were subjected to gross and microscopic examination.
On cross-section, grossly, the arteries from normal broilers and those showing dilated cardiomyopathy without ascites appeared circular, with firm wall tone characteristic of the normal artery. In contrast, the arteries from ascitic broilers appeared flaccid and lacked elasticity, which was evidenced by collapsing, ellipsoid cross-sectional arterial lumen owing to the structural weakness of the arterial walls. Microscopically, ascitic broilers showed thinning or occasionally total loss of elastic elements in the arterial wall, and reduced network density of the structural matrix of the vascular wall, as well as increased thickness of fibers in vena cava.
The structural changes seen in the major arteries from ascitic broilers are maladaptive, and as such would definitively impose an increased hemodynamic burden on the already failing heart pump. The changes in veins are indicative of pathological remodeling conducive to increased permeability of the vascular wall, particularly in the situation when a poorly distensible structure is further subjected to wall stress associated with increased pressure and volume overload. Taken together, increased hemodynamic burden and reduced structural density of the venous wall constitute conditions conducive for seepage and accumulation of ascitic fluid.