Submitted to: Journal of Veterinary Medicine
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/28/2006
Publication Date: 6/1/2006
Citation: Barraza, M.L., Strickland, J.R., Zepada, H., Taylor, J.B., Krehbiel, C.R., Bell, G.S., Koltz, J.L., 2006. Gross and histopathological observations of long term catheterized vessels in experimental sheep. Journal of Veterinary Medicine. 53:230-238 (2006). Interpretive Summary: Central vein catheritization in experimental sheep is a difficult technique. Several aspects of the methodology must be addressed. The study of biofilms in intravascular devices must continue as well as the use of anti-coagulants tha may replace the use of heparin. The role of calcium in tissues responding acutely to catheterized vessels in sheep should attract our attention. A better understanding of the causes of catheter dysfunction following surgery will allow us to improve our experimental collection of data and reduction in the number of animals needed for nutrient flux studies.
Technical Abstract: To identify physiological occurrences common with catheter patency complications that arise during post-operative and experimental periods. Nineteen multi-catheterizes sheep, with bodyweights of approximately 61.0 kilograms. Catheters had been surgically placed in the hepatic portal vein (PVS), a hepatic vein (HVC), a distal mesenteric vein (MVC), and a mesenteric artery (MAC). In the previous study, catheters (PVC, HVC, and MAC) were used to collect blood samples or infuse (MVC) p-aminohippurate. Two sheep died during surgery and seven more died during posoperative care. Cetheters were maintained in the surviving sheep for a total of 58 d before necropsies. Histopathological findings indicated that catheter failures were associated with the following tissue responses: 1) thromboses with frequest focal vasculitius; 2) euplastic tissues associated with extensive fibrosis; 3) granulomas; 4) neo-vascularization of the media; 5) calcification processes; and 6) micro-absecesses. Little information regarding these anomalies exists for comparison in experiemntal ruminants. Additional studies are needed to help expand the knowledge of catheter failures in experimental animals. A greater understanding of the mechanisms leading to failure will help researchers improve catheter performance.