Researchers at the University of Copenhagen and the Karolinska Institutet published a paper titled "Carotid Catheterization and Automated Blood Sampling Induce Systemic IL-6 Secretion and Local Tissue Damage and Inflammation in the Heart, Kidneys, Liver and Salivary Glands in NMRI Mice" in the journal PLOS One. The authors found that NMRI mice with carotid artery catheters and subjected to automated blood sampling had elevated levels of the cytokine IL-6 compared to control mice.
The catheterized mice also displayed tissue damage and inflammation in regions far from the surgical site, including the heart and kidney. The authors attributed this to thrombi which detached from the catheter end and mobilized to sites throughout the body.
Based on these findings, researchers should be aware of potential confounding effects from procedures such as catheterization.