In situ quantification of endothelial cell damage caused by iodinated contrast media using a rat vena cava model

Abstract

Quantification of vascular endothelial cell damage induced by iodinated contrast media using an in situ perfused rat vena cava model. The institutional review board approved this study protocol prior to the commencement of all studies. A laparotomy was performed in 90 rats divided into 18 groups of five, and an 18 G-catheter was inserted into the abdominal vena cava (mean length: ca 8mm). After sacrificing, a thoracotomy was done and the outflow perfusate was emitted via a polyethylene tube inserted into the thoracic vena cava through the right atrium for an open system. Iopamidol (300 or 370 mgI/mL, 50 or 100mL) was injected via the abdominal vena cava at a rate of 1, 4, or 8 mL/s. The abdominal vena cava was removed for histological analysis (n=5). Physiological saline was injected as a negative control. The detachment percentage of endothelial cells was calculated by measuring the circumference and detachment section of the endothelium. The difference of the detachment percentage and circumference between each group was compared with Tukey's range test. In contrast media groups, the severity of damage to the vascular endothelial cell was direct proportional to the increase of injection rate. The detachment percentage at 4 or 8 mL/s was significantly higher than that at 1 mL/s. As a result, the correlation between the injection rate and severity of cell damage was significant; however, the detachment percentage among contrast media groups was not significant at any injection rate. The in situ vena cava model was able to quantify contrast media injection related endothelial damage based on histopathological endpoints. Moreover, our results indicate that mechanical shear stress besides physico-chemical properties such as osmolality or viscosity cause endothelial damage.