Factors impacting technical success rate of image-guided intra-arterial therapy in rat orthotopic liver tumor model.

Transcatheter hepatic arterial chemoembolization (TACE) is the current standard of care for intermediate stage hepatocellular carcinoma (HCC) patients. To study the effects of TACE in the tumor immune microenvironment, an immunocompetent rat model is required. The purpose of this study was to determine factors influencing technical success during hepatic arterial catheterization in immunocompetent orthotopic rat liver models. To this end, 91 Sprague-Dawley and eighty-three F344 rats underwent transcatheter hepatic arterial embolization using a transcarotid approach and were divided into a non-tumor-bearing (n = 41) and tumor-bearing (n = 133) groups. Vascular diameters of the hepatic arterial branches were evaluated from angiographic images. Catheterization of the proper hepatic artery (PHA) was achieved in 92% of the tumor-bearing and 68.3% of the non-tumor-bearing rats. We found a strong positive association between the diameter of the PHA and animals' body weight in both groups (P < 0.005), independently of the rat's strain. Results of the logistic regression model predicting a successful catheter placement into the PHA according to the animal's weight indicate that successful PHA catheterization is likely to be achieved in tumor-bearing animals weighing ≥ 250 g and > 308 g in non-tumor-bearing rats, with a sensitivity and specificity of 91.3% and 100.0% and 96.4% and 92.3%, respectively. In conclusion, animal's body weight at the time of catheterization is the principal determinant of technical success for transcatheter arterial embolization. Familiarity with these technical factors during animal selection will improve TACE technical success rates.