Temporal variations in stump pressure and assessment of images obtained from cone-beam computed tomography during balloon-occluded transarterial chemoembolization

Aim: Balloon-occluded transcatheter arterial chemoembolization (B-TACE) was used to show the optimized duration of balloon occlusion to start injection of lipiodol in order to maximize lipiodol deposition in the nodule, and to reveal the end-point of lipiodol injection. Methods: Of 29 consecutive patients who underwent balloon-occluded TACE between November 2013 and February 2014, we were able to measure stump pressure for 219 nodules in 27 patients. Tumors were counted, measured and could be visually assessed in 20 of these patients at 26 sites. Tumors with multiple feeders were found in eight patients. Arterial blood pressure was measured before, immediately after and 5 min after balloon occlusion prior to intra-arterial injection, as well as before and after balloon deflation after intra-arterial injection. Images were assessed qualitatively by two radiologists as well as quantitatively by calculating the contrast-to-noise ratio. Results: We found no significant difference in pressure between immediately after and 5 min after balloon occlusion. Mean stump pressure before balloon deflation after intra-arterial injection was 70.4 mmHg. We observed a significant increase in qualitative scores after balloon occlusion (P < 0.001), and the mean score in the third-order branch was significantly higher than that in the first-order branch (P = 0.048). Conclusion: Our results indicate that intra-arterial injection can be started at any time after balloon occlusion and that 70 mmHg may be considered as a possible indicator of the end-point for arterial injection.