Angiographic, Microangiographic and Hemodynamic Evaluation of Hepatic Artery Embolization in the Rabbit

Abstract

The effect of transcatheter embolization of the proper hepatic artery was investigated in the rabbit. A preliminary study in over 100 animals using various embolic materials (autologous clots, gelfoam, isobutyl-cyanoacrylate, lead particles and different sizes microspheres) showed that liver infarction up to 80% was tolerated. In the final study in 20 rabbits 175 µ polystyrene microspheres were used. A threshold dose of 675 microspheres produced neither significant angiographic changes nor a reduction in the hepatic arterial blood flow (radioactive microsphere technique) nor significant liver infarction. Dosages of 1350, 2700 and 5400 microspheres caused liver infarction of 3.8 ± 1.6%, 5.8 ± 2.6% and 37 ± 11%, respectively. With these dosages a temporary reduction in the hepatic arterial blood How was found in both the infarcted and noninfarcted liver although somewhat less in the latter. After one week the hepatic arterial blood flow was slightly above normal in the infarcted areas. Based on angiographic, microangiographic and histologic findings the rearterialization of the infarcts, recognizable at that time radiographically by an increased abnormal blush, occurred by proliferation of new vascular channels rather than through pre-existing collaterals. Gallbladder infarction was a noteworthy dose-dependent complication.