Background
Reversible PVE is of interest when generating sufficient hypertrophy while preserving the embolized liver lobe. The aim of this study is to modulate lysis time of a fibrin-glue based embolization material by using different concentrations of Aprotinin.

Materials and Methods
PVE of the cranial liver lobes (80% of total liver volume) was performed in twenty-four rabbits using fibrin glue (FG) with different quantities of Aprotinin ( resp. 1000/700/500/300/0 KIU (Kallikrein Inactivator Unit)).
CTvolumetry of non-embolized lobe (NELVol) and (non-embolized) liver-to-body weight ratio were evaluated. Data were compared with a previous series using a permanent embolization material, i.e. polyvinyl alcohol + coils (PVAc).

Result
FG-0KIU-Aprot was completely absorbed in 7 days without hypertrophy of the NEL. At sacrifice (day 7), the embolized portal veins in all animals of the FG1000KIU group were still occluded. The FG700KIU group survived 14 days and in two of five rabbits, the embolized portal vein was recanalized at sacrifice. In the FG500KIU and 300KIU group, 7 out of 10 (70%) showed recanalization of the cranial portal branches. The later groups survived longer (49 days) to evaluate the effect of portal recanalization and atrophy of the embolized lobe. All groups showed a hypertrophy response comparable with the PVAc group. CT volumetry data were supported by liver-to-body weight ratio.

Conclusion
Fibrin glue with the concentrations 300KIU and 500KIU Aprotinin resulted in 70% reversible embolization with a hypertrophy response comparable to the PVAc group.