Temporary portal vein embolization is as efficient as permanent portal vein embolization in mice

Background: Temporary portal vein embolization may be a safe alternative to permanent portal vein embolization. Such a new approach could be applied in living-related liver transplantation to increase graft volume before procurement. The impact of temporary portal vein embolization on occluded liver after recanalization, however, has never been assessed. Using a mouse model of temporary portal vein embolization, we investigated (1) the efficiency of temporary portal vein embolization in inducing nonoccluded liver hypertrophy and (2) the regeneration potential and functional recovery of embolized liver after recanalization.

Methods: Selected portal vein branches were occluded using gelfoam powder (temporary portal vein embolization) or embospheres (permanent portal vein embolization), n = 5/group. Magnetic resonance volumetry and angiography were used to determine volumes of the liver lobe and portal vein branch recanalization. In order to assess the functional and regenerative capacity of occluded liver lobes, nonoccluded lobes were resected 14 days (timespan of complete portal vein recanalization) after temporary portal vein embolization or permanent portal vein embolization. Subsequently, RNA sequencing was performed to compare the signaling pathways of early liver regeneration among the groups.

Results: Hypertrophy of nonoccluded lobes 30 days after temporary portal vein embolization and permanent portal vein embolization was similar (103 ± 26% and 129 ± 13%, P = .11). Temporary occluded lobes increased their volumes after nonoccluded lobes resection, reaching similar liver-to-body-weight ratios and similar functional capacity after 7 days compared with partial hepatectomy controls (4 ± 1% vs 4 ± 1%, P = .22). Partial hepatectomy activated similar signaling pathways in temporary occluded and native liver.

Conclusion: Temporary portal vein embolization induces hypertrophy of contralateral liver lobes similarly to permanent portal vein embolization in mice. This experimental work suggests that temporary portal vein embolization may be considered as a possibility in living liver donation, because regenerative and functional capacities are preserved in the embolized liver after recanalization in mice.