Published online Sep 14, 2013. doi: 10.3748/wjg.v19.i34.5700
Revised: June 8, 2013
Accepted: July 23, 2013
Published online: September 14, 2013
Processing time: 131 Days and 13.3 Hours
AIM: To investigate time-dependent changes caused by temporal portal vein obstruction and subsequent reperfusion in the lobe with or without an occluded portal vein.
METHODS: The portal vein (PV) of the anterior lobe of the liver of a male Wistar rat (8 wk-old) was obstructed (70%) for 12, 24, 36 and 48 h, respectively, and models were sacrificed at 48 h after reperfusion (each group: n = 10). The histological changes and the status of liver regeneration were compared between a liver biopsy performed on each lobe after temporary obstruction of the portal vein in the same rat liver, and the liver extracted at the time of sacrifice (48 h after reperfusion).
RESULTS: With regard to the obstructed lobe, the liver weight/body weight ratio significantly decreased according to obstruction time. On the other hand, in the non-obstructed lobe, there were no significant differences within each group. The duration of PV occlusion did not seem to be strong enough to introduce liver weight increase. Stimulation of liver regeneration was brought about in the non-occluded lobe by 12-h occlusion, and was sustained even at 48 h after reperfusion. The obstructed lobe atrophied with the passage of time in the obstructed state. However, the proliferating-cell nuclear antigen labeling index also increased at 48 h after reperfusion, and a repair mechanism was observed.
CONCLUSION: Temporary blood flow obstruction of the portal vein may become a significant trigger for liver regeneration, even with an obstruction of 12 h.
Core tip: This paper describes the chronological effects of temporary portal venous branch ligation on liver regeneration in rats. These results imply that, in the future, it might be possible to control liver regeneration. In the clinical setting, we have just completely occluded the portal venous branch irreversibly.