Safety limit of the extent of hepatectomy for rats with moderately fatty liver: experimental study concerning living liver donor safety.

Introduction: The aim of the present study was to determine whether rats with moderately fatty liver could withstand a 90% hepatectomy, which rats with normal livers can survive.

Material And Methods: Nine-week-old male Wistar rats were used. Normal rat chow was fed to the normal liver group, and fat-enriched rat chow was fed to the fatty liver group for 4 weeks to induce a moderately fatty liver. The authors have previously reported that this fatty liver rat model can cause fatal liver dysfunction after reduced-size-liver transplantation. A 90% and 95% hepatectomy were performed using rats of both groups to evaluate posthepatectomized liver function.

Results: All rats undergoing a 90% hepatectomy were still alive 30 days after the hepatectomy, but the rats that underwent a 95% hepatectomy were all dead within 4 days regardless of group. Increases in the liver remnant wet weight measured until 7 postoperative days after 90% hepatectomy were almost similar among the two groups. Alanin aminotransferase measured at 24, 48, 72, and 168 h after a 90% hepatectomy were significantly higher in the fatty liver group than in the normal liver group. Similarly, at up to 72 h postoperatively, the serum hyarulonic acids were significantly higher in the fatty liver group.

Conclusion: A moderately fatty liver did not cause mortality in 90% hepatectomized rats. However, it caused a higher degree of hepatic parenchymal as well as sinusoidal injury.