Background:Although major or extended hepatectomy may result in drastic alterations in the hemodynamics and oxygen metabolism of the residual livers, this issue remains to be elucidated in detail.Material/Methods: In this study, in vivo near-infrared spectroscopy (NIRs) was performed to determine oxy-/deoxy-hemoglobin (Hb) and oxidized/reduced cytochrome oxidase (Cyt.aa[sub]3[/sub]) contents in hepatic tissues in a rat 70% hepatectomy model. We also investigated the effectiveness of Pringle occlusion for minimizing bleeding and the therapeutic effects of prostaglandin E[sub]1[/sub] (PGE[sub]1[/sub]) on haemodynamics alteration after hepatectomy.Results: After 70% hepatectomy, total Hb (oxy-Hb + deoxy-Hb) content was persistently elevated in the residual hepatic tissues, indicating congestion probably caused by surplus portal inflow. Oxidized Cyt.aa[sub]3[/sub] contents were elevated after hepatectomy, whereas reduced Cyt.aa[sub]3[/sub] contents were not significantly altered, indicating that mitochondrial respiration was not impaired. Pringle occlusion before hepatectomy per se did not cause deterioration of the hemodynamics or oxygen metabolism of the residual livers. The congestion of the residual liver after 70% hepatectomy was significantly improved by continuous injection of PGE[sub]1[/sub] (1.0 mg/kg/min) via the portal vein.Conclusions: The alteration of hemodynamics and oxygen metabolism in the liver after extended hepatectomy has been quantitatively evaluated using the NIRs.

Keywords: Hemodynamic Processes, Hepatectomy, Liver - blood supply, Liver - metabolism, Liver - surgery, Oxygen - metabolism, Spectroscopy, Near-Infrared, Water - metabolism, Hemodynamics, Hepatectomy, Liver - surgery, Oxygen - metabolism, Spectroscopy, Near-Infrared, Water - metabolism