Continuous assessment of intrahepatic metabolism by microdialysis during and after portal triad clamping.

Background: Ischemia-reperfusion injury is a major concern with portal triad clamping (PTC) in liver surgery. Microdialysis allows continuous intraoperative monitoring of tissue metabolism in the liver. Our aim was to evaluate the feasibility of microdialysis as a tool to assess the intrahepatic metabolic effects of PTC in patients undergoing liver resection.

Methods: Eleven patients who underwent liver resection were subjected to intrahepatic microdialysis. Dialysis fluid samples were collected before, during, and after a 20-min period of PTC. Glucose, lactate, pyruvate (markers of ischemia), and glycerol (marker of cell membrane damage) were analyzed and the lactate/pyruvate ratio was calculated.

Results: During PTC, intrahepatic glucose, lactate, and glycerol increased from 9.1±2.2 to 14.5±2.4 mM, from 2.2±0.3 to 5.8±0.5 mM, and from 63±14 to 142±28 μM, respectively. Pyruvate was unchanged, resulting in an increased lactate/pyruvate ratio (from 39±10 to 104±32). During initial reperfusion, glucose further increased to 16.4±2.9 mM. Pyruvate increased after reperfusion (from 93±18 to 138±23 μM), while lactate was stable, resulting in a normalized lactate/pyruvate ratio. Glycerol continued to increase during initial reperfusion.

Conclusions: PTC was associated with considerable intrahepatic metabolic alterations with anaerobic metabolism, increased glycogenolysis, and cellular membrane damage resulting in increased levels of glucose, lactate, glycerol, and lactate/pyruvate ratio. Microdialysis is easy to use and allows continuous monitoring of intrahepatic metabolism during liver surgery.