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.

[Radiologic diagnosis of liver diseases--method development taking place on a wide front]. / Radiologisk leverdiagnostik--metodutveckling sker på bred front.

Radiological techniques, ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) are increasingly being used to detect and characterise liver diseases. US-guided percutaneous approaches are performed to obtain tissue specimen from the liver and for local treatment of liver tumours. Technical developments of all different modalities, new contrast agents for US and MRI, improvements in liver resection techniques as well as several ways to locally treat liver tumours have emerged during the past few years. In this overview we summarise the present status of different imaging modalities in the diagnosis of liver disease.

Adding 11C-acetate to 18F-FDG at PET Examination Has an Incremental Value in the Diagnosis of Hepatocellular Carcinoma.

OBJECTIVE: The sensitivity of FDG at PET examination of Hepatocellular Carcinoma (HCC) is restricted. In a few studies, all done in Oriental patients, PET-examination with (11)C-acetate has shown a higher accuracy than with FDG. In the current study, the uptake of (11)C-acetate has been compared with the uptake of FDG in the primary HCC in a cohort of Occidental patients. MATERIAL AND METHODS: 44 patients underwent PET-examination with both tracers with a mean of 9 days between the examinations. 26 patients had a microscopical diagnosis and 18 were diagnosed with multimodal radiological methods. At least one relevant radiological examination was available for comparison. RESULTS: At visual evaluation, 13 of the HCC's were positive at PET-examination using FDG and 34 were positive using (11)C-acetate (p<0.001). Median tumor SUVmean of (11)C-acetate was 4.7 and of FDG was 1.9 (p<0.001). There was also a higher uptake of (11)C-acetate by the surrounding liver tissue than of FDG. Median liver SUVmean of [u]11[/u]C-acetate was 3.2 and of FDG it was 1.7 (p<0.001). This corresponded to a median tumour/liver tissue ratio for (11)C-acetate of 1.4 and for FDG of 1.0 (p<0.05). Previous reports of a negative correlation between the uptake of the tracers were weakly supported. In 4 large tumors some portions being hot using one of the tracers were cold using the other tracer and vice versa. CONCLUSION: Adding registration with (11)C-acetate to registration with FDG at PET-examination has an incremental value in the diagnosis of HCC. A higher tumor uptake of (11)C-acetate cannot be taken full advantage of because of a higher uptake also by the surrounding liver tissue. CONFLICT OF INTEREST: None declared.