Significance of altered bilirubin subfractions in bile following hepatectomy

Liver regeneration is dependent on the extent of hepatectomy

BACKGROUND

The upper limit for the size of hepatectomy is approximately 90% in rats. The aim of the study was to assess quantitatively using stereological methods the impact on liver function, regeneration rate (RR), and hepatocyte proliferation of varying hepatectomy size in a rat model.

MATERIALS AND METHODS

A total of 104 male Wistar rats were subjected to 30%, 70%, or 90% partial hepatectomy, sham operation, or no operation. Euthanization and harvesting of liver tissue and blood took place at postoperative days 1, 3, and 5 (n = 8 per group). Liver-specific biochemistry and RR were evaluated. Hepatocyte proliferation was estimated by immunohistochemical staining for Ki-67 antigen using unbiased stereological principles.

RESULTS

Liver RR in the 90% group increased by a 6.6 fold during the 5 postoperative days compared with only a minor increase in both the 70% and 30% partial hepatectomy groups. The highest number of Ki-67-positive hepatocytes was observed in the 70% group at postoperative day 1 and for the 90% group at postoperative day 3. Prothrombin-proconvertin ratio was significantly lower in the 90% group 1 d after surgery compared with all other groups, however, nearly normalized at postoperative day 5.

CONCLUSIONS

We show that liver RR and the number of proliferating hepatocytes increase, whereas the initial hepatic synthetic capacity decreases with increasing hepatectomy size.

Plasma bilirubin correlations in non-obstructive cholestasis after partial hepatectomy

BACKGROUND

The aim of this study was to provide an improved outline of the patterns and correlates of changes in plasma bilirubin after partial hepatectomy.

METHODS

A large series of blood measurements and complementary variables were prospectively collected from 85 patients undergoing liver resection, and bilirubin correlations were assessed by regression analysis.

RESULTS

Early postoperatively, the best simultaneous correlates of increasing bilirubin were the preoperative value, the duration of surgery, and the number of blood transfusions (r2 = 0.74, p < 0.001). Subsequently, increasing bilirubin became related to the number of resected liver segments, the duration of intraoperative liver ischemia, the use of continuous vs. intermittent ischemia, and the presence of sepsis (r2 = 0.82, p < 0.001); these were also the best simultaneous correlates of peak bilirubin. This pattern was characterized by prominently conjugated hyperbilirubinemia, hypocholesterolemia, and moderately increased alkaline phosphatase, and occurred in the absence of obstructive cholestasis.

CONCLUSIONS

Major hepatectomy, parenchymal ischemia, and sepsis have similar and synergistic impacts as determinants of prominently conjugated hyperbilirubinemia after liver resection. This is likely related to impaired hepatocellular bilirubin transport and occurs in the absence of obstructive components.