Perioperative real-time monitoring of indocyanine green clearance by pulse spectrophotometry predicts remnant liver functional reserve in resection of hepatocellular carcinoma

Background: There is no standard method for predicting remnant liver functional reserve after hepatectomy or for monitoring it in real time. Methods: Indocyanine green (ICG) clearance (K) was measured non-invasively and instantaneously using pulse spectrophotometry before surgery, during inflow occlusion and after hepatectomy in 75 patients who underwent anatomical liver resection for hepatocellular carcinoma (HCC). Results: Eight patients (11 per cent) suffered liver failure and one (1 per cent) died in hospital. An estimated remnant K value of 0(.)090 per min was the cut-off value for liver failure. In a logistic regression model, the estimated remnant K (0(.)090 per min; P = 0(.)022) and age (65 years; P = 0(.)025) were significant predictors of postoperative liver failure. There was a correlation between the estimated and measured post-hepatectomy K, and between the inflow occlusion K and measured post-hepatectomy K (P < 0(.)001). The cut-off value of less than 0(.)090 per min for the estimated remnant K resulted in 88 per cent sensitivity and 82 per cent specificity for predicting liver failure. Conclusion: Perioperative real-time monitoring of ICG-K is useful for evaluating the remnant liver functional reserve before, during and after liver resection for HCC. The estimated remnant K is a significant predictor of liver failure.