Objectives: (99m)Tc-galactosyl human serum albumin (GSA) scintigraphy is helpful in estimating liver function and the extent of liver fibrosis. Estimation of the liver function necessary for evaluating hepatic resection damage may be difficult in patients with chronic liver damage because of the discrepancy between liver functional parameters. The aim of this study was to develop a classification system for liver function using indocyanine green retention rate at 15 min (ICG R15) and the ratio of uptake by the liver to that by the liver and the heart at 15 min (LHL15) in GSA scintigraphy for hepatic resection.
Methods: A total of 548 consecutive patients who underwent hepatectomy were enrolled in this study. On the basis of ICG R15 cutoff values, the corresponding LHL15 values were determined for rank classification. Postoperative outcomes were compared between patients who met the classification and those who did not.
Results: Ranks were classified into four categories (rank, ICG R15 range, LHL15 range, minimum percentage of future liver remnant volume) - rank 1: ≤10%, ≥0.935, >35%; rank 2: ≤20%, ≥0.90, >60%; rank 3: ≤30%, ≥0.87, >80%; and rank 4: >30%, <0.87, >90%. Patients meeting each classification showed significantly better morbidity, mortality, postoperative prothrombin time (PT) activity, and total bilirubin value on day 5 compared with those who did not. In the ICG rank 2 group (n=249), patients with LHL rank 4 had significantly worse platelet count, PT activity, and histological fibrosis than those with LHL rank 1 despite similar ICG R15 values.
Conclusion: Rank classification can predict the safety of hepatic resection. LHL15 contributes to the classification by predicting histological liver fibrosis.