Clinical implication of ICG test in major hepatectomy for biliary tract cancer

Major hepatectomy with bile duct resection (BDR) is associated with severe postoperative complications; therefore, evaluation of preoperative liver function is important. However, little is known about mechanisms of increased severe complications in patients with poor liver function. The aim of this study was to evaluate whether indocyanine green retention rate after 15 minutes of injection (ICG-R15) is useful for predicting the risk of severe postoperative complications in this operation, and to reveal the mechanisms of increasing severe complications by focusing on immune function and liver regeneration after hepatectomy.

Patients receiving major hepatectomy with BDR between 2000 and 2017 were retrospectively reviewed. Severe postoperative complications were defined as Clavien-Dindo grade ≥IV.

In 284 patients undergoing major hepatectomy with BDR, ICG-R15 was correlated with severe postoperative complications, with cut-off value of 11.8%. In brief, the incidences of hyperbilirubinemia, coagulopathy, liver failure, respiratory failure, severe complications, and mortality were higher in the high ICG-R15 group. Moreover, high ICG-R15 (≥11.8%) was an independent factor for predicting severe complications after major hepatectomy with BDR. Immune dysfunction in the early phase after operation, prolonged postoperative immunosuppression, and delayed liver regeneration were reasons for increasing severe postoperative complications in patients with high ICG-R15.

High ICG-R15 is an independent risk factor for severe complications after major hepatectomy with BDR, and its cut-off value is 11.8%. Compromised condition and delayed liver regeneration induced by immune dysfunction are reasons of increased severe postoperative complications in patients with high ICG-R15.