Correlation Between Portal Pressure and Indocyanine Green Retention Rate is Unaffected by the Cause of Cirrhosis: A Prospective Study

Background Accurate estimation of the hepatic functional reserve before liver resection is important to avoid post-hepatectomy liver failure (PHLF). The aim of the present study was to evaluate the association of indocyanine green retention test with portal pressure by the cause of cirrhosis (non-viral vs. viral) and assessed postoperative outcomes including incidence of PHLF in patients with viral and non-viral cirrhosis. Methods The cohort includes 50 consecutive patients with liver cirrhosis scheduled for liver resection for primary liver tumors at the Lausanne University Hospital between 2009 and 2018. Results There were 31 patients with non-viral liver cirrhosis (Non-virus group) and 19 with viral liver cirrhosis (virus group). The indocyanine green retention rate at 15 min (ICG-R15) (p = 0.276), Hepatic Venous Portal Gradient (HVPG; p = 0.301), and postoperative outcomes did not differ between the non-virus group and viral group. ICG-R15 and HVPG showed a significant linear correlation in all patients (Spearman’s rank correlation coefficient, ρ = 0.599, p < 0.001), the non-virus group (ρ = 0.555, p = 0.026), and the virus group (ρ = 0.534, p = 0.007). A receiver operating characteristic curve analysis showed that ICG-R15 was a predictor for presence of portal hypertension (PH; HVPG ≥ 12 mmHg) (area under the curve [AUC] = 0.780). The cut-off value of ICG-R15 for predicting the presence of PH was 16.0% with 72.3% of sensitivity and 79.0% of specificity. Conclusions The ICG-R15 level was associated with portal pressure in both patients with non-virus cirrhosis and patients with virus cirrhosis and predicts the incidence of PH with relatively good discriminatory ability. Clinical trial number https://clinicalTrials.gov(ID:NCT00827723) Local ethics committee number CER-VD 251.08

Development of a simple indocyanine green measurement method using an automated biochemical analyser

Background The indocyanine green retention rate is important for assessing the severity of liver disorders. In the conventional method, blood needs to be collected twice. In the present study, we developed an automated indocyanine green method that does not require blood sampling before intravenous indocyanine green injections and is applicable to an automated biochemical analyser. Methods The serum samples of 471 patients collected before and after intravenous indocyanine green injections and submitted to the clinical laboratory of our hospital were used as samples. The standard procedure established by the Japan Society of Hepatology was used as the standard method. In the automated indocyanine green method, serum collected after an intravenous indocyanine green injection was mixed with the saline reagent containing a surfactant, and the indocyanine green concentration was measured at a dominant wavelength of 805 nm and a complementary wavelength of 884 nm. Results The coefficient of variations of the within- and between-run reproducibilities of this method were 2% or lower, and dilution linearity passing the origin was noted up to 10 mg/L indocyanine green. The reagent was stable for four weeks or longer. Haemoglobin, bilirubin and chyle had no impact on the results obtained. The correlation coefficient between the standard method (x) and this method (y) was r=0.995; however, slight divergence was noted in turbid samples. Conclusion Divergence in turbid samples may have corresponded to false negativity with the standard procedure. Our method may be highly practical because blood sampling before indocyanine green loading is unnecessary and measurements are simple.