Preoperative estimation of future remnant liver function following portal vein embolization using relative enhancement on gadoxetic acid disodium-enhanced magnetic resonance imaging

Impact of aging on hepatic reserve after preoperative portal vein embolization in hepatectomy for perihilar cholangiocarcinoma

PURPOSE

In the current situation of an increasing older adult population with perihilar cholangiocarcinoma (PHCC), the benefits and risks of surgical treatment of PHCC in older people remain controversial. Portal vein embolization (PVE) is a useful preoperative procedure to improve hepatic reserve in the future remnant liver (FRL) and avoid postoperative liver failure after extended hepatectomy for PHCC. This study aimed to evaluate the influence of aging on PVE.

METHODS

We enrolled 25 patients who underwent right hepatectomy with percutaneous transhepatic PVE. Participants aged <70 years (n = 13) and ≥70 years (n = 12) were compared; correlation coefficients were evaluated using all cases. The FRL volume/total liver volume (FRLV/TLV) ratio and the indocyanine green (ICG) clearance rate (ICG-K) fraction of FRL to total liver (ICG-Krem) were analyzed as FRL hepatic reserves.

RESULTS

FRLV/TLV ratio increased after PVE in <70 years and ≥70 years groups (p = 0.002 and p = 0.013, respectively). The change in ICG-K values from before to after PVE varied between both groups (p = 0.040). The ICG-Krem value after PVE increased only in the <70 years group (p = 0.009). A review of all cases showed a negative correlation between the change (after - before PVE) in the ICG-K and ICG-Krem values and age (r = -0.4827, p = 0.0145 and r = -0.4328, p = 0.0306, respectively).

CONCLUSIONS

This study showed aging suppresses hepatic reserve improvement in the FRL, particularly in ICG clearance after PVE in PHCC cases.

Management of potential portal vein thrombus during laparoscopic right hemihepatectomy following portal vein embolization

BACKGROUND

Portal vein embolization (PVE) is often performed prior to right hemihepatectomy (RH) to increase the future liver remnants. However, intraoperative removal of portal vein thrombus (PVT) is occasionally required. An algorithm for treating the right branch of the PV using laparoscopic RH (LRH) after PVE is lacking and requires further investigation.

METHODS

In our department, after the confirmation of a lack of extension of PVT to the main portal trunk or left branch on preoperative examination (ultrasound and contrast-enhanced computed tomography), a final evaluation was performed using intraoperative ultrasonography (IOUS). Here we present the cases of eight patients who underwent LRH after PVE and examine the safety of our treatment strategies.

RESULTS

IOUS revealed PVT extension into the main portal trunk in two cases. For the other six patients without PVT extension, we continued the laparoscopic procedure. In contrast, in the two cases with PVT extension, we converted to laparotomy after hepatic transection and removed the PVT. The median operation time for hepatectomy was 562 min (421-659 min), the median blood loss was 293 mL (85-1010 mL), no liver-related postoperative complications were observed, and the median length of stay was 10 days (6-34 days).

CONCLUSIONS

PVT evaluation and removal are important in cases of LRH after PVE. Our strategy is safe and IOUS is particularly useful for laparoscopically evaluating PVT extension.

Risk Stratification of Patients with Marginal Hepatic Functional Reserve Using the Remnant Hepatocyte Uptake Index in Gadoxetic Acid-Enhanced Magnetic Resonance Imaging for Safe Liver Surgery

BACKGROUND

This study aimed to explore the efficacy of gadoxetic acid-enhanced (Gd-EOB) magnetic resonance imaging (MRI) in surgical risk estimation among patients with marginal hepatic function estimated by indocyanine green (ICG) clearance test.

METHODS

This analysis focused on 120 patients with marginal hepatic functional reserve (ICG clearance rate of future liver remnant [ICG-Krem] < 0.10). Preoperative Gd-EOB MRI was retrospectively reviewed, and the remnant hepatocyte uptake index (rHUI) was calculated for quantitative measurement of liver function. The predictive power of rHUI for posthepatectomy liver failure was compared with several clinical measures used in current risk estimation before hepatectomy.

RESULTS

Receiver operating curve analysis showed that rHUI had the best predictive power for posthepatectomy liver failure among the tested variables (ICG-R15, ICG-Krem, albumin + bilirubin score, and albumin + ICG-R15 score). Cross-validation showed that a threshold of 925 could be the best cut-off value for estimating the postoperative risk of liver failure with sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 0.689, 0.884, 5.94, and 0.352, respectively.

CONCLUSION

rHUI could be a sensitive substitute measure for posthepatectomy liver failure risk estimation among patients with marginal hepatic functional reserve.

Predictive value of gadoxetic acid-enhanced MRI for posthepatectomy liver failure: a systematic review

Objectives

Effective and non-invasive biomarkers to predict and avoid posthepatectomy liver failure (PHLF) are urgently needed. This systematic review aims to evaluate the efficacy of gadoxetic acid–enhanced MRI-derived parameters as an imaging biomarker in preoperative prediction of PHLF.

Methods

A systematic literature search was performed in the databases of PubMed/Medline, Web of Science, Embase, and Cochrane Library up to 11 December 2020. Studies evaluating the incidence of PHLF on patients who underwent hepatectomy with preoperative liver function assessment using gadoxetic acid–enhanced MRI were included. Data was extracted using pre-designed tables. The Quality In Prognostic Studies (QUIPS) tool was adopted to evaluate the risk of bias.

Results

A total of 15 studies were identified for qualitative synthesis and most studies were marked as low to moderate risk of bias in each domain of QUIPS. The most commonly used parameter was relative liver enhancement or its related parameters. The reported incidence of PHLF ranged from 3.9 to 40%. The predictive sensitivity and specificity of gadoxetic acid–enhanced MRI parameters varied from 75 to 100% and from 54 to 93% in ten reported studies. A majority of the studies revealed that the gadoxetic acid–enhanced MRI parameter was a predictor for PHLF.

Conclusions

Gadoxetic acid–enhanced MRI showed a high predictive capacity for PHLF and represents a promising imaging biomarker in prediction of PHLF. Multicenter, prospective trials with large sample size and reliable, unified liver function parameters are required to validate the efficacy of individual liver function parameters.

Key Points

• There is an obvious heterogeneity of the published studies, not only in variance of MRI liver function parameters but also in indication and extent of the liver resection.

• Signal intensity (SI)–based parameters derived from gadoxetic acid–enhanced MRI are the commonly used method for PHLF prediction.

• Gadoxetic acid–enhanced MRI-derived parameters showed high predictive efficacy for PHLF and can potentially serve as a predictor for the incidence of PHLF.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08297-8.

Hepatic function assessment to predict post-hepatectomy liver failure: what can we trust? A systematic review

Post hepatectomy liver failure (PHLF) could occur even though an adequate liver volume is preserved. Liver function is not strictly related to the volume and the necessity to pre-operatively predict the future liver remnant (FLR) function is emerging, together with the wide spreading of techniques, aiming to optimize the FLR. The aim of this study was to systematically review all the available tests, to pre-operatively assess the liver function and to estimate the risk of PHLF. A systematic literature research of Medline, Embase, Scopus was performed in accordance to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, to identify all the studies available for pre-operative liver function tests to assess the risk of PHLF and/or complications. From the 1122 references retrieved, 79 were included in the review. Dynamic functional tests, such as indocyanine green test (ICG), could evaluate only global liver function, with no definition of functional capacity of the remnant. Magnetic resonance imaging (MRI) with liver-specific contrast agents enables both liver function and volume evaluation; the absence of ionizing radiation showed a better patient's compliance. Nuclear imaging studies as hepatobiliary scintigraphy (HBS) present the unique ability to allow a precise evaluation of the segmental liver function of the remnant liver. Liver volume could overestimate liver function. Several liver function tests are available to evaluate the risk of PHLF in the pre-operative setting. However, no single test alone could accurately predict PHLF. Pre-operative combination between a dynamic quantitative test, such as ICG, with MRI or HBS, should enable a more complete functional evaluation. Functional tests to predict PHLF should be chosen according to patient's characteristics, disease, and center experience.

Prediction of Posthepatectomy Liver Failure: MRI With Hepatocyte-Specific Contrast Agent Versus Indocyanine Green Clearance Test

OBJECTIVE

The objective of our study was to identify whether quantitative measurements from gadoxetic acid-enhanced MRI are useful for predicting posthepatectomy liver failure (PHLF) in patients with hepatocellular carcinoma (HCC) compared with and in combination with future remnant liver volume (FRLV) and an indocyanine green (ICG) clearance test.

MATERIALS AND METHODS

Preoperative gadoxetic acid-enhanced MR images were retrospectively evaluated in 73 patients who underwent anatomic liver resection for HCC between 2011 and 2013. For quantitative measurement of hepatocyte function, relative liver enhancement (RLE) and remnant hepatocyte uptake index (rHUI) were measured using hepatobiliary phase MR images. FRLV was determined using measurements from preoperative CT scans. Univariate and multivariate analyses of measurements from gadoxetic acid-enhanced MRI, ICG clearance tests, and FRLV for finding predictors of PHLF were performed. To compare the diagnostic performance of predictors, ROC analyses were also performed.

RESULTS

Eighteen (25%) of 73 patients met the criteria for PHLF. Univariate analysis revealed that all measurements related to MRI including RLE, rHUI, ICG clearance, and FRLV were significantly associated with PHLF. Multivariate analysis showed that RLE, FRLV, ICG-plasma disappearance rate (ICG-PDR), rHUI, and rHUI corrected for body weight (rHUI-BW) were independent predictors of PHLF (p = 0.011, p = 0.034, p = 0.003, p < 0.001, and p = 0.001, respectively). In ROC analyses, AUCs of rHUI and rHUI-BW were larger than those of other independent predictors; the differences were statistically significant (for rHUI-BW vs RLE, ICG-PDR, and FRLV, p = 0.016, 0.007, and 0.046, respectively; for rHUI vs RLE and ICG-PDR, p = 0.045 and 0.016, respectively).

CONCLUSION

Measurements from gadoxetic acid-enhanced MRI predicted PHLF better than the ICG clearance test in patients with HCC who underwent hepatectomy.

Quantitative Measurement of Hepatic Fibrosis with Gadoxetic Acid-Enhanced Magnetic Resonance Imaging in Patients with Chronic Hepatitis B Infection: A Comparative Study on Aspartate Aminotransferase to Platelet Ratio Index and Fibrosis-4 Index

Objective

To quantitatively measure hepatic fibrosis on gadoxetic acid-enhanced magnetic resonance (MR) in chronic hepatitis B (CHB) patients and identify the correlations with aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 index (FIB-4) values.

Materials and Methods

This study on gadoxetic acid-enhanced 3T MR imaging included 81 patients with CHB infection. To quantitatively measure hepatic fibrosis, MR images were analyzed with an aim to identify inhomogeneous signal intensities calculated from a coefficient of variation (CV) map in the liver parenchyma. We also carried out a comparative analysis between APRI and FIB-4 based on metaregression results. The diagnostic performance of the CV map was evaluated using a receiver-operating characteristic (ROC) curve.

Results

In the MR images, the mean CV values in control, groups I, II, and III based on APRI were 4.08 ± 0.92, 4.24 ± 0.80, 5.64 ± 1.11, and 5.73 ± 1.28, respectively (p < 0.001). In CHB patients grouped by FIB-4, the mean CV values of groups A, B, and C were 4.22 ± 0.95, 5.40 ± 1.19, and 5.71 ± 1.17, respectively (p < 0.001). The mean CV values correlated well with APRI (r = 0.392, p < 0.001) and FIB-4 (r = 0.294, p < 0.001). In significant fibrosis group, ROC curve analysis yielded an area under the curve of 0.875 using APRI and 0.831 using FIB-4 in HB, respectively.

Conclusion

Gadoxetic acid-enhanced MR imaging for calculating a CV map showed moderate correlation with APRI and FIB-4 values and could be employed to quantitatively measure hepatic fibrosis in patients with CHB.

Can contrast-enhanced MRI with gadoxetic acid predict liver failure and other complications after major hepatic resection?

AIM

To determine whether a combination of clinical factors, the future liver remnant (FLR) ratio, and hepatic uptake of gadoxetic acid can be used to predict post-hepatectomy liver failure (PHLF) and other major complications (OMC).

MATERIALS AND METHODS

Sixty-five consecutive patients who underwent pre-hepatectomy gadoxetic acid-enhanced magnetic resonance imaging (MRI) between October 2010 and December 2013 were included. The relative liver enhancement (RLE) of gadoxetic acid was calculated from regions of interest on MRI, and FLR ratios were obtained from computed tomography (CT). PHLF and OMC were defined by the International Study Group of Liver Surgery criteria and Clavien-Dindo grade of ≥3, respectively. Multivariate logistic regression modelling was performed to identify predictors of PHLF and OMC, including RLE, FLR ratio, age, sex, chemotherapy history, intra-operative blood loss, and intra-operative transfusion.

RESULTS

Nine patients experienced PHLF and another nine patients experienced OMC. RLE was comparable to the FLR ratio in predicting PHLF (areas under the receiver operating characteristic [AUROC] curves, 0.665 and 0.705), but performed poorly in predicting OMCs (AUROCs, 0.556 and 0.702). Combining all clinical and imaging parameters as predictors yielded the best performing predictive models (AUROCs, 0.875 and 0.742 for PHLF and OMC, respectively).

CONCLUSION

A model based on clinical parameters, the FLR ratio, and RLE of gadoxetic acid may improve pre-hepatectomy risk assessment.

Assessment of liver function by Gd-EOB-DTPA enhanced magnetic resonance imaging

Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA), a liver-specific magnetic resonance imaging (MRI) contrast agent, is increasingly used for imaging-based liver function tests. Like indocyanine green and mebrofenin, Gd-EOB-DTPA is taken up by hepatocytes through organic anion-transporting polypeptides 1 (OATP₁) B₁ and B₃ and is then excreted into the bile by multi-drug resistance protein (MRP₂). The advantages of Gd-EOB-DTPA-based liver function tests include function measurement integrated in an existing MRI protocol, ability of evaluating segmental liver function, and no ionizing radiation. The approaches based on Gd-EOB-DTPA for function measurement are as follows: measurement of biliary elimination, hepatic parenchymal enhancement, MR relaxometry, and MR perfusion. These approaches have potential value for assessing liver reserve, hepatic fibrosis, non-alcoholic fatty liver disease and so on.

Prediction of postoperative liver failure using gadoxetic acid-enhanced magnetic resonance imaging in patients with hepatocellular carcinoma

BACKGROUND

We intended to determine the usefulness of gadoxetic acid-enhanced magnetic resonance (MR) imaging on preoperative prediction of the risk of postoperative liver failure (PLF) using measurement of relative liver enhancement (RLE) in patients who underwent surgical resection of hepatocellular carcinoma (HCC).

METHODS

A total of 121 HCC patients who had underwent gadoxetic acid-enhanced MRI before surgery between January 2012 and April 2015 at our hospital was retrospectively analyzed. RLE was calculated as the ratio of signal intensity measurements of the liver parenchyma in each liver segment before and 20 min after intravenous administration of gadoxetic acid. PLF was defined based on the "50-50 criteria" (prothrombin time <50% and serum bilirubin >5 mg/dL on 5 days after surgery).

RESULTS

Of the 121 patients, 74 (61.2%) patients had liver cirrhosis, clinically. Median tumor size 2.8 cm (range, 1-14 cm), 106 (87.6%) patients had a single HCC, and 101 (83.5%) patients had HCC within Milan criteria. Based on the "50-50 criteria", PLF was observed in 7 (5.8%) patients. Mean RLE was significantly lower in patients with PLF than those without it (55.9% vs 85.5%, P < 0.01). In a multivariate analysis, decreased RLE was a significant independent risk factor for PLF in HCC patients (odds ratio 0.97, P = 0.03). Optimal cut-off RLE value was 82.36.

CONCLUSIONS

RLE was significantly lower in patients with PLF than those without it. Measurement of RLE using gadoxetic acid-enhanced MR imaging before surgery can be useful for prediction of PLF in HCC patients who receive surgical treatment.