ICG Clearance Test and 99mTc-GSA SPECT/CT Fusion Images

Pancreaticoduodenectomy after bilirubin adsorption for distal cholangiocarcinoma with severe obstructive jaundice refractory to repeat preoperative endoscopic biliary drainage: a case report

The necessity of biliary drainage before pancreaticoduodenectomy remains controversial in cases involving malignant obstructive jaundice; however, the benefits of biliary drainage have been reported in cases with severe hyperbilirubinemia. Herein, we present the case of a 61-year-old man suffering from jaundice due to distal cholangiocarcinoma. In this case, obstructive jaundice was refractory to repeat endoscopic drainage and bilirubin adsorption. Hyperbilirubinemia persisted despite successful implementation of biliary endoscopic sphincterotomy and two rounds of plastic stent placements. Stent occlusion and migration were unlikely and oral cholagogues proved ineffective. Owing to the patient's surgical candidacy and his aversion to nasobiliary drainage due to discomfort, bilirubin adsorption was introduced as an alternative therapeutic intervention. Following repeated adsorption sessions, a gradual decline in serum total bilirubin levels was observed and pancreaticoduodenectomy was scheduled. The patient successfully underwent pancreaticoduodenectomy with portal vein resection and reconstruction and D2 lymph node dissection. After the surgery, the serum bilirubin levels gradually decreased and the patient remained alive, with no recurrence at 26 months postoperatively. Therefore, this case highlights the feasibility and safety of performing pancreaticoduodenectomy in patients with severe, refractory jaundice who have not responded to repeated endoscopic interventions and have partially responded to bilirubin adsorption.

Assessing regional hepatic function changes after hypertrophy induction by radioembolisation: comparison of gadoxetic acid-enhanced MRI and 99mTc-mebrofenin hepatobiliary scintigraphy

BACKGROUND

To compare Gd-ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and 99mTc-labelled mebrofenin hepatobiliary scintigraphy (HBS) as imaging-based liver function tests after unilateral radioembolisation (RE) in patients with primary or secondary liver malignancies.

METHODS

Twenty-three patients with primary or secondary liver malignancies who underwent Gd-EOB-DTPA-enhanced MRI within a prospective study (REVoluTion) were evaluated. REVoluTion was a prospective open-label, non-randomised, therapy-optimising study of patients undergoing right-sided or sequential RE for contralateral liver hypertrophy at a single centre in Germany. MRI and hepatobiliary scintigraphy were performed before RE (baseline) and 6 weeks after (follow-up). This exploratory subanalysis compared liver enhancement on hepatobiliary phase MRI normalised to the spleen (liver-to-spleen ratio (LSR)) and the muscle (liver-to-muscle ratio (LMR)) with mebrofenin uptake on HBS for the total liver (TL) and separately for the right (RLL) and left liver lobe (LLL).

RESULTS

Mebrofenin uptake at baseline and follow-up each correlated significantly with LSR and LMR on MRI for TL (≤ 0.013) and RLL (≤ 0.049). Regarding the LLL, mebrofenin uptake correlated significantly with LMR (baseline, p = 0.013; follow-up, p = 0.004), whereas with LSR, a borderline significant correlation was only seen at follow-up (p = 0.051; p = 0.046).

CONCLUSION

LSRs and LMR correlate with mebrofenin uptake in HBS. This study indicates that Gd-EOB-DTPA-enhanced MRI and 99mTc-labelled mebrofenin HBS may equally be used to assess an increase in contralateral liver lobe function after right-sided RE.

RELEVANCE STATEMENT

MRI may be a convenient and reliable method for assessing the future liver remnant facilitating treatment planning and monitoring of patients after RE-induced hypertrophy induction.

KEY POINTS

• Both MRI and HBS can assess liver function after RE. • Liver enhancement on MRI correlates with mebrofenin uptake on HBS. • MRI might be a convenient alternative for estimating future liver remnants after hypertrophy induction.

Is an intraoperative liver function assessment possible? Application of the 13C-methacetin-breath-test during major liver resections - a pilot study

BACKGROUND

As prevention of posthepatectomy-liver-failure is crucial, there is need of dynamic assessment of liver function, even intraoperatively. 13C-methacetin-breath-test estimates the organ's microsomal functional capacity. This is its first intraoperative evaluation in major liver surgery.

METHODS

30 patients planed for resection of ≥3 liver segments, between March-November 2019, were prospectively enrolled in this "single-center", pilot study. Using the 13C-methacetin-breath-test, liver function was assessed four times: preoperatively, intraoperatively before and after resection and postoperatively. The resulted maximum-liver-function-capacity (LiMAx)-values and delta-over-baseline (DOB)-curves were compared, further analyzed and correlated to respective liver volumes.

RESULTS

The intraoperative LiMAx-values before resection were mostly lower than the preoperative ones (-11.3% ± 28%). The intraoperative measurements after resection resulted to mostly higher values than the postoperative ones (42.35% ± 46.19%). Pharmacokinetically, an interference between the two intraoperative tests was observed. There was no strong correlation between residual liver volume and function with a percentual residual-LiMAx mostly lower than the percentual residual volume (-17.7% ± 4.1%).

CONCLUSIONS

Intraoperative application of the 13C-methacetin-breath-test during major liver resections seems to deliver lower values than the standard preoperative test. As multiple intraoperative tests interfere significantly to each other, a single intraoperative measurement is suggested. Multicentric standardized measurements could define the "normal" range for intraoperative measurements and control their predictive value.

In vivo evaluation of liver function by multimodal imaging in an alcohol-induced liver injury model

Background

Visually evaluating liver function is a hot topic in hepatology research. There are few reliable and practical visualization methods for evaluating the liver function in vivo in experimental studies. In this study, we established a multimodal imaging approach for in vivo liver function evaluation and compared healthy mice with chronic alcoholic liver injury (cALI) model mice to explore its potential applicability in experimental research.

Methods

In vivo fluorescence imaging (IVFI) technology was utilized to visually represent the clearance of indocyanine green from the liver of both healthy mice and mice with cALI. The reserve liver function was evaluated via IVFI using the Cy5.5-galactosylated polylysine probe, which targets the asialoglycoprotein receptor of hepatocytes. Hepatic microcirculation was assessed through laser speckle perfusion imaging of hepatic blood perfusion. The liver microstructure was then investigated by in vivo confocal laser endomicroscopy imaging. Finally, hepatic asialoglycoprotein receptor expression, histology, and the levels of serum alanine aminotransferase and aspartate aminotransferase were measured.

Results

In vivo multimodal imaging results intuitively and dynamically showed that indocyanine green clearance [mean ± standard deviation (SD): 30.83±14.71, 95% confidence interval (CI): 20.3 to 41.35], the fluorescence signal intensity (mean ± SD: 1,217.92±117.63; 95% CI: 1,148.38 to 1,290.84) and fluorescence aggregation area (mean ± SD: 5,855.80±1,271.81; 95% CI: 5,051.57 to 6,653.88) of Cy5.5-galactosylated polylysine targeting the asialoglycoprotein receptor, and hepatic blood perfusion (mean ± SD: 1,494.86±299.33; 95% CI: 1,316.98 to 1,690.16) in model mice were significantly lower than those in healthy mice (all P<0.001). Compared to healthy mice, the model mice exhibited a significant decline in liver asialoglycoprotein receptor expression (mean ± SD: 219.03±16.34; 95% CI: 208.97 to 230.69; P<0.001), increased serum alanine aminotransferase (mean ± SD: 149.70±47.89 U/L; 95% CI: 81.75 to 128.89; P=0.01) and aspartate aminotransferase levels (mean ± SD: 106.30±36.13 U/L; 95% CI: 122.01 to 180.17; P=0.021), hepatocyte swelling and deformation, disappearance of the hepatic cord structure, partial necrosis, and disintegration of hepatocytes. The imaging features of fluorescence signals in liver regions, hepatic blood perfusion and microstructure were biologically related to hepatic asialoglycoprotein receptor expression, serum indices of liver function, and histopathology in model mice.

Conclusions

Utilizing in vivo multimodal imaging technology to assess liver function is a viable approach for experimental research, providing dynamic and intuitive visual evaluations in a rapid manner.

A radiomics model based on preoperative gadoxetic acid-enhanced magnetic resonance imaging for predicting post-hepatectomy liver failure in patients with hepatocellular carcinoma

Background

Post-hepatectomy liver failure (PHLF) is a fatal complication after liver resection in patients with hepatocellular carcinoma (HCC). It is of clinical importance to estimate the risk of PHLF preoperatively.

Aims

This study aimed to develop and validate a prediction model based on preoperative gadoxetic acid-enhanced magnetic resonance imaging to estimate the risk of PHLF in patients with HCC.

Methods

A total of 276 patients were retrospectively included and randomly divided into training and test cohorts (194:82). Clinicopathological variables were assessed to identify significant indicators for PHLF prediction. Radiomics features were extracted from the normal liver parenchyma at the hepatobiliary phase and the reproducible, robust and non-redundant ones were filtered for modeling. Prediction models were developed using clinicopathological variables (Clin-model), radiomics features (Rad-model), and their combination.

Results

The PHLF incidence rate was 24% in the whole cohort. The combined model, consisting of albumin-bilirubin (ALBI) score, indocyanine green retention test at 15 min (ICG-R15), and Rad-score (derived from 16 radiomics features) outperformed the Clin-model and the Rad-model. It yielded an area under the receiver operating characteristic curve (AUC) of 0.84 (95% confidence interval (CI): 0.77-0.90) in the training cohort and 0.82 (95% CI: 0.72-0.91) in the test cohort. The model demonstrated a good consistency by the Hosmer-Lemeshow test and the calibration curve. The combined model was visualized as a nomogram for estimating individual risk of PHLF.

Conclusion

A model combining clinicopathological risk factors and radiomics signature can be applied to identify patients with high risk of PHLF and serve as a decision aid when planning surgery treatment in patients with HCC.

Unsupervised Machine Learning of MRI Radiomics Features Identifies Two Distinct Subgroups with Different Liver Function Reserve and Risks of Post-Hepatectomy Liver Failure in Patients with Hepatocellular Carcinoma

OBJECTIVE

To identify subgroups of patients with hepatocellular carcinoma (HCC) with different liver function reserves using an unsupervised machine-learning approach on the radiomics features from preoperative gadoxetic-acid-enhanced MRIs and to evaluate their association with the risk of post-hepatectomy liver failure (PHLF).

METHODS

Clinical data from 276 consecutive HCC patients who underwent liver resections between January 2017 and March 2019 were retrospectively collected. Radiomics features were extracted from the non-tumorous liver tissue at the gadoxetic-acid-enhanced hepatobiliary phase MRI. The reproducible and non-redundant features were selected for consensus clustering analysis to detect distinct subgroups. After that, clinical variables were compared between the identified subgroups to evaluate the clustering efficacy. The liver function reserve of the subgroups was compared and the correlations between the subgroups and PHLF, postoperative complications, and length of hospital stay were evaluated.

RESULTS

A total of 107 radiomics features were extracted and 37 were selected for unsupervised clustering analysis, which identified two distinct subgroups (138 patients in each subgroup). Compared with subgroup 1, subgroup 2 had significantly more patients with older age, albumin-bilirubin grades 2 and 3, a higher indocyanine green retention rate, and a lower indocyanine green plasma disappearance rate (all p < 0.05). Subgroup 2 was also associated with a higher risk of PHLF, postoperative complications, and longer hospital stays (>18 days) than that of subgroup 1, with an odds ratio of 2.83 (95% CI: 1.58-5.23), 2.41(95% CI: 1.15-5.35), and 2.14 (95% CI: 1.32-3.47), respectively. The odds ratio of our method was similar to the albumin-bilirubin grade for postoperative complications and length of hospital stay (2.41 vs. 2.29 and 2.14 vs. 2.16, respectively), but was inferior for PHLF (2.83 vs. 4.55).

CONCLUSIONS

Based on the radiomics features of gadoxetic-acid-enhanced MRI, unsupervised clustering analysis identified two distinct subgroups with different liver function reserves and risks of PHLF in HCC patients. Future studies are required to validate our findings.

Effect of Hepatic Pathology on Liver Regeneration: The Main Metabolic Mechanisms Causing Impaired Hepatic Regeneration

Liver regeneration has been studied for many decades, and the mechanisms underlying regeneration of normal liver following resection are well described. However, no less relevant is the study of mechanisms that disrupt the process of liver regeneration. First of all, a violation of liver regeneration can occur in the presence of concomitant hepatic pathology, which is a key factor reducing the liver's regenerative potential. Understanding these mechanisms could enable the rational targeting of specific therapies to either reduce the factors inhibiting regeneration or to directly stimulate liver regeneration. This review describes the known mechanisms of normal liver regeneration and factors that reduce its regenerative potential, primarily at the level of hepatocyte metabolism, in the presence of concomitant hepatic pathology. We also briefly discuss promising strategies for stimulating liver regeneration and those concerning methods for assessing the regenerative potential of the liver, especially intraoperatively.

Comparative study of indocyanine green (ICG)-R15 and Albumin-Indocyanine Green Evaluation (ALICE) grading system in the prediction of posthepatectomy liver failure and postoperative mortality in patients with hepatic alveolar echinococcosis

BACKGROUND

A precise evaluation of liver reserve function in patients with hepatic alveolar echinococcosis (HAE) prior to hepatectomy could substantially increase the success rate of the operation and reduce the incidence of postoperative complications. The present study aimed to investigate the significance of the indocyanine green retention test at 15 min (ICG-R15) and the Albumin-Indocyanine Green Evaluation (ALICE) grading system in predicting severe posthepatectomy liver failure (PHLF) and postoperative mortality in HAE patients undergoing liver resection.

METHODS

A total of 105 HAE patients undergoing hepatectomy were enrolled in this study. The value of each variable in predicting severe PHLF was evaluated by univariate and multivariate logistic regression analyses. The area under the receiver operating characteristic (ROC) curves (AUC) were calculated to evaluate the predictive ability of the Child-Pugh grade, ICG-R15, and ALICE grading system. Also, patients were classified using the optimal cutoff value for ICG-R15 and different ALICE grades, and the incidence of severe PHLF and postoperative mortality were compared with the predicted values.

RESULTS

Out of the 105 HAE patients enrolled in this study, 34 patients (32.4%) developed severe PHLF. The ALICE grade and operative time were identified as independent predictors of severe PHLF. According to ROC analysis, the AUCs of the Child-Pugh grade, ICG-R15, and ALICE grade for predicting severe PHLF were 0.733 (95% confidence interval (CI), 0.637-0.814), 0.823 (95% CI, 0.737-0.891), 0.834 (95% CI, 0.749-0.900). The incidence of severe PHLF and postoperative 90-day mortality in patients with ICG-R15 > 7.2% were significantly higher than those with ICG-R15 ≤ 7.2% (P < 0.001; P = 0.008). Likewise, the incidence of severe PHLF and postoperative 90-day mortality in patients with ALICE grade 2 were higher than those with ALICE grade 1 within the Child-Pugh grade A (P < 0.001; P = 0.083).

CONCLUSION

ICG-R15 and ALICE grading system are powerful predictors of severe PHLF and postoperative mortality among HAE patients undergoing hepatectomy. Furthermore, a combination of the preoperative Child-Pugh grade and ALICE grading system may provide an even more precise and objective guidance and facilitate surgical decision-making for HAE patients.

Usefulness of serum Mac-2 binding protein glycosylation isomer in patients undergoing hepatectomy: A case controlled study

Background

To evaluate the clinical significance of Mac-2 binding protein glycosylation isomer (M2BPGi), we investigated the relationship between M2BPGi and clinicopathological and surgical parameters and posthepatectomy complications.

Materials and methods

We examined M2BPGi in 115 patients with hepatic malignancies undergoing hepatectomy. Significance as an independent prognostic marker was determined with multivariate logistic regression analysis.

Results

The mean serum M2BPGi level was 1.14 ± 1.03 C.O.I. (range 0.2–5.79). M2BPGi in the chronic viral hepatitis group (1.42 ± 1.25) was significantly higher than that in the other disease groups (p < 0.05). The M2BPGi level correlated negatively with platelet count, LHL15 and GSA-Rmax (r = −0.36, −0.69 and −0.56, respectively; p < 0.01) but correlated positively with serum hyaluronate level (fibrotic marker), ICGR15 and HH15 (r = 0.52, 0.63 and 0.57, respectively; p < 0.01). In 53 patients examined for histological hepatic fibrosis, the M2BPGi level was highest for hepatic fibrosis stage 4, indicating cirrhosis (2.15 ± 1.56), and was significantly higher than that for stages 0–2 (p < 0.05). M2BPGi level did not correlate significantly with any surgical parameters. The preoperative level correlated significantly only with increased alanine aminotransferase level (r = −0.21, p < 0.05) and was significantly higher in patients with (1.35 ± 0.78) than without (1.11 ± 1.07) hepatectomy-related complications (p < 0.05). Area under the ROC curve analysis for prediction of hepatic fibrosis score 4 showed a cut-off value of 0.78 for M2BPGi to have high sensitivity (90%) and specificity (58%). For postoperative hepatectomy-related complications, only the M2BPGi level (at a cut-off value 0.90) tended to show significance (p = 0.06).

Conclusions

The non-invasively measured serum level of M2BPGi reflected impaired liver function or cirrhosis and hepatectomy-related complications after surgery, making it potentially useful as a complementary parameter accompanying other liver function parameters.

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The M2BPGi level was higher in patients with posthepatectomy complications.

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The M2BPGi level correlated negatively with the platelet count, LHL 15 and GSA-Rmax by liver scintigraphy.

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The M2BPGi level was highest in the patients with hepatic fibrosis.

Metal-Based Complexes as Pharmaceuticals for Molecular Imaging of the Liver

This article reviews the use of metal complexes as contrast agents (CA) and radiopharmaceuticals for the anatomical and functional imaging of the liver. The main focus was on two established imaging modalities: magnetic resonance imaging (MRI) and nuclear medicine, the latter including scintigraphy and positron emission tomography (PET). The review provides an overview on approved pharmaceuticals like Gd-based CA and ^99mTc-based radiometal complexes, and also on novel agents such as ⁶⁸Ga-based PET tracers. Metal complexes are presented by their imaging modality, with subsections focusing on their structure and mode of action. Uptake mechanisms, metabolism, and specificity are presented, in context with advantages and limitations of the diagnostic application and taking into account the respective imaging technique.

Conversion therapy and suitable timing for subsequent salvage surgery for initially unresectable hepatocellular carcinoma: What is new?

AIM

To review the conversion therapy for initially unresectable hepatocellular carcinoma (HCC) patients and the suitable timing for subsequent salvage surgery.

METHODS

A PubMed search was undertaken from 1987 to 2017 to identify articles using the keywords including “unresectable” “hepatocellular carcinoma”, ”hepatectomy”, ”conversion therapy”, “resection”, “salvage surgery” and “downstaging”. Additional studies were investigated through a manual search of the references from the articles. The exclusion criteria were duplicates, case reports, case series, videos, contents unrelated to the topic, comments, and editorial essays. The main and widely used conversion therapies and the suitable timing for subsequent salvage surgery were discussed in detail. Two members of our group independently performed the literature search and data extraction.

RESULTS

Liver volume measurements [future liver remnant (FLR)/total liver volume or residual liver volume/bodyweight ratio] and function tests (scoring systems and liver stiffness) were often performed in order to justify whether patients were suitable candidates for surgery. Successful conversion therapy was usually defined as downstaging the tumor, increasing FLR and providing subsequent salvage surgery, without increasing complications, morbidity or mortality. The requirements for performing salvage surgery after transcatheter arterial chemoembolization were the achievement of a partial remission in radiology, the disappearance of the portal vein thrombosis, and the lack of extrahepatic metastasis. Patients with a standardized FLR (sFLR) > 20% were good candidates for surgery after portal vein embolization, while other predictive parameters like growth rate, kinetic growth rate were treated as an effective supplementary. There was probably not enough evidence to provide a standard operation time after associating liver partition and portal vein ligation for staged hepatectomy or yttrium-90 microsphere radioembolization. The indications of any combinations of conversion therapies and the subsequent salvage surgery time still need to be carefully and comprehensively evaluated.

CONCLUSION

Conversion therapy is recommended for the treatment of initially unresectable HCC, and the suitable subsequent salvage surgery time should be reappraised and is closely related to its previous therapeutic effect.