Predicting liver failure following major hepatectomy

CIRSE Standards of Practice on Portal Vein Embolization and Double Vein Embolization/Liver Venous Deprivation

This CIRSE Standards of Practice document is aimed at interventional radiologists and provides best practices for performing liver regeneration therapies prior to major hepatectomies, including portal vein embolization, double vein embolization and liver venous deprivation. It has been developed by an expert writing group under the guidance of the CIRSE Standards of Practice Committee. It encompasses all clinical and technical details required to perform liver regeneration therapies, revising the indications, contra-indications, outcome measures assessed, technique and expected outcomes.

Single-Center Retrospective Study Comparing Double Vein Embolization via a Trans-Jugular Approach with Liver Venous Deprivation via a Trans-Hepatic Approach

PURPOSE

To compare safety, technical and clinical outcomes of double vein embolization (DVE) via a trans-jugular approach with liver venous deprivation (LVD) via a trans-hepatic approach.

MATERIALS AND METHODS

A single-center retrospective analysis was conducted on patients undergoing simultaneous portal and hepatic veins embolization in view of a major hepatectomy (June 2019-November 2022). Hepatic vein embolization was performed either by transjugular plug (DVE) or by transhepatic plug followed by glue injection (LVD). Inclusion criteria were availability of pre-procedural CT scan, and availability of CT scans acquired 10 days and 25 days post-procedure. Comparative data included complication rate, fluoroscopy time, dose area product (DAP), Future Liver Remnant volume and function increase (FLR-V and FLR-F increase, respectively) and clinical outcomes.

RESULTS

Thirty-six patients (n = 14 DVE; n = 22 LVD) were included. No baseline significant differences were observed among the two groups. One grade-3 complication (2.8%) was observed in the LVD group; one case of technical failure (2.8%) was observed in the DVE group. Fluoroscopy time and DAP were similar between DVE and LVD (29 ± 17.7 vs. 25 ± 8.2 min, p = 0.97; 105.1 ± 63.5 vs. 143.4 ± 79.5 Gy·cm2, p = 0.15). No differences arose at either time-point in FLR-V increase (46.7 ± 23.1% vs. 48.2 ± 28.2%, 52.9 ± 30.9% vs. 53.2 ± 29%, respectively, p = 0.9). FLR-F increase also did not differ significantly (62.8 ± 55.2 vs. 67.4 ± 57.5, p = 0.9). No differences in drop-out rate from surgery were observed. (28.6% vs. 27.3%, p = 0.93). One case of grade-B post-hepatectomy liver failure (2.8%) was observed in the LVD group.

CONCLUSION

LVD via transhepatic approach and DVE via transjugular approach seem equally safe and effective. Level of Evidence Level 3, Retrospective Cohort Study.

Spleen volume is a predictor of posthepatectomy liver failure and short-term mortality for hepatocellular carcinoma

BACKGROUND

The study aimed at retrospectively assessing the impact of spleen volume (SpV) on the development of posthepatectomy liver failure (PHLF) in patients who underwent hepatectomy for hepatocellular carcinoma (HCC).

METHODS

152 patients with primary HCC who underwent hepatectomy (sectionectomy or more) were classified into PHLF and non-PHLF groups, and then the relationship between PHLF and SpV was assessed. SpV (cm3) was obtained from preoperative CT and standardized based on the patient's body surface area (BSA, m2).

RESULTS

PHLF was observed in 39 (26%) of the 152 cases. SpV/BSA was significantly higher in the PHLF group, and the postoperative 1-year survival rate was significantly worse in the PHLF group than that in the non-PHLF group (p = 0.044). Multivariable analysis revealed SpV/BSA as a significant independent risk factor for PHLF. Using the cut-off value (160 cm3/m2), the 152 cases were divided into small SpV and large SpV groups. The incidence of PHLF was significantly higher in the large SpV group (p = 0.002), the liver failure-related mortality rate was also significantly higher in the large SpV group (p = 0.007), and the 1-year survival rate was significantly worse in the large SpV group (p = 0.035).

CONCLUSION

These results suggest SpV as a predictor of PHLF and short-term mortality in patients who underwent hepatectomy for HCC. Moreover, SpV measurement is a simple and potentially useful method for predicting PHLF in patients with HCC.

Quantitative liver SPECT/CT is a novel tool to assess liver function, prognosis, and response to treatment in cirrhosis

Background

Functional liver reserve is an important determinant of survival in cirrhosis. The traditional indocyanine green test (ICG) is cumbersome. Hence, we developed and validated a novel liver imaging, a hybrid of SPECT and CT (Q-SPECT/CT), for evaluating disease severity, outcomes, and response to treatment in decompensated cirrhosis (DC).

Methods

We recruited a cohort of DC patients at a tertiary institute between 2016-2019. First, we standardized the Q-SPECT/CT across a predefined range of volumes through phantom experiments. Then we performed clinical and laboratory evaluations, ICG test (retention at 15 min), and Q-SPECT/CT at baseline and 12 months of granulocyte colony-stimulating factor (G-CSF) and standard medical treatment (SMT).

Results

In 109 DC patients, 87.1% males, aged 51 ± 10 years, MELD: 14 (7-21), the percent quantitative liver uptake (%QLU) on Q-SPECT/CT exhibited a strong correlation with CTP (r = -0.728, p < 0.001), MELD (r = -0.743; p < 0.001) and ICG-R-15 (r = -0.720, p < 0.001) at baseline. %QLU had the maximum discrimination (AUC: 0.890-0.920), sensitivity (88.9-90.3%), specificity (81.2-90.7%), and accuracy (85.8-89.4%) than liver volumes on Q-SPECT/CT or ICG test for classifying patients in CTP/MELD based prognostic categories. A significant increase in %QLU (26.09 ± 10.06 to 31.2 ± 12.19, p = 0.001) and improvement in CTP/MELD correlated with better survival of G-CSF treated DC patients (p < 0.05). SMT did not show any improvement in Q-SPECT/CT or clinical severity scores (p > 0.05). %QLU > 25 (adj.H.R.: 0.234, p = 0.003) and G-CSF treatment (adj.H.R.: 0.414, p = 0.009) were independent predictors of better 12-months survival in DC.

Conclusion

Q-SPECT/CT (%QLU) is a novel non-invasive, diagnostic, prognostic, and theragnostic marker of liver reserve and its functions in cirrhosis patients.

Clinical trial registration

Clinicaltrials.gov, NCT02451033 and NCT03415698.

Determination of the segmental hepatic clearance rate of 99mTc-mebrofenin and its application in the functional assessment of future liver remnant after liver resection

^99mTc-mebrofenin hepatobiliary scintigraphy with SPECT/CT (HBS-M) has become an important quantitative method to evaluate global liver function and future liver remnant (FLR) function in patients who are candidates for resective liver surgery. The purpose of this work was to describe the method in the prediction of post-surgical liver failure. The overall liver function and that of the FLR are obtained by analysis of the initial dynamic phase of the scan. Liver volume to be preserved is expressed as a percentage of the total liver volume measured in both CT sections. HBS-M is able to accurately gauge regional liver function abnormalities that could be represented as normal liver tissue parenchyma in the CT study. This technique can provide very valuable prognostic information for the estimation of the postoperative risk of liver failure in all patients who are candidates for resective liver surgery.

The biological effects of radiation-induced liver damage and its natural protective medicine

The biological damage caused by the environmental factors such as radiation and its control methods are one of the frontiers of life science research that has received widespread attention. Ionizing radiation can directly interact with target molecules (such as DNA, proteins and lipids) or decomposed by radiation from water, leading to changes in oxidative events and biological activities in cells. Liver is a radiation-sensitive organ, and its radiosensitivity is second only to bone marrow, lymph, gastrointestinal tissue, gonads, embryos and kidneys. In addition, as a key organ of mammals, liver performs a series of functions, including the production of bile, the metabolism of nutrients, the elimination of waste, the storage of glycogen, and the synthesis of proteins. Therefore, liver is prone to various pathophysiological changes. In this review, the effects of radiation on liver injury, its pathogenesis, bystander effect and the natural traditional Chinese medicine to protect the radiation induced liver damage are discussed.

Additional partial hepatectomy at the time of portal vein ligation accelerates the regeneration of the future liver remnant

Portal vein ligation (PVL) has been adopted to induce hypertrophy of the future liver remnant (FLR) in patients with primarily irresectable liver tumor. However, regeneration of the FLR is not always sufficient to allow curative resection of the portally-deprived tumor-bearing liver lobe. We hypothesize that simultaneous hepatectomy (PHx) and PVL augments regeneration of the FLR and that the effect is related to the extent of the additional resection. Seventy-two Lewis rats were enrolled into 3 groups: 20%PVL + 70%PHx; 70%PVL + 20%PHx; 90%PVL. Animals were observed for 1, 2, 3 and 7 days postoperatively (n = 6/time point). Liver enzymes, caudate liver/body-weight-ratio, BrdU-proliferation-index (PI), proliferating-cell-nuclear-antigen (PCNA)-mRNA-expression level and autophagy-related-proteins were evaluated. Compared with 90% PVL, additional PHx induced significantly more hypertrophy during the observation time, which was confirmed by significantly higher PI and higher level of PCNA-mRNA expression. Similarly, the additional PHx induced more autophagy in the FLR compared with PVL alone. However, both effects were not clearly related to the extent of additional resection. Additional resection augmented liver regeneration and autophagy substantially compared with PVL alone. Therefore, we concluded that autophagy might play a critical role in regulating hepatocyte proliferation and the size of the FLR after simultaneous PVL + PHx.

Preoperative ICG Test to Predict Posthepatectomy Liver Failure and Postoperative Outcomes in Hilar Cholangiocarcinoma

Preoperative evaluation of hepatic functional reserve in patients with hilar cholangiocarcinoma (hCCA) has vital clinical significance for prevention of posthepatectomy liver failure (PHLF) and mortality. The aim of the present study was to evaluate the clinical significance of the indocyanine green retention rate at 15 minutes (ICG R15) and related factors of postoperative outcomes in patients with hCCA. 147 patients who scheduled for hCCA resection underwent a preoperative ICG test between May 2015 and May 2020 and were prospectively analyzed. Single-factor analysis was used to evaluate the risk factors for PHLF and postoperative outcomes in hCCA. After univariate analysis, significant differences in ICG R15 were found between the PHLF group and the liver function recovered well (LFRW) group (P ≤ 0.05). In terms of postoperative complications, ICG R15 was also a risk factor for moderate-to-severe postoperative complications. Preoperative ICG R15 was significantly associated with PHLF and moderate-to-severe postoperative complications. ICG R15 may become an ideal clinical indicator for the evaluation of liver function reserve before hCCA and can better predict the postoperative complications.

Preoperative Portal Vein Embolization for Liver Resection: An updated meta-analysis

Background: Portal vein embolization (PVE) is performed before major liver resection to increase liver volume remnant, controversy remains on the adverse effect of PVE on liver tumor patients. The current study highlighted the effect of PVE on the degree of hypertrophy of future liver remnant (FLR) and summarized PVE-related complications, aiming to provide a guideline for surgeons.

Methods: A search of current published studies on PVE was performed. Meta-analysis was conducted to assess the effect of PVE on hypertrophy of FLR and summarized PVE-related complications.

Results: 26 studies including 2335 patients were enrolled in the meta-analysis. All enrolled studies reported data regarding FLR hypertrophy rate, pooled effect size (ES) for FLR hypertrophy rate using a fixed-effect model was 0.105 (95%CI: 0.094-0.117, p=0.000), indicating PVE is favored in inducing FLR hypertrophy. Metatrim method indicated no obvious evidence of publication bias in the present meta-analysis. 247 (10.6%) patients exhibited PVE-related complications, receiving expectant treatment without affecting planned liver resection. Total 1782 patients (76%) underwent a subsequent liver resection after PVE, which is an encouraging result comparing with traditional resection rate in liver tumor patients.

Conclusions: PVE is a safe and effective procedure with a low occurrence of related complications for inducing sufficient hypertrophy of FLR in liver tumor patients, which could elevate the resection rate of liver tumor patients. Careful patient cohort selection is crucial to avoid overuse of PVE in technically resectable patients. Further multiple central clinical trials are conducive to select optimal patient cohorts and provide a guideline for surgeons.

Early Prediction of Post-hepatectomy Liver Failure in Patients Undergoing Major Hepatectomy Using a PHLF Prognostic Nomogram

BACKGROUND

Liver resection (LR) is the main modality of treatment for hepatocellular carcinoma (HCC) and colorectal liver metastasis (CRLM). Post-hepatectomy liver failure (PHLF) remains the most dreaded complication. We aim to create a prognostic score for early risk stratification of patients undergoing LR.

METHODOLOGY

Clinical and operative data of 472 patients between 2000 and 2016 with HCC or CRLM undergoing major hepatectomy were extracted and analysed from a prospectively maintained database. PHLF was defined using the 50-50 criteria.

RESULTS

Liver cirrhosis and fatty liver were histologically confirmed in 35.6% and 53% of patients. 4.7% (n = 22) of patients had PHLF. A 90-day mortality was 5.1% (n = 24). Pre-operative albumin-bilirubin score (p = 0.0385), prothrombin time (p < 0.0001) and the natural logarithm of the ratio of post-operative day 1 to pre-operative serum bilirubin (SB) (ln(_POD1Bil/_pre-opBil); p < 0.0001) were significantly independent predictors of PHLF. The PHLF prognostic nomogram was developed using these factors with receiver operating curve showing area under curve of 0.88. Excellent sensitivity (94.7%) and specificity (95.7%) for the prediction of PHLF (50-50 criteria) were achieved at cut-offs of 9 and 11 points on this model. This score was also predictive of PHLF according to _PeakBil > 7 and International Study Group for Liver Surgery criteria, intensive care unit admissions, length of stay, all complications, major complications, re-admissions and mortality (p < 0.05).

CONCLUSIONS

The PHLF nomogram ( https://tinyurl.com/SGH-PHLF-Risk-Calculator ) can serve as a useful tool for early identification of patients at high risk of PHLF before the 'point of no return'. This allows enforcement of closer monitoring, timely intervention and mitigation of adverse outcomes.

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.

Radiomics model based on preoperative gadoxetic acid-enhanced MRI for predicting liver failure

BACKGROUND

Postoperative liver failure is the most severe complication in cirrhotic patients with hepatocellular carcinoma (HCC) after major hepatectomy. Current available clinical indexes predicting postoperative residual liver function are not sufficiently accurate.

AIM

To determine a radiomics model based on preoperative gadoxetic acid-enhanced magnetic resonance imaging for predicting liver failure in cirrhotic patients with HCC after major hepatectomy.

METHODS

For this retrospective study, a radiomics-based model was developed based on preoperative hepatobiliary phase gadoxetic acid-enhanced magnetic resonance images in 101 patients with HCC between June 2012 and June 2018. Sixty-one radiomic features were extracted from hepatobiliary phase images and selected by the least absolute shrinkage and selection operator method to construct a radiomics signature. A clinical prediction model, and radiomics-based model incorporating significant clinical indexes and radiomics signature were built using multivariable logistic regression analysis. The integrated radiomics-based model was presented as a radiomics nomogram. The performances of clinical prediction model, radiomics signature, and radiomics-based model for predicting post-operative liver failure were determined using receiver operating characteristics curve, calibration curve, and decision curve analyses.

RESULTS

Five radiomics features from hepatobiliary phase images were selected to construct the radiomics signature. The clinical prediction model, radiomics signature, and radiomics-based model incorporating indocyanine green clearance rate at 15 min and radiomics signature showed favorable performance for predicting postoperative liver failure (area under the curve: 0.809-0.894). The radiomics-based model achieved the highest performance for predicting liver failure (area under the curve: 0.894; 95%CI: 0.823-0.964). The integrated discrimination improvement analysis showed a significant improvement in the accuracy of liver failure prediction when radiomics signature was added to the clinical prediction model (integrated discrimination improvement = 0.117, P = 0.002). The calibration curve and an insignificant Hosmer-Lemeshow test statistic (P = 0.841) demonstrated good calibration of the radiomics-based model. The decision curve analysis showed that patients would benefit more from a radiomics-based prediction model than from a clinical prediction model and radiomics signature alone.

CONCLUSION

A radiomics-based model of preoperative gadoxetic acid–enhanced MRI can be used to predict liver failure in cirrhotic patients with HCC after major hepatectomy.

Predictors of post-hepatectomy liver failure in patients undergoing extensive liver resections for hepatocellular carcinoma

Backgrounds/Aims

To determine the prevalence of post-hepatectomy liver failure/insufficiency (PHLF/I) in patients undergoing extensive hepatic resections for hepatocellular carcinoma (HCC) and to assess the predictive value of preoperative factors for post-hepatectomy liver failure or insufficiency (PHLF/I).

Methods

A retrospective review of patients who underwent liver resections for HCC between 2001 and 2013 was conducted. Preoperative parameters were assessed and analyzed for their predictive value of PHLF/I. Definitions used included the 50–50, International Study Group of Liver Surgery (ISGLS) and Memorial Sloan Kettering Cancer Centre (MSKCC) criteria.

Results

Among the 848 patients who underwent liver resections for HCC between 2001 and 2013, 157 underwent right hepatectomy (RH) and extended right hepatectomy (ERH). The prevalence of PHLF/I was 7%, 41% and 28% based on the 50–50, ISGLS and MSKCC criteria, respectively. There were no significant differences in PHLF/I between RH and ERH. Model for End-Stage Liver Disease (MELD) score and bilirubin were the strongest independent predictors of PHLF/I based on the 50–50 and ISGLS/MSKCC criteria, respectively. Predictive models were developed for each of the criteria with multiple logistic regression.

Conclusions

MELD score, bilirubin, alpha-fetoprotein and platelet count showed significant predictive value for PHLF/I (all p<0.05). A composite score based on these factors serves as guideline for physicians to better select patients undergoing extensive resections to minimize PHLF.

Influence of liver fibrosis on prognosis after surgical resection for resectable single hepatocellular carcinoma

BACKGROUND

Surgical resection (SR) is recommended for single hepatocellular carcinoma (HCC) in patients with well-preserved liver function. However, unexpected liver fibrosis sometimes found at the SR which leads to a poor outcome. This study investigated the influence of liver fibrosis on prognosis after SR for HCC.

METHODS

A total of 189 patients with Child-Turcotte-Pugh grade A who underwent curative SR for a single HCC <5 cm were evaluated. Patients were assigned to two groups based on the degree of fibrosis (mild or severe), as determined by histological evaluation.

RESULTS

Severe fibrosis was present in 49 patients (25.9%); these patients had greater posthepatectomy liver failure (P = 0.000) and HCC recurrence (P = 0.016). Severe liver fibrosis (hazard ratio (HR) = 1.849, 95% confidence interval (CI) 1.191-2.869; P = 0.006), microvascular invasion (HR = 1.854, 95% CI 1.183-2.906; P = 0.007), and poor histologic grade (HR = 2.097, 95% CI 1.230-3.574; P = 0.007) were related to HCC recurrence.

CONCLUSION

Severe fibrosis can be found even in patients with well-preserved liver function and it leads to poorer early post-operative and late oncologic outcomes, therefore it should be considered before therapeutic decision making of HCC.

Portal Vein Embolization: Correlation of Future Liver Remnant Hypertrophy to Type of Embolic Agent Used

Purpose

The purpose of this study was to compare the effectiveness of portal vein embolization (PVE) with different embolic agents used at our centre. Specifically, the effectiveness of N-butyl cyanoacrylate (NBCA) glue is compared with that of polyvinyl alcohol (PVA) particles.

Methods

We performed a retrospective chart review of all patients (N = 77) who underwent PVE at our institution over a 5-year period. Pre- and postprocedural computed tomography or magnetic resonance imaging, when available, were used to measure the volume of total liver volume and future liver remnant (FLR). The absolute values obtained were used to calculate percentage of FLR. The growth in FLR was determined 4–6 weeks after PVE. Technical details of the procedure including the type and amount of embolic agent used were obtained from the chart reviews, electronic patient records, and radiology reports. Statistical analysis was performed using Kruskal-Wallis test, Wilcoxon rank sum test, and the Spearman correlation coefficient with post hoc analysis. Results are expressed as mean ± SD ( P < .05 considered statistically significant).

Results

NBCA (n = 29) produced a mean change in FLR of 14.8% compared with 9.3% for PVA particles (n = 24; P = .007). Mean change in FLR was 10.1% in the group where a combination of NBCA and PVA particles was used (n = 24). The effect of glue volume and glue-to-lipiodol ratio on the outcome was not found to be statistically significant ( P = .5 and .7, respectively).

Conclusions

We conclude that NBCA glue is a better embolic agent than PVA particles in inducing liver hypertrophy.

Feasibility of Percutaneous Intrahepatic Split by Microwave Ablation (PISA) After Portal Vein Embolization for Hypertrophy of Future Liver Remnant: The Radiological Stage-1 ALPPS

PURPOSE

To assess the feasibility of radiological stage-1 ALPPS, associating liver partition and portal vein ligation for staged hepatectomy, by combining portal vein embolization (PVE) with percutaneous intrahepatic split by ablation (PISA).

MATERIALS AND METHODS

Three patients (mean age 65.0 ± 7.3 years) underwent PVE and PISA. PISA was performed 21 days after PVE by microwave ablation to create a continuous intrahepatic cutting plane. Abdominal CT examinations were performed before and after PVE and PISA. The future liver remnant (FLR) volume was calculated by semiautomatic segmentation, and increase was reported as a percentage of the pre-procedural volume. The FLR/body weight (FLR/BW) ratio was calculated; a ratio greater than 0.8% was considered sufficient for guaranteeing adequate liver function after surgery. The liver function before and after PISA was also evaluated by 99mTc-mebrofenin hepatobiliary scintigraphy. Patients' laboratory tests, performance status, ability to walk were assessed before and after PVE and PISA procedures.

RESULTS

No procedure-related complications were recorded. The FLR volume increase in each patient was 42.0, 33.1 and 30.4% within 21 days of PVE and 109.3, 68.1 and 71.7% within 10 days after PISA. The FLR/BW ratios were 0.76, 0.66, 0.63% and 1.13, 0.83, 0.83% after PVE and PISA procedures, respectively. Two patients underwent successful right hepatectomy; in one patient, despite 1.13% FLR/BW, surgery was not performed because of the absolute rejection of blood transfusion due to the patient's religious convictions.

CONCLUSION

Radiological stage-1 ALPPS is a feasible, minimally invasive option to be further investigated to become an effective alternative to surgical stage-1 ALPPS.

Resection for Klatskin tumors: technical complexities and results

Klatskin's tumors, actually-redefined as perihilar cholangiocarcinoma (phCCA) do represent 50-70% of all CCAs and develop in a context of chronic inflammation and cholestasis of bile ducts. Surgical resection provides the only chance of cure for this disease but is technically challenging because of the complex, intimate and variable relationship between biliary and vascular structures at this location. Five years survival rates range between 25-45% (median 27-58 months) in case of R0 resection and 0-23% (median 12-21 months) in case of R1 resection respectively. It should be noted that the major costs of high radicality are represented by relative high morbidity and mortality rates (i.e., 20-66% and 0-9% respectively). Considering the fact that radical resection may represent the only curative treatment of phCCA, we focused our review on surgical planning and techniques that may improve resectability rates and outcomes for locally advanced phCCA. The surgical treatment of phCCA can be successful when following aspects have been fulfilled: (I) accurate preoperative diagnostic aimed to identify the tumor in all its details (localization and extension) and to study all the risk factors influencing a posthepatectomy liver failure (PHLF): i.e., liver volume, liver function, liver quality, haemodynamics and patient characteristics; (II) High end surgical skills taking in consideration the local extension of the tumor and the vascular invasion which usually require an extended hepatic resection and often a vascular resection; (III) adequate postoperative management aimed to avoid major complications (i.e., PHLF and biliary complications). These are technically challenging operations and must be performed in a high volume centres by hepato-biliary-pancreas (HBP)-surgeons with experience in microsurgical vascular techniques.

Functional shift with maintained regenerative potential following portal vein ligation

Selective portal vein ligation (PVL) allows the two-stage surgical resection of primarily unresectable liver tumours by generating the atrophy and hypertrophy of portally ligated (LL) and non-ligated lobes (NLL), respectively. To evaluate critically important underlying functional alterations, present study characterised in vitro and vivo liver function in male Wistar rats (n = 106; 210-250 g) before, and 24/48/72/168/336 h after PVL. Lobe weights and volumes by magnetic resonance imaging confirmed the atrophy-hypertrophy complex. Proper expression and localization of key liver transporters (Ntcp, Bsep) and tight junction protein ZO-1 in isolated hepatocytes demonstrated constantly present viable and well-polarised cells in both lobes. In vitro taurocholate and bilirubin transport, as well as in vivo immunohistochemical Ntcp and Mrp2 expressions were bilaterally temporarily diminished, whereas LL and NLL structural acinar changes were divergent. In vivo bile and bilirubin-glucuronide excretion mirrored macroscopic changes, whereas serum bilirubin levels remained unaffected. In vivo functional imaging (indocyanine-green clearance test; ^99mTc-mebrofenin hepatobiliary scintigraphy; confocal laser endomicroscopy) indicated transitionally reduced global liver uptake and -excretion. While LL functional involution was permanent, NLL uptake and excretory functions recovered excessively. Following PVL, functioning cells remain even in LL. Despite extensive bilateral morpho-functional changes, NLL functional increment restores temporary declined transport functions, emphasising liver functional assessment.

Current Modalities for the Assessment of Future Remnant Liver Function

While imaging studies such as computed tomography or magnetic resonance imaging allow the volumetric assessment of the liver segments, only indirect information is provided concerning the quality of the liver parenchyma and its actual functional capacity. Assessment of liver function is therefore crucial in the preoperative workup of patients who require extensive liver resection and in whom portal vein embolization is considered. This review deals with the modalities currently available for the measurement of liver function. Passive liver function tests include biochemical parameters and clinical grading systems such as the Child-Pugh and MELD scores. Dynamic quantitative tests of liver function can be based on clearance capacity tests such as the indocyanine green (ICG) clearance test. Although widely used, discrepancies have been reported for the ICG clearance test in relation with clinical outcome. Nuclear imaging studies have the advantage of providing simultaneous morphologic (visual) and physiologic (quantitative functional) information about the liver. In addition, regional (segmental) differentiation allows specific functional assessment of the future remnant liver. Technetium-99m (^99mTc)-galactosyl human serum albumin scintigraphy and ^99mTc-mebrofenin hepatobiliary scintigraphy potentially identify patients at risk for post-resectional liver failure who might benefit from liver-augmenting techniques. As there is no one test that can measure all the components of liver function, liver functional reserve is estimated based on a combination of clinical parameters and quantitative liver function tests.

Transection of the hepatic parenchyma associated or not with the contralateral portal vein branch ligature and its effect in liver regeneration

Objective

To analyze the influence of portal vein ligation in hepatic regeneration by immunohistochemical criteria.

Methods

Ten pigs divided into two groups of five animals underwent hepatectomy in two stages, and the groups were differentiated by ligation or not of the left portal vein tributary, which is responsible for vascularization of the left lateral and medial lobes of the pig liver. Five days after the procedure, the animals underwent liver biopsies for further analysis of histological and immunohistochemical with marker Ki67.

Results

The group submitted to hepatectomy with vascular ligation showed an increase of approximately 4% of hepatocytes in regeneration status, as well as a greater presence of Kupffer and inflammatory cells as compared to control.

Conclusion

As a result of positive cell replication observed through the Ki67 marker, we can suspect that the ligation of a tributary of the portal vein associated with liver resection promoted a greater stimulus of liver regeneration when compared to liver resection alone.

Integration of Child-Pugh score with future liver remnant yields improved prediction of liver dysfunction risk for HBV-related hepatocellular carcinoma following hepatic resection

Assessment of hepatic functional reserve is important to enable the selection of appropriate treatment methods and safe hepatic resection in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). In the present study, an evaluation was made of the clinical value of combining the Child-Pugh score (CPS) with the standardized future liver remnant (sFLR) measurement to predict postoperative liver dysfunction (PLD). A total of 61 HBV-related HCC patients undergoing liver volumetry prior to hepatectomy were enrolled in the study. The sFLR was calculated as the ratio of FLR volume to standardized liver volume. PLD was defined as a prothrombin time of >18 sec or a peak serum bilirubin level of >51.3 µmol/l for 7 days after surgery. Univariate analysis and multivariate logistic regression analysis were performed to identify risk factors associated with PLD. The correlation between PLD and the combination of sFLR and CPS was analyzed. In total, 18 out of 61 patients developed PLD (29.5%), with a significantly higher PLD incidence for a CPS of 6 than a CPS of 5 (P<0.05). Multivariate logistic regression analysis revealed that a prothrombin time of <13.3 sec and an sFLR of <0.55 were independent risk factors for PLD. Receiver operating characteristic (ROC) curve analysis revealed that the cut-off values of sFLR and sFLR/CPS for predicting PLD were 54.5% and 0.0916, respectively, with areas under the ROC curve of 0.820 and 0.860, respectively. The combination of CPS and sFLR appears to yield improved prediction of the occurrence of PLD compared with either CPS or sFLR alone.

Quantification of hepatic functional capacity: a call for standardization

Reliable assessments of liver function are becoming increasingly important as more patients with surgically amenable liver disease are considered for treatment. Static markers of liver function are not sufficient to provide accurate assessments of hepatic function in order to risk stratify patients undergoing hepatic resection. Metabolic tests are dynamic indicators of liver function, but can be unreliable under certain conditions and thus difficult to make comparisons. Clearance tests avoid some of the pitfalls encountered during metabolic testing, but depend on hepatic blood flow and say little about hepatocyte function. Testing that combines imaging with measures of hepatocyte uptake may offer the most utility when planning surgical resections.

Application of magnetic resonance imaging-based liver function assessment in hepatic surgery

Liver function is often assessed before liver surgery for surgical planning and prognosis prediction. The commonly used methods are not accurate as desired and cannot fully meet the clinical requirements. The advancement of imaging technology and contrast agents has made it possible to use liver-specific contrast agent-enhanced magnetic resonance imaging (MRI) to estimate the total and segmental liver function. Herein, we summarize several evaluation methods currently used and their shortcomings, and describe the principle of hepatic tissue-specific MRI contrast agents, a variety of relevant methods and the latest technological advances. The hepatic tissue-specific contrast-based MRI holds a promise to become a quantitative method for preoperative evaluation of liver function, and achieve the precise assessment of liver function that is needed for precise hepatic surgery.

Measuring total liver function on sulfur colloid SPECT/CT for improved risk stratification and outcome prediction of hepatocellular carcinoma patients

Background

Assessment of liver function is critical in hepatocellular carcinoma (HCC) patient management. We evaluated parameters of [^99mTc] sulfur colloid (SC) SPECT/CT liver uptake for association with clinical measures of liver function and outcome in HCC patients.

Methods

Thirty patients with HCC and variable Child-Turcotte-Pugh scores (CTP A5-C10) underwent [^99mTc]SC SPECT/CT scans for radiotherapy planning. Gross tumor volume (GTV), anatomic liver volume (ALV), and spleen were contoured on CT. SC SPECT image parameters include threshold-based functional liver volumes (FLV) relative to ALV, mean liver-to-spleen uptake ratio (L/S_mean), and total liver function (TLF) ratio derived from the product of FLV and L/S_mean. Optimal SC uptake thresholds were determined by ROC analysis for maximizing CTP classification accuracy. Image metrics were tested for rank correlation to composite scores and clinical liver function parameters. Image parameters of liver function were tested for association to overall survival with Cox proportional hazard regression.

Results

Optimized thresholds on SC SPECT were 58 % of maximum uptake for FLV, 38 % for L/S_mean, and 58 % for TLF. TLF produced the highest CTP classification accuracy (AUC = 0.93) at threshold of 0.35 (sensitivity = 0.88, specificity = 0.86). Higher TLF was associated with lower CTP score: TLF_A = 0.6 (0.4–0.8) versus TLF_B = 0.2 (0.1–0.3), p < 10⁻⁴. TLF was rank correlated to albumin and bilirubin (|R| > 0.63). Only TLF >0.30 was independently associated with overall survival when adjusting for CTP class (HR = 0.12, 95 % CI = 0.02–0.58, p = 0.008).

Conclusions

SC SPECT/CT liver uptake correlated with differential liver function. TLF was associated with improved overall survival and may aid in personalized oncologic management of HCC patients.

Liver Function Assessment Using Parenchyma-Specific Contrast-Enhanced Ultrasonography

The aim of this study was to assess hepatic functional reserve by analyzing the hepatic parenchyma enhancement curve of parenchyma-specific contrast-enhanced ultrasonography (CEUS). Fifty-two patients with cirrhosis who underwent CEUS and indocyanine green tests (ICG) because of a focal liver lesion were enrolled. We evaluated the hemodynamic-related parameters of the time-intensity curve and compared these findings with the ICG retention rate at 15 min (ICG R15). The correlation between the time from peak to one half (s) and ICG R15 was statistically significant and was relatively proportional to the ICG R15. A cut-off value of 149 s was determined for the time from peak to one half for abnormal ICG R15 (>14). The sensitivity and specificity were 85.7% and 92.3%, respectively, for the detection of abnormal ICG R15. In conclusion, the time from peak to one half of the time-intensity curve of parenchyma-specific CEUS of the liver can be a useful parameter to predict the hepatic reserve in liver cirrhosis.

Portable device for the analysis of liver function: a boon to liver surgery and critical care

Liver biology, liver disease and its management present a myriad of challenges to clinicians. Difficulties arise in determining liver functional capacity, which must be effectively measured in a quantitative reproducible manner. Measurement of indocyanine green (ICG) clearance, an exceptional tool that has been used for decades to assess liver function, has traditionally been cumbersome to perform. New technology now allows for rapid and noninvasive determination of ICG clearance making it clinically accessible. This adds ICG clearance measurement to the armamentarium of physiologic monitors that could be routinely used in the evaluation of patients undergoing liver surgery or in the intensive care setting.

Hepatoprotective activity of total iridoid glycosides isolated from Paederia scandens (lour.) Merr. var. tomentosa

ETHNOPHARMACOLOGICAL RELEVANCE

Currently, human liver is susceptible to injury caused by alcohol and virus infiltration, resulting in hepatitis, cirrhosis, and even hepatocellular carcinoma. Paederia scandens (Lour.) Merr. var. tomentosa (Rubiaceae) has been used as traditional medicine in Asian countries to treat jaundice, dysentery, and abdominal mass. Furthermore, the abundance of iridoid glycosides in Paederia species indicates their notable hepatoprotective potential.

MATERIALS AND METHODS

Total iridoid glycosides (TG) was prepared, and constituents of TG were analyzed by HPLC. TG and silymarin (positive) were orally administered for 15 days. Then, acute liver injury rats was induced by intraperitoneally injection (i.p.) of 10% CCl4 (0.12%, v/v, dissolved in olive oil, 10 mL/kg, body weight). Rats were sacrificed at 16 h after CCl4 injection. Liver tissues and blood were collected. Serum samples were prepared to determine the activities of alanine transaminase (ALT) and aspartate transaminase (AST), whereas liver tissue sections were prepared for the purpose of examining possible liver histopathological changes. In addition, antioxidant enzyme activities in liver tissues were also evaluated.

RESULTS

Our results demonstrated that TG significantly decreased the levels of AST and ALT, compared with those in control rats. In addition, pre-treatment of the rats with TG clearly alleviated their liver tissue injuries. What's more, the activities of GSH, GAT and SOD in the groups of TG-treated rats were significantly increased compared with those of rats in the control group, whereas the levels of MDA were decreased.

CONCLUSIONS

Our present research indicated that TG possessed notable hepatoprotective activity via decreasing oxidative stress level in liver tissues.

Update in management of hepatocellular carcinoma in Eastern population

Hepatocellular carcinoma (HCC) is one of the commonest malignant tumours in the East. Although the management of HCC in the West is mainly based on the Barcelona Clinic for Liver Cancer staging, it is considered too conservative by Asian countries where the number of HCC patients is huge. Scientific and clinical advances were made in aspects of diagnosis, staging, and treatment of HCC. HCC is well known to be associated with cirrhosis and the treatment of HCC must take into account the presence and stage of chronic liver disease. The major treatment modalities of HCC include: (1) surgical resection; (2) liver transplantation; (3) local ablation therapy; (4) transarterial locoregional treatment; and (5) systemic treatment. Among these, resection, liver transplantation and ablation therapy for small HCC are considered as curative treatment. Portal vein embolisation and the associating liver partition with portal vein ligation for staged hepatectomy may reduce dropout in patients with marginally resectable disease but the midterm and long-term results are still to be confirmed. Patient selection for the best treatment modality is the key to success of treatment of HCC. The purpose of current review is to provide a description of the current advances in diagnosis, staging, pre-operative liver function assessment and treatment options for patients with HCC in the east.

Intraoperative simulation of remnant liver function during anatomic liver resection with indocyanine green clearance (LiMON) measurements

OBJECTIVE

Post-hepatectomy liver failure (PHLF) is the major cause of death following liver resection. The aim of this study was to evaluate the feasibility of an intraoperative simulation of post-resection liver function.

METHODS

Intraoperative liver function was measured by indocyanine green (ICG) clearance using the LiMON technology. In 20 patients undergoing anatomic liver resection, ICG plasma disappearance rate (PDR (%/min) and ICG retention at 15 min (R15 ) (%) were measured immediately after the induction of anaesthesia (t0 ), after selective arterial and portovenous inflow trial clamping (TC) of the resected liver segments (t1 ), after the completion of resection (t2 ) and before the closure of the abdominal cavity (t3 ).

RESULTS

The median baseline (t0 ) PDR was 16.5%/min. Trial clamping of the inflow (t1 ) resulted in a significant reduction in PDR to 10.5%/min. Results under TC were similar to those obtained after resection (t2 ) (median PDR: 10.5%/min). Linear regression modelling showed that post-resection liver volume could be accurately predicted by TC of liver inflow (P < 0.0001), but not by determining the resected liver volume. Simulated post-resection liver function under TC correlated well with PHLF and length of hospital stay.

CONCLUSIONS

Intraoperative ICG clearance measurements allow real-time monitoring of intraoperative liver function during surgery. Trial clamping of arterial and portovenous inflow accurately predicts immediate post-resection liver function. The intraoperative measurement of liver function and simulation of post-resection liver function may help to avoid PHLF.

Functional imaging of radiation liver injury in a liver metastasis patient: imaging and pathologic correlation

BACKGROUND

Radiation therapy (RT) is increasingly being utilized as a treatment modality for the treatment of primary and metastatic liver malignancies. Accurate assessment of liver function and prediction of radiation induced liver disease (RILD) remains a challenge with conventional laboratory tests and imaging. Imaging-pathology correlation of hepatic injury after RT has been described with computer tomography (CT) imaging that depicts perfusion changes. However, these imaging changes may not directly characterize the functional capacity of the liver.

CASE PRESENTATION

This case report describes a patient that received preoperative chemoradiation and surgical resection for a liver metastasis from endometrial cancer. Sulfur colloid (SC) single photon emission computed tomography (SPECT/CT) was obtained post-chemoradiation and prior to surgery. Imaging-pathology correlation between radiation changes depicted on functional imaging using SC SPECT/CT and corresponding histopathology is described.

DISCUSSION

Quantitative SC SPECT/CT may allow non-invasive assessment of global and spatial liver function before treatment and enable personalized treatment approaches for liver-directed therapies.

Hepatic cytoprotective effect of ischemic and anesthetic preconditioning before liver resection when using intermittent vascular inflow occlusion: a randomized clinical trial

BACKGROUND

Ischemic preconditioning (IPC) and anesthetic preconditioning (APC) have been reported to attenuate ischemia-reperfusion (IR) injury after liver resection under continuous inflow occlusion. This study evaluates whether these strategies enhance hepatic protection of remnant liver against IR after liver resection with intermittent clamping (INT).

METHODS

A total of 106 patients without underlying liver disease and submitted to liver resection using INT were randomized into 3 groups: IPC (10 minutes of inflow occlusion followed by 10 minutes of reperfusion before liver transection), APC (sevoflurane administration for 20 minutes before liver transection), and INT (no preconditioning). Patients were also stratified according to the extent of the hepatectomy. Cytoprotection was evaluated by comparing hepatocyte and endothelial dysfunction markers, apoptosis, histologic lesions, and postoperative outcome.

RESULTS

No differences were observed in preoperative chemotherapy and steatosis, total warm ischemia time, operative time, or blood loss. Kinetics of transaminases (aspartate aminotransferase, P = .137; alanine aminotransferase, P = .616), bilirubin (P = .980), and hyaluronic acid increase (P = .514) revealed no differences. Significant apoptosis was present in 40% of patients, mild-to-moderate leukocyte infiltration and steatosis in 45% and 55%, respectively, and mild sinusoidal congestion in 65%, with a similar distribution in the 3 groups. When patients were stratified by major versus minor resections, no differences were observed in any of the variables studied. Postoperative clinical outcomes were also similar.

CONCLUSION

These results suggest that these protocols of IPC and APC used in this study do not provide better cytoprotection from IR when INT is used.

ALPPS: challenging the concept of unresectability--a systematic review

INTRODUCTION

Hepatic resection for malignancy is limited by the amount of liver parenchyma left behind. As a result, two-staged hepatectomy and portal vein occlusion (PVO) have become part of the treatment algorithm. Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has been recently described as a method to stimulate rapid and profound hypertrophy.

MATERIALS AND METHODS

A systematic review of the literature pertaining to ALPPS was undertaken. Peer-reviewed articles relating to portal vein ligation (PVL) and in situ split (ISS) of the parenchyma were included.

RESULTS

To date, ALPPS has been employed for a variety of primary and metastatic liver tumors. In early case series, the perioperative morbidity and mortality was unacceptably high. However with careful patient selection and improved technique, many centers have reported a 0% 90-day mortality. The benefits of ALPPS include hypertrophy of 61-93% over a median 9-14 days, 95-100% completion of the second stage, and high likelihood of R0 resection (86-100%).

DISCUSSION

ALPPS is only indicated when a two-stage hepatectomy is necessary and the future liver remnant (FLR) is deemed inadequate (<30%). Use in patients with poor functional status, or advanced age (>70 years) is cautioned. Discretion should be used when considering this in patients with pathology other than colorectal liver metastases (CRLM), especially hilar tumors requiring biliary reconstruction. Biliary ligation during the first stage and routine lymphadenectomy of the hepatoduodenal ligament should be avoided.

CONCLUSIONS

A consensus on the indications and contraindications for ALPPS and a standardized operative protocol are needed.

New perspectives in the assessment of future remnant liver

In order to achieve microscopic radical resection margins and thus better survival, surgical treatment of hepatic tumors has become more aggressive in the last decades, resulting in an increased rate of complex and extended liver resections. Postoperative outcomes mainly depend on the size and quality of the future remnant liver (FRL). Liver resection, when performed in the absence of sufficient FRL, inevitably leads to postresection liver failure. The current gold standard in the preoperative assessment of the FRL is computed tomography volumetry. In addition to the volume of the liver remnant after resection, postoperative function of the liver remnant is directly related to the quality of liver parenchyma. The latter is mainly influenced by underlying diseases such as cirrhosis and steatosis, which are often inaccurately defined until microscopic examination after the resection. Postresection liver failure remains a point of major concern that calls for accurate methods of preoperative FRL assessment. A wide spectrum of tests has become available in the past years, attesting to the fact that the ideal methodology has yet to be defined. The aim of this review is to discuss the current modalities available and new perspectives in the assessment of FRL in patients scheduled for major liver resection.

Green light for liver function monitoring using indocyanine green? An overview of current clinical applications

The dye indocyanine green is familiar to anaesthetists, and has been studied for more than half a century for cardiovascular and hepatic function monitoring. It is still, however, not yet in routine clinical use in anaesthesia and critical care, at least in Europe. This review is intended to provide a critical analysis of the available evidence concerning the indications for clinical measurement of indocyanine green elimination as a diagnostic and prognostic tool in two areas: its role in peri-operative liver function monitoring during major hepatic resection and liver transplantation; and its role in critically ill patients on the intensive care unit, where it is used for prediction of mortality, and for assessment of the severity of acute liver failure or that of intra-abdominal hypertension. Although numerous studies have demonstrated that indocyanine green elimination measurements in these patient populations can provide diagnostic or prognostic information to the clinician, 'hard' evidence - i.e. high-quality prospective randomised controlled trials - is lacking, and therefore it is not yet time to give a green light for use of indocyanine green in routine clinical practice.

Clinical application of three-dimensional reconstruction in precise hepatectomy

AIM: To explore the clinical application of three-dimensional reconstruction in precise hepatectomy for primary liver cancer.

METHODS: 3D virtual surgical planning system (IQQA-Liver) can be applied clinically to precise hepatectomy. Fifty-three patients with primary liver cancer who did not undergo three-dimensional reconstruction (group A) and 39 who underwent three-dimensional reconstruction (group B) were included. The design, planning and implementation of the operation were based on the traditional two-dimensional image data in group A. Intraoperative and postoperative conditions such as operative time, blood loss and complications were analyzed and compared with those in group B. In group B, two-dimensional and three-dimensional measures were used to measure total liver volume and pre-cut volume, and the operation was performed based on preoperative assessments using three-dimensional reconstruction technology.

RESULTS: The rate of complications in group B was lower than that in group A, but there was no significant difference. The results of precision hepatectomy based on three-dimensional reconstruction data were not worse than those on two-dimensional preoperative data. No significant difference (t = 1.985, P > 0.05) was found in the resected liver volume calculated based on three-dimensional reconstruction data and on two-dimensional reconstruction data.

CONCLUSION: Three-dimensional reconstruction can help achieve the goals of certainty, predictability and controllability of precise hepatectomy.

Defining indications to ALPPS procedure: technical aspects and open issues

The limit to surgical treatment of patients with hepatic tumors is represented by the proportion of residual hepatic parenchyma at the end of surgery (FLR, future liver remnant) that provides an estimation of the risk of postoperative liver failure. Recently, a new two-stage technique has been developed with the acronym (ALPPS) associating liver partitioning and portal vein ligation for staged hepatectomy with the aim of obtaining a more rapid and effective increase in FLR, even though indications are not clear yet. Between January and December 2012, eight patients were candidates to ALPPS at the Hepatobiliary Surgery Unit of San Raffaele Hospital, Milan. The first three patients (Series 1) underwent right trisectionectomy and were affected by tumors infiltrating biliary confluence, while the others (Series 2) were candidates to right hepatectomy for colorectal liver metastases. Two patients were then excluded from Series 2 because intraoperative finding of irresectable disease. Intra- and postoperative outcome was evaluated with the aim of defining indications to ALPPS. All patients reached an adequate FLR after a median of 7.5 days from the first procedure (rate of program completion 100 %). In Series 1 two patients developed complications related to bile leakage from the raw surface of the liver to be resected and septic events secondary to ischemic necrosis of the liver segment IV. One patient died following multi-organ failure secondary to sepsis. In Series 2 postoperative course was uneventful in all the patients, and in particular no patient showed disease progression between the two procedures or signs of postoperative liver failure. ALPPS approach was initially considered suitable for patients affected by Klatskin tumors who require, despite a small tumor volume, extended hepatectomies associated with surgery of the biliary tract: the analysis of this first series of patients has led to a re-evaluation of the indication to this strategy, as a consequence of encountered criticisms. Actually only a subset of patients affected by colorectal liver metastases are candidates to ALPPS.

Effects of neurolytic celiac plexus block on liver regeneration in rats with partial hepatectomy

Liver regeneration is the basic physiological process after partial hepatectomy (PH), and is important for the functional rehabilitation of the liver after acute hepatic injury. This study was designed to explore the effects of neurolytic celiac plexus block (NCPB) on liver regeneration after PH. We established a model of PH in rats, assessing hepatic blood flow, liver function, and serum CRP, TNF-α, IL-1β and IL-6 concentrations of the residuary liver after PH. Additionally, histopathological studies, immunohistochemistry, and western blotting were also performed. Our results indicated that NCPB treatment after PH improved liver regeneration and survival rates, increased hepatic blood flow, reduced hepatocyte damage, decreased the secretion and release of inflammatory cytokines, increased the expression of B cell lymphoma/leukemia-2 (Bcl-2), and decreased the expression of Bcl-2 associated X protein (Bax). Additionally, Western blotting revealed that the expression of NF-κB p65 and c-Jun were decreased in liver after NCPB. In conclusion, the results of our present study indicate that NCPB treatment has a favorable effect on liver regeneration after PH. We suggest that NCPB can be utilized as an effective therapeutic method to help the functional rehabilitation of the liver after acute hepatic injury or liver cancer surgery.

Physiological and biochemical basis of clinical liver function tests: a review

OBJECTIVE

To review the literature on the most clinically relevant and novel liver function tests used for the assessment of hepatic function before liver surgery.

BACKGROUND

Postoperative liver failure is the major cause of mortality and morbidity after partial liver resection and develops as a result of insufficient remnant liver function. Therefore, accurate preoperative assessment of the future remnant liver function is mandatory in the selection of candidates for safe partial liver resection.

METHODS

A MEDLINE search was performed using the key words "liver function tests," "functional studies in the liver," "compromised liver," "physiological basis," and "mechanistic background," with and without Boolean operators.

RESULTS

Passive liver function tests, including biochemical parameters and clinical grading systems, are not accurate enough in predicting outcome after liver surgery. Dynamic quantitative liver function tests, such as the indocyanine green test and galactose elimination capacity, are more accurate as they measure the elimination process of a substance that is cleared and/or metabolized almost exclusively by the liver. However, these tests only measure global liver function. Nuclear imaging techniques ((99m)Tc-galactosyl serum albumin scintigraphy and (99m)Tc-mebrofenin hepatobiliary scintigraphy) can measure both total and future remnant liver function and potentially identify patients at risk for postresectional liver failure.

CONCLUSIONS

Because of the complexity of liver function, one single test does not represent overall liver function. In addition to computed tomography volumetry, quantitative liver function tests should be used to determine whether a safe resection can be performed. Presently, (99m)Tc-mebrofenin hepatobiliary scintigraphy seems to be the most valuable quantitative liver function test, as it can measure multiple aspects of liver function in, specifically, the future remnant liver.

Prealbumin is predictive for postoperative liver insufficiency in patients undergoing liver resection

AIM: To investigate the risk factors for postoperative liver insufficiency in patients with Child-Pugh class A liver function undergoing liver resection.

METHODS: A total of 427 consecutive patients undergoing partial hepatectomy from October 2007 to April 2011 at a single center (Department of Hepatic SurgeryI, Eastern Hepatobiliary Surgery Hospital, Shanghai, China) were included in the study. All the patients had preoperative liver function of Child-Pugh class A and were diagnosed as having primary liver cancer by postoperative histopathology. Surgery was performed by the same team and hepatic resection was carried out by a clamp crushing method. A clamp/unclamp time of 15 min/5 min was adopted for hepatic inflow occlusion. Patients’ records of demographic variables, intraoperative parameters, pathological findings and laboratory test results were reviewed. Postoperative liver insufficiency and failure were defined as prolonged hyperbilirubinemia unrelated to biliary obstruction or leak, clinically apparent ascites, prolonged coagulopathy requiring frozen fresh plasma, and/or hepatic encephalopathy. The incidence of postoperative liver insufficiency or liver failure was observed and the attributing risk factors were analyzed. A multivariate analysis was conducted to determine the independent predictive factors.

RESULTS: Among the 427 patients, there were 362 males and 65 females, with a mean age of 51.1 ± 10.4 years. Most patients (86.4%) had a background of viral hepatitis and 234 (54.8%) patients had liver cirrhosis. Indications for partial hepatectomy included hepatocellular carcinoma (391 patients), intrahepatic cholangiocarcinoma (31 patients) and a combination of both (5 patients). Hepatic resections of ≤ 3 and ≥ 4 liver segments were performed in 358 (83.8%) and 69 (16.2%) patients, respectively. Seventeen (4.0%) patients developed liver insufficiency after hepatectomy, of whom 10 patients manifested as prolonged hyperbilirubinemia unrelated to biliary obstruction or leak, 6 patients had clinically apparent ascites and prolonged coagulopathy, 1 patient had hepatic encephalopathy and died on day 21 after surgery. On univariate analysis, age ≥ 60 years and prealbumin < 170 mg/dL were found to be significantly correlated with postoperative liver insufficiency (P = 0.045 and P = 0.009, respectively). There was no statistical difference in postoperative liver insufficiency between patients with or without hepatitis, liver cirrhosis and esophagogastric varices. Intraoperative parameters (type of resection, inflow blood occlusion time, blood loss and blood transfusion) and laboratory test results were not associated with postoperative liver insufficiency either. Age ≥ 60 years and prealbumin < 170 mg/dL were selected on multivariate analysis, and only prealbumin < 170 mg/dL remained predictive (hazard ratio, 3.192; 95%CI: 1.185-8.601, P = 0.022).

CONCLUSION: Prealbumin serum level is a predictive factor for postoperative liver insufficiency in patients with liver function of Child-Pugh class A undergoing hepatectomy. Since prealbumin is a good marker of nutritional status, the improved nutritional status may decrease the incidence of liver insufficiency.

A prospective experimental study of liver fibrosis with ultrasound and its correlation with hepatic reserve function and hemodynamics

Background

Progressive hepatic fibrosis is the eventual cause of liver cirrhosis. Doppler ultrasound has been used to detect hemodynamic changes that are known to be present during the pre-cirrhotic stages of hepatic fibrogenesis. However, the relationship between the Doppler ultrasound parameters and the impairment of the liver function has not been fully investigated. The purpose of this study was to explore the hepatic function reserve and its relationship with the hepatic hemodynamics in a rabbit model of liver fibrosis using Doppler ultrasound.

Methods

A prospective study was performed. Sixty healthy New Zealand rabbits were included in this study. Eleven of them served as controls and were normally fed and provided with water drink; the rest of 49 rabbits that served as fibrosis group were normally fed but provided with 1.2 g/L of thioacetamide to create liver fibrosis model. Doppler measurements were performed in the portal trunk, proper hepatic artery and proper splenic artery. The hepatic circulation index (HCI) was calculated. Hepatic function reverse was evaluated by measuring the indocyanine green clearance and retention rate at 15 min (ICG R15) test. Portal venous pressure (PVP) was measured using the portal vein punctuation equipment.

Results

HCI was significantly decreased and PVP increased in the advanced fibrotic stage (F4) compared to mild and moderate fibrotic stage (F1-3), respectively (p<0.05). PVP and ICG R15 in the fibrotic group were significantly higher than that in the control group (ICG: 0.209±0.086 vs. 0.093±0.023, p<0.01). Within the fibrotic groups, PVP was higher in advanced fibrotic stage (F4) than those in mild (F1-2) or moderate (F3) fibrotic stages (p<0.05). Both HCI and PVP correlated well with ICG R15 (r = −0.890, and r = 0.780, p <0.01).

Conclusions

Hepatic function reserve closely relates to the hepatic hemodynamics in the rabbit model of liver fibrosis. Doppler Ultrasound could be reliably used to assess the hepatic function reserve and hemodynamic changes in different stages of liver fibrosis.

Surgical risk in patients with cirrhosis

Surgery in the patient with cirrhosis is problematic, as encephalopathy, ascites, sepsis and bleeding are common in the postoperative period. Accurate preoperative assessment and planning, and careful postoperative management have the potential to reduce the frequency and severity of such complications, and reduce the length of hospital stay, but there is little literature evidence to prove this. Operative mortality and other risks correlate with the severity of the liver disease, co-morbidities and the type of surgery. The Child-Turcott-Pugh (CTP) score or model for end-stage liver disease (MELD) score may be used to determine the severity of the liver disease, but must also take into account recent changes in the patient's condition. Surgery that does not involve opening the peritoneum may have slightly better outcomes, as the risk of ascitic leak, sepsis and difficult fluid management are reduced. Mortality rates range from 10% in CTP-A patients to 82% in CTP-C patients. The presence of portal hypertension is an important negative predictor, especially in abdominal surgery, as refractory ascites may occur. Careful monitoring in the postoperative period and early intervention of complications are essential. Hepatic resections in cirrhosis are associated with other considerations such as leaving sufficient liver tissue to prevent liver failure, and are beyond the scope of this review.

Liver function testing with nuclear medicine techniques is coming of age

Liver function is a broad term, as the organ participates in a multitude of different physiological and biochemical processes, including metabolic, synthetic, and detoxifying functions. However, it is the function of the hepatocyte that is central to sustaining normal life and dealing with disease states. When the liver begins to fail in severely ill patients, it forecasts a terminal outcome. However, unlike the glomerular filtration rate which clearly quantifies the key renal function, at most practice sites, there is no clinically available quantitative test for liver function. Although it is commonplace to assess indirect evidence of that function (by measuring blood levels of its end products and by-products) and to detect an acute injury (by following rising transaminases), a widely available test that would directly measure hepatocellular function is lacking. This article reviews current knowledge on liver function studies and focuses on those nuclear medicine tests available to study the whole liver and regional liver function. The clinical application driving these tests, prediction of remnant liver function after partial hepatectomy for primary liver malignancy or metastatic disease, is addressed here in detail. The test was recently validated for this specific application and was shown to be better than the current standard of practice (computed tomography volumetry), particularly in patients with hepatic comorbidities like cirrhosis, steatosis, or cholestasis. Furthermore, early assessment of regional liver function increase after preoperative portal vein embolization becomes possible with this technology. The limiting factor to a wider acceptance of this test is based on the lack of clinical software that would allow calculation of liver function parameters. This article provides information that enables a clinical nuclear medicine facility to provide this test using readily available equipment. Furthermore, it addresses emerging clinical applications that are under investigation.

Portal vein embolization before liver resection: a systematic review

Purpose

This is a review of literature on the indications, technique, and outcome of portal vein embolization (PVE).

Methods

A systematic literature search on outcome of PVE from 1990 to 2011 was performed in Medline, Cochrane, and Embase databases.

Results

Forty-four articles were selected, including 1,791 patients with a mean age of 61 ± 4.1 years. Overall technical success rate was 99.3 %. The mean hypertrophy rate of the FRL after PVE was 37.9 ± 0.1 %. In 70 patients (3.9 %), surgery was not performed because of failure of PVE (clinical success rate 96.1 %). In 51 patients (2.8 %), the hypertrophy response was insufficient to perform liver resection. In the other 17 cases, 12 did not technically succeed (0.7 %) and 7 caused a complication leading to unresectability (0.4 %). In 6.1 %, resection was cancelled because of local tumor progression after PVE. Major complications were seen in 2.5 %, and the mortality rate was 0.1 %. A head-to-head comparison shows a negative effect of liver cirrhosis on hypertrophy response. The use of n-butyl cyanoacrylate seems to have a greater effect on hypertrophy, but the difference with other embolization materials did not reach statistical significance. No difference in regeneration is seen in patients with cholestasis or chemotherapy.

Conclusions

Preoperative PVE has a high technical and clinical success rate. Liver cirrhosis has a negative effect on regeneration, but cholestasis and chemotherapy do not seem to have an influence on the hypertrophy response. The use of n-butyl cyanoacrylate may result in a greater hypertrophy response compared with other embolization materials used.

Application of multi-slice spiral CT three-dimensional reconstruction technique in liver resection for hepatic carcinoma

Hepatic carcinoma is a very common disease across the world, and hepatic resection is still the best treatment. As the liver has complex anatomy and frequent vascular variations, it is of great importance to obtain some preoperative data, such as the position of liver cancer and its relationship with liver vessels and adjacent structures. Now, three-dimensional reconstruction technique allows to clearly show the relationship of the hepatic artery, portal vein, hepatic vein and tumor with surrounding strctures and accurately calculate the remnant liver volume, providing valuable preoperative imaging data for liver resection. This article will give an overview of three-dimensional reconstruction technique and discuss its ability to display liver vascularity, show the relationship between tumors and liver blood vessels, and predict liver resection volume.

Assessment of liver function in primary biliary cirrhosis using Gd-EOB-DTPA-enhanced liver MRI

OBJECTIVES

Gd-EOB-DTPA (gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid) is a gadolinium-based hepatocyte-specific contrast agent for magnetic resonance imaging (MRI). The aim of this study was to determine whether the hepatic uptake and excretion of Gd-EOB-DTPA differ between patients with primary biliary cirrhosis (PBC) and healthy controls, and whether differences could be quantified.

METHODS

Gd-EOB-DTPA-enhanced liver MRI was performed in 20 healthy volunteers and 12 patients with PBC. The uptake of Gd-EOB-DTPA was assessed using traditional semi-quantitative parameters (C(max) , T(max) and T(1/2) ), as well as model-free parameters derived after deconvolutional analysis (hepatic extraction fraction [HEF], input-relative blood flow [irBF] and mean transit time [MTT]). In each individual, all parameters were calculated for each liver segment and the median of the segmental values was used to define a global liver median (GLM).

RESULTS

Although the PBC patients had relatively mild disease according to their Model for End-stage Liver Disease (MELD), Child-Pugh and Mayo risk scores, they had significantly lower HEF and shorter MTT values compared with the healthy controls. These differences significantly increased with increasing MELD and Child-Pugh scores.

CONCLUSIONS

Dynamic hepatocyte-specific contrast-enhanced MRI (DHCE-MRI) has a potential role as an imaging-based liver function test. The high spatial resolution of MRI enables hepatic function to be assessed on segmental and sub-segmental levels.

Undetectable late hepatic sequelae after hypofractionated stereotactic radiotherapy for liver tumors

Hypofractionated liver stereotactic radiotherapy has produced long-term survival, but the hepatobiliary system is radiosensitive and may be severely damaged by the treatment. We have evaluated long-term radiation effects on hepatobiliary functions in the first long-term survivors reported after radiotherapy to the hepatobiliary system for liver tumors. Eleven patients were followed for up to 13 years after treatment of tumors≤9 cm in size. Conventional blood chemistry, clearance of indocyanine green and segmental uptake and excretion of radiolabeled mebrofenin were assayed. Slightly abnormal routine blood chemistry was found during the first 2 years in some patients with pre-existing liver damage. Other parameters were seemingly unaffected, and liver segments which received differing mean doses did not differ measurably with regard to parenchymal or ductal function. Late liver functions were therefore not demonstrably affected by the radiotherapy in most patients even in the presence of mild cirrhosis, after previous exposure to liver toxic agents, or after resection. However, slight to moderate late dysfunction occurred in one patient after three courses of irradiation, and in a cirrhotic patient after two major liver resections following radiotherapy. Our previous doses for irradiation of liver tumors gave no measurable chronic side effects and may be increased in order to control tumors more effectively. In selected patients, irradiation is possible even in the presence of liver dysfunction, and previous irradiation or resection does not absolutely contraindicate salvage treatment by re-irradiation or resection.