Preoperative galactose elimination capacity predicts complications and survival after hepatic resection

How Much Is Enough? A Surgical Perspective on Imaging Modalities to Estimate Function and Volume of the Future Liver Remnant before Hepatic Resection

Liver resection is the first curative option for most hepatic primary and secondary malignancies. However, post-hepatectomy liver failure (PHLF) still represents a non-negligible postoperative complication, embodying the most frequent cause of hepatic-related mortality. In the absence of a specific treatment, the most effective way to deal with PHLF is its prevention through a careful preoperative assessment of future liver remnant (FLR) volume and function. Apart from the clinical score and classical criteria to define the safe limit of resectability, new imaging modalities have shown their ability to assist surgeons in planning the best operative strategy with a precise estimation of the FLR amount. New technologies leading to liver and tumor 3D reconstruction may guide the surgeon along the best resection planes combining the least liver parenchymal sacrifice with oncological appropriateness. Integration with imaging modalities, such as hepatobiliary scintigraphy, capable of estimating total and regional liver function, may bring about a decrease in postoperative complications. Magnetic resonance imaging with hepatobiliary contrast seems to be predominant since it simultaneously integrates hepatic function and volume information along with a precise characterization of the target malignancy.

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.

Effect of stereotactic body radiotherapy on regional metabolic liver function investigated in patients by dynamic [18F]FDGal PET/CT

Purpose

Stereotactic body radiotherapy (SBRT) is increasingly used for treatment of liver tumors but the effect on metabolic liver function in surrounding tissue is largely unknown. Using 2-deoxy-2-[¹⁸F]fluoro-d-galactose ([¹⁸F]FDGal) positron emission tomography (PET)/computed tomography (CT), we aimed to determine a dose–response relationship between radiation dose and metabolic liver function as well as recovery.

Procedures.

One male subject with intrahepatic cholangiocarcinoma and five subjects (1 female, 4 male) with liver metastases from colorectal cancer (mCRC) underwent [¹⁸F]FDGal PET/CT before SBRT and after 1 and 3 months. The dose response was calculated using the data after 1 month and the relative recovery was evaluated after 3 months. All patients had normal liver function at time of inclusion.

Results

A linear dose–response relationship for the individual liver voxel dose was seen until approximately 30 Gy. By fitting a polynomial curve to data, a mean TD₅₀ of 18 Gy was determined with a 95% CI from 12 to 26 Gy. After 3 months, a substantial recovery was observed except in tissue receiving more than 25 Gy.

Conclusions

[¹⁸F]FDGal PET/CT makes it possible to determine a dose–response relationship between radiation dose and metabolic liver function, here with a TD₅₀ of 18 Gy (95% CI 12–26 Gy). Moreover, the method makes it possible to estimate metabolic recovery in liver tissue.

Predictors of complications after liver surgery: a systematic review of the literature

BACKGROUND

Numerous potential predictors of adverse outcomes have been reported but their performance and utilization in practice seem heterogenous. This study aimed to systematically review the literature on the role and value of predictors of complications after hepatectomy.

METHODS

A systematic review following the PRISMA guidelines was performed. Studies on liver transplant were excluded. Only studies assessing overall or major complications were included.

RESULTS

A total of 10'965 abstracts were screened. After application of exclusion criteria, 72 articles including 68'480 patients were included. A total of 72 markers with 48 pre-, 9 intra- and 15 postoperative factors were identified as predictors of complications. Preoperative and intraoperative predictive markers retrieved several times with the highest odds ratios (OR) were ASA score (OR range: 1.3-7.5, significant in 8 studies) and intraoperative need for red blood cell transfusion (OR range: 1.2-17.1, significant in 24 studies), respectively.

CONCLUSION

Numerous markers have been described to predict the complication risk after hepatectomy. Because of their intrinsic characteristics, most markers such as ASA score and need for red blood cell transfusion are of limited clinical interest. There is a clear need to identify new biomarkers and to develop scores that could easily be implemented in clinical practice.

Perioperative assessment of indocyanine green elimination rate accurately predicts postoperative liver failure in patients undergoing hepatectomy

BACKGROUND

This study aimed to evaluate the usefulness of perioperative indocyanine green elimination rate (ICG-K) as a predictive factor of posthepatectomy liver failure (PHLF).

METHODS

This study enrolled 193 patients who underwent hepatectomy between 2013 and 2019. We analyzed the relationship between estimated ICG-K (ICG-Krem) calculated by the preoperative ICG-K and the residual liver volume ratio, ICG-K at days 1 and 7 after hepatectomy (ICG-Kpod1, ICG-Kpod7), and grade B or C PHLF.

RESULTS

Grade B and C PHLF were observed in eight and two patients, respectively. ICG-Krem and ICG-Kpod1 were highly correlated (correlation coefficient [CC] 0.715), and ICG-Krem and ICG-Kpod7 were moderately correlated (CC 0.653). Receiver-operating characteristic curve analyses indicated that ICG-Krem and ICG-Kpod1 had moderate diagnostic value, while ICG-Kpod7 had high diagnostic value (area under the curve 0.703, 0.845 and 0.937, respectively). Multivariate analysis demonstrated that ICG-Kpod7 (relative risk [RR] 26.04, P = .012) and postoperative bile leakage (PBL) (RR 226.0, P < .001) were independent predictive factors for PHLF. PBL induced PHLF in seven patients, respectively.

CONCLUSIONS

ICG-Krem correlated well with postoperative ICG-K, having moderate accuracy as a predictor of PHLF. However, the clinical relevance of postoperatively measuring ICG-K is limited because PHLF is greatly affected by surgical and postoperative factors.

Optimizing hepatectomy for hepatocellular carcinoma in Asia-patient selection and special considerations

Hepatocellular carcinoma (HCC) is a common affliction in Asia. The treatment of HCC depends on the tumor status as well as the underlying liver function. Resection is the cornerstone of surgical management of HCC. For those unfit to undergo resection, local ablative therapy is a viable alternative. For patients with multiple small unresectable HCCs, liver transplantation offers another option, having the simultaneous benefit of removing the cancer in addition to replacing the pre-malignant and cirrhotic liver together. However, the paucity of liver grafts limits the applicability of this operation. In assessing for the appropriate treatment, the traditional TNM staging is not widely applied to HCC. Conventionally, doctors in the West have relied on the Barcelona staging system. Asian surgeons, on the other hand, have long adopted a more aggressive approach for their patients. Borne out of the need for a system which better suited Asian patients, the Hong Kong guidelines have been established. For the surgical resection of HCC, considerations must take into account issues regarding the tumor, the underlying liver and the patient. For the tumor, the size, the presence vascular invasion and presence of extra-hepatic metastasis will determine operability. Another important issue is the liver function and, by extension, the estimated residual liver volume after resection. Thirdly, patient factors i.e., fitness to undergo general anesthesia must be properly assessed. With improved surgical technique and better patient selection, peri-operative morbidity and long-term survival results after operation have improved drastically over the past decades.

Quantitative PET of liver functions

Improved understanding of liver physiology and pathophysiology is urgently needed to assist the choice of new and upcoming therapeutic modalities for patients with liver diseases. In this review, we focus on functional PET of the liver: 1) Dynamic PET with 2-deoxy-2-[18F]fluoro-D-galactose (18F-FDGal) provides quantitative images of the hepatic metabolic clearance Kmet (mL blood/min/mL liver tissue) of regional and whole-liver hepatic metabolic function. Standard-uptake-value (SUV) from a static liver 18F-FDGal PET/CT scan can replace Kmet and is currently used clinically. 2) Dynamic liver PET/CT in humans with 11C-palmitate and with the conjugated bile acid tracer [N-methyl-11C]cholylsarcosine (11C-CSar) can distinguish between individual intrahepatic transport steps in hepatic lipid metabolism and in hepatic transport of bile acid from blood to bile, respectively, showing diagnostic potential for individual patients. 3) Standard compartment analysis of dynamic PET data can lead to physiological inconsistencies, such as a unidirectional hepatic clearance of tracer from blood (K1; mL blood/min/mL liver tissue) greater than the hepatic blood perfusion. We developed a new microvascular compartment model with more physiology, by including tracer uptake into the hepatocytes from the blood flowing through the sinusoids, backflux from hepatocytes into the sinusoidal blood, and re-uptake along the sinusoidal path. Dynamic PET data include information on liver physiology which cannot be extracted using a standard compartment model. In conclusion, SUV of non-invasive static PET with 18F-FDGal provides a clinically useful measurement of regional and whole-liver hepatic metabolic function. Secondly, assessment of individual intrahepatic transport steps is a notable feature of dynamic liver PET.

Advances in preoperative assessment of liver function

BACKGROUND

Postoperative liver failure remains a life-threatening complication. Preoperative evaluation of liver function is essential in reducing the complications after hepatectomy. However, it is difficult to accurately evaluate liver function before surgery because of the limitations of the liver function tests available. Recent advances in liver function tests improved the ability to assess liver function. The present review was to analyze these methods and their advantages.

DATA SOURCES

MEDLINE was searched using the terms of "liver function test", "liver function evaluation" and "galactosyl serum albumin". Relevant articles published in English and Chinese from 1961 to 2014 were reviewed.

RESULTS

Although serological tests are used frequently in practice, they reflect the degree of total liver damage or function, not the remnant of liver function. Child-Pugh score and model for end-stage liver disease (MELD) score assess whole liver function, and are particularly useful in determining whether patients with hepatocellular carcinoma and cirrhosis are candidates for resection or transplantation, but cannot determine the safe extent or removal. The indocyanine green and other metabolic quantitative liver function tests can evaluate functional hepatocytes, making them more accurate in predicting liver function. Computed tomography (CT) volumetry can provide anatomic information on the remnant liver volume but not on functional volume. 99mTc-galactosyl serum albumin scintigraphy, combined with single photon emission computed tomography, CT and three-dimensional reconstruction, may be a better quantitative measure of liver function, especially of remnant liver function.

CONCLUSIONS

Tests used to evaluate liver functional reserve and to predict surgical risk have limitations. 99mTc-galactosyl serum albumin scintigraphy, which can more accurately evaluate the whole and regional liver function, may be promising in predicting resection margins and risks of liver failure.

Hepatic radioembolization as a bridge to liver surgery

Treatment of oncologic disease has improved significantly in the last decades and in the future a vast majority of cancer types will continue to increase worldwide. As a result, many patients are confronted with primary liver cancers or metastatic liver disease. Surgery in liver malignancies has steeply improved and curative resections are applicable in wider settings, leading to a prolonged survival. Simultaneously, radiofrequency ablation (RFA) and liver transplantation (LTx) have been applied more commonly in oncologic settings with improving results. To minimize adverse events in treatments of liver malignancies, locoregional minimal invasive treatments have made their appearance in this field, in which radioembolization (RE) has shown promising results in recent years with few adverse events and high response rates. We discuss several other applications of RE for oncologic patients, other than its use in the palliative setting, whether or not combined with other treatments. This review is focused on the role of RE in acquiring patient eligibility for radical treatments, like surgery, RFA, and LTx. Inducing significant tumor reduction can downstage patients for resection or, through attaining stable disease, patients can stay on the LTx waiting list. Hereby, RE could make a difference between curative of palliative intent in oncologic patient management. Prior to surgery, the future remnant liver volume might be inadequate in some patients. In these patients, forming an adequate liver reserve through RE leads to prolonged survival without risking post-operative liver failure and minimizing tumor progression while inducing hypertrophy. In order to optimize results, developments in procedures surrounding RE are equally important. Predicting the remaining liver function after radical treatment and finding the right balance between maximum tumor irradiation and minimizing the chance of inducing radiation-related complications are still challenges.

Major hepatectomy is a safe modality for the treatment of intrahepatic cholangiocarcinoma in selected patients complicated with cirrhosis

OBJECTIVE

The objective of this paper is to evaluate the perioperative outcomes of major hepatectomy for intrahepatic cholangiocarcinoma (ICC) in patients with cirrhosis.

METHODS

We retrospectively evaluated the preoperative, intraoperative, and postoperative findings in 42 consecutive patients with cirrhosis and in 102 patients with normal livers who underwent major hepatectomy for ICC.

RESULTS

Preoperative liver function was worse in patients with cirrhosis compared to patients without cirrhosis. Cirrhotic patients had significantly higher intraoperative blood loss, longer operation time, and longer hospital stay than non-cirrhotic patients. However, the two groups had similar overall morbidity and hospital mortality rates and similar rates of liver failure or other complications. Their R0 resection rates, resection margin widths and disease-free survival rates were also similar.

CONCLUSIONS

Major hepatectomy for ICC can be performed in selected cirrhotic patients with acceptable morbidity and mortality rates, as compared to patients without cirrhosis.

Serum arterial lactate concentration predicts mortality and organ dysfunction following liver resection

BACKGROUND

The aim of this study was to determine if the post-operative serum arterial lactate concentration is associated with mortality, length of hospital stay or complications following hepatic resection.

METHODS

Serum lactate concentration was recorded at the end of liver resection in a consecutive series of 488 patients over a seven-year period. Liver function, coagulation and electrolyte tests were performed post-operatively. Renal dysfunction was defined as a creatinine rise of >1.5x the pre-operative value.

RESULTS

The median lactate was 2.8 mmol/L (0.6 to 16 mmol/L) and was elevated (≥2 mmol/L) in 72% of patients. The lactate concentration was associated with peak post-operative bilirubin, prothrombin time, renal dysfunction, length of hospital stay and 90-day mortality (P < 0.001). The 90-day mortality in patients with a post-operative lactate ≥6 mmol/L was 28% compared to 0.7% in those with lactate ≤2 mmol/L. Pre-operative diabetes, number of segments resected, the surgeon's assessment of liver parenchyma, blood loss and transfusion were independently associated with lactate concentration.

CONCLUSIONS

Initial post-operative lactate concentration is a useful predictor of outcome following hepatic resection. Patients with normal post-operative lactate are unlikely to suffer significant hepatic or renal dysfunction and may not require intensive monitoring or critical care.

Surgical therapy for hepatocellular carcinoma: formulating a rational approach

Hepatocellular carcinoma is one of the most common malignancies worldwide, and its incidence continues to rise in the United States. Partial hepatectomy and liver transplantation remains the mainstay of treatment for localized disease and provides significant improvement in long-term survival, as well as the potential for cure. The indications and criteria for resection and transplantation are well established, but continue to undergo significant modification over time. Surgical resection is the primary therapeutic modality in patients with well-compensated liver disease, and transplantation is highly effective in early-stage tumors in patients with severe underlying liver disease. The relative role for each of these modalities must be tailored to individual patients based on a rational approach designed to balance quality of life, organ allocation, and patient survival.

Atrial natriuretic peptide reduces hepatic ischemia-reperfusion injury in rabbits

PURPOSE

Atrial natriuretic peptide (ANP) has been known to be protective against hepatic ischemia/reperfusion injury. The purpose of this study was to verify the hypothesis that ANP conserves microvascular circulation and reduces ischemia-reperfusion injury in the in vivo rabbit model.

METHODS

With IRB approval, 30 male Japanese white rabbits under pentobarbital anesthesia were studied. These animals were randomly assigned to the following three groups (n = 10 each): control, ANP, and sham group. Animals in the ANP group received continuous infusion of ANP at 0.1 μg/kg/min throughout the study period. Animals in control and ANP groups underwent 90 min of partial hepatic ischemia by clamping the right hepatic artery and portal vein. Descending aortic blood flow (AoF) was monitored with a transit-time ultrasound flowmeter. Hepatic tissue microvascular blood flow (HTBF) at both right (ischemic) and left (nonischemic) lobe was intermittently evaluated with the hydrogen clearance method. After 180 min of reperfusion, hepatic injury was determined with serum AST and ALT. Galactose clearance of reperfused right lobe was also measured as an indicator of hepatic metabolic function. Histopathological change and the number of apoptotic hepatocytes were also evaluated.

RESULTS

Systemic hemodynamic data including mean arterial pressure, heart rate, and AoF did not differ among the three groups during the study period. ANP attenuated ischemia-induced right HTBF decrease. ANP also suppressed histopathological degeneration, apoptosis, and decline in galactose clearance after reperfusion.

CONCLUSIONS

ANP attenuated hepatic microvascular dysfunction and hepatocyte injury after reperfusion without significant hemodynamic change.

Regional metabolic liver function measured in patients with cirrhosis by 2-[¹⁸F]fluoro-2-deoxy-D-galactose PET/CT

BACKGROUND & AIMS

There is a clinical need for methods that can quantify regional hepatic function non-invasively in patients with cirrhosis. Here we validate the use of 2-[(18)F]fluoro-2-deoxy-d-galactose (FDGal) PET/CT for measuring regional metabolic function to this purpose, and apply the method to test the hypothesis of increased intrahepatic metabolic heterogeneity in cirrhosis.

METHODS

Nine cirrhotic patients underwent dynamic liver FDGal PET/CT with blood samples from a radial artery and a liver vein. Hepatic blood flow was measured by indocyanine green infusion/Fick's principle. From blood measurements, hepatic systemic clearance (Ksyst, Lblood/min) and hepatic intrinsic clearance (Vmax/Km, Lblood/min) of FDGal were calculated. From PET data, hepatic systemic clearance of FDGal in liver parenchyma (Kmet, mL blood/mL liver tissue/min) was calculated. Intrahepatic metabolic heterogeneity was evaluated in terms of coefficient-of-variation (CoV, %) using parametric images of Kmet.

RESULTS

Mean approximation of Ksyst to Vmax/Km was 86% which validates the use of FDGal as PET tracer of hepatic metabolic function. Mean Kmet was 0.157 mL blood/mL liver tissue/min, which was lower than 0.274 mL blood/mL liver tissue/min, previously found in healthy subjects (p<0.001), in accordance with decreased metabolic function in cirrhotic livers. Mean CoV for Kmet in liver tissue was 24.4% in patients and 14.4% in healthy subjects (p<0.0001). The degree of intrahepatic metabolic heterogeneity correlated positively with HVPG (p<0.05).

CONCLUSIONS

A 20-min dynamic FDGal PET/CT with arterial sampling provides an accurate measure of regional hepatic metabolic function in patients with cirrhosis. This is likely to have clinical implications for the assessment of patients with liver disease as well as treatment planning and monitoring.

Functional liver reserve parameters predictive for posthepatectomy complications

BACKGROUND

Posthepatectomy complications have markedly decreased with advances in techniques and management; however, surgical risk to patients with injured livers is still not negligible. We evaluated several preoperative parameters of functional liver reserve tests in patients with various liver diseases as predictors of posthepatectomy complications. A comprehensive evaluation of preoperative liver functions is necessary for the prediction of the risk of posthepatectomy complications.

METHODS

Over a 10-y period, we examined 442 patients who underwent hepatectomy for liver and biliary diseases. The patients' background liver diseases included chronic viral liver diseases in 211 patients, obstructive jaundice in 29 patients, and normal liver in 202 patients. Hepatectomy-related postoperative complications (i.e., long-term ascites, intra-abdominal infection, and hepatic failure) occurred in 115 (26%) patients. A multivariate logistic analysis was performed to detect the predictive parameters, and a multivariate linear regression analysis was performed to derive a predictive formula for complications.

RESULTS

A univariate analysis identified 15 significant parameters associated with hepatectomy-related complications, and eight parameters (i.e., presence of chronic hepatic injury, clearance index by technetium-99 m galactosyl human serum albumin liver scintigraphy of ≥ 0.60, total bilirubin level of >1 mg/dL, serum hyaluronic acid level of ≥ 75 ng/mL, major hepatectomy, blood loss of ≥ 950 mL, operating time of ≥ 500 min, and combined resection of another organ or major vessel) were independent predictive factors identified in the multivariate analysis. Clearance index by technetium-99 m galactosyl human serum albumin liver, bilirubin level, hyaluronic acid level, and major hepatectomy were the parameters included in the predictive formula.

CONCLUSIONS

In the present study, we present a comprehensive formula based on the predictive parameters for hepatic complications for prospective assessment to avoid posthepatectomy morbidity.

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.

Increase in left liver lobe function after preoperative right portal vein embolisation assessed with gadolinium-EOB-DTPA MRI

OBJECTIVES

To prospectively evaluate the early development of regional liver function after right portal vein embolisation (PVE) with Gd-EOB-DTPA-enhanced MRI in patients scheduled for extended right hemihepatectomy.

METHODS

Ten patients who received a PVE before an extended hemihepatectomy were examined before and 14 days after PVE using Gd-EOB-DTPA-enhanced MRI of the liver. In these sequences representative region of interest measurements were performed in the embolised right (RLL) and the non-embolised left liver lobe (LLL). The volume as well as hepatic uptake index (HUI) was calculated independently for each lobe.

RESULTS

Relative enhancement 14 days after PVE decreased in the RLL and increased significantly in the LLL (P < 0.05). Average hepatic uptake index (HUI) for RLL was significantly lower 14 days after PVE than before PVE (P < 0.05) and significantly higher for LLL (P < 0.05).

CONCLUSIONS

A significant shift of contrast uptake from the right to the left liver lobe can be depicted as early as 14 days after right PVE by using Gd-EOB-DTPA-enhanced MRI, which could reflect the redirected portal venous blood flow and the rapid utilisation of a hepatic functional reserve.

KEY POINTS

• Preoperative portal vein embolisation (PVE) is widely performed before right-sided hepatic resection. • PVE increases intravenous contrast medium uptake in the left lobe of liver. • The hepatic uptake index for the left liver lobe increases rapidly after PVE. • Left liver lobe function increase may be visualised by Gd-EOB-DTPA-enhanced MRI.

Kinetics of liver function tests after a hepatectomy for colorectal liver metastases predict post-operative liver failure as defined by the International Study Group for Liver Surgery

BACKGROUND

Post-hepatectomy liver failure (PHLF) has been defined by the International Study Group for Liver Surgery (ISGLS). The purpose of the present study was to examine the kinetics of conventional liver function tests (LFT) after a major liver resection and is the first to examine their utility in predicting PHLF in groups defined by the ISGLS.

METHODS

Consecutive patients undergoing a major liver resection for colorectal liver metastases were stratified into ISGLS groups and their LFT up to 1 year after surgery compared. Receiving-operating characteristic (ROC) analysis of LFT identified optimal thresholds in predicting category C liver failure.

RESULTS

In total, 32, 22 and 19 patients belonged to ISGLS groups A, B and C, respectively. The median international normalized ratio (INR) and bilirubin values on post-operative days 1, 3, 5 and 7 were significantly different among the groups (all P-values <0.05). ROC analysis of day 1 INR (AUC 0.813) and day 5 bilirubin (AUC 0.798) revealed thresholds of 1.35 and 52 μmol/l to have sensitivities of 85% and 81% and specificities of 63% and 73%, respectively, to predict group C liver failure.

DISCUSSION

Post-operative LFT after a major liver resection differs significantly among the three ISGLS groups. Thresholds of bilirubin and INR can be used to identify patients who are at a maximum risk of complications.

Hepatectomy in a hepatocellular carcinoma case with Dubin-Johnson syndrome and indocyanine green excretory defect

A 77-year-old male patient with history of jaundice was referred to our hospital for treatment of hepatocellular carcinoma (HCC). He was found to have Dubin-Johnson syndrome (DJS), a clinical feature of constitutional jaundice with conjugated hyperbilirubinemia, and indocyanine green (ICG) excretory defect, both of which are rare conditions. Total bilirubin was 5.1 mg/dl and ICG retention at 15 min (ICGR15) (77.1 %). Converted ICGR15 from GSA scintigraphy was 15.9 %. Resection of the medial segment and ventral region of the anterior segment of the liver as well as cholecystectomy were performed. The background of the liver tissue was blackish yellow and consistent with DJS and chronic hepatitis. Although total bilirubin level increased to 8.2 mg/dl on the 2nd postoperative day, the patient ultimately recovered and he was discharged on the 14th day. His 1- and 2-year medical checkups indicated recurrence of HCC. He underwent transarterial chemoembolization and is presently doing well 39 months after surgery. We report here on evaluation and treatment of patients with such disorders.

Galactose half-life is a useful tool in assessing prognosis of chronic liver disease in children

In children, optimal timing of liver transplantation (LT) is crucial, but reliable prognostic tools for chronic liver diseases are scarce. We assessed the predictive value of galactose half-life (Gal½) for LT or death. A retrospective search of hospital database 2003-2010 revealed 92 consecutive children with chronic liver disease (36 biliary atresia) whose liver function was assessed with Gal½ measurement. Gal½, follow-up data, and liver biochemistry were recorded and pediatric/model for end-stage liver disease (P/MELD) scores calculated. Patients listed for LT or those who died within 1 year of the Gal½ measurement (Group 1) were compared to those surviving without listing (Group 2). Predictive value of Gal½ and P/MELD for listing for LT was assessed with area under the receiver operating characteristic curve (AUROC) analysis. Group 1 had markedly increased median Gal½ [17.0 (interquartile range 12.5-28.5) min] and higher P/MELD [13 (-1-23)] compared with group 2, [10.5 (9.5-12.5) min and -1 (-8-8); P < 0.001 for both]. Both Gal½ and P/MELD (P < 0.001) predicted listing or death with respective AUROCs of 0.808 (95% CI 0.704-0.913) and 0.780 (0.676-0.890), and 85% sensitivity and 69% specificity for Gal½≥12.0 min. Gal½ is a useful tool when evaluating 1-year prognosis in children with chronic liver disease.

Hepatic galactose metabolism quantified in humans using 2-18F-fluoro-2-deoxy-D-galactose PET/CT

Accurate quantification of regional liver function is needed, and PET of specific hepatic metabolic pathways offers a unique method for this purpose. Here, we quantify hepatic galactose elimination in humans using PET and the galactose analog 2-(18)F-fluoro-2-deoxy-d-galactose ((18)F-FDGal) as the PET tracer.

METHODS

Eight healthy human subjects underwent (18)F-FDGal PET/CT of the liver with and without a simultaneous infusion of galactose. Hepatic systemic clearance of (18)F-FDGal was determined from linear representation of the PET data. Hepatic galactose removal kinetics were determined using measurements of hepatic blood flow and arterial and liver vein galactose concentrations at increasing galactose infusions. The hepatic removal kinetics of (18)F-FDGal and galactose and the lumped constant (LC) were determined.

RESULTS

The mean hepatic systemic clearance of (18)F-FDGal was significantly higher in the absence than in the presence of galactose (0.274 ± 0.001 vs. 0.019 ± 0.001 L blood/min/L liver tissue; P < 0.01), showing competitive substrate inhibition of galactokinase. The LC was 0.13 ± 0.01, and the (18)F-FDGal PET with galactose infusion provided an accurate measure of the local maximum removal rate of galactose (V(max)) in liver tissue compared with the V(max) estimated from arterio-liver venous (A-V) differences (1.41 ± 0.24 vs. 1.76 ± 0.08 mmol/min/L liver tissue; P = 0.60). The first-order hepatic systemic clearance of (18)F-FDGal was enzyme-determined and can thus be used as an indirect estimate of galactokinase capacity without the need for galactose infusion or knowledge of the LC.

CONCLUSION

(18)F-FDGal PET/CT provides an accurate in vivo measurement of human galactose metabolism, which enables the quantification of regional hepatic metabolic function.

Usefulness of Tc-99m-GSA scintigraphy for liver surgery

Postoperative mortality remains high after hepatectomy compared with other types of surgery in patients who have cirrhosis or chronic hepatitis. Although there are several useful perioperative indicators of liver dysfunction, no standard markers are available to predict postoperative liver failure in patients with hepatocellular carcinoma (HCC) undergoing hepatectomy. The best preoperative method for evaluating the hepatic functional reserve of patients with HCC remains unclear, but technetium-99m diethylenetriamine pentaacetic acid galactosyl human serum albumin ((99m)Tc-GSA) scintigraphy is a candidate. (99m)Tc-GSA is a liver scintigraphy agent that binds to the asialoglycoprotein receptor, and can be used to assess the functional hepatocyte mass and thus determine the hepatic functional reserve in various physiological and pathological states. The maximum removal rate of (99m) Tc-GSA (GSA-Rmax) calculated by using a radiopharmacokinetic model is correlated with the severity of liver disease. There is also a significant difference of GSA-Rmax between patients with chronic hepatitis and persons with normal liver function. Regeneration of the remnant liver and recurrence of hepatitis C virus infection in the donor organ after living donor liver transplantation have also been investigated by (99m)Tc-GSA scintigraphy. This review discusses the usefulness of (99m)Tc-GSA scintigraphy for liver surgery.

Nucleophilic radiosynthesis of 2-[18F]fluoro-2-deoxy-D-galactose from Talose triflate and biodistribution in a porcine model

INTRODUCTION

The galactose analogue 2-[(18)F]fluoro-2-deoxy-D-galactose (FDGal) is a promising positron emission tomography (PET) tracer for studies of regional differences in liver metabolic function and for clinical evaluation of patients with liver cirrhosis and patients undergoing treatment of liver diseases. However, there is an unmet need for routine production of FDGal from readily available starting material. In this study, we present the preparation of FDGal with high radiochemical purity and in amounts sufficient for clinical investigations from commercially available Talose triflate (1,3,4,6-tetra-O-acetyl-2-O-trifluoromethanesulfonyl-β-D-talopyranose). In addition, the biodistribution of FDGal in the pig is presented.

METHODS

FDGal was prepared by nucleophilic fluorination of Talose triflate followed by basic hydrolysis. The entire synthesis was performed using the GE TRACERlab MX 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG) synthesizer and existing methods for quality control of FDG were applied. Biodistribution of FDGal was studied by successive whole-body PET recordings of two anaesthetized 37-kg pigs.

RESULTS

Up to 3.7 GBq sterile, pyrogen-free and no-carrier-added FDGal was produced with a radiochemical yield of 3.8±1.2% and a radiochemical purity of 98±1% (42 productions; yield is decay corrected). The adopted quality control methods for FDG were directly applicable for FDGal. Biodistribution studies in the pig revealed the liver and the urinary bladder as critical organs in terms of radiation dose.

CONCLUSION

Commercially available Talose triflate is a suitable starting material for routine productions of FDGal. The presented radiosynthesis and quality control methods allow for the production of pure, no-carrier-added FDGal in sufficient amounts for clinical PET-investigations of the liver.

Increase in future remnant liver function after preoperative portal vein embolization

BACKGROUND

Preoperative portal vein embolization (PVE) is performed in patients with insufficient future remnant liver (FRL) to allow safe resection. Although many studies have demonstrated an increase in FRL volume after PVE, little is known about the increase in FRL function. This study evaluated the increase in FRL function after PVE using (⁹⁹m) Tc-labelled mebrofenin hepatobiliary scintigraphy (HBS) with single photon emission computed tomography (SPECT) and compared this with the increase in FRL volume.

METHODS

In 24 patients, computed tomography volumetry and (⁹⁹m) Tc-labelled mebrofenin HBS with SPECT were performed before and 3-4 weeks after PVE to measure FRL volume, standardized FRL and FRL function. A hypothetical model was used to assess safe resectability after PVE. The limit for safe resection for FRL function was set at an uptake of 2·69 per cent per min per m². For FRL volume and standardized FRL, 25 or 40 per cent of total liver volume was used, depending on the presence of underlying liver disease.

RESULTS

After PVE, FRL function increased significantly more than FRL volume. The correlation between the increase in FRL volume and FRL function was poor. Using the hypothetical model, seven patients did not achieve a sufficient increase in FRL function to allow safe resection 3-4 weeks after PVE, compared with 12 and nine patients based on FRL volume and standardized FRL respectively.

CONCLUSION

The increase in FRL function after PVE is more pronounced than the increase in FRL volume, suggesting that the necessary waiting time until resection may be shorter than indicated by volumetric parameters.

Age-dependency of galactose elimination capacity in healthy children and children with chronic liver disease

OBJECTIVE

Galactose elimination capacity (GEC) is used as a quantitative measure of liver metabolic function with prognostic value in adults with acute and chronic liver failure. Almost no data are available regarding GEC in children, however. This study thus aims to meet the previously unmet clinical need for age-related data on GEC in children.

MATERIAL AND METHODS

We studied galactose elimination in 10 healthy children (median age 10.7 years; range 7 months to 16 years) and 30 children with chronic liver disease (median age 8.6 years; range 3 months to 16 years). GEC was estimated from the linear decrease in concentration of galactose in arterialized capillary blood from the ear following intravenous infusion of galactose.

RESULTS

In both groups of children, GEC (μmol/min/kg body weight) was highest in the youngest children and decreased with age, although at a significantly lower level in the children with liver disease (p = 0.05). GEC was significantly higher in healthy children than in healthy adults, diminishing to the adult level by the age of 16 years.

CONCLUSIONS

GEC was found to be higher in children than in adults until the age of 16 years. Moreover, GEC was significantly lower in children with chronic liver disease than in healthy children, underlining that GEC testing also has potential clinical usefulness as a quantitative measure of liver metabolic function in children.

Safety and efficacy of trisectionectomy for hepatocellular carcinoma

BACKGROUND

Right or left trisectionectomy represents the most extensive and difficult type of hepatic resection, and carries an unfavourably high morbidity and mortality. This retrospective study aimed to evaluate the safety and efficacy of trisectionectomy for hepatocellular carcinoma (HCC).

METHODS

From January 2000 to December 2008, 35 patients with HCC were treated with trisectionectomy. The treatment outcomes of these patients were retrospectively analysed.

RESULTS

Twenty-three right and 12 left trisectionectomies were performed. The overall operative morbidity and mortality were 42.8% (n= 15) and 2.8% (n= 1), respectively. The 1-, 3-, and 5-year overall survival rates were 82.9%, 51.4% and 23.8%, while the 1-, 3- and 5-year disease-free survival rates were 71.4%, 42.9% and 12.9%, respectively.

CONCLUSIONS

With careful patient selection and meticulous surgical technique, trisectionectomy can be performed safely and is associated with long-term survival in a subset of patients with HCC.

Determination of hepatic galactose elimination capacity using 2-[¹⁸F]fluoro-2-deoxy-D-galactose PET/CT: reproducibility of the method and metabolic heterogeneity in a normal pig liver model

OBJECTIVE

A PET method is developed for non-invasive measurement of regional metabolic liver function using the galactose analog 2-[¹⁸F]fluoro-2-deoxy-D-galactose, FDGal. The aim of the present study was to determine the reproducibility of the method in pigs before translating it to human studies.

MATERIAL AND METHODS

Five anesthetized pigs were studied twice within an interval of three days. A dynamic PET recording was performed with an injection of 100 MBq FDGal. Non-radioactive galactose was administered throughout the PET recordings to achieve near-saturated elimination kinetics. Arterial blood samples were collected for determination of blood concentrations of FDGal and galactose (c(gal)). Net metabolic clearance of FDGal, K(FDGal), was calculated from linear representation of data. The approximate maximal hepatic removal rate, V(max), of galactose (mmol/l tissue/min) was calculated as K(FDGal) c(gal). The estimates from Day 1 and Day 2 were compared and the coefficient of variation, COV, of the estimates calculated. Functional heterogeneity in normal pig liver was evaluated as COV of the tissue concentration of radioactivity during quasi steady-state metabolism.

RESULTS

There was no significant difference between V(max) from Day 1 and Day 2 (p = 0.38), and the reproducibility was good with a COV of 14% for the whole liver. In normal pig liver tissue, mean COV after an injection of FDGal was on average 15.6% with no day-to-day variation (p = 0.7).

CONCLUSIONS

The novel FDGal PET method for determination of hepatic metabolic function has a good reproducibility and is promising for future human studies of regional liver function.

A review of factors predicting perioperative death and early outcome in hepatopancreaticobiliary cancer surgery

OBJECTIVES

In the context of comparisons of surgical outcomes, risk adjustment is the retrospective adjustment of a provider's or a surgeon's results for case mix and/or hospital volume. It allows accurate, meaningful inter-provider comparison. It is therefore an essential component of any audit and quality improvement process. The aim of this study was to review the literature to identify those factors known to affect prognosis in hepatobiliary and pancreatic cancer surgery.

METHODS

PubMed was used to identify studies assessing risk in patients undergoing resection surgery, rather than bypass surgery, for hepatobiliary and pancreatic cancer.

RESULTS

In total, 63 and 68 papers, pertaining to 24 609 and 63 654 patients who underwent hepatic or pancreatic resection for malignancy, respectively, were identified. Overall, 22 generic preoperative factors predicting outcome on multivariate analysis, including demographics, blood results, preoperative biliary drainage and co-morbidities, were identified, with tumour characteristics proving disease-specific factors. Operative duration, transfusion, operative extent, vascular resection and additional intra-abdominal procedures were also found to be predictive of early outcome.

CONCLUSIONS

The development of a risk adjustment model will allow for the identification of those factors with most influence on early outcome and will thus identify potential targets for preoperative optimization and allow for the development of a multicentre risk prediction model.

Nuclear imaging techniques for the assessment of hepatic function in liver surgery and transplantation

This review describes the application of 2 nuclear imaging techniques for assessment of hepatic function in the setting of liver surgery and transplantation. The biochemical and technical background, as well as the clinical applications, of (99m)Tc-labeled diethylenetriaminepentaacetic acid galactosyl human serum albumin (GSA) scintigraphy and hepatobiliary scintigraphy (HBS) with (99m)Tc-labeled iminodiacetic acid derivates is discussed. (99m)Tc-mebrofenin is considered the most suitable iminodiacetic acid agent for (99m)Tc-HBS. (99m)Tc-GSA scintigraphy and (99m)Tc-mebrofenin HBS are based on 2 different principles. (99m)Tc-GSA scintigraphy is a receptor-mediated technique whereas HBS represents hepatic uptake and excretion function. Both techniques are noninvasive and provide visual and quantitative information on both total and regional liver function. They can be used for preoperative assessment of future remnant liver function, follow-up after preoperative portal vein embolization, and evaluation of postoperative liver regeneration. In liver transplantation, these methods are used to assess graft function and biliary complications.

Assessment of future remnant liver function using hepatobiliary scintigraphy in patients undergoing major liver resection

BACKGROUND

(99m)Tc-mebrofenin hepatobiliary scintigraphy (HBS) was used as a quantitative method to evaluate liver function. The aim of this study was to compare future remnant liver function assessed by (99m)Tc-mebrofenin hepatobiliary scintigraphy with future remnant liver volume in the prediction of liver failure after major liver resection.

METHODS

Computed tomography (CT) volumetry and (99m)Tc-mebrofenin hepatobiliary scintigraphy were performed prior to major resection in 55 high-risk patients, including 30 patients with parenchymal liver disease. Liver volume was expressed as percentage of total liver volume or as standardized future remnant liver volume. Receiver operating characteristic (ROC) curve analysis was performed to identify a cutoff value for future remnant liver function in predicting postoperative liver failure.

RESULTS

Postoperative liver failure occurred in nine patients. A liver function cutoff value of 2.69%/min/m(2) was calculated by ROC curve analysis. (99m)Tc-mebrofenin hepatobiliary scintigraphy demonstrated better sensitivity, specificity, and positive and negative predictive value compared to future remnant liver volume. Using 99mTc-mebrofenin hepatobiliary scintigraphy, one cutoff value suffices in both compromised and noncompromised patients.

CONCLUSION

Preoperative (99m)Tc-mebrofenin hepatobiliary scintigraphy is a valuable technique to estimate the risk of postoperative liver failure. Especially in patients with uncertain quality of the liver parenchyma, (99m)Tc-mebrofenin HBS proved of more value than CT volumetry.

Perioperative risk assessment for hepatocellular carcinoma by using the MELD score

BACKGROUND/AIMS

The aim of this study was to evaluate the ability of Model for End-Stage Liver Disease (MELD) in predicting post hepatectomy outcome for hepatocellular carcinoma (HCC).

METHODS

Between 2001 and 2005, 94 cirrhotic patients with HCC underwent hepatectomy and were analyzed retrospectively. MELD score associated with postoperative mortality and morbidity, hospital stay, and 3-year survival.

RESULTS

Twenty-eight major and 66 minor resections were performed. Thirty-day mortality rate was 6.4%. MELD <or= 9 was associated with no perioperative mortality vs 15.3% when MELD > 9 (p = 0.01). Overall morbidity rate was 32%; 21% when MELD <or= 9 vs 42% when MELD > 9 (p = 0.01). Median hospital stay was 11 days (7 days, when MELD <or= 9 and 14 days when MELD > 9; p = 0.03). Three-year survival reached 48% (63% when MELD <or= 9; 30% when MELD > 9; p < 0.01). In multivariate analysis, MELD > 9 (p = 0.01), clinical tumor symptoms (p = 0.04), and American Society of Anesthesiologists score (p = 0.04) were independent predictors of perioperative mortality; MELD > 9 (p = 0.01), tumor size >5 cm (p = 0.01), presence of tumor symptoms (p = 0.02), high tumor grade (p = 0.01), and absence of tumor capsule (p = 0.01) were independent predictors of decreased long-term survival.

CONCLUSION

MELD score seems to predict outcome of cirrhotic patients with HCC after hepatectomy.

Predicting liver failure following major hepatectomy

Pre-operative determination of the risk of liver dysfunction has come under criticism with regards to its usefulness in clinical practice. Opinion is split between centres which use such tests uniformly on all patients and those where clinical judgment alone is used. Published data would not suggest any difference in mortality, morbidity or liver failure rates between these groups. This review outlines and presents the evidence for pre-operative quantification of functional liver remnant volume.

Prediction of postoperative outcome after hepatectomy with a new bedside test for maximal liver function capacity

OBJECTIVE

To validate the LiMAx test, a new bedside test for the determination of maximal liver function capacity based on C-methacetin kinetics. To investigate the diagnostic performance of different liver function tests and scores including the LiMAx test for the prediction of postoperative outcome after hepatectomy.

SUMMARY BACKGROUND DATA

Liver failure is a major cause of mortality after hepatectomy. Preoperative prediction of residual liver function has been limited so far.

METHODS

Sixty-four patients undergoing hepatectomy were analyzed in a prospective observational study. Volumetric analysis of the liver was carried out using preoperative computed tomography and intraoperative measurements. Perioperative factors associated with morbidity and mortality were analyzed. Cutoff values of the LiMAx test were evaluated by receiver operating characteristic.

RESULTS

Residual LiMAx demonstrated an excellent linear correlation with residual liver volume (r = 0.94, P < 0.001) after hepatectomy. The multivariate analysis revealed LiMAx on postoperative day 1 as the only predictor of liver failure (P = 0.003) and mortality (P = 0.004). AUROC for the prediction of liver failure and liver failure related death by the LiMAx test was both 0.99. Preoperative volume/function analysis combining CT volumetry and LiMAx allowed an accurate calculation of the remnant liver function capacity prior to surgery (r = 0.85, P < 0.001).

CONCLUSIONS

Residual liver function is the major factor influencing the outcome of patients after hepatectomy and can be predicted preoperatively by a combination of LiMAx and CT volumetry.

Model for end-stage liver disease (MELD) score, as a prognostic factor for post-operative morbidity and mortality in cirrhotic patients, undergoing hepatectomy for hepatocellular carcinoma

BACKGROUND/AIMS

To evaluate the ability of the model for end-stage liver disease (MELD) in predicting the post-hepatectomy outcome for hepatocellular carcinoma (HCC).

METHODS

Between 2001 and 2004, 69 cirrhotic patients with HCC underwent hepatectomy and the results were retrospectively analysed. MELD score was associated with post-operative mortality and morbidity, hospital stay and 3-year survival.

RESULTS

Seventeen major and 52 minor resections were performed. Thirty-day mortality rate was 7.2%. MELD < or = 9 was associated with no peri-operative mortality vs. 19% when MELD > 9 (P < 0.02). Overall morbidity rate was 36.23%; 48% when MELD > 9 vs. 25% when MELD < or = 9 (P < 0.02). Median hospital stay was 12 days [8.8 days, when MELD < or = 9 and 15.6 days when MELD > 9 (P = 0.037)]. Three-year survival reached 49% (66% when MELD < or = 9; 32% when MELD > 9 (P < 0.01). In multivariate analysis, MELD > 9 (P < 0.01), clinical tumour symptoms (P < 0.05) and American Society of Anesthesiologists (ASA) score (P < 0.05) were independent predictors of peri-operative mortality; MELD > 9 (P < 0.01), tumour size >5 cm (P < 0.01), high tumour grade (P = 0.01) and absence of tumour capsule (P < 0.01) were independent predictors of decreased long-term survival.

CONCLUSION

MELD score seems to predict outcome of cirrhotic patients with HCC, after hepatectomy.

Quantitative assessment of hepatic function and its relevance to the liver surgeon

BACKGROUND

Standard evaluation of patients undergoing hepatic surgery has been through radiological and quantitative determination of liver function. As more complex and extensive surgery is now being performed, often in the presence of cirrhosis/fibrosis or following administration of chemotherapy, it is questioned whether additional assessment may be required prior to embarking on such surgery. The aim of this review was to determine the current knowledge base in relation to the performance of quantitative assessment of hepatic function both pre- and post-operatively in patients undergoing hepatic resectional surgery and liver transplantation.

METHODS

An electronic search was performed of the medical literature using the MEDLINE database to identify relevant articles with cross-referencing of all identified papers to ensure full literature capture.

RESULTS AND CONCLUSIONS

The review has identified a number of different methods of dynamically assessing hepatic function, the most frequently performed being through the use of indocyanine green clearance. With the recent and further anticipated developments in hepatic resectional surgery, it is likely that quantitative assessment will become more widely practiced in order to reduce post-operative hepatic failure and improve outcome.

Assessment of liver function for safe hepatic resection

The preoperative assessment of liver function is extremely important for preventing postoperative liver failure and mortality after hepatic resection. Liver function tests may be divided into three types; conventional liver function tests, general scores, and quantitative liver function tests. General scores are based on selected clinical symptoms and conventional test results. Child-Turcotte-Pugh score has been the gold standard for four decades, but the Child-Turcotte-Pugh score has difficulty discriminating a good risk from a poor risk in patients with mild to moderate liver dysfunction. The model for end-stage liver disease score has also been applied to predict short-term outcome after hepatectomy, but it is only useful in patients with advanced cirrhosis. Quantitative liver function tests overcome the drawbacks of general scores. The indocyanine green retention rate at 15 minutes (ICG R15) has been reported to be a significant predictor of postoperative liver failure and mortality. The safety limit of the hepatic parenchymal resection rate can be estimated using the ICG R15, and a decision tree (known as the Makuuchi criteria) for selecting patients and hepatectomy procedures has been proposed. Hepatic resection can be performed with a mortality rate of nearly zero using this decision tree. If the future remnant liver volume does not fulfill the Makuuchi criteria, preoperative portal vein embolization should be performed to prevent postoperative liver failure. Galactosyl human serum albumin-diethylenetriamine-pentaacetic acid scintigraphy also provides data that complement the ICG test. Other quantitative liver function tests, however, require further validation and simplification.

Evaluation of model for end stage liver disease (MELD)-based systems as prognostic index for hepatocellular carcinoma

BACKGROUND

The Cancer of Liver Italian Program (CLIP) and Japan Integrated Scoring System (JIS) used the Child-Turcotte-Pugh (CTP) score to evaluate the liver function.

AIM

We aimed to evaluate the performance of Model for End Stage Liver Disease (MELD) based CLIP and JIS to predict the prognosis of hepatocellular carcinoma (HCC).

METHODS

Consecutive patients with HCC who presented to our Hepatoma Clinic from January 2003 to April 2005 were studied. MELD-based CLIP and JIS were generated by replacing the original CTP score with MELD score at three categories (<10, 10-14 and >14).

RESULTS

Among 471 HCC patients (85.1% males; aged 58.8 +/- 12.2 years), 73% had chronic hepatitis B, 37.4% had >1 nodule, 84.1% had tumor size >2 cm, 55.0% had Child's B cirrhosis, 12.7% underwent tumor resection and 20.6% received locoregional therapy. The cumulative survival at 3 and 6 months were 67% and 55%, respectively. For 3-month survival, the area under the receiver operating characteristic curves (AUC) of MELD-CLIP (0.69) and MELD-JIS (0.69) were superior to the original systems (0.64, P = 0.004 and 0.64, P = 0.0018, respectively). For 6-month survival, AUC of MELD-CLIP (0.64) and MELD-JIS (0.62) were also superior to the original systems (0.54, P = 0.003 and 0.59, P = 0.002, respectively). The MELD-based systems performed best among patients who received locoregional therapy to HCC. Advanced cirrhosis (hypoalbuminemia, hyperbilirubinemia, ascites, coagulopathy and elevated creatinine), and cancer (portal vein thrombosis, elevated alpha-fetoprotein, large and multiple tumors) were associated with higher mortality.

CONCLUSIONS

MELD-based systems performed better than Child-Pugh based systems as prognostic indexes for HCC.

Liver failure after partial hepatic resection: definition, pathophysiology, risk factors and treatment

Liver failure is a dreaded and often fatal complication that sometimes follows a partial hepatic resection. This article reviews the definition, incidence, pathogenesis, risk factors, risk assessment, prevention, clinical features and treatment of post-resectional liver failure (PLF). A systematic, computerized search was performed using key words related to 'partial hepatic resection' and 'liver failure' to review most relevant literature about PLF published in the last 20 years. The reported incidence of PLF ranges between 0.7 and 9.1%. An inadequate quantity or quality of residual liver mass are key events in its pathogenesis. Major risk factors are the presence of comorbid conditions, pre-existent liver disease and small remnant liver volume (RLV). It is essential to identify these risk factors during the pre-operative assessment that includes evaluation of liver volume, anatomy and function. Preventive measures should be applied whenever possible as curative treatment options for PLF are limited. These preventive measures intend to increase RLV and protect remnant liver function. Management principles focus on support of end-organ and liver function. Further research is needed to elucidate the exact pathogenesis of PLF and to develop and validate adequate treatment options.

Liver surgery in the presence of cirrhosis or steatosis: Is morbidity increased?

Background data

The prevalence of steatosis and hepatitis-related liver cirrhosis is dramatically increasing together worldwide. Cirrhosis and, more recently, steatosis are recognized as a clinically important feature that influences patient morbidity and mortality after hepatic resection when compared with patients with healthy liver.

Objective

To review present knowledge regarding how the presence of cirrhosis or steatosis can influence postoperative outcome after liver resection.

Methods

A critical review of the English literature was performed to provide data concerning postoperative outcome of patients presenting injured livers who required hepatectomy.

Results

In clinical studies, the presence of steatosis impaired postoperative outcome regardless the severity and quality of the hepatic fat. A great improvement in postoperative outcome has been achieved using modern and multidisciplinary preoperative workup in cirrhotic patients. Due to the lack of a proper classification for morbidity and a clear definition of hepatic failure in the literature, the comparison between different studies is very limited. Although, many surgical strategies have been developed to protect injured liver surgery, no one have gained worldwide acceptance.

Conclusion

Surgeons should take the presence of underlying injured livers into account when planning the extent and type of hepatic surgery. Preoperative and perioperative interventions should be considered to minimize the additional damage. Further randomized trials should focus on the evaluation of novel preoperative strategies to minimize risk in these patients. Each referral liver center should have the commitment to report all deaths related to postoperative hepatic failure and to use a common classification system for postoperative complications.

Improving outcome in patients undergoing liver surgery

Liver surgery is associated with many factors, which may affect outcome. Preoperative assessment of patient's general condition, resectability, and liver reserve are paramount for success. The Child-Pugh score and other scoring systems only partially enables to assess the risk associated with liver surgery. The presence of portal hypertension per se is a major risk factor for hepatectomy. Intraoperatively, any attempts should be made to minimize blood loss. Low central venous pressure and inflow occlusion best prevent bleeding. Ischemic preconditioning and intermittent clamping are routinely applied in many centers to protect against long periods of ischemia, although the mechanisms of protection remain unclear. In this review we describe recent advances in activated pathways associated with protection against ischemia. Postoperatively, the best factor impacting on outcome probably resides in experienced medical care particularly in the intensive care setting. Currently, no drug or gene therapy approaches has reached the clinic. The future relies on new insight into mechanisms of ischemia-reperfusion injury.