The LiMAx test: a new liver function test for predicting postoperative outcome in liver surgery

Multidisciplinary strategies to improve treatment outcomes in hepatocellular carcinoma: a European perspective

Hepatocellular carcinoma (HCC) is a complex disease with a poor prognosis. Incidence and mortality rates are increasing in many geographical regions, indicating a need for better management strategies. Among several risk factors for HCC, the most common are cirrhosis because of chronic hepatitis B virus or hepatitis C virus infection and alcohol consumption, obesity, and diabetes. In some patients, combined risk factors present additional challenges to the prevention and treatment of HCC. Screening and surveillance of high-risk populations varies widely by geographic regions, and access to optimal surveillance is critical for early diagnosis. The treatment choice for HCC depends on the cancer stage, patient performance status, and liver function and requires a multidisciplinary approach and close cooperation among specialists for the best patient outcomes. Despite advances in surgical treatments and locoregional therapies, recurrence and liver failure remain significant challenges. The pathogenesis of HCC is a multistep and complex process, wherein angiogenesis plays an important role. The multikinase inhibitor sorafenib is the only approved targeted agent for advanced HCC, although promising results have been obtained with other targeted agents and combinations, and the results of ongoing trials are eagerly awaited. Clinical trials with rigorous study designs, including molecular classification and validation of new molecular biomarkers, are required to improve the personalized treatment of HCC. This article provides an overview of HCC and was developed through a review of relevant literature, clinical trial data, and updated clinical guidelines.

A rapid and accurate new bedside test to assess maximal liver function: a case report

Background

In liver surgery, appropriate preoperative evaluation and preparation of the patient is of cardinal importance. The up-to-date, preoperative prediction of residual liver function has thus far been limited. As post-hepatectomy liver failure is a major cause of mortality, a new and simple bedside test (LiMAx) has been developed to predict postoperative liver function in conjunction with preoperative volumetric analysis of the liver.

Case presentation

A 45-year-old patient presented with a cecal carcinoma and a large synchronous liver metastasis for major liver surgery. Liver function was determined by the LiMAx-test for the enzymatic capacity of cytochrome P450 1A2, which is ubiquitously and solely active in the liver. A solution of 2 mg/kg body weight ¹³C-labeled methacetin was injected as a bolus into an intravenous catheter and, thereafter, was metabolized into acetaminophen and ¹³CO2 and pulmonarily exhaled. The analysis of the ¹³CO2/¹²CO2 ratio was performed using online breath sampling over a period of maximally 60 minutes. Based on this test, a value of more than 315 μg/kg/h represents normal liver function. A laparoscopic right hemihepatectomy was planned during virtual resection with a residual liver volume of 48% and a preoperative anticipated residual LiMAx of 301 μg/kg/h. After successful resection, the initial postoperative LiMAx value was 316 μg/kg/h, indicating good liver function and a correct prediction of the outcome.

Conclusion

In the presented patient, residual liver function could be accurately predicted preoperatively using a combination of the new LiMax test with CT-volumetry. This test might significantly improve preoperative evaluation and postoperative outcomes in liver surgery.

Gd-EOB-DTPA-enhanced MRI for the assessment of liver function and volume in liver cirrhosis

OBJECTIVE

The aims of this study were to use dynamic hepatocyte-specific contrast-enhanced MRI to evaluate liver volume and function in liver cirrhosis, correlate the results with standard scoring models and explore the inhomogeneous distribution of liver function in cirrhotic livers.

METHODS

10 patients with liver cirrhosis and 20 healthy volunteers, serving as controls, were included. Hepatic extraction fraction (HEF), input relative blood flow and mean transit time were calculated on a voxel-by-voxel basis using deconvolutional analysis. Segmental and total liver volumes as well as segmental and total hepatic extraction capacity, expressed in HEFml, were calculated. An incongruence score (IS) was constructed to reflect the uneven distribution of liver function. The Mann-Whitney U-test was used for group comparison of the quantitative liver function parameters, liver volumes and ISs. Correlations between liver function parameters and clinical scores were assessed using Spearman rank correlation.

RESULTS

Patients had larger parenchymal liver volume, lower hepatocyte function and more inhomogeneous distribution of function compared with healthy controls.

CONCLUSION

The study demonstrates the non-homogeneous nature of liver cirrhosis and underlines the necessity of a liver function test able to compensate for the heterogeneous distribution of liver function in patients with diseased liver parenchyma.

ADVANCES IN KNOWLEDGE

The study describes a new way to quantitatively assess the hepatic uptake of gadoxetate or gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid in the liver as a whole as well as on a segmental level.

Effect of pre- and probiotics on liver regeneration after resection: a randomised, double-blind pilot study

Liver regeneration is a prerequisite for extended liver surgery. Several studies have shown that the bacterial gut flora is able to modulate liver function. Previously we observed that synbiotics could partly reverse the impaired mitosis rate of hepatocytes in a rat model of synchronous liver resection and colon anastomosis. The effect of synbiotics on liver function after hepatic resection has not been analysed yet. A prospective randomised double-blind pilot trial was undertaken in 19 patients scheduled for right hepatectomy. All patients received enteral nutrition immediately post-operatively. Comparison was made between a group receiving a combination of four probiotics and four fibres and a placebo group receiving the fibres only starting the day before surgery and continuing for 10 days. Primary study endpoint was the liver function capacity measured by 13C-methacetin breath test and indocyanine green plasma disappearance rate. Portal vein flow, liver volumetry, laboratory parameters for liver function, length of hospital stay, post-operative complications and side effects of synbiotic therapy were recorded. Liver function capacity was comparable in both groups. Complications had a negative impact on liver function. Because complications were more severe in the verum group, a sub-analysis was performed. In case of an uncomplicated course, liver function capacity was better in the patients with synbiotics. No severe side effects occurred. Synbiotics might be able to increase liver function capacity in patients after liver resection, but patient numbers were too small and the clinical courses too heterogeneous to draw any definite conclusions.

[Resection of Klatskin tumors]

Curative treatment of Klatskin tumors by radical surgical procedures with surgical preparation distant to the tumor region results in 5-year survival rates of 30-50%. This requires mandatory en bloc liver resection and resection of the extrahepatic bile duct often together with vascular resection. Nevertheless, the ideal safety margin of 0.5-1 cm remote from the macroscopic tumor extensions cannot be achieved in all cases. Based on hilar anatomy the probability of an adequate safety margin is higher using extended right hemihepatectomy together with portal vein resection compared to left hemihepatectomy. However, due to severe atrophy of the left liver lobe solely left-sided hepatectomy is feasible in some patients. In cases of eligibility for both procedures right hemihepatectomy is preferentially used due to the higher oncological radicality if sufficient liver function is present. Postoperative hepatic insufficiency and bile leakage after demanding biliary reconstruction, often with several small orifices, contribute to the postoperative complication rate of this complex surgical disease pattern.

Chemotherapy-associated liver injury in patients with colorectal liver metastases: a systematic review and meta-analysis

BACKGROUND

Chemotherapy-associated liver injury is a major cause for concern when treating patients with colorectal liver metastases. The aim of this review was to determine the pathological effect of specific chemotherapy regimens on the hepatic parenchyma as well as on surgical morbidity, mortality and overall survival.

METHODS

A systematic review of the published literature and a meta-analysis were performed. For each of the variables under consideration, the effects of different chemotherapy regimens were determined by calculation of relative risks by a random-effects model.

RESULTS

Hepatic parenchymal injury is regimen specific, with oxaliplatin-based regimens being associated with grade 2 or greater sinusoidal injury (number needed to harm 8; 95 % confidence interval [CI] 6.4-13.6), whereas irinotecan-based regimens associated with steatohepatitis (number needed to harm 12; 95 % CI 7.8-26). The use of bevacizumab alongside FOLFOX reduces the risk of grade 2 or greater sinusoidal injury (relative risk 0.34; 95 % CI 0.15-0.75).

CONCLUSIONS

Chemotherapy before resection of colorectal liver metastases is associated with an increased risk of regimen-specific liver injury. This liver injury may have implications for the functional reserve of the liver for patients undergoing major hepatectomy for colorectal liver metastases.

Function and volume recovery after partial hepatectomy: influence of preoperative liver function, residual liver volume, and obesity

BACKGROUND

The regenerative capacity of the liver is an essential pre-condition for the successful application of partial hepatectomy. However, the actual kinetics of functional recovery remains unspecified and no adequate tool for its clinical monitoring has yet been available.

METHODS

Eighty-five patients receiving major hepatectomy were investigated from the preoperative evaluation until 12 weeks after surgery. Liver function was determined by the LiMAx test for the enzymatic capacity of cytochrome P450 1A2. Liver volume was determined by volumetric analysis of repeated computer tomography scans. Functional and volume recovery were compared during follow-up.

RESULTS

Major hepatectomy decreased liver function capacity to 35.7 ± 13.8% of preoperative function. It was shown that functional recovery already reaches 77.2 ± 33.5% of preoperative values within 10 days. The actual kinetics were dependent from the type and extent of hepatectomy. Complete functional restoration was achieved within 12 weeks, while liver volume still remained at 73.2 ± 14.8% of preoperative. A constant but interindividually variable correlation between function and volume was observed at all points in time.

CONCLUSION

Partial hepatectomy leads to fast and complete functional recovery, while volume recovery is delayed and remains often incomplete. The functional recovery is mainly influenced by the preoperative liver function, the residual liver volume, and by obesity.

[Monitoring of organ functions. Dysfunction of kidneys, liver, gastrointestinal tract, and coagulation]

Monitoring of organ function is one of the core tasks of intensive care medicine. Although various monitoring devices and parameters have already been established for some organs, there are no or only few conditionally useful parameters or scores available for the kidneys, liver, gastrointestinal tract, and blood coagulation. Therefore, specific biomarkers and scores as well as combinations of both are currently investigated for better monitoring of these organs. This article gives a critical overview of currently used as well as investigational biomarkers, tests and scores in general, and shows some examples of the implications for common diseases, clinical situations and constellations in the intensive care unit.

[Liver transplantation for hilar cholangiocarcinoma]

Local non-resectable, hilar cholangiocarcinoma can be cured by performing a liver transplantation. The initially poor results after transplantation have significantly improved since neoadjuvant therapy protocols have been established. Therefore, hilar cholangiocarcinoma is now an accepted indication for liver transplantation in selected patients. This article summarizes the current state, recommendations and results of liver transplantation for these patients.

Surgical intensive care unit--the trauma surgery perspective

PURPOSE

This review addresses and summarizes the key issues and unique specific intensive care treatment of adult patients from the trauma surgery perspective.

MATERIALS AND METHODS

The cornerstones of successful surgical intensive care management are fluid resuscitation, transfusion protocol and extracorporeal organ replacement therapies. The injury-type specific complications and unique pathophysiologic regulatory mechanisms of the traumatized patients influencing the critical care treatment are discussed.

CONCLUSIONS

Furthermore, the fundamental knowledge of the injury severity, understanding of the trauma mechanism, surgical treatment strategies and specific techniques of surgical intensive care are pointed out as essentials for a successful intensive care therapy.

Initial liver graft function is a reliable predictor of tacrolimus trough levels during the first post-transplant week

The narrow therapeutic range of tacrolimus requires careful management after liver transplantation (LT). The aim of this study was to investigate the influence of graft function on tacrolimus trough levels during the first post-transplant week. Ninety-three patients receiving deceased-donor LT were observed in a prospective observational study. Graft function was determined by the new LiMAx test (maximal liver function capacity). Significant correlations between LiMAx readouts and consecutive tacrolimus levels, up to r = -0.529 (p < 0.0001), were determined throughout the observed period of time. Patients with initially poor graft function revealed higher trough levels (n = 24; 20.1 ± 11.6ng/mL) in comparison with fair (n = 40; 13.7 ± 7.8 ng/mL) and good function (n = 29; 9.5 ± 4.4ng/mL; p < 0.0001) already at the second post-transplant day. Toxic levels could be predicted with an area under receiver operating characteristic analysis AUROC=0.751 (p = 0.001) with high sensitivity and specificity. Insufficient levels could be predicted with AUROC=0.800 (p = 0.003). In conclusion, initial graft function is a major factor influencing the pharmacokinetics of tacrolimus and can be validly determined by the LiMAx test. Thus, recipients with poor functioning grafts are prone of developing toxic levels within the first week after LT, whereas patients with good functioning grafts frequently develop insufficient levels with the current immunosuppressive protocols.