Search

Hepatic failure is a feared complication that accounts for up to 75% of mortality after extensive liver resection. Despite improved perioperative care, the increasing complexity and extensiveness of surgical interventions, in combination with an expanding number of resections in patients with compromised liver function, still results in an incidence of postresectional liver failure (PLF) of 1-9%. Preventive measures aim to enhance future remnant liver size and function. Numerous non-invasive techniques to assess liver function and predict remnant liver volume are being developed, along with introduction of novel surgical strategies that augment growth of the future remnant liver. Detection of PLF is often too late and treatment is primarily symptomatic. Current therapeutic research focuses on ([bio]artificial) liver function support and regenerative medicine. In this review we discuss the current state and new developments in prediction, prevention and management of PLF, in light of novel insights into the aetiology of this complex syndrome., Lay Summary: Liver failure is the main cause of death after partial liver resection for cancer, and is presumably caused by an insufficient quantity and function of the liver remnant. Detection of liver failure is often too late, and current treatment focuses on relieve of symptoms. New research initiatives explore artificial support of liver function and stimulation of regrowth of the remnant liver., (Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Introduction: Postoperative liver failure (PLF) is a dreaded complication after partial hepatectomy. The peak bilirubin criterion (>7.0 mg/dL or ≥120 μmol/L) is used to define PLF. This study aimed to validate the peak bilirubin criterion as postoperative risk indicator for 90-day liver-related mortality., Methods: Characteristics of 956 consecutive patients who underwent partial hepatectomy at the Maastricht University Medical Centre or Royal Free London between 2005 and 2012 were analyzed by uni- and multivariable analyses with odds ratios (OR) and 95% confidence intervals (95%CI)., Results: Thirty-five patients (3.7%) met the postoperative peak bilirubin criterion at median day 19 with a median bilirubin level of 183 [121-588] μmol/L. Sensitivity and specificity for liver-related mortality after major hepatectomy were 41.2% and 94.6%, respectively. The positive predictive value was 22.6%. Predictors of liver-related mortality were the peak bilirubin criterion (p < 0.001, OR = 15.9 [95%CI 5.2-48.7]), moderate-severe steatosis and fibrosis (p = 0.013, OR = 8.5 [95%CI 1.6-46.6]), ASA 3-4 (p = 0.047, OR = 3.0 [95%CI 1.0-8.8]) and age (p = 0.044, OR = 1.1 [95%CI 1.0-1.1])., Conclusion: The peak bilirubin criterion has a low sensitivity and positive predictive value for 90-day liver-related mortality after major hepatectomy., (Copyright © 2016 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.)

Background: After extended liver resection, a remnant liver that is too small can lead to postresection liver failure. To reduce this risk, preoperative evaluation of the future liver remnant volume (FLRV) is critical. The open-source OsiriX PAC software system can be downloaded for free and used by nonradiologists to calculate liver volume using a stand-alone Apple computer. The purpose of this study was to assess the accuracy of OsiriX CT volumetry for predicting liver resection volume and FLVR in patients undergoing partial hepatectomy., Methods: Preoperative contrast-enhanced liver CT scans of patients who underwent partial hepatectomy were analyzed by three observers. Two surgical trainees measured the total liver volume, resection volume, and tumor volume using OsiriX, and a radiologist measured these volumes using CT scanner-linked Aquarius iNtuition software. Resection volume was correlated with prospectively determined resection weight, and differences in the measured liver volumes were analyzed. Interobserver variability was assessed using Bland-Altman plots., Results: 25 patients (M/F ratio: 13/12) with a median age of 61 (range, 34-77) years were included. There were significant correlations between the weight and volume of the resected specimens (Pearson's correlation coefficient: R(2) = 0.95). There were no major differences in total liver volumes, resection volumes, or tumor volumes for observers 1, 2, and 3. Bland-Altman plots showed a small interobserver variability. The mean time to complete liver volumetry for one patient using OsiriX was 19 +/- 3 min., Conclusions: OsiriX liver volumetry performed by surgeons is an accurate and time-efficient method for predicting resection volume and FLRV.

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 failure is associated with hepatic encephalopathy (HE). An imbalance in plasma levels of aromatic amino acids (AAA) phenylalanine, tyrosine, and tryptophan and branched chain amino acids (BCAA) and their BCAA/AAA ratio has been suggested to play a causal role in HE by enhanced brain AAA uptake and subsequently disturbed neurotransmission. Until recently, data on this subject and the role of the liver and splanchnic bed were scarce, particularly in humans, due to inaccessibility of portal and hepatic veins. Here, we discuss, against a background of relevant literature, data obtained in patients undergoing liver resection or with a transjugular intrahepatic portasystemic stent shunt (TIPSS), where these veins are accessible. The BCAA/AAA ratio remained unchanged after major liver resection, but plasma AAA levels were inversely correlated (P < 0.001) with residual liver volume, in keeping with the observed hepatic AAA uptake. In patients with stable cirrhosis and a TIPSS, the plasma BCAA/AAA ratio was lower than in controls (1.19 +/- 0.09 vs. controls: 3.63 +/- 0.34). Gastrointestinal bleeding in cirrhotics with a TIPSS induced disturbances in BCAA levels and the BCAA/AAA ratio and induced catabolism, which could partly be corrected by isoleucine administration. AAA may be important in the pathogenesis of HE, but it is unlikely that they are the sole factors. HE most likely is a syndrome with multifactorial pathogenesis, where hyperammonemia, AAA/BCAA imbalances, inflammation, brain edema, and neurotransmitter changes interact. Novel therapies to normalize AAA levels in patients with liver failure (such as the molecular adsorbent recirculating system dialysis device) should probably be combined with supplementation of e.g. isoleucine and enhancing ammonia excretion by the kidneys.

In the post-absorptive state, ammonia is produced in equal amounts in the small and large bowel. Small intestinal synthesis of ammonia is related to amino acid breakdown, whereas large bowel ammonia production is caused by bacterial breakdown of amino acids and urea. The contribution of the gut to the hyperammonemic state observed during liver failure is mainly due to portacaval shunting and not the result of changes in the metabolism of ammonia in the gut. Patients with liver disease have reduced urea synthesis capacity and reduced peri-venous glutamine synthesis capacity, resulting in reduced capacity to detoxify ammonia in the liver. The kidneys produce ammonia but adapt to liver failure in experimental portacaval shunting by reducing ammonia release into the systemic circulation. The kidneys have the ability to switch from net ammonia production to net ammonia excretion, which is beneficial for the hyperammonemic patient. Data in experimental animals suggest that the kidneys could have a major role in post-feeding and post-haemorrhagic hyperammonemia.During hyperammonemia, muscle takes up ammonia and plays a major role in (temporarily) detoxifying ammonia to glutamine. Net uptake of ammonia by the brain occurs in patients and experimental animals with acute and chronic liver failure. Concomitant release of glutamine has been demonstrated in experimental animals, together with large increases of the cerebral cortex ammonia and glutamine concentrations. In this review we will discuss interorgan trafficking of ammonia during acute and chronic liver failure. Interorgan glutamine metabolism is also briefly discussed, since glutamine synthesis from glutamate and ammonia is an important alternative pathway of ammonia detoxification. The main ammonia producing organs are the intestines and the kidneys, whereas the major ammonia consuming organs are the liver and the muscle.

Background: A small remnant liver volume is an important risk factor for posthepatectomy liver failure. ImageJ and OsiriX are both free, open-source image processing software packages. The aim of the present study was to compare ImageJ and OsiriX in performing prospective computed tomography (CT) volumetric analysis of the liver on a personal computer (PC) in patients undergoing major liver resection. Methods: Patients scheduled for a right hemihepatectomy were eligible for inclusion. Two surgeons and one surgical trainee measured volumes of total liver, tumor, and future resection specimen prospectively with ImageJ and OsiriX. A radiologist also measured these volumes with CT scanner-linked Aquarius iNtuition software. Resection volumes were compared with the actual weights of the liver specimens removed during surgery, and differences between the measured liver volumes were analyzed. Results: A total of 15 patients (8 men, 7 women) with a median age of 63 years (48-79 years) were included. There was a significant correlation between the measured weights of resection specimens and the volumes calculated prospectively with ImageJ and OsiriX ( r = 0.89; r = 0.83, respectively). There was also a significant correlation between the volumes measured with radiological software iNtuition and the volumes measured with ImageJ and OsiriX ( r = 0.93; r = 0.95, respectively). Conclusions: There were no major differences in total liver volumes, resection volumes, or tumour volumes for these three software packages. Prospective hepatic CT volumetry with ImageJ or OsiriX is reliable and can be accurately used on a PC by nonradiologists. ImageJ and OsiriX yield results comparable to the radiological software iNtuition. [ABSTRACT FROM AUTHOR]

Liver failure following liver surgery is caused by an insufficient functioning remnant cell mass. This can be due to insufficient liver volume and can be aggravated by additional cell death during or after surgery. The aim of this study was to elucidate the causes of hepatocellular injury in patients undergoing liver resection. Markers of hepatocyte injury (AST, GSTα, and L-FABP) and inflammation (IL-6) were measured in plasma of patients undergoing liver resection with and without intermittent inflow occlusion. To study the separate involvement of the intestines and the liver in systemic L-FABP release, arteriovenous concentration differences for L-FABP were measured. During liver manipulation, liver injury markers increased significantly. Arterial plasma levels and transhepatic and transintestinal concentration gradients of L-FABP indicated that this increase was exclusively due to hepatic and not due to intestinal release. Intermittent hepatic inflow occlusion, anesthesia, and liver transection did not further enhance arterial L-FABP and GSTα levels. Hepatocyte injury was followed by an inflammatory response. This study shows that liver manipulation is a leading cause of hepatocyte injury during liver surgery. A potential causal relation between liver manipulation and systemic inflammation remains to be established; but since the inflammatory response is apparently initiated early during major abdominal surgery, interventions aimed at reducing postoperative inflammation and related complications should be started early during surgery or beforehand. [ABSTRACT FROM AUTHOR]

Background: Volumetric assessment of the liver is essential in the prevention of postresectional liver failure after partial hepatectomy. Currently used methods are accurate but time-consuming. This study aimed to test a new automated method for preoperative volumetric liver assessment. Methods: Patients who underwent a contrast enhanced portovenous phase CT-scan prior to hepatectomy in 2012 were included. Total liver volume (TLV) and future remnant liver volume (FRLV) were measured using TeraRecon Aquarius iNtuition® (autosegmentation) and OsiriX® (manual segmentation) software by two observers for each software package. Remnant liver volume percentage (RLV%) was calculated. Time needed to determine TLV and FRLV was measured. Inter-observer variability was assessed using Bland-Altman plots. Results: Twenty-seven patients were included. There were no significant differences in measured volumes between OsiriX® and iNtuition®. Moreover, there were significant correlations between the OsiriX® observers, the iNtuition® observers and between OsiriX® and iNtuition® post-processing systems (all R2 > 0.97). The median time needed for complete liver volumetric analysis was 18.4 ± 4.9 min with OsiriX® and 5.8 ± 1.7 min using iNtuition® (p < 0.001). Conclusion: Both OsiriX® and iNtuition® liver volumetry are accurate and easily applicable. However, volumetric assessment of the liver with iNtuition® auto-segmentation is three times faster compared to manual OsiriX® volumetry. [ABSTRACT FROM AUTHOR]