Steatosis as a risk factor in liver surgery

Non-invasive evaluation of liver steatosis with imaging modalities: New techniques and applications

In the world, nonalcoholic fatty liver disease (NAFLD) accounts for majority of diffuse hepatic diseases. Notably, substantial liver fat accumulation can trigger and accelerate hepatic fibrosis, thus contributing to disease progression. Moreover, the presence of NAFLD not only puts adverse influences for liver but is also associated with an increased risk of type 2 diabetes and cardiovascular diseases. Therefore, early detection and quantified measurement of hepatic fat content are of great importance. Liver biopsy is currently the most accurate method for the evaluation of hepatic steatosis. However, liver biopsy has several limitations, namely, its invasiveness, sampling error, high cost and moderate intraobserver and interobserver reproducibility. Recently, various quantitative imaging techniques have been developed for the diagnosis and quantified measurement of hepatic fat content, including ultrasound- or magnetic resonance-based methods. These quantitative imaging techniques can provide objective continuous metrics associated with liver fat content and be recorded for comparison when patients receive check-ups to evaluate changes in liver fat content, which is useful for longitudinal follow-up. In this review, we introduce several imaging techniques and describe their diagnostic performance for the diagnosis and quantified measurement of hepatic fat content.

Melatonin and its protective role in attenuating warm or cold hepatic ischaemia/reperfusion injury

Although the liver is the only organ with regenerative capacity, various injury factors induce irreversible liver dysfunction and end‐stage liver disease. Liver resection and liver transplantation (LT) are effective treatments for individuals with liver failure, liver cirrhosis and liver cancers. The remnant or transplanted liver tissues will undergo hepatic ischaemia/reperfusion (IR), which leads to oxidative stress, inflammation, immune injury and liver damage. Moreover, systemic ischaemia induced by trauma, stroke, myocardial ischaemia, haemorrhagic shock and other injury factors also induces liver ischaemia/reperfusion injury (IRI) in individuals. Hepatic IRI can be divided into warm IRI, which is induced by liver surgery and systemic ischaemia, and cold IRI, which is induced by LT. Multiple studies have shown that melatonin (MT) acts as an endogenous free radical scavenger with antioxidant capacity and is also able to attenuate hepatic IRI via its anti‐inflammatory and antiapoptotic capacities. In this review, we discuss the potential mechanisms and current strategies of MT administration in liver surgery for protecting against warm or cold hepatic IRI. We highlight strategies to improve the efficacy and safety of MT for attenuating hepatic IRI in different conditions. After the potential mechanisms underlying the interactions between MT and other important cellular processes during hepatic IR are clarified, more opportunities will be available to use MT to treat liver diseases in the future.

Comparison of Hepatectomy for Patients with Metabolic Syndrome-Related HCC and HBV-Related HCC

BACKGROUND

Metabolic syndrome (MetS) is a group of clinicopathological manifestations. The outcome of liver surgery in metabolic syndrome-related hepatocellular carcinoma (MetS-HCC) still needs to be evaluated. We aim to clarify the outcomes following liver resection in patients with MetS-HCC compared those with hepatitis B virus-related HCC (HBV-HCC).

METHODS

All the consecutive patients undergoing hepatectomy for HCC between January 2009 and December 2012 were retrospectively considered. Patients were divided into three groups: MetS-HCC, MetS-HBV-HCC, and HBV-HCC. Data on clinical characteristics, postoperative complications, and long-term outcome were collected and analyzed.

RESULTS

A total of 1352 patients were included in this study. In MetS-HCC group, the severe morbidity rate was 33.33%, which was higher than that of HBV-HCC group (15.68%). In subgroup analysis, patients with MetS-HCC in American Joint Committee on Cancer (AJCC) stage I had superior DFS and OS when compared with those of the other two groups.

CONCLUSIONS

We should pay more attention to patients with MetS-HCC perioperatively due to the high rate of surgical complications. Nevertheless, curative treatment should be provided to patients with MetS.

Underlying steatohepatitis, but not simple hepatic steatosis, increases morbidity after liver resection: a case-control study

Despite the high prevalence of fatty liver disease, the safety of liver resection in settings of steatohepatitis (SH) or hepatic steatosis is poorly understood. The aim of this study was to determine whether underlying SH or simple hepatic steatosis increases morbidity after liver resection. We compared patients undergoing liver resection with underlying SH or greater than 33% simple hepatic steatosis to controls selected for similar demographics, diagnoses, comorbidities, preoperative chemotherapy treatments, and extent of partial hepatectomy. Primary endpoints included postoperative overall and hepatic-related morbidity. One hundred and two patients with SH and 72 with greater than 33% simple hepatic steatosis who underwent liver resection from 2000 to 2011 were compared to corresponding controls. There were no differences in extent or approach of liver resection, malignant indications, preoperative chemotherapy treatment, elements of metabolic syndrome, alcohol use history, American Society of Anesthesiologists score, age, or gender between patients with SH or simple steatosis and corresponding controls. Ninety-day postoperative overall morbidity (56.9% versus 37.3%; P = 0.008), any hepatic-related morbidity (28.4% versus 15.7%; P = 0.043), surgical hepatic complications (19.6% versus 8.8%; P = 0.046), and hepatic decompensation (16.7% versus 6.9%; P = 0.049) were greater among SH patients, compared to corresponding controls. In contrast, there were no differences in postoperative overall morbidity (34.7% versus 44.4%; P = 0.310), any hepatic-related morbidity (19.4% versus 19.4%; P = 1.000), surgical hepatic complications (13.9% versus 9.7%; P = 0.606), or hepatic decompensation (8.3% versus 9.7%; P = 0.778) between simple hepatic steatosis patients and corresponding controls. Using multivariable logistic regression, SH was independently associated with postoperative overall (odds ratio [OR], 2.316; 95% confidence interval [95% CI]: 1.267-4.241; P = 0.007) and any hepatic-related (OR, 2.722; 95% CI: 1.201-6.168; P = 0.016) morbidity.

CONCLUSION

Underlying SH, but not simple hepatic steatosis, increases overall and hepatic-related morbidity after liver resection.

Metabolic syndrome and hepatic resection: improving outcome

OBJECTIVE

A review of the peri-operative risk associated with hepatic resection in patients with metabolic syndrome (MetS) and identification of measures for the improvement of cardiometabolic disturbances and liver-related mortality.

BACKGROUND

MetS and its hepatic manifestation non-alcoholic fatty liver disease (NAFLD) are associated with an increased operative mortality in spite of a significant improvement in peri-operative outcome after hepatic resection.

METHODS

A review of the English literature on MetS, liver resection and steatosis was performed from 1980 to 2011 using the MEDLINE and PubMed databases.

RESULTS

MetS is a predictor of NAFLD and patients with multiple metabolic risk factors may harbour non-alcoholic steatohepatitis (NASH) predictive of operative and cardiovascular mortality. Pre-operative diagnosis of unsuspected NASH with the selective use of a liver biopsy can modify the operative strategy by limiting the extent of hepatic resection, avoiding or altering the pre-operative chemotherapy regimen and the utilization of portal vein embolization. Thiazolidinediones are therapeutic for MetS and NASH and Vitamin E for active NASH; however, their utility in improving the peri-operative outcome after hepatic resection is unknown. A short-term regimen for weight loss improves post-operative patient and liver-related outcomes in patients with >30% steatosis. Cardiovascular disease associated with MetS or NAFLD should be managed aggressively. Peri-operative measures to minimize thrombotic events and acute renal injury secondary to the pro-inflammatory, prothrombotic state of MetS may further improve the outcome.

CONCLUSION

Potential candidates for hepatic resection should be screened for MetS as the pre-operative identification of NASH, short-term treatment of significant steatosis, cardiovascular risk assessment and optimization of each component of MetS may improve the peri-operative outcome in this high-risk subset of patients.