Shorter Survival after Liver Pedicle Clamping in Patients Undergoing Liver Resection for Hepatocellular Carcinoma Revealed by a Systematic Review and Meta-Analysis

Perioperative Changes in Serum Transaminases Levels Predicts Long-Term Survival Following Liver Resection of Hepatocellular Carcinoma

BACKGROUND

We sought to define whether and how hepatic ischemia/reperfusion (I/R) as manifested by perioperative aspartate aminotransferase (AST) and alanine aminotransaminase (ALT) levels impact long-term outcomes after curative-intent resection of hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Intrasplenic injection of HCC cells was used to establish a murine model of HCC recurrence with versus without I/R injury. Patients who underwent curative resection for HCC were identified from a multi-institutional derivative cohort (DC) and separate external validation (VC) cohort. Perioperative changes of transaminase levels were examined relative to the recurrence-free (RFS) and overall survival (OS) among patients following HCC resection.

RESULTS

Mice exposed to hepatic I/R injury were more likely to experience tumor recurrence, as well as higher luminescence signal intensity (all p < 0.05) versus mice with no I/R injury. Relative changes between AST and ALT (sum of AST/ALT ratios, SAAR) on postoperative day (POD) 1 and POD 3AST 1 ALT 1 and AST 3 ALT 3 were calculated using the formula: SAAR = 1 2 AST 1 ALT 1 + AST 3 ALT 3 via Fourier transform theory. Among 734 patients in DC, the median SAAR was 2.1. After adjusting for other competing risk factors, SAAR ≥ 2.0 remained strongly associated with risk of postoperative recurrence (ref. SAAR < 2.0, HR 1.32, p = 0.03), whereas SAAR ≥ 3.5 was associated with risk of postoperative mortality (ref. SAAR < 3.5, HR 1.86, p < 0.01). SAAR demonstrated good accuracy to predict postoperative recurrence (c-index 0.724, 0.731) and mortality (c-index 0.655, 0.765) in DC and VC, respectively.

CONCLUSIONS

Use of routine labs such as AST and ALT can help identify patients at high risk of recurrence and mortality following HCC resection.

FTO Alleviates Hepatic Ischemia-Reperfusion Injury by Regulating Apoptosis and Autophagy

Objective: Despite N6-methyladenosine (m6A) being closely involved in various pathophysiological processes, its potential role in liver injury is largely unknown. We designed the current research to study the potential role of fat mass and obesity-associated protein (FTO), an m6A demethylase, on hepatic ischemia-reperfusion injury (IRI). Methods: Wild-type mice injected with an adeno-associated virus carrying fat mass and obesity-associated protein (AAV-FTO) or adeno-associated virus carrying green fluorescent protein (GFP) (AAV-GFP) were subjected to a hepatic IRI model in vivo. Hematoxylin-eosin staining was performed to observe IRI. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was used to observe the cell apoptosis. Reverse transcription polymerase chain reaction (RT-PCR) was used to observe the expression of FTO. The protein levels of FTO, apoptosis, or autophagy-associated signaling proteins were detected by western blot. Reactive oxygen species (ROS) levels were determined by flow cytometry, and immunohistochemistry was used to detect the FTO and LC3-II expression. For in vitro experiments, cultured hepatocytes were subjected to hypoxia/reoxygenation (H/R) stimulation. Monodansylcadaverine (MDC) staining was used to visualize autophagic vesicles. Results: In the present study, we showed that FTO was involved in hepatic IRI, apoptosis, and autophagy. Specifically, the expression level of FTO was significantly reduced in the hepatic IRI. Besides, increasing FTO expression (AAV-FTO) ameliorated the hepatic IRI in animal models, accompanied by decreased apoptosis and autophagy. Furthermore, the FTO inhibitor (FB23-2) aggravated autophagy in hepatocytes upon H/R-induced damage. Conclusion: FTO could act as a protective effector during hepatic IRI, associated with decreased apoptosis and autophagy. FTO-mediated m6A demethylation modification may be an important therapeutic target for hepatic IRI.

Impact of Hepatic Pedicle Clamping on Long-Term Survival Following Hepatectomy for Hepatocellular Carcinoma: Stratified Analysis Based on Intraoperative Blood Transfusion Status

BACKGROUND

Hepatic pedicle clamping (HPC) is frequently utilized during hepatectomy to reduce intraoperative bleeding and diminish the need for intraoperative blood transfusion (IBT). The long-term prognostic implications of HPC following hepatectomy for hepatocellular carcinoma (HCC) remain under debate. This study aims to elucidate the association between HPC and oncologic outcomes after HCC resection, stratified by whether IBT was administered.

PATIENTS AND METHODS

Prospectively collected data on patients with HCC who underwent curative resection from a multicenter database was studied. Patients were stratified into two cohorts on the basis of whether IBT was administered. The impact of HPC on long-term overall survival (OS) and recurrence-free survival (RFS) between the two cohorts was assessed by univariable and multivariable Cox regression analyses.

RESULTS

Of 3362 patients, 535 received IBT. In the IBT cohort, using or not using HPC showed no significant difference in OS and RFS outcomes (5-year OS and RFS rates 27.9% vs. 24.6% and 13.8% vs. 12.0%, P = 0.810 and 0.530). However, in the non-IBT cohort of 2827 patients, the HPC subgroup demonstrated significantly decreased OS (5-year 45.9% vs. 56.5%, P < 0.001) and RFS (5-year 24.7% vs. 33.3%, P < 0.001) when compared with the subgroup without HPC. Multivariable Cox regression analysis identified HPC as an independent risk factor of OS and RFS [hazard ratios (HR) 1.16 and 1.12, P = 0.024 and 0.044, respectively] among patients who did not receive IBT.

CONCLUSIONS

The impact of HPC on the oncological outcomes following hepatectomy for patients with HCC differed significantly whether IBT was administered, and HPC adversely impacted on long-term survival for patients without receiving IBT during hepatectomy.

Effect of intermittent Pringle maneuver on perioperative outcomes and long-term survival following liver resection in patients with hepatocellular carcinoma: a meta-analysis and systemic review

BACKGROUND

Intermittent Pringle maneuver (IPM) is commonly used to control bleeding during liver resection. IPM can cause ischemia-reperfusion injury, which may affect the prognosis of patients with hepatocellular carcinoma (HCC). The present meta-analysis was conducted to evaluate the effect of IPM use on perioperative outcomes and long-term survival in patients with HCC.

METHODS

A systemic literature search was performed in the PubMed, Embase, Web of Science, and Cochrane Library databases to identify randomized controlled trials and retrospective studies that compared the effect of IPM with no Pringle maneuver during liver resection in patients with HCC. Hazard ratio (HR), risk ratio, standardized mean difference, and their 95% confidence interval (CI) values were calculated based on the type of variables.

RESULTS

This meta-analysis included nine studies comprising one RCT and eight retrospective studies and involved a total of 3268 patients. Perioperative outcomes, including operation time, complications, and length of hospital stay, except for blood loss, were comparable between the two groups. After removing the studies that led to heterogeneity, the results showed that IPM was effective in reducing blood loss. Five studies reported overall survival (OS) and disease-free survival (DFS) data and eight studies reported perioperative outcomes. No significant difference in OS and DFS was observed between the two groups (OS: HR, 1.01; 95% CI, 0.85-1.20; p = 0.95; DFS: HR, 1.01; 95% CI, 0.88-1.17; p = 0.86).

CONCLUSION

IPM is a useful technique to control blood loss during liver resection and does not affect the long-term survival of patients with HCC.

Molecular Mechanisms of Ischaemia-Reperfusion Injury and Regeneration in the Liver-Shock and Surgery-Associated Changes

Hepatic ischemia-reperfusion injury (IRI) represents a major challenge during liver surgery, liver preservation for transplantation, and can cause hemorrhagic shock with severe hypoxemia and trauma. The reduction of blood supply with a concomitant deficit in oxygen delivery initiates various molecular mechanisms involving the innate and adaptive immune response, alterations in gene transcription, induction of cell death programs, and changes in metabolic state and vascular function. Hepatic IRI is a major cause of morbidity and mortality, and is associated with an increased risk for tumor growth and recurrence after oncologic surgery for primary and secondary hepatobiliary malignancies. Therapeutic strategies to prevent or treat hepatic IRI have been investigated in animal models but, for the most part, have failed to provide a protective effect in a clinical setting. This review focuses on the molecular mechanisms underlying hepatic IRI and regeneration, as well as its clinical implications. A better understanding of this complex and highly dynamic process may allow for the development of innovative therapeutic approaches and optimize patient outcomes.

TRPM2 Non-Selective Cation Channels in Liver Injury Mediated by Reactive Oxygen Species

TRPM2 channels admit Ca²⁺ and Na⁺ across the plasma membrane and release Ca²⁺ and Zn²⁺ from lysosomes. Channel activation is initiated by reactive oxygen species (ROS), leading to a subsequent increase in ADP-ribose and the binding of ADP-ribose to an allosteric site in the cytosolic NUDT9 homology domain. In many animal cell types, Ca²⁺ entry via TRPM2 channels mediates ROS-initiated cell injury and death. The aim of this review is to summarise the current knowledge of the roles of TRPM2 and Ca²⁺ in the initiation and progression of chronic liver diseases and acute liver injury. Studies to date provide evidence that TRPM2-mediated Ca²⁺ entry contributes to drug-induced liver toxicity, ischemia–reperfusion injury, and the progression of non-alcoholic fatty liver disease to cirrhosis, fibrosis, and hepatocellular carcinoma. Of particular current interest are the steps involved in the activation of TRPM2 in hepatocytes following an increase in ROS, the downstream pathways activated by the resultant increase in intracellular Ca²⁺, and the chronology of these events. An apparent contradiction exists between these roles of TRPM2 and the role identified for ROS-activated TRPM2 in heart muscle and in some other cell types in promoting Ca²⁺-activated mitochondrial ATP synthesis and cell survival. Inhibition of TRPM2 by curcumin and other “natural” compounds offers an attractive strategy for inhibiting ROS-induced liver cell injury. In conclusion, while it has been established that ROS-initiated activation of TRPM2 contributes to both acute and chronic liver injury, considerable further research is needed to elucidate the mechanisms involved, and the conditions under which pharmacological inhibition of TRPM2 can be an effective clinical strategy to reduce ROS-initiated liver injury.

New Insights in Mechanisms and Therapeutics for Short- and Long-Term Impacts of Hepatic Ischemia Reperfusion Injury Post Liver Transplantation

Liver transplantation has been identified as the most effective treatment for patients with end-stage liver diseases. However, hepatic ischemia reperfusion injury (IRI) is associated with poor graft function and poses a risk of adverse clinical outcomes post transplantation. Cell death, including apoptosis, necrosis, ferroptosis and pyroptosis, is induced during the acute phase of liver IRI. The release of danger-associated molecular patterns (DAPMs) and mitochondrial dysfunction resulting from the disturbance of metabolic homeostasis initiates graft inflammation. The inflammation in the short term exacerbates hepatic damage, leading to graft dysfunction and a higher incidence of acute rejection. The subsequent changes in the graft immune environment due to hepatic IRI may result in chronic rejection, cancer recurrence and fibrogenesis in the long term. In this review, we mainly focus on new mechanisms of inflammation initiated by immune activation related to metabolic alteration in the short term during liver IRI. The latest mechanisms of cancer recurrence and fibrogenesis due to the long-term impact of inflammation in hepatic IRI is also discussed. Furthermore, the development of therapeutic strategies, including ischemia preconditioning, pharmacological inhibitors and machine perfusion, for both attenuating acute inflammatory injury and preventing late-phase disease recurrence, will be summarized in the context of clinical, translational and basic research.