Gruenberger, Thomas

Hepatic resection (HR) and liver transplantation (LT) are curative-intent treatments for hepatocellular carcinoma (HCC). Patients without cirrhosis are typically analyzed as a single group, obscuring potentially important differences between those with histologically normal liver and those with non-cirrhotic parenchymal disease. We aimed to characterize long-term outcomes following HR stratified by underlying parenchymal quality, with a contemporary LT cohort as an external benchmark. Retrospective cohort study of 662 adults undergoing curative-intent surgery for HCC at 2 tertiary centers (2010–2024). Resection patients (n=380) were stratified by non-tumor parenchymal histology into HR-Normal (n=84), HR-Diseased non-cirrhotic (n=159), and HR-Cirrhotic (n=137). A total of 282 LT recipients served as an external reference but were not entered into comparative models. Overall survival (OS) was analyzed by Kaplan–Meier and multivariable Cox regression, and recurrence by Fine–Gray competing-risks regression. Ninety-day mortality was low across resection strata (1.2%–3.2%). OS differed significantly across parenchymal groups (log-rank p =0.01), driven by superior outcomes in HR-Normal patients compared with both HR-Cirrhotic ( p =0.008) and HR-Diseased ( p =0.005). HR-Cirrhotic and HR-Diseased did not differ ( p =0.97). Five-year OS was 74.4%, 59.8% and 57.2%, respectively. On multivariable Cox regression, both cirrhosis (HR 2.03, 95% CI 1.16–3.54, p =0.01) and diseased non-cirrhotic parenchyma (HR 2.04, 95% CI 1.21–3.43, p =0.008) independently predicted death versus normal liver. Fine–Gray analysis confirmed higher recurrence risk in cirrhotic (sHR 2.09, p =0.01) and diseased non-cirrhotic (sHR 1.80, p =0.04) groups. The LT benchmark cohort achieved a 5-year OS of 82.4%. Histologically normal liver identifies a distinct HR subgroup with favorable oncologic outcomes. The conventional cirrhotic/non-cirrhotic dichotomy underestimates the prognostic impact of underlying parenchymal disease.

Abstract Background Liver surgery carries a high risk of complications due to the complex interplay of patient-related factors, disease characteristics, and liver function. Expertise is essential for healthcare professionals managing hepatobiliary patients. This European consensus provides evidence-based guidance on selected aspects of peri- and postoperative care. Methods A modified Delphi process was used to achieve consensus, with a 70% agreement threshold. The expert panel comprised hepatobiliary surgeons, anaesthetists, hepatologists, a specialist nurse, and a physiotherapist. A systematic literature search was conducted in PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases. Six topics were addressed: thromboprophylaxis; perioperative antibiotics; prehabilitation/nutrition/mobilization; bile leak including bilioenteric anastomosis leaks; post-hepatectomy haemorrhage; and post-hepatectomy liver failure (PHLF). Evidence appraisal and statement development followed Scottish Intercollegiate Guidelines Network methodology. A patient representative reviewed the guideline. Results Searching the literature yielded 204 included publications from an initial 6514. Thirty-two statements were formulated with a median evidence level of 2. Evidence strength varied by topic with noticeably lower evidence levels in complex surgery settings and less prevalent conditions. In some topics, study heterogeneity and specific inclusion criteria resulted in conditional recommendations, despite high-level evidence. Notably, the weakest evidence was found for perioperative thromboprophylaxis and PHLF management. Strong recommendations were formulated for prehabilitation, early postoperative mobilization, and avoidance of routine drain use. Several evidence gaps warranting multicentre studies were identified. Conclusion Optimizing peri- and postoperative care after liver resection remains challenging. Standardizing key practices and addressing evidence gaps through collaborative research are vital to improve outcomes.

Liver resection (LR) is the primary treatment for hepatic tumors, yet posthepatectomy liver failure (PHLF) remains a significant concern. While the precise etiology of PHLF remains elusive, dysregulated inflammatory processes are pivotal. Therefore, we explored the theragnostic potential of extracellular high-mobility-group-box protein 1 (HMGB1), a key damage-associated molecular pattern (DAMP) released by hepatocytes, in liver recovery post LR in patients and animal models. Plasma from 96 LR patients and liver tissues from a subset of 24 LR patients were analyzed for HMGB1 levels, and associations with PHLF and liver injury markers were assessed. In a murine LR model, the HMGB1 inhibitor glycyrrhizin, was administered to assess its impact on liver regeneration. Furthermore, plasma levels of keratin-18 (K18) and cleaved cytokeratin-18 (ccK18) were quantified to assess suitability as predictive biomarkers for PHLF. Patients experiencing PHLF exhibited elevated levels of intrahepatic and circulating HMGB1, correlating with markers of liver injury. In a murine LR model, inhibition of HMGB1 improved liver function, reduced steatosis, enhanced regeneration and decreased hepatic cell death. Elevated levels of hepatic cell death markers K18 and ccK18 were detected in patients with PHLF and correlations with levels of circulating HMGB1 was observed. Our study underscores the therapeutic and predictive potential of HMGB1 in PHLF mitigation. Elevated HMGB1, K18, and ccK18 levels correlate with patient outcomes, highlighting their predictive significance. Targeting HMGB1 enhances liver regeneration in murine LR models, emphasizing its role in potential intervention and prediction strategies for liver surgery.

The activation of the receptor tyrosine kinase Axl by Gas6 is a major driver of tumorigenesis. Despite recent insights, tumor cell-intrinsic and -extrinsic Axl functions are poorly understood in hepatocellular carcinoma (HCC). Thus, we analyzed the cell-specific aspects of Axl in liver cancer cells and in the tumor microenvironment. We show that tumor-intrinsic Axl expression decreased the survival of mice and elevated the number of pulmonary metastases in a model of resection-based tumor recurrence. Axl expression increased the invasion of hepatospheres by the activation of Akt signaling and a partial epithelial-to-mesenchymal transition (EMT). However, the liver tumor burden of Axl+/+ mice induced by diethylnitrosamine plus carbon tetrachloride was reduced compared to systemic Axl−/− mice. Tumors of Axl+/+ mice were highly infiltrated with cytotoxic cells, suggesting a key immune-modulatory role of Axl. Interestingly, hepatocyte-specific Axl deficiency did not alter T cell infiltration, indicating that these changes are independent of tumor cell-intrinsic Axl. In this context, we observed an upregulation of multiple chemokines in Axl+/+ compared to Axl−/− tumors, correlating with HCC patient data. In line with this, Axl is associated with a cytotoxic immune signature in HCC patients. Together these data show that tumor-intrinsic Axl expression fosters progression, while tumor-extrinsic Axl expression shapes an inflammatory microenvironment.

Background: Posthepatectomy liver failure (PHLF) represents a life-threatening complication with limited therapeutic options. Neutrophils play a critical and dynamic role during regeneratory processes, but their role in human liver regeneration is incompletely understood, especially as underlying liver disease, detectable in the majority of patients, critically affects hepatic regeneration. Here we explored intrahepatic neutrophil accumulation and neutrophil extracellular traps (NETs) in patients with PHLF and validated the functional relevance of NETs in a murine partial hepatectomy (PHx) model. Methods: We investigated the influx of neutrophils, macrophages, eosinophils, and mast cells and the presence of their respective extracellular traps in liver biopsies of 35 patients undergoing hepatectomy (10 patients with PHLF) before and after the initiation of liver regeneration by fluorescence microscopy. In addition, NET formation and neutrophil activation were confirmed by plasma analysis of 99 patients (24 patients with PHLF) before and up to 5 days after surgery. Furthermore, we inhibited NETs via DNase I in a murine PHx model of mice with metabolically induced liver disease. Results: We detected rapid intrahepatic neutrophil accumulation, elevated levels of myeloperoxidase release, and NET formation in regenerating human livers, with a significantly higher increase of infiltrating neutrophils and NETs in patients with PHLF. Circulating markers of neutrophil activation, including elastase, myeloperoxidase, and citrullinated histone H3, correlated with markers of liver injury. In a murine PHx model, we showed that the inhibition of NET accelerated hepatocyte proliferation and liver regeneration. Conclusions: Patients with PHLF showed accelerated intrahepatic neutrophil infiltration and NET formation, which were associated with liver damage. Further, we identified postsurgical myeloperoxidase levels as predictive markers for adverse outcomes and observed that blocking NETs in a murine PHx model accelerated tissue regeneration.

Objective and Background: Clinically significant posthepatectomy liver failure (PHLF B+C) remains the main cause of mortality after major hepatic resection. This study aimed to establish an aspartate aminotransferase to platelet ratio combined with an albumin-bilirubin grade (APRI+ALBI), based multivariable model (MVM) to predict PHLF and compare its performance to indocyanine green clearance (ICG-R15 or ICG-PDR) and albumin-ICG evaluation (ALICE). Methods: A total of 12,056 patients from the National Surgical Quality Improvement Program database were used to generate a MVM to predict PHLF B+C. The model was determined using stepwise backwards elimination. The performance of the model was tested using receiver operating characteristic curve analysis and validated in an international cohort of 2525 patients. In 620 patients, the APRI+ALBI MVM, trained in the National Surgical Quality Improvement Program cohort, was compared with the MVM’s based on other liver function tests (ICG clearance, ALICE) by comparing the areas under the curve (AUC). Results: A MVM including APRI+ALBI, age, sex, tumor type, and extent of resection was found to predict PHLF B+C with an AUC of 0.77, with comparable performance in the validation cohort (AUC: 0.74). In direct comparison with other MVM’s based on more expensive and time-consuming liver function tests (ICG clearance, ALICE), the APRI+ALBI MVM demonstrated equal predictive potential for PHLF B+C. A smartphone application for the calculation of the APRI+ALBI MVM was designed. Conclusion: Risk assessment through the APRI+ALBI MVM for PHLF B+C increases preoperative predictive accuracy and represents a universally available and cost-effective risk assessment before hepatectomy, facilitated by a freely available smartphone app.

Abstract Background Posthepatectomy liver failure (PHLF) contributes significantly to morbidity and mortality after liver surgery. Standardized assessment of preoperative liver function is crucial to identify patients at risk. These European consensus guidelines provide guidance for preoperative patient assessment. Methods A modified Delphi approach was used to achieve consensus. The expert panel consisted of hepatobiliary surgeons, radiologists, nuclear medicine specialists, and hepatologists. The guideline process was supervised by a methodologist and reviewed by a patient representative. A systematic literature search was performed in PubMed/MEDLINE, the Cochrane library, and the WHO International Clinical Trials Registry. Evidence assessment and statement development followed Scottish Intercollegiate Guidelines Network methodology. Results Based on 271 publications covering 4 key areas, 21 statements (at least 85 per cent agreement) were produced (median level of evidence 2− to 2+). Only a few systematic reviews (2++) and one RCT (1+) were identified. Preoperative liver function assessment should be considered before complex resections, and in patients with suspected or known underlying liver disease, or chemotherapy-associated or drug-induced liver injury. Clinical assessment and blood-based scores reflecting liver function or portal hypertension (for example albumin/bilirubin, platelet count) aid in identifying risk of PHLF. Volumetry of the future liver remnant represents the foundation for assessment, and can be combined with indocyanine green clearance or LiMAx® according to local expertise and availability. Functional MRI and liver scintigraphy are alternatives, combining FLR volume and function in one examination. Conclusion These guidelines reflect established methods to assess preoperative liver function and PHLF risk, and have uncovered evidence gaps of interest for future research.

AbstractExperimental data suggested activation of yes‐associated protein (YAP‐1) as a critical regulator of liver regeneration (LR). Serotonin (5‐HT) promotes LR in rodent models and has been proposed to act via YAP‐1. How 5‐HT affects LR is incompletely understood. A possible mechanism how 5‐HT affects human LR was explored. Sixty‐one patients were included. Tissue samples prior and 2 h after induction of LR were collected. Circulating levels of 5‐HT and osteopontin (OPN) were assessed. YAP‐1, its phosphorylation states, cytokeratin 19 (CK‐19) and OPN were assessed using immunofluorescence. A mouse model of biliary epithelial cells (BECs) specific deletion of YAP/TAZ was developed. YAP‐1 increased as early as 2 h after induction of LR (p = 0.025) predominantly in BECs. BEC specific deletion of YAP/TAZ reduced LR after 70% partial hepatectomy in mice (Ki67%, p < 0.001). SSRI treatment, depleting intra‐platelet 5‐HT, abolished YAP‐1 and OPN induction upon LR. Portal vein 5‐HT levels correlated with intrahepatic YAP‐1 expression upon LR (R = 0.703, p = 0.035). OPN colocalized with YAP‐1 in BECs and its circulating levels increased in the liver vein 2 h after induction of LR (p = 0.017). In the context of LR tyrosine‐phosphorylated YAP‐1 significantly increased (p = 0.042). Stimulating BECs with 5‐HT resulted in increased YAP‐1 activation via tyrosine‐phosphorylation and subsequently increased OPN expression. BECs YAP‐1 appears to be critical for LR in mice and humans. Our evidence suggests that 5‐HT, at least in part, exerts its pro‐regenerative effects via YAP‐1 tyrosine‐phosphorylation in BECs and subsequent OPN‐dependent paracrine immunomodulation.

AXL and its corresponding ligand growth arrest–specific 6 (GAS‐6) are critically involved in hepatic immunomodulation and regenerative processes. Pleiotropic inhibitory effects on innate inflammatory responses might essentially involve the shift of macrophage phenotype from a pro‐inflammatory M1 to an anti‐inflammatory M2. We aimed to assess the relevance of the AXL/GAS‐6‐pathway in human liver regeneration and, consequently, its association with clinical outcome after hepatic resection. Soluble AXL (sAXL) and GAS‐6 levels were analyzed at preoperative and postoperative stages in 154 patients undergoing partial hepatectomy and correlated with clinical outcome. Perioperative dynamics of interleukin (IL)‐6, soluble tyrosine‐protein kinase MER (sMerTK), soluble CD163 (sCD163), and cytokeratin (CK) 18 were assessed to reflect pathophysiological processes. Preoperatively elevated sAXL and GAS‐6 levels predicted postoperative liver dysfunction (area under the curve = 0.721 and 0.722; P < 0.005) and worse clinical outcome. These patients failed to respond with an immediate increase of sAXL and GAS‐6 upon induction of liver regeneration. Abolished AXL pathway response resulted in a restricted increase of sCD163, suggesting a disrupted phenotypical switch to regeneratory M2 macrophages. No association with sMerTK was observed. Concomitantly, a distinct association of IL‐6 levels with an absent increase of AXL/GAS‐6 signaling indicated pronounced postoperative inflammation. This was further supported by increased intrahepatic secondary necrosis as reflected by CK18M65. sAXL and GAS‐6 represent not only potent and easily accessible preoperative biomarkers for the postoperative outcome but also AXL/GAS‐6 signaling might be of critical relevance in human liver regeneration. Refractory AXL/GAS‐6 signaling, due to chronic overactivation/stimulation in the context of underlying liver disease, appears to abolish their immediate release following induction of liver regeneration, causing overwhelming immune activation, presumably via intrahepatic immune regulation.

Background and Aims Platelet‐stored serotonin critically affects liver regeneration in mice and humans. Selective serotonin reuptake inhibitors (SSRIs) and serotonin noradrenalin reuptake inhibitors (SNRIs) reduce intraplatelet serotonin. As SSRIs/SNRIs are now one of the most commonly prescribed drugs in the United States and Europe and given serotonin’s impact on liver regeneration, we evaluated whether perioperative use of SSRIs/SNRIs affects outcome after hepatic resection. Approach and Results Consecutive patients undergoing hepatic resection (n = 754) were retrospectively included from prospectively maintained databases from two European institutions. Further, an independent cohort of 495 patients from the United States was assessed to validate our exploratory findings. Perioperative intake of SSRIs/SNRIs was recorded, and patients were followed up for postoperative liver dysfunction (LD), morbidity, and mortality. Perioperative intraplatelet serotonin levels were significantly decreased in patients receiving SSRI/SNRI treatment. Patients treated with SSRIs/SNRIs showed a higher incidence of morbidity, severe morbidity, LD, and LD requiring intervention. Associations were confirmed in the independent validation cohort. Combined cohorts documented a significant increase in deleterious postoperative outcome (morbidity odds ratio [OR], 1.56; 95% confidence interval [CI], 1.07‐2.31; severe morbidity OR, 1.86; 95% CI, 1.22‐2.79; LD OR, 1.96; 95% CI, 1.23‐3.06; LD requiring intervention OR, 2.22; 95% CI, 1.03‐4.36). Further, multivariable analysis confirmed the independent association of SSRIs/SNRIs with postoperative LD, which was closely associated with postoperative 90‐day mortality and 1‐year overall survival. Conclusions We observed a significant association of perioperative SSRI/SNRI intake with adverse postoperative outcome after hepatic resection. This indicates that SSRIs/SNRIs should be avoided perioperatively in patients undergoing hepatic resections.