Systematic review and meta-analysis of thrombocytopenia as a predictor of post-hepatectomy liver failure

Evidence for platelet-derived transforming growth factor β1 as an early inducer of liver regeneration after hepatectomy in mice

Platelets play a crucial role in tissue regeneration, and their involvement in liver regeneration is well-established. However, the specific contribution of platelet-derived Transforming Growth Factor Beta 1 (TGFβ1) to liver regeneration remains unexplored. This study investigated the role of platelet-derived TGFβ1 in initiating liver regeneration following 2/3 liver resection. Using platelet-specific TGFβ1 knockout (Plt.TGFβ1 KO) mice and wild-type littermates (Plt.TGFβ1 WT) as controls, the study assessed circulating levels and hepatic gene expression of TGFβ1, Platelet Factor 4 (PF4), and Thrombopoietin (TPO) at early time points post-hepatectomy (post-PHx). Hepatocyte proliferation was quantified through Ki67 staining and PCNA expression in total liver lysates at various intervals, and phosphohistone-H3 (PHH3) staining was employed to mark mitotic cells. Circulating levels of hepatic mitogens, Hepatocyte Growth Factor (HGF), and Interleukin-6 (IL6) were also assessed. Results revealed that platelet-TGFβ1 deficiency significantly reduced total plasma TGFβ1 levels at 5 h post-PHx in Plt.TGFβ1 KO mice compared to controls. While circulating PF4 levels, liver platelet recruitment and activation appeared normal at early time points, Plt.TGFβ1 KO mice showed more stable circulating platelet numbers with higher numbers at 48 h post-PHx. Notably, hepatocyte proliferation was significantly reduced in Plt.TGFβ1 KO mice. The results show that a lack of TGFβ1 in platelets leads to an unbalanced expression of IL6 in the liver and to strongly increased HGF levels 48 h after liver resection, and yet liver regeneration remains reduced. The study identifies platelet-TGFβ1 as a regulator of hepatocyte proliferation and platelet homeostasis in the early stages of liver regeneration.

Noninvasive assessment of liver fibrosis in mini pigs using an 18F-AlF-NOTA-RGD2 PET/CT molecular probe

To evaluate the efficacy of the 18F-AlF-NOTA-RGD2 positron emission tomography (PET)/computed tomography (CT) molecular probe for the noninvasive staging of liver fibrosis in mini pigs, a potential alternative to invasive diagnostic methods was revealed. This study used 18F-AlF-NOTA-RGD2 PET/CT imaging of mini pigs to assess liver fibrosis. The methods included synthesis and quality control of the molecular probe, establishment of an animal model of liver fibrosis, blood serum enzymatic tests, histopathological examination, PET/CT imaging, collagen content and expression, and mitochondrial reserve function assessment. The 18F-AlF-NOTA-RGD2 PET/CT molecular probe effectively differentiated various stages of liver fibrosis in mini pigs. Blood serum enzymatic tests revealed distinct stages of liver fibrosis, revealing significant increases in AST, ALT, TBIL, and DBIL levels as fibrosis advanced. Notably, ALT levels increased markedly in severe fibrosis patients. A gradual increase in collagen deposition and increasing α-SMA RNA expression and protein levels effectively differentiated between mild and severe fibrosis stages. Pathological examinations and Sirius Red staining confirmed these findings, highlighting substantial increases in collagen accumulation. PET/CT imaging results aligned with histopathological findings, showing that increased radiotracer uptake correlated with fibrosis severity. Assessments of mitochondrial function revealed a decrease in total liver glutathione content and mitochondrial reserve capacity, especially in patients with severe fibrosis. The 18F-AlF-NOTA-RGD2 PET/CT molecular probe is a promising tool for the noninvasive assessment of liver fibrosis, offering potential benefits over traditional diagnostic methods in hepatology.

Approaching Thrombospondin-1 as a Potential Target for Mesenchymal Stromal Cells to Support Liver Regeneration after Partial Hepatectomy in Mouse and Humans

Extended liver resection carries the risk of post-surgery liver failure involving thrombospondin-1-mediated aggravation of hepatic epithelial plasticity and function. Mesenchymal stromal cells (MSCs), by interfering with thrombospondin-1 (THBS1), counteract hepatic dysfunction, though the mechanisms involved remain unknown. Herein, two-thirds partial hepatectomy in mice increased hepatic THBS1, downstream transforming growth factor-β3, and perturbation of liver tissue homeostasis. All these events were ameliorated by hepatic transfusion of human bone marrow-derived MSCs. Treatment attenuated platelet and macrophage recruitment to the liver, both major sources of THBS1. By mitigating THBS1, MSCs muted surgery-induced tissue deterioration and dysfunction, and thus supported post-hepatectomy regeneration. After liver surgery, patients displayed increased tissue THBS1, which is associated with functional impairment and may indicate a higher risk of post-surgery complications. Since liver dysfunction involving THBS1 improves with MSC treatment in various animal models, it seems feasible to also modulate THBS1 in humans to impede post-surgery acute liver failure.

The role of platelet mediated thromboinflammation in acute liver injury

Acute liver injuries have wide and varied etiologies and they occur both in patients with and without pre-existent chronic liver disease. Whilst the pathophysiological mechanisms remain distinct, both acute and acute-on-chronic liver injury is typified by deranged serum transaminase levels and if severe or persistent can result in liver failure manifest by a combination of jaundice, coagulopathy and encephalopathy. It is well established that platelets exhibit diverse functions as immune cells and are active participants in inflammation through processes including immunothrombosis or thromboinflammation. Growing evidence suggests platelets play a dualistic role in liver inflammation, shaping the immune response through direct interactions and release of soluble mediators modulating function of liver sinusoidal endothelial cells, stromal cells as well as migrating and tissue-resident leucocytes. Elucidating the pathways involved in initiation, propagation and resolution of the immune response are of interest to identify therapeutic targets. In this review the provocative role of platelets is outlined, highlighting beneficial and detrimental effects in a spatial, temporal and disease-specific manner.

A Novel Nomogram for Prediction of Post-Hepatectomy Liver Failure in Patients with Resectable Hepatocellular Carcinoma: A Multicenter Study

Objective

To develop a nomogram for predicting post-hepatectomy liver failure (PHLF) in patients with resectable hepatocellular carcinoma (HCC) based on portal hypertension, the extent of resection, ALT, total bilirubin, and platelet count.

Methods

Patients with HCC hospitalized from January 2015 to December 2020 were included in a retrospective cohort study. 595 HCC patients were divided into a training cohort (n=416) and a validation cohort (n=179) by random sampling. Univariate and multivariable analyses were performed to identify the independent variables to predict PHLF. The nomogram models for predicting the overall risk of PHLF and the risk of PHLF B+C were constructed based on the independent variables. Comparisons were made by using receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) with traditional models, such as FIB-4 score, APRI score, CP class (Child-Pugh), MELD score (model of end-stage liver disease), and ALBI score (albumin-bilirubin) to analyze the accuracy and superiority of the nomogram.

Results

We discovered that portal hypertension (yes vs no) (OR=1.677,95% CI:1.817-4.083, p=0.002), the extent of liver resection (OR=1.872,95% CI:3.937-47.096, p=0.001), ALT (OR=1.003,95% CI:1.003-1.016, P=0.003), total bilirubin (OR=1.036,95% CI:1.031-1.184, p=0.005), and platelet count (OR= 1.004, 95% CI:0.982-0.998, p=0.020) were independent risk factors for PHLF using multifactorial analysis. The nomogram models were constructed using well-fit calibration curves for each of these five covariates. When compared to the FIB4, ALBI, MELD, and CP score, our nomogram models have a better predictive value for predicting the overall risk of PHLF or the risk of PHLF B+C. The validation cohort's results were consistent. DCA also confirmed the conclusion.

Conclusion

Our models, in the form of static nomogram or web application, were developed to predict PHLF overall risk and PHLF B+C risk in patients with HCC, with a high prediction sensitivity and specificity performance than other commonly used scoring systems.

Influence of cytokines, circulating markers and growth factors on liver regeneration and post-hepatectomy liver failure: a systematic review and meta-analysis

The pathophysiology of post-hepatectomy liver failure is not entirely understood but is rooted in the disruption of normal hepatocyte regeneration and homeostasis. Current investigations of post-hepatectomy liver failure and regeneration are focused on evaluation of circulating hepatic function parameters (transaminases, cholestasis, and coagulation parameters), volumetry and hepatic hemodynamics. However, identification of biochemical factors associated with regeneration and post hepatectomy liver failure is crucial for understanding the pathophysiology and identification of patients at risk. The objective of the present systematic review was to identify circulating factors associated with liver regeneration and post hepatectomy liver failure in patients undergoing hepatectomy. The quantitative analysis was intended if studies provided sufficient data. Electronic databases (MEDLINE via PubMed, Web of Knowledge, Cochrane Library and WHO International Clinical Trials Registry Platform) were searched for publications on cell signaling factors in liver regeneration and post-hepatectomy liver failure following liver resection in clinical setting. No date restriction was given. No language restriction was used. Studies were assessed using MINORS. This study was registered at PROSPERO (CRD42020165384) prior to data extraction. In total 1953 publications were evaluated for titles and abstracts after exclusion of duplicates. Full texts of 167 studies were further evaluated for inclusion. 26 articles were included in the review and 6 publications were included in the meta-analyses. High levels of serum hyaluronic acid even preoperatively are associated with PHLF but especially increased levels early after resection are predictive of PHLF with high sensitivity and specificity. Postoperative elevation of HA to levels between 100 and 500 ng/ml is increased the risk for PHLF ([OR] = 246.28, 95% [CI]: 11.82 to 5131.83; p = 0.0004) Inteleukin-6 levels show contradicting result in association with organ dysfunction. HGF positively correlates with liver regeneration. Overall, due to heterogeneity, scarcity, observational study design and largely retrospective analysis, the certainty of evidence, assessed with GRADE, is very low. High levels of serum hyaluronic acid show a strong association with PHLF and increased levels after resection are predictive of PHLF with high sensitivity and specificity, even on POD1. Interleukin-6 levels need to be studied further due to contradictive results in association with organ dysfunction. For HGF, no quantitative analysis could be made. Yet, most studies find positive correlation between high HGF levels and regeneration. Prospective studies investigating HGF and other growth factors, hyaluronic acid and interleukins 1 and 6 in correlation with liver regeneration measured sequentially through e.g. volumetry, and liver function parameters, preferably expanding the analysis to include dynamic liver function tests, are needed to sufficiently illustrate the connection between biomolecule levels and clinical outcomes.

Preoperative platelet count does not predict the occurrence of post-hepatectomy liver failure after partial hepatectomy in a retrospective monocentric cohort study

In humans, thrombocytopenic patients have increased incidence of post-hepatectomy liver failure (PHLF), but existing evidence is heterogeneous. Our objective was to determine if preoperative platelet count or antiplatelet drugs were associated with PHLF.Patients who underwent hepatic resection in the University Hospitals of Geneva, Switzerland, from 01.12.2009 to 18.12.2018 were identified. Platelet count at day 0, postoperative days (POD) 1, 3, and 5 were retrieved. Occurrence of PHLF according to the ISGLS definition was determined. Logistic regression was performed to determine if platelet count or antiplatelet drug were predictors for PHLF.Five hundred ninety seven patients were included. Eighty patients (17.8%) had a preoperative platelet count <150 (G/l) and 24 patients (5.3%) had a platelet count <100 (G/l). Thirty five patients (5.9%) were under antiplatelet drug. Platelet count significantly decreased at POD 1 and POD 3 when compared to preoperative platelet count (182 ± 71.61 (G/l) vs 212 ± 85.26 (G/l), P < .0001; 162 ± 68.5 (G/l) vs 212 ± 85.26 (G/l), P < .0001). At POD 5, post-operative platelet count did not significantly differ from its preoperative value. Forty three patients (11.2%) suffered from PHLF. Their platelet count was not significantly different than patients without PHLF (211 ± 89.7 (G/l) vs 211 ± 83.5 (G/l), P = .671). One patient with PHLF had a platelet count <100 (G/l) and 5 had a count <150 (G/l). Univariate logistic regression did not identify preoperative thrombocytopenia (<100 (G/l) or <150 (G/l)), postoperative thrombocytopenia, or the presence of antiagregant drug, as predictors of PHLF. We did not identify preoperative or postoperative thrombocytopenia as predictor of PHLF in a cohort of 597 patients.

A cohort study of hepatectomy-related complications and prediction model for postoperative liver failure after major liver resection in 1,441 patients without obstructive jaundice

Background

This cohort study, based on a large sample of extensive hepatectomy cases, aimed to analyze the distribution of hepatectomy-related complications and to develop a predictive model of posthepatectomy liver failure (PHLF).

Methods

Data of patients who underwent hepatectomy of ≥3 liver segments at the Eastern Hepatobiliary Surgery Hospital from 2000 to 2016 were collected and analyzed. Information on hepatectomy-related complications was collected and risk factors were analyzed. A total of 1,441 eligible patients were randomly assigned at 3:1 ratio into the derivation (n=1,080) and validation (n=361) cohorts. The multivariable logistic regression model was used to establish the prediction model of PHLF in the derivation cohort.

Results

The incidence rates of PHLF, ascites, bile leakage, intra-abdominal bleeding, and abscesses were 58.22%, 10.76%, 11.17%, 9.71%, and 4.16%, respectively. The 90-day perioperative mortality rate was 1.32%. Multivariate analyses found that age, gender, platelet, creatinine, gamma-glutamyltransferase, thrombin time, fibrinogen, hepatitis B e (HBe) antigen positive, and number of resected liver segments were independent prognostic factors of PHLF in the derivation cohort and included in the nomogram. The prediction model demonstrated good discrimination [area under the curve =0.726, 95% confidence interval (CI), 0.696–0.760, P<0.0001] and calibration.

Conclusions

Our study showed a high perioperative safety and a low risk of serious complications in patients who underwent major liver resection (MLR) at a large hepatobiliary surgery center. Routine preoperative clinical information can be used to develop a postoperative liver failure risk prediction model for rational planning of surgery.

Laparoscopic left hemihepatectomy in small dogs: an easy and effective new technique

The present report describes a novel approach to and presents the surgical results for laparoscopic hepatectomy of the left lobes in small dogs. A purely laparoscopic four-port approach was used in seven beagles. The left triangular ligament was cut first, then the base of the left medial lobe (LMB) was ligated with silk thread using a needle, and the liver parenchyma of the LMB approximately 0.5 cm above the ligation site was removed with LigaSure. The left lateral lobe (LLB) was removed in the same manner. Blood was collected on postoperative days 1, 3, 7, and 14 for laboratory testing. Left hepatic lobe resection was successfully completed in all dogs, with an average operation time of 102.53 ± 9.07 min and an average blood loss of 32.10 ± 6.43 ml. Serious postoperative complications were not observed. The white blood cell (WBC) count and alkaline phosphatase (ALP) level were significantly increased in experimental dogs 1 day after surgery (P< 0.05); aspartate transferase (AST) and alanine transaminase (ALT) were significantly different before and after surgery (P< 0.01); and all the indicators were basically normal seven days after the operation. Exploratory laparoscopy at 28 days revealed adhesion of the surface of the liver section to the omentum or the gastric wall, but there were no other abnormal findings. The combined application of liver pedicle ligation and LigaSure for liver lobectomy provides a simple and effective method for generating liver lobectomy models for research on liver disease and regeneration and a feasible laparoscopic liver lobectomy operation scheme for small dogs (10–15 kg).

Comparison of anatomic and non-anatomic resections for very early-stage hepatocellular carcinoma: The importance of surgical resection margin width in non-anatomic resection

BACKGROUND

The superiority of anatomic resection (AR) over non-anatomic resection (NAR) for very early-stage hepatocellular carcinoma (HCC) has remained a topic of debate. Thus, this study aimed to compare the prognosis after AR and NAR for single HCC less than 2 cm in diameter.

METHODS

Consecutive patients with single HCC of diameter less than 2 cm who underwent curative hepatectomy between 1997 and 2017 were included in this retrospective study.

RESULTS

In total, 159 patients were included in this study. Of these, 52 patients underwent AR (AR group) and 107 patients underwent NAR (NAR group). No significant differences were noted in recurrence-free survival (RFS) and overall survival (OS) between the AR and NAR groups (P = 0.236 and P = 0.363, respectively). Multivariate analysis revealed that low preoperative platelet count and presence of satellite nodules were independent prognostic factors of RFS and OS. Wide surgical resection margin did not affect RFS (P = 0.692) in the AR group; however, in the NAR group, RFS was found to be higher with surgical resection margin widths ≥1 cm than with surgical resection margin widths <1 cm (P = 0.038).

CONCLUSIONS

Prognosis was comparable between the NAR and AR groups for very early-stage HCC with well-preserved liver function. For better oncologic outcomes, surgeons should endeavor in keeping the surgical resection margin widths during NAR ≥1 cm.

Liver resection in Cirrhotic liver: Are there any limits?

Liver resection remains one of the most technically challenging surgical procedure in abdominal surgery due to the complex anatomical arrangement in the liver and its rich blood supply that constitutes about 20% of the cardiac output per cycle. The challenge for resection in cirrhotic livers is even higher because of the impact of surgical stress and trauma imposed on borderline liver function and the impaired ability for liver regeneration in cirrhotic livers. Nonetheless, evolution and advancement in surgical techniques as well as knowledge in perioperative management of liver resection has led to a substantial improvement in surgical outcome in recent decade. The objective of this article was to provide updated information on the recent developments in liver surgery, from preoperative evaluation, to technicality of resection, future liver remnant augmentation and finally, postoperative management of complications.

Platelet Interactions with Liver Sinusoidal Endothelial Cells and Hepatic Stellate Cells Lead to Hepatocyte Proliferation

(1) Background: Platelets were postulated to constitute the trigger of liver regeneration. The aim of this study was to dissect the cellular interactions between the various liver cells involved in liver regeneration and to clarify the role of platelets. (2) Methods: Primary mouse liver sinusoidal endothelial cells (LSECs) were co-incubated with increasing numbers of resting platelets, activated platelets, or platelet releasates. Alterations in the secretion of growth factors were measured. The active fractions of platelet releasates were characterized and their effects on hepatocyte proliferation assessed. Finally, conditioned media of LSECs exposed to platelets were added to primary hepatic stellate cells (HSCs). Secretion of hepatocyte growth factor (HGF) and hepatocyte proliferation were measured. After partial hepatectomy in mice, platelet and liver sinusoidal endothelial cell (LSEC) interactions were analyzed in vivo by confocal microscopy, and interleukin-6 (IL-6) and HGF levels were determined. (3) Results: Co-incubation of increasing numbers of platelets with LSECs resulted in enhanced IL-6 secretion by LSECs. The effect was mediated by the platelet releasate, notably a thermolabile soluble factor with a molecular weight over 100 kDa. The conditioned medium of LSECs exposed to platelets did not increase proliferation of primary hepatocytes when compared to LSECs alone but stimulated hepatocyte growth factor (HGF) secretion by HSCs, which led to hepatocyte proliferation. Following partial hepatectomy, in vivo adhesion of platelets to LSECs was significantly increased when compared to sham-operated mice. Clopidogrel inhibited HGF secretion after partial hepatectomy. (4) Conclusion: Our findings indicate that platelets interact with LSECs after partial hepatectomy and activate them to release a large molecule of protein nature, which constitutes the initial trigger for liver regeneration.

Evaluation and Management of Cirrhotic Patients Undergoing Elective Surgery

PURPOSE OF REVIEW

Cirrhotic patients have an increased risk of surgical complications and higher perioperative morbidity and mortality based on the severity of their liver disease. Liver disease predisposes patients to perioperative coagulopathies, volume overload, and encephalopathy. The goal of this paper is to discuss the surgical risk of cirrhotic patients undergoing elective surgeries and to discuss perioperative optimization strategies.

RECENT FINDINGS

Literature thus far varies by surgery type and the magnitude of surgical risk. CTP and MELD classification scores allow for the assessment of surgical risk in cirrhotic patients. Once the decision has been made to undergo elective surgery, cirrhotic patients can be optimized pre-procedure with the help of a checklist and by the involvement of a multidisciplinary team. Elective surgeries should be performed at hospital centers staffed by healthcare providers experienced in caring for cirrhotic patients. Further research is needed to develop ways to prepare this complicated patient population before elective surgery.