Functional hepatocellular regeneration in elderly patients undergoing hepatectomy

Evaluation of liver regeneration after hemi-hepatectomy by combining computed tomography and post-operative liver function

Background

Accurate evaluation of postoperative liver regeneration is essential to prevent postoperative liver failure.

Aims

To analyze the predictors that affect liver regeneration after hemi-hepatectomy.

Method

Patients who underwent hemi-hepatectomy in Hangzhou First People's Hospital and Hangzhou Shulan Hospital from January 2016 to December 2021 were enrolled in this study. The regeneration index (RI) was calculated by the following equation: RI = [(postoperative total liver volume {TLVpost} - future liver remnant volume {FLRV}/FLRV] × 100 %. Hepatic dysfunction was defined according to the "TBilpeak>7" standard, which was interpreted as (peak) total bilirubin (TBil) >7.0 mg/dL. Good liver regeneration was defined solely when the RI surpassed the median with hepatic dysfunction. Logistic regression analyses were performed to estimate prognostic factors affecting liver regeneration.

Result

A total of 153 patients were enrolled, with 33 in the benign group and 120 patients in the malignant group. In the entire study population, FLRV% [OR 4.087 (1.405-11.889), P = 0.010], international normalized ratio (INR) [OR 2.763 (95%CI, 1.008-7.577), P = 0.048] and TBil [OR 2.592 (95%CI, 1.177-5.710), P = 0.018] were independent prognostic factors associated with liver regeneration. In the benign group, only the computed tomography (CT) parameter FLRV% [OR, 11.700 (95%CI, 1.265-108.200), P = 0.030] predicted regeneration. In the malignant group, parenchymal hepatic resection rate (PHRR%) [OR 0.141 (95%CI, 0.040-0.499), P = 0.002] and TBil [OR 3.384 (95%CI, 1.377-8.319), P = 0.008] were independent prognostic factors.

Conclusion

FLRV%, PHRR%, TBil and INR were predictive factors associated with liver regeneration.

A biomarker framework for liver aging: the Aging Biomarker Consortium consensus statement

In human aging, liver aging per se not only increases susceptibility to liver diseases but also increases vulnerability of other organs given its central role in regulating metabolism. Total liver function tends to be well maintained in the healthy elderly, so liver aging is generally difficult to identify early. In response to this critical challenge, the Aging Biomarker Consortium of China has formulated an expert consensus on biomarkers of liver aging by synthesizing the latest scientific literature, comprising insights from both scientists and clinicians. This consensus provides a comprehensive assessment of biomarkers associated with liver aging and presents a systematic framework to characterize these into three dimensions: functional, imaging, and humoral. For the functional domain, we highlight biomarkers associated with cholesterol metabolism and liver-related coagulation function. For the imaging domain, we note that hepatic steatosis and liver blood flow can serve as measurable biomarkers for liver aging. Finally, in the humoral domain, we pinpoint hepatokines and enzymatic alterations worthy of attention. The aim of this expert consensus is to establish a foundation for assessing the extent of liver aging and identify early signs of liver aging-related diseases, thereby improving liver health and the healthy life expectancy of the elderly population.

Systematic review and meta-analysis of 90-day and 30-day mortality after liver resection in the elderly

BACKGROUND

With the aging population worldwide, the number of elderly patients presenting for liver resection because of liver malignancies is increasing. Data on the perioperative mortality in this population are limited and contradictory. We performed a systematic review and meta-analysis to determine the mortality of elderly patients after hepatectomy.

METHODS

Using the Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 guidelines, we searched 3 databases to identify studies that investigated 30-day and 90-day mortality after hepatectomy for patients ≥65 years of age. We categorized the patients by age into 4 groups (≥65, ≥70, ≥75, and ≥80 years), which were analyzed separately for mortality. All analyses were conducted with IBM SPSS Statistics for Windows version 28.

RESULTS

Using PubMed, Embase, and Scopus, we identified 441 articles. After study selection and quality assessment, we included 66 studies consisting of 29,998 patients in the final meta-analysis. The pooled estimates for 30-day and 90-day mortality in the ≥65, ≥70, ≥75, and ≥80 age groups years were 1.3% (95% confidence interval 0.59%-2.06%), 2.8% (95% confidence interval 1.80%-3.69%), 3.0% (95% confidence interval 1.68%-4.30%), and 1.7% (95% confidence interval 1.22%-2.20%) and 2.7% (95% confidence interval 1.45%-3.87%), 2.8% (95% confidence interval 1.49%-4.02%), 5.1% (95% confidence interval 2.76%-7.42%), and 2.4% (95% confidence interval 0.60%-4.16%), respectively.

CONCLUSION

This meta-analysis summarizes the 30-day and 90-day mortality rates after liver resection in the elderly patients. Liver resection in this population selected for surgery appears to be relatively safe. Advanced age alone may not be a sufficient exclusion criterion for surgery. These age-specific mortality data can be used to educate patients at the time of preoperative counseling.

Mitochondrial bioenergetics boost macrophage activation, promoting liver regeneration in metabolically compromised animals

BACKGROUND AND AIMS

Hepatic ischemia-reperfusion injury (IRI) is the leading cause of early posttransplantation organ failure as mitochondrial respiration and ATP production are affected. A shortage of donors has extended liver donor criteria, including aged or steatotic livers, which are more susceptible to IRI. Given the lack of an effective treatment and the extensive transplantation waitlist, we aimed at characterizing the effects of an accelerated mitochondrial activity by silencing methylation-controlled J protein (MCJ) in three preclinical models of IRI and liver regeneration, focusing on metabolically compromised animal models.

APPROACH AND RESULTS

Wild-type (WT), MCJ knockout (KO), and Mcj silenced WT mice were subjected to 70% partial hepatectomy (Phx), prolonged IRI, and 70% Phx with IRI. Old and young mice with metabolic syndrome were also subjected to these procedures. Expression of MCJ, an endogenous negative regulator of mitochondrial respiration, increases in preclinical models of Phx with or without vascular occlusion and in donor livers. Mice lacking MCJ initiate liver regeneration 12 h faster than WT and show reduced ischemic injury and increased survival. MCJ knockdown enables a mitochondrial adaptation that restores the bioenergetic supply for enhanced regeneration and prevents cell death after IRI. Mechanistically, increased ATP secretion facilitates the early activation of Kupffer cells and production of TNF, IL-6, and heparin-binding EGF, accelerating the priming phase and the progression through G1 /S transition during liver regeneration. Therapeutic silencing of MCJ in 15-month-old mice and in mice fed a high-fat/high-fructose diet for 12 weeks improves mitochondrial respiration, reduces steatosis, and overcomes regenerative limitations.

CONCLUSIONS

Boosting mitochondrial activity by silencing MCJ could pave the way for a protective approach after major liver resection or IRI, especially in metabolically compromised, IRI-susceptible organs.

Accuracy of estimated total liver volume formulas before liver resection

BACKGROUND

Future remnant liver volume is used to predict the risk for liver failure in patients who will undergo major liver resection. Formulas to estimate total liver volume based on biometric data are widely used to calculate future remnant liver volume; however, it remains unclear which formula is most accurate. This study evaluated published estimate total liver volume formulas to determine which formula best predicts the actual future remnant liver volume based on measurements in a large number of patients who underwent associating liver partition and portal vein ligation for staged hepatectomy surgery.

METHODS

All patients with complete liver volume data in the associating liver partition and portal vein ligation for staged hepatectomy registry were included in this study. Estimate total liver volume and estimated future remnant liver volume were calculated for 16 published formulas. The median over- or underestimation compared with actual measured volumes were determined for estimate total liver volume and future remnant liver volume. The proportion of patients with an under- or overestimated future remnant liver volume for each formula were compared with each other using a 25% cut-off for each formula.

RESULTS

Among 529 studied patients, the formulas ranged from a 19% underestimation to a 63% overestimation of estimate total liver volume. Estimation of future remnant liver volume lead to a 10% underestimation to a 5% overestimation among the formulas. Of all studied formulas, the Vauthey1 formula was the most accurate, generating underestimation of future remnant liver volume in 20% and overestimation of future remnant liver volume in 6% of patients.

CONCLUSION

Validation of 16 published total liver volume formulas in a multicenter international cohort of 529 patients that underwent staged hepatectomy revealed that the Vauthey formula (estimate total liver volume = 18.51 × body weight + 191.8) provides the most accurate prediction of the actual future remnant liver volume.

Evaluation of liver regeneration and post-hepatectomy liver failure after hemihepatectomy in patients with hepatocellular carcinoma

Aim: To explore clinical factors associated with extent of liver regeneration after hemihepatectomy to treat hepatocellular carcinoma (HCC).Methods: Future liver remnant volume (as a percentage of functional liver volume, %FLRV) and remnant liver volume were measured preoperatively and at 1, 5, 9, and 13 weeks postoperatively.Results: After hepatectomy, 1 of 125 patients (0.8%) died within 3 months, 13 (10.4%) experienced liver failure, and 99 (79.2%) experienced complications. %FLRV was able to predict liver failure with an area under the receiver operating characteristic curve of 0.900, and a cut-off value of 42.7% showed sensitivity of 85.7% and specificity of 88.6%. Postoperative median growth ratio was 21.3% at 1 week, 30.9% at 5 weeks, 34.6% at 9 weeks, and 37.1% at 13 weeks. Multivariate analysis identified three predictors associated with liver regeneration: FLRV < 601 cm3, %FLRV, and liver cirrhosis. At postoperative weeks (POWs) 1 and 5, liver function indicators were significantly better among patients showing high extent of regeneration than among those showing low extent, but these differences disappeared by POW 9.Conclusions: FLRV, %FLRV, and liver cirrhosis strongly influence extent of liver regeneration after hepatectomy. %FLRV values below 42.7% are associated with greater risk of post-hepatectomy liver failure.

Influence of donor liver telomere and G-tail on clinical outcome after living donor liver transplantation

It has been reported that donor age affects patient outcomes after liver transplantation, and that telomere length is associated with age. However, to our knowledge, the impact of donor age and donor liver telomere length in liver transplantation has not been well investigated. This study aimed to clarify the influence of the length of telomere and G-tail from donor livers on the outcomes of living donors and recipients after living donor liver transplantation. The length of telomere and G-tail derived from blood samples and liver tissues of 55 living donors, measured using the hybridization protection assay. The length of telomeres from blood samples was inversely correlated with ages, whereas G-tail length from blood samples and telomere and G-tail lengths from liver tissues were not correlated with ages. Age, telomere, and G-tail length from blood did not affect postoperative liver failure and early liver regeneration of donors. On the other hand, the longer the liver telomere, the poorer the liver regeneration tended to be, especially with significant difference in donor who underwent right hemihepatectomy. We found that the survival rate of recipients who received liver graft with longer telomeres was inferior to that of those who received liver graft with shorter ones. An elderly donor, longer liver telomere, and higher Model for End-Stage Liver Disease score were identified as independent risk factors for recipient survival after transplantation. In conclusion, telomere shortening in healthy liver does not correlate with age, whereas longer liver telomeres negatively influence donor liver regeneration and recipient survival after living donor liver transplantation. These results can direct future studies and investigations on telomere shortening in the clinical and experimental transplant setting.

Neoadjuvant chemotherapy does not affect future liver remnant growth and outcomes of associating liver partition and portal vein ligation for staged hepatectomy

BACKGROUND

The only potentially curative treatment for patients with colorectal liver metastases is hepatectomy. Associating liver partition and portal vein ligation for staged hepatectomy has emerged as a method of treatment for patients with inadequate future liver remnant. One concern about associating liver partition and portal vein ligation for staged hepatectomy is that preoperative chemotherapy may negatively affect the volume increase of the future liver remnant and outcomes.

METHODS

This study from the International Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy Registry (NCT01924741) includes 442 patients with colorectal liver metastases registered from 2012-2016. Future liver remnant hypertrophy (absolute increase, percent increase, and kinetic growth rate) and clinical outcome were analyzed retrospectively in relation to type and amount of chemotherapy. The analyzed groups included patients with no chemotherapy, 1 regimen of chemotherapy, >1 regimen, and a group that received monoclonal antibodies in addition to chemotherapy.

RESULTS

Ninety percent of the patients received neoadjuvant oncologic therapy including 42% with 1 regimen of chemotherapy, 44% with monoclonal antibodies, and 4% with >1 regimen. Future liver remnant increased between 74-92% with the largest increase in the group with 1 regimen of chemotherapy. The increase in milliliters was between 241 mL (>1 regimen) and 306 mL (1 regimen). Kinetic growth rate was between 14-18% per week and was greatest for the group with 1 regimen of chemotherapy. No statistical significance was found between the groups with any of the measurements of future liver remnant hypertrophy.

CONCLUSION

Neoadjuvant chemotherapy, including monoclonal antibodies, does not negatively affect future liver remnant growth. Patients with colorectal liver metastases who might be potential candidates for associating liver partition and portal vein ligation for staged hepatectomy should be considered for neoadjuvant chemotherapy.

Biological Substrate of the Rapid Volumetric Changes Observed in the Human Liver During the Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy Approach

BACKGROUND

The associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) strategy induces rapid future liver remnant (FLR) hypertrophy. Hepatocyte cellular and molecular changes associated with liver hypertrophy during ALPPS remain ill-defined in humans.

METHODS

Patients undergoing the ALPPS approach between June 2011 and October 2014 were extracted. Biopsies from the FLR were obtained during the first and second stages. Hematoxylin-eosin staining and immunohistochemical analysis for expression of the proliferating cell nuclear antigen (PCNA) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) were performed. The proliferative index was defined as: PCNA-TUNEL ratio.

RESULTS

Eleven of 34 patients treated were studied during both stages. Median FLR hypertrophy was 104 % in 6 days, with a mean difference between preoperative and postoperative volume of 361 ml (P < 0.001). The mean hepatocyte number increased from 52.7 cells/mm(2) in the first stage to 89.6 cells/mm(2) in the second stage (P = 0.001). PCNA expression increased by 190 % between stages with a linear correlation (r = 0.58) with macroscopic hypertrophy. The proliferative index increased from -3.78 cells/mm(2) in first stage to 2.32 cells/mm(2) in the second stage (P = 0.034).

CONCLUSIONS

The results of the present study indicate that the rapid FLR volumetric increase observed in ALPPS is accompanied by histological and molecular features of hepatocyte cell proliferation.