Liver regeneration after major liver hepatectomy: Impact of body mass index

Surgical Implications for Nonalcoholic Steatohepatitis-Related Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is an aggressive form of liver cancer that arises in a background of chronic hepatic injury. Metabolic syndrome-associated fatty liver disease (MAFLD) and its severe form, nonalcoholic steatohepatitis (NASH), are increasingly common mechanisms for new HCC cases. NASH-HCC patients are frequently obese and medically complex, posing challenges for clinical management. In this review, we discuss NASH-specific challenges and the associated implications, including benefits of minimally invasive operative approaches in obese patients; the value of y90 as a locoregional therapy; and the roles of weight loss and immunotherapy in disease management. The relevant literature was identified through queries of PubMed, Google Scholar, and clinicaltrials.gov. Provider understanding of clinical nuances specific to NASH-HCC can improve treatment strategy and patient outcomes.

Post-hepatectomy liver failure: A timeline centered review

BACKGROUND

Post-hepatectomy liver failure (PHLF) is a leading cause of postoperative mortality after liver surgery. Due to its significant impact, it is imperative to understand the risk stratification and preventative strategies for PHLF. The main objective of this review is to highlight the role of these strategies in a timeline centered way around curative resection.

DATA SOURCES

This review includes studies on both humans and animals, where they addressed PHLF. A literature search was conducted across the Cochrane Library, Embase, MEDLINE/PubMed, and Web of Knowledge electronic databases for English language studies published between July 1997 and June 2020. Studies presented in other languages were equally considered. The quality of included publications was assessed using Downs and Black's checklist. The results were presented in qualitative summaries owing to the lack of studies qualifying for quantitative analysis.

RESULTS

This systematic review with 245 studies, provides insight into the current prediction, prevention, diagnosis, and management options for PHLF. This review highlighted that liver volume manipulation is the most frequently studied preventive measure against PHLF in clinical practice, with modest improvement in the treatment strategies over the past decade.

CONCLUSIONS

Remnant liver volume manipulation is the most consistent preventive measure against PHLF.

Liver growth prediction in ALPPS - A multicenter analysis from the international ALPPS registry

BACKGROUND

While ALPPS triggers a fast liver hypertrophy, it is still unclear which factors matter most to achieve accelerated hypertrophy within a short period of time. The aim of the study was to identify patient-intrinsic factors related to the growth of the future liver remnant (FLR).

METHODS

This cohort study is composed of data derived from the International ALPPS Registry from November 2011 and October 2018. We analyse the influence of demographic, tumour type and perioperative data on the growth of the FLR. The volume of the FLR was calculated in millilitre and percentage using computed-tomography (CT) scans before and after stage 1, both according to Vauthey formula.

RESULTS

A total of 734 patients were included from 99 centres. The median sFLR at stage 1 and stage 2 was 0.23 (IQR, 0.18-0.28) and 0.39 (IQR: 0.31-0.46), respectively. The variables associated with a lower increase from sFLR1 to sFLR2 were age˃68 years (p = .02), height ˃1.76 m (p ˂ .01), weight ˃83 kg (p ˂ .01), BMI˃28 (p ˂ .01), male gender (p ˂ .01), antihypertensive therapy (p ˂ .01), operation time ˃370 minutes (p ˂ .01) and hospital stay˃14 days (p ˂ .01). The time required to reach sufficient volume for stage 2, male gender accounts 40.3% in group ˂7 days, compared with 50% of female, and female present 15.3% in group ˃14 days compared with 20.6% of male.

CONCLUSIONS

Height, weight, FLR size and gender could be the variables that most constantly influence both daily growths, the interstage increase and the standardized FLR before the second stage.

Hepatic Epigenetic Reprogramming After Liver Resection in Offspring Alleviates the Effects of Maternal Obesity

Obesity has become a public health problem in recent decades, and during pregnancy, it can lead to an increased risk of gestational complications and permanent changes in the offspring resulting from a process known as metabolic programming. The offspring of obese dams are at increased risk of developing non-alcoholic fatty liver disease (NAFLD), even in the absence of high-fat diet consumption. NAFLD is a chronic fatty liver disease that can progress to extremely severe conditions that require surgical intervention with the removal of the injured tissue. Liver regeneration is necessary to preserve organ function. A range of pathways is activated in the liver regeneration process, including the Hippo, TGFβ, and AMPK signaling pathways that are under epigenetic control. We investigated whether microRNA modulation in the liver of the offspring of obese dams would impact gene expression of Hippo, TGFβ, and AMPK pathways and tissue regeneration after partial hepatectomy (PHx). Female Swiss mice fed a standard chow or a high-fat diet (HFD) before and during pregnancy and lactation were mated with male control mice. The offspring from control (CT-O) and obese (HF-O) dams weaned to standard chow diet until day 56 were submitted to PHx surgery. Prior to the surgery, HF-O presented alterations in miR-122, miR-370, and Let-7a expression in the liver compared to CT-O, as previously shown, as well as in its target genes involved in liver regeneration. However, after the PHx (4 h or 48 h post-surgery), differences in gene expression between CT-O and HF-O were suppressed, as well as in microRNA expression in the liver. Furthermore, both CT-O and HF-O presented a similar regenerative capacity of the liver within 48 h after PHx. Our results suggest that survival and regenerative mechanisms induced by the partial hepatectomy may overcome the epigenetic changes in the liver of offspring programmed by maternal obesity.

Impact of laparoscopic liver resection on liver regeneration

BACKGROUND

Liver regeneration after liver resection plays an important role in preventing posthepatectomy liver failure. In this study, we aimed to evaluate and compare the impact of laparoscopic liver resection (LLR) and open liver resection (OLR) on liver regeneration.

METHODS

Patients who underwent curative anatomical liver resection for hepatocellular carcinoma, cholangiocellular carcinoma, and colorectal liver metastases at our institution between January 2010 and December 2018 were included in this study. The patients were divided into the OLR and LLR groups. Preoperative liver volume (PLV), future remnant liver volume, resected liver volume (RLV), liver volume at 1 month after the surgery, and liver volume at 6 months after the surgery were calculated. The liver regeneration rate was defined as the increase in the rate of RLV, and the liver recovery rate was defined as the rate of return to the PLV.

RESULTS

The study included 72 patients. Among them, 43 were included in the OLR group and 29 were included in the LLR group. No differences were observed in the baseline characteristics and surgical procedures between the two groups. Moreover, no significant difference was observed in the liver regeneration rate at 1 month after the surgery (OLR vs. LLR: 68.9% vs. 69.0%, p = 0.875) and at 6 months after the surgery (91.8% vs. 93.2%, p = 0.995). Furthermore, the liver recovery rates were not significantly different between the two groups at 1 month after the surgery (90.3% vs. 90.6%, p = 0.893) and at 6 months after the surgery (96.9% vs. 98.8%, p = 0.986).

CONCLUSION

Liver regeneration after liver resection is not affected by the type of surgical procedure and both laparoscopic and open procedures yield similar regeneration and recovery rates.

Maternal high-fat diet consumption programs male offspring to mitigate complications in liver regeneration

In the last decades, obesity and nonalcoholic fatty liver disease (NAFLD) have become increasingly prevalent in wide world. Fatty liver can be detrimental to liver regeneration (LR) and offspring of obese dams (HFD-O) are susceptible to NAFLD development. Here we evaluated LR capacity in HFD-O after partial hepatectomy (PHx). HFD-O re-exposed or not to HFD in later life were evaluated for metabolic parameters, inflammation, proliferation, tissue repair markers and survival rate after PHx. Increasing adiposity and fatty liver were observed in HFD-O. Despite lower IL-6 levels, Ki67 labeling, cells in S phase and Ciclin D1/PCNA protein content, a lower impact on survival rate was found after PHx, even when re-exposed to HFD. However, no difference was observed between offspring of control dams (SC-O) and HFD-O after surgery. Although LR impairment is dependent of steatosis development, offspring of obese dams are programmed to be protected from the damage promoted by HFD.

Diabetes mellitus and postoperative blood glucose value help predict posthepatectomy liver failure in patients with hepatocellular carcinoma

Background

Many complications after hepatectomy can lead to perioperative death, among which posthepatectomy liver failure (PHLF) is the leading one. Existing studies suggest that one of the most important risk factors for PHLF is cirrhosis. Hepatitis B virus (HBV) infection is an important factor in the occurrence of cirrhosis, and the exact relationship between HBV infection and PHLF is not obvious. Diabetes mellitus and postoperative blood glucose are closely associated with liver regeneration, but its exact relationship with PHLF remains unclear.

Methods

We collected clinical indicators from 920 adult patients treated at the Liver Surgery and Transplantation Center of West China Hospital of Sichuan University from April 2009 and April 2019. We conducted a univariate analysis find out the risk factors of PHLF, follow by a multivariate analysis to ascertain the independent risk factors. Receiver operating characteristic (ROC) curves were plotted to evaluate the predictive efficiency of each risk factor.

Results

Following hepatectomy, 205 (22.2%) of patients were diagnosed with PHLF. Several variables were confirmed to related with PHLF significantly: diabetes [P<0.01, odds ratio (OR) =10.845, 95% confidence interval (CI): 5.450-21.579], HBV (P<0.01, OR =0.345, 95% CI: 0.187-0.635), blood glucose on the first postoperative day (post-BG1) (P=0.027, OR =1.059, 95% CI: 1.006-1.115), blood glucose on the third postoperative day (post-BG3) (P=0.021, OR =1.085, 95% CI: 1.012-1.162), blood glucose on the fifth postoperative day (post-BG5) (P=0.014, OR =1.119, 95% CI: 1.023-1.225), postoperative total bilirubin (post-TB) (P<0.01, OR =1.160, 95% CI: 1.133-1.187), and liver cirrhosis (P<0.01, OR =0.982, 95% CI: 0.561-1.717) identified to be independent risk factors of PHLF.

Conclusions

Diabetes, HBV, post-BG1, post-BG3, and post-BG5 are related to the development of PHLF, and diabetes and post-BG can be used as predictors of the development of PHLF in patients with hepatocellular carcinoma (HCC).

Influence of diabetes on short-term outcome after major hepatectomy: an underestimated risk?

BACKGROUND

Patient-related risk factors such as diabetes mellitus and obesity are increasing in western countries. At the same time the indications for liver resection in both benign and malignant diseases have been significantly extended in recent years. Major liver resection is performed more frequently in a patient population of old age, comorbidity and high rates of neoadjuvant chemotherapy. The aim of this study was to evaluate whether diabetes mellitus, obesity and overweight are risk factors for the short-term post-operative outcome after major liver resection.

METHODS

Four hundred seventeen major liver resections (≥ 3 segments) were selected from a prospective database. Exclusion criteria were prior liver resection in patient's history and synchronous major intra-abdominal procedures. Overweight was defined as BMI ≥ 25 kg/m2 and < 30 kg/m2 and obesity as BMI ≥ 30 kg/m2. Primary end point was 90-day mortality and logistic regression was used for multivariate analysis. Secondary end points included morbidity, complications according to Clavien-Dindo classification, unplanned readmission, bile leakage, and liver failure. Morbidity was defined as occurrence of a post-operative complication during hospital stay or within 90 days postoperatively.

RESULTS

Fifty-nine patients had diabetes mellitus (14.1%), 48 were obese (11.6%) and 147 were overweight (35.5%). There were no statistically significant differences in mortality rates between the groups. In the multivariate analysis, diabetes was an independent predictor of morbidity (OR = 2.44, p = 0.02), Clavien-Dindo grade IV complications (OR = 3.6, p = 0.004), unplanned readmission (OR = 2.44, p = 0.04) and bile leakage (OR = 2.06, p = 0.046). Obese and overweight patients did not have an impaired post-operative outcome compared patients with normal weight.

CONCLUSIONS

Diabetes has direct influence on the short-term postoperative outcome with an increased risk of morbidity but not mortality. Preoperative identification of high-risk patients will potentially decrease complication rates and allow for individual patient counseling as part of a shared decision-making process. For obese and overweight patients, major liver resection is a safe procedure.

Model-based virtual patient analysis of human liver regeneration predicts critical perioperative factors controlling the dynamic mode of response to resection

BACKGROUND

Liver has the unique ability to regenerate following injury, with a wide range of variability of the regenerative response across individuals. Existing computational models of the liver regeneration are largely tuned based on rodent data and hence it is not clear how well these models capture the dynamics of human liver regeneration. Recent availability of human liver volumetry time series data has enabled new opportunities to tune the computational models for human-relevant time scales, and to predict factors that can significantly alter the dynamics of liver regeneration following a resection.

METHODS

We utilized a mathematical model that integrates signaling mechanisms and cellular functional state transitions. We tuned the model parameters to match the time scale of human liver regeneration using an elastic net based regularization approach for identifying optimal parameter values. We initially examined the effect of each parameter individually on the response mode (normal, suppressed, failure) and extent of recovery to identify critical parameters. We employed phase plane analysis to compute the threshold of resection. We mapped the distribution of the response modes and threshold of resection in a virtual patient cohort generated in silico via simultaneous variations in two most critical parameters.

RESULTS

Analysis of the responses to resection with individual parameter variations showed that the response mode and extent of recovery following resection were most sensitive to variations in two perioperative factors, metabolic load and cell death post partial hepatectomy. Phase plane analysis identified two steady states corresponding to recovery and failure, with a threshold of resection separating the two basins of attraction. The size of the basin of attraction for the recovery mode varied as a function of metabolic load and cell death sensitivity, leading to a change in the multiplicity of the system in response to changes in these two parameters.

CONCLUSIONS

Our results suggest that the response mode and threshold of failure are critically dependent on the metabolic load and cell death sensitivity parameters that are likely to be patient-specific. Interventions that modulate these critical perioperative factors may be helpful to drive the liver regenerative response process towards a complete recovery mode.