The Influence of Aging on Hepatic Regeneration and Early Outcome after Portal Vein Occlusion: A Case-Control Study

Current Perspectives and Progress in Preoperative Portal Vein Embolization with Stem Cell Augmentation (PVESA)

Portal vein embolization with stem cell augmentation (PVESA) is an emerging approach for enhancing the growth of the liver segment that will remain after surgery (i.e., future liver remnant, FLR) in patients with liver cancer. Conventional portal vein embolization (PVE) aims to induce preoperative FLR growth, but it has a risk of failure in patients with underlying liver dysfunction and comorbid illnesses. PVESA combines PVE with stem cell therapy to potentially improve FLR size and function more effectively and efficiently. Various types of stem cells can help improve liver growth by secreting paracrine signals for hepatocyte growth or by transforming into hepatocytes. Mesenchymal stem cells (MSCs), unrestricted somatic stem cells, and small hepatocyte-like progenitor cells have been used to augment liver growth in preclinical animal models, while clinical studies have demonstrated the benefit of CD133 + bone marrow-derived MSCs and hematopoietic stem cells. These investigations have shown that PVESA is generally safe and enhances liver growth after PVE. However, optimizing the selection, collection, and application of stem cells remains crucial to maximize benefits and minimize risks. Additionally, advanced stem cell technologies, such as priming, genetic modification, and extracellular vesicle-based therapy, that could further enhance efficacy outcomes should be evaluated. Despite its potential, PVESA requires more investigations, particularly mechanistic studies that involve orthotopic animal models of liver cancer with concomitant liver injury as well as larger human trials.

Systematic Reviews and Meta-Analyses of Portal Vein Embolization, Associated Liver Partition and Portal Vein Ligation, and Radiation Lobectomy Outcomes in Hepatocellular Carcinoma Patients

PURPOSE OF REVIEW

To understand portal vein embolization (PVE), associated liver partition and portal vein ligation (ALPPS) and radiation lobectomy (RL) outcomes in hepatocellular carcinoma (HCC) patients. Systematic reviews of future liver remnant (FLR) percent hypertrophy, proportion undergoing hepatectomy and proportion with major complications following PVE, ALPPS, and RL were performed by searching Ovid MEDLINE, Ovid EMBASE, The Cochrane Library, and Web of Science. Separate meta-analyses using random-effects models with assessment of study heterogeneity and publication bias were performed whenever allowable by available data.

RECENT FINDINGS

Of the 10,616 articles screened, 21 articles with 636 subjects, 4 articles with 65 subjects, and 4 articles with 195 subjects met the inclusion criteria for systematic reviews and meta-analyses for PVE, ALPPS, and RL, respectively. The pooled estimate of mean percent FLR hypertrophy was 30.9% (95%CI: 22-39%, Q = 4034.8, p < 0.0001) over 40.3 +/- 26.3 days for PVE, 54.9% (95%CI: 36-74%, Q = 73.8, p < 0.0001) over 11.1 +/- 3.1 days for ALPPS, and 29.0% (95%CI: 23-35%, Q = 56.2, p < 0.0001) over 138.5 +/- 56.5 days for RL. The pooled proportion undergoing hepatectomy was 91% (95%CI: 83-95%, Q = 43.9, p = 0.002) following PVE and 98% (95%CI: 50-100%, Q = 0.0, p = 1.0) following ALPPS. The pooled proportion with major complications was 5% (95%CI: 2-10%, Q = 7.3, p = 0.887) following PVE and 38% (95%CI: 18-63%, Q = 10.0, p = 0.019) following ALPPS. Though liver hypertrophy occurs following all three treatments in HCC patients, PVE balances effective hypertrophy with a short time frame and low major complication rate.

Cell Sources and Influencing Factors of Liver Regeneration: A Review

Liver regeneration (LR) is a set of complicated mechanisms between cells and molecules in which the processes of initiation, maintenance, and termination of liver repair are regulated. Although LR has been studied extensively, there are still numerous challenges in gaining its full understanding. Cells for LR have a wide range of sources and the feature of plasticity, and regeneration patterns are not the same under different conditions. Many patients undergoing partial hepatectomy develop cirrhosis or steatosis. The changes of LR in these cases are not clear. Many types of cells participate in LR. Hepatocytes, biliary epithelial cells, hepatic progenitor cells, and human liver stem cells can serve as the cell sources for LR. However, different types and degrees of damage trigger the response from the most suitable cells. Exploring the cell sources of LR is of great significance for accelerating recovery of liver function under different pathological patterns and developing a cell therapy strategy to cope with the shortage of donors for liver transplantation. In clinical practice, the background of the liver influences regeneration. Fibrosis and steatosis create different LR microenvironments and signal molecule interaction patterns. In addition, factors such as partial hepatectomy, aging, platelets, nerves, hormones, bile acids, and gut microbiota are widely involved in this process. Understanding the influencing factors of LR has practical value for individualized treatment of patients with liver diseases. In this review, we have summarized recent studies and proposed our views. We discuss cell sources and the influential factors on LR to help in solving clinical problems.

Pros and Cons of Portal Vein Embolization With Hematopoietic Stem Cells Application in Colorectal Liver Metastases Surgery

BACKGROUND/AIM

Portal vein embolization (PVE) with autologous stem cells application (aHSC) is a method for future liver remnant volume (FLRV) increase. The aim of the study was to evaluate the positivite and negativite aspects of the method in clinical practice.

PATIENTS AND METHODS

PVE with aHSC application was used in 32 patients with colorectal liver metastases and insufficient FLRV. Preoperative number of colorectal liver metastases (CLMs) was 5.2±3.6, CLMs volume 70.1±102.3 mm³ Results: FLRV growth occurred after 2-3 weeks in 31 (96.9%) patients, with volume increase from 528.2±170.5 to 715.4±143.3 ml (p=0.0001). Postoperative thirty days mortality, morbidity was 0% and 3.1%, respectively. Insufficient FLRV growth occurred in one patient. R0 liver resection was performed in 27(87.1%) patients. CLMs volume progression was in 5 (15.6%) patients from 680.0±59.4 to 723.1±57.1 ml (p=0.01). One and two-year overall survival were 88% and 62.9% respectively. Six and twelve-month recurrence-free survival rates were 50.7% and 39.6% respectively.

CONCLUSION

PVE with aHSC application is a safe and useful method for FLRV growth. It significantly increases secondary CLMs resectability. However, it can cause CLMs progression. Liver resection should, therefore, be performed as soon as possible after achieving optimal increase of FLRV.

Short-term autonomy and survival after hepatectomy in the elderly

AIM

To study morbi-mortality, survival after hepatectomy in elderly patients, and influence on their short-term autonomy.

PATIENTS AND METHODS

This is a retrospective study conducted between 2002 and 2017 comparing patients less than 65 years old (controls) to those more than 65 years old (cases) from a prospective database, with retrospective collection of geriatric data. Cases were divided into three sub-groups (65-70 years, 70-80 years and>80 years).

RESULTS

Four hundred and eighty-two patients were included. There was no age difference in number of major hepatectomies (P=0.5506), length of stay (P=0.3215), mortality at 90 days (P=0.3915), and surgical complications (P=0.1467). There were more Grade 1 Clavien medical complications among the patients aged over 65 years (P=0.1737). There was no difference in overall survival (P=0.460) or disease-free survival (P=0.108) according to age after adjustment for type of disease and hepatectomy. One-third of patients had geriatric complications. The "home discharge" rate decreased significantly with age from 92% to 68% (P=0.0001). Early loss of autonomy after hospitalization increased with age, 16% between 65 and 70 years, 23% between 70 and 80 years and 36% after 80 years (P=0.10). We identified four independent predictors of loss of autonomy: age>70 years, cholangiocarcinoma, length of stay>10 days, and metachronous colorectal cancer.

CONCLUSIONS

Elderly patients had the same management as young patients, with no difference in surgery or survival, but with an increase in early loss of autonomy.

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.

Effect of Hyperbilirubinemia on Hepatic Hypertrophy after Portal Vein Embolization and Liver Failure after Hepatectomy in Primary Biliary Malignancy

PURPOSE

To retrospectively investigate the impact of hyperbilirubinemia on future liver remnant (FLR) volume after percutaneous transhepatic portal vein embolization (PVE) and incidence of post-hepatectomy liver failure in primary biliary malignancy.

MATERIALS AND METHODS

Eighty-seven patients (62 men, overall mean age 66.9 y) who underwent PVE, using Gelfoam and coils before major hepatectomy between January 2004 and June 2016, were included in this study and divided into a hyperbilirubinemia (serum total bilirubin level at PVE 5.80 ± 2.44 mg/dL; n = 41) group and a control group (1.09 ± 0.73 mg/dL; n = 46). Liver volume was measured from computerized tomographic data before and 18.5 days, on average, after PVE. Correlation between FLR hypertrophy (degree of hypertrophy and percentage increase in future liver remnant [%FLR]) and total bilirubin were analyzed. FLR hypertrophy and incidence of post-hepatectomy liver failure were compared. Simple and multiple regressions were used for univariable and multivariable analyses, respectively.

RESULTS

Mean FLR volumes before and after PVE were 529.1 cm³ and 640.5 cm³, respectively. Degree of hypertrophy and %FLR were 7.64 ± 4.22 and 21.77 ± 13.34, respectively. There was no significant correlation between FLR hypertrophy and total bilirubin (P > .5). FLR hypertrophy was not significantly different between the 2 groups. Planned major hepatectomy was performed in 73 patients (83.9%). Grade 3 post-hepatectomy liver failure occurred in 6 patients (8.2%; 2 in the hyperbilirubinemia group and 4 in the control group), and its incidence was not significantly different between the groups (P = .354).

CONCLUSIONS

Hyperbilirubinemia at the time of PVE seems to have no effect on FLR hypertrophy. The incidence of grade 3 post-hepatectomy liver failure is not likely to be influenced, either.

Impact of age on short-term outcomes of liver surgery: Lessons learned in 10-years' experience in a tertiary referral hepato-pancreato-biliary center

We investigate the surgical outcomes of patients undergoing hepatectomy according to different age intervals, identify the clinical factors related to surgical outcomes, and propose clinical risk scores for severe morbidity and mortality based on the clinical factors.Eight hundred three patients undergoing liver resection were divided into 3 groups: young patients (YP), <65 years (n = 387), elderly patients (EP), from 65 to 74 years (n = 279); very-elderly patients (VEP), ≥75 years (n = 137).Severe morbidity was 10.6%, 12.2%, and 17.5% (P = .103), and mortality was 0.3%, 1.4%, and 4.4% (P = .002) in group YP, EP, and VEP, respectively. Ischemic heart disease, cirrhosis, major hepatectomy, biliary tract-associated procedure, and red blood cells (RBC) transfusion ≥3 U were related with severe morbidity. Ischemic heart disease, cirrhosis, major hepatectomy, and RBC transfusion were independent risk factors for postoperative mortality. Age did not result an independent factor related to mortality and severe morbidity. Two different scores were developed and have proved to be statistically related with severe morbidity and mortality. Moreover, in patients with score ≥2, severe morbidity increased from 24.2% in YP, to 29.3% in EP, and to 40.0% in VEP, P = .047. Likewise, mortality increased from 2.3% in YP, to 7.0% in EP, and to 22.7% in VEP, in patients with score ≥2, P = .017.Age alone should not be considered a contraindication for hepatectomy. We identified factors and proposed 2 scores that can be useful to stratify the risk of morbidity and mortality after hepatectomy. Moreover, severe morbidity and mortality increases according to the different age intervals in patients with scores ≥2.