Impact of sarcopenia on the future liver remnant growth after portal vein embolization and associating liver partition and portal vein ligation for staged hepatectomy in patients with liver cancer: A systematic review

Correlation between sarcopenia and hypertrophy of the future liver remnant in patients undergoing portal vein embolization before liver resection

OBJECTIVES

To study the correlation between sarcopenia and hypertrophy of the future liver remnant (FLR) in patients undergoing portal vein embolization (PVE) before liver resection, and to assess the outcomes after resection.

METHODS

This retrospective study examined patients underwent PVE from May 2012 to May 2023. Demographic, clinical, and laboratory features were documented and total liver volumes and FLR volumes were measured before and 2-4 weeks after PVE. Degree of hypertrophy (DH), percentage hypertrophy (PH), and kinetic growth rate (KGR) of the FLR were calculated. Sarcopenia was defined using the skeletal muscle index (SMI) at the L3 vertebral level. Subcutaneous adipose index, visceral adipose index (VAI), cross-sectional area of psoas muscle at the largest diameter, and L3 vertebral level mean muscle attenuation (MA) were also assessed.

RESULTS

Forty patients were included in the analysis and the median age was 57.5 (IQR 51-64) and majority were males 27/40(67.5%). Twenty-two patients were non-sarcopenics and 18 were sarcopenics. All patients showed hypertrophy of FLR (P = 0.001). SMI demonstrated moderate positive correlations with DH (r = 0.46, P = 0.003), PH (r = 0.47, P = 0.002), and KGR (r = 0.44, P = 0.004). VAI showed weak positive correlations with DH (r = 0.22, P = 0.17), PH (r = 0.18, P = 0.27), and KGR (r = 0.14, P = 0.37). Pre-PVE FLR demonstrated a weak negative correlation with PH (r = -0.35, P = 0.03) and KGR (r = -0.12, P = 0.47).

CONCLUSIONS

Sarcopenia, specifically SMI, significantly correlates with FLR hypertrophy after PVE. Assessment of sarcopenia and body compartments prior to PVE could help in stratifying and treats patients with impaired FLR growth.

ADVANCES IN KNOWLEDGE

This study with data spanning over 11 years, is the first in the Indian population to demonstrate a significant correlation between SMI, a marker of sarcopenia, and FLR hypertrophy following PVE.

Development and External Validation of a Combined Clinical-Radiomic Model for Predicting Insufficient Hypertrophy of the Future Liver Remnant following Portal Vein Embolization

OBJECTIVES

This study aimed to develop and externally validate a model for predicting insufficient future liver remnant (FLR) hypertrophy after portal vein embolization (PVE) based on clinical factors and radiomics of pretreatment computed tomography (CT) PATIENTS AND METHODS: Clinical information and CT scans of 241 consecutive patients from three Swedish centers were retrospectively collected. One center (120 patients) was applied for model development, and the other two (59 and 62 patients) as test cohorts. Logistic regression analysis was adopted for clinical model development. A FLR radiomics signature was constructed from the CT images using the support vector machine. A model combining clinical factors and FLR radiomics signature was developed. Area under the curve (AUC) was adopted for predictive performance evaluation RESULTS: Three independent clinical factors were identified for model construction: pretreatment standardized FLR (odds ratio (OR): 1.12, 95% confidence interval (CI): 1.04-1.20), alanine transaminase (ALT) level (OR: 0.98, 95% CI: 0.97-0.99), and PVE material (OR: 0.27, 95% CI: 0.08-0.87). This clinical model showed an AUC of 0.75, 0.71, and 0.68 in the three cohorts, respectively. A total of 833 radiomics features were extracted, and after feature dimension reduction, 16 features were selected for FLR radiomics signature construction. When adding it to the clinical model, the AUC of the combined model increased to 0.80, 0.76, and 0.72, respectively. However, the increase was not significant.

CONCLUSIONS

Pretreatment CT radiomics showed added value to the clinical model for predicting FLR hypertrophy following PVE. Although not reaching statistically significant, the evolving radiomics holds a potential to supplement traditional predictors of FLR hypertrophy.

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.