Irreversible electroporation for liver cancer ablation: A meta analysis

Irreversible electroporation: Beyond the limits of tumor ablation

Irreversible Electroporation (IRE) is a non-thermal tumor ablation technique. High-voltage electrical pulses are applied between pairs of electrodes inserted around and/or inside a tumor. The generated electric current induces the creation of nanopores in the cell membrane, triggering apoptosis. As a result, IRE can be safely used in areas near delicate vascular structures where other thermal ablation methods are contraindicated. Currently, IRE has demonstrated to be a successful ablation technique for pancreatic, renal, and liver tumors and is widely used as a focal therapeutic option for prostate cancer. The need for specific anesthetic management and accurate parallel placement of multiple electrodes entails a high level of complexity and great expertise from the interventional team is required. Nevertheless, IRE is a very promising technique with a remarkable systemic immunological capability and may impact on distant metastases (abscopal effect).

Biomedical Application of Decellularized Scaffolds

Tissue loss and end-stage organ failure are serious health problems across the world. Natural and synthetic polymer scaffold material based artificial organs play an important role in the field of tissue engineering and organ regeneration, but they are not from the body and may cause side effects such as rejection. In recent years, the biomimetic decellularized scaffold based materials have drawn great attention in the tissue engineering field for their good biocompatibility, easy modification, and excellent organism adaptability. Therefore, in this review, we comprehensively summarize the application of decellularized scaffolds in tissue engineering and biomedicine in recent years. The preparation methods, modification strategies, construction of artificial tissues, and application in biomedical applications are discussed. We hope that this review will provide a useful reference for research on decellularized scaffolds and promote their application tissue engineering.

Non-Thermal Liver Ablation: Existing and New Technology

Cancer has and continues to be a complex health crisis plaguing millions around the world. Alcohol ablation was one of the initial methods used for the treatment of liver lesions. It was surpassed by thermal ablation which has played a big role in the therapeutic arsenal for primary and metastatic liver tumors. However, thermal ablation has several shortcomings and limitations that prompted the development of alternative technologies including electroporation and histotripsy. Percutaneous alcohol injection in the liver lesion leads to dehydration and coagulative necrosis. This technology is limited to the lesion with relative sparing of the surrounding tissue, making it safe to use adjacent to sensitive structures. Electroporation utilizes short high-voltage pulses to permeabilize the cell membrane and can result in cell death dependent on the threshold reached. It can effectively target the tumor margins and has lower damage rates to surrounding structures due to the short pulse duration. Histotripsy is a novel technology, and although the first human trial was just completed, its results are encouraging, given the sharp demarcation of the targeted tissue, lack of thermal damage, and potential for immunomodulation of the tumor microenvironment. Herein, we discuss these techniques, their uses, and overall clinical benefit.

Prevention of major biliary complications by fusion imaging for thermal ablation of malignant liver tumors adjacent to the bile ducts: a preliminary comparative study

PURPOSE

Ultrasound (US)-guided thermal ablation (TA) may cause major biliary complications, particularly in patients with malignant liver tumors (MLTs) adjacent to the bile ducts. Fusion imaging (FI), is postulated to reduce complication rate; however, there is a lack of clinical data to support this theory. Thus, the aim of our study was to evaluate the safety and efficacy of FI for TA of MLTs proximal to the bile ducts.

METHODS

A retrospective single-center review was conducted on a total of 289 patients with 316 MLTs adjacent to the bile ducts. The patients were divided into two groups based on whether FI was used in the ablation procedures. The choice of the FI-assisted procedure always depends on different operation periods and whether registrations will succeed. The baseline demographics and outcomes of these patients were compared. The efficacy was determined at the 1-month follow-up using contrast-enhanced computed tomography/magnetic resonance. Biliary complications and local tumor progression were subsequently followed-up every 3-6 months. The last follow-up visit was before August 30, 2019.

RESULTS

Among the included tumors, the incidence rate of major biliary complications after ablation in the FI group was 1.6%, which was significantly lower than that in the non-FI group (7.9%, p = 0.005). There was no significant difference in the efficacy rates of the techniques [99.5% (185/186) versus 98.4% (123/125), p = 0.56] or local progression rates [3.8% (7/185) versus 5.7% (7/123), p = 0.61] between the FI and non-FI groups.

CONCLUSION

FI for US-guided TA could be a noninvasive means to decrease major biliary complications. Trial registration number and date of registration: retrospectively registered.

The Safety and Efficacy of Nanosecond Pulsed Electric Field in Patients With Hepatocellular Carcinoma: A Prospective Phase 1 Clinical Study Protocol

Background

Hepatocellular carcinoma (HCC) is a highly aggressive malignancy. Irreversible electroporation (IRE) is an ablative modality that uses high-voltage electrical pulses to permeabilize the cell membrane leading to cell necrosis. Unlike traditional thermal ablation, IRE is hardly affected by the “heat-sink” effect and can prevent damage of the adjacent vital structures. Nanosecond pulsed electric field (nsPEF) is a new IRE technique using ultra-short pulses (nanosecond duration), can not only penetrate the cell membranes, but also act on the organelles. Sufficient preclinical researches have shown that nsPEF can eliminate HCC without damaging vital organs, and elicit potent anti-tumor immune response.

Objective

This is the first clinical study to evaluate feasibility, efficacy, and safety of nsPEF for the treatment of HCC, where thermal ablation is unsuitable due to proximity to critical structures.

Methods and analysis

We will conduct an open-labeled, single-arm, prospective, multicenter, and objective performance criteria trial. One hundred and ninety-two patients with HCC, in which the tumor is located immediately (<0.5 cm) adjacent to the portal vein, hepatic veins, bile duct, gastrointestinal tract, or diaphragm, will be enrolled among 4 academic medical centers. The primary outcomes are the rate of complete ablation at 1 month and adverse events. Secondary outcomes include technical success, technique efficacy, nsPEF procedural characteristics, local tumor progression, and local progression-free survival.

Ethics and dissemination

The trial will be conducted according to the ethical principles of the Declaration of Helsinki and has been approved by the ethics committee of all participating centers. The results of this study will be published in peer-reviewed scientific journals and presented at relevant academic conferences.

Conclusions

This study is the Phase 1 clinical trial to evaluate the efficacy and safety of nsPEF in patients with HCC at high-risk locations where thermal ablation is contra-indicated. The results may expand the options and offer an alternative therapy for HCC.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT04309747.

Image-Guided Percutaneous Ablation for Primary and Metastatic Tumors

Image-guided percutaneous ablation methods have been further developed during the recent two decades and have transformed the minimally invasive and precision features of treatment options targeting primary and metastatic tumors. They work by percutaneously introducing applicators to precisely destroy a tumor and offer much lower risks than conventional methods. There are usually shorter recovery periods, less bleeding, and more preservation of organ parenchyma, expanding the treatment options of patients with cancer who may not be eligible for resection. Image-guided ablation techniques are currently utilized for the treatment of primary and metastatic tumors in various organs including the liver, pancreas, kidneys, thyroid and parathyroid, prostate, lung, bone, and soft tissue. This article provides a brief review of the various imaging modalities and available ablation techniques and discusses their applications and associated complications in various organs.