Search results for "Radiofrequency"

Ultrasound-guided ablation for hepatocellular carcinoma: time for a reappraisal?

2015

Ultrasound-guided techniques play a key role in the clinical management of hepatocellular carcinoma. Among these, percutaneous ethanol injection (PEI) was the first technique to be proposed for the treatment of nodular-type hepatocellular carcinoma: the role of PEI was first discussed during the European Association for the Study of the Liver conference held in Barcelona in 2000, 15 years ago. Since then, other techniques have been introduced and radiofrequency ablation now represents the most widely used percutaneous technique. PEI and radiofrequency ablation are widely used in clinical practice. However, only scant progresses in the application of these techniques have been performed over…

Imaging appearance of treated hepatocellular carcinoma

2013

Surgical resection and imaging guided treatments play a crucial role in the management of hepatocellular carcinoma (HCC). Although the primary end point of treatment of HCC is survival, radiological response could be a surrogate end point of survival, and has a key role in HCC decision-making process. However, radiological assessment of HCC treatment efficacy is often controversial. There are few doubts on the evaluation of surgical resection; in fact, all known tumor sites should be removed. However, an unenhancing partial linear peripheral halo, in most cases, surrounding a fluid collection reducing in size during follow-up is demonstrated in successfully resected tumor with bipolar radio…

Needle track seeding following percutaneous procedures for hepatocellular carcinoma.

2009

Neoplastic seeding may arise after diagnostic or therapeutic percutaneous procedures for hepatocellular carcinoma. The true incidence of seeding with hepatocellular carcinoma is difficult to assess precisely, but a significant risk of seeding exists and is greater when performing diagnostic biopsy as compared to therapeutic percutaneous procedures [radiofrequency ablation, radiofrequency ablation (RFA); percutaneous ethanol injection, Percutaneous ethanol injection (PEI)]. Whenever liver transplantation is feasible, diagnostic needle biopsies should be avoided, but RFA and PEI are often needed as “bridge” treatments. The role of adjuvant treatments in reducing the incidence of seeding follo…

Reconstruction of vertebral body after radiofrequency ablation and augmentation in dorsolumbar metastatic vertebral fracture: Analysis of clinical an…

2017

Background: Painful spinal metastases usually occur in malignant neoplastic disease. Treatment for bone metastases has been largely conservative, and it includes the use of high doses of analgesics, radiotherapy, chemotherapy, hormone therapy, and bisphosphonates; however, results are sometimes transient and ineffective. In the presence of neurological involvement a surgical strategy should be considered. Recently, percutaneous procedures such as radiofrequency ablation, vertebroplasty, and kyphoplasty have been introduced as palliative techniques to treat painful vertebral metastases [3, 11, 25]. Methods: In our study we combined the use of radiofrequency ablation with vertebroplasty in th…

Modifications in Ventricular Fibrillation and Capture Capacity Induced by a Linear Radiofrequency Lesion

2012

[EN] Introduction and objectives: An analysis was made of the effects of a radiofrequency-induced linear lesion during ventricular fibrillation and the capacity to capture myocardium through high-frequency pacing. Methods: Using multiple epicardial electrodes, ventricular fibrillation was recorded in 22 isolated perfused rabbit hearts, analyzing the activation maps upon applying trains of stimuli at 3 different frequencies close to that of the arrhythmia: a) at baseline; b) after radio-frequency ablation to induce a lesion of the left ventricular free wall (length=10 [1] mm), and c) after lengthening the lesion (length=23 [2] mm). Results: Following lesion induction, the regularity of the r…

Endoscopic radiofrequency ablation of a cholangiocarcinoma with targeted intraductal cholangioscopic access.

2020

Simplified Electrophysiology Modeling Framework to Assess Ventricular Arrhythmia Risk in Infarcted Patients

2021

Patients that have suffered a myocardial infarction are at lifetime high risk for sudden cardiac death (SCD). Personalized 3D computational modeling and simulation can help to find non-invasively arrhythmogenic features of patients’ infarcts, and to provide additional information for stratification and planning of radiofrequency ablation (RFA). Currently, multiscale biophysical models require high computational resources and long simulations times, which make them impractical for clinical environments. In this paper, we develop a phenomenological solver based on cellular automata to simulate cardiac electrophysiology, with results comparable to those of biophysical models. The solver can ru…

A hybrid stimulation strategy for suppression of spiral waves in cardiac tissue

2011

International audience; Atrial fibrillation (AF) is the most common cardiac arrhythmia whose mechanisms are thought to be mainly due to the self perpetuation of spiral waves (SW). To date, available treatment strategies (antiarrhythmic drugs, radiofrequency ablation of the substrate, electrical cardioversion) to restore and to maintain a normal sinus rhythm have limitations and are associated with AF recurrences. The aim of this study was to assess a way of suppressing SW by applying multifocal electrical stimulations in a simulated cardiac tissue using a 2D FitzHugh-Nagumo model specially convenient for AF investigations. We identified stimulation parameters for successful termination of S…

Changes in the Spectral Characteristics of Ventricular Fibrillation in Lesions Produced by Radiofrequency Ablation. An Experimental Study

2008

INTRODUCTION AND OBJECTIVES Although electro- physiological databases contain information about changes in the time domain in lesions produced by radiofrequency ablation, very few data on changes in the frequency domain are available. The aim of this study was to investigate changes in the spectral characteristics of ventricular fibrillation in zones with radiofrequency lesions. METHODS Recordings of ventricular fibrillation were obtained in 11 isolated perfused rabbit heart preparations using a multiple epicardial electrode located on the left ventricular free wall. Spectral parameters derived by Fourier analysis before and after the creation of transmural radiofrequency lesions were compa…

Personalized Cardiac Computational Models: From Clinical Data to Simulation of Infarct-Related Ventricular Tachycardia.

2019

In the chronic stage of myocardial infarction, a significant number of patients develop life-threatening ventricular tachycardias (VT) due to the arrhythmogenic nature of the remodeled myocardium. Radiofrequency ablation (RFA) is a common procedure to isolate reentry pathways across the infarct scar that are responsible for VT. Unfortunately, this strategy show relatively low success rates; up to 50% of patients experience recurrent VT after the procedure. In the last decade, intensive research in the field of computational cardiac electrophysiology (EP) has demonstrated the ability of three-dimensional (3D) cardiac computational models to perform in-silico EP studies. However, the personal…