Abstract 430: Spectral Changes Caused by Radiofrequency Ablation of Cardiac Tissue

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Mohammed Aljishi ◽  
Huda Asfour ◽  
Tigran Chahbazian ◽  
Narine Muselimyan ◽  
Luther Swift ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Visual Information ◽  
Thermal Ablation ◽  
Cardiac Tissue ◽  
Cardiac Activity ◽  
Soret Band ◽  
Quantitative Information ◽  
Thermal Coagulation ◽  
Spectral Changes ◽  
Nadh Fluorescence

Persistent atrial fibrillation is commonly treated using an endoscopic catheter to eliminate anomalous sources of cardiac activity via thermal ablation. However, the procedure lacks real-time feedback. Newly developed radiofrequency ablation (RFA) catheters include a fiberoptic bundle through which visual information of tissue conditions may be collected offering an opportunity to reveal subtle differences in tissue physiology. Currently little is known about the spectral changes caused by RFA. We hypothesized that by comparing spectral changes in various areas in the heart before and after RFA, optical signatures can be used to distinguish healthy cardiac tissue from thermally ablated tissue. Excitation emission matrices (EEM) were acquired from excised porcine hearts (300-600nm). Distinct EEMs were collected from the endocardium of the left atria, ventricle, and aorta. Additionally, the fluorescence and reflectance profiles of each tissue were altered by thermal ablation. In the ventricular muscle, a reduction in the NADH fluorescence peak (360/460nm excitation/emission maxima) was most prominent. While in the aorta, collagen and elastin fluorescence peaks fused and broadened upon ablation. Changes in atrial tissue included a drop in NADH fluorescence and an overall increase in reflectance. The latter is likely caused by thermal coagulation of heme-containing proteins such as myoglobin and a weaker absorption within the Soret band. We concluded that optical signals revealed by EEMs offer quantitative information that can be used to develop diagnostic catheters, including hyperspectral imaging protocols to discern spectral changes elicited by RFA treatment.

scholarly journals Use of Excitation Emission Matrices to Reveal Spectral Changes Caused by Radiofrequency Ablation of Cardiac Tissue

2016 ◽  
Vol 110 (3) ◽  
pp. 494a
Author(s):  
Mohammed Aljishi ◽  
Huda Asfour ◽  
Luther Swift ◽  
Narine Muselimyan ◽  
Tigran Chahbazian ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Cardiac Tissue ◽  
Spectral Changes ◽  
Excitation Emission Matrices

scholarly journals Optical signatures of radiofrequency ablation in biological tissues

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pranav Lanka ◽  
Kalloor Joseph Francis ◽  
Hindrik Kruit ◽  
Andrea Farina ◽  
Rinaldo Cubeddu ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Treatment Time ◽  
Ex Vivo ◽  
Biological Tissues ◽  
Tissue Response ◽  
Optical Monitoring ◽  
Diffuse Optical Spectroscopy ◽  
Spectral Changes ◽  
Scattering Spectra ◽  
Optical Behavior

AbstractAccurate monitoring of treatment is crucial in minimally-invasive radiofrequency ablation in oncology and cardiovascular disease. We investigated alterations in optical properties of ex-vivo bovine tissues of the liver, heart, muscle, and brain, undergoing the treatment. Time-domain diffuse optical spectroscopy was used, which enabled us to disentangle and quantify absorption and reduced scattering spectra. In addition to the well-known global (1) decrease in absorption, and (2) increase in reduced scattering, we uncovered new features based on sensitive detection of spectral changes. These absorption spectrum features are: (3) emergence of a peak around 840 nm, (4) redshift of the 760 nm deoxyhemoglobin peak, and (5) blueshift of the 970 nm water peak. Treatment temperatures above 100 °C led to (6) increased absorption at shorter wavelengths, and (7) further decrease in reduced scattering. This optical behavior provides new insights into tissue response to thermal treatment and sets the stage for optical monitoring of radiofrequency ablation.

Treatment of Arrhythmias by Radiofrequency Ablation

2013 ◽  
Author(s):  
M. Erol Ulucakli ◽  
Evan P. Sheehan
Keyword(s):  
Radiofrequency Ablation ◽  
Cardiac Tissue ◽  
Clinical Applications ◽  
Bioheat Transfer ◽  
Temperature Profiles ◽  
Cellular Injury ◽  
Rf Ablation ◽  
Transcatheter Therapy ◽  
Wide Range ◽  
Primary Modality

Radiofrequency ablation may be described as a thermal strategy to destroy tissue by increasing its temperature and causing irreversible cellular injury. Radiofrequency ablation is a relatively new modality which has found use in a wide range of medical applications and gained acceptance. RF ablation has been used to destroy tumors in the liver, prostate, breasts, lungs, kidneys, bones, and eyes. One of the early clinical applications was its use in treating supraventricular arrhythmias by selectively destroying cardiac tissue. Radiofrequency ablation has become established as the primary modality of transcatheter therapy for the treatment of symptomatic arrhythmias. Radiofrequency catheter ablation of cardiac arrhythmias was investigated using a finite-element based solution of the bioheat transfer equation. Spatial and temporal temperature profiles in the cardiac tissue were visualized.

scholarly journals Radiofrequency Ablation for Treatment of Symptomatic Uterine Fibroids

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Siân Jones ◽  
Peter O'Donovan ◽  
David Toub
Keyword(s):  
Radiofrequency Ablation ◽  
Thermal Energy ◽  
Thermal Ablation ◽  
Mechanical Energy ◽  
Symptomatic Relief ◽  
Uterine Fibroids ◽  
Ultrasound Waves ◽  
Associated Symptoms ◽  
Fibroid Volume

The use of thermal energy-based systems to treat uterine fibroids has resulted in a plethora of devices that are less invasive and potentially as effective in reducing symptoms as traditional options such as myomectomy. Most thermal ablation devices involve hyperthermia (heating of tissue), which entails the conversion of an external electromagnetic or ultrasound waves into intracellular mechanical energy, generating heat. What has emerged from two decades of peer-reviewed research is the concept that hyperthermic fibroid ablation, regardless of the thermal energy source, can create large areas of necrosis within fibroids resulting in reductions in fibroid volume, associated symptoms and the need for reintervention. When a greater percentage of a fibroid's volume is ablated, symptomatic relief is more pronounced, quality of life increases, and it is more likely that such improvements will be durable. We review radiofrequency ablation (RFA), one modality of hyperthermic fibroid ablation.

Recent Advances in Local Thermal Ablation Therapy for Hepatocellular Carcinoma

2021 ◽  
pp. 000313482110545
Author(s):  
Min Deng ◽  
Shao-Hua Li ◽  
Rong-Ping Guo
Keyword(s):  
Hepatocellular Carcinoma ◽  
Radiofrequency Ablation ◽  
Liver Resection ◽  
Thermal Ablation ◽  
Good Choice ◽  
Local Tumor Recurrence ◽  
Ablation Therapy ◽  
First Line Therapy ◽  
Thermal Ablation Therapy ◽  
Arterial Chemoembolization

Image-guided local thermal ablation (LTA) plays an important role in the treatment of hepatocellular carcinoma (HCC), especially in patients with HCC who are not suitable for hepatectomy. Radiofrequency ablation (RFA) and microwave ablation (MWA) are the most widely used LTA clinically. Radiofrequency ablation can achieve the best result; that is, a similar therapeutic effect as hepatectomy if the tumor ≤3 cm, while MWA can effectively ablate tumors ≤5 cm. Local thermal ablation has an advantage over liver resection in terms of minimally invasive surgery and can achieve a comparable prognosis and efficacy to liver resection. For borderline liver function, selecting LTA as the first-line therapy may bring more benefits to patients with cirrhosis background. In addition, a combination of multiple therapies for HCC is a good choice, such as LTA combined with transcatheter arterial chemoembolization (TACE), which can achieve a better prognosis than single therapy for larger tumors. For patients who are awaiting liver transplantation, LTA is a good choice. The main problem of LTA needed to be solved is to prevent the local tumor recurrence after ablation in patients with HCC.

scholarly journals Percutaneous Ablation-Induced Immunomodulation in Hepatocellular Carcinoma

2020 ◽  
Vol 21 (12) ◽  
pp. 4398 ◽  
Author(s):  
Lucile Dumolard ◽  
Julien Ghelfi ◽  
Gael Roth ◽  
Thomas Decaens ◽  
Zuzana Macek Jilkova
Keyword(s):  
Hepatocellular Carcinoma ◽  
Radiofrequency Ablation ◽  
Thermal Ablation ◽  
Microwave Ablation ◽  
Treatment Options ◽  
Ablation Techniques ◽  
High Rate ◽  
Percutaneous Ablation ◽  
Ablative Therapies ◽  
Immune Changes

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related deaths worldwide and its incidence is rising. Percutaneous locoregional therapies, such as radiofrequency ablation and microwave ablation, are widely used as curative treatment options for patients with small HCC, but their effectiveness remains restricted because of the associated high rate of recurrence, occurring in about 70% of patients at five years. These thermal ablation techniques have the particularity to induce immunomodulation by destroying tumours, although this is not sufficient to raise an effective antitumour immune response. Ablative therapies combined with immunotherapies could act synergistically to enhance antitumour immunity. This review aims to understand the different immune changes triggered by radiofrequency ablation and microwave ablation as well as the interest in using immunotherapies in combination with thermal ablation techniques as a tool for complementary immunomodulation.

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