Interventional Radiofrequency Research Articles

Catheter ablation of ventricular tachycardia in patients with structural heart disease

Ventricular cardiac rhythm disorders are potentially life-threatening arrhythmias. Ventricular tachycardia (VT) in patients with structural heart disease carries an increased risk of sudden cardiac death. Interventional radiofrequency catheter ablation is increasingly becoming the focus of treatment for ventricular arrhythmias. So far, no randomized study has been able to demonstrate areduction in mortality; however, depending on the existing cardiomyopathy, interventional VT ablation has proven to be more effective for rhythm stabilization than antiarrhythmic therapy and is subsequently associated with improve quality of life through reduced implantable cardioverter defibrillator (ICD) treatment. The aim of this work is to discuss the pathophysiology, mechanism and treatment of VT with structural heart disease in order to define the role of catheter ablation.

Retrospective Study of the Analgesic Effect of Sacroiliac Joint Radiofrequency Denervation

Interventional radiofrequency (RF) ablation techniques are indicated when an adequate effect is not obtained with conservative measures. The primary objective of this study was to evaluate pain relief after RF denervation of the sacroiliac joint. The secondary objective was to evaluate pain intensity and relief duration. The study was retrospective. The study was conducted at Vera Cruz Hospital, Campinas, Brazil. Data were collected from the medical records of patients undergoing RF denervation for low back pain originating in the sacroiliac joint, from January 2015 to December 2017. There were 78 patients studied, between 18 and 65 years old, of both genders, ASA I or II, who underwent knee arthroscopic meniscectomy. The patients were submitted to denervation of sacroiliac joint by 3 types of RF (conventional, pulsed, and cooled). The following parameters were evaluated, number of patients who obtained ? 50% pain relief; pain intensity, measured using the visual analog scale (before the procedure and 15, 30, 90 and 180 days after, performed by the same evaluator); and the use of complementary analgesic for 2 weeks. Of the 78 included patients, 56 (71.8%) underwent conventional RF, 9 (11.5%) underwent pulsed RF, and 13 (16.7%) underwent cooled RF. There were losses to follow-up including 40 patients who underwent conventional RF, 5 who underwent pulsed RF, and 12 who underwent cooled RF, who were retained for 6 months. There was significant pain relief with the three types of RF for up to 6 months of follow-up, with no difference among the types. After 6 months, 90.2% of patients who underwent conventional RF, 100% who underwent pulsed RF, and 91.7% who underwent cooled RF maintained ≥ 50% pain relief. Complementary analgesics were used by 95% of the patients who underwent conventional RF, 80% who underwent pulsed RF, and 91% who underwent cooled RF 2 weeks after the procedure. There were mild adverse effects, such as edema, hematoma, and local pain, without complications. As for limitations, the number of pulsed and cooled RF is low and in a retrospective study some data may be missing, especially from follow-up. RF denervation of the sacroiliac joint is effective and promotes a long-lasting analgesic effect.

Interventional Radiofrequency Treatment for the Sympathetic Nervous System: A Review Article.

IntroductionInterventional techniques such as radiofrequency (RF) treatment can be used to interrupt pain signals transmitted through the sympathetic nervous system (SNS). RF treatments including the pulsed (PRF) and continuous (CRF) modalities show enhanced control over lesion size and enhanced ability to confirm accurate positioning compared to other interventional methods. PRF also acts to reduce the area of the lesion. In this article, we characterize the currently available evidence supporting the use and efficacy of RF treatments in sympathetically mediated pain (SMP) conditions.Study DesignA comprehensive literature review.MethodsA PubMed and Cochrane Library database search was performed for human studies applying RF treatment at sympathetic sites (sphenopalatine ganglion, stellate ganglion, cervical, thoracic, or lumbar sympathetic ganglia, celiac plexus, splanchnic nerves, superior hypogastric plexus, and ganglion impar) between January 1970 to May 2020. Data were extracted, summarized into tables, and qualitatively analyzed.ResultsPRF and CRF both show promise in relieving SMP conditions, such as complex regional pain syndrome (CRPS), pain in the perineal region, headache and facial pain, and oncologic and non-oncologic abdominal pain, in addition to other types of pain, with minimal complications. Furthermore, in most comparative studies, outcomes using RF treatments exceeded other interventional techniques, such as anesthetic block and chemical neurolysis.ConclusionsRF treatments can be effective in carefully selected patients who are refractory to conservative management. However, further randomized controlled studies are needed prior to implementing it into common practice.

Pulsed radiofrequency ablation of the posterior spinal root ganglia (PRF DRG) for the treatment of chronic lumbar radicular pain

Radicular lumbar pain constitutes a significant proportion of the total number of pain syndromes. Conservative treatment of this pathology is effective in 60 % of patients. In other cases, the pain may become chronic, leading to disability. These facts have been a stimulus for the development of minimally-invasive procedures which are sufficiently effective and have a low risk of potential complications. The most common of these is interventional radiofrequency treatment.The purpose of this study is to investigate the dynamics of pain and social adaptation in patients suffering from chronic lumbar radicular pain, who have been treated with pulsed radiofrequency ablation of the posterior spinal root ganglia (pulsed radiofrequency of dorsal root ganglion, PRF DRG).Materials and methods. A retrospective study included 42 patients aged from 27 to 78 years (49.7 ± 14.8) who were treated in 2016–2017 at the Neuromed Clinic in Kyiv and the Institute of Traumatology and Orthopedics of NAMS of Ukraine. The study included patients suffering from reactive lumbosacral radicular pain due to degenerative-dystrophic lesions of the spine. Pain syndrome was assessed on a visual analogue scale (VAS) before manipulation, immediately after it, and six months afterwards. Social adaptation in everyday life was objectified using the Oswestry Low Back Pain Disability Questionnaire.Results. No complications were registered. Absolutely all patients confirmed a decrease in pain. Before the manipulation, most of the patients described their pain as “very strong” (VAS 7.14 ± 0.68), whilst after the procedure the majority answered that their pain decreased to “average” (VAS 4.02 ± 0.81). A similar trend persisted for six months after treatment (VAS 1.85 ± 0.78). Before manipulation, the index of impairment due to pain (ODI) was 71.42 ± 6.83. Six months after the procedure, the ODI index was 18.57 ± 7.83.Conclusion. Pulsed radiofrequency of the dorsal spinal ganglia (PRF DRG) is a safe and effective procedure for the treatment of chronic lumbar radicular pain.

Interventional radiofrequency ablation: A promising therapeutic modality in the management of malignant biliary and pancreatic duct obstruction.

Background: Malignant biliary and/or pancreatic obstruction has often encountered in the advanced stages of periampullary and cholangicarcinomas. HabibTM Radiofrequency (RF) ablation has been successfully used in the management of various cancers of liver and pancreas. Percutaneous HPB probe (EMcision Ltd, London, UK) is a new addition to this class of tools. It is an endoluminal Radiofrequency (RF) catheter which works on the principle of ablation and induces coagulative necrosis to recanalize the obstructed duct. The aim of this study is to address the technical details of canalization, feasibilities and outcomes of percutaneous endo-luminal Radiofrequency (RF) catheter in patients with unresectable malignancy with obstructed bile and pancreatic duct (PD).Material and Method: A total of 134 patients with inoperable malignant obstruction of biliary and PD underwent RF based percutaneous endoluminal RF ablation in a tertiary referral centre between December 15th, 2010 to August 7th, 2015. This device was used in a sequential manner with an intent to recanalize the obstructed. Following the initial catheter drainage of the duct, subsequent percutaneous endobiliary RF ablation, the metallic stent was placed to recanalize the obstructed bile and PD secondary to unresectable malignancy under real-time fluoroscopic guidance.Results: The percutaneous RF based ablation of obstructed bile duct and PD with metallic stent placement was successfully achieved in 130 (97.01%) cases. The three failures were noted in cases of biliary obstruction whilst, one with PD obstruction. The patency restored in 124 and patients, where the procedure was successfully completed and revealed clinical improvement reported.Conclusion: The percutaneous endoluminal RF based ablation of obstructed duct with metallic stent placement appeared to be a safe, effective procedure and may improve survival in patients with advanced stage cancer presenting with biliary and PD obstruction. Considering the above mentioned evidence, this modality may stand ahead of stenting alone. This could be considered as viable modality in management of such patients where very limited treatment options are available.

Orthotopic hepatic cancer: radiofrequency hyperthermia-enhanced intratumoral herpes simplex virus-thymidine kinase gene therapy.

PurposeTo validate the feasibility of using interventional radiofrequency hyperthermia(RFH) to enhance herpes simplex virus-thymidine kinase (HSV-TK)/ganciclovir (GCV) gene therapy of rat orthotopic hepatic cancer.Material and MethodsRat hepatocellular carcinoma cells (MCA-RH-7777) were transduced with lentivirus/luciferase gene for optical imaging. In-vitro experiments with the luciferase cells and in-vivo experiments on rats with orthotopic hepatic tumors were divided into four treatment groups: (i) HSV-TK/GCV-mediated gene therapy combined with RFH; (ii) gene therapy alone; (iii) RFH alone; and (iv) phosphate buffered saline (PBS). Cell viability was evaluated by MTS assay and confocal microscopy, and HSV-TK gene expression in cells and tumors was quantified by western blotting. Bioluminescent optical imaging and ultrasound imaging were used to monitor and compare the photon signal and tumor size changes among different treatment groups overtime, respectively. The imaging findings were correlated with histology.ResultsFor in-vitro experiments, the combination therapy group (gene therapy + RFH) demonstrated the lowest cell proliferation by MTS assay, compared to the gene therapy alone, RFH alone, and PBS (26.1±3.2% vs 50.4±4.6% vs 82.9±6.3% vs 100%, p<0.01). The combination therapy group also showed fewer survived cells by the confocal microscopy and the lowest bioluminescent signal by the optical imaging. For in-vivo experiments, the combination therapy group demonstrated a significantly decreased signal intensity on the bioluminescent optical imaging (0.57±0.09, 1.06±0.10 vs 3.43±0.27 vs 3.85±0.12, p<0.05) and smallest tumor volume by ultrasound imaging (0.28±0.11 vs 1.28±0.23vs 4.64±0.35 vs 6.37±0.36, p<0.05), compared to the other three groups. Additionally, these imaging findings correlated well with the histological confirmation.ConclusionIt is feasible to use RFH to enhance HSV-TK/GCV gene therapy of hepatic tumors in in-vitro and in-vivo settings, as assessed by molecular imaging. This technical development may provide a novel opportunity for effective treatment of liver malignancies by employing simultaneous integration of radiofrequency technology, interventional oncology, and direct intratumoral gene therapy.

Interventional radiofrequency (RF) ablation as a therapeutic modality for patients with unresectable malignant pancreato-biliary and portal vein thrombus obstruction due to locally advanced malignancies

Interventional radiofrequency (RF) ablation as a therapeutic modality for patients with unresectable malignant pancreato-biliary and portal vein thrombus obstruction due to locally advanced malignancies

English

Valvar pulmonary atresia is a rare congenital anomaly usually associated with ventricular septal defects or intact ventricular septum. The patent ductus arteriosus (56%) and systemic pulmonary collaterals maintain pulmonary blood flow. Presentation beyond childhood is unusual, as there is usually high morbidity in the first year of life. The two index cases highlight the rarity of adolescents with valvar pulmonary atresia and focusses on the transthoracic echocardiographic features, whose diagnoses provide definitive and curative options with adequate size pulmonary dimensions. Options available are transcatheter interventional radiofrequency pulmonary valvotomy, which is both diagnostic and therapeutic, and intraoperative valve replacement, thus eliminating the need for right ventricle pulmonary artery external valved conduit during corrective surgery. They are the first cases of adolescents with isolated cardiac anomaly of valvar pulmonary atresia, documented in Afro-Caribbeans.

Design and initial evaluation of a low‐cost 3‐Tesla research system for combined optical and functional MR imaging with interventional capability

A 3-Tesla research system has been developed for functional and interventional magnetic resonance imaging (MRI) procedures on animal models based on a low field niche spectrometer. Use of two stages of fourth harmonic frequency multiplication has allowed us to produce a high-frequency spectrometer with good frequency stability based on a low-frequency direct digital synthesizer. The system has been designed with the ability to introduce interventional tools such as biopsy needles, radiofrequency (RF) electrodes, and fiber optics for optical spectroscopy and thermal ablation as well as drug infusions to allow function to be studied in the presence of external challenges. Full MR-compatible physiologic support capability allows animals to be maintained in a stable condition over extended periods of study. Functional MR images have been acquired by using gradient echoes (TR/TE = 40/12 msec) from the rat whisker barrel cortex using electrical stimulation (5-V, 1.5-mA, 1-msec pulses at 5 Hz via two needle electrodes inserted into the rat whisker pad). Initial results using respiratory gas challenges of 100% N2, 100% O2, and 10% CO2 have shown excellent agreement between single wavelength (633 nm) optical and functional MR time series with subsecond time resolution. The 1-mm copper electrodes for interventional radiofrequency ablation procedures were easily visualized in the superior colliculus by using gradient echo sequences. This novel, low-cost, high field system appears to be a useful research tool for functional and interventional studies of rat brain and allows concurrent optical spectroscopy. J. Magn. Reson. Imaging 2001;13:87–92. © 2001 Wiley-Liss, Inc.

Design and initial evaluation of a low-cost 3-Tesla research system for combined optical and functional MR imaging with interventional capability.

A 3-Tesla research system has been developed for functional and interventional magnetic resonance imaging (MRI) procedures on animal models based on a low field niche spectrometer. Use of two stages of fourth harmonic frequency multiplication has allowed us to produce a high-frequency spectrometer with good frequency stability based on a low-frequency direct digital synthesizer. The system has been designed with the ability to introduce interventional tools such as biopsy needles, radiofrequency (RF) electrodes, and fiber optics for optical spectroscopy and thermal ablation as well as drug infusions to allow function to be studied in the presence of external challenges. Full MR-compatible physiologic support capability allows animals to be maintained in a stable condition over extended periods of study. Functional MR images have been acquired by using gradient echoes (TR/TE = 40/12 msec) from the rat whisker barrel cortex using electrical stimulation (5-V, 1.5-mA, 1-msec pulses at 5 Hz via two needle electrodes inserted into the rat whisker pad). Initial results using respiratory gas challenges of 100% N(2), 100% O(2), and 10% CO(2) have shown excellent agreement between single wavelength (633 nm) optical and functional MR time series with subsecond time resolution. The 1-mm copper electrodes for interventional radiofrequency ablation procedures were easily visualized in the superior colliculus by using gradient echo sequences. This novel, low-cost, high field system appears to be a useful research tool for functional and interventional studies of rat brain and allows concurrent optical spectroscopy. J. Magn. Reson. Imaging 2001;13:87-92.