Thermal Ablation Modalities Research Articles

Comparison of pulsed field ablation versus cryoballon and radiofrequency ablation for pulmonary vein isolation in atrial fibrillation patients with heart failure

Abstract Background Pulmonary vein isolation (PVI) is the gold standard for atrial fibrillation (AF) ablation and can be achieved by a variety of technical methodes. While thermal ablation modalities (TA), such as cryoballon (CB) and radiofrequency ablation (RF) have been established as the standard approaches, PFA has been introduced as a nvel non-thermal modality showing comparable safety and procedural efficiency. Despite the high incidence of AF in heart failure (HF) patients, data comparing outcomes of HF patients undergoing PVI by either PFA or thermal ablation (RFA/CB) are limited. Purpose This study’s aim was to compare the efficacy and safety of PFA for AF ablation versus CB/RFA in HF patients. Methods Consecutive HF patients with preserved (HFpEF), mildly reduced (HFmrEF) and reduced (HFrEF) ejection fraction undergoing PVI for AF by either PFA or CB/RFA at our institution were included. The primary end-point was time to death or recurrence of AF. Secondary end-points were periprocedural complications and clinical and echocardiographic parameters. Results We included 140 HF patients who underwent PVI either by PFA (PFA group, 76 patients) or thermal ablation approaches (TA group, 64 patients). Our patients had a mean age of 69 years and were predominantly male (62%). There was no significant difference in the baseline characteristics and in the type of AF between both groups (42% with ParAF, 45% with PersAF) and 13% LSPersAF). The distribution of heart failure types was similar between both groups: HFpEF (PFA: 71%, TA: 75%), HFmrEF (PFA: 21%, TA: 20%) and HFrEF (PFA: 8 %, TA: 5%). After the 365-days follow-up period we observed no significant difference for the primary end-point between both groups (HR: 0.79, 95% CI 0.35-1.78; p=0.575). In total 58% of the PFA patients and 59% of the TA group were still free from AF. While symptom improvement was documented in both groups, patients in the PFA group showed significant improvement of left atrial volume index (p = 0.014), NT-pro BNP levels (p = 0.046), and left ventricular ejection fraction (LVEF) (p = 0.005). Conclusion In this study, PFA and thermal ablation modalities showed comparable results in terms of safety and procedural efficiency in patients with heart failure. Since previous studies have shown that HF patients with AF benefit from PVI using thermal ablation modalities, our results suggest that PFA might also be a promising ablation method in this vulnerable population, inducing left atrial reverse remodeling and thereby contributing to improvement of left ventricular systolic function.

Microwave ablation: a technical and clinical comparison to other thermal ablation modalities to treat benign and malignant thyroid nodules.

Microwave ablation (MWA) is a novel modality for thermal ablation (TA) to treat benign and malignant thyroid nodules, mostly papillary thyroid cancer (PTC). Compared to surgery, TA is less invasive and less painful, has faster recovery, better cosmetic outcomes, and fewer complications. TA techniques have been evolving over the past decade to be more energy efficient, precise, and produce long-lasting results. The general approach is similar between various TA techniques. However, each technique has uniqueness in its energy delivery and, thus, risk profile and outcomes. MWA has a few critical technical differences that make it safer for patients with surgical implants and cardiac comorbidities. It has proven effective in treating benign thyroid nodules (BTNs) in adults and pediatric populations with benign and malignant lesions. The clinical and theoretical outcomes of MWA compared to other thermal ablative techniques, such as radiofrequency ablation (RFA) and laser ablation (LA), have been investigated in some studies and meta-analyses. Minimally invasive procedures such as MWA are an important tool for the management of thyroid lesions. Thus, it is crucial for clinicians to be equipped with the knowledge to use these tools. In this review, we provide a clinical review detailing the technical differences and clinical outcomes for the three major TA techniques-MWA, RFA, and LA.

Tissue Radiologic and Pathologic Response to Biphasic Pulsed Electric Field Technology in a Porcine Model

PurposeTo evaluate the radiologic, pathologic, and safety characteristics of a commercially available pulsed electric field (PEF) ablation system in a porcine model. Materials and MethodsMonopolar biphasic PEF ablation was delivered to the liver, kidney, and longissimus dorsi muscle through a single needle via a percutaneous or open approach with the Aliya System (Galvanize Therapeutics, Redwood City, California). Six animals were ablated and evaluated in 2 cohorts (Day 3 and Day 28). Muscle, kidney, and liver were ablated in each animal. Intraprocedural cone-beam computed tomography (CT), follow-up weekly CT, blood serology, gross pathology, and histopathology were performed to characterize the radiographic evolution and tissue response. ResultsThere were no adverse events and no findings of electrocardiographic abnormalities, and serologic values returned to baseline by Day 28. Ablation zones were visible on noncontrast CT images during follow-up. Most identified zones became radiographically smaller over time, with some fully resolved by Day 28. The relative decrease in gross ablation zone volume in the liver and skeletal muscle was 20% and 26%, respectively, whereas kidney sites grew by 22%. Ablation sites were focal and contained within the intended target tissue without extension to nontarget tissues or collateral structures. ConclusionsThe biphasic PEF system evaluated here resulted in a safe and predictable ablation response, with preservation of structural tissues in an animal model, offering an alternative to thermal ablative modalities, particularly near critical structures.

Procedural and outcome impact of body mass index on pulsed field ablation of atrial fibrillation: insights from the EU-PORIA Registry

Abstract Introduction Pulsed field ablation (PFA) is a "single-shot" non thermal ablation modality for atrial fibrillation (AF). In general, obesity is associated with increased risk of AF recurrence after catheter ablation with thermal energy sources. Purpose We aimed to assess the impact of body mass index (BMI) on procedural characteristics, safety, acute efficacy and long-term outcomes of PFA for symptomatic AF. Methods Of 1233 subjects enrolled in the EU-PORIA registry, in our subanalysis we included 1055 patients undergoing de novo pulmonary vein isolation (PVI)-only ablation procedure for symptomatic AF using the pentaspline PFA catheter from March 2021 until May 2022 at seven high-volume European centers. Patients were divided into two groups based on BMI: normal weight (nW, < 25 kg/m2) and overweight (oW, ≥ 25 kg/m2). Overweight patients were further categorized into three subgroups: pre-obesity (pOb, 25-29.9 kg/m2), obesity (Ob, 30-34.9 kg/m2) and severe obesity (sOb, ≥ 35 kg/m2). Clinical and procedural characteristics, complications and follow up data were collected. Results A total of 1055 patients (39% female, mean age 65,7±10,9 years, 65% paroxysmal AF) were enrolled. 32% of patients were normal weight (nW) and 68% overweight (oW). Among oW group, 438 subjects (41%) were assigned to pOb group, 204 (19%) to Ob, and 71 (7%) to sOb. Acute PVI was achieved in 100% of cases. The median skin-to-skin procedure and the median fluoroscopy time were similar between nW and oW and in all investigational subgroups, but radiation exposure increased in line with BMI (p<0.001). Periprocedural complications were 5% in nW, 1.6% in pOb, 3.9% in Ob, and 2.8% in sOb (p=0.06). The Kaplan-Meier estimate of arrhythmia-free survival was 80.2% in nW and 71.9% in oW (p=0.017). Each unit increment in BMI was associated with 4.2% increase in risk of AF/AT recurrence. Severe obese patients presented the highest 1-year AT/AF recurrence rate (37.2%). In the sOb group the rate of recurrence was not influenced by the type of AF (PAF 65.7% vs. pers AF 59.4%; p=0.484). Conclusion Overweight patients seem to experience more AF recurrences even after PFA PVI, mainly driven by a higher recurrence rate for BMI ≥ 35 kg/m2. Weight reduction programs remain crucial, nevertheless, reduced procedural times, good safety profile and acceptable 1-year observed AF/AT freedom make PFA a feasible strategy for AF rhythm control in patients with BMI ≥ 25 kg/m2.Freedom from AF/AT recurrence

Nano-Pulse Stimulation Therapy Initiates Regulated Cell Death in Skin, Unlike Bovie Radiofrequency Ablation and Cryoablation.

This study describes a unique new bioelectric approach for clearing skin lesions and illustrates the clinical and histological differences between this new method and the standards of cryoablation and Bovie® radiofrequency ablation (RFA). To determine the advantage of stimulating regulated cell death with nanosecond pulsed electric fields over the necrosis response elicited by thermal ablation modalities. Human abdominal skin was treated with cryoablation, Bovie® RFA, and nano-pulse stimulation (NPS) therapy four times before an abdominoplasty procedure was performed to collect skin for histology. The clinical appearance and corresponding histology of each treatment were documented over time and compared. NPS therapy triggered regulated cell death as indicated by the appearance of activated Caspase-3 at 2 h post treatment and the absence of nuclear staining 1 day post treatment. Epidermal regeneration follows without impacting the noncellular dermis in contrast to cryoablation and Bovie® RFA which trigger necrosis and often cause scarring, inflammation, or permanent pigmentary changes. The main differences between NPS therapy and other ablation modalities are the level of fibrosis, amount of scarring, elastic fiber concentration, and inflammation. An analysis of the skin thickness 30 days after the treatment indicates that NPS-treated skin is the most similar to untreated skin but cryoablated and RF-ablated skin were 2- and 3.5-fold thicker, respectively, suggesting that they initiate necrosis rather than regulated cell death. We conclude that NPS therapy is a unique nonthermal modality that may be applied for clearing benign skin lesions by initiating the skin's own programmed cell death pathway instead of necrosis as used by cryoablation and Bovie® RFA.

Novel Ablation Catheters for Atrial Fibrillation.

Various ablation technologies with different energy sources are currently being either used or being investigated for atrial fibrillation (AF) ablation. Potential complications continue to occur due to the indiscriminate thermal effects on non-targeted tissues adjacent to the myocardium that are common to all thermal ablation modalities. Pulsed field ablation (PFA) has recently gained significant attention and interest as an approach to AF ablation. PFA uniquely has the ability to circumvent certain complications related to thermal energy. PFA is a non-thermal ablation modality with the potential for unique-tissue selectivity that can minimize damage to collateral cardiac structures. Several PFA systems for AF ablation are currently being investigated. Some PFA systems have been designed to serve as single-shot approaches to achieve pulmonary vein isolation (PVI), and others have focal designs enabling flexible PVI lesion sets as well as linear/focal ablations. Favorable acute success rates and low incidence of complications with short procedure times have been reported with several PFA systems regardless of catheter design (single-shot or focal catheter). Clinical PFA studies in which chronic remapping was conducted, demonstrated pulmonary vein (PV) durability improved with evolutional modifications of pulsed field waveforms/dosing, achieving over 90% PV durability with optimized waveforms. Rare adverse events related to PFA may surface with its increasing use worldwide and as sicker patients get exposed to PFA. We believe that both excitement and vigilance are in order as we embark on yet another new chapter of AF ablation.

Cost, efficiency, and outcomes of pulsed field ablation vs thermal ablation for atrial fibrillation: A real-world study

BackgroundWith the exponential growth of catheter ablation for atrial fibrillation (AF), there is increasing interest in associated health care costs. Pulsed field ablation (PFA) using a single-shot pentaspline multielectrode catheter has been shown to be safe and effective for AF ablation, but its cost efficiency compared to conventional thermal ablation modalities (cryoballoon [CB] or radiofrequency [RF]) has not been evaluated. ObjectiveThe purpose of this study was to compare cost, efficiency, effectiveness, and safety between PFA, CB, and RF for AF ablation. MethodsWe studied 707 consecutive patients (PFA: 208 [46.0%]; CB: 325 [29.4%]; RF: 174 [24.6%]) undergoing first-time AF ablation. Individual procedural costs were calculated, including equipment, laboratory use, and hospital stay, and compared between ablation modalities, as were effectiveness and safety. ResultsSkin-to-skin times and catheter laboratory times were significantly shorter with PFA (68 and 102 minutes, respectively) than with CB (91 and 122 minutes) and RF (89 and 123 minutes) (P < .001). General anesthesia use differed across modalities (PFA 100%; CB 10.2%; RF 61.5%) (P < .001). Major complications occurred in 1% of cases, with no significant differences between modalities. Shorter procedural times resulted in lower staffing and laboratory costs with PFA, but these savings were offset by substantially higher equipment costs, resulting in higher overall median costs with PFA (£10,010) than with CB (£8106) and RF (£8949) (P < .001). ConclusionIn this contemporary real-world study of the 3 major AF ablation modalities used concurrently, PFA had shorter skin-to-skin and catheter laboratory times than did CB and RF, with similarly low rates of complications. However, PFA procedures were considerably more expensive, largely because of higher equipment cost.

Pulsed Field Ablation and Neurocardiology: Inert to Efferents or Delayed Destruction?

The therapeutic use of irreversible electroporation in clinical cardiac laboratories, termed pulsed field ablation (PFA), is gaining pre-regulatory approval momentum among rhythm specialists for the mitigation of arrhythmogenic substrate without increased procedural risk. Though electroporation has been utilized in other branches of science and medicine for decades, apprehension regarding all the possible off-target complications of PFA have yet to be thoroughly identified and investigated. This brief review will summarize the preclinical and adult clinical data published to date on PFA's effects on the autonomic system that interplays closely with the cardiovascular system, termed the neurocardiovascular system. These data are contrasted with the findings of efferent destruction secondary to thermal cardiac ablation modalities, namely radiofrequency energy and liquid nitrogen-based cryoablation. In vitro neurocardiology findings, in vivo neurocardiology findings, and clinical neurocardiology findings to date nearly unanimously support the preservation of a critical mass of perineural structures and extracellular matrices to allow for long-term nervous regeneration in both cardiac and non-cardiac settings. Limited histopathologic data exist for neurocardiovascular outcomes post-PFA. Neuron damage is not only theoretically possible, but has been observed with irreversible electroporation, however regeneration is almost always concomitantly described.

Cardiac blood vessels and irreversible electroporation: findings from pulsed field ablation.

The clinical use of irreversible electroporation in invasive cardiac laboratories, termed pulsed field ablation (PFA), is gaining early enthusiasm among electrophysiologists for the management of both atrial and ventricular arrhythmogenic substrates. Though electroporation is regularly employed in other branches of science and medicine, concerns regarding the acute and permanent vascular effects of PFA remain. This comprehensive review aims to summarize the preclinical and adult clinical data published to date on PFA's effects on pulmonary veins and coronary arteries. These data will be contrasted with the incidences of iatrogenic pulmonary vein stenosis and coronary artery injury secondary to thermal cardiac ablation modalities, namely radiofrequency energy, laser energy, and liquid nitrogen-based cryoablation.

Efficacy and safety of thermal ablation modalities for the treatment of papillary thyroid microcarcinoma: Systematic Review and network meta-analysis

BackgroundThermal ablation (TA) modalities such as radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA) have been widely used in the treatment of papillary thyroid microcarcinoma (PTMC) patients. Based on previous small-sample meta-analyses, this network meta was designed to further compare the efficacy and safety of these thermal ablation methods in PTMC patients. MethodsChina National Knowledge Infrastructure (CNKI), Wanfang, PubMed, Embase, and the Cochrane Library databases were searched to retrieve relevant studies published before May 2022. The efficacy outcomes was recurrence and lymph node metastasis (LNM), the safety outcome included operation time, intra-operative blood loss, hospital stays and complications. The Newcastle-Ottawa Scale (NOS) was selected for the risk of bias assessment. Stata 14.0 was used for statistical analysis. ResultsTwenty-nine articles were included. Based on as least 6 months follow up, our analysis discovered no significant statistical differences in all efficacy and safety outcomes between MWA, RFA, and LA groups. Moreover, three TA treatments all produced significant least operation time, hospital stays, and complications than surgery group. Additionally, our study found that RFA showed relatively less complications, LNM, operation time and intra-operative blood loss, compared with other TA treatments. MWA indicated the lowest probability of recurrence, LA showed the longest hospital stays. ConclusionsMWA, RFA, and LA are all effective treatment strategies for patients with PTMC, but could not completely replace conventional surgical treatment.

Opportunities and Challenges in Catheter-Based Irreversible Electroporation for Ventricular Tachycardia.

The use of catheter-based irreversible electroporation in clinical cardiac laboratories, termed pulsed-field ablation (PFA), is gaining international momentum among cardiac electrophysiology proceduralists for the non-thermal management of both atrial and ventricular tachyrhythmogenic substrates. One area of potential application for PFA is in the mitigation of ventricular tachycardia (VT) risk in the setting of ischemia-mediated myocardial fibrosis, as evidenced by recently published clinical case reports. The efficacy of tissue electroporation has been documented in other branches of science and medicine; however, ventricular PFA's potential advantages and pitfalls are less understood. This comprehensive review will briefly summarize the pathophysiological mechanisms underlying VT and then summarize the pre-clinical and adult clinical data published to date on PFA's effectiveness in treating monomorphic VT. These data will be contrasted with the effectiveness ascribed to thermal cardiac ablation modalities to treat VT, namely radiofrequency energy and liquid nitrogen-based cryoablation.

Toward Large Ablations With Single-Needle High-Frequency Irreversible Electroporation in Vivo.

Irreversible electroporation (IRE) is a minimally thermal tissue ablation modality used to treat solid tumors adjacent to critical structures. Widespread clinical adoption of IRE has been limited due to complicated anesthetic management requirements and technical demands associated with placing multiple needle electrodes in anatomically challenging environments. High-frequency irreversible electroporation (H-FIRE) delivered using a novel single-insertion bipolar probe system could potentially overcome these limitations, but ablation volumes have remained small using this approach. While H-FIRE is minimally thermal in mode of action, high voltages or multiple pulse trains can lead to unwanted Joule heating. In this work, we improve the H-FIRE waveform design to increase the safe operating voltage using a single-insertion bipolar probe before electrical arcing occurs. By uniformly increasing interphase ( d1) and interpulse ( d2) delays, we achieved higher maximum operating voltages for all pulse lengths. Additionally, increasing pulse length led to higher operating voltages up to a certain delay length ( ∼25 μs), after which shorter pulses enabled higher voltages. We then delivered novel H-FIRE waveforms via an actively cooled single-insertion bipolar probe in swine liver in vivo to determine the upper limits to ablation volume possible using a single-needle H-FIRE device. Ablations up to 4.62 ± 0.12cm x 1.83 ± 0.05cm were generated in 5 minutes without a requirement for cardiac synchronization during treatment. Ablations were minimally thermal, easily visualized with ultrasound, and stimulated an immune response 24 hours post H-FIRE delivery. These data suggest H-FIRE can rapidly produce clinically relevant, minimally thermal ablations with a more user-friendly electrode design.

Esophageal injury, perforation, and fistula formation following atrial fibrillation ablation.

Esophageal perforation and fistula formation are rare but serious complications following atrial fibrillation ablation. In this review article, we outline the incidence, pathophysiology, predictors, and preventative strategies of this dreaded complication. We conducted an electronic search in 10 databases/electronic search engines to access relevant publications. All articles reporting complications following atrial fibrillation ablation, including esophageal injury and fistula formation, were included for systematic review. A total of 130 manuscripts were identified for the final review process. The overall incidence of esophageal injury following atrial fibrillation ablation was significantly higher with thermal ablation modalities (radiofrequency 5-40%, cryoballoon 3-25%, high-intensity focused ultrasound < 10%) as opposed to non-thermal ablation modalities (no cases reported to date). The incidence of esophageal perforation and fistula formation with the use of thermal ablation modalities is estimated to occur in less than 0.25% of all atrial fibrillation ablation procedures. The use of luminal esophageal temperature monitoring probe and mechanical esophageal deviation showed protective effect toward reducing the incidence of this complication. The prognosis is very poor for patients who develop atrioesophageal fistula, and the condition is rapidly fatal without surgical intervention. Esophageal perforation and fistula formation following atrial fibrillation ablation are rare complications with poor prognosis. Various strategies have been proposed to protect the esophagus and reduce the incidence of this fearful complication. Pulsed field ablation is a promising new ablation technology that may be the future answer toward reducing the incidence of esophageal complications.

Minimally-invasive and non-invasive methods of thermal destruction in the treatment of patients with aggressive fibromatosis

The purpose of the study was to characterize various methods of local physical destruction used in the treatment of patients with aggressive fibromatosis and demonstrate international experience of their use.Material and Methods. literature search was conducted in the electronic databases Rsci (Russian science citation index) and NcBi (National centre for Biotechnology information) in the interval time between 2002 and 2022. The review was devoted to the thermal ablation modalities (radiofrequency, microwave ablation, cryodestruction, high-intensity focused ultrasound ablations) used in therapy of patients with desmoid fibromas of various locations, as well as their safety and efficacy.Results. The review presents the current data on safety and efficacy of minimally-invasive and non-invasive methods of hypo- and hyperthermic local destruction in patients with aggressive fibromatosis, gives the characteristics of exposure and biological effects when performing radiofrequency and microwave ablation, cryodestruction, high-intensity focused ultrasound therapy, describes the main limitations of the methods, indications and contraindications for their application, as well as the methods of prevention of the development of desmoid fibromas.Conclusion. The described methods of local destruction are used in clinical practice mainly for palliative and symptomatic purposes, in case of persistent tumor growth or recurrence, ineffectiveness of other treatment options or contraindications to them due to concomitant somatic pathology or functional status of the patient. Inclusion of these methods in the treatment plan of patients with aggressive fibromatosis can contribute to the reduction of pain syndrome, improvement of functional status of patients as well as long survival with no evidence of tumor progression.

Clinical Outcomes by Sex After Pulsed Field Ablation of Atrial Fibrillation

Previous studies evaluating the association of patient sex with clinical outcomes using conventional thermal ablative modalities for atrial fibrillation (AF) such as radiofrequency or cryoablation are controversial due to mixed results. Pulsed field ablation (PFA) is a novel AF ablation energy modality that has demonstrated preferential myocardial tissue ablation with a unique safety profile. To compare sex differences in patients undergoing PFA for AF in the Multinational Survey on the Methods, Efficacy, and Safety on the Postapproval Clinical Use of Pulsed Field Ablation (MANIFEST-PF) registry. This was a retrospective cohort study of MANIFEST-PF registry data, which included consecutive patients undergoing postregulatory approval treatment with PFA to treat AF between March 2021 and May 2022 with a median follow-up of 1 year. MANIFEST-PF is a multinational, retrospectively analyzed, prospectively enrolled patient-level registry including 24 European centers. The study included all consecutive registry patients (age ≥18 years) who underwent first-ever PFA for paroxysmal or persistent AF. PFA was performed on patients with AF. All patients underwent pulmonary vein isolation and additional ablation, which was performed at the discretion of the operator. The primary effectiveness outcome was freedom from clinically documented atrial arrhythmia for 30 seconds or longer after a 3-month blanking period. The primary safety outcome was the composite of acute (<7 days postprocedure) and chronic (>7 days) major adverse events (MAEs). Of 1568 patients (mean [SD] age, 64.5 [11.5] years; 1015 male [64.7%]) with AF who underwent PFA, female patients, as compared with male patients, were older (mean [SD] age, 68 [10] years vs 62 [12] years; P < .001), had more paroxysmal AF (70.2% [388 of 553] vs 62.4% [633 of 1015]; P = .002) but had fewer comorbidities such as coronary disease (9% [38 of 553] vs 15.9% [129 of 1015]; P < .001), heart failure (10.5% [58 of 553] vs 16.6% [168 of 1015]; P = .001), and sleep apnea (4.7% [18 of 553] vs 11.7% [84 of 1015]; P < .001). Pulmonary vein isolation was performed in 99.8% of female (552 of 553) and 98.9% of male (1004 of 1015; P = .90) patients. Additional ablation was performed in 22.4% of female (124 of 553) and 23.1% of male (235 of 1015; P = .79) patients. The 1-year Kaplan-Meier estimate for freedom from atrial arrhythmia was similar in male and female patients (79.0%; 95% CI, 76.3%-81.5% vs 76.3%; 95% CI, 72.5%-79.8%; P = .28). There was also no significant difference in acute major AEs between groups (male, 1.5% [16 of 1015] vs female, 2.5% [14 of 553]; P = .19). Results of this cohort study suggest that after PFA for AF, there were no significant sex differences in clinical effectiveness or safety events.

Thermal ablation of metastatic disease to the musculoskeletal system

A variety of indications have been published regarding the use of percutaneous thermal ablation for treating tumors of the musculoskeletal system, including bone and soft tissue lesions, benign and malignant lesions, and primary and metastatic tumors. In the appropriately selected patient, the advantages of percutaneous thermal ablation include decreased morbidity, decreased cost, and shorter hospitalization stays compared to surgery. The number of different thermal ablation modalities is increasing, and each modality has its advantages and disadvantages. Studies directly comparing the effectiveness of the various thermal ablation modalities are sparse, however, so the choice of ablation modality often depends on availability, user preference, and local expertise. Although the list of uses for percutaneous thermal ablation is ever-expanding, in this article, we will discuss the two most well-established indications, which are palliation of pain attributed to bone and soft tissue metastases and local control of oligometastatic disease. Numerous clinical trials have shown percutaneous thermal ablation to be an effective method of palliating pain due to bone and soft tissue metastases and of achieving local control in the setting of oligometastatic disease with low rates of complication.

PO-04-042 GENDER DIFFERENCES IN CLINICAL OUTCOMES AFTER PULSED FIELD ABLATION OF ATRIAL FIBRILLATION: INTERIM ANALYSIS OF THE MANIFEST-PF EFFICACY REGISTRY

Prior studies have shown that atrial fibrillation (AF) ablation with conventional thermal ablative modalities, radiofrequency (RF) or cryo, is associated with a higher risk of complications in women compared with men, and a lower success rate of freedom from AF recurrences. Pulsed-field ablation (PFA) is a novel AF ablation energy modality which, in first-in-human clinical trials, has demonstrated preferential myocardial tissue ablation with a unique safety profile. We performed an interim analysis of the MANIFEST-PF registry to explore gender differences in real-world outcomes after PFA of AF. MANIFEST-PF is a retrospective patient-level registry from the first 23 European centers performing clinical PFA procedures, including all consecutive patients who received first-ever ablation for paroxysmal or persistent AF between March to December 2021 using the pentaspline PFA catheter (Farawave, Farapulse-Boston Scientific Inc). We compared baseline and procedural characteristics, and clinical outcomes between men and women. The efficacy endpoint was freedom from atrial arrhythmia (AF/atrial flutter/atrial tachycardia) recurrence ≥30 seconds after a 3 month-blanking period. Safety endpoints included major/minor adverse events (AEs <7 days post-procedure). Binary logistic regression model was created using -- Age, CAD, CHF, Sleep apnea, LVEF, LAD, Non-parox AF, Female, diabetes, HTN and stroke/TIA. Of the 1,332 AF pts who underwent an AF ablation, 454 (34%) were female. Woman, compared to men, were older (67±10 vs 62±11 yrs) and had more paroxysmal AF (72% vs 61%), but less comorbidities such as coronary disease, heart failure and sleep apnea. (Figure A) Following ablation, there was no significant difference in major (2.6% vs 1.1%, p=0.14) or minor (3.3% vs 4.4%, p=0.18) AEs between groups. Multivariable analysis showed that women (Odds ratio 4.1, 95% CI [1.21–13.78], p=0.02) were more likely to have a higher risk of acute major AEs. After a mean follow-up of 196 days, there was no difference in recurrence of atrial arrhythmia (14.5% vs 18%, p=0.14) or redo-ablations (5.1% vs. 7.7%, p=0.07) between women and men, respectively, even after adjusting for the type of AF (ie, PAF vs PerAF). (Figure B) As compared with men, women undergoing PFA to treat AF experience more acute major procedural complications, though the overall rate of complications was low with PFA. On the other hand, women have a similar success rate of freedom from recurrent atrial arrhythmias.

Ablation of pulmonary neoplasms: review of literature and future perspectives.

Thermal ablation is a minimally invasive technology used to treat many types of tumors, including lung cancer. Specifically, lung ablation has been increasingly performed for unsurgical fit patients with both early-stage primi-tive lung cancer and pulmonary metastases. Image-guided available techniques include radiofrequency ablation, microwave ablation, cryoablation, laser ablation and irreversible electroporation. Aim of this review is to illustrate the major thermal ablation modalities, their indications and contraindications, complications, outcomes and notably the possible future challenges.

Non-surgical Treatment of Metastatic Liver Tumors with Microwave Ablation.

With all the measures taken, the trend of liver cancer cases has increased worldwide, as a consequence, this is accompanied by an increase in mortality by 43% (10.3 per 100,000 in 2016 (USA)) [1, 2].&#x0D; Liver cancer is also associated with the lowest 5-year survival rate among all types of cancer (19%) [1].&#x0D; Liver cancer (including intrahepatic bile duct cancer) was the ninth leading cause of cancer death in 2000 and rose to sixth in 2016 [3].&#x0D; This shows that the identification of safe and effective treatments for liver cancer is urgent now.&#x0D; Microwave ablation is a thermal ablation modality that has particular applicability in treating hepatic malignancies primary tumors or metastases. Microwaves can generate very high temperatures in short time periods, potentially leading to improved treatment efficiency in larger ablation zones.&#x0D; We will show a patient male 55 years old. Post-surgery of colon cancer 6 months ago. Normal exam. There is e liver metastasis in the right lobe subcapsular 22mm. The patient was a good candidate for MWA.&#x0D; Conclusions&#x0D; MWA is an effective and safe alternative in patients/tumors that are not suitable for resection. Survival and recurrence outcomes after MWA are significantly improved with significantly shorter hospital stays and operative times, with little or no intraoperative blood loss and minor complications. Its use should be extended more and more in the field of treatment of these patients depending on the therapeutic indications

PO-624-01 FIRST-IN-HUMAN CLINICAL EXPERIENCE OF A “SINGLE-SHOT” MAP-AND-ABLATE MULTIELECTRODE SPHERICAL ARRAY PULSED FIELD ABLATION CATHETER TO ISOLATE PULMONARY VEINS

Pulsed field ablation (PFA) has safety and procedural workflow advantages over conventional thermal ablation modalities. Most “single-shot” PFA catheter technologies are either not linked to electroanatomical mapping systems, require serial re-positioning or cannot easily accommodate varying pulmonary vein (PV) anatomical sizes / shapes. Recently, a multielectrode spherical array catheter (Globe, Kardium Inc, Canada) capable of single-shot “mapping and ablation”, previously capable of radiofrequency (RF) ablation, has now been enhanced to also deliver PFA.