Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 162
Filtrar
1.
Diagnostics (Basel) ; 14(9)2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38732326

RESUMO

Circulating tumor DNA (ctDNA) holds promise as a biomarker for predicting clinical responses to therapy in solid tumors, and multiple ctDNA assays are in development. However, the heterogeneity in ctDNA levels prior to treatment (baseline) across different cancer types and stages and across ctDNA assays has not been widely studied. Friends of Cancer Research formed a collaboration across multiple commercial ctDNA assay developers to assess baseline ctDNA levels across five cancer types in early- and late-stage disease. This retrospective study included eight commercial ctDNA assay developers providing summary-level de-identified data for patients with non-small cell lung cancer (NSCLC), bladder, breast, prostate, and head and neck squamous cell carcinoma following a common analysis protocol. Baseline ctDNA levels across late-stage cancer types were similarly detected, highlighting the potential use of ctDNA as a biomarker in these cancer types. Variability was observed in ctDNA levels across assays in early-stage NSCLC, indicative of the contribution of assay analytical performance and methodology on variability. We identified key data elements, including assay characteristics and clinicopathological metadata, that need to be standardized for future meta-analyses across multiple assays. This work facilitates evidence generation opportunities to support the use of ctDNA as a biomarker for clinical response.

2.
J Pharm Sci ; 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38777176

RESUMO

The formulation of paediatric medicines faces significant challenges to meet the requirements for safe and accurate administration, while maintaining a suitable taste. Multiparticulate formulations have a strong potential to address these challenges because they combine dose flexibility with ease of administration. Understanding the stability of multiparticulate formulations over storage as a function of time and environmental parameters, such as humidity and temperature, is important to manage their commercialisation and use. In this work, we have expanded the toolkit of available techniques for studying multiparticulates beyond those such as scanning electron microscopy (SEM) and confocal laser scanning microscopy. We include advanced methods of environmentally-controlled SEM to monitor temperature- and humidity-induced changes in-situ, and a variety of Raman spectroscopies including stimulated Raman scattering microscopy to identify and localise the different ingredients at the surface and inside the multiparticulates. These techniques allowed unprecedented monitoring of specific changes to the particulate structure and distribution of individual ingredients due to product aging. These methods should be considered as valuable novel tools for in-depth characterisation of multiparticulate formulations to further understand chemical changes occurring during their development, manufacturing and long-term storage. We envisage these techniques to be useful in furthering the development of future medicine formulations.

3.
Cytotherapy ; 2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38583170

RESUMO

BACKGROUND: Significant advancements have been made in the field of cellular therapy as anti-cancer treatments, with the approval of chimeric antigen receptor (CAR)-T cell therapies and the development of other genetically engineered cellular therapies. CAR-T cell therapies have demonstrated remarkable clinical outcomes in various hematological malignancies, establishing their potential to change the current cancer treatment paradigm. Due to the increasing importance of genetically engineered cellular therapies in the oncology treatment landscape, implementing strategies to expedite development and evidence generation for the next generation of cellular therapy products can have a positive impact on patients. METHODS: We outline a risk-based methodology and assessment aid for the data extrapolation approach across related genetically engineered cellular therapy products. This systematic data extrapolation approach has applicability beyond CAR-T cells and can influence clinical development strategies for a variety of immune therapies such as T cell receptor (TCR) or genetically engineered and other cell-based therapies (e.g., tumor infiltrating lymphocytes, natural killer cells and macrophages). RESULTS: By analyzing commonalities in manufacturing processes, clinical trial designs, and regulatory considerations, key learnings were identified. These insights support optimization of the development and regulatory approval of novel cellular therapies. CONCLUSIONS: The field of cellular therapy holds immense promise in safely and effectively treating cancer. The ability to extrapolate data across related products presents opportunities to streamline the development process and accelerate the delivery of novel therapies to patients.

4.
Clin Cancer Res ; 30(5): 937-941, 2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38085161

RESUMO

The FDA's Oncology Center of Excellence's (OCE) launch of Project Optimus signals increased focus on dose optimization approaches in oncology drug development, particularly toward optimization in the premarket setting. Although sponsors continue to adapt premarket study designs and approaches to align with FDA's expectations for dose optimization, including consideration of the optimal dosage(s), there are still instances where questions remain at the time of approval about whether the approved doses or schedules are optimal. In these cases, FDA can exercise regulatory flexibility by issuing postmarketing requirements (PMR) and avoid delaying patient access to promising therapies. This landscape analysis demonstrates that over the past decade (2012-2022), FDA frequently used PMRs to answer additional questions about dosing for novel oncology approvals. We found more than half of drugs (78/132, 59.1%) had a dosing PMR and observed a recent increase in PMRs intended to evaluate whether a lower dose could be more optimal. These results suggest there are opportunities to adapt premarket dose optimization strategies and leverage innovative development tools to ensure timely identification of the optimal dose.


Assuntos
Desenvolvimento de Medicamentos , Exercício Físico , Estados Unidos , Humanos , United States Food and Drug Administration , Oncologia , Projetos de Pesquisa
5.
PLoS One ; 18(10): e0292395, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37788286

RESUMO

To ensure uncertainty in match outcomes, professional sporting leagues have used various competitive balance policies, including player salary caps, revenue sharing among teams and player drafts. The Australian Football League (AFL) introduced a player draft in 1986, and to refine its operation, a draft value index (DVI) was introduced in 2015. The DVI allocates a numeric value to each individual player draft pick, with these values determined by the AFL using historic player compensation or wage and salary data. The AFL DVI plays an essential role in the operation of its player draft; however, other research has questioned the validity of such indexes. This paper aims to produce an alternative to the AFL DVI. The former index uses career compensation as the determinant of value, whereas we use other measures of player performance. First, various models were developed to predict on-field performance, such as games played (both in a recruit's career and season) after a draftee was selected for the first time by a team. This was then retrofitted to the pick used to select these draftees to create the new DVIs. Even though the predicted DVI followed an inverse monotonic function like the existing index, the decline in value for the DVI produced here was less steep, unlike the AFL's. This allowed us to conclude that players' salaries did not always strongly correlate to performance. The change in performance between players selected at different points in the draft did not vary as much as their wages. Though this scheme is applied to the AFL, the underlying concept could be directly exported to other player drafts.


Assuntos
Desempenho Atlético , Austrália , Coleta de Dados , Esportes de Equipe
6.
JCO Oncol Pract ; 19(10): 907-916, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37643386

RESUMO

PURPOSE: The onset of the COVID-19 pandemic created major disruptions in the conduct of cancer clinical trials. In response, regulators and sponsors allowed modifications to traditional trial processes to enable clinical research and care to continue. We systematically evaluated how these mitigation strategies affected data quality and overall trial conduct. METHODS: This study used surveys and live interviews. Forty-one major industry and National Cancer Institute Network groups (sponsors) overseeing anticancer treatment trials open in the United States from January 2015 to May 2022 were invited to participate. Descriptive statistics were used for survey data summaries. Key themes from interviews were identified. RESULTS: Twenty sponsors (48.8%; 15 industry and five Network groups) completed the survey; 11/20 (55.0%) participated in interviews. Sponsors predominantly (n = 12; 60.0%) reported large (≥11 trials) portfolios of phase II and/or phase III trials. The proportion of sponsors reporting a moderate (9) or substantial (8) increase in protocol deviations in the initial pandemic wave versus the pre-pandemic period was 89.5% (17/19); the proportion reporting a substantial increased dropped from 42.1% (n = 8/19) in the initial wave to 15.8% (n = 3/19) thereafter. The most commonly adopted mitigation strategies were remote distribution of oral anticancer therapies (70.0%), remote adverse event monitoring (65.0%), and remote consenting (65.0%). Most respondents (15/18; 83.3%) reported that the pandemic had minimal (n = 14) or no impact (n = 1) on overall data integrity. CONCLUSION: Despite nearly all sponsors observing a temporary increase in protocol deviations, most reported the pandemic had minimal/no impact on overall data integrity. The COVID-19 pandemic accelerated an emerging trend toward greater flexibility in trial conduct, with potential benefits of reduced burden on trial participants and sites and improved patient access to research.


Assuntos
COVID-19 , Neoplasias , Humanos , COVID-19/epidemiologia , Confiabilidade dos Dados , Neoplasias/epidemiologia , Neoplasias/terapia , Pandemias , Inquéritos e Questionários , Estados Unidos/epidemiologia , Protocolos de Ensaio Clínico como Assunto
7.
Front Cardiovasc Med ; 10: 1160231, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37424913

RESUMO

Introduction: Pulsed field ablation is an emerging modality for catheter-based cardiac ablation. The main mechanism of action is irreversible electroporation (IRE), a threshold-based phenomenon in which cells die after exposure to intense pulsed electric fields. Lethal electric field threshold for IRE is a tissue property that determines treatment feasibility and enables the development of new devices and therapeutic applications, but it is greatly dependent on the number of pulses and their duration. Methods: In the study, lesions were generated by applying IRE in porcine and human left ventricles using a pair of parallel needle electrodes at different voltages (500-1500 V) and two different pulse waveforms: a proprietary biphasic waveform (Medtronic) and monophasic 48 × 100 µs pulses. The lethal electric field threshold, anisotropy ratio, and conductivity increase by electroporation were determined by numerical modeling, comparing the model outputs with segmented lesion images. Results: The median threshold was 535 V/cm in porcine ((N = 51 lesions in n = 6 hearts) and 416 V/cm in the human donor hearts ((N = 21 lesions in n = 3 hearts) for the biphasic waveform. The median threshold value was 368 V/cm in porcine hearts ((N = 35 lesions in n = 9 hearts) cm for 48 × 100 µs pulses. Discussion: The values obtained are compared with an extensive literature review of published lethal electric field thresholds in other tissues and were found to be lower than most other tissues, except for skeletal muscle. These findings, albeit preliminary, from a limited number of hearts suggest that treatments in humans with parameters optimized in pigs should result in equal or greater lesions.

9.
J Immunother Cancer ; 11(5)2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37137552

RESUMO

With multiple PD-(L)1 inhibitors approved across dozens of indications by the US Food and Drug Administration, the number of patients exposed to these agents in adjuvant, first-line metastatic, second-line metastatic, and refractory treatment settings is increasing rapidly. Although some patients will experience durable benefit, many have either no clinical response or see their disease progress following an initial response to therapy. There is a significant need to identify therapeutic approaches to overcome resistance and confer clinical benefits for these patients. PD-1 pathway blockade has the longest history of use in melanoma, non-small cell lung cancer (NSCLC), and renal cell carcinoma (RCC). Therefore, these settings also have the most extensive clinical experience with resistance. In 2021, six non-profit organizations representing patients with these diseases undertook a year-long effort, culminating in a 2-day workshop (including academic, industry, and regulatory participants) to understand the challenges associated with developing effective therapies for patients previously exposed to anti-PD-(L)1 agents and outline recommendations for designing clinical trials in this setting. This manuscript presents key discussion themes and positions reached through this effort, with a specific focus on the topics of eligibility criteria, comparators, and endpoints, as well as tumor-specific trial design options for combination therapies designed to treat patients with melanoma, NSCLC, or RCC after prior PD-(L)1 pathway blockade.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Carcinoma de Células Renais , Neoplasias Renais , Neoplasias Pulmonares , Melanoma , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/tratamento farmacológico , Receptor de Morte Celular Programada 1/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Ensaios Clínicos como Assunto , Melanoma/tratamento farmacológico , Neoplasias Renais/tratamento farmacológico
10.
JCO Clin Cancer Inform ; 7: e2200161, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36821804

RESUMO

PURPOSE: Using patient-reported outcomes (PROs) provides important insights from the patient's perspective and can be valuable to monitor and manage treatment-related adverse events during cancer treatment. Additionally, the digital administration of PROs (electronic PROs [ePROs]) provides real-time updates to clinical care teams on treatment-related symptoms in-between clinic visits. However, given the variability in the methodology and timing of the data collection, using and harmonizing these data across different systems remains challenging. Identifying data elements to capture and operating procedures for harmonization across ePRO tools will expedite efforts to generate relevant and robust data on use of ePRO data in clinical care. METHODS: Friends of Cancer Research assembled a consortium of project partners from key health care sectors to align on a framework for ePRO data capture across ePRO tools and assessment of the impact of ePRO data capture on patient outcomes. RESULTS: We identified challenges and opportunities to align ePRO data capture across ePRO tools and aligned on key data elements for assessing the impact of ePRO data capture on patient care and outcomes. Ultimately, we proposed a study protocol to leverage ePRO data for symptom and adverse event management to measure real-world effectiveness of ePRO tool implementation on patient care and outcomes. CONCLUSION: This work provides considerations for harmonizing ePRO data sets and a common framework to align across multiple ePRO tools to assess the value of ePROs for improving patient outcomes. Future efforts to interpret evidence and evaluate the impact of ePRO tools on patient outcomes will be aided by improved alignment across studies.


Assuntos
Medidas de Resultados Relatados pelo Paciente , Software , Humanos , Coleta de Dados , Assistência ao Paciente , Projetos de Pesquisa
12.
J Immunother Cancer ; 11(1)2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36657817

RESUMO

Liquid biopsies are gaining momentum as minimally invasive means for cancer detection, characterization, monitoring, and interception. Composed of five expert-opinion review articles and five accompanying expert-physician viewpoints, this Journal for ImmunoTherapy of Cancer Special Review Series focuses on capturing and synthesizing the current state of science of liquid biopsies and their clinical relevance for cancer immunotherapy and beyond.


Assuntos
Prova Pericial , Neoplasias , Humanos , Biópsia Líquida , Neoplasias/terapia , Neoplasias/diagnóstico , Imunoterapia , Biologia
13.
Clin Cancer Res ; 29(13): 2371-2374, 2023 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35616593

RESUMO

The breakthrough therapy designation (BTD) process was created to expedite clinical development timelines for drugs intended to treat serious conditions and preliminary clinical evidence indicates the drug may demonstrate substantial improvement over existing therapies. This analysis demonstrates that BTD is a valuable tool for expediting approval of promising therapies in oncology. By comparing drugs indicated to treat non-small cell lung cancer (NSCLC) approved with BTD or without BTD between January 2013 and October 2021, BTD drugs reduced the risk of death by a median of 31% and progression by a median of 48%, while drugs never receiving BTD reduced the risk of death and progression by a median of 15% and 41.9%, respectively. These findings show that BTD criteria accurately identify drugs that improve long-term outcomes for patients with cancer and warrant coordinated efforts to ensure timely coverage decisions and access for patients.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Estados Unidos , Humanos , Aprovação de Drogas , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , United States Food and Drug Administration , Oncologia
15.
Clin Pharmacol Ther ; 113(6): 1217-1222, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36408668

RESUMO

Legislative and technological advancements over the past decade have given rise to the proliferation of healthcare data generated from routine clinical practice, often referred to as real-world data (RWD). These data have piqued the interest of healthcare stakeholders due to their potential utility in generating evidence to support clinical and regulatory decision making. In the oncology setting, studies leveraging RWD offer distinct advantages that are complementary to randomized controlled trials (RCTs). They also permit the conduct of investigations that may not be possible through prospective designs due to ethics or feasibility. Despite its promise, the use of RWD for the generation of clinical evidence remains controversial due to concerns of unmeasured confounding and other sources of bias that must be carefully addressed in the study design and analysis. To facilitate a better understanding of when RWD can provide reliable conclusions on drug effectiveness, we seek to conduct 10 RWD-based studies that emulate RCTs in oncology using a systematic, protocol-driven approach described herein. Results of this investigation will help inform clinical, scientific, and regulatory stakeholders on the applications of RWD in the context of product labeling expansion, drug safety, and comparative effectiveness in oncology.


Assuntos
Oncologia , Projetos de Pesquisa , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
16.
Front Neurol ; 13: 1021042, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36408527

RESUMO

During physiological stress responses such as vigorous exercise, emotional states of fear and rage, and asphyxia, the nervous system induces a massive release of systemic catecholamines that prepares the body for survival by increasing cardiac output and redirecting blood flow from non-essential organs into the cardiopulmonary circulation. A curious byproduct of this vital response is a sudden, transient, and redistributive leukocytosis provoked mostly by the resultant shear forces exerted by rapid blood flow on marginated leukocytes. Generalized convulsive seizures, too, result in catecholamine surges accompanied by similar leukocytoses, the magnitude of which appears to be rooted in semiological factors such as convulsive duration and intensity. This manuscript reviews the history, kinetics, physiology, and clinical significance of post-convulsive leukocyte elevations and discusses their clinical utility, including a proposed role in the scientific investigation of sudden unexpected death in epilepsy (SUDEP).

17.
JCO Precis Oncol ; 6: e2200454, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36446042

RESUMO

PURPOSE: Immune checkpoint inhibition (ICI) therapy represents one of the great advances in the field of oncology, highlighted by the Nobel Prize in 2018. Multiple predictive biomarkers for ICI benefit have been proposed. These include assessment of programmed death ligand-1 expression by immunohistochemistry, and determination of mutational genotype (microsatellite instability or mismatch repair deficiency or tumor mutational burden) as a reflection of neoantigen expression. However, deployment of these assays has been challenging for oncologists and pathologists alike. METHODS: To address these issues, ASCO and the College of American Pathologists convened a virtual Predictive Factor Summit from September 14 to 15, 2021. Representatives from the academic community, US Food and Drug Administration, Centers for Medicare and Medicaid Services, National Institutes of Health, health insurance organizations, pharmaceutical companies, in vitro diagnostics manufacturers, and patient advocate organizations presented state-of-the-art predictive factors for ICI, associated problems, and possible solutions. RESULTS: The Summit provided an overview of the challenges and opportunities for improvement in assay execution, interpretation, and clinical applications of programmed death ligand-1, microsatellite instability-high or mismatch repair deficient, and tumor mutational burden-high for ICI therapies, as well as issues related to regulation, reimbursement, and next-generation ICI biomarker development. CONCLUSION: The Summit concluded with a plan to generate a joint ASCO/College of American Pathologists strategy for consideration of future research in each of these areas to improve tumor biomarker tests for ICI therapy.


Assuntos
Inibidores de Checkpoint Imunológico , Neoplasias , Idoso , Estados Unidos , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Instabilidade de Microssatélites , Patologistas , Medicare , Biomarcadores Tumorais/genética , Neoplasias/diagnóstico
18.
Circ Arrhythm Electrophysiol ; 15(11): e011131, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36306333

RESUMO

BACKGROUND: Irreversible electroporation is an energy form utilizing high-voltage pulsed electric field, leading to cellular homeostasis disruption and cell death. Recently, irreversible electroporation has shown promising results for the treatment of cardiac arrhythmias. However, reversible and irreversible effects of pulsed electric field on cardiac myocytes remain poorly understood. Here, we evaluated the influence of a monophasic single electric pulse (EP) on the contractility, Ca2+ homeostasis and recovery of cardiac myocytes. METHODS: Isolated rat left ventricular myocytes were electroporated using single monophasic EP of different durations and voltages. Sarcomere length and intracellular Ca2+ were simultaneously monitored for up to 20 minutes after EP application in Fura-2 loaded left ventricular myocytes. Lethal voltage thresholds were determined using 100 µs and 10 ms pulses and by discriminating cell orientation with respect to the electric field. RESULTS: Electroporation led to an immediate increase in intracellular Ca2+ which was dependent upon the voltage delivered to the cell. Intermediate-voltage EP (140 V, 100 µs) increased sarcomere shortening, Ca2+ transient amplitude, and diastolic Ca2+ level measured 1 minute post-EP. Although sarcomere shortening returned to pre-EP level within 5 minutes, Ca2+ transient amplitude decreased further below pre-EP level and diastolic Ca2+ level remained elevated within 20 minutes post-EP. Spontaneous contractions were observed after sublethal EP application but their frequency decreased progressively within 20 minutes. Lethal EP voltage threshold was lower in myocytes oriented perpendicular than parallel to the electric field using 100 µs pulses while an opposite effect was found using 10 ms pulses. CONCLUSIONS: Sublethal EP affected rat left ventricular myocytes contractility and disrupted Ca2+ homeostasis as a function of the EP voltage. Moreover, EP-induced lethality was preceded by a large increase in intracellular Ca2+ and was dependent upon the EP duration, amplitude and left ventricular myocytes orientation with respect to the electric field. These findings provide new insights into the effect of pulsed electric field on cardiac myocytes.


Assuntos
Cálcio , Miócitos Cardíacos , Ratos , Animais , Miócitos Cardíacos/metabolismo , Cálcio/metabolismo , Ventrículos do Coração/metabolismo , Eletroporação , Homeostase
19.
ACS Pharmacol Transl Sci ; 5(9): 735-751, 2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36110379

RESUMO

Whereas treatment of allergic diseases such as asthma relies largely on the targeting of dysregulated effector pathways, the conceptually attractive alternative of preventing them by a pharmaceutical, at-source intervention has been stymied until now by uncertainties about suitable targets and the challenges facing drug design. House dust mites (HDMs) are globally significant triggers of allergy. Group 1 HDM allergens, exemplified by Der p 1, are cysteine proteases. Their degradome has a strong disease linkage that underlies their status as risk and initiator allergens acting directly and through bystander effects on other allergens. Our objective was to test whether target-selective inhibitors of group 1 HDM allergens might provide a viable route to novel therapies. Using structure-directed design to optimize a series of pyruvamides, we undertook the first examination of whether pharmaceutically developable inhibitors of group 1 allergens might offer protection against HDM exposure. Developability criteria included durable inhibition of clinically relevant signals after a single aerosolized dose of the drug. The compounds suppressed acute airway responses of rats and mice when challenged with an HDM extract representing the HDM allergome. Inhibitory effects operated through a miscellany of downstream pathways involving, among others, IL-33, thymic stromal lymphopoietin, chemokines, and dendritic cells. IL-13 and eosinophil recruitment, indices of Th2 pathway activation, were strongly attenuated. The surprisingly expansive benefits arising from a unique at-source intervention suggest a novel approach to multiple allergic diseases in which HDMs play prominent roles and encourage exploration of these pharmaceutically developable molecules in a clinical setting.

20.
Circ Arrhythm Electrophysiol ; 15(10): e011110, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36166690

RESUMO

BACKGROUND: Pulsed field ablation (PFA) is a novel energy modality for treatment of cardiac arrhythmias. The impact of electrode-tissue proximity on lesion formation by PFA has not been conclusively assessed. The objective of this investigation was to evaluate the effects of electrode-tissue proximity on cardiac lesion formation with a biphasic, bipolar PFA system. METHODS: PFA was delivered on the ventricular epicardial surface in an isolated porcine heart model (n=8) via a 4-electrode prototype catheter. An offset tool was designed to control the distance between electrodes and target tissue; deliveries were placed 0 mm (0 mm offset), 2 mm (2 mm offset), and 4 mm away from the tissue (4 mm offset). Lesions were assessed using tetrazolium chloride staining. Numerical models for the experimental setup with and without the offset tool validated and supported results. RESULTS: Cardiac lesion dimensions decreased proportional to the distance between epicardial surface and electrodes. Lesion depth averaged 4.3±0.4 mm, 2.7±0.4 mm, and 1.3±0.4 mm for the 0, 2, and 4 mm and lesion width averaged 9.4±1.1 mm, 7.5±0.8 mm and 5.8±1.4 mm for the 0, 2, and 4 mm offset distances, respectively. Numerical modeling matched ex vivo results well and predicted lesion creation with and without the offset tool. CONCLUSIONS: Using a biphasic, bipolar PFA system resulted in cardiac lesions even in the 0 mm offset distance case. The relationship between lesion depth and offset distance was linear, and the deepest lesions were created with 0 mm offset distance, that is, with electrodes in contact with tissue. Therefore, close electrode-tissue proximity increases the likelihood of achieving transmural lesions by maximizing the electric field penetration into the target tissue.


Assuntos
Ablação por Cateter , Suínos , Animais , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Cloretos , Eletrodos , Ventrículos do Coração/cirurgia , Coração
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA