Ablation Research Articles

Gold nanoparticles for photothermal therapy – Influence of experimental conditions on the properties of resulting AuNPs

Gold nanoparticles (AuNPs)-mediated Photothermal Therapy (PTT) is a minimally-invasive therapeutic approach that uses AuNPs to convert light into heat, leading to the thermal ablation of tumors. Thus, the efficacy of this strategy strongly relies on the photothermal conversion potential of AuNPs. The ability to convert light into heat can be enhanced by tuning the physicochemical and optical properties of AuNPs. This can be achieved by changing the conditions of AuNP's synthesis, such as the order of addition of reagents. The present work entails to explore how varying the order of reagents addition modulates the properties of AuNPs, particularly enhancing the photothermal conversion potential of the resulting AuNPs and consequently, improving PTT efficacy. For this, eleven different AuNPs' nanoformulations were synthetized following different sequences of addition of reagents. These nanoformulations were characterized regarding their physicochemical properties namely size, surface charge, gold concentration, surface morphology and maximum absorbance wavelength. In addition, their thermal activation profiles were determined in vitro. Furthermore, the biocompatibility of different nanoformulations was also assessed. Three nanoformulations, with the most favorable photothermal activation profiles (AuNPs 2, 3 and 7), were then selected for preliminary in vitro safety and efficacy assays using a panel of cell lines. These three nanoformulations were deemed safe in vitro at the tested concentrations. At 250 μM of gold content, and after an incubation period of 4 h, followed by 5 min irradiation with a laser emitting at 808 nm (7.96 W/cm2), AuNPs 7 significantly reduced the cell viability of all cancer cell lines tested (MCF-7, HCT-116 and A375) by ≥ 45 %. However, such cytotoxic effect was not observed for the human keratinocyte cell line (HaCat), thus demonstrating its specificity towards cancer cells. Overall, the results herein presented reinforce that the order of reagents addition is highly important for achieving adequate AuNPs for PTT.

Assessment of thermochromic phantoms for characterizing microwave ablation devices.

Thermochromic gel phantoms provide a controlled medium for visual assessment of thermal ablation device performance. However, there are limited studies reporting on the comparative assessment of ablation profiles assessed in thermochromic gel phantoms against those in ex vivo tissue. The objective of this study was to compare microwave ablation zones in a thermochromic tissue-mimicking gel phantom and ex vivo bovine liver and to report on measurements of the temperature-dependent dielectric and thermal properties of the phantom. Thermochromic polyacrylamide phantoms were fabricated following a previously reported protocol. Phantom samples were heated to temperatures in the range of 20°C-90°C in a temperature-controlled water bath, and colorimetric analysis of images of the phantom taken after heating was used to develop a calibration between color changes and the temperature to which the phantom was heated. Using a custom, 2.45GHz water-cooled microwave ablation antenna, ablations were performed in fresh ex vivo liver and phantoms using 65W applied for 5min or 10min (n=3 samples in each medium for each power/time combination). Broadband (500MHz-6GHz) temperature-dependent dielectric and thermal properties of the phantom were measured over the temperature range of 22°C-100°C. Colorimetric analysis showed that the sharp change in gel phantom color commences at a temperature of 57°C. Short and long axes of the ablation zone in the phantom (as assessed by the 57°C isotherm) for 65W, 5min ablations were aligned with the extents of the ablation zone observed in ex vivo bovine liver. However, for the 65W, 10min setting, ablations in the phantom were on average 23.7% smaller in the short axis and 7.4 % smaller in the long axis than those observed in ex vivo liver. Measurements of the temperature-dependent relative permittivity, thermal conductivity, and volumetric heat capacity of the phantom largely followed similar trends to published values for ex vivo liver tissue. Thermochromic tissue-mimicking phantoms provides a controlled, and reproducible medium for comparative assessment of microwave ablation devices and energy delivery settings. However, ablation zone size and shapes in the thermochromic phantom do not accurately represent ablation sizes and shapes observed in ex vivoliver tissue for high energy delivery treatments (65W, 10min). One cause for this limitation is the difference in temperature-dependent thermal and dielectric properties of the thermochromic phantom compared to ex vivobovine liver tissue, as reported in the present study.

Stepwise dual-target magnetic resonance-guided focused ultrasound in tremor-dominant Parkinson disease: One-year follow-up.

Magnetic resonance-guided focused ultrasound (MRgFUS) is a nonsurgical treatment for Parkinson disease (PD). Some selected anatomical structures can be targeted by MRgFUS in PD. However, there is no uniform target yet. We have reported that stepwise dual-target MRgFUS was successfully applied to treat refractory tremors with akinetic-rigid features in PD. It generated two precise thermal ablations in the ventral intermediate nucleus (VIM) and pallidothalamic tract (PTT). Here, we report more PD patients to verify the safety and efficacy of stepwise dual-target MRgFUS. Ten tremor-dominant PD patients (mean age = 66.7 ± 3.2 years, eight men) received the stepwise dual-target MRgFUS treatment with a series of primary and secondary outcome measures. The VIM and PTT were navigated based on brain magnetic resonance images. Outcome measures were categorized into primary and secondary assessments. The primary outcome measures consisted of resting tremor, action/kinetic tremor, rigidity, and bradykinesia. Secondary outcome measures encompassed non-motor symptoms scale of PD. Data collected at follow-up time points, including 1 day, 3 months, 6 months, and 1 year posttreatment, were compared with baseline data. The severity of tremor and motor deficits represented by Clinical Rating Scale for Tremor parts A and B during off-medication status and Unified Parkinson's Disease Rating Scale III on the treated side were significantly improved (p < 0.05 by paired t-test) at 1-year follow-up. At the 1-year follow-up, significant improvement was observed in the non-motor symptoms scale. Additionally, no severe adverse effects were reported, except temporary treatment-related discomfort during the procedure. In conclusion, stepwise dual-target MRgFUS emerges as a safe and effective therapeutic modality for PD patients, particularly in addressing medication-refractory tremor and akinetic-rigid syndrome.

Fertility and Miscarriage Incidence After Cervical Intraepithelial Neoplasia Treatment by Thermal Ablation: A Cohort Study.

To assess the impact of thermal ablation (TA) for the treatment of cervical dysplasia on fertility and pregnancy outcomes among women screened for cervical cancer in Cameroon. Retrospective cohort study. Dschang health district, Cameroon. Participants aged 30-45 years from two screening trials conducted between 2015 and 2020 in Dschang District Hospital. Participants were primarily screened for human papillomavirus infection, triaged by visual inspection and treated by TA if needed. Between October 2021 and March 2022, interviews on subsequent fertility were conducted with participants treated by TA and a control group of untreated women. Pregnancy and miscarriage after screening/treatment. A total of 760 participants (219 treated and 541 untreated) completed the survey, with a mean follow-up time of 1297 days. Sixty-two women (28.3%) treated by TA reported a pregnancy postscreening versus 165 (30.5%) in the control group (p = 0.550). Adjusted for potential confounders, the hazard ratio of pregnancy for treated compared with untreated women was 0.82 (0.54-1.24, p = 0.350). Among women reporting pregnancies with a known outcome and which were not voluntarily terminated, 18 (35.3%) treated participants had a miscarriage versus 31 (21.4%) in the control group (p = 0.048). In the adjusted model, no association remained between TA and miscarriage (1.04, 0.39-2.78, p = 0.935). In our study population, TA did not significantly impact fertility nor miscarriage risk. Our results support the widespread use of TA as a treatment of choice for precancerous cervical lesions in low-income settings.

Magnetic Induction Heating in a Conducting Polymer for Biomedical Applications.

In this study, we investigate the magnetic induction heating induced in a conducting polymer (CP) under alternative magnetic fields (AMFs). Experimental results and numerical simulations have proved that the magneto-thermal conversion of the CP is caused by the induced eddy current, which is related to the shape and intensity of the applied external AMF, and the intrinsic electrical conductivity, macrostructure and microstructure of the CP. By employing various fabrication methods, specific temperature distribution and control of thermal field within conducting polymer films and aerogels could be achieved. To exploit the potential of magnetic induction heating in CP for biomedical applications, we designed a conducting polymer aerogel-based self-adaptive heat patch and demonstrated its AMF-enabled localized heating of skin. In addition to the thermal ablation of tumor cells via magneto-thermal conversion of the CP, the promotion of neuronal differentiation at mild temperature by noninvasive magneto-electrical stimulation has also been demonstrated to be an effective strategy for tissue engineering.

Exploiting the mechanical effects of ultrasound for noninvasive therapy.

Focused ultrasound is a platform technology capable of eliciting a wide range of biological responses with high spatial precision deep within the body. Although focused ultrasound is already in clinical use for focal thermal ablation of tissue, there has been a recent growth in development and translation of ultrasound-mediated nonthermal therapies. These approaches exploit the physical forces of ultrasound to produce a range of biological responses dependent on exposure conditions. This review discusses recent advances in four application areas that have seen particular growth and have immense clinical potential: brain drug delivery, neuromodulation, focal tissue destruction, and endogenous immune system activation. Owing to the maturation of transcranial ultrasound technology, the brain is a major target organ; however, clinical indications outside the brain are also discussed.

Exploring the Efficacy of Combining Radiofrequency Thermal Ablation or Microwave Ablation with Vertebroplasty for Pain Control and Disease Management in Metastatic Bone Disease-A Systematic Review.

Interventional radiology techniques have become pivotal in recent years in managing metastatic bone disease, which frequently results in skeletal complications such as fractures and severe pain. Thermoablative methods like radiofrequency ablation (RFA) and microwave ablation (MWA), when combined with vertebroplasty (VP), are proving increasingly beneficial for these patients. The search was independently conducted by two radiologists on MEDLINE databases, using specified strings up to April 2024. Methodological quality was assessed using PRISMA guidelines. Studies meeting inclusion criteria investigated thermoablation techniques (RFA and/or MWA) combined with VP, focusing on pain management and disease control outcomes in adults. Among 147 results, 42 articles met the criteria, with varied prospective and retrospective designs and sample sizes averaging 49 patients, predominantly involving RFA (30 studies), MWA (11 studies), and one comparative study. Our review highlights significant pain reduction, effective local tumor control, and favorable safety of combined RFA or MWA with VP, supporting its potential in managing vertebral pathologies and warranting further clinical integration. The combined treatment of RFA/MWA with VP demonstrates significant pain reduction and local tumor control, with a rapid onset of analgesic effect. These findings support its crucial role in clinical practice for managing vertebral metastases.

Revealing the ablative behavior and mechanism of a 2D C/SiC Ti3SiC2 modified composite through a multi-scale laser ablation model

Ti3SiC2 MAX phase ceramic has effectively enhanced the oxidation resistance of C/SiC composites. However, there is still a need for a numerical ablation model that can analyze the ablative behavior of 2D C/SiC composites. To address this, an efficient, phenomenological multi-scale ablation model, including the thermal property theoretical model, oxidation, decomposition, and sublimation ablation models, is established for revealing the effect of Ti3SiC2 on the ablation resistance of the 2D C/SiC composite. The ablative behavior is evaluated using the continuous-wave laser with different laser power densities as the heat source and used as a basis for numerical model verification. The results show that the Ti3SiC2 MAX phase ceramic can improve the ablation resistance of the 2D C/SiC composite under different laser power densities. The ablation roughness is reconstructed through the mesoscopic geometry structure and maximum/minimum ablation depth. The numerical model can analyze the effect of the mesoscopic geometry structure parameters on the ablation behavior. The model can provide a predicting method for the quantitative ablative calculation of 2D C/SiC and matrix-modified composites.

Esophageal Damage Following Left Atrial Ablation in a Patient on Dabigatran: Adding Insult to Injury.

Dabigatran-induced esophagitis (DIE) should be considered in patients on dabigatran developing esophageal symptoms after radiofrequency ablation for atrial fibrillation.DIE is a condition characterized clinically by symptoms related to esophageal dysfunction and histologically by significant inflammation of the esophageal mucosa.Physicians should be aware of the signs and symptoms of DIE and must educate patients on proper medication administration to avoid such risks.

Interstitial dual-mode ultrasound with a 3-mm MR-compatible catheter for image-guided HIFU and directional in-vitro tissue ablations.

Current interstitial techniques of tumor ablation face challenges that ultrasound technologies could meet. The ablation radius and directionality of the ultrasound beam could improve the efficiency and precision. Here, a 9-gauge MR-compatible dual-mode ultrasound catheter prototype was experimentally evaluated for Ultrasound Image-guided High Intensity Focused Ultrasound (USgHIFU) conformal ablations. The prototype consisted of 64 piezocomposite linear array elements and was driven by an open research programmable dual-mode ultrasound platform. After verifying the US-image guidance capabilities of the prototype, the HIFU output performances (dynamic focusing and HIFU intensities) were quantitatively characterized, together with the associated 3D HIFU-induced thermal heating in tissue phantoms (using MR thermometry). Finally, the ability to produce robustly HIFU-induced thermal ablations in in-vitro liver was studied experimentally and compared to numerical modeling. Investigations of several HIFU dynamic focusing allowed overcoming the challenges of miniaturizing the device: mono-focal focusing maximized deep energy deposition, while multi-focal strategies eliminated grating lobes. The linear-array design of the prototype made it possible to produce interstitial ultrasound images of tissue and tumor mimics in situ. Multi-focal pressure fields were generated without grating lobes and transducer surface intensities reached up to Isapa = 14 W·cm-2. Seventeen elementary thermal ablations were performed in vitro. Rotation of the catheter proved the directionality of ablation, sparing non-targeted tissue. This experimental proof of concept demonstrates the feasibility of treating volumes comparable to those of primary solid tumors with a miniaturized USgHIFU catheter whose dimensions are close to those of tools traditionally used in interventional radiology, while offering new functionalities.

Focal therapy for oligometastatic and oligoprogressive renal cell carcinoma: a narrative review.

Metastatic renal cell carcinoma (RCC) can present with oligometastatic disease and/or develop oligoprogression following systemic therapy. Cytoreductive and focal metastasis-directed therapy options include resection, stereotactic ablative radiation and thermal ablation. Aggressive focal therapy may allow delay in initiation of or modification to systemic therapy and improve clinical outcomes. In this narrative review we synthesize current practice guidelines and prospective data on focal therapy management options and highlight future research. Patient selection and the choice of focal treatment techniques are controversial due to limited and heterogeneous data and patients may benefit from multidisciplinary evaluation. Prospective comparative trials with clearly defined inclusion criteria and relevant end points are needed to clarify the risks and benefits of different approaches.

Innovative Approaches and Future Directions in the Management and Understanding of Varicose Veins: A Systematic Review.

Varicose veins, a prevalent condition that primarily affects the lower limbs, present significant hurdles in diagnosis and treatment due to their diverse causes. This study dives into the complex hormonal, environmental, and molecular elements that influence varicose vein genesis, emphasizing the need for precise diagnostic methods and changing therapy approaches to improve patient outcomes. It investigates the epidemiology and demographic distribution of varicose veins, delves into their pathophysiology, and assesses diagnostic methods such as duplex ultrasonography and the CEAP classification system. In addition, the study discusses novel therapies such as sclerotherapy and endovenous thermal ablation, as well as the effectiveness of existing diagnostic methods in detecting chronic venous illnesses. By investigating venous wall remodeling and inflammatory pathways, it gives a thorough knowledge of varicose vein formation. The study calls for future research that focuses on patient-centered methods, bioengineering advances, digital health applications, and genetic and molecular studies to improve the accuracy and effectiveness of vascular therapy. As a result, a multidisciplinary literature analysis was done, drawing on insights from vascular medicine, epidemiology, genetics, and pharmacology, to consolidate existing knowledge and identify possibilities to enhance varicose vein diagnosis, treatment, and patient care outcomes.

A randomized phase III trial of stereotactic ablative radiotherapy for patients with up to 10 oligometastases and a synchronous primary tumor (SABR-SYNC): study protocol

BackgroundEmerging randomized data, mostly from phase II trials, have suggested that patients with oligometastatic cancers may benefit from ablative treatments such as stereotactic ablative radiotherapy (SABR). However, phase III data testing this paradigm are lacking, and many studies have examined SABR in the setting of metachronous oligometastatic disease. The goal of the SABR-SYNC trial is to assess the effect of SABR in patients with oligometastatic cancers and a synchronous primary tumor.MethodsOne hundred and eighty patients will be randomized in a 1:2 ratio between standard of care (SOC) palliative-intent treatments vs. SOC + ablative therapy (SABR preferred) to all sites of known disease. Randomization will be stratified based on histology and number of metastases at enrollment. SABR may be delivered in 1-, 3- and 5-fraction regimens, with recommended doses of 20 Gy, 30 Gy, and 35 Gy, respectively. Non-SABR local modalities (e.g. surgery, thermal ablation, conventional radiation) may be used for treatment of the primary or metastases at the discretion of the treating physicians, if those modalities are clinically preferred. The primary endpoint is overall survival, and secondary endpoints include progression-free survival, time to development of new metastatic lesions, time to initiation of next systemic therapy, quality of life, and toxicity. Translational endpoints include assessment of circulating tumor DNA and immunological predictors of outcomes.DiscussionSABR-SYNC will provide phase III data to assess the impact of SABR on overall survival in a population of patients with synchronous oligometastases. The translational component will attempt to identify novel prognostic and predictive biomarkers to aid in clinical decision making.Trial registrationClinicaltrials.gov NCT05717166 (registration date: Feb. 8, 2023).

The Safety and Efficacy of Left Atrial BOX Ablation in Persistent Atrial Fibrillation: A Meta-Analysis.

Circumferential pulmonary vein isolation (CPVI) has a high recurrence rate in managing persistent atrial fibrillation (AF). While some studies suggest that augmenting CPVI with additional left atrial BOX ablation can diminish this recurrence rate among patients with persistent AF, this approach remains controversial. This meta-analysis assesses the safety and efficacy of adjunctive left atrial BOX ablation in treating persistent atrial fibrillation. We conducted a comprehensive literature search across China National Knowledge Infrastructure (CNKI), PubMed, Web of Science, and Cochrane Library, focusing on randomized controlled trials. The primary outcome was the recurrence rate of any atrial arrhythmias (AAs) within one-year post-treatment, with the secondary outcome being the frequency of adverse events related to the surgery. The combination of CPVI and left atrial BOX ablation did not lead to a significant reduction in the overall recurrence rate of atrial arrhythmias (risk ratios (RR) = 0.86, 95% confidence interval (CI) = 0.73-1.02, I2 = 35%). However, subgroup analyses revealed that this therapeutic approach significantly decreased the recurrence rates of all atrial arrhythmias (RR = 0.67, 95% CI = 0.49-0.92, I2 = 15%) and specifically atrial fibrillation (RR = 0.53, 95% CI = 0.37-0.77, I2 = 0%) in patients with a left atrial diameter ≤44 mm. Notably, there was no significant increase in the incidence of procedure-related adverse events (RR = 1.04, 95% CI = 0.56-1.94, I2 = 0%). However, the durations of both the ablation (mean difference (MD) = 19.77, 95% CI = 15.84-23.70, I2 = 0%) and the overall procedure (MD = 15.64, 95% CI = 6.99-24.29, I2 = 0%) were longer due to the additional ablation steps. In patients with smaller left atrial diameters, augmenting CPVI with left atrial BOX ablation significantly lowers the recurrence rates of atrial arrhythmias and atrial fibrillation without elevating surgical risk levels.

Artificial intelligence estimated electrocardiographic age as a recurrence predictor after atrial fibrillation catheter ablation

The application of artificial intelligence (AI) algorithms to 12-lead electrocardiogram (ECG) provides promising age prediction models. We explored whether the gap between the pre-procedural AI-ECG age and chronological age can predict atrial fibrillation (AF) recurrence after catheter ablation. We validated a pre-trained residual network-based model for age prediction on four multinational datasets. Then we estimated AI-ECG age using a pre-procedural sinus rhythm ECG among individuals on anti-arrhythmic drugs who underwent de-novo AF catheter ablation from two independent AF ablation cohorts. We categorized the AI-ECG age gap based on the mean absolute error of the AI-ECG age gap obtained from four model validation datasets; aged-ECG (≥10 years) and normal ECG age (<10 years) groups. In the two AF ablation cohorts, aged-ECG was associated with a significantly increased risk of AF recurrence compared to the normal ECG age group. These associations were independent of chronological age or left atrial diameter. In summary, a pre-procedural AI-ECG age has a prognostic value for AF recurrence after catheter ablation.

Sex-Differences in Post-Procedural Pain Experiences After Thermal Liver Ablations for Liver Tumors: A Retrospective Study

IntroductionLiterature shows differences in pain experiences between sexes. The exact influence of thermal liver ablation on experienced pain is still not well-known. This study aims to investigate the maximum pain intensity at the recovery between men and women after percutaneous thermal liver ablation.MethodsPatients treated with percutaneous thermal liver ablation (radiofrequency or microwave ablation) in Maastricht University Medical Center + between 2018 and 2022 for primary or secondary liver tumors were included retrospectively. Outcomes included maximum numerical rating scale (NRS, scale:0–10) score at the recovery room, prevalence of post-procedural pain (defined as NRS score ≥ 4), duration of anesthesia, length of stay at recovery, and complications. Regression analyses were adjusted for age, ASA-score, BMI, tumor type, maximum diameter of lesion, chronic pain in patients’ history, and history of psychological disorder.Results183 patients were included of which 123 men (67%). Results showed higher average maximum NRS scores in women patients compared to men (mean:3.88 versus 2.73), but not after adjustments (aß:0.75, 95%CI:−0.13–1.64). Women suffered more from acute post-procedural pain (59% versus 35%; aOR:2.50, 95%CI:1.16–5.39), and needed analgesics more often at the recovery room (aOR:2.43, 95%CI:1.07–5.48) compared to men. NRS score at recovery arrival did not significantly differ (aß:0.37, 95%CI:-0.48–1.22). No differences were seen in the length of stay at the recovery, duration of anesthesia, procedure time, and complication rate. Location of the tumor (subcapsular or deep), total tumors per patient, and distinction between primary and secondary tumors had no influence on the NRS.ConclusionThis retrospective single-center study shows higher post-procedural pain rates after thermal liver ablation in women, resulting in higher analgesics use at the recovery room. The results suggest considering higher dosage of analgesics during thermal liver ablation in women to reduce post-procedural pain.Level of Evidence 3Non-controlled retrospective cohort study.Graphical

Thermal Ablation for Benign Thyroid Nodules and Papillary Thyroid Microcarcinoma.

Ultrasound-guided minimally invasive thermoablative (MIT) therapies are a therapeutic option for selected patients with large, hypoenhancing, benign thyroid nodules that cause compression disorders or aesthetic discomfort. MIT, which does not require general anaesthesia, causes thermal necrosis of the treated nodule, which is reduced in size by 50 % without functional consequences, and is indicated for patients who are not too young or in the presence of anaesthesia-related risk factors or recurrence following thyroidectomy or refusal of surgery. For the above indications, MIT complements surgery but does not replace it; it must always be performed in centres and by surgeons with proven technical skills and clinical experience. Subject to appropriate informed consent, the treatment is short-duration, well-tolerated by the patient, safe, and non-invasive. It does not require anaesthesia and complications are rare and transient. MIT, and in particular laser-based procedures (TAL), can also be effective and safe for the treatment of potentially destructible papillary microcarcinoma, as shown by the limited but sufficient literature, including the most recent guidelines, which consider it to be a therapeutic alternative that requires a better understanding of its efficacy and safety.

Effect of Low-Dose Aspirin Use After Thermal Ablation in Patients with Hepatocellular Carcinoma: A Retrospective Study.

To determine the effect of aspirin on hepatocellular carcinoma (HCC) recurrence and survival after thermal ablation. A retrospective analysis was performed to evaluate the efficacy and safety of aspirin in combination with thermal ablation. The clinical data were collected for the enrolled patients. Progression-free survival (PFS), overall survival (OS), and adverse events were analyzed. A total of 174 patients with HCC were enrolled. The median PFS was 11.1 (95% confidence interval [CI]: 8.1-14.0) months for patients who took aspirin and 8.6 (95% CI: 5.5-11.8) months for patients who did not take aspirin. The median OS of patients in the aspirin group was 76.7 (95% CI: 58.1-95.3) months and that in the non-aspirin group was 53.5 (95% CI: 42.7-64.3) months. In patients with non-viral HCC, OS was significantly better for the aspirin group (P = 0.03) after ablation. The PFS of patients who underwent ablation alone in the aspirin group was obviously superior to that of patients in the non-aspirin group (P = 0.002). Stratified Cox regression analysis demonstrated that aspirin use after ablation might be a protective factor in specific HCC patient subgroups. The incidence of major adverse events did not significantly differ between the two groups. Low-dose aspirin use was associated with better OS in patients with non-viral HCC after thermal ablation. In patients who received thermal ablation alone, the administration of low-dose aspirin could improve PFS. Aspirin use might be a protective factor in some patients after ablation.

Correlation of Needle Biopsy–Acquired Histopathologic Grade of Hepatocellular Carcinoma with Outcomes after Thermal Ablation

PurposeTo correlate preablation needle biopsy–acquired histopathologic grade of Liver Imaging Reporting and Data System (LI-RADS) 5 hepatocellular carcinoma (HCC) with postablation local tumor control rate, intrahepatic distant tumor progression–free survival, and overall survival. Materials and MethodsThis single-center, retrospective cohort study included adult patients with LI-RADS 5 HCC who underwent a preablation core needle biopsy within 3 months prior to thermal ablation from January 2015 to December 2022. Histopathologic grade from the needle biopsy was evaluated as predictor of local tumor control rate, intrahepatic distant tumor progression–free survival, and overall survival. Kaplan-Meier survival curves were compared using the Gehan generalized Wilcoxon test. ResultsThe study group comprised 133 patients (mean age, 67 years [SD ± 10]; 107 men) with LI-RADS 5 confirmed HCC, stratified into 18 poorly differentiated tumors (median follow-up, 27.7 months; interquartile range [IQR], 15.5–55.4 months) and 115 well-differentiated/moderately differentiated tumors (median follow-up, 29.2 months; IQR, 15.4–59.9 months). No difference in local tumor control rate was noted between the 2 cohorts (hazard ratio [HR], 1.16; 95% CI, 0.32–4.23; P = .898). There was significantly lower intrahepatic distant tumor progression–free survival after thermal ablation in the poorly differentiated cohort (HR, 2.54; 95% CI, 0.92–7.05; P < .001). The overall survival in the poorly differentiated cohort was also lower, although this did not reach statistical significance (HR, 1.77; 95% CI, 0.60–5.26; P = .202). ConclusionsPatients with needle biopsy–proven poorly differentiated LI-RADS 5 HCC have significantly lower intrahepatic distant tumor progression–free survival after thermal ablation compared with those with well-differentiated/moderately differentiated HCC.

Interactions of contact force, impedance, and power during repeated atrial arrhythmia ablation after previous atrial fibrillation ablation

BackgroundAcutely effective repeated radiofrequency catheter ablation (RFCA) after previous atrial fibrillation ablation depends on several parameters including local impedance (LI), contact force (CF), and power. ObjectiveWe aimed to investigate the relationship of LI, CF, and power to the LI drop in a repeated atrial RFCA environment. MethodsConsecutive patients undergoing repeated atrial RFCA were studied. High-quality local electrograms were analyzed for morphology changes indicating effective RFCA and associated LI dynamics. The influence of baseline LI, mean CF, and power on the LI drop was analyzed. Investigated power levels included ≤25 W, 30 W, and ≥40 W. ResultsA total of 1390 RFCA points from 48 patients (48% female; median age, 70 years) were analyzed. Of 309 analyzed electrograms, 40.5% showed effective RFCA morphology changes with an elevated median LI drop (effective, 19.7 Ω; partially effective, 14.1 Ω; P < .001). CF showed the highest correlation to the LI drop within high baseline LI and when applying ≥40 W (low baseline LI, R = 0.39; intermediate, R = 0.66; high, R = 0.72). Within low baseline LI regions, CF levels showed a lower correlation to the LI drop (≤25 W, R = 0.30; 30 W, R = 0.35; ≥40 W, R = 0.39). A mean CF ≥10 g resulted in elevated LI drops with higher power compared with lower power within all baseline LI tertiles (P < .001 each). ConclusionWithin high baseline LI regions, CF plays a greater role for the maximum LI drop when higher power is chosen. A mean CF ≥10 g ensures elevated LI drops with increasing power levels.