Conventional Radiofrequency Ablation Research Articles

Local Ablation Therapy for Hepatocellular Carcinoma: Clinical Significance of Tumor Size, Location, and Biology.

Local ablation therapy, encompassing radiofrequency ablation (RFA), microwave ablation, and cryoablation, has emerged as a crucial strategy for managing small hepatocellular carcinomas (HCCs), complementing liver resection and transplantation. This review delves into the clinical significance of tumor size, location, and biology in guiding treatment decisions for HCCs undergoing local ablation therapy, with a focus on tumors smaller than 3 cm. Tumor size significantly influences treatment outcomes, with larger tumors associated with poorer local tumor control due to challenges in creating sufficient ablative margins and the likelihood of microvascular invasion and peritumoral satellite nodules. Advanced ablation techniques such as centripetal or no-touch RFA using multiple electrodes, cryoablation using multiple cryoprobes, and microwave ablation offer diverse options for HCC treatment. Notably, no-touch RFA demonstrates superior local tumor control compared with conventional RFA by achieving sufficient ablative margins, making it particularly promising for hepatic dome lesions or tumors with aggressive biology. Laparoscopic RFA proves beneficial for treating anterior subphrenic HCCs, whereas artificial pleural effusion-assisted RFA is effective for controlling posterior subphrenic HCCs. However, surgical resection generally offers better survival outcomes for periportal HCCs compared with RFA. Cryoablation exhibits a lower incidence of vascular or biliary complications than RFA for HCCs adjacent to perivascular or periductal regions. Additionally, aggressive tumor biology, such as microvascular invasion, can be predicted using magnetic resonance imaging findings and serum tumor markers. Aggressive HCC subtypes frequently exhibit Liver Imaging Reporting and Data System M features on magnetic resonance imaging, aiding in prognosis. A comprehensive understanding of tumor size, location, and biology is imperative for optimizing the benefits of local ablation therapy in managing HCCs.

The Feasibility, Safety and Outcome of Very High-Power Short Duration Radiofrequency Ablation in Pulmonary Vein Isolation: A Real-World Observation Study.

Pulmonary vein isolation (PVI) ablation is the established gold standard therapy for patients with symptomatic drug refractory atrial fibrillation (AF). Advancements in radiofrequency (RF) ablation, have led to the development of the novel contact force-sensing temperature-controlled very high-power short-duration (vHPSD) RF ablation. This setting delivers 90 W for up to 4 seconds with a constant irrigation flow rate of 8 mL/min. The aim of this study was to compare procedural outcomes and safety with conventional radiofrequency ablation. An observational study was conducted with patients who underwent first time PVI ablation between August 2020 and January 2022. The cohort was divided into: (1) vHPSD ablation; (2) High-power short duration (HPSD) ablation; (3) THERMOCOOL SMARTTOUCH™ SF (STSF). The vHPSD ablation group was prospectively recruited while the HPSD and STSF group were retrospectively collected. Primary outcomes were procedural success, PVI duration, ablation duration and incidence of perioperative adverse events. Secondary outcomes were intraprocedural morphine and midazolam requirement. A total of 175 patients were included in the study with 100, 30 and 45 patients in the vHPSD, HPSD and STSF group, respectively. PVI was successfully attained in all vHPSD patients. vHPSD demonstrated significantly reduced time required for PVI and total energy application in comparison to the HPSD and STSF groups (67.7 29.7 vs. 92.9 25.7 vs. 93.6 29.1 min, p 0.0001; 9.87 4.16 vs. 33.9 7.49 vs. 36.0 10.5 min, p 0.0001, respectively). Intravenous morphine and midazolam requirement was lower in the vHPSD group compared to the HPSD and STSF groups (10.2 3.43 vs. 16.1 4.58 vs. 15.3 3.94 mg, p 0.0001; 4.04 3.24 vs. 8.63 5.22 vs. 8.58 4.72 mg, p 0.0001). One cardiac tamponade was observed in both the vHPSD and HPSD groups while the STSF group exhibited an embolic stoke and two pericardial effusions that did not require drainage. In this study, vHPSD demonstrated a comparable safety profile to the other treatment arms. Procedural duration and energy application time was substantially reduced along with sedation requirement notwithstanding the limitations of observational study design, these preliminary findings are promising with respect to periprocedural outcomes and safety of vHPSD however longitudinal outcomes will be essential to assessing the overall efficacy of this novel technology.

Is conventional radiofrequency ablation of the superolateral branch, one of the three genicular nerves targeted as standard, necessary or not? A non-inferiority randomized controlled trial.

Radiofrequency ablation is an effective treatment modality in the symptomatic treatment of knee osteoarthritis. Our aim was to compare the efficacy of radiofrequency ablation of the superomedial and inferomedial genicular nerves (2 branches) with the superolateral, superomedial, and inferomedial genicular nerves (3 branches) and to show whether the 2-branch procedure is inferior to the 3-branch procedure. This study is a prospective, randomized, single-blind clinical study. Eligible participants were randomized into 2 groups: group A, which applied the procedure to the superomedial and inferomedial genicular nerves, and group B, which applied it to the superomedial, superolateral and inferomedial genicular nerves. Pain was evaluated with the numerical rating scale, quality of life with the Short Form-36 (SF-36), and disability with the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index before, and at 1 and 3 months after the procedure. A total of 41 patients were included. There were no differences between the groups except for the SF-36 physical health sub-score at baseline. A significant improvement was seen in the numeric rating scale (NRS) score, SF-36 sub-scores, WOMAC Index total, as well as pain and physical function scores in both groups, though no significant difference was detected between the groups during follow-up. Although we were unable to establish the noninferiority of conventional radiofrequency ablation (CRFA) applied to 2 branches to CRFA applied to 3 branches, in this trial, significant and similar improvement was observed in NRS, WOMAC total, pain, and physical function and SF-36 scores in both groups.

Clinical effectiveness of focused ultrasound combined with plasma radiofrequency ablation technique in the treatment of persistent strain rhinitis

Examine the effects of focused ultrasound in combination with plasma radiofrequency ablation technology on the physiological stability and postoperative recovery of persistent strain rhinitis. For a control experiment, 90 patients with persistent strain rhinitis were chosen and split into two groups: the control group (CG) and the experimental group (EG). The CG used conventional radiofrequency ablation technology, while the EG used focused ultrasound technology combined with radiofrequency ablation technology to treat persistent strain rhinitis. Between the EG and the CG, compare and contrast the recovery of nasal symptoms, nasal signs, postoperative discomfort, and postoperative respiratory status. One quarter after surgery, there was a substantial difference in physical sign ratings between the EG and the CG, and a particularly significant difference was seen after six months of treatment. One year following surgery, there was a statistical difference between the EG and the CG in the comparison of effective rates at various intervals, with a P value of .013. At 6 months following surgery, the MTT times in the EG and CG for the comparison of nasal function were 12.63 2.65 and 17.68 2.84, respectively, with statistically significant differences. The difference between the EG and the CG in the MTR comparison is statistically significant. In the comparison of NNO values between the EG and the CG after different treatment times. The nitric oxide value of the EG patients decreased over time, with statistical significance one month after surgery and one year after surgery. It is evident from the comparison of various symptom efficacy rates that the EG has a higher treatment effectiveness rate than the CG, and the total treatment effect difference following surgery has statistical significance. Indicators for PONV, PA, directional ability, respiratory recovery, and olfactory recovery performed better in the EG than in the CG, and the differences were statistically significant. Focused ultrasound and plasma radiofrequency ablation technology have a good therapeutic impact in the treatment of persistent strain rhinitis and can significantly reduce MTT. This technology can effectively improve symptoms such as nasal congestion, nasal flow, and headache in patients, and the therapeutic effect is long-lasting. The hospitalization time after treatment is significantly shortened.

Efficacy and Safety of Laser Balloon Versus Irrigated Radiofrequency Ablation as Initial Therapies for Atrial Fibrillation: A Meta-Analysis.

Catheter ablation (CA) is an effective therapy for atrial fibrillation (AF) and, although radiofrequency ablation (RFA) is the standard treatment for pulmonary vein isolation (PVI), it is complex and time-consuming. Laser balloon ablation (LBA) has been introduced to simplify the conventional RFA; however, results of studies comparing LBA and RFA remain controversial. As such, this investigation aimed to comprehensively evaluate the efficacy and safety of LBA versus RFA. The PubMed, Embase, Cochrane Library, and ClinicalTrials.gov databases were searched for relevant studies. The primary endpoints were the freedom from atrial tachyarrhythmia (ATA) and procedure-related complications. Twelve studies including 1274 subjects were included. LBA and RFA yielded similar rates of freedom from ATA (72.5% vs. 68.7%, odds ratio [OR] = 1.26, 95% confidence interval [CI] 1.0-1.7, p = 0.11) and procedure-related complications (7.7% vs. 6.5%, OR = 1.17, 95% CI 0.72-1.90, p = 0.536). LBA with the second- and third-generation laser balloons (LB2/3) yielded remarkably higher rates of freedom from ATA than RFA using contact-force technology (RFA-CF) (OR = 1.91, p = 0.013). Significantly lower pulmonary vein (PV) reconnection rates (OR = 0.51, p = 0.021), but higher phrenic nerve palsy (PNP) rates (OR = 3.42, p = 0.023) were observed in the LBA group. LBA had comparable procedure (weighted mean difference [WMD] = 8.43 min, p = 0.337) and fluoroscopy times (WMD = 3.09 min, p = 0.174), but a longer ablation time (WMD = 12.57 min, p = 0.00) than those for RFA. LBA and RFA treatments were comparable in terms of freedom from ATA and postprocedural complications in patients with AF. Compared with RFA, LBA was associated with significantly lower PV reconnection rates, but a higher incidence of PNP and longer ablation time.

Head-to-head comparison of pulsed field ablation, very high power-short duration, cryoballoon and conventional radiofrequency ablation by LGE-MRI-based ablation lesion assessment

Abstract Background Novel concepts for pulmonary vein isolation (PVI) like pulsed field ablation (PFA) or high power-short duration ablation (HPSD) promise favourable profiles of safety and efficacy. However, clinical comparisons of ablation lesion quality are lacking. Purpose To systematically investigate lesion characteristics of novel ablation concepts, we performed a prospective head-to-head comparison between PFA, HPSD, conventional RF and latest generation cryoballoon ablation using late gadolinium enhancement (LGE)-MRI-based ablation lesion assessment. Methods This study included patients that underwent first-time PVI-only atrial fibrillation ablation - either by ablation index-guided RF ablation, cryoballoon ablation (Arctic Front Advance Pro), HPSD ablation (QDOT micro catheter, QMODE+, 90W, 4s) or PFA (Farapulse PFA system). All patients received an LGE-MRI 3 months post-ablation. LGE was quantified based on the signal intensity ratio of each voxel relative to the blood pool, applying a previously validated threshold of >1.2 to define LGE indicative of ablation-induced scarring using a dedicated software. LGE discontinuations of >3 mm were considered as gaps, and complete lesions were defined as LGE covering >90% of the peri-antral circumference of ipsilateral pulmonary vein (PV) pairs. Results Post-ablation LGE-MRIs from 120 patients were analysed (40 RF, 40 cryoballoon, 20 PFA, 20 HPSD). The proportion of complete PV-encircling LGE lesions was significantly higher with conventional RF than with cryoballoon ablation (50% vs. 34%; p=0.023). Importantly, HPSD ablation resulted in even more complete lesions than conventional RF (68%, p=0.004), whereas the proportion of complete LGE lesions was lowest with PFA (21%). Accordingly, the total number of gaps was lower with HPSD ablation (1.9 gaps/patient) compared to the other ablation concepts (conventional RF 2.7, cryoballoon 3.2, PFA 3.4 gaps/patient; p=0.034). As expected, large-area ablation with the cryoballoon (13.8 mm) and PFA (12.8 mm) single-shot devices resulted in the widest lesions. Of note, HPSD lesions were significantly wider than conventional RF lesions (11.1 mm vs. 8.9 mm; p=0.004). Conclusions HPSD ablation resulted in the most continuous lesions, translating in the lowest number of gaps. Of note, HPSD lesions were also significantly wider than conventional RF lesions, thus corroborating the concept of a shallower HPSD lesion geometry from experimental studies. Interestingly, conventional RF showed a higher proportion of complete PV-encircling lesions than cryoballoon ablation. While PFA lesions cover relatively large areas, comparable to cryoballoon ablation, lesions are more inhomogeneous. However, it remains to be determined, to what extent LGE discontinuities in PFA lesions indicate ineffective ablation or only reflect a different kind of remodeling compared to thermal ablation, which may be less detectable by LGE-MRI.

Coronary venous ethanol ablation of refractory left ventricular summit arrhythmias: comparison with radiofrequency ablation

Abstract Background Radiofrequency (RF) ablation of ventricular premature beats (VPBs) and ventricular tachycardia (VT) arising from the left ventricular (LV) summit is challenging and may fail due to anatomical inaccessibility of the substrate. Coronary Venous Ethanol Ablation (CVEA) has been suggested as a bailout strategy following failed RF ablation of LV Summit Arrhythmias (LVSA). Comparison with RF ablation strategies are lacking. Purpose To compare CVEA with RF ablation for the treatment of LVSA. Methods Between January and November 2023, 20 patients were treated with CVEA for LVSA. Results were compared to 36 patients that underwent RF ablation for LVSA (Panel A). Endo- and/or epicardial RF ablation was performed based on local signal precocity and pace-mapping. Coronary venogram-guided mapping of coronary sinus side-branches was performed using an angioplasty wire connected to our EP-recording system using a crocodile clamp. The target veins were specifically selected based on early presystolic potentials and confirmed by matching VPB pace-maps. For the treatment, angioplasty balloon(s) measuring 2-2.5×6-8 mm were employed to administer ethanol into the target branch of the coronary sinus. Data are reported as mean ± standard deviation, unless otherwise indicated. P-values are two-tailed. Results (Panel B): Patient characteristics were similar for both groups, except for the number of prior failed ablation procedures (75% males; mean age: 63 ± 13 y; 31 with structural heart disease; mean LVEF 39 ± 9%; VPB burden 25 ± 12%; Number of (NS)VT 72 ± 151; 65% redo in case of CVEA, 28% for RF). Mean pace-match was 97 ± 1% (99.8% max.) for CVEA versus 93 ± 8% (97% max.) for RF ablation (P = 0.002). Earliest presystolic signal was -70 ms (-49 ± 12) for CVEA versus -50 ms (-31 ± 12) for RF (P = 0.0002). Acute success, defined as elimination of VPB/VT was 95% versus 83% for CVEA and RF ablation respectively. VPB burden at Holter was 1 ± 3% 6-8 weeks after CVEA versus 8 ± 10% following RF ablation (P = 0.024). In patients with VT, number of (NS)VT decreased by 90% after CVEA (P = 0.014), while this was not significant for RF ablation. After a median follow-up of 8 months (IQR 2-10), 15% of CVEA patients showed residual non-LV summit ventricular arrhythmia as compared to 39% showing recurrence of LV summit VPB or VT following RF ablation. No patients died. One patient developed tamponade following RF ablation and one patient received PCI in the CVEA group. Conclusion Retrograde coronary venous ethanol ablation is an effective ablation strategy for the treatment of LV summit arrhythmias, also compared to conventional RF ablation.

Bipolar catheter ablation of left ventricular summit PVC

Abstract Background Premature ventricular contractions (PVC) arising from the left ventricular summit are a challenging arrhythmia to manage, often refractory to conventional radiofrequency ablation. This study aimed to investigate the effectiveness of bipolar ablation as a therapeutic option for PVCs originating from this anatomically complex region. Methods We conducted a retrospective analysis of a prospective ablation registry to identify patients with recurrent, symptomatic PVCs originating from the left ventricular (LV) summit who underwent bipolar ablation. Bipolar ablation involved the use of two ablation catheters, delivering radiofrequency energy from opposite sides of the summit. The catheters were connected by a dedicated adapter, allowing to connect one ablation catheter in position of a return electrode. Procedural success was defined as the elimination of PVCs during the procedure and freedom from PVCs on follow-up monitoring. Results were compared to a similar patient group who had received unipolar ablation of summit-PVCs. Results A total of 12 pts received bipolar ablation between July 2022 and October 2023. Three pts underwent ablation for VT and were excluded. A total of 9 pts (mean age 57±18 years, n=7 [78%] male, BMI 28±5kg/m2) were included in the analysis. All but one had a history of a previous unsuccessful ablation attempt (median 1 [1-2]). In a group of 33 patients undergoing unipolar ablation 8 (32%) had received ≥ 1 previous ablation and were included in the analysis. Baseline parameters did not differ between groups. The acute procedural success rate for bipolar ablation was 89% in bipolar pts and 75% in unipolar pts, with a mean procedural time of 173±33 min, a mean fluoroscopy time of 14±9 min (158±55 min [p=0.478] and 14±12 min [p=0.995] for unipolar pts). Bipolar ablation was performed between the LVOT and RVOT in 6, and between LVOT and the distal CS in 6 pts with 25-35 W. No major complications were detected in bipolar pts while one non-fatal tamponade occurred in the unipolar pts group. Follow-up data at 97 [93-269] days revealed a sustained reduction in PVC burden in bipolar pts (from 18±13% to 7±9%; p=0.026) while unipolar ablation did not show a significant burden reduction (15±6% to 11±10%; p=0.382). The success rate of a relative burden reduction >50% did not differ significantly between the groups (bipolar: 6 pts [67%] 3 pts [38%]; p=0.347). Conclusion Bipolar ablation offers an effective and safe therapeutic approach for PVCs originating from the LV summit. It significantly reduced PVC burden in this analysis. The data suggest that a repeat procedure after a failed summit PVC ablation should only be performed if bipolar ablation is available during the second procedure. Larger studies are warranted to confirm efficacy and safety of this ablation method.

Pulsed field ablation versus very high power short duration radiofrequency ablation in atrial fibrillation: what is better?

Abstract Background The newly introduced non-thermal pulsed field ablation (PFA) is a promising technology for catheter ablation (CA) of atrial fibrillation (AF) with high acute success rates and good safety features. However studies have shown that very high power short duration (VHPSD) ablation is also highly effective and fast with potentially less arrhythmia recurrence compared to conventional radiofrequency ablation. Data comparing this two methods are lacking Objective The aim of this study is to compare two source of energy used for CA of AF in terms of procedural, clinical and outcome data Methods We conduced a retrospective observational study enrolling all patients (pts) from september 2021 to may 2023 who underwent CA of AF with PFA system and VHPSD. In the PFA group pulmonary veins isolation (PVI) was obtained using 2KV with eight application each vein, posterior wall isolation (PWI) of left atrium (LA) was obtained with application in the flower configuration of the catheter and then additional lesion were deployed at the operator’s discretion. In the VHPSD group the encircling of PV was obtained with 90W for 4 seconds radiofrequency pulses in posterior portions of the LA including LA PW, whereas 50W with ablation index target of 500 was used in the anterior portions of the PV and additional lesions. General anesthesia or deep sedation was carried out in all pts Results A total of 205 pts were included, n = 86 (42%) in the PFA group and N = 119 (58%) in the VHPSD group: paroxysmal (n = 62[72%], N = 64[54%]), persistent (n = 19[22%], N = 43[36%]), long standing persistent (n = 5[5%], N = 10[8%]). PVI was successful in all pts and additional lesions were delivered in n = 26 (30%) in PFA group and N = 76 (64%) in HVPSD group, mostly at the PW (n = 24[92%]; N = 50[66%]). The PFA group revealed a shorter procedura duration (80 ± 29 min vs 108 ± 39 min; p = 0,00001) but longer fluoroscopic time (21 ± 8 min vs 14 ± 10 min; p = 0,00001). The VHPSD group revealed more complications (N = 7[6%] vs n = 3[3%]) but without statistically significant difference (p = 0,43), the most frequent in the PFA group was vascular access complications instead in the VHPSD group was post-procedural pericarditis. Only one patient in VHPSD group had major complication with a post-procedural stroke but without residual neurological deficits. At follow-up after median of 14 (26-6) months, n = 61 pts in the PFA group (71%) and N = 91 in the VHPSD group (76%) were free from atrial arrhythmia (p = 0,79). In both group 7 pts recurrenced as atypical atrial flutter (n = 7[28%] PFA; N = 7[25%] VHPSD; p = 0,061) Conclusion PFA and VHPSD are effective and safe to CA of AF with comparable arrhythmia recurrenses. However procedure duration with PFA is significantly shorter and therefore may be of potential benefit in particular for elderly and frail pts. Further research, including randomized controlled trials, is needed to validate and compare these techniques more comprehensively

Dual-energy lattice-tip ablation system for persistent atrial fibrillation: a randomized trial

Clinical outcomes of catheter ablation for atrial fibrillation (AF) are suboptimal due, in part, to challenges in achieving durable lesions. Although focal point-by-point ablation allows for the creation of any required lesion set, this strategy necessitates the generation of contiguous lesions without gaps. A large-tip catheter, capable of creating wide-footprint ablation lesions, may increase ablation effectiveness and efficiency. In a randomized, single-blind, non-inferiority trial, 420 patients with persistent AF underwent ablation using a large-tip catheter with dual pulsed field and radiofrequency energies versus ablation using a conventional radiofrequency ablation system. The primary composite effectiveness endpoint was evaluated through 1 year and included freedom from acute procedural failure and repeat ablation at any time, plus arrhythmia recurrence, drug initiation or escalation or cardioversion after a 3-month blanking period. The primary safety endpoint was freedom from a composite of serious procedure-related or device-related adverse events. The primary effectiveness endpoint was observed for 73.8% and 65.8% of patients in the investigational and control arms, respectively (P < 0.0001 for non-inferiority). Major procedural or device-related complications occurred in three patients in the investigational arm and in two patients in the control arm (P < 0.0001 for non-inferiority). In a secondary analysis, procedural times were shorter in the investigational arm as compared to the control arm (P < 0.0001). These results demonstrate non-inferior safety and effectiveness of the dual-energy catheter for the treatment of persistent AF. Future large-scale studies are needed to gather real-world evidence on the impact of the focal dual-energy lattice catheter on the broader population of patients with AF. ClinicalTrials.gov identifier: NCT05120193.

Long-Term Safety and Efficacy of Transcatheter Microwave and Radiofrequency Denervation in a Chronic Ovine Model.

Transcatheter renal denervation (RDN) has had inconsistent efficacy and concerns for durability of denervation. We aimed to investigate long-term safety and efficacy of transcatheter microwave RDN invivo in normotensive sheep in comparison to conventional radiofrequency ablation. Sheep underwent bilateral RDN, receiving 1 to 2 microwave ablations (maximum power of 80-120 W for 240 s-480 s) and 12 to 16 radiofrequency ablations (180 s-240 s) in the main renal artery in a paired fashion, alternating the side of treatment, euthanized at 2 weeks (acute N=15) or 5.5 months (chronic N=15), and compared with undenervated controls (N=4). Microwave RDN produced substantial circumferential perivascular injury compared with radiofrequency at both 2 weeks [area 239.8 (interquartile range [IQR] 152.0-343.4) mm2 versus 50.1 (IQR, 32.0-74.6) mm2, P <0.001; depth 16.4 (IQR, 13.9-18.9) mm versus 7.5 (IQR, 6.0-8.9) mm P <0.001] and 5.5 months [area 20.0 (IQR, 3.4-31.8) mm2 versus 5.0 (IQR, 1.4-7.3) mm2, P=0.025; depth 5.9 (IQR, 1.9-8.8) mm versus 3.1 (IQR, 1.2-4.1) mm, P=0.005] using mixed models. Renal denervation resulted in significant long-term reductions in viability of renal sympathetic nerves [58.9% reduction with microwave (P=0.01) and 45% reduction with radiofrequency (P=0.017)] and median cortical norepinephrine levels [71% reduction with microwave (P <0.001) and 72.9% reduction with radiofrequency (P <0.001)] at 5.5 months compared with undenervated controls. Transcatheter microwave RDN produces deep circumferential perivascular ablations without significant arterial injury to provide effective and durable RDN at 5.5 months compared with radiofrequency RDN.

Investigation of Optimal Needle Position for Radiofrequency Ablation-Based Blockade of Interspace between the Popliteal Artery and the Posterior Capsule of the Knee: A Cadaveric Study.

Background and Objectives: The interspace between the popliteal artery and the posterior capsule of the knee (iPACK) block has been widely used in perioperative settings to control posterior knee pain and can additionally be used for chronic knee pain. In this cadaveric study, we aimed to investigate the needle tip position and its proximity to the articular branch of the tibial nerve (ABTN) during an iPACK-targeted radiofrequency procedure. Materials and Methods: An ultrasound-guided iPACK block was performed on 20 knees of 10 cadavers. We injected 0.1 mL each of blue and green gelatinous dye near the tibial artery (point A) and posterior knee capsule (point B), respectively, and evaluated the spread of both around the ABTN. For a hypothetical conventional radiofrequency ablation (RFA) lesion (diameter, 2.95 mm) and cooled RFA lesion (diameter, 4.9 mm), we counted the number of specimens in which the ABTNs would be captured. Results: The percentage of specimens in which the ABTN would be captured by a cooled RFA lesion was 64.71% at point A and 43.75% at point B (p = 0.334). Meanwhile, the percentage of specimens in which the ABTN would be captured by a conventional RFA lesion was 58.82% from point A and 25% from point B (p = 0.065). Conclusions: When performing an RFA-based iPACK block, the needle tip may be positioned either lateral to the tibial artery or in the space between the posterior knee capsule and the tibial artery. However, more studies with larger samples are needed to verify these results before the clinical use of this procedure can be recommended.

A rare case of an unexpected trigger of paroxysmal atrial fibrillation in the right atrial appendage diverticulum

IntroductionWe described a rare case of an adolescent girl with paroxysmal atrial fibrillation originating from the right atrial appendage diverticulum and successfully converted to sinus rhythm after surgical intervention.MethodsA 19-year-old girl was referred to the hospital for a catheter ablation of paroxysmal atrial fibrillation. conventional radiofrequency ablation using 3-D mapping were ineffective. Activation mapping showed the root of the free wall atrial appendage was first excited and catheter modeling (3D Carto map) showed a sac-like structure.ResultsWe did selective angiography and further Computed tomography angiography (CTA) and Transesophageal echocardiography (TEE) which showed diverticulum originating from the right atrial appendage. Hence the patient was referred to cardiac surgery and had no recurrent atrial fibrillation at three months postoperative follow up.ConclusionsRight atrial appendage diverticulum was an extremely rare malformation that can coexist with atrial tachyarrhythmia. Surgical ligation or excision of the abnormal structure with local ablation can achieve excellent results.

Bipolar radiofrequency ablation lesion areas and confluence: An exvivo study and technical report.

Radiofrequency ablation (RFA) has been used for nearly 100 years, treating an array of medical conditions including chronic pain. Radiofrequency (RF) energy depolarizes and repolarizes tissues adjacent to a probe producing heat and causing direct thermal injury. When positioned adjacent to neural structures, it leads to neural tissue injury and cell death interrupting pain signaling with the ultimate goal of providing lasting pain relief. Today, RFA is commonly used to treat cervical, thoracic, and lumbar zygapophyseal joints, sacroiliac joint, and more recently large peripheral joint-mediated pain. There are several applications of RFA systems, including bipolar, conventional thermal, cooled, protruding, and pulsed. As yet, no study has determined the best technical practice for bipolar RFA. This exvivo study examines RFA lesion midpoint (LMP) area and lesion confluence comparing three different commonly used gauge (g) probes (18-g, 20-g, and 22-g) with 10-mm active tips at various interprobe distances (IPD) to guide best technical practices for its clinical application. Bipolar RFA lesions were generated in preservative-free chicken breast specimens using three different gauge probes (18-g, 20-g, and 22-g) with 10-mm active tips at various IPD (6, 8, 10, 12, 14, 16, and 18 mm). RF was applied for 105 s (15-s ramp time) at 80°C for each lesion at both room and human physiological temperature. The specimen tissues were dissected through the lesion to obtain a length, width, and depth, which were used to calculate the LMP area (mm2 ). The LMP areas of each thermal ablation were investigated using visualization and descriptive analysis. The Kruskal-Wallis test was performed to compare LMP areas between the two temperature groups and the three different gauge probe subgroups at the various IPDs. Of the 36 RF lesions (14: 18-g, 12: 20-g, and 10: 22-g) performed, 24 demonstrated lesion confluence. The average time to reach 80°C was 16-17 s; therefore, the average time of RF-energy delivery (at goal temperature) was 88-89 s despite varying needle size or IPD. Comparing the 25 and 37°C groups, 18-g probes produced mean LMP areas of 73.7 and 79.2 mm2 , respectively; 20-g probes produced mean LMP areas of 66 and 66.8 mm2 , respectively; 22-g probes produced mean LMP areas of 56.6 and 59.7 mm2 , respectively. There was no statistical evidence to state a difference regarding LMP area between temperature groups; however, the 18-g probes produced consistently larger LMP areas in the 37°C compared to 25°C specimen groups at each IPD. Lesion confluence was lost for 18-g, 20-g, and 22-g probes at IPD of 14, 12, and 10 mm, respectively, in both 25 and 37°C groups. LMP area was similar between 6 and 8 mm IPD in all of the three-gauge groups; however, there was a significant drop in LMP area from 8 mm IPD to 10 mm and greater. The 18-g, 20-g, and 22-g probes all demonstrated a sharp decline in LMP area when increasing the IPD from 8 to 10 mm. This exvivo technical study evaluated bipolar RFA LMP areas and lesion confluence, and determined the recommended IPD of 18-g, 20-g, and 22-g probes to be less than 12, 10, and 8 mm, respectively, for best clinical practice. Placing bipolar probes at an IPD greater than 14, 12, and 10 mm, respectively, risks the loss of lesion confluence and failure to produce a clinically significant treatment response due to lack of nerve capture. In clinical practice, the use of injectate may produce larger lesions than demonstrated in this study. Additionally, invivo factors may impact ablation zone size and ablation patterns. As there are a paucity of studies comparing various RFA applications and conventional RFA needles are least expensive, it is possible that bipolar conventional RFA is more cost-effective than other techniques.

Experience of left ventricular outflow tract arrhythmia ablation in paediatric patients using limited fluoroscopy and three-dimensional mapping technique.

The left ventricular outflow tract is an important source of ventricular arrhythmias. Up to one-third of all idiopathic ventricular arrhythmias in patients with structurally normal hearts may arise from this region. We would like to share the results of our left ventricular outflow tract ablation using three-dimensional mapping and limited fluoroscopy. This is a single-centre retrospective cohort study. Forty-six consecutive patients who underwent left ventricular outflow tract ablation procedures between January 2015 and June 2023 were included in the study. The EnSite Precision System (Abbott, St. Paul, MN, USA) was used to facilitate mapping and to reduce or eliminate the need for fluoroscopy. The study group comprised 29 males and 17 females, with a mean age of 13.4 ± 4.5 years. The most common location for arrhythmias was the left coronary cusp (n : 21). Other locations, in sequence, included the junction of the right and left coronary commissure (n : 10), right coronary cusp (n : 10), left ventricular outflow tract endocardium (n:4), aorto-mitral junction (n : 1), and great cardiac vein (n : 1). Nine of these patients had previously undergone unsuccessful right ventricular outflow tract ablation at another centre. Cryoablation was performed in three patients, irrigated radiofrequency ablation in three patients, and conventional radiofrequency ablation in the remaining patients. The acute success rate was 100%, and no recurrences were observed. The mean follow-up period was 49.6 ± 24.4 months. All patients were asymptomatic and were being followed without antiarrhythmic medication. Although left ventricular outflow tract ablations pose a risk for coronary artery and heart valve complications, they can be performed successfully and safely with the guidance of three-dimensional mapping.

The Effect of Superficial Venous Incompetence Treatment on Combined Segmental Deep Venous Reflux

The aim of this study was to assess the role of treatment of superficial venous reflux (SVR) in patients with combined deep segmental venous reflux as regards clinical symptoms as well as reflux improvement of the deep veins. We reviewed 80 patients, retrospectively selected on the inclusion criteria and having combined SVR and segmental deep venous reflux who underwent SVR ablation. The contralateral limb of 44 patients was used as a control group, asked to wear compression stockings for 3months during day time with no surgical intervention. Duplex ultrasounds follow-up was performed at 3, 6, and 12months postoperatively. Clinical severity of venous disease was graded from C1 to C6 according to the CEAP (Clinical, Etiology, Anatomy, and Pathophysiology) classification. Duplex ultrasound was done in both supine and standing positions with non-weight-bearing of the examined limb. The venous reflux time, the venous flow volume and the peak venous flow velocity were registered. Removal of SVR was performed using either conventional surgery or radiofrequency ablation. The patient was required to wear compression stockings during the day time for the following weeks. During the follow-up period, all patients were improved clinically as regards pain, edema, and ulcer healing. All patients included in this study had no signs of residual SVR. Corrected deep venous segment reflux was in 36 (45%). Similar data at 3, 6, and 12months postoperatively after SVR removal. The popliteal vein reflux responded less than the femoral vein reflux did. Treatment of the SVR eliminates segmental deep venous reflux in a good percentage of patients regardless of the treatment modality. Also, symptoms improvement and ulcer healing were documented, and hence, more studies are recommended to evaluate this role.

Comparison of pulsed-field ablation versus very high power short duration-ablation for pulmonary vein isolation.

The newly introduced nonthermal pulsed field ablation (PFA) is a promising technology to achieve fast pulmonary vein isolation (PVI) with high acute success rates and good safety features. However, previous studies have shown that very high power short duration ablation (VHPSD) is also highly effective and fast to achieve PVI with potentially less arrhythmia recurrence compared to conventional radiofrequency ablation. Data comparing PFA to VHPSD-PVI is lacking. This study compared procedural and outcome data for PFA-PVI to VHPSD-PVI in patients with paroxysmal or persistent atrial fibrillation (PAF/persAF). Consecutive patients undergoing de novo PVI (PFA or VHPSD) were included in this analysis. For PFA-PVI a pentaspline 20 electrode catheter was used. For VHPSD-PVI an enhanced irrigated catheter with a power setting of 70 W/7 s (70 W/5 s at posterior wall) was employed in conjunction with electro-anatomical mapping. All procedures were performed in deep analgo-sedation. A total of n = 114 patients (n = 57[50%] PFA, n = 17[30%] PAF; n = 40[70%] persAF) were included in this analysis. PVI was successful in all patients. The PFA group revealed a significantly shorter procedure duration (65 ± 17 min vs. 95 ± 23 min, p < 0.01) but longer fluoroscopy time (PFA 15 ± 5 min and VHPSD 12 ± 3 min; p < 0.001). At follow-up after median 125 days (interquartile range: 109-162) n = 46 PFA (80.7%) and n = 44 VHPSD pts (77.2%) were free from atrial arrhythmia after a single procedure (p = 0.819). Two tamponades occurred in the PFA while in VHPSD two pts suffered groin bleedings. One clinically nonsignificant PV stenosis occurred in the VHPSD group. Pulsed-field ablation and VHPSD-PVI seem to be highly effective and safe to achieve PVI in the setting of PAF and persAF with comparable arrhythmia-free survival. However, procedure duration for PFA PVI is significantly shorter and therefore may be of potential benefit. Compared to PFA VHPSD-PVI might ensure information on left atrial substrate allowing to target concomitant secondary tachycardias.

Comparison of pulmonary vein isolation using cryoballoon, high-power short-duration, and conventional radiofrequency ablation for atrial fibrillation: a propensity score-weighted study.

The comparative efficacy, saftey, and heart rate variability (HRV) parameters after pulmonary vein isolation using cryoballoon (Cryo-PVI), high-power short-duration (HPSD-PVI), and conventional radiofrequency ablation (conventional-PVI) for atrial fibrillation (AF) is unclear. In this propensity score-weighted, retrospective analysis of a single-center cohort, we analyzed 3,395 patients (26.2% female, 74.5% paroxysmal AF) who underwent AF catheter ablation without an empirical left atrial ablation. Procedural factors, recurrence rates, complication rates, and the post-procedural HRV parameters were compared across the Cryo-PVI (n = 625), HPSD-PVI (n = 748), and conventional-PVI (n = 2,022) groups. Despite the shortest procedural time in the Cryo-PVI group (74 min for Cryo-PVI vs. 104 min for HPSD-PVI vs. 153 min for conventional-PVI, p < 0.001), the major complication (p = 0.906) and clinical recurrence rates were similar across the three ablation groups (weighted log-rank, p = 0.824). However, the Cryo-PVI group was associated with a significantly lower risk of recurrent AF in patients with paroxysmal AF [weighted hazard ratio (WHR) 0.57, 95% confidence interval (CI) 0.37-0.86], whereas it was associated with a higher risk of recurrent AF in patients with persistent AF (WHR 1.41, 95% CI 1.06-1.89, p for interaction of <0.001) compared with the conventional-PVI group. In the subgroup analysis for the HRV, the Cryo-PVI group had the highest low-frequency-to-high-frequency ratio at 1-year post-procedure, whereas the HPSD-PVI group had the lowest low-frequency-to-high-frequency ratio at 1-year post-procedure (p < 0.001). The Cryo-PVI group had better rhythm outcomes in patients with paroxysmal AF but worse rhythm outcomes in patients with persistent AF and a higher long-term post-procedural sympathetic nervous activity and sympatho-vagal balance compared with the conventional-PVI group.

COMPARISON BETWEEN CONVENTIONAL HIGH LIGATION AND STRIPPING AND RADIOFREQUENCY ABLATION FOR GREAT SAPHENOUS VARICOSE VEINS

The prospective study was conducted from December 2022 to May 2023 to assess patient-based, radiological, and clinical outcomes after conventional surgery and radiofrequency ablation for great saphenous varicose veins. Patients were randomly divided to undergo conventional surgery or RFA. American Society of Anesthesiologists fitness grade, Venous Disability Score (VDS), Total Clinical Severity Score (TCSS), Michael's, and CEAP clinical classes were recorded. VEINES-QoL/Sym questionnaire and Aberdeen Varicose Vein Questionnaire were used to estimate baseline QoL. Patients were called for follow-up at the end of 1st and 5th week. The study was conducted on a total of 110 patients. Patients were randomly divided; 57 underwent RFA, and 53 underwent conventional surgery. Results showed that the difference between both groups regarding anesthesia induction, recovery, and discharge from surgery was insignificant. RFA had significantly longer total theater time compared to conventional surgery. Duplex imaging showed that RFA resulted in successful ablation except in two cases where veins had segmental brisk flow. These cases were retreated successfully. Conventional surgery only had the problem of incomplete stripping (6 cases). Post-operative pain, bruising, and the need for analgesia were significantly higher following conservative surgery. Patients in the RFA group returned to work and normal activities more quickly than the conventional surgery group. It is concluded that RFA had a longer intervention time but significantly better outcomes than conventional surgery.

Comparison of the effects of contrast-enhanced ultrasound and conventional ultrasound-guided radiofrequency ablation on benign thyroid nodules.

To compare the effect of contrast-enhanced ultrasound (CEUS) and conventional ultrasound-guided radiofrequency ablation (RFA) on benign thyroid nodules (BTNs). In this retrospective observational study, the data of 72 patients with BTNs who received RFA treatment in The Fourth Affiliated Hospital of Zhejiang University School of Medicine from January 2020 to December 2021 were retrospectively reviewed and selected. The records showed that 34 patients received RFA under the guidance of conventional ultrasound (conventional ultrasound group) and 38 patients received RFA under the guidance of CEUS (CEUS group). The effect of treatment, complications and recurrence of the two groups were compared and analyzed. There was a smaller volume of thyroid nodules in the two groups immediately post-operation. The incidence of complications was lower in the CEUS group (5.26%) compared to the conventional ultrasound group (23.53%) (P<0.05). The recurrence rate at 6-months (0.00% vs 11.76%) and 12- months (2.63% vs 20.59%) post-operation was lower in the CEUS group compared to the conventional ultrasound group (P<0.05). Compared with conventional ultrasound, CEUS-guided RFA is effective in treating BTNs, with smaller postoperative nodule volume, reduced occurrence of surgical complications, and reduced recurrence rate of thyroid nodules.