Novel approach for pericapsular radiofrequency ablation of sacrococcygeal junction for patients with coccydynia

IntroductionCoccydynia is a multifactorial complex clinical challenge. A multimodal approach with both conservative measures and procedural interventions is often recommended. We described a novel approach of radiofrequency (RF) ablation for the management of coccydynia.MethodsThree patients with known history of coccydynia refractory to conservative therapy were referred to our clinic. All received different types of RF ablation before: one with anterior bipolar lesion with no analgesia benefit, one with posterior stripped lesion with good benefit but only after 8 weeks of pain flare and one received anterior monopolar lesion with 50% pain reduction for 2–3 months. All subjects underwent a novel RF ablation to the anterior surface of the sacrococcygeal and intercoccygeal joints with two bipolar lesions using multi-tined needles under fluoroscopy guidance. One bipolar lesion was between two needles: one in the sacrococcygeal and another in the intercoccygeal (between first and second coccyx) joints. Another bipolar lesion was between needles on both side of the sacrococcygeal joint.ResultsAll experienced at least 65% pain relief for 6 months. The sitting endurance increased from less than 5 min to an average of 70 min. No adverse effect was observed in two and in the patient who used to have pain flare after lesioning, the pain flare lasted only for 2 weeks.DiscussionThe configuration of the two bipolar lesions with multi-tined needles in this case series stimulates the thinking of new approach for the ablation technique for pain from coccyx. Further prospective large case cohort study is needed.

Predictors of VT recurrence in patients with VT inducibility at the end of radiofrequency ablation: Should we use VT non-inducibility as a routine endpoint?

Introduction: It has been reported that ventricular tachycardia (VT) non-inducibility at the end of ablation is associated with less likely VT recurrence. However, it is not clear whether we should use VT non-inducibility as routine end point in VT ablation. The aim of this study was to evaluate VT recurrence in patients in whom VT non-inducibility could not be achieved at the end of the RF ablation and the factors attributing to the VT recurrence. METHODS and RESULTS: We analyzed 84 consecutive patients that underwent RF ablation, and 64 patients in whom VT non-inducibility could not be achieved were studied. The primary endpoint was recurrence of any sustained VT during the follow-up. During a median follow-up period of 1.4 years (IQR:0.3-2.0), 22 (34%) of the cases had VT recurrences. In the multivariate analysis showed that an LVEF≥35% (HR:0.21; 95% CI:0.07- 0.54; P<0.01) and successful identification and ablation of all clinical VT isthmuses (HR:0.21; 95% CI:0.03- 0.72; P=0.01) were independent predictors of fewer VT recurrences. RF ablation was associated with a 91.1% reduction in VT episodes. CONCLUSION: Even if VT non-inducibility could not be achieved, the patients with LVEF≥35% or in whom all clinical VT isthmuses could successfully be identify and ablated might be prevented from having VT recurrences. The validity of VT non-inducibility of any VT should be evaluated by each patient’s background and the results of the procedure.

Evaluatıon Of The Effect Of Pulmonary Veın Isolatıon Treatment With Left Atrıal Catheter Ablatıon Method On Atrıal Conductıon Tımes In Patıents With Paroxysmal Atrıal Fıbrıllatıon

Purpose:Atrial fibrillation(AF) causes structural, electrical, and cellular remodeling in the atrium. Evaluation of intra- and interatrial conduction time, which is measured by tissue doppler echocardiography, indicates structural and electrical remodeling in the atrium. The aim of this study was to evaluate the effect of pulmonary vein isolation applied with RF ablation therapy on intra- and interatrial conduction time and to investigate the structural and electrically remodeling after treatment. Methods:Fifty-two patients with symptomatic PAF despite at least one antiarrhythmic drug and without structural heart disease were included in the study. Two patients were excluded because of complications developed during and after the operation. Fifty patients (28 female; mean age: 51.68 ± 11.731; mean left atrial diameter: 36.79 ± 4.318) who underwent CARTO® 3D pulmonary vein isolation applied with the RF ablation system were followed-up. Intra- and the inter-atrial electromechanical delay was measured in all patients by tissue doppler echocardiography before and three months after RF ablation. Results:All intra- and interatrial conduction times were significantly decreased 3 months after RF ablation procedure(PA lateral p = 0.022; PA septum p = 0.002; PA tricuspid p = 0.019, interatrial conduction delay p= 0,012, intra-atrial conduction delay p = 0.029). Conclusion:The results of our study suggest that providing stable sinus rhythm by the elimination of the AF triggering mechanisms with RF ablation of pulmonary vein isolation may slow down,stop or even improve structural remodeling at substrate level secondary to AF even in patients who did not yet develop atrial fibrosis and permanent structural changes.

Post-cardiac injury syndrome triggered by radiofrequency ablation for AVNRT

Background Post-cardiac injury syndrome (PCIS) is an inflammatory condition following myocardial or pericardial damage. In response to catheter ablation, PCIS most frequently occurs after extensive radiofrequency (RF) ablation of large areas of atrial myocardium. Minor myocardial injury from right septal slow pathway ablation for atrioventricular nodal reentrant tachycardia (AVNRT) is not an established cause of the syndrome. Case presentation A 62-year-old women with a 6-year history of symptomatic narrow-complex tachycardia was referred to perform an electrophysiological study. During the procedure AVNRT was recorded and a total of two RF burns were applied to the region between the coronary sinus and the tricuspid annulus. Pericardial effusion was routinely ruled out by focused cardiac ultrasound. In the following days, the patient developed fever, elevated inflammatory and cardiac markers, new-onset pericardial effusion, characteristic ECG changes, and complained of pleuritic chest pain. An extensive workup for infectious, metabolic, rheumatologic, neoplastic, and toxic causes of pericarditis and myocarditis was unremarkable. Cardiac magnetic resonance imaging showed no signs of ischemia, infiltrative disease or structural abnormalities. The patient was diagnosed with PCIS and initiated on aspirin and low-dose colchicine. At a 1-month follow-up visit the patient was free of symptoms but still had a small pericardial effusion. After three months of treatment the pericardial effusion had resolved completely. Conclusions Inflammatory pericardial reactions can occur after minor myocardial damage from RF ablation without involvement of structures in close proximity to the pericardium.

Concomitant real-time measurement and correlation of contact force to baseline local impedance and local impedance drops in RF ablation of left and right atrial procedures

Introduction Radiofrequency (RF) ablation is performed in various arrhythmias. Still, arrhythmia recurrence is a challenging problem, not only in atrial fibrillation (AF). One reason for arrhythmia recurrence is suspected to be due to remaining gaps. Measurement of local impedance (LI) and change of LI during RF application can be used as a predictor and surrogate for successful ablation. Another tool, used for the last couple of years, estimating sufficient tissue contact is provided by catheters with real-time contact force (CF) measurement. The new INTELLANAV STABLEPOINT™ catheter by Boston Scientific was recently introduced combing both strategies. We sought to investigate the parallel measurement and correlation of LI and CF in real-time during left atrial (LA) and right atrial (RA) procedures. Methods We included the first n=20 patients who underwent LA ablation for AF or atypical atrial flutter and n=7 patients who underwent RA procedures for atrial flutter or atrial tachycardia and analysed retrospectively procedural data. For every RF delivery RF duration, CF, baseline LI, minimal LI, LI drop, as well as minimal LI and LI drop after 5 and 10 sec was documented. Only RF deliveries with stable contact (ablation without delay) were included. We then correlated baseline LI to LI drop (maximum, after 5 sec, after 10 sec) and to the documented CF at baseline. Results A total of 27 procedures was analysed. In total, 777 RF deliveries (663 in LA, 114 in RA) were documented with a mean RF duration of 21.7 sec. Mean baseline LI was 148.4 Ω, minimal LI 130.6Ω, LI after 5 sec 135.0 Ω and LI after 10sec 132.5 Ω. Mean complete LI drop was 17.8 Ω (13.4 Ω after 5 sec, 15.8 Ω after 10 sec). Mean CF was 15.5g. We could see a significant positive correlation between average CF and LI drop (p&lt;0.01) (figure 1A), as well as between average CF and LI drop after 5 sec (p&lt;0.01) and after 10 sec (p&lt;0.01). Also, for baseline LI we could see a significant strong positive correlation to LI drop (p&lt;0.001) (figure 1B), LI drop after 5 sec (p&lt;0.001) and after 10 sec (p&lt;0.001). Baseline LI did not correlate to average CF. Baseline LI was significantly higher in RA, when compared to LA (152.5Ω vs. 147.7Ω; p&lt;0.05). LI drop did not differ between RA and LA procedures (17.8Ω vs. 17.7Ω), whereas mean RF duration per RF application was significantly longer in LA compared to RA procedures (22.8sec vs. 15.3sec; p&lt;0.001) and applied CF was also higher in LA compared to RA procedures (16.0Ω vs. 12.8Ω; p&lt;0.001). Conclusion Parallel real-time measurement of LI and CF is providing further insights into ablation biophysics. Based on these results the CF values might provide a prediction of subsequent lesion formation. A combination with LI measurement seems to be useful to prevent insufficient lesions, predisposing to gap formation and associated with arrhythmia recurrence, but also to potentially guarantee a higher safety by visualizing the applied CF and consecutive LI drop. FUNDunding Acknowledgement Type of funding sources: None. Figure 1

A tertiary centre experience comparing new temperature-controlled high-power short-duration ablation technology with standard radiofrequency and cryo-energy ablation

Introduction Pulmonary vein isolation (PVI) is an established treatment strategy for atrial fibrillation (AF). Radiofrequency (RF) ablation technology has evolved over the last decade with the very high-power short-duration (vHPSD) temperature-controlled ablation approach emerging as the latest development. The aim of this study was to determine the procedural efficacy, metrics and safety of vHPSD ablation with conventional power-controlled RF (PCRF) ablation and cryo-energy ablation (CRYO). Methods A prospective single tertiary centre analysis was performed on patients undergoing first time PVI ablation from 2019 to 2020. The population was divided in to 4 treatment arms; vHPSD, high-power short-duration (HPSD), PCRF and CRYO. Demographics, clinical and procedural metrics such as PVI duration, ablation time and sedation requirement were collated. Patients were monitored for perioperative complications. Results One hundred patients underwent ablation with 25 cases conducted in each arm. Complete PVI was attained in all study subjects. For the vHPSD group, PVI procedural duration, ablation and fluoroscopy times were 71.7±6.35 min, 9.21±0.76 min and 15.1±1.50 min respectively. The HSPD group exhibited total PVI, burn and fluoroscopy times of 90.2±5.59 min (p=0.03), 10.3±2.40 min (p&lt;0.0001) and 34.1±1.67 min (p=0.1) respectively. In comparison, the PCRF group exhibited longer procedure duration, ablation and fluoroscopy times of 93.3±6.50 min (p=0.01), 15.2±1.73 min (p&lt;0.0001), 37.8±2.47 min (p=0.870). Whereas procedural and fluoroscopy times of 96.3±7.1 min (p=0.01) and 18.8±1.31 (p=0.05) were observed in the cryo-ablation group. Procedural doses of morphine and midazolam for the vHPSD, HPSD, PCRF and CRYO group were 11.3 mg + 4.00 mg, 15.5 mg (p=0.0003) + 9.33 mg (p=0.0003), 15.7 mg (p=0.0002) + 8.03 mg (p=0.02), and 8.19 mg (p=0.01) + 4.84 mg (p=0.303) respectively. No adverse procedural events were recorded for the vHPSD while 2 pericardial effusions occurred in the PCRF group, 1 cardiac tamponade in the HPSD group and 2 transient ischaemic attacks in the CRYO group. Conclusion With the emergence of vHPSD RF ablation, preliminary findings indicate significant potential in reduction of procedural and ablation time. Further analysis is ongoing in order to ascertain longer-term efficacy and patient safety. FUNDunding Acknowledgement Type of funding sources: None. Intraprocedural outcomes Intraprocedural outcomes

Second-generation cryoballoon versus contact force radiofrequency ablation for atrial fibrillation: an updated meta-analysis of evidence from randomized controlled trials

Catheter ablation has been recommended for patients with symptomatic atrial fibrillation (AF), with pulmonary vein isolation being the cornerstone of the ablation procedure. Newly developed technologies, such as cryoballoon ablation with a second-generation cryoballoon (CB2) and the contact force radiofrequency (CF-RF) ablation, have been introduced in recent years to overcome the shortcomings of the widely used RF ablation approach. However, high-quality results comparing CB2 and CF-RF remain controversial. Thus, we conducted this meta-analysis to assess the efficacy and safety between CB2 and CF-RF using evidence from randomized controlled trials (RCTs). Databases including Embase, PubMed, the Cochrane Library, and ClinicalTrials.gov were systematically searched from their date of inception to January 2021. Only RCTs that met the inclusion criteria were included for analysis. The primary outcome of interest was freedom from atrial tachyarrhythmia (AT) during follow-up. Secondary outcomes included procedure-related complications, procedure time and fluoroscopy time. Six RCTs with a total of 987 patients were finally enrolled. No significant differences were found between CB2 and CF-RF in terms of freedom from AT (relative risk [RR] = 1.03, 95% confidence interval [CI] 0.92–1.14, p = 0.616) or total procedural-related complications (RR = 1.25, 95% CI 0.69–2.27, p = 0.457). CB2 treatment was associated with a significantly higher risk of phrenic nerve palsy (PNP) than CF-RF (RR = 4.93, 95% CI 1.12–21.73, p = 0.035). The occurrences of pericardial effusion/tamponade and vascular complications were comparable between the CB2 and CF-RF treatments (RR = 0.41, p = 0.398; RR = 0.82, p = 0.632). In addition, CB2 treatment had a significantly shorter procedure time than CF-RF (weighted mean difference [WMD] = − 20.75 min, 95% CI − 25.44 ~ − 16.05 min, P < 0.001), whereas no difference was found in terms of fluoroscopy time (WMD = 4.63 min, p = 0.179). CB2 and CF-RF treatment are comparable for AF patients regarding freedom from AT and procedure-related complications. Compared to CF-RF, CB2 treatment was associated with a shorter procedure time but a higher incidence of PNP. Further large-scale studies are warranted to compare these two techniques and provide an up-to-date recommendation.

Percutaneous Radiofrequency Ablation Treatment of Hepatocellular Carcinoma in Caudate Lobe Using Expandable Electrodes

Objective: To evaluate the outcome of radiofrequency (RF) ablation using expandable electrodes in the treatment of hepatocellular carcinoma (HCC) located in the caudate lobe.Materials and Methods: Between January 2011 and April 2017, 29 consecutive patients with HCC at the caudate lobe were treated with RF ablation using expandable electrodes. The electrodes were placed on the targeted tumor under combined ultrasound and computed tomography (CT) guidance for each tumor in all the patients. Out of the 29 cases, 19 (65.5%) were accessed via the left hepatic lobe. The technical success, primary efficacy, local tumor progression, secondary efficacy, overall survival, and complications were evaluated. Univariate analysis was performed of the various prognostic factors for technical success, primary efficacy, and local tumor progression.Results: The technical success rate was 86.2%, primary efficacy was 89.7%, and secondary efficacy was 82.8%. The local tumor progression (LTP) rate was 12.3% at one year and 31.5% at two years. The median time of LTP was 6.9 months. The overall survival rate was 85.8% at one year and 57.1% at two years. Ten patients died during the follow-up period (mean 22.5 months; with a range of 3.6–53.2 months). A minor complication of asymptomatic biloma was found in one patient (3.5%). Small-sized tumors (≤2 cm) and Spiegel’s lobe location had significantly better treatment outcomes (p = 0.007 and 0.045, respectively).Conclusion: Radiofrequency ablation using expandable electrodes is feasible and safe in treating HCCs located in the caudate lobe, especially for small-sized tumors (≤2 cm).