Cryoballoon ablation versus radiofrequency ablation for atrial fibrillation

Catheter ablation (CA) provides the most effective treatment option for patients suffering from symptomatic atrial fibrillation (AF). The procedural cornerstone of all ablation strategies and for all entities of AF is the electrical isolation of the pulmonary veins (PV). CA with the use of radiofrequency (RF) in conjunction with a 3-dimensional electroanatomical mapping system is the most established ablation approach, but it demands a long learning curve and recurrences of AF are commonly the result of recovered PV conduction. As a consequence, novel ablation systems such as the Cryoballoon (CB) have been evolved aiming at facilitation and increased efficacy of pulmonary vein isolation (PVI). CB ablation is characterized by a short learning curve as well as short procedure times and demonstrated non-inferiority with regard to safety and efficacy when being directly compared to RF ablation for treatment of paroxysmal AF. However, RF ablation is first choice for treatment of persistent AF, in particular when expanded ablation strategies beyond PVI are intended in order to improve clinical outcomes.     

房颤治疗:外科射频消融术与内科导管射频消融术孰优?

诸学时:2006年10月13日,中国第一家房颤研究治疗中心——北京安贞医院房颤中心,在北京召开的第四届五洲国际心血管病研讨会上正式宣告成立。该中心集医疗、科研、教学、培训和咨询五位一体,整合了安贞医院心脏内科和外科两支房颤研究治疗团队的力量,优势互补。其学科带头人均是我国著名心脏病学专家。心脏内科马长生教授于1998年率先在国内开展房颤的经导管射频消融治疗,截至目前已累计完成近千例,为国内最大系列。在心脏外科孟旭教授带领下,2002年安贞医院开始外科直视下的房颤射频消融术,至今累计完成420例,为国内最大系列,也是亚洲范围内…     

Cryosurgical versus catheter ablation of the atrioventricular junction

Results of catheter ablation of the atrioventricular (AV) junction in 41 patients were compared with results of cryosurgical ablation in 42 patients. Mean follow-up was 29 months among patients who underwent catheter ablation and 53 months among those who underwent cryosurgical ablation. In both groups complete heart block was produced in most patients (88% in the catheter ablation group, 86% in the cryosurgery group), and similar proportions of patients continued to receive antiarrhythmic drugs (27% in the catheter ablation group, 36% in the cryosurgery group). However, the short-term morbidity rate was significantly lower among patients who underwent catheter ablation (12% vs 42%) (p = 0.004). Long-term mortality and morbidity rates were not significantly different; most deaths were related to underlying cardiopulmonary disease and morbidity to problems with permanent pacemakers. Both catheter ablation and cryosurgical ablation of the AV junction are effective in creating complete AV block and controlling supraventricular tachycardia in medically refractory patients. Because catheter ablation is associated with lower short-term morbidity and avoids the need for a major surgical procedure, it is preferable to cryosurgical ablation of the AV junction when permanent abolition of AV conduction is necessary.     

Supraventricular tachyarrhythmias: Drug therapy versus catheter ablation

Until recently, the only options available for treatment of supraventricular arrhythmias involved the use of drug therapy or cardiac surgery. However, over the past several years with the introduction of radiofrequency energy sources as well as steerable catheters, the clinician has a variety of additional nonpharmacologic options. This article reviews the use of pharmacologic therapy versus catheter ablation for the treatment of reentrant supraventricular arrhythmias, involving the atrioventricular junction and/or accessory atrioventricular connection, as well as arrhythmias emanating from the atria such as atrial fibrillation, atrial flutter, and atrial tachycardia.     

Microwave ablation versus radiofrequency ablation for perivascular hepatocellular carcinoma: a propensity score analysis

BackgroundTo compare the efficacy and safety of microwave ablation (MWA) and radiofrequency ablation (RFA) as first-line treatments for perivascular HCC.MethodsThis multicentre study enrolled 170 patients with perivascular HCC who underwent MWA or RFA. The ablation response, progression-free survival (PFS), overall survival (OS), and complications between the treatment groups for the total and propensity score-matched (PSM) cohorts were compared.ResultsThe disease control rates for MWA and RFA were similar in total (94% vs. 91%, p = 0.492) and PSM (93% vs. 93%, p = 1.00) cohorts. The PFS rates at 1, 3, and 5 years were 71%, 55% and 52% in MWA group and 61%, 33% and 28% in RFA group (p = 0.017). The OS rates were comparable between two groups in total (p = 0.249) and PSM cohorts (p = 0.345). In subgroup analyses, the PFS of patients with periportal HCC (45 vs. 36 months, p = 0.048) and a single HCC nodule (51 vs. 42 months, p = 0.014) were significantly better in MWA group than RFA. Major complications were more frequent in the MWA group than in RFA (27% vs. 7%, p < 0.001).ConclusionCompared with RFA, MWA provides better control of tumour progression especially in periportal HCC or single-nodule perivascular HCC patients.     

Percutaneous radiofrequency ablation versus surgical radiofrequency ablation for malignant liver tumours: the long-term results

Background

Radiofrequency ablation (RFA) has been used to treat hepatocellular carcinoma (HCC) and liver metastases for more than 10 years with promising early outcomes. Preliminary results comparing percutaneous and surgical approaches have shown no difference in short-term outcomes. In this study, the longer-term outcomes were presented.

Methods

Patients with liver malignancies treated by RFA were prospectively studied from 2003 to 2011. Post-ablation assessment by computed tomography (CT) scan and serum biochemistry was performed at regular intervals. Recurrence rates and long-term survival were analysed.

Results

A total of 233 patients with liver malignancies (75.5% HCC and 24.5% liver metastases) were analysed. Three RFA approaches were used (percutaneous 58.4%, laparoscopic 9.4% and open 32.2%). The median follow-up time was 29 months. Complete ablation was achieved in 83.7%, with no difference between the two approaches. More wound and chest complications were observed in the surgical group. Intra-hepatic recurrences were observed in 69.5%; extra-hepatic recurrences were detected in 22.3%, with no difference between the two groups. There was no statistical difference between the two approaches in overall 1-, 3- and 5-year survival.

Conclusion

An extended period of follow-up in patients with liver malignancies showed that RFA is an effective treatment. No difference was demonstrated between the percutaneous and surgical approach, in terms of recurrence and survival.     

Cryoablation versus radiofrequency ablation of atrioventricular nodal reentrant tachycardia

Background

Ablation of the slow pathway is an established cure for atrioventricular nodal reentrant tachycardia (AVNRT). Periprocedural damage to the conduction system is a major concern during AVNRT ablation, and cryoablation (CRYO) has been suggested to improve the procedural safety compared to standard radiofrequency (RF) ablation, without reducing the procedural success.

Objective

We performed a systematic review and meta-analysis of studies comparing CRYO with RF ablation of AVNRT.

Methods

We searched PubMed, CENTRAL, the BioMed Central, EMBASE, CardioSource, clinicaltrials.gov, and ISI Web of Science (January 1980 to July 2013). No language restriction was applied. Two independent reviewers screened titles and abstracts to identify studies that compared the procedural outcomes of AVNRT ablation with either CRYO or RF energy. Two independent reviewers assessed the risk of bias according to the Cochrane Collaboration, and extracted patient, study characteristics, and procedural outcome data. Results are expressed as odds ratio (OR) or as weighted mean difference (WMD) with their 95 % confidence interval (CI).

Results

Fourteen studies (5 prospective randomized and 9 observational) with 2,340 patients (mean age range 13 to 53 years, 1,522 (65 %) females) were included in the analysis. RF ablation was performed in 1,262 (54 %) patients, while CRYO in 1,078 (46 %) patients. Acute success (abolition of dual atrioventricular node physiology or single echo beats) was achieved in 88 % of patients treated with RF versus 83 % of those treated with CRYO (OR?=?0.72, 95 % CI 0.46 to 1.13; P?=?0.157). RF ablation was associated with shorter total procedure time (WMD?=??13.7 min, 95 % CI ?23 to ?4.3 min; P?=?0.004), but slightly longer fluoroscopy time (WMD?=?+4.6 min 95 % CI +1.7 to +7.6 min; P?=?0.002). Permanent atrioventricular block occurred in 0.87 % RF cases and in no CRYO case (OR?=?3.60, 95 % CI 1.09 to 11.81; P?=?0.035). Over a median follow-up of 10.5 months (range 6 to 12 months), freedom from recurrent AVNRT was 96.5 % in the RF group versus 90.9 % in the CRYO group (OR?=?0.40, 95 % CI 0.28 to 0.58; P?<?0.001). At meta-regression analysis, no clinical or procedural variable had a significant interaction with the results above.

Conclusions

In patients undergoing AVNRT ablation, RF significantly reduces the risk of long-term arrhythmia recurrence compared to CRYO, but is associated with a higher risk of permanent atrioventricular block.     

冷冻球囊与射频消融术治疗阵发性心房颤动有效性及安全性的比较

目的:导管消融术是一项治疗心房颤动(AF)的成熟技术。冷冻球囊消融术(CBA)是射频消融术(RFA)的替代选择。然而,两种术式治疗中国阵发性AF患者的对比资料较少。本研究将从手术资料、有效性、安全性等方面对两种术式进行比较。方法:本研究纳入自2014年7月1日至2017年6月30日,于首都医科大学附属北京安贞医院选择CBA或RFA治疗阵发性AF的患者。主要终点事件为AF复发,即术后3个月的空白期外,由心电图记录到持续时间30s的AF、心房扑动或房性心动过速。此外,本研究对手术相关资料以及主要并发症进行对比。结果:共纳入阵发性AF患者399例(CBA组102例,RFA组297例)。CBA组总手术时间[(124.6±40.0)vs.(112.6±41.4)min,P=0.012]及总透视时间[15.0(10.0,25.0)vs. 10.0(8.0,16.0)min,P0.001]均长于RFA组。两组的并发症发生率,差异无统计学意义。在为期1年的随访期间,两组的复发率差异无统计学意义(29.4%vs. 27.9%,P=0.706)。结论:CBA和RFA治疗阵发性AF的1年复发率差异无统计学意义,RFA的总手术时间及总透视时间更短。     

Comparison of radiofrequency ablation in normal versus scarred myocardium

INTRODUCTION: Reentrant circuits causing ventricular tachycardia are closely associated with previously scarred myocardium. The presence of scar has been blamed for the poor success rate of radiofrequency ablation (RFA) in that context. This article investigates the in vivo effects of radiofrequency ablation in myocardium scarred from acute myocardial infarction. METHODS AND RESULTS: Anterior myocardial infarction was induced in five dogs by ligating the left anterior descending artery. The mean left ventricular ejection fraction after infarction was 38%. At a mean of 15 weeks following myocardial infarction, 50 RFA lesions were created in random order, 25 in scarred and 25 in normal myocardium using a needle electrode (21 gauge, 5 mm in length) introduced from the epicardium of the left ventricle at thoracotomy. During unipolar temperature-controlled RFA (90 degrees C for 60 seconds), intramural temperatures were measured by thermistors at distances of 1, 2, 3, 4, and 5 mm from the ablating electrode. The margins of the lesions were clearly discernible in scar at histological examination in 64% of ablations where the scarring was patchy. There were no significant differences between lesion sizes, intramural temperatures at different distances, total energy required for ablation, or mean impedance during ablation of normal versus scarred myocardium. CONCLUSIONS: Scar does not affect lesion size or intramural temperature profile during RFA if electrode size, tissue contact, and tip temperature are controlled. More radiofrequency energy is not required to maintain tip temperature at 90 degrees C in scar compared to normal myocardium.     

The case for saphenous ablation versus simple proximal ligation.

New modalities of treatment for primary varicose veins are being increasingly used. This is because traditional stripping and sapheno-femoral junction ligation is requires a general anaesthetic and is associated with postoperative pain and bruising. This article aims to address the evidence and long-term follow up of the new surgical techniques and compare them to traditional sapheno-femoral ligation.     

Comparison of unipolar versus bipolar ablation and single electrode control versus simultaneous multielectrode temperature control

Background Creation of linear lesions using multielectrode catheters may be effective at treating cardiac arrhythmias. Objective We compared unipolar versus bipolar ablation, evaluated the effects of varying effective electrode areas, and compared single electrode versus multielectrode temperature control during multielectrode radiofrequency ablation. Methods Intramural radiofrequency ablation was performed on five greyhounds at thoracotomy, from an epicardial approach using a 0.8 mm diameter bipolar electrode needle. Fifteen left ventricular ablations were performed per animal. Intramural ablation was performed to maintain a constant electrode–tissue interface. The distal and proximal electrodes measured 1.5 and 1.0 mm in length respectively with an interelectrode distance of 4 mm. Radiofrequency energy was applied to both electrodes simultaneously for 60 s using a target temperature of 80°C. During bipolar ablation, the temperature was regulated from either the distal (BPA1.5) or proximal (BPA1.0) electrode only. During unipolar ablation (UPA), the temperature at both electrodes were simultaneously controlled. Lesions were assessed histologically. Results During UPA, consistent target temperatures were achieved at both electrodes. In comparison to UPA, the temperature at both electrodes were significantly decreased during BPA1.0. During BPA1.5 a significant (p < 0.001) temperature increase (94.7 ± 2.1°C) was observed at the 1.0 mm electrode. BPA1.0 resulted in reduced (p = 0.008) lesion width at the 1.5 mm electrode and no change in lesion depth (p = 0.064) at both electrodes compared to UPA. Conversely, lesion dimensions increase significantly at both electrodes during BPA1.5. Conclusion Unipolar multielectrode ablation with simultaneous temperature control at both electrodes is more predictable and hence likely to be safer than bipolar ablation.