Cryoablation versus radiofrequency ablation for treatment of pediatric atrioventricular nodal reentrant tachycardia: Initial experience with 4-mm cryocatheter

BACKGROUND: Initial reports have shown cryoablation to be safe and efficacious for treatment of atrioventricular nodal reentrant tachycardia (AVNRT). No direct comparisons of cryoablation vs radiofrequency (RF) catheter ablation in pediatric patients have been made. OBJECTIVES: The purpose of this study was to compare the outcomes of cryothermal vs RF catheter ablation for treatment of AVNRT in pediatric patients. METHODS: We retrospectively reviewed consecutive ablation procedures for treatment of AVNRT at a single arrhythmia center. The RF group consisted of patients who underwent RF ablation from 2002 until cryothermy became available. The cryoablation group consisted of patients who underwent cryothermal ablation from 2004 to 2005. The groups were compared for procedural and electrophysiologic outcomes. RESULTS: RF (n = 60, age 14 +/- 4 years) and cryoablation (n = 57, age 14 +/- 4 years) groups had similar demographic and baseline parameters. Procedural times were shorter in the RF group (RF ablation 112 +/- 31 minutes vs cryoablation 148 +/- 46 minutes, P < .001). Fluoroscopy times were comparable (RF ablation 21 +/- 15 minutes vs cryoablation 20 +/- 13 minutes, P = .77). In an intention-to-treat analysis, success of the procedure was 100% for RF ablation and 95% for cryoablation (P = .11). No permanent AV block occurred in either group. Recurrence rates were higher for the cryoablation group, but this did not reach statistical significance (RF ablation 2% vs cryoablation 8%, P = .19). CONCLUSION: Cryoablation appears to be similar to RF for ablation of AVNRT with respect to short-term efficacy and safety of the procedure in a pediatric population. Recurrence rates are higher with cryoablation.     

手术切除联合术中氩氦刀冷冻和无水乙醇注射治疗结直肠癌多发性肝转移

目的探讨手术切除联合术中氩氦刀冷冻和无水乙醇注射治疗结直肠癌多发性肝转移的疗效与安全性。方法回顾性分析2005年1月至2010年12月间在广州医学院附属肿瘤医院胃肠肿瘤外科接受手术切除联合术中B超引导下氩氦刀冷冻消融和无水乙醇注射的23例无法完全切除的结直肠癌多发性肝转移患者的临床和随访资料。结果本组23例患者男15例,女8例．年龄34-69（平均52．2）岁。23例患者均顺利完成治疗,98个肝转移灶中,经手术切除45个,经氩氦刀联合无水乙醇注射处理53个。肝转移灶手术时间27-96min．术中出血量50～450ml。无围手术期死亡病例：术后出现少量胸腔积液和肌红蛋白尿各1例。所有患者均接受了8～70（中位时间34）个月的术后随访,1、3、5年总体生存率分别为83．2％、45．5％和37．6％。结论对于无法完全切除的结直肠癌多发性肝转移,采用手术切除联合术中氩氦刀冷冻和无水乙醇注射治疗安全有效。     

Prolongation of the fast pathway effective refractory period during cryoablation in children: A marker of slow pathway modification

BACKGROUND: The fast pathway effective refractory period (ERP) has been reported to decrease after slow pathway modification with radiofrequency (RF) energy. How the fast pathway ERP changes during the ablation application has not been reported with either RF or cryoenergy. OBJECTIVES: Using the unique features of cryotherapy, this study assesses the short-term changes in fast pathway ERP during cryomodification of the slow pathway and examines whether these changes are a useful marker for successful slow pathway modification in children. METHODS: Nineteen pediatric patients (median age 15.1 years, range 9.6-19.6 years; weight 60.7 kg, range 35.6-130.2 kg) with anterograde dual AV nodal physiology underwent slow pathway modification with catheter-based cryoablation. Programmed stimulation was performed during cryoapplications after reaching -25 degrees C to assess fast pathway and slow pathway conduction. Data were analyzed from 59 of 237 cryoapplications where the fast pathway ERP was measured more than once (n = 13 patients). RESULTS: For 23 of 59 applications where the slow pathway was modified, the fast pathway ERP significantly increased during cryotherapy (Delta = 33.5 ms, P <.0001). The magnitude of fast pathway ERP prolongation during cryotherapy was larger when the slow pathway was modified than when there was no effect on slow pathway conduction (33.5 +/- 30.5 vs 5.8 +/- 18.9 ms, P =.0005). Prolongation of fast pathway ERP by >/=20 ms had 70% sensitivity and 72% specificity for predicting slow pathway modification. Following termination of cryoapplications, which resulted in slow pathway modification, the fast pathway ERP had significantly decreased from baseline (difference 44.5 ms, P <.0001). The effect on fast pathway ERP was not related to changes in cycle length during (R(2) = 0.04, P = .045) or after ablation (R(2) = 0.13, P = .012). CONCLUSION: The fast pathway ERP prolongs during cryoapplications that result in slow pathway modification and shortens after termination of cryoapplications. The magnitude of fast pathway ERP prolongation during cryoapplication may be useful as a marker for successful slow pathway modification.     

冻融治疗后肝癌库普弗细胞分泌功能的变化

目的探讨冻融治疗后库普弗细胞(KCs)的分泌功能对肝癌细胞的影响及其变化机制。方法将实验分为16组:37℃对照组、三组低温组(0℃、5℃、10℃)、冻融坏死物质组和三组联合刺激组及以上每组分别设置一个平行组。8个平行组分别加入吡咯烷二硫代氨基甲酸酯(PDTC),终浓度为100μmol/ml。ELISA法测定16组KCs上清液中能反映KCs分泌功能的TNF-α、IL-1β和INF-γ的浓度,Western blot检测各组NF-κB蛋白的表达。结果低温和冻融坏死物质联合刺激KCs后,炎性因子TNF-α、IL-1β和IFN-γ的分泌增加(P<0.01),三组低温(0℃、5℃、10℃)与冻融坏死物质联合刺激均表现出叠加效应。低温刺激对NF-κB蛋白的表达无显著影响(P>0.05),联合刺激组和冻融坏死物质组NF-κB蛋白表达明显上调(P<0.05)。NF-κB抑制剂处理后,8组平行组间NF-κB蛋白的表达和炎性因子的分泌水平无明显变化(P>0.05)。TNF-α、IL-1β和INF-γ浓度与KCs上清液中NF-κB蛋白表达呈正相关(r=0.870, P=0.000)。...     

热消融治疗肿瘤的研究进展

随着现代医学成像技术的快速发展,影像引导热消融技术在越来越多的肿瘤治疗中发挥着不可替代的作用。本文就五种最常见的热消融技术,即射频消融、微波消融、冷冻消融、高强度聚焦超声、激光消融,并对各自的基本原理和优缺点进行综述,以期指导临床热消融技术的进一步推广和应用。     

光动力和经皮氩氦系统冷消融联合治疗非小细胞性阻塞性肺癌

目的 研究联合应用光动力疗法和经皮氩氦系统冷消融，对不能切除性非小细胞性阻塞性肺癌的治疗价值。方法 41例非小细胞性阻塞性肺癌患者，或者固为肿瘤局部进展(按TNM分期为Ⅲb期)，或者因为肺功能差(严重阻塞性肺病)，被认为是不能切除性的。先予光动力疗法。静脉注射光敏剂Photofrin 2mg／kg(或血卟啉5mg／kg，华鼎药业)，48和72小时分别在支气管镜下输入630nm红色激光照射；再在B超或CT引导下通过氩氦系统进行经皮冷消融。按症状、肿瘤大小和生存期判断疗效。结果 41例经此种联合疗法治疗后，90．2％的患者主观症状有不同程度改善，症状积分治疗后明显降低，呼吸困难的改善最为明显；支气管镜复查，发现全部惠者支气管内肿瘤均得到不同程度消融，其中41．5％完全消失；CT复查发现肺内肿瘤CR34．1％，PR41．4％；X线片上，原有肺塌陷的病例中29．6％的塌陷完全消失，70．4％的肺塌陷减轻；半年和1年生存率分别达44和71％。无论光动力抑或经皮氩氦系统冷消融，均未发生严重并发症。结论 联合应用光动力疗法和氩氦系统经皮冷消融，能分别消除支气管内、外的病变，两者相辅相成，因而可提高不能切除性非小细胞性阻塞性肺癌的治疗效果。     

胶质瘤氩氦冻融产物负载树突状细胞对颅内胶质瘤大鼠的免疫治疗研究

目的 观察C6胶质瘤细胞经氩氦冷冻后,冻融产物对Wistar大鼠骨髓源性树突状细胞(BM-DCs)成熟的影响,以及致敏的树突状细胞(DCs)对胶质瘤模型大鼠的抗肿瘤作用. 方法 体外常规培养C6胶质瘤细胞,双循环氩氦冷冻法冻融C6细胞悬液为实验组,只插入探针不作冷冻为阴性对照组,双循环氩氦冷冻法冻融等量PBS为空白对照组;应用重组大鼠白细胞介素-4(rmIL-4)、重组大鼠粒一巨噬细胞集落刺激因子(rmGM-CSF)和肿瘤坏死因子α(TNFα)诱导Wistar大鼠骨髓DCs成熟,培养第7天分别加入各组冷冻产物,48 h后光镜下观察DCs细胞形态,流式细胞仪检测各组DCs细胞表面共刺激分子CD80和CD86的表达,ELISA法检测各组上清液中IL-12含量;将C6细胞接种于Wistar大鼠建立荷脑胶质瘤模型,第3、10天分别皮下注射空白对照组、阴性对照组、实验组DCs疫苗,比较各组大鼠的中位生存期. 结果 培养第7天未成熟DCs加入冷冻产物48 h后实验组具有成熟DCs形态学特征,表面分子CD80、CD86阳性表达率、上清中[L-12的分泌量高于阴性对照组和空白对照组,差异有统计学意义(P＜0.05);实验组DCs疫苗治疗后荷脑胶质瘤大鼠中位生存期高于阴性对照组和空白对照组,差异有统计学意义(P＜0.05). 结论 胶质瘤氩氦冻融产物可以诱导DCs成熟,介导大鼠脑胶质瘤的免疫治疗,为冷冻免疫机制提供一定理论基础,同时该DCs疫苗为胶质瘤个体化治疗的研究提供一种新的方法.     

氩氦刀靶向治疗的机制及在肿瘤消融治疗中的应用进展

氩氦刀是一种新兴的靶向冷热消融治疗技术,分别使用氩气和氦气对冷冻探头进行加热和制冷。在持续的影像引导和监测下,经过两次冷热循环,氩氦刀能够完全有效地摧毁肿瘤细胞组织。目前,氩氦刀已单独或与其他的治疗方法一起广泛地应用于多种肿瘤的治疗,且是一种安全、有效的微创治疗方法。     

Low clinical recurrence and procedure benefits following treatment of common atrial flutter by electrogram-guided hot spot focal cryoablation

Background: The study sought to evaluate whether electrogram-aided identification of hot spot targets produces additional clinical and/or procedure benefits when using a non-traditional focal cryo ablation method to treat common atrial flutter. Methods: A preliminary study identified a specific electrogram criterion (e.g., a stimulus to onset of electrogram time of 74 [± 5] ms) that produced successful cryo testing plus subsequent cryoablation with demonstrable bi-directional isthmus block created at intervention site. In the present study, 26 consecutive patients with symptomatic common atrial flutter were ablated with a 9FR 8 mm tip cryo catheter using electrogram-aided identification of hot spot targets with a stimulus to onset of electrogram time of ≥70 ms. Outcomes measured were bi-directional isthmus block at intervention, symptom and conduction recurrence at 3 month follow-up, symptom recurrence at 6 month follow-up, and procedure characteristics. Results: Acute success rate at intervention was 100%. The percentage of patients with symptom recurrence by 3 month follow-up was 4.5% and no additional patients had arrhythmia symptoms documented by 12 month follow-up. Repeat electrophysiological study (EPS) at 3 month follow-up identified 44% of patients with conduction recurrence. The mean ± SD number of cryo tests and ablations were 11 ± 9 and 2 ± 1, respectively. Procedure, fluoroscopy and cryoapplication times were 77 ± 29 min, 11 ± 7 min, and 28 ± 11 min, respectively. Conclusions: A high acute success rate, plus low long-term clinical recurrence rate and procedure benefits may be achieved with electrogram-aided identification of hot spots for focal cryo ablation treatment of common atrial flutter using a 9FR 8 mm tip cryo catheter. The population of patients who were asymptomatic and had demonstrated conduction recurrence on repeat EPS at 3 month follow-up require close scrutiny over the long-term to ascertain whether they eventually experience arrhythmic symptoms. However, should these patients remain symptom-free over the long-term it would suggest that the entire isthmus may not be needed to support symptomatic common atrial flutter.     

肝脏肿瘤冷冻消融治疗的进展

自从1850年冷冻外科诞生以来,冷冻治疗设备已取得里程碑式进展。第三代氩氦冷冻系统的研制成功,有效地满足了组织冷冻消融术的监控、快速降到致死温度、缓慢复温、重复的冻-融循环四个方面。在肝脏肿瘤领域单独或联合外科、化疗、介入等综合应用显示了良好的应用前景,但如何合理应用仍需进一步研究。