Temperature-controlled radiofrequency catheter ablation of AV conduction: first clinical experience

A new technique for catheter ablation of atrioventricular (AV)conduction, using temperature-controlled radiofrequency energyand a bipolar asymmetrical electrode configuration, was appliedto 12 patients (mean age, 48 ± 15 years; range, 18–69years) with medically refractory atrioventricular nodal reentranttachycardia (AVNRT) or rapid atrial rhythms. The energy sourcewas a 500 kHz generator with automatic power regulation to apreselected temperature of 80 °C. A specially designed 7F bipolar asymmetric thermo-catheter was used for ablation inall cases. The endpoints of the procedure were: first-degreeAV block in patients with AVN R T and third-degree block inpatients with atrial fibrillation or flutter. Energy was appliedover a range of 1–14 times per patient. After a mean follow-upof 8±4 months, third- or first degree AV block persistedin eight patients. In comparison to constant-power radiofrequencyablation, where impedance rises are commonly observed, no impedancerise or coating of the electrode occurred during any of the97 energy applications in this study. Variable wall contactof the electrode was identified in 20 of 97 applications bya slow temperature rise or a drop in temperature and frequentpower adjustments. Thus, monitoring temperature and automaticpower regulation may help to reduce the total delivered energy.Temperature control during radiofrequency energy avoids coagulumformation and consequently the associated potential hazardsof constant-power application.     

MR monitoring of MR-guided radiofrequency thermal ablation of normal liver in an animal model

The purpose of this study was to determine the suitability of MRI to accurately detect radiofrequency (RF) thermoablative lesions created under MR guidance. In vivo RF lesions were created in the livers of six New Zealand White rabbits using a 2-mm-diameter titanium alloy RF electrode with a 20-mm exposed tip and a 50-W RF generator. This was performed using a 0.2T clinical C-arm MR imager for guidance and monitoring. Each animal was sacrificed and gross evaluation was performed. Histologic correlation was performed on the first two animals. The MR-compatible RF electrode was easily identified on rapid gradient-echo images used to guide electrode placement. A single lesion was created in each rabbit liver. Lesions ranged from approximately 10 to 17 mm in diameter (mean, 13.5 mm). T2-weighted and short T1 inversion recovery (STIR) images demonstrated lesions ranging in diameter from 12 to 18 mm (mean, 14.6 mm). Lesion dimensions determined from images closely correlated with those determined at gross examination with the discrepancy never exceeding 2 mm, for an r² value of .87. MRI performed at the time of MR-guided RF ablation accurately demonstrated created lesions. This modality may provide a new option for the treatment of local and regional neoplastic disease.     

导管射频消融术治疗持续性交界区反复性心动过速2例报告

本文报告两例持续性交界区反复性心动过速(PJRT)患者,应用导管射频消融术治疗,成功地阻断了位于后间隔具有递减传导特性的稳若旁路.随访7～10个月.病人无心动过速发作,提示导管射频消融术是治疗PJRT的有效方法.     

CT引导下射频联合臭氧治疗腰椎间盘突出症日间手术的疗效

探讨螺旋CT引导下射频热凝联合臭氧消融治疗腰椎间盘突出症日间手术的临床疗效。方法 回顾性收集2020年1月—2022年6月我院日间病房住院的137例腰椎间盘突出症患者的临床资料,所有患者均行螺旋CT引导下射频联合臭氧消融治疗日间手术。收集手术时间,术毕至出院时间,总住院时间,术前、术后1月、3月的疼痛数字评分(NRS),Oswestry功能障碍指数(ODI)评分,改良 Macnab评级和手术相关并发症,并进行术前与术后的对比分析。结果 所有患者在螺旋CT引导下穿刺成功率为100%,并在手术当日出院,平均手术时间为（35.55±10.44）min,平均术毕至出院时间为（58.36±25.26） min,平均总住院时间为（453.91±27.18）min。术后1、3月的NRS评分和ODI评分均低于术前;术后1、3月改良Macnab疗效评定标准有效率分别为86.13%、89.05%。所有患者均未有穿刺或治疗相关的并发症。结论 螺旋CT引导下射频联合臭氧消融治疗腰椎间盘突出症日间手术是可行的,其可降低腰椎间盘突出症患者的疼痛程度、改善日常功能障碍、安全性高,可在临床推广应用     

Pathological Aspects of Radiofrequency Catheter Ablation of the Canine Atrioventricular Node and Bundle of His

Radiofrequency catheter ablation of the atrioventricular (AV) node or bundle of His was performed in 12 adult mongrel dogs. The aim was to create chronic incomplete AV block (first- and second-degree AV block) and to examine the histopathology of the ablated lesions. However, the late electrophysiological results (2 4 weeks follow up) were various: normal in 2 dogs, mild PR prolongation (< 50%) in 2 dogs, first-degree AV block (PR prolongation a 50%) in 2 dogs, second degree AV block in 2 dogs, complete AV block in 4 dogs. The maximally ablated area (%) of the atrioventricular conduction system in serial histologic sections from dogs with these conditions was 69%, 75%, 89.5%, 95% and 99.5%, respectively. The number of intact conduction cells at the maximally ablated site varied from 6 to 30 in the four cases of incomplete AV block. The mean ablated volume (%) of either the AV node or penetrating His bundle correlated roughly with the degree of AV block. The ablated lesions were well demarcated and almost replaced by dense fibrous tissue at 4 weeks. Interruption (3 dogs) or thinning (1 dog) of the endocardial elastic lamellae was detected, in association with endocardial thickening (mean 913 μm). Endocardial thrombi were found in 3 dogs (2 fresh, 1 organized). We conclude that radiofrequency catheter ablation does not cause severe complicated lesions. Several possible conditions for creating chronic incomplete AV block are discussed. Acta Pathol Jpn 41: 487–498, 1991.     

185例快速心律失常射频消融体会

目的探讨射频消融(RFCA)在治疗快速心率失常中的应用价值.方法我院自1996年10月～2000年11月RFCA治疗快速心率失常185例,其中男80例,女105例,年龄8～77岁.局麻后经皮穿刺颈内静脉、股静脉、股动脉,插入四极电生理电极导管,先行心内电生理检查明确心率失常类型,后以大头导管精确定位标测,最后开始RF放电,直至射频消融成功结果腔内电生理检查结果,房室旁路折返心动过速(AVNRT)70例,房速(AT)3例心房扑动(AF)2例,特发性室速(IVT)2例,平均随访1年,3例复发均再次消融成功,失败2例,无严重并发症.结论;RFCA是治疗快速心率失常的有效方法.安全,创伤小,可重复应用.     

鼻内窥镜下射频治疗顽固性鼻出血的探讨（附30例报告）

目的:探讨鼻内窥镜下射频治疗顽固性鼻出血的效果。方法：应用鼻内窥镜找到出血部位,再用射频治疗仪热凝止血。结果：30例顽固性鼻出血病人均治愈。结论：鼻内窥镜下射频治疗顽固性鼻出血具有定位准确,安全有效,病人痛苦少,并发症少的优点, 值得推广。     

The Efficacy of Radiofrequency Ablation for Bone Tumors Unsuitable for Radical Excision

BackgroundBone tumors can cause severe pain and poor quality of life due to recurrence and non-achievement of complete remission after surgery, chemotherapy, or radiotherapy. Radiofrequency ablation (RFA) can be considered for minimally invasive treatment of bone tumors that are difficult to radically excise. In this study, RFA was performed for bone tumors that were difficult to radically excise and did not respond to surgery, chemotherapy, or radiotherapy due to their large sizes and/or locations. The purpose of this study was to retrospectively analyze the clinical characteristics and survival rates of bone tumors after RFA and provide one more treatment option for the future.MethodsThere were 43 patients with bone tumors who underwent percutaneous RFA at our hospital from April 2007 to October 2017. The median age of the patients was 59 years (range, 31–75 years), and the median follow-up duration was 67.2 months (range, 10.2–130.5 months). Of the 43 patients, 26 were male and 17 were female. Thirty-four cases were metastatic bone tumors, 5 were chordomas, 3 were osteosarcomas, and 1 was a giant cell tumor. Pain and functional ability of the patients were evaluated using a visual analog scale (VAS) and the Musculoskeletal Tumor Society (MSTS) functional scoring system, respectively. Scores were recorded preoperatively, 1 week postoperatively, and 4 weeks postoperatively. The 1-year, 2-year, and 5-year survival rates were evaluated using the Kaplan-Meier method.ResultsThe mean VAS score was 8.21 preoperatively. The mean VAS score at 1 week, 4 weeks, 12 weeks, and 24 weeks postoperatively were 3.91, 3.67, 3.31, and 3.12, respectively. The mean preoperative MSTS score was 64.0% (range, 32%–87%). The mean postoperative MSTS score was 71.0% (range, 40%–90%). The 1-year, 2-year, and 5-year survival rates were 95.3%, 69.8%, and 30.2%, respectively.ConclusionsAs per our study findings, RFA was effective in reducing pain and improving functional ability of patients with bone tumors that were difficult to radically excise.     

Spinal metastases treated with bipolar radiofrequency ablation with increased (> 70 °C) target temperature: Pain management and local tumor control

PurposeTo investigate the safety and clinical efficacy of bipolar radiofrequency ablation (b-RFA) with increased (> 70 °C) target temperature for the treatment of spine metastases with the intent of achieving pain relief or local tumor control.Materials and methodsThirty-one patients with a total of 37 metastases who were treated with b-RFA with increased temperature and vertebroplasty from January 2016 to May 2019 were retrospectively included. There were 20 women and 11 men with a mean age of 62.4 ± 10.5 (SD) years (range: 40–78 years). Patients and metastases characteristics, procedure details and clinical outcomes were analyzed.ResultsMetastases were predominantly located in lumbar (22/37; 59.5%) or thoracic spine (13/37; 35.1%). Mean target temperature was 88.4 ± 3.5 (SD) °C (range: 70–90 °C). Technical success was 100% (37/37 metastases). One (1/37; 2.7%) major complication unrelated to b-RFA was reported. One (1/37; 2.7%) metastasis was lost to follow-up. Favorable outcome was noted in patients receiving b-RFA for pain management (16/20 metastases; 80%; mean follow-up, 3.4 ± 2.9 [SD] months) or with oligometastatic/oligoprogressive disease (6/6 metastases; 100%; mean follow-up, 5.0 ± 4.6 [SD] months). In patients receiving b-RFA to prevent complications, favorable outcome was noted in 6/10 metastases (60%; mean follow-up, 3.8 ± 4.8 [SD] months).ConclusionsB-RFA with increased target temperature has an excellent safety profile and results in high rates of pain relief and local metastasis control in patients with oligometastatic/oligoprogressive disease. Suboptimal results are achieved in patients receiving b-RFA to prevent complications related to the growth of the index tumor.     

侧后路椎间孔镜下髓核摘除术治疗青少年腰椎间盘突出症的早期疗效观察

目的探讨经皮侧后路椎间孔镜下髓核摘除术治疗青少年腰椎间盘突出症的临床疗效。方法 2010年2月~2011年7月,我院收治的12例青少年腰椎间盘突出症患者接受了经皮侧后路椎间孔镜下髓核摘除术治疗并获得随访。其中男8例,女4例;年龄12~20岁,平均14.6岁。比较手术前后Oswestry功能障碍指数(Oswestry Disability Index,ODI)、下肢疼痛视觉模拟评分(visual analogue scale,VAS)及术后12个月时Macnab评分对临床疗效进行分析。结果 12例患者均获得随访,随访时间17~30个月,平均21.3个月。术后1周、3个月,6个月,12个月及末次随访时ODI指数、下肢疼痛VAS评分与术前相比均明显降低,差异有统计学意义(P0.05)。按照Macnab评分标准,术后12个月时,优7例,良4例,可1例,优良率为91.7%(11/12)。结论经皮侧后路椎间孔镜下髓核摘除术治疗青少年腰椎间盘突出症短期内能取得满意的临床疗效,其长期疗效及安全性有待进一步研究。