超声引导下多电极射频消融治疗原发性肝癌的临床价值

目前 ,超声引导射频技术无疑是一种有效的治疗肝脏肿瘤的新方法 ,射频消融治疗具有操作简便 ,定位准确 ,定时监测 ,创伤小 ,疗效好 ,毒副作用轻等优点 ,为微创治疗肝癌提供了一种可选择的方法。随着技术的改进 ,设备的更新以及临床经验的积累 ,射频治疗术将可更有效地治疗较大肝癌肿瘤。观察术前后肝癌血供状态 ,声像图变化提供主要依据 ,对指导治疗判定疗效有着重要意义。我院于 2 0 0 2年 5月至今在超声引导下用多电极射频消融治疗肝癌 15例 ,疗效显著 ,现报告如下 :1　资料与方法1.1　临床资料 :肝癌患者 15例 ,年龄 40～ 65岁 ,男 10例 …     

Paiban骨组织单电极射频消融的范围及热场分布

背景：保证射频消融治疗效果的关键问题是准确判定病灶内的加热温度及范围。目的：观察骨组织单电极射频消融的范围和热场分布情况。设计、时间、地点：对比观察实验,于2007-09/12在上海长海医院中心实验室完成。材料：成年黄牛胫骨新鲜标本15例,MSIS-1500型射频仪为美国迈德医疗科技有限公司生产。方法：使用射频仪及单电极射频针对15例新鲜牛胫骨标本进行射频消融,设置中心温度95℃,持续15min,消融中测量电极旁20mm范围内骨皮质和骨髓内16个测温点的温度。主要观察指标：消融过程中各测温点温度随时间变化及骨组织内部凝固形态和范围。结果：在骨髓和骨皮质分别形成以电极为中心半径为10mm和5mm的50℃以上高温区;电极周围骨皮质成苍白色,界限不清;骨髓凝固区域沿电极呈纵椭圆形,垂直电极方向最大横经约17.2mm,沿电极方向的最大长径平均约23.6mm。结论：单电极骨组织射频消融范围较小,用于较大骨肿瘤的治疗需多点次消融;骨皮质有明显隔热作用。     

多电极射频联合肝动脉栓塞化疗治疗肝癌的应用研究

目的：探讨多电极射频联合肝动脉栓塞化疗对肝癌治疗的方法及效果。方法：经皮穿刺组织病理学证实的16例肝癌31个结节，多电极射频治疗后1－2周，行肝动脉栓塞化疗。结果：经选择性肝动脉造影证实，12个小结节完全坏死，占小结节的38．7％（12／31），17个临近肝脏边缘的较大结节及2个特殊部位的小结节有肿瘤残留，占所有结节的61．3％（19／31）。其中3个较大的结节联合栓塞化疗后3月仍见肿瘤生长。16例患者半年后瘤生存率75．0％（12／16）。所有患者治疗后临床症状明显改善。结论：先射频后栓塞的方法可以发现并治疗肿瘤残留，提高治疗效果。     

超声引导可扩展多电极射频消融原发性肝癌的术后护理

目前，外科手术切除仍是原发性肝癌根治术的首选方法。然而，很多肝癌患者在确诊为肝癌的时候常常由于肿瘤的大小，部位，数目，血管以及肝脏功能失代偿而不能施行手术切除。而射频消融（Radiofrequency ablation RFA）作为一种新型的微创治疗手段，已经获得了较大的发展。近期国内外的研究表明对不能手术切除的原发性肝癌有较好的疗效。尤其是随着电极针制作技术的进步，已经用可扩展的多电极射频针取代了原来的单电极射频针，在消融范围和效果上有了质的突破。     

超声波引导下多电极射频治疗肝癌的护理

原发性肝癌 (ＨＣＣ)和转移性肝癌 (ＭＬＣ)是常见的恶性肿瘤 ,由于受肿瘤部位、大小、数量、血管和肝外转移及身体衰竭等因素的影响 ,只有部分患者能转外科手术切除 ,年老体弱及晚期患者因此失去手术机会。近年 ,国内外学者先后开展了许多微创性的局部治疗手术 ,其中多电极射频技术以其微创、出血少、疗程短、见效快、安全可靠等诸多优点 ,为肝癌患者提供了一条新的治疗途径[1] 。我院用此术式治疗 3 6例 (包括院外治疗 ) ,近期疗效满意 ,现将治疗和护理体会总结如下。1　资料与方法1 1　临床资料　本组 3 6例中男 3 0例 ,女 6例 ,2 9～ 69…     

超声引导下射频消融治疗肝癌的临床价值

目的：探讨超声引导下多极射频介入治疗肝癌的临床价值。方法：19例肝癌患者26枚结节在超声引导下进行射频消融治疗，采取由深到浅，多点多部位，重叠消融的治疗原因，结果：12个结节（46．2％）缩小，肿瘤回声均增强16个（61．5％）血流信号减少或消失；病检8例阴性（8／12）；10例甲胎蛋白下降（10／13）；7例（7／13）肝功能改善，结论：超声引导下多电极射频治疗肝癌是一种疗效确切，操作简便，损伤小，安全性高的有效方法。     

超声引导下射频消融治疗肝癌的临床价值

目的探讨超声引导下射频消融(RFA)治疗肝癌的疗效。方法35例肝癌49个病灶行超声引导下RFA治疗,对治疗前后病灶的超声影像、超声造影、螺旋CT检查、肝功能、AFP变化以及机体免疫功能的影响等进行综合研究以评价疗效。结果RFA后5min,超声造影,肿块中83.7%(41/49)各个时相无增强,即回声缺失;1周后彩超示肿块中87.8%(43/49)血流信号明显减少或消失;1个月后螺旋CT扫描肿块中81.6%(40/49)大小无明显变化,但肿块内无强化。肝功能有不同程度改善,甲胎蛋白下降,CD4 、CD4 /CD8 明显升高,sIL-2R明显降低。结论超声引导下射频消融治疗肝癌是有效的微创治疗手段,其为操作简便、损伤小、安全性高的有效方法。     

超声引导下多电极射频治疗大肠癌肝转移

大肠癌患者初次手术时 ,有 10 %～ 2 5 %的患者已有肝局部或弥漫性转移 ;而术后有近 5 0 %的患者在近期内发生肝转移。为探索微创治疗大肠癌肝转移的方法 ,我院于 1996年 6月至 2 0 0 0年 7月采用超声引导下多电极射频治疗大肠癌肝转移患者 2 6例 ,现报告如下。资料与方法本组患者 2 6例 ,其中男性 2 3例 ,女性 3例 ,年龄 33～ 82岁 ,平均 5 7.5岁。本组病历均根据病史、体征、超声及ＣＴ等检查诊断为大肠癌肝转移。经皮肝穿刺活检确诊为肝转移腺癌 2 2例 ,术中快速冰冻切片病理报告为肝脏转移癌 4例。共治疗 43个肿块 ,最大直径 3 .9～ 14 …     

超声引导经皮双极射频消融治疗肝癌的局部疗效观察

目的观察超声引导经皮双极射频消融治疗肝癌的局部疗效。方法选取我院2012年5月~2013年10月收治、以治愈性治疗为目的的24例肝癌患者32个病灶,对所有患者均采取超声引导下经皮双极射频消融进行治疗,术后1个月观察患者影像学(超声造影、增强CT或增强MRI)检查结果,以评价局部疗效,以后每3个月随访一次,以观察患者复发情况。结果病灶完全消融(CA)率96.9%(31/32),其中最大径3cm病灶CA率为100%(27/27),最大径≥3cm病灶CA率为80%(4/5);原发性肝癌完全CA率95.7%(22/23),转移性肝癌CA率100%(9/9)。所有患者均未出现严重并发症及与手术相关的死亡。随访2~19个月,局部复发率为6.3%(2/32)远处复发率为33.3%(8/24)。结论超声引导下经皮双极射频消融治疗肝癌安全可靠、局部疗效确切,对小肝癌尤其明显。     

集束电极射频热凝治疗肝癌的护理128例

肝癌是最常见的恶性肿瘤之一，年病死率位居恶性肿瘤的第2位，目前手术切除仍是肝癌的主要治疗方法。但多数肝癌病人，当确诊时，限于肿瘤的位置、大小、多病灶及其肝功能储备、全身情况无法耐受手术等原因，根治性切除已不可能进行，射频热凝技术被认为是目前治疗无法手术切除肝癌的较     

In Vivo Ventricular Lesion Growth in Radiofrequency Catheter Ablation

While radiofrequency catheter ablation has proved highly effective in the treafment of various supravenfricular tQchyarrhythmias, resulls in the trentment of ventricular tachycardia invite improvement. Knowledge of lesion growth in vivo might improve understanding of this discrepancy. So far only information from in vitro and in vivo studies using a small 2 mm tip eiectrode is available. Growlh of ventricular radiofrequency lesions created with a 4 mm ahlalion electrode was studied in 11 closed-chest dogs. Endocardia] ablations were performed at 31 left and 35 right ventricuiar sites at a power setting of 25 Watts and 5, 10, 20, 30 or 60 seconds pulse duration. Macroscopic and histopathologic lesion examination were performed after one week survival. Mean lesion volume increased from 52 mm³ after 5 seconds pulse duration to a maximum 388 mm³ and approximately 7 mm depth after 30 seconds. Lesions were prolate spheroid in form, with a sparing of subendocardial myocardium and maximum lesion diameter at some millimeters depth. Results indicate that catheter positioning at no more tlian 7 mm from the target is required for successful ablation. Due to lesion geometry, subendocardial targets demand even more exact catheter positioning, while subepicardial substrates may not be ammenable to ablation if ventricular wall thickness exceeds 7 mm at the ablation site. Repeated pulses at adjacent sites may be required for ablation of extended arrhytbmogenic areas. Volume at 5 seconds was only approximately 15% of mature lesions. Therefore, the use of a short'test pulse after careful mapping may be useful to pinpoint the most appropriate site for ablation in discrete pathways.     

Feasibility of Radiofrequency Powered, Thermal Balloon Ablation of Atrioventricular Bypass Tracts Via the Coronary Sinus: In Vivo Canine Studies

Radiofeequency catheter ablation of left sided accessory pathways is technically demanding and usually requires left heart catheterization. The feasibility of creating lesions from within the coronary sinus of sufficient size to ablate accessory pathways in humans using a thermal balloon catheter was studied in 20 dogs. In group 1 (n == 14), 17 thermal inflations were performed in 12 dogs at either 70°, 80°, or 90°C each for 30 or 60 seconds (in 2 dogs two non-thermal control inflations were performed). Animals were sacrificed 6.3 ± 1.6 days later. In group 2 (n = 6), seven thermal inflations were performed at 90°C each for 180, 300, or 360 seconds. Group 2 animals received antiplatelet and anticoagulant therapy for 1 week and were sacrificed at 13 ± 10.7 days. In both groups, hemodynamic, angiographic, and electrocardiographic studies were performed at baseline, 1 hour after inflation, and prior to sacrifice. All dogs remained clinically stable throughout the procedure and no complications were attributed to the effect of thermal inflation. Thermal lesions measured 14.4 ± 4.4 mm in length and extended from the coronary sinus intima to a mean depth of 2.9 ± 1.2 mm (range 1.4-6.5 mm). Group 2 lesions were significantly deeper than group 1 lesions (P = 0.03). Of the 24 thermal lesions created, atrial necrosis was present in 23 and ventricular necrosis in 11. In all lesions there was some degree of either atrial necrosis, ventricular necrosis, or both. A variable degree of coronary sinus thrombus was present in 18 dogs without clinical sequelae. It is concluded that radiofrequency balloon heating via the coronary sinus can create thermal lesions in the atrioventricular sulcus of dogs that may be of sufficient size to ablate accessory left-sided pathways in humans. (PACE 1995; 18: 1518-1530)     

Performance of Shear Wave Elastography in Delineating the Radiofrequency Ablation Boundary: An in Vivo experiment

This study was aimed at exploring the cutoff value of Young's modulus of ablated tissue and the optimal scale at which shear wave elastography (SWE) can delineate the ablation boundary. The livers of 30 rabbits were radiofrequency (RF) ablated, and ultrasonic imaging, including SWE and contrast-enhanced ultrasound (CEUS), was performed. The ablation boundary in the SWE image was located using CEUS, and the SWE parameters of the boundary were measured to calculate the cutoff value of Young's modulus. The cutoff value of the ablated tissue was 48–50 kPa 2 h to 28 d post-ablation. The regions of increased stiffness in SWE images at a scale of 0–50 kPa overlapped well with the non-enhanced regions of CEUS images in 88% of specimens. Therefore, elasticity values differed significantly between ablated and non-ablated tissues, and the cutoff value for Young's modulus differentiated these tissues. SWE delineated the ablation boundary well at the optimal SWE scale with respect to the cutoff value.     

Thermal Catheter Disruption During Closed-Chest Radiofrequency Ablation of the Atrioventricular Conduction System

Radiofrequency ablation of the atrioventricular conduction system was attempted in a 63-year-old man with drug refractory atrial fibrillation. A total of 5 radiofrequency pulses (750 kHz, power setting: 25-50 W, pulse duration: 9-20 sec) were delivered in a unipolar fashion via the distal electrode of a 7 Fr bipolar electrode catheter without induction of permanent AV block. No direct measurements of current (I) and voltage (U) were made. During the fifth pulse catheter disruption occurred at the interface of the shaft and the proximal electrode. Inspection of the catheter shaft revealed carbonized insulation material indicating overheating of the catheter tip. Overheating was presumably due to an impedance rise with unrecognized clot formation on the distal electrode. This led to progressive melting of insulation material during repeated radiofrequency applications and short circuiting of current flow to the proximal ring electrode that resulted in catheter disruption. This case report is the first to describe a serious complication of radiofrequency ablation. The complication might have been prevented by measurements of U and I, reflecting changes in impedance or by measurements of catheter tip temperature (T). It is concluded that measurements of U, I, and/or T are necessary to control the coagulation process thereby reducing the risk of serious complications during transcatheter radiofrequency ablation.     

Initial Assessment of Boiling Histotripsy for Mechanical Ablation of Ex Vivo Human Prostate Tissue

Boiling histotripsy (BH) is a focused ultrasound technology that uses millisecond-long pulses with shock fronts to induce mechanical tissue ablation. The pulsing scheme and mechanisms of BH differ from those of cavitation cloud histotripsy, which was previously developed for benign prostatic hyperplasia. The goal of the work described here was to evaluate the feasibility of using BH to ablate fresh ex vivo human prostate tissue as a proof of principle for developing BH for prostate applications. Fresh human prostate samples (N = 24) were obtained via rapid autopsy (<24 h after death, institutional review board exempt). Samples were analyzed using shear wave elastography to ensure that mechanical properties of autopsy tissue were clinically representative. Samples were exposed to BH using 10- or 1-ms pulses with 1% duty cycle under real-time B-mode and Doppler imaging. Volumetric lesions were created by sonicating 1–4 rectangular planes spaced 1 mm apart, containing a grid of foci spaced 1–2 mm apart. Tissue then was evaluated grossly and histologically, and the lesion content was analyzed using transmission electron microscopy and scanning electron microscopy. Observed shear wave elastography characterization of ex vivo prostate tissue (37.9 ± 22.2 kPa) was within the typical range observed clinically. During BH, hyperechoic regions were visualized at the focus on B-mode, and BH-induced bubbles were also detected using power Doppler. As treatment progressed, hypoechoic regions of tissue appeared, suggesting successful tissue fractionation. BH treatment was twofold faster using shorter pulses (1 ms vs. 10 ms). Histological analysis revealed lesions containing completely homogenized cell debris, consistent with histotripsy-induced mechanical ablation. It was therefore determined that BH is feasible in fresh ex vivo human prostate tissue producing desired mechanical ablation. The study supports further work aimed at translating BH technology as a clinical option for prostate ablation.     

Biosafety in Ex Vivo Gene Therapy and Conditional Ablation of Lentivirally Transduced Hepatocytes in Nonhuman Primates

Ex vivo gene therapy is an interesting alternative to orthotopic liver transplantation (OLT) for treating metabolic liver diseases. In this study, we investigated its efficacy and biosafety in nonhuman primates. Hepatocytes isolated from liver lobectomy were transduced in suspension with a bicistronic liver-specific lentiviral vector and immediately autotransplanted (SLIT) into three cynomolgus monkeys. The vector encoded cynomolgus erythropoietin (EPO) and the conditional suicide gene herpes simplex virus-thymidine kinase (HSV-TK). Survival of transduced hepatocytes and vector dissemination were evaluated by detecting transgene expression and vector DNA. SLIT was safely performed within a day in all three subjects. Serum EPO and hematocrit rapidly increased post-SLIT and their values returned to baseline within about 1 month. Isoforms of EPO detected in monkeys'' sera differed from the physiological renal EPO. In liver biopsies at months 8 and 15, we detected EPO protein, vector mRNA and DNA, demonstrating long-term survival and functionality of transplanted lentivirally transduced hepatocytes. Valganciclovir administration resulted in complete ablation of the transduced hepatocytes. We demonstrated the feasibility and biosafety of SLIT, and the long term (>1 year) functionality of lentivirally transduced hepatocytes in nonhuman primates. The HSV-TK/valganciclovir suicide strategy can increase the biosafety of liver gene therapy protocols by safely and completely ablating transduced hepatocytes on demand.     

射频电消融术治疗心律失常的机理探讨

采用全细胞膜片钳技术研究射频电消融术对豚鼠心室肌细胞膜钙离子流（ＩＣａ）的影响。结果发现，在２０Ｗ×１０ｓ能量下，射频消融明显减小ＩＣａ，其影响范围达消融点外１．２ｃｍ以上。而在该能量下，其造成的组织学损伤范围仅为０．４１±０．１１ｃｍ。提示射频消融除了热效应引起小范围的组织学损伤外，并在更大的范围内影响细胞膜的离子流。为阐明射频消融组织损伤范围小而疗效高的机理提供了重要的实验依据．     

Radiofrequency Catheter Ablation: The Effect of Electrode Size on Lesion Volume In Vivo

Radiofrequency current is a promising alternative to high voltage direct current defibrillator discharges for catheter ablation of arrhythmias. However, lesions produced with radiofrequency current are relatively small and use of high power is limited by the impedance rise that occurs with desiccation of tissue and coagulum formation. The effect of electrode size on radiofrequency ablation was assessed by comparing results of radiofrequency application using a standard 6 French electrode catheter (distal electrode 2 mm in length) to those using catheters modified with longer distal electrodes (3, 4, 6, 8, and 10 mm in length). Radiofrequency ablation was performed at 47 left ventricular endocardial sites in 20 anesthetized dogs. A constant power of 13.3 +/- 1.3 watts at 550 kHz was applied between the distal catheter electrode and a skin electrode until a total of 500 joules had been delivered or a rise in impedance occurred. Increasing electrode length from 2 to 4 mm more than doubled lesion volume from a mean of 143 to 326 mm3 (P = 0.025). Increasing electrode length beyond 4 mm produced progressively smaller lesions (157 mm3, 155 mm3, and 67 mm3 for 6-, 8-, and 10-mm electrode lengths, respectively). Impedance rise was significantly less likely with larger electrodes and took longer to occur. Increasing the size of electrodes used for radiofrequency ablation allows application of higher power without an impedance rise. Optimizing electrode size (3 or 4 mm in this study) results in larger lesions and may improve the effectiveness of radiofrequency ablation of arrhythmias.     

Thoracoscopic Radiofrequency Ablation of the Myocardium

Radiofrequency (RF) catheter ablation has been used for the treatment of ventricular tachycardia (VT), however, in some patients VT might result from subepicardiai macroreentry that could be successfully terminated by epicardial approach. This study examined the feasibility of thoracoscopic RF ablation of myocardium from epicardium using a custom made electrode. In five mongrel dogs, the thoracoscope was introduced through the 7th intercostal space. A 500-kHz continuous wave RF energy was connected to a custom made multiple electrode probe. Under thoracoscopic guidance, the heart was exposed and the RF probe was introduced. RF ablation was performed on the nonvascular ventricular wall of the beating heart. The left ventricular free wall and right ventricular outflow tract were satisfactorily visualized and ablated. The total dose of RF energy ranged from 50 to 500 J. and the estimated volume of ablated lesions ranged from 41.0–799 mm³. There were significant correlations between the RF discharge output and the irradiated lesion volume (P < 0.01), and the depth of the lesions (P < 0.01). Grossly, after RF ablation the ventricular myocardium demonstrated a circular, well-demarcated area of thermal injury. Volume and depth of the lesion depended upon the total dose of delivered RF energy. Thoracoscopic RF ablation appears to be a minimally invasive and useful method for creating irradiated myocardial lesions from epicardial surface. This method could he technically feasible for the treatment of Vts for which endocardial RF ablation is ineffective.     

微波与射频消融肝组织比较的实验研究

目的比较微波和射频消融肝组织的特点,以指导临床应用。方法小型香猪4头,麻醉后剖腹暴露肝脏,采用微波和射频进行凝固。能量为60W·600s,旁开电极5、10、15、20mm测温,比较2种凝固方法的热场特点、凝固范围及形状。结果60W·600s微波和射频凝固的纵径分别为(4.5±0.03)cm,(3.5±0.15)cm,横径分别为(3.0±0.15)cm,(3.0±0.35)cm,纵径二者差异显著(P<0.05),横径无显著差异。射频形成的凝固体较微波更接近球形(P<0.05)。微波的中心温度较射频高,差异有统计学意义(P<0.05),边缘温度微波和射频无显著差异。微波凝固形成的充血带较射频略窄,微波和射频形成的凝固体的病理变化无显著差异。结论微波和射频肝组织凝固的热场分布、凝固形状及凝固范围存在差异,了解各自的凝固特性有利于2种技术的合理应用。