射频消融犬心室流出道间隔初步实验研究

目的 初步探讨射频消融犬心室流出道间隔对左心室结构与功能的影响.方法 以健康实验犬为模型,射频消融心室流出道间隔处肌肉.术前经胸超声检测左心室流出道宽度、收缩期室间隔厚度和射血分数等指标,消融成功后即刻检测超声指标,术后1、3个月分别复查存活犬超声指标,作组织病理学检查.结果 10只实验犬中9只消融成功,1只术中发生室颤死亡;1只消融成功但麻醉过深,出现呼吸抑制死亡.手术即刻成功率为80％,8只术后存活至预定随访时间点.与术前相比,存活犬术后即刻、术后1个月、术后3个月左心室流出道宽度、收缩期室间隔厚度差异均有统计学意义(P＜0.05),射血分数差异均无统计学意义(P＞0.05);组织病理学检查可见明显改变;心电图、血压未见明显变化.结论 初步验证射频消融实验犬心室流出道间隔心肌具有一定的安全性和有效性,为进一步动物实验和临床试验提供了有用参数和实验依据.     

肾交感神经消融治疗顽固性高血压——基础研究与临床应用

顽固性高血压,往往合并心脑肾等靶器官的损害,是发生心血管事件的高危人群。研究已经 证实交感神经的 兴奋性 程度与患者的血压水平呈正相关。20世纪50年代报道,外科去交感神经术用于高血压治疗,实施内脏神经、内脏交感神经切除术的效果和安全性未得到认可。20世纪70年代许多学者在不同实验高血压模型（遗传性、盐敏感性、肥胖型、肾动脉性高血压）上探索肾交感神经阻断方法,证实肾交感神经与高血压密切相关。2007年报道经皮导管肾脏交感神经消融术,选择性阻断肾脏交感神经,术后1、3、6、12个月血压分别下降14/10、22/11、22/10、26/11 mm Hg,治疗未发生消融相关严重并发症。随后的研究进一步证实其临床效果。经导管肾交感神经消融在顽固性高血压治疗的有效性和安全性得到初步确定。     

超选择性肾动脉栓塞术联合射频消融治疗肾癌的临床应用

目的 探讨超选择性肾动脉栓塞术联合射频消融(RFA)治疗肾癌的疗效.方法 分析2009年1月至2011年4月9例肾癌患者超选择性肾动脉栓塞联合RFA.患者均在超选择性肾动脉栓塞术后3～7 d,在CT引导下行RFA.术后1个月行肾脏病灶穿刺活检和CT增强检查评价其疗效.结果 9例患者随访1～6个月,未发现.肾脏肿瘤增大,...     

肾交感神经射频消融术对高血压犬去甲肾上腺素溢出率及交感神经活性的影响

目的评价肾交感神经射频消融术(RSD)治疗腹主动脉缩窄型高血压犬的有效性和作用机制。方法成年健康杂种犬20只,采用腹主动脉缩窄法建立高血压模型。模型建立后,随机分为治疗组(n=10)和对照组(n=10)。治疗组犬于建模后1个月行双侧肾交感神经射频消融术。分别于建立模型前和建立模型后1、2、3个月,测定犬前上臂血压、交感神经活性及去甲肾上腺素溢出率并观察其变化趋势。结果建模后1个月,对照组前上臂收缩压(SBP)、舒张压(DBP)和平均动脉压(MAP)与建模前比较均明显升高(P<0.05),肾交感神经活性冲动明显增强,去甲肾上腺素溢出率水平明显增高(P<0.05)。治疗组RSD手术即刻肾交感神经活性明显下降,至消融后2个月略有增高;去甲肾上腺素溢出率水平在建模后1个月显著增高(P<0.05),消融后显著降低并一直持续至实验结束(P<0.05)。与对照组比较,治疗组消融后1个月、2个月去甲肾上腺素溢出率水平显著降低(P<0.05)。结论 RSD对于高血压犬去甲肾上腺素溢出率及交感神经活性均有明显抑制作用。     

犬慢性缺血性肾病模型的建立及超声造影定量分析可行性评价

目的:建立犬慢性缺血性肾病模型,评价其在超声造影定量分析慢性缺血性肾功能改变中应用的可行性.方法:选择5只健康实验犬,用Ameroid环制作犬右.肾动脉慢性狭窄模型.建模后每隔一周对犬右肾行超声造影定量分析,连续观察4～16周,所有犬于实验结束后,取出双肾、右肾动脉做组织病理学检查.结果:犬造模成功率为100%.成功应用于超声造影定量分析100%,实验结束后,分离Ameroid环,显示环内血管腔不同程度的狭窄,管壁增厚.犬右肾及右肾动脉町观察到典型的缺血病理改变.结论:实验犬慢性缺血性肾病模型采用Ameroid环收缩法建立成功,组织学结果令人满意,肾皮质有慢性缺血表现,是较理想的超声造影定量分析慢性缺血性肾病的模型.     

经皮经腔肾动脉成形术:双导管技术

一例有2年高血压病史的11岁男孩,血管造影证实左肾有两支肾动脉,两者开口部位相距很近。主肾动脉近端明显狭窄。作者成功地采用双管技术施行了成形术。一根5F眼镜蛇导管插进不狭窄的肾副动脉内,作保护用;另根5F胶囊导管经对侧股动脉对狭窄的主肾动脉进行扩张。术后血管造影复查,主肾动脉狭窄完全得到解除,肾副动脉完好无损,动脉内无压差。因肾副动脉直径约2mm,故而     

CT引导下经皮穿刺射频消融补救性治疗晚期肾癌

目的探讨射频消融治疗肾细胞癌（RCC）的有效性及安全性。 方法收集56例不适宜外科切除治疗的RCC患者。肿瘤直径为2.6～8.6 cm,平均（5.6±1.2）cm。CT引导下行经皮穿刺射频消融术。随访评估临床效果、肾功能和并发症状况。 结果本组56例患者中,病灶直径<4 cm的35患者射频治疗后1、3、6个月复查时均未见病灶强化,病灶直径>4 cm的21例,在术后3个月复查时13例出现治疗边缘强化,活检证实为复发病灶,再次行射频消融治疗。截止随访时间内,50例存活,6例死于非肿瘤原因。射频治疗前后肾功能变化差异无统计学意义。并发症轻微,无肾脏出血、感染、肾盂损伤等严重并发症。 结论经皮穿刺射频消融治疗可使无外科手术机会的RCC患者生存获益,并能很好的保护患者肾功能,同时并发症轻微,可作为一种重要的治疗手段。     

肾移植术后血管并发症的介入治疗

目的 探讨肾移植术后血管并发症介入治疗的价值。资料与方法 14例肾移植患者中，11例移植肾动脉狭窄，行球囊扩张或支架置入术；2例假性动脉瘤，行导管栓塞术；1例移植肾动脉血栓形成，行导管动脉溶栓术。结果 11例移植肾动脉狭窄患者均成功完成球囊扩张术，其中3例行支架置入术，术后患者血压均恢复正常，随3－35个月，未见狭窄；2例假性动脉瘤患者行栓塞术后，1例血流恢复正常，1例行移植肾摘除；1例移植肾动脉溶栓者，由于并发出血行移植肾摘除。结论 介入治疗是肾移植术后血管并发症有效的治疗方法。     

经皮微波消融活体兔肺的实验研究

目的探讨经皮微波消融活体肺组织的有效性及安全性。方法在CT引导下经皮微波消融7只新西兰大白兔的肺组织。消融后即刻处死2只实验动物,观察组织微波消融后的病理变化;其余5只实验动物分别于消融后1周、3个月复查CT。结果术后即刻CT扫描,消融区直径1.1～1.6cm;1周后范围略有缩小;3个月后明显缩小,甚至消失。2只实验动物出现少量气胸,未经治疗,1周后复查已自愈。微波消融后组织病理学改变的特点是中央坏死和周围组织水肿。结论经皮微波消融活体兔肺是安全的,它有望成为治疗肺肿瘤的微创、有效的方法。     

肾动脉主干加分支射频消融在难治性高血压治疗中的应用

【摘要】 目的 探讨肾动脉分支去神经化在经皮肾交感神经射频消融治疗难治性高血压中的应用。 方法 入选难治性高血压患者60例,完成肾动脉造影后随机分为单纯主支消融组、主支＋分支消融组,各30例。观察分析患者基本资料,手术相关参数（消融点数、温度、平均能量）,术前和术后2年诊室血压、动态血压等。 结果 两组患者年龄、伴发疾病、用药情况差异无统计学意义（P＞0.05）。主支＋分支消融组消融点数与单纯主支消融组相比呈显著增加趋势。两组患者术后诊室血压、动态血压均低于术前（P＜0.05）。术后3～12个月期间主支＋分支消融组诊室血压显著低于单纯主支消融组（P＜0.001）,但术后15～24个月期间两组差异无统计学意义（P＞0.05）。 结论 肾动脉主支＋分支消融术治疗难治性高血压安全有效,但远期随访中与单纯主支消融相比无明显优势。     

热消融在肺癌中的应用和展望

肺癌作为高发病率和高致死率的恶性肿瘤,严重影响人类的健康。目前,外科手术、化学治疗、放射治疗、分子靶向治疗和基因治疗等均是肺癌治疗和提高预后的主要手段。热消融作为肺癌治疗的新兴手段,因其微创、安全、可靠已经引起广泛的关注。文章主要回顾射频消融和微波消融在肺癌中的应用,比较几种不同治疗方式并对热消融在肺癌中的应用做出展望。     

Chemical ablation of liver cancer

Percutaneous chemical ablation is an established image-guided therapy for liver cancer that is relatively simple to perform and requires no specialized equipment. Chemical ablation has been used extensively for hepatocellular carcinoma (HCC), and has achieved outcomes comparable to surgical resection for small, solitary HCC. More recent experience with chemical ablation has combined it with TACE or thermal ablation as part of a multimodality approach to liver cancer.     

Internally gas-cooled radiofrequency applicators as an alternative to conventional radiofrequency and microwave ablation devices: An in vivo comparison

Purpose

To test the efficacy of internally CO₂-cooled radiofrequency (RF) ablation in vivo and to compare its effectiveness to a standard water-cooled RF probe and to a gas-cooled microwave (MW) device.

Method and materials

49 ablations were performed on 15 pigs under general anesthesia using 15G monopolar CO₂-cooled RF applicators, 17G monopolar water-cooled RF applicators and 15G internally CO₂-cooled microwave devices. The power of the MW device was 45 W, the current of the gas-cooled RF device was 1200–1600 mA. At the water-cooled RF probe, maximum power of 200 W was set. Ablation time was 15 min. The short and long axes of the ablation zone were measured. Histological analyses and NADH-staining were performed. The diameters and the ablation volumes were compared using an analysis of variance.

Results

No spots of untreated tissue were observed close to the cooled needle track in any of the ablation zones. The largest short axis diameter was 3.4 ± 0.5 cm achieved with the gas-cooled monopolar applicator. With the water-cooled applicators, short axis diameter was significantly smaller, reaching 2.5 ± 0.4 cm. Gas-cooled MW probes achieved 2.9 ± 1.0 cm. The largest ablation volume was 31.5 ± 12 ml (gas-cooled RF), and the smallest was 12.7 ± 4 ml (water-cooled RF). Short/long axis ratio was largest for gas-cooled RF probes with 0.73 ± 0.08 versus 0.64 ± 0.04 for the water-cooled probes and 0.49 ± 0.25 for the microwave applicator.

Conclusion

Gas-cooled RF applicators may have a higher potential for effective destruction of liver lesions than comparable water-cooled RF systems, and may be an alternative to standard RF and MW ablation devices.     

Ultrasound-guided microwave ablation of hepatocellular carcinoma: Initial institutional experience

BackgroundMicrowave ablation (MWA) is a new treatment modality for hepatocellular carcinoma (HCC) at our institution. The aim of this study is to evaluate the safety, procedure time and rate of complete ablation of this new modality.Material and methodsHospital medical ethics committee approval and informed consent were obtained. A total of 98 nodules in 72 patients (59 male, 13 female; mean age 57 (±4.6) years, range 50–70 years) with HCC were treated with microwave ablation at our institution from June 2010 to February 2011. A 14 G cooled shaft Amica probe was introduced into the tumors under analgesic sedation and by US guidance. The patients were then followed up with contrast enhanced computed tomography (CT) and serum α-fetoprotein levels.ResultsOne month after therapy, complete ablation was obtained in 96% (94/98) nodules. The complete ablation rate in tumors ?3 cm and those >3 cm were 98%, and 94%, respectively. MW ablation success was higher with nodules ?3 cm (57/58, 98.3%) in comparison to nodules >3 cm (37/40, 92.5%): however, the difference was non-significant (P = 0.301). No complication occurred related to the ablation procedure, only minor complications post-ablation, as pain in (3/72) patients, mild fever in (48/72) patients, and discharge from wound in (2/72) patients. No local recurrence was detected, however, new lesions at other sites of the liver occurred in 11 (15%) patients.ConclusionSonographically guided percutaneous microwave ablation proved to be safe, fast, and effective for treatment of hepatocellular carcinoma.     

Ultrasound-guided percutaneous thermal ablation of hepatocellular carcinoma using microwave and radiofrequency ablation

AIM: To investigate the therapeutic efficacy of thermal ablation for treatment of hepatocellular carcinoma (HCC) using microwave and radiofrequency (RF) energy application. MATERIALS AND METHODS: A total of 190 nodules in 97 patients (84 male, 13 female; mean age 53.4 years, range 24-74 years) with HCC were treated with microwave or RF ablation in the last 4 years. The applicators were introduced into the tumours under conscious analgesic sedation by intravenous administration of fentanyl citrate and droperidol and local anaesthesia in both thermal ablation procedures. The patients were then followed up with contrast-enhanced computed tomography (CT) to evaluate treatment response. Survival was analysed using the Kaplan-Meier method. RESULTS: Complete ablation was obtained in 92.6% (176/190) nodules. The complete ablation rates were 94.6% (106/112) in microwave ablation and 89.7% (70/78) in RF ablation. The complete ablation rates in tumours/=4.0 cm were 93.1, 93.8 and 86.4%, respectively. Local recurrence was found in 9.5% nodules and the rates in tumours/=4.0 cm in diameter were 3.4, 9.9 and 31.8%, respectively. In the follow-up period, 7.1% nodules ablated by microwave and 12.8% by RF presented local recurrence. The 1, 2 and 3-year distant recurrence-free survivals were 47.2, 34.9 and 31.0%, respectively. Estimated mean survival was 32 months, and 1, 2 and 3-year cumulative survivals were 75.6, 58.5, and 50.0%, respectively. One and 2 years survivals of Child-Pugh class A, B and C patients were 83.8 and 70.4%, 78.2 and 53.2%, 36.3 and 27.3%, respectively. CONCLUSION: Thermal ablation therapy by means of microwave and RF energy application is an effective and safe therapeutic technique for hepatocellular carcinoma. Large tumours can be completely ablated, but have a significantly higher risk of local recurrence at follow-up.     

Thermal Ablation for Benign Thyroid Nodules: Radiofrequency and Laser

Although ethanol ablation has been successfully used to treat cystic thyroid nodules, this procedure is less effective when the thyroid nodules are solid. Radiofrequency (RF) ablation, a newer procedure used to treat malignant liver tumors, has been valuable in the treatment of benign thyroid nodules regardless of the extent of the solid component. This article reviews the basic physics, techniques, applications, results, and complications of thyroid RF ablation, in comparison to laser ablation.     

Thermal ablation of lung tumors

Thermal ablation can be applied to treat any thoracic malignancy: primary lung cancers, recurrent primary lung cancers, metastatic disease, chest wall masses, and painful, bony metastases. Since the first reported use of thermal ablation for lung cancer in 2000 there has been an explosive use of the procedure, and by 2010 the number of procedures to treat thoracic malignancy is expected to exceed 150,000 per year. Presently, thermal ablation is best used for patients with early-stage lung cancers in patients who are not surgical candidates, patients with small and favorably located pulmonary metastases, and patients in whom palliation of tumor-related symptoms is the goal. Radiofrequency ablation, microwave ablation, and cryoablation are novel treatment modalities for lung cancer and can safely accomplish tumor destruction and even complete eradication of tumor in patients who are not candidates for surgical resection. In this article, we discuss technical considerations for each modality and the periprocedure and postprocedure management of patients with this disease.     

Ultrasonography-guided percutaneous radiofrequency ablation of hepatocellular carcinomas: A feasibility scoring system for planning sonography

Purpose

This study was designed to evaluate whether a feasibility scoring system for planning sonography is a reliable predictor of a safe and complete ablation in ultrasonography (US)-guided percutaneous radiofrequency ablation (RFA) of hepatocellular carcinomas (HCCs).

Materials and methods

We retrospectively evaluated the therapeutic outcomes of 108 consecutive patients (M:F, 78:30; mean age, 57.4 years) with a single nodular HCC (mean diameter, 2.0 cm) treated by percutaneous RFA. All patients were assessed for the feasibility of performing an RFA at planning sonography prior to the ablation. The feasibility scoring system consisted of five categories: the safe electrode path (P); the vital organs adjacent to the RFA zone (O); tumor size (S); tumor conspicuity (C); and the heat-sink effect (H). Each category was divided into a four-point scale [1-4]. If a score of 4 in any category was determined, the patient was not considered to be a suitable candidate for percutaneous RFA. We assessed if the score of each category, safety score (P + O), and curability score (S + C + H) correlated with a safe and complete ablation using the chi-squared test and likelihood ratio test for trend.

Results

The technical success rate was 100% (108/108) based on CT images obtained immediately after ablation. There was no 30-day mortality after RFA. There were major complications (one case of severe vasovagal reflex, one case of hemoperitoneum and one case of a pseudoaneurysm) in three (2.7%) patients, and minor complications (one case of a biloma, one case of subsegmental infarction and one case of abscess) in three (2.7%) patients. Post-ablation syndrome as a side effect was noted in 38 (35.1%) of 108 patients. The primary technique effectiveness rate at 1 month was 95.1% (105/108). Local tumor progression was noted in eight (7.6%) of 105 patients during the follow-up period (range, 3.0-11.5 months; median, 5.8 months; mean, 5.7 months). There was no significant single category to predict complication and local tumor progression (Fisher's exact test, p > 0.05). Contrary to the safety score for the probability of complication (p > 0.05), the curability score was significantly associated with the probability of local tumor progression (likelihood ratio test for trend; p = 0.03).

Conclusion

The new feasibility scoring system for planning US can be used as objective criteria to predict therapeutic efficacy rather than the safety of percutaneous RFA of an HCC.