肝癌患者射频消融与手术前后外周血中CD4^＋CD25^＋调节性T细胞的变化及意义

目的：探讨肝癌患者接受射频消融或手术治疗前后外周血中CD4^＋、CD25^＋调节性T细胞水平的变化及意义。方法：分析35例原发性肝细胞肝癌患者射频消融治疗前和治疗后1周外周血中CD4^＋、CD25^＋调节性T细胞水平变化,并与20例原发性肝细胞肝癌手术切除患者外周血中CD4^＋、CD25^＋调节性T细胞水平进行对比分析。另外检测10例因患胆囊结石行胆囊切除患者手术前后的CD4^＋、CD25^＋调节性T细胞水平作为对照。结果：所有肝癌患者在射频消融治疗后7d外周血中CD4^＋、CD25^＋调节性T细胞水平降低,而手术组明显升高,对照组无明显变化。结论：采用射频消融治疗肝癌,可以改善患者的细胞免疫状态。     

多电极射频治疗肝肿瘤的并发症及防治（附１１４例临床分析）

目的 探讨多电极射频治疗肝肿瘤的并发症及其防治方法。方法 对１１４例肝肿瘤病人进行了１７０次多电极射频治疗,临床观察治疗后的并发症及防治情况。结果 并发症率９.６％,包括结肠穿孔１例,皮肤烧伤４例,胸腔积液５例,皮下出血１例;但无一例死亡。结论 多电极射频技术用于治疗肝肿瘤的并发症率较低,且其并发症是可以防治的。     

Radio-frequency tissue ablation of the liver: effects of vascular occlusion on lesion diameter and biliary and portal damages in a pig model

The aim of this study was to assess the effect of vascular occlusion on radio-frequency (RF) lesion size and on potential associated biliary and portal lesions. Radio-frequency lesions using a 1-cm exposed-tip cooled electrode were created in pig liver. Liver perfusion was modified by arterial embolization (n=2), left portal clamping (n=2), and both (n=2). Two pigs were used as controls. Two weeks after, control portography was performed, animals were killed, and ex-vivo cholangiography was carried out. Pathological studies evaluated the lesion surface and associated portal and biliary damages. A mathematical regression model showed that portal occlusion increased by 43 mm2 (+40%) the surface of RF lesions, arterial occlusion by 135 mm2 (+126%), and associated occlusion by 466 mm2 (+435%). Biliary stenoses were found in 4 cases (two arterial occlusions, one portal occlusion, and one associated occlusion). One case of partial portal vein thrombosis was found in one case of portal occlusion and resolved at 2 weeks. Ischemic damages adjacent to RF lesions were found in cases of combined occlusions. The reduction of liver perfusion increases significantly the size of RF lesions but is associated with a risk of biliary, portal, or parenchymal complications.     

Treatment of hepatocellular carcinoma by percutaneous interventional methods

In the treatment of early and intermediate hepatocellular carcinoma the range of indications for percutaneous ablation techniques is becoming wider than surgery or intra-arterial therapies. Indeed, whereas for some years only patients with up to three small tumours were treated, with the introduction of the single-session technique performed under general anaesthesia, even patients with more advanced disease are now being treated. Although it is understood that partial resection assures the highest local control, the survival rates after surgery are roughly comparable with percutaneous ethanol injection (PEI). The explanation is due to a balance among advantages and disadvantages of the two therapies. PEI survival curves are better than curves of resected patients who present adverse prognostic factors, and this means that surgery needs a better selection of the patients. Indications for both of therapies are reported. An unanswered question remains the choice between PEI and other new ablation procedures. In our department we currently use radio-frequency ablation in the majority of patients but consider PEI and segmental transarterial chemoembolisation complementary, and use them according to the features of the disease and the response. Evaluation of therapeutic efficacy, technique and results of them are reported.     

全麻支撑喉镜联合电子喉镜行射频揭盖术治疗会厌囊肿30例

目的：观察全麻支撑喉镜联合电子喉镜行射频揭盖术治疗会厌囊肿的疗效。方法选取我院耳鼻喉科收治的会厌囊肿患者60例,随机分为观察组和对照组,每组30例。对照组在全麻下行支撑喉镜下圈套器圈套治疗,观察组行全麻支撑喉镜联合电子喉镜行射频揭盖术治疗。记录两组患者的手术时间和术中出血量。术后采用门诊随访的形式,随访12个月以上,观察患者术后治疗效果。结果观察组和对照组手术时间分别为(12.8±3.2) min和(46.5±8.6) min,术中出血量分别为(2.2±0.3) ml和(10.4±2.6) ml,观察组手术时间和术中出血量显著低于对照组,差异均有显著统计学意义(P<0.01)。随访6个月时,观察组和对照组总有效率分别为96.67%和86.67%,复发率分别为3.33%和13.33%;随访12个月时,观察组和对照组总有效率分别为93.33%和76.67%,复发率分别为6.67%和23.33%;观察组总有效率明显高于对照组,复发率显著低于对照组,差异均有统计学意义(P<0.05或P<0.01)。结论全麻支撑喉镜联合电子喉镜行射频揭盖术治疗会厌囊肿疗效好,且具有手术时间短、出血量少的特点。     

Liquid metal bath as conformable soft electrodes for target tissue ablation in radio-frequency ablation therapy

Background: Radio-frequency ablation has been an important physical method for tumor hyperthermia therapy. The conventional rigid electrode boards are often uncomfortable and inconvenient for performing surgery on irregular tumors, especially for those tumors near the joints, such as ankles, knee-joints or other facets like finger joints.

Material and methods: We proposed and demonstrated a highly conformable tumor ablation strategy through introducing liquid metal bath as conformable soft electrodes. Different heights of liquid metal bath electrodes were adopted to perform radio-frequency ablation on targeted tissues. Temperature and ablation area were measured to compare the ablation effect with plate metal electrodes.

Results: The recorded temperature around the ablation electrode was almost twice as high as that with the plate electrode and the effective ablated area was 2–3 fold larger in all the mimicking situations of bone tumors, span-shaped or round-shaped tumors. Another unique feature of the liquid metal electrode therapy is that the incidence of heat injury was reduced, which is a severe accident that can occur during the treatment of irregular tumors with plate metal boards.

Conclusions: The present method suggests a new way of using soft liquid metal bath electrodes for targeted minimally invasive tumor ablation in future clinical practice.     

Maximum electrogram-guided ablation of cavotricuspid isthmus-dependent atrial flutter

Aims

To verify and re-emphasise the efficacy of the max electrogram-guided approach for ablation of cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL).

Methods

Consecutive patients were alternatively assigned to receive either conventional linear radio-frequency (RF) ablation between the tricuspid annulus and inferior vena cava (the linear approach) or RF ablation at sites with the highest electrograms (the max electrogram-guided approach). Sustained, bi-directional CTI block was the endpoint. Procedure parameters and follow-up data were obtained.

Results

In total, 80 patients were included, 40 each for the linear approach and the max electrogram-guided approach. To achieve sustained bi-directional CTI block, the linear approach needed 841 ± 594 sec or 14.0 ± 9.9 RF applications, with total fluoroscopy time of 18.6 ± 9.4 min and total procedure time of 152 ± 58 min, as compared to the max electrogram-guided approach which needed 350 ± 319 sec (p < 0.0001) or 5.8 ± 5.3 RF applications (p < 0.0001), with total fluoroscopy time of 14.8 ± 6.0 min (p < 0.05) and total procedure time of 111 ± 36 min (p < 0.0005). The CTI block was obtained with 3 or less RF applications in 18 patients in the max electrogram-guided group (45%), but only in 2 patients in the linear ablation group (5%). During follow-up of 28 ± 14 months, recurrence cases were 2 in the linear and 1 in the max electrogram-guided group (NS).

Conclusion

During ablation of AFL, directly targeting muscle bundles in the CTI as guided by the highest electrograms is more efficient than making a linear lesion across the entire CTI, since using the former approach needed less RF application, shorter fluoroscopy and procedure times than using the latter. The max electrogram-guided approach may be recommended for routine clinical use to replace the conventional linear ablation approach.     

Three-dimensional electrode displacement elastography using the Siemens C7F2 fourSight four-dimensional ultrasound transducer

Because ablation therapy alters the elastic modulus of tissues, emerging strain imaging methods may enable clinicians for the first time to have readily available, cost-effective, real-time guidance to identify the location and boundaries of thermal lesions. Electrode displacement elastography is a method of strain imaging tailored specifically to ultrasound-guided electrode-based ablative therapies (e.g., radio-frequency ablation). Here tissue deformation is achieved by applying minute perturbations to the unconstrained end of the treatment electrode, resulting in localized motion around the end of the electrode embedded in tissue. In this article, we present a method for three-dimensional (3D) elastographic reconstruction from volumetric data acquired using the C7F2 fourSight four-dimensional ultrasound transducer, provided by Siemens Medical Solutions USA, Inc. (Issaquah, WA, USA). Lesion reconstruction is demonstrated for a spherical inclusion centered in a tissue-mimicking phantom, which simulates a thermal lesion embedded in a normal tissue background. Elastographic reconstruction is also performed for a thermal lesion created in vitro in canine liver using radio-frequency ablation. Postprocessing is done on the acquired raw radio-frequency data to form surface-rendered 3D elastograms of the inclusion. Elastographic volume estimates of the inclusion compare reasonably well with the actual known inclusion volume, with 3D electrode displacement elastography slightly underestimating the true inclusion volume.     

73例老年肝癌患者经皮射频消融治疗的护理体会

肝癌在我国的恶性肿瘤死亡分类构成中已列居第2位,占癌症死亡总数的14.56%,且死亡人群年龄有上升趋势[1]。我院自2009年11月至2011年11月进行了157例超声引导下经皮肝脏肿瘤射频消融治疗（radio-frequency ablation,RFA）,其中73例为老年肝癌患者,在护士适时的护理干预下,治疗均得以顺利完成,现将护理体会总结如下。     

Ring electrode for radio-frequency heating of the cornea: Modelling and<Emphasis Type="Italic">in vitro</Emphasis> experiments

Radio-frequency thermokeratoplasty (RF-TKP) is a technique used to reshape the cornea curvature by means of thermal lesions using radio-frequency currents. This curvature change allows refractive disorders such as hyperopia to be corrected. A new electrode with ring geometry is proposed for RF-TKP. It was designed to create a single thermal lesion with a full-circle shape. Finite element models were developed, and the temperature distributions in the cornea were analysed for different ring electrode characteristics. The computer results indicated that the maximum temperature in the cornea was located in the vicinity of the ring electrode outer perimeter, and that the lesions had a semi-torus shape. The results also indicated that the electrode thickness, electrode radius and electrode thermal conductivity had a significant influence on the temperature distributions. In addition,in vitro experiments were performed on rabbit eyes. At 5 W power, the lesions were fully circular. Some lesions showed non-uniform characteristics along their circular path. Lesion depth depended on heating duration (60% of corneal thickness for 20s, and 30% for 10s). The results suggest that the critical shrinkage temperature (55–63°C) was reached at the central stroma and along the entire circular path in all the cases.