Plowing the atrium and growing thrombi: two cases of large atrial thrombi following ablative and surgical procedure for atrial fibrillation.

AIM: We present two patients with a large left atrial (LA) thrombus following invasive treatment for atrial fibrillation and inadequate anticoagulation. METHODS AND RESULTS: Case 1: A 30-year-old woman, with a one-year history of symptomatic paroxysmal atrial fibrillation resistant to medical therapy, underwent catheter ablation for atrial fibrillation. Three days after the procedure the patient presented with dizziness, fatigue, rapid atrial fibrillation with a sub-therapeutic INR. Transesophageal echocardiography (TEE) revealed a large LA thrombus. Case 2: A 59-year-old male, with severe mitral regurgitation and chronic atrial fibrillation, underwent mitral valve repair and Cox-Maze procedure. Three months later, while asymptomatic, a follow-up transthoracic echocardiography a large posterior LA thrombus was imaged. His INR was also sub-therapeutic. Both patients were treated by enhancing anticoagulation and close echocardiographic follow-up. So far both patients have remained asymptomatic two months following discharge. CONCLUSION: Large LA thrombi detected by transthoracic echocardiography are a rare complication of the Cox-Maze procedure and radio-frequency ablation for atrial fibrillation, which may occur even in patients with restored normal sinus rhythm receiving inadequate anticoagulation therapy.     

医院病区智能安全防控系统的设计

目的：设计医院病区智能安全防控系统,有效防止患者物品或人员的安全,提高了医院管理水平。方法：基于射频识别（RFID）技术,通过患者佩戴的电子标签和院内安装的信号接收装置,实现对患者位置的实时监控和追踪,通过信息化方式监控违规行为并及时报警。结果：安全防控系统的设计从多方的利益出发,利用成熟的信息化科技手段,防止患者意外的发生。结论：医院病区智能安全防控系统的设计,提高了医院信息化的管理水平,该系统软件具有一定的推广应用价值。     

Role of catheter ablation of ventricular tachycardia associated with structural heart disease

In patients with structural heart disease, ventricular tachycardia (VT) worsens the clinical condition and may severely affect the shortand long-term prognosis. Several therapeutic options can be considered for the management of this arrhythmia. Among others, catheter ablation, a closed-chest therapy, can prevent arrhythmia recurrences by abolishing the arrhythmogenic substrate. Over the last two decades, different techniques have been developed for an effective approach to both tolerated and untolerated VTs. The clinical outcome of patients undergoing ablation has been evaluated in multiple studies. This editorial gives an overview of the role, methodology, clinical outcome and innovative approaches in catheter ablation of VT.     

灵芝孢子滴眼液对辐射性兔眼防护作用的研究

目的：探讨灵芝孢子滴眼液对兔眼辐射性损伤的作用和房水中相关酶活性的影响。方法：将破壁灵芝孢子制剂成滴眼液。选取黑眼睛健康獭兔30只随机分成5组，每组6只。1组为空白对照组；另4组采取每日2次紫外线辐射，每次辐射40min，其中3组为高、中、低浓度灵芝孢子滴眼液试验组，每日滴眼药3次；1组不用药为辐射模型组。试验60d。分别检测兔眼房水中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH—Px）的活性和丙二醛（MDA）的含量；在光学显微镜下观察兔眼角膜结构的变化及细胞分布情况。结果：辐射滴眼药组兔眼房水中SOD和GSH．Px活性较辐射模型组明显升高，MDA含量明显降低，角膜组织结构紧密连续且形态完整。结论：灵芝孢子滴跟液对辐射性兔眼具有保护作用。     

Current status of radio-frequency ablation for hepatocellular carcinoma

Summary BACKGROUND: Radio-frequency ablation (RFA) is the latest developed and widely practised local ablation therapy for liver tumours. It has the merit of effective tumour ablation and preservation of the maximal normal liver parenchyma. In the past few years, there has been tremendous expansion in the application of RFA for hepatocellular carcinoma (HCC) patients. However, the therapeutic effect of this local-ablation treatment needs to be balanced against its risks and possible local failure. METHODS: This review focuses on the current status of RFA for HCC, with attention to its indications, approaches, risks, local failure, and survival benefit. RESULTS: Although the results of most clinical studies of RFA seem optimistic, the associated complication and tumour recurrence should not be overlooked. Careful patient selection, meticulous RFA techniques, and prompt treatment of residual and recurrent tumours are necessary to ensure a better outcome after RFA. CONCLUSIONS: Until recently, there has been no strong evidence showing that RFA can replace any treatment modalities in the management of HCC. Nonetheless, more convincing evidence by randomised trials is required for the establishment of a treatment protocol of RFA for HCC patients.      

Radio-frequency thermal ablation of liver metastases with a cooled-tip electrode needle: results of a pilot clinical trial

The aim of this study was to evaluate feasibility, safety, and effectiveness of radio-frequency (RF) thermal ablation, performed by using a cooled-tip electrode needle, in the treatment of liver metastases. Twenty-nine patients (20 males and 9 females; age range 43–77 years) with one to four hepatic metastases 1.1–4.8 cm in diameter (mean 2.9 ± 0.8 cm) from previously resected intra-abdominal primary malignancies were treated. All patients were excluded from surgery and had partial or no response to chemotherapy. Radio-frequency ablation was performed by using a 100-W generator and 17-gauge, dual-lumen, cooled-tip electrode needles with a 2- to 3-cm exposed tip. Exposure time was 12 min for each needle insertion. Findings at spiral CT were used to assess the therapeutic response. A total of 127 insertions were performed (mean 2.4 ± 1.7 insertions/lesion) during 84 treatment sessions (mean 1.6 ± 0.7 sessions/lesion) in absence of major complications. Complete tumor response (i. e., unenhancing area of thermal necrosis larger than the treated tumor) was seen in 41 (77 %) of 53 lesions, including 33 (87 %) of 38 lesions 3 cm or less in diameter. After a mean follow-up period of 6.5 ± 2.1 months (range 3–9 months), recurrence of the treated lesion was seen in 5 (12 %) of the 41 cases. New metastatic lesions appeared in 7 patients. Two patients died after 6 and 8 months, respectively. Of the 27 patients still in follow-up, 14 are currently free of disease. Radio-frequency thermal ablation with a cooled-tip electrode needle is a safe and effective local treatment for hepatic metastases 3 cm or less in greatest dimension. Received: 5 September 1997: Revised: 8 January 1998: Accepted: 14 January 1998     

MR appearances of radiofrequency thermal ablation region: histopathologic correlation with dog liver models and an autopsy case

RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate the utility of magnetic resonance (MR) imaging for indicating the extent of true tissue necrosis of the liver after radiofrequency (RF) ablation in comparison with histopathologic findings in dog models and an autopsy case. MATERIALS AND METHODS: RF ablation of the liver parenchyma was performed on three dogs under general anesthesia. MR appearances of the RF-ablated regions on T1-weighted fast-low angle shot (FLASH; repetition time/echo time [TR/TE]/flip angle: 120/3.8/70),T2-weighted turbo spin echo (3000/80/echo train = 25) and contrast-enhanced T1-weighted images were compared with histopathologic findings. An autopsy case with hepatocellular carcinoma was also enrolled in this study. RESULTS: All ablated regions showed three zones on T1-weighted FLASH images: a central zone with low intensity, a broad hyperintense middle zone, and a surrounding hypointense band. The central and middle zones corresponded to the degrees of coagulation necrosis observed during histopathologic examination, whereas no viable cells were seen in these zones during the microscopic examination using nicotinamide adenine dinucleotide diaphorase stain. The surrounding hypointense band corresponded to sinusoidal congestion in the acute phase and to fibrotic change in the subacute phase. CONCLUSION: MR imaging using the FLASH sequence can accurately determine the extent of the necrotic area after RF ablation.     

Primary lung cancer: treatment with radio-frequency thermal ablation

Primary lung cancer is the most frequently diagnosed malignancy in the world and the leading cause of death from cancer [1]. When the initial diagnosis is made, most cases are inoperable or the patients condition does not permit surgical interventions [2]. For patients with inoperable lung cancer, percutaneous radio-frequency thermal ablation (RFA) under CT guidance represents an alternative and minimally invasive treatment. It can also be applied in combination with radiation therapy and chemotherapy. We report three cases treated by percutaneous CT-guided RF ablation, from which two had post-operative recurrent tumor and one was inoperable.     

Open radio-frequency thermal ablation of renal VX2 tumors in a rabbit model using a cooled-tip electrode: feasibility,safety, and effectiveness

The purpose of this study was to evaluate the feasibility, safety, and effectiveness of radio-frequency (RF) ablation using an internally cooled-tip electrode on renal VX2 tumors implanted in rabbits. Thirty-three rabbits with implanted renal VX2 tumors were divided into two groups: an RF ablation (RFA) group (n=27) and a control group (n=6). In the RFA group, RFA was performed on 27 implanted VX2 tumors using a cooled RF electrode and they were divided into three subgroups according to the follow-up period: acute (1–3 days, n=12); subacute (1–4 weeks, n=9); and chronic (2–7 months, n=6). Contrast-enhanced spiral CT was performed before the RFA and at the day, day 3, weeks 1, 2, 4, and months 2 and 7, after the RFA. The therapeutic efficacy was evaluated by the survival rate, CT, and pathologic findings. The RFA of renal tumors was technically successful in each instance. Complete tumor ablation was achieved in 22 of the 27 rabbits (81.5%) in the RFA group: 5 rabbits survived longer than 8 weeks without any evidence of viable tumor (18.5%) and 17 rabbits were found free of viable tumors when killed (63.0%). Five rabbits showed local tumor relapse and/or hematogenous lung metastasis after ablation (a recurrence rate of 18.5%). There were 11 (40.7%) complications related to the procedure. This experimental study demonstrates the feasibility of RFA therapy to treat renal VX2 tumors in rabbits, although RFA for central tumors carries some major potential complications, including renal arterial injury. Electronic Publication     

Linear Enhancement After Radio-Frequency Ablation for Hepatocellular Carcinoma: Is It a Sign of Recurrence?

This prospective study was performed in 179 hepatocellular carcinoma (HCC) lesions treated by radio-frequency ablation (RFA) to explore the clinical outcome of “linear enhancement” on contrast-enhanced sonogram. Thirty-three lesions (18.4%) showed linear enhancement, a linear-shaped positive enhancement in the RFA-treated area. Seventeen of them were followed up with no treatment (remaining 16; dropout in eight, additional RFA in six and ineffective treatment in two) and three lesions (3/17, 17.6%) showed local tumor progression corresponding to linear enhancement at 7, 14, 19 months after RFA. Although there was no significant difference in local recurrence rate between the lesions with (3/17) and without linear enhancement (10/35), local tumor progression inside the ablation zone occurred only in the lesions with linear enhancement. In conclusion, linear enhancement inside the RFA-treated area should be followed up within 7 months because it has a risk of local tumor progression. Histology of linear enhancement and its influence on distant recurrence remain to be solved.