A new cool-tip radiofrequency (RF) ablation therapeutic instrument based on impedance control algorithm is introduced in this paper. The equipment is composed of hardware system and software system. The RF power output and real time data acquisition are completed by the hardware system, while the software is used mainly to finish the control of the ablation range, the core of which is impedance control algorithm, and it also used to complete the display of the real time data in the course of the experiment. The impedance algorithm has solved the problem of impedance increased rapidly during the RF ablation, which has also expanded the scope of ablation. The pig liver experiments showed that the impedance control algorithm had strong adaptability. It also obtained a result of ablation range up to 3.5~4.5 cm single needle. It has the high clinical practical value of one-time inactivation of 3~5 cm tumor.
Objective To explore efficacy and safety of radiofrequency ablation (RFA) in the treatment of large hepatocarcinoma. MethodsFortythree cases of large hepatocarcinoma underwent RFA with the expandable cluster electrode,eight of all cases had undergone transcatheter artery chemoembolization (TAE) for 1-2 sessions within 2 months before RFA; the tumors were 5-10 cm in diameter, mean 7.5 cm. Hepatic function examination, alphafetoprotein, enhanced CT scans,color ultrasonography and needle biopsy were performed,pre and posttreatment. Complete necrosis was evaluated by dynamic enhanced CT scans and biopsy. Therapeutic time and sessions of RFA,length of stay in hospital and complications of RFA were observed; and thirtynine of 43 cases after RFA were followed up for 12-18 months.ResultsFortythree cases of large hepatocarcinoma received RFA for 67 sessions, 1-3 sessions per case,mean 1.6 sessions; therapeutic time 55-150 min,mean 75 min; length of stay in hospital 3-15 day, mean 8.7 day; major complications of RFA included local skin burn of electrode board in 2 cases (4.6%) and moderatetolarge right pleural effusion in 3 cases (7.0%),overall complications rate was 11.6%; complete necrosis was achieved in 41.0% of cases which were evaluated by dynamic enhanced CT scans at least 6 months followed RFA; of thirtyone cases of positive AFP, AFP level became negative in 3,decreased obviously in 5 within 6-12 months after RFA; in 12-18 months followup,oneyear survival rate was 69.2%.Conclusion RFA appears to be safe, effective and minor invasive for the treatment of large hepatocarcinoma.
ObjectiveTo summarize clinical advantages and outcomes of minimally invasive mitral valve replacement (MVR) combined with atrial fibrillation (AF) radiofrequency ablation via right minithoracotomy. MethodsEight patients with mitral valve disease and AF who received surgical therapy in the First Hospital of China Medical University between October 2009 and October 2012 were included in the study. There were 4 males and 4 females with their age of 34-67 (52.4±17.5) years. All the patients underwent minimally invasive MVR combined with AF radiofrequency ablation via right minithoracotomy. Clinical outcomes were summarized. ResultsThere was no in-hospital death or conversion to conventional sternotomy in this group. Two patients received biological valve replacement and 6 patients received mechanical prosthesis. Operation time was 207.9±18.1 minutes, cardiopulmonary bypass time was 81.7±23.9 minutes, and chest drainage amount was 126.7±34.5 ml. AF recurred in 1 patient on the 3rd postoperative day. All the patients were in sinus rhythm at discharge. These patients were followed up for 18.3±7.4 months. During follow-up, 1 patient had AF recurrence. Seven patients were in NYHA class Ⅰ, and 1 patients was in NYHA class Ⅱ. ConclusionMinimally invasive MVR combined with AF radiofrequency ablation via right minithoracotomy can achieve satisfactory clinical results and esthetic appearance, and is a good choice for patients with mitral valve disease and AF.
Objective To investigate the impact of injection of acetic acid hypertonic saline solution (AHS) in dog liver during radiofrequency ablation (RFA) on its destructive zone. Methods RFAs were performed in dog livers by using LDRF-120S mutiple probe ablation system combining 50% acetic acid 5% hypertonic saline solution injection. Thirty healthy adult hybrid dogs were randomly divided into 5 groups (n=6). Group A: RFA was performed immediately after injection of 2 ml AHS; Group B: RFA was performed 5 min after injection of 2 ml AHS; Group C: RFA was performed immediately after injection of 4 ml AHS; Group D: RFA was performed 5 min after injection of 4 ml AHS; Group E: RFA was performed immediately after injection of 6 ml AHS. Results There were no significant differences in the mean initial impedance within 5 groups. The mean ablation times were different significantly among 5 groups (F=83.831, P<0.001). The mean ablation time was different significantly between any two groups by LSD-t analysis (P<0.001). The mean coagulation diameters were different significantly among 5 groups (F=53.488, P<0.001). The mean coagulation diameter of group E was the largest among 5 groups. Besides mean coagulation diameter was no significant difference between group D and E (Pgt;0.05), the mean coagulation diameter was different significantly between any two groups by LSD-t analysis (P<0.001). Obviously thrombus were shown in coagulation necrosis zone and nearly normal tissue with gordon amp; sweet. AHS spillage from the injection site occurred in group E. Four dogs died in group E within 14 d but no dog died in the other groups. Conclusion RFA is performed 5 min after injection of 4 ml AHS in dog liver produces the ideal ablation destructive zone.
ObjectiveTo investigate influence of left atrial contraction on lone atrial fibrillation recurrence after minimally invasive radiofrequency ablation. MethodsClinical data of 57 patients with lone atrial fibrillation underwent minimally invasive radiofrequency ablation in Department of Cardiothoracic Surgery, Xinhua Hospital, Medical School of Shanghai Jiaotong University from September 2010 to December 2011 were retrospectively analyzed. According to the absence of mitral A velocity, patients were divided into Group A (absence of mitral A velocity, 20 patients with their age of 56.32±17.18 years, including 5 females) and Group B (mitral A velocity exists, 37 patients with their age of 60.33±11.22 years, including 17 females). Minimally invasive radiofrequency ablation via thoracoscope were performed in all patients. Preoperative and postoperative left atrial diameter (LAD), left ventricular ejection fraction (LVEF) and mitral A velocity, as well as clinical and follow-up data were recorded and compared. ResultsPreoperative clinical characters were not statistically different between two groups (P > 0.05). All the patients were followed up for 24.3±8.8 months (range, 12-26 months). Rate of postoperative atrial fibrillation recurrence in group A was significantly higher than that in group B (20.0% vs. 2.7%, P < 0.05). LAD and LVEF of 57 patients at 6 months after surgery were significantly higher than preoperative LAD and LVEF (P < 0.05), but there was no statistic difference between two groups (P > 0.05). ConclusionDamage of left atrial contraction was related to lone atrial fibrillation recurrence after minimally invasive radiofrequency ablation. Absence of mitral A velocity could be a crucial predictor of postoperative lone atrial fibrillation recurrence.
摘要:目的:探讨三维电解剖标测系统(CARTO)指导下进行房性心动过速射频消融的方法及效果。方法:对40例房性心动过速患者应用CARTO标测心房, 构建三维电解剖图,分析房性心动过速的电生理机制。局灶性房速消融最早激动点,大折返性房速消融折返环的关键性峡部。选择利用常规方法行消融的28 例患者作为对照组。比较两组消融的成功率、X线曝光时间。结果:38例患者CARTO三维标测系统标测提示为局灶性房性心动过速, 最早激动点位于右心房35例,其中冠状静脉窦口8例(20%)、间隔部10例(25%)、侧壁8例(20%)、上腔静脉口附近4例(10%)、后壁4例(10 %),1例患者(2.5%)有3种类型房速(分别为间隔部、上腔静脉口的局灶房速和三尖瓣峡部依赖的大折返房速)。位于左心房的局灶房速3例,分别位于右上肺静脉口(2.5%)、左上肺静脉口(2.5%)及左心耳(2.5%)。2例患者为大折返房速(5%),1例为三尖瓣峡部依赖性,1例为围绕界嵴的大折返房速。均消融成功(100%),随访4~16个月,均无复发。常规消融组成功率为89.3%(Plt;0.05)。CARTO组X线曝光时间比常规组明显缩短,分别为(13.8±5.5 ) min 和( 30.4±12.9 ) min,差异有统计学意义(Plt;0.05)。结论:应用CARTO标测房性心动过速, 对分析房性心动过速的机制准确快速, 能有效指导射频消融。Abstract: Objective: To evaluate the methods and effects of radiofrequency ablation of atrial tachycardia guided by CARTO. Methods: The atria of 40 cases were mapped by three dimensional electroanatomic mapping system. In order to analyse the mechanism of atrial tachycardia and perform the ablation of the earliest excited point in focal atrial tachycardia and isthmus in macroreentry atrial tachycardia. 28 cases ablated by conventional procedure were selected as controlled group. The success rate and fluoroscopic time were compared between the two groups. Results: Focal atrial tachycardia was seen in 38 patients. The sites of origin from right atrium were at the coronary sinus ostium in 8 cases (20%), septal in 10 cases (25%), lateral wall in 8 cases (20%), superior vena cava ostium in 4 cases (10%), posterior wall in 4 cases (10%). One case had 3 types of atrial tachycardia (2.5%). The sites of origin from left atrium were at right pulmonary vein ostium in 1 case (2.5%), left pulmonary vein ostium in 1 case (2.5%), left auricular appendage in 1 case (2.5%). 2 cases were macroreentry atrial tachycardia (5%). Ablation was performed successfully (100%) without any complication. No recurrence was found during a followup of 416 months. Success rate in conventional group was 89.3%(Plt;0.05)。Comparing the CARTO group and conventional group, the fluoroscopic time was shorter, ( 13.8±5.5 ) min vs ( 30.4±12.9 ) min (Plt;0.05).Conclusion: The mechanism of atrial tachycardia can be evaluated quickly and accurately. Ablation can be performed safely and effectively guided by CARTO.
ObjectiveTo analyze the clinical presentations and radiological characteristics of pulmonary vein stenosis after radiofrequency ablation. MethodsClinical and radiological data of 2 patients with pulmonary vein stenosis after radiofrequency ablation for atrial fibrillation were retrospectively analyzed and literatures were reviewed. ResultsBoth patients had undergone circumferential pulmonary vein isolation. The symptoms appeared approximately 2 months after the operation. The major symptoms were cough, hemoptysis, exacerbation of dyspnea and chest pain. Both patients were misdiagnosed as other diseases such as pneumonia in other hospitals, and the anti-infection therapy was invalid. Both CT scans showed parenchymal exudative consolidation with varying degrees of interstitial septal thickening and small nodules. Both patients were confirmed as pulmonary vein stenosis by CT angiography. Literature review identified 21 cases of pulmonary vein stenosis after radiofrequency ablation for atrial fibrillation. The main clinical features are hemoptysis, chest pain, shortness of breath and cough. The most common features of thoracic radiological imaging are consolidation, groud-glass attenuation, pleural effusion and interstitial septal thickening. ConclusionsIf a patient presents with hemoptysis, dyspnea, chest pain or other clinical manifestations after ablation therapy and image findings show parenchymal exudative consolidation with interstitial septal thickening and multiple small nodules, the possibility of pulmonary vein stenosis should be considered. Contrast-enhanced CT combined with pulmonary vein imaging technology can clearly show the opening diameter of each pulmonary vein and its branches, so it is an important non-invasive examination method for the evaluation and diagnosis of pulmonary vein stenosis.
In 2022, there were 367.7 thousands new cases and 316.5 thousands deaths of primary liver cancer in China. Radiofrequency ablation (RFA) is one of the radical treatments for liver cancer. It has the characteristics of definite curative effect, minimal invasion and low cost. In patients with early liver cancer, the curative effect is similar to surgical resection. The concept and practice of precision surgery provide new ideas for improving the efficacy of RFA. Based on the RFA treatment experience of more than ten thousand cases, the author’s team has carried out research on the precise ablation treatment of primary liver cancer. Now, the author will combine the existing literature and our team’s experience to discuss the application and prospect of the precise surgery concept in RFA treatment.