[Clinical results of Mei mini maze procedure for atrial fibrillation patients with previously failed catheter ablation].

Objective: To evaluate the efficacy of Mei mini maze procedure for treating atrial fibrillation (AF) patients with previously failed catheter ablation. Methods: Between August 2010 and May 2016, 48 AF (8 proximal AF, 15 persistent AF and 25 long-standing persistent AF) patients (29 males, 19 females, mean age: (62.5±7.3) years old) with previously 1-3 failed catheter ablation results were treated with Mei mini maze procedure in our department. Under thoracoscopic assistance, the procedure was performed through three ports on left chest wall, pulmonary vein isolation and ablations of the roof and posterior wall of left atrium was made by bipolar radiofrequency ablation. Ganglionic plexus ablation was made by the ablation pen. Left atrial appendage was excluded. Patients were followed at outpatient clinic and per telephone. Electrocardiogram, CT and echocardiography examinations were performed at 1, 3, 6 and 12 months post operation. The success rate of the procedure was analyzed by Kaplan-Meier curves and evaluated by the log-rank test. Results: Mean AF history was (8.1±6.3) years and left atria dimension was (44.1±6.2) mm in this patient cohort. All procedures were performed successfully in these 48 patients. Pericardial adhesions were dissected in 21 patients. Durations of the procedures were (142.3±35.6) minutes.There were no serious complications. The hospital stay was (9.3±1.8) days. Sinus rhythm was documented in 44 patients (91.7%) at discharge. The mean follow-up duration was (28.0±17.2) months. Thirty-eight patients (82.6%) were in sinus rhythm. There was no stroke, thrombus in the left atrium and stenosis of pulmonary vein during the follow-up. Sinus rhythm was achieved in 7 out of 8 paroxysmal AF patients, in 31 out of 38 non-paroxysmal AF patients, and in 13 out of 15 persistent AF patients. Kaplan-Meier curve showed that the success rate in the long-standing persistent AF group was lower than in the other two groups, but there was no statistical difference. Conclusions: Mei mini maze procedure has a high success rate for AF patients with previously failed catheter ablation history, which could completely isolate the bilateral pulmonary vein and left atrial posterior wall with good quality and integrity of ablation line, and left atrial appendage is also resected during the procedure.

Interferon-ß efficiently inhibited endothelial progenitor cell-induced tumor angiogenesis.

Neovascularization has a critical role in the growth and metastatic spread of tumors, and involves recruitment of circulating endothelial progenitor cells (EPCs) from bone marrow. In this study, we examined whether EPCs could promote tumor angiogenesis, and found that the tumor growth was enhanced by the administration of EPCs. To test the hypothesis that genetically modified bone marrow-derived EPCs can be effective carriers of therapeutic agents to tumor sites, we conducted human interferon-beta (HuIFN-ß) gene transfection of EPCs with a virus vector in vitro. When HuIFN-ß was applied in the ex vivo culture of EPCs, HuIFN-ß-transduced EPCs achieved efficient killing of the total population of SPC-A1 cells, indicating a bystander effect was elicited by HuIFN-ß-transduced EPCs in vitro. When SCP-A1 cancer cells were coimplanted along with ex vivo cultivated EPCs subcutaneous injection in nude mice, the tumor growth was increased. However, the anti-tumor effect of interferon-beta (IFN-ß) offset the tumor-progressive character of EPCs and the tumor growth, and the vascular density of tumor tissues increased by coimplanted EPCs were decreased upon IFN-ß treatment. In addition, overall expression levels of vascular endothelial growth factor in tumor tissues were decreased upon IFN-ß treatment. Therefore, our results suggest that gene-transfected EPCs could be useful as a tumor-specific drug delivery system.