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Purpose. Video-assisted pericardioscopic surgery (VAPS) for epimyocardial lead implantation has demonstrated positive acute results concerning the safety and degree of freedom inside the pericardium. We evaluated the employment of a newly developed trocar for pericardioscopy with regard to long-term effects and feasibility of reoperation. Description. Eight adult sheep were divided into three groups. In two animals, VAPS was used exclusively. All other animals received four small-caliber epicardial leads through VAPS. After 6 and 12 months (n = 3 each), reoperation was conducted for reevaluation of entry site, intrapericardial adhesions, lead position, and morphology of the implantation site. Evaluation. Reentry close to the previous entry site proves unproblematic. Adhesions were mild to moderate in the immediate area of the implanted leads. Throughout the follow-up, pacing parameters were satisfactory. Lead dislodgement occurred in 1 of 24 leads. The deployment of small-caliber flexible endoscopes through the new trocar provided sufficient navigation, stability, and maneuverability. Conclusions. Reoperation from the same subxiphoid approach proved feasible. Lead removal and reimplantation were feasible at both 6 months and 12 months after initial implantation. The intrapericardial adhesions caused by VAPS alone are mild. [ABSTRACT FROM AUTHOR]

Objective: Transcatheter replacement or repair of mitral valve regurgitation has proved demanding. We aimed for a new approach to anchor a biologic heart valve in the mitral position by inserting a valve-carrying hollow body into the left atrium. This approach was investigated in both a simulation and an animal model. Methods: After creating a mold representing the porcine left atrium from the pulmonary veins as far as the mitral valve, a nitinol skeleton was sutured onto interlaced yarns of polyvinylidene flouride fitting the mold. The resulting device was equipped with a commercially available stentless valve (25 mm) and investigated in a simulator regarding basic functionality. Furthermore, the device was implanted in 8 female pigs through incision of the left atrium during extracorporeal circulation. Before implantation, artificial regurgitation was created by means of excision from the posterior mitral leaflet. Hemodynamic, echocardiographic, and radiologic examinations followed. For a postmortem examination, the entire heart and the lungs were excised. Results: We could demonstrate the functionality of the heart valve in a complex, collapsible, and self-expanding hollow body. The device adapted to the surrounding structures, leading to an exclusion of the left atrium. Sufficient treatment of mitral regurgitation was monitored hemodynamically and by means of echocardiographic analysis, although overall visualization remained difficult. Therefore in 4 animals computed tomographic scans were performed. Autopsy revealed proper positioning without major trauma to the surrounding structures. Conclusion: Anchoring an additional heart valve in the atrioventricular position does not necessarily need to be performed in the heart valve structure itself. Placement of an additional valve in the mitral position is feasible through this approach. [Copyright &y& Elsevier]

Introduction: Anthracyclines are widely used in oncogenic therapy. Owing to their cardiotoxic side effects, their application is subdued to dose limitations. Many cardioprotective approaches have failed. This study examined the role of matrix metalloproteinases (MMP) in the remodeling process of extracellular matrix after treatment with doxorubicin (Adriamycin) as a toehold for a new therapeutic approach, for example, treatment with MMP inhibitors. Methods: Severe heart failure was induced in 6 pigs by the repetitive intracoronary application of Adriamycin. Degree of dilatation and insufficiency were measured by echocardiography and hemodynamics. Before and after treatment, MMP activity (fluorogenic assay: MMP-1, MMP-2) and gene expression (reverse transcription-polymerase chain reaction [RT-PCR]: MMP-1, -2, -9; membrane type-1 matrix metalloproteinase, [MT1MMP]; tissue inhibitor of metalloproteinase 1 [TIMP-1]) were measured. Spatial distribution of MMP-1, MMP-2, and collagen were visualized in antibody-stained frozen sections. One-way analysis of variance was used for data analysis. Results: Severe myocardial insufficiency (ejection fractions < 50% of baseline values) developed in all animals. No severe side effects were encountered. We found a strong activation of MMP-1 and MMP-2 in fluorogenic and PCR assays. RT-PCR revealed a significant activation of MMP-9 and MT1-MMP and a weaker induction of TIMP-1. Histology showed typical signs of myocardial fibrosis, with myocardial cell loss, collagen disorder, and vacuoles. Conclusion: We showed a strong transcriptional activation for several specific MMPs in Adriamycin-induced cardiac remodeling. Contrary to published data on myocardial infarction, early inhibitory therapy before myocardial injury is possible in Adriamycin-treated patients. Local application by our catheter-based system would additionally help to avoid systemic side effects. [Copyright &y& Elsevier]