VATS-GUIDED EPICARDIAL PACEMAKER IMPLANTATION - HAND-SUTURED FIXATIONOF ATRIOVENTRICULAR LEADS IN AN EXPERIMENTAL SETTING

Background: In neonates and infants epicardial stimulation may be pref erred to endocardial stimulation because of growth-associated lead pro blems and the risk of vascular complications associated with transveno us electrodes. This study analyzes the feasibility of atrioventricular implantation of a new epicardial lead using the video-assisted thorac ic surgical (VATS) technique in an animal model. Methods: Bipolar ster oid-eluting epicardial leads were implanted in seven young white pigs. In five animals bipolar atrial and ventricular pacing leads (n = 10) were inserted and fixed by the VATS technique, while two animals serve d as controls and underwent implantation through anterolateral thoraco tomy. Surgical feasibility, pacing, and sensing thresholds of the lead s as well as hemodynamic parameters during pacing were studied. Histol ogical changes beneath the electrodes were evaluated 1 week after the implantation. Results: All animals survived the pacemaker lead implant ation. One animal which underwent thoracotomy died because of irrevers ible ventricular fibrillation induced by rapid ventricular pacing. One animal in the VATS group exhibited intraoperative herniation of the h eart through the pericardial window. All animals with left-sided VATS implantations demonstrated good individual pacing and sensing threshol d values. The mean cardiac output was 1.6 times higher during AAI-mode pacing as compared to VVI-mode pacing at a heart rate of 140/min. One animal died postoperatively due to respiratory failure. No displaceme nts of the pacemaker leads were observed in the survivors. Conclusion: While VATS-guided implantation of epicardial, atrial, and ventricular leads is feasible, technical improvements of the system are mandatory for safe clinical application.