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DOI: 10.1055/s-0029-1246778
Evaluation of a self-centering patch system for closure of muscular ventricular septal defects in a pig model
Objective: Closure of muscular ventricular septal defects (mVSDs) beyond the moderator band is still challenging. Recently, we established a new hybrid technique for closure of mVSDs on the beating heart. Here, we evaluated a self-centering patch system for this technique.
Methods: 8 pigs underwent left anterolateral thoracotomy to expose the left ventricle (LV). mVSDs were created via under epicardial echocardiographic control. The self-centering patch system consists of a removable centering system and a releasable attached patch. After creation of an arterio-venous circuit, an implantation sheath was forwarded from the venous side via the guide wire into the LV. The system was loaded, advanced and deployed in the LV and pulled back into the VSD. Then, the patch was attached to the septum with Nitinol anchors under epicardial echocardiographic and fluoroscopic guidance. Finally, the patch system is drawn back into the sheath. All hearts were explanted for macroscopic evaluation.
Results: Closure of mVSDs was successful in 6 out of 9 pigs without residual shunting. Macropathology revealed adequate positioning and fixation of the patch. In three cases, the patch is fixated to the delivery system by nitinol anchors. Consequently, the patch could not be detached from the delivery system. After using smaller anchors, this complication did not occur anymore.
Conclusions: Closure of mVSDs can be successfully performed with our new patch system. A big advantage is the self centering mechanism. However, further modifications and improvement of imaging is needed before clinical application is possible.