Creation of ventricular septal defects on the beating heart in a new pig model

Background/ Aims: So far, surgical and interventional therapies for
muscular ventricular septal defects ( mVSDs) beyond the moderator
band have had their limitations. Thus, alternative therapeutic
strategies should be developed. We present a new animal model for
the evaluation of such strategies. Methods: In a pig model ( n =
9), anterolateral thoracotomy was performed for exposure of the
left ventricle. mVSDs were created under two- and three-
dimensional echocardiography with a 7.5- mm sharp punch instrument,
which was forwarded via a left ventricular puncture without
extracorporeal circulation. Results: Creation of mVSDs was
successful in all animals ( n = 9) confirmed by echocardiography,
hemodynamic measurements and autopsy. The defects were located in
the midmuscular ( n = 4), apical ( n = 1), inlet ( n = 2) and
anterior part ( n = 2) of the muscular septum. All animals were
hemodynamically stable for further procedures. The diameter and
shunt volume of the mVSDs were 4.8 - 7.3 mm ( mean: 5.9 mm) and
12.9 - 41.3% ( mean: 22.1%), respectively. Autopsy confirmed in all
animals the creation of a substantial defect. Conclusion: The
described new technique for creation of an mVSD on the beating
heart in a pig model is suitable for the evaluation of new
therapeutic strategies for mVSD closure. Copyright (C) 2008 S.
Karger AG, Basel.