Effect of ventricular size and patch stiffness in surgical anterior ventricular restoration: a finite element model study.

BACKGROUND: Surgical anterior ventricular restoration (SAVER) has been proposed for dilated ischemic cardiomyopathy with an akinetic distal anterior left ventricular wall. We tested the hypothesis that SAVER increases stroke volume, reduces mean myofiber stress and achieves optimal results without a patch. METHODS: A finite element model of the left ventricle (LV) with an akinetic but contractile anteroapical LV wall segment was used. Separate versions of the model with normal and dilated LV sizes were developed and used to simulate the SAVER operation with and without a patch of varying stiffness from 10 to 100 kilopascals. RESULTS: The SAVER operation reduced myofiber stress in the akinetic infarct and infarct borderzone, but caused a reduction in the Starling relationship. In all cases, stroke volume decreased while ejection fraction increased after SAVER. The SAVER operation was more beneficial in dilated ventricles, and the reduction in stroke volume after SAVER without patch was minimal. The effect of patch stiffness was mixed as stiffer material causes a greater reduction in stress yet has the greatest negative effect on stroke volume. CONCLUSIONS: These simulations support the use of SAVER in dilated hearts without a patch.