COMMENT
Acute post-infarction posterior VSD causes a left to right shunt with increased pulmonary blood flow resulting in biventricular failure. An early surgical intervention without optimizing the hemodynamics can lead to high mortality (4). In addition, surgical repair of the posteriorly positioned VSD can be more challenging and is often associated with higher mortality (1, 2). Mechanical circulatory support in the form of a veno-arterial ECMO can help stabilize the patient and drain the right ventricle, thus preventing acute pulmonary edema. Moreover left ventricle can be decompressed into the right ventricle through the VSD so that left ventricular distention can also be avoided. Hence a VA ECMO can help the patient to recover from acute cardiogenic shock and give time for the VSD to fibrose so as to aid in operative repair (5).
Both trans-atrial and trans-ventricular techniques have been described in the literature to access the post-infarction posterior VSD. We feel the trans-atrial approach is associated with less bleeding complications but a higher need of tricuspid valve replacement in comparison to a trans-ventricular repair (6). In our case, the papillary muscle to the posterior leaflet of the tricuspid valve had already necrosed and ruptured, resulting in severe tricuspid regurgitation. Hence, replacement of tricuspid valve was likely going to be mandatory.
Based on our experience, we recommend that all patients in cardiogenic shock due to a post-infarct posterior VSD should be considered for VA ECMO support. Staged right atrial approach gives excellent exposure and helps avoid morbidity and mortality due to bleeding complications associated with ventriculotomy. The timing of the surgical intervention should be tailored depending upon the hemodynamic stability and presence of the cardiogenic shock.