Comment
These cases illustrate employment of a unique central ECMO strategy to delay repair of post-MI VSD complicated by cardiogenic shock. Given the high mortality and low likelihood of successful repair in the immediate post-infarction period, both patients were stabilized with central ECMO for 3 weeks, granting time for recovery from cardiogenic shock and myocardial healing for successful patch closure.
Many mechanical circulatory support strategies have been used to stabilize patients before VSD repair5,6; however, each has its limitations. Percutaneous devices (i.e. IABP, Impella, TandemHeart) are readily placed and augment LV unloading and myocardial and peripheral tissue perfusion. However, such devices are limited by flow capability and inadequate support for biventricular failure, a common feature of post-MI VSD. Femoral VA-ECMO provides additional support but is limited by increased afterload and root stasis as seen in our cases. Furthermore, it limits ambulation, leading to progressive deconditioning. An axillary-jugular VA-ECMO configuration may also be used; however, flow is limited by arterial size and may lead to hyperperfusion of the arm and significant nerve injury if prolonged support is required.
Alternatively, a temporary external VAD may provide sufficient biventricular support in cardiogenic shock; however, insertion requires a sternotomy and cardiopulmonary bypass. Our approach addresses each of these limitations. Firstly, it facilitates biventricular unloading while providing full cardiopulmonary support with antegrade oxygenated flow. Additionally, it allows preservation of a virgin chest, with very minimal intrapericardial adhesions noted, for the planned VSD closure and permits ambulatory therapy prior to surgical repair.
VSD closure was performed using a double-patch repair through a right ventriculotomy. In this novel technique, two patches are anchored to the VSD margin using interrupted horizontal mattress sutures placed transeptally or transmurally from the LV (via the VSD) to the RV cavity or LV wall, creating a “sandwich” closure. There are many advantages to this approach, including preservation of contractile function by avoiding a left ventriculotomy and reproducibility for anterior and posterior defects.
In conclusion, our approach is a feasible bridge strategy in the management of post-MI VSD with cardiogenic shock. Further experience with this modality is required.