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.