Discussion
In this report, we describe a patient who presented with an
inferolateral wall myocardial infarction and subsequently developed the
mechanical complication of VSR during a planned CABG procedure. In this
case, we elected to perform immediate surgical repair and utilized ECMO
as a perioperative support strategy to alleviate biventricular
dysfunction and allow for revision of the repair after the patient’s
condition had stabilized. Despite the ultimate patient outcome, we
believe this case highlights several important points regarding
perioperative management of VSR.
First and foremost, we acknowledge that the widespread use of early
reperfusion therapy has made the incidence of VSR relatively
minimal,5,6 and for that reason it may not be high on
the clinician’s differential diagnosis when a patient decompensates.
Particularly for the surgeon, who does not often encounter such a
problem intraoperatively, it is important to be aware of this potential
complication. We believe this to be of particular importance during the
COVID-19 pandemic, as patients are more likely to delay seeking care in
an effort to avoid exposure to the virus in the healthcare
setting.11 Indeed, multiple studies have demonstrated
a longer time from symptom onset to first medical contact in the setting
of MI during the COVID-19 pandemic.12-14
Exemplifying this fact, we were surprised to encounter a similar case
report by Kok et al. published in 2021.15 The authors
similarly describe a case of VSR during a CABG operation, in which the
patient was managed with ECMO cannulation and delayed surgical repair.
Despite the differences in management, this phenomenon of intraoperative
VSR had not been described in the literature prior to 2021, and may
reflect a rising rate of mechanical complications of MI due to delayed
patient presentation. To date, there have been several case series and
single institutional reviews that have demonstrated an increased
incidence of mechanical complications during the COVID-19
pandemic,16-18 but this has not yet been explored with
a large database or multi-institutional review.
It is also worth noting the differences in patient management between
the case report presented here and that of Kok et al, and more
specifically, the differences in timing of surgical repair. The
literature is divided in terms of optimal timing of VSR repair. While
several studies have reported lower operative mortality in patients with
delayed surgical repair,19-22 these studies may have a
significant component of selection bias, given that patients with
smaller defects and preserved LV function have more favorable overall
prognosis and are able to be medically temporized until definitive
surgical repair. The advocates for delayed surgical repair argue that
the delay allows for fibrosis of the septum and a more durable
repair,19,21 however without prompt repair many
patients will develop progressive heart failure and will not survive the
delay. Ultimately, we would argue that patient selection is critical,
and the timing of surgical repair does not fall into a
“one-size-fits-all” approach.
Finally, this case highlights the utility of ECMO as an adjunctive
therapy in management of patients with VSR. Although no large
prospective or retrospective studies have evaluated the efficacy of ECMO
in the setting of VSR, several case reports and case series have
reported good results when using ECMO in the perioperative
period.23-27 By affording complete cardiopulmonary
support in the setting of cardiogenic shock, ECMO serves as a salvage
therapy to allow time for myocardial rest and recovery. In this case,
ECMO cannulation and delayed sternal closure provided the opportunity
for myocardial recovery and hemodynamic stabilization with subsequent
re-evaluation and revision of the ventricular septal repair.
In summary, VSR is a rare and often fatal mechanical complication of MI
that merits clinical awareness and discussion. Although uncommon, given
the additional myocardial manipulation that occurs in the operating
room, the surgeon should be aware of the potential for intraoperative
development of this complication. In these cases, the decision between
immediate and delayed repair should be based on the size of the defect
and the patient’s overall clinical picture. In cases such as this, where
immediate repair was needed to alleviate biventricular dysfunction, ECMO
is a viable option both for temporary mechanical support and as a
bridging modality to allow for re-evaluation and revision of the VSR
repair at a later date.