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.