Patrick Harkins, MD1; Rebecca M. Gerlach, MD FRCPC2
- CA-2 Resident
- Assistant Professor, Department of Anesthesia and Critical Care, University of Chicago, Chicago, IL
Question 1: Choices b and c
A muscular ventricular septal defect (VSD) is visualized at the apical portion of the septum with color flow Doppler demonstrated through the defect. The left ventricular (LV) apex is dilated and akinetic, which is consistent with an LV aneurysm. Transesophageal echocardiography (TEE) imaging can differentiate a true aneurysm from a pseudo aneurysm. Findings with a true aneurysm include gradual thinning of the myocardial wall, with a diameter of the orifice that is larger than the diameter of the aneurysm itself. In contrast, a pseudo aneurysm shows an abrupt discontinuation/transition zone thinning of the myocardial wall with a diameter of the orifice that is smaller than the diameter of the aneurysm. Takotsubo cardiomyopathy is an apical ballooning syndrome in which the LV apex is dyskinetic, possibly mimicking an LV aneurysm. It is differentiated by the lack of myocardial thinning and a clinical history consistent with a stress-inducing event, as opposed to the result of ischemia from significant coronary artery disease.
Surgical correction of a post-myocardial infarction (MI) VSD is associated with high mortality rates between 19% and 60% in the Society of Thoracic Surgery (STS) database.1 The gold standard is surgical repair with endocardial patch and concurrent coronary artery bypass grafting, but there are situations in which minimally invasive VSD closure may be beneficial. As occurred in our patient, acute post-MI VSD repair is difficult due to the soft and friable myocardial tissue surrounding the VSD, and patch repairs may fail. Better results may occur when the surrounding tissue edges have scarred and myocardial fibrosis have produced more favorable surgical conditions. Minimally invasive options such as percutaneous transcatheter closure of the VSD may be promising in the following situations:2
- as a bridge to stabilize high-risk patients (cardiogenic shock, need for intra-aortic balloon pump, renal dysfunction) for future surgical VSD repair
- primary interventions in patients with small, uncomplicated post-MI VSDs or non-ischemic VSDs
- patients found to have a residual leak after VSD surgical repair.
Question 2: Choice d
A surgical patch closure of VSD was chosen as an initial approach over a percutaneous technique due to the size of the VSD and the surrounding ventricular abnormalities. In the case presented here, a post-MI VSD requiring patch repair can be combined with ventricular remodeling techniques to ensure best overall surgical outcome. The Dor procedure (endoventricular circular patch plasty or surgical ventricular restoration) is typically combined with coronary revascularization to treat LV structural abnormalities usually resulting from ischemic injury or dilation. The procedure involves resecting an LV aneurysm or dilated segment and using sutures and endocardial patch repair to re-establish ventricular wall continuity. This allows the ventricle to regain its natural elliptical orientation.
This technique has been shown to significantly improve LV function, improve NYHA class at 1-year post surgery, and reduce ventricular volumes. The heart failure symptoms in the case presented here were largely due to left-to-right shunt (as the LV function was only mildly reduced); the Dor procedure was felt by the surgeons in this setting to improve the likelihood of successful repair the VSD. Indications for the Dor procedure when performed for LV volume reduction include the following settings:3
- symptomatic heart failure, angina, or arrhythmias
- anteroseptal infarction and LV dilation (LV end-diastolic volume index of > 100 ml/m2)
- regional LV akinesia or dyskinesia (>35% of ventricular perimeter)
- inducible ischemia
- reduced LV function.
- Arnaoutakis GJ, Zhao Y, George TJ, Sciortino CM, McCarthy PM, Conte JV. Surgical repair of ventricular septal defect after myocardial infarction: outcomes from the Society Of Thoracic Surgeons National Database. Ann Thorac Surg. 2012;94(2):436–44.
- Egbe, AC, Poterucha, JT, Rihal, CS, et al. Transcatheter closure of postmyocardial infarction, iatrogenic, and postoperative ventricular septal defects: The Mayo Clinic experience. Cathet Cardiovasc Intervent. 2015;86(7): 1264–1270.
- Sartipy U, Albage A, Lindblom D. The Dor procedure for left ventricular reconstruction. Ten-year clinical experience. Eur J Cardiothorac Surg. 2005; 27(6):1005–1010.